X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fnsproxy.c;h=63598dca2d0c9080448a5f6ab421d72c542f18c1;hb=168b6b1d0594c7866caa73b12f3b8d91075695f2;hp=a4fb7d46971f48a8655ba8e5087025593cf6e79e;hpb=20c2df83d25c6a95affe6157a4c9cac4cf5ffaac;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a4fb7d4..63598dc 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -14,30 +14,18 @@
  */
 
 #include <linux/module.h>
-#include <linux/version.h>
 #include <linux/nsproxy.h>
 #include <linux/init_task.h>
 #include <linux/mnt_namespace.h>
 #include <linux/utsname.h>
 #include <linux/pid_namespace.h>
+#include <net/net_namespace.h>
+#include <linux/ipc_namespace.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
-static inline void get_nsproxy(struct nsproxy *ns)
-{
-	atomic_inc(&ns->count);
-}
-
-void get_task_namespaces(struct task_struct *tsk)
-{
-	struct nsproxy *ns = tsk->nsproxy;
-	if (ns) {
-		get_nsproxy(ns);
-	}
-}
-
 /*
  * creates a copy of "orig" with refcount 1.
  */
@@ -86,21 +74,21 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
 		goto out_ipc;
 	}
 
-	new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
+	new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
 	if (IS_ERR(new_nsp->pid_ns)) {
 		err = PTR_ERR(new_nsp->pid_ns);
 		goto out_pid;
 	}
 
-	new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
-	if (IS_ERR(new_nsp->user_ns)) {
-		err = PTR_ERR(new_nsp->user_ns);
-		goto out_user;
+	new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns);
+	if (IS_ERR(new_nsp->net_ns)) {
+		err = PTR_ERR(new_nsp->net_ns);
+		goto out_net;
 	}
 
 	return new_nsp;
 
-out_user:
+out_net:
 	if (new_nsp->pid_ns)
 		put_pid_ns(new_nsp->pid_ns);
 out_pid:
@@ -132,7 +120,8 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 
 	get_nsproxy(old_ns);
 
-	if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER)))
+	if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
+				CLONE_NEWPID | CLONE_NEWNET)))
 		return 0;
 
 	if (!capable(CAP_SYS_ADMIN)) {
@@ -140,6 +129,18 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 		goto out;
 	}
 
+	/*
+	 * CLONE_NEWIPC must detach from the undolist: after switching
+	 * to a new ipc namespace, the semaphore arrays from the old
+	 * namespace are unreachable.  In clone parlance, CLONE_SYSVSEM
+	 * means share undolist with parent, so we must forbid using
+	 * it along with CLONE_NEWIPC.
+	 */
+	if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	new_ns = create_new_namespaces(flags, tsk, tsk->fs);
 	if (IS_ERR(new_ns)) {
 		err = PTR_ERR(new_ns);
@@ -147,6 +148,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 	}
 
 	tsk->nsproxy = new_ns;
+
 out:
 	put_nsproxy(old_ns);
 	return err;
@@ -162,8 +164,7 @@ void free_nsproxy(struct nsproxy *ns)
 		put_ipc_ns(ns->ipc_ns);
 	if (ns->pid_ns)
 		put_pid_ns(ns->pid_ns);
-	if (ns->user_ns)
-		put_user_ns(ns->user_ns);
+	put_net(ns->net_ns);
 	kmem_cache_free(nsproxy_cachep, ns);
 }
 
@@ -177,7 +178,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 	int err = 0;
 
 	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
-			       CLONE_NEWUSER)))
+			       CLONE_NEWNET)))
 		return 0;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -185,15 +186,49 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 
 	*new_nsp = create_new_namespaces(unshare_flags, current,
 				new_fs ? new_fs : current->fs);
-	if (IS_ERR(*new_nsp))
+	if (IS_ERR(*new_nsp)) {
 		err = PTR_ERR(*new_nsp);
+		goto out;
+	}
+
+	err = ns_cgroup_clone(current, task_pid(current));
+	if (err)
+		put_nsproxy(*new_nsp);
+
+out:
 	return err;
 }
 
+void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
+{
+	struct nsproxy *ns;
+
+	might_sleep();
+
+	ns = p->nsproxy;
+
+	rcu_assign_pointer(p->nsproxy, new);
+
+	if (ns && atomic_dec_and_test(&ns->count)) {
+		/*
+		 * wait for others to get what they want from this nsproxy.
+		 *
+		 * cannot release this nsproxy via the call_rcu() since
+		 * put_mnt_ns() will want to sleep
+		 */
+		synchronize_rcu();
+		free_nsproxy(ns);
+	}
+}
+
+void exit_task_namespaces(struct task_struct *p)
+{
+	switch_task_namespaces(p, NULL);
+}
+
 static int __init nsproxy_cache_init(void)
 {
-	nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
-					   0, SLAB_PANIC, NULL);
+	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
 	return 0;
 }