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1/*
2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * Author: Artem Bityutskiy (Битюцкий Артём)
20 */
21
22/*
23 * UBI input/output sub-system.
24 *
25 * This sub-system provides a uniform way to work with all kinds of the
26 * underlying MTD devices. It also implements handy functions for reading and
27 * writing UBI headers.
28 *
29 * We are trying to have a paranoid mindset and not to trust to what we read
30 * from the flash media in order to be more secure and robust. So this
31 * sub-system validates every single header it reads from the flash media.
32 *
33 * Some words about how the eraseblock headers are stored.
34 *
35 * The erase counter header is always stored at offset zero. By default, the
36 * VID header is stored after the EC header at the closest aligned offset
37 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
38 * header at the closest aligned offset. But this default layout may be
39 * changed. For example, for different reasons (e.g., optimization) UBI may be
40 * asked to put the VID header at further offset, and even at an unaligned
41 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
42 * proper padding in front of it. Data offset may also be changed but it has to
43 * be aligned.
44 *
45 * About minimal I/O units. In general, UBI assumes flash device model where
46 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
47 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
48 * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
49 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
50 * to do different optimizations.
51 *
52 * This is extremely useful in case of NAND flashes which admit of several
53 * write operations to one NAND page. In this case UBI can fit EC and VID
54 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
55 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
56 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
57 * users.
58 *
59 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
60 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
61 * headers.
62 *
63 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
64 * device, e.g., make @ubi->min_io_size = 512 in the example above?
65 *
66 * A: because when writing a sub-page, MTD still writes a full 2K page but the
67 * bytes which are not relevant to the sub-page are 0xFF. So, basically,
68 * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
69 * Thus, we prefer to use sub-pages only for EC and VID headers.
70 *
71 * As it was noted above, the VID header may start at a non-aligned offset.
72 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
73 * the VID header may reside at offset 1984 which is the last 64 bytes of the
74 * last sub-page (EC header is always at offset zero). This causes some
75 * difficulties when reading and writing VID headers.
76 *
77 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
78 * the data and want to write this VID header out. As we can only write in
79 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
80 * to offset 448 of this buffer.
81 *
82 * The I/O sub-system does the following trick in order to avoid this extra
83 * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
84 * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
85 * When the VID header is being written out, it shifts the VID header pointer
86 * back and writes the whole sub-page.
87 */
88
89#include <linux/crc32.h>
90#include <linux/err.h>
91#include <linux/slab.h>
92#include "ubi.h"
93
94#ifdef CONFIG_MTD_UBI_DEBUG
95static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
96static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
97static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
98 const struct ubi_ec_hdr *ec_hdr);
99static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
100static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
101 const struct ubi_vid_hdr *vid_hdr);
102#else
103#define paranoid_check_not_bad(ubi, pnum) 0
104#define paranoid_check_peb_ec_hdr(ubi, pnum) 0
105#define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0
106#define paranoid_check_peb_vid_hdr(ubi, pnum) 0
107#define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
108#endif
109
110/**
111 * ubi_io_read - read data from a physical eraseblock.
112 * @ubi: UBI device description object
113 * @buf: buffer where to store the read data
114 * @pnum: physical eraseblock number to read from
115 * @offset: offset within the physical eraseblock from where to read
116 * @len: how many bytes to read
117 *
118 * This function reads data from offset @offset of physical eraseblock @pnum
119 * and stores the read data in the @buf buffer. The following return codes are
120 * possible:
121 *
122 * o %0 if all the requested data were successfully read;
123 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
124 * correctable bit-flips were detected; this is harmless but may indicate
125 * that this eraseblock may become bad soon (but do not have to);
126 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
127 * example it can be an ECC error in case of NAND; this most probably means
128 * that the data is corrupted;
129 * o %-EIO if some I/O error occurred;
130 * o other negative error codes in case of other errors.
131 */
132int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
133 int len)
134{
135 int err, retries = 0;
136 size_t read;
137 loff_t addr;
138
139 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
140
141 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
142 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
143 ubi_assert(len > 0);
144
145 err = paranoid_check_not_bad(ubi, pnum);
146 if (err)
147 return err;
148
149 /*
150 * Deliberately corrupt the buffer to improve robustness. Indeed, if we
151 * do not do this, the following may happen:
152 * 1. The buffer contains data from previous operation, e.g., read from
153 * another PEB previously. The data looks like expected, e.g., if we
154 * just do not read anything and return - the caller would not
155 * notice this. E.g., if we are reading a VID header, the buffer may
156 * contain a valid VID header from another PEB.
157 * 2. The driver is buggy and returns us success or -EBADMSG or
158 * -EUCLEAN, but it does not actually put any data to the buffer.
159 *
160 * This may confuse UBI or upper layers - they may think the buffer
161 * contains valid data while in fact it is just old data. This is
162 * especially possible because UBI (and UBIFS) relies on CRC, and
163 * treats data as correct even in case of ECC errors if the CRC is
164 * correct.
165 *
166 * Try to prevent this situation by changing the first byte of the
167 * buffer.
168 */
169 *((uint8_t *)buf) ^= 0xFF;
170
171 addr = (loff_t)pnum * ubi->peb_size + offset;
172retry:
173 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
174 if (err) {
175 const char *errstr = (err == -EBADMSG) ? " (ECC error)" : "";
176
177 if (err == -EUCLEAN) {
178 /*
179 * -EUCLEAN is reported if there was a bit-flip which
180 * was corrected, so this is harmless.
181 *
182 * We do not report about it here unless debugging is
183 * enabled. A corresponding message will be printed
184 * later, when it is has been scrubbed.
185 */
186 dbg_msg("fixable bit-flip detected at PEB %d", pnum);
187 ubi_assert(len == read);
188 return UBI_IO_BITFLIPS;
189 }
190
191 if (retries++ < UBI_IO_RETRIES) {
192 dbg_io("error %d%s while reading %d bytes from PEB "
193 "%d:%d, read only %zd bytes, retry",
194 err, errstr, len, pnum, offset, read);
195 yield();
196 goto retry;
197 }
198
199 ubi_err("error %d%s while reading %d bytes from PEB %d:%d, "
200 "read %zd bytes", err, errstr, len, pnum, offset, read);
201 ubi_dbg_dump_stack();
202
203 /*
204 * The driver should never return -EBADMSG if it failed to read
205 * all the requested data. But some buggy drivers might do
206 * this, so we change it to -EIO.
207 */
208 if (read != len && err == -EBADMSG) {
209 ubi_assert(0);
210 err = -EIO;
211 }
212 } else {
213 ubi_assert(len == read);
214
215 if (ubi_dbg_is_bitflip(ubi)) {
216 dbg_gen("bit-flip (emulated)");
217 err = UBI_IO_BITFLIPS;
218 }
219 }
220
221 return err;
222}
223
224/**
225 * ubi_io_write - write data to a physical eraseblock.
226 * @ubi: UBI device description object
227 * @buf: buffer with the data to write
228 * @pnum: physical eraseblock number to write to
229 * @offset: offset within the physical eraseblock where to write
230 * @len: how many bytes to write
231 *
232 * This function writes @len bytes of data from buffer @buf to offset @offset
233 * of physical eraseblock @pnum. If all the data were successfully written,
234 * zero is returned. If an error occurred, this function returns a negative
235 * error code. If %-EIO is returned, the physical eraseblock most probably went
236 * bad.
237 *
238 * Note, in case of an error, it is possible that something was still written
239 * to the flash media, but may be some garbage.
240 */
241int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
242 int len)
243{
244 int err;
245 size_t written;
246 loff_t addr;
247
248 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
249
250 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
251 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
252 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
253 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
254
255 if (ubi->ro_mode) {
256 ubi_err("read-only mode");
257 return -EROFS;
258 }
259
260 /* The below has to be compiled out if paranoid checks are disabled */
261
262 err = paranoid_check_not_bad(ubi, pnum);
263 if (err)
264 return err;
265
266 /* The area we are writing to has to contain all 0xFF bytes */
267 err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);
268 if (err)
269 return err;
270
271 if (offset >= ubi->leb_start) {
272 /*
273 * We write to the data area of the physical eraseblock. Make
274 * sure it has valid EC and VID headers.
275 */
276 err = paranoid_check_peb_ec_hdr(ubi, pnum);
277 if (err)
278 return err;
279 err = paranoid_check_peb_vid_hdr(ubi, pnum);
280 if (err)
281 return err;
282 }
283
284 if (ubi_dbg_is_write_failure(ubi)) {
285 dbg_err("cannot write %d bytes to PEB %d:%d "
286 "(emulated)", len, pnum, offset);
287 ubi_dbg_dump_stack();
288 return -EIO;
289 }
290
291 addr = (loff_t)pnum * ubi->peb_size + offset;
292 err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
293 if (err) {
294 ubi_err("error %d while writing %d bytes to PEB %d:%d, written "
295 "%zd bytes", err, len, pnum, offset, written);
296 ubi_dbg_dump_stack();
297 ubi_dbg_dump_flash(ubi, pnum, offset, len);
298 } else
299 ubi_assert(written == len);
300
301 if (!err) {
302 err = ubi_dbg_check_write(ubi, buf, pnum, offset, len);
303 if (err)
304 return err;
305
306 /*
307 * Since we always write sequentially, the rest of the PEB has
308 * to contain only 0xFF bytes.
309 */
310 offset += len;
311 len = ubi->peb_size - offset;
312 if (len)
313 err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);
314 }
315
316 return err;
317}
318
319/**
320 * erase_callback - MTD erasure call-back.
321 * @ei: MTD erase information object.
322 *
323 * Note, even though MTD erase interface is asynchronous, all the current
324 * implementations are synchronous anyway.
325 */
326static void erase_callback(struct erase_info *ei)
327{
328 wake_up_interruptible((wait_queue_head_t *)ei->priv);
329}
330
331/**
332 * do_sync_erase - synchronously erase a physical eraseblock.
333 * @ubi: UBI device description object
334 * @pnum: the physical eraseblock number to erase
335 *
336 * This function synchronously erases physical eraseblock @pnum and returns
337 * zero in case of success and a negative error code in case of failure. If
338 * %-EIO is returned, the physical eraseblock most probably went bad.
339 */
340static int do_sync_erase(struct ubi_device *ubi, int pnum)
341{
342 int err, retries = 0;
343 struct erase_info ei;
344 wait_queue_head_t wq;
345
346 dbg_io("erase PEB %d", pnum);
347 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
348
349 if (ubi->ro_mode) {
350 ubi_err("read-only mode");
351 return -EROFS;
352 }
353
354retry:
355 init_waitqueue_head(&wq);
356 memset(&ei, 0, sizeof(struct erase_info));
357
358 ei.mtd = ubi->mtd;
359 ei.addr = (loff_t)pnum * ubi->peb_size;
360 ei.len = ubi->peb_size;
361 ei.callback = erase_callback;
362 ei.priv = (unsigned long)&wq;
363
364 err = ubi->mtd->erase(ubi->mtd, &ei);
365 if (err) {
366 if (retries++ < UBI_IO_RETRIES) {
367 dbg_io("error %d while erasing PEB %d, retry",
368 err, pnum);
369 yield();
370 goto retry;
371 }
372 ubi_err("cannot erase PEB %d, error %d", pnum, err);
373 ubi_dbg_dump_stack();
374 return err;
375 }
376
377 err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
378 ei.state == MTD_ERASE_FAILED);
379 if (err) {
380 ubi_err("interrupted PEB %d erasure", pnum);
381 return -EINTR;
382 }
383
384 if (ei.state == MTD_ERASE_FAILED) {
385 if (retries++ < UBI_IO_RETRIES) {
386 dbg_io("error while erasing PEB %d, retry", pnum);
387 yield();
388 goto retry;
389 }
390 ubi_err("cannot erase PEB %d", pnum);
391 ubi_dbg_dump_stack();
392 return -EIO;
393 }
394
395 err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size);
396 if (err)
397 return err;
398
399 if (ubi_dbg_is_erase_failure(ubi)) {
400 dbg_err("cannot erase PEB %d (emulated)", pnum);
401 return -EIO;
402 }
403
404 return 0;
405}
406
407/* Patterns to write to a physical eraseblock when torturing it */
408static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
409
410/**
411 * torture_peb - test a supposedly bad physical eraseblock.
412 * @ubi: UBI device description object
413 * @pnum: the physical eraseblock number to test
414 *
415 * This function returns %-EIO if the physical eraseblock did not pass the
416 * test, a positive number of erase operations done if the test was
417 * successfully passed, and other negative error codes in case of other errors.
418 */
419static int torture_peb(struct ubi_device *ubi, int pnum)
420{
421 int err, i, patt_count;
422
423 ubi_msg("run torture test for PEB %d", pnum);
424 patt_count = ARRAY_SIZE(patterns);
425 ubi_assert(patt_count > 0);
426
427 mutex_lock(&ubi->buf_mutex);
428 for (i = 0; i < patt_count; i++) {
429 err = do_sync_erase(ubi, pnum);
430 if (err)
431 goto out;
432
433 /* Make sure the PEB contains only 0xFF bytes */
434 err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
435 if (err)
436 goto out;
437
438 err = ubi_check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
439 if (err == 0) {
440 ubi_err("erased PEB %d, but a non-0xFF byte found",
441 pnum);
442 err = -EIO;
443 goto out;
444 }
445
446 /* Write a pattern and check it */
447 memset(ubi->peb_buf1, patterns[i], ubi->peb_size);
448 err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
449 if (err)
450 goto out;
451
452 memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
453 err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
454 if (err)
455 goto out;
456
457 err = ubi_check_pattern(ubi->peb_buf1, patterns[i],
458 ubi->peb_size);
459 if (err == 0) {
460 ubi_err("pattern %x checking failed for PEB %d",
461 patterns[i], pnum);
462 err = -EIO;
463 goto out;
464 }
465 }
466
467 err = patt_count;
468 ubi_msg("PEB %d passed torture test, do not mark it as bad", pnum);
469
470out:
471 mutex_unlock(&ubi->buf_mutex);
472 if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
473 /*
474 * If a bit-flip or data integrity error was detected, the test
475 * has not passed because it happened on a freshly erased
476 * physical eraseblock which means something is wrong with it.
477 */
478 ubi_err("read problems on freshly erased PEB %d, must be bad",
479 pnum);
480 err = -EIO;
481 }
482 return err;
483}
484
485/**
486 * nor_erase_prepare - prepare a NOR flash PEB for erasure.
487 * @ubi: UBI device description object
488 * @pnum: physical eraseblock number to prepare
489 *
490 * NOR flash, or at least some of them, have peculiar embedded PEB erasure
491 * algorithm: the PEB is first filled with zeroes, then it is erased. And
492 * filling with zeroes starts from the end of the PEB. This was observed with
493 * Spansion S29GL512N NOR flash.
494 *
495 * This means that in case of a power cut we may end up with intact data at the
496 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the
497 * EC and VID headers are OK, but a large chunk of data at the end of PEB is
498 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it
499 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
500 *
501 * This function is called before erasing NOR PEBs and it zeroes out EC and VID
502 * magic numbers in order to invalidate them and prevent the failures. Returns
503 * zero in case of success and a negative error code in case of failure.
504 */
505static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
506{
507 int err, err1;
508 size_t written;
509 loff_t addr;
510 uint32_t data = 0;
511 /*
512 * Note, we cannot generally define VID header buffers on stack,
513 * because of the way we deal with these buffers (see the header
514 * comment in this file). But we know this is a NOR-specific piece of
515 * code, so we can do this. But yes, this is error-prone and we should
516 * (pre-)allocate VID header buffer instead.
517 */
518 struct ubi_vid_hdr vid_hdr;
519
520 /*
521 * It is important to first invalidate the EC header, and then the VID
522 * header. Otherwise a power cut may lead to valid EC header and
523 * invalid VID header, in which case UBI will treat this PEB as
524 * corrupted and will try to preserve it, and print scary warnings (see
525 * the header comment in scan.c for more information).
526 */
527 addr = (loff_t)pnum * ubi->peb_size;
528 err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data);
529 if (!err) {
530 addr += ubi->vid_hdr_aloffset;
531 err = ubi->mtd->write(ubi->mtd, addr, 4, &written,
532 (void *)&data);
533 if (!err)
534 return 0;
535 }
536
537 /*
538 * We failed to write to the media. This was observed with Spansion
539 * S29GL512N NOR flash. Most probably the previously eraseblock erasure
540 * was interrupted at a very inappropriate moment, so it became
541 * unwritable. In this case we probably anyway have garbage in this
542 * PEB.
543 */
544 err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
545 if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
546 err1 == UBI_IO_FF) {
547 struct ubi_ec_hdr ec_hdr;
548
549 err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
550 if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
551 err1 == UBI_IO_FF)
552 /*
553 * Both VID and EC headers are corrupted, so we can
554 * safely erase this PEB and not afraid that it will be
555 * treated as a valid PEB in case of an unclean reboot.
556 */
557 return 0;
558 }
559
560 /*
561 * The PEB contains a valid VID header, but we cannot invalidate it.
562 * Supposedly the flash media or the driver is screwed up, so return an
563 * error.
564 */
565 ubi_err("cannot invalidate PEB %d, write returned %d read returned %d",
566 pnum, err, err1);
567 ubi_dbg_dump_flash(ubi, pnum, 0, ubi->peb_size);
568 return -EIO;
569}
570
571/**
572 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
573 * @ubi: UBI device description object
574 * @pnum: physical eraseblock number to erase
575 * @torture: if this physical eraseblock has to be tortured
576 *
577 * This function synchronously erases physical eraseblock @pnum. If @torture
578 * flag is not zero, the physical eraseblock is checked by means of writing
579 * different patterns to it and reading them back. If the torturing is enabled,
580 * the physical eraseblock is erased more than once.
581 *
582 * This function returns the number of erasures made in case of success, %-EIO
583 * if the erasure failed or the torturing test failed, and other negative error
584 * codes in case of other errors. Note, %-EIO means that the physical
585 * eraseblock is bad.
586 */
587int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
588{
589 int err, ret = 0;
590
591 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
592
593 err = paranoid_check_not_bad(ubi, pnum);
594 if (err != 0)
595 return err;
596
597 if (ubi->ro_mode) {
598 ubi_err("read-only mode");
599 return -EROFS;
600 }
601
602 if (ubi->nor_flash) {
603 err = nor_erase_prepare(ubi, pnum);
604 if (err)
605 return err;
606 }
607
608 if (torture) {
609 ret = torture_peb(ubi, pnum);
610 if (ret < 0)
611 return ret;
612 }
613
614 err = do_sync_erase(ubi, pnum);
615 if (err)
616 return err;
617
618 return ret + 1;
619}
620
621/**
622 * ubi_io_is_bad - check if a physical eraseblock is bad.
623 * @ubi: UBI device description object
624 * @pnum: the physical eraseblock number to check
625 *
626 * This function returns a positive number if the physical eraseblock is bad,
627 * zero if not, and a negative error code if an error occurred.
628 */
629int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
630{
631 struct mtd_info *mtd = ubi->mtd;
632
633 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
634
635 if (ubi->bad_allowed) {
636 int ret;
637
638 ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
639 if (ret < 0)
640 ubi_err("error %d while checking if PEB %d is bad",
641 ret, pnum);
642 else if (ret)
643 dbg_io("PEB %d is bad", pnum);
644 return ret;
645 }
646
647 return 0;
648}
649
650/**
651 * ubi_io_mark_bad - mark a physical eraseblock as bad.
652 * @ubi: UBI device description object
653 * @pnum: the physical eraseblock number to mark
654 *
655 * This function returns zero in case of success and a negative error code in
656 * case of failure.
657 */
658int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
659{
660 int err;
661 struct mtd_info *mtd = ubi->mtd;
662
663 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
664
665 if (ubi->ro_mode) {
666 ubi_err("read-only mode");
667 return -EROFS;
668 }
669
670 if (!ubi->bad_allowed)
671 return 0;
672
673 err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
674 if (err)
675 ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
676 return err;
677}
678
679/**
680 * validate_ec_hdr - validate an erase counter header.
681 * @ubi: UBI device description object
682 * @ec_hdr: the erase counter header to check
683 *
684 * This function returns zero if the erase counter header is OK, and %1 if
685 * not.
686 */
687static int validate_ec_hdr(const struct ubi_device *ubi,
688 const struct ubi_ec_hdr *ec_hdr)
689{
690 long long ec;
691 int vid_hdr_offset, leb_start;
692
693 ec = be64_to_cpu(ec_hdr->ec);
694 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
695 leb_start = be32_to_cpu(ec_hdr->data_offset);
696
697 if (ec_hdr->version != UBI_VERSION) {
698 ubi_err("node with incompatible UBI version found: "
699 "this UBI version is %d, image version is %d",
700 UBI_VERSION, (int)ec_hdr->version);
701 goto bad;
702 }
703
704 if (vid_hdr_offset != ubi->vid_hdr_offset) {
705 ubi_err("bad VID header offset %d, expected %d",
706 vid_hdr_offset, ubi->vid_hdr_offset);
707 goto bad;
708 }
709
710 if (leb_start != ubi->leb_start) {
711 ubi_err("bad data offset %d, expected %d",
712 leb_start, ubi->leb_start);
713 goto bad;
714 }
715
716 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
717 ubi_err("bad erase counter %lld", ec);
718 goto bad;
719 }
720
721 return 0;
722
723bad:
724 ubi_err("bad EC header");
725 ubi_dbg_dump_ec_hdr(ec_hdr);
726 ubi_dbg_dump_stack();
727 return 1;
728}
729
730/**
731 * ubi_io_read_ec_hdr - read and check an erase counter header.
732 * @ubi: UBI device description object
733 * @pnum: physical eraseblock to read from
734 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
735 * header
736 * @verbose: be verbose if the header is corrupted or was not found
737 *
738 * This function reads erase counter header from physical eraseblock @pnum and
739 * stores it in @ec_hdr. This function also checks CRC checksum of the read
740 * erase counter header. The following codes may be returned:
741 *
742 * o %0 if the CRC checksum is correct and the header was successfully read;
743 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
744 * and corrected by the flash driver; this is harmless but may indicate that
745 * this eraseblock may become bad soon (but may be not);
746 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
747 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
748 * a data integrity error (uncorrectable ECC error in case of NAND);
749 * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
750 * o a negative error code in case of failure.
751 */
752int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
753 struct ubi_ec_hdr *ec_hdr, int verbose)
754{
755 int err, read_err;
756 uint32_t crc, magic, hdr_crc;
757
758 dbg_io("read EC header from PEB %d", pnum);
759 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
760
761 read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
762 if (read_err) {
763 if (read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
764 return read_err;
765
766 /*
767 * We read all the data, but either a correctable bit-flip
768 * occurred, or MTD reported a data integrity error
769 * (uncorrectable ECC error in case of NAND). The former is
770 * harmless, the later may mean that the read data is
771 * corrupted. But we have a CRC check-sum and we will detect
772 * this. If the EC header is still OK, we just report this as
773 * there was a bit-flip, to force scrubbing.
774 */
775 }
776
777 magic = be32_to_cpu(ec_hdr->magic);
778 if (magic != UBI_EC_HDR_MAGIC) {
779 if (read_err == -EBADMSG)
780 return UBI_IO_BAD_HDR_EBADMSG;
781
782 /*
783 * The magic field is wrong. Let's check if we have read all
784 * 0xFF. If yes, this physical eraseblock is assumed to be
785 * empty.
786 */
787 if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
788 /* The physical eraseblock is supposedly empty */
789 if (verbose)
790 ubi_warn("no EC header found at PEB %d, "
791 "only 0xFF bytes", pnum);
792 dbg_bld("no EC header found at PEB %d, "
793 "only 0xFF bytes", pnum);
794 if (!read_err)
795 return UBI_IO_FF;
796 else
797 return UBI_IO_FF_BITFLIPS;
798 }
799
800 /*
801 * This is not a valid erase counter header, and these are not
802 * 0xFF bytes. Report that the header is corrupted.
803 */
804 if (verbose) {
805 ubi_warn("bad magic number at PEB %d: %08x instead of "
806 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
807 ubi_dbg_dump_ec_hdr(ec_hdr);
808 }
809 dbg_bld("bad magic number at PEB %d: %08x instead of "
810 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
811 return UBI_IO_BAD_HDR;
812 }
813
814 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
815 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
816
817 if (hdr_crc != crc) {
818 if (verbose) {
819 ubi_warn("bad EC header CRC at PEB %d, calculated "
820 "%#08x, read %#08x", pnum, crc, hdr_crc);
821 ubi_dbg_dump_ec_hdr(ec_hdr);
822 }
823 dbg_bld("bad EC header CRC at PEB %d, calculated "
824 "%#08x, read %#08x", pnum, crc, hdr_crc);
825
826 if (!read_err)
827 return UBI_IO_BAD_HDR;
828 else
829 return UBI_IO_BAD_HDR_EBADMSG;
830 }
831
832 /* And of course validate what has just been read from the media */
833 err = validate_ec_hdr(ubi, ec_hdr);
834 if (err) {
835 ubi_err("validation failed for PEB %d", pnum);
836 return -EINVAL;
837 }
838
839 /*
840 * If there was %-EBADMSG, but the header CRC is still OK, report about
841 * a bit-flip to force scrubbing on this PEB.
842 */
843 return read_err ? UBI_IO_BITFLIPS : 0;
844}
845
846/**
847 * ubi_io_write_ec_hdr - write an erase counter header.
848 * @ubi: UBI device description object
849 * @pnum: physical eraseblock to write to
850 * @ec_hdr: the erase counter header to write
851 *
852 * This function writes erase counter header described by @ec_hdr to physical
853 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
854 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
855 * field.
856 *
857 * This function returns zero in case of success and a negative error code in
858 * case of failure. If %-EIO is returned, the physical eraseblock most probably
859 * went bad.
860 */
861int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
862 struct ubi_ec_hdr *ec_hdr)
863{
864 int err;
865 uint32_t crc;
866
867 dbg_io("write EC header to PEB %d", pnum);
868 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
869
870 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
871 ec_hdr->version = UBI_VERSION;
872 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
873 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
874 ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);
875 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
876 ec_hdr->hdr_crc = cpu_to_be32(crc);
877
878 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
879 if (err)
880 return err;
881
882 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
883 return err;
884}
885
886/**
887 * validate_vid_hdr - validate a volume identifier header.
888 * @ubi: UBI device description object
889 * @vid_hdr: the volume identifier header to check
890 *
891 * This function checks that data stored in the volume identifier header
892 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
893 */
894static int validate_vid_hdr(const struct ubi_device *ubi,
895 const struct ubi_vid_hdr *vid_hdr)
896{
897 int vol_type = vid_hdr->vol_type;
898 int copy_flag = vid_hdr->copy_flag;
899 int vol_id = be32_to_cpu(vid_hdr->vol_id);
900 int lnum = be32_to_cpu(vid_hdr->lnum);
901 int compat = vid_hdr->compat;
902 int data_size = be32_to_cpu(vid_hdr->data_size);
903 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
904 int data_pad = be32_to_cpu(vid_hdr->data_pad);
905 int data_crc = be32_to_cpu(vid_hdr->data_crc);
906 int usable_leb_size = ubi->leb_size - data_pad;
907
908 if (copy_flag != 0 && copy_flag != 1) {
909 dbg_err("bad copy_flag");
910 goto bad;
911 }
912
913 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
914 data_pad < 0) {
915 dbg_err("negative values");
916 goto bad;
917 }
918
919 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
920 dbg_err("bad vol_id");
921 goto bad;
922 }
923
924 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
925 dbg_err("bad compat");
926 goto bad;
927 }
928
929 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
930 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
931 compat != UBI_COMPAT_REJECT) {
932 dbg_err("bad compat");
933 goto bad;
934 }
935
936 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
937 dbg_err("bad vol_type");
938 goto bad;
939 }
940
941 if (data_pad >= ubi->leb_size / 2) {
942 dbg_err("bad data_pad");
943 goto bad;
944 }
945
946 if (vol_type == UBI_VID_STATIC) {
947 /*
948 * Although from high-level point of view static volumes may
949 * contain zero bytes of data, but no VID headers can contain
950 * zero at these fields, because they empty volumes do not have
951 * mapped logical eraseblocks.
952 */
953 if (used_ebs == 0) {
954 dbg_err("zero used_ebs");
955 goto bad;
956 }
957 if (data_size == 0) {
958 dbg_err("zero data_size");
959 goto bad;
960 }
961 if (lnum < used_ebs - 1) {
962 if (data_size != usable_leb_size) {
963 dbg_err("bad data_size");
964 goto bad;
965 }
966 } else if (lnum == used_ebs - 1) {
967 if (data_size == 0) {
968 dbg_err("bad data_size at last LEB");
969 goto bad;
970 }
971 } else {
972 dbg_err("too high lnum");
973 goto bad;
974 }
975 } else {
976 if (copy_flag == 0) {
977 if (data_crc != 0) {
978 dbg_err("non-zero data CRC");
979 goto bad;
980 }
981 if (data_size != 0) {
982 dbg_err("non-zero data_size");
983 goto bad;
984 }
985 } else {
986 if (data_size == 0) {
987 dbg_err("zero data_size of copy");
988 goto bad;
989 }
990 }
991 if (used_ebs != 0) {
992 dbg_err("bad used_ebs");
993 goto bad;
994 }
995 }
996
997 return 0;
998
999bad:
1000 ubi_err("bad VID header");
1001 ubi_dbg_dump_vid_hdr(vid_hdr);
1002 ubi_dbg_dump_stack();
1003 return 1;
1004}
1005
1006/**
1007 * ubi_io_read_vid_hdr - read and check a volume identifier header.
1008 * @ubi: UBI device description object
1009 * @pnum: physical eraseblock number to read from
1010 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
1011 * identifier header
1012 * @verbose: be verbose if the header is corrupted or wasn't found
1013 *
1014 * This function reads the volume identifier header from physical eraseblock
1015 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
1016 * volume identifier header. The error codes are the same as in
1017 * 'ubi_io_read_ec_hdr()'.
1018 *
1019 * Note, the implementation of this function is also very similar to
1020 * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
1021 */
1022int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
1023 struct ubi_vid_hdr *vid_hdr, int verbose)
1024{
1025 int err, read_err;
1026 uint32_t crc, magic, hdr_crc;
1027 void *p;
1028
1029 dbg_io("read VID header from PEB %d", pnum);
1030 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1031
1032 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1033 read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1034 ubi->vid_hdr_alsize);
1035 if (read_err && read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
1036 return read_err;
1037
1038 magic = be32_to_cpu(vid_hdr->magic);
1039 if (magic != UBI_VID_HDR_MAGIC) {
1040 if (read_err == -EBADMSG)
1041 return UBI_IO_BAD_HDR_EBADMSG;
1042
1043 if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
1044 if (verbose)
1045 ubi_warn("no VID header found at PEB %d, "
1046 "only 0xFF bytes", pnum);
1047 dbg_bld("no VID header found at PEB %d, "
1048 "only 0xFF bytes", pnum);
1049 if (!read_err)
1050 return UBI_IO_FF;
1051 else
1052 return UBI_IO_FF_BITFLIPS;
1053 }
1054
1055 if (verbose) {
1056 ubi_warn("bad magic number at PEB %d: %08x instead of "
1057 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
1058 ubi_dbg_dump_vid_hdr(vid_hdr);
1059 }
1060 dbg_bld("bad magic number at PEB %d: %08x instead of "
1061 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
1062 return UBI_IO_BAD_HDR;
1063 }
1064
1065 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1066 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1067
1068 if (hdr_crc != crc) {
1069 if (verbose) {
1070 ubi_warn("bad CRC at PEB %d, calculated %#08x, "
1071 "read %#08x", pnum, crc, hdr_crc);
1072 ubi_dbg_dump_vid_hdr(vid_hdr);
1073 }
1074 dbg_bld("bad CRC at PEB %d, calculated %#08x, "
1075 "read %#08x", pnum, crc, hdr_crc);
1076 if (!read_err)
1077 return UBI_IO_BAD_HDR;
1078 else
1079 return UBI_IO_BAD_HDR_EBADMSG;
1080 }
1081
1082 err = validate_vid_hdr(ubi, vid_hdr);
1083 if (err) {
1084 ubi_err("validation failed for PEB %d", pnum);
1085 return -EINVAL;
1086 }
1087
1088 return read_err ? UBI_IO_BITFLIPS : 0;
1089}
1090
1091/**
1092 * ubi_io_write_vid_hdr - write a volume identifier header.
1093 * @ubi: UBI device description object
1094 * @pnum: the physical eraseblock number to write to
1095 * @vid_hdr: the volume identifier header to write
1096 *
1097 * This function writes the volume identifier header described by @vid_hdr to
1098 * physical eraseblock @pnum. This function automatically fills the
1099 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
1100 * header CRC checksum and stores it at vid_hdr->hdr_crc.
1101 *
1102 * This function returns zero in case of success and a negative error code in
1103 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1104 * bad.
1105 */
1106int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1107 struct ubi_vid_hdr *vid_hdr)
1108{
1109 int err;
1110 uint32_t crc;
1111 void *p;
1112
1113 dbg_io("write VID header to PEB %d", pnum);
1114 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1115
1116 err = paranoid_check_peb_ec_hdr(ubi, pnum);
1117 if (err)
1118 return err;
1119
1120 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1121 vid_hdr->version = UBI_VERSION;
1122 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1123 vid_hdr->hdr_crc = cpu_to_be32(crc);
1124
1125 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1126 if (err)
1127 return err;
1128
1129 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1130 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1131 ubi->vid_hdr_alsize);
1132 return err;
1133}
1134
1135#ifdef CONFIG_MTD_UBI_DEBUG
1136
1137/**
1138 * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
1139 * @ubi: UBI device description object
1140 * @pnum: physical eraseblock number to check
1141 *
1142 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1143 * it is bad and a negative error code if an error occurred.
1144 */
1145static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
1146{
1147 int err;
1148
1149 if (!ubi->dbg->chk_io)
1150 return 0;
1151
1152 err = ubi_io_is_bad(ubi, pnum);
1153 if (!err)
1154 return err;
1155
1156 ubi_err("paranoid check failed for PEB %d", pnum);
1157 ubi_dbg_dump_stack();
1158 return err > 0 ? -EINVAL : err;
1159}
1160
1161/**
1162 * paranoid_check_ec_hdr - check if an erase counter header is all right.
1163 * @ubi: UBI device description object
1164 * @pnum: physical eraseblock number the erase counter header belongs to
1165 * @ec_hdr: the erase counter header to check
1166 *
1167 * This function returns zero if the erase counter header contains valid
1168 * values, and %-EINVAL if not.
1169 */
1170static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1171 const struct ubi_ec_hdr *ec_hdr)
1172{
1173 int err;
1174 uint32_t magic;
1175
1176 if (!ubi->dbg->chk_io)
1177 return 0;
1178
1179 magic = be32_to_cpu(ec_hdr->magic);
1180 if (magic != UBI_EC_HDR_MAGIC) {
1181 ubi_err("bad magic %#08x, must be %#08x",
1182 magic, UBI_EC_HDR_MAGIC);
1183 goto fail;
1184 }
1185
1186 err = validate_ec_hdr(ubi, ec_hdr);
1187 if (err) {
1188 ubi_err("paranoid check failed for PEB %d", pnum);
1189 goto fail;
1190 }
1191
1192 return 0;
1193
1194fail:
1195 ubi_dbg_dump_ec_hdr(ec_hdr);
1196 ubi_dbg_dump_stack();
1197 return -EINVAL;
1198}
1199
1200/**
1201 * paranoid_check_peb_ec_hdr - check erase counter header.
1202 * @ubi: UBI device description object
1203 * @pnum: the physical eraseblock number to check
1204 *
1205 * This function returns zero if the erase counter header is all right and and
1206 * a negative error code if not or if an error occurred.
1207 */
1208static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1209{
1210 int err;
1211 uint32_t crc, hdr_crc;
1212 struct ubi_ec_hdr *ec_hdr;
1213
1214 if (!ubi->dbg->chk_io)
1215 return 0;
1216
1217 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1218 if (!ec_hdr)
1219 return -ENOMEM;
1220
1221 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1222 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1223 goto exit;
1224
1225 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1226 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1227 if (hdr_crc != crc) {
1228 ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
1229 ubi_err("paranoid check failed for PEB %d", pnum);
1230 ubi_dbg_dump_ec_hdr(ec_hdr);
1231 ubi_dbg_dump_stack();
1232 err = -EINVAL;
1233 goto exit;
1234 }
1235
1236 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
1237
1238exit:
1239 kfree(ec_hdr);
1240 return err;
1241}
1242
1243/**
1244 * paranoid_check_vid_hdr - check that a volume identifier header is all right.
1245 * @ubi: UBI device description object
1246 * @pnum: physical eraseblock number the volume identifier header belongs to
1247 * @vid_hdr: the volume identifier header to check
1248 *
1249 * This function returns zero if the volume identifier header is all right, and
1250 * %-EINVAL if not.
1251 */
1252static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1253 const struct ubi_vid_hdr *vid_hdr)
1254{
1255 int err;
1256 uint32_t magic;
1257
1258 if (!ubi->dbg->chk_io)
1259 return 0;
1260
1261 magic = be32_to_cpu(vid_hdr->magic);
1262 if (magic != UBI_VID_HDR_MAGIC) {
1263 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1264 magic, pnum, UBI_VID_HDR_MAGIC);
1265 goto fail;
1266 }
1267
1268 err = validate_vid_hdr(ubi, vid_hdr);
1269 if (err) {
1270 ubi_err("paranoid check failed for PEB %d", pnum);
1271 goto fail;
1272 }
1273
1274 return err;
1275
1276fail:
1277 ubi_err("paranoid check failed for PEB %d", pnum);
1278 ubi_dbg_dump_vid_hdr(vid_hdr);
1279 ubi_dbg_dump_stack();
1280 return -EINVAL;
1281
1282}
1283
1284/**
1285 * paranoid_check_peb_vid_hdr - check volume identifier header.
1286 * @ubi: UBI device description object
1287 * @pnum: the physical eraseblock number to check
1288 *
1289 * This function returns zero if the volume identifier header is all right,
1290 * and a negative error code if not or if an error occurred.
1291 */
1292static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1293{
1294 int err;
1295 uint32_t crc, hdr_crc;
1296 struct ubi_vid_hdr *vid_hdr;
1297 void *p;
1298
1299 if (!ubi->dbg->chk_io)
1300 return 0;
1301
1302 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
1303 if (!vid_hdr)
1304 return -ENOMEM;
1305
1306 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1307 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1308 ubi->vid_hdr_alsize);
1309 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1310 goto exit;
1311
1312 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
1313 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1314 if (hdr_crc != crc) {
1315 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
1316 "read %#08x", pnum, crc, hdr_crc);
1317 ubi_err("paranoid check failed for PEB %d", pnum);
1318 ubi_dbg_dump_vid_hdr(vid_hdr);
1319 ubi_dbg_dump_stack();
1320 err = -EINVAL;
1321 goto exit;
1322 }
1323
1324 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1325
1326exit:
1327 ubi_free_vid_hdr(ubi, vid_hdr);
1328 return err;
1329}
1330
1331/**
1332 * ubi_dbg_check_write - make sure write succeeded.
1333 * @ubi: UBI device description object
1334 * @buf: buffer with data which were written
1335 * @pnum: physical eraseblock number the data were written to
1336 * @offset: offset within the physical eraseblock the data were written to
1337 * @len: how many bytes were written
1338 *
1339 * This functions reads data which were recently written and compares it with
1340 * the original data buffer - the data have to match. Returns zero if the data
1341 * match and a negative error code if not or in case of failure.
1342 */
1343int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
1344 int offset, int len)
1345{
1346 int err, i;
1347 size_t read;
1348 void *buf1;
1349 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1350
1351 if (!ubi->dbg->chk_io)
1352 return 0;
1353
1354 buf1 = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1355 if (!buf1) {
1356 ubi_err("cannot allocate memory to check writes");
1357 return 0;
1358 }
1359
1360 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf1);
1361 if (err && err != -EUCLEAN)
1362 goto out_free;
1363
1364 for (i = 0; i < len; i++) {
1365 uint8_t c = ((uint8_t *)buf)[i];
1366 uint8_t c1 = ((uint8_t *)buf1)[i];
1367 int dump_len;
1368
1369 if (c == c1)
1370 continue;
1371
1372 ubi_err("paranoid check failed for PEB %d:%d, len %d",
1373 pnum, offset, len);
1374 ubi_msg("data differ at position %d", i);
1375 dump_len = max_t(int, 128, len - i);
1376 ubi_msg("hex dump of the original buffer from %d to %d",
1377 i, i + dump_len);
1378 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1379 buf + i, dump_len, 1);
1380 ubi_msg("hex dump of the read buffer from %d to %d",
1381 i, i + dump_len);
1382 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1383 buf1 + i, dump_len, 1);
1384 ubi_dbg_dump_stack();
1385 err = -EINVAL;
1386 goto out_free;
1387 }
1388
1389 vfree(buf1);
1390 return 0;
1391
1392out_free:
1393 vfree(buf1);
1394 return err;
1395}
1396
1397/**
1398 * ubi_dbg_check_all_ff - check that a region of flash is empty.
1399 * @ubi: UBI device description object
1400 * @pnum: the physical eraseblock number to check
1401 * @offset: the starting offset within the physical eraseblock to check
1402 * @len: the length of the region to check
1403 *
1404 * This function returns zero if only 0xFF bytes are present at offset
1405 * @offset of the physical eraseblock @pnum, and a negative error code if not
1406 * or if an error occurred.
1407 */
1408int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
1409{
1410 size_t read;
1411 int err;
1412 void *buf;
1413 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1414
1415 if (!ubi->dbg->chk_io)
1416 return 0;
1417
1418 buf = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1419 if (!buf) {
1420 ubi_err("cannot allocate memory to check for 0xFFs");
1421 return 0;
1422 }
1423
1424 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
1425 if (err && err != -EUCLEAN) {
1426 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
1427 "read %zd bytes", err, len, pnum, offset, read);
1428 goto error;
1429 }
1430
1431 err = ubi_check_pattern(buf, 0xFF, len);
1432 if (err == 0) {
1433 ubi_err("flash region at PEB %d:%d, length %d does not "
1434 "contain all 0xFF bytes", pnum, offset, len);
1435 goto fail;
1436 }
1437
1438 vfree(buf);
1439 return 0;
1440
1441fail:
1442 ubi_err("paranoid check failed for PEB %d", pnum);
1443 ubi_msg("hex dump of the %d-%d region", offset, offset + len);
1444 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
1445 err = -EINVAL;
1446error:
1447 ubi_dbg_dump_stack();
1448 vfree(buf);
1449 return err;
1450}
1451
1452#endif /* CONFIG_MTD_UBI_DEBUG */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2006, 2007
5 *
6 * Author: Artem Bityutskiy (Битюцкий Артём)
7 */
8
9/*
10 * UBI input/output sub-system.
11 *
12 * This sub-system provides a uniform way to work with all kinds of the
13 * underlying MTD devices. It also implements handy functions for reading and
14 * writing UBI headers.
15 *
16 * We are trying to have a paranoid mindset and not to trust to what we read
17 * from the flash media in order to be more secure and robust. So this
18 * sub-system validates every single header it reads from the flash media.
19 *
20 * Some words about how the eraseblock headers are stored.
21 *
22 * The erase counter header is always stored at offset zero. By default, the
23 * VID header is stored after the EC header at the closest aligned offset
24 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
25 * header at the closest aligned offset. But this default layout may be
26 * changed. For example, for different reasons (e.g., optimization) UBI may be
27 * asked to put the VID header at further offset, and even at an unaligned
28 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
29 * proper padding in front of it. Data offset may also be changed but it has to
30 * be aligned.
31 *
32 * About minimal I/O units. In general, UBI assumes flash device model where
33 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
34 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
35 * @ubi->mtd->writesize field. But as an exception, UBI admits use of another
36 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
37 * to do different optimizations.
38 *
39 * This is extremely useful in case of NAND flashes which admit of several
40 * write operations to one NAND page. In this case UBI can fit EC and VID
41 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
42 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
43 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
44 * users.
45 *
46 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
47 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
48 * headers.
49 *
50 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
51 * device, e.g., make @ubi->min_io_size = 512 in the example above?
52 *
53 * A: because when writing a sub-page, MTD still writes a full 2K page but the
54 * bytes which are not relevant to the sub-page are 0xFF. So, basically,
55 * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
56 * Thus, we prefer to use sub-pages only for EC and VID headers.
57 *
58 * As it was noted above, the VID header may start at a non-aligned offset.
59 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
60 * the VID header may reside at offset 1984 which is the last 64 bytes of the
61 * last sub-page (EC header is always at offset zero). This causes some
62 * difficulties when reading and writing VID headers.
63 *
64 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
65 * the data and want to write this VID header out. As we can only write in
66 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
67 * to offset 448 of this buffer.
68 *
69 * The I/O sub-system does the following trick in order to avoid this extra
70 * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
71 * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
72 * When the VID header is being written out, it shifts the VID header pointer
73 * back and writes the whole sub-page.
74 */
75
76#include <linux/crc32.h>
77#include <linux/err.h>
78#include <linux/slab.h>
79#include "ubi.h"
80
81static int self_check_not_bad(const struct ubi_device *ubi, int pnum);
82static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
83static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
84 const struct ubi_ec_hdr *ec_hdr);
85static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
86static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
87 const struct ubi_vid_hdr *vid_hdr);
88static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
89 int offset, int len);
90
91/**
92 * ubi_io_read - read data from a physical eraseblock.
93 * @ubi: UBI device description object
94 * @buf: buffer where to store the read data
95 * @pnum: physical eraseblock number to read from
96 * @offset: offset within the physical eraseblock from where to read
97 * @len: how many bytes to read
98 *
99 * This function reads data from offset @offset of physical eraseblock @pnum
100 * and stores the read data in the @buf buffer. The following return codes are
101 * possible:
102 *
103 * o %0 if all the requested data were successfully read;
104 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
105 * correctable bit-flips were detected; this is harmless but may indicate
106 * that this eraseblock may become bad soon (but do not have to);
107 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
108 * example it can be an ECC error in case of NAND; this most probably means
109 * that the data is corrupted;
110 * o %-EIO if some I/O error occurred;
111 * o other negative error codes in case of other errors.
112 */
113int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
114 int len)
115{
116 int err, retries = 0;
117 size_t read;
118 loff_t addr;
119
120 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
121
122 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
123 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
124 ubi_assert(len > 0);
125
126 err = self_check_not_bad(ubi, pnum);
127 if (err)
128 return err;
129
130 /*
131 * Deliberately corrupt the buffer to improve robustness. Indeed, if we
132 * do not do this, the following may happen:
133 * 1. The buffer contains data from previous operation, e.g., read from
134 * another PEB previously. The data looks like expected, e.g., if we
135 * just do not read anything and return - the caller would not
136 * notice this. E.g., if we are reading a VID header, the buffer may
137 * contain a valid VID header from another PEB.
138 * 2. The driver is buggy and returns us success or -EBADMSG or
139 * -EUCLEAN, but it does not actually put any data to the buffer.
140 *
141 * This may confuse UBI or upper layers - they may think the buffer
142 * contains valid data while in fact it is just old data. This is
143 * especially possible because UBI (and UBIFS) relies on CRC, and
144 * treats data as correct even in case of ECC errors if the CRC is
145 * correct.
146 *
147 * Try to prevent this situation by changing the first byte of the
148 * buffer.
149 */
150 *((uint8_t *)buf) ^= 0xFF;
151
152 addr = (loff_t)pnum * ubi->peb_size + offset;
153retry:
154 err = mtd_read(ubi->mtd, addr, len, &read, buf);
155 if (err) {
156 const char *errstr = mtd_is_eccerr(err) ? " (ECC error)" : "";
157
158 if (mtd_is_bitflip(err)) {
159 /*
160 * -EUCLEAN is reported if there was a bit-flip which
161 * was corrected, so this is harmless.
162 *
163 * We do not report about it here unless debugging is
164 * enabled. A corresponding message will be printed
165 * later, when it is has been scrubbed.
166 */
167 ubi_msg(ubi, "fixable bit-flip detected at PEB %d",
168 pnum);
169 ubi_assert(len == read);
170 return UBI_IO_BITFLIPS;
171 }
172
173 if (retries++ < UBI_IO_RETRIES) {
174 ubi_warn(ubi, "error %d%s while reading %d bytes from PEB %d:%d, read only %zd bytes, retry",
175 err, errstr, len, pnum, offset, read);
176 yield();
177 goto retry;
178 }
179
180 ubi_err(ubi, "error %d%s while reading %d bytes from PEB %d:%d, read %zd bytes",
181 err, errstr, len, pnum, offset, read);
182 dump_stack();
183
184 /*
185 * The driver should never return -EBADMSG if it failed to read
186 * all the requested data. But some buggy drivers might do
187 * this, so we change it to -EIO.
188 */
189 if (read != len && mtd_is_eccerr(err)) {
190 ubi_assert(0);
191 err = -EIO;
192 }
193 } else {
194 ubi_assert(len == read);
195
196 if (ubi_dbg_is_bitflip(ubi)) {
197 dbg_gen("bit-flip (emulated)");
198 return UBI_IO_BITFLIPS;
199 }
200
201 if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE)) {
202 ubi_warn(ubi, "cannot read %d bytes from PEB %d:%d (emulated)",
203 len, pnum, offset);
204 return -EIO;
205 }
206
207 if (ubi_dbg_is_eccerr(ubi)) {
208 ubi_warn(ubi, "ECC error (emulated) while reading %d bytes from PEB %d:%d, read %zd bytes",
209 len, pnum, offset, read);
210 return -EBADMSG;
211 }
212 }
213
214 return err;
215}
216
217/**
218 * ubi_io_write - write data to a physical eraseblock.
219 * @ubi: UBI device description object
220 * @buf: buffer with the data to write
221 * @pnum: physical eraseblock number to write to
222 * @offset: offset within the physical eraseblock where to write
223 * @len: how many bytes to write
224 *
225 * This function writes @len bytes of data from buffer @buf to offset @offset
226 * of physical eraseblock @pnum. If all the data were successfully written,
227 * zero is returned. If an error occurred, this function returns a negative
228 * error code. If %-EIO is returned, the physical eraseblock most probably went
229 * bad.
230 *
231 * Note, in case of an error, it is possible that something was still written
232 * to the flash media, but may be some garbage.
233 */
234int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
235 int len)
236{
237 int err;
238 size_t written;
239 loff_t addr;
240
241 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
242
243 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
244 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
245 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
246 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
247
248 if (ubi->ro_mode) {
249 ubi_err(ubi, "read-only mode");
250 return -EROFS;
251 }
252
253 err = self_check_not_bad(ubi, pnum);
254 if (err)
255 return err;
256
257 /* The area we are writing to has to contain all 0xFF bytes */
258 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
259 if (err)
260 return err;
261
262 if (offset >= ubi->leb_start) {
263 /*
264 * We write to the data area of the physical eraseblock. Make
265 * sure it has valid EC and VID headers.
266 */
267 err = self_check_peb_ec_hdr(ubi, pnum);
268 if (err)
269 return err;
270 err = self_check_peb_vid_hdr(ubi, pnum);
271 if (err)
272 return err;
273 }
274
275 if (ubi_dbg_is_write_failure(ubi)) {
276 ubi_err(ubi, "cannot write %d bytes to PEB %d:%d (emulated)",
277 len, pnum, offset);
278 dump_stack();
279 return -EIO;
280 }
281
282 addr = (loff_t)pnum * ubi->peb_size + offset;
283 err = mtd_write(ubi->mtd, addr, len, &written, buf);
284 if (err) {
285 ubi_err(ubi, "error %d while writing %d bytes to PEB %d:%d, written %zd bytes",
286 err, len, pnum, offset, written);
287 dump_stack();
288 ubi_dump_flash(ubi, pnum, offset, len);
289 } else
290 ubi_assert(written == len);
291
292 if (!err) {
293 err = self_check_write(ubi, buf, pnum, offset, len);
294 if (err)
295 return err;
296
297 /*
298 * Since we always write sequentially, the rest of the PEB has
299 * to contain only 0xFF bytes.
300 */
301 offset += len;
302 len = ubi->peb_size - offset;
303 if (len)
304 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
305 }
306
307 return err;
308}
309
310/**
311 * do_sync_erase - synchronously erase a physical eraseblock.
312 * @ubi: UBI device description object
313 * @pnum: the physical eraseblock number to erase
314 *
315 * This function synchronously erases physical eraseblock @pnum and returns
316 * zero in case of success and a negative error code in case of failure. If
317 * %-EIO is returned, the physical eraseblock most probably went bad.
318 */
319static int do_sync_erase(struct ubi_device *ubi, int pnum)
320{
321 int err, retries = 0;
322 struct erase_info ei;
323
324 dbg_io("erase PEB %d", pnum);
325 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
326
327 if (ubi->ro_mode) {
328 ubi_err(ubi, "read-only mode");
329 return -EROFS;
330 }
331
332retry:
333 memset(&ei, 0, sizeof(struct erase_info));
334
335 ei.addr = (loff_t)pnum * ubi->peb_size;
336 ei.len = ubi->peb_size;
337
338 err = mtd_erase(ubi->mtd, &ei);
339 if (err) {
340 if (retries++ < UBI_IO_RETRIES) {
341 ubi_warn(ubi, "error %d while erasing PEB %d, retry",
342 err, pnum);
343 yield();
344 goto retry;
345 }
346 ubi_err(ubi, "cannot erase PEB %d, error %d", pnum, err);
347 dump_stack();
348 return err;
349 }
350
351 err = ubi_self_check_all_ff(ubi, pnum, 0, ubi->peb_size);
352 if (err)
353 return err;
354
355 if (ubi_dbg_is_erase_failure(ubi)) {
356 ubi_err(ubi, "cannot erase PEB %d (emulated)", pnum);
357 return -EIO;
358 }
359
360 return 0;
361}
362
363/* Patterns to write to a physical eraseblock when torturing it */
364static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
365
366/**
367 * torture_peb - test a supposedly bad physical eraseblock.
368 * @ubi: UBI device description object
369 * @pnum: the physical eraseblock number to test
370 *
371 * This function returns %-EIO if the physical eraseblock did not pass the
372 * test, a positive number of erase operations done if the test was
373 * successfully passed, and other negative error codes in case of other errors.
374 */
375static int torture_peb(struct ubi_device *ubi, int pnum)
376{
377 int err, i, patt_count;
378
379 ubi_msg(ubi, "run torture test for PEB %d", pnum);
380 patt_count = ARRAY_SIZE(patterns);
381 ubi_assert(patt_count > 0);
382
383 mutex_lock(&ubi->buf_mutex);
384 for (i = 0; i < patt_count; i++) {
385 err = do_sync_erase(ubi, pnum);
386 if (err)
387 goto out;
388
389 /* Make sure the PEB contains only 0xFF bytes */
390 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
391 if (err)
392 goto out;
393
394 err = ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->peb_size);
395 if (err == 0) {
396 ubi_err(ubi, "erased PEB %d, but a non-0xFF byte found",
397 pnum);
398 err = -EIO;
399 goto out;
400 }
401
402 /* Write a pattern and check it */
403 memset(ubi->peb_buf, patterns[i], ubi->peb_size);
404 err = ubi_io_write(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
405 if (err)
406 goto out;
407
408 memset(ubi->peb_buf, ~patterns[i], ubi->peb_size);
409 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
410 if (err)
411 goto out;
412
413 err = ubi_check_pattern(ubi->peb_buf, patterns[i],
414 ubi->peb_size);
415 if (err == 0) {
416 ubi_err(ubi, "pattern %x checking failed for PEB %d",
417 patterns[i], pnum);
418 err = -EIO;
419 goto out;
420 }
421 }
422
423 err = patt_count;
424 ubi_msg(ubi, "PEB %d passed torture test, do not mark it as bad", pnum);
425
426out:
427 mutex_unlock(&ubi->buf_mutex);
428 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
429 /*
430 * If a bit-flip or data integrity error was detected, the test
431 * has not passed because it happened on a freshly erased
432 * physical eraseblock which means something is wrong with it.
433 */
434 ubi_err(ubi, "read problems on freshly erased PEB %d, must be bad",
435 pnum);
436 err = -EIO;
437 }
438 return err;
439}
440
441/**
442 * nor_erase_prepare - prepare a NOR flash PEB for erasure.
443 * @ubi: UBI device description object
444 * @pnum: physical eraseblock number to prepare
445 *
446 * NOR flash, or at least some of them, have peculiar embedded PEB erasure
447 * algorithm: the PEB is first filled with zeroes, then it is erased. And
448 * filling with zeroes starts from the end of the PEB. This was observed with
449 * Spansion S29GL512N NOR flash.
450 *
451 * This means that in case of a power cut we may end up with intact data at the
452 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the
453 * EC and VID headers are OK, but a large chunk of data at the end of PEB is
454 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it
455 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
456 *
457 * This function is called before erasing NOR PEBs and it zeroes out EC and VID
458 * magic numbers in order to invalidate them and prevent the failures. Returns
459 * zero in case of success and a negative error code in case of failure.
460 */
461static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
462{
463 int err;
464 size_t written;
465 loff_t addr;
466 uint32_t data = 0;
467 struct ubi_ec_hdr ec_hdr;
468 struct ubi_vid_io_buf vidb;
469
470 /*
471 * Note, we cannot generally define VID header buffers on stack,
472 * because of the way we deal with these buffers (see the header
473 * comment in this file). But we know this is a NOR-specific piece of
474 * code, so we can do this. But yes, this is error-prone and we should
475 * (pre-)allocate VID header buffer instead.
476 */
477 struct ubi_vid_hdr vid_hdr;
478
479 /*
480 * If VID or EC is valid, we have to corrupt them before erasing.
481 * It is important to first invalidate the EC header, and then the VID
482 * header. Otherwise a power cut may lead to valid EC header and
483 * invalid VID header, in which case UBI will treat this PEB as
484 * corrupted and will try to preserve it, and print scary warnings.
485 */
486 addr = (loff_t)pnum * ubi->peb_size;
487 err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
488 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
489 err != UBI_IO_FF){
490 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
491 if(err)
492 goto error;
493 }
494
495 ubi_init_vid_buf(ubi, &vidb, &vid_hdr);
496 ubi_assert(&vid_hdr == ubi_get_vid_hdr(&vidb));
497
498 err = ubi_io_read_vid_hdr(ubi, pnum, &vidb, 0);
499 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
500 err != UBI_IO_FF){
501 addr += ubi->vid_hdr_aloffset;
502 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
503 if (err)
504 goto error;
505 }
506 return 0;
507
508error:
509 /*
510 * The PEB contains a valid VID or EC header, but we cannot invalidate
511 * it. Supposedly the flash media or the driver is screwed up, so
512 * return an error.
513 */
514 ubi_err(ubi, "cannot invalidate PEB %d, write returned %d", pnum, err);
515 ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
516 return -EIO;
517}
518
519/**
520 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
521 * @ubi: UBI device description object
522 * @pnum: physical eraseblock number to erase
523 * @torture: if this physical eraseblock has to be tortured
524 *
525 * This function synchronously erases physical eraseblock @pnum. If @torture
526 * flag is not zero, the physical eraseblock is checked by means of writing
527 * different patterns to it and reading them back. If the torturing is enabled,
528 * the physical eraseblock is erased more than once.
529 *
530 * This function returns the number of erasures made in case of success, %-EIO
531 * if the erasure failed or the torturing test failed, and other negative error
532 * codes in case of other errors. Note, %-EIO means that the physical
533 * eraseblock is bad.
534 */
535int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
536{
537 int err, ret = 0;
538
539 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
540
541 err = self_check_not_bad(ubi, pnum);
542 if (err != 0)
543 return err;
544
545 if (ubi->ro_mode) {
546 ubi_err(ubi, "read-only mode");
547 return -EROFS;
548 }
549
550 /*
551 * If the flash is ECC-ed then we have to erase the ECC block before we
552 * can write to it. But the write is in preparation to an erase in the
553 * first place. This means we cannot zero out EC and VID before the
554 * erase and we just have to hope the flash starts erasing from the
555 * start of the page.
556 */
557 if (ubi->nor_flash && ubi->mtd->writesize == 1) {
558 err = nor_erase_prepare(ubi, pnum);
559 if (err)
560 return err;
561 }
562
563 if (torture) {
564 ret = torture_peb(ubi, pnum);
565 if (ret < 0)
566 return ret;
567 }
568
569 err = do_sync_erase(ubi, pnum);
570 if (err)
571 return err;
572
573 return ret + 1;
574}
575
576/**
577 * ubi_io_is_bad - check if a physical eraseblock is bad.
578 * @ubi: UBI device description object
579 * @pnum: the physical eraseblock number to check
580 *
581 * This function returns a positive number if the physical eraseblock is bad,
582 * zero if not, and a negative error code if an error occurred.
583 */
584int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
585{
586 struct mtd_info *mtd = ubi->mtd;
587
588 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
589
590 if (ubi->bad_allowed) {
591 int ret;
592
593 ret = mtd_block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
594 if (ret < 0)
595 ubi_err(ubi, "error %d while checking if PEB %d is bad",
596 ret, pnum);
597 else if (ret)
598 dbg_io("PEB %d is bad", pnum);
599 return ret;
600 }
601
602 return 0;
603}
604
605/**
606 * ubi_io_mark_bad - mark a physical eraseblock as bad.
607 * @ubi: UBI device description object
608 * @pnum: the physical eraseblock number to mark
609 *
610 * This function returns zero in case of success and a negative error code in
611 * case of failure.
612 */
613int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
614{
615 int err;
616 struct mtd_info *mtd = ubi->mtd;
617
618 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
619
620 if (ubi->ro_mode) {
621 ubi_err(ubi, "read-only mode");
622 return -EROFS;
623 }
624
625 if (!ubi->bad_allowed)
626 return 0;
627
628 err = mtd_block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
629 if (err)
630 ubi_err(ubi, "cannot mark PEB %d bad, error %d", pnum, err);
631 return err;
632}
633
634/**
635 * validate_ec_hdr - validate an erase counter header.
636 * @ubi: UBI device description object
637 * @ec_hdr: the erase counter header to check
638 *
639 * This function returns zero if the erase counter header is OK, and %1 if
640 * not.
641 */
642static int validate_ec_hdr(const struct ubi_device *ubi,
643 const struct ubi_ec_hdr *ec_hdr)
644{
645 long long ec;
646 int vid_hdr_offset, leb_start;
647
648 ec = be64_to_cpu(ec_hdr->ec);
649 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
650 leb_start = be32_to_cpu(ec_hdr->data_offset);
651
652 if (ec_hdr->version != UBI_VERSION) {
653 ubi_err(ubi, "node with incompatible UBI version found: this UBI version is %d, image version is %d",
654 UBI_VERSION, (int)ec_hdr->version);
655 goto bad;
656 }
657
658 if (vid_hdr_offset != ubi->vid_hdr_offset) {
659 ubi_err(ubi, "bad VID header offset %d, expected %d",
660 vid_hdr_offset, ubi->vid_hdr_offset);
661 goto bad;
662 }
663
664 if (leb_start != ubi->leb_start) {
665 ubi_err(ubi, "bad data offset %d, expected %d",
666 leb_start, ubi->leb_start);
667 goto bad;
668 }
669
670 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
671 ubi_err(ubi, "bad erase counter %lld", ec);
672 goto bad;
673 }
674
675 return 0;
676
677bad:
678 ubi_err(ubi, "bad EC header");
679 ubi_dump_ec_hdr(ec_hdr);
680 dump_stack();
681 return 1;
682}
683
684/**
685 * ubi_io_read_ec_hdr - read and check an erase counter header.
686 * @ubi: UBI device description object
687 * @pnum: physical eraseblock to read from
688 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
689 * header
690 * @verbose: be verbose if the header is corrupted or was not found
691 *
692 * This function reads erase counter header from physical eraseblock @pnum and
693 * stores it in @ec_hdr. This function also checks CRC checksum of the read
694 * erase counter header. The following codes may be returned:
695 *
696 * o %0 if the CRC checksum is correct and the header was successfully read;
697 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
698 * and corrected by the flash driver; this is harmless but may indicate that
699 * this eraseblock may become bad soon (but may be not);
700 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
701 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
702 * a data integrity error (uncorrectable ECC error in case of NAND);
703 * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
704 * o a negative error code in case of failure.
705 */
706int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
707 struct ubi_ec_hdr *ec_hdr, int verbose)
708{
709 int err, read_err;
710 uint32_t crc, magic, hdr_crc;
711
712 dbg_io("read EC header from PEB %d", pnum);
713 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
714
715 read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
716 if (read_err) {
717 if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
718 return read_err;
719
720 /*
721 * We read all the data, but either a correctable bit-flip
722 * occurred, or MTD reported a data integrity error
723 * (uncorrectable ECC error in case of NAND). The former is
724 * harmless, the later may mean that the read data is
725 * corrupted. But we have a CRC check-sum and we will detect
726 * this. If the EC header is still OK, we just report this as
727 * there was a bit-flip, to force scrubbing.
728 */
729 }
730
731 magic = be32_to_cpu(ec_hdr->magic);
732 if (magic != UBI_EC_HDR_MAGIC) {
733 if (mtd_is_eccerr(read_err))
734 return UBI_IO_BAD_HDR_EBADMSG;
735
736 /*
737 * The magic field is wrong. Let's check if we have read all
738 * 0xFF. If yes, this physical eraseblock is assumed to be
739 * empty.
740 */
741 if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
742 /* The physical eraseblock is supposedly empty */
743 if (verbose)
744 ubi_warn(ubi, "no EC header found at PEB %d, only 0xFF bytes",
745 pnum);
746 dbg_bld("no EC header found at PEB %d, only 0xFF bytes",
747 pnum);
748 if (!read_err)
749 return UBI_IO_FF;
750 else
751 return UBI_IO_FF_BITFLIPS;
752 }
753
754 /*
755 * This is not a valid erase counter header, and these are not
756 * 0xFF bytes. Report that the header is corrupted.
757 */
758 if (verbose) {
759 ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
760 pnum, magic, UBI_EC_HDR_MAGIC);
761 ubi_dump_ec_hdr(ec_hdr);
762 }
763 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
764 pnum, magic, UBI_EC_HDR_MAGIC);
765 return UBI_IO_BAD_HDR;
766 }
767
768 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
769 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
770
771 if (hdr_crc != crc) {
772 if (verbose) {
773 ubi_warn(ubi, "bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
774 pnum, crc, hdr_crc);
775 ubi_dump_ec_hdr(ec_hdr);
776 }
777 dbg_bld("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
778 pnum, crc, hdr_crc);
779
780 if (!read_err)
781 return UBI_IO_BAD_HDR;
782 else
783 return UBI_IO_BAD_HDR_EBADMSG;
784 }
785
786 /* And of course validate what has just been read from the media */
787 err = validate_ec_hdr(ubi, ec_hdr);
788 if (err) {
789 ubi_err(ubi, "validation failed for PEB %d", pnum);
790 return -EINVAL;
791 }
792
793 /*
794 * If there was %-EBADMSG, but the header CRC is still OK, report about
795 * a bit-flip to force scrubbing on this PEB.
796 */
797 if (read_err)
798 return UBI_IO_BITFLIPS;
799
800 if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_EC)) {
801 ubi_warn(ubi, "cannot read EC header from PEB %d (emulated)",
802 pnum);
803 return -EIO;
804 }
805
806 if (ubi_dbg_is_ff(ubi, MASK_IO_FF_EC)) {
807 ubi_warn(ubi, "bit-all-ff (emulated)");
808 return UBI_IO_FF;
809 }
810
811 if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_EC)) {
812 ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)");
813 return UBI_IO_FF_BITFLIPS;
814 }
815
816 if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_EC)) {
817 ubi_warn(ubi, "bad_hdr (emulated)");
818 return UBI_IO_BAD_HDR;
819 }
820
821 if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_EC)) {
822 ubi_warn(ubi, "bad_hdr with ECC error (emulated)");
823 return UBI_IO_BAD_HDR_EBADMSG;
824 }
825
826 return 0;
827}
828
829/**
830 * ubi_io_write_ec_hdr - write an erase counter header.
831 * @ubi: UBI device description object
832 * @pnum: physical eraseblock to write to
833 * @ec_hdr: the erase counter header to write
834 *
835 * This function writes erase counter header described by @ec_hdr to physical
836 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
837 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
838 * field.
839 *
840 * This function returns zero in case of success and a negative error code in
841 * case of failure. If %-EIO is returned, the physical eraseblock most probably
842 * went bad.
843 */
844int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
845 struct ubi_ec_hdr *ec_hdr)
846{
847 int err;
848 uint32_t crc;
849
850 dbg_io("write EC header to PEB %d", pnum);
851 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
852
853 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
854 ec_hdr->version = UBI_VERSION;
855 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
856 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
857 ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);
858 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
859 ec_hdr->hdr_crc = cpu_to_be32(crc);
860
861 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
862 if (err)
863 return err;
864
865 if (ubi_dbg_is_power_cut(ubi, MASK_POWER_CUT_EC)) {
866 ubi_warn(ubi, "emulating a power cut when writing EC header");
867 ubi_ro_mode(ubi);
868 return -EROFS;
869 }
870
871 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
872 return err;
873}
874
875/**
876 * validate_vid_hdr - validate a volume identifier header.
877 * @ubi: UBI device description object
878 * @vid_hdr: the volume identifier header to check
879 *
880 * This function checks that data stored in the volume identifier header
881 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
882 */
883static int validate_vid_hdr(const struct ubi_device *ubi,
884 const struct ubi_vid_hdr *vid_hdr)
885{
886 int vol_type = vid_hdr->vol_type;
887 int copy_flag = vid_hdr->copy_flag;
888 int vol_id = be32_to_cpu(vid_hdr->vol_id);
889 int lnum = be32_to_cpu(vid_hdr->lnum);
890 int compat = vid_hdr->compat;
891 int data_size = be32_to_cpu(vid_hdr->data_size);
892 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
893 int data_pad = be32_to_cpu(vid_hdr->data_pad);
894 int data_crc = be32_to_cpu(vid_hdr->data_crc);
895 int usable_leb_size = ubi->leb_size - data_pad;
896
897 if (copy_flag != 0 && copy_flag != 1) {
898 ubi_err(ubi, "bad copy_flag");
899 goto bad;
900 }
901
902 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
903 data_pad < 0) {
904 ubi_err(ubi, "negative values");
905 goto bad;
906 }
907
908 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
909 ubi_err(ubi, "bad vol_id");
910 goto bad;
911 }
912
913 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
914 ubi_err(ubi, "bad compat");
915 goto bad;
916 }
917
918 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
919 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
920 compat != UBI_COMPAT_REJECT) {
921 ubi_err(ubi, "bad compat");
922 goto bad;
923 }
924
925 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
926 ubi_err(ubi, "bad vol_type");
927 goto bad;
928 }
929
930 if (data_pad >= ubi->leb_size / 2) {
931 ubi_err(ubi, "bad data_pad");
932 goto bad;
933 }
934
935 if (data_size > ubi->leb_size) {
936 ubi_err(ubi, "bad data_size");
937 goto bad;
938 }
939
940 if (vol_type == UBI_VID_STATIC) {
941 /*
942 * Although from high-level point of view static volumes may
943 * contain zero bytes of data, but no VID headers can contain
944 * zero at these fields, because they empty volumes do not have
945 * mapped logical eraseblocks.
946 */
947 if (used_ebs == 0) {
948 ubi_err(ubi, "zero used_ebs");
949 goto bad;
950 }
951 if (data_size == 0) {
952 ubi_err(ubi, "zero data_size");
953 goto bad;
954 }
955 if (lnum < used_ebs - 1) {
956 if (data_size != usable_leb_size) {
957 ubi_err(ubi, "bad data_size");
958 goto bad;
959 }
960 } else if (lnum > used_ebs - 1) {
961 ubi_err(ubi, "too high lnum");
962 goto bad;
963 }
964 } else {
965 if (copy_flag == 0) {
966 if (data_crc != 0) {
967 ubi_err(ubi, "non-zero data CRC");
968 goto bad;
969 }
970 if (data_size != 0) {
971 ubi_err(ubi, "non-zero data_size");
972 goto bad;
973 }
974 } else {
975 if (data_size == 0) {
976 ubi_err(ubi, "zero data_size of copy");
977 goto bad;
978 }
979 }
980 if (used_ebs != 0) {
981 ubi_err(ubi, "bad used_ebs");
982 goto bad;
983 }
984 }
985
986 return 0;
987
988bad:
989 ubi_err(ubi, "bad VID header");
990 ubi_dump_vid_hdr(vid_hdr);
991 dump_stack();
992 return 1;
993}
994
995/**
996 * ubi_io_read_vid_hdr - read and check a volume identifier header.
997 * @ubi: UBI device description object
998 * @pnum: physical eraseblock number to read from
999 * @vidb: the volume identifier buffer to store data in
1000 * @verbose: be verbose if the header is corrupted or wasn't found
1001 *
1002 * This function reads the volume identifier header from physical eraseblock
1003 * @pnum and stores it in @vidb. It also checks CRC checksum of the read
1004 * volume identifier header. The error codes are the same as in
1005 * 'ubi_io_read_ec_hdr()'.
1006 *
1007 * Note, the implementation of this function is also very similar to
1008 * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
1009 */
1010int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
1011 struct ubi_vid_io_buf *vidb, int verbose)
1012{
1013 int err, read_err;
1014 uint32_t crc, magic, hdr_crc;
1015 struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb);
1016 void *p = vidb->buffer;
1017
1018 dbg_io("read VID header from PEB %d", pnum);
1019 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1020
1021 read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1022 ubi->vid_hdr_shift + UBI_VID_HDR_SIZE);
1023 if (read_err && read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
1024 return read_err;
1025
1026 magic = be32_to_cpu(vid_hdr->magic);
1027 if (magic != UBI_VID_HDR_MAGIC) {
1028 if (mtd_is_eccerr(read_err))
1029 return UBI_IO_BAD_HDR_EBADMSG;
1030
1031 if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
1032 if (verbose)
1033 ubi_warn(ubi, "no VID header found at PEB %d, only 0xFF bytes",
1034 pnum);
1035 dbg_bld("no VID header found at PEB %d, only 0xFF bytes",
1036 pnum);
1037 if (!read_err)
1038 return UBI_IO_FF;
1039 else
1040 return UBI_IO_FF_BITFLIPS;
1041 }
1042
1043 if (verbose) {
1044 ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
1045 pnum, magic, UBI_VID_HDR_MAGIC);
1046 ubi_dump_vid_hdr(vid_hdr);
1047 }
1048 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
1049 pnum, magic, UBI_VID_HDR_MAGIC);
1050 return UBI_IO_BAD_HDR;
1051 }
1052
1053 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1054 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1055
1056 if (hdr_crc != crc) {
1057 if (verbose) {
1058 ubi_warn(ubi, "bad CRC at PEB %d, calculated %#08x, read %#08x",
1059 pnum, crc, hdr_crc);
1060 ubi_dump_vid_hdr(vid_hdr);
1061 }
1062 dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
1063 pnum, crc, hdr_crc);
1064 if (!read_err)
1065 return UBI_IO_BAD_HDR;
1066 else
1067 return UBI_IO_BAD_HDR_EBADMSG;
1068 }
1069
1070 err = validate_vid_hdr(ubi, vid_hdr);
1071 if (err) {
1072 ubi_err(ubi, "validation failed for PEB %d", pnum);
1073 return -EINVAL;
1074 }
1075
1076 if (read_err)
1077 return UBI_IO_BITFLIPS;
1078
1079 if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_VID)) {
1080 ubi_warn(ubi, "cannot read VID header from PEB %d (emulated)",
1081 pnum);
1082 return -EIO;
1083 }
1084
1085 if (ubi_dbg_is_ff(ubi, MASK_IO_FF_VID)) {
1086 ubi_warn(ubi, "bit-all-ff (emulated)");
1087 return UBI_IO_FF;
1088 }
1089
1090 if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_VID)) {
1091 ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)");
1092 return UBI_IO_FF_BITFLIPS;
1093 }
1094
1095 if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_VID)) {
1096 ubi_warn(ubi, "bad_hdr (emulated)");
1097 return UBI_IO_BAD_HDR;
1098 }
1099
1100 if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_VID)) {
1101 ubi_warn(ubi, "bad_hdr with ECC error (emulated)");
1102 return UBI_IO_BAD_HDR_EBADMSG;
1103 }
1104
1105 return 0;
1106}
1107
1108/**
1109 * ubi_io_write_vid_hdr - write a volume identifier header.
1110 * @ubi: UBI device description object
1111 * @pnum: the physical eraseblock number to write to
1112 * @vidb: the volume identifier buffer to write
1113 *
1114 * This function writes the volume identifier header described by @vid_hdr to
1115 * physical eraseblock @pnum. This function automatically fills the
1116 * @vidb->hdr->magic and the @vidb->hdr->version fields, as well as calculates
1117 * header CRC checksum and stores it at vidb->hdr->hdr_crc.
1118 *
1119 * This function returns zero in case of success and a negative error code in
1120 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1121 * bad.
1122 */
1123int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1124 struct ubi_vid_io_buf *vidb)
1125{
1126 struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb);
1127 int err;
1128 uint32_t crc;
1129 void *p = vidb->buffer;
1130
1131 dbg_io("write VID header to PEB %d", pnum);
1132 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1133
1134 err = self_check_peb_ec_hdr(ubi, pnum);
1135 if (err)
1136 return err;
1137
1138 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1139 vid_hdr->version = UBI_VERSION;
1140 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1141 vid_hdr->hdr_crc = cpu_to_be32(crc);
1142
1143 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1144 if (err)
1145 return err;
1146
1147 if (ubi_dbg_is_power_cut(ubi, MASK_POWER_CUT_VID)) {
1148 ubi_warn(ubi, "emulating a power cut when writing VID header");
1149 ubi_ro_mode(ubi);
1150 return -EROFS;
1151 }
1152
1153 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1154 ubi->vid_hdr_alsize);
1155 return err;
1156}
1157
1158/**
1159 * self_check_not_bad - ensure that a physical eraseblock is not bad.
1160 * @ubi: UBI device description object
1161 * @pnum: physical eraseblock number to check
1162 *
1163 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1164 * it is bad and a negative error code if an error occurred.
1165 */
1166static int self_check_not_bad(const struct ubi_device *ubi, int pnum)
1167{
1168 int err;
1169
1170 if (!ubi_dbg_chk_io(ubi))
1171 return 0;
1172
1173 err = ubi_io_is_bad(ubi, pnum);
1174 if (!err)
1175 return err;
1176
1177 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1178 dump_stack();
1179 return err > 0 ? -EINVAL : err;
1180}
1181
1182/**
1183 * self_check_ec_hdr - check if an erase counter header is all right.
1184 * @ubi: UBI device description object
1185 * @pnum: physical eraseblock number the erase counter header belongs to
1186 * @ec_hdr: the erase counter header to check
1187 *
1188 * This function returns zero if the erase counter header contains valid
1189 * values, and %-EINVAL if not.
1190 */
1191static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1192 const struct ubi_ec_hdr *ec_hdr)
1193{
1194 int err;
1195 uint32_t magic;
1196
1197 if (!ubi_dbg_chk_io(ubi))
1198 return 0;
1199
1200 magic = be32_to_cpu(ec_hdr->magic);
1201 if (magic != UBI_EC_HDR_MAGIC) {
1202 ubi_err(ubi, "bad magic %#08x, must be %#08x",
1203 magic, UBI_EC_HDR_MAGIC);
1204 goto fail;
1205 }
1206
1207 err = validate_ec_hdr(ubi, ec_hdr);
1208 if (err) {
1209 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1210 goto fail;
1211 }
1212
1213 return 0;
1214
1215fail:
1216 ubi_dump_ec_hdr(ec_hdr);
1217 dump_stack();
1218 return -EINVAL;
1219}
1220
1221/**
1222 * self_check_peb_ec_hdr - check erase counter header.
1223 * @ubi: UBI device description object
1224 * @pnum: the physical eraseblock number to check
1225 *
1226 * This function returns zero if the erase counter header is all right and
1227 * a negative error code if not or if an error occurred.
1228 */
1229static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1230{
1231 int err;
1232 uint32_t crc, hdr_crc;
1233 struct ubi_ec_hdr *ec_hdr;
1234
1235 if (!ubi_dbg_chk_io(ubi))
1236 return 0;
1237
1238 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1239 if (!ec_hdr)
1240 return -ENOMEM;
1241
1242 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1243 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1244 goto exit;
1245
1246 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1247 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1248 if (hdr_crc != crc) {
1249 ubi_err(ubi, "bad CRC, calculated %#08x, read %#08x",
1250 crc, hdr_crc);
1251 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1252 ubi_dump_ec_hdr(ec_hdr);
1253 dump_stack();
1254 err = -EINVAL;
1255 goto exit;
1256 }
1257
1258 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
1259
1260exit:
1261 kfree(ec_hdr);
1262 return err;
1263}
1264
1265/**
1266 * self_check_vid_hdr - check that a volume identifier header is all right.
1267 * @ubi: UBI device description object
1268 * @pnum: physical eraseblock number the volume identifier header belongs to
1269 * @vid_hdr: the volume identifier header to check
1270 *
1271 * This function returns zero if the volume identifier header is all right, and
1272 * %-EINVAL if not.
1273 */
1274static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1275 const struct ubi_vid_hdr *vid_hdr)
1276{
1277 int err;
1278 uint32_t magic;
1279
1280 if (!ubi_dbg_chk_io(ubi))
1281 return 0;
1282
1283 magic = be32_to_cpu(vid_hdr->magic);
1284 if (magic != UBI_VID_HDR_MAGIC) {
1285 ubi_err(ubi, "bad VID header magic %#08x at PEB %d, must be %#08x",
1286 magic, pnum, UBI_VID_HDR_MAGIC);
1287 goto fail;
1288 }
1289
1290 err = validate_vid_hdr(ubi, vid_hdr);
1291 if (err) {
1292 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1293 goto fail;
1294 }
1295
1296 return err;
1297
1298fail:
1299 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1300 ubi_dump_vid_hdr(vid_hdr);
1301 dump_stack();
1302 return -EINVAL;
1303
1304}
1305
1306/**
1307 * self_check_peb_vid_hdr - check volume identifier header.
1308 * @ubi: UBI device description object
1309 * @pnum: the physical eraseblock number to check
1310 *
1311 * This function returns zero if the volume identifier header is all right,
1312 * and a negative error code if not or if an error occurred.
1313 */
1314static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1315{
1316 int err;
1317 uint32_t crc, hdr_crc;
1318 struct ubi_vid_io_buf *vidb;
1319 struct ubi_vid_hdr *vid_hdr;
1320 void *p;
1321
1322 if (!ubi_dbg_chk_io(ubi))
1323 return 0;
1324
1325 vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
1326 if (!vidb)
1327 return -ENOMEM;
1328
1329 vid_hdr = ubi_get_vid_hdr(vidb);
1330 p = vidb->buffer;
1331 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1332 ubi->vid_hdr_alsize);
1333 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1334 goto exit;
1335
1336 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1337 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1338 if (hdr_crc != crc) {
1339 ubi_err(ubi, "bad VID header CRC at PEB %d, calculated %#08x, read %#08x",
1340 pnum, crc, hdr_crc);
1341 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1342 ubi_dump_vid_hdr(vid_hdr);
1343 dump_stack();
1344 err = -EINVAL;
1345 goto exit;
1346 }
1347
1348 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1349
1350exit:
1351 ubi_free_vid_buf(vidb);
1352 return err;
1353}
1354
1355/**
1356 * self_check_write - make sure write succeeded.
1357 * @ubi: UBI device description object
1358 * @buf: buffer with data which were written
1359 * @pnum: physical eraseblock number the data were written to
1360 * @offset: offset within the physical eraseblock the data were written to
1361 * @len: how many bytes were written
1362 *
1363 * This functions reads data which were recently written and compares it with
1364 * the original data buffer - the data have to match. Returns zero if the data
1365 * match and a negative error code if not or in case of failure.
1366 */
1367static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
1368 int offset, int len)
1369{
1370 int err, i;
1371 size_t read;
1372 void *buf1;
1373 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1374
1375 if (!ubi_dbg_chk_io(ubi))
1376 return 0;
1377
1378 buf1 = __vmalloc(len, GFP_NOFS);
1379 if (!buf1) {
1380 ubi_err(ubi, "cannot allocate memory to check writes");
1381 return 0;
1382 }
1383
1384 err = mtd_read(ubi->mtd, addr, len, &read, buf1);
1385 if (err && !mtd_is_bitflip(err))
1386 goto out_free;
1387
1388 for (i = 0; i < len; i++) {
1389 uint8_t c = ((uint8_t *)buf)[i];
1390 uint8_t c1 = ((uint8_t *)buf1)[i];
1391 int dump_len;
1392
1393 if (c == c1)
1394 continue;
1395
1396 ubi_err(ubi, "self-check failed for PEB %d:%d, len %d",
1397 pnum, offset, len);
1398 ubi_msg(ubi, "data differ at position %d", i);
1399 dump_len = max_t(int, 128, len - i);
1400 ubi_msg(ubi, "hex dump of the original buffer from %d to %d",
1401 i, i + dump_len);
1402 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1403 buf + i, dump_len, 1);
1404 ubi_msg(ubi, "hex dump of the read buffer from %d to %d",
1405 i, i + dump_len);
1406 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1407 buf1 + i, dump_len, 1);
1408 dump_stack();
1409 err = -EINVAL;
1410 goto out_free;
1411 }
1412
1413 vfree(buf1);
1414 return 0;
1415
1416out_free:
1417 vfree(buf1);
1418 return err;
1419}
1420
1421/**
1422 * ubi_self_check_all_ff - check that a region of flash is empty.
1423 * @ubi: UBI device description object
1424 * @pnum: the physical eraseblock number to check
1425 * @offset: the starting offset within the physical eraseblock to check
1426 * @len: the length of the region to check
1427 *
1428 * This function returns zero if only 0xFF bytes are present at offset
1429 * @offset of the physical eraseblock @pnum, and a negative error code if not
1430 * or if an error occurred.
1431 */
1432int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
1433{
1434 size_t read;
1435 int err;
1436 void *buf;
1437 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1438
1439 if (!ubi_dbg_chk_io(ubi))
1440 return 0;
1441
1442 buf = __vmalloc(len, GFP_NOFS);
1443 if (!buf) {
1444 ubi_err(ubi, "cannot allocate memory to check for 0xFFs");
1445 return 0;
1446 }
1447
1448 err = mtd_read(ubi->mtd, addr, len, &read, buf);
1449 if (err && !mtd_is_bitflip(err)) {
1450 ubi_err(ubi, "err %d while reading %d bytes from PEB %d:%d, read %zd bytes",
1451 err, len, pnum, offset, read);
1452 goto error;
1453 }
1454
1455 err = ubi_check_pattern(buf, 0xFF, len);
1456 if (err == 0) {
1457 ubi_err(ubi, "flash region at PEB %d:%d, length %d does not contain all 0xFF bytes",
1458 pnum, offset, len);
1459 goto fail;
1460 }
1461
1462 vfree(buf);
1463 return 0;
1464
1465fail:
1466 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1467 ubi_msg(ubi, "hex dump of the %d-%d region", offset, offset + len);
1468 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
1469 err = -EINVAL;
1470error:
1471 dump_stack();
1472 vfree(buf);
1473 return err;
1474}