1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
4 */
5
6 #include <linux/device.h>
7 #include <linux/fs.h>
8 #include <linux/mm.h>
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/mutex.h>
16 #include <linux/backing-dev.h>
17 #include <linux/compat.h>
18 #include <linux/mount.h>
19 #include <linux/blkpg.h>
20 #include <linux/magic.h>
21 #include <linux/major.h>
22 #include <linux/mtd/mtd.h>
23 #include <linux/mtd/partitions.h>
24 #include <linux/mtd/map.h>
25
26 #include <linux/uaccess.h>
27
28 #include "mtdcore.h"
29
30 /*
31 * Data structure to hold the pointer to the mtd device as well
32 * as mode information of various use cases.
33 */
34 struct mtd_file_info {
35 struct mtd_info *mtd;
36 enum mtd_file_modes mode;
37 };
38
mtdchar_lseek(struct file * file,loff_t offset,int orig)39 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
40 {
41 struct mtd_file_info *mfi = file->private_data;
42 return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
43 }
44
mtdchar_open(struct inode * inode,struct file * file)45 static int mtdchar_open(struct inode *inode, struct file *file)
46 {
47 int minor = iminor(inode);
48 int devnum = minor >> 1;
49 int ret = 0;
50 struct mtd_info *mtd;
51 struct mtd_file_info *mfi;
52
53 pr_debug("MTD_open\n");
54
55 /* You can't open the RO devices RW */
56 if ((file->f_mode & FMODE_WRITE) && (minor & 1))
57 return -EACCES;
58
59 mtd = get_mtd_device(NULL, devnum);
60
61 if (IS_ERR(mtd))
62 return PTR_ERR(mtd);
63
64 if (mtd->type == MTD_ABSENT) {
65 ret = -ENODEV;
66 goto out1;
67 }
68
69 /* You can't open it RW if it's not a writeable device */
70 if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
71 ret = -EACCES;
72 goto out1;
73 }
74
75 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
76 if (!mfi) {
77 ret = -ENOMEM;
78 goto out1;
79 }
80 mfi->mtd = mtd;
81 file->private_data = mfi;
82 return 0;
83
84 out1:
85 put_mtd_device(mtd);
86 return ret;
87 } /* mtdchar_open */
88
89 /*====================================================================*/
90
mtdchar_close(struct inode * inode,struct file * file)91 static int mtdchar_close(struct inode *inode, struct file *file)
92 {
93 struct mtd_file_info *mfi = file->private_data;
94 struct mtd_info *mtd = mfi->mtd;
95
96 pr_debug("MTD_close\n");
97
98 /* Only sync if opened RW */
99 if ((file->f_mode & FMODE_WRITE))
100 mtd_sync(mtd);
101
102 put_mtd_device(mtd);
103 file->private_data = NULL;
104 kfree(mfi);
105
106 return 0;
107 } /* mtdchar_close */
108
109 /* Back in June 2001, dwmw2 wrote:
110 *
111 * FIXME: This _really_ needs to die. In 2.5, we should lock the
112 * userspace buffer down and use it directly with readv/writev.
113 *
114 * The implementation below, using mtd_kmalloc_up_to, mitigates
115 * allocation failures when the system is under low-memory situations
116 * or if memory is highly fragmented at the cost of reducing the
117 * performance of the requested transfer due to a smaller buffer size.
118 *
119 * A more complex but more memory-efficient implementation based on
120 * get_user_pages and iovecs to cover extents of those pages is a
121 * longer-term goal, as intimated by dwmw2 above. However, for the
122 * write case, this requires yet more complex head and tail transfer
123 * handling when those head and tail offsets and sizes are such that
124 * alignment requirements are not met in the NAND subdriver.
125 */
126
mtdchar_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)127 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
128 loff_t *ppos)
129 {
130 struct mtd_file_info *mfi = file->private_data;
131 struct mtd_info *mtd = mfi->mtd;
132 size_t retlen;
133 size_t total_retlen=0;
134 int ret=0;
135 int len;
136 size_t size = count;
137 char *kbuf;
138
139 pr_debug("MTD_read\n");
140
141 if (*ppos + count > mtd->size) {
142 if (*ppos < mtd->size)
143 count = mtd->size - *ppos;
144 else
145 count = 0;
146 }
147
148 if (!count)
149 return 0;
150
151 kbuf = mtd_kmalloc_up_to(mtd, &size);
152 if (!kbuf)
153 return -ENOMEM;
154
155 while (count) {
156 len = min_t(size_t, count, size);
157
158 switch (mfi->mode) {
159 case MTD_FILE_MODE_OTP_FACTORY:
160 ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
161 &retlen, kbuf);
162 break;
163 case MTD_FILE_MODE_OTP_USER:
164 ret = mtd_read_user_prot_reg(mtd, *ppos, len,
165 &retlen, kbuf);
166 break;
167 case MTD_FILE_MODE_RAW:
168 {
169 struct mtd_oob_ops ops = {};
170
171 ops.mode = MTD_OPS_RAW;
172 ops.datbuf = kbuf;
173 ops.oobbuf = NULL;
174 ops.len = len;
175
176 ret = mtd_read_oob(mtd, *ppos, &ops);
177 retlen = ops.retlen;
178 break;
179 }
180 default:
181 ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
182 }
183 /* Nand returns -EBADMSG on ECC errors, but it returns
184 * the data. For our userspace tools it is important
185 * to dump areas with ECC errors!
186 * For kernel internal usage it also might return -EUCLEAN
187 * to signal the caller that a bitflip has occurred and has
188 * been corrected by the ECC algorithm.
189 * Userspace software which accesses NAND this way
190 * must be aware of the fact that it deals with NAND
191 */
192 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
193 *ppos += retlen;
194 if (copy_to_user(buf, kbuf, retlen)) {
195 kfree(kbuf);
196 return -EFAULT;
197 }
198 else
199 total_retlen += retlen;
200
201 count -= retlen;
202 buf += retlen;
203 if (retlen == 0)
204 count = 0;
205 }
206 else {
207 kfree(kbuf);
208 return ret;
209 }
210
211 }
212
213 kfree(kbuf);
214 return total_retlen;
215 } /* mtdchar_read */
216
mtdchar_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)217 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
218 loff_t *ppos)
219 {
220 struct mtd_file_info *mfi = file->private_data;
221 struct mtd_info *mtd = mfi->mtd;
222 size_t size = count;
223 char *kbuf;
224 size_t retlen;
225 size_t total_retlen=0;
226 int ret=0;
227 int len;
228
229 pr_debug("MTD_write\n");
230
231 if (*ppos >= mtd->size)
232 return -ENOSPC;
233
234 if (*ppos + count > mtd->size)
235 count = mtd->size - *ppos;
236
237 if (!count)
238 return 0;
239
240 kbuf = mtd_kmalloc_up_to(mtd, &size);
241 if (!kbuf)
242 return -ENOMEM;
243
244 while (count) {
245 len = min_t(size_t, count, size);
246
247 if (copy_from_user(kbuf, buf, len)) {
248 kfree(kbuf);
249 return -EFAULT;
250 }
251
252 switch (mfi->mode) {
253 case MTD_FILE_MODE_OTP_FACTORY:
254 ret = -EROFS;
255 break;
256 case MTD_FILE_MODE_OTP_USER:
257 ret = mtd_write_user_prot_reg(mtd, *ppos, len,
258 &retlen, kbuf);
259 break;
260
261 case MTD_FILE_MODE_RAW:
262 {
263 struct mtd_oob_ops ops = {};
264
265 ops.mode = MTD_OPS_RAW;
266 ops.datbuf = kbuf;
267 ops.oobbuf = NULL;
268 ops.ooboffs = 0;
269 ops.len = len;
270
271 ret = mtd_write_oob(mtd, *ppos, &ops);
272 retlen = ops.retlen;
273 break;
274 }
275
276 default:
277 ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
278 }
279
280 /*
281 * Return -ENOSPC only if no data could be written at all.
282 * Otherwise just return the number of bytes that actually
283 * have been written.
284 */
285 if ((ret == -ENOSPC) && (total_retlen))
286 break;
287
288 if (!ret) {
289 *ppos += retlen;
290 total_retlen += retlen;
291 count -= retlen;
292 buf += retlen;
293 }
294 else {
295 kfree(kbuf);
296 return ret;
297 }
298 }
299
300 kfree(kbuf);
301 return total_retlen;
302 } /* mtdchar_write */
303
304 /*======================================================================
305
306 IOCTL calls for getting device parameters.
307
308 ======================================================================*/
309
otp_select_filemode(struct mtd_file_info * mfi,int mode)310 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
311 {
312 struct mtd_info *mtd = mfi->mtd;
313 size_t retlen;
314
315 switch (mode) {
316 case MTD_OTP_FACTORY:
317 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
318 -EOPNOTSUPP)
319 return -EOPNOTSUPP;
320
321 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
322 break;
323 case MTD_OTP_USER:
324 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
325 -EOPNOTSUPP)
326 return -EOPNOTSUPP;
327
328 mfi->mode = MTD_FILE_MODE_OTP_USER;
329 break;
330 case MTD_OTP_OFF:
331 mfi->mode = MTD_FILE_MODE_NORMAL;
332 break;
333 default:
334 return -EINVAL;
335 }
336
337 return 0;
338 }
339
mtdchar_writeoob(struct file * file,struct mtd_info * mtd,uint64_t start,uint32_t length,void __user * ptr,uint32_t __user * retp)340 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
341 uint64_t start, uint32_t length, void __user *ptr,
342 uint32_t __user *retp)
343 {
344 struct mtd_info *master = mtd_get_master(mtd);
345 struct mtd_file_info *mfi = file->private_data;
346 struct mtd_oob_ops ops = {};
347 uint32_t retlen;
348 int ret = 0;
349
350 if (length > 4096)
351 return -EINVAL;
352
353 if (!master->_write_oob)
354 return -EOPNOTSUPP;
355
356 ops.ooblen = length;
357 ops.ooboffs = start & (mtd->writesize - 1);
358 ops.datbuf = NULL;
359 ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
360 MTD_OPS_PLACE_OOB;
361
362 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
363 return -EINVAL;
364
365 ops.oobbuf = memdup_user(ptr, length);
366 if (IS_ERR(ops.oobbuf))
367 return PTR_ERR(ops.oobbuf);
368
369 start &= ~((uint64_t)mtd->writesize - 1);
370 ret = mtd_write_oob(mtd, start, &ops);
371
372 if (ops.oobretlen > 0xFFFFFFFFU)
373 ret = -EOVERFLOW;
374 retlen = ops.oobretlen;
375 if (copy_to_user(retp, &retlen, sizeof(length)))
376 ret = -EFAULT;
377
378 kfree(ops.oobbuf);
379 return ret;
380 }
381
mtdchar_readoob(struct file * file,struct mtd_info * mtd,uint64_t start,uint32_t length,void __user * ptr,uint32_t __user * retp)382 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
383 uint64_t start, uint32_t length, void __user *ptr,
384 uint32_t __user *retp)
385 {
386 struct mtd_file_info *mfi = file->private_data;
387 struct mtd_oob_ops ops = {};
388 int ret = 0;
389
390 if (length > 4096)
391 return -EINVAL;
392
393 ops.ooblen = length;
394 ops.ooboffs = start & (mtd->writesize - 1);
395 ops.datbuf = NULL;
396 ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
397 MTD_OPS_PLACE_OOB;
398
399 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
400 return -EINVAL;
401
402 ops.oobbuf = kmalloc(length, GFP_KERNEL);
403 if (!ops.oobbuf)
404 return -ENOMEM;
405
406 start &= ~((uint64_t)mtd->writesize - 1);
407 ret = mtd_read_oob(mtd, start, &ops);
408
409 if (put_user(ops.oobretlen, retp))
410 ret = -EFAULT;
411 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
412 ops.oobretlen))
413 ret = -EFAULT;
414
415 kfree(ops.oobbuf);
416
417 /*
418 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
419 * data. For our userspace tools it is important to dump areas
420 * with ECC errors!
421 * For kernel internal usage it also might return -EUCLEAN
422 * to signal the caller that a bitflip has occurred and has
423 * been corrected by the ECC algorithm.
424 *
425 * Note: currently the standard NAND function, nand_read_oob_std,
426 * does not calculate ECC for the OOB area, so do not rely on
427 * this behavior unless you have replaced it with your own.
428 */
429 if (mtd_is_bitflip_or_eccerr(ret))
430 return 0;
431
432 return ret;
433 }
434
435 /*
436 * Copies (and truncates, if necessary) OOB layout information to the
437 * deprecated layout struct, nand_ecclayout_user. This is necessary only to
438 * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
439 * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
440 * can describe any kind of OOB layout with almost zero overhead from a
441 * memory usage point of view).
442 */
shrink_ecclayout(struct mtd_info * mtd,struct nand_ecclayout_user * to)443 static int shrink_ecclayout(struct mtd_info *mtd,
444 struct nand_ecclayout_user *to)
445 {
446 struct mtd_oob_region oobregion;
447 int i, section = 0, ret;
448
449 if (!mtd || !to)
450 return -EINVAL;
451
452 memset(to, 0, sizeof(*to));
453
454 to->eccbytes = 0;
455 for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
456 u32 eccpos;
457
458 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
459 if (ret < 0) {
460 if (ret != -ERANGE)
461 return ret;
462
463 break;
464 }
465
466 eccpos = oobregion.offset;
467 for (; i < MTD_MAX_ECCPOS_ENTRIES &&
468 eccpos < oobregion.offset + oobregion.length; i++) {
469 to->eccpos[i] = eccpos++;
470 to->eccbytes++;
471 }
472 }
473
474 for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
475 ret = mtd_ooblayout_free(mtd, i, &oobregion);
476 if (ret < 0) {
477 if (ret != -ERANGE)
478 return ret;
479
480 break;
481 }
482
483 to->oobfree[i].offset = oobregion.offset;
484 to->oobfree[i].length = oobregion.length;
485 to->oobavail += to->oobfree[i].length;
486 }
487
488 return 0;
489 }
490
get_oobinfo(struct mtd_info * mtd,struct nand_oobinfo * to)491 static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
492 {
493 struct mtd_oob_region oobregion;
494 int i, section = 0, ret;
495
496 if (!mtd || !to)
497 return -EINVAL;
498
499 memset(to, 0, sizeof(*to));
500
501 to->eccbytes = 0;
502 for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
503 u32 eccpos;
504
505 ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
506 if (ret < 0) {
507 if (ret != -ERANGE)
508 return ret;
509
510 break;
511 }
512
513 if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
514 return -EINVAL;
515
516 eccpos = oobregion.offset;
517 for (; eccpos < oobregion.offset + oobregion.length; i++) {
518 to->eccpos[i] = eccpos++;
519 to->eccbytes++;
520 }
521 }
522
523 for (i = 0; i < 8; i++) {
524 ret = mtd_ooblayout_free(mtd, i, &oobregion);
525 if (ret < 0) {
526 if (ret != -ERANGE)
527 return ret;
528
529 break;
530 }
531
532 to->oobfree[i][0] = oobregion.offset;
533 to->oobfree[i][1] = oobregion.length;
534 }
535
536 to->useecc = MTD_NANDECC_AUTOPLACE;
537
538 return 0;
539 }
540
mtdchar_blkpg_ioctl(struct mtd_info * mtd,struct blkpg_ioctl_arg * arg)541 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
542 struct blkpg_ioctl_arg *arg)
543 {
544 struct blkpg_partition p;
545
546 if (!capable(CAP_SYS_ADMIN))
547 return -EPERM;
548
549 if (copy_from_user(&p, arg->data, sizeof(p)))
550 return -EFAULT;
551
552 switch (arg->op) {
553 case BLKPG_ADD_PARTITION:
554
555 /* Only master mtd device must be used to add partitions */
556 if (mtd_is_partition(mtd))
557 return -EINVAL;
558
559 /* Sanitize user input */
560 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
561
562 return mtd_add_partition(mtd, p.devname, p.start, p.length);
563
564 case BLKPG_DEL_PARTITION:
565
566 if (p.pno < 0)
567 return -EINVAL;
568
569 return mtd_del_partition(mtd, p.pno);
570
571 default:
572 return -EINVAL;
573 }
574 }
575
adjust_oob_length(struct mtd_info * mtd,uint64_t start,struct mtd_oob_ops * ops)576 static void adjust_oob_length(struct mtd_info *mtd, uint64_t start,
577 struct mtd_oob_ops *ops)
578 {
579 uint32_t start_page, end_page;
580 u32 oob_per_page;
581
582 if (ops->len == 0 || ops->ooblen == 0)
583 return;
584
585 start_page = mtd_div_by_ws(start, mtd);
586 end_page = mtd_div_by_ws(start + ops->len - 1, mtd);
587 oob_per_page = mtd_oobavail(mtd, ops);
588
589 ops->ooblen = min_t(size_t, ops->ooblen,
590 (end_page - start_page + 1) * oob_per_page);
591 }
592
593 static noinline_for_stack int
mtdchar_write_ioctl(struct mtd_info * mtd,struct mtd_write_req __user * argp)594 mtdchar_write_ioctl(struct mtd_info *mtd, struct mtd_write_req __user *argp)
595 {
596 struct mtd_info *master = mtd_get_master(mtd);
597 struct mtd_write_req req;
598 const void __user *usr_data, *usr_oob;
599 uint8_t *datbuf = NULL, *oobbuf = NULL;
600 size_t datbuf_len, oobbuf_len;
601 int ret = 0;
602 u64 end;
603
604 if (copy_from_user(&req, argp, sizeof(req)))
605 return -EFAULT;
606
607 usr_data = (const void __user *)(uintptr_t)req.usr_data;
608 usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
609
610 if (!master->_write_oob)
611 return -EOPNOTSUPP;
612
613 if (!usr_data)
614 req.len = 0;
615
616 if (!usr_oob)
617 req.ooblen = 0;
618
619 req.len &= 0xffffffff;
620 req.ooblen &= 0xffffffff;
621
622 if (check_add_overflow(req.start, req.len, &end) || end > mtd->size)
623 return -EINVAL;
624
625 datbuf_len = min_t(size_t, req.len, mtd->erasesize);
626 if (datbuf_len > 0) {
627 datbuf = kvmalloc(datbuf_len, GFP_KERNEL);
628 if (!datbuf)
629 return -ENOMEM;
630 }
631
632 oobbuf_len = min_t(size_t, req.ooblen, mtd->erasesize);
633 if (oobbuf_len > 0) {
634 oobbuf = kvmalloc(oobbuf_len, GFP_KERNEL);
635 if (!oobbuf) {
636 kvfree(datbuf);
637 return -ENOMEM;
638 }
639 }
640
641 while (req.len > 0 || (!usr_data && req.ooblen > 0)) {
642 struct mtd_oob_ops ops = {
643 .mode = req.mode,
644 .len = min_t(size_t, req.len, datbuf_len),
645 .ooblen = min_t(size_t, req.ooblen, oobbuf_len),
646 .datbuf = datbuf,
647 .oobbuf = oobbuf,
648 };
649
650 /*
651 * Shorten non-page-aligned, eraseblock-sized writes so that
652 * the write ends on an eraseblock boundary. This is necessary
653 * for adjust_oob_length() to properly handle non-page-aligned
654 * writes.
655 */
656 if (ops.len == mtd->erasesize)
657 ops.len -= mtd_mod_by_ws(req.start + ops.len, mtd);
658
659 /*
660 * For writes which are not OOB-only, adjust the amount of OOB
661 * data written according to the number of data pages written.
662 * This is necessary to prevent OOB data from being skipped
663 * over in data+OOB writes requiring multiple mtd_write_oob()
664 * calls to be completed.
665 */
666 adjust_oob_length(mtd, req.start, &ops);
667
668 if (copy_from_user(datbuf, usr_data, ops.len) ||
669 copy_from_user(oobbuf, usr_oob, ops.ooblen)) {
670 ret = -EFAULT;
671 break;
672 }
673
674 ret = mtd_write_oob(mtd, req.start, &ops);
675 if (ret)
676 break;
677
678 req.start += ops.retlen;
679 req.len -= ops.retlen;
680 usr_data += ops.retlen;
681
682 req.ooblen -= ops.oobretlen;
683 usr_oob += ops.oobretlen;
684 }
685
686 kvfree(datbuf);
687 kvfree(oobbuf);
688
689 return ret;
690 }
691
692 static noinline_for_stack int
mtdchar_read_ioctl(struct mtd_info * mtd,struct mtd_read_req __user * argp)693 mtdchar_read_ioctl(struct mtd_info *mtd, struct mtd_read_req __user *argp)
694 {
695 struct mtd_info *master = mtd_get_master(mtd);
696 struct mtd_read_req req;
697 void __user *usr_data, *usr_oob;
698 uint8_t *datbuf = NULL, *oobbuf = NULL;
699 size_t datbuf_len, oobbuf_len;
700 size_t orig_len, orig_ooblen;
701 int ret = 0;
702 u64 end;
703
704 if (copy_from_user(&req, argp, sizeof(req)))
705 return -EFAULT;
706
707 orig_len = req.len;
708 orig_ooblen = req.ooblen;
709
710 usr_data = (void __user *)(uintptr_t)req.usr_data;
711 usr_oob = (void __user *)(uintptr_t)req.usr_oob;
712
713 if (!master->_read_oob)
714 return -EOPNOTSUPP;
715
716 if (!usr_data)
717 req.len = 0;
718
719 if (!usr_oob)
720 req.ooblen = 0;
721
722 req.ecc_stats.uncorrectable_errors = 0;
723 req.ecc_stats.corrected_bitflips = 0;
724 req.ecc_stats.max_bitflips = 0;
725
726 req.len &= 0xffffffff;
727 req.ooblen &= 0xffffffff;
728
729 if (check_add_overflow(req.start, req.len, &end) || end > mtd->size) {
730 ret = -EINVAL;
731 goto out;
732 }
733
734 datbuf_len = min_t(size_t, req.len, mtd->erasesize);
735 if (datbuf_len > 0) {
736 datbuf = kvmalloc(datbuf_len, GFP_KERNEL);
737 if (!datbuf) {
738 ret = -ENOMEM;
739 goto out;
740 }
741 }
742
743 oobbuf_len = min_t(size_t, req.ooblen, mtd->erasesize);
744 if (oobbuf_len > 0) {
745 oobbuf = kvmalloc(oobbuf_len, GFP_KERNEL);
746 if (!oobbuf) {
747 ret = -ENOMEM;
748 goto out;
749 }
750 }
751
752 while (req.len > 0 || (!usr_data && req.ooblen > 0)) {
753 struct mtd_req_stats stats;
754 struct mtd_oob_ops ops = {
755 .mode = req.mode,
756 .len = min_t(size_t, req.len, datbuf_len),
757 .ooblen = min_t(size_t, req.ooblen, oobbuf_len),
758 .datbuf = datbuf,
759 .oobbuf = oobbuf,
760 .stats = &stats,
761 };
762
763 /*
764 * Shorten non-page-aligned, eraseblock-sized reads so that the
765 * read ends on an eraseblock boundary. This is necessary in
766 * order to prevent OOB data for some pages from being
767 * duplicated in the output of non-page-aligned reads requiring
768 * multiple mtd_read_oob() calls to be completed.
769 */
770 if (ops.len == mtd->erasesize)
771 ops.len -= mtd_mod_by_ws(req.start + ops.len, mtd);
772
773 ret = mtd_read_oob(mtd, (loff_t)req.start, &ops);
774
775 req.ecc_stats.uncorrectable_errors +=
776 stats.uncorrectable_errors;
777 req.ecc_stats.corrected_bitflips += stats.corrected_bitflips;
778 req.ecc_stats.max_bitflips =
779 max(req.ecc_stats.max_bitflips, stats.max_bitflips);
780
781 if (ret && !mtd_is_bitflip_or_eccerr(ret))
782 break;
783
784 if (copy_to_user(usr_data, ops.datbuf, ops.retlen) ||
785 copy_to_user(usr_oob, ops.oobbuf, ops.oobretlen)) {
786 ret = -EFAULT;
787 break;
788 }
789
790 req.start += ops.retlen;
791 req.len -= ops.retlen;
792 usr_data += ops.retlen;
793
794 req.ooblen -= ops.oobretlen;
795 usr_oob += ops.oobretlen;
796 }
797
798 /*
799 * As multiple iterations of the above loop (and therefore multiple
800 * mtd_read_oob() calls) may be necessary to complete the read request,
801 * adjust the final return code to ensure it accounts for all detected
802 * ECC errors.
803 */
804 if (!ret || mtd_is_bitflip(ret)) {
805 if (req.ecc_stats.uncorrectable_errors > 0)
806 ret = -EBADMSG;
807 else if (req.ecc_stats.corrected_bitflips > 0)
808 ret = -EUCLEAN;
809 }
810
811 out:
812 req.len = orig_len - req.len;
813 req.ooblen = orig_ooblen - req.ooblen;
814
815 if (copy_to_user(argp, &req, sizeof(req)))
816 ret = -EFAULT;
817
818 kvfree(datbuf);
819 kvfree(oobbuf);
820
821 return ret;
822 }
823
mtdchar_ioctl(struct file * file,u_int cmd,u_long arg)824 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
825 {
826 struct mtd_file_info *mfi = file->private_data;
827 struct mtd_info *mtd = mfi->mtd;
828 struct mtd_info *master = mtd_get_master(mtd);
829 void __user *argp = (void __user *)arg;
830 int ret = 0;
831 struct mtd_info_user info;
832
833 pr_debug("MTD_ioctl\n");
834
835 /*
836 * Check the file mode to require "dangerous" commands to have write
837 * permissions.
838 */
839 switch (cmd) {
840 /* "safe" commands */
841 case MEMGETREGIONCOUNT:
842 case MEMGETREGIONINFO:
843 case MEMGETINFO:
844 case MEMREADOOB:
845 case MEMREADOOB64:
846 case MEMREAD:
847 case MEMISLOCKED:
848 case MEMGETOOBSEL:
849 case MEMGETBADBLOCK:
850 case OTPSELECT:
851 case OTPGETREGIONCOUNT:
852 case OTPGETREGIONINFO:
853 case ECCGETLAYOUT:
854 case ECCGETSTATS:
855 case MTDFILEMODE:
856 case BLKPG:
857 case BLKRRPART:
858 break;
859
860 /* "dangerous" commands */
861 case MEMERASE:
862 case MEMERASE64:
863 case MEMLOCK:
864 case MEMUNLOCK:
865 case MEMSETBADBLOCK:
866 case MEMWRITEOOB:
867 case MEMWRITEOOB64:
868 case MEMWRITE:
869 case OTPLOCK:
870 case OTPERASE:
871 if (!(file->f_mode & FMODE_WRITE))
872 return -EPERM;
873 break;
874
875 default:
876 return -ENOTTY;
877 }
878
879 switch (cmd) {
880 case MEMGETREGIONCOUNT:
881 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
882 return -EFAULT;
883 break;
884
885 case MEMGETREGIONINFO:
886 {
887 uint32_t ur_idx;
888 struct mtd_erase_region_info *kr;
889 struct region_info_user __user *ur = argp;
890
891 if (get_user(ur_idx, &(ur->regionindex)))
892 return -EFAULT;
893
894 if (ur_idx >= mtd->numeraseregions)
895 return -EINVAL;
896
897 kr = &(mtd->eraseregions[ur_idx]);
898
899 if (put_user(kr->offset, &(ur->offset))
900 || put_user(kr->erasesize, &(ur->erasesize))
901 || put_user(kr->numblocks, &(ur->numblocks)))
902 return -EFAULT;
903
904 break;
905 }
906
907 case MEMGETINFO:
908 memset(&info, 0, sizeof(info));
909 info.type = mtd->type;
910 info.flags = mtd->flags;
911 info.size = mtd->size;
912 info.erasesize = mtd->erasesize;
913 info.writesize = mtd->writesize;
914 info.oobsize = mtd->oobsize;
915 /* The below field is obsolete */
916 info.padding = 0;
917 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
918 return -EFAULT;
919 break;
920
921 case MEMERASE:
922 case MEMERASE64:
923 {
924 struct erase_info *erase;
925
926 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
927 if (!erase)
928 ret = -ENOMEM;
929 else {
930 if (cmd == MEMERASE64) {
931 struct erase_info_user64 einfo64;
932
933 if (copy_from_user(&einfo64, argp,
934 sizeof(struct erase_info_user64))) {
935 kfree(erase);
936 return -EFAULT;
937 }
938 erase->addr = einfo64.start;
939 erase->len = einfo64.length;
940 } else {
941 struct erase_info_user einfo32;
942
943 if (copy_from_user(&einfo32, argp,
944 sizeof(struct erase_info_user))) {
945 kfree(erase);
946 return -EFAULT;
947 }
948 erase->addr = einfo32.start;
949 erase->len = einfo32.length;
950 }
951
952 ret = mtd_erase(mtd, erase);
953 kfree(erase);
954 }
955 break;
956 }
957
958 case MEMWRITEOOB:
959 {
960 struct mtd_oob_buf buf;
961 struct mtd_oob_buf __user *buf_user = argp;
962
963 /* NOTE: writes return length to buf_user->length */
964 if (copy_from_user(&buf, argp, sizeof(buf)))
965 ret = -EFAULT;
966 else
967 ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
968 buf.ptr, &buf_user->length);
969 break;
970 }
971
972 case MEMREADOOB:
973 {
974 struct mtd_oob_buf buf;
975 struct mtd_oob_buf __user *buf_user = argp;
976
977 /* NOTE: writes return length to buf_user->start */
978 if (copy_from_user(&buf, argp, sizeof(buf)))
979 ret = -EFAULT;
980 else
981 ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
982 buf.ptr, &buf_user->start);
983 break;
984 }
985
986 case MEMWRITEOOB64:
987 {
988 struct mtd_oob_buf64 buf;
989 struct mtd_oob_buf64 __user *buf_user = argp;
990
991 if (copy_from_user(&buf, argp, sizeof(buf)))
992 ret = -EFAULT;
993 else
994 ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
995 (void __user *)(uintptr_t)buf.usr_ptr,
996 &buf_user->length);
997 break;
998 }
999
1000 case MEMREADOOB64:
1001 {
1002 struct mtd_oob_buf64 buf;
1003 struct mtd_oob_buf64 __user *buf_user = argp;
1004
1005 if (copy_from_user(&buf, argp, sizeof(buf)))
1006 ret = -EFAULT;
1007 else
1008 ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
1009 (void __user *)(uintptr_t)buf.usr_ptr,
1010 &buf_user->length);
1011 break;
1012 }
1013
1014 case MEMWRITE:
1015 {
1016 ret = mtdchar_write_ioctl(mtd,
1017 (struct mtd_write_req __user *)arg);
1018 break;
1019 }
1020
1021 case MEMREAD:
1022 {
1023 ret = mtdchar_read_ioctl(mtd,
1024 (struct mtd_read_req __user *)arg);
1025 break;
1026 }
1027
1028 case MEMLOCK:
1029 {
1030 struct erase_info_user einfo;
1031
1032 if (copy_from_user(&einfo, argp, sizeof(einfo)))
1033 return -EFAULT;
1034
1035 ret = mtd_lock(mtd, einfo.start, einfo.length);
1036 break;
1037 }
1038
1039 case MEMUNLOCK:
1040 {
1041 struct erase_info_user einfo;
1042
1043 if (copy_from_user(&einfo, argp, sizeof(einfo)))
1044 return -EFAULT;
1045
1046 ret = mtd_unlock(mtd, einfo.start, einfo.length);
1047 break;
1048 }
1049
1050 case MEMISLOCKED:
1051 {
1052 struct erase_info_user einfo;
1053
1054 if (copy_from_user(&einfo, argp, sizeof(einfo)))
1055 return -EFAULT;
1056
1057 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
1058 break;
1059 }
1060
1061 /* Legacy interface */
1062 case MEMGETOOBSEL:
1063 {
1064 struct nand_oobinfo oi;
1065
1066 if (!master->ooblayout)
1067 return -EOPNOTSUPP;
1068
1069 ret = get_oobinfo(mtd, &oi);
1070 if (ret)
1071 return ret;
1072
1073 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
1074 return -EFAULT;
1075 break;
1076 }
1077
1078 case MEMGETBADBLOCK:
1079 {
1080 loff_t offs;
1081
1082 if (copy_from_user(&offs, argp, sizeof(loff_t)))
1083 return -EFAULT;
1084 return mtd_block_isbad(mtd, offs);
1085 }
1086
1087 case MEMSETBADBLOCK:
1088 {
1089 loff_t offs;
1090
1091 if (copy_from_user(&offs, argp, sizeof(loff_t)))
1092 return -EFAULT;
1093 return mtd_block_markbad(mtd, offs);
1094 }
1095
1096 case OTPSELECT:
1097 {
1098 int mode;
1099 if (copy_from_user(&mode, argp, sizeof(int)))
1100 return -EFAULT;
1101
1102 mfi->mode = MTD_FILE_MODE_NORMAL;
1103
1104 ret = otp_select_filemode(mfi, mode);
1105
1106 file->f_pos = 0;
1107 break;
1108 }
1109
1110 case OTPGETREGIONCOUNT:
1111 case OTPGETREGIONINFO:
1112 {
1113 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
1114 size_t retlen;
1115 if (!buf)
1116 return -ENOMEM;
1117 switch (mfi->mode) {
1118 case MTD_FILE_MODE_OTP_FACTORY:
1119 ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
1120 break;
1121 case MTD_FILE_MODE_OTP_USER:
1122 ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
1123 break;
1124 default:
1125 ret = -EINVAL;
1126 break;
1127 }
1128 if (!ret) {
1129 if (cmd == OTPGETREGIONCOUNT) {
1130 int nbr = retlen / sizeof(struct otp_info);
1131 ret = copy_to_user(argp, &nbr, sizeof(int));
1132 } else
1133 ret = copy_to_user(argp, buf, retlen);
1134 if (ret)
1135 ret = -EFAULT;
1136 }
1137 kfree(buf);
1138 break;
1139 }
1140
1141 case OTPLOCK:
1142 case OTPERASE:
1143 {
1144 struct otp_info oinfo;
1145
1146 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
1147 return -EINVAL;
1148 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
1149 return -EFAULT;
1150 if (cmd == OTPLOCK)
1151 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
1152 else
1153 ret = mtd_erase_user_prot_reg(mtd, oinfo.start, oinfo.length);
1154 break;
1155 }
1156
1157 /* This ioctl is being deprecated - it truncates the ECC layout */
1158 case ECCGETLAYOUT:
1159 {
1160 struct nand_ecclayout_user *usrlay;
1161
1162 if (!master->ooblayout)
1163 return -EOPNOTSUPP;
1164
1165 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
1166 if (!usrlay)
1167 return -ENOMEM;
1168
1169 shrink_ecclayout(mtd, usrlay);
1170
1171 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
1172 ret = -EFAULT;
1173 kfree(usrlay);
1174 break;
1175 }
1176
1177 case ECCGETSTATS:
1178 {
1179 if (copy_to_user(argp, &mtd->ecc_stats,
1180 sizeof(struct mtd_ecc_stats)))
1181 return -EFAULT;
1182 break;
1183 }
1184
1185 case MTDFILEMODE:
1186 {
1187 mfi->mode = 0;
1188
1189 switch(arg) {
1190 case MTD_FILE_MODE_OTP_FACTORY:
1191 case MTD_FILE_MODE_OTP_USER:
1192 ret = otp_select_filemode(mfi, arg);
1193 break;
1194
1195 case MTD_FILE_MODE_RAW:
1196 if (!mtd_has_oob(mtd))
1197 return -EOPNOTSUPP;
1198 mfi->mode = arg;
1199 break;
1200
1201 case MTD_FILE_MODE_NORMAL:
1202 break;
1203 default:
1204 ret = -EINVAL;
1205 }
1206 file->f_pos = 0;
1207 break;
1208 }
1209
1210 case BLKPG:
1211 {
1212 struct blkpg_ioctl_arg __user *blk_arg = argp;
1213 struct blkpg_ioctl_arg a;
1214
1215 if (copy_from_user(&a, blk_arg, sizeof(a)))
1216 ret = -EFAULT;
1217 else
1218 ret = mtdchar_blkpg_ioctl(mtd, &a);
1219 break;
1220 }
1221
1222 case BLKRRPART:
1223 {
1224 /* No reread partition feature. Just return ok */
1225 ret = 0;
1226 break;
1227 }
1228 }
1229
1230 return ret;
1231 } /* memory_ioctl */
1232
mtdchar_unlocked_ioctl(struct file * file,u_int cmd,u_long arg)1233 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1234 {
1235 struct mtd_file_info *mfi = file->private_data;
1236 struct mtd_info *mtd = mfi->mtd;
1237 struct mtd_info *master = mtd_get_master(mtd);
1238 int ret;
1239
1240 mutex_lock(&master->master.chrdev_lock);
1241 ret = mtdchar_ioctl(file, cmd, arg);
1242 mutex_unlock(&master->master.chrdev_lock);
1243
1244 return ret;
1245 }
1246
1247 #ifdef CONFIG_COMPAT
1248
1249 struct mtd_oob_buf32 {
1250 u_int32_t start;
1251 u_int32_t length;
1252 compat_caddr_t ptr; /* unsigned char* */
1253 };
1254
1255 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
1256 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
1257
mtdchar_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1258 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1259 unsigned long arg)
1260 {
1261 struct mtd_file_info *mfi = file->private_data;
1262 struct mtd_info *mtd = mfi->mtd;
1263 struct mtd_info *master = mtd_get_master(mtd);
1264 void __user *argp = compat_ptr(arg);
1265 int ret = 0;
1266
1267 mutex_lock(&master->master.chrdev_lock);
1268
1269 switch (cmd) {
1270 case MEMWRITEOOB32:
1271 {
1272 struct mtd_oob_buf32 buf;
1273 struct mtd_oob_buf32 __user *buf_user = argp;
1274
1275 if (!(file->f_mode & FMODE_WRITE)) {
1276 ret = -EPERM;
1277 break;
1278 }
1279
1280 if (copy_from_user(&buf, argp, sizeof(buf)))
1281 ret = -EFAULT;
1282 else
1283 ret = mtdchar_writeoob(file, mtd, buf.start,
1284 buf.length, compat_ptr(buf.ptr),
1285 &buf_user->length);
1286 break;
1287 }
1288
1289 case MEMREADOOB32:
1290 {
1291 struct mtd_oob_buf32 buf;
1292 struct mtd_oob_buf32 __user *buf_user = argp;
1293
1294 /* NOTE: writes return length to buf->start */
1295 if (copy_from_user(&buf, argp, sizeof(buf)))
1296 ret = -EFAULT;
1297 else
1298 ret = mtdchar_readoob(file, mtd, buf.start,
1299 buf.length, compat_ptr(buf.ptr),
1300 &buf_user->start);
1301 break;
1302 }
1303
1304 case BLKPG:
1305 {
1306 /* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1307 struct blkpg_compat_ioctl_arg __user *uarg = argp;
1308 struct blkpg_compat_ioctl_arg compat_arg;
1309 struct blkpg_ioctl_arg a;
1310
1311 if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1312 ret = -EFAULT;
1313 break;
1314 }
1315
1316 memset(&a, 0, sizeof(a));
1317 a.op = compat_arg.op;
1318 a.flags = compat_arg.flags;
1319 a.datalen = compat_arg.datalen;
1320 a.data = compat_ptr(compat_arg.data);
1321
1322 ret = mtdchar_blkpg_ioctl(mtd, &a);
1323 break;
1324 }
1325
1326 default:
1327 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1328 }
1329
1330 mutex_unlock(&master->master.chrdev_lock);
1331
1332 return ret;
1333 }
1334
1335 #endif /* CONFIG_COMPAT */
1336
1337 /*
1338 * try to determine where a shared mapping can be made
1339 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1340 * mappings)
1341 */
1342 #ifndef CONFIG_MMU
mtdchar_get_unmapped_area(struct file * file,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1343 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1344 unsigned long addr,
1345 unsigned long len,
1346 unsigned long pgoff,
1347 unsigned long flags)
1348 {
1349 struct mtd_file_info *mfi = file->private_data;
1350 struct mtd_info *mtd = mfi->mtd;
1351 unsigned long offset;
1352 int ret;
1353
1354 if (addr != 0)
1355 return (unsigned long) -EINVAL;
1356
1357 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1358 return (unsigned long) -EINVAL;
1359
1360 offset = pgoff << PAGE_SHIFT;
1361 if (offset > mtd->size - len)
1362 return (unsigned long) -EINVAL;
1363
1364 ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1365 return ret == -EOPNOTSUPP ? -ENODEV : ret;
1366 }
1367
mtdchar_mmap_capabilities(struct file * file)1368 static unsigned mtdchar_mmap_capabilities(struct file *file)
1369 {
1370 struct mtd_file_info *mfi = file->private_data;
1371
1372 return mtd_mmap_capabilities(mfi->mtd);
1373 }
1374 #endif
1375
1376 /*
1377 * set up a mapping for shared memory segments
1378 */
mtdchar_mmap(struct file * file,struct vm_area_struct * vma)1379 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1380 {
1381 #ifdef CONFIG_MMU
1382 struct mtd_file_info *mfi = file->private_data;
1383 struct mtd_info *mtd = mfi->mtd;
1384 struct map_info *map = mtd->priv;
1385
1386 /* This is broken because it assumes the MTD device is map-based
1387 and that mtd->priv is a valid struct map_info. It should be
1388 replaced with something that uses the mtd_get_unmapped_area()
1389 operation properly. */
1390 if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1391 #ifdef pgprot_noncached
1392 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1393 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1394 #endif
1395 return vm_iomap_memory(vma, map->phys, map->size);
1396 }
1397 return -ENODEV;
1398 #else
1399 return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1400 #endif
1401 }
1402
1403 static const struct file_operations mtd_fops = {
1404 .owner = THIS_MODULE,
1405 .llseek = mtdchar_lseek,
1406 .read = mtdchar_read,
1407 .write = mtdchar_write,
1408 .unlocked_ioctl = mtdchar_unlocked_ioctl,
1409 #ifdef CONFIG_COMPAT
1410 .compat_ioctl = mtdchar_compat_ioctl,
1411 #endif
1412 .open = mtdchar_open,
1413 .release = mtdchar_close,
1414 .mmap = mtdchar_mmap,
1415 #ifndef CONFIG_MMU
1416 .get_unmapped_area = mtdchar_get_unmapped_area,
1417 .mmap_capabilities = mtdchar_mmap_capabilities,
1418 #endif
1419 };
1420
init_mtdchar(void)1421 int __init init_mtdchar(void)
1422 {
1423 int ret;
1424
1425 ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1426 "mtd", &mtd_fops);
1427 if (ret < 0) {
1428 pr_err("Can't allocate major number %d for MTD\n",
1429 MTD_CHAR_MAJOR);
1430 return ret;
1431 }
1432
1433 return ret;
1434 }
1435
cleanup_mtdchar(void)1436 void __exit cleanup_mtdchar(void)
1437 {
1438 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1439 }
1440
1441 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1442