[PATCH] io_uring: rw: Fix an unsigned comparison which can never be negative

From: Jiapeng Chong
Date: Thu Sep 15 2022 - 01:49:27 EST


The parameter 'res' is defined as unsigned type, so the following if
statement is invalid, we can modify the type of res to long.
if (res < 0)
res = io->bytes_done;
else
res += io->bytes_done;

io_uring/rw.c:265 io_fixup_rw_res() warn: unsigned 'res' is never less than zero.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2184
Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx>
---
io_uring/rw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/rw.c b/io_uring/rw.c
index b777c35378b9..08d88481153c 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -256,7 +256,7 @@ static bool __io_complete_rw_common(struct io_kiocb *req, long res)
return false;
}

-static inline unsigned io_fixup_rw_res(struct io_kiocb *req, unsigned res)
+static inline unsigned io_fixup_rw_res(struct io_kiocb *req, long res)
{
struct io_async_rw *io = req->async_data;

--
2.20.1.7.g153144c