document de_thread() with exit_notify() connection

Add a couple of small comments, it is not easy to see what this code does.

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>

2 files changed, 2 insertions, 1 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 8fccc276d40d..9f9f931ef949 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -798,7 +798,7 @@ static int de_thread(struct task_struct *tsk)
         if (!thread_group_leader(tsk)) {
                 leader = tsk->group_leader;
 
-                sig->notify_count = -1;
+                sig->notify_count = -1; /* for exit_notify() */
                 for (;;) {
                         write_lock_irq(&tasklist_lock);
                         if (likely(leader->exit_state))
diff --git a/kernel/exit.c b/kernel/exit.c
index 413c81ec858e..879ed6e1c883 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -877,6 +877,7 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
                 state = EXIT_DEAD;
         tsk->exit_state = state;
 
+        /* mt-exec, de_thread() is waiting for us */
         if (thread_group_leader(tsk) &&
             tsk->signal->notify_count < 0 &&
             tsk->signal->group_exit_task)