posix-timers: always do get_task_struct(timer->it_process)
Oleg Nesterov [Mon, 22 Sep 2008 21:42:46 +0000 (14:42 -0700)]
Change the code to get/put timer->it_process regardless of
SIGEV_THREAD_ID.  This streamlines the create/destroy paths and allows us
to simplify the usage of exit_itimers() in de_thread().

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>

kernel/posix-timers.c

index 3dfd15a..bd9c931 100644 (file)
@@ -540,11 +540,10 @@ sys_timer_create(const clockid_t which_clock,
                         */
                        spin_lock_irqsave(&process->sighand->siglock, flags);
                        if (!(process->flags & PF_EXITING)) {
+                               get_task_struct(process);
                                new_timer->it_process = process;
                                list_add(&new_timer->list,
                                         &process->signal->posix_timers);
-                               if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
-                                       get_task_struct(process);
                                spin_unlock_irqrestore(&process->sighand->siglock, flags);
                        } else {
                                spin_unlock_irqrestore(&process->sighand->siglock, flags);
@@ -561,6 +560,7 @@ sys_timer_create(const clockid_t which_clock,
                new_timer->it_sigev_signo = SIGALRM;
                new_timer->it_sigev_value.sival_int = new_timer->it_id;
                process = current->group_leader;
+               get_task_struct(process);
                spin_lock_irqsave(&process->sighand->siglock, flags);
                new_timer->it_process = process;
                list_add(&new_timer->list, &process->signal->posix_timers);
@@ -853,8 +853,7 @@ retry_delete:
         * This keeps any tasks waiting on the spin lock from thinking
         * they got something (see the lock code above).
         */
-       if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
-               put_task_struct(timer->it_process);
+       put_task_struct(timer->it_process);
        timer->it_process = NULL;
 
        unlock_timer(timer, flags);
@@ -881,8 +880,7 @@ retry_delete:
         * This keeps any tasks waiting on the spin lock from thinking
         * they got something (see the lock code above).
         */
-       if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
-               put_task_struct(timer->it_process);
+       put_task_struct(timer->it_process);
        timer->it_process = NULL;
 
        unlock_timer(timer, flags);