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

[Mike Frysinger]

From: Bryan Wu <bryan.wu at 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 at analog.com>
Signed-off-by: Mike Frysinger <vapier at 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