From ba552461e389361a0efeaa963bd84a20719234bd Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Fri, 8 Feb 2008 04:19:06 -0800
Subject: [PATCH] --- yaml --- r: 84655 b: refs/heads/master c:
 f2cc3eb133baa2e9dc8efd40f417106b2ee520f3 h: refs/heads/master i:   84653:
 b49faafc79dda3e3ff490931b3088165c1738dae   84651:
 959df5d6cedf1c02ad35b2a84343aa282b98329c   84647:
 9bf711bfb469185a3a9588390e0182cfa329b84d   84639:
 7d3a65a050f27ea90180b4ac587aeec6f117e9ae v: v3

---
 [refs]              |  2 +-
 trunk/kernel/exit.c | 39 ++++++++++++++++++---------------------
 2 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/[refs] b/[refs]
index 6daf470068f7..5d6986842520 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 96fabbf55ae79826f2e8a86f4066d7e8834315ae
+refs/heads/master: f2cc3eb133baa2e9dc8efd40f417106b2ee520f3
diff --git a/trunk/kernel/exit.c b/trunk/kernel/exit.c
index 9ee229ea97e4..ee607720ae58 100644
--- a/trunk/kernel/exit.c
+++ b/trunk/kernel/exit.c
@@ -1142,10 +1142,14 @@ static int eligible_child(pid_t pid, int options, struct task_struct *p)
 		return 0;
 
 	err = security_task_wait(p);
-	if (err)
-		return err;
+	if (likely(!err))
+		return 1;
 
-	return 1;
+	if (pid <= 0)
+		return 0;
+	/* This child was explicitly requested, abort */
+	read_unlock(&tasklist_lock);
+	return err;
 }
 
 static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
@@ -1476,7 +1480,6 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 	DECLARE_WAITQUEUE(wait, current);
 	struct task_struct *tsk;
 	int flag, retval;
-	int allowed, denied;
 
 	add_wait_queue(&current->signal->wait_chldexit,&wait);
 repeat:
@@ -1484,8 +1487,7 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 	 * We will set this flag if we see any child that might later
 	 * match our criteria, even if we are not able to reap it yet.
 	 */
-	flag = 0;
-	allowed = denied = 0;
+	flag = retval = 0;
 	current->state = TASK_INTERRUPTIBLE;
 	read_lock(&tasklist_lock);
 	tsk = current;
@@ -1498,13 +1500,8 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 				continue;
 
 			if (unlikely(ret < 0)) {
-				denied = ret;
-				continue;
-			}
-			allowed = 1;
-
-			retval = 0;
-			if (task_is_stopped_or_traced(p)) {
+				retval = ret;
+			} else if (task_is_stopped_or_traced(p)) {
 				/*
 				 * It's stopped now, so it might later
 				 * continue, exit, or stop again.
@@ -1544,11 +1541,14 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 		}
 		if (!flag) {
 			list_for_each_entry(p, &tsk->ptrace_children,
-					    ptrace_list) {
-				if (!eligible_child(pid, options, p))
+								ptrace_list) {
+				flag = eligible_child(pid, options, p);
+				if (!flag)
 					continue;
-				flag = 1;
-				break;
+				if (likely(flag > 0))
+					break;
+				retval = flag;
+				goto end;
 			}
 		}
 		if (options & __WNOTHREAD)
@@ -1556,10 +1556,9 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 		tsk = next_thread(tsk);
 		BUG_ON(tsk->signal != current->signal);
 	} while (tsk != current);
-
 	read_unlock(&tasklist_lock);
+
 	if (flag) {
-		retval = 0;
 		if (options & WNOHANG)
 			goto end;
 		retval = -ERESTARTSYS;
@@ -1569,8 +1568,6 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
 		goto repeat;
 	}
 	retval = -ECHILD;
-	if (unlikely(denied) && !allowed)
-		retval = denied;
 end:
 	current->state = TASK_RUNNING;
 	remove_wait_queue(&current->signal->wait_chldexit,&wait);