GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-21 14:11:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

cgroup: implement "nsdelegate" mount option

Browse source 
Currently, cgroup only supports delegation to !root users and cgroup
namespaces don't get any special treatments.  This limits the
usefulness of cgroup namespaces as they by themselves can't be safe
delegation boundaries.  A process inside a cgroup can change the
resource control knobs of the parent in the namespace root and may
move processes in and out of the namespace if cgroups outside its
namespace are visible somehow.

This patch adds a new mount option "nsdelegate" which makes cgroup
namespaces delegation boundaries.  If set, cgroup behaves as if write
permission based delegation took place at namespace boundaries -
writes to the resource control knobs from the namespace root are
denied and migration crossing the namespace boundary aren't allowed
from inside the namespace.

This allows cgroup namespace to function as a delegation boundary by
itself.

v2: Silently ignore nsdelegate specified on !init mounts.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Aravind Anbudurai <aru7@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Eric Biederman <ebiederm@xmission.com>
This commit is contained in:
Tejun Heo 2017-06-27 14:30:28 -04:00
parent 824ecbe01c
commit 5136f6365c
3 changed files with 134 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

9
include/linux/cgroup-defs.h
View file

@ -67,12 +67,21 @@ enum {
enum {
CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
/*
* Consider namespaces as delegation boundaries. If this flag is
* set, controller specific interface files in a namespace root
* aren't writeable from inside the namespace.
*/
CGRP_ROOT_NS_DELEGATE = (1 << 3),
};
/* cftype->flags */
enum {
CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
CFTYPE_NS_DELEGATABLE = (1 << 2), /* writeable beyond delegation boundaries */
CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */