Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/fcntl.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | #include <linux/syscalls.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/mm.h> | |
29930025 | 11 | #include <linux/sched/task.h> |
1da177e4 LT |
12 | #include <linux/fs.h> |
13 | #include <linux/file.h> | |
9f3acc31 | 14 | #include <linux/fdtable.h> |
16f7e0fe | 15 | #include <linux/capability.h> |
1da177e4 | 16 | #include <linux/dnotify.h> |
1da177e4 LT |
17 | #include <linux/slab.h> |
18 | #include <linux/module.h> | |
35f3d14d | 19 | #include <linux/pipe_fs_i.h> |
1da177e4 LT |
20 | #include <linux/security.h> |
21 | #include <linux/ptrace.h> | |
7ed20e1a | 22 | #include <linux/signal.h> |
ab2af1f5 | 23 | #include <linux/rcupdate.h> |
b488893a | 24 | #include <linux/pid_namespace.h> |
1d151c33 | 25 | #include <linux/user_namespace.h> |
5d752600 | 26 | #include <linux/memfd.h> |
80f0cce6 | 27 | #include <linux/compat.h> |
9eccd12c | 28 | #include <linux/mount.h> |
1da177e4 | 29 | |
cfe39442 | 30 | #include <linux/poll.h> |
1da177e4 | 31 | #include <asm/siginfo.h> |
7c0f6ba6 | 32 | #include <linux/uaccess.h> |
1da177e4 | 33 | |
76398425 | 34 | #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) |
1da177e4 LT |
35 | |
36 | static int setfl(int fd, struct file * filp, unsigned long arg) | |
37 | { | |
496ad9aa | 38 | struct inode * inode = file_inode(filp); |
1da177e4 LT |
39 | int error = 0; |
40 | ||
7d95c8f2 | 41 | /* |
42 | * O_APPEND cannot be cleared if the file is marked as append-only | |
43 | * and the file is open for write. | |
44 | */ | |
45 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
1da177e4 LT |
46 | return -EPERM; |
47 | ||
48 | /* O_NOATIME can only be set by the owner or superuser */ | |
49 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) | |
9eccd12c | 50 | if (!inode_owner_or_capable(file_mnt_user_ns(filp), inode)) |
1da177e4 LT |
51 | return -EPERM; |
52 | ||
53 | /* required for strict SunOS emulation */ | |
54 | if (O_NONBLOCK != O_NDELAY) | |
55 | if (arg & O_NDELAY) | |
56 | arg |= O_NONBLOCK; | |
57 | ||
0dbf5f20 | 58 | /* Pipe packetized mode is controlled by O_DIRECT flag */ |
45063097 | 59 | if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) { |
1da177e4 LT |
60 | if (!filp->f_mapping || !filp->f_mapping->a_ops || |
61 | !filp->f_mapping->a_ops->direct_IO) | |
62 | return -EINVAL; | |
63 | } | |
64 | ||
72c2d531 | 65 | if (filp->f_op->check_flags) |
1da177e4 LT |
66 | error = filp->f_op->check_flags(arg); |
67 | if (error) | |
68 | return error; | |
69 | ||
218d11a8 | 70 | /* |
76398425 | 71 | * ->fasync() is responsible for setting the FASYNC bit. |
218d11a8 | 72 | */ |
72c2d531 | 73 | if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) { |
76398425 JC |
74 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); |
75 | if (error < 0) | |
76 | goto out; | |
60aa4924 JC |
77 | if (error > 0) |
78 | error = 0; | |
1da177e4 | 79 | } |
db1dd4d3 | 80 | spin_lock(&filp->f_lock); |
1da177e4 | 81 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
db1dd4d3 | 82 | spin_unlock(&filp->f_lock); |
76398425 | 83 | |
1da177e4 | 84 | out: |
1da177e4 LT |
85 | return error; |
86 | } | |
87 | ||
609d7fa9 | 88 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
2f38d70f | 89 | int force) |
1da177e4 | 90 | { |
80e1e823 | 91 | write_lock_irq(&filp->f_owner.lock); |
1da177e4 | 92 | if (force || !filp->f_owner.pid) { |
609d7fa9 EB |
93 | put_pid(filp->f_owner.pid); |
94 | filp->f_owner.pid = get_pid(pid); | |
95 | filp->f_owner.pid_type = type; | |
2f38d70f ON |
96 | |
97 | if (pid) { | |
98 | const struct cred *cred = current_cred(); | |
99 | filp->f_owner.uid = cred->uid; | |
100 | filp->f_owner.euid = cred->euid; | |
101 | } | |
1da177e4 | 102 | } |
80e1e823 | 103 | write_unlock_irq(&filp->f_owner.lock); |
1da177e4 LT |
104 | } |
105 | ||
e0b93edd | 106 | void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
609d7fa9 | 107 | int force) |
1da177e4 | 108 | { |
e0b93edd | 109 | security_file_set_fowner(filp); |
2f38d70f | 110 | f_modown(filp, pid, type, force); |
1da177e4 | 111 | } |
609d7fa9 | 112 | EXPORT_SYMBOL(__f_setown); |
1da177e4 | 113 | |
393cc3f5 | 114 | int f_setown(struct file *filp, unsigned long arg, int force) |
609d7fa9 EB |
115 | { |
116 | enum pid_type type; | |
f7312735 JL |
117 | struct pid *pid = NULL; |
118 | int who = arg, ret = 0; | |
119 | ||
01919134 | 120 | type = PIDTYPE_TGID; |
609d7fa9 | 121 | if (who < 0) { |
fc3dc674 JS |
122 | /* avoid overflow below */ |
123 | if (who == INT_MIN) | |
124 | return -EINVAL; | |
125 | ||
609d7fa9 EB |
126 | type = PIDTYPE_PGID; |
127 | who = -who; | |
128 | } | |
f7312735 | 129 | |
609d7fa9 | 130 | rcu_read_lock(); |
f7312735 JL |
131 | if (who) { |
132 | pid = find_vpid(who); | |
133 | if (!pid) | |
134 | ret = -ESRCH; | |
135 | } | |
136 | ||
137 | if (!ret) | |
138 | __f_setown(filp, pid, type, force); | |
609d7fa9 | 139 | rcu_read_unlock(); |
393cc3f5 | 140 | |
f7312735 | 141 | return ret; |
609d7fa9 | 142 | } |
1da177e4 LT |
143 | EXPORT_SYMBOL(f_setown); |
144 | ||
145 | void f_delown(struct file *filp) | |
146 | { | |
01919134 | 147 | f_modown(filp, NULL, PIDTYPE_TGID, 1); |
609d7fa9 EB |
148 | } |
149 | ||
150 | pid_t f_getown(struct file *filp) | |
151 | { | |
cc4a3f88 | 152 | pid_t pid = 0; |
43fa1adb | 153 | read_lock(&filp->f_owner.lock); |
cc4a3f88 PT |
154 | rcu_read_lock(); |
155 | if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) { | |
156 | pid = pid_vnr(filp->f_owner.pid); | |
157 | if (filp->f_owner.pid_type == PIDTYPE_PGID) | |
158 | pid = -pid; | |
159 | } | |
160 | rcu_read_unlock(); | |
43fa1adb | 161 | read_unlock(&filp->f_owner.lock); |
609d7fa9 | 162 | return pid; |
1da177e4 LT |
163 | } |
164 | ||
ba0a6c9f PZ |
165 | static int f_setown_ex(struct file *filp, unsigned long arg) |
166 | { | |
63784dd0 | 167 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f PZ |
168 | struct f_owner_ex owner; |
169 | struct pid *pid; | |
170 | int type; | |
171 | int ret; | |
172 | ||
173 | ret = copy_from_user(&owner, owner_p, sizeof(owner)); | |
174 | if (ret) | |
5b54470d | 175 | return -EFAULT; |
ba0a6c9f PZ |
176 | |
177 | switch (owner.type) { | |
178 | case F_OWNER_TID: | |
01919134 | 179 | type = PIDTYPE_PID; |
ba0a6c9f PZ |
180 | break; |
181 | ||
182 | case F_OWNER_PID: | |
01919134 | 183 | type = PIDTYPE_TGID; |
ba0a6c9f PZ |
184 | break; |
185 | ||
978b4053 | 186 | case F_OWNER_PGRP: |
ba0a6c9f PZ |
187 | type = PIDTYPE_PGID; |
188 | break; | |
189 | ||
190 | default: | |
191 | return -EINVAL; | |
192 | } | |
193 | ||
194 | rcu_read_lock(); | |
195 | pid = find_vpid(owner.pid); | |
196 | if (owner.pid && !pid) | |
197 | ret = -ESRCH; | |
198 | else | |
e0b93edd | 199 | __f_setown(filp, pid, type, 1); |
ba0a6c9f PZ |
200 | rcu_read_unlock(); |
201 | ||
202 | return ret; | |
203 | } | |
204 | ||
205 | static int f_getown_ex(struct file *filp, unsigned long arg) | |
206 | { | |
63784dd0 | 207 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
cc4a3f88 | 208 | struct f_owner_ex owner = {}; |
ba0a6c9f PZ |
209 | int ret = 0; |
210 | ||
211 | read_lock(&filp->f_owner.lock); | |
cc4a3f88 PT |
212 | rcu_read_lock(); |
213 | if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) | |
214 | owner.pid = pid_vnr(filp->f_owner.pid); | |
215 | rcu_read_unlock(); | |
ba0a6c9f | 216 | switch (filp->f_owner.pid_type) { |
01919134 | 217 | case PIDTYPE_PID: |
ba0a6c9f PZ |
218 | owner.type = F_OWNER_TID; |
219 | break; | |
220 | ||
01919134 | 221 | case PIDTYPE_TGID: |
ba0a6c9f PZ |
222 | owner.type = F_OWNER_PID; |
223 | break; | |
224 | ||
225 | case PIDTYPE_PGID: | |
978b4053 | 226 | owner.type = F_OWNER_PGRP; |
ba0a6c9f PZ |
227 | break; |
228 | ||
229 | default: | |
230 | WARN_ON(1); | |
231 | ret = -EINVAL; | |
232 | break; | |
233 | } | |
234 | read_unlock(&filp->f_owner.lock); | |
235 | ||
5b54470d | 236 | if (!ret) { |
ba0a6c9f | 237 | ret = copy_to_user(owner_p, &owner, sizeof(owner)); |
5b54470d DC |
238 | if (ret) |
239 | ret = -EFAULT; | |
240 | } | |
ba0a6c9f PZ |
241 | return ret; |
242 | } | |
243 | ||
1d151c33 CG |
244 | #ifdef CONFIG_CHECKPOINT_RESTORE |
245 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
246 | { | |
247 | struct user_namespace *user_ns = current_user_ns(); | |
63784dd0 | 248 | uid_t __user *dst = (void __user *)arg; |
1d151c33 CG |
249 | uid_t src[2]; |
250 | int err; | |
251 | ||
252 | read_lock(&filp->f_owner.lock); | |
253 | src[0] = from_kuid(user_ns, filp->f_owner.uid); | |
254 | src[1] = from_kuid(user_ns, filp->f_owner.euid); | |
255 | read_unlock(&filp->f_owner.lock); | |
256 | ||
257 | err = put_user(src[0], &dst[0]); | |
258 | err |= put_user(src[1], &dst[1]); | |
259 | ||
260 | return err; | |
261 | } | |
262 | #else | |
263 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
264 | { | |
265 | return -EINVAL; | |
266 | } | |
267 | #endif | |
268 | ||
c75b1d94 JA |
269 | static bool rw_hint_valid(enum rw_hint hint) |
270 | { | |
271 | switch (hint) { | |
9a7f12ed | 272 | case RWH_WRITE_LIFE_NOT_SET: |
c75b1d94 JA |
273 | case RWH_WRITE_LIFE_NONE: |
274 | case RWH_WRITE_LIFE_SHORT: | |
275 | case RWH_WRITE_LIFE_MEDIUM: | |
276 | case RWH_WRITE_LIFE_LONG: | |
277 | case RWH_WRITE_LIFE_EXTREME: | |
278 | return true; | |
279 | default: | |
280 | return false; | |
281 | } | |
282 | } | |
283 | ||
284 | static long fcntl_rw_hint(struct file *file, unsigned int cmd, | |
285 | unsigned long arg) | |
286 | { | |
287 | struct inode *inode = file_inode(file); | |
e2003277 | 288 | u64 __user *argp = (u64 __user *)arg; |
c75b1d94 | 289 | enum rw_hint hint; |
5657cb07 | 290 | u64 h; |
c75b1d94 JA |
291 | |
292 | switch (cmd) { | |
293 | case F_GET_FILE_RW_HINT: | |
5657cb07 JA |
294 | h = file_write_hint(file); |
295 | if (copy_to_user(argp, &h, sizeof(*argp))) | |
c75b1d94 JA |
296 | return -EFAULT; |
297 | return 0; | |
298 | case F_SET_FILE_RW_HINT: | |
5657cb07 | 299 | if (copy_from_user(&h, argp, sizeof(h))) |
c75b1d94 | 300 | return -EFAULT; |
5657cb07 | 301 | hint = (enum rw_hint) h; |
c75b1d94 JA |
302 | if (!rw_hint_valid(hint)) |
303 | return -EINVAL; | |
304 | ||
305 | spin_lock(&file->f_lock); | |
306 | file->f_write_hint = hint; | |
307 | spin_unlock(&file->f_lock); | |
308 | return 0; | |
309 | case F_GET_RW_HINT: | |
5657cb07 JA |
310 | h = inode->i_write_hint; |
311 | if (copy_to_user(argp, &h, sizeof(*argp))) | |
c75b1d94 JA |
312 | return -EFAULT; |
313 | return 0; | |
314 | case F_SET_RW_HINT: | |
5657cb07 | 315 | if (copy_from_user(&h, argp, sizeof(h))) |
c75b1d94 | 316 | return -EFAULT; |
5657cb07 | 317 | hint = (enum rw_hint) h; |
c75b1d94 JA |
318 | if (!rw_hint_valid(hint)) |
319 | return -EINVAL; | |
320 | ||
321 | inode_lock(inode); | |
322 | inode->i_write_hint = hint; | |
323 | inode_unlock(inode); | |
324 | return 0; | |
325 | default: | |
326 | return -EINVAL; | |
327 | } | |
328 | } | |
329 | ||
1da177e4 LT |
330 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, |
331 | struct file *filp) | |
332 | { | |
a75d30c7 CH |
333 | void __user *argp = (void __user *)arg; |
334 | struct flock flock; | |
1da177e4 LT |
335 | long err = -EINVAL; |
336 | ||
337 | switch (cmd) { | |
338 | case F_DUPFD: | |
fe17f22d AV |
339 | err = f_dupfd(arg, filp, 0); |
340 | break; | |
22d2b35b | 341 | case F_DUPFD_CLOEXEC: |
12197718 | 342 | err = f_dupfd(arg, filp, O_CLOEXEC); |
1da177e4 LT |
343 | break; |
344 | case F_GETFD: | |
345 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; | |
346 | break; | |
347 | case F_SETFD: | |
348 | err = 0; | |
349 | set_close_on_exec(fd, arg & FD_CLOEXEC); | |
350 | break; | |
351 | case F_GETFL: | |
352 | err = filp->f_flags; | |
353 | break; | |
354 | case F_SETFL: | |
355 | err = setfl(fd, filp, arg); | |
356 | break; | |
5d50ffd7 JL |
357 | #if BITS_PER_LONG != 32 |
358 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d | 359 | case F_OFD_GETLK: |
5d50ffd7 | 360 | #endif |
1da177e4 | 361 | case F_GETLK: |
a75d30c7 CH |
362 | if (copy_from_user(&flock, argp, sizeof(flock))) |
363 | return -EFAULT; | |
364 | err = fcntl_getlk(filp, cmd, &flock); | |
365 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
366 | return -EFAULT; | |
1da177e4 | 367 | break; |
5d50ffd7 JL |
368 | #if BITS_PER_LONG != 32 |
369 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d JL |
370 | case F_OFD_SETLK: |
371 | case F_OFD_SETLKW: | |
df561f66 | 372 | fallthrough; |
e8865537 | 373 | #endif |
1da177e4 LT |
374 | case F_SETLK: |
375 | case F_SETLKW: | |
a75d30c7 CH |
376 | if (copy_from_user(&flock, argp, sizeof(flock))) |
377 | return -EFAULT; | |
378 | err = fcntl_setlk(fd, filp, cmd, &flock); | |
1da177e4 LT |
379 | break; |
380 | case F_GETOWN: | |
381 | /* | |
382 | * XXX If f_owner is a process group, the | |
383 | * negative return value will get converted | |
384 | * into an error. Oops. If we keep the | |
385 | * current syscall conventions, the only way | |
386 | * to fix this will be in libc. | |
387 | */ | |
609d7fa9 | 388 | err = f_getown(filp); |
1da177e4 LT |
389 | force_successful_syscall_return(); |
390 | break; | |
391 | case F_SETOWN: | |
393cc3f5 | 392 | err = f_setown(filp, arg, 1); |
1da177e4 | 393 | break; |
ba0a6c9f PZ |
394 | case F_GETOWN_EX: |
395 | err = f_getown_ex(filp, arg); | |
396 | break; | |
397 | case F_SETOWN_EX: | |
398 | err = f_setown_ex(filp, arg); | |
399 | break; | |
1d151c33 CG |
400 | case F_GETOWNER_UIDS: |
401 | err = f_getowner_uids(filp, arg); | |
402 | break; | |
1da177e4 LT |
403 | case F_GETSIG: |
404 | err = filp->f_owner.signum; | |
405 | break; | |
406 | case F_SETSIG: | |
407 | /* arg == 0 restores default behaviour. */ | |
7ed20e1a | 408 | if (!valid_signal(arg)) { |
1da177e4 LT |
409 | break; |
410 | } | |
411 | err = 0; | |
412 | filp->f_owner.signum = arg; | |
413 | break; | |
414 | case F_GETLEASE: | |
415 | err = fcntl_getlease(filp); | |
416 | break; | |
417 | case F_SETLEASE: | |
418 | err = fcntl_setlease(fd, filp, arg); | |
419 | break; | |
420 | case F_NOTIFY: | |
421 | err = fcntl_dirnotify(fd, filp, arg); | |
422 | break; | |
35f3d14d JA |
423 | case F_SETPIPE_SZ: |
424 | case F_GETPIPE_SZ: | |
425 | err = pipe_fcntl(filp, cmd, arg); | |
426 | break; | |
40e041a2 DH |
427 | case F_ADD_SEALS: |
428 | case F_GET_SEALS: | |
5aadc431 | 429 | err = memfd_fcntl(filp, cmd, arg); |
40e041a2 | 430 | break; |
c75b1d94 JA |
431 | case F_GET_RW_HINT: |
432 | case F_SET_RW_HINT: | |
433 | case F_GET_FILE_RW_HINT: | |
434 | case F_SET_FILE_RW_HINT: | |
435 | err = fcntl_rw_hint(filp, cmd, arg); | |
436 | break; | |
1da177e4 LT |
437 | default: |
438 | break; | |
439 | } | |
440 | return err; | |
441 | } | |
442 | ||
1abf0c71 AV |
443 | static int check_fcntl_cmd(unsigned cmd) |
444 | { | |
445 | switch (cmd) { | |
446 | case F_DUPFD: | |
447 | case F_DUPFD_CLOEXEC: | |
448 | case F_GETFD: | |
449 | case F_SETFD: | |
450 | case F_GETFL: | |
451 | return 1; | |
452 | } | |
453 | return 0; | |
454 | } | |
455 | ||
a26eab24 | 456 | SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
1da177e4 | 457 | { |
2903ff01 | 458 | struct fd f = fdget_raw(fd); |
1da177e4 LT |
459 | long err = -EBADF; |
460 | ||
2903ff01 | 461 | if (!f.file) |
1da177e4 LT |
462 | goto out; |
463 | ||
2903ff01 | 464 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
465 | if (!check_fcntl_cmd(cmd)) |
466 | goto out1; | |
1abf0c71 AV |
467 | } |
468 | ||
2903ff01 | 469 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 | 470 | if (!err) |
2903ff01 | 471 | err = do_fcntl(fd, cmd, arg, f.file); |
1da177e4 | 472 | |
545ec2c7 | 473 | out1: |
2903ff01 | 474 | fdput(f); |
1da177e4 LT |
475 | out: |
476 | return err; | |
477 | } | |
478 | ||
479 | #if BITS_PER_LONG == 32 | |
a26eab24 HC |
480 | SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
481 | unsigned long, arg) | |
1da177e4 | 482 | { |
a75d30c7 | 483 | void __user *argp = (void __user *)arg; |
2903ff01 | 484 | struct fd f = fdget_raw(fd); |
a75d30c7 | 485 | struct flock64 flock; |
545ec2c7 | 486 | long err = -EBADF; |
1da177e4 | 487 | |
2903ff01 | 488 | if (!f.file) |
1da177e4 LT |
489 | goto out; |
490 | ||
2903ff01 | 491 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
492 | if (!check_fcntl_cmd(cmd)) |
493 | goto out1; | |
1abf0c71 AV |
494 | } |
495 | ||
2903ff01 | 496 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 AV |
497 | if (err) |
498 | goto out1; | |
1da177e4 LT |
499 | |
500 | switch (cmd) { | |
5d50ffd7 | 501 | case F_GETLK64: |
0d3f7a2d | 502 | case F_OFD_GETLK: |
a75d30c7 CH |
503 | err = -EFAULT; |
504 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
505 | break; | |
506 | err = fcntl_getlk64(f.file, cmd, &flock); | |
507 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
508 | err = -EFAULT; | |
5d50ffd7 JL |
509 | break; |
510 | case F_SETLK64: | |
511 | case F_SETLKW64: | |
0d3f7a2d JL |
512 | case F_OFD_SETLK: |
513 | case F_OFD_SETLKW: | |
a75d30c7 CH |
514 | err = -EFAULT; |
515 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
516 | break; | |
517 | err = fcntl_setlk64(fd, f.file, cmd, &flock); | |
5d50ffd7 JL |
518 | break; |
519 | default: | |
520 | err = do_fcntl(fd, cmd, arg, f.file); | |
521 | break; | |
1da177e4 | 522 | } |
545ec2c7 | 523 | out1: |
2903ff01 | 524 | fdput(f); |
1da177e4 LT |
525 | out: |
526 | return err; | |
527 | } | |
528 | #endif | |
529 | ||
80f0cce6 | 530 | #ifdef CONFIG_COMPAT |
8c6657cb | 531 | /* careful - don't use anywhere else */ |
b59eea55 LT |
532 | #define copy_flock_fields(dst, src) \ |
533 | (dst)->l_type = (src)->l_type; \ | |
534 | (dst)->l_whence = (src)->l_whence; \ | |
535 | (dst)->l_start = (src)->l_start; \ | |
536 | (dst)->l_len = (src)->l_len; \ | |
537 | (dst)->l_pid = (src)->l_pid; | |
538 | ||
539 | static int get_compat_flock(struct flock *kfl, const struct compat_flock __user *ufl) | |
80f0cce6 | 540 | { |
8c6657cb AV |
541 | struct compat_flock fl; |
542 | ||
543 | if (copy_from_user(&fl, ufl, sizeof(struct compat_flock))) | |
80f0cce6 | 544 | return -EFAULT; |
b59eea55 | 545 | copy_flock_fields(kfl, &fl); |
80f0cce6 AV |
546 | return 0; |
547 | } | |
548 | ||
b59eea55 | 549 | static int get_compat_flock64(struct flock *kfl, const struct compat_flock64 __user *ufl) |
80f0cce6 | 550 | { |
8c6657cb AV |
551 | struct compat_flock64 fl; |
552 | ||
553 | if (copy_from_user(&fl, ufl, sizeof(struct compat_flock64))) | |
80f0cce6 | 554 | return -EFAULT; |
b59eea55 | 555 | copy_flock_fields(kfl, &fl); |
80f0cce6 AV |
556 | return 0; |
557 | } | |
558 | ||
b59eea55 | 559 | static int put_compat_flock(const struct flock *kfl, struct compat_flock __user *ufl) |
80f0cce6 | 560 | { |
8c6657cb AV |
561 | struct compat_flock fl; |
562 | ||
563 | memset(&fl, 0, sizeof(struct compat_flock)); | |
b59eea55 | 564 | copy_flock_fields(&fl, kfl); |
8c6657cb | 565 | if (copy_to_user(ufl, &fl, sizeof(struct compat_flock))) |
80f0cce6 AV |
566 | return -EFAULT; |
567 | return 0; | |
568 | } | |
80f0cce6 | 569 | |
b59eea55 | 570 | static int put_compat_flock64(const struct flock *kfl, struct compat_flock64 __user *ufl) |
80f0cce6 | 571 | { |
8c6657cb AV |
572 | struct compat_flock64 fl; |
573 | ||
4d2dc2cc JL |
574 | BUILD_BUG_ON(sizeof(kfl->l_start) > sizeof(ufl->l_start)); |
575 | BUILD_BUG_ON(sizeof(kfl->l_len) > sizeof(ufl->l_len)); | |
576 | ||
8c6657cb | 577 | memset(&fl, 0, sizeof(struct compat_flock64)); |
b59eea55 | 578 | copy_flock_fields(&fl, kfl); |
8c6657cb | 579 | if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64))) |
80f0cce6 AV |
580 | return -EFAULT; |
581 | return 0; | |
582 | } | |
8c6657cb | 583 | #undef copy_flock_fields |
80f0cce6 AV |
584 | |
585 | static unsigned int | |
586 | convert_fcntl_cmd(unsigned int cmd) | |
587 | { | |
588 | switch (cmd) { | |
589 | case F_GETLK64: | |
590 | return F_GETLK; | |
591 | case F_SETLK64: | |
592 | return F_SETLK; | |
593 | case F_SETLKW64: | |
594 | return F_SETLKW; | |
595 | } | |
596 | ||
597 | return cmd; | |
598 | } | |
599 | ||
94073ad7 CH |
600 | /* |
601 | * GETLK was successful and we need to return the data, but it needs to fit in | |
602 | * the compat structure. | |
603 | * l_start shouldn't be too big, unless the original start + end is greater than | |
604 | * COMPAT_OFF_T_MAX, in which case the app was asking for trouble, so we return | |
605 | * -EOVERFLOW in that case. l_len could be too big, in which case we just | |
606 | * truncate it, and only allow the app to see that part of the conflicting lock | |
607 | * that might make sense to it anyway | |
608 | */ | |
609 | static int fixup_compat_flock(struct flock *flock) | |
610 | { | |
611 | if (flock->l_start > COMPAT_OFF_T_MAX) | |
612 | return -EOVERFLOW; | |
613 | if (flock->l_len > COMPAT_OFF_T_MAX) | |
614 | flock->l_len = COMPAT_OFF_T_MAX; | |
615 | return 0; | |
616 | } | |
617 | ||
e02af2ff DB |
618 | static long do_compat_fcntl64(unsigned int fd, unsigned int cmd, |
619 | compat_ulong_t arg) | |
80f0cce6 | 620 | { |
94073ad7 CH |
621 | struct fd f = fdget_raw(fd); |
622 | struct flock flock; | |
623 | long err = -EBADF; | |
624 | ||
625 | if (!f.file) | |
626 | return err; | |
627 | ||
628 | if (unlikely(f.file->f_mode & FMODE_PATH)) { | |
629 | if (!check_fcntl_cmd(cmd)) | |
630 | goto out_put; | |
631 | } | |
632 | ||
633 | err = security_file_fcntl(f.file, cmd, arg); | |
634 | if (err) | |
635 | goto out_put; | |
80f0cce6 AV |
636 | |
637 | switch (cmd) { | |
638 | case F_GETLK: | |
94073ad7 CH |
639 | err = get_compat_flock(&flock, compat_ptr(arg)); |
640 | if (err) | |
641 | break; | |
642 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
643 | if (err) | |
644 | break; | |
645 | err = fixup_compat_flock(&flock); | |
9280a601 JL |
646 | if (!err) |
647 | err = put_compat_flock(&flock, compat_ptr(arg)); | |
94073ad7 CH |
648 | break; |
649 | case F_GETLK64: | |
650 | case F_OFD_GETLK: | |
651 | err = get_compat_flock64(&flock, compat_ptr(arg)); | |
652 | if (err) | |
653 | break; | |
654 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
4d2dc2cc JL |
655 | if (!err) |
656 | err = put_compat_flock64(&flock, compat_ptr(arg)); | |
94073ad7 | 657 | break; |
80f0cce6 AV |
658 | case F_SETLK: |
659 | case F_SETLKW: | |
94073ad7 CH |
660 | err = get_compat_flock(&flock, compat_ptr(arg)); |
661 | if (err) | |
80f0cce6 | 662 | break; |
94073ad7 | 663 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 664 | break; |
80f0cce6 AV |
665 | case F_SETLK64: |
666 | case F_SETLKW64: | |
80f0cce6 AV |
667 | case F_OFD_SETLK: |
668 | case F_OFD_SETLKW: | |
94073ad7 CH |
669 | err = get_compat_flock64(&flock, compat_ptr(arg)); |
670 | if (err) | |
80f0cce6 | 671 | break; |
94073ad7 | 672 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 673 | break; |
80f0cce6 | 674 | default: |
94073ad7 | 675 | err = do_fcntl(fd, cmd, arg, f.file); |
80f0cce6 AV |
676 | break; |
677 | } | |
94073ad7 CH |
678 | out_put: |
679 | fdput(f); | |
680 | return err; | |
80f0cce6 AV |
681 | } |
682 | ||
e02af2ff DB |
683 | COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
684 | compat_ulong_t, arg) | |
685 | { | |
686 | return do_compat_fcntl64(fd, cmd, arg); | |
687 | } | |
688 | ||
80f0cce6 AV |
689 | COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, |
690 | compat_ulong_t, arg) | |
691 | { | |
692 | switch (cmd) { | |
693 | case F_GETLK64: | |
694 | case F_SETLK64: | |
695 | case F_SETLKW64: | |
696 | case F_OFD_GETLK: | |
697 | case F_OFD_SETLK: | |
698 | case F_OFD_SETLKW: | |
699 | return -EINVAL; | |
700 | } | |
e02af2ff | 701 | return do_compat_fcntl64(fd, cmd, arg); |
80f0cce6 AV |
702 | } |
703 | #endif | |
704 | ||
1da177e4 LT |
705 | /* Table to convert sigio signal codes into poll band bitmaps */ |
706 | ||
5dc533c6 | 707 | static const __poll_t band_table[NSIGPOLL] = { |
a9a08845 LT |
708 | EPOLLIN | EPOLLRDNORM, /* POLL_IN */ |
709 | EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND, /* POLL_OUT */ | |
710 | EPOLLIN | EPOLLRDNORM | EPOLLMSG, /* POLL_MSG */ | |
711 | EPOLLERR, /* POLL_ERR */ | |
712 | EPOLLPRI | EPOLLRDBAND, /* POLL_PRI */ | |
713 | EPOLLHUP | EPOLLERR /* POLL_HUP */ | |
1da177e4 LT |
714 | }; |
715 | ||
716 | static inline int sigio_perm(struct task_struct *p, | |
717 | struct fown_struct *fown, int sig) | |
718 | { | |
c69e8d9c DH |
719 | const struct cred *cred; |
720 | int ret; | |
721 | ||
722 | rcu_read_lock(); | |
723 | cred = __task_cred(p); | |
8e96e3b7 EB |
724 | ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) || |
725 | uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) || | |
726 | uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) && | |
c69e8d9c DH |
727 | !security_file_send_sigiotask(p, fown, sig)); |
728 | rcu_read_unlock(); | |
729 | return ret; | |
1da177e4 LT |
730 | } |
731 | ||
732 | static void send_sigio_to_task(struct task_struct *p, | |
8eeee4e2 | 733 | struct fown_struct *fown, |
9c2db007 | 734 | int fd, int reason, enum pid_type type) |
1da177e4 | 735 | { |
8eeee4e2 ON |
736 | /* |
737 | * F_SETSIG can change ->signum lockless in parallel, make | |
738 | * sure we read it once and use the same value throughout. | |
739 | */ | |
6aa7de05 | 740 | int signum = READ_ONCE(fown->signum); |
8eeee4e2 ON |
741 | |
742 | if (!sigio_perm(p, fown, signum)) | |
1da177e4 LT |
743 | return; |
744 | ||
8eeee4e2 | 745 | switch (signum) { |
0a68ff5e KC |
746 | default: { |
747 | kernel_siginfo_t si; | |
748 | ||
1da177e4 LT |
749 | /* Queue a rt signal with the appropriate fd as its |
750 | value. We use SI_SIGIO as the source, not | |
751 | SI_KERNEL, since kernel signals always get | |
752 | delivered even if we can't queue. Failure to | |
753 | queue in this case _should_ be reported; we fall | |
754 | back to SIGIO in that case. --sct */ | |
faf1f22b | 755 | clear_siginfo(&si); |
8eeee4e2 | 756 | si.si_signo = signum; |
1da177e4 LT |
757 | si.si_errno = 0; |
758 | si.si_code = reason; | |
d08477aa EB |
759 | /* |
760 | * Posix definies POLL_IN and friends to be signal | |
761 | * specific si_codes for SIG_POLL. Linux extended | |
762 | * these si_codes to other signals in a way that is | |
763 | * ambiguous if other signals also have signal | |
764 | * specific si_codes. In that case use SI_SIGIO instead | |
765 | * to remove the ambiguity. | |
766 | */ | |
54640d23 | 767 | if ((signum != SIGPOLL) && sig_specific_sicodes(signum)) |
d08477aa EB |
768 | si.si_code = SI_SIGIO; |
769 | ||
1da177e4 LT |
770 | /* Make sure we are called with one of the POLL_* |
771 | reasons, otherwise we could leak kernel stack into | |
772 | userspace. */ | |
d08477aa | 773 | BUG_ON((reason < POLL_IN) || ((reason - POLL_IN) >= NSIGPOLL)); |
1da177e4 LT |
774 | if (reason - POLL_IN >= NSIGPOLL) |
775 | si.si_band = ~0L; | |
776 | else | |
c71d227f | 777 | si.si_band = mangle_poll(band_table[reason - POLL_IN]); |
1da177e4 | 778 | si.si_fd = fd; |
40b3b025 | 779 | if (!do_send_sig_info(signum, &si, p, type)) |
1da177e4 | 780 | break; |
0a68ff5e | 781 | } |
df561f66 | 782 | fallthrough; /* fall back on the old plain SIGIO signal */ |
1da177e4 | 783 | case 0: |
40b3b025 | 784 | do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, type); |
1da177e4 LT |
785 | } |
786 | } | |
787 | ||
788 | void send_sigio(struct fown_struct *fown, int fd, int band) | |
789 | { | |
790 | struct task_struct *p; | |
609d7fa9 | 791 | enum pid_type type; |
8d1ddb5e | 792 | unsigned long flags; |
609d7fa9 | 793 | struct pid *pid; |
1da177e4 | 794 | |
8d1ddb5e | 795 | read_lock_irqsave(&fown->lock, flags); |
ba0a6c9f | 796 | |
609d7fa9 | 797 | type = fown->pid_type; |
1da177e4 LT |
798 | pid = fown->pid; |
799 | if (!pid) | |
800 | goto out_unlock_fown; | |
01919134 EB |
801 | |
802 | if (type <= PIDTYPE_TGID) { | |
803 | rcu_read_lock(); | |
804 | p = pid_task(pid, PIDTYPE_PID); | |
84fe4cc0 EB |
805 | if (p) |
806 | send_sigio_to_task(p, fown, fd, band, type); | |
01919134 EB |
807 | rcu_read_unlock(); |
808 | } else { | |
809 | read_lock(&tasklist_lock); | |
810 | do_each_pid_task(pid, type, p) { | |
9c2db007 | 811 | send_sigio_to_task(p, fown, fd, band, type); |
01919134 EB |
812 | } while_each_pid_task(pid, type, p); |
813 | read_unlock(&tasklist_lock); | |
814 | } | |
1da177e4 | 815 | out_unlock_fown: |
8d1ddb5e | 816 | read_unlock_irqrestore(&fown->lock, flags); |
1da177e4 LT |
817 | } |
818 | ||
819 | static void send_sigurg_to_task(struct task_struct *p, | |
9c2db007 | 820 | struct fown_struct *fown, enum pid_type type) |
1da177e4 LT |
821 | { |
822 | if (sigio_perm(p, fown, SIGURG)) | |
40b3b025 | 823 | do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, type); |
1da177e4 LT |
824 | } |
825 | ||
826 | int send_sigurg(struct fown_struct *fown) | |
827 | { | |
828 | struct task_struct *p; | |
609d7fa9 EB |
829 | enum pid_type type; |
830 | struct pid *pid; | |
8d1ddb5e | 831 | unsigned long flags; |
609d7fa9 | 832 | int ret = 0; |
1da177e4 | 833 | |
8d1ddb5e | 834 | read_lock_irqsave(&fown->lock, flags); |
ba0a6c9f | 835 | |
609d7fa9 | 836 | type = fown->pid_type; |
1da177e4 LT |
837 | pid = fown->pid; |
838 | if (!pid) | |
839 | goto out_unlock_fown; | |
840 | ||
841 | ret = 1; | |
01919134 EB |
842 | |
843 | if (type <= PIDTYPE_TGID) { | |
844 | rcu_read_lock(); | |
845 | p = pid_task(pid, PIDTYPE_PID); | |
84fe4cc0 EB |
846 | if (p) |
847 | send_sigurg_to_task(p, fown, type); | |
01919134 EB |
848 | rcu_read_unlock(); |
849 | } else { | |
850 | read_lock(&tasklist_lock); | |
851 | do_each_pid_task(pid, type, p) { | |
9c2db007 | 852 | send_sigurg_to_task(p, fown, type); |
01919134 EB |
853 | } while_each_pid_task(pid, type, p); |
854 | read_unlock(&tasklist_lock); | |
855 | } | |
1da177e4 | 856 | out_unlock_fown: |
8d1ddb5e | 857 | read_unlock_irqrestore(&fown->lock, flags); |
1da177e4 LT |
858 | return ret; |
859 | } | |
860 | ||
989a2979 | 861 | static DEFINE_SPINLOCK(fasync_lock); |
e18b890b | 862 | static struct kmem_cache *fasync_cache __read_mostly; |
1da177e4 | 863 | |
989a2979 ED |
864 | static void fasync_free_rcu(struct rcu_head *head) |
865 | { | |
866 | kmem_cache_free(fasync_cache, | |
867 | container_of(head, struct fasync_struct, fa_rcu)); | |
868 | } | |
869 | ||
1da177e4 | 870 | /* |
53281b6d LT |
871 | * Remove a fasync entry. If successfully removed, return |
872 | * positive and clear the FASYNC flag. If no entry exists, | |
873 | * do nothing and return 0. | |
874 | * | |
875 | * NOTE! It is very important that the FASYNC flag always | |
876 | * match the state "is the filp on a fasync list". | |
877 | * | |
1da177e4 | 878 | */ |
f7347ce4 | 879 | int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp) |
1da177e4 LT |
880 | { |
881 | struct fasync_struct *fa, **fp; | |
1da177e4 LT |
882 | int result = 0; |
883 | ||
53281b6d | 884 | spin_lock(&filp->f_lock); |
989a2979 | 885 | spin_lock(&fasync_lock); |
53281b6d LT |
886 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
887 | if (fa->fa_file != filp) | |
888 | continue; | |
989a2979 | 889 | |
7a107c0f | 890 | write_lock_irq(&fa->fa_lock); |
989a2979 | 891 | fa->fa_file = NULL; |
7a107c0f | 892 | write_unlock_irq(&fa->fa_lock); |
989a2979 | 893 | |
53281b6d | 894 | *fp = fa->fa_next; |
989a2979 | 895 | call_rcu(&fa->fa_rcu, fasync_free_rcu); |
53281b6d LT |
896 | filp->f_flags &= ~FASYNC; |
897 | result = 1; | |
898 | break; | |
1da177e4 | 899 | } |
989a2979 | 900 | spin_unlock(&fasync_lock); |
53281b6d LT |
901 | spin_unlock(&filp->f_lock); |
902 | return result; | |
903 | } | |
904 | ||
f7347ce4 LT |
905 | struct fasync_struct *fasync_alloc(void) |
906 | { | |
907 | return kmem_cache_alloc(fasync_cache, GFP_KERNEL); | |
908 | } | |
909 | ||
53281b6d | 910 | /* |
f7347ce4 LT |
911 | * NOTE! This can be used only for unused fasync entries: |
912 | * entries that actually got inserted on the fasync list | |
913 | * need to be released by rcu - see fasync_remove_entry. | |
53281b6d | 914 | */ |
f7347ce4 | 915 | void fasync_free(struct fasync_struct *new) |
53281b6d | 916 | { |
f7347ce4 LT |
917 | kmem_cache_free(fasync_cache, new); |
918 | } | |
53281b6d | 919 | |
f7347ce4 LT |
920 | /* |
921 | * Insert a new entry into the fasync list. Return the pointer to the | |
922 | * old one if we didn't use the new one. | |
55f335a8 LT |
923 | * |
924 | * NOTE! It is very important that the FASYNC flag always | |
925 | * match the state "is the filp on a fasync list". | |
f7347ce4 LT |
926 | */ |
927 | struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new) | |
928 | { | |
929 | struct fasync_struct *fa, **fp; | |
4a6a4499 | 930 | |
4a6a4499 | 931 | spin_lock(&filp->f_lock); |
989a2979 | 932 | spin_lock(&fasync_lock); |
1da177e4 | 933 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
53281b6d LT |
934 | if (fa->fa_file != filp) |
935 | continue; | |
989a2979 | 936 | |
7a107c0f | 937 | write_lock_irq(&fa->fa_lock); |
53281b6d | 938 | fa->fa_fd = fd; |
7a107c0f | 939 | write_unlock_irq(&fa->fa_lock); |
53281b6d | 940 | goto out; |
1da177e4 LT |
941 | } |
942 | ||
7a107c0f | 943 | rwlock_init(&new->fa_lock); |
53281b6d LT |
944 | new->magic = FASYNC_MAGIC; |
945 | new->fa_file = filp; | |
946 | new->fa_fd = fd; | |
947 | new->fa_next = *fapp; | |
989a2979 | 948 | rcu_assign_pointer(*fapp, new); |
53281b6d LT |
949 | filp->f_flags |= FASYNC; |
950 | ||
1da177e4 | 951 | out: |
989a2979 | 952 | spin_unlock(&fasync_lock); |
4a6a4499 | 953 | spin_unlock(&filp->f_lock); |
f7347ce4 LT |
954 | return fa; |
955 | } | |
956 | ||
957 | /* | |
958 | * Add a fasync entry. Return negative on error, positive if | |
959 | * added, and zero if did nothing but change an existing one. | |
f7347ce4 LT |
960 | */ |
961 | static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp) | |
962 | { | |
963 | struct fasync_struct *new; | |
964 | ||
965 | new = fasync_alloc(); | |
966 | if (!new) | |
967 | return -ENOMEM; | |
968 | ||
969 | /* | |
970 | * fasync_insert_entry() returns the old (update) entry if | |
971 | * it existed. | |
972 | * | |
973 | * So free the (unused) new entry and return 0 to let the | |
974 | * caller know that we didn't add any new fasync entries. | |
975 | */ | |
976 | if (fasync_insert_entry(fd, filp, fapp, new)) { | |
977 | fasync_free(new); | |
978 | return 0; | |
979 | } | |
980 | ||
981 | return 1; | |
1da177e4 LT |
982 | } |
983 | ||
53281b6d LT |
984 | /* |
985 | * fasync_helper() is used by almost all character device drivers | |
986 | * to set up the fasync queue, and for regular files by the file | |
987 | * lease code. It returns negative on error, 0 if it did no changes | |
988 | * and positive if it added/deleted the entry. | |
989 | */ | |
990 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) | |
991 | { | |
992 | if (!on) | |
993 | return fasync_remove_entry(filp, fapp); | |
994 | return fasync_add_entry(fd, filp, fapp); | |
995 | } | |
996 | ||
1da177e4 LT |
997 | EXPORT_SYMBOL(fasync_helper); |
998 | ||
989a2979 ED |
999 | /* |
1000 | * rcu_read_lock() is held | |
1001 | */ | |
1002 | static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) | |
1da177e4 LT |
1003 | { |
1004 | while (fa) { | |
989a2979 | 1005 | struct fown_struct *fown; |
f4985dc7 | 1006 | |
1da177e4 LT |
1007 | if (fa->magic != FASYNC_MAGIC) { |
1008 | printk(KERN_ERR "kill_fasync: bad magic number in " | |
1009 | "fasync_struct!\n"); | |
1010 | return; | |
1011 | } | |
7a107c0f | 1012 | read_lock(&fa->fa_lock); |
989a2979 ED |
1013 | if (fa->fa_file) { |
1014 | fown = &fa->fa_file->f_owner; | |
1015 | /* Don't send SIGURG to processes which have not set a | |
1016 | queued signum: SIGURG has its own default signalling | |
1017 | mechanism. */ | |
1018 | if (!(sig == SIGURG && fown->signum == 0)) | |
1019 | send_sigio(fown, fa->fa_fd, band); | |
1020 | } | |
7a107c0f | 1021 | read_unlock(&fa->fa_lock); |
989a2979 | 1022 | fa = rcu_dereference(fa->fa_next); |
1da177e4 LT |
1023 | } |
1024 | } | |
1025 | ||
1da177e4 LT |
1026 | void kill_fasync(struct fasync_struct **fp, int sig, int band) |
1027 | { | |
1028 | /* First a quick test without locking: usually | |
1029 | * the list is empty. | |
1030 | */ | |
1031 | if (*fp) { | |
989a2979 ED |
1032 | rcu_read_lock(); |
1033 | kill_fasync_rcu(rcu_dereference(*fp), sig, band); | |
1034 | rcu_read_unlock(); | |
1da177e4 LT |
1035 | } |
1036 | } | |
1037 | EXPORT_SYMBOL(kill_fasync); | |
1038 | ||
454eedb8 | 1039 | static int __init fcntl_init(void) |
1da177e4 | 1040 | { |
3ab04d5c JB |
1041 | /* |
1042 | * Please add new bits here to ensure allocation uniqueness. | |
1043 | * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY | |
1044 | * is defined as O_NONBLOCK on some platforms and not on others. | |
1045 | */ | |
80f18379 CH |
1046 | BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ != |
1047 | HWEIGHT32( | |
1048 | (VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) | | |
1049 | __FMODE_EXEC | __FMODE_NONOTIFY)); | |
454eedb8 | 1050 | |
1da177e4 | 1051 | fasync_cache = kmem_cache_create("fasync_cache", |
20c2df83 | 1052 | sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
1da177e4 LT |
1053 | return 0; |
1054 | } | |
1055 | ||
454eedb8 | 1056 | module_init(fcntl_init) |