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| author | Peter Zijlstra <peterz@infradead.org> | 2017-09-05 13:23:44 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-10-27 10:31:57 +0200 |
| commit | ca0dd44cf37bfe316751e1701439c3ff44beb05c (patch) | |
| tree | 2c8b7b0d6fb8fb31ae29d00ab2cb25523b9bf9c5 /kernel/events | |
| parent | perf/bpf: Extend the perf_event_read_local() interface, a.k.a. "bpf: perf eve... (diff) | |
| download | linux-ca0dd44cf37bfe316751e1701439c3ff44beb05c.tar.xz linux-ca0dd44cf37bfe316751e1701439c3ff44beb05c.zip | |
perf/core: Fix perf_event_read_value() locking
perf_event_read_value() is an external accessor, just like
perf_event_{en,dis}able() and should thus use perf_event_ctx_lock().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f63a8daa5812 ("perf: Fix event->ctx locking")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 74671e101b92..d636f1d0e2ab 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4398,7 +4398,7 @@ 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; @@ -4426,6 +4426,18 @@ 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, @@ -4528,7 +4540,7 @@ 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) |