From fe826cc2654e8561b64246325e6a51b62bf2488c Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 13 Aug 2024 22:55:11 +0200 Subject: 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 Reported-by: Naresh Kamboju Tested-by: Pengfei Xu Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'kernel/events/core.c') 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(); } /* -- cgit v1.2.3