device_cgroup: Fix RCU list debugging warning
exceptions may be traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section BUT under the
protection of decgroup_mutex. Hence add the corresponding
lockdep expression to fix the following false-positive
warning:
[ 2.304417] =============================
[ 2.304418] WARNING: suspicious RCU usage
[ 2.304420] 5.5.4-stable #17 Tainted: G E
[ 2.304422] -----------------------------
[ 2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!!
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 43ab0ad4..04375df 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -354,7 +354,8 @@
{
struct dev_exception_item *ex;
- list_for_each_entry_rcu(ex, exceptions, list) {
+ list_for_each_entry_rcu(ex, exceptions, list,
+ lockdep_is_held(&devcgroup_mutex)) {
if ((type & DEVCG_DEV_BLOCK) && !(ex->type & DEVCG_DEV_BLOCK))
continue;
if ((type & DEVCG_DEV_CHAR) && !(ex->type & DEVCG_DEV_CHAR))
