[PATCH 3/9] rcu: Record callback registration stack for Tiny RCU

[Kunwu Chan <kunwu.chan@gmail.com>]

Record the callback registration stack in call_rcu()
for KASAN diagnostics involving Tiny RCU callbacks.

Suggested-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
---
 kernel/rcu/tiny.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 656b6a682e31..bd22fa43108d 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -12,6 +12,7 @@
 #include <linux/completion.h>
 #include <linux/interrupt.h>
 #include <linux/irq_work.h>
+#include <linux/kasan.h>
 #include <linux/llist.h>
 #include <linux/notifier.h>
 #include <linux/rcupdate_wait.h>
@@ -251,6 +252,9 @@ EXPORT_SYMBOL_GPL(synchronize_rcu);
  */
 void call_rcu(struct rcu_head *head, rcu_callback_t func)
 {
+	/* Record the caller: the irq_work's stack says nothing about it. */
+	kasan_record_aux_stack(head);
+
 	if (should_rcu_defer()) {
 		call_rcu_defer(head, func);
 		return;
-- 
2.43.0