Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
7ed1ee61 | 2 | #include <linux/syscalls.h> |
630d9c47 | 3 | #include <linux/export.h> |
7ed1ee61 AV |
4 | #include <linux/fs.h> |
5 | #include <linux/file.h> | |
365b1818 | 6 | #include <linux/mount.h> |
7ed1ee61 AV |
7 | #include <linux/namei.h> |
8 | #include <linux/statfs.h> | |
9 | #include <linux/security.h> | |
10 | #include <linux/uaccess.h> | |
4ada54ee | 11 | #include <linux/compat.h> |
cf31e70d | 12 | #include "internal.h" |
7ed1ee61 | 13 | |
365b1818 CH |
14 | static int flags_by_mnt(int mnt_flags) |
15 | { | |
16 | int flags = 0; | |
17 | ||
18 | if (mnt_flags & MNT_READONLY) | |
19 | flags |= ST_RDONLY; | |
20 | if (mnt_flags & MNT_NOSUID) | |
21 | flags |= ST_NOSUID; | |
22 | if (mnt_flags & MNT_NODEV) | |
23 | flags |= ST_NODEV; | |
24 | if (mnt_flags & MNT_NOEXEC) | |
25 | flags |= ST_NOEXEC; | |
26 | if (mnt_flags & MNT_NOATIME) | |
27 | flags |= ST_NOATIME; | |
28 | if (mnt_flags & MNT_NODIRATIME) | |
29 | flags |= ST_NODIRATIME; | |
30 | if (mnt_flags & MNT_RELATIME) | |
31 | flags |= ST_RELATIME; | |
dab741e0 MN |
32 | if (mnt_flags & MNT_NOSYMFOLLOW) |
33 | flags |= ST_NOSYMFOLLOW; | |
365b1818 CH |
34 | return flags; |
35 | } | |
36 | ||
37 | static int flags_by_sb(int s_flags) | |
38 | { | |
39 | int flags = 0; | |
1751e8a6 | 40 | if (s_flags & SB_SYNCHRONOUS) |
365b1818 | 41 | flags |= ST_SYNCHRONOUS; |
1751e8a6 | 42 | if (s_flags & SB_MANDLOCK) |
365b1818 | 43 | flags |= ST_MANDLOCK; |
1751e8a6 | 44 | if (s_flags & SB_RDONLY) |
a8e2b636 | 45 | flags |= ST_RDONLY; |
365b1818 CH |
46 | return flags; |
47 | } | |
48 | ||
49 | static int calculate_f_flags(struct vfsmount *mnt) | |
50 | { | |
51 | return ST_VALID | flags_by_mnt(mnt->mnt_flags) | | |
52 | flags_by_sb(mnt->mnt_sb->s_flags); | |
53 | } | |
54 | ||
cf31e70d | 55 | static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf) |
7ed1ee61 | 56 | { |
ebabe9a9 CH |
57 | int retval; |
58 | ||
59 | if (!dentry->d_sb->s_op->statfs) | |
60 | return -ENOSYS; | |
61 | ||
62 | memset(buf, 0, sizeof(*buf)); | |
63 | retval = security_sb_statfs(dentry); | |
64 | if (retval) | |
65 | return retval; | |
66 | retval = dentry->d_sb->s_op->statfs(dentry, buf); | |
67 | if (retval == 0 && buf->f_frsize == 0) | |
68 | buf->f_frsize = buf->f_bsize; | |
7ed1ee61 AV |
69 | return retval; |
70 | } | |
71 | ||
ec86ff56 AG |
72 | int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid) |
73 | { | |
74 | struct kstatfs st; | |
75 | int error; | |
76 | ||
77 | error = statfs_by_dentry(dentry, &st); | |
78 | if (error) | |
79 | return error; | |
80 | ||
81 | *fsid = st.f_fsid; | |
82 | return 0; | |
83 | } | |
84 | EXPORT_SYMBOL(vfs_get_fsid); | |
85 | ||
f0bb5aaf | 86 | int vfs_statfs(const struct path *path, struct kstatfs *buf) |
ebabe9a9 | 87 | { |
365b1818 CH |
88 | int error; |
89 | ||
90 | error = statfs_by_dentry(path->dentry, buf); | |
91 | if (!error) | |
92 | buf->f_flags = calculate_f_flags(path->mnt); | |
93 | return error; | |
ebabe9a9 | 94 | } |
7ed1ee61 AV |
95 | EXPORT_SYMBOL(vfs_statfs); |
96 | ||
c8b91acc | 97 | int user_statfs(const char __user *pathname, struct kstatfs *st) |
7ed1ee61 | 98 | { |
c8b91acc | 99 | struct path path; |
96948fc6 JL |
100 | int error; |
101 | unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT; | |
102 | retry: | |
103 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
c8b91acc AV |
104 | if (!error) { |
105 | error = vfs_statfs(&path, st); | |
106 | path_put(&path); | |
96948fc6 JL |
107 | if (retry_estale(error, lookup_flags)) { |
108 | lookup_flags |= LOOKUP_REVAL; | |
109 | goto retry; | |
110 | } | |
c8b91acc AV |
111 | } |
112 | return error; | |
113 | } | |
7ed1ee61 | 114 | |
c8b91acc AV |
115 | int fd_statfs(int fd, struct kstatfs *st) |
116 | { | |
04818199 AV |
117 | CLASS(fd_raw, f)(fd); |
118 | ||
119 | if (fd_empty(f)) | |
120 | return -EBADF; | |
121 | return vfs_statfs(&fd_file(f)->f_path, st); | |
c8b91acc | 122 | } |
7ed1ee61 | 123 | |
c8b91acc AV |
124 | static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) |
125 | { | |
126 | struct statfs buf; | |
127 | ||
128 | if (sizeof(buf) == sizeof(*st)) | |
129 | memcpy(&buf, st, sizeof(*st)); | |
7ed1ee61 | 130 | else { |
ed40866e | 131 | memset(&buf, 0, sizeof(buf)); |
c8b91acc AV |
132 | if (sizeof buf.f_blocks == 4) { |
133 | if ((st->f_blocks | st->f_bfree | st->f_bavail | | |
134 | st->f_bsize | st->f_frsize) & | |
7ed1ee61 AV |
135 | 0xffffffff00000000ULL) |
136 | return -EOVERFLOW; | |
137 | /* | |
138 | * f_files and f_ffree may be -1; it's okay to stuff | |
139 | * that into 32 bits | |
140 | */ | |
c8b91acc AV |
141 | if (st->f_files != -1 && |
142 | (st->f_files & 0xffffffff00000000ULL)) | |
7ed1ee61 | 143 | return -EOVERFLOW; |
c8b91acc AV |
144 | if (st->f_ffree != -1 && |
145 | (st->f_ffree & 0xffffffff00000000ULL)) | |
7ed1ee61 AV |
146 | return -EOVERFLOW; |
147 | } | |
148 | ||
c8b91acc AV |
149 | buf.f_type = st->f_type; |
150 | buf.f_bsize = st->f_bsize; | |
151 | buf.f_blocks = st->f_blocks; | |
152 | buf.f_bfree = st->f_bfree; | |
153 | buf.f_bavail = st->f_bavail; | |
154 | buf.f_files = st->f_files; | |
155 | buf.f_ffree = st->f_ffree; | |
156 | buf.f_fsid = st->f_fsid; | |
157 | buf.f_namelen = st->f_namelen; | |
158 | buf.f_frsize = st->f_frsize; | |
159 | buf.f_flags = st->f_flags; | |
7ed1ee61 | 160 | } |
c8b91acc AV |
161 | if (copy_to_user(p, &buf, sizeof(buf))) |
162 | return -EFAULT; | |
7ed1ee61 AV |
163 | return 0; |
164 | } | |
165 | ||
c8b91acc | 166 | static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) |
7ed1ee61 | 167 | { |
c8b91acc AV |
168 | struct statfs64 buf; |
169 | if (sizeof(buf) == sizeof(*st)) | |
170 | memcpy(&buf, st, sizeof(*st)); | |
7ed1ee61 | 171 | else { |
ed40866e | 172 | memset(&buf, 0, sizeof(buf)); |
c8b91acc AV |
173 | buf.f_type = st->f_type; |
174 | buf.f_bsize = st->f_bsize; | |
175 | buf.f_blocks = st->f_blocks; | |
176 | buf.f_bfree = st->f_bfree; | |
177 | buf.f_bavail = st->f_bavail; | |
178 | buf.f_files = st->f_files; | |
179 | buf.f_ffree = st->f_ffree; | |
180 | buf.f_fsid = st->f_fsid; | |
181 | buf.f_namelen = st->f_namelen; | |
182 | buf.f_frsize = st->f_frsize; | |
183 | buf.f_flags = st->f_flags; | |
7ed1ee61 | 184 | } |
c8b91acc AV |
185 | if (copy_to_user(p, &buf, sizeof(buf))) |
186 | return -EFAULT; | |
7ed1ee61 AV |
187 | return 0; |
188 | } | |
189 | ||
190 | SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) | |
191 | { | |
c8b91acc AV |
192 | struct kstatfs st; |
193 | int error = user_statfs(pathname, &st); | |
194 | if (!error) | |
195 | error = do_statfs_native(&st, buf); | |
7ed1ee61 AV |
196 | return error; |
197 | } | |
198 | ||
199 | SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) | |
200 | { | |
c8b91acc AV |
201 | struct kstatfs st; |
202 | int error; | |
7ed1ee61 AV |
203 | if (sz != sizeof(*buf)) |
204 | return -EINVAL; | |
c8b91acc AV |
205 | error = user_statfs(pathname, &st); |
206 | if (!error) | |
207 | error = do_statfs64(&st, buf); | |
7ed1ee61 AV |
208 | return error; |
209 | } | |
210 | ||
211 | SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) | |
212 | { | |
c8b91acc AV |
213 | struct kstatfs st; |
214 | int error = fd_statfs(fd, &st); | |
215 | if (!error) | |
216 | error = do_statfs_native(&st, buf); | |
7ed1ee61 AV |
217 | return error; |
218 | } | |
219 | ||
220 | SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) | |
221 | { | |
c8b91acc | 222 | struct kstatfs st; |
7ed1ee61 AV |
223 | int error; |
224 | ||
225 | if (sz != sizeof(*buf)) | |
226 | return -EINVAL; | |
227 | ||
c8b91acc AV |
228 | error = fd_statfs(fd, &st); |
229 | if (!error) | |
230 | error = do_statfs64(&st, buf); | |
7ed1ee61 AV |
231 | return error; |
232 | } | |
233 | ||
53fd88ab | 234 | static int vfs_ustat(dev_t dev, struct kstatfs *sbuf) |
7ed1ee61 | 235 | { |
4e7b5671 | 236 | struct super_block *s = user_get_super(dev, false); |
7ed1ee61 | 237 | int err; |
7ed1ee61 AV |
238 | if (!s) |
239 | return -EINVAL; | |
240 | ||
cf31e70d | 241 | err = statfs_by_dentry(s->s_root, sbuf); |
7ed1ee61 | 242 | drop_super(s); |
cf31e70d AV |
243 | return err; |
244 | } | |
245 | ||
246 | SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf) | |
247 | { | |
248 | struct ustat tmp; | |
249 | struct kstatfs sbuf; | |
250 | int err = vfs_ustat(new_decode_dev(dev), &sbuf); | |
7ed1ee61 AV |
251 | if (err) |
252 | return err; | |
253 | ||
254 | memset(&tmp,0,sizeof(struct ustat)); | |
255 | tmp.f_tfree = sbuf.f_bfree; | |
96c0a6a7 HC |
256 | if (IS_ENABLED(CONFIG_ARCH_32BIT_USTAT_F_TINODE)) |
257 | tmp.f_tinode = min_t(u64, sbuf.f_ffree, UINT_MAX); | |
258 | else | |
259 | tmp.f_tinode = sbuf.f_ffree; | |
7ed1ee61 AV |
260 | |
261 | return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0; | |
262 | } | |
4ada54ee AV |
263 | |
264 | #ifdef CONFIG_COMPAT | |
265 | static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf) | |
266 | { | |
ae2a9762 | 267 | struct compat_statfs buf; |
4ada54ee AV |
268 | if (sizeof ubuf->f_blocks == 4) { |
269 | if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | | |
270 | kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) | |
271 | return -EOVERFLOW; | |
272 | /* f_files and f_ffree may be -1; it's okay | |
273 | * to stuff that into 32 bits */ | |
274 | if (kbuf->f_files != 0xffffffffffffffffULL | |
275 | && (kbuf->f_files & 0xffffffff00000000ULL)) | |
276 | return -EOVERFLOW; | |
277 | if (kbuf->f_ffree != 0xffffffffffffffffULL | |
278 | && (kbuf->f_ffree & 0xffffffff00000000ULL)) | |
279 | return -EOVERFLOW; | |
280 | } | |
ae2a9762 AV |
281 | memset(&buf, 0, sizeof(struct compat_statfs)); |
282 | buf.f_type = kbuf->f_type; | |
283 | buf.f_bsize = kbuf->f_bsize; | |
284 | buf.f_blocks = kbuf->f_blocks; | |
285 | buf.f_bfree = kbuf->f_bfree; | |
286 | buf.f_bavail = kbuf->f_bavail; | |
287 | buf.f_files = kbuf->f_files; | |
288 | buf.f_ffree = kbuf->f_ffree; | |
289 | buf.f_namelen = kbuf->f_namelen; | |
290 | buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; | |
291 | buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; | |
292 | buf.f_frsize = kbuf->f_frsize; | |
293 | buf.f_flags = kbuf->f_flags; | |
294 | if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs))) | |
4ada54ee AV |
295 | return -EFAULT; |
296 | return 0; | |
297 | } | |
298 | ||
299 | /* | |
300 | * The following statfs calls are copies of code from fs/statfs.c and | |
301 | * should be checked against those from time to time | |
302 | */ | |
303 | COMPAT_SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct compat_statfs __user *, buf) | |
304 | { | |
305 | struct kstatfs tmp; | |
306 | int error = user_statfs(pathname, &tmp); | |
307 | if (!error) | |
308 | error = put_compat_statfs(buf, &tmp); | |
309 | return error; | |
310 | } | |
311 | ||
312 | COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, buf) | |
313 | { | |
314 | struct kstatfs tmp; | |
315 | int error = fd_statfs(fd, &tmp); | |
316 | if (!error) | |
317 | error = put_compat_statfs(buf, &tmp); | |
318 | return error; | |
319 | } | |
320 | ||
321 | static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) | |
322 | { | |
ae2a9762 | 323 | struct compat_statfs64 buf; |
cc3a7bfe ES |
324 | |
325 | if ((kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) | |
326 | return -EOVERFLOW; | |
327 | ||
ae2a9762 AV |
328 | memset(&buf, 0, sizeof(struct compat_statfs64)); |
329 | buf.f_type = kbuf->f_type; | |
330 | buf.f_bsize = kbuf->f_bsize; | |
331 | buf.f_blocks = kbuf->f_blocks; | |
332 | buf.f_bfree = kbuf->f_bfree; | |
333 | buf.f_bavail = kbuf->f_bavail; | |
334 | buf.f_files = kbuf->f_files; | |
335 | buf.f_ffree = kbuf->f_ffree; | |
336 | buf.f_namelen = kbuf->f_namelen; | |
337 | buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; | |
338 | buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; | |
339 | buf.f_frsize = kbuf->f_frsize; | |
340 | buf.f_flags = kbuf->f_flags; | |
341 | if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs64))) | |
4ada54ee AV |
342 | return -EFAULT; |
343 | return 0; | |
344 | } | |
345 | ||
9b54bf9d | 346 | int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf) |
4ada54ee AV |
347 | { |
348 | struct kstatfs tmp; | |
349 | int error; | |
350 | ||
351 | if (sz != sizeof(*buf)) | |
352 | return -EINVAL; | |
353 | ||
354 | error = user_statfs(pathname, &tmp); | |
355 | if (!error) | |
356 | error = put_compat_statfs64(buf, &tmp); | |
357 | return error; | |
358 | } | |
359 | ||
9b54bf9d MR |
360 | COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) |
361 | { | |
362 | return kcompat_sys_statfs64(pathname, sz, buf); | |
363 | } | |
364 | ||
365 | int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf) | |
4ada54ee AV |
366 | { |
367 | struct kstatfs tmp; | |
368 | int error; | |
369 | ||
370 | if (sz != sizeof(*buf)) | |
371 | return -EINVAL; | |
372 | ||
373 | error = fd_statfs(fd, &tmp); | |
374 | if (!error) | |
375 | error = put_compat_statfs64(buf, &tmp); | |
376 | return error; | |
377 | } | |
378 | ||
9b54bf9d MR |
379 | COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) |
380 | { | |
381 | return kcompat_sys_fstatfs64(fd, sz, buf); | |
382 | } | |
383 | ||
4ada54ee AV |
384 | /* |
385 | * This is a copy of sys_ustat, just dealing with a structure layout. | |
386 | * Given how simple this syscall is that apporach is more maintainable | |
387 | * than the various conversion hacks. | |
388 | */ | |
389 | COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u) | |
390 | { | |
391 | struct compat_ustat tmp; | |
392 | struct kstatfs sbuf; | |
393 | int err = vfs_ustat(new_decode_dev(dev), &sbuf); | |
394 | if (err) | |
395 | return err; | |
396 | ||
397 | memset(&tmp, 0, sizeof(struct compat_ustat)); | |
398 | tmp.f_tfree = sbuf.f_bfree; | |
399 | tmp.f_tinode = sbuf.f_ffree; | |
400 | if (copy_to_user(u, &tmp, sizeof(struct compat_ustat))) | |
401 | return -EFAULT; | |
402 | return 0; | |
403 | } | |
404 | #endif |