Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2018-12-15

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) fix liveness propagation of callee saved registers, from Jakub.

2) fix overflow in bpf_jit_limit knob, from Daniel.

3) bpf_flow_dissector api fix, from Stanislav.

4) bpf_perf_event api fix on powerpc, from Sandipan.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 25 insertions, 9 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index b1a3545d0ec8..b2890c268cb3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -365,13 +365,11 @@ void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
 }
 
 #ifdef CONFIG_BPF_JIT
-# define BPF_JIT_LIMIT_DEFAULT	(PAGE_SIZE * 40000)
-
 /* All BPF JIT sysctl knobs here. */
 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
 int bpf_jit_harden   __read_mostly;
 int bpf_jit_kallsyms __read_mostly;
-int bpf_jit_limit    __read_mostly = BPF_JIT_LIMIT_DEFAULT;
+long bpf_jit_limit   __read_mostly;
 
 static __always_inline void
 bpf_get_prog_addr_region(const struct bpf_prog *prog,
@@ -580,16 +578,27 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 
 static atomic_long_t bpf_jit_current;
 
+/* Can be overridden by an arch's JIT compiler if it has a custom,
+ * dedicated BPF backend memory area, or if neither of the two
+ * below apply.
+ */
+u64 __weak bpf_jit_alloc_exec_limit(void)
+{
 #if defined(MODULES_VADDR)
+	return MODULES_END - MODULES_VADDR;
+#else
+	return VMALLOC_END - VMALLOC_START;
+#endif
+}
+
 static int __init bpf_jit_charge_init(void)
 {
 	/* Only used as heuristic here to derive limit. */
-	bpf_jit_limit = min_t(u64, round_up((MODULES_END - MODULES_VADDR) >> 2,
-					    PAGE_SIZE), INT_MAX);
+	bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
+					    PAGE_SIZE), LONG_MAX);
 	return 0;
 }
 pure_initcall(bpf_jit_charge_init);
-#endif
 
 static int bpf_jit_charge_modmem(u32 pages)
 {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fc760d00a38c..51ba84d4d34a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5102,9 +5102,16 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 	}
 	new_sl->next = env->explored_states[insn_idx];
 	env->explored_states[insn_idx] = new_sl;
-	/* connect new state to parentage chain */
-	for (i = 0; i < BPF_REG_FP; i++)
-		cur_regs(env)[i].parent = &new->frame[new->curframe]->regs[i];
+	/* connect new state to parentage chain. Current frame needs all
+	 * registers connected. Only r6 - r9 of the callers are alive (pushed
+	 * to the stack implicitly by JITs) so in callers' frames connect just
+	 * r6 - r9 as an optimization. Callers will have r1 - r5 connected to
+	 * the state of the call instruction (with WRITTEN set), and r0 comes
+	 * from callee with its full parentage chain, anyway.
+	 */
+	for (j = 0; j <= cur->curframe; j++)
+		for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++)
+			cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i];
 	/* clear write marks in current state: the writes we did are not writes
 	 * our child did, so they don't screen off its reads from us.
 	 * (There are no read marks in current state, because reads always mark