[U-Boot] [PATCH] fat: fix unaligned errors

Mike Frysinger
2009-01-02T00:54:32Z

From: Bryan Wu <bryan.wu@analog.com>

A couple of buffers in the fat code are declared as an array of bytes. But
it is then cast up to a structure with 16bit and 32bit members. Since GCC
assumes structure alignment here, we have to force the buffers to be
aligned according to the structure usage.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
fs/fat/fat.c | 19 +++++++++++++++----
1 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index a9dde7d..06736d9 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -429,12 +429,16 @@ slot2str(dir_slot *slotptr, char *l_name, int *idx)

/*
+ * We need align this buffer to 16bit, cause it will be cast up to
+ * a dir_slot structure
+ */
+__u8 get_vfatname_block[MAX_CLUSTSIZE] __attribute__ ((aligned(sizeof(__u16))));
+/*
* Extract the full long filename starting at 'retdent' (which is really
* a slot) into 'l_name'. If successful also copy the real directory entry
* into 'retdent'
* Return 0 on success, -1 otherwise.
*/
-__u8 get_vfatname_block[MAX_CLUSTSIZE];
static int
get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
dir_entry *retdent, char *l_name)
@@ -517,10 +521,14 @@ mkcksum(const char *str)

/*
+ * We need align this buffer to 32bit, cause it will be cast up to
+ * a dir_entry structure
+ */
+__u8 get_dentfromdir_block[MAX_CLUSTSIZE] __attribute__ ((aligned(sizeof(__u32))));
+/*
* Get the directory entry associated with 'filename' from the directory
* starting at 'startsect'
*/
-__u8 get_dentfromdir_block[MAX_CLUSTSIZE];
static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
char *filename, dir_entry * retdent,
int dols)
@@ -725,8 +733,11 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
return -1;
}

-
-__u8 do_fat_read_block[MAX_CLUSTSIZE]; /* Block buffer */
+/*
+ * We need align this buffer to 32bit, cause it will be cast up to
+ * a dir_entry structure
+ */
+__u8 do_fat_read_block[MAX_CLUSTSIZE] __attribute__ ((aligned(sizeof(__u32))));
long
do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
int dols)
--
1.6.0.6