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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/blkdev.h>
9#include <linux/export.h>
10#include <linux/mm.h>
11#include <linux/errno.h>
12#include <linux/file.h>
13#include <linux/highuid.h>
14#include <linux/fs.h>
15#include <linux/namei.h>
16#include <linux/security.h>
17#include <linux/cred.h>
18#include <linux/syscalls.h>
19#include <linux/pagemap.h>
20#include <linux/compat.h>
21#include <linux/iversion.h>
22
23#include <linux/uaccess.h>
24#include <asm/unistd.h>
25
26#include "internal.h"
27#include "mount.h"
28
29/**
30 * generic_fillattr - Fill in the basic attributes from the inode struct
31 * @idmap: idmap of the mount the inode was found from
32 * @request_mask: statx request_mask
33 * @inode: Inode to use as the source
34 * @stat: Where to fill in the attributes
35 *
36 * Fill in the basic attributes in the kstat structure from data that's to be
37 * found on the VFS inode structure. This is the default if no getattr inode
38 * operation is supplied.
39 *
40 * If the inode has been found through an idmapped mount the idmap of
41 * the vfsmount must be passed through @idmap. This function will then
42 * take care to map the inode according to @idmap before filling in the
43 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
44 * performed on the raw inode simply pass @nop_mnt_idmap.
45 */
46void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
47 struct inode *inode, struct kstat *stat)
48{
49 vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
50 vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
51
52 stat->dev = inode->i_sb->s_dev;
53 stat->ino = inode->i_ino;
54 stat->mode = inode->i_mode;
55 stat->nlink = inode->i_nlink;
56 stat->uid = vfsuid_into_kuid(vfsuid);
57 stat->gid = vfsgid_into_kgid(vfsgid);
58 stat->rdev = inode->i_rdev;
59 stat->size = i_size_read(inode);
60 stat->atime = inode_get_atime(inode);
61 stat->mtime = inode_get_mtime(inode);
62 stat->ctime = inode_get_ctime(inode);
63 stat->blksize = i_blocksize(inode);
64 stat->blocks = inode->i_blocks;
65
66 if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
67 stat->result_mask |= STATX_CHANGE_COOKIE;
68 stat->change_cookie = inode_query_iversion(inode);
69 }
70
71}
72EXPORT_SYMBOL(generic_fillattr);
73
74/**
75 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
76 * @inode: Inode to use as the source
77 * @stat: Where to fill in the attribute flags
78 *
79 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
80 * inode that are published on i_flags and enforced by the VFS.
81 */
82void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
83{
84 if (inode->i_flags & S_IMMUTABLE)
85 stat->attributes |= STATX_ATTR_IMMUTABLE;
86 if (inode->i_flags & S_APPEND)
87 stat->attributes |= STATX_ATTR_APPEND;
88 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
89}
90EXPORT_SYMBOL(generic_fill_statx_attr);
91
92/**
93 * vfs_getattr_nosec - getattr without security checks
94 * @path: file to get attributes from
95 * @stat: structure to return attributes in
96 * @request_mask: STATX_xxx flags indicating what the caller wants
97 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
98 *
99 * Get attributes without calling security_inode_getattr.
100 *
101 * Currently the only caller other than vfs_getattr is internal to the
102 * filehandle lookup code, which uses only the inode number and returns no
103 * attributes to any user. Any other code probably wants vfs_getattr.
104 */
105int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
106 u32 request_mask, unsigned int query_flags)
107{
108 struct mnt_idmap *idmap;
109 struct inode *inode = d_backing_inode(path->dentry);
110
111 memset(stat, 0, sizeof(*stat));
112 stat->result_mask |= STATX_BASIC_STATS;
113 query_flags &= AT_STATX_SYNC_TYPE;
114
115 /* allow the fs to override these if it really wants to */
116 /* SB_NOATIME means filesystem supplies dummy atime value */
117 if (inode->i_sb->s_flags & SB_NOATIME)
118 stat->result_mask &= ~STATX_ATIME;
119
120 /*
121 * Note: If you add another clause to set an attribute flag, please
122 * update attributes_mask below.
123 */
124 if (IS_AUTOMOUNT(inode))
125 stat->attributes |= STATX_ATTR_AUTOMOUNT;
126
127 if (IS_DAX(inode))
128 stat->attributes |= STATX_ATTR_DAX;
129
130 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
131 STATX_ATTR_DAX);
132
133 idmap = mnt_idmap(path->mnt);
134 if (inode->i_op->getattr)
135 return inode->i_op->getattr(idmap, path, stat,
136 request_mask,
137 query_flags | AT_GETATTR_NOSEC);
138
139 generic_fillattr(idmap, request_mask, inode, stat);
140 return 0;
141}
142EXPORT_SYMBOL(vfs_getattr_nosec);
143
144/*
145 * vfs_getattr - Get the enhanced basic attributes of a file
146 * @path: The file of interest
147 * @stat: Where to return the statistics
148 * @request_mask: STATX_xxx flags indicating what the caller wants
149 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
150 *
151 * Ask the filesystem for a file's attributes. The caller must indicate in
152 * request_mask and query_flags to indicate what they want.
153 *
154 * If the file is remote, the filesystem can be forced to update the attributes
155 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
156 * suppress the update by passing AT_STATX_DONT_SYNC.
157 *
158 * Bits must have been set in request_mask to indicate which attributes the
159 * caller wants retrieving. Any such attribute not requested may be returned
160 * anyway, but the value may be approximate, and, if remote, may not have been
161 * synchronised with the server.
162 *
163 * 0 will be returned on success, and a -ve error code if unsuccessful.
164 */
165int vfs_getattr(const struct path *path, struct kstat *stat,
166 u32 request_mask, unsigned int query_flags)
167{
168 int retval;
169
170 if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))
171 return -EPERM;
172
173 retval = security_inode_getattr(path);
174 if (retval)
175 return retval;
176 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
177}
178EXPORT_SYMBOL(vfs_getattr);
179
180/**
181 * vfs_fstat - Get the basic attributes by file descriptor
182 * @fd: The file descriptor referring to the file of interest
183 * @stat: The result structure to fill in.
184 *
185 * This function is a wrapper around vfs_getattr(). The main difference is
186 * that it uses a file descriptor to determine the file location.
187 *
188 * 0 will be returned on success, and a -ve error code if unsuccessful.
189 */
190int vfs_fstat(int fd, struct kstat *stat)
191{
192 struct fd f;
193 int error;
194
195 f = fdget_raw(fd);
196 if (!f.file)
197 return -EBADF;
198 error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
199 fdput(f);
200 return error;
201}
202
203int getname_statx_lookup_flags(int flags)
204{
205 int lookup_flags = 0;
206
207 if (!(flags & AT_SYMLINK_NOFOLLOW))
208 lookup_flags |= LOOKUP_FOLLOW;
209 if (!(flags & AT_NO_AUTOMOUNT))
210 lookup_flags |= LOOKUP_AUTOMOUNT;
211 if (flags & AT_EMPTY_PATH)
212 lookup_flags |= LOOKUP_EMPTY;
213
214 return lookup_flags;
215}
216
217/**
218 * vfs_statx - Get basic and extra attributes by filename
219 * @dfd: A file descriptor representing the base dir for a relative filename
220 * @filename: The name of the file of interest
221 * @flags: Flags to control the query
222 * @stat: The result structure to fill in.
223 * @request_mask: STATX_xxx flags indicating what the caller wants
224 *
225 * This function is a wrapper around vfs_getattr(). The main difference is
226 * that it uses a filename and base directory to determine the file location.
227 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
228 * at the given name from being referenced.
229 *
230 * 0 will be returned on success, and a -ve error code if unsuccessful.
231 */
232static int vfs_statx(int dfd, struct filename *filename, int flags,
233 struct kstat *stat, u32 request_mask)
234{
235 struct path path;
236 unsigned int lookup_flags = getname_statx_lookup_flags(flags);
237 int error;
238
239 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
240 AT_STATX_SYNC_TYPE))
241 return -EINVAL;
242
243retry:
244 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
245 if (error)
246 goto out;
247
248 error = vfs_getattr(&path, stat, request_mask, flags);
249
250 if (request_mask & STATX_MNT_ID_UNIQUE) {
251 stat->mnt_id = real_mount(path.mnt)->mnt_id_unique;
252 stat->result_mask |= STATX_MNT_ID_UNIQUE;
253 } else {
254 stat->mnt_id = real_mount(path.mnt)->mnt_id;
255 stat->result_mask |= STATX_MNT_ID;
256 }
257
258 if (path.mnt->mnt_root == path.dentry)
259 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
260 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
261
262 /* Handle STATX_DIOALIGN for block devices. */
263 if (request_mask & STATX_DIOALIGN) {
264 struct inode *inode = d_backing_inode(path.dentry);
265
266 if (S_ISBLK(inode->i_mode))
267 bdev_statx_dioalign(inode, stat);
268 }
269
270 path_put(&path);
271 if (retry_estale(error, lookup_flags)) {
272 lookup_flags |= LOOKUP_REVAL;
273 goto retry;
274 }
275out:
276 return error;
277}
278
279int vfs_fstatat(int dfd, const char __user *filename,
280 struct kstat *stat, int flags)
281{
282 int ret;
283 int statx_flags = flags | AT_NO_AUTOMOUNT;
284 struct filename *name;
285
286 /*
287 * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH)
288 *
289 * If AT_EMPTY_PATH is set, we expect the common case to be that
290 * empty path, and avoid doing all the extra pathname work.
291 */
292 if (dfd >= 0 && flags == AT_EMPTY_PATH) {
293 char c;
294
295 ret = get_user(c, filename);
296 if (unlikely(ret))
297 return ret;
298
299 if (likely(!c))
300 return vfs_fstat(dfd, stat);
301 }
302
303 name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);
304 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
305 putname(name);
306
307 return ret;
308}
309
310#ifdef __ARCH_WANT_OLD_STAT
311
312/*
313 * For backward compatibility? Maybe this should be moved
314 * into arch/i386 instead?
315 */
316static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
317{
318 static int warncount = 5;
319 struct __old_kernel_stat tmp;
320
321 if (warncount > 0) {
322 warncount--;
323 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
324 current->comm);
325 } else if (warncount < 0) {
326 /* it's laughable, but... */
327 warncount = 0;
328 }
329
330 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
331 tmp.st_dev = old_encode_dev(stat->dev);
332 tmp.st_ino = stat->ino;
333 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
334 return -EOVERFLOW;
335 tmp.st_mode = stat->mode;
336 tmp.st_nlink = stat->nlink;
337 if (tmp.st_nlink != stat->nlink)
338 return -EOVERFLOW;
339 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
340 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
341 tmp.st_rdev = old_encode_dev(stat->rdev);
342#if BITS_PER_LONG == 32
343 if (stat->size > MAX_NON_LFS)
344 return -EOVERFLOW;
345#endif
346 tmp.st_size = stat->size;
347 tmp.st_atime = stat->atime.tv_sec;
348 tmp.st_mtime = stat->mtime.tv_sec;
349 tmp.st_ctime = stat->ctime.tv_sec;
350 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
351}
352
353SYSCALL_DEFINE2(stat, const char __user *, filename,
354 struct __old_kernel_stat __user *, statbuf)
355{
356 struct kstat stat;
357 int error;
358
359 error = vfs_stat(filename, &stat);
360 if (error)
361 return error;
362
363 return cp_old_stat(&stat, statbuf);
364}
365
366SYSCALL_DEFINE2(lstat, const char __user *, filename,
367 struct __old_kernel_stat __user *, statbuf)
368{
369 struct kstat stat;
370 int error;
371
372 error = vfs_lstat(filename, &stat);
373 if (error)
374 return error;
375
376 return cp_old_stat(&stat, statbuf);
377}
378
379SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
380{
381 struct kstat stat;
382 int error = vfs_fstat(fd, &stat);
383
384 if (!error)
385 error = cp_old_stat(&stat, statbuf);
386
387 return error;
388}
389
390#endif /* __ARCH_WANT_OLD_STAT */
391
392#ifdef __ARCH_WANT_NEW_STAT
393
394#ifndef INIT_STRUCT_STAT_PADDING
395# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
396#endif
397
398static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
399{
400 struct stat tmp;
401
402 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
403 return -EOVERFLOW;
404 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
405 return -EOVERFLOW;
406#if BITS_PER_LONG == 32
407 if (stat->size > MAX_NON_LFS)
408 return -EOVERFLOW;
409#endif
410
411 INIT_STRUCT_STAT_PADDING(tmp);
412 tmp.st_dev = new_encode_dev(stat->dev);
413 tmp.st_ino = stat->ino;
414 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
415 return -EOVERFLOW;
416 tmp.st_mode = stat->mode;
417 tmp.st_nlink = stat->nlink;
418 if (tmp.st_nlink != stat->nlink)
419 return -EOVERFLOW;
420 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
421 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
422 tmp.st_rdev = new_encode_dev(stat->rdev);
423 tmp.st_size = stat->size;
424 tmp.st_atime = stat->atime.tv_sec;
425 tmp.st_mtime = stat->mtime.tv_sec;
426 tmp.st_ctime = stat->ctime.tv_sec;
427#ifdef STAT_HAVE_NSEC
428 tmp.st_atime_nsec = stat->atime.tv_nsec;
429 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
430 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
431#endif
432 tmp.st_blocks = stat->blocks;
433 tmp.st_blksize = stat->blksize;
434 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
435}
436
437SYSCALL_DEFINE2(newstat, const char __user *, filename,
438 struct stat __user *, statbuf)
439{
440 struct kstat stat;
441 int error = vfs_stat(filename, &stat);
442
443 if (error)
444 return error;
445 return cp_new_stat(&stat, statbuf);
446}
447
448SYSCALL_DEFINE2(newlstat, const char __user *, filename,
449 struct stat __user *, statbuf)
450{
451 struct kstat stat;
452 int error;
453
454 error = vfs_lstat(filename, &stat);
455 if (error)
456 return error;
457
458 return cp_new_stat(&stat, statbuf);
459}
460
461#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
462SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
463 struct stat __user *, statbuf, int, flag)
464{
465 struct kstat stat;
466 int error;
467
468 error = vfs_fstatat(dfd, filename, &stat, flag);
469 if (error)
470 return error;
471 return cp_new_stat(&stat, statbuf);
472}
473#endif
474
475SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
476{
477 struct kstat stat;
478 int error = vfs_fstat(fd, &stat);
479
480 if (!error)
481 error = cp_new_stat(&stat, statbuf);
482
483 return error;
484}
485#endif
486
487static int do_readlinkat(int dfd, const char __user *pathname,
488 char __user *buf, int bufsiz)
489{
490 struct path path;
491 int error;
492 int empty = 0;
493 unsigned int lookup_flags = LOOKUP_EMPTY;
494
495 if (bufsiz <= 0)
496 return -EINVAL;
497
498retry:
499 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
500 if (!error) {
501 struct inode *inode = d_backing_inode(path.dentry);
502
503 error = empty ? -ENOENT : -EINVAL;
504 /*
505 * AFS mountpoints allow readlink(2) but are not symlinks
506 */
507 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
508 error = security_inode_readlink(path.dentry);
509 if (!error) {
510 touch_atime(&path);
511 error = vfs_readlink(path.dentry, buf, bufsiz);
512 }
513 }
514 path_put(&path);
515 if (retry_estale(error, lookup_flags)) {
516 lookup_flags |= LOOKUP_REVAL;
517 goto retry;
518 }
519 }
520 return error;
521}
522
523SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
524 char __user *, buf, int, bufsiz)
525{
526 return do_readlinkat(dfd, pathname, buf, bufsiz);
527}
528
529SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
530 int, bufsiz)
531{
532 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
533}
534
535
536/* ---------- LFS-64 ----------- */
537#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
538
539#ifndef INIT_STRUCT_STAT64_PADDING
540# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
541#endif
542
543static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
544{
545 struct stat64 tmp;
546
547 INIT_STRUCT_STAT64_PADDING(tmp);
548#ifdef CONFIG_MIPS
549 /* mips has weird padding, so we don't get 64 bits there */
550 tmp.st_dev = new_encode_dev(stat->dev);
551 tmp.st_rdev = new_encode_dev(stat->rdev);
552#else
553 tmp.st_dev = huge_encode_dev(stat->dev);
554 tmp.st_rdev = huge_encode_dev(stat->rdev);
555#endif
556 tmp.st_ino = stat->ino;
557 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
558 return -EOVERFLOW;
559#ifdef STAT64_HAS_BROKEN_ST_INO
560 tmp.__st_ino = stat->ino;
561#endif
562 tmp.st_mode = stat->mode;
563 tmp.st_nlink = stat->nlink;
564 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
565 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
566 tmp.st_atime = stat->atime.tv_sec;
567 tmp.st_atime_nsec = stat->atime.tv_nsec;
568 tmp.st_mtime = stat->mtime.tv_sec;
569 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
570 tmp.st_ctime = stat->ctime.tv_sec;
571 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
572 tmp.st_size = stat->size;
573 tmp.st_blocks = stat->blocks;
574 tmp.st_blksize = stat->blksize;
575 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
576}
577
578SYSCALL_DEFINE2(stat64, const char __user *, filename,
579 struct stat64 __user *, statbuf)
580{
581 struct kstat stat;
582 int error = vfs_stat(filename, &stat);
583
584 if (!error)
585 error = cp_new_stat64(&stat, statbuf);
586
587 return error;
588}
589
590SYSCALL_DEFINE2(lstat64, const char __user *, filename,
591 struct stat64 __user *, statbuf)
592{
593 struct kstat stat;
594 int error = vfs_lstat(filename, &stat);
595
596 if (!error)
597 error = cp_new_stat64(&stat, statbuf);
598
599 return error;
600}
601
602SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
603{
604 struct kstat stat;
605 int error = vfs_fstat(fd, &stat);
606
607 if (!error)
608 error = cp_new_stat64(&stat, statbuf);
609
610 return error;
611}
612
613SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
614 struct stat64 __user *, statbuf, int, flag)
615{
616 struct kstat stat;
617 int error;
618
619 error = vfs_fstatat(dfd, filename, &stat, flag);
620 if (error)
621 return error;
622 return cp_new_stat64(&stat, statbuf);
623}
624#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
625
626static noinline_for_stack int
627cp_statx(const struct kstat *stat, struct statx __user *buffer)
628{
629 struct statx tmp;
630
631 memset(&tmp, 0, sizeof(tmp));
632
633 /* STATX_CHANGE_COOKIE is kernel-only for now */
634 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
635 tmp.stx_blksize = stat->blksize;
636 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
637 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
638 tmp.stx_nlink = stat->nlink;
639 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
640 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
641 tmp.stx_mode = stat->mode;
642 tmp.stx_ino = stat->ino;
643 tmp.stx_size = stat->size;
644 tmp.stx_blocks = stat->blocks;
645 tmp.stx_attributes_mask = stat->attributes_mask;
646 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
647 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
648 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
649 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
650 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
651 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
652 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
653 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
654 tmp.stx_rdev_major = MAJOR(stat->rdev);
655 tmp.stx_rdev_minor = MINOR(stat->rdev);
656 tmp.stx_dev_major = MAJOR(stat->dev);
657 tmp.stx_dev_minor = MINOR(stat->dev);
658 tmp.stx_mnt_id = stat->mnt_id;
659 tmp.stx_dio_mem_align = stat->dio_mem_align;
660 tmp.stx_dio_offset_align = stat->dio_offset_align;
661
662 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
663}
664
665int do_statx(int dfd, struct filename *filename, unsigned int flags,
666 unsigned int mask, struct statx __user *buffer)
667{
668 struct kstat stat;
669 int error;
670
671 if (mask & STATX__RESERVED)
672 return -EINVAL;
673 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
674 return -EINVAL;
675
676 /* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
677 * from userland.
678 */
679 mask &= ~STATX_CHANGE_COOKIE;
680
681 error = vfs_statx(dfd, filename, flags, &stat, mask);
682 if (error)
683 return error;
684
685 return cp_statx(&stat, buffer);
686}
687
688/**
689 * sys_statx - System call to get enhanced stats
690 * @dfd: Base directory to pathwalk from *or* fd to stat.
691 * @filename: File to stat or "" with AT_EMPTY_PATH
692 * @flags: AT_* flags to control pathwalk.
693 * @mask: Parts of statx struct actually required.
694 * @buffer: Result buffer.
695 *
696 * Note that fstat() can be emulated by setting dfd to the fd of interest,
697 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
698 */
699SYSCALL_DEFINE5(statx,
700 int, dfd, const char __user *, filename, unsigned, flags,
701 unsigned int, mask,
702 struct statx __user *, buffer)
703{
704 int ret;
705 struct filename *name;
706
707 name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);
708 ret = do_statx(dfd, name, flags, mask, buffer);
709 putname(name);
710
711 return ret;
712}
713
714#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
715static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
716{
717 struct compat_stat tmp;
718
719 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
720 return -EOVERFLOW;
721 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
722 return -EOVERFLOW;
723
724 memset(&tmp, 0, sizeof(tmp));
725 tmp.st_dev = new_encode_dev(stat->dev);
726 tmp.st_ino = stat->ino;
727 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
728 return -EOVERFLOW;
729 tmp.st_mode = stat->mode;
730 tmp.st_nlink = stat->nlink;
731 if (tmp.st_nlink != stat->nlink)
732 return -EOVERFLOW;
733 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
734 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
735 tmp.st_rdev = new_encode_dev(stat->rdev);
736 if ((u64) stat->size > MAX_NON_LFS)
737 return -EOVERFLOW;
738 tmp.st_size = stat->size;
739 tmp.st_atime = stat->atime.tv_sec;
740 tmp.st_atime_nsec = stat->atime.tv_nsec;
741 tmp.st_mtime = stat->mtime.tv_sec;
742 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
743 tmp.st_ctime = stat->ctime.tv_sec;
744 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
745 tmp.st_blocks = stat->blocks;
746 tmp.st_blksize = stat->blksize;
747 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
748}
749
750COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
751 struct compat_stat __user *, statbuf)
752{
753 struct kstat stat;
754 int error;
755
756 error = vfs_stat(filename, &stat);
757 if (error)
758 return error;
759 return cp_compat_stat(&stat, statbuf);
760}
761
762COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
763 struct compat_stat __user *, statbuf)
764{
765 struct kstat stat;
766 int error;
767
768 error = vfs_lstat(filename, &stat);
769 if (error)
770 return error;
771 return cp_compat_stat(&stat, statbuf);
772}
773
774#ifndef __ARCH_WANT_STAT64
775COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
776 const char __user *, filename,
777 struct compat_stat __user *, statbuf, int, flag)
778{
779 struct kstat stat;
780 int error;
781
782 error = vfs_fstatat(dfd, filename, &stat, flag);
783 if (error)
784 return error;
785 return cp_compat_stat(&stat, statbuf);
786}
787#endif
788
789COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
790 struct compat_stat __user *, statbuf)
791{
792 struct kstat stat;
793 int error = vfs_fstat(fd, &stat);
794
795 if (!error)
796 error = cp_compat_stat(&stat, statbuf);
797 return error;
798}
799#endif
800
801/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
802void __inode_add_bytes(struct inode *inode, loff_t bytes)
803{
804 inode->i_blocks += bytes >> 9;
805 bytes &= 511;
806 inode->i_bytes += bytes;
807 if (inode->i_bytes >= 512) {
808 inode->i_blocks++;
809 inode->i_bytes -= 512;
810 }
811}
812EXPORT_SYMBOL(__inode_add_bytes);
813
814void inode_add_bytes(struct inode *inode, loff_t bytes)
815{
816 spin_lock(&inode->i_lock);
817 __inode_add_bytes(inode, bytes);
818 spin_unlock(&inode->i_lock);
819}
820
821EXPORT_SYMBOL(inode_add_bytes);
822
823void __inode_sub_bytes(struct inode *inode, loff_t bytes)
824{
825 inode->i_blocks -= bytes >> 9;
826 bytes &= 511;
827 if (inode->i_bytes < bytes) {
828 inode->i_blocks--;
829 inode->i_bytes += 512;
830 }
831 inode->i_bytes -= bytes;
832}
833
834EXPORT_SYMBOL(__inode_sub_bytes);
835
836void inode_sub_bytes(struct inode *inode, loff_t bytes)
837{
838 spin_lock(&inode->i_lock);
839 __inode_sub_bytes(inode, bytes);
840 spin_unlock(&inode->i_lock);
841}
842
843EXPORT_SYMBOL(inode_sub_bytes);
844
845loff_t inode_get_bytes(struct inode *inode)
846{
847 loff_t ret;
848
849 spin_lock(&inode->i_lock);
850 ret = __inode_get_bytes(inode);
851 spin_unlock(&inode->i_lock);
852 return ret;
853}
854
855EXPORT_SYMBOL(inode_get_bytes);
856
857void inode_set_bytes(struct inode *inode, loff_t bytes)
858{
859 /* Caller is here responsible for sufficient locking
860 * (ie. inode->i_lock) */
861 inode->i_blocks = bytes >> 9;
862 inode->i_bytes = bytes & 511;
863}
864
865EXPORT_SYMBOL(inode_set_bytes);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/export.h>
9#include <linux/mm.h>
10#include <linux/errno.h>
11#include <linux/file.h>
12#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
16#include <linux/cred.h>
17#include <linux/syscalls.h>
18#include <linux/pagemap.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22#include <asm/unistd.h>
23
24#include "internal.h"
25#include "mount.h"
26
27/**
28 * generic_fillattr - Fill in the basic attributes from the inode struct
29 * @mnt_userns: user namespace of the mount the inode was found from
30 * @inode: Inode to use as the source
31 * @stat: Where to fill in the attributes
32 *
33 * Fill in the basic attributes in the kstat structure from data that's to be
34 * found on the VFS inode structure. This is the default if no getattr inode
35 * operation is supplied.
36 *
37 * If the inode has been found through an idmapped mount the user namespace of
38 * the vfsmount must be passed through @mnt_userns. This function will then
39 * take care to map the inode according to @mnt_userns before filling in the
40 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
41 * performed on the raw inode simply passs init_user_ns.
42 */
43void generic_fillattr(struct user_namespace *mnt_userns, struct inode *inode,
44 struct kstat *stat)
45{
46 stat->dev = inode->i_sb->s_dev;
47 stat->ino = inode->i_ino;
48 stat->mode = inode->i_mode;
49 stat->nlink = inode->i_nlink;
50 stat->uid = i_uid_into_mnt(mnt_userns, inode);
51 stat->gid = i_gid_into_mnt(mnt_userns, inode);
52 stat->rdev = inode->i_rdev;
53 stat->size = i_size_read(inode);
54 stat->atime = inode->i_atime;
55 stat->mtime = inode->i_mtime;
56 stat->ctime = inode->i_ctime;
57 stat->blksize = i_blocksize(inode);
58 stat->blocks = inode->i_blocks;
59}
60EXPORT_SYMBOL(generic_fillattr);
61
62/**
63 * vfs_getattr_nosec - getattr without security checks
64 * @path: file to get attributes from
65 * @stat: structure to return attributes in
66 * @request_mask: STATX_xxx flags indicating what the caller wants
67 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
68 *
69 * Get attributes without calling security_inode_getattr.
70 *
71 * Currently the only caller other than vfs_getattr is internal to the
72 * filehandle lookup code, which uses only the inode number and returns no
73 * attributes to any user. Any other code probably wants vfs_getattr.
74 */
75int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
76 u32 request_mask, unsigned int query_flags)
77{
78 struct user_namespace *mnt_userns;
79 struct inode *inode = d_backing_inode(path->dentry);
80
81 memset(stat, 0, sizeof(*stat));
82 stat->result_mask |= STATX_BASIC_STATS;
83 query_flags &= AT_STATX_SYNC_TYPE;
84
85 /* allow the fs to override these if it really wants to */
86 /* SB_NOATIME means filesystem supplies dummy atime value */
87 if (inode->i_sb->s_flags & SB_NOATIME)
88 stat->result_mask &= ~STATX_ATIME;
89
90 /*
91 * Note: If you add another clause to set an attribute flag, please
92 * update attributes_mask below.
93 */
94 if (IS_AUTOMOUNT(inode))
95 stat->attributes |= STATX_ATTR_AUTOMOUNT;
96
97 if (IS_DAX(inode))
98 stat->attributes |= STATX_ATTR_DAX;
99
100 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
101 STATX_ATTR_DAX);
102
103 mnt_userns = mnt_user_ns(path->mnt);
104 if (inode->i_op->getattr)
105 return inode->i_op->getattr(mnt_userns, path, stat,
106 request_mask, query_flags);
107
108 generic_fillattr(mnt_userns, inode, stat);
109 return 0;
110}
111EXPORT_SYMBOL(vfs_getattr_nosec);
112
113/*
114 * vfs_getattr - Get the enhanced basic attributes of a file
115 * @path: The file of interest
116 * @stat: Where to return the statistics
117 * @request_mask: STATX_xxx flags indicating what the caller wants
118 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
119 *
120 * Ask the filesystem for a file's attributes. The caller must indicate in
121 * request_mask and query_flags to indicate what they want.
122 *
123 * If the file is remote, the filesystem can be forced to update the attributes
124 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
125 * suppress the update by passing AT_STATX_DONT_SYNC.
126 *
127 * Bits must have been set in request_mask to indicate which attributes the
128 * caller wants retrieving. Any such attribute not requested may be returned
129 * anyway, but the value may be approximate, and, if remote, may not have been
130 * synchronised with the server.
131 *
132 * 0 will be returned on success, and a -ve error code if unsuccessful.
133 */
134int vfs_getattr(const struct path *path, struct kstat *stat,
135 u32 request_mask, unsigned int query_flags)
136{
137 int retval;
138
139 retval = security_inode_getattr(path);
140 if (retval)
141 return retval;
142 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
143}
144EXPORT_SYMBOL(vfs_getattr);
145
146/**
147 * vfs_fstat - Get the basic attributes by file descriptor
148 * @fd: The file descriptor referring to the file of interest
149 * @stat: The result structure to fill in.
150 *
151 * This function is a wrapper around vfs_getattr(). The main difference is
152 * that it uses a file descriptor to determine the file location.
153 *
154 * 0 will be returned on success, and a -ve error code if unsuccessful.
155 */
156int vfs_fstat(int fd, struct kstat *stat)
157{
158 struct fd f;
159 int error;
160
161 f = fdget_raw(fd);
162 if (!f.file)
163 return -EBADF;
164 error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
165 fdput(f);
166 return error;
167}
168
169/**
170 * vfs_statx - Get basic and extra attributes by filename
171 * @dfd: A file descriptor representing the base dir for a relative filename
172 * @filename: The name of the file of interest
173 * @flags: Flags to control the query
174 * @stat: The result structure to fill in.
175 * @request_mask: STATX_xxx flags indicating what the caller wants
176 *
177 * This function is a wrapper around vfs_getattr(). The main difference is
178 * that it uses a filename and base directory to determine the file location.
179 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
180 * at the given name from being referenced.
181 *
182 * 0 will be returned on success, and a -ve error code if unsuccessful.
183 */
184static int vfs_statx(int dfd, const char __user *filename, int flags,
185 struct kstat *stat, u32 request_mask)
186{
187 struct path path;
188 unsigned lookup_flags = 0;
189 int error;
190
191 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
192 AT_STATX_SYNC_TYPE))
193 return -EINVAL;
194
195 if (!(flags & AT_SYMLINK_NOFOLLOW))
196 lookup_flags |= LOOKUP_FOLLOW;
197 if (!(flags & AT_NO_AUTOMOUNT))
198 lookup_flags |= LOOKUP_AUTOMOUNT;
199 if (flags & AT_EMPTY_PATH)
200 lookup_flags |= LOOKUP_EMPTY;
201
202retry:
203 error = user_path_at(dfd, filename, lookup_flags, &path);
204 if (error)
205 goto out;
206
207 error = vfs_getattr(&path, stat, request_mask, flags);
208 stat->mnt_id = real_mount(path.mnt)->mnt_id;
209 stat->result_mask |= STATX_MNT_ID;
210 if (path.mnt->mnt_root == path.dentry)
211 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
212 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
213 path_put(&path);
214 if (retry_estale(error, lookup_flags)) {
215 lookup_flags |= LOOKUP_REVAL;
216 goto retry;
217 }
218out:
219 return error;
220}
221
222int vfs_fstatat(int dfd, const char __user *filename,
223 struct kstat *stat, int flags)
224{
225 return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,
226 stat, STATX_BASIC_STATS);
227}
228
229#ifdef __ARCH_WANT_OLD_STAT
230
231/*
232 * For backward compatibility? Maybe this should be moved
233 * into arch/i386 instead?
234 */
235static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
236{
237 static int warncount = 5;
238 struct __old_kernel_stat tmp;
239
240 if (warncount > 0) {
241 warncount--;
242 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
243 current->comm);
244 } else if (warncount < 0) {
245 /* it's laughable, but... */
246 warncount = 0;
247 }
248
249 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
250 tmp.st_dev = old_encode_dev(stat->dev);
251 tmp.st_ino = stat->ino;
252 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
253 return -EOVERFLOW;
254 tmp.st_mode = stat->mode;
255 tmp.st_nlink = stat->nlink;
256 if (tmp.st_nlink != stat->nlink)
257 return -EOVERFLOW;
258 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
259 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
260 tmp.st_rdev = old_encode_dev(stat->rdev);
261#if BITS_PER_LONG == 32
262 if (stat->size > MAX_NON_LFS)
263 return -EOVERFLOW;
264#endif
265 tmp.st_size = stat->size;
266 tmp.st_atime = stat->atime.tv_sec;
267 tmp.st_mtime = stat->mtime.tv_sec;
268 tmp.st_ctime = stat->ctime.tv_sec;
269 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
270}
271
272SYSCALL_DEFINE2(stat, const char __user *, filename,
273 struct __old_kernel_stat __user *, statbuf)
274{
275 struct kstat stat;
276 int error;
277
278 error = vfs_stat(filename, &stat);
279 if (error)
280 return error;
281
282 return cp_old_stat(&stat, statbuf);
283}
284
285SYSCALL_DEFINE2(lstat, const char __user *, filename,
286 struct __old_kernel_stat __user *, statbuf)
287{
288 struct kstat stat;
289 int error;
290
291 error = vfs_lstat(filename, &stat);
292 if (error)
293 return error;
294
295 return cp_old_stat(&stat, statbuf);
296}
297
298SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
299{
300 struct kstat stat;
301 int error = vfs_fstat(fd, &stat);
302
303 if (!error)
304 error = cp_old_stat(&stat, statbuf);
305
306 return error;
307}
308
309#endif /* __ARCH_WANT_OLD_STAT */
310
311#ifdef __ARCH_WANT_NEW_STAT
312
313#if BITS_PER_LONG == 32
314# define choose_32_64(a,b) a
315#else
316# define choose_32_64(a,b) b
317#endif
318
319#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
320#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
321
322#ifndef INIT_STRUCT_STAT_PADDING
323# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
324#endif
325
326static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
327{
328 struct stat tmp;
329
330 if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
331 return -EOVERFLOW;
332#if BITS_PER_LONG == 32
333 if (stat->size > MAX_NON_LFS)
334 return -EOVERFLOW;
335#endif
336
337 INIT_STRUCT_STAT_PADDING(tmp);
338 tmp.st_dev = encode_dev(stat->dev);
339 tmp.st_ino = stat->ino;
340 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
341 return -EOVERFLOW;
342 tmp.st_mode = stat->mode;
343 tmp.st_nlink = stat->nlink;
344 if (tmp.st_nlink != stat->nlink)
345 return -EOVERFLOW;
346 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
347 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
348 tmp.st_rdev = encode_dev(stat->rdev);
349 tmp.st_size = stat->size;
350 tmp.st_atime = stat->atime.tv_sec;
351 tmp.st_mtime = stat->mtime.tv_sec;
352 tmp.st_ctime = stat->ctime.tv_sec;
353#ifdef STAT_HAVE_NSEC
354 tmp.st_atime_nsec = stat->atime.tv_nsec;
355 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
356 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
357#endif
358 tmp.st_blocks = stat->blocks;
359 tmp.st_blksize = stat->blksize;
360 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
361}
362
363SYSCALL_DEFINE2(newstat, const char __user *, filename,
364 struct stat __user *, statbuf)
365{
366 struct kstat stat;
367 int error = vfs_stat(filename, &stat);
368
369 if (error)
370 return error;
371 return cp_new_stat(&stat, statbuf);
372}
373
374SYSCALL_DEFINE2(newlstat, const char __user *, filename,
375 struct stat __user *, statbuf)
376{
377 struct kstat stat;
378 int error;
379
380 error = vfs_lstat(filename, &stat);
381 if (error)
382 return error;
383
384 return cp_new_stat(&stat, statbuf);
385}
386
387#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
388SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
389 struct stat __user *, statbuf, int, flag)
390{
391 struct kstat stat;
392 int error;
393
394 error = vfs_fstatat(dfd, filename, &stat, flag);
395 if (error)
396 return error;
397 return cp_new_stat(&stat, statbuf);
398}
399#endif
400
401SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
402{
403 struct kstat stat;
404 int error = vfs_fstat(fd, &stat);
405
406 if (!error)
407 error = cp_new_stat(&stat, statbuf);
408
409 return error;
410}
411#endif
412
413static int do_readlinkat(int dfd, const char __user *pathname,
414 char __user *buf, int bufsiz)
415{
416 struct path path;
417 int error;
418 int empty = 0;
419 unsigned int lookup_flags = LOOKUP_EMPTY;
420
421 if (bufsiz <= 0)
422 return -EINVAL;
423
424retry:
425 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
426 if (!error) {
427 struct inode *inode = d_backing_inode(path.dentry);
428
429 error = empty ? -ENOENT : -EINVAL;
430 /*
431 * AFS mountpoints allow readlink(2) but are not symlinks
432 */
433 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
434 error = security_inode_readlink(path.dentry);
435 if (!error) {
436 touch_atime(&path);
437 error = vfs_readlink(path.dentry, buf, bufsiz);
438 }
439 }
440 path_put(&path);
441 if (retry_estale(error, lookup_flags)) {
442 lookup_flags |= LOOKUP_REVAL;
443 goto retry;
444 }
445 }
446 return error;
447}
448
449SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
450 char __user *, buf, int, bufsiz)
451{
452 return do_readlinkat(dfd, pathname, buf, bufsiz);
453}
454
455SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
456 int, bufsiz)
457{
458 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
459}
460
461
462/* ---------- LFS-64 ----------- */
463#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
464
465#ifndef INIT_STRUCT_STAT64_PADDING
466# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
467#endif
468
469static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
470{
471 struct stat64 tmp;
472
473 INIT_STRUCT_STAT64_PADDING(tmp);
474#ifdef CONFIG_MIPS
475 /* mips has weird padding, so we don't get 64 bits there */
476 tmp.st_dev = new_encode_dev(stat->dev);
477 tmp.st_rdev = new_encode_dev(stat->rdev);
478#else
479 tmp.st_dev = huge_encode_dev(stat->dev);
480 tmp.st_rdev = huge_encode_dev(stat->rdev);
481#endif
482 tmp.st_ino = stat->ino;
483 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
484 return -EOVERFLOW;
485#ifdef STAT64_HAS_BROKEN_ST_INO
486 tmp.__st_ino = stat->ino;
487#endif
488 tmp.st_mode = stat->mode;
489 tmp.st_nlink = stat->nlink;
490 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
491 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
492 tmp.st_atime = stat->atime.tv_sec;
493 tmp.st_atime_nsec = stat->atime.tv_nsec;
494 tmp.st_mtime = stat->mtime.tv_sec;
495 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
496 tmp.st_ctime = stat->ctime.tv_sec;
497 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
498 tmp.st_size = stat->size;
499 tmp.st_blocks = stat->blocks;
500 tmp.st_blksize = stat->blksize;
501 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
502}
503
504SYSCALL_DEFINE2(stat64, const char __user *, filename,
505 struct stat64 __user *, statbuf)
506{
507 struct kstat stat;
508 int error = vfs_stat(filename, &stat);
509
510 if (!error)
511 error = cp_new_stat64(&stat, statbuf);
512
513 return error;
514}
515
516SYSCALL_DEFINE2(lstat64, const char __user *, filename,
517 struct stat64 __user *, statbuf)
518{
519 struct kstat stat;
520 int error = vfs_lstat(filename, &stat);
521
522 if (!error)
523 error = cp_new_stat64(&stat, statbuf);
524
525 return error;
526}
527
528SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
529{
530 struct kstat stat;
531 int error = vfs_fstat(fd, &stat);
532
533 if (!error)
534 error = cp_new_stat64(&stat, statbuf);
535
536 return error;
537}
538
539SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
540 struct stat64 __user *, statbuf, int, flag)
541{
542 struct kstat stat;
543 int error;
544
545 error = vfs_fstatat(dfd, filename, &stat, flag);
546 if (error)
547 return error;
548 return cp_new_stat64(&stat, statbuf);
549}
550#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
551
552static noinline_for_stack int
553cp_statx(const struct kstat *stat, struct statx __user *buffer)
554{
555 struct statx tmp;
556
557 memset(&tmp, 0, sizeof(tmp));
558
559 tmp.stx_mask = stat->result_mask;
560 tmp.stx_blksize = stat->blksize;
561 tmp.stx_attributes = stat->attributes;
562 tmp.stx_nlink = stat->nlink;
563 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
564 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
565 tmp.stx_mode = stat->mode;
566 tmp.stx_ino = stat->ino;
567 tmp.stx_size = stat->size;
568 tmp.stx_blocks = stat->blocks;
569 tmp.stx_attributes_mask = stat->attributes_mask;
570 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
571 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
572 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
573 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
574 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
575 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
576 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
577 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
578 tmp.stx_rdev_major = MAJOR(stat->rdev);
579 tmp.stx_rdev_minor = MINOR(stat->rdev);
580 tmp.stx_dev_major = MAJOR(stat->dev);
581 tmp.stx_dev_minor = MINOR(stat->dev);
582 tmp.stx_mnt_id = stat->mnt_id;
583
584 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
585}
586
587int do_statx(int dfd, const char __user *filename, unsigned flags,
588 unsigned int mask, struct statx __user *buffer)
589{
590 struct kstat stat;
591 int error;
592
593 if (mask & STATX__RESERVED)
594 return -EINVAL;
595 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
596 return -EINVAL;
597
598 error = vfs_statx(dfd, filename, flags, &stat, mask);
599 if (error)
600 return error;
601
602 return cp_statx(&stat, buffer);
603}
604
605/**
606 * sys_statx - System call to get enhanced stats
607 * @dfd: Base directory to pathwalk from *or* fd to stat.
608 * @filename: File to stat or "" with AT_EMPTY_PATH
609 * @flags: AT_* flags to control pathwalk.
610 * @mask: Parts of statx struct actually required.
611 * @buffer: Result buffer.
612 *
613 * Note that fstat() can be emulated by setting dfd to the fd of interest,
614 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
615 */
616SYSCALL_DEFINE5(statx,
617 int, dfd, const char __user *, filename, unsigned, flags,
618 unsigned int, mask,
619 struct statx __user *, buffer)
620{
621 return do_statx(dfd, filename, flags, mask, buffer);
622}
623
624#ifdef CONFIG_COMPAT
625static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
626{
627 struct compat_stat tmp;
628
629 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
630 return -EOVERFLOW;
631
632 memset(&tmp, 0, sizeof(tmp));
633 tmp.st_dev = old_encode_dev(stat->dev);
634 tmp.st_ino = stat->ino;
635 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
636 return -EOVERFLOW;
637 tmp.st_mode = stat->mode;
638 tmp.st_nlink = stat->nlink;
639 if (tmp.st_nlink != stat->nlink)
640 return -EOVERFLOW;
641 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
642 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
643 tmp.st_rdev = old_encode_dev(stat->rdev);
644 if ((u64) stat->size > MAX_NON_LFS)
645 return -EOVERFLOW;
646 tmp.st_size = stat->size;
647 tmp.st_atime = stat->atime.tv_sec;
648 tmp.st_atime_nsec = stat->atime.tv_nsec;
649 tmp.st_mtime = stat->mtime.tv_sec;
650 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
651 tmp.st_ctime = stat->ctime.tv_sec;
652 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
653 tmp.st_blocks = stat->blocks;
654 tmp.st_blksize = stat->blksize;
655 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
656}
657
658COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
659 struct compat_stat __user *, statbuf)
660{
661 struct kstat stat;
662 int error;
663
664 error = vfs_stat(filename, &stat);
665 if (error)
666 return error;
667 return cp_compat_stat(&stat, statbuf);
668}
669
670COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
671 struct compat_stat __user *, statbuf)
672{
673 struct kstat stat;
674 int error;
675
676 error = vfs_lstat(filename, &stat);
677 if (error)
678 return error;
679 return cp_compat_stat(&stat, statbuf);
680}
681
682#ifndef __ARCH_WANT_STAT64
683COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
684 const char __user *, filename,
685 struct compat_stat __user *, statbuf, int, flag)
686{
687 struct kstat stat;
688 int error;
689
690 error = vfs_fstatat(dfd, filename, &stat, flag);
691 if (error)
692 return error;
693 return cp_compat_stat(&stat, statbuf);
694}
695#endif
696
697COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
698 struct compat_stat __user *, statbuf)
699{
700 struct kstat stat;
701 int error = vfs_fstat(fd, &stat);
702
703 if (!error)
704 error = cp_compat_stat(&stat, statbuf);
705 return error;
706}
707#endif
708
709/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
710void __inode_add_bytes(struct inode *inode, loff_t bytes)
711{
712 inode->i_blocks += bytes >> 9;
713 bytes &= 511;
714 inode->i_bytes += bytes;
715 if (inode->i_bytes >= 512) {
716 inode->i_blocks++;
717 inode->i_bytes -= 512;
718 }
719}
720EXPORT_SYMBOL(__inode_add_bytes);
721
722void inode_add_bytes(struct inode *inode, loff_t bytes)
723{
724 spin_lock(&inode->i_lock);
725 __inode_add_bytes(inode, bytes);
726 spin_unlock(&inode->i_lock);
727}
728
729EXPORT_SYMBOL(inode_add_bytes);
730
731void __inode_sub_bytes(struct inode *inode, loff_t bytes)
732{
733 inode->i_blocks -= bytes >> 9;
734 bytes &= 511;
735 if (inode->i_bytes < bytes) {
736 inode->i_blocks--;
737 inode->i_bytes += 512;
738 }
739 inode->i_bytes -= bytes;
740}
741
742EXPORT_SYMBOL(__inode_sub_bytes);
743
744void inode_sub_bytes(struct inode *inode, loff_t bytes)
745{
746 spin_lock(&inode->i_lock);
747 __inode_sub_bytes(inode, bytes);
748 spin_unlock(&inode->i_lock);
749}
750
751EXPORT_SYMBOL(inode_sub_bytes);
752
753loff_t inode_get_bytes(struct inode *inode)
754{
755 loff_t ret;
756
757 spin_lock(&inode->i_lock);
758 ret = __inode_get_bytes(inode);
759 spin_unlock(&inode->i_lock);
760 return ret;
761}
762
763EXPORT_SYMBOL(inode_get_bytes);
764
765void inode_set_bytes(struct inode *inode, loff_t bytes)
766{
767 /* Caller is here responsible for sufficient locking
768 * (ie. inode->i_lock) */
769 inode->i_blocks = bytes >> 9;
770 inode->i_bytes = bytes & 511;
771}
772
773EXPORT_SYMBOL(inode_set_bytes);