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authorTejun Heo <tj@kernel.org>2012-11-19 08:13:37 -0800
committerTejun Heo <tj@kernel.org>2012-11-19 08:13:37 -0800
commit02ae7486d05ae6df8395409a4945b2420f1e35c2 (patch)
tree18d3f09250a850d9d6dfe3f62dfe13f4f6353374 /kernel/cgroup.c
parent648bb56d076bde31113f09a7d24d95bc8d4155ac (diff)
cgroup: fix harmless bugs in cgroup_load_subsys() fail path and cgroup_unload_subsys()
* If idr init fails, cgroup_load_subsys() cleared dummytop->subsys[] before calilng ->destroy() making CSS inaccessible to the callback, and didn't unlink ss->sibling. As no modular controller uses ->use_id, this doesn't cause any actual problems. * cgroup_unload_subsys() was forgetting to free idr, call ->pre_destroy() and clear ->active. As there currently is no modular controller which uses ->use_id, ->pre_destroy() or ->active, this doesn't cause any actual problems. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 09751657abdc..5679cb1ce43f 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4420,9 +4420,10 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
if (ss->use_id) {
int ret = cgroup_init_idr(ss, css);
if (ret) {
- dummytop->subsys[ss->subsys_id] = NULL;
ss->destroy(dummytop);
+ dummytop->subsys[ss->subsys_id] = NULL;
subsys[ss->subsys_id] = NULL;
+ list_del_init(&ss->sibling);
mutex_unlock(&cgroup_mutex);
return ret;
}
@@ -4490,7 +4491,19 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
*/
BUG_ON(ss->root != &rootnode);
+ /* ->pre_destroy() should be called outside cgroup_mutex for now */
+ if (ss->pre_destroy)
+ ss->pre_destroy(dummytop);
+
mutex_lock(&cgroup_mutex);
+
+ ss->active = 0;
+
+ if (ss->use_id) {
+ idr_remove_all(&ss->idr);
+ idr_destroy(&ss->idr);
+ }
+
/* deassign the subsys_id */
subsys[ss->subsys_id] = NULL;