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perf: Really fix event_function_call() locking

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Commit 558abc7e3f ("perf: Fix event_function_call() locking") lost
IRQ disabling by mistake.

Fixes: 558abc7e3f ("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>
This commit is contained in:
Namhyung Kim
2024-08-13 22:55:11 +02:00
committed by Peter Zijlstra
parent 3e15a3fe3a
commit fe826cc265
1 changed files with 8 additions and 5 deletions
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13
kernel/events/core.c
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@@ -298,8 +298,8 @@ unlock:
static void event_function_call(struct perf_event *event, event_f func, void *data) static void event_function_call(struct perf_event *event, event_f func, void *data)
{ {
struct perf_event_context *ctx = event->ctx; 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 task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
struct perf_cpu_context *cpuctx;
struct event_function_struct efs = { struct event_function_struct efs = {
.event = event, .event = event,
.func = func, .func = func,
@@ -327,22 +327,25 @@ again:
if (!task_function_call(task, event_function, &efs)) if (!task_function_call(task, event_function, &efs))
return; return;
local_irq_disable();
cpuctx = this_cpu_ptr(&perf_cpu_context);
perf_ctx_lock(cpuctx, ctx); perf_ctx_lock(cpuctx, ctx);
/* /*
* Reload the task pointer, it might have been changed by * Reload the task pointer, it might have been changed by
* a concurrent perf_event_context_sched_out(). * a concurrent perf_event_context_sched_out().
*/ */
task = ctx->task; task = ctx->task;
if (task == TASK_TOMBSTONE) { if (task == TASK_TOMBSTONE)
perf_ctx_unlock(cpuctx, ctx); goto unlock;
return;
}
if (ctx->is_active) { if (ctx->is_active) {
perf_ctx_unlock(cpuctx, ctx); perf_ctx_unlock(cpuctx, ctx);
local_irq_enable();
goto again; goto again;
} }
func(event, NULL, ctx, data); func(event, NULL, ctx, data);
unlock:
perf_ctx_unlock(cpuctx, ctx); perf_ctx_unlock(cpuctx, ctx);
local_irq_enable();
} }
/* /*