posix-timers: sys_timer_create: cleanup the error handling

Cleanup.

- sys_timer_create() is big and complicated. The code above the "out:"
  label relies on the fact that "error" must be == 0. This is not very
  robust, make the code more explicit. Remove the unneeded initialization
  of error.

- If idr_get_new() succeeds (as it normally should), we check the returned
  value twice. Move the "-EAGAIN" check under "if (error)".

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>

1 files changed, 7 insertions, 8 deletions

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index c459b29efdd4..7be385fe4eca 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -454,9 +454,8 @@ sys_timer_create(const clockid_t which_clock,
                  struct sigevent __user *timer_event_spec,
                  timer_t __user * created_timer_id)
 {
-        int error = 0;
         struct k_itimer *new_timer;
-        int new_timer_id;
+        int error, new_timer_id;
         struct task_struct *process;
         sigevent_t event;
         int it_id_set = IT_ID_NOT_SET;
@@ -478,9 +477,9 @@ sys_timer_create(const clockid_t which_clock,
         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) {
+        if (error) {
+                if (error == -EAGAIN)
+                        goto retry;
                 /*
                  * Weird looking, but we return EAGAIN if the IDR is
                  * full (proper POSIX return value for this)
@@ -541,6 +540,8 @@ sys_timer_create(const clockid_t which_clock,
         new_timer->it_process = process;
         list_add(&new_timer->list, &current->signal->posix_timers);
         spin_unlock_irq(&current->sighand->siglock);
+
+        return 0;
         /*
          * In the case of the timer belonging to another task, after
          * the task is unlocked, the timer is owned by the other task
@@ -548,9 +549,7 @@ sys_timer_create(const clockid_t which_clock,
          * new_timer after the unlock call.
          */
 out:
-        if (error)
-                release_posix_timer(new_timer, it_id_set);
-
+        release_posix_timer(new_timer, it_id_set);
         return error;
 }