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| author | Tejun Heo <tj@kernel.org> | 2015-09-18 17:54:23 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2015-09-18 17:54:23 -0400 |
| commit | 7dbdb199d3bf88f043ea17e97113eb28d5b100bc (patch) | |
| tree | 648451cd5f719dafe1c01a18cf2a7903d6166f93 /mm/memcontrol.c | |
| parent | 4a07c222d3afb00e1113834fee38d23a8e5d71dc (diff) | |
| download | lwn-7dbdb199d3bf88f043ea17e97113eb28d5b100bc.tar.gz lwn-7dbdb199d3bf88f043ea17e97113eb28d5b100bc.zip | |
cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE
cftype->mode allows controllers to give arbitrary permissions to
interface knobs. Except for "cgroup.event_control", the existing uses
are spurious.
* Some explicitly specify S_IRUGO | S_IWUSR even though that's the
default.
* "cpuset.memory_pressure" specifies S_IRUGO while also setting a
write callback which returns -EACCES. All it needs to do is simply
not setting a write callback.
"cgroup.event_control" uses cftype->mode to make the file
world-writable. It's a misdesigned interface and we don't want
controllers to be tweaking interface file permissions in general.
This patch removes cftype->mode and all its spurious uses and
implements CFTYPE_WORLD_WRITABLE for "cgroup.event_control" which is
marked as compatibility-only.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b35c4cc47a30..e672f2689326 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4060,8 +4060,7 @@ static struct cftype mem_cgroup_legacy_files[] = { { .name = "cgroup.event_control", /* XXX: for compat */ .write = memcg_write_event_control, - .flags = CFTYPE_NO_PREFIX, - .mode = S_IWUGO, + .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, }, { .name = "swappiness", |