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| author | Namhyung Kim <namhyung@kernel.org> | 2024-08-13 22:55:11 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-08-14 07:39:09 +0200 |
| commit | fe826cc2654e8561b64246325e6a51b62bf2488c (patch) | |
| tree | b9e56954867f519127029d26b3f16847346b3f4f /kernel/events/core.c | |
| parent | 3e15a3fe3a2a170c5be52783667706875c088f96 (diff) | |
| download | lwn-fe826cc2654e8561b64246325e6a51b62bf2488c.tar.gz lwn-fe826cc2654e8561b64246325e6a51b62bf2488c.zip | |
perf: Really fix event_function_call() locking
Commit 558abc7e3f89 ("perf: Fix event_function_call() locking") lost
IRQ disabling by mistake.
Fixes: 558abc7e3f89 ("perf: Fix event_function_call() locking")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 9893ba5e98aa..c6a720f41225 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -298,8 +298,8 @@ unlock: static void event_function_call(struct perf_event *event, event_f func, void *data) { struct perf_event_context *ctx = event->ctx; - struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ + struct perf_cpu_context *cpuctx; struct event_function_struct efs = { .event = event, .func = func, @@ -327,22 +327,25 @@ again: if (!task_function_call(task, event_function, &efs)) return; + local_irq_disable(); + cpuctx = this_cpu_ptr(&perf_cpu_context); perf_ctx_lock(cpuctx, ctx); /* * Reload the task pointer, it might have been changed by * a concurrent perf_event_context_sched_out(). */ task = ctx->task; - if (task == TASK_TOMBSTONE) { - perf_ctx_unlock(cpuctx, ctx); - return; - } + if (task == TASK_TOMBSTONE) + goto unlock; if (ctx->is_active) { perf_ctx_unlock(cpuctx, ctx); + local_irq_enable(); goto again; } func(event, NULL, ctx, data); +unlock: perf_ctx_unlock(cpuctx, ctx); + local_irq_enable(); } /* |