kill_pid_info: don't take now unneeded tasklist_lock
Previously handle_stop_signal(SIGCONT) could drop ->siglock. That is why
kill_pid_info(SIGCONT) takes tasklist_lock to make sure the target task can't
go away after unlock. Not needed now.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index 115c04f..ce53ab1 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1039,9 +1039,6 @@
struct task_struct *p;
rcu_read_lock();
- if (unlikely(sig_needs_tasklist(sig)))
- read_lock(&tasklist_lock);
-
retry:
p = pid_task(pid, PIDTYPE_PID);
if (p) {
@@ -1055,10 +1052,8 @@
*/
goto retry;
}
-
- if (unlikely(sig_needs_tasklist(sig)))
- read_unlock(&tasklist_lock);
rcu_read_unlock();
+
return error;
}