diff options
Diffstat (limited to 'kernel')
225 files changed, 4493 insertions, 2548 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index ed470aac53da..172d151d429c 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # # Makefile for the linux kernel. # diff --git a/kernel/acct.c b/kernel/acct.c index 5e72af29ab73..d15c0ee4d955 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/acct.c * @@ -146,7 +147,7 @@ static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) again: smp_rmb(); rcu_read_lock(); - res = to_acct(ACCESS_ONCE(ns->bacct)); + res = to_acct(READ_ONCE(ns->bacct)); if (!res) { rcu_read_unlock(); return NULL; @@ -158,7 +159,7 @@ again: } rcu_read_unlock(); mutex_lock(&res->lock); - if (res != to_acct(ACCESS_ONCE(ns->bacct))) { + if (res != to_acct(READ_ONCE(ns->bacct))) { mutex_unlock(&res->lock); acct_put(res); goto again; diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 011d46e5f73f..fd353120e0d9 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "audit.h" #include <linux/fsnotify_backend.h> #include <linux/namei.h> @@ -1007,7 +1008,7 @@ static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify * We are guaranteed to have at least one reference to the mark from * either the inode or the caller of fsnotify_destroy_mark(). */ - BUG_ON(atomic_read(&entry->refcnt) < 1); + BUG_ON(refcount_read(&entry->refcnt) < 1); } static const struct fsnotify_ops audit_tree_ops = { diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ecc23e25c9eb..9c723e978245 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2390,6 +2390,12 @@ void __audit_log_kern_module(char *name) context->type = AUDIT_KERN_MODULE; } +void __audit_fanotify(unsigned int response) +{ + audit_log(current->audit_context, GFP_KERNEL, + AUDIT_FANOTIFY, "resp=%u", response); +} + static void audit_log_task(struct audit_buffer *ab) { kuid_t auid, uid; diff --git a/kernel/bounds.c b/kernel/bounds.c index e1d1d1952bfa..c373e887c066 100644 --- a/kernel/bounds.c +++ b/kernel/bounds.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Generate definitions needed by the preprocessor. * This code generates raw asm output which is post-processed diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 897daa005b23..af3ab6164ff5 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-y := core.o obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 98c0f00c3f5e..c4b9ab01bba5 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -98,7 +98,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) array_size += (u64) attr->max_entries * elem_size * num_possible_cpus(); if (array_size >= U32_MAX - PAGE_SIZE || - elem_size > PCPU_MIN_UNIT_SIZE || bpf_array_alloc_percpu(array)) { + bpf_array_alloc_percpu(array)) { bpf_map_area_free(array); return ERR_PTR(-ENOMEM); } @@ -492,7 +492,7 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, ee = ERR_PTR(-EOPNOTSUPP); event = perf_file->private_data; - if (perf_event_read_local(event, &value) == -EOPNOTSUPP) + if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP) goto err_out; ee = bpf_event_entry_gen(perf_file, map_file); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 917cc04a0a94..7b62df86be1d 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1022,7 +1022,7 @@ select_insn: struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; struct bpf_array *array = container_of(map, struct bpf_array, map); struct bpf_prog *prog; - u64 index = BPF_R3; + u32 index = BPF_R3; if (unlikely(index >= array->map.max_entries)) goto out; diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index e093d9a2c4dd..e745d6a88224 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -69,7 +69,7 @@ static LIST_HEAD(dev_map_list); static u64 dev_map_bitmap_size(const union bpf_attr *attr) { - return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long); + return BITS_TO_LONGS((u64) attr->max_entries) * sizeof(unsigned long); } static struct bpf_map *dev_map_alloc(union bpf_attr *attr) @@ -78,6 +78,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) int err = -EINVAL; u64 cost; + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) @@ -111,8 +114,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) err = -ENOMEM; /* A per cpu bitfield with a bit per possible net device */ - dtab->flush_needed = __alloc_percpu(dev_map_bitmap_size(attr), - __alignof__(unsigned long)); + dtab->flush_needed = __alloc_percpu_gfp(dev_map_bitmap_size(attr), + __alignof__(unsigned long), + GFP_KERNEL | __GFP_NOWARN); if (!dtab->flush_needed) goto free_dtab; diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 431126f31ea3..6533f08d1238 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -317,10 +317,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) */ goto free_htab; - if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE) - /* make sure the size for pcpu_alloc() is reasonable */ - goto free_htab; - htab->elem_size = sizeof(struct htab_elem) + round_up(htab->map.key_size, 8); if (percpu) diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index e833ed914358..be1dde967208 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -363,6 +363,7 @@ out: putname(pname); return ret; } +EXPORT_SYMBOL_GPL(bpf_obj_get_user); static void bpf_evict_inode(struct inode *inode) { diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 6424ce0e4969..dbd7b322a86b 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -39,6 +39,7 @@ #include <linux/workqueue.h> #include <linux/list.h> #include <net/strparser.h> +#include <net/tcp.h> struct bpf_stab { struct bpf_map map; @@ -92,21 +93,45 @@ static inline struct smap_psock *smap_psock_sk(const struct sock *sk) return rcu_dereference_sk_user_data(sk); } +/* compute the linear packet data range [data, data_end) for skb when + * sk_skb type programs are in use. + */ +static inline void bpf_compute_data_end_sk_skb(struct sk_buff *skb) +{ + TCP_SKB_CB(skb)->bpf.data_end = skb->data + skb_headlen(skb); +} + +enum __sk_action { + __SK_DROP = 0, + __SK_PASS, + __SK_REDIRECT, +}; + static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) { struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict); int rc; if (unlikely(!prog)) - return SK_DROP; + return __SK_DROP; skb_orphan(skb); + /* We need to ensure that BPF metadata for maps is also cleared + * when we orphan the skb so that we don't have the possibility + * to reference a stale map. + */ + TCP_SKB_CB(skb)->bpf.map = NULL; skb->sk = psock->sock; - bpf_compute_data_end(skb); + bpf_compute_data_end_sk_skb(skb); + preempt_disable(); rc = (*prog->bpf_func)(skb, prog->insnsi); + preempt_enable(); skb->sk = NULL; - return rc; + /* Moving return codes from UAPI namespace into internal namespace */ + return rc == SK_PASS ? + (TCP_SKB_CB(skb)->bpf.map ? __SK_REDIRECT : __SK_PASS) : + __SK_DROP; } static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) @@ -114,17 +139,10 @@ static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) struct sock *sk; int rc; - /* Because we use per cpu values to feed input from sock redirect - * in BPF program to do_sk_redirect_map() call we need to ensure we - * are not preempted. RCU read lock is not sufficient in this case - * with CONFIG_PREEMPT_RCU enabled so we must be explicit here. - */ - preempt_disable(); rc = smap_verdict_func(psock, skb); switch (rc) { - case SK_REDIRECT: - sk = do_sk_redirect_map(); - preempt_enable(); + case __SK_REDIRECT: + sk = do_sk_redirect_map(skb); if (likely(sk)) { struct smap_psock *peer = smap_psock_sk(sk); @@ -139,10 +157,8 @@ static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) } } /* Fall through and free skb otherwise */ - case SK_DROP: + case __SK_DROP: default: - if (rc != SK_REDIRECT) - preempt_enable(); kfree_skb(skb); } } @@ -369,7 +385,7 @@ static int smap_parse_func_strparser(struct strparser *strp, * any socket yet. */ skb->sk = psock->sock; - bpf_compute_data_end(skb); + bpf_compute_data_end_sk_skb(skb); rc = (*prog->bpf_func)(skb, prog->insnsi); skb->sk = NULL; rcu_read_unlock(); @@ -487,6 +503,9 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) int err = -EINVAL; u64 cost; + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) @@ -840,6 +859,12 @@ static int sock_map_update_elem(struct bpf_map *map, return -EINVAL; } + if (skops.sk->sk_type != SOCK_STREAM || + skops.sk->sk_protocol != IPPROTO_TCP) { + fput(socket->file); + return -EOPNOTSUPP; + } + err = sock_map_ctx_update_elem(&skops, map, key, flags); fput(socket->file); return err; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b914fbe1383e..c48ca2a34b5e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -653,6 +653,10 @@ static void mark_reg_read(const struct bpf_verifier_state *state, u32 regno) { struct bpf_verifier_state *parent = state->parent; + if (regno == BPF_REG_FP) + /* We don't need to worry about FP liveness because it's read-only */ + return; + while (parent) { /* if read wasn't screened by an earlier write ... */ if (state->regs[regno].live & REG_LIVE_WRITTEN) @@ -1112,7 +1116,12 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn /* ctx accesses must be at a fixed offset, so that we can * determine what type of data were returned. */ - if (!tnum_is_const(reg->var_off)) { + if (reg->off) { + verbose("dereference of modified ctx ptr R%d off=%d+%d, ctx+const is allowed, ctx+const+const is not\n", + regno, reg->off, off - reg->off); + return -EACCES; + } + if (!tnum_is_const(reg->var_off) || reg->var_off.value) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); @@ -1120,7 +1129,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn tn_buf, off, size); return -EACCES; } - off += reg->var_off.value; err = check_ctx_access(env, insn_idx, off, size, t, ®_type); if (!err && t == BPF_READ && value_regno >= 0) { /* ctx access returns either a scalar, or a @@ -2345,6 +2353,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) * copy register state to dest reg */ regs[insn->dst_reg] = regs[insn->src_reg]; + regs[insn->dst_reg].live |= REG_LIVE_WRITTEN; } else { /* R1 = (u32) R2 */ if (is_pointer_value(env, insn->src_reg)) { @@ -2421,12 +2430,15 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) } static void find_good_pkt_pointers(struct bpf_verifier_state *state, - struct bpf_reg_state *dst_reg) + struct bpf_reg_state *dst_reg, + bool range_right_open) { struct bpf_reg_state *regs = state->regs, *reg; + u16 new_range; int i; - if (dst_reg->off < 0) + if (dst_reg->off < 0 || + (dst_reg->off == 0 && range_right_open)) /* This doesn't give us any range */ return; @@ -2437,9 +2449,13 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state, */ return; - /* LLVM can generate four kind of checks: + new_range = dst_reg->off; + if (range_right_open) + new_range--; + + /* Examples for register markings: * - * Type 1/2: + * pkt_data in dst register: * * r2 = r3; * r2 += 8; @@ -2456,7 +2472,7 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state, * r2=pkt(id=n,off=8,r=0) * r3=pkt(id=n,off=0,r=0) * - * Type 3/4: + * pkt_data in src register: * * r2 = r3; * r2 += 8; @@ -2474,7 +2490,9 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state, * r3=pkt(id=n,off=0,r=0) * * Find register r3 and mark its range as r3=pkt(id=n,off=0,r=8) - * so that range of bytes [r3, r3 + 8) is safe to access. + * or r3=pkt(id=n,off=0,r=8-1), so that range of bytes [r3, r3 + 8) + * and [r3, r3 + 8-1) respectively is safe to access depending on + * the check. */ /* If our ids match, then we must have the same max_value. And we @@ -2485,14 +2503,14 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state, for (i = 0; i < MAX_BPF_REG; i++) if (regs[i].type == PTR_TO_PACKET && regs[i].id == dst_reg->id) /* keep the maximum range already checked */ - regs[i].range = max_t(u16, regs[i].range, dst_reg->off); + regs[i].range = max(regs[i].range, new_range); for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) { if (state->stack_slot_type[i] != STACK_SPILL) continue; reg = &state->spilled_regs[i / BPF_REG_SIZE]; if (reg->type == PTR_TO_PACKET && reg->id == dst_reg->id) - reg->range = max_t(u16, reg->range, dst_reg->off); + reg->range = max(reg->range, new_range); } } @@ -2856,19 +2874,43 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT && dst_reg->type == PTR_TO_PACKET && regs[insn->src_reg].type == PTR_TO_PACKET_END) { - find_good_pkt_pointers(this_branch, dst_reg); + /* pkt_data' > pkt_end */ + find_good_pkt_pointers(this_branch, dst_reg, false); + } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT && + dst_reg->type == PTR_TO_PACKET_END && + regs[insn->src_reg].type == PTR_TO_PACKET) { + /* pkt_end > pkt_data' */ + find_good_pkt_pointers(other_branch, ®s[insn->src_reg], true); } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT && dst_reg->type == PTR_TO_PACKET && regs[insn->src_reg].type == PTR_TO_PACKET_END) { - find_good_pkt_pointers(other_branch, dst_reg); + /* pkt_data' < pkt_end */ + find_good_pkt_pointers(other_branch, dst_reg, true); + } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT && + dst_reg->type == PTR_TO_PACKET_END && + regs[insn->src_reg].type == PTR_TO_PACKET) { + /* pkt_end < pkt_data' */ + find_good_pkt_pointers(this_branch, ®s[insn->src_reg], false); + } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE && + dst_reg->type == PTR_TO_PACKET && + regs[insn->src_reg].type == PTR_TO_PACKET_END) { + /* pkt_data' >= pkt_end */ + find_good_pkt_pointers(this_branch, dst_reg, true); } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE && dst_reg->type == PTR_TO_PACKET_END && regs[insn->src_reg].type == PTR_TO_PACKET) { - find_good_pkt_pointers(other_branch, ®s[insn->src_reg]); + /* pkt_end >= pkt_data' */ + find_good_pkt_pointers(other_branch, ®s[insn->src_reg], false); + } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE && + dst_reg->type == PTR_TO_PACKET && + regs[insn->src_reg].type == PTR_TO_PACKET_END) { + /* pkt_data' <= pkt_end */ + find_good_pkt_pointers(other_branch, dst_reg, false); } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE && dst_reg->type == PTR_TO_PACKET_END && regs[insn->src_reg].type == PTR_TO_PACKET) { - find_good_pkt_pointers(this_branch, ®s[insn->src_reg]); + /* pkt_end <= pkt_data' */ + find_good_pkt_pointers(this_branch, ®s[insn->src_reg], true); } else if (is_pointer_value(env, insn->dst_reg)) { verbose("R%d pointer comparison prohibited\n", insn->dst_reg); return -EACCES; diff --git a/kernel/capability.c b/kernel/capability.c index f97fe77ceb88..1e1c0236f55b 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/capability.c * diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile index ce693ccb8c58..ae448f7632cc 100644 --- a/kernel/cgroup/Makefile +++ b/kernel/cgroup/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-y := cgroup.o namespace.o cgroup-v1.o obj-$(CONFIG_CGROUP_FREEZER) += freezer.o diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 5151ff256c29..bf54ade001be 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __CGROUP_INTERNAL_H #define __CGROUP_INTERNAL_H diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index d6551cd45238..44857278eb8a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2311,6 +2311,14 @@ out_release_tset: list_del_init(&cset->mg_node); } spin_unlock_irq(&css_set_lock); + + /* + * Re-initialize the cgroup_taskset structure in case it is reused + * again in another cgroup_migrate_add_task()/cgroup_migrate_execute() + * iteration. + */ + tset->nr_tasks = 0; + tset->csets = &tset->src_csets; return ret; } diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 4657e2924ecb..f7efa7b4d825 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -57,7 +57,7 @@ #include <linux/backing-dev.h> #include <linux/sort.h> #include <linux/oom.h> - +#include <linux/sched/isolation.h> #include <linux/uaccess.h> #include <linux/atomic.h> #include <linux/mutex.h> @@ -656,7 +656,6 @@ static int generate_sched_domains(cpumask_var_t **domains, int csn; /* how many cpuset ptrs in csa so far */ int i, j, k; /* indices for partition finding loops */ cpumask_var_t *doms; /* resulting partition; i.e. sched domains */ - cpumask_var_t non_isolated_cpus; /* load balanced CPUs */ struct sched_domain_attr *dattr; /* attributes for custom domains */ int ndoms = 0; /* number of sched domains in result */ int nslot; /* next empty doms[] struct cpumask slot */ @@ -666,10 +665,6 @@ static int generate_sched_domains(cpumask_var_t **domains, dattr = NULL; csa = NULL; - if (!alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL)) - goto done; - cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); - /* Special case for the 99% of systems with one, full, sched domain */ if (is_sched_load_balance(&top_cpuset)) { ndoms = 1; @@ -683,7 +678,7 @@ static int generate_sched_domains(cpumask_var_t **domains, update_domain_attr_tree(dattr, &top_cpuset); } cpumask_and(doms[0], top_cpuset.effective_cpus, - non_isolated_cpus); + housekeeping_cpumask(HK_FLAG_DOMAIN)); goto done; } @@ -707,7 +702,8 @@ static int generate_sched_domains(cpumask_var_t **domains, */ if (!cpumask_empty(cp->cpus_allowed) && !(is_sched_load_balance(cp) && - cpumask_intersects(cp->cpus_allowed, non_isolated_cpus))) + cpumask_intersects(cp->cpus_allowed, + housekeeping_cpumask(HK_FLAG_DOMAIN)))) continue; if (is_sched_load_balance(cp)) @@ -789,7 +785,7 @@ restart: if (apn == b->pn) { cpumask_or(dp, dp, b->effective_cpus); - cpumask_and(dp, dp, non_isolated_cpus); + cpumask_and(dp, dp, housekeeping_cpumask(HK_FLAG_DOMAIN)); if (dattr) update_domain_attr_tree(dattr + nslot, b); @@ -802,7 +798,6 @@ restart: BUG_ON(nslot != ndoms); done: - free_cpumask_var(non_isolated_cpus); kfree(csa); /* diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c index f661b4cc5efd..5f780d8f6a9d 100644 --- a/kernel/cgroup/debug.c +++ b/kernel/cgroup/debug.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Debug controller * diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c index 66129eb4371d..b05f1dd58a62 100644 --- a/kernel/cgroup/namespace.c +++ b/kernel/cgroup/namespace.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "cgroup-internal.h" #include <linux/sched/task.h> diff --git a/kernel/cpu.c b/kernel/cpu.c index 8de11a29e495..04892a82f6ac 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -24,6 +24,7 @@ #include <linux/lockdep.h> #include <linux/tick.h> #include <linux/irq.h> +#include <linux/nmi.h> #include <linux/smpboot.h> #include <linux/relay.h> #include <linux/slab.h> @@ -631,6 +632,11 @@ cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, __cpuhp_kick_ap(st); } + /* + * Clean up the leftovers so the next hotplug operation wont use stale + * data. + */ + st->node = st->last = NULL; return ret; } @@ -897,6 +903,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, out: cpus_write_unlock(); + /* + * Do post unplug cleanup. This is still protected against + * concurrent CPU hotplug via cpu_add_remove_lock. + */ + lockup_detector_cleanup(); return ret; } diff --git a/kernel/dma.c b/kernel/dma.c index 6c6262f86c17..3506fc34a712 100644 --- a/kernel/dma.c +++ b/kernel/dma.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/dma.c: A DMA channel allocator. Inspired by linux/kernel/irq.c. * diff --git a/kernel/elfcore.c b/kernel/elfcore.c index e556751d15d9..fc482c8e0bd8 100644 --- a/kernel/elfcore.c +++ b/kernel/elfcore.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/elf.h> #include <linux/fs.h> #include <linux/mm.h> diff --git a/kernel/events/Makefile b/kernel/events/Makefile index 2925188f50ea..3c022e33c109 100644 --- a/kernel/events/Makefile +++ b/kernel/events/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE) endif diff --git a/kernel/events/core.c b/kernel/events/core.c index 6bc21e202ae4..4c39c05e029a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -209,7 +209,7 @@ static int event_function(void *info) struct perf_event_context *task_ctx = cpuctx->task_ctx; int ret = 0; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); perf_ctx_lock(cpuctx, task_ctx); /* @@ -306,7 +306,7 @@ static void event_function_local(struct perf_event *event, event_f func, void *d struct task_struct *task = READ_ONCE(ctx->task); struct perf_event_context *task_ctx = NULL; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (task) { if (task == TASK_TOMBSTONE) @@ -582,6 +582,88 @@ static inline u64 perf_event_clock(struct perf_event *event) return event->clock(); } +/* + * State based event timekeeping... + * + * The basic idea is to use event->state to determine which (if any) time + * fields to increment with the current delta. This means we only need to + * update timestamps when we change state or when they are explicitly requested + * (read). + * + * Event groups make things a little more complicated, but not terribly so. The + * rules for a group are that if the group leader is OFF the entire group is + * OFF, irrespecive of what the group member states are. This results in + * __perf_effective_state(). + * + * A futher ramification is that when a group leader flips between OFF and + * !OFF, we need to update all group member times. + * + * + * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we + * need to make sure the relevant context time is updated before we try and + * update our timestamps. + */ + +static __always_inline enum perf_event_state +__perf_effective_state(struct perf_event *event) +{ + struct perf_event *leader = event->group_leader; + + if (leader->state <= PERF_EVENT_STATE_OFF) + return leader->state; + + return event->state; +} + +static __always_inline void +__perf_update_times(struct perf_event *event, u64 now, u64 *enabled, u64 *running) +{ + enum perf_event_state state = __perf_effective_state(event); + u64 delta = now - event->tstamp; + + *enabled = event->total_time_enabled; + if (state >= PERF_EVENT_STATE_INACTIVE) + *enabled += delta; + + *running = event->total_time_running; + if (state >= PERF_EVENT_STATE_ACTIVE) + *running += delta; +} + +static void perf_event_update_time(struct perf_event *event) +{ + u64 now = perf_event_time(event); + + __perf_update_times(event, now, &event->total_time_enabled, + &event->total_time_running); + event->tstamp = now; +} + +static void perf_event_update_sibling_time(struct perf_event *leader) +{ + struct perf_event *sibling; + + list_for_each_entry(sibling, &leader->sibling_list, group_entry) + perf_event_update_time(sibling); +} + +static void +perf_event_set_state(struct perf_event *event, enum perf_event_state state) +{ + if (event->state == state) + return; + + perf_event_update_time(event); + /* + * If a group leader gets enabled/disabled all its siblings + * are affected too. + */ + if ((event->state < 0) ^ (state < 0)) + perf_event_update_sibling_time(event); + + WRITE_ONCE(event->state, state); +} + #ifdef CONFIG_CGROUP_PERF static inline bool @@ -662,7 +744,7 @@ static inline void update_cgrp_time_from_event(struct perf_event *event) /* * Do not update time when cgroup is not active */ - if (cgrp == event->cgrp) + if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) __update_cgrp_time(event->cgrp); } @@ -841,40 +923,6 @@ perf_cgroup_set_shadow_time(struct perf_event *event, u64 now) event->shadow_ctx_time = now - t->timestamp; } -static inline void -perf_cgroup_defer_enabled(struct perf_event *event) -{ - /* - * when the current task's perf cgroup does not match - * the event's, we need to remember to call the - * perf_mark_enable() function the first time a task with - * a matching perf cgroup is scheduled in. - */ - if (is_cgroup_event(event) && !perf_cgroup_match(event)) - event->cgrp_defer_enabled = 1; -} - -static inline void -perf_cgroup_mark_enabled(struct perf_event *event, - struct perf_event_context *ctx) -{ - struct perf_event *sub; - u64 tstamp = perf_event_time(event); - - if (!event->cgrp_defer_enabled) - return; - - event->cgrp_defer_enabled = 0; - - event->tstamp_enabled = tstamp - event->total_time_enabled; - list_for_each_entry(sub, &event->sibling_list, group_entry) { - if (sub->state >= PERF_EVENT_STATE_INACTIVE) { - sub->tstamp_enabled = tstamp - sub->total_time_enabled; - sub->cgrp_defer_enabled = 0; - } - } -} - /* * Update cpuctx->cgrp so that it is set when first cgroup event is added and * cleared when last cgroup event is removed. @@ -901,9 +949,11 @@ list_update_cgroup_event(struct perf_event *event, cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/ if (add) { + struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); + list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); - if (perf_cgroup_from_task(current, ctx) == event->cgrp) - cpuctx->cgrp = event->cgrp; + if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) + cpuctx->cgrp = cgrp; } else { list_del(cpuctx_entry); cpuctx->cgrp = NULL; @@ -973,17 +1023,6 @@ static inline u64 perf_cgroup_event_time(struct perf_event *event) } static inline void -perf_cgroup_defer_enabled(struct perf_event *event) -{ -} - -static inline void -perf_cgroup_mark_enabled(struct perf_event *event, - struct perf_event_context *ctx) -{ -} - -static inline void list_update_cgroup_event(struct perf_event *event, struct perf_event_context *ctx, bool add) { @@ -1004,7 +1043,7 @@ static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) struct perf_cpu_context *cpuctx; int rotations = 0; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); rotations = perf_rotate_context(cpuctx); @@ -1091,7 +1130,7 @@ static void perf_event_ctx_activate(struct perf_event_context *ctx) { struct list_head *head = this_cpu_ptr(&active_ctx_list); - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); WARN_ON(!list_empty(&ctx->active_ctx_list)); @@ -1100,7 +1139,7 @@ static void perf_event_ctx_activate(struct perf_event_context *ctx) static void perf_event_ctx_deactivate(struct perf_event_context *ctx) { - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); WARN_ON(list_empty(&ctx->active_ctx_list)); @@ -1200,7 +1239,7 @@ perf_event_ctx_lock_nested(struct perf_event *event, int nesting) again: rcu_read_lock(); - ctx = ACCESS_ONCE(event->ctx); + ctx = READ_ONCE(event->ctx); if (!atomic_inc_not_zero(&ctx->refcount)) { rcu_read_unlock(); goto again; @@ -1396,60 +1435,6 @@ static u64 perf_event_time(struct perf_event *event) return ctx ? ctx->time : 0; } -/* - * Update the total_time_enabled and total_time_running fields for a event. - */ -static void update_event_times(struct perf_event *event) -{ - struct perf_event_context *ctx = event->ctx; - u64 run_end; - - lockdep_assert_held(&ctx->lock); - - if (event->state < PERF_EVENT_STATE_INACTIVE || - event->group_leader->state < PERF_EVENT_STATE_INACTIVE) - return; - - /* - * in cgroup mode, time_enabled represents - * the time the event was enabled AND active - * tasks were in the monitored cgroup. This is - * independent of the activity of the context as - * there may be a mix of cgroup and non-cgroup events. - * - * That is why we treat cgroup events differently - * here. - */ - if (is_cgroup_event(event)) - run_end = perf_cgroup_event_time(event); - else if (ctx->is_active) - run_end = ctx->time; - else - run_end = event->tstamp_stopped; - - event->total_time_enabled = run_end - event->tstamp_enabled; - - if (event->state == PERF_EVENT_STATE_INACTIVE) - run_end = event->tstamp_stopped; - else - run_end = perf_event_time(event); - - event->total_time_running = run_end - event->tstamp_running; - -} - -/* - * Update total_time_enabled and total_time_running for all events in a group. - */ -static void update_group_times(struct perf_event *leader) -{ - struct perf_event *event; - - update_event_times(leader); - list_for_each_entry(event, &leader->sibling_list, group_entry) - update_event_times(event); -} - static enum event_type_t get_event_type(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; @@ -1492,6 +1477,8 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); event->attach_state |= PERF_ATTACH_CONTEXT; + event->tstamp = perf_event_time(event); + /* * If we're a stand alone event or group leader, we go to the context * list, group events are kept attached to the group so that @@ -1699,8 +1686,6 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) if (event->group_leader == event) list_del_init(&event->group_entry); - update_group_times(event); - /* * If event was in error state, then keep it * that way, otherwise bogus counts will be @@ -1709,7 +1694,7 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) * of the event */ if (event->state > PERF_EVENT_STATE_OFF) - event->state = PERF_EVENT_STATE_OFF; + perf_event_set_state(event, PERF_EVENT_STATE_OFF); ctx->generation++; } @@ -1808,38 +1793,24 @@ event_sched_out(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { - u64 tstamp = perf_event_time(event); - u64 delta; + enum perf_event_state state = PERF_EVENT_STATE_INACTIVE; WARN_ON_ONCE(event->ctx != ctx); lockdep_assert_held(&ctx->lock); - /* - * An event which could not be activated because of - * filter mismatch still needs to have its timings - * maintained, otherwise bogus information is return - * via read() for time_enabled, time_running: - */ - if (event->state == PERF_EVENT_STATE_INACTIVE && - !event_filter_match(event)) { - delta = tstamp - event->tstamp_stopped; - event->tstamp_running += delta; - event->tstamp_stopped = tstamp; - } - if (event->state != PERF_EVENT_STATE_ACTIVE) return; perf_pmu_disable(event->pmu); - event->tstamp_stopped = tstamp; event->pmu->del(event, 0); event->oncpu = -1; - event->state = PERF_EVENT_STATE_INACTIVE; + if (event->pending_disable) { event->pending_disable = 0; - event->state = PERF_EVENT_STATE_OFF; + state = PERF_EVENT_STATE_OFF; } + perf_event_set_state(event, state); if (!is_software_event(event)) cpuctx->active_oncpu--; @@ -1859,7 +1830,9 @@ group_sched_out(struct perf_event *group_event, struct perf_event_context *ctx) { struct perf_event *event; - int state = group_event->state; + + if (group_event->state != PERF_EVENT_STATE_ACTIVE) + return; perf_pmu_disable(ctx->pmu); @@ -1873,7 +1846,7 @@ group_sched_out(struct perf_event *group_event, perf_pmu_enable(ctx->pmu); - if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive) + if (group_event->attr.exclusive) cpuctx->exclusive = 0; } @@ -1893,6 +1866,11 @@ __perf_remove_from_context(struct perf_event *event, { unsigned long flags = (unsigned long)info; + if (ctx->is_active & EVENT_TIME) { + update_context_time(ctx); + update_cgrp_time_from_cpuctx(cpuctx); + } + event_sched_out(event, cpuctx, ctx); if (flags & DETACH_GROUP) perf_group_detach(event); @@ -1955,14 +1933,17 @@ static void __perf_event_disable(struct perf_event *event, if (event->state < PERF_EVENT_STATE_INACTIVE) return; - update_context_time(ctx); - update_cgrp_time_from_event(event); - update_group_times(event); + if (ctx->is_active & EVENT_TIME) { + update_context_time(ctx); + update_cgrp_time_from_event(event); + } + if (event == event->group_leader) group_sched_out(event, cpuctx, ctx); else event_sched_out(event, cpuctx, ctx); - event->state = PERF_EVENT_STATE_OFF; + + perf_event_set_state(event, PERF_EVENT_STATE_OFF); } /* @@ -2019,8 +2000,7 @@ void perf_event_disable_inatomic(struct perf_event *event) } static void perf_set_shadow_time(struct perf_event *event, - struct perf_event_context *ctx, - u64 tstamp) + struct perf_event_context *ctx) { /* * use the correct time source for the time snapshot @@ -2048,9 +2028,9 @@ static void perf_set_shadow_time(struct perf_event *event, * is cleaner and simpler to understand. */ if (is_cgroup_event(event)) - perf_cgroup_set_shadow_time(event, tstamp); + perf_cgroup_set_shadow_time(event, event->tstamp); else - event->shadow_ctx_time = tstamp - ctx->timestamp; + event->shadow_ctx_time = event->tstamp - ctx->timestamp; } #define MAX_INTERRUPTS (~0ULL) @@ -2063,7 +2043,6 @@ event_sched_in(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { - u64 tstamp = perf_event_time(event); int ret = 0; lockdep_assert_held(&ctx->lock); @@ -2073,11 +2052,12 @@ event_sched_in(struct perf_event *event, WRITE_ONCE(event->oncpu, smp_processor_id()); /* - * Order event::oncpu write to happen before the ACTIVE state - * is visible. + * Order event::oncpu write to happen before the ACTIVE state is + * visible. This allows perf_event_{stop,read}() to observe the correct + * ->oncpu if it sees ACTIVE. */ smp_wmb(); - WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE); + perf_event_set_state(event, PERF_EVENT_STATE_ACTIVE); /* * Unthrottle events, since we scheduled we might have missed several @@ -2089,26 +2069,19 @@ event_sched_in(struct perf_event *event, event->hw.interrupts = 0; } - /* - * The new state must be visible before we turn it on in the hardware: - */ - smp_wmb(); - perf_pmu_disable(event->pmu); - perf_set_shadow_time(event, ctx, tstamp); + perf_set_shadow_time(event, ctx); perf_log_itrace_start(event); if (event->pmu->add(event, PERF_EF_START)) { - event->state = PERF_EVENT_STATE_INACTIVE; + perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); event->oncpu = -1; ret = -EAGAIN; goto out; } - event->tstamp_running += tstamp - event->tstamp_stopped; - if (!is_software_event(event)) cpuctx->active_oncpu++; if (!ctx->nr_active++) @@ -2132,8 +2105,6 @@ group_sched_in(struct perf_event *group_event, { struct perf_event *event, *partial_group = NULL; struct pmu *pmu = ctx->pmu; - u64 now = ctx->time; - bool simulate = false; if (group_event->state == PERF_EVENT_STATE_OFF) return 0; @@ -2163,27 +2134,13 @@ group_error: /* * Groups can be scheduled in as one unit only, so undo any * partial group before returning: - * The events up to the failed event are scheduled out normally, - * tstamp_stopped will be updated. - * - * The failed events and the remaining siblings need to have - * their timings updated as if they had gone thru event_sched_in() - * and event_sched_out(). This is required to get consistent timings - * across the group. This also takes care of the case where the group - * could never be scheduled by ensuring tstamp_stopped is set to mark - * the time the event was actually stopped, such that time delta - * calculation in update_event_times() is correct. + * The events up to the failed event are scheduled out normally. */ list_for_each_entry(event, &group_event->sibling_list, group_entry) { if (event == partial_group) - simulate = true; + break; - if (simulate) { - event->tstamp_running += now - event->tstamp_stopped; - event->tstamp_stopped = now; - } else { - event_sched_out(event, cpuctx, ctx); - } + event_sched_out(event, cpuctx, ctx); } event_sched_out(group_event, cpuctx, ctx); @@ -2225,46 +2182,11 @@ static int group_can_go_on(struct perf_event *event, return can_add_hw; } -/* - * Complement to update_event_times(). This computes the tstamp_* values to - * continue 'enabled' state from @now, and effectively discards the time - * between the prior tstamp_stopped and now (as we were in the OFF state, or - * just switched (context) time base). - * - * This further assumes '@event->state == INACTIVE' (we just came from OFF) and - * cannot have been scheduled in yet. And going into INACTIVE state means - * '@event->tstamp_stopped = @now'. - * - * Thus given the rules of update_event_times(): - * - * total_time_enabled = tstamp_stopped - tstamp_enabled - * total_time_running = tstamp_stopped - tstamp_running - * - * We can insert 'tstamp_stopped == now' and reverse them to compute new - * tstamp_* values. - */ -static void __perf_event_enable_time(struct perf_event *event, u64 now) -{ - WARN_ON_ONCE(event->state != PERF_EVENT_STATE_INACTIVE); - - event->tstamp_stopped = now; - event->tstamp_enabled = now - event->total_time_enabled; - event->tstamp_running = now - event->total_time_running; -} - static void add_event_to_ctx(struct perf_event *event, struct perf_event_context *ctx) { - u64 tstamp = perf_event_time(event); - list_add_event(event, ctx); perf_group_attach(event); - /* - * We can be called with event->state == STATE_OFF when we create with - * .disabled = 1. In that case the IOC_ENABLE will call this function. - */ - if (event->state == PERF_EVENT_STATE_INACTIVE) - __perf_event_enable_time(event, tstamp); } static void ctx_sched_out(struct perf_event_context *ctx, @@ -2496,28 +2418,6 @@ again: } /* - * Put a event into inactive state and update time fields. - * Enabling the leader of a group effectively enables all - * the group members that aren't explicitly disabled, so we - * have to update their ->tstamp_enabled also. - * Note: this works for group members as well as group leaders - * since the non-leader members' sibling_lists will be empty. - */ -static void __perf_event_mark_enabled(struct perf_event *event) -{ - struct perf_event *sub; - u64 tstamp = perf_event_time(event); - - event->state = PERF_EVENT_STATE_INACTIVE; - __perf_event_enable_time(event, tstamp); - list_for_each_entry(sub, &event->sibling_list, group_entry) { - /* XXX should not be > INACTIVE if event isn't */ - if (sub->state >= PERF_EVENT_STATE_INACTIVE) - __perf_event_enable_time(sub, tstamp); - } -} - -/* * Cross CPU call to enable a performance event */ static void __perf_event_enable(struct perf_event *event, @@ -2535,14 +2435,12 @@ static void __perf_event_enable(struct perf_event *event, if (ctx->is_active) ctx_sched_out(ctx, cpuctx, EVENT_TIME); - __perf_event_mark_enabled(event); + perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); if (!ctx->is_active) return; if (!event_filter_match(event)) { - if (is_cgroup_event(event)) - perf_cgroup_defer_enabled(event); ctx_sched_in(ctx, cpuctx, EVENT_TIME, current); return; } @@ -2862,18 +2760,10 @@ static void __perf_event_sync_stat(struct perf_event *event, * we know the event must be on the current CPU, therefore we * don't need to use it. */ - switch (event->state) { - case PERF_EVENT_STATE_ACTIVE: + if (event->state == PERF_EVENT_STATE_ACTIVE) event->pmu->read(event); - /* fall-through */ - - case PERF_EVENT_STATE_INACTIVE: - update_event_times(event); - break; - default: - break; - } + perf_event_update_time(event); /* * In order to keep per-task stats reliable we need to flip the event @@ -3110,10 +3000,6 @@ ctx_pinned_sched_in(struct perf_event_context *ctx, if (!event_filter_match(event)) continue; - /* may need to reset tstamp_enabled */ - if (is_cgroup_event(event)) - perf_cgroup_mark_enabled(event, ctx); - if (group_can_go_on(event, cpuctx, 1)) group_sched_in(event, cpuctx, ctx); @@ -3121,10 +3007,8 @@ ctx_pinned_sched_in(struct perf_event_context *ctx, * If this pinned group hasn't been scheduled, * put it in error state. */ - if (event->state == PERF_EVENT_STATE_INACTIVE) { - update_group_times(event); - event->state = PERF_EVENT_STATE_ERROR; - } + if (event->state == PERF_EVENT_STATE_INACTIVE) + perf_event_set_state(event, PERF_EVENT_STATE_ERROR); } } @@ -3146,10 +3030,6 @@ ctx_flexible_sched_in(struct perf_event_context *ctx, if (!event_filter_match(event)) continue; - /* may need to reset tstamp_enabled */ - if (is_cgroup_event(event)) - perf_cgroup_mark_enabled(event, ctx); - if (group_can_go_on(event, cpuctx, can_add_hw)) { if (group_sched_in(event, cpuctx, ctx)) can_add_hw = 0; @@ -3521,7 +3401,7 @@ void perf_event_task_tick(void) struct perf_event_context *ctx, *tmp; int throttled; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); __this_cpu_inc(perf_throttled_seq); throttled = __this_cpu_xchg(perf_throttled_count, 0); @@ -3541,7 +3421,7 @@ static int event_enable_on_exec(struct perf_event *event, if (event->state >= PERF_EVENT_STATE_INACTIVE) return 0; - __perf_event_mark_enabled(event); + perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); return 1; } @@ -3635,12 +3515,15 @@ static void __perf_event_read(void *info) return; raw_spin_lock(&ctx->lock); - if (ctx->is_active) { + if (ctx->is_active & EVENT_TIME) { update_context_time(ctx); update_cgrp_time_from_event(event); } - update_event_times(event); + perf_event_update_time(event); + if (data->group) + perf_event_update_sibling_time(event); + if (event->state != PERF_EVENT_STATE_ACTIVE) goto unlock; @@ -3655,7 +3538,6 @@ static void __perf_event_read(void *info) pmu->read(event); list_for_each_entry(sub, &event->sibling_list, group_entry) { - update_event_times(sub); if (sub->state == PERF_EVENT_STATE_ACTIVE) { /* * Use sibling's PMU rather than @event's since @@ -3684,7 +3566,8 @@ static inline u64 perf_event_count(struct perf_event *event) * will not be local and we cannot read them atomically * - must not have a pmu::count method */ -int perf_event_read_local(struct perf_event *event, u64 *value) +int perf_event_read_local(struct perf_event *event, u64 *value, + u64 *enabled, u64 *running) { unsigned long flags; int ret = 0; @@ -3718,6 +3601,7 @@ int perf_event_read_local(struct perf_event *event, u64 *value) goto out; } + /* * If the event is currently on this CPU, its either a per-task event, * or local to this CPU. Furthermore it means its ACTIVE (otherwise @@ -3727,6 +3611,16 @@ int perf_event_read_local(struct perf_event *event, u64 *value) event->pmu->read(event); *value = local64_read(&event->count); + if (enabled || running) { + u64 now = event->shadow_ctx_time + perf_clock(); + u64 __enabled, __running; + + __perf_update_times(event, now, &__enabled, &__running); + if (enabled) + *enabled = __enabled; + if (running) + *running = __running; + } out: local_irq_restore(flags); @@ -3735,23 +3629,35 @@ out: static int perf_event_read(struct perf_event *event, bool group) { + enum perf_event_state state = READ_ONCE(event->state); int event_cpu, ret = 0; /* * If event is enabled and currently active on a CPU, update the * value in the event structure: */ - if (event->state == PERF_EVENT_STATE_ACTIVE) { - struct perf_read_data data = { - .event = event, - .group = group, - .ret = 0, - }; +again: + if (state == PERF_EVENT_STATE_ACTIVE) { + struct perf_read_data data; + + /* + * Orders the ->state and ->oncpu loads such that if we see + * ACTIVE we must also see the right ->oncpu. + * + * Matches the smp_wmb() from event_sched_in(). + */ + smp_rmb(); event_cpu = READ_ONCE(event->oncpu); if ((unsigned)event_cpu >= nr_cpu_ids) return 0; + data = (struct perf_read_data){ + .event = event, + .group = group, + .ret = 0, + }; + preempt_disable(); event_cpu = __perf_event_read_cpu(event, event_cpu); @@ -3768,24 +3674,30 @@ static int perf_event_read(struct perf_event *event, bool group) (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); preempt_enable(); ret = data.ret; - } else if (event->state == PERF_EVENT_STATE_INACTIVE) { + + } else if (state == PERF_EVENT_STATE_INACTIVE) { struct perf_event_context *ctx = event->ctx; unsigned long flags; raw_spin_lock_irqsave(&ctx->lock, flags); + state = event->state; + if (state != PERF_EVENT_STATE_INACTIVE) { + raw_spin_unlock_irqrestore(&ctx->lock, flags); + goto again; + } + /* - * may read while context is not active - * (e.g., thread is blocked), in that case - * we cannot update context time + * May read while context is not active (e.g., thread is + * blocked), in that case we cannot update context time */ - if (ctx->is_active) { + if (ctx->is_active & EVENT_TIME) { update_context_time(ctx); update_cgrp_time_from_event(event); } + + perf_event_update_time(event); if (group) - update_group_times(event); - else - update_event_times(event); + perf_event_update_sibling_time(event); raw_spin_unlock_irqrestore(&ctx->lock, flags); } @@ -4231,7 +4143,7 @@ static void perf_remove_from_owner(struct perf_event *event) * indeed free this event, otherwise we need to serialize on * owner->perf_event_mutex. */ - owner = lockless_dereference(event->owner); + owner = READ_ONCE(event->owner); if (owner) { /* * Since delayed_put_task_struct() also drops the last @@ -4328,7 +4240,7 @@ again: * Cannot change, child events are not migrated, see the * comment with perf_event_ctx_lock_nested(). */ - ctx = lockless_dereference(child->ctx); + ctx = READ_ONCE(child->ctx); /* * Since child_mutex nests inside ctx::mutex, we must jump * through hoops. We start by grabbing a reference on the ctx. @@ -4388,7 +4300,7 @@ static int perf_release(struct inode *inode, struct file *file) return 0; } -u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) +static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) { struct perf_event *child; u64 total = 0; @@ -4416,6 +4328,18 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) return total; } + +u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) +{ + struct perf_event_context *ctx; + u64 count; + + ctx = perf_event_ctx_lock(event); + count = __perf_event_read_value(event, enabled, running); + perf_event_ctx_unlock(event, ctx); + + return count; +} EXPORT_SYMBOL_GPL(perf_event_read_value); static int __perf_read_group_add(struct perf_event *leader, @@ -4431,6 +4355,8 @@ static int __perf_read_group_add(struct perf_event *leader, if (ret) return ret; + raw_spin_lock_irqsave(&ctx->lock, flags); + /* * Since we co-schedule groups, {enabled,running} times of siblings * will be identical to those of the leader, so we only publish one @@ -4453,8 +4379,6 @@ static int __perf_read_group_add(struct perf_event *leader, if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(leader); - raw_spin_lock_irqsave(&ctx->lock, flags); - list_for_each_entry(sub, &leader->sibling_list, group_entry) { values[n++] += perf_event_count(sub); if (read_format & PERF_FORMAT_ID) @@ -4518,7 +4442,7 @@ static int perf_read_one(struct perf_event *event, u64 values[4]; int n = 0; - values[n++] = perf_event_read_value(event, &enabled, &running); + values[n++] = __perf_event_read_value(event, &enabled, &running); if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) values[n++] = enabled; if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) @@ -4897,8 +4821,7 @@ static void calc_timer_values(struct perf_event *event, *now = perf_clock(); ctx_time = event->shadow_ctx_time + *now; - *enabled = ctx_time - event->tstamp_enabled; - *running = ctx_time - event->tstamp_running; + __perf_update_times(event, ctx_time, enabled, running); } static void perf_event_init_userpage(struct perf_event *event) @@ -5302,8 +5225,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) if (!rb) goto aux_unlock; - aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); - aux_size = ACCESS_ONCE(rb->user_page->aux_size); + aux_offset = READ_ONCE(rb->user_page->aux_offset); + aux_size = READ_ONCE(rb->user_page->aux_size); if (aux_offset < perf_data_size(rb) + PAGE_SIZE) goto aux_unlock; @@ -8072,6 +7995,7 @@ static void bpf_overflow_handler(struct perf_event *event, struct bpf_perf_event_data_kern ctx = { .data = data, .regs = regs, + .event = event, }; int ret = 0; @@ -8955,6 +8879,14 @@ static struct perf_cpu_context __percpu *find_pmu_context(int ctxn) static void free_pmu_context(struct pmu *pmu) { + /* + * Static contexts such as perf_sw_context have a global lifetime + * and may be shared between different PMUs. Avoid freeing them + * when a single PMU is going away. + */ + if (pmu->task_ctx_nr > perf_invalid_context) + return; + mutex_lock(&pmus_lock); free_percpu(pmu->pmu_cpu_context); mutex_unlock(&pmus_lock); @@ -9394,6 +9326,11 @@ static void account_event(struct perf_event *event) inc = true; if (inc) { + /* + * We need the mutex here because static_branch_enable() + * must complete *before* the perf_sched_count increment + * becomes visible. + */ if (atomic_inc_not_zero(&perf_sched_count)) goto enabled; @@ -10519,7 +10456,7 @@ perf_event_exit_event(struct perf_event *child_event, if (parent_event) perf_group_detach(child_event); list_del_event(child_event, child_ctx); - child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ + perf_event_set_state(child_event, PERF_EVENT_STATE_EXIT); /* is_event_hup() */ raw_spin_unlock_irq(&child_ctx->lock); /* @@ -10757,7 +10694,7 @@ inherit_event(struct perf_event *parent_event, struct perf_event *group_leader, struct perf_event_context *child_ctx) { - enum perf_event_active_state parent_state = parent_event->state; + enum perf_event_state parent_state = parent_event->state; struct perf_event *child_event; unsigned long flags; @@ -11093,6 +11030,7 @@ static void __perf_event_exit_context(void *__info) struct perf_event *event; raw_spin_lock(&ctx->lock); + ctx_sched_out(ctx, cpuctx, EVENT_TIME); list_for_each_entry(event, &ctx->event_list, event_entry) __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); raw_spin_unlock(&ctx->lock); diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 843e97047335..09b1537ae06c 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _KERNEL_EVENTS_INTERNAL_H #define _KERNEL_EVENTS_INTERNAL_H diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 6d9bffe4d6cc..141aa2ca8728 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -381,7 +381,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle, * (B) <-> (C) ordering is still observed by the pmu driver. */ if (!rb->aux_overwrite) { - aux_tail = ACCESS_ONCE(rb->user_page->aux_tail); + aux_tail = READ_ONCE(rb->user_page->aux_tail); handle->wakeup = rb->aux_wakeup + rb->aux_watermark; if (aux_head - aux_tail < perf_aux_size(rb)) handle->size = CIRC_SPACE(aux_head, aux_tail, perf_aux_size(rb)); diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index 6873bb3e6b7e..0975b0268545 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Handling of different ABIs (personalities). * diff --git a/kernel/exit.c b/kernel/exit.c index f2cd53e92147..6b4298a41167 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1339,7 +1339,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition * can't confuse the checks below. */ - int exit_state = ACCESS_ONCE(p->exit_state); + int exit_state = READ_ONCE(p->exit_state); int ret; if (unlikely(exit_state == EXIT_DEAD)) @@ -1610,6 +1610,9 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, if (!infop) return err; + if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop))) + return -EFAULT; + user_access_begin(); unsafe_put_user(signo, &infop->si_signo, Efault); unsafe_put_user(0, &infop->si_errno, Efault); @@ -1735,6 +1738,9 @@ COMPAT_SYSCALL_DEFINE5(waitid, if (!infop) return err; + if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop))) + return -EFAULT; + user_access_begin(); unsafe_put_user(signo, &infop->si_signo, Efault); unsafe_put_user(0, &infop->si_errno, Efault); diff --git a/kernel/extable.c b/kernel/extable.c index 9aa1cc41ecf7..a17fdb63dc3e 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -31,6 +31,8 @@ * mutex protecting text section modification (dynamic code patching). * some users need to sleep (allocating memory...) while they hold this lock. * + * Note: Also protects SMP-alternatives modification on x86. + * * NOT exported to modules - patching kernel text is a really delicate matter. */ DEFINE_MUTEX(text_mutex); diff --git a/kernel/fork.c b/kernel/fork.c index 10646182440f..07cc743698d3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -215,6 +215,10 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) if (!s) continue; +#ifdef CONFIG_DEBUG_KMEMLEAK + /* Clear stale pointers from reused stack. */ + memset(s->addr, 0, THREAD_SIZE); +#endif tsk->stack_vm_area = s; return s->addr; } @@ -946,6 +950,24 @@ void mmput(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(mmput); +#ifdef CONFIG_MMU +static void mmput_async_fn(struct work_struct *work) +{ + struct mm_struct *mm = container_of(work, struct mm_struct, + async_put_work); + + __mmput(mm); +} + +void mmput_async(struct mm_struct *mm) +{ + if (atomic_dec_and_test(&mm->mm_users)) { + INIT_WORK(&mm->async_put_work, mmput_async_fn); + schedule_work(&mm->async_put_work); + } +} +#endif + /** * set_mm_exe_file - change a reference to the mm's executable file * diff --git a/kernel/futex.c b/kernel/futex.c index 0518a0bfc746..76ed5921117a 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -903,11 +903,27 @@ void exit_pi_state_list(struct task_struct *curr) */ raw_spin_lock_irq(&curr->pi_lock); while (!list_empty(head)) { - next = head->next; pi_state = list_entry(next, struct futex_pi_state, list); key = pi_state->key; hb = hash_futex(&key); + + /* + * We can race against put_pi_state() removing itself from the + * list (a waiter going away). put_pi_state() will first + * decrement the reference count and then modify the list, so + * its possible to see the list entry but fail this reference + * acquire. + * + * In that case; drop the locks to let put_pi_state() make + * progress and retry the loop. + */ + if (!atomic_inc_not_zero(&pi_state->refcount)) { + raw_spin_unlock_irq(&curr->pi_lock); + cpu_relax(); + raw_spin_lock_irq(&curr->pi_lock); + continue; + } raw_spin_unlock_irq(&curr->pi_lock); spin_lock(&hb->lock); @@ -918,8 +934,10 @@ void exit_pi_state_list(struct task_struct *curr) * task still owns the PI-state: */ if (head->next != next) { + /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); spin_unlock(&hb->lock); + put_pi_state(pi_state); continue; } @@ -927,9 +945,8 @@ void exit_pi_state_list(struct task_struct *curr) WARN_ON(list_empty(&pi_state->list)); list_del_init(&pi_state->list); pi_state->owner = NULL; - raw_spin_unlock(&curr->pi_lock); - get_pi_state(pi_state); + raw_spin_unlock(&curr->pi_lock); raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); spin_unlock(&hb->lock); @@ -1570,8 +1587,16 @@ static int futex_atomic_op_inuser(unsigned int encoded_op, u32 __user *uaddr) int oldval, ret; if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) { - if (oparg < 0 || oparg > 31) - return -EINVAL; + if (oparg < 0 || oparg > 31) { + char comm[sizeof(current->comm)]; + /* + * kill this print and return -EINVAL when userspace + * is sane again + */ + pr_info_ratelimited("futex_wake_op: %s tries to shift op by %d; fix this program\n", + get_task_comm(comm, current), oparg); + oparg &= 31; + } oparg = 1 << oparg; } diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 3f409968e466..83f830acbb5f 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/futex_compat.c * diff --git a/kernel/gcov/Makefile b/kernel/gcov/Makefile index 752d6486b67e..c6c50e5c680e 100644 --- a/kernel/gcov/Makefile +++ b/kernel/gcov/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"' obj-y := base.o fs.o diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c index c51a49c9be70..9c7c8d5c18f2 100644 --- a/kernel/gcov/base.c +++ b/kernel/gcov/base.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * This code maintains a list of active profiling data structures. * diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c index edf67c493a8e..6e40ff6be083 100644 --- a/kernel/gcov/fs.c +++ b/kernel/gcov/fs.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * This code exports profiling data as debugfs files to userspace. * diff --git a/kernel/gcov/gcc_3_4.c b/kernel/gcov/gcc_3_4.c index 27bc88a35013..1e32e66c9563 100644 --- a/kernel/gcov/gcc_3_4.c +++ b/kernel/gcov/gcc_3_4.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * This code provides functions to handle gcc's profiling data format * introduced with gcc 3.4. Future versions of gcc may change the gcov diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c index 46a18e72bce6..ca5e5c0ef853 100644 --- a/kernel/gcov/gcc_4_7.c +++ b/kernel/gcov/gcc_4_7.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * This code provides functions to handle gcc's profiling data format * introduced with gcc 4.7. diff --git a/kernel/gcov/gcov.h b/kernel/gcov/gcov.h index 92c8e22a29ed..de118ad4a024 100644 --- a/kernel/gcov/gcov.h +++ b/kernel/gcov/gcov.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Profiling infrastructure declarations. * diff --git a/kernel/groups.c b/kernel/groups.c index 434f6665f187..e357bc800111 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Supplementary group IDs */ diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index a117adf7084b..89e355866450 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -97,6 +97,12 @@ config HANDLE_DOMAIN_IRQ config IRQ_TIMINGS bool +config GENERIC_IRQ_MATRIX_ALLOCATOR + bool + +config GENERIC_IRQ_RESERVATION_MODE + bool + config IRQ_DOMAIN_DEBUG bool "Expose hardware/virtual IRQ mapping via debugfs" depends on IRQ_DOMAIN && DEBUG_FS diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile index 1970cafe8f2a..ff6e352e3a6c 100644 --- a/kernel/irq/Makefile +++ b/kernel/irq/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o obj-$(CONFIG_IRQ_TIMINGS) += timings.o @@ -13,3 +14,4 @@ obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o obj-$(CONFIG_GENERIC_IRQ_IPI) += ipi.o obj-$(CONFIG_SMP) += affinity.o obj-$(CONFIG_GENERIC_IRQ_DEBUGFS) += debugfs.o +obj-$(CONFIG_GENERIC_IRQ_MATRIX_ALLOCATOR) += matrix.o diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index d69bd77252a7..e12d35108225 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2016 Thomas Gleixner. * Copyright (C) 2016-2017 Christoph Hellwig. diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index d30a0dd5cc02..4e8089b319ae 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/irq/autoprobe.c * @@ -53,7 +54,7 @@ unsigned long probe_irq_on(void) if (desc->irq_data.chip->irq_set_type) desc->irq_data.chip->irq_set_type(&desc->irq_data, IRQ_TYPE_PROBE); - irq_startup(desc, IRQ_NORESEND, IRQ_START_FORCE); + irq_activate_and_startup(desc, IRQ_NORESEND); } raw_spin_unlock_irq(&desc->lock); } diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 6fc89fd93824..043bfc35b353 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -207,20 +207,24 @@ __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force) * Catch code which fiddles with enable_irq() on a managed * and potentially shutdown IRQ. Chained interrupt * installment or irq auto probing should not happen on - * managed irqs either. Emit a warning, break the affinity - * and start it up as a normal interrupt. + * managed irqs either. */ if (WARN_ON_ONCE(force)) - return IRQ_STARTUP_NORMAL; + return IRQ_STARTUP_ABORT; /* * The interrupt was requested, but there is no online CPU * in it's affinity mask. Put it into managed shutdown * state and let the cpu hotplug mechanism start it up once * a CPU in the mask becomes available. */ - irqd_set_managed_shutdown(d); return IRQ_STARTUP_ABORT; } + /* + * Managed interrupts have reserved resources, so this should not + * happen. + */ + if (WARN_ON(irq_domain_activate_irq(d, false))) + return IRQ_STARTUP_ABORT; return IRQ_STARTUP_MANAGED; } #else @@ -236,7 +240,9 @@ static int __irq_startup(struct irq_desc *desc) struct irq_data *d = irq_desc_get_irq_data(desc); int ret = 0; - irq_domain_activate_irq(d); + /* Warn if this interrupt is not activated but try nevertheless */ + WARN_ON_ONCE(!irqd_is_activated(d)); + if (d->chip->irq_startup) { ret = d->chip->irq_startup(d); irq_state_clr_disabled(desc); @@ -265,10 +271,11 @@ int irq_startup(struct irq_desc *desc, bool resend, bool force) irq_setup_affinity(desc); break; case IRQ_STARTUP_MANAGED: + irq_do_set_affinity(d, aff, false); ret = __irq_startup(desc); - irq_set_affinity_locked(d, aff, false); break; case IRQ_STARTUP_ABORT: + irqd_set_managed_shutdown(d); return 0; } } @@ -278,6 +285,22 @@ int irq_startup(struct irq_desc *desc, bool resend, bool force) return ret; } +int irq_activate(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + + if (!irqd_affinity_is_managed(d)) + return irq_domain_activate_irq(d, false); + return 0; +} + +void irq_activate_and_startup(struct irq_desc *desc, bool resend) +{ + if (WARN_ON(irq_activate(desc))) + return; + irq_startup(desc, resend, IRQ_START_FORCE); +} + static void __irq_disable(struct irq_desc *desc, bool mask); void irq_shutdown(struct irq_desc *desc) @@ -953,7 +976,7 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, irq_settings_set_norequest(desc); irq_settings_set_nothread(desc); desc->action = &chained_action; - irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE); + irq_activate_and_startup(desc, IRQ_RESEND); } } diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index 638eb9c83d9f..9eb09aef0313 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -18,8 +18,34 @@ static inline bool irq_needs_fixup(struct irq_data *d) { const struct cpumask *m = irq_data_get_effective_affinity_mask(d); + unsigned int cpu = smp_processor_id(); - return cpumask_test_cpu(smp_processor_id(), m); +#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK + /* + * The cpumask_empty() check is a workaround for interrupt chips, + * which do not implement effective affinity, but the architecture has + * enabled the config switch. Use the general affinity mask instead. + */ + if (cpumask_empty(m)) + m = irq_data_get_affinity_mask(d); + + /* + * Sanity check. If the mask is not empty when excluding the outgoing + * CPU then it must contain at least one online CPU. The outgoing CPU + * has been removed from the online mask already. + */ + if (cpumask_any_but(m, cpu) < nr_cpu_ids && + cpumask_any_and(m, cpu_online_mask) >= nr_cpu_ids) { + /* + * If this happens then there was a missed IRQ fixup at some + * point. Warn about it and enforce fixup. + */ + pr_warn("Eff. affinity %*pbl of IRQ %u contains only offline CPUs after offlining CPU %u\n", + cpumask_pr_args(m), d->irq, cpu); + return true; + } +#endif + return cpumask_test_cpu(cpu, m); } static bool migrate_one_irq(struct irq_desc *desc) diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h index e75e29e4434a..17f05ef8f575 100644 --- a/kernel/irq/debug.h +++ b/kernel/irq/debug.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Debugging printout: */ diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index c3fdb36dec30..7f608ac39653 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -81,6 +81,8 @@ irq_debug_show_data(struct seq_file *m, struct irq_data *data, int ind) data->domain ? data->domain->name : ""); seq_printf(m, "%*shwirq: 0x%lx\n", ind + 1, "", data->hwirq); irq_debug_show_chip(m, data, ind + 1); + if (data->domain && data->domain->ops && data->domain->ops->debug_show) + data->domain->ops->debug_show(m, NULL, data, ind + 1); #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY if (!data->parent_data) return; @@ -149,6 +151,7 @@ static int irq_debug_show(struct seq_file *m, void *p) raw_spin_lock_irq(&desc->lock); data = irq_desc_get_irq_data(desc); seq_printf(m, "handler: %pf\n", desc->handle_irq); + seq_printf(m, "device: %s\n", desc->dev_name); seq_printf(m, "status: 0x%08x\n", desc->status_use_accessors); irq_debug_show_bits(m, 0, desc->status_use_accessors, irqdesc_states, ARRAY_SIZE(irqdesc_states)); @@ -226,6 +229,15 @@ static const struct file_operations dfs_irq_ops = { .release = single_release, }; +void irq_debugfs_copy_devname(int irq, struct device *dev) +{ + struct irq_desc *desc = irq_to_desc(irq); + const char *name = dev_name(dev); + + if (name) + desc->dev_name = kstrdup(name, GFP_KERNEL); +} + void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *desc) { char name [10]; diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c index 5270a54b9fa4..c26c5bb6b491 100644 --- a/kernel/irq/generic-chip.c +++ b/kernel/irq/generic-chip.c @@ -135,17 +135,26 @@ void irq_gc_ack_clr_bit(struct irq_data *d) } /** - * irq_gc_mask_disable_reg_and_ack - Mask and ack pending interrupt + * irq_gc_mask_disable_and_ack_set - Mask and ack pending interrupt * @d: irq_data + * + * This generic implementation of the irq_mask_ack method is for chips + * with separate enable/disable registers instead of a single mask + * register and where a pending interrupt is acknowledged by setting a + * bit. + * + * Note: This is the only permutation currently used. Similar generic + * functions should be added here if other permutations are required. */ -void irq_gc_mask_disable_reg_and_ack(struct irq_data *d) +void irq_gc_mask_disable_and_ack_set(struct irq_data *d) { struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); struct irq_chip_type *ct = irq_data_get_chip_type(d); u32 mask = d->mask; irq_gc_lock(gc); - irq_reg_writel(gc, mask, ct->regs.mask); + irq_reg_writel(gc, mask, ct->regs.disable); + *ct->mask_cache &= ~mask; irq_reg_writel(gc, mask, ct->regs.ack); irq_gc_unlock(gc); } diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index a4aa39009f0d..07d08ca701ec 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * IRQ subsystem internal functions and variables: * @@ -74,6 +75,8 @@ extern void __enable_irq(struct irq_desc *desc); #define IRQ_START_FORCE true #define IRQ_START_COND false +extern int irq_activate(struct irq_desc *desc); +extern void irq_activate_and_startup(struct irq_desc *desc, bool resend); extern int irq_startup(struct irq_desc *desc, bool resend, bool force); extern void irq_shutdown(struct irq_desc *desc); @@ -436,6 +439,18 @@ static inline bool irq_fixup_move_pending(struct irq_desc *desc, bool fclear) } #endif /* !CONFIG_GENERIC_PENDING_IRQ */ +#if !defined(CONFIG_IRQ_DOMAIN) || !defined(CONFIG_IRQ_DOMAIN_HIERARCHY) +static inline int irq_domain_activate_irq(struct irq_data *data, bool early) +{ + irqd_set_activated(data); + return 0; +} +static inline void irq_domain_deactivate_irq(struct irq_data *data) +{ + irqd_clr_activated(data); +} +#endif + #ifdef CONFIG_GENERIC_IRQ_DEBUGFS #include <linux/debugfs.h> @@ -443,7 +458,9 @@ void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *desc); static inline void irq_remove_debugfs_entry(struct irq_desc *desc) { debugfs_remove(desc->debugfs_file); + kfree(desc->dev_name); } +void irq_debugfs_copy_devname(int irq, struct device *dev); # ifdef CONFIG_IRQ_DOMAIN void irq_domain_debugfs_init(struct dentry *root); # else @@ -458,4 +475,7 @@ static inline void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *d) static inline void irq_remove_debugfs_entry(struct irq_desc *d) { } +static inline void irq_debugfs_copy_devname(int irq, struct device *dev) +{ +} #endif /* CONFIG_GENERIC_IRQ_DEBUGFS */ diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 694c1a9d6485..49b54e9979cc 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -27,7 +27,7 @@ static struct lock_class_key irq_desc_lock_class; #if defined(CONFIG_SMP) static int __init irq_affinity_setup(char *str) { - zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); + alloc_bootmem_cpumask_var(&irq_default_affinity); cpulist_parse(str, irq_default_affinity); /* * Set at least the boot cpu. We don't want to end up with @@ -40,10 +40,8 @@ __setup("irqaffinity=", irq_affinity_setup); static void __init init_irq_default_affinity(void) { -#ifdef CONFIG_CPUMASK_OFFSTACK - if (!irq_default_affinity) + if (!cpumask_available(irq_default_affinity)) zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); -#endif if (cpumask_empty(irq_default_affinity)) cpumask_setall(irq_default_affinity); } @@ -448,7 +446,7 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node, } } - flags = affinity ? IRQD_AFFINITY_MANAGED : 0; + flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0; mask = NULL; for (i = 0; i < cnt; i++) { @@ -462,6 +460,7 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node, goto err; irq_insert_desc(start + i, desc); irq_sysfs_add(start + i, desc); + irq_add_debugfs_entry(start + i, desc); } bitmap_set(allocated_irqs, start, cnt); return start; diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index ac4644e92b49..4f4f60015e8a 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -21,7 +21,6 @@ static LIST_HEAD(irq_domain_list); static DEFINE_MUTEX(irq_domain_mutex); -static DEFINE_MUTEX(revmap_trees_mutex); static struct irq_domain *irq_default_domain; static void irq_domain_check_hierarchy(struct irq_domain *domain); @@ -211,6 +210,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size, /* Fill structure */ INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL); + mutex_init(&domain->revmap_tree_mutex); domain->ops = ops; domain->host_data = host_data; domain->hwirq_max = hwirq_max; @@ -462,9 +462,9 @@ static void irq_domain_clear_mapping(struct irq_domain *domain, if (hwirq < domain->revmap_size) { domain->linear_revmap[hwirq] = 0; } else { - mutex_lock(&revmap_trees_mutex); + mutex_lock(&domain->revmap_tree_mutex); radix_tree_delete(&domain->revmap_tree, hwirq); - mutex_unlock(&revmap_trees_mutex); + mutex_unlock(&domain->revmap_tree_mutex); } } @@ -475,9 +475,9 @@ static void irq_domain_set_mapping(struct irq_domain *domain, if (hwirq < domain->revmap_size) { domain->linear_revmap[hwirq] = irq_data->irq; } else { - mutex_lock(&revmap_trees_mutex); + mutex_lock(&domain->revmap_tree_mutex); radix_tree_insert(&domain->revmap_tree, hwirq, irq_data); - mutex_unlock(&revmap_trees_mutex); + mutex_unlock(&domain->revmap_tree_mutex); } } @@ -921,8 +921,7 @@ static void virq_debug_show_one(struct seq_file *m, struct irq_desc *desc) chip = irq_data_get_irq_chip(data); seq_printf(m, "%-15s ", (chip && chip->name) ? chip->name : "none"); - seq_printf(m, data ? "0x%p " : " %p ", - irq_data_get_irq_chip_data(data)); + seq_printf(m, "0x%p ", irq_data_get_irq_chip_data(data)); seq_printf(m, " %c ", (desc->action && desc->action->handler) ? '*' : ' '); direct = (irq == hwirq) && (irq < domain->revmap_direct_max_irq); @@ -1459,11 +1458,11 @@ static void irq_domain_fix_revmap(struct irq_data *d) return; /* Not using radix tree. */ /* Fix up the revmap. */ - mutex_lock(&revmap_trees_mutex); + mutex_lock(&d->domain->revmap_tree_mutex); slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq); if (slot) radix_tree_replace_slot(&d->domain->revmap_tree, slot, d); - mutex_unlock(&revmap_trees_mutex); + mutex_unlock(&d->domain->revmap_tree_mutex); } /** @@ -1682,28 +1681,36 @@ void irq_domain_free_irqs_parent(struct irq_domain *domain, } EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent); -static void __irq_domain_activate_irq(struct irq_data *irq_data) +static void __irq_domain_deactivate_irq(struct irq_data *irq_data) { if (irq_data && irq_data->domain) { struct irq_domain *domain = irq_data->domain; + if (domain->ops->deactivate) + domain->ops->deactivate(domain, irq_data); if (irq_data->parent_data) - __irq_domain_activate_irq(irq_data->parent_data); - if (domain->ops->activate) - domain->ops->activate(domain, irq_data); + __irq_domain_deactivate_irq(irq_data->parent_data); } } -static void __irq_domain_deactivate_irq(struct irq_data *irq_data) +static int __irq_domain_activate_irq(struct irq_data *irqd, bool early) { - if (irq_data && irq_data->domain) { - struct irq_domain *domain = irq_data->domain; + int ret = 0; - if (domain->ops->deactivate) - domain->ops->deactivate(domain, irq_data); - if (irq_data->parent_data) - __irq_domain_deactivate_irq(irq_data->parent_data); + if (irqd && irqd->domain) { + struct irq_domain *domain = irqd->domain; + + if (irqd->parent_data) + ret = __irq_domain_activate_irq(irqd->parent_data, + early); + if (!ret && domain->ops->activate) { + ret = domain->ops->activate(domain, irqd, early); + /* Rollback in case of error */ + if (ret && irqd->parent_data) + __irq_domain_deactivate_irq(irqd->parent_data); + } } + return ret; } /** @@ -1714,12 +1721,15 @@ static void __irq_domain_deactivate_irq(struct irq_data *irq_data) * This is the second step to call domain_ops->activate to program interrupt * controllers, so the interrupt could actually get delivered. */ -void irq_domain_activate_irq(struct irq_data *irq_data) +int irq_domain_activate_irq(struct irq_data *irq_data, bool early) { - if (!irqd_is_activated(irq_data)) { - __irq_domain_activate_irq(irq_data); + int ret = 0; + + if (!irqd_is_activated(irq_data)) + ret = __irq_domain_activate_irq(irq_data, early); + if (!ret) irqd_set_activated(irq_data); - } + return ret; } /** @@ -1810,6 +1820,8 @@ irq_domain_debug_show_one(struct seq_file *m, struct irq_domain *d, int ind) d->revmap_size + d->revmap_direct_max_irq); seq_printf(m, "%*smapped: %u\n", ind + 1, "", d->mapcount); seq_printf(m, "%*sflags: 0x%08x\n", ind +1 , "", d->flags); + if (d->ops && d->ops->debug_show) + d->ops->debug_show(m, d, NULL, ind + 1); #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY if (!d->parent) return; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index d00132b5c325..2ff1c0c82fc9 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -168,6 +168,19 @@ void irq_set_thread_affinity(struct irq_desc *desc) set_bit(IRQTF_AFFINITY, &action->thread_flags); } +static void irq_validate_effective_affinity(struct irq_data *data) +{ +#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK + const struct cpumask *m = irq_data_get_effective_affinity_mask(data); + struct irq_chip *chip = irq_data_get_irq_chip(data); + + if (!cpumask_empty(m)) + return; + pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n", + chip->name, data->irq); +#endif +} + int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force) { @@ -175,12 +188,16 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, struct irq_chip *chip = irq_data_get_irq_chip(data); int ret; + if (!chip || !chip->irq_set_affinity) + return -EINVAL; + ret = chip->irq_set_affinity(data, mask, force); switch (ret) { case IRQ_SET_MASK_OK: case IRQ_SET_MASK_OK_DONE: cpumask_copy(desc->irq_common_data.affinity, mask); case IRQ_SET_MASK_OK_NOCOPY: + irq_validate_effective_affinity(data); irq_set_thread_affinity(desc); ret = 0; } @@ -381,7 +398,8 @@ int irq_select_affinity_usr(unsigned int irq) /** * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt * @irq: interrupt number to set affinity - * @vcpu_info: vCPU specific data + * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU + * specific data for percpu_devid interrupts * * This function uses the vCPU specific data to set the vCPU * affinity for an irq. The vCPU specific data is passed from @@ -519,7 +537,7 @@ void __enable_irq(struct irq_desc *desc) * time. If it was already started up, then irq_startup() * will invoke irq_enable() under the hood. */ - irq_startup(desc, IRQ_RESEND, IRQ_START_COND); + irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE); break; } default: @@ -1288,7 +1306,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * thread_mask assigned. See the loop above which or's * all existing action->thread_mask bits. */ - new->thread_mask = 1 << ffz(thread_mask); + new->thread_mask = 1UL << ffz(thread_mask); } else if (new->handler == irq_default_primary_handler && !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) { @@ -1325,6 +1343,21 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) goto out_unlock; } + /* + * Activate the interrupt. That activation must happen + * independently of IRQ_NOAUTOEN. request_irq() can fail + * and the callers are supposed to handle + * that. enable_irq() of an interrupt requested with + * IRQ_NOAUTOEN is not supposed to fail. The activation + * keeps it in shutdown mode, it merily associates + * resources if necessary and if that's not possible it + * fails. Interrupts which are in managed shutdown mode + * will simply ignore that activation request. + */ + ret = irq_activate(desc); + if (ret) + goto out_unlock; + desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \ IRQS_ONESHOT | IRQS_WAITING); irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); @@ -1400,7 +1433,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) wake_up_process(new->secondary->thread); register_irq_proc(irq, desc); - irq_add_debugfs_entry(irq, desc); new->dir = NULL; register_handler_proc(irq, new); return 0; diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c new file mode 100644 index 000000000000..a3cbbc8191c5 --- /dev/null +++ b/kernel/irq/matrix.c @@ -0,0 +1,443 @@ +/* + * Copyright (C) 2017 Thomas Gleixner <tglx@linutronix.de> + * + * SPDX-License-Identifier: GPL-2.0 + */ +#include <linux/spinlock.h> +#include <linux/seq_file.h> +#include <linux/bitmap.h> +#include <linux/percpu.h> +#include <linux/cpu.h> +#include <linux/irq.h> + +#define IRQ_MATRIX_SIZE (BITS_TO_LONGS(IRQ_MATRIX_BITS) * sizeof(unsigned long)) + +struct cpumap { + unsigned int available; + unsigned int allocated; + unsigned int managed; + bool online; + unsigned long alloc_map[IRQ_MATRIX_SIZE]; + unsigned long managed_map[IRQ_MATRIX_SIZE]; +}; + +struct irq_matrix { + unsigned int matrix_bits; + unsigned int alloc_start; + unsigned int alloc_end; + unsigned int alloc_size; + unsigned int global_available; + unsigned int global_reserved; + unsigned int systembits_inalloc; + unsigned int total_allocated; + unsigned int online_maps; + struct cpumap __percpu *maps; + unsigned long scratch_map[IRQ_MATRIX_SIZE]; + unsigned long system_map[IRQ_MATRIX_SIZE]; +}; + +#define CREATE_TRACE_POINTS +#include <trace/events/irq_matrix.h> + +/** + * irq_alloc_matrix - Allocate a irq_matrix structure and initialize it + * @matrix_bits: Number of matrix bits must be <= IRQ_MATRIX_BITS + * @alloc_start: From which bit the allocation search starts + * @alloc_end: At which bit the allocation search ends, i.e first + * invalid bit + */ +__init struct irq_matrix *irq_alloc_matrix(unsigned int matrix_bits, + unsigned int alloc_start, + unsigned int alloc_end) +{ + struct irq_matrix *m; + + if (matrix_bits > IRQ_MATRIX_BITS) + return NULL; + + m = kzalloc(sizeof(*m), GFP_KERNEL); + if (!m) + return NULL; + + m->matrix_bits = matrix_bits; + m->alloc_start = alloc_start; + m->alloc_end = alloc_end; + m->alloc_size = alloc_end - alloc_start; + m->maps = alloc_percpu(*m->maps); + if (!m->maps) { + kfree(m); + return NULL; + } + return m; +} + +/** + * irq_matrix_online - Bring the local CPU matrix online + * @m: Matrix pointer + */ +void irq_matrix_online(struct irq_matrix *m) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + BUG_ON(cm->online); + + bitmap_zero(cm->alloc_map, m->matrix_bits); + cm->available = m->alloc_size - (cm->managed + m->systembits_inalloc); + cm->allocated = 0; + m->global_available += cm->available; + cm->online = true; + m->online_maps++; + trace_irq_matrix_online(m); +} + +/** + * irq_matrix_offline - Bring the local CPU matrix offline + * @m: Matrix pointer + */ +void irq_matrix_offline(struct irq_matrix *m) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + /* Update the global available size */ + m->global_available -= cm->available; + cm->online = false; + m->online_maps--; + trace_irq_matrix_offline(m); +} + +static unsigned int matrix_alloc_area(struct irq_matrix *m, struct cpumap *cm, + unsigned int num, bool managed) +{ + unsigned int area, start = m->alloc_start; + unsigned int end = m->alloc_end; + + bitmap_or(m->scratch_map, cm->managed_map, m->system_map, end); + bitmap_or(m->scratch_map, m->scratch_map, cm->alloc_map, end); + area = bitmap_find_next_zero_area(m->scratch_map, end, start, num, 0); + if (area >= end) + return area; + if (managed) + bitmap_set(cm->managed_map, area, num); + else + bitmap_set(cm->alloc_map, area, num); + return area; +} + +/** + * irq_matrix_assign_system - Assign system wide entry in the matrix + * @m: Matrix pointer + * @bit: Which bit to reserve + * @replace: Replace an already allocated vector with a system + * vector at the same bit position. + * + * The BUG_ON()s below are on purpose. If this goes wrong in the + * early boot process, then the chance to survive is about zero. + * If this happens when the system is life, it's not much better. + */ +void irq_matrix_assign_system(struct irq_matrix *m, unsigned int bit, + bool replace) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + BUG_ON(bit > m->matrix_bits); + BUG_ON(m->online_maps > 1 || (m->online_maps && !replace)); + + set_bit(bit, m->system_map); + if (replace) { + BUG_ON(!test_and_clear_bit(bit, cm->alloc_map)); + cm->allocated--; + m->total_allocated--; + } + if (bit >= m->alloc_start && bit < m->alloc_end) + m->systembits_inalloc++; + + trace_irq_matrix_assign_system(bit, m); +} + +/** + * irq_matrix_reserve_managed - Reserve a managed interrupt in a CPU map + * @m: Matrix pointer + * @msk: On which CPUs the bits should be reserved. + * + * Can be called for offline CPUs. Note, this will only reserve one bit + * on all CPUs in @msk, but it's not guaranteed that the bits are at the + * same offset on all CPUs + */ +int irq_matrix_reserve_managed(struct irq_matrix *m, const struct cpumask *msk) +{ + unsigned int cpu, failed_cpu; + + for_each_cpu(cpu, msk) { + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + unsigned int bit; + + bit = matrix_alloc_area(m, cm, 1, true); + if (bit >= m->alloc_end) + goto cleanup; + cm->managed++; + if (cm->online) { + cm->available--; + m->global_available--; + } + trace_irq_matrix_reserve_managed(bit, cpu, m, cm); + } + return 0; +cleanup: + failed_cpu = cpu; + for_each_cpu(cpu, msk) { + if (cpu == failed_cpu) + break; + irq_matrix_remove_managed(m, cpumask_of(cpu)); + } + return -ENOSPC; +} + +/** + * irq_matrix_remove_managed - Remove managed interrupts in a CPU map + * @m: Matrix pointer + * @msk: On which CPUs the bits should be removed + * + * Can be called for offline CPUs + * + * This removes not allocated managed interrupts from the map. It does + * not matter which one because the managed interrupts free their + * allocation when they shut down. If not, the accounting is screwed, + * but all what can be done at this point is warn about it. + */ +void irq_matrix_remove_managed(struct irq_matrix *m, const struct cpumask *msk) +{ + unsigned int cpu; + + for_each_cpu(cpu, msk) { + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + unsigned int bit, end = m->alloc_end; + + if (WARN_ON_ONCE(!cm->managed)) + continue; + + /* Get managed bit which are not allocated */ + bitmap_andnot(m->scratch_map, cm->managed_map, cm->alloc_map, end); + + bit = find_first_bit(m->scratch_map, end); + if (WARN_ON_ONCE(bit >= end)) + continue; + + clear_bit(bit, cm->managed_map); + + cm->managed--; + if (cm->online) { + cm->available++; + m->global_available++; + } + trace_irq_matrix_remove_managed(bit, cpu, m, cm); + } +} + +/** + * irq_matrix_alloc_managed - Allocate a managed interrupt in a CPU map + * @m: Matrix pointer + * @cpu: On which CPU the interrupt should be allocated + */ +int irq_matrix_alloc_managed(struct irq_matrix *m, unsigned int cpu) +{ + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + unsigned int bit, end = m->alloc_end; + + /* Get managed bit which are not allocated */ + bitmap_andnot(m->scratch_map, cm->managed_map, cm->alloc_map, end); + bit = find_first_bit(m->scratch_map, end); + if (bit >= end) + return -ENOSPC; + set_bit(bit, cm->alloc_map); + cm->allocated++; + m->total_allocated++; + trace_irq_matrix_alloc_managed(bit, cpu, m, cm); + return bit; +} + +/** + * irq_matrix_assign - Assign a preallocated interrupt in the local CPU map + * @m: Matrix pointer + * @bit: Which bit to mark + * + * This should only be used to mark preallocated vectors + */ +void irq_matrix_assign(struct irq_matrix *m, unsigned int bit) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end)) + return; + if (WARN_ON_ONCE(test_and_set_bit(bit, cm->alloc_map))) + return; + cm->allocated++; + m->total_allocated++; + cm->available--; + m->global_available--; + trace_irq_matrix_assign(bit, smp_processor_id(), m, cm); +} + +/** + * irq_matrix_reserve - Reserve interrupts + * @m: Matrix pointer + * + * This is merily a book keeping call. It increments the number of globally + * reserved interrupt bits w/o actually allocating them. This allows to + * setup interrupt descriptors w/o assigning low level resources to it. + * The actual allocation happens when the interrupt gets activated. + */ +void irq_matrix_reserve(struct irq_matrix *m) +{ + if (m->global_reserved <= m->global_available && + m->global_reserved + 1 > m->global_available) + pr_warn("Interrupt reservation exceeds available resources\n"); + + m->global_reserved++; + trace_irq_matrix_reserve(m); +} + +/** + * irq_matrix_remove_reserved - Remove interrupt reservation + * @m: Matrix pointer + * + * This is merily a book keeping call. It decrements the number of globally + * reserved interrupt bits. This is used to undo irq_matrix_reserve() when the + * interrupt was never in use and a real vector allocated, which undid the + * reservation. + */ +void irq_matrix_remove_reserved(struct irq_matrix *m) +{ + m->global_reserved--; + trace_irq_matrix_remove_reserved(m); +} + +/** + * irq_matrix_alloc - Allocate a regular interrupt in a CPU map + * @m: Matrix pointer + * @msk: Which CPUs to search in + * @reserved: Allocate previously reserved interrupts + * @mapped_cpu: Pointer to store the CPU for which the irq was allocated + */ +int irq_matrix_alloc(struct irq_matrix *m, const struct cpumask *msk, + bool reserved, unsigned int *mapped_cpu) +{ + unsigned int cpu; + + for_each_cpu(cpu, msk) { + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + unsigned int bit; + + if (!cm->online) + continue; + + bit = matrix_alloc_area(m, cm, 1, false); + if (bit < m->alloc_end) { + cm->allocated++; + cm->available--; + m->total_allocated++; + m->global_available--; + if (reserved) + m->global_reserved--; + *mapped_cpu = cpu; + trace_irq_matrix_alloc(bit, cpu, m, cm); + return bit; + } + } + return -ENOSPC; +} + +/** + * irq_matrix_free - Free allocated interrupt in the matrix + * @m: Matrix pointer + * @cpu: Which CPU map needs be updated + * @bit: The bit to remove + * @managed: If true, the interrupt is managed and not accounted + * as available. + */ +void irq_matrix_free(struct irq_matrix *m, unsigned int cpu, + unsigned int bit, bool managed) +{ + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + + if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end)) + return; + + if (cm->online) { + clear_bit(bit, cm->alloc_map); + cm->allocated--; + m->total_allocated--; + if (!managed) { + cm->available++; + m->global_available++; + } + } + trace_irq_matrix_free(bit, cpu, m, cm); +} + +/** + * irq_matrix_available - Get the number of globally available irqs + * @m: Pointer to the matrix to query + * @cpudown: If true, the local CPU is about to go down, adjust + * the number of available irqs accordingly + */ +unsigned int irq_matrix_available(struct irq_matrix *m, bool cpudown) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + return m->global_available - cpudown ? cm->available : 0; +} + +/** + * irq_matrix_reserved - Get the number of globally reserved irqs + * @m: Pointer to the matrix to query + */ +unsigned int irq_matrix_reserved(struct irq_matrix *m) +{ + return m->global_reserved; +} + +/** + * irq_matrix_allocated - Get the number of allocated irqs on the local cpu + * @m: Pointer to the matrix to search + * + * This returns number of allocated irqs + */ +unsigned int irq_matrix_allocated(struct irq_matrix *m) +{ + struct cpumap *cm = this_cpu_ptr(m->maps); + + return cm->allocated; +} + +#ifdef CONFIG_GENERIC_IRQ_DEBUGFS +/** + * irq_matrix_debug_show - Show detailed allocation information + * @sf: Pointer to the seq_file to print to + * @m: Pointer to the matrix allocator + * @ind: Indentation for the print format + * + * Note, this is a lockless snapshot. + */ +void irq_matrix_debug_show(struct seq_file *sf, struct irq_matrix *m, int ind) +{ + unsigned int nsys = bitmap_weight(m->system_map, m->matrix_bits); + int cpu; + + seq_printf(sf, "Online bitmaps: %6u\n", m->online_maps); + seq_printf(sf, "Global available: %6u\n", m->global_available); + seq_printf(sf, "Global reserved: %6u\n", m->global_reserved); + seq_printf(sf, "Total allocated: %6u\n", m->total_allocated); + seq_printf(sf, "System: %u: %*pbl\n", nsys, m->matrix_bits, + m->system_map); + seq_printf(sf, "%*s| CPU | avl | man | act | vectors\n", ind, " "); + cpus_read_lock(); + for_each_online_cpu(cpu) { + struct cpumap *cm = per_cpu_ptr(m->maps, cpu); + + seq_printf(sf, "%*s %4d %4u %4u %4u %*pbl\n", ind, " ", + cpu, cm->available, cm->managed, cm->allocated, + m->matrix_bits, cm->alloc_map); + } + cpus_read_unlock(); +} +#endif diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 6ca054a3f91d..86ae0eb80b53 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/irq.h> #include <linux/interrupt.h> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 3fa4bd59f569..edb987b2c58d 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -16,6 +16,8 @@ #include <linux/msi.h> #include <linux/slab.h> +#include "internals.h" + /** * alloc_msi_entry - Allocate an initialize msi_entry * @dev: Pointer to the device for which this is allocated @@ -100,13 +102,14 @@ int msi_domain_set_affinity(struct irq_data *irq_data, return ret; } -static void msi_domain_activate(struct irq_domain *domain, - struct irq_data *irq_data) +static int msi_domain_activate(struct irq_domain *domain, + struct irq_data *irq_data, bool early) { struct msi_msg msg; BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg)); irq_chip_write_msi_msg(irq_data, &msg); + return 0; } static void msi_domain_deactivate(struct irq_domain *domain, @@ -373,8 +376,10 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, return ret; } - for (i = 0; i < desc->nvec_used; i++) + for (i = 0; i < desc->nvec_used; i++) { irq_set_msi_desc_off(virq, i, desc); + irq_debugfs_copy_devname(virq + i, dev); + } } if (ops->msi_finish) @@ -396,11 +401,28 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, struct irq_data *irq_data; irq_data = irq_domain_get_irq_data(domain, desc->irq); - irq_domain_activate_irq(irq_data); + ret = irq_domain_activate_irq(irq_data, true); + if (ret) + goto cleanup; + if (info->flags & MSI_FLAG_MUST_REACTIVATE) + irqd_clr_activated(irq_data); } } - return 0; + +cleanup: + for_each_msi_entry(desc, dev) { + struct irq_data *irqd; + + if (desc->irq == virq) + break; + + irqd = irq_domain_get_irq_data(domain, desc->irq); + if (irqd_is_activated(irqd)) + irq_domain_deactivate_irq(irqd); + } + msi_domain_free_irqs(domain, dev); + return ret; } /** diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 6376b4a598d3..e8f374971e37 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/irq/proc.c * @@ -154,8 +155,9 @@ static ssize_t write_irq_affinity(int type, struct file *file, */ err = irq_select_affinity_usr(irq) ? -EINVAL : count; } else { - irq_set_affinity(irq, new_value); - err = count; + err = irq_set_affinity(irq, new_value); + if (!err) + err = count; } free_cpumask: diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index b86886beee4f..1d08f45135c2 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/irq/resend.c * diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index 320579d89091..e43795cd2ccf 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Internal header to deal with irq_desc->status which will be renamed * to irq_desc->settings. diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 061ba7eed4ed..1215229d1c12 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/irq/spurious.c * @@ -20,7 +21,7 @@ static int irqfixup __read_mostly; #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) static void poll_spurious_irqs(unsigned long dummy); -static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); +static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs); static int irq_poll_cpu; static atomic_t irq_poll_active; diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c index c8c1d073fbf1..e0923fa4927a 100644 --- a/kernel/irq/timings.c +++ b/kernel/irq/timings.c @@ -264,7 +264,7 @@ u64 irq_timings_next_event(u64 now) * order to prevent the timings circular buffer to be updated * while we are reading it. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); /* * Number of elements in the circular buffer: If it happens it diff --git a/kernel/irq_work.c b/kernel/irq_work.c index bcf107ce0854..40e9d739c169 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -56,7 +56,6 @@ void __weak arch_irq_work_raise(void) */ } -#ifdef CONFIG_SMP /* * Enqueue the irq_work @work on @cpu unless it's already pending * somewhere. @@ -68,6 +67,8 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(cpu)); +#ifdef CONFIG_SMP + /* Arch remote IPI send/receive backend aren't NMI safe */ WARN_ON_ONCE(in_nmi()); @@ -78,10 +79,12 @@ bool irq_work_queue_on(struct irq_work *work, int cpu) if (llist_add(&work->llnode, &per_cpu(raised_list, cpu))) arch_send_call_function_single_ipi(cpu); +#else /* #ifdef CONFIG_SMP */ + irq_work_queue(work); +#endif /* #else #ifdef CONFIG_SMP */ + return true; } -EXPORT_SYMBOL_GPL(irq_work_queue_on); -#endif /* Enqueue the irq work @work on the current CPU */ bool irq_work_queue(struct irq_work *work) @@ -128,9 +131,9 @@ bool irq_work_needs_cpu(void) static void irq_work_run_list(struct llist_head *list) { - unsigned long flags; - struct irq_work *work; + struct irq_work *work, *tmp; struct llist_node *llnode; + unsigned long flags; BUG_ON(!irqs_disabled()); @@ -138,11 +141,7 @@ static void irq_work_run_list(struct llist_head *list) return; llnode = llist_del_all(list); - while (llnode != NULL) { - work = llist_entry(llnode, struct irq_work, llnode); - - llnode = llist_next(llnode); - + llist_for_each_entry_safe(work, tmp, llnode, llnode) { /* * Clear the PENDING bit, after this point the @work * can be re-used. @@ -188,7 +187,7 @@ void irq_work_tick(void) */ void irq_work_sync(struct irq_work *work) { - WARN_ON_ONCE(irqs_disabled()); + lockdep_assert_irqs_enabled(); while (work->flags & IRQ_WORK_BUSY) cpu_relax(); diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 0bf2e8f5244a..8ff4ca4665ff 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -83,7 +83,7 @@ static void static_key_slow_inc_cpuslocked(struct static_key *key) { int v, v1; - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); /* * Careful if we get concurrent static_key_slow_inc() calls; @@ -128,7 +128,7 @@ EXPORT_SYMBOL_GPL(static_key_slow_inc); void static_key_enable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) > 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); @@ -158,7 +158,7 @@ EXPORT_SYMBOL_GPL(static_key_enable); void static_key_disable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); @@ -224,21 +224,21 @@ static void jump_label_update_timeout(struct work_struct *work) void static_key_slow_dec(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(key, 0, NULL); } EXPORT_SYMBOL_GPL(static_key_slow_dec); void static_key_slow_dec_deferred(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(&key->key, key->timeout, &key->work); } EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred); void static_key_deferred_flush(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); flush_delayed_work(&key->work); } EXPORT_SYMBOL_GPL(static_key_deferred_flush); @@ -246,7 +246,7 @@ EXPORT_SYMBOL_GPL(static_key_deferred_flush); void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); key->timeout = rl; INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); } diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 127e7cfafa55..1e6ae66c6244 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -480,6 +480,7 @@ struct kallsym_iter { char name[KSYM_NAME_LEN]; char module_name[MODULE_NAME_LEN]; int exported; + int show_value; }; static int get_ksymbol_mod(struct kallsym_iter *iter) @@ -582,12 +583,15 @@ static void s_stop(struct seq_file *m, void *p) static int s_show(struct seq_file *m, void *p) { + unsigned long value; struct kallsym_iter *iter = m->private; /* Some debugging symbols have no name. Ignore them. */ if (!iter->name[0]) return 0; + value = iter->show_value ? iter->value : 0; + if (iter->module_name[0]) { char type; @@ -597,10 +601,10 @@ static int s_show(struct seq_file *m, void *p) */ type = iter->exported ? toupper(iter->type) : tolower(iter->type); - seq_printf(m, "%pK %c %s\t[%s]\n", (void *)iter->value, + seq_printf(m, KALLSYM_FMT " %c %s\t[%s]\n", value, type, iter->name, iter->module_name); } else - seq_printf(m, "%pK %c %s\n", (void *)iter->value, + seq_printf(m, KALLSYM_FMT " %c %s\n", value, iter->type, iter->name); return 0; } @@ -612,6 +616,40 @@ static const struct seq_operations kallsyms_op = { .show = s_show }; +static inline int kallsyms_for_perf(void) +{ +#ifdef CONFIG_PERF_EVENTS + extern int sysctl_perf_event_paranoid; + if (sysctl_perf_event_paranoid <= 1) + return 1; +#endif + return 0; +} + +/* + * We show kallsyms information even to normal users if we've enabled + * kernel profiling and are explicitly not paranoid (so kptr_restrict + * is clear, and sysctl_perf_event_paranoid isn't set). + * + * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to + * block even that). + */ +int kallsyms_show_value(void) +{ + switch (kptr_restrict) { + case 0: + if (kallsyms_for_perf()) + return 1; + /* fallthrough */ + case 1: + if (has_capability_noaudit(current, CAP_SYSLOG)) + return 1; + /* fallthrough */ + default: + return 0; + } +} + static int kallsyms_open(struct inode *inode, struct file *file) { /* @@ -625,6 +663,7 @@ static int kallsyms_open(struct inode *inode, struct file *file) return -ENOMEM; reset_iter(iter, 0); + iter->show_value = kallsyms_show_value(); return 0; } diff --git a/kernel/kcmp.c b/kernel/kcmp.c index ea34ed8bb952..a0e3d7a0e8b8 100644 --- a/kernel/kcmp.c +++ b/kernel/kcmp.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/kernel.h> #include <linux/syscalls.h> #include <linux/fdtable.h> @@ -131,7 +132,7 @@ static int kcmp_epoll_target(struct task_struct *task1, if (filp_epoll) { filp_tgt = get_epoll_tfile_raw_ptr(filp_epoll, slot.tfd, slot.toff); fput(filp_epoll); - } else + } if (IS_ERR(filp_tgt)) return PTR_ERR(filp_tgt); diff --git a/kernel/kcov.c b/kernel/kcov.c index 3f693a0f6f3e..fc6af9e1308b 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) "kcov: " fmt #define DISABLE_BRANCH_PROFILING diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 9f48f4412297..e5bcd94c1efb 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -406,9 +406,10 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, return 1; } -static int locate_mem_hole_callback(u64 start, u64 end, void *arg) +static int locate_mem_hole_callback(struct resource *res, void *arg) { struct kexec_buf *kbuf = (struct kexec_buf *)arg; + u64 start = res->start, end = res->end; unsigned long sz = end - start + 1; /* Returning 0 will take to next memory range */ @@ -437,7 +438,7 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) * func returning non-zero, then zero will be returned. */ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, - int (*func)(u64, u64, void *)) + int (*func)(struct resource *, void *)) { if (kbuf->image->type == KEXEC_TYPE_CRASH) return walk_iomem_res_desc(crashk_res.desc, diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h index 50dfcb039a41..48aaf2ac0d0d 100644 --- a/kernel/kexec_internal.h +++ b/kernel/kexec_internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef LINUX_KEXEC_INTERNAL_H #define LINUX_KEXEC_INTERNAL_H diff --git a/kernel/kprobes.c b/kernel/kprobes.c index a1606a4224e1..da2ccf142358 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -117,7 +117,7 @@ enum kprobe_slot_state { SLOT_USED = 2, }; -static void *alloc_insn_page(void) +void __weak *alloc_insn_page(void) { return module_alloc(PAGE_SIZE); } @@ -573,13 +573,15 @@ static void kprobe_optimizer(struct work_struct *work) do_unoptimize_kprobes(); /* - * Step 2: Wait for quiesence period to ensure all running interrupts - * are done. Because optprobe may modify multiple instructions - * there is a chance that Nth instruction is interrupted. In that - * case, running interrupt can return to 2nd-Nth byte of jump - * instruction. This wait is for avoiding it. + * Step 2: Wait for quiesence period to ensure all potentially + * preempted tasks to have normally scheduled. Because optprobe + * may modify multiple instructions, there is a chance that Nth + * instruction is preempted. In that case, such tasks can return + * to 2nd-Nth byte of jump instruction. This wait is for avoiding it. + * Note that on non-preemptive kernel, this is transparently converted + * to synchronoze_sched() to wait for all interrupts to have completed. */ - synchronize_sched(); + synchronize_rcu_tasks(); /* Step 3: Optimize kprobes after quiesence period */ do_optimize_kprobes(); @@ -1769,6 +1771,7 @@ unsigned long __weak arch_deref_entry_point(void *entry) return (unsigned long)entry; } +#if 0 int register_jprobes(struct jprobe **jps, int num) { int ret = 0, i; @@ -1837,6 +1840,7 @@ void unregister_jprobes(struct jprobe **jps, int num) } } EXPORT_SYMBOL_GPL(unregister_jprobes); +#endif #ifdef CONFIG_KRETPROBES /* diff --git a/kernel/kthread.c b/kernel/kthread.c index 1c19edf82427..8af313081b0d 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -20,7 +20,6 @@ #include <linux/freezer.h> #include <linux/ptrace.h> #include <linux/uaccess.h> -#include <linux/cgroup.h> #include <trace/events/sched.h> static DEFINE_SPINLOCK(kthread_create_lock); @@ -47,6 +46,9 @@ struct kthread { void *data; struct completion parked; struct completion exited; +#ifdef CONFIG_BLK_CGROUP + struct cgroup_subsys_state *blkcg_css; +#endif }; enum KTHREAD_BITS { @@ -74,11 +76,17 @@ static inline struct kthread *to_kthread(struct task_struct *k) void free_kthread_struct(struct task_struct *k) { + struct kthread *kthread; + /* * Can be NULL if this kthread was created by kernel_thread() * or if kmalloc() in kthread() failed. */ - kfree(to_kthread(k)); + kthread = to_kthread(k); +#ifdef CONFIG_BLK_CGROUP + WARN_ON_ONCE(kthread && kthread->blkcg_css); +#endif + kfree(kthread); } /** @@ -196,7 +204,7 @@ static int kthread(void *_create) struct kthread *self; int ret; - self = kmalloc(sizeof(*self), GFP_KERNEL); + self = kzalloc(sizeof(*self), GFP_KERNEL); set_kthread_struct(self); /* If user was SIGKILLed, I release the structure. */ @@ -212,7 +220,6 @@ static int kthread(void *_create) do_exit(-ENOMEM); } - self->flags = 0; self->data = data; init_completion(&self->exited); init_completion(&self->parked); @@ -798,15 +805,14 @@ EXPORT_SYMBOL_GPL(kthread_queue_work); /** * kthread_delayed_work_timer_fn - callback that queues the associated kthread * delayed work when the timer expires. - * @__data: pointer to the data associated with the timer + * @t: pointer to the expired timer * * The format of the function is defined by struct timer_list. * It should have been called from irqsafe timer with irq already off. */ -void kthread_delayed_work_timer_fn(unsigned long __data) +void kthread_delayed_work_timer_fn(struct timer_list *t) { - struct kthread_delayed_work *dwork = - (struct kthread_delayed_work *)__data; + struct kthread_delayed_work *dwork = from_timer(dwork, t, timer); struct kthread_work *work = &dwork->work; struct kthread_worker *worker = work->worker; @@ -837,8 +843,7 @@ void __kthread_queue_delayed_work(struct kthread_worker *worker, struct timer_list *timer = &dwork->timer; struct kthread_work *work = &dwork->work; - WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn || - timer->data != (unsigned long)dwork); + WARN_ON_ONCE(timer->function != (TIMER_FUNC_TYPE)kthread_delayed_work_timer_fn); /* * If @delay is 0, queue @dwork->work immediately. This is for @@ -1154,3 +1159,54 @@ void kthread_destroy_worker(struct kthread_worker *worker) kfree(worker); } EXPORT_SYMBOL(kthread_destroy_worker); + +#ifdef CONFIG_BLK_CGROUP +/** + * kthread_associate_blkcg - associate blkcg to current kthread + * @css: the cgroup info + * + * Current thread must be a kthread. The thread is running jobs on behalf of + * other threads. In some cases, we expect the jobs attach cgroup info of + * original threads instead of that of current thread. This function stores + * original thread's cgroup info in current kthread context for later + * retrieval. + */ +void kthread_associate_blkcg(struct cgroup_subsys_state *css) +{ + struct kthread *kthread; + + if (!(current->flags & PF_KTHREAD)) + return; + kthread = to_kthread(current); + if (!kthread) + return; + + if (kthread->blkcg_css) { + css_put(kthread->blkcg_css); + kthread->blkcg_css = NULL; + } + if (css) { + css_get(css); + kthread->blkcg_css = css; + } +} +EXPORT_SYMBOL(kthread_associate_blkcg); + +/** + * kthread_blkcg - get associated blkcg css of current kthread + * + * Current thread must be a kthread. + */ +struct cgroup_subsys_state *kthread_blkcg(void) +{ + struct kthread *kthread; + + if (current->flags & PF_KTHREAD) { + kthread = to_kthread(current); + if (kthread) + return kthread->blkcg_css; + } + return NULL; +} +EXPORT_SYMBOL(kthread_blkcg); +#endif diff --git a/kernel/livepatch/Makefile b/kernel/livepatch/Makefile index 2b8bdb1925da..b36ceda6488e 100644 --- a/kernel/livepatch/Makefile +++ b/kernel/livepatch/Makefile @@ -1,3 +1,3 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o -livepatch-objs := core.o patch.o transition.o +livepatch-objs := core.o patch.o shadow.o transition.o diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index b9628e43c78f..de9e45dca70f 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -54,11 +54,6 @@ static bool klp_is_module(struct klp_object *obj) return obj->name; } -static bool klp_is_object_loaded(struct klp_object *obj) -{ - return !obj->name || obj->mod; -} - /* sets obj->mod if object is not vmlinux and module is found */ static void klp_find_object_module(struct klp_object *obj) { @@ -285,6 +280,11 @@ static int klp_write_object_relocations(struct module *pmod, static int __klp_disable_patch(struct klp_patch *patch) { + struct klp_object *obj; + + if (WARN_ON(!patch->enabled)) + return -EINVAL; + if (klp_transition_patch) return -EBUSY; @@ -295,6 +295,10 @@ static int __klp_disable_patch(struct klp_patch *patch) klp_init_transition(patch, KLP_UNPATCHED); + klp_for_each_object(patch, obj) + if (obj->patched) + klp_pre_unpatch_callback(obj); + /* * Enforce the order of the func->transition writes in * klp_init_transition() and the TIF_PATCH_PENDING writes in @@ -388,13 +392,18 @@ static int __klp_enable_patch(struct klp_patch *patch) if (!klp_is_object_loaded(obj)) continue; - ret = klp_patch_object(obj); + ret = klp_pre_patch_callback(obj); if (ret) { - pr_warn("failed to enable patch '%s'\n", - patch->mod->name); + pr_warn("pre-patch callback failed for object '%s'\n", + klp_is_module(obj) ? obj->name : "vmlinux"); + goto err; + } - klp_cancel_transition(); - return ret; + ret = klp_patch_object(obj); + if (ret) { + pr_warn("failed to patch object '%s'\n", + klp_is_module(obj) ? obj->name : "vmlinux"); + goto err; } } @@ -403,6 +412,11 @@ static int __klp_enable_patch(struct klp_patch *patch) patch->enabled = true; return 0; +err: + pr_warn("failed to enable patch '%s'\n", patch->mod->name); + + klp_cancel_transition(); + return ret; } /** @@ -830,6 +844,47 @@ int klp_register_patch(struct klp_patch *patch) } EXPORT_SYMBOL_GPL(klp_register_patch); +/* + * Remove parts of patches that touch a given kernel module. The list of + * patches processed might be limited. When limit is NULL, all patches + * will be handled. + */ +static void klp_cleanup_module_patches_limited(struct module *mod, + struct klp_patch *limit) +{ + struct klp_patch *patch; + struct klp_object *obj; + + list_for_each_entry(patch, &klp_patches, list) { + if (patch == limit) + break; + + klp_for_each_object(patch, obj) { + if (!klp_is_module(obj) || strcmp(obj->name, mod->name)) + continue; + + /* + * Only unpatch the module if the patch is enabled or + * is in transition. + */ + if (patch->enabled || patch == klp_transition_patch) { + + if (patch != klp_transition_patch) + klp_pre_unpatch_callback(obj); + + pr_notice("reverting patch '%s' on unloading module '%s'\n", + patch->mod->name, obj->mod->name); + klp_unpatch_object(obj); + + klp_post_unpatch_callback(obj); + } + + klp_free_object_loaded(obj); + break; + } + } +} + int klp_module_coming(struct module *mod) { int ret; @@ -871,13 +926,25 @@ int klp_module_coming(struct module *mod) pr_notice("applying patch '%s' to loading module '%s'\n", patch->mod->name, obj->mod->name); + ret = klp_pre_patch_callback(obj); + if (ret) { + pr_warn("pre-patch callback failed for object '%s'\n", + obj->name); + goto err; + } + ret = klp_patch_object(obj); if (ret) { pr_warn("failed to apply patch '%s' to module '%s' (%d)\n", patch->mod->name, obj->mod->name, ret); + + klp_post_unpatch_callback(obj); goto err; } + if (patch != klp_transition_patch) + klp_post_patch_callback(obj); + break; } } @@ -894,7 +961,7 @@ err: pr_warn("patch '%s' failed for module '%s', refusing to load module '%s'\n", patch->mod->name, obj->mod->name, obj->mod->name); mod->klp_alive = false; - klp_free_object_loaded(obj); + klp_cleanup_module_patches_limited(mod, patch); mutex_unlock(&klp_mutex); return ret; @@ -902,9 +969,6 @@ err: void klp_module_going(struct module *mod) { - struct klp_patch *patch; - struct klp_object *obj; - if (WARN_ON(mod->state != MODULE_STATE_GOING && mod->state != MODULE_STATE_COMING)) return; @@ -917,25 +981,7 @@ void klp_module_going(struct module *mod) */ mod->klp_alive = false; - list_for_each_entry(patch, &klp_patches, list) { - klp_for_each_object(patch, obj) { - if (!klp_is_module(obj) || strcmp(obj->name, mod->name)) - continue; - - /* - * Only unpatch the module if the patch is enabled or - * is in transition. - */ - if (patch->enabled || patch == klp_transition_patch) { - pr_notice("reverting patch '%s' on unloading module '%s'\n", - patch->mod->name, obj->mod->name); - klp_unpatch_object(obj); - } - - klp_free_object_loaded(obj); - break; - } - } + klp_cleanup_module_patches_limited(mod, NULL); mutex_unlock(&klp_mutex); } diff --git a/kernel/livepatch/core.h b/kernel/livepatch/core.h index c74f24c47837..48a83d4364cf 100644 --- a/kernel/livepatch/core.h +++ b/kernel/livepatch/core.h @@ -1,6 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LIVEPATCH_CORE_H #define _LIVEPATCH_CORE_H +#include <linux/livepatch.h> + extern struct mutex klp_mutex; +static inline bool klp_is_object_loaded(struct klp_object *obj) +{ + return !obj->name || obj->mod; +} + +static inline int klp_pre_patch_callback(struct klp_object *obj) +{ + int ret = 0; + + if (obj->callbacks.pre_patch) + ret = (*obj->callbacks.pre_patch)(obj); + + obj->callbacks.post_unpatch_enabled = !ret; + + return ret; +} + +static inline void klp_post_patch_callback(struct klp_object *obj) +{ + if (obj->callbacks.post_patch) + (*obj->callbacks.post_patch)(obj); +} + +static inline void klp_pre_unpatch_callback(struct klp_object *obj) +{ + if (obj->callbacks.pre_unpatch) + (*obj->callbacks.pre_unpatch)(obj); +} + +static inline void klp_post_unpatch_callback(struct klp_object *obj) +{ + if (obj->callbacks.post_unpatch_enabled && + obj->callbacks.post_unpatch) + (*obj->callbacks.post_unpatch)(obj); + + obj->callbacks.post_unpatch_enabled = false; +} + #endif /* _LIVEPATCH_CORE_H */ diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 52c4e907c14b..82d584225dc6 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -28,6 +28,7 @@ #include <linux/slab.h> #include <linux/bug.h> #include <linux/printk.h> +#include "core.h" #include "patch.h" #include "transition.h" diff --git a/kernel/livepatch/patch.h b/kernel/livepatch/patch.h index 0db227170c36..e72d8250d04b 100644 --- a/kernel/livepatch/patch.h +++ b/kernel/livepatch/patch.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LIVEPATCH_PATCH_H #define _LIVEPATCH_PATCH_H diff --git a/kernel/livepatch/shadow.c b/kernel/livepatch/shadow.c new file mode 100644 index 000000000000..fdac27588d60 --- /dev/null +++ b/kernel/livepatch/shadow.c @@ -0,0 +1,277 @@ +/* + * shadow.c - Shadow Variables + * + * Copyright (C) 2014 Josh Poimboeuf <jpoimboe@redhat.com> + * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com> + * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +/** + * DOC: Shadow variable API concurrency notes: + * + * The shadow variable API provides a simple relationship between an + * <obj, id> pair and a pointer value. It is the responsibility of the + * caller to provide any mutual exclusion required of the shadow data. + * + * Once a shadow variable is attached to its parent object via the + * klp_shadow_*alloc() API calls, it is considered live: any subsequent + * call to klp_shadow_get() may then return the shadow variable's data + * pointer. Callers of klp_shadow_*alloc() should prepare shadow data + * accordingly. + * + * The klp_shadow_*alloc() API calls may allocate memory for new shadow + * variable structures. Their implementation does not call kmalloc + * inside any spinlocks, but API callers should pass GFP flags according + * to their specific needs. + * + * The klp_shadow_hash is an RCU-enabled hashtable and is safe against + * concurrent klp_shadow_free() and klp_shadow_get() operations. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/hashtable.h> +#include <linux/slab.h> +#include <linux/livepatch.h> + +static DEFINE_HASHTABLE(klp_shadow_hash, 12); + +/* + * klp_shadow_lock provides exclusive access to the klp_shadow_hash and + * the shadow variables it references. + */ +static DEFINE_SPINLOCK(klp_shadow_lock); + +/** + * struct klp_shadow - shadow variable structure + * @node: klp_shadow_hash hash table node + * @rcu_head: RCU is used to safely free this structure + * @obj: pointer to parent object + * @id: data identifier + * @data: data area + */ +struct klp_shadow { + struct hlist_node node; + struct rcu_head rcu_head; + void *obj; + unsigned long id; + char data[]; +}; + +/** + * klp_shadow_match() - verify a shadow variable matches given <obj, id> + * @shadow: shadow variable to match + * @obj: pointer to parent object + * @id: data identifier + * + * Return: true if the shadow variable matches. + */ +static inline bool klp_shadow_match(struct klp_shadow *shadow, void *obj, + unsigned long id) +{ + return shadow->obj == obj && shadow->id == id; +} + +/** + * klp_shadow_get() - retrieve a shadow variable data pointer + * @obj: pointer to parent object + * @id: data identifier + * + * Return: the shadow variable data element, NULL on failure. + */ +void *klp_shadow_get(void *obj, unsigned long id) +{ + struct klp_shadow *shadow; + + rcu_read_lock(); + + hash_for_each_possible_rcu(klp_shadow_hash, shadow, node, + (unsigned long)obj) { + + if (klp_shadow_match(shadow, obj, id)) { + rcu_read_unlock(); + return shadow->data; + } + } + + rcu_read_unlock(); + + return NULL; +} +EXPORT_SYMBOL_GPL(klp_shadow_get); + +static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, + size_t size, gfp_t gfp_flags, bool warn_on_exist) +{ + struct klp_shadow *new_shadow; + void *shadow_data; + unsigned long flags; + + /* Check if the shadow variable already exists */ + shadow_data = klp_shadow_get(obj, id); + if (shadow_data) + goto exists; + + /* Allocate a new shadow variable for use inside the lock below */ + new_shadow = kzalloc(size + sizeof(*new_shadow), gfp_flags); + if (!new_shadow) + return NULL; + + new_shadow->obj = obj; + new_shadow->id = id; + + /* Initialize the shadow variable if data provided */ + if (data) + memcpy(new_shadow->data, data, size); + + /* Look for <obj, id> again under the lock */ + spin_lock_irqsave(&klp_shadow_lock, flags); + shadow_data = klp_shadow_get(obj, id); + if (unlikely(shadow_data)) { + /* + * Shadow variable was found, throw away speculative + * allocation. + */ + spin_unlock_irqrestore(&klp_shadow_lock, flags); + kfree(new_shadow); + goto exists; + } + + /* No <obj, id> found, so attach the newly allocated one */ + hash_add_rcu(klp_shadow_hash, &new_shadow->node, + (unsigned long)new_shadow->obj); + spin_unlock_irqrestore(&klp_shadow_lock, flags); + + return new_shadow->data; + +exists: + if (warn_on_exist) { + WARN(1, "Duplicate shadow variable <%p, %lx>\n", obj, id); + return NULL; + } + + return shadow_data; +} + +/** + * klp_shadow_alloc() - allocate and add a new shadow variable + * @obj: pointer to parent object + * @id: data identifier + * @data: pointer to data to attach to parent + * @size: size of attached data + * @gfp_flags: GFP mask for allocation + * + * Allocates @size bytes for new shadow variable data using @gfp_flags + * and copies @size bytes from @data into the new shadow variable's own + * data space. If @data is NULL, @size bytes are still allocated, but + * no copy is performed. The new shadow variable is then added to the + * global hashtable. + * + * If an existing <obj, id> shadow variable can be found, this routine + * will issue a WARN, exit early and return NULL. + * + * Return: the shadow variable data element, NULL on duplicate or + * failure. + */ +void *klp_shadow_alloc(void *obj, unsigned long id, void *data, + size_t size, gfp_t gfp_flags) +{ + return __klp_shadow_get_or_alloc(obj, id, data, size, gfp_flags, true); +} +EXPORT_SYMBOL_GPL(klp_shadow_alloc); + +/** + * klp_shadow_get_or_alloc() - get existing or allocate a new shadow variable + * @obj: pointer to parent object + * @id: data identifier + * @data: pointer to data to attach to parent + * @size: size of attached data + * @gfp_flags: GFP mask for allocation + * + * Returns a pointer to existing shadow data if an <obj, id> shadow + * variable is already present. Otherwise, it creates a new shadow + * variable like klp_shadow_alloc(). + * + * This function guarantees that only one shadow variable exists with + * the given @id for the given @obj. It also guarantees that the shadow + * variable will be initialized by the given @data only when it did not + * exist before. + * + * Return: the shadow variable data element, NULL on failure. + */ +void *klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, + size_t size, gfp_t gfp_flags) +{ + return __klp_shadow_get_or_alloc(obj, id, data, size, gfp_flags, false); +} +EXPORT_SYMBOL_GPL(klp_shadow_get_or_alloc); + +/** + * klp_shadow_free() - detach and free a <obj, id> shadow variable + * @obj: pointer to parent object + * @id: data identifier + * + * This function releases the memory for this <obj, id> shadow variable + * instance, callers should stop referencing it accordingly. + */ +void klp_shadow_free(void *obj, unsigned long id) +{ + struct klp_shadow *shadow; + unsigned long flags; + + spin_lock_irqsave(&klp_shadow_lock, flags); + + /* Delete <obj, id> from hash */ + hash_for_each_possible(klp_shadow_hash, shadow, node, + (unsigned long)obj) { + + if (klp_shadow_match(shadow, obj, id)) { + hash_del_rcu(&shadow->node); + kfree_rcu(shadow, rcu_head); + break; + } + } + + spin_unlock_irqrestore(&klp_shadow_lock, flags); +} +EXPORT_SYMBOL_GPL(klp_shadow_free); + +/** + * klp_shadow_free_all() - detach and free all <*, id> shadow variables + * @id: data identifier + * + * This function releases the memory for all <*, id> shadow variable + * instances, callers should stop referencing them accordingly. + */ +void klp_shadow_free_all(unsigned long id) +{ + struct klp_shadow *shadow; + unsigned long flags; + int i; + + spin_lock_irqsave(&klp_shadow_lock, flags); + + /* Delete all <*, id> from hash */ + hash_for_each(klp_shadow_hash, i, shadow, node) { + if (klp_shadow_match(shadow, shadow->obj, id)) { + hash_del_rcu(&shadow->node); + kfree_rcu(shadow, rcu_head); + } + } + + spin_unlock_irqrestore(&klp_shadow_lock, flags); +} +EXPORT_SYMBOL_GPL(klp_shadow_free_all); diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index b004a1fb6032..56add6327736 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -82,6 +82,10 @@ static void klp_complete_transition(void) unsigned int cpu; bool immediate_func = false; + pr_debug("'%s': completing %s transition\n", + klp_transition_patch->mod->name, + klp_target_state == KLP_PATCHED ? "patching" : "unpatching"); + if (klp_target_state == KLP_UNPATCHED) { /* * All tasks have transitioned to KLP_UNPATCHED so we can now @@ -109,9 +113,6 @@ static void klp_complete_transition(void) } } - if (klp_target_state == KLP_UNPATCHED && !immediate_func) - module_put(klp_transition_patch->mod); - /* Prevent klp_ftrace_handler() from seeing KLP_UNDEFINED state */ if (klp_target_state == KLP_PATCHED) klp_synchronize_transition(); @@ -130,6 +131,27 @@ static void klp_complete_transition(void) } done: + klp_for_each_object(klp_transition_patch, obj) { + if (!klp_is_object_loaded(obj)) + continue; + if (klp_target_state == KLP_PATCHED) + klp_post_patch_callback(obj); + else if (klp_target_state == KLP_UNPATCHED) + klp_post_unpatch_callback(obj); + } + + pr_notice("'%s': %s complete\n", klp_transition_patch->mod->name, + klp_target_state == KLP_PATCHED ? "patching" : "unpatching"); + + /* + * See complementary comment in __klp_enable_patch() for why we + * keep the module reference for immediate patches. + */ + if (!klp_transition_patch->immediate && !immediate_func && + klp_target_state == KLP_UNPATCHED) { + module_put(klp_transition_patch->mod); + } + klp_target_state = KLP_UNDEFINED; klp_transition_patch = NULL; } @@ -145,6 +167,9 @@ void klp_cancel_transition(void) if (WARN_ON_ONCE(klp_target_state != KLP_PATCHED)) return; + pr_debug("'%s': canceling patching transition, going to unpatch\n", + klp_transition_patch->mod->name); + klp_target_state = KLP_UNPATCHED; klp_complete_transition(); } @@ -408,9 +433,6 @@ void klp_try_complete_transition(void) } success: - pr_notice("'%s': %s complete\n", klp_transition_patch->mod->name, - klp_target_state == KLP_PATCHED ? "patching" : "unpatching"); - /* we're done, now cleanup the data structures */ klp_complete_transition(); } @@ -426,7 +448,8 @@ void klp_start_transition(void) WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED); - pr_notice("'%s': %s...\n", klp_transition_patch->mod->name, + pr_notice("'%s': starting %s transition\n", + klp_transition_patch->mod->name, klp_target_state == KLP_PATCHED ? "patching" : "unpatching"); /* @@ -482,6 +505,9 @@ void klp_init_transition(struct klp_patch *patch, int state) */ klp_target_state = state; + pr_debug("'%s': initializing %s transition\n", patch->mod->name, + klp_target_state == KLP_PATCHED ? "patching" : "unpatching"); + /* * If the patch can be applied or reverted immediately, skip the * per-task transitions. @@ -547,6 +573,11 @@ void klp_reverse_transition(void) unsigned int cpu; struct task_struct *g, *task; + pr_debug("'%s': reversing transition from %s\n", + klp_transition_patch->mod->name, + klp_target_state == KLP_PATCHED ? "patching to unpatching" : + "unpatching to patching"); + klp_transition_patch->enabled = !klp_transition_patch->enabled; klp_target_state = !klp_target_state; diff --git a/kernel/livepatch/transition.h b/kernel/livepatch/transition.h index ce09b326546c..0f6e27c481f9 100644 --- a/kernel/livepatch/transition.h +++ b/kernel/livepatch/transition.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LIVEPATCH_TRANSITION_H #define _LIVEPATCH_TRANSITION_H diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 760158d9d98d..392c7f23af76 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # Any varying coverage in these files is non-deterministic # and is generally not a function of system call inputs. KCOV_INSTRUMENT := n diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 44c8d0d17170..db933d063bfc 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -76,6 +76,19 @@ module_param(lock_stat, int, 0644); #define lock_stat 0 #endif +#ifdef CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK +static int crossrelease_fullstack = 1; +#else +static int crossrelease_fullstack; +#endif +static int __init allow_crossrelease_fullstack(char *str) +{ + crossrelease_fullstack = 1; + return 0; +} + +early_param("crossrelease_fullstack", allow_crossrelease_fullstack); + /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. @@ -1873,10 +1886,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, struct held_lock *next, int distance, struct stack_trace *trace, int (*save)(struct stack_trace *trace)) { + struct lock_list *uninitialized_var(target_entry); struct lock_list *entry; - int ret; struct lock_list this; - struct lock_list *uninitialized_var(target_entry); + int ret; /* * Prove that the new <prev> -> <next> dependency would not @@ -1890,8 +1903,17 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, this.class = hlock_class(next); this.parent = NULL; ret = check_noncircular(&this, hlock_class(prev), &target_entry); - if (unlikely(!ret)) + if (unlikely(!ret)) { + if (!trace->entries) { + /* + * If @save fails here, the printing might trigger + * a WARN but because of the !nr_entries it should + * not do bad things. + */ + save(trace); + } return print_circular_bug(&this, target_entry, next, prev, trace); + } else if (unlikely(ret < 0)) return print_bfs_bug(ret); @@ -1938,7 +1960,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, return print_bfs_bug(ret); - if (save && !save(trace)) + if (!trace->entries && !save(trace)) return 0; /* @@ -1958,20 +1980,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, if (!ret) return 0; - /* - * Debugging printouts: - */ - if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) { - graph_unlock(); - printk("\n new dependency: "); - print_lock_name(hlock_class(prev)); - printk(KERN_CONT " => "); - print_lock_name(hlock_class(next)); - printk(KERN_CONT "\n"); - dump_stack(); - if (!graph_lock()) - return 0; - } return 2; } @@ -1986,8 +1994,12 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) { int depth = curr->lockdep_depth; struct held_lock *hlock; - struct stack_trace trace; - int (*save)(struct stack_trace *trace) = save_trace; + struct stack_trace trace = { + .nr_entries = 0, + .max_entries = 0, + .entries = NULL, + .skip = 0, + }; /* * Debugging checks. @@ -2018,18 +2030,11 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) */ if (hlock->read != 2 && hlock->check) { int ret = check_prev_add(curr, hlock, next, - distance, &trace, save); + distance, &trace, save_trace); if (!ret) return 0; /* - * Stop saving stack_trace if save_trace() was - * called at least once: - */ - if (save && ret == 2) - save = NULL; - - /* * Stop after the first non-trylock entry, * as non-trylock entries have added their * own direct dependencies already, so this @@ -4871,8 +4876,14 @@ static void add_xhlock(struct held_lock *hlock) xhlock->trace.nr_entries = 0; xhlock->trace.max_entries = MAX_XHLOCK_TRACE_ENTRIES; xhlock->trace.entries = xhlock->trace_entries; - xhlock->trace.skip = 3; - save_stack_trace(&xhlock->trace); + + if (crossrelease_fullstack) { + xhlock->trace.skip = 3; + save_stack_trace(&xhlock->trace); + } else { + xhlock->trace.nr_entries = 1; + xhlock->trace.entries[0] = hlock->acquire_ip; + } } static inline int same_context_xhlock(struct hist_lock *xhlock) diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 1da4669d57a7..d459d624ba2a 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * kernel/lockdep_internals.h * diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 68d9e267ccd4..ad69bbc9bd28 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * kernel/lockdep_proc.c * diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index 6a385aabcce7..f046b7ce9dd6 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * MCS lock defines * diff --git a/kernel/locking/mutex-debug.h b/kernel/locking/mutex-debug.h index 4174417d5309..1edd3f45a4ec 100644 --- a/kernel/locking/mutex-debug.h +++ b/kernel/locking/mutex-debug.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Mutexes: blocking mutual exclusion locks * diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h index 6ebc1902f779..1c2287d3fa71 100644 --- a/kernel/locking/mutex.h +++ b/kernel/locking/mutex.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Mutexes: blocking mutual exclusion locks * diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c index a74ee6abd039..6ef600aa0f47 100644 --- a/kernel/locking/osq_lock.c +++ b/kernel/locking/osq_lock.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/percpu.h> #include <linux/sched.h> #include <linux/osq_lock.h> diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c index 2655f26ec882..c7471c3fb798 100644 --- a/kernel/locking/qrwlock.c +++ b/kernel/locking/qrwlock.c @@ -23,49 +23,11 @@ #include <linux/spinlock.h> #include <asm/qrwlock.h> -/* - * This internal data structure is used for optimizing access to some of - * the subfields within the atomic_t cnts. - */ -struct __qrwlock { - union { - atomic_t cnts; - struct { -#ifdef __LITTLE_ENDIAN - u8 wmode; /* Writer mode */ - u8 rcnts[3]; /* Reader counts */ -#else - u8 rcnts[3]; /* Reader counts */ - u8 wmode; /* Writer mode */ -#endif - }; - }; - arch_spinlock_t lock; -}; - -/** - * rspin_until_writer_unlock - inc reader count & spin until writer is gone - * @lock : Pointer to queue rwlock structure - * @writer: Current queue rwlock writer status byte - * - * In interrupt context or at the head of the queue, the reader will just - * increment the reader count & wait until the writer releases the lock. - */ -static __always_inline void -rspin_until_writer_unlock(struct qrwlock *lock, u32 cnts) -{ - while ((cnts & _QW_WMASK) == _QW_LOCKED) { - cpu_relax(); - cnts = atomic_read_acquire(&lock->cnts); - } -} - /** * queued_read_lock_slowpath - acquire read lock of a queue rwlock * @lock: Pointer to queue rwlock structure - * @cnts: Current qrwlock lock value */ -void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) +void queued_read_lock_slowpath(struct qrwlock *lock) { /* * Readers come here when they cannot get the lock without waiting @@ -73,13 +35,11 @@ void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) if (unlikely(in_interrupt())) { /* * Readers in interrupt context will get the lock immediately - * if the writer is just waiting (not holding the lock yet). - * The rspin_until_writer_unlock() function returns immediately - * in this case. Otherwise, they will spin (with ACQUIRE - * semantics) until the lock is available without waiting in - * the queue. + * if the writer is just waiting (not holding the lock yet), + * so spin with ACQUIRE semantics until the lock is available + * without waiting in the queue. */ - rspin_until_writer_unlock(lock, cnts); + atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED)); return; } atomic_sub(_QR_BIAS, &lock->cnts); @@ -88,14 +48,14 @@ void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) * Put the reader into the wait queue */ arch_spin_lock(&lock->wait_lock); + atomic_add(_QR_BIAS, &lock->cnts); /* * The ACQUIRE semantics of the following spinning code ensure * that accesses can't leak upwards out of our subsequent critical * section in the case that the lock is currently held for write. */ - cnts = atomic_fetch_add_acquire(_QR_BIAS, &lock->cnts); - rspin_until_writer_unlock(lock, cnts); + atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED)); /* * Signal the next one in queue to become queue head @@ -110,8 +70,6 @@ EXPORT_SYMBOL(queued_read_lock_slowpath); */ void queued_write_lock_slowpath(struct qrwlock *lock) { - u32 cnts; - /* Put the writer into the wait queue */ arch_spin_lock(&lock->wait_lock); @@ -120,30 +78,14 @@ void queued_write_lock_slowpath(struct qrwlock *lock) (atomic_cmpxchg_acquire(&lock->cnts, 0, _QW_LOCKED) == 0)) goto unlock; - /* - * Set the waiting flag to notify readers that a writer is pending, - * or wait for a previous writer to go away. - */ - for (;;) { - struct __qrwlock *l = (struct __qrwlock *)lock; - - if (!READ_ONCE(l->wmode) && - (cmpxchg_relaxed(&l->wmode, 0, _QW_WAITING) == 0)) - break; + /* Set the waiting flag to notify readers that a writer is pending */ + atomic_add(_QW_WAITING, &lock->cnts); - cpu_relax(); - } - - /* When no more readers, set the locked flag */ - for (;;) { - cnts = atomic_read(&lock->cnts); - if ((cnts == _QW_WAITING) && - (atomic_cmpxchg_acquire(&lock->cnts, _QW_WAITING, - _QW_LOCKED) == _QW_WAITING)) - break; - - cpu_relax(); - } + /* When no more readers or writers, set the locked flag */ + do { + atomic_cond_read_acquire(&lock->cnts, VAL == _QW_WAITING); + } while (atomic_cmpxchg_relaxed(&lock->cnts, _QW_WAITING, + _QW_LOCKED) != _QW_WAITING); unlock: arch_spin_unlock(&lock->wait_lock); } diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 43555681c40b..6ee477765e6c 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _GEN_PV_LOCK_SLOWPATH #error "do not include this file" #endif @@ -60,21 +61,50 @@ struct pv_node { #include "qspinlock_stat.h" /* + * Hybrid PV queued/unfair lock + * * By replacing the regular queued_spin_trylock() with the function below, * it will be called once when a lock waiter enter the PV slowpath before - * being queued. By allowing one lock stealing attempt here when the pending - * bit is off, it helps to reduce the performance impact of lock waiter - * preemption without the drawback of lock starvation. + * being queued. + * + * The pending bit is set by the queue head vCPU of the MCS wait queue in + * pv_wait_head_or_lock() to signal that it is ready to spin on the lock. + * When that bit becomes visible to the incoming waiters, no lock stealing + * is allowed. The function will return immediately to make the waiters + * enter the MCS wait queue. So lock starvation shouldn't happen as long + * as the queued mode vCPUs are actively running to set the pending bit + * and hence disabling lock stealing. + * + * When the pending bit isn't set, the lock waiters will stay in the unfair + * mode spinning on the lock unless the MCS wait queue is empty. In this + * case, the lock waiters will enter the queued mode slowpath trying to + * become the queue head and set the pending bit. + * + * This hybrid PV queued/unfair lock combines the best attributes of a + * queued lock (no lock starvation) and an unfair lock (good performance + * on not heavily contended locks). */ -#define queued_spin_trylock(l) pv_queued_spin_steal_lock(l) -static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock) +#define queued_spin_trylock(l) pv_hybrid_queued_unfair_trylock(l) +static inline bool pv_hybrid_queued_unfair_trylock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; - if (!(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && - (cmpxchg_acquire(&l->locked, 0, _Q_LOCKED_VAL) == 0)) { - qstat_inc(qstat_pv_lock_stealing, true); - return true; + /* + * Stay in unfair lock mode as long as queued mode waiters are + * present in the MCS wait queue but the pending bit isn't set. + */ + for (;;) { + int val = atomic_read(&lock->val); + + if (!(val & _Q_LOCKED_PENDING_MASK) && + (cmpxchg_acquire(&l->locked, 0, _Q_LOCKED_VAL) == 0)) { + qstat_inc(qstat_pv_lock_stealing, true); + return true; + } + if (!(val & _Q_TAIL_MASK) || (val & _Q_PENDING_MASK)) + break; + + cpu_relax(); } return false; diff --git a/kernel/locking/rtmutex-debug.c b/kernel/locking/rtmutex-debug.c index f4a74e78d467..fd4fe1f5b458 100644 --- a/kernel/locking/rtmutex-debug.c +++ b/kernel/locking/rtmutex-debug.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * RT-Mutexes: blocking mutual exclusion locks with PI support * diff --git a/kernel/locking/rtmutex-debug.h b/kernel/locking/rtmutex-debug.h index 5078c6ddf4a5..fc549713bba3 100644 --- a/kernel/locking/rtmutex-debug.h +++ b/kernel/locking/rtmutex-debug.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * RT-Mutexes: blocking mutual exclusion locks with PI support * diff --git a/kernel/locking/rtmutex.h b/kernel/locking/rtmutex.h index 5c253caffe91..732f96abf462 100644 --- a/kernel/locking/rtmutex.h +++ b/kernel/locking/rtmutex.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * RT-Mutexes: blocking mutual exclusion locks with PI support * diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index 7453be0485a5..124e98ca0b17 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * RT Mutexes: blocking mutual exclusion locks with PI support * diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c index 0848634c5512..a7ffb2a96ede 100644 --- a/kernel/locking/rwsem-spinlock.c +++ b/kernel/locking/rwsem-spinlock.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* rwsem-spinlock.c: R/W semaphores: contention handling functions for * generic spinlock implementation * diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 1fefe6dcafd7..e795908f3607 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* rwsem.c: R/W semaphores: contention handling functions * * Written by David Howells (dhowells@redhat.com). diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 4d48b1c4870d..f549c552dbf1 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* kernel/rwsem.c: R/W semaphores, public implementation * * Written by David Howells (dhowells@redhat.com). @@ -28,6 +29,22 @@ void __sched down_read(struct rw_semaphore *sem) EXPORT_SYMBOL(down_read); +int __sched down_read_killable(struct rw_semaphore *sem) +{ + might_sleep(); + rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); + + if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + return -EINTR; + } + + rwsem_set_reader_owned(sem); + return 0; +} + +EXPORT_SYMBOL(down_read_killable); + /* * trylock for reading -- returns 1 if successful, 0 if contention */ diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index a699f4048ba1..a883b8f1fdc6 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * The owner field of the rw_semaphore structure will be set to * RWSEM_READ_OWNED when a reader grabs the lock. A writer will clear diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index 4b082b5cac9e..1fd1a7543cdd 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (2004) Linus Torvalds * @@ -29,11 +30,10 @@ #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC) /* * The __lock_function inlines are taken from - * include/linux/spinlock_api_smp.h + * spinlock : include/linux/spinlock_api_smp.h + * rwlock : include/linux/rwlock_api_smp.h */ #else -#define raw_read_can_lock(l) read_can_lock(l) -#define raw_write_can_lock(l) write_can_lock(l) /* * Some architectures can relax in favour of the CPU owning the lock. @@ -68,7 +68,7 @@ void __lockfunc __raw_##op##_lock(locktype##_t *lock) \ \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ + while ((lock)->break_lock) \ arch_##op##_relax(&lock->raw_lock); \ } \ (lock)->break_lock = 0; \ @@ -88,7 +88,7 @@ unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \ \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ + while ((lock)->break_lock) \ arch_##op##_relax(&lock->raw_lock); \ } \ (lock)->break_lock = 0; \ diff --git a/kernel/memremap.c b/kernel/memremap.c index 6bcbfbf1a8fd..403ab9cdb949 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -350,7 +350,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, pgprot_t pgprot = PAGE_KERNEL; struct dev_pagemap *pgmap; struct page_map *page_map; - int error, nid, is_ram; + int error, nid, is_ram, i = 0; align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) @@ -448,6 +448,8 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, list_del(&page->lru); page->pgmap = pgmap; percpu_ref_get(ref); + if (!(++i % 1024)) + cond_resched(); } devres_add(dev, page_map); return __va(res->start); diff --git a/kernel/module.c b/kernel/module.c index de66ec825992..32c2cdaccd93 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -278,6 +278,16 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); module_param(sig_enforce, bool_enable_only, 0644); #endif /* !CONFIG_MODULE_SIG_FORCE */ +/* + * Export sig_enforce kernel cmdline parameter to allow other subsystems rely + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. + */ +bool is_module_sig_enforced(void) +{ + return sig_enforce; +} +EXPORT_SYMBOL(is_module_sig_enforced); + /* Block module loading/unloading? */ int modules_disabled = 0; core_param(nomodule, modules_disabled, bint, 0); @@ -1516,7 +1526,7 @@ static void add_sect_attrs(struct module *mod, const struct load_info *info) sattr->mattr.show = module_sect_show; sattr->mattr.store = NULL; sattr->mattr.attr.name = sattr->name; - sattr->mattr.attr.mode = S_IRUGO; + sattr->mattr.attr.mode = S_IRUSR; *(gattr++) = &(sattr++)->mattr.attr; } *gattr = NULL; @@ -4147,6 +4157,7 @@ static int m_show(struct seq_file *m, void *p) { struct module *mod = list_entry(p, struct module, list); char buf[MODULE_FLAGS_BUF_SIZE]; + unsigned long value; /* We always ignore unformed modules. */ if (mod->state == MODULE_STATE_UNFORMED) @@ -4162,7 +4173,8 @@ static int m_show(struct seq_file *m, void *p) mod->state == MODULE_STATE_COMING ? "Loading" : "Live"); /* Used by oprofile and other similar tools. */ - seq_printf(m, " 0x%pK", mod->core_layout.base); + value = m->private ? 0 : (unsigned long)mod->core_layout.base; + seq_printf(m, " 0x" KALLSYM_FMT, value); /* Taints info */ if (mod->taints) @@ -4184,9 +4196,23 @@ static const struct seq_operations modules_op = { .show = m_show }; +/* + * This also sets the "private" pointer to non-NULL if the + * kernel pointers should be hidden (so you can just test + * "m->private" to see if you should keep the values private). + * + * We use the same logic as for /proc/kallsyms. + */ static int modules_open(struct inode *inode, struct file *file) { - return seq_open(file, &modules_op); + int err = seq_open(file, &modules_op); + + if (!err) { + struct seq_file *m = file->private_data; + m->private = kallsyms_show_value() ? NULL : (void *)8ul; + } + + return 0; } static const struct file_operations proc_modules_operations = { diff --git a/kernel/padata.c b/kernel/padata.c index 868f947166d7..f262c9a4e70a 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -131,6 +131,7 @@ int padata_do_parallel(struct padata_instance *pinst, padata->cb_cpu = cb_cpu; target_cpu = padata_cpu_hash(pd); + padata->cpu = target_cpu; queue = per_cpu_ptr(pd->pqueue, target_cpu); spin_lock(&queue->parallel.lock); @@ -275,11 +276,51 @@ static void padata_reorder(struct parallel_data *pd) return; } +static void invoke_padata_reorder(struct work_struct *work) +{ + struct padata_parallel_queue *pqueue; + struct parallel_data *pd; + + local_bh_disable(); + pqueue = container_of(work, struct padata_parallel_queue, reorder_work); + pd = pqueue->pd; + padata_reorder(pd); + local_bh_enable(); +} + static void padata_reorder_timer(unsigned long arg) { struct parallel_data *pd = (struct parallel_data *)arg; + unsigned int weight; + int target_cpu, cpu; - padata_reorder(pd); + cpu = get_cpu(); + + /* We don't lock pd here to not interfere with parallel processing + * padata_reorder() calls on other CPUs. We just need any CPU out of + * the cpumask.pcpu set. It would be nice if it's the right one but + * it doesn't matter if we're off to the next one by using an outdated + * pd->processed value. + */ + weight = cpumask_weight(pd->cpumask.pcpu); + target_cpu = padata_index_to_cpu(pd, pd->processed % weight); + + /* ensure to call the reorder callback on the correct CPU */ + if (cpu != target_cpu) { + struct padata_parallel_queue *pqueue; + struct padata_instance *pinst; + + /* The timer function is serialized wrt itself -- no locking + * needed. + */ + pinst = pd->pinst; + pqueue = per_cpu_ptr(pd->pqueue, target_cpu); + queue_work_on(target_cpu, pinst->wq, &pqueue->reorder_work); + } else { + padata_reorder(pd); + } + + put_cpu(); } static void padata_serial_worker(struct work_struct *serial_work) @@ -323,10 +364,21 @@ void padata_do_serial(struct padata_priv *padata) int cpu; struct padata_parallel_queue *pqueue; struct parallel_data *pd; + int reorder_via_wq = 0; pd = padata->pd; cpu = get_cpu(); + + /* We need to run on the same CPU padata_do_parallel(.., padata, ..) + * was called on -- or, at least, enqueue the padata object into the + * correct per-cpu queue. + */ + if (cpu != padata->cpu) { + reorder_via_wq = 1; + cpu = padata->cpu; + } + pqueue = per_cpu_ptr(pd->pqueue, cpu); spin_lock(&pqueue->reorder.lock); @@ -336,7 +388,13 @@ void padata_do_serial(struct padata_priv *padata) put_cpu(); - padata_reorder(pd); + /* If we're running on the wrong CPU, call padata_reorder() via a + * kernel worker. + */ + if (reorder_via_wq) + queue_work_on(cpu, pd->pinst->wq, &pqueue->reorder_work); + else + padata_reorder(pd); } EXPORT_SYMBOL(padata_do_serial); @@ -384,8 +442,14 @@ static void padata_init_pqueues(struct parallel_data *pd) struct padata_parallel_queue *pqueue; cpu_index = 0; - for_each_cpu(cpu, pd->cpumask.pcpu) { + for_each_possible_cpu(cpu) { pqueue = per_cpu_ptr(pd->pqueue, cpu); + + if (!cpumask_test_cpu(cpu, pd->cpumask.pcpu)) { + pqueue->cpu_index = -1; + continue; + } + pqueue->pd = pd; pqueue->cpu_index = cpu_index; cpu_index++; @@ -393,6 +457,7 @@ static void padata_init_pqueues(struct parallel_data *pd) __padata_list_init(&pqueue->reorder); __padata_list_init(&pqueue->parallel); INIT_WORK(&pqueue->work, padata_parallel_worker); + INIT_WORK(&pqueue->reorder_work, invoke_padata_reorder); atomic_set(&pqueue->num_obj, 0); } } diff --git a/kernel/params.c b/kernel/params.c index 60b2d8101355..cc9108c2a1fd 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -224,7 +224,7 @@ char *parse_args(const char *doing, } \ int param_get_##name(char *buffer, const struct kernel_param *kp) \ { \ - return scnprintf(buffer, PAGE_SIZE, format, \ + return scnprintf(buffer, PAGE_SIZE, format "\n", \ *((type *)kp->arg)); \ } \ const struct kernel_param_ops param_ops_##name = { \ @@ -236,14 +236,14 @@ char *parse_args(const char *doing, EXPORT_SYMBOL(param_ops_##name) -STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8); -STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16); -STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16); -STANDARD_PARAM_DEF(int, int, "%i", kstrtoint); -STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint); -STANDARD_PARAM_DEF(long, long, "%li", kstrtol); -STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); -STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); +STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8); +STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16); +STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16); +STANDARD_PARAM_DEF(int, int, "%i", kstrtoint); +STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint); +STANDARD_PARAM_DEF(long, long, "%li", kstrtol); +STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); +STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); int param_set_charp(const char *val, const struct kernel_param *kp) { @@ -270,7 +270,7 @@ EXPORT_SYMBOL(param_set_charp); int param_get_charp(char *buffer, const struct kernel_param *kp) { - return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg)); + return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg)); } EXPORT_SYMBOL(param_get_charp); @@ -301,7 +301,7 @@ EXPORT_SYMBOL(param_set_bool); int param_get_bool(char *buffer, const struct kernel_param *kp) { /* Y and N chosen as being relatively non-coder friendly */ - return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N'); + return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N'); } EXPORT_SYMBOL(param_get_bool); @@ -360,7 +360,7 @@ EXPORT_SYMBOL(param_set_invbool); int param_get_invbool(char *buffer, const struct kernel_param *kp) { - return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y'); + return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y'); } EXPORT_SYMBOL(param_get_invbool); @@ -460,8 +460,9 @@ static int param_array_get(char *buffer, const struct kernel_param *kp) struct kernel_param p = *kp; for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { + /* Replace \n with comma */ if (i) - buffer[off++] = ','; + buffer[off - 1] = ','; p.arg = arr->elem + arr->elemsize * i; check_kparam_locked(p.mod); ret = arr->ops->get(buffer + off, &p); @@ -507,7 +508,7 @@ EXPORT_SYMBOL(param_set_copystring); int param_get_string(char *buffer, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; - return strlcpy(buffer, kps->string, kps->maxlen); + return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string); } EXPORT_SYMBOL(param_get_string); @@ -549,10 +550,6 @@ static ssize_t param_attr_show(struct module_attribute *mattr, kernel_param_lock(mk->mod); count = attribute->param->ops->get(buf, attribute->param); kernel_param_unlock(mk->mod); - if (count > 0) { - strcat(buf, "\n"); - ++count; - } return count; } @@ -600,7 +597,7 @@ EXPORT_SYMBOL(kernel_param_unlock); /* * add_sysfs_param - add a parameter to sysfs * @mk: struct module_kobject - * @kparam: the actual parameter definition to add to sysfs + * @kp: the actual parameter definition to add to sysfs * @name: name of parameter * * Create a kobject if for a (per-module) parameter if mp NULL, and diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index e8517b63eb37..e880ca22c5a5 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -259,20 +259,6 @@ config APM_EMULATION anything, try disabling/enabling this option (or disabling/enabling APM in your BIOS). -config PM_OPP - bool - select SRCU - ---help--- - SOCs have a standard set of tuples consisting of frequency and - voltage pairs that the device will support per voltage domain. This - is called Operating Performance Point or OPP. The actual definitions - of OPP varies over silicon within the same family of devices. - - OPP layer organizes the data internally using device pointers - representing individual voltage domains and provides SOC - implementations a ready to use framework to manage OPPs. - For more information, read <file:Documentation/power/opp.txt> - config PM_CLK def_bool y depends on PM && HAVE_CLK diff --git a/kernel/power/Makefile b/kernel/power/Makefile index eb4f717705ba..a3f79f0eef36 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 ccflags-$(CONFIG_PM_DEBUG) := -DDEBUG diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c index 9012ecf7b814..41e83a779e19 100644 --- a/kernel/power/autosleep.c +++ b/kernel/power/autosleep.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * kernel/power/autosleep.c * diff --git a/kernel/power/console.c b/kernel/power/console.c index 0e781798b0b3..fcdf0e14a47d 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Functions for saving/restoring console. * diff --git a/kernel/power/power.h b/kernel/power/power.h index 1d2d761e3c25..f29cd178df90 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #include <linux/suspend.h> #include <linux/suspend_ioctls.h> #include <linux/utsname.h> diff --git a/kernel/power/process.c b/kernel/power/process.c index 50f25cb370c6..7381d49a44db 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * drivers/power/process.c - Functions for starting/stopping processes on * suspend transitions. diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 97b0df71303e..9d7503910ce2 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -701,8 +701,8 @@ static int __init pm_qos_power_init(void) for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { ret = register_pm_qos_misc(pm_qos_array[i], d); if (ret < 0) { - printk(KERN_ERR "pm_qos_param: %s setup failed\n", - pm_qos_array[i]->name); + pr_err("%s: %s setup failed\n", + __func__, pm_qos_array[i]->name); return ret; } } diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 0972a8e09d08..a917a301e201 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -10,6 +10,8 @@ * */ +#define pr_fmt(fmt) "PM: " fmt + #include <linux/version.h> #include <linux/module.h> #include <linux/mm.h> @@ -967,7 +969,7 @@ void __init __register_nosave_region(unsigned long start_pfn, region->end_pfn = end_pfn; list_add_tail(®ion->list, &nosave_regions); Report: - printk(KERN_INFO "PM: Registered nosave memory: [mem %#010llx-%#010llx]\n", + pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n", (unsigned long long) start_pfn << PAGE_SHIFT, ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); } @@ -1039,7 +1041,7 @@ static void mark_nosave_pages(struct memory_bitmap *bm) list_for_each_entry(region, &nosave_regions, list) { unsigned long pfn; - pr_debug("PM: Marking nosave pages: [mem %#010llx-%#010llx]\n", + pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n", (unsigned long long) region->start_pfn << PAGE_SHIFT, ((unsigned long long) region->end_pfn << PAGE_SHIFT) - 1); @@ -1095,7 +1097,7 @@ int create_basic_memory_bitmaps(void) free_pages_map = bm2; mark_nosave_pages(forbidden_pages_map); - pr_debug("PM: Basic memory bitmaps created\n"); + pr_debug("Basic memory bitmaps created\n"); return 0; @@ -1131,7 +1133,7 @@ void free_basic_memory_bitmaps(void) memory_bm_free(bm2, PG_UNSAFE_CLEAR); kfree(bm2); - pr_debug("PM: Basic memory bitmaps freed\n"); + pr_debug("Basic memory bitmaps freed\n"); } void clear_free_pages(void) @@ -1152,7 +1154,7 @@ void clear_free_pages(void) pfn = memory_bm_next_pfn(bm); } memory_bm_position_reset(bm); - pr_info("PM: free pages cleared after restore\n"); + pr_info("free pages cleared after restore\n"); #endif /* PAGE_POISONING_ZERO */ } @@ -1690,7 +1692,7 @@ int hibernate_preallocate_memory(void) ktime_t start, stop; int error; - printk(KERN_INFO "PM: Preallocating image memory... "); + pr_info("Preallocating image memory... "); start = ktime_get(); error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); @@ -1821,13 +1823,13 @@ int hibernate_preallocate_memory(void) out: stop = ktime_get(); - printk(KERN_CONT "done (allocated %lu pages)\n", pages); + pr_cont("done (allocated %lu pages)\n", pages); swsusp_show_speed(start, stop, pages, "Allocated"); return 0; err_out: - printk(KERN_CONT "\n"); + pr_cont("\n"); swsusp_free(); return -ENOMEM; } @@ -1867,8 +1869,8 @@ static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) free += zone_page_state(zone, NR_FREE_PAGES); nr_pages += count_pages_for_highmem(nr_highmem); - pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n", - nr_pages, PAGES_FOR_IO, free); + pr_debug("Normal pages needed: %u + %u, available pages: %u\n", + nr_pages, PAGES_FOR_IO, free); return free > nr_pages + PAGES_FOR_IO; } @@ -1961,20 +1963,20 @@ asmlinkage __visible int swsusp_save(void) { unsigned int nr_pages, nr_highmem; - printk(KERN_INFO "PM: Creating hibernation image:\n"); + pr_info("Creating hibernation image:\n"); drain_local_pages(NULL); nr_pages = count_data_pages(); nr_highmem = count_highmem_pages(); - printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem); + pr_info("Need to copy %u pages\n", nr_pages + nr_highmem); if (!enough_free_mem(nr_pages, nr_highmem)) { - printk(KERN_ERR "PM: Not enough free memory\n"); + pr_err("Not enough free memory\n"); return -ENOMEM; } if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) { - printk(KERN_ERR "PM: Memory allocation failed\n"); + pr_err("Memory allocation failed\n"); return -ENOMEM; } @@ -1995,8 +1997,7 @@ asmlinkage __visible int swsusp_save(void) nr_copy_pages = nr_pages; nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); - printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n", - nr_pages); + pr_info("Hibernation image created (%d pages copied)\n", nr_pages); return 0; } @@ -2170,7 +2171,7 @@ static int check_header(struct swsusp_info *info) if (!reason && info->num_physpages != get_num_physpages()) reason = "memory size"; if (reason) { - printk(KERN_ERR "PM: Image mismatch: %s\n", reason); + pr_err("Image mismatch: %s\n", reason); return -EPERM; } return 0; diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 3e2b4f519009..0685c4499431 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -120,22 +120,26 @@ static void s2idle_loop(void) * frozen processes + suspended devices + idle processors. * Thus s2idle_enter() should be called right after * all devices have been suspended. + * + * Wakeups during the noirq suspend of devices may be spurious, + * so prevent them from terminating the loop right away. */ error = dpm_noirq_suspend_devices(PMSG_SUSPEND); if (!error) s2idle_enter(); + else if (error == -EBUSY && pm_wakeup_pending()) + error = 0; - dpm_noirq_resume_devices(PMSG_RESUME); - if (error && (error != -EBUSY || !pm_wakeup_pending())) { - dpm_noirq_end(); - break; - } - - if (s2idle_ops && s2idle_ops->wake) + if (!error && s2idle_ops && s2idle_ops->wake) s2idle_ops->wake(); + dpm_noirq_resume_devices(PMSG_RESUME); + dpm_noirq_end(); + if (error) + break; + if (s2idle_ops && s2idle_ops->sync) s2idle_ops->sync(); @@ -433,7 +437,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) error = suspend_ops->enter(state); trace_suspend_resume(TPS("machine_suspend"), state, false); - events_check_enabled = false; } else if (*wakeup) { error = -EBUSY; } @@ -578,6 +581,7 @@ static int enter_state(suspend_state_t state) pm_restore_gfp_mask(); Finish: + events_check_enabled = false; pm_pr_dbg("Finishing wakeup.\n"); suspend_finish(); Unlock: diff --git a/kernel/power/swap.c b/kernel/power/swap.c index d7cdc426ee38..293ead59eccc 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -12,6 +12,8 @@ * */ +#define pr_fmt(fmt) "PM: " fmt + #include <linux/module.h> #include <linux/file.h> #include <linux/delay.h> @@ -241,9 +243,9 @@ static void hib_end_io(struct bio *bio) struct page *page = bio->bi_io_vec[0].bv_page; if (bio->bi_status) { - printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n", - MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), - (unsigned long long)bio->bi_iter.bi_sector); + pr_alert("Read-error on swap-device (%u:%u:%Lu)\n", + MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), + (unsigned long long)bio->bi_iter.bi_sector); } if (bio_data_dir(bio) == WRITE) @@ -273,8 +275,8 @@ static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr, bio_set_op_attrs(bio, op, op_flags); if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { - printk(KERN_ERR "PM: Adding page to bio failed at %llu\n", - (unsigned long long)bio->bi_iter.bi_sector); + pr_err("Adding page to bio failed at %llu\n", + (unsigned long long)bio->bi_iter.bi_sector); bio_put(bio); return -EFAULT; } @@ -319,7 +321,7 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, swsusp_resume_block, swsusp_header, NULL); } else { - printk(KERN_ERR "PM: Swap header not found!\n"); + pr_err("Swap header not found!\n"); error = -ENODEV; } return error; @@ -413,8 +415,7 @@ static int get_swap_writer(struct swap_map_handle *handle) ret = swsusp_swap_check(); if (ret) { if (ret != -ENOSPC) - printk(KERN_ERR "PM: Cannot find swap device, try " - "swapon -a.\n"); + pr_err("Cannot find swap device, try swapon -a\n"); return ret; } handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); @@ -491,9 +492,9 @@ static int swap_writer_finish(struct swap_map_handle *handle, { if (!error) { flush_swap_writer(handle); - printk(KERN_INFO "PM: S"); + pr_info("S"); error = mark_swapfiles(handle, flags); - printk("|\n"); + pr_cont("|\n"); } if (error) @@ -542,7 +543,7 @@ static int save_image(struct swap_map_handle *handle, hib_init_batch(&hb); - printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n", + pr_info("Saving image data pages (%u pages)...\n", nr_to_write); m = nr_to_write / 10; if (!m) @@ -557,8 +558,8 @@ static int save_image(struct swap_map_handle *handle, if (ret) break; if (!(nr_pages % m)) - printk(KERN_INFO "PM: Image saving progress: %3d%%\n", - nr_pages / m * 10); + pr_info("Image saving progress: %3d%%\n", + nr_pages / m * 10); nr_pages++; } err2 = hib_wait_io(&hb); @@ -566,7 +567,7 @@ static int save_image(struct swap_map_handle *handle, if (!ret) ret = err2; if (!ret) - printk(KERN_INFO "PM: Image saving done.\n"); + pr_info("Image saving done\n"); swsusp_show_speed(start, stop, nr_to_write, "Wrote"); return ret; } @@ -692,14 +693,14 @@ static int save_image_lzo(struct swap_map_handle *handle, page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH); if (!page) { - printk(KERN_ERR "PM: Failed to allocate LZO page\n"); + pr_err("Failed to allocate LZO page\n"); ret = -ENOMEM; goto out_clean; } data = vmalloc(sizeof(*data) * nr_threads); if (!data) { - printk(KERN_ERR "PM: Failed to allocate LZO data\n"); + pr_err("Failed to allocate LZO data\n"); ret = -ENOMEM; goto out_clean; } @@ -708,7 +709,7 @@ static int save_image_lzo(struct swap_map_handle *handle, crc = kmalloc(sizeof(*crc), GFP_KERNEL); if (!crc) { - printk(KERN_ERR "PM: Failed to allocate crc\n"); + pr_err("Failed to allocate crc\n"); ret = -ENOMEM; goto out_clean; } @@ -726,8 +727,7 @@ static int save_image_lzo(struct swap_map_handle *handle, "image_compress/%u", thr); if (IS_ERR(data[thr].thr)) { data[thr].thr = NULL; - printk(KERN_ERR - "PM: Cannot start compression threads\n"); + pr_err("Cannot start compression threads\n"); ret = -ENOMEM; goto out_clean; } @@ -749,7 +749,7 @@ static int save_image_lzo(struct swap_map_handle *handle, crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); if (IS_ERR(crc->thr)) { crc->thr = NULL; - printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); + pr_err("Cannot start CRC32 thread\n"); ret = -ENOMEM; goto out_clean; } @@ -760,10 +760,9 @@ static int save_image_lzo(struct swap_map_handle *handle, */ handle->reqd_free_pages = reqd_free_pages(); - printk(KERN_INFO - "PM: Using %u thread(s) for compression.\n" - "PM: Compressing and saving image data (%u pages)...\n", - nr_threads, nr_to_write); + pr_info("Using %u thread(s) for compression\n", nr_threads); + pr_info("Compressing and saving image data (%u pages)...\n", + nr_to_write); m = nr_to_write / 10; if (!m) m = 1; @@ -783,10 +782,8 @@ static int save_image_lzo(struct swap_map_handle *handle, data_of(*snapshot), PAGE_SIZE); if (!(nr_pages % m)) - printk(KERN_INFO - "PM: Image saving progress: " - "%3d%%\n", - nr_pages / m * 10); + pr_info("Image saving progress: %3d%%\n", + nr_pages / m * 10); nr_pages++; } if (!off) @@ -813,15 +810,14 @@ static int save_image_lzo(struct swap_map_handle *handle, ret = data[thr].ret; if (ret < 0) { - printk(KERN_ERR "PM: LZO compression failed\n"); + pr_err("LZO compression failed\n"); goto out_finish; } if (unlikely(!data[thr].cmp_len || data[thr].cmp_len > lzo1x_worst_compress(data[thr].unc_len))) { - printk(KERN_ERR - "PM: Invalid LZO compressed length\n"); + pr_err("Invalid LZO compressed length\n"); ret = -1; goto out_finish; } @@ -857,7 +853,7 @@ out_finish: if (!ret) ret = err2; if (!ret) - printk(KERN_INFO "PM: Image saving done.\n"); + pr_info("Image saving done\n"); swsusp_show_speed(start, stop, nr_to_write, "Wrote"); out_clean: if (crc) { @@ -888,7 +884,7 @@ static int enough_swap(unsigned int nr_pages, unsigned int flags) unsigned int free_swap = count_swap_pages(root_swap, 1); unsigned int required; - pr_debug("PM: Free swap pages: %u\n", free_swap); + pr_debug("Free swap pages: %u\n", free_swap); required = PAGES_FOR_IO + nr_pages; return free_swap > required; @@ -915,12 +911,12 @@ int swsusp_write(unsigned int flags) pages = snapshot_get_image_size(); error = get_swap_writer(&handle); if (error) { - printk(KERN_ERR "PM: Cannot get swap writer\n"); + pr_err("Cannot get swap writer\n"); return error; } if (flags & SF_NOCOMPRESS_MODE) { if (!enough_swap(pages, flags)) { - printk(KERN_ERR "PM: Not enough free swap\n"); + pr_err("Not enough free swap\n"); error = -ENOSPC; goto out_finish; } @@ -1068,8 +1064,7 @@ static int load_image(struct swap_map_handle *handle, hib_init_batch(&hb); clean_pages_on_read = true; - printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n", - nr_to_read); + pr_info("Loading image data pages (%u pages)...\n", nr_to_read); m = nr_to_read / 10; if (!m) m = 1; @@ -1087,8 +1082,8 @@ static int load_image(struct swap_map_handle *handle, if (ret) break; if (!(nr_pages % m)) - printk(KERN_INFO "PM: Image loading progress: %3d%%\n", - nr_pages / m * 10); + pr_info("Image loading progress: %3d%%\n", + nr_pages / m * 10); nr_pages++; } err2 = hib_wait_io(&hb); @@ -1096,7 +1091,7 @@ static int load_image(struct swap_map_handle *handle, if (!ret) ret = err2; if (!ret) { - printk(KERN_INFO "PM: Image loading done.\n"); + pr_info("Image loading done\n"); snapshot_write_finalize(snapshot); if (!snapshot_image_loaded(snapshot)) ret = -ENODATA; @@ -1190,14 +1185,14 @@ static int load_image_lzo(struct swap_map_handle *handle, page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES); if (!page) { - printk(KERN_ERR "PM: Failed to allocate LZO page\n"); + pr_err("Failed to allocate LZO page\n"); ret = -ENOMEM; goto out_clean; } data = vmalloc(sizeof(*data) * nr_threads); if (!data) { - printk(KERN_ERR "PM: Failed to allocate LZO data\n"); + pr_err("Failed to allocate LZO data\n"); ret = -ENOMEM; goto out_clean; } @@ -1206,7 +1201,7 @@ static int load_image_lzo(struct swap_map_handle *handle, crc = kmalloc(sizeof(*crc), GFP_KERNEL); if (!crc) { - printk(KERN_ERR "PM: Failed to allocate crc\n"); + pr_err("Failed to allocate crc\n"); ret = -ENOMEM; goto out_clean; } @@ -1226,8 +1221,7 @@ static int load_image_lzo(struct swap_map_handle *handle, "image_decompress/%u", thr); if (IS_ERR(data[thr].thr)) { data[thr].thr = NULL; - printk(KERN_ERR - "PM: Cannot start decompression threads\n"); + pr_err("Cannot start decompression threads\n"); ret = -ENOMEM; goto out_clean; } @@ -1249,7 +1243,7 @@ static int load_image_lzo(struct swap_map_handle *handle, crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); if (IS_ERR(crc->thr)) { crc->thr = NULL; - printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); + pr_err("Cannot start CRC32 thread\n"); ret = -ENOMEM; goto out_clean; } @@ -1274,8 +1268,7 @@ static int load_image_lzo(struct swap_map_handle *handle, if (!page[i]) { if (i < LZO_CMP_PAGES) { ring_size = i; - printk(KERN_ERR - "PM: Failed to allocate LZO pages\n"); + pr_err("Failed to allocate LZO pages\n"); ret = -ENOMEM; goto out_clean; } else { @@ -1285,10 +1278,9 @@ static int load_image_lzo(struct swap_map_handle *handle, } want = ring_size = i; - printk(KERN_INFO - "PM: Using %u thread(s) for decompression.\n" - "PM: Loading and decompressing image data (%u pages)...\n", - nr_threads, nr_to_read); + pr_info("Using %u thread(s) for decompression\n", nr_threads); + pr_info("Loading and decompressing image data (%u pages)...\n", + nr_to_read); m = nr_to_read / 10; if (!m) m = 1; @@ -1348,8 +1340,7 @@ static int load_image_lzo(struct swap_map_handle *handle, if (unlikely(!data[thr].cmp_len || data[thr].cmp_len > lzo1x_worst_compress(LZO_UNC_SIZE))) { - printk(KERN_ERR - "PM: Invalid LZO compressed length\n"); + pr_err("Invalid LZO compressed length\n"); ret = -1; goto out_finish; } @@ -1400,16 +1391,14 @@ static int load_image_lzo(struct swap_map_handle *handle, ret = data[thr].ret; if (ret < 0) { - printk(KERN_ERR - "PM: LZO decompression failed\n"); + pr_err("LZO decompression failed\n"); goto out_finish; } if (unlikely(!data[thr].unc_len || data[thr].unc_len > LZO_UNC_SIZE || data[thr].unc_len & (PAGE_SIZE - 1))) { - printk(KERN_ERR - "PM: Invalid LZO uncompressed length\n"); + pr_err("Invalid LZO uncompressed length\n"); ret = -1; goto out_finish; } @@ -1420,10 +1409,8 @@ static int load_image_lzo(struct swap_map_handle *handle, data[thr].unc + off, PAGE_SIZE); if (!(nr_pages % m)) - printk(KERN_INFO - "PM: Image loading progress: " - "%3d%%\n", - nr_pages / m * 10); + pr_info("Image loading progress: %3d%%\n", + nr_pages / m * 10); nr_pages++; ret = snapshot_write_next(snapshot); @@ -1448,15 +1435,14 @@ out_finish: } stop = ktime_get(); if (!ret) { - printk(KERN_INFO "PM: Image loading done.\n"); + pr_info("Image loading done\n"); snapshot_write_finalize(snapshot); if (!snapshot_image_loaded(snapshot)) ret = -ENODATA; if (!ret) { if (swsusp_header->flags & SF_CRC32_MODE) { if(handle->crc32 != swsusp_header->crc32) { - printk(KERN_ERR - "PM: Invalid image CRC32!\n"); + pr_err("Invalid image CRC32!\n"); ret = -ENODATA; } } @@ -1513,9 +1499,9 @@ int swsusp_read(unsigned int *flags_p) swap_reader_finish(&handle); end: if (!error) - pr_debug("PM: Image successfully loaded\n"); + pr_debug("Image successfully loaded\n"); else - pr_debug("PM: Error %d resuming\n", error); + pr_debug("Error %d resuming\n", error); return error; } @@ -1552,13 +1538,13 @@ put: if (error) blkdev_put(hib_resume_bdev, FMODE_READ); else - pr_debug("PM: Image signature found, resuming\n"); + pr_debug("Image signature found, resuming\n"); } else { error = PTR_ERR(hib_resume_bdev); } if (error) - pr_debug("PM: Image not found (code %d)\n", error); + pr_debug("Image not found (code %d)\n", error); return error; } @@ -1570,7 +1556,7 @@ put: void swsusp_close(fmode_t mode) { if (IS_ERR(hib_resume_bdev)) { - pr_debug("PM: Image device not initialised\n"); + pr_debug("Image device not initialised\n"); return; } @@ -1594,7 +1580,7 @@ int swsusp_unmark(void) swsusp_resume_block, swsusp_header, NULL); } else { - printk(KERN_ERR "PM: Cannot find swsusp signature!\n"); + pr_err("Cannot find swsusp signature!\n"); error = -ENODEV; } diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c index 1896386e16bb..dfba59be190b 100644 --- a/kernel/power/wakelock.c +++ b/kernel/power/wakelock.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * kernel/power/wakelock.c * diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c index 61d41ca41844..1d21ebacfdb8 100644 --- a/kernel/printk/braille.c +++ b/kernel/printk/braille.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> diff --git a/kernel/printk/braille.h b/kernel/printk/braille.h index 749a6756843a..123154f86304 100644 --- a/kernel/printk/braille.h +++ b/kernel/printk/braille.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _PRINTK_BRAILLE_H #define _PRINTK_BRAILLE_H diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h index 2ca4a8b5fe57..11f19c466af5 100644 --- a/kernel/printk/console_cmdline.h +++ b/kernel/printk/console_cmdline.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _CONSOLE_CMDLINE_H #define _CONSOLE_CMDLINE_H diff --git a/kernel/range.c b/kernel/range.c index 82cfc285b046..d84de6766472 100644 --- a/kernel/range.c +++ b/kernel/range.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Range add and subtract */ diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile index 13c0fc852767..020e8b6a644b 100644 --- a/kernel/rcu/Makefile +++ b/kernel/rcu/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # Any varying coverage in these files is non-deterministic # and is generally not a function of system call inputs. KCOV_INSTRUMENT := n diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index e4b43fef89f5..59c471de342a 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -203,6 +203,21 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head) extern int rcu_cpu_stall_suppress; int rcu_jiffies_till_stall_check(void); +#define rcu_ftrace_dump_stall_suppress() \ +do { \ + if (!rcu_cpu_stall_suppress) \ + rcu_cpu_stall_suppress = 3; \ +} while (0) + +#define rcu_ftrace_dump_stall_unsuppress() \ +do { \ + if (rcu_cpu_stall_suppress == 3) \ + rcu_cpu_stall_suppress = 0; \ +} while (0) + +#else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */ +#define rcu_ftrace_dump_stall_suppress() +#define rcu_ftrace_dump_stall_unsuppress() #endif /* #ifdef CONFIG_RCU_STALL_COMMON */ /* @@ -220,8 +235,12 @@ do { \ static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \ \ if (!atomic_read(&___rfd_beenhere) && \ - !atomic_xchg(&___rfd_beenhere, 1)) \ + !atomic_xchg(&___rfd_beenhere, 1)) { \ + tracing_off(); \ + rcu_ftrace_dump_stall_suppress(); \ ftrace_dump(oops_dump_mode); \ + rcu_ftrace_dump_stall_unsuppress(); \ + } \ } while (0) void rcu_early_boot_tests(void); diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c index 7649fcd2c4c7..88cba7c2956c 100644 --- a/kernel/rcu/rcu_segcblist.c +++ b/kernel/rcu/rcu_segcblist.c @@ -23,6 +23,7 @@ #include <linux/types.h> #include <linux/kernel.h> #include <linux/interrupt.h> +#include <linux/rcupdate.h> #include "rcu_segcblist.h" diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 45f2ffbc1e78..74f6b0146b98 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -51,6 +51,7 @@ #include <asm/byteorder.h> #include <linux/torture.h> #include <linux/vmalloc.h> +#include <linux/sched/debug.h> #include "rcu.h" @@ -89,6 +90,7 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); torture_param(int, stall_cpu_holdoff, 10, "Time to wait before starting stall (s)."); +torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); torture_param(int, stutter, 5, "Number of seconds to run/halt test"); @@ -1076,7 +1078,7 @@ static void rcu_torture_timer_cb(struct rcu_head *rhp) * counter in the element should never be greater than 1, otherwise, the * RCU implementation is broken. */ -static void rcu_torture_timer(unsigned long unused) +static void rcu_torture_timer(struct timer_list *unused) { int idx; unsigned long started; @@ -1163,7 +1165,7 @@ rcu_torture_reader(void *arg) VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); set_user_nice(current, MAX_NICE); if (irqreader && cur_ops->irq_capable) - setup_timer_on_stack(&t, rcu_torture_timer, 0); + timer_setup_on_stack(&t, rcu_torture_timer, 0); do { if (irqreader && cur_ops->irq_capable) { @@ -1239,6 +1241,7 @@ rcu_torture_stats_print(void) long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; static unsigned long rtcv_snap = ULONG_MAX; + static bool splatted; struct task_struct *wtp; for_each_possible_cpu(cpu) { @@ -1324,6 +1327,10 @@ rcu_torture_stats_print(void) gpnum, completed, flags, wtp == NULL ? ~0UL : wtp->state, wtp == NULL ? -1 : (int)task_cpu(wtp)); + if (!splatted && wtp) { + sched_show_task(wtp); + splatted = true; + } show_rcu_gp_kthreads(); rcu_ftrace_dump(DUMP_ALL); } @@ -1357,7 +1364,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " "test_boost=%d/%d test_boost_interval=%d " "test_boost_duration=%d shutdown_secs=%d " - "stall_cpu=%d stall_cpu_holdoff=%d " + "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " "n_barrier_cbs=%d " "onoff_interval=%d onoff_holdoff=%d\n", torture_type, tag, nrealreaders, nfakewriters, @@ -1365,7 +1372,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, test_boost, cur_ops->can_boost, test_boost_interval, test_boost_duration, shutdown_secs, - stall_cpu, stall_cpu_holdoff, + stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, n_barrier_cbs, onoff_interval, onoff_holdoff); } @@ -1430,12 +1437,19 @@ static int rcu_torture_stall(void *args) if (!kthread_should_stop()) { stop_at = get_seconds() + stall_cpu; /* RCU CPU stall is expected behavior in following code. */ - pr_alert("rcu_torture_stall start.\n"); rcu_read_lock(); - preempt_disable(); + if (stall_cpu_irqsoff) + local_irq_disable(); + else + preempt_disable(); + pr_alert("rcu_torture_stall start on CPU %d.\n", + smp_processor_id()); while (ULONG_CMP_LT(get_seconds(), stop_at)) continue; /* Induce RCU CPU stall warning. */ - preempt_enable(); + if (stall_cpu_irqsoff) + local_irq_enable(); + else + preempt_enable(); rcu_read_unlock(); pr_alert("rcu_torture_stall end.\n"); } diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 729a8706751d..6d5880089ff6 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -854,7 +854,7 @@ void __call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, /** * call_srcu() - Queue a callback for invocation after an SRCU grace period * @sp: srcu_struct in queue the callback - * @head: structure to be used for queueing the SRCU callback. + * @rhp: structure to be used for queueing the SRCU callback. * @func: function to be invoked after the SRCU grace period * * The callback function will be invoked some time after a full SRCU diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index 50d1861f7759..3f943efcf61c 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -85,6 +85,9 @@ void rcu_sync_init(struct rcu_sync *rsp, enum rcu_sync_type type) } /** + * rcu_sync_enter_start - Force readers onto slow path for multiple updates + * @rsp: Pointer to rcu_sync structure to use for synchronization + * * Must be called after rcu_sync_init() and before first use. * * Ensures rcu_sync_is_idle() returns false and rcu_sync_{enter,exit}() @@ -142,7 +145,7 @@ void rcu_sync_enter(struct rcu_sync *rsp) /** * rcu_sync_func() - Callback function managing reader access to fastpath - * @rsp: Pointer to rcu_sync structure to use for synchronization + * @rhp: Pointer to rcu_head in rcu_sync structure to use for synchronization * * This function is passed to one of the call_rcu() functions by * rcu_sync_exit(), so that it is invoked after a grace period following the @@ -158,9 +161,9 @@ void rcu_sync_enter(struct rcu_sync *rsp) * rcu_sync_exit(). Otherwise, set all state back to idle so that readers * can again use their fastpaths. */ -static void rcu_sync_func(struct rcu_head *rcu) +static void rcu_sync_func(struct rcu_head *rhp) { - struct rcu_sync *rsp = container_of(rcu, struct rcu_sync, cb_head); + struct rcu_sync *rsp = container_of(rhp, struct rcu_sync, cb_head); unsigned long flags; BUG_ON(rsp->gp_state != GP_PASSED); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 0c44c7b42e6d..f9c0ca2ccf0c 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -534,8 +534,8 @@ module_param(rcu_kick_kthreads, bool, 0644); * How long the grace period must be before we start recruiting * quiescent-state help from rcu_note_context_switch(). */ -static ulong jiffies_till_sched_qs = HZ / 20; -module_param(jiffies_till_sched_qs, ulong, 0644); +static ulong jiffies_till_sched_qs = HZ / 10; +module_param(jiffies_till_sched_qs, ulong, 0444); static bool rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp); @@ -734,7 +734,7 @@ static int rcu_future_needs_gp(struct rcu_state *rsp) int idx = (READ_ONCE(rnp->completed) + 1) & 0x1; int *fp = &rnp->need_future_gp[idx]; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_future_needs_gp() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); return READ_ONCE(*fp); } @@ -746,7 +746,7 @@ static int rcu_future_needs_gp(struct rcu_state *rsp) static bool cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "cpu_needs_another_gp() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_gp_in_progress(rsp)) return false; /* No, a grace period is already in progress. */ if (rcu_future_needs_gp(rsp)) @@ -773,7 +773,7 @@ static void rcu_eqs_enter_common(bool user) struct rcu_data *rdp; struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_eqs_enter_common() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); trace_rcu_dyntick(TPS("Start"), rdtp->dynticks_nesting, 0); if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current)) { @@ -837,10 +837,13 @@ static void rcu_eqs_enter(bool user) * We crowbar the ->dynticks_nesting field to zero to allow for * the possibility of usermode upcalls having messed up our count * of interrupt nesting level during the prior busy period. + * + * If you add or remove a call to rcu_idle_enter(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_idle_enter(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_idle_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rcu_eqs_enter(false); } @@ -852,10 +855,13 @@ void rcu_idle_enter(void) * is permitted between this call and rcu_user_exit(). This way the * CPU doesn't need to maintain the tick for RCU maintenance purposes * when the CPU runs in userspace. + * + * If you add or remove a call to rcu_user_enter(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_user_enter(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_user_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rcu_eqs_enter(true); } #endif /* CONFIG_NO_HZ_FULL */ @@ -875,16 +881,19 @@ void rcu_user_enter(void) * Use things like work queues to work around this limitation. * * You have been warned. + * + * If you add or remove a call to rcu_irq_exit(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_irq_exit(void) { struct rcu_dynticks *rdtp; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_exit() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); /* Page faults can happen in NMI handlers, so check... */ - if (READ_ONCE(rdtp->dynticks_nmi_nesting)) + if (rdtp->dynticks_nmi_nesting) return; WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && @@ -899,6 +908,9 @@ void rcu_irq_exit(void) /* * Wrapper for rcu_irq_exit() where interrupts are enabled. + * + * If you add or remove a call to rcu_irq_exit_irqson(), be sure to test + * with CONFIG_RCU_EQS_DEBUG=y. */ void rcu_irq_exit_irqson(void) { @@ -947,7 +959,7 @@ static void rcu_eqs_exit(bool user) struct rcu_dynticks *rdtp; long long oldval; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_eqs_exit() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && oldval < 0); @@ -971,6 +983,9 @@ static void rcu_eqs_exit(bool user) * allow for the possibility of usermode upcalls messing up our count * of interrupt nesting level during the busy period that is just * now starting. + * + * If you add or remove a call to rcu_idle_exit(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_idle_exit(void) { @@ -987,6 +1002,9 @@ void rcu_idle_exit(void) * * Exit RCU idle mode while entering the kernel because it can * run a RCU read side critical section anytime. + * + * If you add or remove a call to rcu_user_exit(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_user_exit(void) { @@ -1012,17 +1030,20 @@ void rcu_user_exit(void) * Use things like work queues to work around this limitation. * * You have been warned. + * + * If you add or remove a call to rcu_irq_enter(), be sure to test with + * CONFIG_RCU_EQS_DEBUG=y. */ void rcu_irq_enter(void) { struct rcu_dynticks *rdtp; long long oldval; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); /* Page faults can happen in NMI handlers, so check... */ - if (READ_ONCE(rdtp->dynticks_nmi_nesting)) + if (rdtp->dynticks_nmi_nesting) return; oldval = rdtp->dynticks_nesting; @@ -1037,6 +1058,9 @@ void rcu_irq_enter(void) /* * Wrapper for rcu_irq_enter() where interrupts are enabled. + * + * If you add or remove a call to rcu_irq_enter_irqson(), be sure to test + * with CONFIG_RCU_EQS_DEBUG=y. */ void rcu_irq_enter_irqson(void) { @@ -1055,6 +1079,9 @@ void rcu_irq_enter_irqson(void) * that the CPU is active. This implementation permits nested NMIs, as * long as the nesting level does not overflow an int. (You will probably * run out of stack space first.) + * + * If you add or remove a call to rcu_nmi_enter(), be sure to test + * with CONFIG_RCU_EQS_DEBUG=y. */ void rcu_nmi_enter(void) { @@ -1087,6 +1114,9 @@ void rcu_nmi_enter(void) * RCU-idle period, update rdtp->dynticks and rdtp->dynticks_nmi_nesting * to let the RCU grace-period handling know that the CPU is back to * being RCU-idle. + * + * If you add or remove a call to rcu_nmi_exit(), be sure to test + * with CONFIG_RCU_EQS_DEBUG=y. */ void rcu_nmi_exit(void) { @@ -1207,6 +1237,22 @@ static int rcu_is_cpu_rrupt_from_idle(void) } /* + * We are reporting a quiescent state on behalf of some other CPU, so + * it is our responsibility to check for and handle potential overflow + * of the rcu_node ->gpnum counter with respect to the rcu_data counters. + * After all, the CPU might be in deep idle state, and thus executing no + * code whatsoever. + */ +static void rcu_gpnum_ovf(struct rcu_node *rnp, struct rcu_data *rdp) +{ + lockdep_assert_held(&rnp->lock); + if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4, rnp->gpnum)) + WRITE_ONCE(rdp->gpwrap, true); + if (ULONG_CMP_LT(rdp->rcu_iw_gpnum + ULONG_MAX / 4, rnp->gpnum)) + rdp->rcu_iw_gpnum = rnp->gpnum + ULONG_MAX / 4; +} + +/* * Snapshot the specified CPU's dynticks counter so that we can later * credit them with an implicit quiescent state. Return 1 if this CPU * is in dynticks idle mode, which is an extended quiescent state. @@ -1216,15 +1262,34 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp) rdp->dynticks_snap = rcu_dynticks_snap(rdp->dynticks); if (rcu_dynticks_in_eqs(rdp->dynticks_snap)) { trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti")); - if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4, - rdp->mynode->gpnum)) - WRITE_ONCE(rdp->gpwrap, true); + rcu_gpnum_ovf(rdp->mynode, rdp); return 1; } return 0; } /* + * Handler for the irq_work request posted when a grace period has + * gone on for too long, but not yet long enough for an RCU CPU + * stall warning. Set state appropriately, but just complain if + * there is unexpected state on entry. + */ +static void rcu_iw_handler(struct irq_work *iwp) +{ + struct rcu_data *rdp; + struct rcu_node *rnp; + + rdp = container_of(iwp, struct rcu_data, rcu_iw); + rnp = rdp->mynode; + raw_spin_lock_rcu_node(rnp); + if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) { + rdp->rcu_iw_gpnum = rnp->gpnum; + rdp->rcu_iw_pending = false; + } + raw_spin_unlock_rcu_node(rnp); +} + +/* * Return true if the specified CPU has passed through a quiescent * state by virtue of being in or having passed through an dynticks * idle state since the last call to dyntick_save_progress_counter() @@ -1235,8 +1300,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) unsigned long jtsq; bool *rnhqp; bool *ruqp; - unsigned long rjtsc; - struct rcu_node *rnp; + struct rcu_node *rnp = rdp->mynode; /* * If the CPU passed through or entered a dynticks idle phase with @@ -1249,34 +1313,25 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) if (rcu_dynticks_in_eqs_since(rdp->dynticks, rdp->dynticks_snap)) { trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti")); rdp->dynticks_fqs++; + rcu_gpnum_ovf(rnp, rdp); return 1; } - /* Compute and saturate jiffies_till_sched_qs. */ - jtsq = jiffies_till_sched_qs; - rjtsc = rcu_jiffies_till_stall_check(); - if (jtsq > rjtsc / 2) { - WRITE_ONCE(jiffies_till_sched_qs, rjtsc); - jtsq = rjtsc / 2; - } else if (jtsq < 1) { - WRITE_ONCE(jiffies_till_sched_qs, 1); - jtsq = 1; - } - /* * Has this CPU encountered a cond_resched_rcu_qs() since the * beginning of the grace period? For this to be the case, * the CPU has to have noticed the current grace period. This * might not be the case for nohz_full CPUs looping in the kernel. */ - rnp = rdp->mynode; + jtsq = jiffies_till_sched_qs; ruqp = per_cpu_ptr(&rcu_dynticks.rcu_urgent_qs, rdp->cpu); if (time_after(jiffies, rdp->rsp->gp_start + jtsq) && READ_ONCE(rdp->rcu_qs_ctr_snap) != per_cpu(rcu_dynticks.rcu_qs_ctr, rdp->cpu) && READ_ONCE(rdp->gpnum) == rnp->gpnum && !rdp->gpwrap) { trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("rqc")); + rcu_gpnum_ovf(rnp, rdp); return 1; - } else { + } else if (time_after(jiffies, rdp->rsp->gp_start + jtsq)) { /* Load rcu_qs_ctr before store to rcu_urgent_qs. */ smp_store_release(ruqp, true); } @@ -1285,6 +1340,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) if (!(rdp->grpmask & rcu_rnp_online_cpus(rnp))) { trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("ofl")); rdp->offline_fqs++; + rcu_gpnum_ovf(rnp, rdp); return 1; } @@ -1304,10 +1360,6 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) * updates are only once every few jiffies, the probability of * lossage (and thus of slight grace-period extension) is * quite low. - * - * Note that if the jiffies_till_sched_qs boot/sysfs parameter - * is set too high, we override with half of the RCU CPU stall - * warning delay. */ rnhqp = &per_cpu(rcu_dynticks.rcu_need_heavy_qs, rdp->cpu); if (!READ_ONCE(*rnhqp) && @@ -1316,15 +1368,26 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) WRITE_ONCE(*rnhqp, true); /* Store rcu_need_heavy_qs before rcu_urgent_qs. */ smp_store_release(ruqp, true); - rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */ + rdp->rsp->jiffies_resched += jtsq; /* Re-enable beating. */ } /* - * If more than halfway to RCU CPU stall-warning time, do - * a resched_cpu() to try to loosen things up a bit. + * If more than halfway to RCU CPU stall-warning time, do a + * resched_cpu() to try to loosen things up a bit. Also check to + * see if the CPU is getting hammered with interrupts, but only + * once per grace period, just to keep the IPIs down to a dull roar. */ - if (jiffies - rdp->rsp->gp_start > rcu_jiffies_till_stall_check() / 2) + if (jiffies - rdp->rsp->gp_start > rcu_jiffies_till_stall_check() / 2) { resched_cpu(rdp->cpu); + if (IS_ENABLED(CONFIG_IRQ_WORK) && + !rdp->rcu_iw_pending && rdp->rcu_iw_gpnum != rnp->gpnum && + (rnp->ffmask & rdp->grpmask)) { + init_irq_work(&rdp->rcu_iw, rcu_iw_handler); + rdp->rcu_iw_pending = true; + rdp->rcu_iw_gpnum = rnp->gpnum; + irq_work_queue_on(&rdp->rcu_iw, rdp->cpu); + } + } return 0; } @@ -1513,6 +1576,7 @@ static void print_cpu_stall(struct rcu_state *rsp) { int cpu; unsigned long flags; + struct rcu_data *rdp = this_cpu_ptr(rsp->rda); struct rcu_node *rnp = rcu_get_root(rsp); long totqlen = 0; @@ -1528,7 +1592,9 @@ static void print_cpu_stall(struct rcu_state *rsp) */ pr_err("INFO: %s self-detected stall on CPU", rsp->name); print_cpu_stall_info_begin(); + raw_spin_lock_irqsave_rcu_node(rdp->mynode, flags); print_cpu_stall_info(rsp, smp_processor_id()); + raw_spin_unlock_irqrestore_rcu_node(rdp->mynode, flags); print_cpu_stall_info_end(); for_each_possible_cpu(cpu) totqlen += rcu_segcblist_n_cbs(&per_cpu_ptr(rsp->rda, @@ -1922,6 +1988,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, rdp->core_needs_qs = need_gp; zero_cpu_stall_ticks(rdp); WRITE_ONCE(rdp->gpwrap, false); + rcu_gpnum_ovf(rnp, rdp); } return ret; } @@ -3097,9 +3164,10 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, * read-side critical sections have completed. call_rcu_sched() assumes * that the read-side critical sections end on enabling of preemption * or on voluntary preemption. - * RCU read-side critical sections are delimited by : - * - rcu_read_lock_sched() and rcu_read_unlock_sched(), OR - * - anything that disables preemption. + * RCU read-side critical sections are delimited by: + * + * - rcu_read_lock_sched() and rcu_read_unlock_sched(), OR + * - anything that disables preemption. * * These may be nested. * @@ -3124,11 +3192,12 @@ EXPORT_SYMBOL_GPL(call_rcu_sched); * handler. This means that read-side critical sections in process * context must not be interrupted by softirqs. This interface is to be * used when most of the read-side critical sections are in softirq context. - * RCU read-side critical sections are delimited by : - * - rcu_read_lock() and rcu_read_unlock(), if in interrupt context. - * OR - * - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context. - * These may be nested. + * RCU read-side critical sections are delimited by: + * + * - rcu_read_lock() and rcu_read_unlock(), if in interrupt context, OR + * - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context. + * + * These may be nested. * * See the description of call_rcu() for more detailed information on * memory ordering guarantees. @@ -3700,6 +3769,8 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->cpu_no_qs.b.norm = true; rdp->rcu_qs_ctr_snap = per_cpu(rcu_dynticks.rcu_qs_ctr, cpu); rdp->core_needs_qs = false; + rdp->rcu_iw_pending = false; + rdp->rcu_iw_gpnum = rnp->gpnum - 1; trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl")); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } @@ -3737,10 +3808,24 @@ static void rcutree_affinity_setting(unsigned int cpu, int outgoing) */ int rcutree_online_cpu(unsigned int cpu) { - sync_sched_exp_online_cleanup(cpu); - rcutree_affinity_setting(cpu, -1); + unsigned long flags; + struct rcu_data *rdp; + struct rcu_node *rnp; + struct rcu_state *rsp; + + for_each_rcu_flavor(rsp) { + rdp = per_cpu_ptr(rsp->rda, cpu); + rnp = rdp->mynode; + raw_spin_lock_irqsave_rcu_node(rnp, flags); + rnp->ffmask |= rdp->grpmask; + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); + } if (IS_ENABLED(CONFIG_TREE_SRCU)) srcu_online_cpu(cpu); + if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE) + return 0; /* Too early in boot for scheduler work. */ + sync_sched_exp_online_cleanup(cpu); + rcutree_affinity_setting(cpu, -1); return 0; } @@ -3750,6 +3835,19 @@ int rcutree_online_cpu(unsigned int cpu) */ int rcutree_offline_cpu(unsigned int cpu) { + unsigned long flags; + struct rcu_data *rdp; + struct rcu_node *rnp; + struct rcu_state *rsp; + + for_each_rcu_flavor(rsp) { + rdp = per_cpu_ptr(rsp->rda, cpu); + rnp = rdp->mynode; + raw_spin_lock_irqsave_rcu_node(rnp, flags); + rnp->ffmask &= ~rdp->grpmask; + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); + } + rcutree_affinity_setting(cpu, cpu); if (IS_ENABLED(CONFIG_TREE_SRCU)) srcu_offline_cpu(cpu); @@ -4198,8 +4296,7 @@ void __init rcu_init(void) for_each_online_cpu(cpu) { rcutree_prepare_cpu(cpu); rcu_cpu_starting(cpu); - if (IS_ENABLED(CONFIG_TREE_SRCU)) - srcu_online_cpu(cpu); + rcutree_online_cpu(cpu); } } diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 8e1f285f0a70..46a5d1991450 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -103,6 +103,7 @@ struct rcu_node { /* Online CPUs for next expedited GP. */ /* Any CPU that has ever been online will */ /* have its bit set. */ + unsigned long ffmask; /* Fully functional CPUs. */ unsigned long grpmask; /* Mask to apply to parent qsmask. */ /* Only one bit will be set in this mask. */ int grplo; /* lowest-numbered CPU or group here. */ @@ -285,6 +286,10 @@ struct rcu_data { /* 8) RCU CPU stall data. */ unsigned int softirq_snap; /* Snapshot of softirq activity. */ + /* ->rcu_iw* fields protected by leaf rcu_node ->lock. */ + struct irq_work rcu_iw; /* Check for non-irq activity. */ + bool rcu_iw_pending; /* Is ->rcu_iw pending? */ + unsigned long rcu_iw_gpnum; /* ->gpnum associated with ->rcu_iw. */ int cpu; struct rcu_state *rsp; diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index e012b9be777e..db85ca3975f1 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -29,6 +29,7 @@ #include <linux/oom.h> #include <linux/sched/debug.h> #include <linux/smpboot.h> +#include <linux/sched/isolation.h> #include <uapi/linux/sched/types.h> #include "../time/tick-internal.h" @@ -54,6 +55,7 @@ DEFINE_PER_CPU(char, rcu_cpu_has_work); * This probably needs to be excluded from -rt builds. */ #define rt_mutex_owner(a) ({ WARN_ON_ONCE(1); NULL; }) +#define rt_mutex_futex_unlock(x) WARN_ON_ONCE(1) #endif /* #else #ifdef CONFIG_RCU_BOOST */ @@ -325,7 +327,7 @@ static void rcu_preempt_note_context_switch(bool preempt) struct rcu_data *rdp; struct rcu_node *rnp; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_preempt_note_context_switch() invoked with interrupts enabled!!!\n"); + lockdep_assert_irqs_disabled(); WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0); if (t->rcu_read_lock_nesting > 0 && !t->rcu_read_unlock_special.b.blocked) { @@ -530,7 +532,7 @@ void rcu_read_unlock_special(struct task_struct *t) /* Unboost if we were boosted. */ if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex) - rt_mutex_unlock(&rnp->boost_mtx); + rt_mutex_futex_unlock(&rnp->boost_mtx); /* * If this was the last task on the expedited lists, @@ -911,8 +913,6 @@ void exit_rcu(void) #ifdef CONFIG_RCU_BOOST -#include "../locking/rtmutex_common.h" - static void rcu_wake_cond(struct task_struct *t, int status) { /* @@ -1421,7 +1421,7 @@ int rcu_needs_cpu(u64 basemono, u64 *nextevt) struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); unsigned long dj; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_needs_cpu() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); /* Snapshot to detect later posting of non-lazy callback. */ rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; @@ -1470,7 +1470,7 @@ static void rcu_prepare_for_idle(void) struct rcu_state *rsp; int tne; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_prepare_for_idle() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_is_nocb_cpu(smp_processor_id())) return; @@ -1507,7 +1507,7 @@ static void rcu_prepare_for_idle(void) rdtp->last_accelerate = jiffies; for_each_rcu_flavor(rsp) { rdp = this_cpu_ptr(rsp->rda); - if (rcu_segcblist_pend_cbs(&rdp->cblist)) + if (!rcu_segcblist_pend_cbs(&rdp->cblist)) continue; rnp = rdp->mynode; raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */ @@ -1525,7 +1525,7 @@ static void rcu_prepare_for_idle(void) */ static void rcu_cleanup_after_idle(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_cleanup_after_idle() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_is_nocb_cpu(smp_processor_id())) return; if (rcu_try_advance_all_cbs()) @@ -1671,6 +1671,7 @@ static void print_cpu_stall_info_begin(void) */ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) { + unsigned long delta; char fast_no_hz[72]; struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_dynticks *rdtp = rdp->dynticks; @@ -1685,11 +1686,15 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) ticks_value = rsp->gpnum - rdp->gpnum; } print_cpu_stall_fast_no_hz(fast_no_hz, cpu); - pr_err("\t%d-%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", + delta = rdp->mynode->gpnum - rdp->rcu_iw_gpnum; + pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", cpu, "O."[!!cpu_online(cpu)], "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)], "N."[!!(rdp->grpmask & rdp->mynode->qsmaskinitnext)], + !IS_ENABLED(CONFIG_IRQ_WORK) ? '?' : + rdp->rcu_iw_pending ? (int)min(delta, 9UL) + '0' : + "!."[!delta], ticks_value, ticks_title, rcu_dynticks_snap(rdtp) & 0xfff, rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting, @@ -2012,7 +2017,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_data *my_rdp, struct rcu_data *rdp, unsigned long flags) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_nocb_adopt_orphan_cbs() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (!rcu_is_nocb_cpu(smp_processor_id())) return false; /* Not NOCBs CPU, caller must migrate CBs. */ __call_rcu_nocb_enqueue(my_rdp, rcu_segcblist_head(&rdp->cblist), @@ -2261,9 +2266,11 @@ static void do_nocb_deferred_wakeup_common(struct rcu_data *rdp) } /* Do a deferred wakeup of rcu_nocb_kthread() from a timer handler. */ -static void do_nocb_deferred_wakeup_timer(unsigned long x) +static void do_nocb_deferred_wakeup_timer(struct timer_list *t) { - do_nocb_deferred_wakeup_common((struct rcu_data *)x); + struct rcu_data *rdp = from_timer(rdp, t, nocb_timer); + + do_nocb_deferred_wakeup_common(rdp); } /* @@ -2327,8 +2334,7 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) init_swait_queue_head(&rdp->nocb_wq); rdp->nocb_follower_tail = &rdp->nocb_follower_head; raw_spin_lock_init(&rdp->nocb_lock); - setup_timer(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, - (unsigned long)rdp); + timer_setup(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, 0); } /* @@ -2583,7 +2589,7 @@ static void rcu_bind_gp_kthread(void) if (!tick_nohz_full_enabled()) return; - housekeeping_affine(current); + housekeeping_affine(current, HK_FLAG_RCU); } /* Record the current task on dyntick-idle entry. */ diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 5033b66d2753..fbd56d6e575b 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -51,6 +51,7 @@ #include <linux/kthread.h> #include <linux/tick.h> #include <linux/rcupdate_wait.h> +#include <linux/sched/isolation.h> #define CREATE_TRACE_POINTS @@ -494,6 +495,7 @@ EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read); #endif int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ +EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress); static int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT; module_param(rcu_cpu_stall_suppress, int, 0644); @@ -575,7 +577,6 @@ DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); static int rcu_task_stall_timeout __read_mostly = RCU_TASK_STALL_TIMEOUT; module_param(rcu_task_stall_timeout, int, 0644); -static void rcu_spawn_tasks_kthread(void); static struct task_struct *rcu_tasks_kthread_ptr; /** @@ -600,7 +601,6 @@ void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func) { unsigned long flags; bool needwake; - bool havetask = READ_ONCE(rcu_tasks_kthread_ptr); rhp->next = NULL; rhp->func = func; @@ -610,11 +610,8 @@ void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func) rcu_tasks_cbs_tail = &rhp->next; raw_spin_unlock_irqrestore(&rcu_tasks_cbs_lock, flags); /* We can't create the thread unless interrupts are enabled. */ - if ((needwake && havetask) || - (!havetask && !irqs_disabled_flags(flags))) { - rcu_spawn_tasks_kthread(); + if (needwake && READ_ONCE(rcu_tasks_kthread_ptr)) wake_up(&rcu_tasks_cbs_wq); - } } EXPORT_SYMBOL_GPL(call_rcu_tasks); @@ -718,7 +715,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) LIST_HEAD(rcu_tasks_holdouts); /* Run on housekeeping CPUs by default. Sysadm can move if desired. */ - housekeeping_affine(current); + housekeeping_affine(current, HK_FLAG_RCU); /* * Each pass through the following loop makes one check for @@ -853,27 +850,18 @@ static int __noreturn rcu_tasks_kthread(void *arg) } } -/* Spawn rcu_tasks_kthread() at first call to call_rcu_tasks(). */ -static void rcu_spawn_tasks_kthread(void) +/* Spawn rcu_tasks_kthread() at core_initcall() time. */ +static int __init rcu_spawn_tasks_kthread(void) { - static DEFINE_MUTEX(rcu_tasks_kthread_mutex); struct task_struct *t; - if (READ_ONCE(rcu_tasks_kthread_ptr)) { - smp_mb(); /* Ensure caller sees full kthread. */ - return; - } - mutex_lock(&rcu_tasks_kthread_mutex); - if (rcu_tasks_kthread_ptr) { - mutex_unlock(&rcu_tasks_kthread_mutex); - return; - } t = kthread_run(rcu_tasks_kthread, NULL, "rcu_tasks_kthread"); BUG_ON(IS_ERR(t)); smp_mb(); /* Ensure others see full kthread. */ WRITE_ONCE(rcu_tasks_kthread_ptr, t); - mutex_unlock(&rcu_tasks_kthread_mutex); + return 0; } +core_initcall(rcu_spawn_tasks_kthread); /* Do the srcu_read_lock() for the above synchronize_srcu(). */ void exit_tasks_rcu_start(void) diff --git a/kernel/resource.c b/kernel/resource.c index 9b5f04404152..54ba6de3757c 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -397,9 +397,32 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc, res->start = p->start; if (res->end > p->end) res->end = p->end; + res->flags = p->flags; + res->desc = p->desc; return 0; } +static int __walk_iomem_res_desc(struct resource *res, unsigned long desc, + bool first_level_children_only, + void *arg, + int (*func)(struct resource *, void *)) +{ + u64 orig_end = res->end; + int ret = -1; + + while ((res->start < res->end) && + !find_next_iomem_res(res, desc, first_level_children_only)) { + ret = (*func)(res, arg); + if (ret) + break; + + res->start = res->end + 1; + res->end = orig_end; + } + + return ret; +} + /* * Walks through iomem resources and calls func() with matching resource * ranges. This walks through whole tree and not just first level children. @@ -415,29 +438,15 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc, * <linux/ioport.h> and set it in 'desc' of a target resource entry. */ int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, - u64 end, void *arg, int (*func)(u64, u64, void *)) + u64 end, void *arg, int (*func)(struct resource *, void *)) { struct resource res; - u64 orig_end; - int ret = -1; res.start = start; res.end = end; res.flags = flags; - orig_end = res.end; - - while ((res.start < res.end) && - (!find_next_iomem_res(&res, desc, false))) { - - ret = (*func)(res.start, res.end, arg); - if (ret) - break; - - res.start = res.end + 1; - res.end = orig_end; - } - return ret; + return __walk_iomem_res_desc(&res, desc, false, arg, func); } /* @@ -448,25 +457,33 @@ int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, * ranges. */ int walk_system_ram_res(u64 start, u64 end, void *arg, - int (*func)(u64, u64, void *)) + int (*func)(struct resource *, void *)) { struct resource res; - u64 orig_end; - int ret = -1; res.start = start; res.end = end; res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; - orig_end = res.end; - while ((res.start < res.end) && - (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { - ret = (*func)(res.start, res.end, arg); - if (ret) - break; - res.start = res.end + 1; - res.end = orig_end; - } - return ret; + + return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true, + arg, func); +} + +/* + * This function calls the @func callback against all memory ranges, which + * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. + */ +int walk_mem_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + struct resource res; + + res.start = start; + res.end = end; + res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; + + return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true, + arg, func); } #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) @@ -508,6 +525,7 @@ static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) { return 1; } + /* * This generic page_is_ram() returns true if specified address is * registered as System RAM in iomem_resource list. diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 78f54932ea1d..e2f9d4feff40 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE) endif @@ -26,3 +27,4 @@ obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o obj-$(CONFIG_CPU_FREQ) += cpufreq.o obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o obj-$(CONFIG_MEMBARRIER) += membarrier.o +obj-$(CONFIG_CPU_ISOLATION) += isolation.o diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c index de6d7f4dfcb5..a43df5193538 100644 --- a/kernel/sched/autogroup.c +++ b/kernel/sched/autogroup.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "sched.h" #include <linux/proc_fs.h> diff --git a/kernel/sched/autogroup.h b/kernel/sched/autogroup.h index ce40c810cd5c..27cd22b89824 100644 --- a/kernel/sched/autogroup.h +++ b/kernel/sched/autogroup.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifdef CONFIG_SCHED_AUTOGROUP #include <linux/kref.h> diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index ca0f8fc945c6..e086babe6c61 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -388,7 +388,7 @@ void sched_clock_tick(void) if (unlikely(!sched_clock_running)) return; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); scd = this_scd(); __scd_stamp(scd); diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index cc873075c3bd..2ddaec40956f 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Generic wait-for-completion handler; * diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d17c5da523a0..5b82a0073532 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -26,6 +26,7 @@ #include <linux/profile.h> #include <linux/security.h> #include <linux/syscalls.h> +#include <linux/sched/isolation.h> #include <asm/switch_to.h> #include <asm/tlb.h> @@ -42,18 +43,21 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); +#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) /* * Debugging: various feature bits + * + * If SCHED_DEBUG is disabled, each compilation unit has its own copy of + * sysctl_sched_features, defined in sched.h, to allow constants propagation + * at compile time and compiler optimization based on features default. */ - #define SCHED_FEAT(name, enabled) \ (1UL << __SCHED_FEAT_##name) * enabled | - const_debug unsigned int sysctl_sched_features = #include "features.h" 0; - #undef SCHED_FEAT +#endif /* * Number of tasks to iterate in a single balance run. @@ -83,9 +87,6 @@ __read_mostly int scheduler_running; */ int sysctl_sched_rt_runtime = 950000; -/* CPUs with isolated domains */ -cpumask_var_t cpu_isolated_map; - /* * __task_rq_lock - lock the rq @p resides on. */ @@ -505,8 +506,7 @@ void resched_cpu(int cpu) struct rq *rq = cpu_rq(cpu); unsigned long flags; - if (!raw_spin_trylock_irqsave(&rq->lock, flags)) - return; + raw_spin_lock_irqsave(&rq->lock, flags); resched_curr(rq); raw_spin_unlock_irqrestore(&rq->lock, flags); } @@ -526,7 +526,7 @@ int get_nohz_timer_target(void) int i, cpu = smp_processor_id(); struct sched_domain *sd; - if (!idle_cpu(cpu) && is_housekeeping_cpu(cpu)) + if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER)) return cpu; rcu_read_lock(); @@ -535,15 +535,15 @@ int get_nohz_timer_target(void) if (cpu == i) continue; - if (!idle_cpu(i) && is_housekeeping_cpu(i)) { + if (!idle_cpu(i) && housekeeping_cpu(i, HK_FLAG_TIMER)) { cpu = i; goto unlock; } } } - if (!is_housekeeping_cpu(cpu)) - cpu = housekeeping_any_cpu(); + if (!housekeeping_cpu(cpu, HK_FLAG_TIMER)) + cpu = housekeeping_any_cpu(HK_FLAG_TIMER); unlock: rcu_read_unlock(); return cpu; @@ -733,7 +733,7 @@ int tg_nop(struct task_group *tg, void *data) } #endif -static void set_load_weight(struct task_struct *p) +static void set_load_weight(struct task_struct *p, bool update_load) { int prio = p->static_prio - MAX_RT_PRIO; struct load_weight *load = &p->se.load; @@ -747,8 +747,16 @@ static void set_load_weight(struct task_struct *p) return; } - load->weight = scale_load(sched_prio_to_weight[prio]); - load->inv_weight = sched_prio_to_wmult[prio]; + /* + * SCHED_OTHER tasks have to update their load when changing their + * weight + */ + if (update_load && p->sched_class == &fair_sched_class) { + reweight_task(p, prio); + } else { + load->weight = scale_load(sched_prio_to_weight[prio]); + load->inv_weight = sched_prio_to_wmult[prio]; + } } static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) @@ -2358,7 +2366,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) p->static_prio = NICE_TO_PRIO(0); p->prio = p->normal_prio = __normal_prio(p); - set_load_weight(p); + set_load_weight(p, false); /* * We don't need the reset flag anymore after the fork. It has @@ -3805,7 +3813,7 @@ void set_user_nice(struct task_struct *p, long nice) put_prev_task(rq, p); p->static_prio = NICE_TO_PRIO(nice); - set_load_weight(p); + set_load_weight(p, true); old_prio = p->prio; p->prio = effective_prio(p); delta = p->prio - old_prio; @@ -3962,7 +3970,7 @@ static void __setscheduler_params(struct task_struct *p, */ p->rt_priority = attr->sched_priority; p->normal_prio = normal_prio(p); - set_load_weight(p); + set_load_weight(p, true); } /* Actually do priority change: must hold pi & rq lock. */ @@ -4842,6 +4850,7 @@ int __sched _cond_resched(void) preempt_schedule_common(); return 1; } + rcu_all_qs(); return 0; } EXPORT_SYMBOL(_cond_resched); @@ -5165,6 +5174,7 @@ void sched_show_task(struct task_struct *p) show_stack(p, NULL); put_task_stack(p); } +EXPORT_SYMBOL_GPL(sched_show_task); static inline bool state_filter_match(unsigned long state_filter, struct task_struct *p) @@ -5726,10 +5736,6 @@ static inline void sched_init_smt(void) { } void __init sched_init_smp(void) { - cpumask_var_t non_isolated_cpus; - - alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); - sched_init_numa(); /* @@ -5739,16 +5745,12 @@ void __init sched_init_smp(void) */ mutex_lock(&sched_domains_mutex); sched_init_domains(cpu_active_mask); - cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); - if (cpumask_empty(non_isolated_cpus)) - cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); mutex_unlock(&sched_domains_mutex); /* Move init over to a non-isolated CPU */ - if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) + if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) BUG(); sched_init_granularity(); - free_cpumask_var(non_isolated_cpus); init_sched_rt_class(); init_sched_dl_class(); @@ -5933,7 +5935,7 @@ void __init sched_init(void) atomic_set(&rq->nr_iowait, 0); } - set_load_weight(&init_task); + set_load_weight(&init_task, false); /* * The boot idle thread does lazy MMU switching as well: @@ -5952,9 +5954,6 @@ void __init sched_init(void) calc_load_update = jiffies + LOAD_FREQ; #ifdef CONFIG_SMP - /* May be allocated at isolcpus cmdline parse time */ - if (cpu_isolated_map == NULL) - zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); idle_thread_set_boot_cpu(); set_cpu_rq_start_time(smp_processor_id()); #endif diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index f95ab29a45d0..44ab32a4fab6 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/cgroup.h> #include <linux/slab.h> #include <linux/percpu.h> diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h index ba72807c73d4..a8358a57a316 100644 --- a/kernel/sched/cpuacct.h +++ b/kernel/sched/cpuacct.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifdef CONFIG_CGROUP_CPUACCT extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h index f7da8c55bba0..b010d26e108e 100644 --- a/kernel/sched/cpudeadline.h +++ b/kernel/sched/cpudeadline.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_CPUDL_H #define _LINUX_CPUDL_H diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 9209d83ecdcf..2f52ec0f1539 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -282,8 +282,12 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, * Do not reduce the frequency if the CPU has not been idle * recently, as the reduction is likely to be premature then. */ - if (busy && next_f < sg_policy->next_freq) + if (busy && next_f < sg_policy->next_freq) { next_f = sg_policy->next_freq; + + /* Reset cached freq as next_freq has changed */ + sg_policy->cached_raw_freq = 0; + } } sugov_update_commit(sg_policy, time, next_f); } @@ -649,6 +653,7 @@ static int sugov_start(struct cpufreq_policy *policy) struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); memset(sg_cpu, 0, sizeof(*sg_cpu)); + sg_cpu->cpu = cpu; sg_cpu->sg_policy = sg_policy; sg_cpu->flags = SCHED_CPUFREQ_RT; sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; @@ -714,11 +719,6 @@ struct cpufreq_governor *cpufreq_default_governor(void) static int __init sugov_register(void) { - int cpu; - - for_each_possible_cpu(cpu) - per_cpu(sugov_cpu, cpu).cpu = cpu; - return cpufreq_register_governor(&schedutil_gov); } fs_initcall(sugov_register); diff --git a/kernel/sched/cpupri.h b/kernel/sched/cpupri.h index 63cbb9ca0496..bab050019071 100644 --- a/kernel/sched/cpupri.h +++ b/kernel/sched/cpupri.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_CPUPRI_H #define _LINUX_CPUPRI_H diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 14d2dbf97c53..9be8b68a66da 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -259,8 +259,7 @@ static inline u64 account_other_time(u64 max) { u64 accounted; - /* Shall be converted to a lockdep-enabled lightweight check */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); accounted = steal_account_process_time(max); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 0191ec7667c3..f349f7e98dec 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Deadline Scheduling Class (SCHED_DEADLINE) * @@ -242,7 +243,7 @@ static void task_non_contending(struct task_struct *p) if (p->state == TASK_DEAD) sub_rq_bw(p->dl.dl_bw, &rq->dl); raw_spin_lock(&dl_b->lock); - __dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); + __dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); __dl_clear_params(p); raw_spin_unlock(&dl_b->lock); } @@ -1209,7 +1210,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) } raw_spin_lock(&dl_b->lock); - __dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); + __dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); raw_spin_unlock(&dl_b->lock); __dl_clear_params(p); @@ -1364,6 +1365,10 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, update_dl_entity(dl_se, pi_se); } else if (flags & ENQUEUE_REPLENISH) { replenish_dl_entity(dl_se, pi_se); + } else if ((flags & ENQUEUE_RESTORE) && + dl_time_before(dl_se->deadline, + rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) { + setup_new_dl_entity(dl_se); } __enqueue_dl_entity(dl_se); @@ -2166,7 +2171,7 @@ static void set_cpus_allowed_dl(struct task_struct *p, * until we complete the update. */ raw_spin_lock(&src_dl_b->lock); - __dl_clear(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); + __dl_sub(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); raw_spin_unlock(&src_dl_b->lock); } @@ -2255,13 +2260,6 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) return; } - /* - * If p is boosted we already updated its params in - * rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH), - * p's deadline being now already after rq_clock(rq). - */ - if (dl_time_before(p->dl.deadline, rq_clock(rq))) - setup_new_dl_entity(&p->dl); if (rq->curr != p) { #ifdef CONFIG_SMP @@ -2451,7 +2449,7 @@ int sched_dl_overflow(struct task_struct *p, int policy, if (dl_policy(policy) && !task_has_dl_policy(p) && !__dl_overflow(dl_b, cpus, 0, new_bw)) { if (hrtimer_active(&p->dl.inactive_timer)) - __dl_clear(dl_b, p->dl.dl_bw, cpus); + __dl_sub(dl_b, p->dl.dl_bw, cpus); __dl_add(dl_b, new_bw, cpus); err = 0; } else if (dl_policy(policy) && task_has_dl_policy(p) && @@ -2463,7 +2461,7 @@ int sched_dl_overflow(struct task_struct *p, int policy, * But this would require to set the task's "inactive * timer" when the task is not inactive. */ - __dl_clear(dl_b, p->dl.dl_bw, cpus); + __dl_sub(dl_b, p->dl.dl_bw, cpus); __dl_add(dl_b, new_bw, cpus); dl_change_utilization(p, new_bw); err = 0; diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 2f93e4a2d9f6..1ca0130ed4f9 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -441,9 +441,11 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group P_SCHEDSTAT(se->statistics.wait_count); } P(se->load.weight); + P(se->runnable_weight); #ifdef CONFIG_SMP P(se->avg.load_avg); P(se->avg.util_avg); + P(se->avg.runnable_load_avg); #endif #undef PN_SCHEDSTAT @@ -558,16 +560,19 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running); SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); #ifdef CONFIG_SMP + SEQ_printf(m, " .%-30s: %ld\n", "runnable_weight", cfs_rq->runnable_weight); SEQ_printf(m, " .%-30s: %lu\n", "load_avg", cfs_rq->avg.load_avg); SEQ_printf(m, " .%-30s: %lu\n", "runnable_load_avg", - cfs_rq->runnable_load_avg); + cfs_rq->avg.runnable_load_avg); SEQ_printf(m, " .%-30s: %lu\n", "util_avg", cfs_rq->avg.util_avg); - SEQ_printf(m, " .%-30s: %ld\n", "removed_load_avg", - atomic_long_read(&cfs_rq->removed_load_avg)); - SEQ_printf(m, " .%-30s: %ld\n", "removed_util_avg", - atomic_long_read(&cfs_rq->removed_util_avg)); + SEQ_printf(m, " .%-30s: %ld\n", "removed.load_avg", + cfs_rq->removed.load_avg); + SEQ_printf(m, " .%-30s: %ld\n", "removed.util_avg", + cfs_rq->removed.util_avg); + SEQ_printf(m, " .%-30s: %ld\n", "removed.runnable_sum", + cfs_rq->removed.runnable_sum); #ifdef CONFIG_FAIR_GROUP_SCHED SEQ_printf(m, " .%-30s: %lu\n", "tg_load_avg_contrib", cfs_rq->tg_load_avg_contrib); @@ -1004,10 +1009,13 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, "nr_involuntary_switches", (long long)p->nivcsw); P(se.load.weight); + P(se.runnable_weight); #ifdef CONFIG_SMP P(se.avg.load_sum); + P(se.avg.runnable_load_sum); P(se.avg.util_sum); P(se.avg.load_avg); + P(se.avg.runnable_load_avg); P(se.avg.util_avg); P(se.avg.last_update_time); #endif diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 70ba32e08a23..0989676c50e9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH) * @@ -32,6 +33,7 @@ #include <linux/mempolicy.h> #include <linux/migrate.h> #include <linux/task_work.h> +#include <linux/sched/isolation.h> #include <trace/events/sched.h> @@ -716,13 +718,8 @@ void init_entity_runnable_average(struct sched_entity *se) { struct sched_avg *sa = &se->avg; - sa->last_update_time = 0; - /* - * sched_avg's period_contrib should be strictly less then 1024, so - * we give it 1023 to make sure it is almost a period (1024us), and - * will definitely be update (after enqueue). - */ - sa->period_contrib = 1023; + memset(sa, 0, sizeof(*sa)); + /* * Tasks are intialized with full load to be seen as heavy tasks until * they get a chance to stabilize to their real load level. @@ -730,13 +727,10 @@ void init_entity_runnable_average(struct sched_entity *se) * nothing has been attached to the task group yet. */ if (entity_is_task(se)) - sa->load_avg = scale_load_down(se->load.weight); - sa->load_sum = sa->load_avg * LOAD_AVG_MAX; - /* - * At this point, util_avg won't be used in select_task_rq_fair anyway - */ - sa->util_avg = 0; - sa->util_sum = 0; + sa->runnable_load_avg = sa->load_avg = scale_load_down(se->load.weight); + + se->runnable_weight = se->load.weight; + /* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */ } @@ -784,7 +778,6 @@ void post_init_entity_util_avg(struct sched_entity *se) } else { sa->util_avg = cap; } - sa->util_sum = sa->util_avg * LOAD_AVG_MAX; } if (entity_is_task(se)) { @@ -2025,7 +2018,7 @@ static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period) delta = runtime - p->last_sum_exec_runtime; *period = now - p->last_task_numa_placement; } else { - delta = p->se.avg.load_sum / p->se.load.weight; + delta = p->se.avg.load_sum; *period = LOAD_AVG_MAX; } @@ -2692,18 +2685,226 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) cfs_rq->nr_running--; } +/* + * Signed add and clamp on underflow. + * + * Explicitly do a load-store to ensure the intermediate value never hits + * memory. This allows lockless observations without ever seeing the negative + * values. + */ +#define add_positive(_ptr, _val) do { \ + typeof(_ptr) ptr = (_ptr); \ + typeof(_val) val = (_val); \ + typeof(*ptr) res, var = READ_ONCE(*ptr); \ + \ + res = var + val; \ + \ + if (val < 0 && res > var) \ + res = 0; \ + \ + WRITE_ONCE(*ptr, res); \ +} while (0) + +/* + * Unsigned subtract and clamp on underflow. + * + * Explicitly do a load-store to ensure the intermediate value never hits + * memory. This allows lockless observations without ever seeing the negative + * values. + */ +#define sub_positive(_ptr, _val) do { \ + typeof(_ptr) ptr = (_ptr); \ + typeof(*ptr) val = (_val); \ + typeof(*ptr) res, var = READ_ONCE(*ptr); \ + res = var - val; \ + if (res > var) \ + res = 0; \ + WRITE_ONCE(*ptr, res); \ +} while (0) + +#ifdef CONFIG_SMP +/* + * XXX we want to get rid of these helpers and use the full load resolution. + */ +static inline long se_weight(struct sched_entity *se) +{ + return scale_load_down(se->load.weight); +} + +static inline long se_runnable(struct sched_entity *se) +{ + return scale_load_down(se->runnable_weight); +} + +static inline void +enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + cfs_rq->runnable_weight += se->runnable_weight; + + cfs_rq->avg.runnable_load_avg += se->avg.runnable_load_avg; + cfs_rq->avg.runnable_load_sum += se_runnable(se) * se->avg.runnable_load_sum; +} + +static inline void +dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + cfs_rq->runnable_weight -= se->runnable_weight; + + sub_positive(&cfs_rq->avg.runnable_load_avg, se->avg.runnable_load_avg); + sub_positive(&cfs_rq->avg.runnable_load_sum, + se_runnable(se) * se->avg.runnable_load_sum); +} + +static inline void +enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + cfs_rq->avg.load_avg += se->avg.load_avg; + cfs_rq->avg.load_sum += se_weight(se) * se->avg.load_sum; +} + +static inline void +dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) +{ + sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg); + sub_positive(&cfs_rq->avg.load_sum, se_weight(se) * se->avg.load_sum); +} +#else +static inline void +enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { } +static inline void +dequeue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { } +static inline void +enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { } +static inline void +dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { } +#endif + +static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, + unsigned long weight, unsigned long runnable) +{ + if (se->on_rq) { + /* commit outstanding execution time */ + if (cfs_rq->curr == se) + update_curr(cfs_rq); + account_entity_dequeue(cfs_rq, se); + dequeue_runnable_load_avg(cfs_rq, se); + } + dequeue_load_avg(cfs_rq, se); + + se->runnable_weight = runnable; + update_load_set(&se->load, weight); + +#ifdef CONFIG_SMP + do { + u32 divider = LOAD_AVG_MAX - 1024 + se->avg.period_contrib; + + se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum, divider); + se->avg.runnable_load_avg = + div_u64(se_runnable(se) * se->avg.runnable_load_sum, divider); + } while (0); +#endif + + enqueue_load_avg(cfs_rq, se); + if (se->on_rq) { + account_entity_enqueue(cfs_rq, se); + enqueue_runnable_load_avg(cfs_rq, se); + } +} + +void reweight_task(struct task_struct *p, int prio) +{ + struct sched_entity *se = &p->se; + struct cfs_rq *cfs_rq = cfs_rq_of(se); + struct load_weight *load = &se->load; + unsigned long weight = scale_load(sched_prio_to_weight[prio]); + + reweight_entity(cfs_rq, se, weight, weight); + load->inv_weight = sched_prio_to_wmult[prio]; +} + #ifdef CONFIG_FAIR_GROUP_SCHED # ifdef CONFIG_SMP -static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) +/* + * All this does is approximate the hierarchical proportion which includes that + * global sum we all love to hate. + * + * That is, the weight of a group entity, is the proportional share of the + * group weight based on the group runqueue weights. That is: + * + * tg->weight * grq->load.weight + * ge->load.weight = ----------------------------- (1) + * \Sum grq->load.weight + * + * Now, because computing that sum is prohibitively expensive to compute (been + * there, done that) we approximate it with this average stuff. The average + * moves slower and therefore the approximation is cheaper and more stable. + * + * So instead of the above, we substitute: + * + * grq->load.weight -> grq->avg.load_avg (2) + * + * which yields the following: + * + * tg->weight * grq->avg.load_avg + * ge->load.weight = ------------------------------ (3) + * tg->load_avg + * + * Where: tg->load_avg ~= \Sum grq->avg.load_avg + * + * That is shares_avg, and it is right (given the approximation (2)). + * + * The problem with it is that because the average is slow -- it was designed + * to be exactly that of course -- this leads to transients in boundary + * conditions. In specific, the case where the group was idle and we start the + * one task. It takes time for our CPU's grq->avg.load_avg to build up, + * yielding bad latency etc.. + * + * Now, in that special case (1) reduces to: + * + * tg->weight * grq->load.weight + * ge->load.weight = ----------------------------- = tg->weight (4) + * grp->load.weight + * + * That is, the sum collapses because all other CPUs are idle; the UP scenario. + * + * So what we do is modify our approximation (3) to approach (4) in the (near) + * UP case, like: + * + * ge->load.weight = + * + * tg->weight * grq->load.weight + * --------------------------------------------------- (5) + * tg->load_avg - grq->avg.load_avg + grq->load.weight + * + * But because grq->load.weight can drop to 0, resulting in a divide by zero, + * we need to use grq->avg.load_avg as its lower bound, which then gives: + * + * + * tg->weight * grq->load.weight + * ge->load.weight = ----------------------------- (6) + * tg_load_avg' + * + * Where: + * + * tg_load_avg' = tg->load_avg - grq->avg.load_avg + + * max(grq->load.weight, grq->avg.load_avg) + * + * And that is shares_weight and is icky. In the (near) UP case it approaches + * (4) while in the normal case it approaches (3). It consistently + * overestimates the ge->load.weight and therefore: + * + * \Sum ge->load.weight >= tg->weight + * + * hence icky! + */ +static long calc_group_shares(struct cfs_rq *cfs_rq) { - long tg_weight, load, shares; + long tg_weight, tg_shares, load, shares; + struct task_group *tg = cfs_rq->tg; - /* - * This really should be: cfs_rq->avg.load_avg, but instead we use - * cfs_rq->load.weight, which is its upper bound. This helps ramp up - * the shares for small weight interactive tasks. - */ - load = scale_load_down(cfs_rq->load.weight); + tg_shares = READ_ONCE(tg->shares); + + load = max(scale_load_down(cfs_rq->load.weight), cfs_rq->avg.load_avg); tg_weight = atomic_long_read(&tg->load_avg); @@ -2711,7 +2912,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) tg_weight -= cfs_rq->tg_load_avg_contrib; tg_weight += load; - shares = (tg->shares * load); + shares = (tg_shares * load); if (tg_weight) shares /= tg_weight; @@ -2727,63 +2928,86 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) * case no task is runnable on a CPU MIN_SHARES=2 should be returned * instead of 0. */ - if (shares < MIN_SHARES) - shares = MIN_SHARES; - if (shares > tg->shares) - shares = tg->shares; - - return shares; -} -# else /* CONFIG_SMP */ -static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) -{ - return tg->shares; + return clamp_t(long, shares, MIN_SHARES, tg_shares); } -# endif /* CONFIG_SMP */ -static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, - unsigned long weight) +/* + * This calculates the effective runnable weight for a group entity based on + * the group entity weight calculated above. + * + * Because of the above approximation (2), our group entity weight is + * an load_avg based ratio (3). This means that it includes blocked load and + * does not represent the runnable weight. + * + * Approximate the group entity's runnable weight per ratio from the group + * runqueue: + * + * grq->avg.runnable_load_avg + * ge->runnable_weight = ge->load.weight * -------------------------- (7) + * grq->avg.load_avg + * + * However, analogous to above, since the avg numbers are slow, this leads to + * transients in the from-idle case. Instead we use: + * + * ge->runnable_weight = ge->load.weight * + * + * max(grq->avg.runnable_load_avg, grq->runnable_weight) + * ----------------------------------------------------- (8) + * max(grq->avg.load_avg, grq->load.weight) + * + * Where these max() serve both to use the 'instant' values to fix the slow + * from-idle and avoid the /0 on to-idle, similar to (6). + */ +static long calc_group_runnable(struct cfs_rq *cfs_rq, long shares) { - if (se->on_rq) { - /* commit outstanding execution time */ - if (cfs_rq->curr == se) - update_curr(cfs_rq); - account_entity_dequeue(cfs_rq, se); - } + long runnable, load_avg; - update_load_set(&se->load, weight); + load_avg = max(cfs_rq->avg.load_avg, + scale_load_down(cfs_rq->load.weight)); - if (se->on_rq) - account_entity_enqueue(cfs_rq, se); + runnable = max(cfs_rq->avg.runnable_load_avg, + scale_load_down(cfs_rq->runnable_weight)); + + runnable *= shares; + if (load_avg) + runnable /= load_avg; + + return clamp_t(long, runnable, MIN_SHARES, shares); } +# endif /* CONFIG_SMP */ static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); -static void update_cfs_shares(struct sched_entity *se) +/* + * Recomputes the group entity based on the current state of its group + * runqueue. + */ +static void update_cfs_group(struct sched_entity *se) { - struct cfs_rq *cfs_rq = group_cfs_rq(se); - struct task_group *tg; - long shares; + struct cfs_rq *gcfs_rq = group_cfs_rq(se); + long shares, runnable; - if (!cfs_rq) + if (!gcfs_rq) return; - if (throttled_hierarchy(cfs_rq)) + if (throttled_hierarchy(gcfs_rq)) return; - tg = cfs_rq->tg; - #ifndef CONFIG_SMP - if (likely(se->load.weight == tg->shares)) + runnable = shares = READ_ONCE(gcfs_rq->tg->shares); + + if (likely(se->load.weight == shares)) return; +#else + shares = calc_group_shares(gcfs_rq); + runnable = calc_group_runnable(gcfs_rq, shares); #endif - shares = calc_cfs_shares(cfs_rq, tg); - reweight_entity(cfs_rq_of(se), se, shares); + reweight_entity(cfs_rq_of(se), se, shares, runnable); } #else /* CONFIG_FAIR_GROUP_SCHED */ -static inline void update_cfs_shares(struct sched_entity *se) +static inline void update_cfs_group(struct sched_entity *se) { } #endif /* CONFIG_FAIR_GROUP_SCHED */ @@ -2892,7 +3116,7 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3) */ static __always_inline u32 accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, - unsigned long weight, int running, struct cfs_rq *cfs_rq) + unsigned long load, unsigned long runnable, int running) { unsigned long scale_freq, scale_cpu; u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */ @@ -2909,10 +3133,8 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, */ if (periods) { sa->load_sum = decay_load(sa->load_sum, periods); - if (cfs_rq) { - cfs_rq->runnable_load_sum = - decay_load(cfs_rq->runnable_load_sum, periods); - } + sa->runnable_load_sum = + decay_load(sa->runnable_load_sum, periods); sa->util_sum = decay_load((u64)(sa->util_sum), periods); /* @@ -2925,11 +3147,10 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, sa->period_contrib = delta; contrib = cap_scale(contrib, scale_freq); - if (weight) { - sa->load_sum += weight * contrib; - if (cfs_rq) - cfs_rq->runnable_load_sum += weight * contrib; - } + if (load) + sa->load_sum += load * contrib; + if (runnable) + sa->runnable_load_sum += runnable * contrib; if (running) sa->util_sum += contrib * scale_cpu; @@ -2965,8 +3186,8 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, * = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}] */ static __always_inline int -___update_load_avg(u64 now, int cpu, struct sched_avg *sa, - unsigned long weight, int running, struct cfs_rq *cfs_rq) +___update_load_sum(u64 now, int cpu, struct sched_avg *sa, + unsigned long load, unsigned long runnable, int running) { u64 delta; @@ -2999,8 +3220,8 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa, * this happens during idle_balance() which calls * update_blocked_averages() */ - if (!weight) - running = 0; + if (!load) + runnable = running = 0; /* * Now we know we crossed measurement unit boundaries. The *_avg @@ -3009,63 +3230,96 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa, * Step 1: accumulate *_sum since last_update_time. If we haven't * crossed period boundaries, finish. */ - if (!accumulate_sum(delta, cpu, sa, weight, running, cfs_rq)) + if (!accumulate_sum(delta, cpu, sa, load, runnable, running)) return 0; + return 1; +} + +static __always_inline void +___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runnable) +{ + u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib; + /* * Step 2: update *_avg. */ - sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib); - if (cfs_rq) { - cfs_rq->runnable_load_avg = - div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib); - } - sa->util_avg = sa->util_sum / (LOAD_AVG_MAX - 1024 + sa->period_contrib); - - return 1; + sa->load_avg = div_u64(load * sa->load_sum, divider); + sa->runnable_load_avg = div_u64(runnable * sa->runnable_load_sum, divider); + sa->util_avg = sa->util_sum / divider; } +/* + * sched_entity: + * + * task: + * se_runnable() == se_weight() + * + * group: [ see update_cfs_group() ] + * se_weight() = tg->weight * grq->load_avg / tg->load_avg + * se_runnable() = se_weight(se) * grq->runnable_load_avg / grq->load_avg + * + * load_sum := runnable_sum + * load_avg = se_weight(se) * runnable_avg + * + * runnable_load_sum := runnable_sum + * runnable_load_avg = se_runnable(se) * runnable_avg + * + * XXX collapse load_sum and runnable_load_sum + * + * cfq_rs: + * + * load_sum = \Sum se_weight(se) * se->avg.load_sum + * load_avg = \Sum se->avg.load_avg + * + * runnable_load_sum = \Sum se_runnable(se) * se->avg.runnable_load_sum + * runnable_load_avg = \Sum se->avg.runable_load_avg + */ + static int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) { - return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL); + if (entity_is_task(se)) + se->runnable_weight = se->load.weight; + + if (___update_load_sum(now, cpu, &se->avg, 0, 0, 0)) { + ___update_load_avg(&se->avg, se_weight(se), se_runnable(se)); + return 1; + } + + return 0; } static int __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se) { - return ___update_load_avg(now, cpu, &se->avg, - se->on_rq * scale_load_down(se->load.weight), - cfs_rq->curr == se, NULL); + if (entity_is_task(se)) + se->runnable_weight = se->load.weight; + + if (___update_load_sum(now, cpu, &se->avg, !!se->on_rq, !!se->on_rq, + cfs_rq->curr == se)) { + + ___update_load_avg(&se->avg, se_weight(se), se_runnable(se)); + return 1; + } + + return 0; } static int __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq) { - return ___update_load_avg(now, cpu, &cfs_rq->avg, - scale_load_down(cfs_rq->load.weight), - cfs_rq->curr != NULL, cfs_rq); -} + if (___update_load_sum(now, cpu, &cfs_rq->avg, + scale_load_down(cfs_rq->load.weight), + scale_load_down(cfs_rq->runnable_weight), + cfs_rq->curr != NULL)) { -/* - * Signed add and clamp on underflow. - * - * Explicitly do a load-store to ensure the intermediate value never hits - * memory. This allows lockless observations without ever seeing the negative - * values. - */ -#define add_positive(_ptr, _val) do { \ - typeof(_ptr) ptr = (_ptr); \ - typeof(_val) val = (_val); \ - typeof(*ptr) res, var = READ_ONCE(*ptr); \ - \ - res = var + val; \ - \ - if (val < 0 && res > var) \ - res = 0; \ - \ - WRITE_ONCE(*ptr, res); \ -} while (0) + ___update_load_avg(&cfs_rq->avg, 1, 1); + return 1; + } + + return 0; +} #ifdef CONFIG_FAIR_GROUP_SCHED /** @@ -3148,11 +3402,77 @@ void set_task_rq_fair(struct sched_entity *se, se->avg.last_update_time = n_last_update_time; } -/* Take into account change of utilization of a child task group */ + +/* + * When on migration a sched_entity joins/leaves the PELT hierarchy, we need to + * propagate its contribution. The key to this propagation is the invariant + * that for each group: + * + * ge->avg == grq->avg (1) + * + * _IFF_ we look at the pure running and runnable sums. Because they + * represent the very same entity, just at different points in the hierarchy. + * + * + * Per the above update_tg_cfs_util() is trivial (and still 'wrong') and + * simply copies the running sum over. + * + * However, update_tg_cfs_runnable() is more complex. So we have: + * + * ge->avg.load_avg = ge->load.weight * ge->avg.runnable_avg (2) + * + * And since, like util, the runnable part should be directly transferable, + * the following would _appear_ to be the straight forward approach: + * + * grq->avg.load_avg = grq->load.weight * grq->avg.running_avg (3) + * + * And per (1) we have: + * + * ge->avg.running_avg == grq->avg.running_avg + * + * Which gives: + * + * ge->load.weight * grq->avg.load_avg + * ge->avg.load_avg = ----------------------------------- (4) + * grq->load.weight + * + * Except that is wrong! + * + * Because while for entities historical weight is not important and we + * really only care about our future and therefore can consider a pure + * runnable sum, runqueues can NOT do this. + * + * We specifically want runqueues to have a load_avg that includes + * historical weights. Those represent the blocked load, the load we expect + * to (shortly) return to us. This only works by keeping the weights as + * integral part of the sum. We therefore cannot decompose as per (3). + * + * OK, so what then? + * + * + * Another way to look at things is: + * + * grq->avg.load_avg = \Sum se->avg.load_avg + * + * Therefore, per (2): + * + * grq->avg.load_avg = \Sum se->load.weight * se->avg.runnable_avg + * + * And the very thing we're propagating is a change in that sum (someone + * joined/left). So we can easily know the runnable change, which would be, per + * (2) the already tracked se->load_avg divided by the corresponding + * se->weight. + * + * Basically (4) but in differential form: + * + * d(runnable_avg) += se->avg.load_avg / se->load.weight + * (5) + * ge->avg.load_avg += ge->load.weight * d(runnable_avg) + */ + static inline void -update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se) +update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq) { - struct cfs_rq *gcfs_rq = group_cfs_rq(se); long delta = gcfs_rq->avg.util_avg - se->avg.util_avg; /* Nothing to update */ @@ -3168,102 +3488,65 @@ update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se) cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX; } -/* Take into account change of load of a child task group */ static inline void -update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se) +update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq) { - struct cfs_rq *gcfs_rq = group_cfs_rq(se); - long delta, load = gcfs_rq->avg.load_avg; - - /* - * If the load of group cfs_rq is null, the load of the - * sched_entity will also be null so we can skip the formula - */ - if (load) { - long tg_load; + long runnable_sum = gcfs_rq->prop_runnable_sum; + long runnable_load_avg, load_avg; + s64 runnable_load_sum, load_sum; - /* Get tg's load and ensure tg_load > 0 */ - tg_load = atomic_long_read(&gcfs_rq->tg->load_avg) + 1; + if (!runnable_sum) + return; - /* Ensure tg_load >= load and updated with current load*/ - tg_load -= gcfs_rq->tg_load_avg_contrib; - tg_load += load; + gcfs_rq->prop_runnable_sum = 0; - /* - * We need to compute a correction term in the case that the - * task group is consuming more CPU than a task of equal - * weight. A task with a weight equals to tg->shares will have - * a load less or equal to scale_load_down(tg->shares). - * Similarly, the sched_entities that represent the task group - * at parent level, can't have a load higher than - * scale_load_down(tg->shares). And the Sum of sched_entities' - * load must be <= scale_load_down(tg->shares). - */ - if (tg_load > scale_load_down(gcfs_rq->tg->shares)) { - /* scale gcfs_rq's load into tg's shares*/ - load *= scale_load_down(gcfs_rq->tg->shares); - load /= tg_load; - } - } + load_sum = (s64)se_weight(se) * runnable_sum; + load_avg = div_s64(load_sum, LOAD_AVG_MAX); - delta = load - se->avg.load_avg; + add_positive(&se->avg.load_sum, runnable_sum); + add_positive(&se->avg.load_avg, load_avg); - /* Nothing to update */ - if (!delta) - return; + add_positive(&cfs_rq->avg.load_avg, load_avg); + add_positive(&cfs_rq->avg.load_sum, load_sum); - /* Set new sched_entity's load */ - se->avg.load_avg = load; - se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX; + runnable_load_sum = (s64)se_runnable(se) * runnable_sum; + runnable_load_avg = div_s64(runnable_load_sum, LOAD_AVG_MAX); - /* Update parent cfs_rq load */ - add_positive(&cfs_rq->avg.load_avg, delta); - cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * LOAD_AVG_MAX; + add_positive(&se->avg.runnable_load_sum, runnable_sum); + add_positive(&se->avg.runnable_load_avg, runnable_load_avg); - /* - * If the sched_entity is already enqueued, we also have to update the - * runnable load avg. - */ if (se->on_rq) { - /* Update parent cfs_rq runnable_load_avg */ - add_positive(&cfs_rq->runnable_load_avg, delta); - cfs_rq->runnable_load_sum = cfs_rq->runnable_load_avg * LOAD_AVG_MAX; + add_positive(&cfs_rq->avg.runnable_load_avg, runnable_load_avg); + add_positive(&cfs_rq->avg.runnable_load_sum, runnable_load_sum); } } -static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) -{ - cfs_rq->propagate_avg = 1; -} - -static inline int test_and_clear_tg_cfs_propagate(struct sched_entity *se) +static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum) { - struct cfs_rq *cfs_rq = group_cfs_rq(se); - - if (!cfs_rq->propagate_avg) - return 0; - - cfs_rq->propagate_avg = 0; - return 1; + cfs_rq->propagate = 1; + cfs_rq->prop_runnable_sum += runnable_sum; } /* Update task and its cfs_rq load average */ static inline int propagate_entity_load_avg(struct sched_entity *se) { - struct cfs_rq *cfs_rq; + struct cfs_rq *cfs_rq, *gcfs_rq; if (entity_is_task(se)) return 0; - if (!test_and_clear_tg_cfs_propagate(se)) + gcfs_rq = group_cfs_rq(se); + if (!gcfs_rq->propagate) return 0; + gcfs_rq->propagate = 0; + cfs_rq = cfs_rq_of(se); - set_tg_cfs_propagate(cfs_rq); + add_tg_cfs_propagate(cfs_rq, gcfs_rq->prop_runnable_sum); - update_tg_cfs_util(cfs_rq, se); - update_tg_cfs_load(cfs_rq, se); + update_tg_cfs_util(cfs_rq, se, gcfs_rq); + update_tg_cfs_runnable(cfs_rq, se, gcfs_rq); return 1; } @@ -3287,7 +3570,7 @@ static inline bool skip_blocked_update(struct sched_entity *se) * If there is a pending propagation, we have to update the load and * the utilization of the sched_entity: */ - if (gcfs_rq->propagate_avg) + if (gcfs_rq->propagate) return false; /* @@ -3307,27 +3590,10 @@ static inline int propagate_entity_load_avg(struct sched_entity *se) return 0; } -static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {} +static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum) {} #endif /* CONFIG_FAIR_GROUP_SCHED */ -/* - * Unsigned subtract and clamp on underflow. - * - * Explicitly do a load-store to ensure the intermediate value never hits - * memory. This allows lockless observations without ever seeing the negative - * values. - */ -#define sub_positive(_ptr, _val) do { \ - typeof(_ptr) ptr = (_ptr); \ - typeof(*ptr) val = (_val); \ - typeof(*ptr) res, var = READ_ONCE(*ptr); \ - res = var - val; \ - if (res > var) \ - res = 0; \ - WRITE_ONCE(*ptr, res); \ -} while (0) - /** * update_cfs_rq_load_avg - update the cfs_rq's load/util averages * @now: current time, as per cfs_rq_clock_task() @@ -3347,65 +3613,45 @@ static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {} static inline int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) { + unsigned long removed_load = 0, removed_util = 0, removed_runnable_sum = 0; struct sched_avg *sa = &cfs_rq->avg; - int decayed, removed_load = 0, removed_util = 0; + int decayed = 0; + + if (cfs_rq->removed.nr) { + unsigned long r; + u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib; - if (atomic_long_read(&cfs_rq->removed_load_avg)) { - s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0); + raw_spin_lock(&cfs_rq->removed.lock); + swap(cfs_rq->removed.util_avg, removed_util); + swap(cfs_rq->removed.load_avg, removed_load); + swap(cfs_rq->removed.runnable_sum, removed_runnable_sum); + cfs_rq->removed.nr = 0; + raw_spin_unlock(&cfs_rq->removed.lock); + + r = removed_load; sub_positive(&sa->load_avg, r); - sub_positive(&sa->load_sum, r * LOAD_AVG_MAX); - removed_load = 1; - set_tg_cfs_propagate(cfs_rq); - } + sub_positive(&sa->load_sum, r * divider); - if (atomic_long_read(&cfs_rq->removed_util_avg)) { - long r = atomic_long_xchg(&cfs_rq->removed_util_avg, 0); + r = removed_util; sub_positive(&sa->util_avg, r); - sub_positive(&sa->util_sum, r * LOAD_AVG_MAX); - removed_util = 1; - set_tg_cfs_propagate(cfs_rq); + sub_positive(&sa->util_sum, r * divider); + + add_tg_cfs_propagate(cfs_rq, -(long)removed_runnable_sum); + + decayed = 1; } - decayed = __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq); + decayed |= __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq); #ifndef CONFIG_64BIT smp_wmb(); cfs_rq->load_last_update_time_copy = sa->last_update_time; #endif - if (decayed || removed_util) + if (decayed) cfs_rq_util_change(cfs_rq); - return decayed || removed_load; -} - -/* - * Optional action to be done while updating the load average - */ -#define UPDATE_TG 0x1 -#define SKIP_AGE_LOAD 0x2 - -/* Update task and its cfs_rq load average */ -static inline void update_load_avg(struct sched_entity *se, int flags) -{ - struct cfs_rq *cfs_rq = cfs_rq_of(se); - u64 now = cfs_rq_clock_task(cfs_rq); - struct rq *rq = rq_of(cfs_rq); - int cpu = cpu_of(rq); - int decayed; - - /* - * Track task load average for carrying it to new CPU after migrated, and - * track group sched_entity load average for task_h_load calc in migration - */ - if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) - __update_load_avg_se(now, cpu, cfs_rq, se); - - decayed = update_cfs_rq_load_avg(now, cfs_rq); - decayed |= propagate_entity_load_avg(se); - - if (decayed && (flags & UPDATE_TG)) - update_tg_load_avg(cfs_rq, 0); + return decayed; } /** @@ -3418,12 +3664,39 @@ static inline void update_load_avg(struct sched_entity *se, int flags) */ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { + u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib; + + /* + * When we attach the @se to the @cfs_rq, we must align the decay + * window because without that, really weird and wonderful things can + * happen. + * + * XXX illustrate + */ se->avg.last_update_time = cfs_rq->avg.last_update_time; - cfs_rq->avg.load_avg += se->avg.load_avg; - cfs_rq->avg.load_sum += se->avg.load_sum; + se->avg.period_contrib = cfs_rq->avg.period_contrib; + + /* + * Hell(o) Nasty stuff.. we need to recompute _sum based on the new + * period_contrib. This isn't strictly correct, but since we're + * entirely outside of the PELT hierarchy, nobody cares if we truncate + * _sum a little. + */ + se->avg.util_sum = se->avg.util_avg * divider; + + se->avg.load_sum = divider; + if (se_weight(se)) { + se->avg.load_sum = + div_u64(se->avg.load_avg * se->avg.load_sum, se_weight(se)); + } + + se->avg.runnable_load_sum = se->avg.load_sum; + + enqueue_load_avg(cfs_rq, se); cfs_rq->avg.util_avg += se->avg.util_avg; cfs_rq->avg.util_sum += se->avg.util_sum; - set_tg_cfs_propagate(cfs_rq); + + add_tg_cfs_propagate(cfs_rq, se->avg.load_sum); cfs_rq_util_change(cfs_rq); } @@ -3438,39 +3711,47 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s */ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { - - sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg); - sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum); + dequeue_load_avg(cfs_rq, se); sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg); sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum); - set_tg_cfs_propagate(cfs_rq); + + add_tg_cfs_propagate(cfs_rq, -se->avg.load_sum); cfs_rq_util_change(cfs_rq); } -/* Add the load generated by se into cfs_rq's load average */ -static inline void -enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) +/* + * Optional action to be done while updating the load average + */ +#define UPDATE_TG 0x1 +#define SKIP_AGE_LOAD 0x2 +#define DO_ATTACH 0x4 + +/* Update task and its cfs_rq load average */ +static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { - struct sched_avg *sa = &se->avg; + u64 now = cfs_rq_clock_task(cfs_rq); + struct rq *rq = rq_of(cfs_rq); + int cpu = cpu_of(rq); + int decayed; - cfs_rq->runnable_load_avg += sa->load_avg; - cfs_rq->runnable_load_sum += sa->load_sum; + /* + * Track task load average for carrying it to new CPU after migrated, and + * track group sched_entity load average for task_h_load calc in migration + */ + if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) + __update_load_avg_se(now, cpu, cfs_rq, se); + + decayed = update_cfs_rq_load_avg(now, cfs_rq); + decayed |= propagate_entity_load_avg(se); + + if (!se->avg.last_update_time && (flags & DO_ATTACH)) { - if (!sa->last_update_time) { attach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, 0); - } -} -/* Remove the runnable load generated by se from cfs_rq's runnable load average */ -static inline void -dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - cfs_rq->runnable_load_avg = - max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0); - cfs_rq->runnable_load_sum = - max_t(s64, cfs_rq->runnable_load_sum - se->avg.load_sum, 0); + } else if (decayed && (flags & UPDATE_TG)) + update_tg_load_avg(cfs_rq, 0); } #ifndef CONFIG_64BIT @@ -3514,6 +3795,7 @@ void sync_entity_load_avg(struct sched_entity *se) void remove_entity_load_avg(struct sched_entity *se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); + unsigned long flags; /* * tasks cannot exit without having gone through wake_up_new_task() -> @@ -3526,13 +3808,18 @@ void remove_entity_load_avg(struct sched_entity *se) */ sync_entity_load_avg(se); - atomic_long_add(se->avg.load_avg, &cfs_rq->removed_load_avg); - atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg); + + raw_spin_lock_irqsave(&cfs_rq->removed.lock, flags); + ++cfs_rq->removed.nr; + cfs_rq->removed.util_avg += se->avg.util_avg; + cfs_rq->removed.load_avg += se->avg.load_avg; + cfs_rq->removed.runnable_sum += se->avg.load_sum; /* == runnable_sum */ + raw_spin_unlock_irqrestore(&cfs_rq->removed.lock, flags); } static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq) { - return cfs_rq->runnable_load_avg; + return cfs_rq->avg.runnable_load_avg; } static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq) @@ -3552,16 +3839,13 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) #define UPDATE_TG 0x0 #define SKIP_AGE_LOAD 0x0 +#define DO_ATTACH 0x0 -static inline void update_load_avg(struct sched_entity *se, int not_used1) +static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int not_used1) { - cfs_rq_util_change(cfs_rq_of(se)); + cfs_rq_util_change(cfs_rq); } -static inline void -enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} -static inline void -dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} static inline void remove_entity_load_avg(struct sched_entity *se) {} static inline void @@ -3706,9 +3990,9 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * its group cfs_rq * - Add its new weight to cfs_rq->load.weight */ - update_load_avg(se, UPDATE_TG); - enqueue_entity_load_avg(cfs_rq, se); - update_cfs_shares(se); + update_load_avg(cfs_rq, se, UPDATE_TG | DO_ATTACH); + update_cfs_group(se); + enqueue_runnable_load_avg(cfs_rq, se); account_entity_enqueue(cfs_rq, se); if (flags & ENQUEUE_WAKEUP) @@ -3790,8 +4074,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * - For group entity, update its weight to reflect the new share * of its group cfs_rq. */ - update_load_avg(se, UPDATE_TG); - dequeue_entity_load_avg(cfs_rq, se); + update_load_avg(cfs_rq, se, UPDATE_TG); + dequeue_runnable_load_avg(cfs_rq, se); update_stats_dequeue(cfs_rq, se, flags); @@ -3814,7 +4098,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) /* return excess runtime on last dequeue */ return_cfs_rq_runtime(cfs_rq); - update_cfs_shares(se); + update_cfs_group(se); /* * Now advance min_vruntime if @se was the entity holding it back, @@ -3878,7 +4162,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) */ update_stats_wait_end(cfs_rq, se); __dequeue_entity(cfs_rq, se); - update_load_avg(se, UPDATE_TG); + update_load_avg(cfs_rq, se, UPDATE_TG); } update_stats_curr_start(cfs_rq, se); @@ -3980,7 +4264,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) /* Put 'current' back into the tree. */ __enqueue_entity(cfs_rq, prev); /* in !on_rq case, update occurred at dequeue */ - update_load_avg(prev, 0); + update_load_avg(cfs_rq, prev, 0); } cfs_rq->curr = NULL; } @@ -3996,8 +4280,8 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) /* * Ensure that runnable average is periodically updated. */ - update_load_avg(curr, UPDATE_TG); - update_cfs_shares(curr); + update_load_avg(cfs_rq, curr, UPDATE_TG); + update_cfs_group(curr); #ifdef CONFIG_SCHED_HRTICK /* @@ -4914,8 +5198,8 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break; - update_load_avg(se, UPDATE_TG); - update_cfs_shares(se); + update_load_avg(cfs_rq, se, UPDATE_TG); + update_cfs_group(se); } if (!se) @@ -4973,8 +5257,8 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break; - update_load_avg(se, UPDATE_TG); - update_cfs_shares(se); + update_load_avg(cfs_rq, se, UPDATE_TG); + update_cfs_group(se); } if (!se) @@ -5356,91 +5640,62 @@ static int wake_wide(struct task_struct *p) return 1; } -struct llc_stats { - unsigned long nr_running; - unsigned long load; - unsigned long capacity; - int has_capacity; -}; +/* + * The purpose of wake_affine() is to quickly determine on which CPU we can run + * soonest. For the purpose of speed we only consider the waking and previous + * CPU. + * + * wake_affine_idle() - only considers 'now', it check if the waking CPU is (or + * will be) idle. + * + * wake_affine_weight() - considers the weight to reflect the average + * scheduling latency of the CPUs. This seems to work + * for the overloaded case. + */ -static bool get_llc_stats(struct llc_stats *stats, int cpu) +static bool +wake_affine_idle(struct sched_domain *sd, struct task_struct *p, + int this_cpu, int prev_cpu, int sync) { - struct sched_domain_shared *sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); - - if (!sds) - return false; + if (idle_cpu(this_cpu)) + return true; - stats->nr_running = READ_ONCE(sds->nr_running); - stats->load = READ_ONCE(sds->load); - stats->capacity = READ_ONCE(sds->capacity); - stats->has_capacity = stats->nr_running < per_cpu(sd_llc_size, cpu); + if (sync && cpu_rq(this_cpu)->nr_running == 1) + return true; - return true; + return false; } -/* - * Can a task be moved from prev_cpu to this_cpu without causing a load - * imbalance that would trigger the load balancer? - * - * Since we're running on 'stale' values, we might in fact create an imbalance - * but recomputing these values is expensive, as that'd mean iteration 2 cache - * domains worth of CPUs. - */ static bool -wake_affine_llc(struct sched_domain *sd, struct task_struct *p, - int this_cpu, int prev_cpu, int sync) +wake_affine_weight(struct sched_domain *sd, struct task_struct *p, + int this_cpu, int prev_cpu, int sync) { - struct llc_stats prev_stats, this_stats; s64 this_eff_load, prev_eff_load; unsigned long task_load; - if (!get_llc_stats(&prev_stats, prev_cpu) || - !get_llc_stats(&this_stats, this_cpu)) - return false; + this_eff_load = target_load(this_cpu, sd->wake_idx); + prev_eff_load = source_load(prev_cpu, sd->wake_idx); - /* - * If sync wakeup then subtract the (maximum possible) - * effect of the currently running task from the load - * of the current LLC. - */ if (sync) { unsigned long current_load = task_h_load(current); - /* in this case load hits 0 and this LLC is considered 'idle' */ - if (current_load > this_stats.load) + if (current_load > this_eff_load) return true; - this_stats.load -= current_load; + this_eff_load -= current_load; } - /* - * The has_capacity stuff is not SMT aware, but by trying to balance - * the nr_running on both ends we try and fill the domain at equal - * rates, thereby first consuming cores before siblings. - */ - - /* if the old cache has capacity, stay there */ - if (prev_stats.has_capacity && prev_stats.nr_running < this_stats.nr_running+1) - return false; - - /* if this cache has capacity, come here */ - if (this_stats.has_capacity && this_stats.nr_running+1 < prev_stats.nr_running) - return true; - - /* - * Check to see if we can move the load without causing too much - * imbalance. - */ task_load = task_h_load(p); - this_eff_load = 100; - this_eff_load *= prev_stats.capacity; - - prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2; - prev_eff_load *= this_stats.capacity; + this_eff_load += task_load; + if (sched_feat(WA_BIAS)) + this_eff_load *= 100; + this_eff_load *= capacity_of(prev_cpu); - this_eff_load *= this_stats.load + task_load; - prev_eff_load *= prev_stats.load - task_load; + prev_eff_load -= task_load; + if (sched_feat(WA_BIAS)) + prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2; + prev_eff_load *= capacity_of(this_cpu); return this_eff_load <= prev_eff_load; } @@ -5449,22 +5704,13 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int prev_cpu, int sync) { int this_cpu = smp_processor_id(); - bool affine; + bool affine = false; - /* - * Default to no affine wakeups; wake_affine() should not effect a task - * placement the load-balancer feels inclined to undo. The conservative - * option is therefore to not move tasks when they wake up. - */ - affine = false; + if (sched_feat(WA_IDLE) && !affine) + affine = wake_affine_idle(sd, p, this_cpu, prev_cpu, sync); - /* - * If the wakeup is across cache domains, try to evaluate if movement - * makes sense, otherwise rely on select_idle_siblings() to do - * placement inside the cache domain. - */ - if (!cpus_share_cache(prev_cpu, this_cpu)) - affine = wake_affine_llc(sd, p, this_cpu, prev_cpu, sync); + if (sched_feat(WA_WEIGHT) && !affine) + affine = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync); schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts); if (affine) { @@ -5486,6 +5732,8 @@ static unsigned long capacity_spare_wake(int cpu, struct task_struct *p) /* * find_idlest_group finds and returns the least busy CPU group within the * domain. + * + * Assumes p is allowed on at least one CPU in sd. */ static struct sched_group * find_idlest_group(struct sched_domain *sd, struct task_struct *p, @@ -5493,8 +5741,9 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, { struct sched_group *idlest = NULL, *group = sd->groups; struct sched_group *most_spare_sg = NULL; - unsigned long min_runnable_load = ULONG_MAX, this_runnable_load = 0; - unsigned long min_avg_load = ULONG_MAX, this_avg_load = 0; + unsigned long min_runnable_load = ULONG_MAX; + unsigned long this_runnable_load = ULONG_MAX; + unsigned long min_avg_load = ULONG_MAX, this_avg_load = ULONG_MAX; unsigned long most_spare = 0, this_spare = 0; int load_idx = sd->forkexec_idx; int imbalance_scale = 100 + (sd->imbalance_pct-100)/2; @@ -5615,10 +5864,10 @@ skip_spare: } /* - * find_idlest_cpu - find the idlest cpu among the cpus in group. + * find_idlest_group_cpu - find the idlest cpu among the cpus in group. */ static int -find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) +find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) { unsigned long load, min_load = ULONG_MAX; unsigned int min_exit_latency = UINT_MAX; @@ -5667,6 +5916,53 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu; } +static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p, + int cpu, int prev_cpu, int sd_flag) +{ + int new_cpu = cpu; + + if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed)) + return prev_cpu; + + while (sd) { + struct sched_group *group; + struct sched_domain *tmp; + int weight; + + if (!(sd->flags & sd_flag)) { + sd = sd->child; + continue; + } + + group = find_idlest_group(sd, p, cpu, sd_flag); + if (!group) { + sd = sd->child; + continue; + } + + new_cpu = find_idlest_group_cpu(group, p, cpu); + if (new_cpu == cpu) { + /* Now try balancing at a lower domain level of cpu */ + sd = sd->child; + continue; + } + + /* Now try balancing at a lower domain level of new_cpu */ + cpu = new_cpu; + weight = sd->span_weight; + sd = NULL; + for_each_domain(cpu, tmp) { + if (weight <= tmp->span_weight) + break; + if (tmp->flags & sd_flag) + sd = tmp; + } + /* while loop will break here if sd == NULL */ + } + + return new_cpu; +} + #ifdef CONFIG_SCHED_SMT static inline void set_idle_cores(int cpu, int val) @@ -6019,50 +6315,30 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f new_cpu = cpu; } + if (sd && !(sd_flag & SD_BALANCE_FORK)) { + /* + * We're going to need the task's util for capacity_spare_wake + * in find_idlest_group. Sync it up to prev_cpu's + * last_update_time. + */ + sync_entity_load_avg(&p->se); + } + if (!sd) { - pick_cpu: +pick_cpu: if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); - } else while (sd) { - struct sched_group *group; - int weight; - - if (!(sd->flags & sd_flag)) { - sd = sd->child; - continue; - } - - group = find_idlest_group(sd, p, cpu, sd_flag); - if (!group) { - sd = sd->child; - continue; - } - - new_cpu = find_idlest_cpu(group, p, cpu); - if (new_cpu == -1 || new_cpu == cpu) { - /* Now try balancing at a lower domain level of cpu */ - sd = sd->child; - continue; - } - - /* Now try balancing at a lower domain level of new_cpu */ - cpu = new_cpu; - weight = sd->span_weight; - sd = NULL; - for_each_domain(cpu, tmp) { - if (weight <= tmp->span_weight) - break; - if (tmp->flags & sd_flag) - sd = tmp; - } - /* while loop will break here if sd == NULL */ + } else { + new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag); } rcu_read_unlock(); return new_cpu; } +static void detach_entity_cfs_rq(struct sched_entity *se); + /* * Called immediately before a task is migrated to a new cpu; task_cpu(p) and * cfs_rq_of(p) references at time of call are still valid and identify the @@ -6096,14 +6372,25 @@ static void migrate_task_rq_fair(struct task_struct *p) se->vruntime -= min_vruntime; } - /* - * We are supposed to update the task to "current" time, then its up to date - * and ready to go to new CPU/cfs_rq. But we have difficulty in getting - * what current time is, so simply throw away the out-of-date time. This - * will result in the wakee task is less decayed, but giving the wakee more - * load sounds not bad. - */ - remove_entity_load_avg(&p->se); + if (p->on_rq == TASK_ON_RQ_MIGRATING) { + /* + * In case of TASK_ON_RQ_MIGRATING we in fact hold the 'old' + * rq->lock and can modify state directly. + */ + lockdep_assert_held(&task_rq(p)->lock); + detach_entity_cfs_rq(&p->se); + + } else { + /* + * We are supposed to update the task to "current" time, then + * its up to date and ready to go to new CPU/cfs_rq. But we + * have difficulty in getting what current time is, so simply + * throw away the out-of-date time. This will result in the + * wakee task is less decayed, but giving the wakee more load + * sounds not bad. + */ + remove_entity_load_avg(&p->se); + } /* Tell new CPU we are migrated */ p->se.avg.last_update_time = 0; @@ -6371,10 +6658,7 @@ again: set_next_entity(cfs_rq, se); } - if (hrtick_enabled(rq)) - hrtick_start_fair(rq, p); - - return p; + goto done; simple: #endif @@ -6388,6 +6672,16 @@ simple: p = task_of(se); +done: __maybe_unused +#ifdef CONFIG_SMP + /* + * Move the next running task to the front of + * the list, so our cfs_tasks list becomes MRU + * one. + */ + list_move(&p->se.group_node, &rq->cfs_tasks); +#endif + if (hrtick_enabled(rq)) hrtick_start_fair(rq, p); @@ -6823,11 +7117,12 @@ static void detach_task(struct task_struct *p, struct lb_env *env) */ static struct task_struct *detach_one_task(struct lb_env *env) { - struct task_struct *p, *n; + struct task_struct *p; lockdep_assert_held(&env->src_rq->lock); - list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) { + list_for_each_entry_reverse(p, + &env->src_rq->cfs_tasks, se.group_node) { if (!can_migrate_task(p, env)) continue; @@ -6873,7 +7168,7 @@ static int detach_tasks(struct lb_env *env) if (env->idle != CPU_NOT_IDLE && env->src_rq->nr_running <= 1) break; - p = list_first_entry(tasks, struct task_struct, se.group_node); + p = list_last_entry(tasks, struct task_struct, se.group_node); env->loop++; /* We've more or less seen every task there is, call it quits */ @@ -6923,7 +7218,7 @@ static int detach_tasks(struct lb_env *env) continue; next: - list_move_tail(&p->se.group_node, tasks); + list_move(&p->se.group_node, tasks); } /* @@ -6999,7 +7294,7 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) if (cfs_rq->avg.util_sum) return false; - if (cfs_rq->runnable_load_sum) + if (cfs_rq->avg.runnable_load_sum) return false; return true; @@ -7031,7 +7326,7 @@ static void update_blocked_averages(int cpu) /* Propagate pending load changes to the parent, if any: */ se = cfs_rq->tg->se[cpu]; if (se && !skip_blocked_update(se)) - update_load_avg(se, 0); + update_load_avg(cfs_rq_of(se), se, 0); /* * There can be a lot of idle CPU cgroups. Don't let fully @@ -7600,7 +7895,6 @@ static inline enum fbq_type fbq_classify_rq(struct rq *rq) */ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds) { - struct sched_domain_shared *shared = env->sd->shared; struct sched_domain *child = env->sd->child; struct sched_group *sg = env->sd->groups; struct sg_lb_stats *local = &sds->local_stat; @@ -7672,22 +7966,6 @@ next_group: if (env->dst_rq->rd->overload != overload) env->dst_rq->rd->overload = overload; } - - if (!shared) - return; - - /* - * Since these are sums over groups they can contain some CPUs - * multiple times for the NUMA domains. - * - * Currently only wake_affine_llc() and find_busiest_group() - * uses these numbers, only the last is affected by this problem. - * - * XXX fix that. - */ - WRITE_ONCE(shared->nr_running, sds->total_running); - WRITE_ONCE(shared->load, sds->total_load); - WRITE_ONCE(shared->capacity, sds->total_capacity); } /** @@ -7929,8 +8207,11 @@ static struct sched_group *find_busiest_group(struct lb_env *env) if (busiest->group_type == group_imbalanced) goto force_balance; - /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */ - if (env->idle == CPU_NEWLY_IDLE && group_has_capacity(env, local) && + /* + * When dst_cpu is idle, prevent SMP nice and/or asymmetric group + * capacities from resulting in underutilization due to avg_load. + */ + if (env->idle != CPU_NOT_IDLE && group_has_capacity(env, local) && busiest->group_no_capacity) goto force_balance; @@ -8098,6 +8379,13 @@ static int should_we_balance(struct lb_env *env) int cpu, balance_cpu = -1; /* + * Ensure the balancing environment is consistent; can happen + * when the softirq triggers 'during' hotplug. + */ + if (!cpumask_test_cpu(env->dst_cpu, env->cpus)) + return 0; + + /* * In the newly idle case, we will allow all the cpu's * to do the newly idle load balance. */ @@ -8740,7 +9028,7 @@ void nohz_balance_enter_idle(int cpu) return; /* Spare idle load balancing on CPUs that don't want to be disturbed: */ - if (!is_housekeeping_cpu(cpu)) + if (!housekeeping_cpu(cpu, HK_FLAG_SCHED)) return; if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu))) @@ -9205,7 +9493,7 @@ static void propagate_entity_cfs_rq(struct sched_entity *se) if (cfs_rq_throttled(cfs_rq)) break; - update_load_avg(se, UPDATE_TG); + update_load_avg(cfs_rq, se, UPDATE_TG); } } #else @@ -9217,7 +9505,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se) struct cfs_rq *cfs_rq = cfs_rq_of(se); /* Catch up with the cfs_rq and remove our load when we leave */ - update_load_avg(se, 0); + update_load_avg(cfs_rq, se, 0); detach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, false); propagate_entity_cfs_rq(se); @@ -9236,7 +9524,7 @@ static void attach_entity_cfs_rq(struct sched_entity *se) #endif /* Synchronize entity with its cfs_rq */ - update_load_avg(se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); + update_load_avg(cfs_rq, se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); attach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, false); propagate_entity_cfs_rq(se); @@ -9318,11 +9606,7 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; #endif #ifdef CONFIG_SMP -#ifdef CONFIG_FAIR_GROUP_SCHED - cfs_rq->propagate_avg = 0; -#endif - atomic_long_set(&cfs_rq->removed_load_avg, 0); - atomic_long_set(&cfs_rq->removed_util_avg, 0); + raw_spin_lock_init(&cfs_rq->removed.lock); #endif } @@ -9520,8 +9804,8 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) rq_lock_irqsave(rq, &rf); update_rq_clock(rq); for_each_sched_entity(se) { - update_load_avg(se, UPDATE_TG); - update_cfs_shares(se); + update_load_avg(cfs_rq_of(se), se, UPDATE_TG); + update_cfs_group(se); } rq_unlock_irqrestore(rq, &rf); } diff --git a/kernel/sched/features.h b/kernel/sched/features.h index d3fb15555291..9552fd5854bf 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Only give sleepers 50% of their service deficit. This allows * them to run sooner, but does not allow tons of sleepers to @@ -81,3 +82,6 @@ SCHED_FEAT(RT_RUNTIME_SHARE, true) SCHED_FEAT(LB_MIN, false) SCHED_FEAT(ATTACH_AGE_LOAD, true) +SCHED_FEAT(WA_IDLE, true) +SCHED_FEAT(WA_WEIGHT, true) +SCHED_FEAT(WA_BIAS, true) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 257f4f0b4532..7dae9eb8c042 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -209,6 +209,7 @@ exit_idle: */ static void do_idle(void) { + int cpu = smp_processor_id(); /* * If the arch has a polling bit, we maintain an invariant: * @@ -219,14 +220,13 @@ static void do_idle(void) */ __current_set_polling(); - quiet_vmstat(); tick_nohz_idle_enter(); while (!need_resched()) { check_pgt_cache(); rmb(); - if (cpu_is_offline(smp_processor_id())) { + if (cpu_is_offline(cpu)) { cpuhp_report_idle_dead(); arch_cpu_idle_dead(); } diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index 0c00172db63e..d518664cce4f 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "sched.h" /* diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c new file mode 100644 index 000000000000..b71b436f59f2 --- /dev/null +++ b/kernel/sched/isolation.c @@ -0,0 +1,155 @@ +/* + * Housekeeping management. Manage the targets for routine code that can run on + * any CPU: unbound workqueues, timers, kthreads and any offloadable work. + * + * Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker + * + */ + +#include <linux/sched/isolation.h> +#include <linux/tick.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/static_key.h> +#include <linux/ctype.h> + +DEFINE_STATIC_KEY_FALSE(housekeeping_overriden); +EXPORT_SYMBOL_GPL(housekeeping_overriden); +static cpumask_var_t housekeeping_mask; +static unsigned int housekeeping_flags; + +int housekeeping_any_cpu(enum hk_flags flags) +{ + if (static_branch_unlikely(&housekeeping_overriden)) + if (housekeeping_flags & flags) + return cpumask_any_and(housekeeping_mask, cpu_online_mask); + return smp_processor_id(); +} +EXPORT_SYMBOL_GPL(housekeeping_any_cpu); + +const struct cpumask *housekeeping_cpumask(enum hk_flags flags) +{ + if (static_branch_unlikely(&housekeeping_overriden)) + if (housekeeping_flags & flags) + return housekeeping_mask; + return cpu_possible_mask; +} +EXPORT_SYMBOL_GPL(housekeeping_cpumask); + +void housekeeping_affine(struct task_struct *t, enum hk_flags flags) +{ + if (static_branch_unlikely(&housekeeping_overriden)) + if (housekeeping_flags & flags) + set_cpus_allowed_ptr(t, housekeeping_mask); +} +EXPORT_SYMBOL_GPL(housekeeping_affine); + +bool housekeeping_test_cpu(int cpu, enum hk_flags flags) +{ + if (static_branch_unlikely(&housekeeping_overriden)) + if (housekeeping_flags & flags) + return cpumask_test_cpu(cpu, housekeeping_mask); + return true; +} +EXPORT_SYMBOL_GPL(housekeeping_test_cpu); + +void __init housekeeping_init(void) +{ + if (!housekeeping_flags) + return; + + static_branch_enable(&housekeeping_overriden); + + /* We need at least one CPU to handle housekeeping work */ + WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); +} + +static int __init housekeeping_setup(char *str, enum hk_flags flags) +{ + cpumask_var_t non_housekeeping_mask; + int err; + + alloc_bootmem_cpumask_var(&non_housekeeping_mask); + err = cpulist_parse(str, non_housekeeping_mask); + if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) { + pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); + free_bootmem_cpumask_var(non_housekeeping_mask); + return 0; + } + + if (!housekeeping_flags) { + alloc_bootmem_cpumask_var(&housekeeping_mask); + cpumask_andnot(housekeeping_mask, + cpu_possible_mask, non_housekeeping_mask); + if (cpumask_empty(housekeeping_mask)) + cpumask_set_cpu(smp_processor_id(), housekeeping_mask); + } else { + cpumask_var_t tmp; + + alloc_bootmem_cpumask_var(&tmp); + cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask); + if (!cpumask_equal(tmp, housekeeping_mask)) { + pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); + free_bootmem_cpumask_var(tmp); + free_bootmem_cpumask_var(non_housekeeping_mask); + return 0; + } + free_bootmem_cpumask_var(tmp); + } + + if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { + if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { + tick_nohz_full_setup(non_housekeeping_mask); + } else { + pr_warn("Housekeeping: nohz unsupported." + " Build with CONFIG_NO_HZ_FULL\n"); + free_bootmem_cpumask_var(non_housekeeping_mask); + return 0; + } + } + + housekeeping_flags |= flags; + + free_bootmem_cpumask_var(non_housekeeping_mask); + + return 1; +} + +static int __init housekeeping_nohz_full_setup(char *str) +{ + unsigned int flags; + + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC; + + return housekeeping_setup(str, flags); +} +__setup("nohz_full=", housekeeping_nohz_full_setup); + +static int __init housekeeping_isolcpus_setup(char *str) +{ + unsigned int flags = 0; + + while (isalpha(*str)) { + if (!strncmp(str, "nohz,", 5)) { + str += 5; + flags |= HK_FLAG_TICK; + continue; + } + + if (!strncmp(str, "domain,", 7)) { + str += 7; + flags |= HK_FLAG_DOMAIN; + continue; + } + + pr_warn("isolcpus: Error, unknown flag\n"); + return 0; + } + + /* Default behaviour for isolcpus without flags */ + if (!flags) + flags |= HK_FLAG_DOMAIN; + + return housekeeping_setup(str, flags); +} +__setup("isolcpus=", housekeeping_isolcpus_setup); diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c index f14716a3522f..89a989e4d758 100644 --- a/kernel/sched/loadavg.c +++ b/kernel/sched/loadavg.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * kernel/sched/loadavg.c * diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index a92fddc22747..dd7908743dab 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -18,6 +18,7 @@ #include <linux/membarrier.h> #include <linux/tick.h> #include <linux/cpumask.h> +#include <linux/atomic.h> #include "sched.h" /* for cpu_rq(). */ @@ -26,21 +27,26 @@ * except MEMBARRIER_CMD_QUERY. */ #define MEMBARRIER_CMD_BITMASK \ - (MEMBARRIER_CMD_SHARED | MEMBARRIER_CMD_PRIVATE_EXPEDITED) + (MEMBARRIER_CMD_SHARED | MEMBARRIER_CMD_PRIVATE_EXPEDITED \ + | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED) static void ipi_mb(void *info) { smp_mb(); /* IPIs should be serializing but paranoid. */ } -static void membarrier_private_expedited(void) +static int membarrier_private_expedited(void) { int cpu; bool fallback = false; cpumask_var_t tmpmask; + if (!(atomic_read(¤t->mm->membarrier_state) + & MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY)) + return -EPERM; + if (num_online_cpus() == 1) - return; + return 0; /* * Matches memory barriers around rq->curr modification in @@ -94,6 +100,24 @@ static void membarrier_private_expedited(void) * rq->curr modification in scheduler. */ smp_mb(); /* exit from system call is not a mb */ + return 0; +} + +static void membarrier_register_private_expedited(void) +{ + struct task_struct *p = current; + struct mm_struct *mm = p->mm; + + /* + * We need to consider threads belonging to different thread + * groups, which use the same mm. (CLONE_VM but not + * CLONE_THREAD). + */ + if (atomic_read(&mm->membarrier_state) + & MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY) + return; + atomic_or(MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY, + &mm->membarrier_state); } /** @@ -144,7 +168,9 @@ SYSCALL_DEFINE2(membarrier, int, cmd, int, flags) synchronize_sched(); return 0; case MEMBARRIER_CMD_PRIVATE_EXPEDITED: - membarrier_private_expedited(); + return membarrier_private_expedited(); + case MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED: + membarrier_register_private_expedited(); return 0; default: return -EINVAL; diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 0af5ca9e3e3f..d8c43d73e078 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR * policies) @@ -73,10 +74,6 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b) raw_spin_unlock(&rt_b->rt_runtime_lock); } -#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI) -static void push_irq_work_func(struct irq_work *work); -#endif - void init_rt_rq(struct rt_rq *rt_rq) { struct rt_prio_array *array; @@ -96,13 +93,6 @@ void init_rt_rq(struct rt_rq *rt_rq) rt_rq->rt_nr_migratory = 0; rt_rq->overloaded = 0; plist_head_init(&rt_rq->pushable_tasks); - -#ifdef HAVE_RT_PUSH_IPI - rt_rq->push_flags = 0; - rt_rq->push_cpu = nr_cpu_ids; - raw_spin_lock_init(&rt_rq->push_lock); - init_irq_work(&rt_rq->push_work, push_irq_work_func); -#endif #endif /* CONFIG_SMP */ /* We start is dequeued state, because no RT tasks are queued */ rt_rq->rt_queued = 0; @@ -1875,241 +1865,166 @@ static void push_rt_tasks(struct rq *rq) } #ifdef HAVE_RT_PUSH_IPI + /* - * The search for the next cpu always starts at rq->cpu and ends - * when we reach rq->cpu again. It will never return rq->cpu. - * This returns the next cpu to check, or nr_cpu_ids if the loop - * is complete. + * When a high priority task schedules out from a CPU and a lower priority + * task is scheduled in, a check is made to see if there's any RT tasks + * on other CPUs that are waiting to run because a higher priority RT task + * is currently running on its CPU. In this case, the CPU with multiple RT + * tasks queued on it (overloaded) needs to be notified that a CPU has opened + * up that may be able to run one of its non-running queued RT tasks. + * + * All CPUs with overloaded RT tasks need to be notified as there is currently + * no way to know which of these CPUs have the highest priority task waiting + * to run. Instead of trying to take a spinlock on each of these CPUs, + * which has shown to cause large latency when done on machines with many + * CPUs, sending an IPI to the CPUs to have them push off the overloaded + * RT tasks waiting to run. + * + * Just sending an IPI to each of the CPUs is also an issue, as on large + * count CPU machines, this can cause an IPI storm on a CPU, especially + * if its the only CPU with multiple RT tasks queued, and a large number + * of CPUs scheduling a lower priority task at the same time. + * + * Each root domain has its own irq work function that can iterate over + * all CPUs with RT overloaded tasks. Since all CPUs with overloaded RT + * tassk must be checked if there's one or many CPUs that are lowering + * their priority, there's a single irq work iterator that will try to + * push off RT tasks that are waiting to run. + * + * When a CPU schedules a lower priority task, it will kick off the + * irq work iterator that will jump to each CPU with overloaded RT tasks. + * As it only takes the first CPU that schedules a lower priority task + * to start the process, the rto_start variable is incremented and if + * the atomic result is one, then that CPU will try to take the rto_lock. + * This prevents high contention on the lock as the process handles all + * CPUs scheduling lower priority tasks. + * + * All CPUs that are scheduling a lower priority task will increment the + * rt_loop_next variable. This will make sure that the irq work iterator + * checks all RT overloaded CPUs whenever a CPU schedules a new lower + * priority task, even if the iterator is in the middle of a scan. Incrementing + * the rt_loop_next will cause the iterator to perform another scan. * - * rq->rt.push_cpu holds the last cpu returned by this function, - * or if this is the first instance, it must hold rq->cpu. */ static int rto_next_cpu(struct rq *rq) { - int prev_cpu = rq->rt.push_cpu; + struct root_domain *rd = rq->rd; + int next; int cpu; - cpu = cpumask_next(prev_cpu, rq->rd->rto_mask); - /* - * If the previous cpu is less than the rq's CPU, then it already - * passed the end of the mask, and has started from the beginning. - * We end if the next CPU is greater or equal to rq's CPU. + * When starting the IPI RT pushing, the rto_cpu is set to -1, + * rt_next_cpu() will simply return the first CPU found in + * the rto_mask. + * + * If rto_next_cpu() is called with rto_cpu is a valid cpu, it + * will return the next CPU found in the rto_mask. + * + * If there are no more CPUs left in the rto_mask, then a check is made + * against rto_loop and rto_loop_next. rto_loop is only updated with + * the rto_lock held, but any CPU may increment the rto_loop_next + * without any locking. */ - if (prev_cpu < rq->cpu) { - if (cpu >= rq->cpu) - return nr_cpu_ids; + for (;;) { - } else if (cpu >= nr_cpu_ids) { - /* - * We passed the end of the mask, start at the beginning. - * If the result is greater or equal to the rq's CPU, then - * the loop is finished. - */ - cpu = cpumask_first(rq->rd->rto_mask); - if (cpu >= rq->cpu) - return nr_cpu_ids; - } - rq->rt.push_cpu = cpu; + /* When rto_cpu is -1 this acts like cpumask_first() */ + cpu = cpumask_next(rd->rto_cpu, rd->rto_mask); - /* Return cpu to let the caller know if the loop is finished or not */ - return cpu; -} + rd->rto_cpu = cpu; -static int find_next_push_cpu(struct rq *rq) -{ - struct rq *next_rq; - int cpu; + if (cpu < nr_cpu_ids) + return cpu; - while (1) { - cpu = rto_next_cpu(rq); - if (cpu >= nr_cpu_ids) - break; - next_rq = cpu_rq(cpu); + rd->rto_cpu = -1; + + /* + * ACQUIRE ensures we see the @rto_mask changes + * made prior to the @next value observed. + * + * Matches WMB in rt_set_overload(). + */ + next = atomic_read_acquire(&rd->rto_loop_next); - /* Make sure the next rq can push to this rq */ - if (next_rq->rt.highest_prio.next < rq->rt.highest_prio.curr) + if (rd->rto_loop == next) break; + + rd->rto_loop = next; } - return cpu; + return -1; } -#define RT_PUSH_IPI_EXECUTING 1 -#define RT_PUSH_IPI_RESTART 2 +static inline bool rto_start_trylock(atomic_t *v) +{ + return !atomic_cmpxchg_acquire(v, 0, 1); +} -/* - * When a high priority task schedules out from a CPU and a lower priority - * task is scheduled in, a check is made to see if there's any RT tasks - * on other CPUs that are waiting to run because a higher priority RT task - * is currently running on its CPU. In this case, the CPU with multiple RT - * tasks queued on it (overloaded) needs to be notified that a CPU has opened - * up that may be able to run one of its non-running queued RT tasks. - * - * On large CPU boxes, there's the case that several CPUs could schedule - * a lower priority task at the same time, in which case it will look for - * any overloaded CPUs that it could pull a task from. To do this, the runqueue - * lock must be taken from that overloaded CPU. Having 10s of CPUs all fighting - * for a single overloaded CPU's runqueue lock can produce a large latency. - * (This has actually been observed on large boxes running cyclictest). - * Instead of taking the runqueue lock of the overloaded CPU, each of the - * CPUs that scheduled a lower priority task simply sends an IPI to the - * overloaded CPU. An IPI is much cheaper than taking an runqueue lock with - * lots of contention. The overloaded CPU will look to push its non-running - * RT task off, and if it does, it can then ignore the other IPIs coming - * in, and just pass those IPIs off to any other overloaded CPU. - * - * When a CPU schedules a lower priority task, it only sends an IPI to - * the "next" CPU that has overloaded RT tasks. This prevents IPI storms, - * as having 10 CPUs scheduling lower priority tasks and 10 CPUs with - * RT overloaded tasks, would cause 100 IPIs to go out at once. - * - * The overloaded RT CPU, when receiving an IPI, will try to push off its - * overloaded RT tasks and then send an IPI to the next CPU that has - * overloaded RT tasks. This stops when all CPUs with overloaded RT tasks - * have completed. Just because a CPU may have pushed off its own overloaded - * RT task does not mean it should stop sending the IPI around to other - * overloaded CPUs. There may be another RT task waiting to run on one of - * those CPUs that are of higher priority than the one that was just - * pushed. - * - * An optimization that could possibly be made is to make a CPU array similar - * to the cpupri array mask of all running RT tasks, but for the overloaded - * case, then the IPI could be sent to only the CPU with the highest priority - * RT task waiting, and that CPU could send off further IPIs to the CPU with - * the next highest waiting task. Since the overloaded case is much less likely - * to happen, the complexity of this implementation may not be worth it. - * Instead, just send an IPI around to all overloaded CPUs. - * - * The rq->rt.push_flags holds the status of the IPI that is going around. - * A run queue can only send out a single IPI at a time. The possible flags - * for rq->rt.push_flags are: - * - * (None or zero): No IPI is going around for the current rq - * RT_PUSH_IPI_EXECUTING: An IPI for the rq is being passed around - * RT_PUSH_IPI_RESTART: The priority of the running task for the rq - * has changed, and the IPI should restart - * circulating the overloaded CPUs again. - * - * rq->rt.push_cpu contains the CPU that is being sent the IPI. It is updated - * before sending to the next CPU. - * - * Instead of having all CPUs that schedule a lower priority task send - * an IPI to the same "first" CPU in the RT overload mask, they send it - * to the next overloaded CPU after their own CPU. This helps distribute - * the work when there's more than one overloaded CPU and multiple CPUs - * scheduling in lower priority tasks. - * - * When a rq schedules a lower priority task than what was currently - * running, the next CPU with overloaded RT tasks is examined first. - * That is, if CPU 1 and 5 are overloaded, and CPU 3 schedules a lower - * priority task, it will send an IPI first to CPU 5, then CPU 5 will - * send to CPU 1 if it is still overloaded. CPU 1 will clear the - * rq->rt.push_flags if RT_PUSH_IPI_RESTART is not set. - * - * The first CPU to notice IPI_RESTART is set, will clear that flag and then - * send an IPI to the next overloaded CPU after the rq->cpu and not the next - * CPU after push_cpu. That is, if CPU 1, 4 and 5 are overloaded when CPU 3 - * schedules a lower priority task, and the IPI_RESTART gets set while the - * handling is being done on CPU 5, it will clear the flag and send it back to - * CPU 4 instead of CPU 1. - * - * Note, the above logic can be disabled by turning off the sched_feature - * RT_PUSH_IPI. Then the rq lock of the overloaded CPU will simply be - * taken by the CPU requesting a pull and the waiting RT task will be pulled - * by that CPU. This may be fine for machines with few CPUs. - */ -static void tell_cpu_to_push(struct rq *rq) +static inline void rto_start_unlock(atomic_t *v) { - int cpu; + atomic_set_release(v, 0); +} - if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { - raw_spin_lock(&rq->rt.push_lock); - /* Make sure it's still executing */ - if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { - /* - * Tell the IPI to restart the loop as things have - * changed since it started. - */ - rq->rt.push_flags |= RT_PUSH_IPI_RESTART; - raw_spin_unlock(&rq->rt.push_lock); - return; - } - raw_spin_unlock(&rq->rt.push_lock); - } +static void tell_cpu_to_push(struct rq *rq) +{ + int cpu = -1; - /* When here, there's no IPI going around */ + /* Keep the loop going if the IPI is currently active */ + atomic_inc(&rq->rd->rto_loop_next); - rq->rt.push_cpu = rq->cpu; - cpu = find_next_push_cpu(rq); - if (cpu >= nr_cpu_ids) + /* Only one CPU can initiate a loop at a time */ + if (!rto_start_trylock(&rq->rd->rto_loop_start)) return; - rq->rt.push_flags = RT_PUSH_IPI_EXECUTING; + raw_spin_lock(&rq->rd->rto_lock); + + /* + * The rto_cpu is updated under the lock, if it has a valid cpu + * then the IPI is still running and will continue due to the + * update to loop_next, and nothing needs to be done here. + * Otherwise it is finishing up and an ipi needs to be sent. + */ + if (rq->rd->rto_cpu < 0) + cpu = rto_next_cpu(rq); - irq_work_queue_on(&rq->rt.push_work, cpu); + raw_spin_unlock(&rq->rd->rto_lock); + + rto_start_unlock(&rq->rd->rto_loop_start); + + if (cpu >= 0) + irq_work_queue_on(&rq->rd->rto_push_work, cpu); } /* Called from hardirq context */ -static void try_to_push_tasks(void *arg) +void rto_push_irq_work_func(struct irq_work *work) { - struct rt_rq *rt_rq = arg; - struct rq *rq, *src_rq; - int this_cpu; + struct rq *rq; int cpu; - this_cpu = rt_rq->push_cpu; + rq = this_rq(); - /* Paranoid check */ - BUG_ON(this_cpu != smp_processor_id()); - - rq = cpu_rq(this_cpu); - src_rq = rq_of_rt_rq(rt_rq); - -again: + /* + * We do not need to grab the lock to check for has_pushable_tasks. + * When it gets updated, a check is made if a push is possible. + */ if (has_pushable_tasks(rq)) { raw_spin_lock(&rq->lock); - push_rt_task(rq); + push_rt_tasks(rq); raw_spin_unlock(&rq->lock); } - /* Pass the IPI to the next rt overloaded queue */ - raw_spin_lock(&rt_rq->push_lock); - /* - * If the source queue changed since the IPI went out, - * we need to restart the search from that CPU again. - */ - if (rt_rq->push_flags & RT_PUSH_IPI_RESTART) { - rt_rq->push_flags &= ~RT_PUSH_IPI_RESTART; - rt_rq->push_cpu = src_rq->cpu; - } + raw_spin_lock(&rq->rd->rto_lock); - cpu = find_next_push_cpu(src_rq); + /* Pass the IPI to the next rt overloaded queue */ + cpu = rto_next_cpu(rq); - if (cpu >= nr_cpu_ids) - rt_rq->push_flags &= ~RT_PUSH_IPI_EXECUTING; - raw_spin_unlock(&rt_rq->push_lock); + raw_spin_unlock(&rq->rd->rto_lock); - if (cpu >= nr_cpu_ids) + if (cpu < 0) return; - /* - * It is possible that a restart caused this CPU to be - * chosen again. Don't bother with an IPI, just see if we - * have more to push. - */ - if (unlikely(cpu == rq->cpu)) - goto again; - /* Try the next RT overloaded CPU */ - irq_work_queue_on(&rt_rq->push_work, cpu); -} - -static void push_irq_work_func(struct irq_work *work) -{ - struct rt_rq *rt_rq = container_of(work, struct rt_rq, push_work); - - try_to_push_tasks(rt_rq); + irq_work_queue_on(&rq->rd->rto_push_work, cpu); } #endif /* HAVE_RT_PUSH_IPI */ diff --git a/kernel/sched/sched-pelt.h b/kernel/sched/sched-pelt.h index cd200d16529e..a26473674fb7 100644 --- a/kernel/sched/sched-pelt.h +++ b/kernel/sched/sched-pelt.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* Generated by Documentation/scheduler/sched-pelt; do not modify. */ static const u32 runnable_avg_yN_inv[] = { diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 14db76cd496f..45ab0bf564e7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #include <linux/sched.h> #include <linux/sched/autogroup.h> @@ -226,7 +227,7 @@ struct dl_bw { static inline void __dl_update(struct dl_bw *dl_b, s64 bw); static inline -void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw, int cpus) +void __dl_sub(struct dl_bw *dl_b, u64 tsk_bw, int cpus) { dl_b->total_bw -= tsk_bw; __dl_update(dl_b, (s32)tsk_bw / cpus); @@ -255,7 +256,6 @@ extern int sched_dl_overflow(struct task_struct *p, int policy, extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); extern bool __checkparam_dl(const struct sched_attr *attr); -extern void __dl_clear_params(struct task_struct *p); extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); extern int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); @@ -418,6 +418,7 @@ struct cfs_bandwidth { }; /* CFS-related fields in a runqueue */ struct cfs_rq { struct load_weight load; + unsigned long runnable_weight; unsigned int nr_running, h_nr_running; u64 exec_clock; @@ -443,18 +444,22 @@ struct cfs_rq { * CFS load tracking */ struct sched_avg avg; - u64 runnable_load_sum; - unsigned long runnable_load_avg; -#ifdef CONFIG_FAIR_GROUP_SCHED - unsigned long tg_load_avg_contrib; - unsigned long propagate_avg; -#endif - atomic_long_t removed_load_avg, removed_util_avg; #ifndef CONFIG_64BIT u64 load_last_update_time_copy; #endif + struct { + raw_spinlock_t lock ____cacheline_aligned; + int nr; + unsigned long load_avg; + unsigned long util_avg; + unsigned long runnable_sum; + } removed; #ifdef CONFIG_FAIR_GROUP_SCHED + unsigned long tg_load_avg_contrib; + long propagate; + long prop_runnable_sum; + /* * h_load = weight * f(tg) * @@ -501,7 +506,7 @@ static inline int rt_bandwidth_enabled(void) } /* RT IPI pull logic requires IRQ_WORK */ -#ifdef CONFIG_IRQ_WORK +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) # define HAVE_RT_PUSH_IPI #endif @@ -523,12 +528,6 @@ struct rt_rq { unsigned long rt_nr_total; int overloaded; struct plist_head pushable_tasks; -#ifdef HAVE_RT_PUSH_IPI - int push_flags; - int push_cpu; - struct irq_work push_work; - raw_spinlock_t push_lock; -#endif #endif /* CONFIG_SMP */ int rt_queued; @@ -637,6 +636,19 @@ struct root_domain { struct dl_bw dl_bw; struct cpudl cpudl; +#ifdef HAVE_RT_PUSH_IPI + /* + * For IPI pull requests, loop across the rto_mask. + */ + struct irq_work rto_push_work; + raw_spinlock_t rto_lock; + /* These are only updated and read within rto_lock */ + int rto_loop; + int rto_cpu; + /* These atomics are updated outside of a lock */ + atomic_t rto_loop_next; + atomic_t rto_loop_start; +#endif /* * The "RT overload" flag: it gets set if a CPU has more than * one runnable RT task. @@ -654,6 +666,9 @@ extern void init_defrootdomain(void); extern int sched_init_domains(const struct cpumask *cpu_map); extern void rq_attach_root(struct rq *rq, struct root_domain *rd); +#ifdef HAVE_RT_PUSH_IPI +extern void rto_push_irq_work_func(struct irq_work *work); +#endif #endif /* CONFIG_SMP */ /* @@ -1218,8 +1233,6 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) # define const_debug const #endif -extern const_debug unsigned int sysctl_sched_features; - #define SCHED_FEAT(name, enabled) \ __SCHED_FEAT_##name , @@ -1231,6 +1244,13 @@ enum { #undef SCHED_FEAT #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) + +/* + * To support run-time toggling of sched features, all the translation units + * (but core.c) reference the sysctl_sched_features defined in core.c. + */ +extern const_debug unsigned int sysctl_sched_features; + #define SCHED_FEAT(name, enabled) \ static __always_inline bool static_branch_##name(struct static_key *key) \ { \ @@ -1238,13 +1258,27 @@ static __always_inline bool static_branch_##name(struct static_key *key) \ } #include "features.h" - #undef SCHED_FEAT extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) + #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ + +/* + * Each translation unit has its own copy of sysctl_sched_features to allow + * constants propagation at compile time and compiler optimization based on + * features default. + */ +#define SCHED_FEAT(name, enabled) \ + (1UL << __SCHED_FEAT_##name) * enabled | +static const_debug __maybe_unused unsigned int sysctl_sched_features = +#include "features.h" + 0; +#undef SCHED_FEAT + #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) + #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ extern struct static_key_false sched_numa_balancing; @@ -1529,6 +1563,8 @@ extern void init_sched_dl_class(void); extern void init_sched_rt_class(void); extern void init_sched_fair_class(void); +extern void reweight_task(struct task_struct *p, int prio); + extern void resched_curr(struct rq *rq); extern void resched_cpu(int cpu); diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 87e2c9f0c33e..940b1fa1d2ce 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/slab.h> #include <linux/fs.h> diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index d5710651043b..baf500d12b7c 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifdef CONFIG_SCHEDSTATS diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index 9f69fb630853..45caf90b24cd 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "sched.h" /* diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c index 2227e183e202..9ff1555341ed 100644 --- a/kernel/sched/swait.c +++ b/kernel/sched/swait.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/sched/signal.h> #include <linux/swait.h> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index f1cf4f306a82..034cbed7f88b 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1,8 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Scheduler topology setup/handling methods */ #include <linux/sched.h> #include <linux/mutex.h> +#include <linux/sched/isolation.h> #include "sched.h" @@ -268,6 +270,12 @@ static int init_rootdomain(struct root_domain *rd) if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) goto free_dlo_mask; +#ifdef HAVE_RT_PUSH_IPI + rd->rto_cpu = -1; + raw_spin_lock_init(&rd->rto_lock); + init_irq_work(&rd->rto_push_work, rto_push_irq_work_func); +#endif + init_dl_bw(&rd->dl_bw); if (cpudl_init(&rd->cpudl) != 0) goto free_rto_mask; @@ -463,21 +471,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) update_top_cache_domain(cpu); } -/* Setup the mask of CPUs configured for isolated domains */ -static int __init isolated_cpu_setup(char *str) -{ - int ret; - - alloc_bootmem_cpumask_var(&cpu_isolated_map); - ret = cpulist_parse(str, cpu_isolated_map); - if (ret) { - pr_err("sched: Error, all isolcpus= values must be between 0 and %u\n", nr_cpu_ids); - return 0; - } - return 1; -} -__setup("isolcpus=", isolated_cpu_setup); - struct s_data { struct sched_domain ** __percpu sd; struct root_domain *rd; @@ -1157,6 +1150,7 @@ sd_init(struct sched_domain_topology_level *tl, sd->smt_gain = 1178; /* ~15% */ } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { + sd->flags |= SD_PREFER_SIBLING; sd->imbalance_pct = 117; sd->cache_nice_tries = 1; sd->busy_idx = 2; @@ -1331,6 +1325,10 @@ void sched_init_numa(void) if (!sched_domains_numa_distance) return; + /* Includes NUMA identity node at level 0. */ + sched_domains_numa_distance[level++] = curr_distance; + sched_domains_numa_levels = level; + /* * O(nr_nodes^2) deduplicating selection sort -- in order to find the * unique distances in the node_distance() table. @@ -1378,8 +1376,7 @@ void sched_init_numa(void) return; /* - * 'level' contains the number of unique distances, excluding the - * identity distance node_distance(i,i). + * 'level' contains the number of unique distances * * The sched_domains_numa_distance[] array includes the actual distance * numbers. @@ -1441,9 +1438,18 @@ void sched_init_numa(void) tl[i] = sched_domain_topology[i]; /* + * Add the NUMA identity distance, aka single NODE. + */ + tl[i++] = (struct sched_domain_topology_level){ + .mask = sd_numa_mask, + .numa_level = 0, + SD_INIT_NAME(NODE) + }; + + /* * .. and append 'j' levels of NUMA goodness. */ - for (j = 0; j < level; i++, j++) { + for (j = 1; j < level; i++, j++) { tl[i] = (struct sched_domain_topology_level){ .mask = sd_numa_mask, .sd_flags = cpu_numa_flags, @@ -1773,7 +1779,7 @@ int sched_init_domains(const struct cpumask *cpu_map) doms_cur = alloc_sched_domains(ndoms_cur); if (!doms_cur) doms_cur = &fallback_doms; - cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); + cpumask_and(doms_cur[0], cpu_map, housekeeping_cpumask(HK_FLAG_DOMAIN)); err = build_sched_domains(doms_cur[0], NULL); register_sched_domain_sysctl(); @@ -1856,7 +1862,8 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], doms_new = alloc_sched_domains(1); if (doms_new) { n = 1; - cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); + cpumask_and(doms_new[0], cpu_active_mask, + housekeeping_cpumask(HK_FLAG_DOMAIN)); } } else { n = ndoms_new; @@ -1879,7 +1886,8 @@ match1: if (!doms_new) { n = 0; doms_new = &fallback_doms; - cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); + cpumask_and(doms_new[0], cpu_active_mask, + housekeeping_cpumask(HK_FLAG_DOMAIN)); } /* Build new domains: */ diff --git a/kernel/seccomp.c b/kernel/seccomp.c index bb3a38005b9c..5f0dfb2abb8d 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/seccomp.c * @@ -189,7 +190,7 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd, u32 ret = SECCOMP_RET_ALLOW; /* Make sure cross-thread synced filter points somewhere sane. */ struct seccomp_filter *f = - lockless_dereference(current->seccomp.filter); + READ_ONCE(current->seccomp.filter); /* Ensure unexpected behavior doesn't result in failing open. */ if (unlikely(WARN_ON(f == NULL))) @@ -473,7 +474,7 @@ static long seccomp_attach_filter(unsigned int flags, return 0; } -void __get_seccomp_filter(struct seccomp_filter *filter) +static void __get_seccomp_filter(struct seccomp_filter *filter) { /* Reference count is bounded by the number of total processes. */ refcount_inc(&filter->usage); diff --git a/kernel/signal.c b/kernel/signal.c index 800a18f77732..8dcd8825b2de 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2698,7 +2698,7 @@ enum siginfo_layout siginfo_layout(int sig, int si_code) [SIGSEGV] = { NSIGSEGV, SIL_FAULT }, [SIGBUS] = { NSIGBUS, SIL_FAULT }, [SIGTRAP] = { NSIGTRAP, SIL_FAULT }, -#if defined(SIGMET) && defined(NSIGEMT) +#if defined(SIGEMT) && defined(NSIGEMT) [SIGEMT] = { NSIGEMT, SIL_FAULT }, #endif [SIGCHLD] = { NSIGCHLD, SIL_CHLD }, diff --git a/kernel/smp.c b/kernel/smp.c index c94dd85c8d41..084c8b3a2681 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -213,7 +213,7 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline) call_single_data_t *csd, *csd_next; static bool warned; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); head = this_cpu_ptr(&call_single_queue); entry = llist_del_all(head); diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 1d71c051a951..5043e7433f4b 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -344,39 +344,30 @@ EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); * by the client, but only by calling this function. * This function can only be called on a registered smp_hotplug_thread. */ -int smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread, - const struct cpumask *new) +void smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread, + const struct cpumask *new) { struct cpumask *old = plug_thread->cpumask; - cpumask_var_t tmp; + static struct cpumask tmp; unsigned int cpu; - if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) - return -ENOMEM; - - get_online_cpus(); + lockdep_assert_cpus_held(); mutex_lock(&smpboot_threads_lock); /* Park threads that were exclusively enabled on the old mask. */ - cpumask_andnot(tmp, old, new); - for_each_cpu_and(cpu, tmp, cpu_online_mask) + cpumask_andnot(&tmp, old, new); + for_each_cpu_and(cpu, &tmp, cpu_online_mask) smpboot_park_thread(plug_thread, cpu); /* Unpark threads that are exclusively enabled on the new mask. */ - cpumask_andnot(tmp, new, old); - for_each_cpu_and(cpu, tmp, cpu_online_mask) + cpumask_andnot(&tmp, new, old); + for_each_cpu_and(cpu, &tmp, cpu_online_mask) smpboot_unpark_thread(plug_thread, cpu); cpumask_copy(old, new); mutex_unlock(&smpboot_threads_lock); - put_online_cpus(); - - free_cpumask_var(tmp); - - return 0; } -EXPORT_SYMBOL_GPL(smpboot_update_cpumask_percpu_thread); static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) = ATOMIC_INIT(CPU_POST_DEAD); diff --git a/kernel/smpboot.h b/kernel/smpboot.h index 485b81cfab34..34dd3d7ba40b 100644 --- a/kernel/smpboot.h +++ b/kernel/smpboot.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef SMPBOOT_H #define SMPBOOT_H diff --git a/kernel/softirq.c b/kernel/softirq.c index 4e09821f9d9e..662f7b1b7a78 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -137,7 +137,7 @@ EXPORT_SYMBOL(__local_bh_disable_ip); static void __local_bh_enable(unsigned int cnt) { - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (softirq_count() == (cnt & SOFTIRQ_MASK)) trace_softirqs_on(_RET_IP_); @@ -158,7 +158,8 @@ EXPORT_SYMBOL(_local_bh_enable); void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) { - WARN_ON_ONCE(in_irq() || irqs_disabled()); + WARN_ON_ONCE(in_irq()); + lockdep_assert_irqs_enabled(); #ifdef CONFIG_TRACE_IRQFLAGS local_irq_disable(); #endif @@ -396,9 +397,8 @@ void irq_exit(void) #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); #else - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); #endif - account_irq_exit_time(current); preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) @@ -488,7 +488,7 @@ EXPORT_SYMBOL(__tasklet_hi_schedule); void __tasklet_hi_schedule_first(struct tasklet_struct *t) { - BUG_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); t->next = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, t); diff --git a/kernel/sys.c b/kernel/sys.c index c541916b38c6..83ffd7dccf23 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/sys.c * diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 8acef8576ce9..b5189762d275 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/linkage.h> #include <linux/errno.h> diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 423554ad3610..9576bd582d4a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -872,9 +872,9 @@ static struct ctl_table kern_table[] = { #if defined(CONFIG_LOCKUP_DETECTOR) { .procname = "watchdog", - .data = &watchdog_user_enabled, - .maxlen = sizeof (int), - .mode = 0644, + .data = &watchdog_user_enabled, + .maxlen = sizeof(int), + .mode = 0644, .proc_handler = proc_watchdog, .extra1 = &zero, .extra2 = &one, @@ -890,16 +890,12 @@ static struct ctl_table kern_table[] = { }, { .procname = "nmi_watchdog", - .data = &nmi_watchdog_enabled, - .maxlen = sizeof (int), - .mode = 0644, + .data = &nmi_watchdog_user_enabled, + .maxlen = sizeof(int), + .mode = NMI_WATCHDOG_SYSCTL_PERM, .proc_handler = proc_nmi_watchdog, .extra1 = &zero, -#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) .extra2 = &one, -#else - .extra2 = &zero, -#endif }, { .procname = "watchdog_cpumask", @@ -911,9 +907,9 @@ static struct ctl_table kern_table[] = { #ifdef CONFIG_SOFTLOCKUP_DETECTOR { .procname = "soft_watchdog", - .data = &soft_watchdog_enabled, - .maxlen = sizeof (int), - .mode = 0644, + .data = &soft_watchdog_user_enabled, + .maxlen = sizeof(int), + .mode = 0644, .proc_handler = proc_soft_watchdog, .extra1 = &zero, .extra2 = &one, @@ -1346,11 +1342,6 @@ static struct ctl_table vm_table[] = { .extra1 = &zero, }, { - .procname = "nr_pdflush_threads", - .mode = 0444 /* read-only */, - .proc_handler = pdflush_proc_obsolete, - }, - { .procname = "swappiness", .data = &vm_swappiness, .maxlen = sizeof(vm_swappiness), @@ -2188,8 +2179,6 @@ static int do_proc_douintvec_conv(unsigned long *lvalp, if (write) { if (*lvalp > UINT_MAX) return -EINVAL; - if (*lvalp > UINT_MAX) - return -EINVAL; *valp = *lvalp; } else { unsigned int val = *valp; diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index 58ea8c03662e..e8c0dab4fd65 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/stat.h> #include <linux/sysctl.h> #include "../fs/xfs/xfs_sysctl.h" diff --git a/kernel/task_work.c b/kernel/task_work.c index 836a72a66fba..0fef395662a6 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/spinlock.h> #include <linux/task_work.h> #include <linux/tracehook.h> @@ -67,7 +68,7 @@ task_work_cancel(struct task_struct *task, task_work_func_t func) * we raced with task_work_run(), *pprev == NULL/exited. */ raw_spin_lock_irqsave(&task->pi_lock, flags); - while ((work = lockless_dereference(*pprev))) { + while ((work = READ_ONCE(*pprev))) { if (work->func != func) pprev = &work->next; else if (cmpxchg(pprev, work, work->next) == work) diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c index 0dbab6d1acb4..dd53e354f630 100644 --- a/kernel/test_kprobes.c +++ b/kernel/test_kprobes.c @@ -22,7 +22,7 @@ #define div_factor 3 -static u32 rand1, preh_val, posth_val, jph_val; +static u32 rand1, preh_val, posth_val; static int errors, handler_errors, num_tests; static u32 (*target)(u32 value); static u32 (*target2)(u32 value); @@ -34,6 +34,10 @@ static noinline u32 kprobe_target(u32 value) static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs) { + if (preemptible()) { + handler_errors++; + pr_err("pre-handler is preemptible\n"); + } preh_val = (rand1 / div_factor); return 0; } @@ -41,6 +45,10 @@ static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs) static void kp_post_handler(struct kprobe *p, struct pt_regs *regs, unsigned long flags) { + if (preemptible()) { + handler_errors++; + pr_err("post-handler is preemptible\n"); + } if (preh_val != (rand1 / div_factor)) { handler_errors++; pr_err("incorrect value in post_handler\n"); @@ -154,8 +162,15 @@ static int test_kprobes(void) } +#if 0 +static u32 jph_val; + static u32 j_kprobe_target(u32 value) { + if (preemptible()) { + handler_errors++; + pr_err("jprobe-handler is preemptible\n"); + } if (value != rand1) { handler_errors++; pr_err("incorrect value in jprobe handler\n"); @@ -227,11 +242,19 @@ static int test_jprobes(void) return 0; } +#else +#define test_jprobe() (0) +#define test_jprobes() (0) +#endif #ifdef CONFIG_KRETPROBES static u32 krph_val; static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { + if (preemptible()) { + handler_errors++; + pr_err("kretprobe entry handler is preemptible\n"); + } krph_val = (rand1 / div_factor); return 0; } @@ -240,6 +263,10 @@ static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { unsigned long ret = regs_return_value(regs); + if (preemptible()) { + handler_errors++; + pr_err("kretprobe return handler is preemptible\n"); + } if (ret != (rand1 / div_factor)) { handler_errors++; pr_err("incorrect value in kretprobe handler\n"); diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index ac09bc29eb08..d689a9557e17 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -56,7 +56,7 @@ menu "Timers subsystem" # Core internal switch. Selected by NO_HZ_COMMON / HIGH_RES_TIMERS. This is # only related to the tick functionality. Oneshot clockevent devices -# are supported independ of this. +# are supported independent of this. config TICK_ONESHOT bool diff --git a/kernel/time/Makefile b/kernel/time/Makefile index 938dbf33ef49..f1e46f338a9c 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-y += time.o timer.o hrtimer.o obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o obj-y += timeconv.o timecounter.o alarmtimer.o diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 4237e0744e26..16c027e9cc73 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -280,17 +280,22 @@ static int clockevents_program_min_delta(struct clock_event_device *dev) static int clockevents_program_min_delta(struct clock_event_device *dev) { unsigned long long clc; - int64_t delta; + int64_t delta = 0; + int i; - delta = dev->min_delta_ns; - dev->next_event = ktime_add_ns(ktime_get(), delta); + for (i = 0; i < 10; i++) { + delta += dev->min_delta_ns; + dev->next_event = ktime_add_ns(ktime_get(), delta); - if (clockevent_state_shutdown(dev)) - return 0; + if (clockevent_state_shutdown(dev)) + return 0; - dev->retries++; - clc = ((unsigned long long) delta * dev->mult) >> dev->shift; - return dev->set_next_event((unsigned long) clc, dev); + dev->retries++; + clc = ((unsigned long long) delta * dev->mult) >> dev->shift; + if (dev->set_next_event((unsigned long) clc, dev) == 0) + return 0; + } + return -ETIME; } #endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 88f75f92ef36..d32520840fde 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -758,9 +758,7 @@ void clock_was_set(void) */ void hrtimers_resume(void) { - WARN_ONCE(!irqs_disabled(), - KERN_INFO "hrtimers_resume() called with IRQs enabled!"); - + lockdep_assert_irqs_disabled(); /* Retrigger on the local CPU */ retrigger_next_event(NULL); /* And schedule a retrigger for all others */ diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c index 2ef98a02376a..f26acef5d7b4 100644 --- a/kernel/time/itimer.c +++ b/kernel/time/itimer.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/itimer.c * diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index edf19cc53140..8d70da1b9a0d 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * NTP state machine interfaces and logic. * @@ -492,6 +493,67 @@ out: return leap; } +static void sync_hw_clock(struct work_struct *work); +static DECLARE_DELAYED_WORK(sync_work, sync_hw_clock); + +static void sched_sync_hw_clock(struct timespec64 now, + unsigned long target_nsec, bool fail) + +{ + struct timespec64 next; + + getnstimeofday64(&next); + if (!fail) + next.tv_sec = 659; + else { + /* + * Try again as soon as possible. Delaying long periods + * decreases the accuracy of the work queue timer. Due to this + * the algorithm is very likely to require a short-sleep retry + * after the above long sleep to synchronize ts_nsec. + */ + next.tv_sec = 0; + } + + /* Compute the needed delay that will get to tv_nsec == target_nsec */ + next.tv_nsec = target_nsec - next.tv_nsec; + if (next.tv_nsec <= 0) + next.tv_nsec += NSEC_PER_SEC; + if (next.tv_nsec >= NSEC_PER_SEC) { + next.tv_sec++; + next.tv_nsec -= NSEC_PER_SEC; + } + + queue_delayed_work(system_power_efficient_wq, &sync_work, + timespec64_to_jiffies(&next)); +} + +static void sync_rtc_clock(void) +{ + unsigned long target_nsec; + struct timespec64 adjust, now; + int rc; + + if (!IS_ENABLED(CONFIG_RTC_SYSTOHC)) + return; + + getnstimeofday64(&now); + + adjust = now; + if (persistent_clock_is_local) + adjust.tv_sec -= (sys_tz.tz_minuteswest * 60); + + /* + * The current RTC in use will provide the target_nsec it wants to be + * called at, and does rtc_tv_nsec_ok internally. + */ + rc = rtc_set_ntp_time(adjust, &target_nsec); + if (rc == -ENODEV) + return; + + sched_sync_hw_clock(now, target_nsec, rc); +} + #ifdef CONFIG_GENERIC_CMOS_UPDATE int __weak update_persistent_clock(struct timespec now) { @@ -507,76 +569,75 @@ int __weak update_persistent_clock64(struct timespec64 now64) } #endif -#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC) -static void sync_cmos_clock(struct work_struct *work); - -static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); - -static void sync_cmos_clock(struct work_struct *work) +static bool sync_cmos_clock(void) { + static bool no_cmos; struct timespec64 now; - struct timespec64 next; - int fail = 1; + struct timespec64 adjust; + int rc = -EPROTO; + long target_nsec = NSEC_PER_SEC / 2; + + if (!IS_ENABLED(CONFIG_GENERIC_CMOS_UPDATE)) + return false; + + if (no_cmos) + return false; /* - * If we have an externally synchronized Linux clock, then update - * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be - * called as close as possible to 500 ms before the new second starts. - * This code is run on a timer. If the clock is set, that timer - * may not expire at the correct time. Thus, we adjust... - * We want the clock to be within a couple of ticks from the target. + * Historically update_persistent_clock64() has followed x86 + * semantics, which match the MC146818A/etc RTC. This RTC will store + * 'adjust' and then in .5s it will advance once second. + * + * Architectures are strongly encouraged to use rtclib and not + * implement this legacy API. */ - if (!ntp_synced()) { - /* - * Not synced, exit, do not restart a timer (if one is - * running, let it run out). - */ - return; - } - getnstimeofday64(&now); - if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) { - struct timespec64 adjust = now; - - fail = -ENODEV; + if (rtc_tv_nsec_ok(-1 * target_nsec, &adjust, &now)) { if (persistent_clock_is_local) adjust.tv_sec -= (sys_tz.tz_minuteswest * 60); -#ifdef CONFIG_GENERIC_CMOS_UPDATE - fail = update_persistent_clock64(adjust); -#endif - -#ifdef CONFIG_RTC_SYSTOHC - if (fail == -ENODEV) - fail = rtc_set_ntp_time(adjust); -#endif + rc = update_persistent_clock64(adjust); + /* + * The machine does not support update_persistent_clock64 even + * though it defines CONFIG_GENERIC_CMOS_UPDATE. + */ + if (rc == -ENODEV) { + no_cmos = true; + return false; + } } - next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2); - if (next.tv_nsec <= 0) - next.tv_nsec += NSEC_PER_SEC; + sched_sync_hw_clock(now, target_nsec, rc); + return true; +} - if (!fail || fail == -ENODEV) - next.tv_sec = 659; - else - next.tv_sec = 0; +/* + * If we have an externally synchronized Linux clock, then update RTC clock + * accordingly every ~11 minutes. Generally RTCs can only store second + * precision, but many RTCs will adjust the phase of their second tick to + * match the moment of update. This infrastructure arranges to call to the RTC + * set at the correct moment to phase synchronize the RTC second tick over + * with the kernel clock. + */ +static void sync_hw_clock(struct work_struct *work) +{ + if (!ntp_synced()) + return; - if (next.tv_nsec >= NSEC_PER_SEC) { - next.tv_sec++; - next.tv_nsec -= NSEC_PER_SEC; - } - queue_delayed_work(system_power_efficient_wq, - &sync_cmos_work, timespec64_to_jiffies(&next)); + if (sync_cmos_clock()) + return; + + sync_rtc_clock(); } void ntp_notify_cmos_timer(void) { - queue_delayed_work(system_power_efficient_wq, &sync_cmos_work, 0); -} - -#else -void ntp_notify_cmos_timer(void) { } -#endif + if (!ntp_synced()) + return; + if (IS_ENABLED(CONFIG_GENERIC_CMOS_UPDATE) || + IS_ENABLED(CONFIG_RTC_SYSTOHC)) + queue_delayed_work(system_power_efficient_wq, &sync_work, 0); +} /* * Propagate a new txc->status value into the NTP state: @@ -653,67 +714,6 @@ static inline void process_adjtimex_modes(struct timex *txc, } - -/** - * ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex - */ -int ntp_validate_timex(struct timex *txc) -{ - if (txc->modes & ADJ_ADJTIME) { - /* singleshot must not be used with any other mode bits */ - if (!(txc->modes & ADJ_OFFSET_SINGLESHOT)) - return -EINVAL; - if (!(txc->modes & ADJ_OFFSET_READONLY) && - !capable(CAP_SYS_TIME)) - return -EPERM; - } else { - /* In order to modify anything, you gotta be super-user! */ - if (txc->modes && !capable(CAP_SYS_TIME)) - return -EPERM; - /* - * if the quartz is off by more than 10% then - * something is VERY wrong! - */ - if (txc->modes & ADJ_TICK && - (txc->tick < 900000/USER_HZ || - txc->tick > 1100000/USER_HZ)) - return -EINVAL; - } - - if (txc->modes & ADJ_SETOFFSET) { - /* In order to inject time, you gotta be super-user! */ - if (!capable(CAP_SYS_TIME)) - return -EPERM; - - if (txc->modes & ADJ_NANO) { - struct timespec ts; - - ts.tv_sec = txc->time.tv_sec; - ts.tv_nsec = txc->time.tv_usec; - if (!timespec_inject_offset_valid(&ts)) - return -EINVAL; - - } else { - if (!timeval_inject_offset_valid(&txc->time)) - return -EINVAL; - } - } - - /* - * Check for potential multiplication overflows that can - * only happen on 64-bit systems: - */ - if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) { - if (LLONG_MIN / PPM_SCALE > txc->freq) - return -EINVAL; - if (LLONG_MAX / PPM_SCALE < txc->freq) - return -EINVAL; - } - - return 0; -} - - /* * adjtimex mainly allows reading (and writing, if superuser) of * kernel time-keeping variables. used by xntpd. diff --git a/kernel/time/ntp_internal.h b/kernel/time/ntp_internal.h index d8a7c11fa71a..909bd1f1bfb1 100644 --- a/kernel/time/ntp_internal.h +++ b/kernel/time/ntp_internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_NTP_INTERNAL_H #define _LINUX_NTP_INTERNAL_H @@ -7,7 +8,6 @@ extern void ntp_clear(void); extern u64 ntp_tick_length(void); extern ktime_t ntp_get_next_leap(void); extern int second_overflow(time64_t secs); -extern int ntp_validate_timex(struct timex *); extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *); extern void __hardpps(const struct timespec64 *, const struct timespec64 *); #endif /* _LINUX_NTP_INTERNAL_H */ diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 8585ad6e472a..1f27887aa194 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Implement CPU time clocks for the POSIX clock interface. */ @@ -602,7 +603,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, /* * Disarm any old timer after extracting its expiry time. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); ret = 0; old_incr = timer->it.cpu.incr; @@ -1033,7 +1034,7 @@ static void posix_cpu_timer_rearm(struct k_itimer *timer) /* * Now re-arm for the new expiry time. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); arm_timer(timer); unlock: unlock_task_sighand(p, &flags); @@ -1124,7 +1125,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) struct k_itimer *timer, *next; unsigned long flags; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); /* * The fast path checks that there are no expired thread or thread diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c index 06f34feb635e..b258bee13b02 100644 --- a/kernel/time/posix-stubs.c +++ b/kernel/time/posix-stubs.c @@ -117,8 +117,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, const struct timespec __user *, rqtp, struct timespec __user *, rmtp) { - struct timespec64 t64; - struct timespec t; + struct timespec64 t; switch (which_clock) { case CLOCK_REALTIME: @@ -129,16 +128,15 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, return -EINVAL; } - if (copy_from_user(&t, rqtp, sizeof (struct timespec))) + if (get_timespec64(&t, rqtp)) return -EFAULT; - t64 = timespec_to_timespec64(t); - if (!timespec64_valid(&t64)) + if (!timespec64_valid(&t)) return -EINVAL; if (flags & TIMER_ABSTIME) rmtp = NULL; current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE; current->restart_block.nanosleep.rmtp = rmtp; - return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ? + return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL, which_clock); } @@ -203,8 +201,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags, struct compat_timespec __user *, rqtp, struct compat_timespec __user *, rmtp) { - struct timespec64 t64; - struct timespec t; + struct timespec64 t; switch (which_clock) { case CLOCK_REALTIME: @@ -215,16 +212,15 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags, return -EINVAL; } - if (compat_get_timespec(&t, rqtp)) + if (compat_get_timespec64(&t, rqtp)) return -EFAULT; - t64 = timespec_to_timespec64(t); - if (!timespec64_valid(&t64)) + if (!timespec64_valid(&t)) return -EINVAL; if (flags & TIMER_ABSTIME) rmtp = NULL; current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE; current->restart_block.nanosleep.compat_rmtp = rmtp; - return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ? + return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL, which_clock); } diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h index fb303c3be4d3..151e28f5bf30 100644 --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #define TIMER_RETRY 1 struct k_clock { diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c index a7bb8f33ae07..58045eb976c3 100644 --- a/kernel/time/tick-broadcast-hrtimer.c +++ b/kernel/time/tick-broadcast-hrtimer.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/kernel/time/tick-broadcast-hrtimer.c * This file emulates a local clock event device diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index be0ac01f2e12..f8e1845aa464 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * tick internal variable and functions used by low/high res code */ diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index 6b009c207671..c1f518e7aa80 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -33,6 +33,7 @@ int tick_program_event(ktime_t expires, int force) * We don't need the clock event device any more, stop it. */ clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED); + dev->next_event = KTIME_MAX; return 0; } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c7a899c5ce64..99578f06c8d4 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -27,6 +27,7 @@ #include <linux/irq_work.h> #include <linux/posix-timers.h> #include <linux/context_tracking.h> +#include <linux/mm.h> #include <asm/irq_regs.h> @@ -165,7 +166,6 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) #ifdef CONFIG_NO_HZ_FULL cpumask_var_t tick_nohz_full_mask; -cpumask_var_t housekeeping_mask; bool tick_nohz_full_running; static atomic_t tick_dep_mask; @@ -198,7 +198,7 @@ static bool check_tick_dependency(atomic_t *dep) static bool can_stop_full_tick(int cpu, struct tick_sched *ts) { - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (unlikely(!cpu_online(cpu))) return false; @@ -385,20 +385,13 @@ out: local_irq_restore(flags); } -/* Parse the boot-time nohz CPU list from the kernel parameters. */ -static int __init tick_nohz_full_setup(char *str) +/* Get the boot-time nohz CPU list from the kernel parameters. */ +void __init tick_nohz_full_setup(cpumask_var_t cpumask) { alloc_bootmem_cpumask_var(&tick_nohz_full_mask); - if (cpulist_parse(str, tick_nohz_full_mask) < 0) { - pr_warn("NO_HZ: Incorrect nohz_full cpumask\n"); - free_bootmem_cpumask_var(tick_nohz_full_mask); - return 1; - } + cpumask_copy(tick_nohz_full_mask, cpumask); tick_nohz_full_running = true; - - return 1; } -__setup("nohz_full=", tick_nohz_full_setup); static int tick_nohz_cpu_down(unsigned int cpu) { @@ -437,13 +430,6 @@ void __init tick_nohz_init(void) return; } - if (!alloc_cpumask_var(&housekeeping_mask, GFP_KERNEL)) { - WARN(1, "NO_HZ: Can't allocate not-full dynticks cpumask\n"); - cpumask_clear(tick_nohz_full_mask); - tick_nohz_full_running = false; - return; - } - /* * Full dynticks uses irq work to drive the tick rescheduling on safe * locking contexts. But then we need irq work to raise its own @@ -452,7 +438,6 @@ void __init tick_nohz_init(void) if (!arch_irq_work_has_interrupt()) { pr_warn("NO_HZ: Can't run full dynticks because arch doesn't support irq work self-IPIs\n"); cpumask_clear(tick_nohz_full_mask); - cpumask_copy(housekeeping_mask, cpu_possible_mask); tick_nohz_full_running = false; return; } @@ -465,9 +450,6 @@ void __init tick_nohz_init(void) cpumask_clear_cpu(cpu, tick_nohz_full_mask); } - cpumask_andnot(housekeeping_mask, - cpu_possible_mask, tick_nohz_full_mask); - for_each_cpu(cpu, tick_nohz_full_mask) context_tracking_cpu_set(cpu); @@ -477,12 +459,6 @@ void __init tick_nohz_init(void) WARN_ON(ret < 0); pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n", cpumask_pr_args(tick_nohz_full_mask)); - - /* - * We need at least one CPU to handle housekeeping work such - * as timekeeping, unbound timers, workqueues, ... - */ - WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); } #endif @@ -787,6 +763,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, if (!ts->tick_stopped) { calc_load_nohz_start(); cpu_load_update_nohz_start(); + quiet_vmstat(); ts->last_tick = hrtimer_get_expires(&ts->sched_timer); ts->tick_stopped = 1; @@ -960,8 +937,7 @@ void tick_nohz_idle_enter(void) { struct tick_sched *ts; - WARN_ON_ONCE(irqs_disabled()); - + lockdep_assert_irqs_enabled(); /* * Update the idle state in the scheduler domain hierarchy * when tick_nohz_stop_sched_tick() is called from the idle loop. diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index 075444e3d48e..954b43dbf21c 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _TICK_SCHED_H #define _TICK_SCHED_H diff --git a/kernel/time/time.c b/kernel/time/time.c index 44a8c1402133..bd4e6c7dd689 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -82,7 +82,7 @@ SYSCALL_DEFINE1(time, time_t __user *, tloc) SYSCALL_DEFINE1(stime, time_t __user *, tptr) { - struct timespec tv; + struct timespec64 tv; int err; if (get_user(tv.tv_sec, tptr)) @@ -90,11 +90,11 @@ SYSCALL_DEFINE1(stime, time_t __user *, tptr) tv.tv_nsec = 0; - err = security_settime(&tv, NULL); + err = security_settime64(&tv, NULL); if (err) return err; - do_settimeofday(&tv); + do_settimeofday64(&tv); return 0; } @@ -122,7 +122,7 @@ COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc) COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr) { - struct timespec tv; + struct timespec64 tv; int err; if (get_user(tv.tv_sec, tptr)) @@ -130,11 +130,11 @@ COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr) tv.tv_nsec = 0; - err = security_settime(&tv, NULL); + err = security_settime64(&tv, NULL); if (err) return err; - do_settimeofday(&tv); + do_settimeofday64(&tv); return 0; } @@ -158,40 +158,6 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, } /* - * Indicates if there is an offset between the system clock and the hardware - * clock/persistent clock/rtc. - */ -int persistent_clock_is_local; - -/* - * Adjust the time obtained from the CMOS to be UTC time instead of - * local time. - * - * This is ugly, but preferable to the alternatives. Otherwise we - * would either need to write a program to do it in /etc/rc (and risk - * confusion if the program gets run more than once; it would also be - * hard to make the program warp the clock precisely n hours) or - * compile in the timezone information into the kernel. Bad, bad.... - * - * - TYT, 1992-01-01 - * - * The best thing to do is to keep the CMOS clock in universal time (UTC) - * as real UNIX machines always do it. This avoids all headaches about - * daylight saving times and warping kernel clocks. - */ -static inline void warp_clock(void) -{ - if (sys_tz.tz_minuteswest != 0) { - struct timespec adjust; - - persistent_clock_is_local = 1; - adjust.tv_sec = sys_tz.tz_minuteswest * 60; - adjust.tv_nsec = 0; - timekeeping_inject_offset(&adjust); - } -} - -/* * In case for some reason the CMOS clock has not already been running * in UTC, but in some local time: The first time we set the timezone, * we will warp the clock so that it is ticking UTC time instead of @@ -224,7 +190,7 @@ int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz if (firsttime) { firsttime = 0; if (!tv) - warp_clock(); + timekeeping_warp_clock(); } } if (tv) @@ -441,6 +407,7 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0, } EXPORT_SYMBOL(mktime64); +#if __BITS_PER_LONG == 32 /** * set_normalized_timespec - set timespec sec and nsec parts and normalize * @@ -501,6 +468,7 @@ struct timespec ns_to_timespec(const s64 nsec) return ts; } EXPORT_SYMBOL(ns_to_timespec); +#endif /** * ns_to_timeval - Convert nanoseconds to timeval @@ -520,7 +488,6 @@ struct timeval ns_to_timeval(const s64 nsec) } EXPORT_SYMBOL(ns_to_timeval); -#if BITS_PER_LONG == 32 /** * set_normalized_timespec - set timespec sec and nsec parts and normalize * @@ -581,7 +548,7 @@ struct timespec64 ns_to_timespec64(const s64 nsec) return ts; } EXPORT_SYMBOL(ns_to_timespec64); -#endif + /** * msecs_to_jiffies: - convert milliseconds to jiffies * @m: time in milliseconds @@ -853,24 +820,6 @@ unsigned long nsecs_to_jiffies(u64 n) EXPORT_SYMBOL_GPL(nsecs_to_jiffies); /* - * Add two timespec values and do a safety check for overflow. - * It's assumed that both values are valid (>= 0) - */ -struct timespec timespec_add_safe(const struct timespec lhs, - const struct timespec rhs) -{ - struct timespec res; - - set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec, - lhs.tv_nsec + rhs.tv_nsec); - - if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec) - res.tv_sec = TIME_T_MAX; - - return res; -} - -/* * Add two timespec64 values and do a safety check for overflow. * It's assumed that both values are valid (>= 0). * And, each timespec64 is in normalized form. diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 2cafb49aa65e..198afa78bf69 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -60,8 +60,27 @@ struct tk_fast { struct tk_read_base base[2]; }; -static struct tk_fast tk_fast_mono ____cacheline_aligned; -static struct tk_fast tk_fast_raw ____cacheline_aligned; +/* Suspend-time cycles value for halted fast timekeeper. */ +static u64 cycles_at_suspend; + +static u64 dummy_clock_read(struct clocksource *cs) +{ + return cycles_at_suspend; +} + +static struct clocksource dummy_clock = { + .read = dummy_clock_read, +}; + +static struct tk_fast tk_fast_mono ____cacheline_aligned = { + .base[0] = { .clock = &dummy_clock, }, + .base[1] = { .clock = &dummy_clock, }, +}; + +static struct tk_fast tk_fast_raw ____cacheline_aligned = { + .base[0] = { .clock = &dummy_clock, }, + .base[1] = { .clock = &dummy_clock, }, +}; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -477,17 +496,39 @@ u64 notrace ktime_get_boot_fast_ns(void) } EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns); -/* Suspend-time cycles value for halted fast timekeeper. */ -static u64 cycles_at_suspend; -static u64 dummy_clock_read(struct clocksource *cs) +/* + * See comment for __ktime_get_fast_ns() vs. timestamp ordering + */ +static __always_inline u64 __ktime_get_real_fast_ns(struct tk_fast *tkf) { - return cycles_at_suspend; + struct tk_read_base *tkr; + unsigned int seq; + u64 now; + + do { + seq = raw_read_seqcount_latch(&tkf->seq); + tkr = tkf->base + (seq & 0x01); + now = ktime_to_ns(tkr->base_real); + + now += timekeeping_delta_to_ns(tkr, + clocksource_delta( + tk_clock_read(tkr), + tkr->cycle_last, + tkr->mask)); + } while (read_seqcount_retry(&tkf->seq, seq)); + + return now; } -static struct clocksource dummy_clock = { - .read = dummy_clock_read, -}; +/** + * ktime_get_real_fast_ns: - NMI safe and fast access to clock realtime. + */ +u64 ktime_get_real_fast_ns(void) +{ + return __ktime_get_real_fast_ns(&tk_fast_mono); +} +EXPORT_SYMBOL_GPL(ktime_get_real_fast_ns); /** * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. @@ -507,6 +548,7 @@ static void halt_fast_timekeeper(struct timekeeper *tk) memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); cycles_at_suspend = tk_clock_read(tkr); tkr_dummy.clock = &dummy_clock; + tkr_dummy.base_real = tkr->base + tk->offs_real; update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); tkr = &tk->tkr_raw; @@ -654,6 +696,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) update_vsyscall(tk); update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); + tk->tkr_mono.base_real = tk->tkr_mono.base + tk->offs_real; update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); @@ -1264,33 +1307,31 @@ EXPORT_SYMBOL(do_settimeofday64); * * Adds or subtracts an offset value from the current time. */ -int timekeeping_inject_offset(struct timespec *ts) +static int timekeeping_inject_offset(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; - struct timespec64 ts64, tmp; + struct timespec64 tmp; int ret = 0; - if (!timespec_inject_offset_valid(ts)) + if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - ts64 = timespec_to_timespec64(*ts); - raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); /* Make sure the proposed value is valid */ - tmp = timespec64_add(tk_xtime(tk), ts64); - if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 || + tmp = timespec64_add(tk_xtime(tk), *ts); + if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 || !timespec64_valid_strict(&tmp)) { ret = -EINVAL; goto error; } - tk_xtime_add(tk, &ts64); - tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64)); + tk_xtime_add(tk, ts); + tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); @@ -1303,7 +1344,40 @@ error: /* even if we error out, we forwarded the time, so call update */ return ret; } -EXPORT_SYMBOL(timekeeping_inject_offset); + +/* + * Indicates if there is an offset between the system clock and the hardware + * clock/persistent clock/rtc. + */ +int persistent_clock_is_local; + +/* + * Adjust the time obtained from the CMOS to be UTC time instead of + * local time. + * + * This is ugly, but preferable to the alternatives. Otherwise we + * would either need to write a program to do it in /etc/rc (and risk + * confusion if the program gets run more than once; it would also be + * hard to make the program warp the clock precisely n hours) or + * compile in the timezone information into the kernel. Bad, bad.... + * + * - TYT, 1992-01-01 + * + * The best thing to do is to keep the CMOS clock in universal time (UTC) + * as real UNIX machines always do it. This avoids all headaches about + * daylight saving times and warping kernel clocks. + */ +void timekeeping_warp_clock(void) +{ + if (sys_tz.tz_minuteswest != 0) { + struct timespec64 adjust; + + persistent_clock_is_local = 1; + adjust.tv_sec = sys_tz.tz_minuteswest * 60; + adjust.tv_nsec = 0; + timekeeping_inject_offset(&adjust); + } +} /** * __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic @@ -2248,6 +2322,72 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, } /** + * timekeeping_validate_timex - Ensures the timex is ok for use in do_adjtimex + */ +static int timekeeping_validate_timex(struct timex *txc) +{ + if (txc->modes & ADJ_ADJTIME) { + /* singleshot must not be used with any other mode bits */ + if (!(txc->modes & ADJ_OFFSET_SINGLESHOT)) + return -EINVAL; + if (!(txc->modes & ADJ_OFFSET_READONLY) && + !capable(CAP_SYS_TIME)) + return -EPERM; + } else { + /* In order to modify anything, you gotta be super-user! */ + if (txc->modes && !capable(CAP_SYS_TIME)) + return -EPERM; + /* + * if the quartz is off by more than 10% then + * something is VERY wrong! + */ + if (txc->modes & ADJ_TICK && + (txc->tick < 900000/USER_HZ || + txc->tick > 1100000/USER_HZ)) + return -EINVAL; + } + + if (txc->modes & ADJ_SETOFFSET) { + /* In order to inject time, you gotta be super-user! */ + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + /* + * Validate if a timespec/timeval used to inject a time + * offset is valid. Offsets can be postive or negative, so + * we don't check tv_sec. The value of the timeval/timespec + * is the sum of its fields,but *NOTE*: + * The field tv_usec/tv_nsec must always be non-negative and + * we can't have more nanoseconds/microseconds than a second. + */ + if (txc->time.tv_usec < 0) + return -EINVAL; + + if (txc->modes & ADJ_NANO) { + if (txc->time.tv_usec >= NSEC_PER_SEC) + return -EINVAL; + } else { + if (txc->time.tv_usec >= USEC_PER_SEC) + return -EINVAL; + } + } + + /* + * Check for potential multiplication overflows that can + * only happen on 64-bit systems: + */ + if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) { + if (LLONG_MIN / PPM_SCALE > txc->freq) + return -EINVAL; + if (LLONG_MAX / PPM_SCALE < txc->freq) + return -EINVAL; + } + + return 0; +} + + +/** * do_adjtimex() - Accessor function to NTP __do_adjtimex function */ int do_adjtimex(struct timex *txc) @@ -2259,12 +2399,12 @@ int do_adjtimex(struct timex *txc) int ret; /* Validate the data before disabling interrupts */ - ret = ntp_validate_timex(txc); + ret = timekeeping_validate_timex(txc); if (ret) return ret; if (txc->modes & ADJ_SETOFFSET) { - struct timespec delta; + struct timespec64 delta; delta.tv_sec = txc->time.tv_sec; delta.tv_nsec = txc->time.tv_usec; if (!(txc->modes & ADJ_NANO)) diff --git a/kernel/time/timekeeping.h b/kernel/time/timekeeping.h index d0914676d4c5..7a9b4eb7a1d5 100644 --- a/kernel/time/timekeeping.h +++ b/kernel/time/timekeeping.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _KERNEL_TIME_TIMEKEEPING_H #define _KERNEL_TIME_TIMEKEEPING_H /* @@ -10,7 +11,7 @@ extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, extern int timekeeping_valid_for_hres(void); extern u64 timekeeping_max_deferment(void); -extern int timekeeping_inject_offset(struct timespec *ts); +extern void timekeeping_warp_clock(void); extern int timekeeping_suspend(void); extern void timekeeping_resume(void); diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h index 9a18f121f399..fdbeeb02dde9 100644 --- a/kernel/time/timekeeping_internal.h +++ b/kernel/time/timekeeping_internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _TIMEKEEPING_INTERNAL_H #define _TIMEKEEPING_INTERNAL_H /* diff --git a/kernel/time/timer.c b/kernel/time/timer.c index f2674a056c26..af0b8bae4502 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -610,7 +610,7 @@ static bool timer_fixup_init(void *addr, enum debug_obj_state state) } /* Stub timer callback for improperly used timers. */ -static void stub_timer(unsigned long data) +static void stub_timer(struct timer_list *unused) { WARN_ON(1); } @@ -626,7 +626,7 @@ static bool timer_fixup_activate(void *addr, enum debug_obj_state state) switch (state) { case ODEBUG_STATE_NOTAVAILABLE: - setup_timer(timer, stub_timer, 0); + timer_setup(timer, stub_timer, 0); return true; case ODEBUG_STATE_ACTIVE: @@ -665,7 +665,7 @@ static bool timer_fixup_assert_init(void *addr, enum debug_obj_state state) switch (state) { case ODEBUG_STATE_NOTAVAILABLE: - setup_timer(timer, stub_timer, 0); + timer_setup(timer, stub_timer, 0); return true; default: return false; @@ -929,8 +929,11 @@ static struct timer_base *lock_timer_base(struct timer_list *timer, } } +#define MOD_TIMER_PENDING_ONLY 0x01 +#define MOD_TIMER_REDUCE 0x02 + static inline int -__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) +__mod_timer(struct timer_list *timer, unsigned long expires, unsigned int options) { struct timer_base *base, *new_base; unsigned int idx = UINT_MAX; @@ -950,7 +953,11 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) * larger granularity than you would get from adding a new * timer with this expiry. */ - if (timer->expires == expires) + long diff = timer->expires - expires; + + if (!diff) + return 1; + if (options & MOD_TIMER_REDUCE && diff <= 0) return 1; /* @@ -962,6 +969,12 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) base = lock_timer_base(timer, &flags); forward_timer_base(base); + if (timer_pending(timer) && (options & MOD_TIMER_REDUCE) && + time_before_eq(timer->expires, expires)) { + ret = 1; + goto out_unlock; + } + clk = base->clk; idx = calc_wheel_index(expires, clk); @@ -971,7 +984,10 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) * subsequent call will exit in the expires check above. */ if (idx == timer_get_idx(timer)) { - timer->expires = expires; + if (!(options & MOD_TIMER_REDUCE)) + timer->expires = expires; + else if (time_after(timer->expires, expires)) + timer->expires = expires; ret = 1; goto out_unlock; } @@ -981,7 +997,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) } ret = detach_if_pending(timer, base, false); - if (!ret && pending_only) + if (!ret && (options & MOD_TIMER_PENDING_ONLY)) goto out_unlock; debug_activate(timer, expires); @@ -1042,7 +1058,7 @@ out_unlock: */ int mod_timer_pending(struct timer_list *timer, unsigned long expires) { - return __mod_timer(timer, expires, true); + return __mod_timer(timer, expires, MOD_TIMER_PENDING_ONLY); } EXPORT_SYMBOL(mod_timer_pending); @@ -1068,11 +1084,26 @@ EXPORT_SYMBOL(mod_timer_pending); */ int mod_timer(struct timer_list *timer, unsigned long expires) { - return __mod_timer(timer, expires, false); + return __mod_timer(timer, expires, 0); } EXPORT_SYMBOL(mod_timer); /** + * timer_reduce - Modify a timer's timeout if it would reduce the timeout + * @timer: The timer to be modified + * @expires: New timeout in jiffies + * + * timer_reduce() is very similar to mod_timer(), except that it will only + * modify a running timer if that would reduce the expiration time (it will + * start a timer that isn't running). + */ +int timer_reduce(struct timer_list *timer, unsigned long expires) +{ + return __mod_timer(timer, expires, MOD_TIMER_REDUCE); +} +EXPORT_SYMBOL(timer_reduce); + +/** * add_timer - start a timer * @timer: the timer to be added * @@ -1560,8 +1591,11 @@ static int collect_expired_timers(struct timer_base *base, * jiffies, otherwise forward to the next expiry time: */ if (time_after(next, jiffies)) { - /* The call site will increment clock! */ - base->clk = jiffies - 1; + /* + * The call site will increment base->clk and then + * terminate the expiry loop immediately. + */ + base->clk = jiffies; return 0; } base->clk = next; @@ -1668,9 +1702,20 @@ void run_local_timers(void) raise_softirq(TIMER_SOFTIRQ); } -static void process_timeout(unsigned long __data) +/* + * Since schedule_timeout()'s timer is defined on the stack, it must store + * the target task on the stack as well. + */ +struct process_timer { + struct timer_list timer; + struct task_struct *task; +}; + +static void process_timeout(struct timer_list *t) { - wake_up_process((struct task_struct *)__data); + struct process_timer *timeout = from_timer(timeout, t, timer); + + wake_up_process(timeout->task); } /** @@ -1704,7 +1749,7 @@ static void process_timeout(unsigned long __data) */ signed long __sched schedule_timeout(signed long timeout) { - struct timer_list timer; + struct process_timer timer; unsigned long expire; switch (timeout) @@ -1738,13 +1783,14 @@ signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; - setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); - __mod_timer(&timer, expire, false); + timer.task = current; + timer_setup_on_stack(&timer.timer, process_timeout, 0); + __mod_timer(&timer.timer, expire, 0); schedule(); - del_singleshot_timer_sync(&timer); + del_singleshot_timer_sync(&timer.timer); /* Remove the timer from the object tracker */ - destroy_timer_on_stack(&timer); + destroy_timer_on_stack(&timer.timer); timeout = expire - jiffies; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 434c840e2d82..f54b7b6b4a4b 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -224,7 +224,7 @@ config HWLAT_TRACER select GENERIC_TRACER help This tracer, when enabled will create one or more kernel threads, - depening on what the cpumask file is set to, which each thread + depending on what the cpumask file is set to, which each thread spinning in a loop looking for interruptions caused by something other than the kernel. For example, if a System Management Interrupt (SMI) takes a noticeable amount of @@ -239,7 +239,7 @@ config HWLAT_TRACER iteration A kernel thread is created that will spin with interrupts disabled - for "width" microseconds in every "widow" cycle. It will not spin + for "width" microseconds in every "window" cycle. It will not spin for "window - width" microseconds, where the system can continue to operate. diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 90f2701d92a7..19a15b2f1190 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # Do not instrument the tracer itself: diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 45a3928544ce..206e0e2ace53 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -66,7 +66,8 @@ static struct tracer_flags blk_tracer_flags = { }; /* Global reference count of probes */ -static atomic_t blk_probes_ref = ATOMIC_INIT(0); +static DEFINE_MUTEX(blk_probe_mutex); +static int blk_probes_ref; static void blk_register_tracepoints(void); static void blk_unregister_tracepoints(void); @@ -329,14 +330,29 @@ static void blk_trace_free(struct blk_trace *bt) kfree(bt); } +static void get_probe_ref(void) +{ + mutex_lock(&blk_probe_mutex); + if (++blk_probes_ref == 1) + blk_register_tracepoints(); + mutex_unlock(&blk_probe_mutex); +} + +static void put_probe_ref(void) +{ + mutex_lock(&blk_probe_mutex); + if (!--blk_probes_ref) + blk_unregister_tracepoints(); + mutex_unlock(&blk_probe_mutex); +} + static void blk_trace_cleanup(struct blk_trace *bt) { blk_trace_free(bt); - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); + put_probe_ref(); } -int blk_trace_remove(struct request_queue *q) +static int __blk_trace_remove(struct request_queue *q) { struct blk_trace *bt; @@ -349,6 +365,17 @@ int blk_trace_remove(struct request_queue *q) return 0; } + +int blk_trace_remove(struct request_queue *q) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_remove(q); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_remove); static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, @@ -538,8 +565,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, if (cmpxchg(&q->blk_trace, NULL, bt)) goto err; - if (atomic_inc_return(&blk_probes_ref) == 1) - blk_register_tracepoints(); + get_probe_ref(); ret = 0; err: @@ -550,9 +576,8 @@ err: return ret; } -int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - struct block_device *bdev, - char __user *arg) +static int __blk_trace_setup(struct request_queue *q, char *name, dev_t dev, + struct block_device *bdev, char __user *arg) { struct blk_user_trace_setup buts; int ret; @@ -571,6 +596,19 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, } return 0; } + +int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, + struct block_device *bdev, + char __user *arg) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_setup(q, name, dev, bdev, arg); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_setup); #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) @@ -607,7 +645,7 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name, } #endif -int blk_trace_startstop(struct request_queue *q, int start) +static int __blk_trace_startstop(struct request_queue *q, int start) { int ret; struct blk_trace *bt = q->blk_trace; @@ -646,6 +684,17 @@ int blk_trace_startstop(struct request_queue *q, int start) return ret; } + +int blk_trace_startstop(struct request_queue *q, int start) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_startstop(q, start); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_startstop); /* @@ -676,7 +725,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) switch (cmd) { case BLKTRACESETUP: bdevname(bdev, b); - ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); + ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); break; #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) case BLKTRACESETUP32: @@ -687,10 +736,10 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) case BLKTRACESTART: start = 1; case BLKTRACESTOP: - ret = blk_trace_startstop(q, start); + ret = __blk_trace_startstop(q, start); break; case BLKTRACETEARDOWN: - ret = blk_trace_remove(q); + ret = __blk_trace_remove(q); break; default: ret = -ENOTTY; @@ -708,10 +757,14 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) **/ void blk_trace_shutdown(struct request_queue *q) { + mutex_lock(&q->blk_trace_mutex); + if (q->blk_trace) { - blk_trace_startstop(q, 0); - blk_trace_remove(q); + __blk_trace_startstop(q, 0); + __blk_trace_remove(q); } + + mutex_unlock(&q->blk_trace_mutex); } #ifdef CONFIG_BLK_CGROUP @@ -1558,9 +1611,7 @@ static int blk_trace_remove_queue(struct request_queue *q) if (bt == NULL) return -EINVAL; - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); - + put_probe_ref(); blk_trace_free(bt); return 0; } @@ -1591,8 +1642,7 @@ static int blk_trace_setup_queue(struct request_queue *q, if (cmpxchg(&q->blk_trace, NULL, bt)) goto free_bt; - if (atomic_inc_return(&blk_probes_ref) == 1) - blk_register_tracepoints(); + get_probe_ref(); return 0; free_bt: diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index dc498b605d5d..95888ae6c263 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -275,7 +275,7 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) if (!ee) return -ENOENT; - err = perf_event_read_local(ee->event, &value); + err = perf_event_read_local(ee->event, &value, NULL, NULL); /* * this api is ugly since we miss [-22..-2] range of valid * counter values, but that's uapi diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6abfafd7f173..8319e09e15b9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4954,9 +4954,6 @@ static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); -static unsigned long save_global_trampoline; -static unsigned long save_global_flags; - static int __init set_graph_function(char *str) { strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); @@ -6808,17 +6805,6 @@ void unregister_ftrace_graph(void) unregister_pm_notifier(&ftrace_suspend_notifier); unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); -#ifdef CONFIG_DYNAMIC_FTRACE - /* - * Function graph does not allocate the trampoline, but - * other global_ops do. We need to reset the ALLOC_TRAMP flag - * if one was used. - */ - global_ops.trampoline = save_global_trampoline; - if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) - global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; -#endif - out: mutex_unlock(&ftrace_lock); } diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c index 0c7dee221dca..21bb161c2316 100644 --- a/kernel/trace/power-traces.c +++ b/kernel/trace/power-traces.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Power trace points * diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 81279c6602ff..845f3805c73d 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2724,7 +2724,7 @@ rb_reserve_next_event(struct ring_buffer *buffer, * if it happened, we have to fail the write. */ barrier(); - if (unlikely(ACCESS_ONCE(cpu_buffer->buffer) != buffer)) { + if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) { local_dec(&cpu_buffer->committing); local_dec(&cpu_buffer->commits); return NULL; diff --git a/kernel/trace/rpm-traces.c b/kernel/trace/rpm-traces.c index 4b3b5eaf94d1..25dec0b00280 100644 --- a/kernel/trace/rpm-traces.c +++ b/kernel/trace/rpm-traces.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Power trace points * diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 652c682707cd..6b0b343a36a2 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_KERNEL_TRACE_H #define _LINUX_KERNEL_TRACE_H @@ -1459,7 +1460,7 @@ extern struct trace_event_file *find_event_file(struct trace_array *tr, static inline void *event_file_data(struct file *filp) { - return ACCESS_ONCE(file_inode(filp)->i_private); + return READ_ONCE(file_inode(filp)->i_private); } extern struct mutex event_mutex; diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c index 16a8cf02eee9..79f838a75077 100644 --- a/kernel/trace/trace_benchmark.c +++ b/kernel/trace/trace_benchmark.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/delay.h> #include <linux/module.h> #include <linux/kthread.h> diff --git a/kernel/trace/trace_benchmark.h b/kernel/trace/trace_benchmark.h index ebdbfc2f2a64..be1d86ff753d 100644 --- a/kernel/trace/trace_benchmark.h +++ b/kernel/trace/trace_benchmark.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #undef TRACE_SYSTEM #define TRACE_SYSTEM benchmark diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 4d8fdf3184dc..4ad967453b6f 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * unlikely profiler * diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index adcdbbeae010..e954ae3d82c0 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * This file defines the trace event structures that go into the ring * buffer directly. They are created via macros so that changes for them diff --git a/kernel/trace/trace_events_filter_test.h b/kernel/trace/trace_events_filter_test.h index bfd4dba0d603..39d7ef4f57cb 100644 --- a/kernel/trace/trace_events_filter_test.h +++ b/kernel/trace/trace_events_filter_test.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #undef TRACE_SYSTEM #define TRACE_SYSTEM test diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 39aa7aa66468..548e62eb5c46 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * trace_export.c - export basic ftrace utilities to user space * diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index a0910c0cdf2e..27f7ad12c4b1 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * ring buffer based function tracer * diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index b8f1f54731af..23c0b0cb5fb9 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * * Function graph tracer. diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 57149bce6aad..d953c163a079 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * kdb helper for dumping the ftrace buffer * diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index dca78fc48439..b0388016b687 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Memory mapped I/O tracing * diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 49f61fe96a6b..50523f953a5d 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * nop tracer * diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index c738e764e2a5..90db994ac900 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -921,8 +921,8 @@ static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter, trace_assign_type(field, iter->ent); - T = __task_state_to_char(field->next_state); - S = __task_state_to_char(field->prev_state); + T = task_index_to_char(field->next_state); + S = task_index_to_char(field->prev_state); trace_find_cmdline(field->next_pid, comm); trace_seq_printf(&iter->seq, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n", @@ -957,8 +957,8 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S) trace_assign_type(field, iter->ent); if (!S) - S = __task_state_to_char(field->prev_state); - T = __task_state_to_char(field->next_state); + S = task_index_to_char(field->prev_state); + T = task_index_to_char(field->next_state); trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n", field->prev_pid, field->prev_prio, @@ -993,8 +993,8 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S) trace_assign_type(field, iter->ent); if (!S) - S = __task_state_to_char(field->prev_state); - T = __task_state_to_char(field->next_state); + S = task_index_to_char(field->prev_state); + T = task_index_to_char(field->next_state); SEQ_PUT_HEX_FIELD(s, field->prev_pid); SEQ_PUT_HEX_FIELD(s, field->prev_prio); diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index fabc49bcd493..dbba03ed96de 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __TRACE_EVENTS_H #define __TRACE_EVENTS_H diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index b341c02730be..e288168661e1 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * trace context switch * diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 0c331978b1a6..a86b303e6c67 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * trace task wakeup timings * @@ -397,10 +398,10 @@ tracing_sched_switch_trace(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->prev_pid = prev->pid; entry->prev_prio = prev->prio; - entry->prev_state = __get_task_state(prev); + entry->prev_state = task_state_index(prev); entry->next_pid = next->pid; entry->next_prio = next->prio; - entry->next_state = __get_task_state(next); + entry->next_state = task_state_index(next); entry->next_cpu = task_cpu(next); if (!call_filter_check_discard(call, entry, buffer, event)) @@ -425,10 +426,10 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->prev_pid = curr->pid; entry->prev_prio = curr->prio; - entry->prev_state = __get_task_state(curr); + entry->prev_state = task_state_index(curr); entry->next_pid = wakee->pid; entry->next_prio = wakee->prio; - entry->next_state = __get_task_state(wakee); + entry->next_state = task_state_index(wakee); entry->next_cpu = task_cpu(wakee); if (!call_filter_check_discard(call, entry, buffer, event)) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index b17ec642793b..cd70eb5df38e 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* Include in trace.c */ #include <uapi/linux/sched/types.h> diff --git a/kernel/trace/trace_selftest_dynamic.c b/kernel/trace/trace_selftest_dynamic.c index b4c475a0a48b..8cda06a10d66 100644 --- a/kernel/trace/trace_selftest_dynamic.c +++ b/kernel/trace/trace_selftest_dynamic.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include "trace.h" int DYN_FTRACE_TEST_NAME(void) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 49cb41412eec..734accc02418 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com> * @@ -77,7 +78,7 @@ check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; - int frame_size = ACCESS_ONCE(tracer_frame); + int frame_size = READ_ONCE(tracer_frame); int i, x; this_size = ((unsigned long)stack) & (THREAD_SIZE-1); diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 413ff108fbd0..75bf1bcb4a8a 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Infrastructure for statistic tracing (histogram output). * diff --git a/kernel/trace/trace_stat.h b/kernel/trace/trace_stat.h index 8f03914b9a6a..76d30b4ebe83 100644 --- a/kernel/trace/trace_stat.h +++ b/kernel/trace/trace_stat.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __TRACE_STAT_H #define __TRACE_STAT_H diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 696afe72d3b1..a2a642f2c64f 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <trace/syscall.h> #include <trace/events/syscalls.h> #include <linux/syscalls.h> diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h index 618838f5f30a..ab0ca77331d0 100644 --- a/kernel/trace/tracing_map.h +++ b/kernel/trace/tracing_map.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __TRACING_MAP_H #define __TRACING_MAP_H diff --git a/kernel/uid16.c b/kernel/uid16.c index 5c2dc5b2bf4f..ce74a4901d2b 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Wrapper functions for 16bit uid back compatibility. All nicely tied * together in the faint hope we can take the out in five years time. diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index c490f1e4313b..d32b45662fb6 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -894,7 +894,7 @@ static bool new_idmap_permitted(const struct file *file, int proc_setgroups_show(struct seq_file *seq, void *v) { struct user_namespace *ns = seq->private; - unsigned long userns_flags = ACCESS_ONCE(ns->flags); + unsigned long userns_flags = READ_ONCE(ns->flags); seq_printf(seq, "%s\n", (userns_flags & USERNS_SETGROUPS_ALLOWED) ? diff --git a/kernel/watchdog.c b/kernel/watchdog.c index f5d52024f6b7..576d18045811 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Detect hard and soft lockups on a system * @@ -24,25 +25,35 @@ #include <linux/workqueue.h> #include <linux/sched/clock.h> #include <linux/sched/debug.h> +#include <linux/sched/isolation.h> #include <asm/irq_regs.h> #include <linux/kvm_para.h> #include <linux/kthread.h> -/* Watchdog configuration */ -static DEFINE_MUTEX(watchdog_proc_mutex); - -int __read_mostly nmi_watchdog_enabled; +static DEFINE_MUTEX(watchdog_mutex); #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG) -unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED | - NMI_WATCHDOG_ENABLED; +# define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED | NMI_WATCHDOG_ENABLED) +# define NMI_WATCHDOG_DEFAULT 1 #else -unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED; +# define WATCHDOG_DEFAULT (SOFT_WATCHDOG_ENABLED) +# define NMI_WATCHDOG_DEFAULT 0 #endif +unsigned long __read_mostly watchdog_enabled; +int __read_mostly watchdog_user_enabled = 1; +int __read_mostly nmi_watchdog_user_enabled = NMI_WATCHDOG_DEFAULT; +int __read_mostly soft_watchdog_user_enabled = 1; +int __read_mostly watchdog_thresh = 10; +int __read_mostly nmi_watchdog_available; + +struct cpumask watchdog_allowed_mask __read_mostly; + +struct cpumask watchdog_cpumask __read_mostly; +unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); + #ifdef CONFIG_HARDLOCKUP_DETECTOR -/* boot commands */ /* * Should we panic when a soft-lockup or hard-lockup occurs: */ @@ -56,9 +67,9 @@ unsigned int __read_mostly hardlockup_panic = * kernel command line parameters are parsed, because otherwise it is not * possible to override this in hardlockup_panic_setup(). */ -void hardlockup_detector_disable(void) +void __init hardlockup_detector_disable(void) { - watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; + nmi_watchdog_user_enabled = 0; } static int __init hardlockup_panic_setup(char *str) @@ -68,48 +79,24 @@ static int __init hardlockup_panic_setup(char *str) else if (!strncmp(str, "nopanic", 7)) hardlockup_panic = 0; else if (!strncmp(str, "0", 1)) - watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; + nmi_watchdog_user_enabled = 0; else if (!strncmp(str, "1", 1)) - watchdog_enabled |= NMI_WATCHDOG_ENABLED; + nmi_watchdog_user_enabled = 1; return 1; } __setup("nmi_watchdog=", hardlockup_panic_setup); -#endif - -#ifdef CONFIG_SOFTLOCKUP_DETECTOR -int __read_mostly soft_watchdog_enabled; -#endif - -int __read_mostly watchdog_user_enabled; -int __read_mostly watchdog_thresh = 10; - -#ifdef CONFIG_SMP -int __read_mostly sysctl_softlockup_all_cpu_backtrace; +# ifdef CONFIG_SMP int __read_mostly sysctl_hardlockup_all_cpu_backtrace; -#endif -struct cpumask watchdog_cpumask __read_mostly; -unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); -/* - * The 'watchdog_running' variable is set to 1 when the watchdog threads - * are registered/started and is set to 0 when the watchdog threads are - * unregistered/stopped, so it is an indicator whether the threads exist. - */ -static int __read_mostly watchdog_running; -/* - * If a subsystem has a need to deactivate the watchdog temporarily, it - * can use the suspend/resume interface to achieve this. The content of - * the 'watchdog_suspended' variable reflects this state. Existing threads - * are parked/unparked by the lockup_detector_{suspend|resume} functions - * (see comment blocks pertaining to those functions for further details). - * - * 'watchdog_suspended' also prevents threads from being registered/started - * or unregistered/stopped via parameters in /proc/sys/kernel, so the state - * of 'watchdog_running' cannot change while the watchdog is deactivated - * temporarily (see related code in 'proc' handlers). - */ -int __read_mostly watchdog_suspended; +static int __init hardlockup_all_cpu_backtrace_setup(char *str) +{ + sysctl_hardlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0); + return 1; +} +__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup); +# endif /* CONFIG_SMP */ +#endif /* CONFIG_HARDLOCKUP_DETECTOR */ /* * These functions can be overridden if an architecture implements its @@ -121,36 +108,68 @@ int __read_mostly watchdog_suspended; */ int __weak watchdog_nmi_enable(unsigned int cpu) { + hardlockup_detector_perf_enable(); return 0; } + void __weak watchdog_nmi_disable(unsigned int cpu) { + hardlockup_detector_perf_disable(); } -/* - * watchdog_nmi_reconfigure can be implemented to be notified after any - * watchdog configuration change. The arch hardlockup watchdog should - * respond to the following variables: - * - nmi_watchdog_enabled +/* Return 0, if a NMI watchdog is available. Error code otherwise */ +int __weak __init watchdog_nmi_probe(void) +{ + return hardlockup_detector_perf_init(); +} + +/** + * watchdog_nmi_stop - Stop the watchdog for reconfiguration + * + * The reconfiguration steps are: + * watchdog_nmi_stop(); + * update_variables(); + * watchdog_nmi_start(); + */ +void __weak watchdog_nmi_stop(void) { } + +/** + * watchdog_nmi_start - Start the watchdog after reconfiguration + * + * Counterpart to watchdog_nmi_stop(). + * + * The following variables have been updated in update_variables() and + * contain the currently valid configuration: + * - watchdog_enabled * - watchdog_thresh * - watchdog_cpumask - * - sysctl_hardlockup_all_cpu_backtrace - * - hardlockup_panic - * - watchdog_suspended */ -void __weak watchdog_nmi_reconfigure(void) +void __weak watchdog_nmi_start(void) { } + +/** + * lockup_detector_update_enable - Update the sysctl enable bit + * + * Caller needs to make sure that the NMI/perf watchdogs are off, so this + * can't race with watchdog_nmi_disable(). + */ +static void lockup_detector_update_enable(void) { + watchdog_enabled = 0; + if (!watchdog_user_enabled) + return; + if (nmi_watchdog_available && nmi_watchdog_user_enabled) + watchdog_enabled |= NMI_WATCHDOG_ENABLED; + if (soft_watchdog_user_enabled) + watchdog_enabled |= SOFT_WATCHDOG_ENABLED; } - #ifdef CONFIG_SOFTLOCKUP_DETECTOR -/* Helper for online, unparked cpus. */ -#define for_each_watchdog_cpu(cpu) \ - for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask) - -atomic_t watchdog_park_in_progress = ATOMIC_INIT(0); +/* Global variables, exported for sysctl */ +unsigned int __read_mostly softlockup_panic = + CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; +static bool softlockup_threads_initialized __read_mostly; static u64 __read_mostly sample_period; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); @@ -164,50 +183,40 @@ static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved); static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved); static unsigned long soft_lockup_nmi_warn; -unsigned int __read_mostly softlockup_panic = - CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; - static int __init softlockup_panic_setup(char *str) { softlockup_panic = simple_strtoul(str, NULL, 0); - return 1; } __setup("softlockup_panic=", softlockup_panic_setup); static int __init nowatchdog_setup(char *str) { - watchdog_enabled = 0; + watchdog_user_enabled = 0; return 1; } __setup("nowatchdog", nowatchdog_setup); static int __init nosoftlockup_setup(char *str) { - watchdog_enabled &= ~SOFT_WATCHDOG_ENABLED; + soft_watchdog_user_enabled = 0; return 1; } __setup("nosoftlockup", nosoftlockup_setup); #ifdef CONFIG_SMP +int __read_mostly sysctl_softlockup_all_cpu_backtrace; + static int __init softlockup_all_cpu_backtrace_setup(char *str) { - sysctl_softlockup_all_cpu_backtrace = - !!simple_strtol(str, NULL, 0); + sysctl_softlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0); return 1; } __setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup); -#ifdef CONFIG_HARDLOCKUP_DETECTOR -static int __init hardlockup_all_cpu_backtrace_setup(char *str) -{ - sysctl_hardlockup_all_cpu_backtrace = - !!simple_strtol(str, NULL, 0); - return 1; -} -__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup); -#endif #endif +static void __lockup_detector_cleanup(void); + /* * Hard-lockup warnings should be triggered after just a few seconds. Soft- * lockups can have false positives under extreme conditions. So we generally @@ -278,11 +287,15 @@ void touch_all_softlockup_watchdogs(void) int cpu; /* - * this is done lockless - * do we care if a 0 races with a timestamp? - * all it means is the softlock check starts one cycle later + * watchdog_mutex cannpt be taken here, as this might be called + * from (soft)interrupt context, so the access to + * watchdog_allowed_cpumask might race with a concurrent update. + * + * The watchdog time stamp can race against a concurrent real + * update as well, the only side effect might be a cycle delay for + * the softlockup check. */ - for_each_watchdog_cpu(cpu) + for_each_cpu(cpu, &watchdog_allowed_mask) per_cpu(watchdog_touch_ts, cpu) = 0; wq_watchdog_touch(-1); } @@ -322,9 +335,6 @@ static void watchdog_interrupt_count(void) __this_cpu_inc(hrtimer_interrupts); } -static int watchdog_enable_all_cpus(void); -static void watchdog_disable_all_cpus(void); - /* watchdog kicker functions */ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) { @@ -333,7 +343,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) int duration; int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace; - if (atomic_read(&watchdog_park_in_progress) != 0) + if (!watchdog_enabled) return HRTIMER_NORESTART; /* kick the hardlockup detector */ @@ -447,32 +457,38 @@ static void watchdog_set_prio(unsigned int policy, unsigned int prio) static void watchdog_enable(unsigned int cpu) { - struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer); + struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer); - /* kick off the timer for the hardlockup detector */ + /* + * Start the timer first to prevent the NMI watchdog triggering + * before the timer has a chance to fire. + */ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer->function = watchdog_timer_fn; - - /* Enable the perf event */ - watchdog_nmi_enable(cpu); - - /* done here because hrtimer_start can only pin to smp_processor_id() */ hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL_PINNED); - /* initialize timestamp */ - watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1); + /* Initialize timestamp */ __touch_watchdog(); + /* Enable the perf event */ + if (watchdog_enabled & NMI_WATCHDOG_ENABLED) + watchdog_nmi_enable(cpu); + + watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1); } static void watchdog_disable(unsigned int cpu) { - struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer); + struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer); watchdog_set_prio(SCHED_NORMAL, 0); - hrtimer_cancel(hrtimer); - /* disable the perf event */ + /* + * Disable the perf event first. That prevents that a large delay + * between disabling the timer and disabling the perf event causes + * the perf NMI to detect a false positive. + */ watchdog_nmi_disable(cpu); + hrtimer_cancel(hrtimer); } static void watchdog_cleanup(unsigned int cpu, bool online) @@ -499,21 +515,6 @@ static void watchdog(unsigned int cpu) __this_cpu_write(soft_lockup_hrtimer_cnt, __this_cpu_read(hrtimer_interrupts)); __touch_watchdog(); - - /* - * watchdog_nmi_enable() clears the NMI_WATCHDOG_ENABLED bit in the - * failure path. Check for failures that can occur asynchronously - - * for example, when CPUs are on-lined - and shut down the hardware - * perf event on each CPU accordingly. - * - * The only non-obvious place this bit can be cleared is through - * watchdog_nmi_enable(), so a pr_info() is placed there. Placing a - * pr_info here would be too noisy as it would result in a message - * every few seconds if the hardlockup was disabled but the softlockup - * enabled. - */ - if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) - watchdog_nmi_disable(cpu); } static struct smp_hotplug_thread watchdog_threads = { @@ -527,295 +528,174 @@ static struct smp_hotplug_thread watchdog_threads = { .unpark = watchdog_enable, }; -/* - * park all watchdog threads that are specified in 'watchdog_cpumask' - * - * This function returns an error if kthread_park() of a watchdog thread - * fails. In this situation, the watchdog threads of some CPUs can already - * be parked and the watchdog threads of other CPUs can still be runnable. - * Callers are expected to handle this special condition as appropriate in - * their context. - * - * This function may only be called in a context that is protected against - * races with CPU hotplug - for example, via get_online_cpus(). - */ -static int watchdog_park_threads(void) +static void softlockup_update_smpboot_threads(void) { - int cpu, ret = 0; - - atomic_set(&watchdog_park_in_progress, 1); + lockdep_assert_held(&watchdog_mutex); - for_each_watchdog_cpu(cpu) { - ret = kthread_park(per_cpu(softlockup_watchdog, cpu)); - if (ret) - break; - } - - atomic_set(&watchdog_park_in_progress, 0); + if (!softlockup_threads_initialized) + return; - return ret; + smpboot_update_cpumask_percpu_thread(&watchdog_threads, + &watchdog_allowed_mask); } -/* - * unpark all watchdog threads that are specified in 'watchdog_cpumask' - * - * This function may only be called in a context that is protected against - * races with CPU hotplug - for example, via get_online_cpus(). - */ -static void watchdog_unpark_threads(void) +/* Temporarily park all watchdog threads */ +static void softlockup_park_all_threads(void) { - int cpu; - - for_each_watchdog_cpu(cpu) - kthread_unpark(per_cpu(softlockup_watchdog, cpu)); + cpumask_clear(&watchdog_allowed_mask); + softlockup_update_smpboot_threads(); } -static int update_watchdog_all_cpus(void) +/* Unpark enabled threads */ +static void softlockup_unpark_threads(void) { - int ret; - - ret = watchdog_park_threads(); - if (ret) - return ret; - - watchdog_unpark_threads(); - - return 0; + cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask); + softlockup_update_smpboot_threads(); } -static int watchdog_enable_all_cpus(void) +static void lockup_detector_reconfigure(void) { - int err = 0; - - if (!watchdog_running) { - err = smpboot_register_percpu_thread_cpumask(&watchdog_threads, - &watchdog_cpumask); - if (err) - pr_err("Failed to create watchdog threads, disabled\n"); - else - watchdog_running = 1; - } else { - /* - * Enable/disable the lockup detectors or - * change the sample period 'on the fly'. - */ - err = update_watchdog_all_cpus(); - - if (err) { - watchdog_disable_all_cpus(); - pr_err("Failed to update lockup detectors, disabled\n"); - } - } - - if (err) - watchdog_enabled = 0; - - return err; + cpus_read_lock(); + watchdog_nmi_stop(); + softlockup_park_all_threads(); + set_sample_period(); + lockup_detector_update_enable(); + if (watchdog_enabled && watchdog_thresh) + softlockup_unpark_threads(); + watchdog_nmi_start(); + cpus_read_unlock(); + /* + * Must be called outside the cpus locked section to prevent + * recursive locking in the perf code. + */ + __lockup_detector_cleanup(); } -static void watchdog_disable_all_cpus(void) +/* + * Create the watchdog thread infrastructure and configure the detector(s). + * + * The threads are not unparked as watchdog_allowed_mask is empty. When + * the threads are sucessfully initialized, take the proper locks and + * unpark the threads in the watchdog_cpumask if the watchdog is enabled. + */ +static __init void lockup_detector_setup(void) { - if (watchdog_running) { - watchdog_running = 0; - smpboot_unregister_percpu_thread(&watchdog_threads); - } -} + int ret; -#ifdef CONFIG_SYSCTL -static int watchdog_update_cpus(void) -{ - return smpboot_update_cpumask_percpu_thread( - &watchdog_threads, &watchdog_cpumask); -} -#endif + /* + * If sysctl is off and watchdog got disabled on the command line, + * nothing to do here. + */ + lockup_detector_update_enable(); -#else /* SOFTLOCKUP */ -static int watchdog_park_threads(void) -{ - return 0; -} + if (!IS_ENABLED(CONFIG_SYSCTL) && + !(watchdog_enabled && watchdog_thresh)) + return; -static void watchdog_unpark_threads(void) -{ -} + ret = smpboot_register_percpu_thread_cpumask(&watchdog_threads, + &watchdog_allowed_mask); + if (ret) { + pr_err("Failed to initialize soft lockup detector threads\n"); + return; + } -static int watchdog_enable_all_cpus(void) -{ - return 0; + mutex_lock(&watchdog_mutex); + softlockup_threads_initialized = true; + lockup_detector_reconfigure(); + mutex_unlock(&watchdog_mutex); } -static void watchdog_disable_all_cpus(void) +#else /* CONFIG_SOFTLOCKUP_DETECTOR */ +static inline int watchdog_park_threads(void) { return 0; } +static inline void watchdog_unpark_threads(void) { } +static inline int watchdog_enable_all_cpus(void) { return 0; } +static inline void watchdog_disable_all_cpus(void) { } +static void lockup_detector_reconfigure(void) { + cpus_read_lock(); + watchdog_nmi_stop(); + lockup_detector_update_enable(); + watchdog_nmi_start(); + cpus_read_unlock(); } - -#ifdef CONFIG_SYSCTL -static int watchdog_update_cpus(void) +static inline void lockup_detector_setup(void) { - return 0; + lockup_detector_reconfigure(); } -#endif +#endif /* !CONFIG_SOFTLOCKUP_DETECTOR */ -static void set_sample_period(void) +static void __lockup_detector_cleanup(void) { + lockdep_assert_held(&watchdog_mutex); + hardlockup_detector_perf_cleanup(); } -#endif /* SOFTLOCKUP */ -/* - * Suspend the hard and soft lockup detector by parking the watchdog threads. +/** + * lockup_detector_cleanup - Cleanup after cpu hotplug or sysctl changes + * + * Caller must not hold the cpu hotplug rwsem. */ -int lockup_detector_suspend(void) +void lockup_detector_cleanup(void) { - int ret = 0; - - get_online_cpus(); - mutex_lock(&watchdog_proc_mutex); - /* - * Multiple suspend requests can be active in parallel (counted by - * the 'watchdog_suspended' variable). If the watchdog threads are - * running, the first caller takes care that they will be parked. - * The state of 'watchdog_running' cannot change while a suspend - * request is active (see related code in 'proc' handlers). - */ - if (watchdog_running && !watchdog_suspended) - ret = watchdog_park_threads(); - - if (ret == 0) - watchdog_suspended++; - else { - watchdog_disable_all_cpus(); - pr_err("Failed to suspend lockup detectors, disabled\n"); - watchdog_enabled = 0; - } - - watchdog_nmi_reconfigure(); - - mutex_unlock(&watchdog_proc_mutex); - - return ret; + mutex_lock(&watchdog_mutex); + __lockup_detector_cleanup(); + mutex_unlock(&watchdog_mutex); } -/* - * Resume the hard and soft lockup detector by unparking the watchdog threads. +/** + * lockup_detector_soft_poweroff - Interface to stop lockup detector(s) + * + * Special interface for parisc. It prevents lockup detector warnings from + * the default pm_poweroff() function which busy loops forever. */ -void lockup_detector_resume(void) +void lockup_detector_soft_poweroff(void) { - mutex_lock(&watchdog_proc_mutex); - - watchdog_suspended--; - /* - * The watchdog threads are unparked if they were previously running - * and if there is no more active suspend request. - */ - if (watchdog_running && !watchdog_suspended) - watchdog_unpark_threads(); - - watchdog_nmi_reconfigure(); - - mutex_unlock(&watchdog_proc_mutex); - put_online_cpus(); + watchdog_enabled = 0; } #ifdef CONFIG_SYSCTL -/* - * Update the run state of the lockup detectors. - */ -static int proc_watchdog_update(void) +/* Propagate any changes to the watchdog threads */ +static void proc_watchdog_update(void) { - int err = 0; - - /* - * Watchdog threads won't be started if they are already active. - * The 'watchdog_running' variable in watchdog_*_all_cpus() takes - * care of this. If those threads are already active, the sample - * period will be updated and the lockup detectors will be enabled - * or disabled 'on the fly'. - */ - if (watchdog_enabled && watchdog_thresh) - err = watchdog_enable_all_cpus(); - else - watchdog_disable_all_cpus(); - - watchdog_nmi_reconfigure(); - - return err; - + /* Remove impossible cpus to keep sysctl output clean. */ + cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask); + lockup_detector_reconfigure(); } /* * common function for watchdog, nmi_watchdog and soft_watchdog parameter * - * caller | table->data points to | 'which' contains the flag(s) - * -------------------|-----------------------|----------------------------- - * proc_watchdog | watchdog_user_enabled | NMI_WATCHDOG_ENABLED or'ed - * | | with SOFT_WATCHDOG_ENABLED - * -------------------|-----------------------|----------------------------- - * proc_nmi_watchdog | nmi_watchdog_enabled | NMI_WATCHDOG_ENABLED - * -------------------|-----------------------|----------------------------- - * proc_soft_watchdog | soft_watchdog_enabled | SOFT_WATCHDOG_ENABLED + * caller | table->data points to | 'which' + * -------------------|----------------------------|-------------------------- + * proc_watchdog | watchdog_user_enabled | NMI_WATCHDOG_ENABLED | + * | | SOFT_WATCHDOG_ENABLED + * -------------------|----------------------------|-------------------------- + * proc_nmi_watchdog | nmi_watchdog_user_enabled | NMI_WATCHDOG_ENABLED + * -------------------|----------------------------|-------------------------- + * proc_soft_watchdog | soft_watchdog_user_enabled | SOFT_WATCHDOG_ENABLED */ static int proc_watchdog_common(int which, struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int err, old, new; - int *watchdog_param = (int *)table->data; + int err, old, *param = table->data; - get_online_cpus(); - mutex_lock(&watchdog_proc_mutex); + mutex_lock(&watchdog_mutex); - if (watchdog_suspended) { - /* no parameter changes allowed while watchdog is suspended */ - err = -EAGAIN; - goto out; - } - - /* - * If the parameter is being read return the state of the corresponding - * bit(s) in 'watchdog_enabled', else update 'watchdog_enabled' and the - * run state of the lockup detectors. - */ if (!write) { - *watchdog_param = (watchdog_enabled & which) != 0; + /* + * On read synchronize the userspace interface. This is a + * racy snapshot. + */ + *param = (watchdog_enabled & which) != 0; err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); } else { + old = READ_ONCE(*param); err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (err) - goto out; - - /* - * There is a race window between fetching the current value - * from 'watchdog_enabled' and storing the new value. During - * this race window, watchdog_nmi_enable() can sneak in and - * clear the NMI_WATCHDOG_ENABLED bit in 'watchdog_enabled'. - * The 'cmpxchg' detects this race and the loop retries. - */ - do { - old = watchdog_enabled; - /* - * If the parameter value is not zero set the - * corresponding bit(s), else clear it(them). - */ - if (*watchdog_param) - new = old | which; - else - new = old & ~which; - } while (cmpxchg(&watchdog_enabled, old, new) != old); - - /* - * Update the run state of the lockup detectors. There is _no_ - * need to check the value returned by proc_watchdog_update() - * and to restore the previous value of 'watchdog_enabled' as - * both lockup detectors are disabled if proc_watchdog_update() - * returns an error. - */ - if (old == new) - goto out; - - err = proc_watchdog_update(); + if (!err && old != READ_ONCE(*param)) + proc_watchdog_update(); } -out: - mutex_unlock(&watchdog_proc_mutex); - put_online_cpus(); + mutex_unlock(&watchdog_mutex); return err; } @@ -835,6 +715,8 @@ int proc_watchdog(struct ctl_table *table, int write, int proc_nmi_watchdog(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + if (!nmi_watchdog_available && write) + return -ENOTSUPP; return proc_watchdog_common(NMI_WATCHDOG_ENABLED, table, write, buffer, lenp, ppos); } @@ -855,39 +737,17 @@ int proc_soft_watchdog(struct ctl_table *table, int write, int proc_watchdog_thresh(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int err, old, new; - - get_online_cpus(); - mutex_lock(&watchdog_proc_mutex); + int err, old; - if (watchdog_suspended) { - /* no parameter changes allowed while watchdog is suspended */ - err = -EAGAIN; - goto out; - } + mutex_lock(&watchdog_mutex); - old = ACCESS_ONCE(watchdog_thresh); + old = READ_ONCE(watchdog_thresh); err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (err || !write) - goto out; + if (!err && write && old != READ_ONCE(watchdog_thresh)) + proc_watchdog_update(); - /* - * Update the sample period. Restore on failure. - */ - new = ACCESS_ONCE(watchdog_thresh); - if (old == new) - goto out; - - set_sample_period(); - err = proc_watchdog_update(); - if (err) { - watchdog_thresh = old; - set_sample_period(); - } -out: - mutex_unlock(&watchdog_proc_mutex); - put_online_cpus(); + mutex_unlock(&watchdog_mutex); return err; } @@ -902,55 +762,26 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, { int err; - get_online_cpus(); - mutex_lock(&watchdog_proc_mutex); - - if (watchdog_suspended) { - /* no parameter changes allowed while watchdog is suspended */ - err = -EAGAIN; - goto out; - } + mutex_lock(&watchdog_mutex); err = proc_do_large_bitmap(table, write, buffer, lenp, ppos); - if (!err && write) { - /* Remove impossible cpus to keep sysctl output cleaner. */ - cpumask_and(&watchdog_cpumask, &watchdog_cpumask, - cpu_possible_mask); + if (!err && write) + proc_watchdog_update(); - if (watchdog_running) { - /* - * Failure would be due to being unable to allocate - * a temporary cpumask, so we are likely not in a - * position to do much else to make things better. - */ - if (watchdog_update_cpus() != 0) - pr_err("cpumask update failed\n"); - } - - watchdog_nmi_reconfigure(); - } -out: - mutex_unlock(&watchdog_proc_mutex); - put_online_cpus(); + mutex_unlock(&watchdog_mutex); return err; } - #endif /* CONFIG_SYSCTL */ void __init lockup_detector_init(void) { - set_sample_period(); - -#ifdef CONFIG_NO_HZ_FULL - if (tick_nohz_full_enabled()) { + if (tick_nohz_full_enabled()) pr_info("Disabling watchdog on nohz_full cores by default\n"); - cpumask_copy(&watchdog_cpumask, housekeeping_mask); - } else - cpumask_copy(&watchdog_cpumask, cpu_possible_mask); -#else - cpumask_copy(&watchdog_cpumask, cpu_possible_mask); -#endif - if (watchdog_enabled) - watchdog_enable_all_cpus(); + cpumask_copy(&watchdog_cpumask, + housekeeping_cpumask(HK_FLAG_TIMER)); + + if (!watchdog_nmi_probe()) + nmi_watchdog_available = true; + lockup_detector_setup(); } diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 3a09ea1b1d3d..e449a23e9d59 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Detect hard lockups on a system * @@ -12,6 +13,7 @@ #define pr_fmt(fmt) "NMI watchdog: " fmt #include <linux/nmi.h> +#include <linux/atomic.h> #include <linux/module.h> #include <linux/sched/debug.h> @@ -21,8 +23,11 @@ static DEFINE_PER_CPU(bool, hard_watchdog_warn); static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); +static DEFINE_PER_CPU(struct perf_event *, dead_event); +static struct cpumask dead_events_mask; static unsigned long hardlockup_allcpu_dumped; +static atomic_t watchdog_cpus = ATOMIC_INIT(0); void arch_touch_nmi_watchdog(void) { @@ -103,15 +108,12 @@ static struct perf_event_attr wd_hw_attr = { /* Callback function for perf event subsystem */ static void watchdog_overflow_callback(struct perf_event *event, - struct perf_sample_data *data, - struct pt_regs *regs) + struct perf_sample_data *data, + struct pt_regs *regs) { /* Ensure the watchdog never gets throttled */ event->hw.interrupts = 0; - if (atomic_read(&watchdog_park_in_progress) != 0) - return; - if (__this_cpu_read(watchdog_nmi_touch) == true) { __this_cpu_write(watchdog_nmi_touch, false); return; @@ -160,104 +162,134 @@ static void watchdog_overflow_callback(struct perf_event *event, return; } -/* - * People like the simple clean cpu node info on boot. - * Reduce the watchdog noise by only printing messages - * that are different from what cpu0 displayed. - */ -static unsigned long firstcpu_err; -static atomic_t watchdog_cpus; - -int watchdog_nmi_enable(unsigned int cpu) +static int hardlockup_detector_event_create(void) { + unsigned int cpu = smp_processor_id(); struct perf_event_attr *wd_attr; - struct perf_event *event = per_cpu(watchdog_ev, cpu); - int firstcpu = 0; - - /* nothing to do if the hard lockup detector is disabled */ - if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) - goto out; - - /* is it already setup and enabled? */ - if (event && event->state > PERF_EVENT_STATE_OFF) - goto out; - - /* it is setup but not enabled */ - if (event != NULL) - goto out_enable; - - if (atomic_inc_return(&watchdog_cpus) == 1) - firstcpu = 1; + struct perf_event *evt; wd_attr = &wd_hw_attr; wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); /* Try to register using hardware perf events */ - event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL); + evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL, + watchdog_overflow_callback, NULL); + if (IS_ERR(evt)) { + pr_info("Perf event create on CPU %d failed with %ld\n", cpu, + PTR_ERR(evt)); + return PTR_ERR(evt); + } + this_cpu_write(watchdog_ev, evt); + return 0; +} - /* save the first cpu's error for future comparision */ - if (firstcpu && IS_ERR(event)) - firstcpu_err = PTR_ERR(event); +/** + * hardlockup_detector_perf_enable - Enable the local event + */ +void hardlockup_detector_perf_enable(void) +{ + if (hardlockup_detector_event_create()) + return; - if (!IS_ERR(event)) { - /* only print for the first cpu initialized */ - if (firstcpu || firstcpu_err) - pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n"); - goto out_save; - } + /* use original value for check */ + if (!atomic_fetch_inc(&watchdog_cpus)) + pr_info("Enabled. Permanently consumes one hw-PMU counter.\n"); - /* - * Disable the hard lockup detector if _any_ CPU fails to set up - * set up the hardware perf event. The watchdog() function checks - * the NMI_WATCHDOG_ENABLED bit periodically. - * - * The barriers are for syncing up watchdog_enabled across all the - * cpus, as clear_bit() does not use barriers. - */ - smp_mb__before_atomic(); - clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled); - smp_mb__after_atomic(); - - /* skip displaying the same error again */ - if (!firstcpu && (PTR_ERR(event) == firstcpu_err)) - return PTR_ERR(event); - - /* vary the KERN level based on the returned errno */ - if (PTR_ERR(event) == -EOPNOTSUPP) - pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu); - else if (PTR_ERR(event) == -ENOENT) - pr_warn("disabled (cpu%i): hardware events not enabled\n", - cpu); - else - pr_err("disabled (cpu%i): unable to create perf event: %ld\n", - cpu, PTR_ERR(event)); - - pr_info("Shutting down hard lockup detector on all cpus\n"); - - return PTR_ERR(event); - - /* success path */ -out_save: - per_cpu(watchdog_ev, cpu) = event; -out_enable: - perf_event_enable(per_cpu(watchdog_ev, cpu)); -out: - return 0; + perf_event_enable(this_cpu_read(watchdog_ev)); } -void watchdog_nmi_disable(unsigned int cpu) +/** + * hardlockup_detector_perf_disable - Disable the local event + */ +void hardlockup_detector_perf_disable(void) { - struct perf_event *event = per_cpu(watchdog_ev, cpu); + struct perf_event *event = this_cpu_read(watchdog_ev); if (event) { perf_event_disable(event); - per_cpu(watchdog_ev, cpu) = NULL; + this_cpu_write(watchdog_ev, NULL); + this_cpu_write(dead_event, event); + cpumask_set_cpu(smp_processor_id(), &dead_events_mask); + atomic_dec(&watchdog_cpus); + } +} + +/** + * hardlockup_detector_perf_cleanup - Cleanup disabled events and destroy them + * + * Called from lockup_detector_cleanup(). Serialized by the caller. + */ +void hardlockup_detector_perf_cleanup(void) +{ + int cpu; + + for_each_cpu(cpu, &dead_events_mask) { + struct perf_event *event = per_cpu(dead_event, cpu); - /* should be in cleanup, but blocks oprofile */ - perf_event_release_kernel(event); + /* + * Required because for_each_cpu() reports unconditionally + * CPU0 as set on UP kernels. Sigh. + */ + if (event) + perf_event_release_kernel(event); + per_cpu(dead_event, cpu) = NULL; + } + cpumask_clear(&dead_events_mask); +} + +/** + * hardlockup_detector_perf_stop - Globally stop watchdog events + * + * Special interface for x86 to handle the perf HT bug. + */ +void __init hardlockup_detector_perf_stop(void) +{ + int cpu; + + lockdep_assert_cpus_held(); + + for_each_online_cpu(cpu) { + struct perf_event *event = per_cpu(watchdog_ev, cpu); + + if (event) + perf_event_disable(event); + } +} + +/** + * hardlockup_detector_perf_restart - Globally restart watchdog events + * + * Special interface for x86 to handle the perf HT bug. + */ +void __init hardlockup_detector_perf_restart(void) +{ + int cpu; + + lockdep_assert_cpus_held(); + + if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) + return; + + for_each_online_cpu(cpu) { + struct perf_event *event = per_cpu(watchdog_ev, cpu); + + if (event) + perf_event_enable(event); + } +} + +/** + * hardlockup_detector_perf_init - Probe whether NMI event is available at all + */ +int __init hardlockup_detector_perf_init(void) +{ + int ret = hardlockup_detector_event_create(); - /* watchdog_nmi_enable() expects this to be zero initially. */ - if (atomic_dec_and_test(&watchdog_cpus)) - firstcpu_err = 0; + if (ret) { + pr_info("Perf NMI watchdog permanently disabled\n"); + } else { + perf_event_release_kernel(this_cpu_read(watchdog_ev)); + this_cpu_write(watchdog_ev, NULL); } + return ret; } diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 64d0edf428f8..7368b57842ea 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -68,6 +68,7 @@ enum { * attach_mutex to avoid changing binding state while * worker_attach_to_pool() is in progress. */ + POOL_MANAGER_ACTIVE = 1 << 0, /* being managed */ POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */ /* worker flags */ @@ -165,7 +166,6 @@ struct worker_pool { /* L: hash of busy workers */ /* see manage_workers() for details on the two manager mutexes */ - struct mutex manager_arb; /* manager arbitration */ struct worker *manager; /* L: purely informational */ struct mutex attach_mutex; /* attach/detach exclusion */ struct list_head workers; /* A: attached workers */ @@ -299,6 +299,7 @@ static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf; static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ +static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */ static LIST_HEAD(workqueues); /* PR: list of all workqueues */ static bool workqueue_freezing; /* PL: have wqs started freezing? */ @@ -801,7 +802,7 @@ static bool need_to_create_worker(struct worker_pool *pool) /* Do we have too many workers and should some go away? */ static bool too_many_workers(struct worker_pool *pool) { - bool managing = mutex_is_locked(&pool->manager_arb); + bool managing = pool->flags & POOL_MANAGER_ACTIVE; int nr_idle = pool->nr_idle + managing; /* manager is considered idle */ int nr_busy = pool->nr_workers - nr_idle; @@ -1375,7 +1376,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, * queued or lose PENDING. Grabbing PENDING and queueing should * happen with IRQ disabled. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); debug_work_activate(work); @@ -1492,9 +1493,9 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq, } EXPORT_SYMBOL(queue_work_on); -void delayed_work_timer_fn(unsigned long __data) +void delayed_work_timer_fn(struct timer_list *t) { - struct delayed_work *dwork = (struct delayed_work *)__data; + struct delayed_work *dwork = from_timer(dwork, t, timer); /* should have been called from irqsafe timer with irq already off */ __queue_work(dwork->cpu, dwork->wq, &dwork->work); @@ -1508,8 +1509,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, struct work_struct *work = &dwork->work; WARN_ON_ONCE(!wq); - WARN_ON_ONCE(timer->function != delayed_work_timer_fn || - timer->data != (unsigned long)dwork); + WARN_ON_ONCE(timer->function != (TIMER_FUNC_TYPE)delayed_work_timer_fn); WARN_ON_ONCE(timer_pending(timer)); WARN_ON_ONCE(!list_empty(&work->entry)); @@ -1832,9 +1832,9 @@ static void destroy_worker(struct worker *worker) wake_up_process(worker->task); } -static void idle_worker_timeout(unsigned long __pool) +static void idle_worker_timeout(struct timer_list *t) { - struct worker_pool *pool = (void *)__pool; + struct worker_pool *pool = from_timer(pool, t, idle_timer); spin_lock_irq(&pool->lock); @@ -1880,9 +1880,9 @@ static void send_mayday(struct work_struct *work) } } -static void pool_mayday_timeout(unsigned long __pool) +static void pool_mayday_timeout(struct timer_list *t) { - struct worker_pool *pool = (void *)__pool; + struct worker_pool *pool = from_timer(pool, t, mayday_timer); struct work_struct *work; spin_lock_irq(&pool->lock); @@ -1980,24 +1980,17 @@ static bool manage_workers(struct worker *worker) { struct worker_pool *pool = worker->pool; - /* - * Anyone who successfully grabs manager_arb wins the arbitration - * and becomes the manager. mutex_trylock() on pool->manager_arb - * failure while holding pool->lock reliably indicates that someone - * else is managing the pool and the worker which failed trylock - * can proceed to executing work items. This means that anyone - * grabbing manager_arb is responsible for actually performing - * manager duties. If manager_arb is grabbed and released without - * actual management, the pool may stall indefinitely. - */ - if (!mutex_trylock(&pool->manager_arb)) + if (pool->flags & POOL_MANAGER_ACTIVE) return false; + + pool->flags |= POOL_MANAGER_ACTIVE; pool->manager = worker; maybe_create_worker(pool); pool->manager = NULL; - mutex_unlock(&pool->manager_arb); + pool->flags &= ~POOL_MANAGER_ACTIVE; + wake_up(&wq_manager_wait); return true; } @@ -2497,15 +2490,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2611,16 +2597,13 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), + .done = COMPLETION_INITIALIZER_ONSTACK_MAP(this_flusher.done, wq->lockdep_map), }; int next_color; if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2883,9 +2866,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work); @@ -3242,13 +3222,10 @@ static int init_worker_pool(struct worker_pool *pool) INIT_LIST_HEAD(&pool->idle_list); hash_init(pool->busy_hash); - setup_deferrable_timer(&pool->idle_timer, idle_worker_timeout, - (unsigned long)pool); + timer_setup(&pool->idle_timer, idle_worker_timeout, TIMER_DEFERRABLE); - setup_timer(&pool->mayday_timer, pool_mayday_timeout, - (unsigned long)pool); + timer_setup(&pool->mayday_timer, pool_mayday_timeout, 0); - mutex_init(&pool->manager_arb); mutex_init(&pool->attach_mutex); INIT_LIST_HEAD(&pool->workers); @@ -3318,13 +3295,15 @@ static void put_unbound_pool(struct worker_pool *pool) hash_del(&pool->hash_node); /* - * Become the manager and destroy all workers. Grabbing - * manager_arb prevents @pool's workers from blocking on - * attach_mutex. + * Become the manager and destroy all workers. This prevents + * @pool's workers from blocking on attach_mutex. We're the last + * manager and @pool gets freed with the flag set. */ - mutex_lock(&pool->manager_arb); - spin_lock_irq(&pool->lock); + wait_event_lock_irq(wq_manager_wait, + !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock); + pool->flags |= POOL_MANAGER_ACTIVE; + while ((worker = first_idle_worker(pool))) destroy_worker(worker); WARN_ON(pool->nr_workers || pool->nr_idle); @@ -3338,8 +3317,6 @@ static void put_unbound_pool(struct worker_pool *pool) if (pool->detach_completion) wait_for_completion(pool->detach_completion); - mutex_unlock(&pool->manager_arb); - /* shut down the timers */ del_timer_sync(&pool->idle_timer); del_timer_sync(&pool->mayday_timer); @@ -4647,7 +4624,7 @@ static void rebind_workers(struct worker_pool *pool) * concurrency management. Note that when or whether * @worker clears REBOUND doesn't affect correctness. * - * ACCESS_ONCE() is necessary because @worker->flags may be + * WRITE_ONCE() is necessary because @worker->flags may be * tested without holding any lock in * wq_worker_waking_up(). Without it, NOT_RUNNING test may * fail incorrectly leading to premature concurrency @@ -4656,7 +4633,7 @@ static void rebind_workers(struct worker_pool *pool) WARN_ON_ONCE(!(worker_flags & WORKER_UNBOUND)); worker_flags |= WORKER_REBOUND; worker_flags &= ~WORKER_UNBOUND; - ACCESS_ONCE(worker->flags) = worker_flags; + WRITE_ONCE(worker->flags, worker_flags); } spin_unlock_irq(&pool->lock); @@ -5390,11 +5367,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq) { } */ #ifdef CONFIG_WQ_WATCHDOG -static void wq_watchdog_timer_fn(unsigned long data); - static unsigned long wq_watchdog_thresh = 30; -static struct timer_list wq_watchdog_timer = - TIMER_DEFERRED_INITIALIZER(wq_watchdog_timer_fn, 0, 0); +static struct timer_list wq_watchdog_timer; static unsigned long wq_watchdog_touched = INITIAL_JIFFIES; static DEFINE_PER_CPU(unsigned long, wq_watchdog_touched_cpu) = INITIAL_JIFFIES; @@ -5408,7 +5382,7 @@ static void wq_watchdog_reset_touched(void) per_cpu(wq_watchdog_touched_cpu, cpu) = jiffies; } -static void wq_watchdog_timer_fn(unsigned long data) +static void wq_watchdog_timer_fn(struct timer_list *unused) { unsigned long thresh = READ_ONCE(wq_watchdog_thresh) * HZ; bool lockup_detected = false; @@ -5510,6 +5484,7 @@ module_param_cb(watchdog_thresh, &wq_watchdog_thresh_ops, &wq_watchdog_thresh, static void wq_watchdog_init(void) { + timer_setup(&wq_watchdog_timer, wq_watchdog_timer_fn, TIMER_DEFERRABLE); wq_watchdog_set_thresh(wq_watchdog_thresh); } diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index 8635417c587b..d390d1be3748 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * kernel/workqueue_internal.h * @@ -9,6 +10,7 @@ #include <linux/workqueue.h> #include <linux/kthread.h> +#include <linux/preempt.h> struct worker_pool; @@ -59,7 +61,7 @@ struct worker { */ static inline struct worker *current_wq_worker(void) { - if (current->flags & PF_WQ_WORKER) + if (in_task() && (current->flags & PF_WQ_WORKER)) return kthread_data(current); return NULL; } |