lock_timer() checks that the timer found by idr_find(timer_id) has
->it_id == timer_id. This buys nothing. This check can fail only if
sys_timer_create() unlocked idr_lock after idr_get_new(), but didn't
set ->it_id = new_timer_id yet. But in that case ->it_process == NULL
so lock_timer() can't succeed anyway.
Also remove a couple of unneeded typecasts.
Note that with or without this patch we have a small problem.
sys_timer_create() doesn't ensure that the result of setting (say)
->it_sigev_notify must be visible if lock_timer() succeeds.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 26-rc2/kernel/posix-timers.c~9_IT_ID 2008-08-05 16:48:22.000000000 +0400
+++ 26-rc2/kernel/posix-timers.c 2008-08-05 17:56:33.000000000 +0400
@@ -475,8 +475,7 @@ sys_timer_create(const clockid_t which_c
goto out;
}
spin_lock_irq(&idr_lock);
- error = idr_get_new(&posix_timers_id, (void *) new_timer,
- &new_timer_id);
+ error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
spin_unlock_irq(&idr_lock);
if (error) {
if (error == -EAGAIN)
@@ -568,12 +567,12 @@ static struct k_itimer * lock_timer(time
*/
spin_lock_irqsave(&idr_lock, *flags);
- timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id);
+ timr = idr_find(&posix_timers_id, (int) timer_id);
if (timr) {
spin_lock(&timr->it_lock);
- if ((timr->it_id != timer_id) || !(timr->it_process) ||
- !same_thread_group(timr->it_process, current)) {
+ if (!timr->it_process ||
+ !same_thread_group(timr->it_process, current)) {
spin_unlock(&timr->it_lock);
spin_unlock_irqrestore(&idr_lock, *flags);
timr = NULL;
--
