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:
144ecf310eb5 ("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>
* 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); \