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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/fcntl.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/syscalls.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/mm.h> | |
29930025 | 10 | #include <linux/sched/task.h> |
1da177e4 LT |
11 | #include <linux/fs.h> |
12 | #include <linux/file.h> | |
9f3acc31 | 13 | #include <linux/fdtable.h> |
16f7e0fe | 14 | #include <linux/capability.h> |
1da177e4 | 15 | #include <linux/dnotify.h> |
1da177e4 LT |
16 | #include <linux/slab.h> |
17 | #include <linux/module.h> | |
35f3d14d | 18 | #include <linux/pipe_fs_i.h> |
1da177e4 LT |
19 | #include <linux/security.h> |
20 | #include <linux/ptrace.h> | |
7ed20e1a | 21 | #include <linux/signal.h> |
ab2af1f5 | 22 | #include <linux/rcupdate.h> |
b488893a | 23 | #include <linux/pid_namespace.h> |
1d151c33 | 24 | #include <linux/user_namespace.h> |
40e041a2 | 25 | #include <linux/shmem_fs.h> |
80f0cce6 | 26 | #include <linux/compat.h> |
1da177e4 LT |
27 | |
28 | #include <asm/poll.h> | |
29 | #include <asm/siginfo.h> | |
7c0f6ba6 | 30 | #include <linux/uaccess.h> |
1da177e4 | 31 | |
76398425 | 32 | #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) |
1da177e4 LT |
33 | |
34 | static int setfl(int fd, struct file * filp, unsigned long arg) | |
35 | { | |
496ad9aa | 36 | struct inode * inode = file_inode(filp); |
1da177e4 LT |
37 | int error = 0; |
38 | ||
7d95c8f2 | 39 | /* |
40 | * O_APPEND cannot be cleared if the file is marked as append-only | |
41 | * and the file is open for write. | |
42 | */ | |
43 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
1da177e4 LT |
44 | return -EPERM; |
45 | ||
46 | /* O_NOATIME can only be set by the owner or superuser */ | |
47 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) | |
2e149670 | 48 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
49 | return -EPERM; |
50 | ||
51 | /* required for strict SunOS emulation */ | |
52 | if (O_NONBLOCK != O_NDELAY) | |
53 | if (arg & O_NDELAY) | |
54 | arg |= O_NONBLOCK; | |
55 | ||
0dbf5f20 | 56 | /* Pipe packetized mode is controlled by O_DIRECT flag */ |
45063097 | 57 | if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) { |
1da177e4 LT |
58 | if (!filp->f_mapping || !filp->f_mapping->a_ops || |
59 | !filp->f_mapping->a_ops->direct_IO) | |
60 | return -EINVAL; | |
61 | } | |
62 | ||
72c2d531 | 63 | if (filp->f_op->check_flags) |
1da177e4 LT |
64 | error = filp->f_op->check_flags(arg); |
65 | if (error) | |
66 | return error; | |
67 | ||
218d11a8 | 68 | /* |
76398425 | 69 | * ->fasync() is responsible for setting the FASYNC bit. |
218d11a8 | 70 | */ |
72c2d531 | 71 | if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) { |
76398425 JC |
72 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); |
73 | if (error < 0) | |
74 | goto out; | |
60aa4924 JC |
75 | if (error > 0) |
76 | error = 0; | |
1da177e4 | 77 | } |
db1dd4d3 | 78 | spin_lock(&filp->f_lock); |
1da177e4 | 79 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
db1dd4d3 | 80 | spin_unlock(&filp->f_lock); |
76398425 | 81 | |
1da177e4 | 82 | out: |
1da177e4 LT |
83 | return error; |
84 | } | |
85 | ||
609d7fa9 | 86 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
2f38d70f | 87 | int force) |
1da177e4 | 88 | { |
80e1e823 | 89 | write_lock_irq(&filp->f_owner.lock); |
1da177e4 | 90 | if (force || !filp->f_owner.pid) { |
609d7fa9 EB |
91 | put_pid(filp->f_owner.pid); |
92 | filp->f_owner.pid = get_pid(pid); | |
93 | filp->f_owner.pid_type = type; | |
2f38d70f ON |
94 | |
95 | if (pid) { | |
96 | const struct cred *cred = current_cred(); | |
97 | filp->f_owner.uid = cred->uid; | |
98 | filp->f_owner.euid = cred->euid; | |
99 | } | |
1da177e4 | 100 | } |
80e1e823 | 101 | write_unlock_irq(&filp->f_owner.lock); |
1da177e4 LT |
102 | } |
103 | ||
e0b93edd | 104 | void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
609d7fa9 | 105 | int force) |
1da177e4 | 106 | { |
e0b93edd | 107 | security_file_set_fowner(filp); |
2f38d70f | 108 | f_modown(filp, pid, type, force); |
1da177e4 | 109 | } |
609d7fa9 | 110 | EXPORT_SYMBOL(__f_setown); |
1da177e4 | 111 | |
393cc3f5 | 112 | int f_setown(struct file *filp, unsigned long arg, int force) |
609d7fa9 EB |
113 | { |
114 | enum pid_type type; | |
115 | struct pid *pid; | |
116 | int who = arg; | |
609d7fa9 EB |
117 | type = PIDTYPE_PID; |
118 | if (who < 0) { | |
119 | type = PIDTYPE_PGID; | |
120 | who = -who; | |
121 | } | |
122 | rcu_read_lock(); | |
b488893a | 123 | pid = find_vpid(who); |
e0b93edd | 124 | __f_setown(filp, pid, type, force); |
609d7fa9 | 125 | rcu_read_unlock(); |
393cc3f5 JS |
126 | |
127 | return 0; | |
609d7fa9 | 128 | } |
1da177e4 LT |
129 | EXPORT_SYMBOL(f_setown); |
130 | ||
131 | void f_delown(struct file *filp) | |
132 | { | |
2f38d70f | 133 | f_modown(filp, NULL, PIDTYPE_PID, 1); |
609d7fa9 EB |
134 | } |
135 | ||
136 | pid_t f_getown(struct file *filp) | |
137 | { | |
138 | pid_t pid; | |
43fa1adb | 139 | read_lock(&filp->f_owner.lock); |
6c5f3e7b | 140 | pid = pid_vnr(filp->f_owner.pid); |
609d7fa9 EB |
141 | if (filp->f_owner.pid_type == PIDTYPE_PGID) |
142 | pid = -pid; | |
43fa1adb | 143 | read_unlock(&filp->f_owner.lock); |
609d7fa9 | 144 | return pid; |
1da177e4 LT |
145 | } |
146 | ||
ba0a6c9f PZ |
147 | static int f_setown_ex(struct file *filp, unsigned long arg) |
148 | { | |
63784dd0 | 149 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f PZ |
150 | struct f_owner_ex owner; |
151 | struct pid *pid; | |
152 | int type; | |
153 | int ret; | |
154 | ||
155 | ret = copy_from_user(&owner, owner_p, sizeof(owner)); | |
156 | if (ret) | |
5b54470d | 157 | return -EFAULT; |
ba0a6c9f PZ |
158 | |
159 | switch (owner.type) { | |
160 | case F_OWNER_TID: | |
161 | type = PIDTYPE_MAX; | |
162 | break; | |
163 | ||
164 | case F_OWNER_PID: | |
165 | type = PIDTYPE_PID; | |
166 | break; | |
167 | ||
978b4053 | 168 | case F_OWNER_PGRP: |
ba0a6c9f PZ |
169 | type = PIDTYPE_PGID; |
170 | break; | |
171 | ||
172 | default: | |
173 | return -EINVAL; | |
174 | } | |
175 | ||
176 | rcu_read_lock(); | |
177 | pid = find_vpid(owner.pid); | |
178 | if (owner.pid && !pid) | |
179 | ret = -ESRCH; | |
180 | else | |
e0b93edd | 181 | __f_setown(filp, pid, type, 1); |
ba0a6c9f PZ |
182 | rcu_read_unlock(); |
183 | ||
184 | return ret; | |
185 | } | |
186 | ||
187 | static int f_getown_ex(struct file *filp, unsigned long arg) | |
188 | { | |
63784dd0 | 189 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f PZ |
190 | struct f_owner_ex owner; |
191 | int ret = 0; | |
192 | ||
193 | read_lock(&filp->f_owner.lock); | |
194 | owner.pid = pid_vnr(filp->f_owner.pid); | |
195 | switch (filp->f_owner.pid_type) { | |
196 | case PIDTYPE_MAX: | |
197 | owner.type = F_OWNER_TID; | |
198 | break; | |
199 | ||
200 | case PIDTYPE_PID: | |
201 | owner.type = F_OWNER_PID; | |
202 | break; | |
203 | ||
204 | case PIDTYPE_PGID: | |
978b4053 | 205 | owner.type = F_OWNER_PGRP; |
ba0a6c9f PZ |
206 | break; |
207 | ||
208 | default: | |
209 | WARN_ON(1); | |
210 | ret = -EINVAL; | |
211 | break; | |
212 | } | |
213 | read_unlock(&filp->f_owner.lock); | |
214 | ||
5b54470d | 215 | if (!ret) { |
ba0a6c9f | 216 | ret = copy_to_user(owner_p, &owner, sizeof(owner)); |
5b54470d DC |
217 | if (ret) |
218 | ret = -EFAULT; | |
219 | } | |
ba0a6c9f PZ |
220 | return ret; |
221 | } | |
222 | ||
1d151c33 CG |
223 | #ifdef CONFIG_CHECKPOINT_RESTORE |
224 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
225 | { | |
226 | struct user_namespace *user_ns = current_user_ns(); | |
63784dd0 | 227 | uid_t __user *dst = (void __user *)arg; |
1d151c33 CG |
228 | uid_t src[2]; |
229 | int err; | |
230 | ||
231 | read_lock(&filp->f_owner.lock); | |
232 | src[0] = from_kuid(user_ns, filp->f_owner.uid); | |
233 | src[1] = from_kuid(user_ns, filp->f_owner.euid); | |
234 | read_unlock(&filp->f_owner.lock); | |
235 | ||
236 | err = put_user(src[0], &dst[0]); | |
237 | err |= put_user(src[1], &dst[1]); | |
238 | ||
239 | return err; | |
240 | } | |
241 | #else | |
242 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
243 | { | |
244 | return -EINVAL; | |
245 | } | |
246 | #endif | |
247 | ||
1da177e4 LT |
248 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, |
249 | struct file *filp) | |
250 | { | |
a75d30c7 CH |
251 | void __user *argp = (void __user *)arg; |
252 | struct flock flock; | |
1da177e4 LT |
253 | long err = -EINVAL; |
254 | ||
255 | switch (cmd) { | |
256 | case F_DUPFD: | |
fe17f22d AV |
257 | err = f_dupfd(arg, filp, 0); |
258 | break; | |
22d2b35b | 259 | case F_DUPFD_CLOEXEC: |
12197718 | 260 | err = f_dupfd(arg, filp, O_CLOEXEC); |
1da177e4 LT |
261 | break; |
262 | case F_GETFD: | |
263 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; | |
264 | break; | |
265 | case F_SETFD: | |
266 | err = 0; | |
267 | set_close_on_exec(fd, arg & FD_CLOEXEC); | |
268 | break; | |
269 | case F_GETFL: | |
270 | err = filp->f_flags; | |
271 | break; | |
272 | case F_SETFL: | |
273 | err = setfl(fd, filp, arg); | |
274 | break; | |
5d50ffd7 JL |
275 | #if BITS_PER_LONG != 32 |
276 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d | 277 | case F_OFD_GETLK: |
5d50ffd7 | 278 | #endif |
1da177e4 | 279 | case F_GETLK: |
a75d30c7 CH |
280 | if (copy_from_user(&flock, argp, sizeof(flock))) |
281 | return -EFAULT; | |
282 | err = fcntl_getlk(filp, cmd, &flock); | |
283 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
284 | return -EFAULT; | |
1da177e4 | 285 | break; |
5d50ffd7 JL |
286 | #if BITS_PER_LONG != 32 |
287 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d JL |
288 | case F_OFD_SETLK: |
289 | case F_OFD_SETLKW: | |
5d50ffd7 JL |
290 | #endif |
291 | /* Fallthrough */ | |
1da177e4 LT |
292 | case F_SETLK: |
293 | case F_SETLKW: | |
a75d30c7 CH |
294 | if (copy_from_user(&flock, argp, sizeof(flock))) |
295 | return -EFAULT; | |
296 | err = fcntl_setlk(fd, filp, cmd, &flock); | |
1da177e4 LT |
297 | break; |
298 | case F_GETOWN: | |
299 | /* | |
300 | * XXX If f_owner is a process group, the | |
301 | * negative return value will get converted | |
302 | * into an error. Oops. If we keep the | |
303 | * current syscall conventions, the only way | |
304 | * to fix this will be in libc. | |
305 | */ | |
609d7fa9 | 306 | err = f_getown(filp); |
1da177e4 LT |
307 | force_successful_syscall_return(); |
308 | break; | |
309 | case F_SETOWN: | |
393cc3f5 | 310 | err = f_setown(filp, arg, 1); |
1da177e4 | 311 | break; |
ba0a6c9f PZ |
312 | case F_GETOWN_EX: |
313 | err = f_getown_ex(filp, arg); | |
314 | break; | |
315 | case F_SETOWN_EX: | |
316 | err = f_setown_ex(filp, arg); | |
317 | break; | |
1d151c33 CG |
318 | case F_GETOWNER_UIDS: |
319 | err = f_getowner_uids(filp, arg); | |
320 | break; | |
1da177e4 LT |
321 | case F_GETSIG: |
322 | err = filp->f_owner.signum; | |
323 | break; | |
324 | case F_SETSIG: | |
325 | /* arg == 0 restores default behaviour. */ | |
7ed20e1a | 326 | if (!valid_signal(arg)) { |
1da177e4 LT |
327 | break; |
328 | } | |
329 | err = 0; | |
330 | filp->f_owner.signum = arg; | |
331 | break; | |
332 | case F_GETLEASE: | |
333 | err = fcntl_getlease(filp); | |
334 | break; | |
335 | case F_SETLEASE: | |
336 | err = fcntl_setlease(fd, filp, arg); | |
337 | break; | |
338 | case F_NOTIFY: | |
339 | err = fcntl_dirnotify(fd, filp, arg); | |
340 | break; | |
35f3d14d JA |
341 | case F_SETPIPE_SZ: |
342 | case F_GETPIPE_SZ: | |
343 | err = pipe_fcntl(filp, cmd, arg); | |
344 | break; | |
40e041a2 DH |
345 | case F_ADD_SEALS: |
346 | case F_GET_SEALS: | |
347 | err = shmem_fcntl(filp, cmd, arg); | |
348 | break; | |
1da177e4 LT |
349 | default: |
350 | break; | |
351 | } | |
352 | return err; | |
353 | } | |
354 | ||
1abf0c71 AV |
355 | static int check_fcntl_cmd(unsigned cmd) |
356 | { | |
357 | switch (cmd) { | |
358 | case F_DUPFD: | |
359 | case F_DUPFD_CLOEXEC: | |
360 | case F_GETFD: | |
361 | case F_SETFD: | |
362 | case F_GETFL: | |
363 | return 1; | |
364 | } | |
365 | return 0; | |
366 | } | |
367 | ||
a26eab24 | 368 | SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
1da177e4 | 369 | { |
2903ff01 | 370 | struct fd f = fdget_raw(fd); |
1da177e4 LT |
371 | long err = -EBADF; |
372 | ||
2903ff01 | 373 | if (!f.file) |
1da177e4 LT |
374 | goto out; |
375 | ||
2903ff01 | 376 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
377 | if (!check_fcntl_cmd(cmd)) |
378 | goto out1; | |
1abf0c71 AV |
379 | } |
380 | ||
2903ff01 | 381 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 | 382 | if (!err) |
2903ff01 | 383 | err = do_fcntl(fd, cmd, arg, f.file); |
1da177e4 | 384 | |
545ec2c7 | 385 | out1: |
2903ff01 | 386 | fdput(f); |
1da177e4 LT |
387 | out: |
388 | return err; | |
389 | } | |
390 | ||
391 | #if BITS_PER_LONG == 32 | |
a26eab24 HC |
392 | SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
393 | unsigned long, arg) | |
1da177e4 | 394 | { |
a75d30c7 | 395 | void __user *argp = (void __user *)arg; |
2903ff01 | 396 | struct fd f = fdget_raw(fd); |
a75d30c7 | 397 | struct flock64 flock; |
545ec2c7 | 398 | long err = -EBADF; |
1da177e4 | 399 | |
2903ff01 | 400 | if (!f.file) |
1da177e4 LT |
401 | goto out; |
402 | ||
2903ff01 | 403 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
404 | if (!check_fcntl_cmd(cmd)) |
405 | goto out1; | |
1abf0c71 AV |
406 | } |
407 | ||
2903ff01 | 408 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 AV |
409 | if (err) |
410 | goto out1; | |
1da177e4 LT |
411 | |
412 | switch (cmd) { | |
5d50ffd7 | 413 | case F_GETLK64: |
0d3f7a2d | 414 | case F_OFD_GETLK: |
a75d30c7 CH |
415 | err = -EFAULT; |
416 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
417 | break; | |
418 | err = fcntl_getlk64(f.file, cmd, &flock); | |
419 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
420 | err = -EFAULT; | |
5d50ffd7 JL |
421 | break; |
422 | case F_SETLK64: | |
423 | case F_SETLKW64: | |
0d3f7a2d JL |
424 | case F_OFD_SETLK: |
425 | case F_OFD_SETLKW: | |
a75d30c7 CH |
426 | err = -EFAULT; |
427 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
428 | break; | |
429 | err = fcntl_setlk64(fd, f.file, cmd, &flock); | |
5d50ffd7 JL |
430 | break; |
431 | default: | |
432 | err = do_fcntl(fd, cmd, arg, f.file); | |
433 | break; | |
1da177e4 | 434 | } |
545ec2c7 | 435 | out1: |
2903ff01 | 436 | fdput(f); |
1da177e4 LT |
437 | out: |
438 | return err; | |
439 | } | |
440 | #endif | |
441 | ||
80f0cce6 AV |
442 | #ifdef CONFIG_COMPAT |
443 | static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) | |
444 | { | |
445 | if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || | |
446 | __get_user(kfl->l_type, &ufl->l_type) || | |
447 | __get_user(kfl->l_whence, &ufl->l_whence) || | |
448 | __get_user(kfl->l_start, &ufl->l_start) || | |
449 | __get_user(kfl->l_len, &ufl->l_len) || | |
450 | __get_user(kfl->l_pid, &ufl->l_pid)) | |
451 | return -EFAULT; | |
452 | return 0; | |
453 | } | |
454 | ||
455 | static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) | |
456 | { | |
457 | if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) || | |
458 | __put_user(kfl->l_type, &ufl->l_type) || | |
459 | __put_user(kfl->l_whence, &ufl->l_whence) || | |
460 | __put_user(kfl->l_start, &ufl->l_start) || | |
461 | __put_user(kfl->l_len, &ufl->l_len) || | |
462 | __put_user(kfl->l_pid, &ufl->l_pid)) | |
463 | return -EFAULT; | |
464 | return 0; | |
465 | } | |
466 | ||
467 | #ifndef HAVE_ARCH_GET_COMPAT_FLOCK64 | |
468 | static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl) | |
469 | { | |
470 | if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || | |
471 | __get_user(kfl->l_type, &ufl->l_type) || | |
472 | __get_user(kfl->l_whence, &ufl->l_whence) || | |
473 | __get_user(kfl->l_start, &ufl->l_start) || | |
474 | __get_user(kfl->l_len, &ufl->l_len) || | |
475 | __get_user(kfl->l_pid, &ufl->l_pid)) | |
476 | return -EFAULT; | |
477 | return 0; | |
478 | } | |
479 | #endif | |
480 | ||
481 | #ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64 | |
482 | static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl) | |
483 | { | |
484 | if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) || | |
485 | __put_user(kfl->l_type, &ufl->l_type) || | |
486 | __put_user(kfl->l_whence, &ufl->l_whence) || | |
487 | __put_user(kfl->l_start, &ufl->l_start) || | |
488 | __put_user(kfl->l_len, &ufl->l_len) || | |
489 | __put_user(kfl->l_pid, &ufl->l_pid)) | |
490 | return -EFAULT; | |
491 | return 0; | |
492 | } | |
493 | #endif | |
494 | ||
495 | static unsigned int | |
496 | convert_fcntl_cmd(unsigned int cmd) | |
497 | { | |
498 | switch (cmd) { | |
499 | case F_GETLK64: | |
500 | return F_GETLK; | |
501 | case F_SETLK64: | |
502 | return F_SETLK; | |
503 | case F_SETLKW64: | |
504 | return F_SETLKW; | |
505 | } | |
506 | ||
507 | return cmd; | |
508 | } | |
509 | ||
94073ad7 CH |
510 | /* |
511 | * GETLK was successful and we need to return the data, but it needs to fit in | |
512 | * the compat structure. | |
513 | * l_start shouldn't be too big, unless the original start + end is greater than | |
514 | * COMPAT_OFF_T_MAX, in which case the app was asking for trouble, so we return | |
515 | * -EOVERFLOW in that case. l_len could be too big, in which case we just | |
516 | * truncate it, and only allow the app to see that part of the conflicting lock | |
517 | * that might make sense to it anyway | |
518 | */ | |
519 | static int fixup_compat_flock(struct flock *flock) | |
520 | { | |
521 | if (flock->l_start > COMPAT_OFF_T_MAX) | |
522 | return -EOVERFLOW; | |
523 | if (flock->l_len > COMPAT_OFF_T_MAX) | |
524 | flock->l_len = COMPAT_OFF_T_MAX; | |
525 | return 0; | |
526 | } | |
527 | ||
80f0cce6 AV |
528 | COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
529 | compat_ulong_t, arg) | |
530 | { | |
94073ad7 CH |
531 | struct fd f = fdget_raw(fd); |
532 | struct flock flock; | |
533 | long err = -EBADF; | |
534 | ||
535 | if (!f.file) | |
536 | return err; | |
537 | ||
538 | if (unlikely(f.file->f_mode & FMODE_PATH)) { | |
539 | if (!check_fcntl_cmd(cmd)) | |
540 | goto out_put; | |
541 | } | |
542 | ||
543 | err = security_file_fcntl(f.file, cmd, arg); | |
544 | if (err) | |
545 | goto out_put; | |
80f0cce6 AV |
546 | |
547 | switch (cmd) { | |
548 | case F_GETLK: | |
94073ad7 CH |
549 | err = get_compat_flock(&flock, compat_ptr(arg)); |
550 | if (err) | |
551 | break; | |
552 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
553 | if (err) | |
554 | break; | |
555 | err = fixup_compat_flock(&flock); | |
556 | if (err) | |
557 | return err; | |
558 | err = put_compat_flock(&flock, compat_ptr(arg)); | |
559 | break; | |
560 | case F_GETLK64: | |
561 | case F_OFD_GETLK: | |
562 | err = get_compat_flock64(&flock, compat_ptr(arg)); | |
563 | if (err) | |
564 | break; | |
565 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
566 | if (err) | |
567 | break; | |
568 | err = fixup_compat_flock(&flock); | |
569 | if (err) | |
570 | return err; | |
571 | err = put_compat_flock64(&flock, compat_ptr(arg)); | |
572 | break; | |
80f0cce6 AV |
573 | case F_SETLK: |
574 | case F_SETLKW: | |
94073ad7 CH |
575 | err = get_compat_flock(&flock, compat_ptr(arg)); |
576 | if (err) | |
80f0cce6 | 577 | break; |
94073ad7 | 578 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 579 | break; |
80f0cce6 AV |
580 | case F_SETLK64: |
581 | case F_SETLKW64: | |
80f0cce6 AV |
582 | case F_OFD_SETLK: |
583 | case F_OFD_SETLKW: | |
94073ad7 CH |
584 | err = get_compat_flock64(&flock, compat_ptr(arg)); |
585 | if (err) | |
80f0cce6 | 586 | break; |
94073ad7 | 587 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 588 | break; |
80f0cce6 | 589 | default: |
94073ad7 | 590 | err = do_fcntl(fd, cmd, arg, f.file); |
80f0cce6 AV |
591 | break; |
592 | } | |
94073ad7 CH |
593 | out_put: |
594 | fdput(f); | |
595 | return err; | |
80f0cce6 AV |
596 | } |
597 | ||
598 | COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, | |
599 | compat_ulong_t, arg) | |
600 | { | |
601 | switch (cmd) { | |
602 | case F_GETLK64: | |
603 | case F_SETLK64: | |
604 | case F_SETLKW64: | |
605 | case F_OFD_GETLK: | |
606 | case F_OFD_SETLK: | |
607 | case F_OFD_SETLKW: | |
608 | return -EINVAL; | |
609 | } | |
610 | return compat_sys_fcntl64(fd, cmd, arg); | |
611 | } | |
612 | #endif | |
613 | ||
1da177e4 LT |
614 | /* Table to convert sigio signal codes into poll band bitmaps */ |
615 | ||
fa3536cc | 616 | static const long band_table[NSIGPOLL] = { |
1da177e4 LT |
617 | POLLIN | POLLRDNORM, /* POLL_IN */ |
618 | POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ | |
619 | POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ | |
620 | POLLERR, /* POLL_ERR */ | |
621 | POLLPRI | POLLRDBAND, /* POLL_PRI */ | |
622 | POLLHUP | POLLERR /* POLL_HUP */ | |
623 | }; | |
624 | ||
625 | static inline int sigio_perm(struct task_struct *p, | |
626 | struct fown_struct *fown, int sig) | |
627 | { | |
c69e8d9c DH |
628 | const struct cred *cred; |
629 | int ret; | |
630 | ||
631 | rcu_read_lock(); | |
632 | cred = __task_cred(p); | |
8e96e3b7 EB |
633 | ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) || |
634 | uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) || | |
635 | uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) && | |
c69e8d9c DH |
636 | !security_file_send_sigiotask(p, fown, sig)); |
637 | rcu_read_unlock(); | |
638 | return ret; | |
1da177e4 LT |
639 | } |
640 | ||
641 | static void send_sigio_to_task(struct task_struct *p, | |
8eeee4e2 | 642 | struct fown_struct *fown, |
ba0a6c9f | 643 | int fd, int reason, int group) |
1da177e4 | 644 | { |
8eeee4e2 ON |
645 | /* |
646 | * F_SETSIG can change ->signum lockless in parallel, make | |
647 | * sure we read it once and use the same value throughout. | |
648 | */ | |
649 | int signum = ACCESS_ONCE(fown->signum); | |
650 | ||
651 | if (!sigio_perm(p, fown, signum)) | |
1da177e4 LT |
652 | return; |
653 | ||
8eeee4e2 | 654 | switch (signum) { |
1da177e4 LT |
655 | siginfo_t si; |
656 | default: | |
657 | /* Queue a rt signal with the appropriate fd as its | |
658 | value. We use SI_SIGIO as the source, not | |
659 | SI_KERNEL, since kernel signals always get | |
660 | delivered even if we can't queue. Failure to | |
661 | queue in this case _should_ be reported; we fall | |
662 | back to SIGIO in that case. --sct */ | |
8eeee4e2 | 663 | si.si_signo = signum; |
1da177e4 LT |
664 | si.si_errno = 0; |
665 | si.si_code = reason; | |
666 | /* Make sure we are called with one of the POLL_* | |
667 | reasons, otherwise we could leak kernel stack into | |
668 | userspace. */ | |
f6298aab | 669 | BUG_ON((reason & __SI_MASK) != __SI_POLL); |
1da177e4 LT |
670 | if (reason - POLL_IN >= NSIGPOLL) |
671 | si.si_band = ~0L; | |
672 | else | |
673 | si.si_band = band_table[reason - POLL_IN]; | |
674 | si.si_fd = fd; | |
ba0a6c9f | 675 | if (!do_send_sig_info(signum, &si, p, group)) |
1da177e4 LT |
676 | break; |
677 | /* fall-through: fall back on the old plain SIGIO signal */ | |
678 | case 0: | |
ba0a6c9f | 679 | do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group); |
1da177e4 LT |
680 | } |
681 | } | |
682 | ||
683 | void send_sigio(struct fown_struct *fown, int fd, int band) | |
684 | { | |
685 | struct task_struct *p; | |
609d7fa9 EB |
686 | enum pid_type type; |
687 | struct pid *pid; | |
ba0a6c9f | 688 | int group = 1; |
1da177e4 LT |
689 | |
690 | read_lock(&fown->lock); | |
ba0a6c9f | 691 | |
609d7fa9 | 692 | type = fown->pid_type; |
ba0a6c9f PZ |
693 | if (type == PIDTYPE_MAX) { |
694 | group = 0; | |
695 | type = PIDTYPE_PID; | |
696 | } | |
697 | ||
1da177e4 LT |
698 | pid = fown->pid; |
699 | if (!pid) | |
700 | goto out_unlock_fown; | |
701 | ||
702 | read_lock(&tasklist_lock); | |
609d7fa9 | 703 | do_each_pid_task(pid, type, p) { |
ba0a6c9f | 704 | send_sigio_to_task(p, fown, fd, band, group); |
609d7fa9 | 705 | } while_each_pid_task(pid, type, p); |
1da177e4 LT |
706 | read_unlock(&tasklist_lock); |
707 | out_unlock_fown: | |
708 | read_unlock(&fown->lock); | |
709 | } | |
710 | ||
711 | static void send_sigurg_to_task(struct task_struct *p, | |
ba0a6c9f | 712 | struct fown_struct *fown, int group) |
1da177e4 LT |
713 | { |
714 | if (sigio_perm(p, fown, SIGURG)) | |
ba0a6c9f | 715 | do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group); |
1da177e4 LT |
716 | } |
717 | ||
718 | int send_sigurg(struct fown_struct *fown) | |
719 | { | |
720 | struct task_struct *p; | |
609d7fa9 EB |
721 | enum pid_type type; |
722 | struct pid *pid; | |
ba0a6c9f | 723 | int group = 1; |
609d7fa9 | 724 | int ret = 0; |
1da177e4 LT |
725 | |
726 | read_lock(&fown->lock); | |
ba0a6c9f | 727 | |
609d7fa9 | 728 | type = fown->pid_type; |
ba0a6c9f PZ |
729 | if (type == PIDTYPE_MAX) { |
730 | group = 0; | |
731 | type = PIDTYPE_PID; | |
732 | } | |
733 | ||
1da177e4 LT |
734 | pid = fown->pid; |
735 | if (!pid) | |
736 | goto out_unlock_fown; | |
737 | ||
738 | ret = 1; | |
739 | ||
740 | read_lock(&tasklist_lock); | |
609d7fa9 | 741 | do_each_pid_task(pid, type, p) { |
ba0a6c9f | 742 | send_sigurg_to_task(p, fown, group); |
609d7fa9 | 743 | } while_each_pid_task(pid, type, p); |
1da177e4 LT |
744 | read_unlock(&tasklist_lock); |
745 | out_unlock_fown: | |
746 | read_unlock(&fown->lock); | |
747 | return ret; | |
748 | } | |
749 | ||
989a2979 | 750 | static DEFINE_SPINLOCK(fasync_lock); |
e18b890b | 751 | static struct kmem_cache *fasync_cache __read_mostly; |
1da177e4 | 752 | |
989a2979 ED |
753 | static void fasync_free_rcu(struct rcu_head *head) |
754 | { | |
755 | kmem_cache_free(fasync_cache, | |
756 | container_of(head, struct fasync_struct, fa_rcu)); | |
757 | } | |
758 | ||
1da177e4 | 759 | /* |
53281b6d LT |
760 | * Remove a fasync entry. If successfully removed, return |
761 | * positive and clear the FASYNC flag. If no entry exists, | |
762 | * do nothing and return 0. | |
763 | * | |
764 | * NOTE! It is very important that the FASYNC flag always | |
765 | * match the state "is the filp on a fasync list". | |
766 | * | |
1da177e4 | 767 | */ |
f7347ce4 | 768 | int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp) |
1da177e4 LT |
769 | { |
770 | struct fasync_struct *fa, **fp; | |
1da177e4 LT |
771 | int result = 0; |
772 | ||
53281b6d | 773 | spin_lock(&filp->f_lock); |
989a2979 | 774 | spin_lock(&fasync_lock); |
53281b6d LT |
775 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
776 | if (fa->fa_file != filp) | |
777 | continue; | |
989a2979 ED |
778 | |
779 | spin_lock_irq(&fa->fa_lock); | |
780 | fa->fa_file = NULL; | |
781 | spin_unlock_irq(&fa->fa_lock); | |
782 | ||
53281b6d | 783 | *fp = fa->fa_next; |
989a2979 | 784 | call_rcu(&fa->fa_rcu, fasync_free_rcu); |
53281b6d LT |
785 | filp->f_flags &= ~FASYNC; |
786 | result = 1; | |
787 | break; | |
1da177e4 | 788 | } |
989a2979 | 789 | spin_unlock(&fasync_lock); |
53281b6d LT |
790 | spin_unlock(&filp->f_lock); |
791 | return result; | |
792 | } | |
793 | ||
f7347ce4 LT |
794 | struct fasync_struct *fasync_alloc(void) |
795 | { | |
796 | return kmem_cache_alloc(fasync_cache, GFP_KERNEL); | |
797 | } | |
798 | ||
53281b6d | 799 | /* |
f7347ce4 LT |
800 | * NOTE! This can be used only for unused fasync entries: |
801 | * entries that actually got inserted on the fasync list | |
802 | * need to be released by rcu - see fasync_remove_entry. | |
53281b6d | 803 | */ |
f7347ce4 | 804 | void fasync_free(struct fasync_struct *new) |
53281b6d | 805 | { |
f7347ce4 LT |
806 | kmem_cache_free(fasync_cache, new); |
807 | } | |
53281b6d | 808 | |
f7347ce4 LT |
809 | /* |
810 | * Insert a new entry into the fasync list. Return the pointer to the | |
811 | * old one if we didn't use the new one. | |
55f335a8 LT |
812 | * |
813 | * NOTE! It is very important that the FASYNC flag always | |
814 | * match the state "is the filp on a fasync list". | |
f7347ce4 LT |
815 | */ |
816 | struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new) | |
817 | { | |
818 | struct fasync_struct *fa, **fp; | |
4a6a4499 | 819 | |
4a6a4499 | 820 | spin_lock(&filp->f_lock); |
989a2979 | 821 | spin_lock(&fasync_lock); |
1da177e4 | 822 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
53281b6d LT |
823 | if (fa->fa_file != filp) |
824 | continue; | |
989a2979 ED |
825 | |
826 | spin_lock_irq(&fa->fa_lock); | |
53281b6d | 827 | fa->fa_fd = fd; |
989a2979 | 828 | spin_unlock_irq(&fa->fa_lock); |
53281b6d | 829 | goto out; |
1da177e4 LT |
830 | } |
831 | ||
989a2979 | 832 | spin_lock_init(&new->fa_lock); |
53281b6d LT |
833 | new->magic = FASYNC_MAGIC; |
834 | new->fa_file = filp; | |
835 | new->fa_fd = fd; | |
836 | new->fa_next = *fapp; | |
989a2979 | 837 | rcu_assign_pointer(*fapp, new); |
53281b6d LT |
838 | filp->f_flags |= FASYNC; |
839 | ||
1da177e4 | 840 | out: |
989a2979 | 841 | spin_unlock(&fasync_lock); |
4a6a4499 | 842 | spin_unlock(&filp->f_lock); |
f7347ce4 LT |
843 | return fa; |
844 | } | |
845 | ||
846 | /* | |
847 | * Add a fasync entry. Return negative on error, positive if | |
848 | * added, and zero if did nothing but change an existing one. | |
f7347ce4 LT |
849 | */ |
850 | static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp) | |
851 | { | |
852 | struct fasync_struct *new; | |
853 | ||
854 | new = fasync_alloc(); | |
855 | if (!new) | |
856 | return -ENOMEM; | |
857 | ||
858 | /* | |
859 | * fasync_insert_entry() returns the old (update) entry if | |
860 | * it existed. | |
861 | * | |
862 | * So free the (unused) new entry and return 0 to let the | |
863 | * caller know that we didn't add any new fasync entries. | |
864 | */ | |
865 | if (fasync_insert_entry(fd, filp, fapp, new)) { | |
866 | fasync_free(new); | |
867 | return 0; | |
868 | } | |
869 | ||
870 | return 1; | |
1da177e4 LT |
871 | } |
872 | ||
53281b6d LT |
873 | /* |
874 | * fasync_helper() is used by almost all character device drivers | |
875 | * to set up the fasync queue, and for regular files by the file | |
876 | * lease code. It returns negative on error, 0 if it did no changes | |
877 | * and positive if it added/deleted the entry. | |
878 | */ | |
879 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) | |
880 | { | |
881 | if (!on) | |
882 | return fasync_remove_entry(filp, fapp); | |
883 | return fasync_add_entry(fd, filp, fapp); | |
884 | } | |
885 | ||
1da177e4 LT |
886 | EXPORT_SYMBOL(fasync_helper); |
887 | ||
989a2979 ED |
888 | /* |
889 | * rcu_read_lock() is held | |
890 | */ | |
891 | static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) | |
1da177e4 LT |
892 | { |
893 | while (fa) { | |
989a2979 | 894 | struct fown_struct *fown; |
f4985dc7 AM |
895 | unsigned long flags; |
896 | ||
1da177e4 LT |
897 | if (fa->magic != FASYNC_MAGIC) { |
898 | printk(KERN_ERR "kill_fasync: bad magic number in " | |
899 | "fasync_struct!\n"); | |
900 | return; | |
901 | } | |
f4985dc7 | 902 | spin_lock_irqsave(&fa->fa_lock, flags); |
989a2979 ED |
903 | if (fa->fa_file) { |
904 | fown = &fa->fa_file->f_owner; | |
905 | /* Don't send SIGURG to processes which have not set a | |
906 | queued signum: SIGURG has its own default signalling | |
907 | mechanism. */ | |
908 | if (!(sig == SIGURG && fown->signum == 0)) | |
909 | send_sigio(fown, fa->fa_fd, band); | |
910 | } | |
f4985dc7 | 911 | spin_unlock_irqrestore(&fa->fa_lock, flags); |
989a2979 | 912 | fa = rcu_dereference(fa->fa_next); |
1da177e4 LT |
913 | } |
914 | } | |
915 | ||
1da177e4 LT |
916 | void kill_fasync(struct fasync_struct **fp, int sig, int band) |
917 | { | |
918 | /* First a quick test without locking: usually | |
919 | * the list is empty. | |
920 | */ | |
921 | if (*fp) { | |
989a2979 ED |
922 | rcu_read_lock(); |
923 | kill_fasync_rcu(rcu_dereference(*fp), sig, band); | |
924 | rcu_read_unlock(); | |
1da177e4 LT |
925 | } |
926 | } | |
927 | EXPORT_SYMBOL(kill_fasync); | |
928 | ||
454eedb8 | 929 | static int __init fcntl_init(void) |
1da177e4 | 930 | { |
3ab04d5c JB |
931 | /* |
932 | * Please add new bits here to ensure allocation uniqueness. | |
933 | * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY | |
934 | * is defined as O_NONBLOCK on some platforms and not on others. | |
935 | */ | |
80f18379 CH |
936 | BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ != |
937 | HWEIGHT32( | |
938 | (VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) | | |
939 | __FMODE_EXEC | __FMODE_NONOTIFY)); | |
454eedb8 | 940 | |
1da177e4 | 941 | fasync_cache = kmem_cache_create("fasync_cache", |
20c2df83 | 942 | sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
1da177e4 LT |
943 | return 0; |
944 | } | |
945 | ||
454eedb8 | 946 | module_init(fcntl_init) |