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