* [PATCH 3/4] posix timers: timer_delete: remove the bogus "->it_process != NULL" check
@ 2008-05-03 17:35 Oleg Nesterov
2008-05-06 2:33 ` Roland McGrath
0 siblings, 1 reply; 2+ messages in thread
From: Oleg Nesterov @ 2008-05-03 17:35 UTC (permalink / raw)
To: Andrew Morton
Cc: Austin Clements, Ingo Molnar, john stultz, Linus Torvalds,
Michael Kerrisk, Roland McGrath, Thomas Gleixner, linux-kernel
sys_timer_delete() and itimer_delete() check "timer->it_process != NULL", this
looks completely bogus. ->it_process == NULL means that this timer is already
under destruction or it is not fully initialized, this must not happen.
sys_timer_delete: the timer is locked, and lock_timer() can't succeed
if ->it_process == NULL.
itimer_delete: it is called by exit_itimers() when there are no other
threads which can play with signal_struct->posix_timers.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 25/kernel/posix-timers.c~3_TDEL_NO_CHECK 2008-04-24 16:52:11.000000000 +0400
+++ 25/kernel/posix-timers.c 2008-05-03 19:55:27.000000000 +0400
@@ -855,11 +855,10 @@ retry_delete:
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
- if (timer->it_process) {
- if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
- put_task_struct(timer->it_process);
- timer->it_process = NULL;
- }
+ if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
+ put_task_struct(timer->it_process);
+ timer->it_process = NULL;
+
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
return 0;
@@ -884,11 +883,10 @@ retry_delete:
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
- if (timer->it_process) {
- if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
- put_task_struct(timer->it_process);
- timer->it_process = NULL;
- }
+ if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
+ put_task_struct(timer->it_process);
+ timer->it_process = NULL;
+
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH 3/4] posix timers: timer_delete: remove the bogus "->it_process != NULL" check
2008-05-03 17:35 [PATCH 3/4] posix timers: timer_delete: remove the bogus "->it_process != NULL" check Oleg Nesterov
@ 2008-05-06 2:33 ` Roland McGrath
0 siblings, 0 replies; 2+ messages in thread
From: Roland McGrath @ 2008-05-06 2:33 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Austin Clements, Ingo Molnar, john stultz,
Linus Torvalds, Michael Kerrisk, Thomas Gleixner, linux-kernel
Signed-off-by: Roland McGrath <roland@redhat.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2008-05-06 2:34 UTC | newest]
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2008-05-03 17:35 [PATCH 3/4] posix timers: timer_delete: remove the bogus "->it_process != NULL" check Oleg Nesterov
2008-05-06 2:33 ` Roland McGrath
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