From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id E68E97F50 for ; Wed, 12 Aug 2015 08:53:32 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay2.corp.sgi.com (Postfix) with ESMTP id BF760304043 for ; Wed, 12 Aug 2015 06:53:26 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by cuda.sgi.com with ESMTP id AbOoCpqMq2DhfTYh (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Wed, 12 Aug 2015 06:53:24 -0700 (PDT) Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B2D14ABC6 for ; Wed, 12 Aug 2015 13:53:22 +0000 (UTC) From: Jan Kara Subject: [PATCH] xfsprogs: Fix attr leaf block definition Date: Wed, 12 Aug 2015 15:53:14 +0200 Message-Id: <1439387594-8747-1-git-send-email-jack@suse.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: Jan Kara struct xfs_attr_leafblock contains 'entries' array which is declared with size 1 altough it can in fact contain much more entries. Since this array is followed by further struct members, gcc (at least in version 4.8.3) thinks that the delared size of the array is the real one and thus optimizes away all accesses beyond the end of array resulting in non-working code. Signed-off-by: Jan Kara --- include/xfs_da_format.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/xfs_da_format.h b/include/xfs_da_format.h index 11f142078e12..39bfeb042844 100644 --- a/include/xfs_da_format.h +++ b/include/xfs_da_format.h @@ -1180,8 +1180,14 @@ typedef struct xfs_attr_leaf_name_remote { typedef struct xfs_attr_leafblock { xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */ xfs_attr_leaf_entry_t entries[1]; /* sorted on key, not name */ + /* + * Definitions below are commented out so that gcc doesn't optimize + * away accesses into 'entries' for indexes larger than 1 + */ +#if 0 xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */ xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */ +#endif } xfs_attr_leafblock_t; /* -- 2.1.4 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs