From e4956dc7a84da074fd8dc10f7abd147f15b3ae58 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 13 Aug 2024 06:10:59 -0600
Subject: [PATCH] io_uring/sqpoll: annotate debug task == current with
data_race()
There's a debug check in io_sq_thread_park() checking if it's the SQPOLL
thread itself calling park. KCSAN warns about this, as we should not be
reading sqd->thread outside of sqd->lock.
Just silence this with data_race(). The pointer isn't used for anything
but this debug check.
Reported-by: syzbot+2b946a3fd80caf971b21@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
io_uring/sqpoll.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index b3722e5275e77..3b50dc9586d14 100644
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -44,7 +44,7 @@ void io_sq_thread_unpark(struct io_sq_data *sqd)
void io_sq_thread_park(struct io_sq_data *sqd)
__acquires(&sqd->lock)
{
- WARN_ON_ONCE(sqd->thread == current);
+ WARN_ON_ONCE(data_race(sqd->thread) == current);
atomic_inc(&sqd->park_pending);
set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
--
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