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authorIngo Molnar <mingo@elte.hu>2008-08-14 12:19:59 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-14 12:19:59 +0200
commit8d7ccaa545490cdffdfaff0842436a8dd85cf47b (patch)
tree8129b5907161bc6ae26deb3645ce1e280c5e1f51 /kernel/posix-timers.c
parentb2139aa0eec330c711c5a279db361e5ef1178e78 (diff)
parent30a2f3c60a84092c8084dfe788b710f8d0768cd4 (diff)
Merge commit 'v2.6.27-rc3' into x86/prototypes
Conflicts: include/asm-x86/dma-mapping.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/posix-timers.c')
-rw-r--r--kernel/posix-timers.c40
1 files changed, 22 insertions, 18 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index dbd8398ddb0..e36d5798cbf 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -289,21 +289,29 @@ 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;
@@ -435,6 +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;
}
@@ -449,9 +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);
}
@@ -856,11 +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;
@@ -885,11 +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);
}