[U-Boot] [PATCH 1/2] fat: fix crash with big sector size
Sergei Shtylyov
sshtylyov at ru.mvista.com
Mon Aug 8 21:38:33 CEST 2011
Apple iPod nanos have sector sizes of 2 or 4 KiB, which crashes U-Boot when it
tries to read the boot sector into 512-byte buffer situated on stack. Make the
FAT code indifferent to the sector size.
Signed-off-by: Sergei Shtylyov <sshtylyov at mvista.com>
---
fs/fat/fat.c | 97 +++++++++++++++++++++++++++++++++++-----------------------
include/fat.h | 20 ++++-------
2 files changed, 67 insertions(+), 50 deletions(-)
Index: u-boot/fs/fat/fat.c
===================================================================
--- u-boot.orig/fs/fat/fat.c
+++ u-boot/fs/fat/fat.c
@@ -27,6 +27,7 @@
#include <common.h>
#include <config.h>
+#include <exports.h>
#include <fat.h>
#include <asm/byteorder.h>
#include <part.h>
@@ -69,8 +70,7 @@ static int disk_read (__u32 startblock,
int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
{
- unsigned char buffer[SECTOR_SIZE];
-
+ unsigned char buffer[dev_desc->blksz];
disk_partition_t info;
if (!dev_desc->block_read)
@@ -209,12 +209,12 @@ static __u32 get_fatent (fsdata *mydata,
/* Read a new block of FAT entries into the cache. */
if (bufnum != mydata->fatbufnum) {
- __u32 getsize = FATBUFSIZE / FS_BLOCK_SIZE;
+ __u32 getsize = FATBUFSIZE / mydata->sect_size;
__u8 *bufptr = mydata->fatbuf;
__u32 fatlength = mydata->fatlength;
__u32 startblock = bufnum * FATBUFBLOCKS;
- fatlength *= SECTOR_SIZE; /* We want it in bytes now */
+ fatlength *= mydata->sect_size; /* We want it in bytes now */
startblock += mydata->fat_sect; /* Offset from start of disk */
if (getsize > fatlength)
@@ -291,21 +291,21 @@ get_cluster (fsdata *mydata, __u32 clust
debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
- if (disk_read(startsect, size / FS_BLOCK_SIZE, buffer) < 0) {
+ if (disk_read(startsect, size / mydata->sect_size, buffer) < 0) {
debug("Error reading data\n");
return -1;
}
- if (size % FS_BLOCK_SIZE) {
- __u8 tmpbuf[FS_BLOCK_SIZE];
+ if (size % mydata->sect_size) {
+ __u8 tmpbuf[mydata->sect_size];
- idx = size / FS_BLOCK_SIZE;
+ idx = size / mydata->sect_size;
if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
debug("Error reading data\n");
return -1;
}
- buffer += idx * FS_BLOCK_SIZE;
+ buffer += idx * mydata->sect_size;
- memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
+ memcpy(buffer, tmpbuf, size % mydata->sect_size);
return 0;
}
@@ -322,7 +322,7 @@ get_contents (fsdata *mydata, dir_entry
unsigned long maxsize)
{
unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
- unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
+ unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
__u32 curclust = START(dentptr);
__u32 endclust, newclust;
unsigned long actsize;
@@ -441,7 +441,7 @@ get_vfatname (fsdata *mydata, int curclu
dir_slot *slotptr = (dir_slot *)retdent;
__u8 *buflimit = cluster + ((curclust == 0) ?
LINEAR_PREFETCH_SIZE :
- (mydata->clust_size * SECTOR_SIZE)
+ (mydata->clust_size * mydata->sect_size)
);
__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
int idx = 0;
@@ -473,7 +473,7 @@ get_vfatname (fsdata *mydata, int curclu
}
if (get_cluster(mydata, curclust, get_vfatname_block,
- mydata->clust_size * SECTOR_SIZE) != 0) {
+ mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return -1;
}
@@ -555,7 +555,7 @@ static dir_entry *get_dentfromdir (fsdat
int i;
if (get_cluster(mydata, curclust, get_dentfromdir_block,
- mydata->clust_size * SECTOR_SIZE) != 0) {
+ mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return NULL;
}
@@ -702,13 +702,24 @@ static dir_entry *get_dentfromdir (fsdat
static int
read_bootsectandvi (boot_sector *bs, volume_info *volinfo, int *fatsize)
{
- __u8 block[FS_BLOCK_SIZE];
-
+ __u8 *block;
volume_info *vistart;
+ int ret = 0;
+
+ if (cur_dev == NULL) {
+ debug("Error: no device selected\n");
+ return -1;
+ }
+
+ block = malloc(cur_dev->blksz);
+ if (block == NULL) {
+ debug("Error: allocating block\n");
+ return -1;
+ }
if (disk_read (0, 1, block) < 0) {
debug("Error: reading block\n");
- return -1;
+ goto fail;
}
memcpy(bs, block, sizeof(boot_sector));
@@ -736,20 +747,24 @@ read_bootsectandvi (boot_sector *bs, vol
if (*fatsize == 32) {
if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
- return 0;
+ goto exit;
} else {
if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 12;
- return 0;
+ goto exit;
}
if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 16;
- return 0;
+ goto exit;
}
}
debug("Error: broken fs_type sign\n");
- return -1;
+fail:
+ ret = -1;
+exit:
+ free(block);
+ return ret;
}
__attribute__ ((__aligned__ (__alignof__ (dir_entry))))
@@ -770,7 +785,7 @@ do_fat_read (const char *filename, void
__u32 cursect;
int idx, isdir = 0;
int files = 0, dirs = 0;
- long ret = 0;
+ long ret = -1;
int firsttime;
__u32 root_cluster;
int rootdir_size = 0;
@@ -793,6 +808,7 @@ do_fat_read (const char *filename, void
cursect = mydata->rootdir_sect
= mydata->fat_sect + mydata->fatlength * bs.fats;
+ mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
mydata->clust_size = bs.cluster_size;
if (mydata->fatsize == 32) {
@@ -802,13 +818,18 @@ do_fat_read (const char *filename, void
rootdir_size = ((bs.dir_entries[1] * (int)256 +
bs.dir_entries[0]) *
sizeof(dir_entry)) /
- SECTOR_SIZE;
+ mydata->sect_size;
mydata->data_begin = mydata->rootdir_sect +
rootdir_size -
(mydata->clust_size * 2);
}
mydata->fatbufnum = -1;
+ mydata->fatbuf = malloc(FATBUFSIZE);
+ if (mydata->fatbuf == NULL) {
+ debug("Error: allocating memory\n");
+ return -1;
+ }
#ifdef CONFIG_SUPPORT_VFAT
debug("VFAT Support enabled\n");
@@ -819,8 +840,9 @@ do_fat_read (const char *filename, void
"Data begins at: %d\n",
root_cluster,
mydata->rootdir_sect,
- mydata->rootdir_sect * SECTOR_SIZE, mydata->data_begin);
- debug("Cluster size: %d\n", mydata->clust_size);
+ mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
+ debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
+ mydata->clust_size);
/* "cwd" is always the root... */
while (ISDIRDELIM(*filename))
@@ -832,7 +854,7 @@ do_fat_read (const char *filename, void
if (*fnamecopy == '\0') {
if (!dols)
- return -1;
+ goto exit;
dols = LS_ROOT;
} else if ((idx = dirdelim(fnamecopy)) >= 0) {
@@ -857,10 +879,10 @@ do_fat_read (const char *filename, void
if (disk_read(cursect,
(mydata->fatsize == 32) ?
(mydata->clust_size) :
- LINEAR_PREFETCH_SIZE / SECTOR_SIZE,
+ LINEAR_PREFETCH_SIZE / mydata->sect_size,
do_fat_read_block) < 0) {
debug("Error: reading rootdir block\n");
- return -1;
+ goto exit;
}
dentptr = (dir_entry *) do_fat_read_block;
@@ -933,9 +955,9 @@ do_fat_read (const char *filename, void
if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
- return 0;
+ ret = 0;
}
- return -1;
+ goto exit;
}
#ifdef CONFIG_SUPPORT_VFAT
else if (dols == LS_ROOT &&
@@ -987,7 +1009,7 @@ do_fat_read (const char *filename, void
}
if (isdir && !(dentptr->attr & ATTR_DIR))
- return -1;
+ goto exit;
debug("RootName: %s", s_name);
debug(", start: 0x%x", START(dentptr));
@@ -1031,10 +1053,9 @@ do_fat_read (const char *filename, void
if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
- return 0;
- } else {
- return -1;
+ ret = 0;
}
+ goto exit;
}
}
rootdir_done:
@@ -1071,13 +1092,13 @@ rootdir_done:
if (get_dentfromdir(mydata, startsect, subname, dentptr,
isdir ? 0 : dols) == NULL) {
if (dols && !isdir)
- return 0;
- return -1;
+ ret = 0;
+ goto exit;
}
if (idx >= 0) {
if (!(dentptr->attr & ATTR_DIR))
- return -1;
+ goto exit;
subname = nextname;
}
}
@@ -1085,6 +1106,8 @@ rootdir_done:
ret = get_contents(mydata, dentptr, buffer, maxsize);
debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
+exit:
+ free(mydata->fatbuf);
return ret;
}
Index: u-boot/include/fat.h
===================================================================
--- u-boot.orig/include/fat.h
+++ u-boot/include/fat.h
@@ -33,22 +33,15 @@
/* Maximum Long File Name length supported here is 128 UTF-16 code units */
#define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */
#define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */
-#define LINEAR_PREFETCH_SIZE (SECTOR_SIZE*2) /* Prefetch buffer size */
-
-#define SECTOR_SIZE FS_BLOCK_SIZE
-
-#define FS_BLOCK_SIZE 512
-
-#if FS_BLOCK_SIZE != SECTOR_SIZE
-#error FS_BLOCK_SIZE != SECTOR_SIZE - This code needs to be fixed!
-#endif
+#define LINEAR_PREFETCH_SIZE (mydata->sect_size*2) /* Prefetch buffer size */
#define MAX_CLUSTSIZE 65536
-#define DIRENTSPERBLOCK (FS_BLOCK_SIZE/sizeof(dir_entry))
-#define DIRENTSPERCLUST ((mydata->clust_size*SECTOR_SIZE)/sizeof(dir_entry))
+#define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry))
+#define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
+ sizeof(dir_entry))
#define FATBUFBLOCKS 6
-#define FATBUFSIZE (FS_BLOCK_SIZE*FATBUFBLOCKS)
+#define FATBUFSIZE (mydata->sect_size * FATBUFBLOCKS)
#define FAT12BUFSIZE ((FATBUFSIZE*2)/3)
#define FAT16BUFSIZE (FATBUFSIZE/2)
#define FAT32BUFSIZE (FATBUFSIZE/4)
@@ -181,11 +174,12 @@ typedef struct dir_slot {
* (see FAT32 accesses)
*/
typedef struct {
- __u8 fatbuf[FATBUFSIZE]; /* Current FAT buffer */
+ __u8 *fatbuf; /* Current FAT buffer */
int fatsize; /* Size of FAT in bits */
__u16 fatlength; /* Length of FAT in sectors */
__u16 fat_sect; /* Starting sector of the FAT */
__u16 rootdir_sect; /* Start sector of root directory */
+ __u16 sect_size; /* Size of sectors in bytes */
__u16 clust_size; /* Size of clusters in sectors */
short data_begin; /* The sector of the first cluster, can be negative */
int fatbufnum; /* Used by get_fatent, init to -1 */
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