From 8a866fee3909c49738e1c4429a8d2b9bf27e015d Mon Sep 17 00:00:00 2001
From: Sean Young <sean@mess.org>
Date: Sun, 8 Oct 2017 12:12:16 -0400
Subject: [PATCH] kfifo: DECLARE_KIFO_PTR(fifo, u64) does not work on arm 32
bit
Git-commit: 8a866fee3909c49738e1c4429a8d2b9bf27e015d
References: git-fixes
Patch-mainline: v4.16-rc1
If you try to store u64 in a kfifo (or a struct with u64 members),
then the buf member of __STRUCT_KFIFO_PTR will cause 4 bytes
padding due to alignment (note that struct __kfifo is 20 bytes
on 32 bit).
That in turn causes the __is_kfifo_ptr() to fail, which is caught
by kfifo_alloc(), which now returns EINVAL.
So, ensure that __is_kfifo_ptr() compares to the right structure.
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
include/linux/kfifo.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 7b45959ebd92..e251533a5939 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -113,7 +113,8 @@ struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
* array is a part of the structure and the fifo type where the array is
* outside of the fifo structure.
*/
-#define __is_kfifo_ptr(fifo) (sizeof(*fifo) == sizeof(struct __kfifo))
+#define __is_kfifo_ptr(fifo) \
+ (sizeof(*fifo) == sizeof(STRUCT_KFIFO_PTR(typeof(*(fifo)->type))))
/**
* DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
--
2.26.2