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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: the physical eraseblock number to erase
523 * @torture: if this physical eraseblock has to be tortured; cleared to zero
524 * once the torture test has completed successfully so that a retry
525 * of the erase does not torture the physical eraseblock again
526 *
527 * This function synchronously erases physical eraseblock @pnum. If @torture
528 * flag is not zero, the physical eraseblock is checked by means of writing
529 * different patterns to it and reading them back. If the torturing is enabled,
530 * the physical eraseblock is erased more than once.
531 *
532 * This function returns the number of erasures made in case of success, %-EIO
533 * if the erasure failed or the torturing test failed, and other negative error
534 * codes in case of other errors. Note, %-EIO means that the physical
535 * eraseblock is bad.
536 */
537int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int *torture)
538{
539 int err, ret = 0;
540
541 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
542
543 err = self_check_not_bad(ubi, pnum);
544 if (err != 0)
545 return err;
546
547 if (ubi->ro_mode) {
548 ubi_err(ubi, "read-only mode");
549 return -EROFS;
550 }
551
552 /*
553 * If the flash is ECC-ed then we have to erase the ECC block before we
554 * can write to it. But the write is in preparation to an erase in the
555 * first place. This means we cannot zero out EC and VID before the
556 * erase and we just have to hope the flash starts erasing from the
557 * start of the page.
558 */
559 if (ubi->nor_flash && ubi->mtd->writesize == 1) {
560 err = nor_erase_prepare(ubi, pnum);
561 if (err)
562 return err;
563 }
564
565 if (*torture) {
566 ret = torture_peb(ubi, pnum);
567 if (ret < 0)
568 return ret;
569 *torture = 0;
570 }
571
572 err = do_sync_erase(ubi, pnum);
573 if (err)
574 return err;
575
576 return ret + 1;
577}
578
579/**
580 * ubi_io_is_bad - check if a physical eraseblock is bad.
581 * @ubi: UBI device description object
582 * @pnum: the physical eraseblock number to check
583 *
584 * This function returns a positive number if the physical eraseblock is bad,
585 * zero if not, and a negative error code if an error occurred.
586 */
587int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
588{
589 struct mtd_info *mtd = ubi->mtd;
590
591 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
592
593 if (ubi->bad_allowed) {
594 int ret;
595
596 ret = mtd_block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
597 if (ret < 0)
598 ubi_err(ubi, "error %d while checking if PEB %d is bad",
599 ret, pnum);
600 else if (ret)
601 dbg_io("PEB %d is bad", pnum);
602 return ret;
603 }
604
605 return 0;
606}
607
608/**
609 * ubi_io_mark_bad - mark a physical eraseblock as bad.
610 * @ubi: UBI device description object
611 * @pnum: the physical eraseblock number to mark
612 *
613 * This function returns zero in case of success and a negative error code in
614 * case of failure.
615 */
616int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
617{
618 int err;
619 struct mtd_info *mtd = ubi->mtd;
620
621 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
622
623 if (ubi->ro_mode) {
624 ubi_err(ubi, "read-only mode");
625 return -EROFS;
626 }
627
628 if (!ubi->bad_allowed)
629 return 0;
630
631 err = mtd_block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
632 if (err)
633 ubi_err(ubi, "cannot mark PEB %d bad, error %d", pnum, err);
634 return err;
635}
636
637/**
638 * validate_ec_hdr - validate an erase counter header.
639 * @ubi: UBI device description object
640 * @ec_hdr: the erase counter header to check
641 *
642 * This function returns zero if the erase counter header is OK, and %1 if
643 * not.
644 */
645static int validate_ec_hdr(const struct ubi_device *ubi,
646 const struct ubi_ec_hdr *ec_hdr)
647{
648 long long ec;
649 int vid_hdr_offset, leb_start;
650
651 ec = be64_to_cpu(ec_hdr->ec);
652 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
653 leb_start = be32_to_cpu(ec_hdr->data_offset);
654
655 if (ec_hdr->version != UBI_VERSION) {
656 ubi_err(ubi, "node with incompatible UBI version found: this UBI version is %d, image version is %d",
657 UBI_VERSION, (int)ec_hdr->version);
658 goto bad;
659 }
660
661 if (vid_hdr_offset != ubi->vid_hdr_offset) {
662 ubi_err(ubi, "bad VID header offset %d, expected %d",
663 vid_hdr_offset, ubi->vid_hdr_offset);
664 goto bad;
665 }
666
667 if (leb_start != ubi->leb_start) {
668 ubi_err(ubi, "bad data offset %d, expected %d",
669 leb_start, ubi->leb_start);
670 goto bad;
671 }
672
673 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
674 ubi_err(ubi, "bad erase counter %lld", ec);
675 goto bad;
676 }
677
678 return 0;
679
680bad:
681 ubi_err(ubi, "bad EC header");
682 ubi_dump_ec_hdr(ec_hdr);
683 dump_stack();
684 return 1;
685}
686
687/**
688 * ubi_io_read_ec_hdr - read and check an erase counter header.
689 * @ubi: UBI device description object
690 * @pnum: physical eraseblock to read from
691 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
692 * header
693 * @verbose: be verbose if the header is corrupted or was not found
694 *
695 * This function reads erase counter header from physical eraseblock @pnum and
696 * stores it in @ec_hdr. This function also checks CRC checksum of the read
697 * erase counter header. The following codes may be returned:
698 *
699 * o %0 if the CRC checksum is correct and the header was successfully read;
700 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
701 * and corrected by the flash driver; this is harmless but may indicate that
702 * this eraseblock may become bad soon (but may be not);
703 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
704 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
705 * a data integrity error (uncorrectable ECC error in case of NAND);
706 * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
707 * o a negative error code in case of failure.
708 */
709int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
710 struct ubi_ec_hdr *ec_hdr, int verbose)
711{
712 int err, read_err;
713 uint32_t crc, magic, hdr_crc;
714
715 dbg_io("read EC header from PEB %d", pnum);
716 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
717
718 read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
719 if (read_err) {
720 if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
721 return read_err;
722
723 /*
724 * We read all the data, but either a correctable bit-flip
725 * occurred, or MTD reported a data integrity error
726 * (uncorrectable ECC error in case of NAND). The former is
727 * harmless, the later may mean that the read data is
728 * corrupted. But we have a CRC check-sum and we will detect
729 * this. If the EC header is still OK, we just report this as
730 * there was a bit-flip, to force scrubbing.
731 */
732 }
733
734 magic = be32_to_cpu(ec_hdr->magic);
735 if (magic != UBI_EC_HDR_MAGIC) {
736 if (mtd_is_eccerr(read_err))
737 return UBI_IO_BAD_HDR_EBADMSG;
738
739 /*
740 * The magic field is wrong. Let's check if we have read all
741 * 0xFF. If yes, this physical eraseblock is assumed to be
742 * empty.
743 */
744 if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
745 /* The physical eraseblock is supposedly empty */
746 if (verbose)
747 ubi_warn(ubi, "no EC header found at PEB %d, only 0xFF bytes",
748 pnum);
749 dbg_bld("no EC header found at PEB %d, only 0xFF bytes",
750 pnum);
751 if (!read_err)
752 return UBI_IO_FF;
753 else
754 return UBI_IO_FF_BITFLIPS;
755 }
756
757 /*
758 * This is not a valid erase counter header, and these are not
759 * 0xFF bytes. Report that the header is corrupted.
760 */
761 if (verbose) {
762 ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
763 pnum, magic, UBI_EC_HDR_MAGIC);
764 ubi_dump_ec_hdr(ec_hdr);
765 }
766 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
767 pnum, magic, UBI_EC_HDR_MAGIC);
768 return UBI_IO_BAD_HDR;
769 }
770
771 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
772 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
773
774 if (hdr_crc != crc) {
775 if (verbose) {
776 ubi_warn(ubi, "bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
777 pnum, crc, hdr_crc);
778 ubi_dump_ec_hdr(ec_hdr);
779 }
780 dbg_bld("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
781 pnum, crc, hdr_crc);
782
783 if (!read_err)
784 return UBI_IO_BAD_HDR;
785 else
786 return UBI_IO_BAD_HDR_EBADMSG;
787 }
788
789 /* And of course validate what has just been read from the media */
790 err = validate_ec_hdr(ubi, ec_hdr);
791 if (err) {
792 ubi_err(ubi, "validation failed for PEB %d", pnum);
793 return -EINVAL;
794 }
795
796 /*
797 * If there was %-EBADMSG, but the header CRC is still OK, report about
798 * a bit-flip to force scrubbing on this PEB.
799 */
800 if (read_err)
801 return UBI_IO_BITFLIPS;
802
803 if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_EC)) {
804 ubi_warn(ubi, "cannot read EC header from PEB %d (emulated)",
805 pnum);
806 return -EIO;
807 }
808
809 if (ubi_dbg_is_ff(ubi, MASK_IO_FF_EC)) {
810 ubi_warn(ubi, "bit-all-ff (emulated)");
811 return UBI_IO_FF;
812 }
813
814 if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_EC)) {
815 ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)");
816 return UBI_IO_FF_BITFLIPS;
817 }
818
819 if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_EC)) {
820 ubi_warn(ubi, "bad_hdr (emulated)");
821 return UBI_IO_BAD_HDR;
822 }
823
824 if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_EC)) {
825 ubi_warn(ubi, "bad_hdr with ECC error (emulated)");
826 return UBI_IO_BAD_HDR_EBADMSG;
827 }
828
829 return 0;
830}
831
832/**
833 * ubi_io_write_ec_hdr - write an erase counter header.
834 * @ubi: UBI device description object
835 * @pnum: physical eraseblock to write to
836 * @ec_hdr: the erase counter header to write
837 *
838 * This function writes erase counter header described by @ec_hdr to physical
839 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
840 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
841 * field.
842 *
843 * This function returns zero in case of success and a negative error code in
844 * case of failure. If %-EIO is returned, the physical eraseblock most probably
845 * went bad.
846 */
847int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
848 struct ubi_ec_hdr *ec_hdr)
849{
850 int err;
851 uint32_t crc;
852
853 dbg_io("write EC header to PEB %d", pnum);
854 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
855
856 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
857 ec_hdr->version = UBI_VERSION;
858 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
859 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
860 ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);
861 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
862 ec_hdr->hdr_crc = cpu_to_be32(crc);
863
864 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
865 if (err)
866 return err;
867
868 if (ubi_dbg_is_power_cut(ubi, MASK_POWER_CUT_EC)) {
869 ubi_warn(ubi, "emulating a power cut when writing EC header");
870 ubi_ro_mode(ubi);
871 return -EROFS;
872 }
873
874 memset((char *)ec_hdr + UBI_EC_HDR_SIZE, 0xFF, ubi->ec_hdr_alsize - UBI_EC_HDR_SIZE);
875
876 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
877 return err;
878}
879
880/**
881 * validate_vid_hdr - validate a volume identifier header.
882 * @ubi: UBI device description object
883 * @vid_hdr: the volume identifier header to check
884 *
885 * This function checks that data stored in the volume identifier header
886 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
887 */
888static int validate_vid_hdr(const struct ubi_device *ubi,
889 const struct ubi_vid_hdr *vid_hdr)
890{
891 int vol_type = vid_hdr->vol_type;
892 int copy_flag = vid_hdr->copy_flag;
893 int vol_id = be32_to_cpu(vid_hdr->vol_id);
894 int lnum = be32_to_cpu(vid_hdr->lnum);
895 int compat = vid_hdr->compat;
896 int data_size = be32_to_cpu(vid_hdr->data_size);
897 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
898 int data_pad = be32_to_cpu(vid_hdr->data_pad);
899 int data_crc = be32_to_cpu(vid_hdr->data_crc);
900 int usable_leb_size = ubi->leb_size - data_pad;
901
902 if (copy_flag != 0 && copy_flag != 1) {
903 ubi_err(ubi, "bad copy_flag");
904 goto bad;
905 }
906
907 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
908 data_pad < 0) {
909 ubi_err(ubi, "negative values");
910 goto bad;
911 }
912
913 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
914 ubi_err(ubi, "bad vol_id");
915 goto bad;
916 }
917
918 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
919 ubi_err(ubi, "bad compat");
920 goto bad;
921 }
922
923 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
924 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
925 compat != UBI_COMPAT_REJECT) {
926 ubi_err(ubi, "bad compat");
927 goto bad;
928 }
929
930 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
931 ubi_err(ubi, "bad vol_type");
932 goto bad;
933 }
934
935 if (data_pad >= ubi->leb_size / 2) {
936 ubi_err(ubi, "bad data_pad");
937 goto bad;
938 }
939
940 if (data_size > ubi->leb_size) {
941 ubi_err(ubi, "bad data_size");
942 goto bad;
943 }
944
945 if (vol_type == UBI_VID_STATIC) {
946 /*
947 * Although from high-level point of view static volumes may
948 * contain zero bytes of data, but no VID headers can contain
949 * zero at these fields, because they empty volumes do not have
950 * mapped logical eraseblocks.
951 */
952 if (used_ebs == 0) {
953 ubi_err(ubi, "zero used_ebs");
954 goto bad;
955 }
956 if (data_size == 0) {
957 ubi_err(ubi, "zero data_size");
958 goto bad;
959 }
960 if (lnum < used_ebs - 1) {
961 if (data_size != usable_leb_size) {
962 ubi_err(ubi, "bad data_size");
963 goto bad;
964 }
965 } else if (lnum > used_ebs - 1) {
966 ubi_err(ubi, "too high lnum");
967 goto bad;
968 }
969 } else {
970 if (copy_flag == 0) {
971 if (data_crc != 0) {
972 ubi_err(ubi, "non-zero data CRC");
973 goto bad;
974 }
975 if (data_size != 0) {
976 ubi_err(ubi, "non-zero data_size");
977 goto bad;
978 }
979 } else {
980 if (data_size == 0) {
981 ubi_err(ubi, "zero data_size of copy");
982 goto bad;
983 }
984 }
985 if (used_ebs != 0) {
986 ubi_err(ubi, "bad used_ebs");
987 goto bad;
988 }
989 }
990
991 return 0;
992
993bad:
994 ubi_err(ubi, "bad VID header");
995 ubi_dump_vid_hdr(vid_hdr);
996 dump_stack();
997 return 1;
998}
999
1000/**
1001 * ubi_io_read_vid_hdr - read and check a volume identifier header.
1002 * @ubi: UBI device description object
1003 * @pnum: physical eraseblock number to read from
1004 * @vidb: the volume identifier buffer to store data in
1005 * @verbose: be verbose if the header is corrupted or wasn't found
1006 *
1007 * This function reads the volume identifier header from physical eraseblock
1008 * @pnum and stores it in @vidb. It also checks CRC checksum of the read
1009 * volume identifier header. The error codes are the same as in
1010 * 'ubi_io_read_ec_hdr()'.
1011 *
1012 * Note, the implementation of this function is also very similar to
1013 * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
1014 */
1015int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
1016 struct ubi_vid_io_buf *vidb, int verbose)
1017{
1018 int err, read_err;
1019 uint32_t crc, magic, hdr_crc;
1020 struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb);
1021 void *p = vidb->buffer;
1022
1023 dbg_io("read VID header from PEB %d", pnum);
1024 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1025
1026 read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1027 ubi->vid_hdr_shift + UBI_VID_HDR_SIZE);
1028 if (read_err && read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
1029 return read_err;
1030
1031 magic = be32_to_cpu(vid_hdr->magic);
1032 if (magic != UBI_VID_HDR_MAGIC) {
1033 if (mtd_is_eccerr(read_err))
1034 return UBI_IO_BAD_HDR_EBADMSG;
1035
1036 if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
1037 if (verbose)
1038 ubi_warn(ubi, "no VID header found at PEB %d, only 0xFF bytes",
1039 pnum);
1040 dbg_bld("no VID header found at PEB %d, only 0xFF bytes",
1041 pnum);
1042 if (!read_err)
1043 return UBI_IO_FF;
1044 else
1045 return UBI_IO_FF_BITFLIPS;
1046 }
1047
1048 if (verbose) {
1049 ubi_warn(ubi, "bad magic number at PEB %d: %08x instead of %08x",
1050 pnum, magic, UBI_VID_HDR_MAGIC);
1051 ubi_dump_vid_hdr(vid_hdr);
1052 }
1053 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
1054 pnum, magic, UBI_VID_HDR_MAGIC);
1055 return UBI_IO_BAD_HDR;
1056 }
1057
1058 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1059 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1060
1061 if (hdr_crc != crc) {
1062 if (verbose) {
1063 ubi_warn(ubi, "bad CRC at PEB %d, calculated %#08x, read %#08x",
1064 pnum, crc, hdr_crc);
1065 ubi_dump_vid_hdr(vid_hdr);
1066 }
1067 dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
1068 pnum, crc, hdr_crc);
1069 if (!read_err)
1070 return UBI_IO_BAD_HDR;
1071 else
1072 return UBI_IO_BAD_HDR_EBADMSG;
1073 }
1074
1075 err = validate_vid_hdr(ubi, vid_hdr);
1076 if (err) {
1077 ubi_err(ubi, "validation failed for PEB %d", pnum);
1078 return -EINVAL;
1079 }
1080
1081 if (read_err)
1082 return UBI_IO_BITFLIPS;
1083
1084 if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_VID)) {
1085 ubi_warn(ubi, "cannot read VID header from PEB %d (emulated)",
1086 pnum);
1087 return -EIO;
1088 }
1089
1090 if (ubi_dbg_is_ff(ubi, MASK_IO_FF_VID)) {
1091 ubi_warn(ubi, "bit-all-ff (emulated)");
1092 return UBI_IO_FF;
1093 }
1094
1095 if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_VID)) {
1096 ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)");
1097 return UBI_IO_FF_BITFLIPS;
1098 }
1099
1100 if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_VID)) {
1101 ubi_warn(ubi, "bad_hdr (emulated)");
1102 return UBI_IO_BAD_HDR;
1103 }
1104
1105 if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_VID)) {
1106 ubi_warn(ubi, "bad_hdr with ECC error (emulated)");
1107 return UBI_IO_BAD_HDR_EBADMSG;
1108 }
1109
1110 return 0;
1111}
1112
1113/**
1114 * ubi_io_write_vid_hdr - write a volume identifier header.
1115 * @ubi: UBI device description object
1116 * @pnum: the physical eraseblock number to write to
1117 * @vidb: the volume identifier buffer to write
1118 *
1119 * This function writes the volume identifier header described by @vid_hdr to
1120 * physical eraseblock @pnum. This function automatically fills the
1121 * @vidb->hdr->magic and the @vidb->hdr->version fields, as well as calculates
1122 * header CRC checksum and stores it at vidb->hdr->hdr_crc.
1123 *
1124 * This function returns zero in case of success and a negative error code in
1125 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1126 * bad.
1127 */
1128int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1129 struct ubi_vid_io_buf *vidb)
1130{
1131 struct ubi_vid_hdr *vid_hdr = ubi_get_vid_hdr(vidb);
1132 int err;
1133 uint32_t crc;
1134 void *p = vidb->buffer;
1135
1136 dbg_io("write VID header to PEB %d", pnum);
1137 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1138
1139 err = self_check_peb_ec_hdr(ubi, pnum);
1140 if (err)
1141 return err;
1142
1143 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1144 vid_hdr->version = UBI_VERSION;
1145 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1146 vid_hdr->hdr_crc = cpu_to_be32(crc);
1147
1148 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1149 if (err)
1150 return err;
1151
1152 if (ubi_dbg_is_power_cut(ubi, MASK_POWER_CUT_VID)) {
1153 ubi_warn(ubi, "emulating a power cut when writing VID header");
1154 ubi_ro_mode(ubi);
1155 return -EROFS;
1156 }
1157
1158 if (ubi->vid_hdr_shift) {
1159 memset((char *)p, 0xFF, ubi->vid_hdr_shift);
1160 memset((char *)p + ubi->vid_hdr_shift + UBI_VID_HDR_SIZE, 0xFF,
1161 ubi->vid_hdr_alsize - (ubi->vid_hdr_shift + UBI_VID_HDR_SIZE));
1162 } else {
1163 memset((char *)p + UBI_VID_HDR_SIZE, 0xFF, ubi->vid_hdr_alsize - UBI_VID_HDR_SIZE);
1164 }
1165
1166 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1167 ubi->vid_hdr_alsize);
1168 return err;
1169}
1170
1171/**
1172 * self_check_not_bad - ensure that a physical eraseblock is not bad.
1173 * @ubi: UBI device description object
1174 * @pnum: physical eraseblock number to check
1175 *
1176 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1177 * it is bad and a negative error code if an error occurred.
1178 */
1179static int self_check_not_bad(const struct ubi_device *ubi, int pnum)
1180{
1181 int err;
1182
1183 if (!ubi_dbg_chk_io(ubi))
1184 return 0;
1185
1186 err = ubi_io_is_bad(ubi, pnum);
1187 if (!err)
1188 return err;
1189
1190 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1191 dump_stack();
1192 return err > 0 ? -EINVAL : err;
1193}
1194
1195/**
1196 * self_check_ec_hdr - check if an erase counter header is all right.
1197 * @ubi: UBI device description object
1198 * @pnum: physical eraseblock number the erase counter header belongs to
1199 * @ec_hdr: the erase counter header to check
1200 *
1201 * This function returns zero if the erase counter header contains valid
1202 * values, and %-EINVAL if not.
1203 */
1204static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1205 const struct ubi_ec_hdr *ec_hdr)
1206{
1207 int err;
1208 uint32_t magic;
1209
1210 if (!ubi_dbg_chk_io(ubi))
1211 return 0;
1212
1213 magic = be32_to_cpu(ec_hdr->magic);
1214 if (magic != UBI_EC_HDR_MAGIC) {
1215 ubi_err(ubi, "bad magic %#08x, must be %#08x",
1216 magic, UBI_EC_HDR_MAGIC);
1217 goto fail;
1218 }
1219
1220 err = validate_ec_hdr(ubi, ec_hdr);
1221 if (err) {
1222 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1223 goto fail;
1224 }
1225
1226 return 0;
1227
1228fail:
1229 ubi_dump_ec_hdr(ec_hdr);
1230 dump_stack();
1231 return -EINVAL;
1232}
1233
1234/**
1235 * self_check_peb_ec_hdr - check erase counter header.
1236 * @ubi: UBI device description object
1237 * @pnum: the physical eraseblock number to check
1238 *
1239 * This function returns zero if the erase counter header is all right and
1240 * a negative error code if not or if an error occurred.
1241 */
1242static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1243{
1244 int err;
1245 uint32_t crc, hdr_crc;
1246 struct ubi_ec_hdr *ec_hdr;
1247
1248 if (!ubi_dbg_chk_io(ubi))
1249 return 0;
1250
1251 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1252 if (!ec_hdr)
1253 return -ENOMEM;
1254
1255 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1256 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1257 goto exit;
1258
1259 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1260 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1261 if (hdr_crc != crc) {
1262 ubi_err(ubi, "bad CRC, calculated %#08x, read %#08x",
1263 crc, hdr_crc);
1264 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1265 ubi_dump_ec_hdr(ec_hdr);
1266 dump_stack();
1267 err = -EINVAL;
1268 goto exit;
1269 }
1270
1271 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
1272
1273exit:
1274 kfree(ec_hdr);
1275 return err;
1276}
1277
1278/**
1279 * self_check_vid_hdr - check that a volume identifier header is all right.
1280 * @ubi: UBI device description object
1281 * @pnum: physical eraseblock number the volume identifier header belongs to
1282 * @vid_hdr: the volume identifier header to check
1283 *
1284 * This function returns zero if the volume identifier header is all right, and
1285 * %-EINVAL if not.
1286 */
1287static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1288 const struct ubi_vid_hdr *vid_hdr)
1289{
1290 int err;
1291 uint32_t magic;
1292
1293 if (!ubi_dbg_chk_io(ubi))
1294 return 0;
1295
1296 magic = be32_to_cpu(vid_hdr->magic);
1297 if (magic != UBI_VID_HDR_MAGIC) {
1298 ubi_err(ubi, "bad VID header magic %#08x at PEB %d, must be %#08x",
1299 magic, pnum, UBI_VID_HDR_MAGIC);
1300 goto fail;
1301 }
1302
1303 err = validate_vid_hdr(ubi, vid_hdr);
1304 if (err) {
1305 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1306 goto fail;
1307 }
1308
1309 return err;
1310
1311fail:
1312 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1313 ubi_dump_vid_hdr(vid_hdr);
1314 dump_stack();
1315 return -EINVAL;
1316
1317}
1318
1319/**
1320 * self_check_peb_vid_hdr - check volume identifier header.
1321 * @ubi: UBI device description object
1322 * @pnum: the physical eraseblock number to check
1323 *
1324 * This function returns zero if the volume identifier header is all right,
1325 * and a negative error code if not or if an error occurred.
1326 */
1327static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1328{
1329 int err;
1330 uint32_t crc, hdr_crc;
1331 struct ubi_vid_io_buf *vidb;
1332 struct ubi_vid_hdr *vid_hdr;
1333 void *p;
1334
1335 if (!ubi_dbg_chk_io(ubi))
1336 return 0;
1337
1338 vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
1339 if (!vidb)
1340 return -ENOMEM;
1341
1342 vid_hdr = ubi_get_vid_hdr(vidb);
1343 p = vidb->buffer;
1344 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1345 ubi->vid_hdr_alsize);
1346 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1347 goto exit;
1348
1349 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1350 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1351 if (hdr_crc != crc) {
1352 ubi_err(ubi, "bad VID header CRC at PEB %d, calculated %#08x, read %#08x",
1353 pnum, crc, hdr_crc);
1354 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1355 ubi_dump_vid_hdr(vid_hdr);
1356 dump_stack();
1357 err = -EINVAL;
1358 goto exit;
1359 }
1360
1361 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1362
1363exit:
1364 ubi_free_vid_buf(vidb);
1365 return err;
1366}
1367
1368/**
1369 * self_check_write - make sure write succeeded.
1370 * @ubi: UBI device description object
1371 * @buf: buffer with data which were written
1372 * @pnum: physical eraseblock number the data were written to
1373 * @offset: offset within the physical eraseblock the data were written to
1374 * @len: how many bytes were written
1375 *
1376 * This functions reads data which were recently written and compares it with
1377 * the original data buffer - the data have to match. Returns zero if the data
1378 * match and a negative error code if not or in case of failure.
1379 */
1380static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
1381 int offset, int len)
1382{
1383 int err, i;
1384 size_t read;
1385 void *buf1;
1386 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1387
1388 if (!ubi_dbg_chk_io(ubi))
1389 return 0;
1390
1391 buf1 = __vmalloc(len, GFP_NOFS);
1392 if (!buf1) {
1393 ubi_err(ubi, "cannot allocate memory to check writes");
1394 return 0;
1395 }
1396
1397 err = mtd_read(ubi->mtd, addr, len, &read, buf1);
1398 if (err && !mtd_is_bitflip(err))
1399 goto out_free;
1400
1401 for (i = 0; i < len; i++) {
1402 uint8_t c = ((uint8_t *)buf)[i];
1403 uint8_t c1 = ((uint8_t *)buf1)[i];
1404 int dump_len;
1405
1406 if (c == c1)
1407 continue;
1408
1409 ubi_err(ubi, "self-check failed for PEB %d:%d, len %d",
1410 pnum, offset, len);
1411 ubi_msg(ubi, "data differ at position %d", i);
1412 dump_len = max_t(int, 128, len - i);
1413 ubi_msg(ubi, "hex dump of the original buffer from %d to %d",
1414 i, i + dump_len);
1415 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1416 buf + i, dump_len, 1);
1417 ubi_msg(ubi, "hex dump of the read buffer from %d to %d",
1418 i, i + dump_len);
1419 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1420 buf1 + i, dump_len, 1);
1421 dump_stack();
1422 err = -EINVAL;
1423 goto out_free;
1424 }
1425
1426 vfree(buf1);
1427 return 0;
1428
1429out_free:
1430 vfree(buf1);
1431 return err;
1432}
1433
1434/**
1435 * ubi_self_check_all_ff - check that a region of flash is empty.
1436 * @ubi: UBI device description object
1437 * @pnum: the physical eraseblock number to check
1438 * @offset: the starting offset within the physical eraseblock to check
1439 * @len: the length of the region to check
1440 *
1441 * This function returns zero if only 0xFF bytes are present at offset
1442 * @offset of the physical eraseblock @pnum, and a negative error code if not
1443 * or if an error occurred.
1444 */
1445int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
1446{
1447 size_t read;
1448 int err;
1449 void *buf;
1450 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1451
1452 if (!ubi_dbg_chk_io(ubi))
1453 return 0;
1454
1455 buf = __vmalloc(len, GFP_NOFS);
1456 if (!buf) {
1457 ubi_err(ubi, "cannot allocate memory to check for 0xFFs");
1458 return 0;
1459 }
1460
1461 err = mtd_read(ubi->mtd, addr, len, &read, buf);
1462 if (err && !mtd_is_bitflip(err)) {
1463 ubi_err(ubi, "err %d while reading %d bytes from PEB %d:%d, read %zd bytes",
1464 err, len, pnum, offset, read);
1465 goto error;
1466 }
1467
1468 err = ubi_check_pattern(buf, 0xFF, len);
1469 if (err == 0) {
1470 ubi_err(ubi, "flash region at PEB %d:%d, length %d does not contain all 0xFF bytes",
1471 pnum, offset, len);
1472 goto fail;
1473 }
1474
1475 vfree(buf);
1476 return 0;
1477
1478fail:
1479 ubi_err(ubi, "self-check failed for PEB %d", pnum);
1480 ubi_msg(ubi, "hex dump of the %d-%d region", offset, offset + len);
1481 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
1482 err = -EINVAL;
1483error:
1484 dump_stack();
1485 vfree(buf);
1486 return err;
1487}