From ac4977719e157bcb3c45c70d9dd781164727530d Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Mon, 8 Aug 2011 09:38:33 +0000 Subject: [PATCH] fat: fix crash with big sector size 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 --- fs/fat/fat.c | 97 +++++++++++++++++++++++++++++++-------------------- include/fat.h | 20 ++++------- 2 files changed, 67 insertions(+), 50 deletions(-) diff --git a/fs/fat/fat.c b/fs/fat/fat.c index c450bf6924..a344469003 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -27,6 +27,7 @@ #include #include +#include #include #include #include @@ -69,8 +70,7 @@ static int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr) 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, __u32 entry) /* 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 clustnum, __u8 *buffer, 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 *dentptr, __u8 *buffer, 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 curclust, __u8 *cluster, 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 curclust, __u8 *cluster, } 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 (fsdata *mydata, int startsect, 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 (fsdata *mydata, int startsect, 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, volume_info *volinfo, int *fatsize) 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 *buffer, unsigned long maxsize, __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 *buffer, unsigned long maxsize, 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 *buffer, unsigned long maxsize, 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 *buffer, unsigned long maxsize, "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 *buffer, unsigned long maxsize, 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 *buffer, unsigned long maxsize, 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 *buffer, unsigned long maxsize, 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 *buffer, unsigned long maxsize, } 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 *buffer, unsigned long maxsize, 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; } diff --git a/include/fat.h b/include/fat.h index afb2116e8e..c2465d2d3e 100644 --- a/include/fat.h +++ b/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 */ -- 2.39.5