Commit bc62d68e authored Apr 06, 2020 by Amol Grover Committed by James Morris Aug 20, 2020

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>

parent bcf87687

security/device_cgroup.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -354,7 +354,8 @@ static bool match_exception_partial(struct list_head *exceptions, short type,
		{
		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))

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