exit_notify: don't take tasklist for TIF_SIGPENDING re-targeting

->siglock provides enough protection to iterate over the thread group.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/exit.c b/kernel/exit.c
index b4d5696..28144b9 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -747,13 +747,11 @@ static void exit_notify(struct task_struct *tsk)
                 * Now we'll wake all the threads in the group just to make
                 * sure someone gets all the pending signals.
                 */
-               read_lock(&tasklist_lock);
                spin_lock_irq(&tsk->sighand->siglock);
                for (t = next_thread(tsk); t != tsk; t = next_thread(t))
                        if (!signal_pending(t) && !(t->flags & PF_EXITING))
                                recalc_sigpending_and_wake(t);
                spin_unlock_irq(&tsk->sighand->siglock);
-               read_unlock(&tasklist_lock);
        }
 
        write_lock_irq(&tasklist_lock);
@@ -781,9 +779,8 @@ static void exit_notify(struct task_struct *tsk)
         * and we were the only connection outside, so our pgrp
         * is about to become orphaned.
         */
-        
        t = tsk->real_parent;
-       
+
        pgrp = task_pgrp(tsk);
        if ((task_pgrp(t) != pgrp) &&
            (task_session(t) == task_session(tsk)) &&