From 88e5ad5a2fd8fd5cf74ba75155e2b856afb3923a Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Wed, 30 Apr 2008 00:54:29 -0700
Subject: [PATCH] --- yaml --- r: 95254 b: refs/heads/master c:
 12a3de0a965826096d8adc593bcf4392a7d5b459 h: refs/heads/master v: v3

---
 [refs]             |  2 +-
 trunk/kernel/sys.c | 36 +++++++++++++++++++++---------------
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/[refs] b/[refs]
index 2f4ccdc31389..8bf231711861 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1dd768c0815334d2319d6377f0750ace075b6142
+refs/heads/master: 12a3de0a965826096d8adc593bcf4392a7d5b459
diff --git a/trunk/kernel/sys.c b/trunk/kernel/sys.c
index ddd28e261f3a..895d2d4c9493 100644
--- a/trunk/kernel/sys.c
+++ b/trunk/kernel/sys.c
@@ -991,31 +991,37 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
 
 asmlinkage long sys_getpgid(pid_t pid)
 {
+	struct task_struct *p;
+	struct pid *grp;
+	int retval;
+
+	rcu_read_lock();
 	if (!pid)
-		return task_pgrp_vnr(current);
+		grp = task_pgrp(current);
 	else {
-		int retval;
-		struct task_struct *p;
-
-		read_lock(&tasklist_lock);
-		p = find_task_by_vpid(pid);
 		retval = -ESRCH;
-		if (p) {
-			retval = security_task_getpgid(p);
-			if (!retval)
-				retval = task_pgrp_vnr(p);
-		}
-		read_unlock(&tasklist_lock);
-		return retval;
+		p = find_task_by_vpid(pid);
+		if (!p)
+			goto out;
+		grp = task_pgrp(p);
+		if (!grp)
+			goto out;
+
+		retval = security_task_getpgid(p);
+		if (retval)
+			goto out;
 	}
+	retval = pid_vnr(grp);
+out:
+	rcu_read_unlock();
+	return retval;
 }
 
 #ifdef __ARCH_WANT_SYS_GETPGRP
 
 asmlinkage long sys_getpgrp(void)
 {
-	/* SMP - assuming writes are word atomic this is fine */
-	return task_pgrp_vnr(current);
+	return sys_getpgid(0);
 }
 
 #endif