From 59707c1b5833d580dbd05bae85b71c0da20c3078 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Fri, 22 May 2015 16:40:51 -0600 Subject: [PATCH] misc: fix alignment warnings on ARM 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 Signed-off-by: Theodore Ts'o --- 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 c1a8684..c8fda48 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 61078cc..cd1d17f 100644 --- a/misc/tune2fs.c +++ b/misc/tune2fs.c @@ -226,7 +226,7 @@ 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; @@ -1936,7 +1936,7 @@ 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)) @@ -2279,7 +2279,7 @@ 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 (sb->s_feature_ro_compat & -- 1.8.3.1