From 8a866fee3909c49738e1c4429a8d2b9bf27e015d Mon Sep 17 00:00:00 2001 From: Sean Young Date: Sun, 8 Oct 2017 12:12:16 -0400 Subject: [PATCH] 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 Acked-by: Stefani Seibold Signed-off-by: Mauro Carvalho Chehab --- 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 7b45959..e251533 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 -- 2.7.4