// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (c) International Business Machines Corp., 2006 * Copyright (c) Nokia Corporation, 2006, 2007 * * Author: Artem Bityutskiy (Битюцкий Артём)
*/
/* * UBI input/output sub-system. * * This sub-system provides a uniform way to work with all kinds of the * underlying MTD devices. It also implements handy functions for reading and * writing UBI headers. * * We are trying to have a paranoid mindset and not to trust to what we read * from the flash media in order to be more secure and robust. So this * sub-system validates every single header it reads from the flash media. * * Some words about how the eraseblock headers are stored. * * The erase counter header is always stored at offset zero. By default, the * VID header is stored after the EC header at the closest aligned offset * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID * header at the closest aligned offset. But this default layout may be * changed. For example, for different reasons (e.g., optimization) UBI may be * asked to put the VID header at further offset, and even at an unaligned * offset. Of course, if the offset of the VID header is unaligned, UBI adds * proper padding in front of it. Data offset may also be changed but it has to * be aligned. * * About minimal I/O units. In general, UBI assumes flash device model where * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1, * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the * @ubi->mtd->writesize field. But as an exception, UBI admits use of another * (smaller) minimal I/O unit size for EC and VID headers to make it possible * to do different optimizations. * * This is extremely useful in case of NAND flashes which admit of several * write operations to one NAND page. In this case UBI can fit EC and VID * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI * users. * * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID * headers. * * Q: why not just to treat sub-page as a minimal I/O unit of this flash * device, e.g., make @ubi->min_io_size = 512 in the example above? * * A: because when writing a sub-page, MTD still writes a full 2K page but the * bytes which are not relevant to the sub-page are 0xFF. So, basically, * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page. * Thus, we prefer to use sub-pages only for EC and VID headers. * * As it was noted above, the VID header may start at a non-aligned offset. * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page, * the VID header may reside at offset 1984 which is the last 64 bytes of the * last sub-page (EC header is always at offset zero). This causes some * difficulties when reading and writing VID headers. * * Suppose we have a 64-byte buffer and we read a VID header at it. We change * the data and want to write this VID header out. As we can only write in * 512-byte chunks, we have to allocate one more buffer and copy our VID header * to offset 448 of this buffer. * * The I/O sub-system does the following trick in order to avoid this extra * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. * When the VID header is being written out, it shifts the VID header pointer * back and writes the whole sub-page.
*/
staticint self_check_not_bad(conststruct ubi_device *ubi, int pnum); staticint self_check_peb_ec_hdr(conststruct ubi_device *ubi, int pnum); staticint self_check_ec_hdr(conststruct ubi_device *ubi, int pnum, conststruct ubi_ec_hdr *ec_hdr); staticint self_check_peb_vid_hdr(conststruct ubi_device *ubi, int pnum); staticint self_check_vid_hdr(conststruct ubi_device *ubi, int pnum, conststruct ubi_vid_hdr *vid_hdr); staticint self_check_write(struct ubi_device *ubi, constvoid *buf, int pnum, int offset, int len);
/** * ubi_io_read - read data from a physical eraseblock. * @ubi: UBI device description object * @buf: buffer where to store the read data * @pnum: physical eraseblock number to read from * @offset: offset within the physical eraseblock from where to read * @len: how many bytes to read * * This function reads data from offset @offset of physical eraseblock @pnum * and stores the read data in the @buf buffer. The following return codes are * possible: * * o %0 if all the requested data were successfully read; * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but * correctable bit-flips were detected; this is harmless but may indicate * that this eraseblock may become bad soon (but do not have to); * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for * example it can be an ECC error in case of NAND; this most probably means * that the data is corrupted; * o %-EIO if some I/O error occurred; * o other negative error codes in case of other errors.
*/ int ubi_io_read(conststruct ubi_device *ubi, void *buf, int pnum, int offset, int len)
{ int err, retries = 0;
size_t read;
loff_t addr;
dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
err = self_check_not_bad(ubi, pnum); 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;
if (mtd_is_bitflip(err)) { /* * -EUCLEAN is reported if there was a bit-flip which * was corrected, so this is harmless. * * We do not report about it here unless debugging is * enabled. A corresponding message will be printed * later, when it is has been scrubbed.
*/
ubi_msg(ubi, "fixable bit-flip detected at PEB %d",
pnum);
ubi_assert(len == read); return UBI_IO_BITFLIPS;
}
if (retries++ < UBI_IO_RETRIES) {
ubi_warn(ubi, "error %d%s while reading %d bytes from PEB %d:%d, read only %zd bytes, retry",
err, errstr, len, pnum, offset, read);
yield(); goto retry;
}
ubi_err(ubi, "error %d%s while reading %d bytes from PEB %d:%d, read %zd bytes",
err, errstr, len, pnum, offset, read);
dump_stack();
/* * The driver should never return -EBADMSG if it failed to read * all the requested data. But some buggy drivers might do * this, so we change it to -EIO.
*/ if (read != len && mtd_is_eccerr(err)) {
ubi_assert(0);
err = -EIO;
}
} else {
ubi_assert(len == read);
if (ubi_dbg_is_bitflip(ubi)) {
dbg_gen("bit-flip (emulated)"); return UBI_IO_BITFLIPS;
}
if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE)) {
ubi_warn(ubi, "cannot read %d bytes from PEB %d:%d (emulated)",
len, pnum, offset); return -EIO;
}
if (ubi_dbg_is_eccerr(ubi)) {
ubi_warn(ubi, "ECC error (emulated) while reading %d bytes from PEB %d:%d, read %zd bytes",
len, pnum, offset, read); return -EBADMSG;
}
}
return err;
}
/** * ubi_io_write - write data to a physical eraseblock. * @ubi: UBI device description object * @buf: buffer with the data to write * @pnum: physical eraseblock number to write to * @offset: offset within the physical eraseblock where to write * @len: how many bytes to write * * This function writes @len bytes of data from buffer @buf to offset @offset * of physical eraseblock @pnum. If all the data were successfully written, * zero is returned. If an error occurred, this function returns a negative * error code. If %-EIO is returned, the physical eraseblock most probably went * bad. * * Note, in case of an error, it is possible that something was still written * to the flash media, but may be some garbage.
*/ int ubi_io_write(struct ubi_device *ubi, constvoid *buf, int pnum, int offset, int len)
{ int err;
size_t written;
loff_t addr;
dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
if (ubi->ro_mode) {
ubi_err(ubi, "read-only mode"); return -EROFS;
}
err = self_check_not_bad(ubi, pnum); if (err) return err;
/* The area we are writing to has to contain all 0xFF bytes */
err = ubi_self_check_all_ff(ubi, pnum, offset, len); if (err) return err;
if (offset >= ubi->leb_start) { /* * We write to the data area of the physical eraseblock. Make * sure it has valid EC and VID headers.
*/
err = self_check_peb_ec_hdr(ubi, pnum); if (err) return err;
err = self_check_peb_vid_hdr(ubi, pnum); if (err) return err;
}
if (ubi_dbg_is_write_failure(ubi)) {
ubi_err(ubi, "cannot write %d bytes to PEB %d:%d (emulated)",
len, pnum, offset);
dump_stack(); return -EIO;
}
if (!err) {
err = self_check_write(ubi, buf, pnum, offset, len); if (err) return err;
/* * Since we always write sequentially, the rest of the PEB has * to contain only 0xFF bytes.
*/
offset += len;
len = ubi->peb_size - offset; if (len)
err = ubi_self_check_all_ff(ubi, pnum, offset, len);
}
return err;
}
/** * do_sync_erase - synchronously erase a physical eraseblock. * @ubi: UBI device description object * @pnum: the physical eraseblock number to erase * * This function synchronously erases physical eraseblock @pnum and returns * zero in case of success and a negative error code in case of failure. If * %-EIO is returned, the physical eraseblock most probably went bad.
*/ staticint do_sync_erase(struct ubi_device *ubi, int pnum)
{ int err, retries = 0; struct erase_info ei;
/* Patterns to write to a physical eraseblock when torturing it */ static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
/** * torture_peb - test a supposedly bad physical eraseblock. * @ubi: UBI device description object * @pnum: the physical eraseblock number to test * * This function returns %-EIO if the physical eraseblock did not pass the * test, a positive number of erase operations done if the test was * successfully passed, and other negative error codes in case of other errors.
*/ staticint torture_peb(struct ubi_device *ubi, int pnum)
{ int err, i, patt_count;
ubi_msg(ubi, "run torture test for PEB %d", pnum);
patt_count = ARRAY_SIZE(patterns);
ubi_assert(patt_count > 0);
mutex_lock(&ubi->buf_mutex); for (i = 0; i < patt_count; i++) {
err = do_sync_erase(ubi, pnum); if (err) goto out;
/* Make sure the PEB contains only 0xFF bytes */
err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size); if (err) goto out;
err = ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->peb_size); if (err == 0) {
ubi_err(ubi, "erased PEB %d, but a non-0xFF byte found",
pnum);
err = -EIO; goto out;
}
/* Write a pattern and check it */
memset(ubi->peb_buf, patterns[i], ubi->peb_size);
err = ubi_io_write(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size); if (err) goto out;
err = patt_count;
ubi_msg(ubi, "PEB %d passed torture test, do not mark it as bad", pnum);
out:
mutex_unlock(&ubi->buf_mutex); if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) { /* * If a bit-flip or data integrity error was detected, the test * has not passed because it happened on a freshly erased * physical eraseblock which means something is wrong with it.
*/
ubi_err(ubi, "read problems on freshly erased PEB %d, must be bad",
pnum);
err = -EIO;
} return err;
}
/** * nor_erase_prepare - prepare a NOR flash PEB for erasure. * @ubi: UBI device description object * @pnum: physical eraseblock number to prepare * * NOR flash, or at least some of them, have peculiar embedded PEB erasure * algorithm: the PEB is first filled with zeroes, then it is erased. And * filling with zeroes starts from the end of the PEB. This was observed with * Spansion S29GL512N NOR flash. * * This means that in case of a power cut we may end up with intact data at the * beginning of the PEB, and all zeroes at the end of PEB. In other words, the * EC and VID headers are OK, but a large chunk of data at the end of PEB is * zeroed. This makes UBI mistakenly treat this PEB as used and associate it * with an LEB, which leads to subsequent failures (e.g., UBIFS fails). * * This function is called before erasing NOR PEBs and it zeroes out EC and VID * magic numbers in order to invalidate them and prevent the failures. Returns * zero in case of success and a negative error code in case of failure.
*/ staticint nor_erase_prepare(struct ubi_device *ubi, int pnum)
{ int err;
size_t written;
loff_t addr;
uint32_t data = 0; struct ubi_ec_hdr ec_hdr; struct ubi_vid_io_buf vidb;
/* * 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;
/* * If VID or EC is valid, we have to corrupt them before erasing. * It is important to first invalidate the EC header, and then the VID * header. Otherwise a power cut may lead to valid EC header and * invalid VID header, in which case UBI will treat this PEB as * corrupted and will try to preserve it, and print scary warnings.
*/
addr = (loff_t)pnum * ubi->peb_size;
err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0); if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
err != UBI_IO_FF){
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data); if(err) goto error;
}
error: /* * The PEB contains a valid VID or EC header, but we cannot invalidate * it. Supposedly the flash media or the driver is screwed up, so * return an error.
*/
ubi_err(ubi, "cannot invalidate PEB %d, write returned %d", pnum, err);
ubi_dump_flash(ubi, pnum, 0, ubi->peb_size); return -EIO;
}
/** * ubi_io_sync_erase - synchronously erase a physical eraseblock. * @ubi: UBI device description object * @pnum: physical eraseblock number to erase * @torture: if this physical eraseblock has to be tortured * * This function synchronously erases physical eraseblock @pnum. If @torture * flag is not zero, the physical eraseblock is checked by means of writing * different patterns to it and reading them back. If the torturing is enabled, * the physical eraseblock is erased more than once. * * This function returns the number of erasures made in case of success, %-EIO * if the erasure failed or the torturing test failed, and other negative error * codes in case of other errors. Note, %-EIO means that the physical * eraseblock is bad.
*/ int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
{ int err, ret = 0;
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
err = self_check_not_bad(ubi, pnum); if (err != 0) return err;
if (ubi->ro_mode) {
ubi_err(ubi, "read-only mode"); return -EROFS;
}
/* * If the flash is ECC-ed then we have to erase the ECC block before we * can write to it. But the write is in preparation to an erase in the * first place. This means we cannot zero out EC and VID before the * erase and we just have to hope the flash starts erasing from the * start of the page.
*/ if (ubi->nor_flash && ubi->mtd->writesize == 1) {
err = nor_erase_prepare(ubi, pnum); if (err) return err;
}
if (torture) {
ret = torture_peb(ubi, pnum); if (ret < 0) return ret;
}
err = do_sync_erase(ubi, pnum); if (err) return err;
return ret + 1;
}
/** * ubi_io_is_bad - check if a physical eraseblock is bad. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * * This function returns a positive number if the physical eraseblock is bad, * zero if not, and a negative error code if an error occurred.
*/ int ubi_io_is_bad(conststruct ubi_device *ubi, int pnum)
{ struct mtd_info *mtd = ubi->mtd;
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (ubi->bad_allowed) { int ret;
ret = mtd_block_isbad(mtd, (loff_t)pnum * ubi->peb_size); if (ret < 0)
ubi_err(ubi, "error %d while checking if PEB %d is bad",
ret, pnum); elseif (ret)
dbg_io("PEB %d is bad", pnum); return ret;
}
return 0;
}
/** * ubi_io_mark_bad - mark a physical eraseblock as bad. * @ubi: UBI device description object * @pnum: the physical eraseblock number to mark * * This function returns zero in case of success and a negative error code in * case of failure.
*/ int ubi_io_mark_bad(conststruct ubi_device *ubi, int pnum)
{ int err; struct mtd_info *mtd = ubi->mtd;
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (ubi->ro_mode) {
ubi_err(ubi, "read-only mode"); return -EROFS;
}
/** * validate_ec_hdr - validate an erase counter header. * @ubi: UBI device description object * @ec_hdr: the erase counter header to check * * This function returns zero if the erase counter header is OK, and %1 if * not.
*/ staticint validate_ec_hdr(conststruct ubi_device *ubi, conststruct ubi_ec_hdr *ec_hdr)
{ longlong ec; int vid_hdr_offset, leb_start;
if (ec_hdr->version != UBI_VERSION) {
ubi_err(ubi, "node with incompatible UBI version found: this UBI version is %d, image version is %d",
UBI_VERSION, (int)ec_hdr->version); goto bad;
}
if (vid_hdr_offset != ubi->vid_hdr_offset) {
ubi_err(ubi, "bad VID header offset %d, expected %d",
vid_hdr_offset, ubi->vid_hdr_offset); goto bad;
}
if (leb_start != ubi->leb_start) {
ubi_err(ubi, "bad data offset %d, expected %d",
leb_start, ubi->leb_start); goto bad;
}
/** * ubi_io_read_ec_hdr - read and check an erase counter header. * @ubi: UBI device description object * @pnum: physical eraseblock to read from * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter * header * @verbose: be verbose if the header is corrupted or was not found * * This function reads erase counter header from physical eraseblock @pnum and * stores it in @ec_hdr. This function also checks CRC checksum of the read * erase counter header. The following codes may be returned: * * o %0 if the CRC checksum is correct and the header was successfully read; * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected * and corrected by the flash driver; this is harmless but may indicate that * this eraseblock may become bad soon (but may be not); * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error); * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was * a data integrity error (uncorrectable ECC error in case of NAND); * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty) * o a negative error code in case of failure.
*/ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, struct ubi_ec_hdr *ec_hdr, int verbose)
{ int err, read_err;
uint32_t crc, magic, hdr_crc;
read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); if (read_err) { if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err)) return read_err;
/* * We read all the data, but either a correctable bit-flip * occurred, or MTD reported a data integrity error * (uncorrectable ECC error in case of NAND). The former is * harmless, the later may mean that the read data is * corrupted. But we have a CRC check-sum and we will detect * this. If the EC header is still OK, we just report this as * there was a bit-flip, to force scrubbing.
*/
}
magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) { if (mtd_is_eccerr(read_err)) return UBI_IO_BAD_HDR_EBADMSG;
/* * The magic field is wrong. Let's check if we have read all * 0xFF. If yes, this physical eraseblock is assumed to be * empty.
*/ if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) { /* The physical eraseblock is supposedly empty */ if (verbose)
ubi_warn(ubi, "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 return UBI_IO_FF_BITFLIPS;
}
/* * This is not a valid erase counter header, and these are not * 0xFF bytes. Report that the header is corrupted.
*/ if (verbose) {
ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_EC_HDR_MAGIC);
ubi_dump_ec_hdr(ec_hdr);
}
dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_EC_HDR_MAGIC); return UBI_IO_BAD_HDR;
}
if (hdr_crc != crc) { if (verbose) {
ubi_warn(ubi, "bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc);
ubi_dump_ec_hdr(ec_hdr);
}
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; else return UBI_IO_BAD_HDR_EBADMSG;
}
/* And of course validate what has just been read from the media */
err = validate_ec_hdr(ubi, ec_hdr); if (err) {
ubi_err(ubi, "validation failed for PEB %d", pnum); return -EINVAL;
}
/* * If there was %-EBADMSG, but the header CRC is still OK, report about * a bit-flip to force scrubbing on this PEB.
*/ if (read_err) return UBI_IO_BITFLIPS;
if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_EC)) {
ubi_warn(ubi, "cannot read EC header from PEB %d (emulated)",
pnum); return -EIO;
}
if (ubi_dbg_is_ff(ubi, MASK_IO_FF_EC)) {
ubi_warn(ubi, "bit-all-ff (emulated)"); return UBI_IO_FF;
}
if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_EC)) {
ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)"); return UBI_IO_FF_BITFLIPS;
}
if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_EC)) {
ubi_warn(ubi, "bad_hdr (emulated)"); return UBI_IO_BAD_HDR;
}
if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_EC)) {
ubi_warn(ubi, "bad_hdr with ECC error (emulated)"); return UBI_IO_BAD_HDR_EBADMSG;
}
return 0;
}
/** * ubi_io_write_ec_hdr - write an erase counter header. * @ubi: UBI device description object * @pnum: physical eraseblock to write to * @ec_hdr: the erase counter header to write * * This function writes erase counter header described by @ec_hdr to physical * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec * field. * * This function returns zero in case of success and a negative error code in * case of failure. If %-EIO is returned, the physical eraseblock most probably * went bad.
*/ int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum, struct ubi_ec_hdr *ec_hdr)
{ int err;
uint32_t crc;
/** * validate_vid_hdr - validate a volume identifier header. * @ubi: UBI device description object * @vid_hdr: the volume identifier header to check * * This function checks that data stored in the volume identifier header * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
*/ staticint validate_vid_hdr(conststruct ubi_device *ubi, conststruct ubi_vid_hdr *vid_hdr)
{ int vol_type = vid_hdr->vol_type; int copy_flag = vid_hdr->copy_flag; int vol_id = be32_to_cpu(vid_hdr->vol_id); int lnum = be32_to_cpu(vid_hdr->lnum); int compat = vid_hdr->compat; int data_size = be32_to_cpu(vid_hdr->data_size); int used_ebs = be32_to_cpu(vid_hdr->used_ebs); int data_pad = be32_to_cpu(vid_hdr->data_pad); int data_crc = be32_to_cpu(vid_hdr->data_crc); int usable_leb_size = ubi->leb_size - data_pad;
if (vol_type == UBI_VID_STATIC) { /* * Although from high-level point of view static volumes may * contain zero bytes of data, but no VID headers can contain * zero at these fields, because they empty volumes do not have * mapped logical eraseblocks.
*/ if (used_ebs == 0) {
ubi_err(ubi, "zero used_ebs"); goto bad;
} if (data_size == 0) {
ubi_err(ubi, "zero data_size"); goto bad;
} if (lnum < used_ebs - 1) { if (data_size != usable_leb_size) {
ubi_err(ubi, "bad data_size"); goto bad;
}
} elseif (lnum > used_ebs - 1) {
ubi_err(ubi, "too high lnum"); goto bad;
}
} else { if (copy_flag == 0) { if (data_crc != 0) {
ubi_err(ubi, "non-zero data CRC"); goto bad;
} if (data_size != 0) {
ubi_err(ubi, "non-zero data_size"); goto bad;
}
} else { if (data_size == 0) {
ubi_err(ubi, "zero data_size of copy"); goto bad;
}
} if (used_ebs != 0) {
ubi_err(ubi, "bad used_ebs"); goto bad;
}
}
return 0;
bad:
ubi_err(ubi, "bad VID header");
ubi_dump_vid_hdr(vid_hdr);
dump_stack(); return 1;
}
/** * ubi_io_read_vid_hdr - read and check a volume identifier header. * @ubi: UBI device description object * @pnum: physical eraseblock number to read from * @vidb: the volume identifier buffer to store data in * @verbose: be verbose if the header is corrupted or wasn't found * * This function reads the volume identifier header from physical eraseblock * @pnum and stores it in @vidb. It also checks CRC checksum of the read * volume identifier header. The error codes are the same as in * 'ubi_io_read_ec_hdr()'. * * Note, the implementation of this function is also very similar to * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
*/ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_io_buf *vidb, int verbose)
{ int err, read_err;
uint32_t crc, magic, hdr_crc; struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb); void *p = vidb->buffer;
dbg_io("read VID header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
magic = be32_to_cpu(vid_hdr->magic); if (magic != UBI_VID_HDR_MAGIC) { if (mtd_is_eccerr(read_err)) return UBI_IO_BAD_HDR_EBADMSG;
if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) { if (verbose)
ubi_warn(ubi, "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 return UBI_IO_FF_BITFLIPS;
}
if (verbose) {
ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_VID_HDR_MAGIC);
ubi_dump_vid_hdr(vid_hdr);
}
dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_VID_HDR_MAGIC); return UBI_IO_BAD_HDR;
}
if (hdr_crc != crc) { if (verbose) {
ubi_warn(ubi, "bad CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc);
ubi_dump_vid_hdr(vid_hdr);
}
dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc); if (!read_err) return UBI_IO_BAD_HDR; else return UBI_IO_BAD_HDR_EBADMSG;
}
err = validate_vid_hdr(ubi, vid_hdr); if (err) {
ubi_err(ubi, "validation failed for PEB %d", pnum); return -EINVAL;
}
if (read_err) return UBI_IO_BITFLIPS;
if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_VID)) {
ubi_warn(ubi, "cannot read VID header from PEB %d (emulated)",
pnum); return -EIO;
}
if (ubi_dbg_is_ff(ubi, MASK_IO_FF_VID)) {
ubi_warn(ubi, "bit-all-ff (emulated)"); return UBI_IO_FF;
}
if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_VID)) {
ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)"); return UBI_IO_FF_BITFLIPS;
}
if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_VID)) {
ubi_warn(ubi, "bad_hdr (emulated)"); return UBI_IO_BAD_HDR;
}
if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_VID)) {
ubi_warn(ubi, "bad_hdr with ECC error (emulated)"); return UBI_IO_BAD_HDR_EBADMSG;
}
return 0;
}
/** * ubi_io_write_vid_hdr - write a volume identifier header. * @ubi: UBI device description object * @pnum: the physical eraseblock number to write to * @vidb: the volume identifier buffer to write * * This function writes the volume identifier header described by @vid_hdr to * physical eraseblock @pnum. This function automatically fills the * @vidb->hdr->magic and the @vidb->hdr->version fields, as well as calculates * header CRC checksum and stores it at vidb->hdr->hdr_crc. * * This function returns zero in case of success and a negative error code in * case of failure. If %-EIO is returned, the physical eraseblock probably went * bad.
*/ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_io_buf *vidb)
{ struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb); int err;
uint32_t crc; void *p = vidb->buffer;
dbg_io("write VID header to PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
err = self_check_peb_ec_hdr(ubi, pnum); if (err) return err;
err = self_check_vid_hdr(ubi, pnum, vid_hdr); if (err) return err;
if (ubi_dbg_is_power_cut(ubi, MASK_POWER_CUT_VID)) {
ubi_warn(ubi, "emulating a power cut when writing VID header");
ubi_ro_mode(ubi); return -EROFS;
}
/** * self_check_not_bad - ensure that a physical eraseblock is not bad. * @ubi: UBI device description object * @pnum: physical eraseblock number to check * * This function returns zero if the physical eraseblock is good, %-EINVAL if * it is bad and a negative error code if an error occurred.
*/ staticint self_check_not_bad(conststruct ubi_device *ubi, int pnum)
{ int err;
if (!ubi_dbg_chk_io(ubi)) return 0;
err = ubi_io_is_bad(ubi, pnum); if (!err) return err;
/** * self_check_ec_hdr - check if an erase counter header is all right. * @ubi: UBI device description object * @pnum: physical eraseblock number the erase counter header belongs to * @ec_hdr: the erase counter header to check * * This function returns zero if the erase counter header contains valid * values, and %-EINVAL if not.
*/ staticint self_check_ec_hdr(conststruct ubi_device *ubi, int pnum, conststruct ubi_ec_hdr *ec_hdr)
{ int err;
uint32_t magic;
if (!ubi_dbg_chk_io(ubi)) return 0;
magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) {
ubi_err(ubi, "bad magic %#08x, must be %#08x",
magic, UBI_EC_HDR_MAGIC); goto fail;
}
err = validate_ec_hdr(ubi, ec_hdr); if (err) {
ubi_err(ubi, "self-check failed for PEB %d", pnum); goto fail;
}
/** * self_check_peb_ec_hdr - check erase counter header. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * * This function returns zero if the erase counter header is all right and * a negative error code if not or if an error occurred.
*/ staticint self_check_peb_ec_hdr(conststruct ubi_device *ubi, int pnum)
{ int err;
uint32_t crc, hdr_crc; struct ubi_ec_hdr *ec_hdr;
if (!ubi_dbg_chk_io(ubi)) return 0;
ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS); if (!ec_hdr) return -ENOMEM;
/** * self_check_vid_hdr - check that a volume identifier header is all right. * @ubi: UBI device description object * @pnum: physical eraseblock number the volume identifier header belongs to * @vid_hdr: the volume identifier header to check * * This function returns zero if the volume identifier header is all right, and * %-EINVAL if not.
*/ staticint self_check_vid_hdr(conststruct ubi_device *ubi, int pnum, conststruct ubi_vid_hdr *vid_hdr)
{ int err;
uint32_t magic;
if (!ubi_dbg_chk_io(ubi)) return 0;
magic = be32_to_cpu(vid_hdr->magic); if (magic != UBI_VID_HDR_MAGIC) {
ubi_err(ubi, "bad VID header magic %#08x at PEB %d, must be %#08x",
magic, pnum, UBI_VID_HDR_MAGIC); goto fail;
}
err = validate_vid_hdr(ubi, vid_hdr); if (err) {
ubi_err(ubi, "self-check failed for PEB %d", pnum); goto fail;
}
/** * self_check_peb_vid_hdr - check volume identifier header. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * * This function returns zero if the volume identifier header is all right, * and a negative error code if not or if an error occurred.
*/ staticint self_check_peb_vid_hdr(conststruct ubi_device *ubi, int pnum)
{ int err;
uint32_t crc, hdr_crc; struct ubi_vid_io_buf *vidb; struct ubi_vid_hdr *vid_hdr; void *p;
if (!ubi_dbg_chk_io(ubi)) return 0;
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS); if (!vidb) return -ENOMEM;
/** * self_check_write - make sure write succeeded. * @ubi: UBI device description object * @buf: buffer with data which were written * @pnum: physical eraseblock number the data were written to * @offset: offset within the physical eraseblock the data were written to * @len: how many bytes were written * * This functions reads data which were recently written and compares it with * the original data buffer - the data have to match. Returns zero if the data * match and a negative error code if not or in case of failure.
*/ staticint self_check_write(struct ubi_device *ubi, constvoid *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;
if (!ubi_dbg_chk_io(ubi)) return 0;
buf1 = __vmalloc(len, GFP_NOFS); if (!buf1) {
ubi_err(ubi, "cannot allocate memory to check writes"); return 0;
}
for (i = 0; i < len; i++) {
uint8_t c = ((uint8_t *)buf)[i];
uint8_t c1 = ((uint8_t *)buf1)[i]; int dump_len;
if (c == c1) continue;
ubi_err(ubi, "self-check failed for PEB %d:%d, len %d",
pnum, offset, len);
ubi_msg(ubi, "data differ at position %d", i);
dump_len = max_t(int, 128, len - i);
ubi_msg(ubi, "hex dump of the original buffer from %d to %d",
i, i + dump_len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
buf + i, dump_len, 1);
ubi_msg(ubi, "hex dump of the read buffer from %d to %d",
i, i + dump_len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
buf1 + i, dump_len, 1);
dump_stack();
err = -EINVAL; goto out_free;
}
vfree(buf1); return 0;
out_free:
vfree(buf1); return err;
}
/** * ubi_self_check_all_ff - check that a region of flash is empty. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * @offset: the starting offset within the physical eraseblock to check * @len: the length of the region to check * * This function returns zero if only 0xFF bytes are present at offset * @offset of the physical eraseblock @pnum, and a negative error code if not * or if an error occurred.
*/ int ubi_self_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;
if (!ubi_dbg_chk_io(ubi)) return 0;
buf = __vmalloc(len, GFP_NOFS); if (!buf) {
ubi_err(ubi, "cannot allocate memory to check for 0xFFs"); return 0;
}
err = ubi_check_pattern(buf, 0xFF, len); if (err == 0) {
ubi_err(ubi, "flash region at PEB %d:%d, length %d does not contain all 0xFF bytes",
pnum, offset, len); goto fail;
}
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
