From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755932AbdJJIsn (ORCPT ); Tue, 10 Oct 2017 04:48:43 -0400 Received: from www84.your-server.de ([213.133.104.84]:34240 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755538AbdJJIsm (ORCPT ); Tue, 10 Oct 2017 04:48:42 -0400 X-Greylist: delayed 1006 seconds by postgrey-1.27 at vger.kernel.org; Tue, 10 Oct 2017 04:48:41 EDT Message-ID: <1507622382.6064.2.camel@seibold.net> Subject: [PATCH v3 26/26] kfifo: DECLARE_KIFO_PTR(fifo, u64) does not work on arm 32 bit From: Sean Young To: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Stefani Seibold , Randy Dunlap Cc: Andrew Morton Date: Tue, 10 Oct 2017 09:59:42 +0200 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.24.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 41eb6fdf87a8..86b5fb08e96c 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