diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-09-22 14:42:46 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-09-24 15:45:47 +0200 |
| commit | 4aa7361179bed905fd0f35b236a5c65db683b9e0 (patch) | |
| tree | 115b16f51fafc38f8a76c9fd7e71ce44884aa8e7 | |
| parent | bb34d92f643086d546b49cef680f6f305ed84414 (diff) | |
posix-timers: don't switch to ->group_leader if ->it_process dies
posix_timer_event() drops SIGEV_THREAD_ID and switches to ->group_leader
if send_sigqueue() fails.
This is not very useful and doesn't work reliably. send_sigqueue() can
only fail if ->it_process is dead. But it can die before it dequeues the
SI_TIMER signal, in that case the timer stops anyway.
Remove this code. I guess it was needed a long ago to ensure that the
timer is not destroyed when when its creator thread dies.
Q: perhaps it makes sense to change sys_timer_settime() to return an error
if ->it_process is dead?
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: mingo@elte.hu
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/posix-timers.c | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e36d5798cbf..3dfd15aecc6 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -298,6 +298,7 @@ void do_schedule_next_timer(struct siginfo *info) int posix_timer_event(struct k_itimer *timr, int si_private) { + int shared, ret; /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->do_schedule_next_timer(). @@ -316,20 +317,10 @@ int posix_timer_event(struct k_itimer *timr, int si_private) timr->sigq->info.si_tid = timr->it_id; timr->sigq->info.si_value = timr->it_sigev_value; - if (timr->it_sigev_notify & SIGEV_THREAD_ID) { - struct task_struct *leader; - int ret = send_sigqueue(timr->sigq, timr->it_process, 0); - - if (likely(ret >= 0)) - return ret; - - timr->it_sigev_notify = SIGEV_SIGNAL; - leader = timr->it_process->group_leader; - put_task_struct(timr->it_process); - timr->it_process = leader; - } - - return send_sigqueue(timr->sigq, timr->it_process, 1); + shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); + ret = send_sigqueue(timr->sigq, timr->it_process, shared); + /* If we failed to send the signal the timer stops. */ + return ret > 0; } EXPORT_SYMBOL_GPL(posix_timer_event); |