From 7a68f12f675c8bc5d2c6ae71b9d73a0fd1ccd6f7 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=E9=BB=84=E6=B6=9B?= <huangtao@rock-chips.com>
Date: Sat, 30 Jul 2011 22:45:02 +0800
Subject: [PATCH] Revert "cgroup: Add generic cgroup subsystem permission
 checks."

This reverts commit 5038d42d2e60c855cf5b097197d95adaa1269d32.
---
 kernel/cgroup.c         | 19 +++++++++----------
 kernel/cgroup_freezer.c |  8 --------
 kernel/cpuset.c         |  7 -------
 kernel/sched.c          |  9 ---------
 4 files changed, 9 insertions(+), 34 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 455689fd1971..0249f4be9b5c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -51,7 +51,6 @@
 #include <linux/pid_namespace.h>
 #include <linux/idr.h>
 #include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
-#include <linux/capability.h>
 
 #include <asm/atomic.h>
 
@@ -1556,15 +1555,6 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 			retval = ss->can_attach(ss, cgrp, tsk, false);
 			if (retval)
 				return retval;
-		} else if (!capable(CAP_SYS_ADMIN)) {
-			const struct cred *cred = current_cred(), *tcred;
-
-			/* No can_attach() - check perms generically */
-			tcred = __task_cred(tsk);
-			if (cred->euid != tcred->uid &&
-			    cred->euid != tcred->suid) {
-				return -EACCES;
-			}
 		}
 	}
 
@@ -1621,6 +1611,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 static int attach_task_by_pid(struct cgroup *cgrp, u64 pid)
 {
 	struct task_struct *tsk;
+	const struct cred *cred = current_cred(), *tcred;
 	int ret;
 
 	if (pid) {
@@ -1630,6 +1621,14 @@ static int attach_task_by_pid(struct cgroup *cgrp, u64 pid)
 			rcu_read_unlock();
 			return -ESRCH;
 		}
+
+		tcred = __task_cred(tsk);
+		if (cred->euid &&
+		    cred->euid != tcred->uid &&
+		    cred->euid != tcred->suid) {
+			rcu_read_unlock();
+			return -EACCES;
+		}
 		get_task_struct(tsk);
 		rcu_read_unlock();
 	} else {
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 67b155f65a6c..59e9ef6aab40 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -163,14 +163,6 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
 {
 	struct freezer *freezer;
 
-	if ((current != task) && (!capable(CAP_SYS_ADMIN))) {
-		const struct cred *cred = current_cred(), *tcred;
-
-		tcred = __task_cred(task);
-		if (cred->euid != tcred->uid && cred->euid != tcred->suid)
-			return -EPERM;
-	}
-
 	/*
 	 * Anything frozen can't move or be moved to/from.
 	 *
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 2b637ca37be4..b5cb469d2545 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1330,13 +1330,6 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
 	int ret;
 	struct cpuset *cs = cgroup_cs(cont);
 
-	if ((current != task) && (!capable(CAP_SYS_ADMIN))) {
-		const struct cred *cred = current_cred(), *tcred;
-
-		if (cred->euid != tcred->uid && cred->euid != tcred->suid)
-			return -EPERM;
-	}
- 
 	if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
 		return -ENOSPC;
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 117b2b4ebbaf..9f11c6c78415 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -10418,15 +10418,6 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
 static int
 cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 {
-	if ((current != tsk) && (!capable(CAP_SYS_NICE))) {
-		const struct cred *cred = current_cred(), *tcred;
-
-		tcred = __task_cred(tsk);
-
-		if (cred->euid != tcred->uid && cred->euid != tcred->suid)
-			return -EPERM;
-	}
-
 #ifdef CONFIG_RT_GROUP_SCHED
 	if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
 		return -EINVAL;
-- 
2.34.1