diff options
| author | Luo Gengkun <luogengkun2@huawei.com> | 2026-09-20 07:50:26 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-10-01 14:02:05 +0200 |
| commit | ffb684f2aa141eeb0caa6308422e7e05d1ded7c4 (patch) | |
| tree | aa7eb2c587cd15c15e802fb9b47249d7f4fdcaf6 /kernel | |
| parent | 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e (diff) | |
perf: Fix race between perf_event_exit_task() and perf_pending_task()
A race condition exists between perf_event_exit_task() and
perf_pending_task() during begin_new_exec().
During begin_new_exec(), perf_event_exit_task() may be called, and the
PF_EXITING flag is not set on task. So perf_sigtrap() continues to execute
and triggers WARN_ON_ONCE(event->ctx->task != current).
Since both task exit and exec paths can call perf_event_exit_task() which
sets ctx->task to TASK_TOMBSTONE, fix this by explicitly checking if
event->ctx->task equals TASK_TOMBSTONE and dropping the redundant
PF_EXITING check.
Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events")
Signed-off-by: Luo Gengkun <luogengkun2@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260920075026.990582-1-luogengkun2@huawei.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 634d2ccbab82..c2882b5be7c3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7626,9 +7626,11 @@ static void perf_sigtrap(struct perf_event *event) { /* * Both perf_pending_task() and perf_pending_irq() can race with the - * task exiting. + * task exiting or exec-ing. We can determine if such a race has + * occurred by checking if perf_event_exit_task(), which will set + * ctx->task to TASK_TOMBSTONE, has already been called. */ - if (current->flags & PF_EXITING) + if (event->ctx->task == TASK_TOMBSTONE) return; /* |