adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-28 03:36:19 +00:00
Code Issues Projects Releases Packages Wiki Activity

cgroup: catch bad css refcnt at css_put

Browse source 
__css_put() doesn't check a bug as refcnt goes to minus.
I think it should be caught. This patch adds a check for it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KAMEZAWA Hiroyuki 2009-10-01 15:44:09 -07:00 committed by Linus Torvalds
parent 26251eaf98
commit 3dece8347d
1 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
kernel/cgroup.c
View file

@ -3708,8 +3708,10 @@ static void check_for_release(struct cgroup *cgrp)
void __css_put(struct cgroup_subsys_state *css) void __css_put(struct cgroup_subsys_state *css)
{ {
struct cgroup *cgrp = css->cgroup; struct cgroup *cgrp = css->cgroup;
int val;
rcu_read_lock(); rcu_read_lock();
if (atomic_dec_return(&css->refcnt) == 1) { val = atomic_dec_return(&css->refcnt);
if (val == 1) {
if (notify_on_release(cgrp)) { if (notify_on_release(cgrp)) {
set_bit(CGRP_RELEASABLE, &cgrp->flags); set_bit(CGRP_RELEASABLE, &cgrp->flags);
check_for_release(cgrp); check_for_release(cgrp);
@ -3717,6 +3719,7 @@ void __css_put(struct cgroup_subsys_state *css)
cgroup_wakeup_rmdir_waiter(cgrp); cgroup_wakeup_rmdir_waiter(cgrp);
} }
rcu_read_unlock(); rcu_read_unlock();
WARN_ON_ONCE(val < 1);
} }
/* /*