[PATCH v5 2/4] kasan: print workqueue stack

[Walter Wu]

The aux_stack[2] is reused to record the call_rcu() call stack
and enqueuing work call stacks. So that we need to change the
auxiliary stack title for common title, print them in KASAN report.

Signed-off-by: Walter Wu <walter-zh.wu at mediatek.com>
Suggested-by: Marco Elver <elver at google.com>
Acked-by: Marco Elver <elver at google.com>
Reviewed-by: Dmitry Vyukov <dvyukov at google.com>
Reviewed-by: Andrey Konovalov <andreyknvl at google.com>
Cc: Andrey Ryabinin <aryabinin at virtuozzo.com>
Cc: Alexander Potapenko <glider at google.com>
---

v4:
- remove a mention of call_rcu() at kasan_record_aux_stack()
  Thanks for Alexander reminder.

v2:
- Thanks for Marco suggestion.
- We modify aux stack title name in KASAN report
  in order to print call_rcu()/timer/workqueue stack.

---
 mm/kasan/generic.c | 3 ---
 mm/kasan/report.c  | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 248264b9cb76..30c0a5038b5c 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -339,9 +339,6 @@ void kasan_record_aux_stack(void *addr)
 	object = nearest_obj(cache, page, addr);
 	alloc_info = get_alloc_info(cache, object);
 
-	/*
-	 * record the last two call_rcu() call stacks.
-	 */
 	alloc_info->aux_stack[1] = alloc_info->aux_stack[0];
 	alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT);
 }
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 00a53f1355ae..5a0102f37171 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -185,12 +185,12 @@ static void describe_object(struct kmem_cache *cache, void *object,
 
 #ifdef CONFIG_KASAN_GENERIC
 		if (alloc_info->aux_stack[0]) {
-			pr_err("Last call_rcu():\n");
+			pr_err("Last potentially related work creation:\n");
 			print_stack(alloc_info->aux_stack[0]);
 			pr_err("\n");
 		}
 		if (alloc_info->aux_stack[1]) {
-			pr_err("Second to last call_rcu():\n");
+			pr_err("Second to last potentially related work creation:\n");
 			print_stack(alloc_info->aux_stack[1]);
 			pr_err("\n");
 		}
-- 
2.18.0