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 | */ |
46 | void 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(node: 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 | } |
72 | EXPORT_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 | */ |
82 | void 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 | } |
90 | EXPORT_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 | */ |
105 | int 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(upper: 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(mnt: 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 | } |
142 | EXPORT_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 | */ |
165 | int 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 | } |
178 | EXPORT_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 | */ |
190 | int 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(fd: f); |
200 | return error; |
201 | } |
202 | |
203 | int 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 | */ |
232 | static 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 | |
243 | retry: |
244 | error = filename_lookup(dfd, name: filename, flags: lookup_flags, path: &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(mnt: path.mnt)->mnt_id_unique; |
252 | stat->result_mask |= STATX_MNT_ID_UNIQUE; |
253 | } else { |
254 | stat->mnt_id = real_mount(mnt: 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(upper: 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, flags: lookup_flags)) { |
272 | lookup_flags |= LOOKUP_REVAL; |
273 | goto retry; |
274 | } |
275 | out: |
276 | return error; |
277 | } |
278 | |
279 | int 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(fd: dfd, stat); |
301 | } |
302 | |
303 | name = getname_flags(filename, getname_statx_lookup_flags(flags: statx_flags), NULL); |
304 | ret = vfs_statx(dfd, filename: name, flags: 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 | */ |
316 | static 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(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(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(to: statbuf,from: &tmp,n: sizeof(tmp)) ? -EFAULT : 0; |
351 | } |
352 | |
353 | SYSCALL_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: &stat); |
360 | if (error) |
361 | return error; |
362 | |
363 | return cp_old_stat(stat: &stat, statbuf); |
364 | } |
365 | |
366 | SYSCALL_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(name: filename, stat: &stat); |
373 | if (error) |
374 | return error; |
375 | |
376 | return cp_old_stat(stat: &stat, statbuf); |
377 | } |
378 | |
379 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) |
380 | { |
381 | struct kstat stat; |
382 | int error = vfs_fstat(fd, stat: &stat); |
383 | |
384 | if (!error) |
385 | error = cp_old_stat(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 | |
398 | static 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(dev: stat->dev)) |
403 | return -EOVERFLOW; |
404 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(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(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(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(to: statbuf,from: &tmp,n: sizeof(tmp)) ? -EFAULT : 0; |
435 | } |
436 | |
437 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
438 | struct stat __user *, statbuf) |
439 | { |
440 | struct kstat stat; |
441 | int error = vfs_stat(filename, stat: &stat); |
442 | |
443 | if (error) |
444 | return error; |
445 | return cp_new_stat(stat: &stat, statbuf); |
446 | } |
447 | |
448 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
449 | struct stat __user *, statbuf) |
450 | { |
451 | struct kstat stat; |
452 | int error; |
453 | |
454 | error = vfs_lstat(name: filename, stat: &stat); |
455 | if (error) |
456 | return error; |
457 | |
458 | return cp_new_stat(stat: &stat, statbuf); |
459 | } |
460 | |
461 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
462 | SYSCALL_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: &stat, flags: flag); |
469 | if (error) |
470 | return error; |
471 | return cp_new_stat(stat: &stat, statbuf); |
472 | } |
473 | #endif |
474 | |
475 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
476 | { |
477 | struct kstat stat; |
478 | int error = vfs_fstat(fd, stat: &stat); |
479 | |
480 | if (!error) |
481 | error = cp_new_stat(stat: &stat, statbuf); |
482 | |
483 | return error; |
484 | } |
485 | #endif |
486 | |
487 | static 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 | |
498 | retry: |
499 | error = user_path_at_empty(dfd, pathname, lookup_flags, &path, empty: &empty); |
500 | if (!error) { |
501 | struct inode *inode = d_backing_inode(upper: 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(dentry: path.dentry) || inode->i_op->readlink) { |
508 | error = security_inode_readlink(dentry: 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, flags: lookup_flags)) { |
516 | lookup_flags |= LOOKUP_REVAL; |
517 | goto retry; |
518 | } |
519 | } |
520 | return error; |
521 | } |
522 | |
523 | SYSCALL_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 | |
529 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
530 | int, bufsiz) |
531 | { |
532 | return do_readlinkat(AT_FDCWD, pathname: 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 | |
543 | static 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 | |
578 | SYSCALL_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 | |
590 | SYSCALL_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 | |
602 | SYSCALL_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 | |
613 | SYSCALL_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 | |
626 | static noinline_for_stack int |
627 | cp_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(), uid: stat->uid); |
640 | tmp.stx_gid = from_kgid_munged(current_user_ns(), gid: 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(to: buffer, from: &tmp, n: sizeof(tmp)) ? -EFAULT : 0; |
663 | } |
664 | |
665 | int 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: &stat, request_mask: mask); |
682 | if (error) |
683 | return error; |
684 | |
685 | return cp_statx(stat: &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 | */ |
699 | SYSCALL_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, filename: name, flags, mask, buffer); |
709 | putname(name); |
710 | |
711 | return ret; |
712 | } |
713 | |
714 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT) |
715 | static 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(dev: stat->dev)) |
720 | return -EOVERFLOW; |
721 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(dev: stat->rdev)) |
722 | return -EOVERFLOW; |
723 | |
724 | memset(&tmp, 0, sizeof(tmp)); |
725 | tmp.st_dev = new_encode_dev(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(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(to: ubuf, from: &tmp, n: sizeof(tmp)) ? -EFAULT : 0; |
748 | } |
749 | |
750 | COMPAT_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: &stat); |
757 | if (error) |
758 | return error; |
759 | return cp_compat_stat(stat: &stat, ubuf: statbuf); |
760 | } |
761 | |
762 | COMPAT_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(name: filename, stat: &stat); |
769 | if (error) |
770 | return error; |
771 | return cp_compat_stat(stat: &stat, ubuf: statbuf); |
772 | } |
773 | |
774 | #ifndef __ARCH_WANT_STAT64 |
775 | COMPAT_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: &stat, flags: flag); |
783 | if (error) |
784 | return error; |
785 | return cp_compat_stat(stat: &stat, ubuf: statbuf); |
786 | } |
787 | #endif |
788 | |
789 | COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd, |
790 | struct compat_stat __user *, statbuf) |
791 | { |
792 | struct kstat stat; |
793 | int error = vfs_fstat(fd, stat: &stat); |
794 | |
795 | if (!error) |
796 | error = cp_compat_stat(stat: &stat, ubuf: statbuf); |
797 | return error; |
798 | } |
799 | #endif |
800 | |
801 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
802 | void __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 | } |
812 | EXPORT_SYMBOL(__inode_add_bytes); |
813 | |
814 | void inode_add_bytes(struct inode *inode, loff_t bytes) |
815 | { |
816 | spin_lock(lock: &inode->i_lock); |
817 | __inode_add_bytes(inode, bytes); |
818 | spin_unlock(lock: &inode->i_lock); |
819 | } |
820 | |
821 | EXPORT_SYMBOL(inode_add_bytes); |
822 | |
823 | void __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 | |
834 | EXPORT_SYMBOL(__inode_sub_bytes); |
835 | |
836 | void inode_sub_bytes(struct inode *inode, loff_t bytes) |
837 | { |
838 | spin_lock(lock: &inode->i_lock); |
839 | __inode_sub_bytes(inode, bytes); |
840 | spin_unlock(lock: &inode->i_lock); |
841 | } |
842 | |
843 | EXPORT_SYMBOL(inode_sub_bytes); |
844 | |
845 | loff_t inode_get_bytes(struct inode *inode) |
846 | { |
847 | loff_t ret; |
848 | |
849 | spin_lock(lock: &inode->i_lock); |
850 | ret = __inode_get_bytes(inode); |
851 | spin_unlock(lock: &inode->i_lock); |
852 | return ret; |
853 | } |
854 | |
855 | EXPORT_SYMBOL(inode_get_bytes); |
856 | |
857 | void 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 | |
865 | EXPORT_SYMBOL(inode_set_bytes); |
866 | |