Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / kernel / posix-timers.c

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 8476956..e36d579 100644 (file)
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -289,29 +289,36 @@ void do_schedule_next_timer(struct siginfo *info)
                else
                        schedule_next_timer(timr);
 
-               info->si_overrun = timr->it_overrun_last;
+               info->si_overrun += timr->it_overrun_last;
        }
 
        if (timr)
                unlock_timer(timr, flags);
 }
 
-int posix_timer_event(struct k_itimer *timr,int si_private)
+int posix_timer_event(struct k_itimer *timr, int si_private)
 {
-       memset(&timr->sigq->info, 0, sizeof(siginfo_t));
+       /*
+        * FIXME: if ->sigq is queued we can race with
+        * dequeue_signal()->do_schedule_next_timer().
+        *
+        * If dequeue_signal() sees the "right" value of
+        * si_sys_private it calls do_schedule_next_timer().
+        * We re-queue ->sigq and drop ->it_lock().
+        * do_schedule_next_timer() locks the timer
+        * and re-schedules it while ->sigq is pending.
+        * Not really bad, but not that we want.
+        */
        timr->sigq->info.si_sys_private = si_private;
-       /* Send signal to the process that owns this timer.*/
 
        timr->sigq->info.si_signo = timr->it_sigev_signo;
-       timr->sigq->info.si_errno = 0;
        timr->sigq->info.si_code = SI_TIMER;
        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->it_sigev_signo, timr->sigq,
-                                       timr->it_process);
+               int ret = send_sigqueue(timr->sigq, timr->it_process, 0);
 
                if (likely(ret >= 0))
                        return ret;
@@ -322,8 +329,7 @@ int posix_timer_event(struct k_itimer *timr,int si_private)
                timr->it_process = leader;
        }
 
-       return send_group_sigqueue(timr->it_sigev_signo, timr->sigq,
-                                  timr->it_process);
+       return send_sigqueue(timr->sigq, timr->it_process, 1);
 }
 EXPORT_SYMBOL_GPL(posix_timer_event);
 
@@ -437,6 +443,7 @@ static struct k_itimer * alloc_posix_timer(void)
                kmem_cache_free(posix_timers_cache, tmr);
                tmr = NULL;
        }
+       memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
        return tmr;
 }
 
@@ -451,9 +458,6 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
                spin_unlock_irqrestore(&idr_lock, flags);
        }
        sigqueue_free(tmr->sigq);
-       if (unlikely(tmr->it_process) &&
-           tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
-               put_task_struct(tmr->it_process);
        kmem_cache_free(posix_timers_cache, tmr);
 }
 
@@ -858,11 +862,10 @@ 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;
@@ -887,11 +890,10 @@ 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);
 }