__exit_signal: don't take rcu lock

There is no reason for rcu_read_lock() in __exit_signal().  tsk->sighand
can only be changed if tsk does exec, obviously this is not possible.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2008-07-25 01:47:29 -07:00 committed by Linus Torvalds
parent 100360f030
commit 3854a77182

View File

@ -85,7 +85,6 @@ static void __exit_signal(struct task_struct *tsk)
BUG_ON(!sig);
BUG_ON(!atomic_read(&sig->count));
rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
@ -136,7 +135,6 @@ static void __exit_signal(struct task_struct *tsk)
tsk->signal = NULL;
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
rcu_read_unlock();
__cleanup_sighand(sighand);
clear_tsk_thread_flag(tsk,TIF_SIGPENDING);