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authorOleg Nesterov <oleg@tv-sign.ru>2008-04-30 00:53:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:37 -0700
commit7a5e873f096e04e6d8719e4ecb7b70d2decca503 (patch)
tree2d3f7cc6c15e03de02484f9d754a9174ce2fff76
parentfae5fa44f1fd079ffbed8e0add929dd7bbd1347f (diff)
downloadop-kernel-dev-7a5e873f096e04e6d8719e4ecb7b70d2decca503.zip
op-kernel-dev-7a5e873f096e04e6d8719e4ecb7b70d2decca503.tar.gz
signals: de_thread: simplify the ->child_reaper switching
Now that we rely on SIGNAL_UNKILLABLE flag, de_thread() doesn't need the nasty hack to kill the old ->child_reaper during the mt-exec. This also means we can avoid taking tasklist_lock around zap_other_threads(). 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>
-rw-r--r--fs/exec.c15
1 files changed, 2 insertions, 13 deletions
diff --git a/fs/exec.c b/fs/exec.c
index a138839..8fccc27 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -766,9 +766,7 @@ static int de_thread(struct task_struct *tsk)
/*
* Kill all other threads in the thread group.
- * We must hold tasklist_lock to call zap_other_threads.
*/
- read_lock(&tasklist_lock);
spin_lock_irq(lock);
if (signal_group_exit(sig)) {
/*
@@ -776,21 +774,10 @@ static int de_thread(struct task_struct *tsk)
* return so that the signal is processed.
*/
spin_unlock_irq(lock);
- read_unlock(&tasklist_lock);
return -EAGAIN;
}
-
- /*
- * child_reaper ignores SIGKILL, change it now.
- * Reparenting needs write_lock on tasklist_lock,
- * so it is safe to do it under read_lock.
- */
- if (unlikely(tsk->group_leader == task_child_reaper(tsk)))
- task_active_pid_ns(tsk)->child_reaper = tsk;
-
sig->group_exit_task = tsk;
zap_other_threads(tsk);
- read_unlock(&tasklist_lock);
/* Account for the thread group leader hanging around: */
count = thread_group_leader(tsk) ? 1 : 2;
@@ -821,6 +808,8 @@ static int de_thread(struct task_struct *tsk)
schedule();
}
+ if (unlikely(task_child_reaper(tsk) == leader))
+ task_active_pid_ns(tsk)->child_reaper = tsk;
/*
* The only record we have of the real-time age of a
* process, regardless of execs it's done, is start_time.
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