MIRRORS/linux-yocto
1
0
Fork 0
mirror of git://git.yoctoproject.org/linux-yocto.git synced 2025-10-22 15:03:53 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

perf/core: Fix WARN in perf_sigtrap()

Browse Source 
Since exit_task_work() runs after perf_event_exit_task_context() updated
ctx->task to TASK_TOMBSTONE, perf_sigtrap() from perf_pending_task() might
observe event->ctx->task == TASK_TOMBSTONE.

Swap the early exit tests in order not to hit WARN_ON_ONCE().

Closes: https://syzkaller.appspot.com/bug?extid=2fe61cb2a86066be6985
Reported-by: syzbot <syzbot+2fe61cb2a86066be6985@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/b1c224bd-97f9-462c-a3e3-125d5e19c983@I-love.SAKURA.ne.jp
This commit is contained in:
Tetsuo Handa 2025-07-09 20:27:52 +09:00 committed by Peter Zijlstra
parent d7b8f8e208
commit 3da6bb4197
1 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
kernel/events/core.c
View File

@ -7203,6 +7203,13 @@ void perf_event_wakeup(struct perf_event *event)
static void perf_sigtrap(struct perf_event *event)
{
/*
* Both perf_pending_task() and perf_pending_irq() can race with the
* task exiting.
*/
if (current->flags & PF_EXITING)
return;
/*
* We'd expect this to only occur if the irq_work is delayed and either
* ctx->task or current has changed in the meantime. This can be the
@ -7211,13 +7218,6 @@ static void perf_sigtrap(struct perf_event *event)
if (WARN_ON_ONCE(event->ctx->task != current))
return;
/*
* Both perf_pending_task() and perf_pending_irq() can race with the
* task exiting.
*/
if (current->flags & PF_EXITING)
return;
send_sig_perf((void __user *)event->pending_addr,
event->orig_type, event->attr.sig_data);
}