This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / kernel / posix-timers.c

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index f846b77..50b7764 100644 (file)
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -397,7 +397,6 @@ static struct k_itimer * alloc_posix_timer(void)
        if (!tmr)
                return tmr;
        memset(tmr, 0, sizeof (struct k_itimer));
-       tmr->it_id = (timer_t)-1;
        if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
                kmem_cache_free(posix_timers_cache, tmr);
                tmr = 0;
@@ -405,9 +404,11 @@ static struct k_itimer * alloc_posix_timer(void)
        return tmr;
 }
 
-static void release_posix_timer(struct k_itimer *tmr)
+#define IT_ID_SET      1
+#define IT_ID_NOT_SET  0
+static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
 {
-       if (tmr->it_id != -1) {
+       if (it_id_set) {
                unsigned long flags;
                spin_lock_irqsave(&idr_lock, flags);
                idr_remove(&posix_timers_id, tmr->it_id);
@@ -429,10 +430,11 @@ sys_timer_create(clockid_t which_clock,
 {
        int error = 0;
        struct k_itimer *new_timer = NULL;
-       timer_t new_timer_id;
+       int new_timer_id;
        struct task_struct *process = 0;
        unsigned long flags;
        sigevent_t event;
+       int it_id_set = IT_ID_NOT_SET;
 
        if ((unsigned) which_clock >= MAX_CLOCKS ||
                                !posix_clocks[which_clock].res)
@@ -443,19 +445,38 @@ sys_timer_create(clockid_t which_clock,
                return -EAGAIN;
 
        spin_lock_init(&new_timer->it_lock);
-       do {
-               if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
-                       error = -EAGAIN;
-                       new_timer->it_id = (timer_t)-1;
-                       goto out;
-               }
-               spin_lock_irq(&idr_lock);
-               new_timer_id = (timer_t) idr_get_new(&posix_timers_id,
-                                                       (void *) new_timer);
-               spin_unlock_irq(&idr_lock);
-       } while (unlikely(new_timer_id == -1));
+ retry:
+       if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
+               error = -EAGAIN;
+               goto out;
+       }
+       spin_lock_irq(&idr_lock);
+       error = idr_get_new(&posix_timers_id,
+                           (void *) new_timer,
+                           &new_timer_id);
+       spin_unlock_irq(&idr_lock);
+       if (error == -EAGAIN)
+               goto retry;
+       else if (error) {
+               /*
+                * Wierd looking, but we return EAGAIN if the IDR is
+                * full (proper POSIX return value for this)
+                */
+               error = -EAGAIN;
+               goto out;
+       }
+
+       it_id_set = IT_ID_SET;
+       new_timer->it_id = (timer_t) new_timer_id;
+       new_timer->it_clock = which_clock;
+       new_timer->it_incr = 0;
+       new_timer->it_overrun = -1;
+       init_timer(&new_timer->it_timer);
+       new_timer->it_timer.expires = 0;
+       new_timer->it_timer.data = (unsigned long) new_timer;
+       new_timer->it_timer.function = posix_timer_fn;
+       set_timer_inactive(new_timer);
 
-       new_timer->it_id = new_timer_id;
        /*
         * return the timer_id now.  The next step is hard to
         * back out if there is an error.
@@ -470,6 +491,10 @@ sys_timer_create(clockid_t which_clock,
                        error = -EFAULT;
                        goto out;
                }
+               new_timer->it_sigev_notify = event.sigev_notify;
+               new_timer->it_sigev_signo = event.sigev_signo;
+               new_timer->it_sigev_value = event.sigev_value;
+
                read_lock(&tasklist_lock);
                if ((process = good_sigevent(&event))) {
                        /*
@@ -489,6 +514,7 @@ sys_timer_create(clockid_t which_clock,
                         */
                        spin_lock_irqsave(&process->sighand->siglock, flags);
                        if (!(process->flags & PF_EXITING)) {
+                               new_timer->it_process = process;
                                list_add(&new_timer->list,
                                         &process->signal->posix_timers);
                                spin_unlock_irqrestore(&process->sighand->siglock, flags);
@@ -503,35 +529,27 @@ sys_timer_create(clockid_t which_clock,
                        error = -EINVAL;
                        goto out;
                }
-               new_timer->it_sigev_notify = event.sigev_notify;
-               new_timer->it_sigev_signo = event.sigev_signo;
-               new_timer->it_sigev_value = event.sigev_value;
        } else {
                new_timer->it_sigev_notify = SIGEV_SIGNAL;
                new_timer->it_sigev_signo = SIGALRM;
                new_timer->it_sigev_value.sival_int = new_timer->it_id;
                process = current->group_leader;
                spin_lock_irqsave(&process->sighand->siglock, flags);
+               new_timer->it_process = process;
                list_add(&new_timer->list, &process->signal->posix_timers);
                spin_unlock_irqrestore(&process->sighand->siglock, flags);
        }
 
-       new_timer->it_clock = which_clock;
-       new_timer->it_incr = 0;
-       new_timer->it_overrun = -1;
-       init_timer(&new_timer->it_timer);
-       new_timer->it_timer.expires = 0;
-       new_timer->it_timer.data = (unsigned long) new_timer;
-       new_timer->it_timer.function = posix_timer_fn;
-       set_timer_inactive(new_timer);
-
-       /*
-        * Once we set the process, it can be found so do it last...
+       /*
+        * In the case of the timer belonging to another task, after
+        * the task is unlocked, the timer is owned by the other task
+        * and may cease to exist at any time.  Don't use or modify
+        * new_timer after the unlock call.
         */
-       new_timer->it_process = process;
+
 out:
        if (error)
-               release_posix_timer(new_timer);
+               release_posix_timer(new_timer, it_id_set);
 
        return error;
 }
@@ -952,7 +970,7 @@ retry_delete:
        timer->it_process = NULL;
        }
        unlock_timer(timer, flags);
-       release_posix_timer(timer);
+       release_posix_timer(timer, IT_ID_SET);
        return 0;
 }
 /*
@@ -989,7 +1007,7 @@ retry_delete:
                timer->it_process = NULL;
        }
        unlock_timer(timer, flags);
-       release_posix_timer(timer);
+       release_posix_timer(timer, IT_ID_SET);
 }
 
 /*