From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Subject: [PATCH] misc: fix alignment warnings on ARM Date: Fri, 22 May 2015 16:40:51 -0600 Message-ID: <1432334451-15863-1-git-send-email-adilger@dilger.ca> Cc: linux-ext4@vger.kernel.org, Andreas Dilger To: tytso@mit.edu Return-path: Received: from smtp-out-05.shaw.ca ([64.59.134.13]:38583 "EHLO smtp-out-05.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756946AbbEVWtB (ORCPT ); Fri, 22 May 2015 18:49:01 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: Some temporary char buffers allocated on the stack are not properly aligned when typecast to a structure containing __u32 or __u64 types, and this can cause alignment warnings on ARM and other alignment sensitive architectures, and potential slowdowns to do fixups. Fix the buffer alignment to avoid such issues. Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=680090 Reported-by: Gordan Bobic Signed-off-by: Andreas Dilger --- misc/filefrag.c | 2 +- misc/tune2fs.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/misc/filefrag.c b/misc/filefrag.c index 3b104c6..46f1218 100644 --- a/misc/filefrag.c +++ b/misc/filefrag.c @@ -198,7 +198,7 @@ static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex, static int filefrag_fiemap(int fd, int blk_shift, int *num_extents, ext2fs_struct_stat *st) { - char buf[16384]; + __u64 buf[2048]; /* __u64 for proper field alignment */ struct fiemap *fiemap = (struct fiemap *)buf; struct fiemap_extent *fm_ext = &fiemap->fm_extents[0]; int count = (sizeof(buf) - sizeof(*fiemap)) / diff --git a/misc/tune2fs.c b/misc/tune2fs.c index d2e8b20..36c2ff7 100644 --- a/misc/tune2fs.c +++ b/misc/tune2fs.c @@ -240,7 +240,7 @@ static int remove_journal_device(ext2_filsys fs) { char *journal_path; ext2_filsys jfs; - char buf[SUPERBLOCK_SIZE]; + char buf[SUPERBLOCK_SIZE] __attribute__ ((aligned(8))); journal_superblock_t *jsb; int i, nr_users; errcode_t retval; @@ -2609,7 +2609,7 @@ fs_update_journal_user(struct ext2_super_block *sb, __u8 old_uuid[UUID_SIZE]) __u8 *j_uuid; char *journal_path; char uuid[UUID_STR_SIZE]; - char buf[SUPERBLOCK_SIZE]; + char buf[SUPERBLOCK_SIZE] __attribute__ ((aligned(8))); if (!(sb->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) || uuid_is_null(sb->s_journal_uuid)) @@ -2964,7 +2964,7 @@ retry_open: if (U_flag) { int set_csum = 0; dgrp_t i; - char buf[SUPERBLOCK_SIZE]; + char buf[SUPERBLOCK_SIZE] __attribute__ ((aligned(8))); __u8 old_uuid[UUID_SIZE]; if (ext2fs_has_group_desc_csum(fs)) { -- 1.7.3.4