mtdchar.c

   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 */
  34struct mtd_file_info {
  35	struct mtd_info *mtd;
  36	enum mtd_file_modes mode;
  37};
  38
  39static 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
  45static 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
  84out1:
  85	put_mtd_device(mtd);
  86	return ret;
  87} /* mtdchar_open */
  88
  89/*====================================================================*/
  90
  91static 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
 127static 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
 217static 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
 310static 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
 340static 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
 382static 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 */
 443static 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
 491static 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
 541static 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
 576static 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
 593static noinline_for_stack int
 594mtdchar_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
 692static noinline_for_stack int
 693mtdchar_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
 811out:
 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
 824static 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
1233static 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
1249struct 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
1258static 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
1343static 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
1368static 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 */
1379static 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
1403static 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
1421int __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
1436void __exit cleanup_mtdchar(void)
1437{
1438	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1439}
1440
1441MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);