From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 24 Jun 2022 05:30:04 +0000 (+0300)
Subject: kfifo: fix kfifo_to_user() return type
X-Git-Tag: baikal/mips/sdk5.9~171
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=ace38563a3257f36673aed22ff99fe03e80682fc;p=kernel.git

kfifo: fix kfifo_to_user() return type

[ Upstream commit 773ac7caabcbbae504658d302e2d268817b2147d ]

The kfifo_to_user() macro is supposed to return zero for success or
negative error codes.  Unfortunately, there is a signedness bug so it
returns unsigned int.  This only affects callers which try to save the
result in ssize_t and as far as I can see the only place which does that
is line6_hwdep_read().

TL;DR: s/_uint/_int/.

Link: https://lkml.kernel.org/r/YrVL3OJVLlNhIMFs@kili
Fixes: 77b8f66938e3 ("kfifo: fix kfifo_alloc() to return a signed int value")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 86249476b57f4..0b35a41440ff1 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -688,7 +688,7 @@ __kfifo_uint_must_check_helper( \
  * writer, you don't need extra locking to use these macro.
  */
 #define	kfifo_to_user(fifo, to, len, copied) \
-__kfifo_uint_must_check_helper( \
+__kfifo_int_must_check_helper( \
 ({ \
 	typeof((fifo) + 1) __tmp = (fifo); \
 	void __user *__to = (to); \