linux/fs/ioctl.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/ioctl.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 */
   7
   8#include <linux/syscalls.h>
   9#include <linux/mm.h>
  10#include <linux/capability.h>
  11#include <linux/compat.h>
  12#include <linux/file.h>
  13#include <linux/fs.h>
  14#include <linux/security.h>
  15#include <linux/export.h>
  16#include <linux/uaccess.h>
  17#include <linux/writeback.h>
  18#include <linux/buffer_head.h>
  19#include <linux/falloc.h>
  20#include <linux/sched/signal.h>
  21
  22#include "internal.h"
  23
  24#include <asm/ioctls.h>
  25
  26/* So that the fiemap access checks can't overflow on 32 bit machines. */
  27#define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))
  28
  29/**
  30 * vfs_ioctl - call filesystem specific ioctl methods
  31 * @filp:       open file to invoke ioctl method on
  32 * @cmd:        ioctl command to execute
  33 * @arg:        command-specific argument for ioctl
  34 *
  35 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
  36 * returns -ENOTTY.
  37 *
  38 * Returns 0 on success, -errno on error.
  39 */
  40long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  41{
  42        int error = -ENOTTY;
  43
  44        if (!filp->f_op->unlocked_ioctl)
  45                goto out;
  46
  47        error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  48        if (error == -ENOIOCTLCMD)
  49                error = -ENOTTY;
  50 out:
  51        return error;
  52}
  53EXPORT_SYMBOL(vfs_ioctl);
  54
  55static int ioctl_fibmap(struct file *filp, int __user *p)
  56{
  57        struct inode *inode = file_inode(filp);
  58        struct super_block *sb = inode->i_sb;
  59        int error, ur_block;
  60        sector_t block;
  61
  62        if (!capable(CAP_SYS_RAWIO))
  63                return -EPERM;
  64
  65        error = get_user(ur_block, p);
  66        if (error)
  67                return error;
  68
  69        if (ur_block < 0)
  70                return -EINVAL;
  71
  72        block = ur_block;
  73        error = bmap(inode, &block);
  74
  75        if (block > INT_MAX) {
  76                error = -ERANGE;
  77                pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
  78                                    current->comm, task_pid_nr(current),
  79                                    sb->s_id, filp);
  80        }
  81
  82        if (error)
  83                ur_block = 0;
  84        else
  85                ur_block = block;
  86
  87        if (put_user(ur_block, p))
  88                error = -EFAULT;
  89
  90        return error;
  91}
  92
  93/**
  94 * fiemap_fill_next_extent - Fiemap helper function
  95 * @fieinfo:    Fiemap context passed into ->fiemap
  96 * @logical:    Extent logical start offset, in bytes
  97 * @phys:       Extent physical start offset, in bytes
  98 * @len:        Extent length, in bytes
  99 * @flags:      FIEMAP_EXTENT flags that describe this extent
 100 *
 101 * Called from file system ->fiemap callback. Will populate extent
 102 * info as passed in via arguments and copy to user memory. On
 103 * success, extent count on fieinfo is incremented.
 104 *
 105 * Returns 0 on success, -errno on error, 1 if this was the last
 106 * extent that will fit in user array.
 107 */
 108#define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
 109#define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
 110#define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
 111int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 112                            u64 phys, u64 len, u32 flags)
 113{
 114        struct fiemap_extent extent;
 115        struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
 116
 117        /* only count the extents */
 118        if (fieinfo->fi_extents_max == 0) {
 119                fieinfo->fi_extents_mapped++;
 120                return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 121        }
 122
 123        if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
 124                return 1;
 125
 126        if (flags & SET_UNKNOWN_FLAGS)
 127                flags |= FIEMAP_EXTENT_UNKNOWN;
 128        if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
 129                flags |= FIEMAP_EXTENT_ENCODED;
 130        if (flags & SET_NOT_ALIGNED_FLAGS)
 131                flags |= FIEMAP_EXTENT_NOT_ALIGNED;
 132
 133        memset(&extent, 0, sizeof(extent));
 134        extent.fe_logical = logical;
 135        extent.fe_physical = phys;
 136        extent.fe_length = len;
 137        extent.fe_flags = flags;
 138
 139        dest += fieinfo->fi_extents_mapped;
 140        if (copy_to_user(dest, &extent, sizeof(extent)))
 141                return -EFAULT;
 142
 143        fieinfo->fi_extents_mapped++;
 144        if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
 145                return 1;
 146        return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 147}
 148EXPORT_SYMBOL(fiemap_fill_next_extent);
 149
 150/**
 151 * fiemap_check_flags - check validity of requested flags for fiemap
 152 * @fieinfo:    Fiemap context passed into ->fiemap
 153 * @fs_flags:   Set of fiemap flags that the file system understands
 154 *
 155 * Called from file system ->fiemap callback. This will compute the
 156 * intersection of valid fiemap flags and those that the fs supports. That
 157 * value is then compared against the user supplied flags. In case of bad user
 158 * flags, the invalid values will be written into the fieinfo structure, and
 159 * -EBADR is returned, which tells ioctl_fiemap() to return those values to
 160 * userspace. For this reason, a return code of -EBADR should be preserved.
 161 *
 162 * Returns 0 on success, -EBADR on bad flags.
 163 */
 164int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
 165{
 166        u32 incompat_flags;
 167
 168        incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
 169        if (incompat_flags) {
 170                fieinfo->fi_flags = incompat_flags;
 171                return -EBADR;
 172        }
 173        return 0;
 174}
 175EXPORT_SYMBOL(fiemap_check_flags);
 176
 177static int fiemap_check_ranges(struct super_block *sb,
 178                               u64 start, u64 len, u64 *new_len)
 179{
 180        u64 maxbytes = (u64) sb->s_maxbytes;
 181
 182        *new_len = len;
 183
 184        if (len == 0)
 185                return -EINVAL;
 186
 187        if (start > maxbytes)
 188                return -EFBIG;
 189
 190        /*
 191         * Shrink request scope to what the fs can actually handle.
 192         */
 193        if (len > maxbytes || (maxbytes - len) < start)
 194                *new_len = maxbytes - start;
 195
 196        return 0;
 197}
 198
 199static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 200{
 201        struct fiemap fiemap;
 202        struct fiemap_extent_info fieinfo = { 0, };
 203        struct inode *inode = file_inode(filp);
 204        struct super_block *sb = inode->i_sb;
 205        u64 len;
 206        int error;
 207
 208        if (!inode->i_op->fiemap)
 209                return -EOPNOTSUPP;
 210
 211        if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
 212                return -EFAULT;
 213
 214        if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 215                return -EINVAL;
 216
 217        error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
 218                                    &len);
 219        if (error)
 220                return error;
 221
 222        fieinfo.fi_flags = fiemap.fm_flags;
 223        fieinfo.fi_extents_max = fiemap.fm_extent_count;
 224        fieinfo.fi_extents_start = ufiemap->fm_extents;
 225
 226        if (fiemap.fm_extent_count != 0 &&
 227            !access_ok(fieinfo.fi_extents_start,
 228                       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
 229                return -EFAULT;
 230
 231        if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
 232                filemap_write_and_wait(inode->i_mapping);
 233
 234        error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
 235        fiemap.fm_flags = fieinfo.fi_flags;
 236        fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 237        if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
 238                error = -EFAULT;
 239
 240        return error;
 241}
 242
 243static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 244                             u64 off, u64 olen, u64 destoff)
 245{
 246        struct fd src_file = fdget(srcfd);
 247        loff_t cloned;
 248        int ret;
 249
 250        if (!src_file.file)
 251                return -EBADF;
 252        ret = -EXDEV;
 253        if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
 254                goto fdput;
 255        cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
 256                                      olen, 0);
 257        if (cloned < 0)
 258                ret = cloned;
 259        else if (olen && cloned != olen)
 260                ret = -EINVAL;
 261        else
 262                ret = 0;
 263fdput:
 264        fdput(src_file);
 265        return ret;
 266}
 267
 268static long ioctl_file_clone_range(struct file *file,
 269                                   struct file_clone_range __user *argp)
 270{
 271        struct file_clone_range args;
 272
 273        if (copy_from_user(&args, argp, sizeof(args)))
 274                return -EFAULT;
 275        return ioctl_file_clone(file, args.src_fd, args.src_offset,
 276                                args.src_length, args.dest_offset);
 277}
 278
 279#ifdef CONFIG_BLOCK
 280
 281static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 282{
 283        return (offset >> inode->i_blkbits);
 284}
 285
 286static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 287{
 288        return (blk << inode->i_blkbits);
 289}
 290
 291/**
 292 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
 293 * @inode: the inode to map
 294 * @fieinfo: the fiemap info struct that will be passed back to userspace
 295 * @start: where to start mapping in the inode
 296 * @len: how much space to map
 297 * @get_block: the fs's get_block function
 298 *
 299 * This does FIEMAP for block based inodes.  Basically it will just loop
 300 * through get_block until we hit the number of extents we want to map, or we
 301 * go past the end of the file and hit a hole.
 302 *
 303 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
 304 * please do not use this function, it will stop at the first unmapped block
 305 * beyond i_size.
 306 *
 307 * If you use this function directly, you need to do your own locking. Use
 308 * generic_block_fiemap if you want the locking done for you.
 309 */
 310
 311int __generic_block_fiemap(struct inode *inode,
 312                           struct fiemap_extent_info *fieinfo, loff_t start,
 313                           loff_t len, get_block_t *get_block)
 314{
 315        struct buffer_head map_bh;
 316        sector_t start_blk, last_blk;
 317        loff_t isize = i_size_read(inode);
 318        u64 logical = 0, phys = 0, size = 0;
 319        u32 flags = FIEMAP_EXTENT_MERGED;
 320        bool past_eof = false, whole_file = false;
 321        int ret = 0;
 322
 323        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 324        if (ret)
 325                return ret;
 326
 327        /*
 328         * Either the i_mutex or other appropriate locking needs to be held
 329         * since we expect isize to not change at all through the duration of
 330         * this call.
 331         */
 332        if (len >= isize) {
 333                whole_file = true;
 334                len = isize;
 335        }
 336
 337        /*
 338         * Some filesystems can't deal with being asked to map less than
 339         * blocksize, so make sure our len is at least block length.
 340         */
 341        if (logical_to_blk(inode, len) == 0)
 342                len = blk_to_logical(inode, 1);
 343
 344        start_blk = logical_to_blk(inode, start);
 345        last_blk = logical_to_blk(inode, start + len - 1);
 346
 347        do {
 348                /*
 349                 * we set b_size to the total size we want so it will map as
 350                 * many contiguous blocks as possible at once
 351                 */
 352                memset(&map_bh, 0, sizeof(struct buffer_head));
 353                map_bh.b_size = len;
 354
 355                ret = get_block(inode, start_blk, &map_bh, 0);
 356                if (ret)
 357                        break;
 358
 359                /* HOLE */
 360                if (!buffer_mapped(&map_bh)) {
 361                        start_blk++;
 362
 363                        /*
 364                         * We want to handle the case where there is an
 365                         * allocated block at the front of the file, and then
 366                         * nothing but holes up to the end of the file properly,
 367                         * to make sure that extent at the front gets properly
 368                         * marked with FIEMAP_EXTENT_LAST
 369                         */
 370                        if (!past_eof &&
 371                            blk_to_logical(inode, start_blk) >= isize)
 372                                past_eof = 1;
 373
 374                        /*
 375                         * First hole after going past the EOF, this is our
 376                         * last extent
 377                         */
 378                        if (past_eof && size) {
 379                                flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
 380                                ret = fiemap_fill_next_extent(fieinfo, logical,
 381                                                              phys, size,
 382                                                              flags);
 383                        } else if (size) {
 384                                ret = fiemap_fill_next_extent(fieinfo, logical,
 385                                                              phys, size, flags);
 386                                size = 0;
 387                        }
 388
 389                        /* if we have holes up to/past EOF then we're done */
 390                        if (start_blk > last_blk || past_eof || ret)
 391                                break;
 392                } else {
 393                        /*
 394                         * We have gone over the length of what we wanted to
 395                         * map, and it wasn't the entire file, so add the extent
 396                         * we got last time and exit.
 397                         *
 398                         * This is for the case where say we want to map all the
 399                         * way up to the second to the last block in a file, but
 400                         * the last block is a hole, making the second to last
 401                         * block FIEMAP_EXTENT_LAST.  In this case we want to
 402                         * see if there is a hole after the second to last block
 403                         * so we can mark it properly.  If we found data after
 404                         * we exceeded the length we were requesting, then we
 405                         * are good to go, just add the extent to the fieinfo
 406                         * and break
 407                         */
 408                        if (start_blk > last_blk && !whole_file) {
 409                                ret = fiemap_fill_next_extent(fieinfo, logical,
 410                                                              phys, size,
 411                                                              flags);
 412                                break;
 413                        }
 414
 415                        /*
 416                         * if size != 0 then we know we already have an extent
 417                         * to add, so add it.
 418                         */
 419                        if (size) {
 420                                ret = fiemap_fill_next_extent(fieinfo, logical,
 421                                                              phys, size,
 422                                                              flags);
 423                                if (ret)
 424                                        break;
 425                        }
 426
 427                        logical = blk_to_logical(inode, start_blk);
 428                        phys = blk_to_logical(inode, map_bh.b_blocknr);
 429                        size = map_bh.b_size;
 430                        flags = FIEMAP_EXTENT_MERGED;
 431
 432                        start_blk += logical_to_blk(inode, size);
 433
 434                        /*
 435                         * If we are past the EOF, then we need to make sure as
 436                         * soon as we find a hole that the last extent we found
 437                         * is marked with FIEMAP_EXTENT_LAST
 438                         */
 439                        if (!past_eof && logical + size >= isize)
 440                                past_eof = true;
 441                }
 442                cond_resched();
 443                if (fatal_signal_pending(current)) {
 444                        ret = -EINTR;
 445                        break;
 446                }
 447
 448        } while (1);
 449
 450        /* If ret is 1 then we just hit the end of the extent array */
 451        if (ret == 1)
 452                ret = 0;
 453
 454        return ret;
 455}
 456EXPORT_SYMBOL(__generic_block_fiemap);
 457
 458/**
 459 * generic_block_fiemap - FIEMAP for block based inodes
 460 * @inode: The inode to map
 461 * @fieinfo: The mapping information
 462 * @start: The initial block to map
 463 * @len: The length of the extect to attempt to map
 464 * @get_block: The block mapping function for the fs
 465 *
 466 * Calls __generic_block_fiemap to map the inode, after taking
 467 * the inode's mutex lock.
 468 */
 469
 470int generic_block_fiemap(struct inode *inode,
 471                         struct fiemap_extent_info *fieinfo, u64 start,
 472                         u64 len, get_block_t *get_block)
 473{
 474        int ret;
 475        inode_lock(inode);
 476        ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
 477        inode_unlock(inode);
 478        return ret;
 479}
 480EXPORT_SYMBOL(generic_block_fiemap);
 481
 482#endif  /*  CONFIG_BLOCK  */
 483
 484/*
 485 * This provides compatibility with legacy XFS pre-allocation ioctls
 486 * which predate the fallocate syscall.
 487 *
 488 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 489 * are used here, rest are ignored.
 490 */
 491static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
 492{
 493        struct inode *inode = file_inode(filp);
 494        struct space_resv sr;
 495
 496        if (copy_from_user(&sr, argp, sizeof(sr)))
 497                return -EFAULT;
 498
 499        switch (sr.l_whence) {
 500        case SEEK_SET:
 501                break;
 502        case SEEK_CUR:
 503                sr.l_start += filp->f_pos;
 504                break;
 505        case SEEK_END:
 506                sr.l_start += i_size_read(inode);
 507                break;
 508        default:
 509                return -EINVAL;
 510        }
 511
 512        return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
 513                        sr.l_len);
 514}
 515
 516/* on ia32 l_start is on a 32-bit boundary */
 517#if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
 518/* just account for different alignment */
 519static int compat_ioctl_preallocate(struct file *file, int mode,
 520                                    struct space_resv_32 __user *argp)
 521{
 522        struct inode *inode = file_inode(file);
 523        struct space_resv_32 sr;
 524
 525        if (copy_from_user(&sr, argp, sizeof(sr)))
 526                return -EFAULT;
 527
 528        switch (sr.l_whence) {
 529        case SEEK_SET:
 530                break;
 531        case SEEK_CUR:
 532                sr.l_start += file->f_pos;
 533                break;
 534        case SEEK_END:
 535                sr.l_start += i_size_read(inode);
 536                break;
 537        default:
 538                return -EINVAL;
 539        }
 540
 541        return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 542}
 543#endif
 544
 545static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
 546{
 547        switch (cmd) {
 548        case FIBMAP:
 549                return ioctl_fibmap(filp, p);
 550        case FS_IOC_RESVSP:
 551        case FS_IOC_RESVSP64:
 552                return ioctl_preallocate(filp, 0, p);
 553        case FS_IOC_UNRESVSP:
 554        case FS_IOC_UNRESVSP64:
 555                return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
 556        case FS_IOC_ZERO_RANGE:
 557                return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
 558        }
 559
 560        return -ENOIOCTLCMD;
 561}
 562
 563static int ioctl_fionbio(struct file *filp, int __user *argp)
 564{
 565        unsigned int flag;
 566        int on, error;
 567
 568        error = get_user(on, argp);
 569        if (error)
 570                return error;
 571        flag = O_NONBLOCK;
 572#ifdef __sparc__
 573        /* SunOS compatibility item. */
 574        if (O_NONBLOCK != O_NDELAY)
 575                flag |= O_NDELAY;
 576#endif
 577        spin_lock(&filp->f_lock);
 578        if (on)
 579                filp->f_flags |= flag;
 580        else
 581                filp->f_flags &= ~flag;
 582        spin_unlock(&filp->f_lock);
 583        return error;
 584}
 585
 586static int ioctl_fioasync(unsigned int fd, struct file *filp,
 587                          int __user *argp)
 588{
 589        unsigned int flag;
 590        int on, error;
 591
 592        error = get_user(on, argp);
 593        if (error)
 594                return error;
 595        flag = on ? FASYNC : 0;
 596
 597        /* Did FASYNC state change ? */
 598        if ((flag ^ filp->f_flags) & FASYNC) {
 599                if (filp->f_op->fasync)
 600                        /* fasync() adjusts filp->f_flags */
 601                        error = filp->f_op->fasync(fd, filp, on);
 602                else
 603                        error = -ENOTTY;
 604        }
 605        return error < 0 ? error : 0;
 606}
 607
 608static int ioctl_fsfreeze(struct file *filp)
 609{
 610        struct super_block *sb = file_inode(filp)->i_sb;
 611
 612        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 613                return -EPERM;
 614
 615        /* If filesystem doesn't support freeze feature, return. */
 616        if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 617                return -EOPNOTSUPP;
 618
 619        /* Freeze */
 620        if (sb->s_op->freeze_super)
 621                return sb->s_op->freeze_super(sb);
 622        return freeze_super(sb);
 623}
 624
 625static int ioctl_fsthaw(struct file *filp)
 626{
 627        struct super_block *sb = file_inode(filp)->i_sb;
 628
 629        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 630                return -EPERM;
 631
 632        /* Thaw */
 633        if (sb->s_op->thaw_super)
 634                return sb->s_op->thaw_super(sb);
 635        return thaw_super(sb);
 636}
 637
 638static int ioctl_file_dedupe_range(struct file *file,
 639                                   struct file_dedupe_range __user *argp)
 640{
 641        struct file_dedupe_range *same = NULL;
 642        int ret;
 643        unsigned long size;
 644        u16 count;
 645
 646        if (get_user(count, &argp->dest_count)) {
 647                ret = -EFAULT;
 648                goto out;
 649        }
 650
 651        size = offsetof(struct file_dedupe_range __user, info[count]);
 652        if (size > PAGE_SIZE) {
 653                ret = -ENOMEM;
 654                goto out;
 655        }
 656
 657        same = memdup_user(argp, size);
 658        if (IS_ERR(same)) {
 659                ret = PTR_ERR(same);
 660                same = NULL;
 661                goto out;
 662        }
 663
 664        same->dest_count = count;
 665        ret = vfs_dedupe_file_range(file, same);
 666        if (ret)
 667                goto out;
 668
 669        ret = copy_to_user(argp, same, size);
 670        if (ret)
 671                ret = -EFAULT;
 672
 673out:
 674        kfree(same);
 675        return ret;
 676}
 677
 678/*
 679 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 680 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 681 *
 682 * When you add any new common ioctls to the switches above and below,
 683 * please ensure they have compatible arguments in compat mode.
 684 */
 685static int do_vfs_ioctl(struct file *filp, unsigned int fd,
 686                        unsigned int cmd, unsigned long arg)
 687{
 688        void __user *argp = (void __user *)arg;
 689        struct inode *inode = file_inode(filp);
 690
 691        switch (cmd) {
 692        case FIOCLEX:
 693                set_close_on_exec(fd, 1);
 694                return 0;
 695
 696        case FIONCLEX:
 697                set_close_on_exec(fd, 0);
 698                return 0;
 699
 700        case FIONBIO:
 701                return ioctl_fionbio(filp, argp);
 702
 703        case FIOASYNC:
 704                return ioctl_fioasync(fd, filp, argp);
 705
 706        case FIOQSIZE:
 707                if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 708                    S_ISLNK(inode->i_mode)) {
 709                        loff_t res = inode_get_bytes(inode);
 710                        return copy_to_user(argp, &res, sizeof(res)) ?
 711                                            -EFAULT : 0;
 712                }
 713
 714                return -ENOTTY;
 715
 716        case FIFREEZE:
 717                return ioctl_fsfreeze(filp);
 718
 719        case FITHAW:
 720                return ioctl_fsthaw(filp);
 721
 722        case FS_IOC_FIEMAP:
 723                return ioctl_fiemap(filp, argp);
 724
 725        case FIGETBSZ:
 726                /* anon_bdev filesystems may not have a block size */
 727                if (!inode->i_sb->s_blocksize)
 728                        return -EINVAL;
 729
 730                return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
 731
 732        case FICLONE:
 733                return ioctl_file_clone(filp, arg, 0, 0, 0);
 734
 735        case FICLONERANGE:
 736                return ioctl_file_clone_range(filp, argp);
 737
 738        case FIDEDUPERANGE:
 739                return ioctl_file_dedupe_range(filp, argp);
 740
 741        case FIONREAD:
 742                if (!S_ISREG(inode->i_mode))
 743                        return vfs_ioctl(filp, cmd, arg);
 744
 745                return put_user(i_size_read(inode) - filp->f_pos,
 746                                (int __user *)argp);
 747
 748        default:
 749                if (S_ISREG(inode->i_mode))
 750                        return file_ioctl(filp, cmd, argp);
 751                break;
 752        }
 753
 754        return -ENOIOCTLCMD;
 755}
 756
 757int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
 758{
 759        struct fd f = fdget(fd);
 760        int error;
 761
 762        if (!f.file)
 763                return -EBADF;
 764
 765        error = security_file_ioctl(f.file, cmd, arg);
 766        if (error)
 767                goto out;
 768
 769        error = do_vfs_ioctl(f.file, fd, cmd, arg);
 770        if (error == -ENOIOCTLCMD)
 771                error = vfs_ioctl(f.file, cmd, arg);
 772
 773out:
 774        fdput(f);
 775        return error;
 776}
 777
 778SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 779{
 780        return ksys_ioctl(fd, cmd, arg);
 781}
 782
 783#ifdef CONFIG_COMPAT
 784/**
 785 * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 786 *
 787 * This is not normally called as a function, but instead set in struct
 788 * file_operations as
 789 *
 790 *     .compat_ioctl = compat_ptr_ioctl,
 791 *
 792 * On most architectures, the compat_ptr_ioctl() just passes all arguments
 793 * to the corresponding ->ioctl handler. The exception is arch/s390, where
 794 * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
 795 * pointers to the second 2GB alias the first 2GB, as is the case for
 796 * native 32-bit s390 user space.
 797 *
 798 * The compat_ptr_ioctl() function must therefore be used only with ioctl
 799 * functions that either ignore the argument or pass a pointer to a
 800 * compatible data type.
 801 *
 802 * If any ioctl command handled by fops->unlocked_ioctl passes a plain
 803 * integer instead of a pointer, or any of the passed data types
 804 * is incompatible between 32-bit and 64-bit architectures, a proper
 805 * handler is required instead of compat_ptr_ioctl.
 806 */
 807long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 808{
 809        if (!file->f_op->unlocked_ioctl)
 810                return -ENOIOCTLCMD;
 811
 812        return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 813}
 814EXPORT_SYMBOL(compat_ptr_ioctl);
 815
 816COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 817                       compat_ulong_t, arg)
 818{
 819        struct fd f = fdget(fd);
 820        int error;
 821
 822        if (!f.file)
 823                return -EBADF;
 824
 825        /* RED-PEN how should LSM module know it's handling 32bit? */
 826        error = security_file_ioctl(f.file, cmd, arg);
 827        if (error)
 828                goto out;
 829
 830        switch (cmd) {
 831        /* FICLONE takes an int argument, so don't use compat_ptr() */
 832        case FICLONE:
 833                error = ioctl_file_clone(f.file, arg, 0, 0, 0);
 834                break;
 835
 836#if defined(CONFIG_X86_64)
 837        /* these get messy on amd64 due to alignment differences */
 838        case FS_IOC_RESVSP_32:
 839        case FS_IOC_RESVSP64_32:
 840                error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
 841                break;
 842        case FS_IOC_UNRESVSP_32:
 843        case FS_IOC_UNRESVSP64_32:
 844                error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
 845                                compat_ptr(arg));
 846                break;
 847        case FS_IOC_ZERO_RANGE_32:
 848                error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
 849                                compat_ptr(arg));
 850                break;
 851#endif
 852
 853        /*
 854         * everything else in do_vfs_ioctl() takes either a compatible
 855         * pointer argument or no argument -- call it with a modified
 856         * argument.
 857         */
 858        default:
 859                error = do_vfs_ioctl(f.file, fd, cmd,
 860                                     (unsigned long)compat_ptr(arg));
 861                if (error != -ENOIOCTLCMD)
 862                        break;
 863
 864                if (f.file->f_op->compat_ioctl)
 865                        error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
 866                if (error == -ENOIOCTLCMD)
 867                        error = -ENOTTY;
 868                break;
 869        }
 870
 871 out:
 872        fdput(f);
 873
 874        return error;
 875}
 876#endif
 877