path: root/include
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authorSean Young <sean@mess.org>2017-10-08 12:12:16 -0400
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-12-14 09:58:35 -0500
commit5ed0d8e09cc1c37d2d848b2127f95cbcd5d517b0 (patch)
tree1d68decc092c0def9e0214abe279c1b395f50f9a /include
parente914eaca465fee65181c3048e4efc3e19a75772a (diff)
kfifo: DECLARE_KIFO_PTR(fifo, u64) does not work on arm 32 bit
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>
Diffstat (limited to 'include')
1 files changed, 2 insertions, 1 deletions
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

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