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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>
hifive-unleashed-5.1
Sean Young 2017-10-08 12:12:16 -04:00 committed by Mauro Carvalho Chehab
parent 62d6f1994b
commit 8a866fee39
1 changed files with 2 additions and 1 deletions
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3
include/linux/kfifo.h
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@ -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