2008-08-04 15:57:36

by Oleg Nesterov

Subject: [PATCH 4/4] 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 <[email protected]>

--- 26-rc2/kernel/posix-timers.c~7_ERROR 2008-08-04 19:14:16.000000000 +0400
+++ 26-rc2/kernel/posix-timers.c 2008-08-04 19:37:07.000000000 +0400
@@ -454,7 +454,7 @@ sys_timer_create(const clockid_t which_c
struct sigevent __user *timer_event_spec,
timer_t __user * created_timer_id)
{
- int error = 0;
+ int error;
struct k_itimer *new_timer;
int new_timer_id;
struct task_struct *process;
@@ -478,9 +478,9 @@ sys_timer_create(const clockid_t which_c
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 +541,8 @@ sys_timer_create(const clockid_t which_c
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 +550,7 @@ sys_timer_create(const clockid_t which_c
* 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;
}