posix-timers: simplify de_thread()->exit_itimers() path

Impact: simplify code

de_thread() postpones release_task(leader) until after exit_itimers().
This was needed because !SIGEV_THREAD_ID timers could use ->group_leader
without get_task_struct(). With the recent changes we can release the
leader earlier and simplify the code.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 5 deletions

diff --git a/fs/exec.c b/fs/exec.c
index ec5df9a38313..b4e5b8a9216a 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -772,7 +772,6 @@ static int de_thread(struct task_struct *tsk)
         struct signal_struct *sig = tsk->signal;
         struct sighand_struct *oldsighand = tsk->sighand;
         spinlock_t *lock = &oldsighand->siglock;
-        struct task_struct *leader = NULL;
         int count;
 
         if (thread_group_empty(tsk))
@@ -810,7 +809,7 @@ static int de_thread(struct task_struct *tsk)
          * and to assume its PID:
          */
         if (!thread_group_leader(tsk)) {
-                leader = tsk->group_leader;
+                struct task_struct *leader = tsk->group_leader;
 
                 sig->notify_count = -1; /* for exit_notify() */
                 for (;;) {
@@ -862,8 +861,9 @@ static int de_thread(struct task_struct *tsk)
 
                 BUG_ON(leader->exit_state != EXIT_ZOMBIE);
                 leader->exit_state = EXIT_DEAD;
-
                 write_unlock_irq(&tasklist_lock);
+
+                release_task(leader);
         }
 
         sig->group_exit_task = NULL;
@@ -872,8 +872,6 @@ static int de_thread(struct task_struct *tsk)
 no_thread_group:
         exit_itimers(sig);
         flush_itimer_signals();
-        if (leader)
-                release_task(leader);
 
         if (atomic_read(&oldsighand->count) != 1) {
                 struct sighand_struct *newsighand;