Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755506Ab3CFUsq (ORCPT ); Wed, 6 Mar 2013 15:48:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:6582 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755384Ab3CFUsp (ORCPT ); Wed, 6 Mar 2013 15:48:45 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 3/4] UAPI: Fix endianness conditionals in linux/raid/md_p.h To: torvalds@linux-foundation.org From: David Howells Cc: linux-arch@vger.kernel.org, sfr@canb.auug.org.au, Joakim.Tjernlund@transmode.se, arnd@arndb.de, Neil Brown , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, akpm@linux-foundation.org Date: Wed, 06 Mar 2013 20:47:51 +0000 Message-ID: <20130306204751.31327.18239.stgit@warthog.procyon.org.uk> In-Reply-To: <20130306204724.31327.43118.stgit@warthog.procyon.org.uk> References: <20130306204724.31327.43118.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2682 Lines: 56 In the UAPI header files, __BIG_ENDIAN and __LITTLE_ENDIAN must be compared against __BYTE_ORDER in preprocessor conditionals where these are exposed to userspace (that is they're not inside __KERNEL__ conditionals). However, in the main kernel the norm is to check for "defined(__XXX_ENDIAN)" rather than comparing against __BYTE_ORDER and this has incorrectly leaked into the userspace headers. The definition of struct mdp_superblock_s in linux/raid/md_p.h is wrong in this way. Note that userspace will likely interpret the ordering of the fields incorrectly as the big-endian variant on a little-endian machines - depending on header inclusion order. [!!!] NOTE [!!!] This patch may adversely change the userspace API. It might be better to fix the ordering of events_hi, events_lo, cp_events_hi and cp_events_lo in struct mdp_superblock_s / typedef mdp_super_t. Signed-off-by: David Howells cc: Neil Brown cc: linux-raid@vger.kernel.org --- include/uapi/linux/raid/md_p.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h index ee75353..fe1a540 100644 --- a/include/uapi/linux/raid/md_p.h +++ b/include/uapi/linux/raid/md_p.h @@ -145,16 +145,18 @@ typedef struct mdp_superblock_s { __u32 failed_disks; /* 4 Number of failed disks */ __u32 spare_disks; /* 5 Number of spare disks */ __u32 sb_csum; /* 6 checksum of the whole superblock */ -#ifdef __BIG_ENDIAN +#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) __u32 events_hi; /* 7 high-order of superblock update count */ __u32 events_lo; /* 8 low-order of superblock update count */ __u32 cp_events_hi; /* 9 high-order of checkpoint update count */ __u32 cp_events_lo; /* 10 low-order of checkpoint update count */ -#else +#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) __u32 events_lo; /* 7 low-order of superblock update count */ __u32 events_hi; /* 8 high-order of superblock update count */ __u32 cp_events_lo; /* 9 low-order of checkpoint update count */ __u32 cp_events_hi; /* 10 high-order of checkpoint update count */ +#else +#error unspecified endianness #endif __u32 recovery_cp; /* 11 recovery checkpoint sector count */ /* There are only valid for minor_version > 90 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/