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> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/file.h> | |
9f3acc31 | 12 | #include <linux/fdtable.h> |
16f7e0fe | 13 | #include <linux/capability.h> |
1da177e4 | 14 | #include <linux/dnotify.h> |
1da177e4 LT |
15 | #include <linux/slab.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/security.h> | |
18 | #include <linux/ptrace.h> | |
7ed20e1a | 19 | #include <linux/signal.h> |
ab2af1f5 | 20 | #include <linux/rcupdate.h> |
b488893a | 21 | #include <linux/pid_namespace.h> |
1da177e4 LT |
22 | |
23 | #include <asm/poll.h> | |
24 | #include <asm/siginfo.h> | |
25 | #include <asm/uaccess.h> | |
26 | ||
fc9b52cd | 27 | void set_close_on_exec(unsigned int fd, int flag) |
1da177e4 LT |
28 | { |
29 | struct files_struct *files = current->files; | |
badf1662 | 30 | struct fdtable *fdt; |
1da177e4 | 31 | spin_lock(&files->file_lock); |
badf1662 | 32 | fdt = files_fdtable(files); |
1da177e4 | 33 | if (flag) |
badf1662 | 34 | FD_SET(fd, fdt->close_on_exec); |
1da177e4 | 35 | else |
badf1662 | 36 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
37 | spin_unlock(&files->file_lock); |
38 | } | |
39 | ||
858119e1 | 40 | static int get_close_on_exec(unsigned int fd) |
1da177e4 LT |
41 | { |
42 | struct files_struct *files = current->files; | |
badf1662 | 43 | struct fdtable *fdt; |
1da177e4 | 44 | int res; |
b835996f | 45 | rcu_read_lock(); |
badf1662 DS |
46 | fdt = files_fdtable(files); |
47 | res = FD_ISSET(fd, fdt->close_on_exec); | |
b835996f | 48 | rcu_read_unlock(); |
1da177e4 LT |
49 | return res; |
50 | } | |
51 | ||
336dd1f7 | 52 | asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags) |
1da177e4 LT |
53 | { |
54 | int err = -EBADF; | |
55 | struct file * file, *tofree; | |
56 | struct files_struct * files = current->files; | |
badf1662 | 57 | struct fdtable *fdt; |
1da177e4 | 58 | |
336dd1f7 UD |
59 | if ((flags & ~O_CLOEXEC) != 0) |
60 | return -EINVAL; | |
61 | ||
6c5d0512 AV |
62 | if (unlikely(oldfd == newfd)) |
63 | return -EINVAL; | |
64 | ||
1da177e4 | 65 | spin_lock(&files->file_lock); |
1da177e4 | 66 | err = expand_files(files, newfd); |
1b7e190b AV |
67 | file = fcheck(oldfd); |
68 | if (unlikely(!file)) | |
69 | goto Ebadf; | |
4e1e018e AV |
70 | if (unlikely(err < 0)) { |
71 | if (err == -EMFILE) | |
1b7e190b AV |
72 | goto Ebadf; |
73 | goto out_unlock; | |
4e1e018e | 74 | } |
1b7e190b AV |
75 | /* |
76 | * We need to detect attempts to do dup2() over allocated but still | |
77 | * not finished descriptor. NB: OpenBSD avoids that at the price of | |
78 | * extra work in their equivalent of fget() - they insert struct | |
79 | * file immediately after grabbing descriptor, mark it larval if | |
80 | * more work (e.g. actual opening) is needed and make sure that | |
81 | * fget() treats larval files as absent. Potentially interesting, | |
82 | * but while extra work in fget() is trivial, locking implications | |
83 | * and amount of surgery on open()-related paths in VFS are not. | |
84 | * FreeBSD fails with -EBADF in the same situation, NetBSD "solution" | |
85 | * deadlocks in rather amusing ways, AFAICS. All of that is out of | |
86 | * scope of POSIX or SUS, since neither considers shared descriptor | |
87 | * tables and this condition does not arise without those. | |
88 | */ | |
1da177e4 | 89 | err = -EBUSY; |
badf1662 DS |
90 | fdt = files_fdtable(files); |
91 | tofree = fdt->fd[newfd]; | |
92 | if (!tofree && FD_ISSET(newfd, fdt->open_fds)) | |
1b7e190b AV |
93 | goto out_unlock; |
94 | get_file(file); | |
ab2af1f5 | 95 | rcu_assign_pointer(fdt->fd[newfd], file); |
badf1662 | 96 | FD_SET(newfd, fdt->open_fds); |
336dd1f7 UD |
97 | if (flags & O_CLOEXEC) |
98 | FD_SET(newfd, fdt->close_on_exec); | |
99 | else | |
100 | FD_CLR(newfd, fdt->close_on_exec); | |
1da177e4 LT |
101 | spin_unlock(&files->file_lock); |
102 | ||
103 | if (tofree) | |
104 | filp_close(tofree, files); | |
1da177e4 | 105 | |
1b7e190b AV |
106 | return newfd; |
107 | ||
108 | Ebadf: | |
109 | err = -EBADF; | |
110 | out_unlock: | |
1da177e4 | 111 | spin_unlock(&files->file_lock); |
1b7e190b | 112 | return err; |
1da177e4 | 113 | } |
336dd1f7 UD |
114 | |
115 | asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd) | |
116 | { | |
6c5d0512 AV |
117 | if (unlikely(newfd == oldfd)) { /* corner case */ |
118 | struct files_struct *files = current->files; | |
119 | rcu_read_lock(); | |
120 | if (!fcheck_files(files, oldfd)) | |
121 | oldfd = -EBADF; | |
122 | rcu_read_unlock(); | |
123 | return oldfd; | |
124 | } | |
336dd1f7 UD |
125 | return sys_dup3(oldfd, newfd, 0); |
126 | } | |
1da177e4 LT |
127 | |
128 | asmlinkage long sys_dup(unsigned int fildes) | |
129 | { | |
130 | int ret = -EBADF; | |
1027abe8 AV |
131 | struct file *file = fget(fildes); |
132 | ||
133 | if (file) { | |
134 | ret = get_unused_fd(); | |
135 | if (ret >= 0) | |
136 | fd_install(ret, file); | |
137 | else | |
138 | fput(file); | |
139 | } | |
1da177e4 LT |
140 | return ret; |
141 | } | |
142 | ||
143 | #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME) | |
144 | ||
145 | static int setfl(int fd, struct file * filp, unsigned long arg) | |
146 | { | |
0f7fc9e4 | 147 | struct inode * inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
148 | int error = 0; |
149 | ||
7d95c8f2 | 150 | /* |
151 | * O_APPEND cannot be cleared if the file is marked as append-only | |
152 | * and the file is open for write. | |
153 | */ | |
154 | if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
1da177e4 LT |
155 | return -EPERM; |
156 | ||
157 | /* O_NOATIME can only be set by the owner or superuser */ | |
158 | if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) | |
3bd858ab | 159 | if (!is_owner_or_cap(inode)) |
1da177e4 LT |
160 | return -EPERM; |
161 | ||
162 | /* required for strict SunOS emulation */ | |
163 | if (O_NONBLOCK != O_NDELAY) | |
164 | if (arg & O_NDELAY) | |
165 | arg |= O_NONBLOCK; | |
166 | ||
167 | if (arg & O_DIRECT) { | |
168 | if (!filp->f_mapping || !filp->f_mapping->a_ops || | |
169 | !filp->f_mapping->a_ops->direct_IO) | |
170 | return -EINVAL; | |
171 | } | |
172 | ||
173 | if (filp->f_op && filp->f_op->check_flags) | |
174 | error = filp->f_op->check_flags(arg); | |
175 | if (error) | |
176 | return error; | |
177 | ||
1da177e4 LT |
178 | if ((arg ^ filp->f_flags) & FASYNC) { |
179 | if (filp->f_op && filp->f_op->fasync) { | |
180 | error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); | |
181 | if (error < 0) | |
182 | goto out; | |
183 | } | |
184 | } | |
185 | ||
186 | filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); | |
187 | out: | |
1da177e4 LT |
188 | return error; |
189 | } | |
190 | ||
609d7fa9 | 191 | static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
1da177e4 LT |
192 | uid_t uid, uid_t euid, int force) |
193 | { | |
194 | write_lock_irq(&filp->f_owner.lock); | |
195 | if (force || !filp->f_owner.pid) { | |
609d7fa9 EB |
196 | put_pid(filp->f_owner.pid); |
197 | filp->f_owner.pid = get_pid(pid); | |
198 | filp->f_owner.pid_type = type; | |
1da177e4 LT |
199 | filp->f_owner.uid = uid; |
200 | filp->f_owner.euid = euid; | |
201 | } | |
202 | write_unlock_irq(&filp->f_owner.lock); | |
203 | } | |
204 | ||
609d7fa9 EB |
205 | int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, |
206 | int force) | |
1da177e4 | 207 | { |
86a264ab | 208 | const struct cred *cred = current_cred(); |
1da177e4 LT |
209 | int err; |
210 | ||
211 | err = security_file_set_fowner(filp); | |
212 | if (err) | |
213 | return err; | |
214 | ||
86a264ab | 215 | f_modown(filp, pid, type, cred->uid, cred->euid, force); |
1da177e4 LT |
216 | return 0; |
217 | } | |
609d7fa9 | 218 | EXPORT_SYMBOL(__f_setown); |
1da177e4 | 219 | |
609d7fa9 EB |
220 | int f_setown(struct file *filp, unsigned long arg, int force) |
221 | { | |
222 | enum pid_type type; | |
223 | struct pid *pid; | |
224 | int who = arg; | |
225 | int result; | |
226 | type = PIDTYPE_PID; | |
227 | if (who < 0) { | |
228 | type = PIDTYPE_PGID; | |
229 | who = -who; | |
230 | } | |
231 | rcu_read_lock(); | |
b488893a | 232 | pid = find_vpid(who); |
609d7fa9 EB |
233 | result = __f_setown(filp, pid, type, force); |
234 | rcu_read_unlock(); | |
235 | return result; | |
236 | } | |
1da177e4 LT |
237 | EXPORT_SYMBOL(f_setown); |
238 | ||
239 | void f_delown(struct file *filp) | |
240 | { | |
609d7fa9 EB |
241 | f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1); |
242 | } | |
243 | ||
244 | pid_t f_getown(struct file *filp) | |
245 | { | |
246 | pid_t pid; | |
43fa1adb | 247 | read_lock(&filp->f_owner.lock); |
6c5f3e7b | 248 | pid = pid_vnr(filp->f_owner.pid); |
609d7fa9 EB |
249 | if (filp->f_owner.pid_type == PIDTYPE_PGID) |
250 | pid = -pid; | |
43fa1adb | 251 | read_unlock(&filp->f_owner.lock); |
609d7fa9 | 252 | return pid; |
1da177e4 LT |
253 | } |
254 | ||
255 | static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, | |
256 | struct file *filp) | |
257 | { | |
258 | long err = -EINVAL; | |
259 | ||
260 | switch (cmd) { | |
261 | case F_DUPFD: | |
22d2b35b | 262 | case F_DUPFD_CLOEXEC: |
4e1e018e AV |
263 | if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) |
264 | break; | |
1027abe8 AV |
265 | err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0); |
266 | if (err >= 0) { | |
267 | get_file(filp); | |
268 | fd_install(err, filp); | |
269 | } | |
1da177e4 LT |
270 | break; |
271 | case F_GETFD: | |
272 | err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; | |
273 | break; | |
274 | case F_SETFD: | |
275 | err = 0; | |
276 | set_close_on_exec(fd, arg & FD_CLOEXEC); | |
277 | break; | |
278 | case F_GETFL: | |
279 | err = filp->f_flags; | |
280 | break; | |
281 | case F_SETFL: | |
282 | err = setfl(fd, filp, arg); | |
283 | break; | |
284 | case F_GETLK: | |
285 | err = fcntl_getlk(filp, (struct flock __user *) arg); | |
286 | break; | |
287 | case F_SETLK: | |
288 | case F_SETLKW: | |
c293621b | 289 | err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); |
1da177e4 LT |
290 | break; |
291 | case F_GETOWN: | |
292 | /* | |
293 | * XXX If f_owner is a process group, the | |
294 | * negative return value will get converted | |
295 | * into an error. Oops. If we keep the | |
296 | * current syscall conventions, the only way | |
297 | * to fix this will be in libc. | |
298 | */ | |
609d7fa9 | 299 | err = f_getown(filp); |
1da177e4 LT |
300 | force_successful_syscall_return(); |
301 | break; | |
302 | case F_SETOWN: | |
303 | err = f_setown(filp, arg, 1); | |
304 | break; | |
305 | case F_GETSIG: | |
306 | err = filp->f_owner.signum; | |
307 | break; | |
308 | case F_SETSIG: | |
309 | /* arg == 0 restores default behaviour. */ | |
7ed20e1a | 310 | if (!valid_signal(arg)) { |
1da177e4 LT |
311 | break; |
312 | } | |
313 | err = 0; | |
314 | filp->f_owner.signum = arg; | |
315 | break; | |
316 | case F_GETLEASE: | |
317 | err = fcntl_getlease(filp); | |
318 | break; | |
319 | case F_SETLEASE: | |
320 | err = fcntl_setlease(fd, filp, arg); | |
321 | break; | |
322 | case F_NOTIFY: | |
323 | err = fcntl_dirnotify(fd, filp, arg); | |
324 | break; | |
325 | default: | |
326 | break; | |
327 | } | |
328 | return err; | |
329 | } | |
330 | ||
331 | asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg) | |
332 | { | |
333 | struct file *filp; | |
334 | long err = -EBADF; | |
335 | ||
336 | filp = fget(fd); | |
337 | if (!filp) | |
338 | goto out; | |
339 | ||
340 | err = security_file_fcntl(filp, cmd, arg); | |
341 | if (err) { | |
342 | fput(filp); | |
343 | return err; | |
344 | } | |
345 | ||
346 | err = do_fcntl(fd, cmd, arg, filp); | |
347 | ||
348 | fput(filp); | |
349 | out: | |
350 | return err; | |
351 | } | |
352 | ||
353 | #if BITS_PER_LONG == 32 | |
354 | asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg) | |
355 | { | |
356 | struct file * filp; | |
357 | long err; | |
358 | ||
359 | err = -EBADF; | |
360 | filp = fget(fd); | |
361 | if (!filp) | |
362 | goto out; | |
363 | ||
364 | err = security_file_fcntl(filp, cmd, arg); | |
365 | if (err) { | |
366 | fput(filp); | |
367 | return err; | |
368 | } | |
369 | err = -EBADF; | |
370 | ||
371 | switch (cmd) { | |
372 | case F_GETLK64: | |
373 | err = fcntl_getlk64(filp, (struct flock64 __user *) arg); | |
374 | break; | |
375 | case F_SETLK64: | |
376 | case F_SETLKW64: | |
c293621b PS |
377 | err = fcntl_setlk64(fd, filp, cmd, |
378 | (struct flock64 __user *) arg); | |
1da177e4 LT |
379 | break; |
380 | default: | |
381 | err = do_fcntl(fd, cmd, arg, filp); | |
382 | break; | |
383 | } | |
384 | fput(filp); | |
385 | out: | |
386 | return err; | |
387 | } | |
388 | #endif | |
389 | ||
390 | /* Table to convert sigio signal codes into poll band bitmaps */ | |
391 | ||
fa3536cc | 392 | static const long band_table[NSIGPOLL] = { |
1da177e4 LT |
393 | POLLIN | POLLRDNORM, /* POLL_IN */ |
394 | POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ | |
395 | POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ | |
396 | POLLERR, /* POLL_ERR */ | |
397 | POLLPRI | POLLRDBAND, /* POLL_PRI */ | |
398 | POLLHUP | POLLERR /* POLL_HUP */ | |
399 | }; | |
400 | ||
401 | static inline int sigio_perm(struct task_struct *p, | |
402 | struct fown_struct *fown, int sig) | |
403 | { | |
404 | return (((fown->euid == 0) || | |
b6dff3ec DH |
405 | (fown->euid == p->cred->suid) || (fown->euid == p->cred->uid) || |
406 | (fown->uid == p->cred->suid) || (fown->uid == p->cred->uid)) && | |
1da177e4 LT |
407 | !security_file_send_sigiotask(p, fown, sig)); |
408 | } | |
409 | ||
410 | static void send_sigio_to_task(struct task_struct *p, | |
411 | struct fown_struct *fown, | |
412 | int fd, | |
413 | int reason) | |
414 | { | |
415 | if (!sigio_perm(p, fown, fown->signum)) | |
416 | return; | |
417 | ||
418 | switch (fown->signum) { | |
419 | siginfo_t si; | |
420 | default: | |
421 | /* Queue a rt signal with the appropriate fd as its | |
422 | value. We use SI_SIGIO as the source, not | |
423 | SI_KERNEL, since kernel signals always get | |
424 | delivered even if we can't queue. Failure to | |
425 | queue in this case _should_ be reported; we fall | |
426 | back to SIGIO in that case. --sct */ | |
427 | si.si_signo = fown->signum; | |
428 | si.si_errno = 0; | |
429 | si.si_code = reason; | |
430 | /* Make sure we are called with one of the POLL_* | |
431 | reasons, otherwise we could leak kernel stack into | |
432 | userspace. */ | |
f6298aab | 433 | BUG_ON((reason & __SI_MASK) != __SI_POLL); |
1da177e4 LT |
434 | if (reason - POLL_IN >= NSIGPOLL) |
435 | si.si_band = ~0L; | |
436 | else | |
437 | si.si_band = band_table[reason - POLL_IN]; | |
438 | si.si_fd = fd; | |
850d6fbe | 439 | if (!group_send_sig_info(fown->signum, &si, p)) |
1da177e4 LT |
440 | break; |
441 | /* fall-through: fall back on the old plain SIGIO signal */ | |
442 | case 0: | |
850d6fbe | 443 | group_send_sig_info(SIGIO, SEND_SIG_PRIV, p); |
1da177e4 LT |
444 | } |
445 | } | |
446 | ||
447 | void send_sigio(struct fown_struct *fown, int fd, int band) | |
448 | { | |
449 | struct task_struct *p; | |
609d7fa9 EB |
450 | enum pid_type type; |
451 | struct pid *pid; | |
1da177e4 LT |
452 | |
453 | read_lock(&fown->lock); | |
609d7fa9 | 454 | type = fown->pid_type; |
1da177e4 LT |
455 | pid = fown->pid; |
456 | if (!pid) | |
457 | goto out_unlock_fown; | |
458 | ||
459 | read_lock(&tasklist_lock); | |
609d7fa9 EB |
460 | do_each_pid_task(pid, type, p) { |
461 | send_sigio_to_task(p, fown, fd, band); | |
462 | } while_each_pid_task(pid, type, p); | |
1da177e4 LT |
463 | read_unlock(&tasklist_lock); |
464 | out_unlock_fown: | |
465 | read_unlock(&fown->lock); | |
466 | } | |
467 | ||
468 | static void send_sigurg_to_task(struct task_struct *p, | |
469 | struct fown_struct *fown) | |
470 | { | |
471 | if (sigio_perm(p, fown, SIGURG)) | |
850d6fbe | 472 | group_send_sig_info(SIGURG, SEND_SIG_PRIV, p); |
1da177e4 LT |
473 | } |
474 | ||
475 | int send_sigurg(struct fown_struct *fown) | |
476 | { | |
477 | struct task_struct *p; | |
609d7fa9 EB |
478 | enum pid_type type; |
479 | struct pid *pid; | |
480 | int ret = 0; | |
1da177e4 LT |
481 | |
482 | read_lock(&fown->lock); | |
609d7fa9 | 483 | type = fown->pid_type; |
1da177e4 LT |
484 | pid = fown->pid; |
485 | if (!pid) | |
486 | goto out_unlock_fown; | |
487 | ||
488 | ret = 1; | |
489 | ||
490 | read_lock(&tasklist_lock); | |
609d7fa9 EB |
491 | do_each_pid_task(pid, type, p) { |
492 | send_sigurg_to_task(p, fown); | |
493 | } while_each_pid_task(pid, type, p); | |
1da177e4 LT |
494 | read_unlock(&tasklist_lock); |
495 | out_unlock_fown: | |
496 | read_unlock(&fown->lock); | |
497 | return ret; | |
498 | } | |
499 | ||
500 | static DEFINE_RWLOCK(fasync_lock); | |
e18b890b | 501 | static struct kmem_cache *fasync_cache __read_mostly; |
1da177e4 LT |
502 | |
503 | /* | |
504 | * fasync_helper() is used by some character device drivers (mainly mice) | |
505 | * to set up the fasync queue. It returns negative on error, 0 if it did | |
506 | * no changes and positive if it added/deleted the entry. | |
507 | */ | |
508 | int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) | |
509 | { | |
510 | struct fasync_struct *fa, **fp; | |
511 | struct fasync_struct *new = NULL; | |
512 | int result = 0; | |
513 | ||
514 | if (on) { | |
e94b1766 | 515 | new = kmem_cache_alloc(fasync_cache, GFP_KERNEL); |
1da177e4 LT |
516 | if (!new) |
517 | return -ENOMEM; | |
518 | } | |
519 | write_lock_irq(&fasync_lock); | |
520 | for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { | |
521 | if (fa->fa_file == filp) { | |
522 | if(on) { | |
523 | fa->fa_fd = fd; | |
524 | kmem_cache_free(fasync_cache, new); | |
525 | } else { | |
526 | *fp = fa->fa_next; | |
527 | kmem_cache_free(fasync_cache, fa); | |
528 | result = 1; | |
529 | } | |
530 | goto out; | |
531 | } | |
532 | } | |
533 | ||
534 | if (on) { | |
535 | new->magic = FASYNC_MAGIC; | |
536 | new->fa_file = filp; | |
537 | new->fa_fd = fd; | |
538 | new->fa_next = *fapp; | |
539 | *fapp = new; | |
540 | result = 1; | |
541 | } | |
542 | out: | |
543 | write_unlock_irq(&fasync_lock); | |
544 | return result; | |
545 | } | |
546 | ||
547 | EXPORT_SYMBOL(fasync_helper); | |
548 | ||
549 | void __kill_fasync(struct fasync_struct *fa, int sig, int band) | |
550 | { | |
551 | while (fa) { | |
552 | struct fown_struct * fown; | |
553 | if (fa->magic != FASYNC_MAGIC) { | |
554 | printk(KERN_ERR "kill_fasync: bad magic number in " | |
555 | "fasync_struct!\n"); | |
556 | return; | |
557 | } | |
558 | fown = &fa->fa_file->f_owner; | |
559 | /* Don't send SIGURG to processes which have not set a | |
560 | queued signum: SIGURG has its own default signalling | |
561 | mechanism. */ | |
562 | if (!(sig == SIGURG && fown->signum == 0)) | |
563 | send_sigio(fown, fa->fa_fd, band); | |
564 | fa = fa->fa_next; | |
565 | } | |
566 | } | |
567 | ||
568 | EXPORT_SYMBOL(__kill_fasync); | |
569 | ||
570 | void kill_fasync(struct fasync_struct **fp, int sig, int band) | |
571 | { | |
572 | /* First a quick test without locking: usually | |
573 | * the list is empty. | |
574 | */ | |
575 | if (*fp) { | |
576 | read_lock(&fasync_lock); | |
577 | /* reread *fp after obtaining the lock */ | |
578 | __kill_fasync(*fp, sig, band); | |
579 | read_unlock(&fasync_lock); | |
580 | } | |
581 | } | |
582 | EXPORT_SYMBOL(kill_fasync); | |
583 | ||
584 | static int __init fasync_init(void) | |
585 | { | |
586 | fasync_cache = kmem_cache_create("fasync_cache", | |
20c2df83 | 587 | sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
1da177e4 LT |
588 | return 0; |
589 | } | |
590 | ||
591 | module_init(fasync_init) |