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