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authorNamhyung Kim <namhyung@kernel.org>2024-08-13 22:55:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-10-10 11:57:41 +0200
commit9629c0c3e87653e7a40ff85249495463943b7f63 (patch)
tree89f3d18de7471aa26a08225fceb862884f3d3005 /kernel
parent42cd165b4cf89fb42b794d3a9ee792a7696c49b3 (diff)
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perf: Really fix event_function_call() locking
[ Upstream commit fe826cc2654e8561b64246325e6a51b62bf2488c ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 18eab7f50ecc..0ff381fa2f58 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -263,8 +263,8 @@ 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,
@@ -292,22 +292,25 @@ 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();
}
/*