1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/syscalls.h>
10 #include <linux/capability.h>
11 #include <linux/compat.h>
12 #include <linux/file.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 #include <linux/fiemap.h>
22 #include <linux/mount.h>
23 #include <linux/fscrypt.h>
24 #include <linux/fileattr.h>
28 #include <asm/ioctls.h>
30 /* So that the fiemap access checks can't overflow on 32 bit machines. */
31 #define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
34 * vfs_ioctl - call filesystem specific ioctl methods
35 * @filp: open file to invoke ioctl method on
36 * @cmd: ioctl command to execute
37 * @arg: command-specific argument for ioctl
39 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
42 * Returns 0 on success, -errno on error.
44 long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
48 if (!filp->f_op->unlocked_ioctl)
51 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
52 if (error == -ENOIOCTLCMD)
57 EXPORT_SYMBOL(vfs_ioctl);
59 static int ioctl_fibmap(struct file *filp, int __user *p)
61 struct inode *inode = file_inode(filp);
62 struct super_block *sb = inode->i_sb;
66 if (!capable(CAP_SYS_RAWIO))
69 error = get_user(ur_block, p);
77 error = bmap(inode, &block);
79 if (block > INT_MAX) {
81 pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
82 current->comm, task_pid_nr(current),
91 if (put_user(ur_block, p))
98 * fiemap_fill_next_extent - Fiemap helper function
99 * @fieinfo: Fiemap context passed into ->fiemap
100 * @logical: Extent logical start offset, in bytes
101 * @phys: Extent physical start offset, in bytes
102 * @len: Extent length, in bytes
103 * @flags: FIEMAP_EXTENT flags that describe this extent
105 * Called from file system ->fiemap callback. Will populate extent
106 * info as passed in via arguments and copy to user memory. On
107 * success, extent count on fieinfo is incremented.
109 * Returns 0 on success, -errno on error, 1 if this was the last
110 * extent that will fit in user array.
112 int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
113 u64 phys, u64 len, u32 flags)
115 struct fiemap_extent extent;
116 struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
118 /* only count the extents */
119 if (fieinfo->fi_extents_max == 0) {
120 fieinfo->fi_extents_mapped++;
121 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
124 if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
127 #define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
128 #define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED)
129 #define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
131 if (flags & SET_UNKNOWN_FLAGS)
132 flags |= FIEMAP_EXTENT_UNKNOWN;
133 if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
134 flags |= FIEMAP_EXTENT_ENCODED;
135 if (flags & SET_NOT_ALIGNED_FLAGS)
136 flags |= FIEMAP_EXTENT_NOT_ALIGNED;
138 memset(&extent, 0, sizeof(extent));
139 extent.fe_logical = logical;
140 extent.fe_physical = phys;
141 extent.fe_length = len;
142 extent.fe_flags = flags;
144 dest += fieinfo->fi_extents_mapped;
145 if (copy_to_user(dest, &extent, sizeof(extent)))
148 fieinfo->fi_extents_mapped++;
149 if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
151 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
153 EXPORT_SYMBOL(fiemap_fill_next_extent);
156 * fiemap_prep - check validity of requested flags for fiemap
157 * @inode: Inode to operate on
158 * @fieinfo: Fiemap context passed into ->fiemap
159 * @start: Start of the mapped range
160 * @len: Length of the mapped range, can be truncated by this function.
161 * @supported_flags: Set of fiemap flags that the file system understands
163 * This function must be called from each ->fiemap instance to validate the
164 * fiemap request against the file system parameters.
166 * Returns 0 on success, or a negative error on failure.
168 int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
169 u64 start, u64 *len, u32 supported_flags)
171 u64 maxbytes = inode->i_sb->s_maxbytes;
177 if (start >= maxbytes)
181 * Shrink request scope to what the fs can actually handle.
183 if (*len > maxbytes || (maxbytes - *len) < start)
184 *len = maxbytes - start;
186 supported_flags |= FIEMAP_FLAG_SYNC;
187 supported_flags &= FIEMAP_FLAGS_COMPAT;
188 incompat_flags = fieinfo->fi_flags & ~supported_flags;
189 if (incompat_flags) {
190 fieinfo->fi_flags = incompat_flags;
194 if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
195 ret = filemap_write_and_wait(inode->i_mapping);
198 EXPORT_SYMBOL(fiemap_prep);
200 static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
202 struct fiemap fiemap;
203 struct fiemap_extent_info fieinfo = { 0, };
204 struct inode *inode = file_inode(filp);
207 if (!inode->i_op->fiemap)
210 if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
213 if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
216 fieinfo.fi_flags = fiemap.fm_flags;
217 fieinfo.fi_extents_max = fiemap.fm_extent_count;
218 fieinfo.fi_extents_start = ufiemap->fm_extents;
220 error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
223 fiemap.fm_flags = fieinfo.fi_flags;
224 fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
225 if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
231 static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
232 u64 off, u64 olen, u64 destoff)
234 struct fd src_file = fdget(srcfd);
240 cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
244 else if (olen && cloned != olen)
252 static long ioctl_file_clone_range(struct file *file,
253 struct file_clone_range __user *argp)
255 struct file_clone_range args;
257 if (copy_from_user(&args, argp, sizeof(args)))
259 return ioctl_file_clone(file, args.src_fd, args.src_offset,
260 args.src_length, args.dest_offset);
264 * This provides compatibility with legacy XFS pre-allocation ioctls
265 * which predate the fallocate syscall.
267 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
268 * are used here, rest are ignored.
270 static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
272 struct inode *inode = file_inode(filp);
273 struct space_resv sr;
275 if (copy_from_user(&sr, argp, sizeof(sr)))
278 switch (sr.l_whence) {
282 sr.l_start += filp->f_pos;
285 sr.l_start += i_size_read(inode);
291 return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
295 /* on ia32 l_start is on a 32-bit boundary */
296 #if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
297 /* just account for different alignment */
298 static int compat_ioctl_preallocate(struct file *file, int mode,
299 struct space_resv_32 __user *argp)
301 struct inode *inode = file_inode(file);
302 struct space_resv_32 sr;
304 if (copy_from_user(&sr, argp, sizeof(sr)))
307 switch (sr.l_whence) {
311 sr.l_start += file->f_pos;
314 sr.l_start += i_size_read(inode);
320 return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
324 static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
328 return ioctl_fibmap(filp, p);
330 case FS_IOC_RESVSP64:
331 return ioctl_preallocate(filp, 0, p);
332 case FS_IOC_UNRESVSP:
333 case FS_IOC_UNRESVSP64:
334 return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
335 case FS_IOC_ZERO_RANGE:
336 return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
342 static int ioctl_fionbio(struct file *filp, int __user *argp)
347 error = get_user(on, argp);
352 /* SunOS compatibility item. */
353 if (O_NONBLOCK != O_NDELAY)
356 spin_lock(&filp->f_lock);
358 filp->f_flags |= flag;
360 filp->f_flags &= ~flag;
361 spin_unlock(&filp->f_lock);
365 static int ioctl_fioasync(unsigned int fd, struct file *filp,
371 error = get_user(on, argp);
374 flag = on ? FASYNC : 0;
376 /* Did FASYNC state change ? */
377 if ((flag ^ filp->f_flags) & FASYNC) {
378 if (filp->f_op->fasync)
379 /* fasync() adjusts filp->f_flags */
380 error = filp->f_op->fasync(fd, filp, on);
384 return error < 0 ? error : 0;
387 static int ioctl_fsfreeze(struct file *filp)
389 struct super_block *sb = file_inode(filp)->i_sb;
391 if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
394 /* If filesystem doesn't support freeze feature, return. */
395 if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
399 if (sb->s_op->freeze_super)
400 return sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE);
401 return freeze_super(sb, FREEZE_HOLDER_USERSPACE);
404 static int ioctl_fsthaw(struct file *filp)
406 struct super_block *sb = file_inode(filp)->i_sb;
408 if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
412 if (sb->s_op->thaw_super)
413 return sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE);
414 return thaw_super(sb, FREEZE_HOLDER_USERSPACE);
417 static int ioctl_file_dedupe_range(struct file *file,
418 struct file_dedupe_range __user *argp)
420 struct file_dedupe_range *same = NULL;
425 if (get_user(count, &argp->dest_count)) {
430 size = offsetof(struct file_dedupe_range, info[count]);
431 if (size > PAGE_SIZE) {
436 same = memdup_user(argp, size);
443 same->dest_count = count;
444 ret = vfs_dedupe_file_range(file, same);
448 ret = copy_to_user(argp, same, size);
458 * fileattr_fill_xflags - initialize fileattr with xflags
459 * @fa: fileattr pointer
460 * @xflags: FS_XFLAG_* flags
462 * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). All
463 * other fields are zeroed.
465 void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
467 memset(fa, 0, sizeof(*fa));
468 fa->fsx_valid = true;
469 fa->fsx_xflags = xflags;
470 if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)
471 fa->flags |= FS_IMMUTABLE_FL;
472 if (fa->fsx_xflags & FS_XFLAG_APPEND)
473 fa->flags |= FS_APPEND_FL;
474 if (fa->fsx_xflags & FS_XFLAG_SYNC)
475 fa->flags |= FS_SYNC_FL;
476 if (fa->fsx_xflags & FS_XFLAG_NOATIME)
477 fa->flags |= FS_NOATIME_FL;
478 if (fa->fsx_xflags & FS_XFLAG_NODUMP)
479 fa->flags |= FS_NODUMP_FL;
480 if (fa->fsx_xflags & FS_XFLAG_DAX)
481 fa->flags |= FS_DAX_FL;
482 if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
483 fa->flags |= FS_PROJINHERIT_FL;
485 EXPORT_SYMBOL(fileattr_fill_xflags);
488 * fileattr_fill_flags - initialize fileattr with flags
489 * @fa: fileattr pointer
490 * @flags: FS_*_FL flags
492 * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags).
493 * All other fields are zeroed.
495 void fileattr_fill_flags(struct fileattr *fa, u32 flags)
497 memset(fa, 0, sizeof(*fa));
498 fa->flags_valid = true;
500 if (fa->flags & FS_SYNC_FL)
501 fa->fsx_xflags |= FS_XFLAG_SYNC;
502 if (fa->flags & FS_IMMUTABLE_FL)
503 fa->fsx_xflags |= FS_XFLAG_IMMUTABLE;
504 if (fa->flags & FS_APPEND_FL)
505 fa->fsx_xflags |= FS_XFLAG_APPEND;
506 if (fa->flags & FS_NODUMP_FL)
507 fa->fsx_xflags |= FS_XFLAG_NODUMP;
508 if (fa->flags & FS_NOATIME_FL)
509 fa->fsx_xflags |= FS_XFLAG_NOATIME;
510 if (fa->flags & FS_DAX_FL)
511 fa->fsx_xflags |= FS_XFLAG_DAX;
512 if (fa->flags & FS_PROJINHERIT_FL)
513 fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
515 EXPORT_SYMBOL(fileattr_fill_flags);
518 * vfs_fileattr_get - retrieve miscellaneous file attributes
519 * @dentry: the object to retrieve from
520 * @fa: fileattr pointer
522 * Call i_op->fileattr_get() callback, if exists.
524 * Return: 0 on success, or a negative error on failure.
526 int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
528 struct inode *inode = d_inode(dentry);
530 if (!inode->i_op->fileattr_get)
533 return inode->i_op->fileattr_get(dentry, fa);
535 EXPORT_SYMBOL(vfs_fileattr_get);
538 * copy_fsxattr_to_user - copy fsxattr to userspace.
539 * @fa: fileattr pointer
540 * @ufa: fsxattr user pointer
542 * Return: 0 on success, or -EFAULT on failure.
544 int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa)
548 memset(&xfa, 0, sizeof(xfa));
549 xfa.fsx_xflags = fa->fsx_xflags;
550 xfa.fsx_extsize = fa->fsx_extsize;
551 xfa.fsx_nextents = fa->fsx_nextents;
552 xfa.fsx_projid = fa->fsx_projid;
553 xfa.fsx_cowextsize = fa->fsx_cowextsize;
555 if (copy_to_user(ufa, &xfa, sizeof(xfa)))
560 EXPORT_SYMBOL(copy_fsxattr_to_user);
562 static int copy_fsxattr_from_user(struct fileattr *fa,
563 struct fsxattr __user *ufa)
567 if (copy_from_user(&xfa, ufa, sizeof(xfa)))
570 fileattr_fill_xflags(fa, xfa.fsx_xflags);
571 fa->fsx_extsize = xfa.fsx_extsize;
572 fa->fsx_nextents = xfa.fsx_nextents;
573 fa->fsx_projid = xfa.fsx_projid;
574 fa->fsx_cowextsize = xfa.fsx_cowextsize;
580 * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject
581 * any invalid configurations.
583 * Note: must be called with inode lock held.
585 static int fileattr_set_prepare(struct inode *inode,
586 const struct fileattr *old_ma,
592 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
593 * the relevant capability.
595 if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
596 !capable(CAP_LINUX_IMMUTABLE))
599 err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags);
604 * Project Quota ID state is only allowed to change from within the init
605 * namespace. Enforce that restriction only if we are trying to change
606 * the quota ID state. Everything else is allowed in user namespaces.
608 if (current_user_ns() != &init_user_ns) {
609 if (old_ma->fsx_projid != fa->fsx_projid)
611 if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
612 FS_XFLAG_PROJINHERIT)
616 * Caller is allowed to change the project ID. If it is being
617 * changed, make sure that the new value is valid.
619 if (old_ma->fsx_projid != fa->fsx_projid &&
620 !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
624 /* Check extent size hints. */
625 if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
628 if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
629 !S_ISDIR(inode->i_mode))
632 if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
633 !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
637 * It is only valid to set the DAX flag on regular files and
638 * directories on filesystems.
640 if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
641 !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
644 /* Extent size hints of zero turn off the flags. */
645 if (fa->fsx_extsize == 0)
646 fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
647 if (fa->fsx_cowextsize == 0)
648 fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
654 * vfs_fileattr_set - change miscellaneous file attributes
655 * @idmap: idmap of the mount
656 * @dentry: the object to change
657 * @fa: fileattr pointer
659 * After verifying permissions, call i_op->fileattr_set() callback, if
662 * Verifying attributes involves retrieving current attributes with
663 * i_op->fileattr_get(), this also allows initializing attributes that have
664 * not been set by the caller to current values. Inode lock is held
665 * thoughout to prevent racing with another instance.
667 * Return: 0 on success, or a negative error on failure.
669 int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
672 struct inode *inode = d_inode(dentry);
673 struct fileattr old_ma = {};
676 if (!inode->i_op->fileattr_set)
679 if (!inode_owner_or_capable(idmap, inode))
683 err = vfs_fileattr_get(dentry, &old_ma);
685 /* initialize missing bits from old_ma */
686 if (fa->flags_valid) {
687 fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON;
688 fa->fsx_extsize = old_ma.fsx_extsize;
689 fa->fsx_nextents = old_ma.fsx_nextents;
690 fa->fsx_projid = old_ma.fsx_projid;
691 fa->fsx_cowextsize = old_ma.fsx_cowextsize;
693 fa->flags |= old_ma.flags & ~FS_COMMON_FL;
695 err = fileattr_set_prepare(inode, &old_ma, fa);
697 err = inode->i_op->fileattr_set(idmap, dentry, fa);
703 EXPORT_SYMBOL(vfs_fileattr_set);
705 static int ioctl_getflags(struct file *file, unsigned int __user *argp)
707 struct fileattr fa = { .flags_valid = true }; /* hint only */
710 err = vfs_fileattr_get(file->f_path.dentry, &fa);
712 err = put_user(fa.flags, argp);
716 static int ioctl_setflags(struct file *file, unsigned int __user *argp)
718 struct mnt_idmap *idmap = file_mnt_idmap(file);
719 struct dentry *dentry = file->f_path.dentry;
724 err = get_user(flags, argp);
726 err = mnt_want_write_file(file);
728 fileattr_fill_flags(&fa, flags);
729 err = vfs_fileattr_set(idmap, dentry, &fa);
730 mnt_drop_write_file(file);
736 static int ioctl_fsgetxattr(struct file *file, void __user *argp)
738 struct fileattr fa = { .fsx_valid = true }; /* hint only */
741 err = vfs_fileattr_get(file->f_path.dentry, &fa);
743 err = copy_fsxattr_to_user(&fa, argp);
748 static int ioctl_fssetxattr(struct file *file, void __user *argp)
750 struct mnt_idmap *idmap = file_mnt_idmap(file);
751 struct dentry *dentry = file->f_path.dentry;
755 err = copy_fsxattr_from_user(&fa, argp);
757 err = mnt_want_write_file(file);
759 err = vfs_fileattr_set(idmap, dentry, &fa);
760 mnt_drop_write_file(file);
767 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
768 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
770 * When you add any new common ioctls to the switches above and below,
771 * please ensure they have compatible arguments in compat mode.
773 static int do_vfs_ioctl(struct file *filp, unsigned int fd,
774 unsigned int cmd, unsigned long arg)
776 void __user *argp = (void __user *)arg;
777 struct inode *inode = file_inode(filp);
781 set_close_on_exec(fd, 1);
785 set_close_on_exec(fd, 0);
789 return ioctl_fionbio(filp, argp);
792 return ioctl_fioasync(fd, filp, argp);
795 if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
796 S_ISLNK(inode->i_mode)) {
797 loff_t res = inode_get_bytes(inode);
798 return copy_to_user(argp, &res, sizeof(res)) ?
805 return ioctl_fsfreeze(filp);
808 return ioctl_fsthaw(filp);
811 return ioctl_fiemap(filp, argp);
814 /* anon_bdev filesystems may not have a block size */
815 if (!inode->i_sb->s_blocksize)
818 return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
821 return ioctl_file_clone(filp, arg, 0, 0, 0);
824 return ioctl_file_clone_range(filp, argp);
827 return ioctl_file_dedupe_range(filp, argp);
830 if (!S_ISREG(inode->i_mode))
831 return vfs_ioctl(filp, cmd, arg);
833 return put_user(i_size_read(inode) - filp->f_pos,
836 case FS_IOC_GETFLAGS:
837 return ioctl_getflags(filp, argp);
839 case FS_IOC_SETFLAGS:
840 return ioctl_setflags(filp, argp);
842 case FS_IOC_FSGETXATTR:
843 return ioctl_fsgetxattr(filp, argp);
845 case FS_IOC_FSSETXATTR:
846 return ioctl_fssetxattr(filp, argp);
849 if (S_ISREG(inode->i_mode))
850 return file_ioctl(filp, cmd, argp);
857 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
859 struct fd f = fdget(fd);
865 error = security_file_ioctl(f.file, cmd, arg);
869 error = do_vfs_ioctl(f.file, fd, cmd, arg);
870 if (error == -ENOIOCTLCMD)
871 error = vfs_ioctl(f.file, cmd, arg);
880 * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
881 * @file: The file to operate on.
882 * @cmd: The ioctl command number.
883 * @arg: The argument to the ioctl.
885 * This is not normally called as a function, but instead set in struct
888 * .compat_ioctl = compat_ptr_ioctl,
890 * On most architectures, the compat_ptr_ioctl() just passes all arguments
891 * to the corresponding ->ioctl handler. The exception is arch/s390, where
892 * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
893 * pointers to the second 2GB alias the first 2GB, as is the case for
894 * native 32-bit s390 user space.
896 * The compat_ptr_ioctl() function must therefore be used only with ioctl
897 * functions that either ignore the argument or pass a pointer to a
898 * compatible data type.
900 * If any ioctl command handled by fops->unlocked_ioctl passes a plain
901 * integer instead of a pointer, or any of the passed data types
902 * is incompatible between 32-bit and 64-bit architectures, a proper
903 * handler is required instead of compat_ptr_ioctl.
905 long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
907 if (!file->f_op->unlocked_ioctl)
910 return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
912 EXPORT_SYMBOL(compat_ptr_ioctl);
914 COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
917 struct fd f = fdget(fd);
923 /* RED-PEN how should LSM module know it's handling 32bit? */
924 error = security_file_ioctl(f.file, cmd, arg);
929 /* FICLONE takes an int argument, so don't use compat_ptr() */
931 error = ioctl_file_clone(f.file, arg, 0, 0, 0);
934 #if defined(CONFIG_X86_64)
935 /* these get messy on amd64 due to alignment differences */
936 case FS_IOC_RESVSP_32:
937 case FS_IOC_RESVSP64_32:
938 error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
940 case FS_IOC_UNRESVSP_32:
941 case FS_IOC_UNRESVSP64_32:
942 error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
945 case FS_IOC_ZERO_RANGE_32:
946 error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
952 * These access 32-bit values anyway so no further handling is
955 case FS_IOC32_GETFLAGS:
956 case FS_IOC32_SETFLAGS:
957 cmd = (cmd == FS_IOC32_GETFLAGS) ?
958 FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
961 * everything else in do_vfs_ioctl() takes either a compatible
962 * pointer argument or no argument -- call it with a modified
966 error = do_vfs_ioctl(f.file, fd, cmd,
967 (unsigned long)compat_ptr(arg));
968 if (error != -ENOIOCTLCMD)
971 if (f.file->f_op->compat_ioctl)
972 error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
973 if (error == -ENOIOCTLCMD)