[tip: core/rcu] rcu: Record kvfree_call_rcu() call stack for KASAN

[tip-bot2 for Zqiang]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     84109ab58590dc6c4e7eb36329fdc7ec121ed5a5
Gitweb:        https://git.kernel.org/tip/84109ab58590dc6c4e7eb36329fdc7ec121ed5a5
Author:        Zqiang <qiang.zhang@xxxxxxxxxxxxx>
AuthorDate:    Fri, 20 Nov 2020 06:53:11 -08:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 04 Jan 2021 13:42:04 -08:00

rcu: Record kvfree_call_rcu() call stack for KASAN

This commit adds a call to kasan_record_aux_stack() in kvfree_call_rcu()
in order to record the call stack of the code that caused the object
to be freed.  Please note that this function does not update the
allocated/freed state, which is important because RCU readers might
still be referencing this object.

Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/rcu/tree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 40e5e3d..2db736c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3498,6 +3498,7 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
 		goto unlock_return;
 	}
 
+	kasan_record_aux_stack(ptr);
 	success = kvfree_call_rcu_add_ptr_to_bulk(krcp, ptr);
 	if (!success) {
 		run_page_cache_worker(krcp);