The patch titled
posix timers: timer_delete: remove the bogus "->it_process != NULL" check
has been added to the -mm tree. Its filename is
posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch
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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: posix timers: timer_delete: remove the bogus "->it_process != NULL" check
From: Oleg Nesterov <oleg@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Roland McGrath <roland@xxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/posix-timers.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff -puN kernel/posix-timers.c~posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check kernel/posix-timers.c
--- a/kernel/posix-timers.c~posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check
+++ a/kernel/posix-timers.c
@@ -856,11 +856,10 @@ 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;
@@ -885,11 +884,10 @@ 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);
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
signals-fix-sigqueue_free-vs-__exit_signal-race.patch
posix-timers-timer_delete-remove-the-bogus-it_process-=-null-check.patch
posix-timers-release_posix_timer-kill-the-bogus-put_task_struct-it_process.patch
signals-sigqueue_free-dont-free-sigqueue-if-it-is-queued.patch
signals-introduce-sigqueue_cancelled.patch
posix-timers-use-sigqueue_cancelled-when-the-timer-is-destroyed.patch
put_pid-make-sure-we-dont-free-the-live-pid.patch
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