]>
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 | 12 | #include <linux/fs.h> |
5970e15d | 13 | #include <linux/filelock.h> |
1da177e4 | 14 | #include <linux/file.h> |
9f3acc31 | 15 | #include <linux/fdtable.h> |
16f7e0fe | 16 | #include <linux/capability.h> |
1da177e4 | 17 | #include <linux/dnotify.h> |
1da177e4 LT |
18 | #include <linux/slab.h> |
19 | #include <linux/module.h> | |
35f3d14d | 20 | #include <linux/pipe_fs_i.h> |
1da177e4 LT |
21 | #include <linux/security.h> |
22 | #include <linux/ptrace.h> | |
7ed20e1a | 23 | #include <linux/signal.h> |
ab2af1f5 | 24 | #include <linux/rcupdate.h> |
b488893a | 25 | #include <linux/pid_namespace.h> |
1d151c33 | 26 | #include <linux/user_namespace.h> |
5d752600 | 27 | #include <linux/memfd.h> |
80f0cce6 | 28 | #include <linux/compat.h> |
9eccd12c | 29 | #include <linux/mount.h> |
fe3944fb | 30 | #include <linux/rw_hint.h> |
1da177e4 | 31 | |
cfe39442 | 32 | #include <linux/poll.h> |
1da177e4 | 33 | #include <asm/siginfo.h> |
7c0f6ba6 | 34 | #include <linux/uaccess.h> |
1da177e4 | 35 | |
76398425 | 36 | #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) |
1da177e4 | 37 | |
bccb5c39 | 38 | static int setfl(int fd, struct file * filp, unsigned int arg) |
1da177e4 | 39 | { |
496ad9aa | 40 | struct inode * inode = file_inode(filp); |
1da177e4 LT |
41 | int error = 0; |
42 | ||
7d95c8f2 | 43 | /* |
44 | * O_APPEND cannot be cleared if the file is marked as append-only | |
45 | * and the file is open for write. | |
46 | */ | |
47 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
1da177e4 LT |
48 | return -EPERM; |
49 | ||
50 | /* O_NOATIME can only be set by the owner or superuser */ | |
51 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) | |
01beba79 | 52 | if (!inode_owner_or_capable(file_mnt_idmap(filp), inode)) |
1da177e4 LT |
53 | return -EPERM; |
54 | ||
55 | /* required for strict SunOS emulation */ | |
56 | if (O_NONBLOCK != O_NDELAY) | |
57 | if (arg & O_NDELAY) | |
58 | arg |= O_NONBLOCK; | |
59 | ||
0dbf5f20 | 60 | /* Pipe packetized mode is controlled by O_DIRECT flag */ |
a2ad63da N |
61 | if (!S_ISFIFO(inode->i_mode) && |
62 | (arg & O_DIRECT) && | |
63 | !(filp->f_mode & FMODE_CAN_ODIRECT)) | |
64 | return -EINVAL; | |
1da177e4 | 65 | |
72c2d531 | 66 | if (filp->f_op->check_flags) |
1da177e4 LT |
67 | error = filp->f_op->check_flags(arg); |
68 | if (error) | |
69 | return error; | |
70 | ||
218d11a8 | 71 | /* |
76398425 | 72 | * ->fasync() is responsible for setting the FASYNC bit. |
218d11a8 | 73 | */ |
72c2d531 | 74 | if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) { |
76398425 JC |
75 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); |
76 | if (error < 0) | |
77 | goto out; | |
60aa4924 JC |
78 | if (error > 0) |
79 | error = 0; | |
1da177e4 | 80 | } |
db1dd4d3 | 81 | spin_lock(&filp->f_lock); |
1da177e4 | 82 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
164f4064 | 83 | filp->f_iocb_flags = iocb_flags(filp); |
db1dd4d3 | 84 | spin_unlock(&filp->f_lock); |
76398425 | 85 | |
1da177e4 | 86 | out: |
1da177e4 LT |
87 | return error; |
88 | } | |
89 | ||
609d7fa9 | 90 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
2f38d70f | 91 | int force) |
1da177e4 | 92 | { |
80e1e823 | 93 | write_lock_irq(&filp->f_owner.lock); |
1da177e4 | 94 | if (force || !filp->f_owner.pid) { |
609d7fa9 EB |
95 | put_pid(filp->f_owner.pid); |
96 | filp->f_owner.pid = get_pid(pid); | |
97 | filp->f_owner.pid_type = type; | |
2f38d70f ON |
98 | |
99 | if (pid) { | |
100 | const struct cred *cred = current_cred(); | |
101 | filp->f_owner.uid = cred->uid; | |
102 | filp->f_owner.euid = cred->euid; | |
103 | } | |
1da177e4 | 104 | } |
80e1e823 | 105 | write_unlock_irq(&filp->f_owner.lock); |
1da177e4 LT |
106 | } |
107 | ||
e0b93edd | 108 | void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
609d7fa9 | 109 | int force) |
1da177e4 | 110 | { |
e0b93edd | 111 | security_file_set_fowner(filp); |
2f38d70f | 112 | f_modown(filp, pid, type, force); |
1da177e4 | 113 | } |
609d7fa9 | 114 | EXPORT_SYMBOL(__f_setown); |
1da177e4 | 115 | |
bccb5c39 | 116 | int f_setown(struct file *filp, int who, int force) |
609d7fa9 EB |
117 | { |
118 | enum pid_type type; | |
f7312735 | 119 | struct pid *pid = NULL; |
bccb5c39 | 120 | int ret = 0; |
f7312735 | 121 | |
01919134 | 122 | type = PIDTYPE_TGID; |
609d7fa9 | 123 | if (who < 0) { |
fc3dc674 JS |
124 | /* avoid overflow below */ |
125 | if (who == INT_MIN) | |
126 | return -EINVAL; | |
127 | ||
609d7fa9 EB |
128 | type = PIDTYPE_PGID; |
129 | who = -who; | |
130 | } | |
f7312735 | 131 | |
609d7fa9 | 132 | rcu_read_lock(); |
f7312735 JL |
133 | if (who) { |
134 | pid = find_vpid(who); | |
135 | if (!pid) | |
136 | ret = -ESRCH; | |
137 | } | |
138 | ||
139 | if (!ret) | |
140 | __f_setown(filp, pid, type, force); | |
609d7fa9 | 141 | rcu_read_unlock(); |
393cc3f5 | 142 | |
f7312735 | 143 | return ret; |
609d7fa9 | 144 | } |
1da177e4 LT |
145 | EXPORT_SYMBOL(f_setown); |
146 | ||
147 | void f_delown(struct file *filp) | |
148 | { | |
01919134 | 149 | f_modown(filp, NULL, PIDTYPE_TGID, 1); |
609d7fa9 EB |
150 | } |
151 | ||
152 | pid_t f_getown(struct file *filp) | |
153 | { | |
cc4a3f88 | 154 | pid_t pid = 0; |
f671a691 DCZX |
155 | |
156 | read_lock_irq(&filp->f_owner.lock); | |
cc4a3f88 PT |
157 | rcu_read_lock(); |
158 | if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) { | |
159 | pid = pid_vnr(filp->f_owner.pid); | |
160 | if (filp->f_owner.pid_type == PIDTYPE_PGID) | |
161 | pid = -pid; | |
162 | } | |
163 | rcu_read_unlock(); | |
f671a691 | 164 | read_unlock_irq(&filp->f_owner.lock); |
609d7fa9 | 165 | return pid; |
1da177e4 LT |
166 | } |
167 | ||
ba0a6c9f PZ |
168 | static int f_setown_ex(struct file *filp, unsigned long arg) |
169 | { | |
63784dd0 | 170 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f PZ |
171 | struct f_owner_ex owner; |
172 | struct pid *pid; | |
173 | int type; | |
174 | int ret; | |
175 | ||
176 | ret = copy_from_user(&owner, owner_p, sizeof(owner)); | |
177 | if (ret) | |
5b54470d | 178 | return -EFAULT; |
ba0a6c9f PZ |
179 | |
180 | switch (owner.type) { | |
181 | case F_OWNER_TID: | |
01919134 | 182 | type = PIDTYPE_PID; |
ba0a6c9f PZ |
183 | break; |
184 | ||
185 | case F_OWNER_PID: | |
01919134 | 186 | type = PIDTYPE_TGID; |
ba0a6c9f PZ |
187 | break; |
188 | ||
978b4053 | 189 | case F_OWNER_PGRP: |
ba0a6c9f PZ |
190 | type = PIDTYPE_PGID; |
191 | break; | |
192 | ||
193 | default: | |
194 | return -EINVAL; | |
195 | } | |
196 | ||
197 | rcu_read_lock(); | |
198 | pid = find_vpid(owner.pid); | |
199 | if (owner.pid && !pid) | |
200 | ret = -ESRCH; | |
201 | else | |
e0b93edd | 202 | __f_setown(filp, pid, type, 1); |
ba0a6c9f PZ |
203 | rcu_read_unlock(); |
204 | ||
205 | return ret; | |
206 | } | |
207 | ||
208 | static int f_getown_ex(struct file *filp, unsigned long arg) | |
209 | { | |
63784dd0 | 210 | struct f_owner_ex __user *owner_p = (void __user *)arg; |
cc4a3f88 | 211 | struct f_owner_ex owner = {}; |
ba0a6c9f PZ |
212 | int ret = 0; |
213 | ||
f671a691 | 214 | read_lock_irq(&filp->f_owner.lock); |
cc4a3f88 PT |
215 | rcu_read_lock(); |
216 | if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) | |
217 | owner.pid = pid_vnr(filp->f_owner.pid); | |
218 | rcu_read_unlock(); | |
ba0a6c9f | 219 | switch (filp->f_owner.pid_type) { |
01919134 | 220 | case PIDTYPE_PID: |
ba0a6c9f PZ |
221 | owner.type = F_OWNER_TID; |
222 | break; | |
223 | ||
01919134 | 224 | case PIDTYPE_TGID: |
ba0a6c9f PZ |
225 | owner.type = F_OWNER_PID; |
226 | break; | |
227 | ||
228 | case PIDTYPE_PGID: | |
978b4053 | 229 | owner.type = F_OWNER_PGRP; |
ba0a6c9f PZ |
230 | break; |
231 | ||
232 | default: | |
233 | WARN_ON(1); | |
234 | ret = -EINVAL; | |
235 | break; | |
236 | } | |
f671a691 | 237 | read_unlock_irq(&filp->f_owner.lock); |
ba0a6c9f | 238 | |
5b54470d | 239 | if (!ret) { |
ba0a6c9f | 240 | ret = copy_to_user(owner_p, &owner, sizeof(owner)); |
5b54470d DC |
241 | if (ret) |
242 | ret = -EFAULT; | |
243 | } | |
ba0a6c9f PZ |
244 | return ret; |
245 | } | |
246 | ||
1d151c33 CG |
247 | #ifdef CONFIG_CHECKPOINT_RESTORE |
248 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
249 | { | |
250 | struct user_namespace *user_ns = current_user_ns(); | |
63784dd0 | 251 | uid_t __user *dst = (void __user *)arg; |
1d151c33 CG |
252 | uid_t src[2]; |
253 | int err; | |
254 | ||
f671a691 | 255 | read_lock_irq(&filp->f_owner.lock); |
1d151c33 CG |
256 | src[0] = from_kuid(user_ns, filp->f_owner.uid); |
257 | src[1] = from_kuid(user_ns, filp->f_owner.euid); | |
f671a691 | 258 | read_unlock_irq(&filp->f_owner.lock); |
1d151c33 CG |
259 | |
260 | err = put_user(src[0], &dst[0]); | |
261 | err |= put_user(src[1], &dst[1]); | |
262 | ||
263 | return err; | |
264 | } | |
265 | #else | |
266 | static int f_getowner_uids(struct file *filp, unsigned long arg) | |
267 | { | |
268 | return -EINVAL; | |
269 | } | |
270 | #endif | |
271 | ||
ec16b147 | 272 | static bool rw_hint_valid(u64 hint) |
c75b1d94 | 273 | { |
e769779c BVA |
274 | BUILD_BUG_ON(WRITE_LIFE_NOT_SET != RWH_WRITE_LIFE_NOT_SET); |
275 | BUILD_BUG_ON(WRITE_LIFE_NONE != RWH_WRITE_LIFE_NONE); | |
276 | BUILD_BUG_ON(WRITE_LIFE_SHORT != RWH_WRITE_LIFE_SHORT); | |
277 | BUILD_BUG_ON(WRITE_LIFE_MEDIUM != RWH_WRITE_LIFE_MEDIUM); | |
278 | BUILD_BUG_ON(WRITE_LIFE_LONG != RWH_WRITE_LIFE_LONG); | |
279 | BUILD_BUG_ON(WRITE_LIFE_EXTREME != RWH_WRITE_LIFE_EXTREME); | |
280 | ||
c75b1d94 | 281 | switch (hint) { |
9a7f12ed | 282 | case RWH_WRITE_LIFE_NOT_SET: |
c75b1d94 JA |
283 | case RWH_WRITE_LIFE_NONE: |
284 | case RWH_WRITE_LIFE_SHORT: | |
285 | case RWH_WRITE_LIFE_MEDIUM: | |
286 | case RWH_WRITE_LIFE_LONG: | |
287 | case RWH_WRITE_LIFE_EXTREME: | |
288 | return true; | |
289 | default: | |
290 | return false; | |
291 | } | |
292 | } | |
293 | ||
1505ba06 BVA |
294 | static long fcntl_get_rw_hint(struct file *file, unsigned int cmd, |
295 | unsigned long arg) | |
c75b1d94 JA |
296 | { |
297 | struct inode *inode = file_inode(file); | |
e2003277 | 298 | u64 __user *argp = (u64 __user *)arg; |
1505ba06 | 299 | u64 hint = READ_ONCE(inode->i_write_hint); |
c75b1d94 | 300 | |
1505ba06 BVA |
301 | if (copy_to_user(argp, &hint, sizeof(*argp))) |
302 | return -EFAULT; | |
303 | return 0; | |
304 | } | |
c75b1d94 | 305 | |
1505ba06 BVA |
306 | static long fcntl_set_rw_hint(struct file *file, unsigned int cmd, |
307 | unsigned long arg) | |
308 | { | |
309 | struct inode *inode = file_inode(file); | |
310 | u64 __user *argp = (u64 __user *)arg; | |
311 | u64 hint; | |
312 | ||
313 | if (copy_from_user(&hint, argp, sizeof(hint))) | |
314 | return -EFAULT; | |
315 | if (!rw_hint_valid(hint)) | |
c75b1d94 | 316 | return -EINVAL; |
1505ba06 BVA |
317 | |
318 | WRITE_ONCE(inode->i_write_hint, hint); | |
319 | ||
ea7d8986 BVA |
320 | /* |
321 | * file->f_mapping->host may differ from inode. As an example, | |
322 | * blkdev_open() modifies file->f_mapping. | |
323 | */ | |
324 | if (file->f_mapping->host != inode) | |
325 | WRITE_ONCE(file->f_mapping->host->i_write_hint, hint); | |
326 | ||
1505ba06 | 327 | return 0; |
c75b1d94 JA |
328 | } |
329 | ||
c62b758b LT |
330 | /* Is the file descriptor a dup of the file? */ |
331 | static long f_dupfd_query(int fd, struct file *filp) | |
332 | { | |
333 | CLASS(fd_raw, f)(fd); | |
334 | ||
335 | /* | |
336 | * We can do the 'fdput()' immediately, as the only thing that | |
337 | * matters is the pointer value which isn't changed by the fdput. | |
338 | * | |
339 | * Technically we didn't need a ref at all, and 'fdget()' was | |
340 | * overkill, but given our lockless file pointer lookup, the | |
341 | * alternatives are complicated. | |
342 | */ | |
343 | return f.file == filp; | |
344 | } | |
345 | ||
1da177e4 LT |
346 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, |
347 | struct file *filp) | |
348 | { | |
a75d30c7 | 349 | void __user *argp = (void __user *)arg; |
bccb5c39 | 350 | int argi = (int)arg; |
a75d30c7 | 351 | struct flock flock; |
1da177e4 LT |
352 | long err = -EINVAL; |
353 | ||
354 | switch (cmd) { | |
355 | case F_DUPFD: | |
bccb5c39 | 356 | err = f_dupfd(argi, filp, 0); |
fe17f22d | 357 | break; |
22d2b35b | 358 | case F_DUPFD_CLOEXEC: |
bccb5c39 | 359 | err = f_dupfd(argi, filp, O_CLOEXEC); |
1da177e4 | 360 | break; |
c62b758b LT |
361 | case F_DUPFD_QUERY: |
362 | err = f_dupfd_query(argi, filp); | |
363 | break; | |
1da177e4 LT |
364 | case F_GETFD: |
365 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; | |
366 | break; | |
367 | case F_SETFD: | |
368 | err = 0; | |
bccb5c39 | 369 | set_close_on_exec(fd, argi & FD_CLOEXEC); |
1da177e4 LT |
370 | break; |
371 | case F_GETFL: | |
372 | err = filp->f_flags; | |
373 | break; | |
374 | case F_SETFL: | |
bccb5c39 | 375 | err = setfl(fd, filp, argi); |
1da177e4 | 376 | break; |
5d50ffd7 JL |
377 | #if BITS_PER_LONG != 32 |
378 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d | 379 | case F_OFD_GETLK: |
5d50ffd7 | 380 | #endif |
1da177e4 | 381 | case F_GETLK: |
a75d30c7 CH |
382 | if (copy_from_user(&flock, argp, sizeof(flock))) |
383 | return -EFAULT; | |
384 | err = fcntl_getlk(filp, cmd, &flock); | |
385 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
386 | return -EFAULT; | |
1da177e4 | 387 | break; |
5d50ffd7 JL |
388 | #if BITS_PER_LONG != 32 |
389 | /* 32-bit arches must use fcntl64() */ | |
0d3f7a2d JL |
390 | case F_OFD_SETLK: |
391 | case F_OFD_SETLKW: | |
df561f66 | 392 | fallthrough; |
e8865537 | 393 | #endif |
1da177e4 LT |
394 | case F_SETLK: |
395 | case F_SETLKW: | |
a75d30c7 CH |
396 | if (copy_from_user(&flock, argp, sizeof(flock))) |
397 | return -EFAULT; | |
398 | err = fcntl_setlk(fd, filp, cmd, &flock); | |
1da177e4 LT |
399 | break; |
400 | case F_GETOWN: | |
401 | /* | |
402 | * XXX If f_owner is a process group, the | |
403 | * negative return value will get converted | |
404 | * into an error. Oops. If we keep the | |
405 | * current syscall conventions, the only way | |
406 | * to fix this will be in libc. | |
407 | */ | |
609d7fa9 | 408 | err = f_getown(filp); |
1da177e4 LT |
409 | force_successful_syscall_return(); |
410 | break; | |
411 | case F_SETOWN: | |
bccb5c39 | 412 | err = f_setown(filp, argi, 1); |
1da177e4 | 413 | break; |
ba0a6c9f PZ |
414 | case F_GETOWN_EX: |
415 | err = f_getown_ex(filp, arg); | |
416 | break; | |
417 | case F_SETOWN_EX: | |
418 | err = f_setown_ex(filp, arg); | |
419 | break; | |
1d151c33 CG |
420 | case F_GETOWNER_UIDS: |
421 | err = f_getowner_uids(filp, arg); | |
422 | break; | |
1da177e4 LT |
423 | case F_GETSIG: |
424 | err = filp->f_owner.signum; | |
425 | break; | |
426 | case F_SETSIG: | |
427 | /* arg == 0 restores default behaviour. */ | |
bccb5c39 | 428 | if (!valid_signal(argi)) { |
1da177e4 LT |
429 | break; |
430 | } | |
431 | err = 0; | |
bccb5c39 | 432 | filp->f_owner.signum = argi; |
1da177e4 LT |
433 | break; |
434 | case F_GETLEASE: | |
435 | err = fcntl_getlease(filp); | |
436 | break; | |
437 | case F_SETLEASE: | |
bccb5c39 | 438 | err = fcntl_setlease(fd, filp, argi); |
1da177e4 LT |
439 | break; |
440 | case F_NOTIFY: | |
bccb5c39 | 441 | err = fcntl_dirnotify(fd, filp, argi); |
1da177e4 | 442 | break; |
35f3d14d JA |
443 | case F_SETPIPE_SZ: |
444 | case F_GETPIPE_SZ: | |
bccb5c39 | 445 | err = pipe_fcntl(filp, cmd, argi); |
35f3d14d | 446 | break; |
40e041a2 DR |
447 | case F_ADD_SEALS: |
448 | case F_GET_SEALS: | |
bccb5c39 | 449 | err = memfd_fcntl(filp, cmd, argi); |
40e041a2 | 450 | break; |
c75b1d94 | 451 | case F_GET_RW_HINT: |
1505ba06 BVA |
452 | err = fcntl_get_rw_hint(filp, cmd, arg); |
453 | break; | |
c75b1d94 | 454 | case F_SET_RW_HINT: |
1505ba06 | 455 | err = fcntl_set_rw_hint(filp, cmd, arg); |
c75b1d94 | 456 | break; |
1da177e4 LT |
457 | default: |
458 | break; | |
459 | } | |
460 | return err; | |
461 | } | |
462 | ||
1abf0c71 AV |
463 | static int check_fcntl_cmd(unsigned cmd) |
464 | { | |
465 | switch (cmd) { | |
466 | case F_DUPFD: | |
467 | case F_DUPFD_CLOEXEC: | |
c62b758b | 468 | case F_DUPFD_QUERY: |
1abf0c71 AV |
469 | case F_GETFD: |
470 | case F_SETFD: | |
471 | case F_GETFL: | |
472 | return 1; | |
473 | } | |
474 | return 0; | |
475 | } | |
476 | ||
a26eab24 | 477 | SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
1da177e4 | 478 | { |
2903ff01 | 479 | struct fd f = fdget_raw(fd); |
1da177e4 LT |
480 | long err = -EBADF; |
481 | ||
2903ff01 | 482 | if (!f.file) |
1da177e4 LT |
483 | goto out; |
484 | ||
2903ff01 | 485 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
486 | if (!check_fcntl_cmd(cmd)) |
487 | goto out1; | |
1abf0c71 AV |
488 | } |
489 | ||
2903ff01 | 490 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 | 491 | if (!err) |
2903ff01 | 492 | err = do_fcntl(fd, cmd, arg, f.file); |
1da177e4 | 493 | |
545ec2c7 | 494 | out1: |
2903ff01 | 495 | fdput(f); |
1da177e4 LT |
496 | out: |
497 | return err; | |
498 | } | |
499 | ||
500 | #if BITS_PER_LONG == 32 | |
a26eab24 HC |
501 | SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
502 | unsigned long, arg) | |
1da177e4 | 503 | { |
a75d30c7 | 504 | void __user *argp = (void __user *)arg; |
2903ff01 | 505 | struct fd f = fdget_raw(fd); |
a75d30c7 | 506 | struct flock64 flock; |
545ec2c7 | 507 | long err = -EBADF; |
1da177e4 | 508 | |
2903ff01 | 509 | if (!f.file) |
1da177e4 LT |
510 | goto out; |
511 | ||
2903ff01 | 512 | if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c7 AV |
513 | if (!check_fcntl_cmd(cmd)) |
514 | goto out1; | |
1abf0c71 AV |
515 | } |
516 | ||
2903ff01 | 517 | err = security_file_fcntl(f.file, cmd, arg); |
545ec2c7 AV |
518 | if (err) |
519 | goto out1; | |
1da177e4 LT |
520 | |
521 | switch (cmd) { | |
5d50ffd7 | 522 | case F_GETLK64: |
0d3f7a2d | 523 | case F_OFD_GETLK: |
a75d30c7 CH |
524 | err = -EFAULT; |
525 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
526 | break; | |
527 | err = fcntl_getlk64(f.file, cmd, &flock); | |
528 | if (!err && copy_to_user(argp, &flock, sizeof(flock))) | |
529 | err = -EFAULT; | |
5d50ffd7 JL |
530 | break; |
531 | case F_SETLK64: | |
532 | case F_SETLKW64: | |
0d3f7a2d JL |
533 | case F_OFD_SETLK: |
534 | case F_OFD_SETLKW: | |
a75d30c7 CH |
535 | err = -EFAULT; |
536 | if (copy_from_user(&flock, argp, sizeof(flock))) | |
537 | break; | |
538 | err = fcntl_setlk64(fd, f.file, cmd, &flock); | |
5d50ffd7 JL |
539 | break; |
540 | default: | |
541 | err = do_fcntl(fd, cmd, arg, f.file); | |
542 | break; | |
1da177e4 | 543 | } |
545ec2c7 | 544 | out1: |
2903ff01 | 545 | fdput(f); |
1da177e4 LT |
546 | out: |
547 | return err; | |
548 | } | |
549 | #endif | |
550 | ||
80f0cce6 | 551 | #ifdef CONFIG_COMPAT |
8c6657cb | 552 | /* careful - don't use anywhere else */ |
b59eea55 LT |
553 | #define copy_flock_fields(dst, src) \ |
554 | (dst)->l_type = (src)->l_type; \ | |
555 | (dst)->l_whence = (src)->l_whence; \ | |
556 | (dst)->l_start = (src)->l_start; \ | |
557 | (dst)->l_len = (src)->l_len; \ | |
558 | (dst)->l_pid = (src)->l_pid; | |
559 | ||
560 | static int get_compat_flock(struct flock *kfl, const struct compat_flock __user *ufl) | |
80f0cce6 | 561 | { |
8c6657cb AV |
562 | struct compat_flock fl; |
563 | ||
564 | if (copy_from_user(&fl, ufl, sizeof(struct compat_flock))) | |
80f0cce6 | 565 | return -EFAULT; |
b59eea55 | 566 | copy_flock_fields(kfl, &fl); |
80f0cce6 AV |
567 | return 0; |
568 | } | |
569 | ||
b59eea55 | 570 | static int get_compat_flock64(struct flock *kfl, const struct compat_flock64 __user *ufl) |
80f0cce6 | 571 | { |
8c6657cb AV |
572 | struct compat_flock64 fl; |
573 | ||
574 | if (copy_from_user(&fl, ufl, sizeof(struct compat_flock64))) | |
80f0cce6 | 575 | return -EFAULT; |
b59eea55 | 576 | copy_flock_fields(kfl, &fl); |
80f0cce6 AV |
577 | return 0; |
578 | } | |
579 | ||
b59eea55 | 580 | static int put_compat_flock(const struct flock *kfl, struct compat_flock __user *ufl) |
80f0cce6 | 581 | { |
8c6657cb AV |
582 | struct compat_flock fl; |
583 | ||
584 | memset(&fl, 0, sizeof(struct compat_flock)); | |
b59eea55 | 585 | copy_flock_fields(&fl, kfl); |
8c6657cb | 586 | if (copy_to_user(ufl, &fl, sizeof(struct compat_flock))) |
80f0cce6 AV |
587 | return -EFAULT; |
588 | return 0; | |
589 | } | |
80f0cce6 | 590 | |
b59eea55 | 591 | static int put_compat_flock64(const struct flock *kfl, struct compat_flock64 __user *ufl) |
80f0cce6 | 592 | { |
8c6657cb AV |
593 | struct compat_flock64 fl; |
594 | ||
4d2dc2cc JL |
595 | BUILD_BUG_ON(sizeof(kfl->l_start) > sizeof(ufl->l_start)); |
596 | BUILD_BUG_ON(sizeof(kfl->l_len) > sizeof(ufl->l_len)); | |
597 | ||
8c6657cb | 598 | memset(&fl, 0, sizeof(struct compat_flock64)); |
b59eea55 | 599 | copy_flock_fields(&fl, kfl); |
8c6657cb | 600 | if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64))) |
80f0cce6 AV |
601 | return -EFAULT; |
602 | return 0; | |
603 | } | |
8c6657cb | 604 | #undef copy_flock_fields |
80f0cce6 AV |
605 | |
606 | static unsigned int | |
607 | convert_fcntl_cmd(unsigned int cmd) | |
608 | { | |
609 | switch (cmd) { | |
610 | case F_GETLK64: | |
611 | return F_GETLK; | |
612 | case F_SETLK64: | |
613 | return F_SETLK; | |
614 | case F_SETLKW64: | |
615 | return F_SETLKW; | |
616 | } | |
617 | ||
618 | return cmd; | |
619 | } | |
620 | ||
94073ad7 CH |
621 | /* |
622 | * GETLK was successful and we need to return the data, but it needs to fit in | |
623 | * the compat structure. | |
624 | * l_start shouldn't be too big, unless the original start + end is greater than | |
625 | * COMPAT_OFF_T_MAX, in which case the app was asking for trouble, so we return | |
626 | * -EOVERFLOW in that case. l_len could be too big, in which case we just | |
627 | * truncate it, and only allow the app to see that part of the conflicting lock | |
628 | * that might make sense to it anyway | |
629 | */ | |
630 | static int fixup_compat_flock(struct flock *flock) | |
631 | { | |
632 | if (flock->l_start > COMPAT_OFF_T_MAX) | |
633 | return -EOVERFLOW; | |
634 | if (flock->l_len > COMPAT_OFF_T_MAX) | |
635 | flock->l_len = COMPAT_OFF_T_MAX; | |
636 | return 0; | |
637 | } | |
638 | ||
e02af2ff DB |
639 | static long do_compat_fcntl64(unsigned int fd, unsigned int cmd, |
640 | compat_ulong_t arg) | |
80f0cce6 | 641 | { |
94073ad7 CH |
642 | struct fd f = fdget_raw(fd); |
643 | struct flock flock; | |
644 | long err = -EBADF; | |
645 | ||
646 | if (!f.file) | |
647 | return err; | |
648 | ||
649 | if (unlikely(f.file->f_mode & FMODE_PATH)) { | |
650 | if (!check_fcntl_cmd(cmd)) | |
651 | goto out_put; | |
652 | } | |
653 | ||
654 | err = security_file_fcntl(f.file, cmd, arg); | |
655 | if (err) | |
656 | goto out_put; | |
80f0cce6 AV |
657 | |
658 | switch (cmd) { | |
659 | case F_GETLK: | |
94073ad7 CH |
660 | err = get_compat_flock(&flock, compat_ptr(arg)); |
661 | if (err) | |
662 | break; | |
663 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
664 | if (err) | |
665 | break; | |
666 | err = fixup_compat_flock(&flock); | |
9280a601 JL |
667 | if (!err) |
668 | err = put_compat_flock(&flock, compat_ptr(arg)); | |
94073ad7 CH |
669 | break; |
670 | case F_GETLK64: | |
671 | case F_OFD_GETLK: | |
672 | err = get_compat_flock64(&flock, compat_ptr(arg)); | |
673 | if (err) | |
674 | break; | |
675 | err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); | |
4d2dc2cc JL |
676 | if (!err) |
677 | err = put_compat_flock64(&flock, compat_ptr(arg)); | |
94073ad7 | 678 | break; |
80f0cce6 AV |
679 | case F_SETLK: |
680 | case F_SETLKW: | |
94073ad7 CH |
681 | err = get_compat_flock(&flock, compat_ptr(arg)); |
682 | if (err) | |
80f0cce6 | 683 | break; |
94073ad7 | 684 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 685 | break; |
80f0cce6 AV |
686 | case F_SETLK64: |
687 | case F_SETLKW64: | |
80f0cce6 AV |
688 | case F_OFD_SETLK: |
689 | case F_OFD_SETLKW: | |
94073ad7 CH |
690 | err = get_compat_flock64(&flock, compat_ptr(arg)); |
691 | if (err) | |
80f0cce6 | 692 | break; |
94073ad7 | 693 | err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); |
80f0cce6 | 694 | break; |
80f0cce6 | 695 | default: |
94073ad7 | 696 | err = do_fcntl(fd, cmd, arg, f.file); |
80f0cce6 AV |
697 | break; |
698 | } | |
94073ad7 CH |
699 | out_put: |
700 | fdput(f); | |
701 | return err; | |
80f0cce6 AV |
702 | } |
703 | ||
e02af2ff DB |
704 | COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, |
705 | compat_ulong_t, arg) | |
706 | { | |
707 | return do_compat_fcntl64(fd, cmd, arg); | |
708 | } | |
709 | ||
80f0cce6 AV |
710 | COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, |
711 | compat_ulong_t, arg) | |
712 | { | |
713 | switch (cmd) { | |
714 | case F_GETLK64: | |
715 | case F_SETLK64: | |
716 | case F_SETLKW64: | |
717 | case F_OFD_GETLK: | |
718 | case F_OFD_SETLK: | |
719 | case F_OFD_SETLKW: | |
720 | return -EINVAL; | |
721 | } | |
e02af2ff | 722 | return do_compat_fcntl64(fd, cmd, arg); |
80f0cce6 AV |
723 | } |
724 | #endif | |
725 | ||
1da177e4 LT |
726 | /* Table to convert sigio signal codes into poll band bitmaps */ |
727 | ||
5dc533c6 | 728 | static const __poll_t band_table[NSIGPOLL] = { |
a9a08845 LT |
729 | EPOLLIN | EPOLLRDNORM, /* POLL_IN */ |
730 | EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND, /* POLL_OUT */ | |
731 | EPOLLIN | EPOLLRDNORM | EPOLLMSG, /* POLL_MSG */ | |
732 | EPOLLERR, /* POLL_ERR */ | |
733 | EPOLLPRI | EPOLLRDBAND, /* POLL_PRI */ | |
734 | EPOLLHUP | EPOLLERR /* POLL_HUP */ | |
1da177e4 LT |
735 | }; |
736 | ||
737 | static inline int sigio_perm(struct task_struct *p, | |
738 | struct fown_struct *fown, int sig) | |
739 | { | |
c69e8d9c DH |
740 | const struct cred *cred; |
741 | int ret; | |
742 | ||
743 | rcu_read_lock(); | |
744 | cred = __task_cred(p); | |
8e96e3b7 EB |
745 | ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) || |
746 | uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) || | |
747 | uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) && | |
c69e8d9c DH |
748 | !security_file_send_sigiotask(p, fown, sig)); |
749 | rcu_read_unlock(); | |
750 | return ret; | |
1da177e4 LT |
751 | } |
752 | ||
753 | static void send_sigio_to_task(struct task_struct *p, | |
8eeee4e2 | 754 | struct fown_struct *fown, |
9c2db007 | 755 | int fd, int reason, enum pid_type type) |
1da177e4 | 756 | { |
8eeee4e2 ON |
757 | /* |
758 | * F_SETSIG can change ->signum lockless in parallel, make | |
759 | * sure we read it once and use the same value throughout. | |
760 | */ | |
6aa7de05 | 761 | int signum = READ_ONCE(fown->signum); |
8eeee4e2 ON |
762 | |
763 | if (!sigio_perm(p, fown, signum)) | |
1da177e4 LT |
764 | return; |
765 | ||
8eeee4e2 | 766 | switch (signum) { |
0a68ff5e KC |
767 | default: { |
768 | kernel_siginfo_t si; | |
769 | ||
1da177e4 LT |
770 | /* Queue a rt signal with the appropriate fd as its |
771 | value. We use SI_SIGIO as the source, not | |
772 | SI_KERNEL, since kernel signals always get | |
773 | delivered even if we can't queue. Failure to | |
774 | queue in this case _should_ be reported; we fall | |
775 | back to SIGIO in that case. --sct */ | |
faf1f22b | 776 | clear_siginfo(&si); |
8eeee4e2 | 777 | si.si_signo = signum; |
1da177e4 LT |
778 | si.si_errno = 0; |
779 | si.si_code = reason; | |
d08477aa EB |
780 | /* |
781 | * Posix definies POLL_IN and friends to be signal | |
782 | * specific si_codes for SIG_POLL. Linux extended | |
783 | * these si_codes to other signals in a way that is | |
784 | * ambiguous if other signals also have signal | |
785 | * specific si_codes. In that case use SI_SIGIO instead | |
786 | * to remove the ambiguity. | |
787 | */ | |
54640d23 | 788 | if ((signum != SIGPOLL) && sig_specific_sicodes(signum)) |
d08477aa EB |
789 | si.si_code = SI_SIGIO; |
790 | ||
1da177e4 LT |
791 | /* Make sure we are called with one of the POLL_* |
792 | reasons, otherwise we could leak kernel stack into | |
793 | userspace. */ | |
d08477aa | 794 | BUG_ON((reason < POLL_IN) || ((reason - POLL_IN) >= NSIGPOLL)); |
1da177e4 LT |
795 | if (reason - POLL_IN >= NSIGPOLL) |
796 | si.si_band = ~0L; | |
797 | else | |
c71d227f | 798 | si.si_band = mangle_poll(band_table[reason - POLL_IN]); |
1da177e4 | 799 | si.si_fd = fd; |
40b3b025 | 800 | if (!do_send_sig_info(signum, &si, p, type)) |
1da177e4 | 801 | break; |
0a68ff5e | 802 | } |
df561f66 | 803 | fallthrough; /* fall back on the old plain SIGIO signal */ |
1da177e4 | 804 | case 0: |
40b3b025 | 805 | do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, type); |
1da177e4 LT |
806 | } |
807 | } | |
808 | ||
809 | void send_sigio(struct fown_struct *fown, int fd, int band) | |
810 | { | |
811 | struct task_struct *p; | |
609d7fa9 | 812 | enum pid_type type; |
8d1ddb5e | 813 | unsigned long flags; |
609d7fa9 | 814 | struct pid *pid; |
1da177e4 | 815 | |
8d1ddb5e | 816 | read_lock_irqsave(&fown->lock, flags); |
ba0a6c9f | 817 | |
609d7fa9 | 818 | type = fown->pid_type; |
1da177e4 LT |
819 | pid = fown->pid; |
820 | if (!pid) | |
821 | goto out_unlock_fown; | |
01919134 EB |
822 | |
823 | if (type <= PIDTYPE_TGID) { | |
824 | rcu_read_lock(); | |
825 | p = pid_task(pid, PIDTYPE_PID); | |
84fe4cc0 EB |
826 | if (p) |
827 | send_sigio_to_task(p, fown, fd, band, type); | |
01919134 EB |
828 | rcu_read_unlock(); |
829 | } else { | |
830 | read_lock(&tasklist_lock); | |
831 | do_each_pid_task(pid, type, p) { | |
9c2db007 | 832 | send_sigio_to_task(p, fown, fd, band, type); |
01919134 EB |
833 | } while_each_pid_task(pid, type, p); |
834 | read_unlock(&tasklist_lock); | |
835 | } | |
1da177e4 | 836 | out_unlock_fown: |
8d1ddb5e | 837 | read_unlock_irqrestore(&fown->lock, flags); |
1da177e4 LT |
838 | } |
839 | ||
840 | static void send_sigurg_to_task(struct task_struct *p, | |
9c2db007 | 841 | struct fown_struct *fown, enum pid_type type) |
1da177e4 LT |
842 | { |
843 | if (sigio_perm(p, fown, SIGURG)) | |
40b3b025 | 844 | do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, type); |
1da177e4 LT |
845 | } |
846 | ||
847 | int send_sigurg(struct fown_struct *fown) | |
848 | { | |
849 | struct task_struct *p; | |
609d7fa9 EB |
850 | enum pid_type type; |
851 | struct pid *pid; | |
8d1ddb5e | 852 | unsigned long flags; |
609d7fa9 | 853 | int ret = 0; |
1da177e4 | 854 | |
8d1ddb5e | 855 | read_lock_irqsave(&fown->lock, flags); |
ba0a6c9f | 856 | |
609d7fa9 | 857 | type = fown->pid_type; |
1da177e4 LT |
858 | pid = fown->pid; |
859 | if (!pid) | |
860 | goto out_unlock_fown; | |
861 | ||
862 | ret = 1; | |
01919134 EB |
863 | |
864 | if (type <= PIDTYPE_TGID) { | |
865 | rcu_read_lock(); | |
866 | p = pid_task(pid, PIDTYPE_PID); | |
84fe4cc0 EB |
867 | if (p) |
868 | send_sigurg_to_task(p, fown, type); | |
01919134 EB |
869 | rcu_read_unlock(); |
870 | } else { | |
871 | read_lock(&tasklist_lock); | |
872 | do_each_pid_task(pid, type, p) { | |
9c2db007 | 873 | send_sigurg_to_task(p, fown, type); |
01919134 EB |
874 | } while_each_pid_task(pid, type, p); |
875 | read_unlock(&tasklist_lock); | |
876 | } | |
1da177e4 | 877 | out_unlock_fown: |
8d1ddb5e | 878 | read_unlock_irqrestore(&fown->lock, flags); |
1da177e4 LT |
879 | return ret; |
880 | } | |
881 | ||
989a2979 | 882 | static DEFINE_SPINLOCK(fasync_lock); |
68279f9c | 883 | static struct kmem_cache *fasync_cache __ro_after_init; |
1da177e4 LT |
884 | |
885 | /* | |
53281b6d LT |
886 | * Remove a fasync entry. If successfully removed, return |
887 | * positive and clear the FASYNC flag. If no entry exists, | |
888 | * do nothing and return 0. | |
889 | * | |
890 | * NOTE! It is very important that the FASYNC flag always | |
891 | * match the state "is the filp on a fasync list". | |
892 | * | |
1da177e4 | 893 | */ |
f7347ce4 | 894 | int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp) |
1da177e4 LT |
895 | { |
896 | struct fasync_struct *fa, **fp; | |
1da177e4 LT |
897 | int result = 0; |
898 | ||
53281b6d | 899 | spin_lock(&filp->f_lock); |
989a2979 | 900 | spin_lock(&fasync_lock); |
53281b6d LT |
901 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
902 | if (fa->fa_file != filp) | |
903 | continue; | |
989a2979 | 904 | |
7a107c0f | 905 | write_lock_irq(&fa->fa_lock); |
989a2979 | 906 | fa->fa_file = NULL; |
7a107c0f | 907 | write_unlock_irq(&fa->fa_lock); |
989a2979 | 908 | |
53281b6d | 909 | *fp = fa->fa_next; |
d0089603 | 910 | kfree_rcu(fa, fa_rcu); |
53281b6d LT |
911 | filp->f_flags &= ~FASYNC; |
912 | result = 1; | |
913 | break; | |
1da177e4 | 914 | } |
989a2979 | 915 | spin_unlock(&fasync_lock); |
53281b6d LT |
916 | spin_unlock(&filp->f_lock); |
917 | return result; | |
918 | } | |
919 | ||
f7347ce4 LT |
920 | struct fasync_struct *fasync_alloc(void) |
921 | { | |
922 | return kmem_cache_alloc(fasync_cache, GFP_KERNEL); | |
923 | } | |
924 | ||
53281b6d | 925 | /* |
f7347ce4 LT |
926 | * NOTE! This can be used only for unused fasync entries: |
927 | * entries that actually got inserted on the fasync list | |
928 | * need to be released by rcu - see fasync_remove_entry. | |
53281b6d | 929 | */ |
f7347ce4 | 930 | void fasync_free(struct fasync_struct *new) |
53281b6d | 931 | { |
f7347ce4 LT |
932 | kmem_cache_free(fasync_cache, new); |
933 | } | |
53281b6d | 934 | |
f7347ce4 LT |
935 | /* |
936 | * Insert a new entry into the fasync list. Return the pointer to the | |
937 | * old one if we didn't use the new one. | |
55f335a8 LT |
938 | * |
939 | * NOTE! It is very important that the FASYNC flag always | |
940 | * match the state "is the filp on a fasync list". | |
f7347ce4 LT |
941 | */ |
942 | struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new) | |
943 | { | |
944 | struct fasync_struct *fa, **fp; | |
4a6a4499 | 945 | |
4a6a4499 | 946 | spin_lock(&filp->f_lock); |
989a2979 | 947 | spin_lock(&fasync_lock); |
1da177e4 | 948 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
53281b6d LT |
949 | if (fa->fa_file != filp) |
950 | continue; | |
989a2979 | 951 | |
7a107c0f | 952 | write_lock_irq(&fa->fa_lock); |
53281b6d | 953 | fa->fa_fd = fd; |
7a107c0f | 954 | write_unlock_irq(&fa->fa_lock); |
53281b6d | 955 | goto out; |
1da177e4 LT |
956 | } |
957 | ||
7a107c0f | 958 | rwlock_init(&new->fa_lock); |
53281b6d LT |
959 | new->magic = FASYNC_MAGIC; |
960 | new->fa_file = filp; | |
961 | new->fa_fd = fd; | |
962 | new->fa_next = *fapp; | |
989a2979 | 963 | rcu_assign_pointer(*fapp, new); |
53281b6d LT |
964 | filp->f_flags |= FASYNC; |
965 | ||
1da177e4 | 966 | out: |
989a2979 | 967 | spin_unlock(&fasync_lock); |
4a6a4499 | 968 | spin_unlock(&filp->f_lock); |
f7347ce4 LT |
969 | return fa; |
970 | } | |
971 | ||
972 | /* | |
973 | * Add a fasync entry. Return negative on error, positive if | |
974 | * added, and zero if did nothing but change an existing one. | |
f7347ce4 LT |
975 | */ |
976 | static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp) | |
977 | { | |
978 | struct fasync_struct *new; | |
979 | ||
980 | new = fasync_alloc(); | |
981 | if (!new) | |
982 | return -ENOMEM; | |
983 | ||
984 | /* | |
985 | * fasync_insert_entry() returns the old (update) entry if | |
986 | * it existed. | |
987 | * | |
988 | * So free the (unused) new entry and return 0 to let the | |
989 | * caller know that we didn't add any new fasync entries. | |
990 | */ | |
991 | if (fasync_insert_entry(fd, filp, fapp, new)) { | |
992 | fasync_free(new); | |
993 | return 0; | |
994 | } | |
995 | ||
996 | return 1; | |
1da177e4 LT |
997 | } |
998 | ||
53281b6d LT |
999 | /* |
1000 | * fasync_helper() is used by almost all character device drivers | |
1001 | * to set up the fasync queue, and for regular files by the file | |
1002 | * lease code. It returns negative on error, 0 if it did no changes | |
1003 | * and positive if it added/deleted the entry. | |
1004 | */ | |
1005 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) | |
1006 | { | |
1007 | if (!on) | |
1008 | return fasync_remove_entry(filp, fapp); | |
1009 | return fasync_add_entry(fd, filp, fapp); | |
1010 | } | |
1011 | ||
1da177e4 LT |
1012 | EXPORT_SYMBOL(fasync_helper); |
1013 | ||
989a2979 ED |
1014 | /* |
1015 | * rcu_read_lock() is held | |
1016 | */ | |
1017 | static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) | |
1da177e4 LT |
1018 | { |
1019 | while (fa) { | |
989a2979 | 1020 | struct fown_struct *fown; |
2f488f69 | 1021 | unsigned long flags; |
f4985dc7 | 1022 | |
1da177e4 LT |
1023 | if (fa->magic != FASYNC_MAGIC) { |
1024 | printk(KERN_ERR "kill_fasync: bad magic number in " | |
1025 | "fasync_struct!\n"); | |
1026 | return; | |
1027 | } | |
2f488f69 | 1028 | read_lock_irqsave(&fa->fa_lock, flags); |
989a2979 ED |
1029 | if (fa->fa_file) { |
1030 | fown = &fa->fa_file->f_owner; | |
1031 | /* Don't send SIGURG to processes which have not set a | |
1032 | queued signum: SIGURG has its own default signalling | |
1033 | mechanism. */ | |
1034 | if (!(sig == SIGURG && fown->signum == 0)) | |
1035 | send_sigio(fown, fa->fa_fd, band); | |
1036 | } | |
2f488f69 | 1037 | read_unlock_irqrestore(&fa->fa_lock, flags); |
989a2979 | 1038 | fa = rcu_dereference(fa->fa_next); |
1da177e4 LT |
1039 | } |
1040 | } | |
1041 | ||
1da177e4 LT |
1042 | void kill_fasync(struct fasync_struct **fp, int sig, int band) |
1043 | { | |
1044 | /* First a quick test without locking: usually | |
1045 | * the list is empty. | |
1046 | */ | |
1047 | if (*fp) { | |
989a2979 ED |
1048 | rcu_read_lock(); |
1049 | kill_fasync_rcu(rcu_dereference(*fp), sig, band); | |
1050 | rcu_read_unlock(); | |
1da177e4 LT |
1051 | } |
1052 | } | |
1053 | EXPORT_SYMBOL(kill_fasync); | |
1054 | ||
454eedb8 | 1055 | static int __init fcntl_init(void) |
1da177e4 | 1056 | { |
3ab04d5c JB |
1057 | /* |
1058 | * Please add new bits here to ensure allocation uniqueness. | |
1059 | * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY | |
1060 | * is defined as O_NONBLOCK on some platforms and not on others. | |
1061 | */ | |
80f18379 CH |
1062 | BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ != |
1063 | HWEIGHT32( | |
1064 | (VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) | | |
1065 | __FMODE_EXEC | __FMODE_NONOTIFY)); | |
454eedb8 | 1066 | |
1da177e4 | 1067 | fasync_cache = kmem_cache_create("fasync_cache", |
839d6820 VA |
1068 | sizeof(struct fasync_struct), 0, |
1069 | SLAB_PANIC | SLAB_ACCOUNT, NULL); | |
1da177e4 LT |
1070 | return 0; |
1071 | } | |
1072 | ||
454eedb8 | 1073 | module_init(fcntl_init) |