/* * Copyright (c) International Business Machines Corp., 2006 * Copyright (c) Nokia Corporation, 2006, 2007 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Author: Artem Bityutskiy (Битюцкий Артём) */ /* * UBI input/output unit. * * This unit 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 unit * 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 of using 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 no relevant to the sub-page are 0xFF. So, basically, writing * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we * prefer to use sub-pages only for EV 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 unit 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. */ #ifdef UBI_LINUX #include #include #endif #include #include "ubi.h" #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID 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, const struct ubi_ec_hdr *ec_hdr); static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum); static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, const struct ubi_vid_hdr *vid_hdr); static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len); #else #define paranoid_check_not_bad(ubi, pnum) 0 #define paranoid_check_peb_ec_hdr(ubi, pnum) 0 #define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0 #define paranoid_check_peb_vid_hdr(ubi, pnum) 0 #define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0 #define paranoid_check_all_ff(ubi, pnum, offset, len) 0 #endif /** * 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(const struct 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); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); ubi_assert(offset >= 0 && offset + len <= ubi->peb_size); ubi_assert(len > 0); err = paranoid_check_not_bad(ubi, pnum); if (err) return err > 0 ? -EINVAL : err; addr = (loff_t)pnum * ubi->peb_size + offset; retry: err = mtd_read(ubi->mtd, addr, len, &read, buf); if (err) { if (err == -EUCLEAN) { /* * -EUCLEAN is reported if there was a bit-flip which * was corrected, so this is harmless. */ ubi_msg("fixable bit-flip detected at PEB %d", pnum); ubi_assert(len == read); return UBI_IO_BITFLIPS; } if (read != len && retries++ < UBI_IO_RETRIES) { dbg_io("error %d while reading %d bytes from PEB %d:%d, " "read only %zd bytes, retry", err, len, pnum, offset, read); yield(); goto retry; } ubi_err("error %d while reading %d bytes from PEB %d:%d, " "read %zd bytes", err, len, pnum, offset, read); ubi_dbg_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 && err == -EBADMSG) { ubi_assert(0); printk("%s[%d] not here\n", __func__, __LINE__); /* err = -EIO; */ } } else { ubi_assert(len == read); if (ubi_dbg_is_bitflip()) { dbg_msg("bit-flip (emulated)"); err = UBI_IO_BITFLIPS; } } 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, const void *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); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); ubi_assert(offset >= 0 && offset + len <= ubi->peb_size); ubi_assert(offset % ubi->hdrs_min_io_size == 0); ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0); if (ubi->ro_mode) { ubi_err("read-only mode"); return -EROFS; } /* The below has to be compiled out if paranoid checks are disabled */ err = paranoid_check_not_bad(ubi, pnum); if (err) return err > 0 ? -EINVAL : err; /* The area we are writing to has to contain all 0xFF bytes */ err = paranoid_check_all_ff(ubi, pnum, offset, len); if (err) return err > 0 ? -EINVAL : 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 = paranoid_check_peb_ec_hdr(ubi, pnum); if (err) return err > 0 ? -EINVAL : err; err = paranoid_check_peb_vid_hdr(ubi, pnum); if (err) return err > 0 ? -EINVAL : err; } if (ubi_dbg_is_write_failure()) { dbg_err("cannot write %d bytes to PEB %d:%d " "(emulated)", len, pnum, offset); ubi_dbg_dump_stack(); return -EIO; } addr = (loff_t)pnum * ubi->peb_size + offset; err = mtd_write(ubi->mtd, addr, len, &written, buf); if (err) { ubi_err("error %d while writing %d bytes to PEB %d:%d, written" " %zd bytes", err, len, pnum, offset, written); ubi_dbg_dump_stack(); } else ubi_assert(written == len); return err; } /** * erase_callback - MTD erasure call-back. * @ei: MTD erase information object. * * Note, even though MTD erase interface is asynchronous, all the current * implementations are synchronous anyway. */ static void erase_callback(struct erase_info *ei) { wake_up_interruptible((wait_queue_head_t *)ei->priv); } /** * 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. */ static int do_sync_erase(struct ubi_device *ubi, int pnum) { int err, retries = 0; struct erase_info ei; wait_queue_head_t wq; dbg_io("erase PEB %d", pnum); retry: init_waitqueue_head(&wq); memset(&ei, 0, sizeof(struct erase_info)); ei.mtd = ubi->mtd; ei.addr = (loff_t)pnum * ubi->peb_size; ei.len = ubi->peb_size; ei.callback = erase_callback; ei.priv = (unsigned long)&wq; err = mtd_erase(ubi->mtd, &ei); if (err) { if (retries++ < UBI_IO_RETRIES) { dbg_io("error %d while erasing PEB %d, retry", err, pnum); yield(); goto retry; } ubi_err("cannot erase PEB %d, error %d", pnum, err); ubi_dbg_dump_stack(); return err; } err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE || ei.state == MTD_ERASE_FAILED); if (err) { ubi_err("interrupted PEB %d erasure", pnum); return -EINTR; } if (ei.state == MTD_ERASE_FAILED) { if (retries++ < UBI_IO_RETRIES) { dbg_io("error while erasing PEB %d, retry", pnum); yield(); goto retry; } ubi_err("cannot erase PEB %d", pnum); ubi_dbg_dump_stack(); return -EIO; } err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size); if (err) return err > 0 ? -EINVAL : err; if (ubi_dbg_is_erase_failure() && !err) { dbg_err("cannot erase PEB %d (emulated)", pnum); return -EIO; } return 0; } /** * check_pattern - check if buffer contains only a certain byte pattern. * @buf: buffer to check * @patt: the pattern to check * @size: buffer size in bytes * * This function returns %1 in there are only @patt bytes in @buf, and %0 if * something else was also found. */ static int check_pattern(const void *buf, uint8_t patt, int size) { int i; for (i = 0; i < size; i++) if (((const uint8_t *)buf)[i] != patt) return 0; return 1; } /* 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. */ static int torture_peb(struct ubi_device *ubi, int pnum) { int err, i, patt_count; 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_buf1, pnum, 0, ubi->peb_size); if (err) goto out; err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size); if (err == 0) { ubi_err("erased PEB %d, but a non-0xFF byte found", pnum); err = -EIO; goto out; } /* Write a pattern and check it */ memset(ubi->peb_buf1, patterns[i], ubi->peb_size); err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size); if (err) goto out; memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size); err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size); if (err) goto out; err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size); if (err == 0) { ubi_err("pattern %x checking failed for PEB %d", patterns[i], pnum); err = -EIO; goto out; } } err = patt_count; out: mutex_unlock(&ubi->buf_mutex); if (err == UBI_IO_BITFLIPS || err == -EBADMSG) { /* * 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("read problems on freshly erased PEB %d, must be bad", pnum); err = -EIO; } return err; } /** * 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 then 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 = paranoid_check_not_bad(ubi, pnum); if (err != 0) return err > 0 ? -EINVAL : err; if (ubi->ro_mode) { ubi_err("read-only mode"); return -EROFS; } 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(const struct 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("error %d while checking if PEB %d is bad", ret, pnum); else if (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(const struct 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("read-only mode"); return -EROFS; } if (!ubi->bad_allowed) return 0; err = mtd_block_markbad(mtd, (loff_t)pnum * ubi->peb_size); if (err) ubi_err("cannot mark PEB %d bad, error %d", pnum, err); return err; } /** * 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. */ static int validate_ec_hdr(const struct ubi_device *ubi, const struct ubi_ec_hdr *ec_hdr) { long long ec; int vid_hdr_offset, leb_start; ec = be64_to_cpu(ec_hdr->ec); vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset); leb_start = be32_to_cpu(ec_hdr->data_offset); if (ec_hdr->version != UBI_VERSION) { ubi_err("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("bad VID header offset %d, expected %d", vid_hdr_offset, ubi->vid_hdr_offset); goto bad; } if (leb_start != ubi->leb_start) { ubi_err("bad data offset %d, expected %d", leb_start, ubi->leb_start); goto bad; } if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) { ubi_err("bad erase counter %lld", ec); goto bad; } return 0; bad: ubi_err("bad EC header"); ubi_dbg_dump_ec_hdr(ec_hdr); ubi_dbg_dump_stack(); return 1; } /** * 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_EC_HDR if the erase counter header is corrupted (a CRC error); * o %UBI_IO_PEB_EMPTY if the physical eraseblock is 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 = 0; uint32_t crc, magic, hdr_crc; dbg_io("read EC header from PEB %d", pnum); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); if (UBI_IO_DEBUG) verbose = 1; err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); if (err) { if (err != UBI_IO_BITFLIPS && err != -EBADMSG) return err; /* * We read all the data, but either a correctable bit-flip * occurred, or MTD reported about some data integrity error, * like an 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. */ read_err = err; } magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) { /* * The magic field is wrong. Let's check if we have read all * 0xFF. If yes, this physical eraseblock is assumed to be * empty. * * But if there was a read error, we do not test it for all * 0xFFs. Even if it does contain all 0xFFs, this error * indicates that something is still wrong with this physical * eraseblock and we anyway cannot treat it as empty. */ if (read_err != -EBADMSG && check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) { /* The physical eraseblock is supposedly empty */ /* * The below is just a paranoid check, it has to be * compiled out if paranoid checks are disabled. */ err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size); if (err) return err > 0 ? UBI_IO_BAD_EC_HDR : err; if (verbose) ubi_warn("no EC header found at PEB %d, " "only 0xFF bytes", pnum); return UBI_IO_PEB_EMPTY; } /* * This is not a valid erase counter header, and these are not * 0xFF bytes. Report that the header is corrupted. */ if (verbose) { 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); } return UBI_IO_BAD_EC_HDR; } crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); hdr_crc = be32_to_cpu(ec_hdr->hdr_crc); if (hdr_crc != crc) { if (verbose) { ubi_warn("bad EC header CRC at PEB %d, calculated %#08x," " read %#08x", pnum, crc, hdr_crc); ubi_dbg_dump_ec_hdr(ec_hdr); } return UBI_IO_BAD_EC_HDR; } /* And of course validate what has just been read from the media */ err = validate_ec_hdr(ubi, ec_hdr); if (err) { ubi_err("validation failed for PEB %d", pnum); return -EINVAL; } return read_err ? UBI_IO_BITFLIPS : 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; dbg_io("write EC header to PEB %d", pnum); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC); ec_hdr->version = UBI_VERSION; ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset); ec_hdr->data_offset = cpu_to_be32(ubi->leb_start); crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); ec_hdr->hdr_crc = cpu_to_be32(crc); err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr); if (err) return -EINVAL; err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize); return err; } /** * 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. */ static int validate_vid_hdr(const struct ubi_device *ubi, const struct 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 (copy_flag != 0 && copy_flag != 1) { dbg_err("bad copy_flag"); goto bad; } if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 || data_pad < 0) { dbg_err("negative values"); goto bad; } if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) { dbg_err("bad vol_id"); goto bad; } if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) { dbg_err("bad compat"); goto bad; } if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE && compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE && compat != UBI_COMPAT_REJECT) { dbg_err("bad compat"); goto bad; } if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { dbg_err("bad vol_type"); goto bad; } if (data_pad >= ubi->leb_size / 2) { dbg_err("bad data_pad"); goto bad; } 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) { dbg_err("zero used_ebs"); goto bad; } if (data_size == 0) { dbg_err("zero data_size"); goto bad; } if (lnum < used_ebs - 1) { if (data_size != usable_leb_size) { dbg_err("bad data_size"); goto bad; } } else if (lnum == used_ebs - 1) { if (data_size == 0) { dbg_err("bad data_size at last LEB"); goto bad; } } else { dbg_err("too high lnum"); goto bad; } } else { if (copy_flag == 0) { if (data_crc != 0) { dbg_err("non-zero data CRC"); goto bad; } if (data_size != 0) { dbg_err("non-zero data_size"); goto bad; } } else { if (data_size == 0) { dbg_err("zero data_size of copy"); goto bad; } } if (used_ebs != 0) { dbg_err("bad used_ebs"); goto bad; } } return 0; bad: ubi_err("bad VID header"); ubi_dbg_dump_vid_hdr(vid_hdr); ubi_dbg_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 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume * identifier header * @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 @vid_hdr. It also checks CRC checksum of the read * volume identifier 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; * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC * error detected); * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID * header there); * o a negative error code in case of failure. */ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_hdr *vid_hdr, int verbose) { int err, read_err = 0; uint32_t crc, magic, hdr_crc; void *p; dbg_io("read VID header from PEB %d", pnum); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); if (UBI_IO_DEBUG) verbose = 1; p = (char *)vid_hdr - ubi->vid_hdr_shift; err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, ubi->vid_hdr_alsize); if (err) { if (err != UBI_IO_BITFLIPS && err != -EBADMSG) return err; /* * We read all the data, but either a correctable bit-flip * occurred, or MTD reported about some data integrity error, * like an ECC error in case of NAND. The former is harmless, * the later may mean the read data is corrupted. But we have a * CRC check-sum and we will identify this. If the VID header is * still OK, we just report this as there was a bit-flip. */ read_err = err; } magic = be32_to_cpu(vid_hdr->magic); if (magic != UBI_VID_HDR_MAGIC) { /* * If we have read all 0xFF bytes, the VID header probably does * not exist and the physical eraseblock is assumed to be free. * * But if there was a read error, we do not test the data for * 0xFFs. Even if it does contain all 0xFFs, this error * indicates that something is still wrong with this physical * eraseblock and it cannot be regarded as free. */ if (read_err != -EBADMSG && check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) { /* The physical eraseblock is supposedly free */ /* * The below is just a paranoid check, it has to be * compiled out if paranoid checks are disabled. */ err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start, ubi->leb_size); if (err) return err > 0 ? UBI_IO_BAD_VID_HDR : err; if (verbose) ubi_warn("no VID header found at PEB %d, " "only 0xFF bytes", pnum); return UBI_IO_PEB_FREE; } /* * This is not a valid VID header, and these are not 0xFF * bytes. Report that the header is corrupted. */ if (verbose) { 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); } return UBI_IO_BAD_VID_HDR; } crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC); hdr_crc = be32_to_cpu(vid_hdr->hdr_crc); if (hdr_crc != crc) { if (verbose) { ubi_warn("bad CRC at PEB %d, calculated %#08x, " "read %#08x", pnum, crc, hdr_crc); ubi_dbg_dump_vid_hdr(vid_hdr); } return UBI_IO_BAD_VID_HDR; } /* Validate the VID header that we have just read */ err = validate_vid_hdr(ubi, vid_hdr); if (err) { ubi_err("validation failed for PEB %d", pnum); return -EINVAL; } return read_err ? UBI_IO_BITFLIPS : 0; } /** * ubi_io_write_vid_hdr - write a volume identifier header. * @ubi: UBI device description object * @pnum: the physical eraseblock number to write to * @vid_hdr: the volume identifier header to write * * This function writes the volume identifier header described by @vid_hdr to * physical eraseblock @pnum. This function automatically fills the * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates * header CRC checksum and stores it at vid_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_hdr *vid_hdr) { int err; uint32_t crc; void *p; dbg_io("write VID header to PEB %d", pnum); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); err = paranoid_check_peb_ec_hdr(ubi, pnum); if (err) return err > 0 ? -EINVAL: err; vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC); vid_hdr->version = UBI_VERSION; crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC); vid_hdr->hdr_crc = cpu_to_be32(crc); err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr); if (err) return -EINVAL; p = (char *)vid_hdr - ubi->vid_hdr_shift; err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset, ubi->vid_hdr_alsize); return err; } #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID /** * paranoid_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, a positive * number if it is bad and a negative error code if an error occurred. */ static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum) { int err; err = ubi_io_is_bad(ubi, pnum); if (!err) return err; ubi_err("paranoid check failed for PEB %d", pnum); ubi_dbg_dump_stack(); return err; } /** * paranoid_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 %1 if not. */ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, const struct ubi_ec_hdr *ec_hdr) { int err; uint32_t magic; magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) { ubi_err("bad magic %#08x, must be %#08x", magic, UBI_EC_HDR_MAGIC); goto fail; } err = validate_ec_hdr(ubi, ec_hdr); if (err) { ubi_err("paranoid check failed for PEB %d", pnum); goto fail; } return 0; fail: ubi_dbg_dump_ec_hdr(ec_hdr); ubi_dbg_dump_stack(); return 1; } /** * paranoid_check_peb_ec_hdr - check that the erase counter header of a * physical eraseblock is in-place and is all right. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * * This function returns zero if the erase counter header is all right, %1 if * not, and a negative error code if an error occurred. */ static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum) { int err; uint32_t crc, hdr_crc; struct ubi_ec_hdr *ec_hdr; ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS); if (!ec_hdr) return -ENOMEM; err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) goto exit; crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); hdr_crc = be32_to_cpu(ec_hdr->hdr_crc); if (hdr_crc != crc) { ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc); ubi_err("paranoid check failed for PEB %d", pnum); ubi_dbg_dump_ec_hdr(ec_hdr); ubi_dbg_dump_stack(); err = 1; goto exit; } err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr); exit: kfree(ec_hdr); return err; } /** * paranoid_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 * %1 if not. */ static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, const struct ubi_vid_hdr *vid_hdr) { int err; uint32_t magic; 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", magic, pnum, UBI_VID_HDR_MAGIC); goto fail; } err = validate_vid_hdr(ubi, vid_hdr); if (err) { ubi_err("paranoid check failed for PEB %d", pnum); goto fail; } return err; fail: ubi_err("paranoid check failed for PEB %d", pnum); ubi_dbg_dump_vid_hdr(vid_hdr); ubi_dbg_dump_stack(); return 1; } /** * paranoid_check_peb_vid_hdr - check that the volume identifier header of a * physical eraseblock is in-place and is all right. * @ubi: UBI device description object * @pnum: the physical eraseblock number to check * * This function returns zero if the volume identifier header is all right, * %1 if not, and a negative error code if an error occurred. */ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum) { int err; uint32_t crc, hdr_crc; struct ubi_vid_hdr *vid_hdr; void *p; vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; p = (char *)vid_hdr - ubi->vid_hdr_shift; err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, ubi->vid_hdr_alsize); if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) goto exit; crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC); hdr_crc = be32_to_cpu(vid_hdr->hdr_crc); if (hdr_crc != crc) { ubi_err("bad VID header CRC at PEB %d, calculated %#08x, " "read %#08x", pnum, crc, hdr_crc); ubi_err("paranoid check failed for PEB %d", pnum); ubi_dbg_dump_vid_hdr(vid_hdr); ubi_dbg_dump_stack(); err = 1; goto exit; } err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr); exit: ubi_free_vid_hdr(ubi, vid_hdr); return err; } /** * paranoid_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, %1 if not, and a negative error * code if an error occurred. */ static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len) { size_t read; int err; loff_t addr = (loff_t)pnum * ubi->peb_size + offset; mutex_lock(&ubi->dbg_buf_mutex); err = mtd_read(ubi->mtd, addr, len, &read, ubi->dbg_peb_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 = check_pattern(ubi->dbg_peb_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); return 0; fail: ubi_err("paranoid check failed for PEB %d", pnum); dbg_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); err = 1; error: ubi_dbg_dump_stack(); mutex_unlock(&ubi->dbg_buf_mutex); return err; } #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */