memcg: enable accounting for new namesapces and struct nsproxy

Container admin can create new namespaces and force kernel to allocate up
to several pages of memory for the namespaces and its associated
structures.

Net and uts namespaces have enabled accounting for such allocations.  It
makes sense to account for rest ones to restrict the host's memory
consumption from inside the memcg-limited container.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Acked-by: Kirill Tkhai <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

fs/namespace.c

@@ -3307,7 +3307,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool a
 	if (!ucounts)
 		return ERR_PTR(-ENOSPC);
 
-	new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
+	new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL_ACCOUNT);
 	if (!new_ns) {
 		dec_mnt_namespaces(ucounts);
 		return ERR_PTR(-ENOMEM);

ipc/namespace.c

@@ -42,7 +42,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 		goto fail;
 
 	err = -ENOMEM;
-	ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
+	ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL_ACCOUNT);
 	if (ns == NULL)
 		goto fail_dec;
 

kernel/cgroup/namespace.c

@@ -24,7 +24,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void)
 	struct cgroup_namespace *new_ns;
 	int ret;
 
-	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL);
+	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL_ACCOUNT);
 	if (!new_ns)
 		return ERR_PTR(-ENOMEM);
 	ret = ns_alloc_inum(&new_ns->ns);

kernel/nsproxy.c

@@ -568,6 +568,6 @@ SYSCALL_DEFINE2(setns, int, fd, int, flags)
 
 int __init nsproxy_cache_init(void)
 {
-	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
+	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC|SLAB_ACCOUNT);
 	return 0;
 }

kernel/pid_namespace.c

@@ -450,7 +450,7 @@ const struct proc_ns_operations pidns_for_children_operations = {
 
 static __init int pid_namespaces_init(void)
 {
-	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
+	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT);
 
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	register_sysctl_paths(kern_path, pid_ns_ctl_table);

kernel/time/namespace.c

@@ -88,13 +88,13 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
 		goto fail;
 
 	err = -ENOMEM;
-	ns = kmalloc(sizeof(*ns), GFP_KERNEL);
+	ns = kmalloc(sizeof(*ns), GFP_KERNEL_ACCOUNT);
 	if (!ns)
 		goto fail_dec;
 
 	refcount_set(&ns->ns.count, 1);
 
-	ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
 	if (!ns->vvar_page)
 		goto fail_free;
 

kernel/user_namespace.c

@@ -1385,7 +1385,7 @@ const struct proc_ns_operations userns_operations = {
 
 static __init int user_namespaces_init(void)
 {
-	user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC);
+	user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC | SLAB_ACCOUNT);
 	return 0;
 }
 subsys_initcall(user_namespaces_init);