diff options
| -rw-r--r-- | arch/s390/include/asm/setup.h | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/perf_cpum_sf.c | 76 | ||||
| -rw-r--r-- | arch/s390/mm/fault.c | 2 |
3 files changed, 78 insertions, 2 deletions
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index 8bc87dcb10eb..2eb0c8a7b664 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -36,7 +36,7 @@ #define MACHINE_FLAG_SCC _BITUL(17) #define LPP_MAGIC _BITUL(31) -#define LPP_PFAULT_PID_MASK _AC(0xffffffff, UL) +#define LPP_PID_MASK _AC(0xffffffff, UL) #ifndef __ASSEMBLY__ diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index dbb62c05805d..227b38bd82c9 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -15,6 +15,7 @@ #include <linux/kernel_stat.h> #include <linux/perf_event.h> #include <linux/percpu.h> +#include <linux/pid.h> #include <linux/notifier.h> #include <linux/export.h> #include <linux/slab.h> @@ -615,6 +616,67 @@ static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si, si->min_sampl_rate, si->max_sampl_rate); } +static u32 cpumsf_pid_type(struct perf_event *event, + u32 pid, enum pid_type type) +{ + struct task_struct *tsk; + + /* Idle process */ + if (!pid) + goto out; + + tsk = find_task_by_pid_ns(pid, &init_pid_ns); + pid = -1; + if (tsk) { + /* + * Only top level events contain the pid namespace in which + * they are created. + */ + if (event->parent) + event = event->parent; + pid = __task_pid_nr_ns(tsk, type, event->ns); + /* + * See also 1d953111b648 + * "perf/core: Don't report zero PIDs for exiting tasks". + */ + if (!pid && !pid_alive(tsk)) + pid = -1; + } +out: + return pid; +} + +static void cpumsf_output_event_pid(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + u32 pid; + struct perf_event_header header; + struct perf_output_handle handle; + + /* + * Obtain the PID from the basic-sampling data entry and + * correct the data->tid_entry.pid value. + */ + pid = data->tid_entry.pid; + + /* Protect callchain buffers, tasks */ + rcu_read_lock(); + + perf_prepare_sample(&header, data, event, regs); + if (perf_output_begin(&handle, event, header.size)) + goto out; + + /* Update the process ID (see also kernel/events/core.c) */ + data->tid_entry.pid = cpumsf_pid_type(event, pid, __PIDTYPE_TGID); + data->tid_entry.tid = cpumsf_pid_type(event, pid, PIDTYPE_PID); + + perf_output_sample(&handle, &header, data, event); + perf_output_end(&handle); +out: + rcu_read_unlock(); +} + static int __hw_perf_event_init(struct perf_event *event) { struct cpu_hw_sf *cpuhw; @@ -748,6 +810,14 @@ static int __hw_perf_event_init(struct perf_event *event) break; } } + + /* If PID/TID sampling is active, replace the default overflow + * handler to extract and resolve the PIDs from the basic-sampling + * data entries. + */ + if (event->attr.sample_type & PERF_SAMPLE_TID) + if (is_default_overflow_handler(event)) + event->overflow_handler = cpumsf_output_event_pid; out: return err; } @@ -985,6 +1055,12 @@ static int perf_push_sample(struct perf_event *event, break; } + /* + * Store the PID value from the sample-data-entry to be + * processed and resolved by cpumsf_output_event_pid(). + */ + data.tid_entry.pid = basic->hpp & LPP_PID_MASK; + overflow = 0; if (perf_exclude_event(event, ®s, sde_regs)) goto out; diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 14654007dce4..93faeca52284 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -728,7 +728,7 @@ static void pfault_interrupt(struct ext_code ext_code, return; inc_irq_stat(IRQEXT_PFL); /* Get the token (= pid of the affected task). */ - pid = param64 & LPP_PFAULT_PID_MASK; + pid = param64 & LPP_PID_MASK; rcu_read_lock(); tsk = find_task_by_pid_ns(pid, &init_pid_ns); if (tsk) |