diff options
Diffstat (limited to 'drivers/mtd/ubi/io.c')
| -rw-r--r-- | drivers/mtd/ubi/io.c | 145 |
1 files changed, 104 insertions, 41 deletions
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c index 811775a..aaa6e1e 100644 --- a/drivers/mtd/ubi/io.c +++ b/drivers/mtd/ubi/io.c @@ -91,7 +91,7 @@ #include <linux/slab.h> #include "ubi.h" -#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +#ifdef CONFIG_MTD_UBI_DEBUG static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum); static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum); static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, @@ -146,6 +146,28 @@ int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset, if (err) return err; + /* + * Deliberately corrupt the buffer to improve robustness. Indeed, if we + * do not do this, the following may happen: + * 1. The buffer contains data from previous operation, e.g., read from + * another PEB previously. The data looks like expected, e.g., if we + * just do not read anything and return - the caller would not + * notice this. E.g., if we are reading a VID header, the buffer may + * contain a valid VID header from another PEB. + * 2. The driver is buggy and returns us success or -EBADMSG or + * -EUCLEAN, but it does not actually put any data to the buffer. + * + * This may confuse UBI or upper layers - they may think the buffer + * contains valid data while in fact it is just old data. This is + * especially possible because UBI (and UBIFS) relies on CRC, and + * treats data as correct even in case of ECC errors if the CRC is + * correct. + * + * Try to prevent this situation by changing the first byte of the + * buffer. + */ + *((uint8_t *)buf) ^= 0xFF; + addr = (loff_t)pnum * ubi->peb_size + offset; retry: err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf); @@ -166,7 +188,7 @@ retry: return UBI_IO_BITFLIPS; } - if (read != len && retries++ < UBI_IO_RETRIES) { + if (retries++ < UBI_IO_RETRIES) { dbg_io("error %d%s while reading %d bytes from PEB %d:%d," " read only %zd bytes, retry", err, errstr, len, pnum, offset, read); @@ -480,6 +502,13 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum) size_t written; loff_t addr; uint32_t data = 0; + /* + * Note, we cannot generally define VID header buffers on stack, + * because of the way we deal with these buffers (see the header + * comment in this file). But we know this is a NOR-specific piece of + * code, so we can do this. But yes, this is error-prone and we should + * (pre-)allocate VID header buffer instead. + */ struct ubi_vid_hdr vid_hdr; /* @@ -507,11 +536,13 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum) * PEB. */ err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0); - if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) { + if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR || + err1 == UBI_IO_FF) { struct ubi_ec_hdr ec_hdr; err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0); - if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) + if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR || + err1 == UBI_IO_FF) /* * Both VID and EC headers are corrupted, so we can * safely erase this PEB and not afraid that it will be @@ -752,9 +783,8 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, if (verbose) ubi_warn("no EC header found at PEB %d, " "only 0xFF bytes", pnum); - else if (UBI_IO_DEBUG) - dbg_msg("no EC header found at PEB %d, " - "only 0xFF bytes", pnum); + dbg_bld("no EC header found at PEB %d, " + "only 0xFF bytes", pnum); if (!read_err) return UBI_IO_FF; else @@ -769,9 +799,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, ubi_warn("bad magic number at PEB %d: %08x instead of " "%08x", pnum, magic, UBI_EC_HDR_MAGIC); ubi_dbg_dump_ec_hdr(ec_hdr); - } else if (UBI_IO_DEBUG) - dbg_msg("bad magic number at PEB %d: %08x instead of " - "%08x", pnum, magic, UBI_EC_HDR_MAGIC); + } + dbg_bld("bad magic number at PEB %d: %08x instead of " + "%08x", pnum, magic, UBI_EC_HDR_MAGIC); return UBI_IO_BAD_HDR; } @@ -783,9 +813,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, ubi_warn("bad EC header CRC at PEB %d, calculated " "%#08x, read %#08x", pnum, crc, hdr_crc); ubi_dbg_dump_ec_hdr(ec_hdr); - } else if (UBI_IO_DEBUG) - dbg_msg("bad EC header CRC at PEB %d, calculated " - "%#08x, read %#08x", pnum, crc, hdr_crc); + } + dbg_bld("bad EC header CRC at PEB %d, calculated " + "%#08x, read %#08x", pnum, crc, hdr_crc); if (!read_err) return UBI_IO_BAD_HDR; @@ -1008,9 +1038,8 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, if (verbose) ubi_warn("no VID header found at PEB %d, " "only 0xFF bytes", pnum); - else if (UBI_IO_DEBUG) - dbg_msg("no VID header found at PEB %d, " - "only 0xFF bytes", pnum); + dbg_bld("no VID header found at PEB %d, " + "only 0xFF bytes", pnum); if (!read_err) return UBI_IO_FF; else @@ -1021,9 +1050,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, ubi_warn("bad magic number at PEB %d: %08x instead of " "%08x", pnum, magic, UBI_VID_HDR_MAGIC); ubi_dbg_dump_vid_hdr(vid_hdr); - } else if (UBI_IO_DEBUG) - dbg_msg("bad magic number at PEB %d: %08x instead of " - "%08x", pnum, magic, UBI_VID_HDR_MAGIC); + } + dbg_bld("bad magic number at PEB %d: %08x instead of " + "%08x", pnum, magic, UBI_VID_HDR_MAGIC); return UBI_IO_BAD_HDR; } @@ -1035,9 +1064,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, ubi_warn("bad CRC at PEB %d, calculated %#08x, " "read %#08x", pnum, crc, hdr_crc); ubi_dbg_dump_vid_hdr(vid_hdr); - } else if (UBI_IO_DEBUG) - dbg_msg("bad CRC at PEB %d, calculated %#08x, " - "read %#08x", pnum, crc, hdr_crc); + } + dbg_bld("bad CRC at PEB %d, calculated %#08x, " + "read %#08x", pnum, crc, hdr_crc); if (!read_err) return UBI_IO_BAD_HDR; else @@ -1097,7 +1126,7 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, return err; } -#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +#ifdef CONFIG_MTD_UBI_DEBUG /** * paranoid_check_not_bad - ensure that a physical eraseblock is not bad. @@ -1111,6 +1140,9 @@ static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum) { int err; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + err = ubi_io_is_bad(ubi, pnum); if (!err) return err; @@ -1135,6 +1167,9 @@ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, int err; uint32_t magic; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) { ubi_err("bad magic %#08x, must be %#08x", @@ -1170,6 +1205,9 @@ static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum) uint32_t crc, hdr_crc; struct ubi_ec_hdr *ec_hdr; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS); if (!ec_hdr) return -ENOMEM; @@ -1211,6 +1249,9 @@ static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, int err; uint32_t magic; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + magic = be32_to_cpu(vid_hdr->magic); if (magic != UBI_VID_HDR_MAGIC) { ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x", @@ -1249,6 +1290,9 @@ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum) struct ubi_vid_hdr *vid_hdr; void *p; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; @@ -1294,15 +1338,26 @@ int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum, int offset, int len) { int err, i; + size_t read; + void *buf1; + loff_t addr = (loff_t)pnum * ubi->peb_size + offset; - mutex_lock(&ubi->dbg_buf_mutex); - err = ubi_io_read(ubi, ubi->dbg_peb_buf, pnum, offset, len); - if (err) - goto out_unlock; + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + + buf1 = __vmalloc(len, GFP_KERNEL | GFP_NOFS, PAGE_KERNEL); + if (!buf1) { + ubi_err("cannot allocate memory to check writes"); + return 0; + } + + err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf1); + if (err && err != -EUCLEAN) + goto out_free; for (i = 0; i < len; i++) { uint8_t c = ((uint8_t *)buf)[i]; - uint8_t c1 = ((uint8_t *)ubi->dbg_peb_buf)[i]; + uint8_t c1 = ((uint8_t *)buf1)[i]; int dump_len; if (c == c1) @@ -1319,17 +1374,17 @@ int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum, ubi_msg("hex dump of the read buffer from %d to %d", i, i + dump_len); print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, - ubi->dbg_peb_buf + i, dump_len, 1); + buf1 + i, dump_len, 1); ubi_dbg_dump_stack(); err = -EINVAL; - goto out_unlock; + goto out_free; } - mutex_unlock(&ubi->dbg_buf_mutex); + vfree(buf1); return 0; -out_unlock: - mutex_unlock(&ubi->dbg_buf_mutex); +out_free: + vfree(buf1); return err; } @@ -1348,36 +1403,44 @@ int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len) { size_t read; int err; + void *buf; loff_t addr = (loff_t)pnum * ubi->peb_size + offset; - mutex_lock(&ubi->dbg_buf_mutex); - err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf); + if (!(ubi_chk_flags & UBI_CHK_IO)) + return 0; + + buf = __vmalloc(len, GFP_KERNEL | GFP_NOFS, PAGE_KERNEL); + if (!buf) { + ubi_err("cannot allocate memory to check for 0xFFs"); + return 0; + } + + err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf); if (err && err != -EUCLEAN) { ubi_err("error %d while reading %d bytes from PEB %d:%d, " "read %zd bytes", err, len, pnum, offset, read); goto error; } - err = ubi_check_pattern(ubi->dbg_peb_buf, 0xFF, len); + err = ubi_check_pattern(buf, 0xFF, len); if (err == 0) { ubi_err("flash region at PEB %d:%d, length %d does not " "contain all 0xFF bytes", pnum, offset, len); goto fail; } - mutex_unlock(&ubi->dbg_buf_mutex); + vfree(buf); return 0; fail: ubi_err("paranoid check failed for PEB %d", pnum); ubi_msg("hex dump of the %d-%d region", offset, offset + len); - print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, - ubi->dbg_peb_buf, len, 1); + print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1); err = -EINVAL; error: ubi_dbg_dump_stack(); - mutex_unlock(&ubi->dbg_buf_mutex); + vfree(buf); return err; } -#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ +#endif /* CONFIG_MTD_UBI_DEBUG */ |
