2020-09-24 04:11:42

by Walter Wu

[permalink] [raw]
Subject: [PATCH v4 2/6] workqueue: kasan: record workqueue stack

Records the last two enqueuing work call stacks in order to print them
in KASAN report. It is useful for programmers to solve use-after-free
or double-free memory workqueue issue.

For workqueue it has turned out to be useful to record the enqueuing
work call stacks. Because user can see KASAN report to determine
whether it is root cause. They don't need to enable debugobjects,
but they have a chance to find out the root cause.

Signed-off-by: Walter Wu <[email protected]>
Suggested-by: Marco Elver <[email protected]>
Acked-by: Marco Elver <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Dmitry Vyukov <[email protected]>
Reviewed-by: Andrey Konovalov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Lai Jiangshan <[email protected]>
---

v2:
- Thanks for Marco suggestion.
- Remove unnecessary code
- reuse kasan_record_aux_stack() and aux_stack
to record timer and workqueue stack

---

kernel/workqueue.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c41c3c17b86a..5fea7dc9180f 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1324,6 +1324,9 @@ static void insert_work(struct pool_workqueue *pwq, struct work_struct *work,
{
struct worker_pool *pool = pwq->pool;

+ /* record the work call stack in order to print it in KASAN reports */
+ kasan_record_aux_stack(work);
+
/* we own @work, set data and link */
set_work_pwq(work, pwq, extra_flags);
list_add_tail(&work->entry, head);
--
2.18.0