blob: 0fda4b6b8fb2aa5d9f37da72157d65b29975281b [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
Paul Gortmaker630d9c42011-11-16 23:57:37 -05008#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/mm.h>
10#include <linux/errno.h>
11#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
Ingo Molnar5b825c32017-02-02 17:54:15 +010016#include <linux/cred.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/syscalls.h>
Theodore Ts'oba52de12006-09-27 01:50:49 -070018#include <linux/pagemap.h>
Al Viroac565de2017-04-08 18:13:00 -040019#include <linux/compat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Linus Torvalds7c0f6ba2016-12-24 11:46:01 -080021#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <asm/unistd.h>
23
David Howellsa528d352017-01-31 16:46:22 +000024/**
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070033void 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;
Linus Torvalds3ddcd052011-08-06 22:45:50 -070042 stat->size = i_size_read(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 stat->atime = inode->i_atime;
44 stat->mtime = inode->i_mtime;
45 stat->ctime = inode->i_ctime;
Fabian Frederick93407472017-02-27 14:28:32 -080046 stat->blksize = i_blocksize(inode);
Linus Torvalds3ddcd052011-08-06 22:45:50 -070047 stat->blocks = inode->i_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
David Howellsa528d352017-01-31 16:46:22 +000049 if (IS_NOATIME(inode))
50 stat->result_mask &= ~STATX_ATIME;
51 if (IS_AUTOMOUNT(inode))
52 stat->attributes |= STATX_ATTR_AUTOMOUNT;
53}
Linus Torvalds1da177e2005-04-16 15:20:36 -070054EXPORT_SYMBOL(generic_fillattr);
55
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -040056/**
57 * vfs_getattr_nosec - getattr without security checks
58 * @path: file to get attributes from
59 * @stat: structure to return attributes in
David Howellsa528d352017-01-31 16:46:22 +000060 * @request_mask: STATX_xxx flags indicating what the caller wants
61 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -040062 *
63 * Get attributes without calling security_inode_getattr.
64 *
65 * Currently the only caller other than vfs_getattr is internal to the
David Howellsa528d352017-01-31 16:46:22 +000066 * filehandle lookup code, which uses only the inode number and returns no
67 * attributes to any user. Any other code probably wants vfs_getattr.
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -040068 */
David Howellsa528d352017-01-31 16:46:22 +000069int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
70 u32 request_mask, unsigned int query_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
David Howellsbb6687342015-03-17 22:26:21 +000072 struct inode *inode = d_backing_inode(path->dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
David Howellsa528d352017-01-31 16:46:22 +000074 memset(stat, 0, sizeof(*stat));
75 stat->result_mask |= STATX_BASIC_STATS;
76 request_mask &= STATX_ALL;
77 query_flags &= KSTAT_QUERY_FLAGS;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 if (inode->i_op->getattr)
David Howellsa528d352017-01-31 16:46:22 +000079 return inode->i_op->getattr(path, stat, request_mask,
80 query_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 generic_fillattr(inode, stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 return 0;
84}
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -040085EXPORT_SYMBOL(vfs_getattr_nosec);
86
David Howellsa528d352017-01-31 16:46:22 +000087/*
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)
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -0400110{
111 int retval;
112
Al Viro3f7036a2015-03-08 19:28:30 -0400113 retval = security_inode_getattr(path);
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -0400114 if (retval)
115 return retval;
David Howellsa528d352017-01-31 16:46:22 +0000116 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
J. Bruce Fieldsb7a6ec52013-10-02 17:01:18 -0400117}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118EXPORT_SYMBOL(vfs_getattr);
119
David Howellsa528d352017-01-31 16:46:22 +0000120/**
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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
Eric Biggers8c7493a2017-03-31 18:31:32 +0100135 struct fd f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 int error = -EBADF;
137
Eric Biggers8c7493a2017-03-31 18:31:32 +0100138 if (query_flags & ~KSTAT_QUERY_FLAGS)
139 return -EINVAL;
140
141 f = fdget_raw(fd);
Al Viro2903ff02012-08-28 12:52:22 -0400142 if (f.file) {
David Howellsa528d352017-01-31 16:46:22 +0000143 error = vfs_getattr(&f.file->f_path, stat,
144 request_mask, query_flags);
Al Viro2903ff02012-08-28 12:52:22 -0400145 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147 return error;
148}
David Howellsa528d352017-01-31 16:46:22 +0000149EXPORT_SYMBOL(vfs_statx_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
David Howellsa528d352017-01-31 16:46:22 +0000151/**
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 *
David Howellsa528d352017-01-31 16:46:22 +0000164 * 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)
Oleg Drokin0112fc22009-04-08 20:05:42 +0400168{
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400169 struct path path;
Oleg Drokin0112fc22009-04-08 20:05:42 +0400170 int error = -EINVAL;
David Howellsa528d352017-01-31 16:46:22 +0000171 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
Oleg Drokin0112fc22009-04-08 20:05:42 +0400172
David Howellsa528d352017-01-31 16:46:22 +0000173 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
174 AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
175 return -EINVAL;
Oleg Drokin0112fc22009-04-08 20:05:42 +0400176
David Howellsa528d352017-01-31 16:46:22 +0000177 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)
Al Viro65cfc672011-03-13 15:56:26 -0400182 lookup_flags |= LOOKUP_EMPTY;
David Howellsa528d352017-01-31 16:46:22 +0000183
Jeff Layton836fb7e2012-12-11 12:10:05 -0500184retry:
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400185 error = user_path_at(dfd, filename, lookup_flags, &path);
186 if (error)
187 goto out;
188
David Howellsa528d352017-01-31 16:46:22 +0000189 error = vfs_getattr(&path, stat, request_mask, flags);
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400190 path_put(&path);
Jeff Layton836fb7e2012-12-11 12:10:05 -0500191 if (retry_estale(error, lookup_flags)) {
192 lookup_flags |= LOOKUP_REVAL;
193 goto retry;
194 }
Oleg Drokin0112fc22009-04-08 20:05:42 +0400195out:
196 return error;
197}
David Howellsa528d352017-01-31 16:46:22 +0000198EXPORT_SYMBOL(vfs_statx);
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400199
Oleg Drokin0112fc22009-04-08 20:05:42 +0400200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201#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;
David Howellsa528d352017-01-31 16:46:22 +0000211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 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;
David Howellsafefdbb2006-10-03 01:13:46 -0700224 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
225 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 tmp.st_mode = stat->mode;
227 tmp.st_nlink = stat->nlink;
228 if (tmp.st_nlink != stat->nlink)
229 return -EOVERFLOW;
Eric W. Biedermana7c19382012-02-09 09:10:30 -0800230 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));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 tmp.st_rdev = old_encode_dev(stat->rdev);
233#if BITS_PER_LONG == 32
234 if (stat->size > MAX_NON_LFS)
235 return -EOVERFLOW;
David Howellsa528d352017-01-31 16:46:22 +0000236#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 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
David Howellsc7887322010-08-11 11:26:22 +0100244SYSCALL_DEFINE2(stat, const char __user *, filename,
245 struct __old_kernel_stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246{
247 struct kstat stat;
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400248 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400250 error = vfs_stat(filename, &stat);
251 if (error)
252 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400254 return cp_old_stat(&stat, statbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255}
Heiko Carstens257ac262009-01-14 14:14:13 +0100256
David Howellsc7887322010-08-11 11:26:22 +0100257SYSCALL_DEFINE2(lstat, const char __user *, filename,
258 struct __old_kernel_stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
260 struct kstat stat;
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400261 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400263 error = vfs_lstat(filename, &stat);
264 if (error)
265 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400267 return cp_old_stat(&stat, statbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268}
Heiko Carstens257ac262009-01-14 14:14:13 +0100269
270SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
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
Linus Torvaldsa52dd972012-05-06 17:47:30 -0700283#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
Linus Torvalds8529f612012-05-06 18:02:40 -0700289#ifndef INIT_STRUCT_STAT_PADDING
290# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
291#endif
292
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
294{
295 struct stat tmp;
296
Mikulas Patocka20160982022-04-12 05:41:00 -0400297 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
298 return -EOVERFLOW;
299 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 return -EOVERFLOW;
Linus Torvaldsa52dd972012-05-06 17:47:30 -0700301#if BITS_PER_LONG == 32
302 if (stat->size > MAX_NON_LFS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return -EOVERFLOW;
304#endif
305
Linus Torvalds8529f612012-05-06 18:02:40 -0700306 INIT_STRUCT_STAT_PADDING(tmp);
Mikulas Patocka20160982022-04-12 05:41:00 -0400307 tmp.st_dev = new_encode_dev(stat->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 tmp.st_ino = stat->ino;
David Howellsafefdbb2006-10-03 01:13:46 -0700309 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
310 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 tmp.st_mode = stat->mode;
312 tmp.st_nlink = stat->nlink;
313 if (tmp.st_nlink != stat->nlink)
314 return -EOVERFLOW;
Eric W. Biedermana7c19382012-02-09 09:10:30 -0800315 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
316 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
Mikulas Patocka20160982022-04-12 05:41:00 -0400317 tmp.st_rdev = new_encode_dev(stat->rdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 tmp.st_size = stat->size;
319 tmp.st_atime = stat->atime.tv_sec;
320 tmp.st_mtime = stat->mtime.tv_sec;
321 tmp.st_ctime = stat->ctime.tv_sec;
322#ifdef STAT_HAVE_NSEC
323 tmp.st_atime_nsec = stat->atime.tv_nsec;
324 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
325 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
326#endif
327 tmp.st_blocks = stat->blocks;
328 tmp.st_blksize = stat->blksize;
329 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
330}
331
David Howellsc7887322010-08-11 11:26:22 +0100332SYSCALL_DEFINE2(newstat, const char __user *, filename,
333 struct stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334{
335 struct kstat stat;
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400336 int error = vfs_stat(filename, &stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400338 if (error)
339 return error;
340 return cp_new_stat(&stat, statbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800342
David Howellsc7887322010-08-11 11:26:22 +0100343SYSCALL_DEFINE2(newlstat, const char __user *, filename,
344 struct stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345{
346 struct kstat stat;
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400347 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400349 error = vfs_lstat(filename, &stat);
350 if (error)
351 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Christoph Hellwig2eae7a12009-04-08 16:34:03 -0400353 return cp_new_stat(&stat, statbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800355
Andreas Schwab2833c282006-04-27 15:46:42 +0200356#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
David Howellsc7887322010-08-11 11:26:22 +0100357SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
Heiko Carstens6559eed82009-01-14 14:14:32 +0100358 struct stat __user *, statbuf, int, flag)
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800359{
360 struct kstat stat;
Oleg Drokin0112fc22009-04-08 20:05:42 +0400361 int error;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800362
Oleg Drokin0112fc22009-04-08 20:05:42 +0400363 error = vfs_fstatat(dfd, filename, &stat, flag);
364 if (error)
365 return error;
366 return cp_new_stat(&stat, statbuf);
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800367}
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800368#endif
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800369
Heiko Carstens257ac262009-01-14 14:14:13 +0100370SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
372 struct kstat stat;
373 int error = vfs_fstat(fd, &stat);
374
375 if (!error)
376 error = cp_new_stat(&stat, statbuf);
377
378 return error;
379}
380
Heiko Carstens6559eed82009-01-14 14:14:32 +0100381SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
382 char __user *, buf, int, bufsiz)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383{
Al Viro2d8f3032008-07-22 09:59:21 -0400384 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 int error;
Andy Whitcroft1fa1e7f2011-11-02 09:44:39 +0100386 int empty = 0;
Jeff Layton79551192012-12-11 12:10:06 -0500387 unsigned int lookup_flags = LOOKUP_EMPTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 if (bufsiz <= 0)
390 return -EINVAL;
391
Jeff Layton79551192012-12-11 12:10:06 -0500392retry:
393 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 if (!error) {
David Howellsbb6687342015-03-17 22:26:21 +0000395 struct inode *inode = d_backing_inode(path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Andy Whitcroft1fa1e7f2011-11-02 09:44:39 +0100397 error = empty ? -ENOENT : -EINVAL;
Miklos Szeredifd4a0ed2016-12-09 16:45:04 +0100398 /*
399 * AFS mountpoints allow readlink(2) but are not symlinks
400 */
401 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
Al Viro2d8f3032008-07-22 09:59:21 -0400402 error = security_inode_readlink(path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 if (!error) {
Al Viro68ac1232012-03-15 08:21:57 -0400404 touch_atime(&path);
Miklos Szeredifd4a0ed2016-12-09 16:45:04 +0100405 error = vfs_readlink(path.dentry, buf, bufsiz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 }
407 }
Al Viro2d8f3032008-07-22 09:59:21 -0400408 path_put(&path);
Jeff Layton79551192012-12-11 12:10:06 -0500409 if (retry_estale(error, lookup_flags)) {
410 lookup_flags |= LOOKUP_REVAL;
411 goto retry;
412 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 }
414 return error;
415}
416
Heiko Carstens002c8972009-01-14 14:14:18 +0100417SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
418 int, bufsiz)
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800419{
420 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
421}
422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
424/* ---------- LFS-64 ----------- */
Catalin Marinas0753f702012-03-19 15:13:51 +0000425#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
Linus Torvalds8529f612012-05-06 18:02:40 -0700427#ifndef INIT_STRUCT_STAT64_PADDING
428# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
429#endif
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
432{
433 struct stat64 tmp;
434
Linus Torvalds8529f612012-05-06 18:02:40 -0700435 INIT_STRUCT_STAT64_PADDING(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436#ifdef CONFIG_MIPS
437 /* mips has weird padding, so we don't get 64 bits there */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 tmp.st_dev = new_encode_dev(stat->dev);
439 tmp.st_rdev = new_encode_dev(stat->rdev);
440#else
441 tmp.st_dev = huge_encode_dev(stat->dev);
442 tmp.st_rdev = huge_encode_dev(stat->rdev);
443#endif
444 tmp.st_ino = stat->ino;
David Howellsafefdbb2006-10-03 01:13:46 -0700445 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
446 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447#ifdef STAT64_HAS_BROKEN_ST_INO
448 tmp.__st_ino = stat->ino;
449#endif
450 tmp.st_mode = stat->mode;
451 tmp.st_nlink = stat->nlink;
Eric W. Biedermana7c19382012-02-09 09:10:30 -0800452 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
453 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 tmp.st_atime = stat->atime.tv_sec;
455 tmp.st_atime_nsec = stat->atime.tv_nsec;
456 tmp.st_mtime = stat->mtime.tv_sec;
457 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
458 tmp.st_ctime = stat->ctime.tv_sec;
459 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
460 tmp.st_size = stat->size;
461 tmp.st_blocks = stat->blocks;
462 tmp.st_blksize = stat->blksize;
463 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
464}
465
David Howellsc7887322010-08-11 11:26:22 +0100466SYSCALL_DEFINE2(stat64, const char __user *, filename,
467 struct stat64 __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
469 struct kstat stat;
470 int error = vfs_stat(filename, &stat);
471
472 if (!error)
473 error = cp_new_stat64(&stat, statbuf);
474
475 return error;
476}
Heiko Carstens257ac262009-01-14 14:14:13 +0100477
David Howellsc7887322010-08-11 11:26:22 +0100478SYSCALL_DEFINE2(lstat64, const char __user *, filename,
479 struct stat64 __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480{
481 struct kstat stat;
482 int error = vfs_lstat(filename, &stat);
483
484 if (!error)
485 error = cp_new_stat64(&stat, statbuf);
486
487 return error;
488}
Heiko Carstens257ac262009-01-14 14:14:13 +0100489
490SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491{
492 struct kstat stat;
493 int error = vfs_fstat(fd, &stat);
494
495 if (!error)
496 error = cp_new_stat64(&stat, statbuf);
497
498 return error;
499}
500
David Howellsc7887322010-08-11 11:26:22 +0100501SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
Heiko Carstens6559eed82009-01-14 14:14:32 +0100502 struct stat64 __user *, statbuf, int, flag)
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800503{
504 struct kstat stat;
Oleg Drokin0112fc22009-04-08 20:05:42 +0400505 int error;
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800506
Oleg Drokin0112fc22009-04-08 20:05:42 +0400507 error = vfs_fstatat(dfd, filename, &stat, flag);
508 if (error)
509 return error;
510 return cp_new_stat64(&stat, statbuf);
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800511}
Catalin Marinas0753f702012-03-19 15:13:51 +0000512#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
Eric Biggers64bd7202017-03-31 18:31:48 +0100514static noinline_for_stack int
515cp_statx(const struct kstat *stat, struct statx __user *buffer)
David Howellsa528d352017-01-31 16:46:22 +0000516{
Eric Biggers64bd7202017-03-31 18:31:48 +0100517 struct statx tmp;
David Howellsa528d352017-01-31 16:46:22 +0000518
Eric Biggers64bd7202017-03-31 18:31:48 +0100519 memset(&tmp, 0, sizeof(tmp));
David Howellsa528d352017-01-31 16:46:22 +0000520
Eric Biggers64bd7202017-03-31 18:31:48 +0100521 tmp.stx_mask = stat->result_mask;
522 tmp.stx_blksize = stat->blksize;
523 tmp.stx_attributes = stat->attributes;
524 tmp.stx_nlink = stat->nlink;
525 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
526 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
527 tmp.stx_mode = stat->mode;
528 tmp.stx_ino = stat->ino;
529 tmp.stx_size = stat->size;
530 tmp.stx_blocks = stat->blocks;
David Howells3209f682017-03-31 18:32:17 +0100531 tmp.stx_attributes_mask = stat->attributes_mask;
Eric Biggers64bd7202017-03-31 18:31:48 +0100532 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
533 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
534 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
535 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
536 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
537 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
538 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
539 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
540 tmp.stx_rdev_major = MAJOR(stat->rdev);
541 tmp.stx_rdev_minor = MINOR(stat->rdev);
542 tmp.stx_dev_major = MAJOR(stat->dev);
543 tmp.stx_dev_minor = MINOR(stat->dev);
David Howellsa528d352017-01-31 16:46:22 +0000544
Eric Biggers64bd7202017-03-31 18:31:48 +0100545 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
David Howellsa528d352017-01-31 16:46:22 +0000546}
547
548/**
549 * sys_statx - System call to get enhanced stats
550 * @dfd: Base directory to pathwalk from *or* fd to stat.
David Howells1e2f82d2017-04-26 22:15:55 +0100551 * @filename: File to stat or "" with AT_EMPTY_PATH
David Howellsa528d352017-01-31 16:46:22 +0000552 * @flags: AT_* flags to control pathwalk.
553 * @mask: Parts of statx struct actually required.
554 * @buffer: Result buffer.
555 *
David Howells1e2f82d2017-04-26 22:15:55 +0100556 * Note that fstat() can be emulated by setting dfd to the fd of interest,
557 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
David Howellsa528d352017-01-31 16:46:22 +0000558 */
559SYSCALL_DEFINE5(statx,
560 int, dfd, const char __user *, filename, unsigned, flags,
561 unsigned int, mask,
562 struct statx __user *, buffer)
563{
564 struct kstat stat;
565 int error;
566
David Howells47071ae2017-03-31 18:32:10 +0100567 if (mask & STATX__RESERVED)
568 return -EINVAL;
David Howellsa528d352017-01-31 16:46:22 +0000569 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
570 return -EINVAL;
David Howellsa528d352017-01-31 16:46:22 +0000571
David Howells1e2f82d2017-04-26 22:15:55 +0100572 error = vfs_statx(dfd, filename, flags, &stat, mask);
David Howellsa528d352017-01-31 16:46:22 +0000573 if (error)
574 return error;
Eric Biggers64bd7202017-03-31 18:31:48 +0100575
576 return cp_statx(&stat, buffer);
David Howellsa528d352017-01-31 16:46:22 +0000577}
578
Al Viroac565de2017-04-08 18:13:00 -0400579#ifdef CONFIG_COMPAT
580static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
581{
582 struct compat_stat tmp;
583
Mikulas Patocka20160982022-04-12 05:41:00 -0400584 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
585 return -EOVERFLOW;
586 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
Al Viroac565de2017-04-08 18:13:00 -0400587 return -EOVERFLOW;
588
589 memset(&tmp, 0, sizeof(tmp));
Mikulas Patocka20160982022-04-12 05:41:00 -0400590 tmp.st_dev = new_encode_dev(stat->dev);
Al Viroac565de2017-04-08 18:13:00 -0400591 tmp.st_ino = stat->ino;
592 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
593 return -EOVERFLOW;
594 tmp.st_mode = stat->mode;
595 tmp.st_nlink = stat->nlink;
596 if (tmp.st_nlink != stat->nlink)
597 return -EOVERFLOW;
598 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
599 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
Mikulas Patocka20160982022-04-12 05:41:00 -0400600 tmp.st_rdev = new_encode_dev(stat->rdev);
Al Viroac565de2017-04-08 18:13:00 -0400601 if ((u64) stat->size > MAX_NON_LFS)
602 return -EOVERFLOW;
603 tmp.st_size = stat->size;
604 tmp.st_atime = stat->atime.tv_sec;
605 tmp.st_atime_nsec = stat->atime.tv_nsec;
606 tmp.st_mtime = stat->mtime.tv_sec;
607 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
608 tmp.st_ctime = stat->ctime.tv_sec;
609 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
610 tmp.st_blocks = stat->blocks;
611 tmp.st_blksize = stat->blksize;
612 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
613}
614
615COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
616 struct compat_stat __user *, statbuf)
617{
618 struct kstat stat;
619 int error;
620
621 error = vfs_stat(filename, &stat);
622 if (error)
623 return error;
624 return cp_compat_stat(&stat, statbuf);
625}
626
627COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
628 struct compat_stat __user *, statbuf)
629{
630 struct kstat stat;
631 int error;
632
633 error = vfs_lstat(filename, &stat);
634 if (error)
635 return error;
636 return cp_compat_stat(&stat, statbuf);
637}
638
639#ifndef __ARCH_WANT_STAT64
640COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
641 const char __user *, filename,
642 struct compat_stat __user *, statbuf, int, flag)
643{
644 struct kstat stat;
645 int error;
646
647 error = vfs_fstatat(dfd, filename, &stat, flag);
648 if (error)
649 return error;
650 return cp_compat_stat(&stat, statbuf);
651}
652#endif
653
654COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
655 struct compat_stat __user *, statbuf)
656{
657 struct kstat stat;
658 int error = vfs_fstat(fd, &stat);
659
660 if (!error)
661 error = cp_compat_stat(&stat, statbuf);
662 return error;
663}
664#endif
665
Dmitry Monakhovb4627072009-12-14 15:21:12 +0300666/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
667void __inode_add_bytes(struct inode *inode, loff_t bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 inode->i_blocks += bytes >> 9;
670 bytes &= 511;
671 inode->i_bytes += bytes;
672 if (inode->i_bytes >= 512) {
673 inode->i_blocks++;
674 inode->i_bytes -= 512;
675 }
Dmitry Monakhovb4627072009-12-14 15:21:12 +0300676}
Al Viroeb315d22017-06-08 21:15:03 -0400677EXPORT_SYMBOL(__inode_add_bytes);
Dmitry Monakhovb4627072009-12-14 15:21:12 +0300678
679void inode_add_bytes(struct inode *inode, loff_t bytes)
680{
681 spin_lock(&inode->i_lock);
682 __inode_add_bytes(inode, bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 spin_unlock(&inode->i_lock);
684}
685
686EXPORT_SYMBOL(inode_add_bytes);
687
Jan Kara1c8924e2013-08-17 09:32:32 -0400688void __inode_sub_bytes(struct inode *inode, loff_t bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 inode->i_blocks -= bytes >> 9;
691 bytes &= 511;
692 if (inode->i_bytes < bytes) {
693 inode->i_blocks--;
694 inode->i_bytes += 512;
695 }
696 inode->i_bytes -= bytes;
Jan Kara1c8924e2013-08-17 09:32:32 -0400697}
698
699EXPORT_SYMBOL(__inode_sub_bytes);
700
701void inode_sub_bytes(struct inode *inode, loff_t bytes)
702{
703 spin_lock(&inode->i_lock);
704 __inode_sub_bytes(inode, bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 spin_unlock(&inode->i_lock);
706}
707
708EXPORT_SYMBOL(inode_sub_bytes);
709
710loff_t inode_get_bytes(struct inode *inode)
711{
712 loff_t ret;
713
714 spin_lock(&inode->i_lock);
Jan Karaf4a8116a2017-08-08 09:54:36 +0200715 ret = __inode_get_bytes(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 spin_unlock(&inode->i_lock);
717 return ret;
718}
719
720EXPORT_SYMBOL(inode_get_bytes);
721
722void inode_set_bytes(struct inode *inode, loff_t bytes)
723{
724 /* Caller is here responsible for sufficient locking
725 * (ie. inode->i_lock) */
726 inode->i_blocks = bytes >> 9;
727 inode->i_bytes = bytes & 511;
728}
729
730EXPORT_SYMBOL(inode_set_bytes);