Blame view
fs/fcntl.c
16.3 KB
1da177e4c
|
1 2 3 4 5 6 7 8 9 10 11 |
/* * linux/fs/fcntl.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/syscalls.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/fs.h> #include <linux/file.h> |
9f3acc314
|
12 |
#include <linux/fdtable.h> |
16f7e0fe2
|
13 |
#include <linux/capability.h> |
1da177e4c
|
14 |
#include <linux/dnotify.h> |
1da177e4c
|
15 16 |
#include <linux/slab.h> #include <linux/module.h> |
35f3d14db
|
17 |
#include <linux/pipe_fs_i.h> |
1da177e4c
|
18 19 |
#include <linux/security.h> #include <linux/ptrace.h> |
7ed20e1ad
|
20 |
#include <linux/signal.h> |
ab2af1f50
|
21 |
#include <linux/rcupdate.h> |
b488893a3
|
22 |
#include <linux/pid_namespace.h> |
1d151c337
|
23 |
#include <linux/user_namespace.h> |
1da177e4c
|
24 25 26 27 |
#include <asm/poll.h> #include <asm/siginfo.h> #include <asm/uaccess.h> |
76398425b
|
28 |
#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) |
1da177e4c
|
29 30 31 |
static int setfl(int fd, struct file * filp, unsigned long arg) { |
0f7fc9e4d
|
32 |
struct inode * inode = filp->f_path.dentry->d_inode; |
1da177e4c
|
33 |
int error = 0; |
7d95c8f27
|
34 35 36 37 38 |
/* * O_APPEND cannot be cleared if the file is marked as append-only * and the file is open for write. */ if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode)) |
1da177e4c
|
39 40 41 42 |
return -EPERM; /* O_NOATIME can only be set by the owner or superuser */ if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME)) |
2e1496707
|
43 |
if (!inode_owner_or_capable(inode)) |
1da177e4c
|
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 |
return -EPERM; /* required for strict SunOS emulation */ if (O_NONBLOCK != O_NDELAY) if (arg & O_NDELAY) arg |= O_NONBLOCK; if (arg & O_DIRECT) { if (!filp->f_mapping || !filp->f_mapping->a_ops || !filp->f_mapping->a_ops->direct_IO) return -EINVAL; } if (filp->f_op && filp->f_op->check_flags) error = filp->f_op->check_flags(arg); if (error) return error; |
218d11a8b
|
61 |
/* |
76398425b
|
62 |
* ->fasync() is responsible for setting the FASYNC bit. |
218d11a8b
|
63 |
*/ |
76398425b
|
64 65 66 67 68 |
if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op && filp->f_op->fasync) { error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); if (error < 0) goto out; |
60aa49243
|
69 70 |
if (error > 0) error = 0; |
1da177e4c
|
71 |
} |
db1dd4d37
|
72 |
spin_lock(&filp->f_lock); |
1da177e4c
|
73 |
filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); |
db1dd4d37
|
74 |
spin_unlock(&filp->f_lock); |
76398425b
|
75 |
|
1da177e4c
|
76 |
out: |
1da177e4c
|
77 78 |
return error; } |
609d7fa95
|
79 |
static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, |
2f38d70fb
|
80 |
int force) |
1da177e4c
|
81 |
{ |
80e1e8239
|
82 |
write_lock_irq(&filp->f_owner.lock); |
1da177e4c
|
83 |
if (force || !filp->f_owner.pid) { |
609d7fa95
|
84 85 86 |
put_pid(filp->f_owner.pid); filp->f_owner.pid = get_pid(pid); filp->f_owner.pid_type = type; |
2f38d70fb
|
87 88 89 90 91 92 |
if (pid) { const struct cred *cred = current_cred(); filp->f_owner.uid = cred->uid; filp->f_owner.euid = cred->euid; } |
1da177e4c
|
93 |
} |
80e1e8239
|
94 |
write_unlock_irq(&filp->f_owner.lock); |
1da177e4c
|
95 |
} |
609d7fa95
|
96 97 |
int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, int force) |
1da177e4c
|
98 99 |
{ int err; |
2f38d70fb
|
100 |
|
1da177e4c
|
101 102 103 |
err = security_file_set_fowner(filp); if (err) return err; |
2f38d70fb
|
104 |
f_modown(filp, pid, type, force); |
1da177e4c
|
105 106 |
return 0; } |
609d7fa95
|
107 |
EXPORT_SYMBOL(__f_setown); |
1da177e4c
|
108 |
|
609d7fa95
|
109 110 111 112 113 114 115 116 117 118 119 120 |
int f_setown(struct file *filp, unsigned long arg, int force) { enum pid_type type; struct pid *pid; int who = arg; int result; type = PIDTYPE_PID; if (who < 0) { type = PIDTYPE_PGID; who = -who; } rcu_read_lock(); |
b488893a3
|
121 |
pid = find_vpid(who); |
609d7fa95
|
122 123 124 125 |
result = __f_setown(filp, pid, type, force); rcu_read_unlock(); return result; } |
1da177e4c
|
126 127 128 129 |
EXPORT_SYMBOL(f_setown); void f_delown(struct file *filp) { |
2f38d70fb
|
130 |
f_modown(filp, NULL, PIDTYPE_PID, 1); |
609d7fa95
|
131 132 133 134 135 |
} pid_t f_getown(struct file *filp) { pid_t pid; |
43fa1adb9
|
136 |
read_lock(&filp->f_owner.lock); |
6c5f3e7b4
|
137 |
pid = pid_vnr(filp->f_owner.pid); |
609d7fa95
|
138 139 |
if (filp->f_owner.pid_type == PIDTYPE_PGID) pid = -pid; |
43fa1adb9
|
140 |
read_unlock(&filp->f_owner.lock); |
609d7fa95
|
141 |
return pid; |
1da177e4c
|
142 |
} |
ba0a6c9f6
|
143 144 |
static int f_setown_ex(struct file *filp, unsigned long arg) { |
63784dd02
|
145 |
struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f6
|
146 147 148 149 150 151 152 |
struct f_owner_ex owner; struct pid *pid; int type; int ret; ret = copy_from_user(&owner, owner_p, sizeof(owner)); if (ret) |
5b54470da
|
153 |
return -EFAULT; |
ba0a6c9f6
|
154 155 156 157 158 159 160 161 162 |
switch (owner.type) { case F_OWNER_TID: type = PIDTYPE_MAX; break; case F_OWNER_PID: type = PIDTYPE_PID; break; |
978b4053a
|
163 |
case F_OWNER_PGRP: |
ba0a6c9f6
|
164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 |
type = PIDTYPE_PGID; break; default: return -EINVAL; } rcu_read_lock(); pid = find_vpid(owner.pid); if (owner.pid && !pid) ret = -ESRCH; else ret = __f_setown(filp, pid, type, 1); rcu_read_unlock(); return ret; } static int f_getown_ex(struct file *filp, unsigned long arg) { |
63784dd02
|
184 |
struct f_owner_ex __user *owner_p = (void __user *)arg; |
ba0a6c9f6
|
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 |
struct f_owner_ex owner; int ret = 0; read_lock(&filp->f_owner.lock); owner.pid = pid_vnr(filp->f_owner.pid); switch (filp->f_owner.pid_type) { case PIDTYPE_MAX: owner.type = F_OWNER_TID; break; case PIDTYPE_PID: owner.type = F_OWNER_PID; break; case PIDTYPE_PGID: |
978b4053a
|
200 |
owner.type = F_OWNER_PGRP; |
ba0a6c9f6
|
201 202 203 204 205 206 207 208 |
break; default: WARN_ON(1); ret = -EINVAL; break; } read_unlock(&filp->f_owner.lock); |
5b54470da
|
209 |
if (!ret) { |
ba0a6c9f6
|
210 |
ret = copy_to_user(owner_p, &owner, sizeof(owner)); |
5b54470da
|
211 212 213 |
if (ret) ret = -EFAULT; } |
ba0a6c9f6
|
214 215 |
return ret; } |
1d151c337
|
216 217 218 219 |
#ifdef CONFIG_CHECKPOINT_RESTORE static int f_getowner_uids(struct file *filp, unsigned long arg) { struct user_namespace *user_ns = current_user_ns(); |
63784dd02
|
220 |
uid_t __user *dst = (void __user *)arg; |
1d151c337
|
221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 |
uid_t src[2]; int err; read_lock(&filp->f_owner.lock); src[0] = from_kuid(user_ns, filp->f_owner.uid); src[1] = from_kuid(user_ns, filp->f_owner.euid); read_unlock(&filp->f_owner.lock); err = put_user(src[0], &dst[0]); err |= put_user(src[1], &dst[1]); return err; } #else static int f_getowner_uids(struct file *filp, unsigned long arg) { return -EINVAL; } #endif |
1da177e4c
|
240 241 242 243 244 245 246 |
static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { long err = -EINVAL; switch (cmd) { case F_DUPFD: |
fe17f22d7
|
247 248 |
err = f_dupfd(arg, filp, 0); break; |
22d2b35b2
|
249 |
case F_DUPFD_CLOEXEC: |
121977187
|
250 |
err = f_dupfd(arg, filp, O_CLOEXEC); |
1da177e4c
|
251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 |
break; case F_GETFD: err = get_close_on_exec(fd) ? FD_CLOEXEC : 0; break; case F_SETFD: err = 0; set_close_on_exec(fd, arg & FD_CLOEXEC); break; case F_GETFL: err = filp->f_flags; break; case F_SETFL: err = setfl(fd, filp, arg); break; case F_GETLK: err = fcntl_getlk(filp, (struct flock __user *) arg); break; case F_SETLK: case F_SETLKW: |
c293621bb
|
270 |
err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); |
1da177e4c
|
271 272 273 274 275 276 277 278 279 |
break; case F_GETOWN: /* * XXX If f_owner is a process group, the * negative return value will get converted * into an error. Oops. If we keep the * current syscall conventions, the only way * to fix this will be in libc. */ |
609d7fa95
|
280 |
err = f_getown(filp); |
1da177e4c
|
281 282 283 284 285 |
force_successful_syscall_return(); break; case F_SETOWN: err = f_setown(filp, arg, 1); break; |
ba0a6c9f6
|
286 287 288 289 290 291 |
case F_GETOWN_EX: err = f_getown_ex(filp, arg); break; case F_SETOWN_EX: err = f_setown_ex(filp, arg); break; |
1d151c337
|
292 293 294 |
case F_GETOWNER_UIDS: err = f_getowner_uids(filp, arg); break; |
1da177e4c
|
295 296 297 298 299 |
case F_GETSIG: err = filp->f_owner.signum; break; case F_SETSIG: /* arg == 0 restores default behaviour. */ |
7ed20e1ad
|
300 |
if (!valid_signal(arg)) { |
1da177e4c
|
301 302 303 304 305 306 307 308 309 310 311 312 313 314 |
break; } err = 0; filp->f_owner.signum = arg; break; case F_GETLEASE: err = fcntl_getlease(filp); break; case F_SETLEASE: err = fcntl_setlease(fd, filp, arg); break; case F_NOTIFY: err = fcntl_dirnotify(fd, filp, arg); break; |
35f3d14db
|
315 316 317 318 |
case F_SETPIPE_SZ: case F_GETPIPE_SZ: err = pipe_fcntl(filp, cmd, arg); break; |
1da177e4c
|
319 320 321 322 323 |
default: break; } return err; } |
1abf0c718
|
324 325 326 327 328 329 330 331 332 333 334 335 |
static int check_fcntl_cmd(unsigned cmd) { switch (cmd) { case F_DUPFD: case F_DUPFD_CLOEXEC: case F_GETFD: case F_SETFD: case F_GETFL: return 1; } return 0; } |
a26eab240
|
336 |
SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
1da177e4c
|
337 |
{ |
2903ff019
|
338 |
struct fd f = fdget_raw(fd); |
1da177e4c
|
339 |
long err = -EBADF; |
2903ff019
|
340 |
if (!f.file) |
1da177e4c
|
341 |
goto out; |
2903ff019
|
342 |
if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c79
|
343 344 |
if (!check_fcntl_cmd(cmd)) goto out1; |
1abf0c718
|
345 |
} |
2903ff019
|
346 |
err = security_file_fcntl(f.file, cmd, arg); |
545ec2c79
|
347 |
if (!err) |
2903ff019
|
348 |
err = do_fcntl(fd, cmd, arg, f.file); |
1da177e4c
|
349 |
|
545ec2c79
|
350 |
out1: |
2903ff019
|
351 |
fdput(f); |
1da177e4c
|
352 353 354 355 356 |
out: return err; } #if BITS_PER_LONG == 32 |
a26eab240
|
357 358 |
SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, unsigned long, arg) |
1da177e4c
|
359 |
{ |
2903ff019
|
360 |
struct fd f = fdget_raw(fd); |
545ec2c79
|
361 |
long err = -EBADF; |
1da177e4c
|
362 |
|
2903ff019
|
363 |
if (!f.file) |
1da177e4c
|
364 |
goto out; |
2903ff019
|
365 |
if (unlikely(f.file->f_mode & FMODE_PATH)) { |
545ec2c79
|
366 367 |
if (!check_fcntl_cmd(cmd)) goto out1; |
1abf0c718
|
368 |
} |
2903ff019
|
369 |
err = security_file_fcntl(f.file, cmd, arg); |
545ec2c79
|
370 371 |
if (err) goto out1; |
1da177e4c
|
372 373 374 |
switch (cmd) { case F_GETLK64: |
2903ff019
|
375 |
err = fcntl_getlk64(f.file, (struct flock64 __user *) arg); |
1da177e4c
|
376 377 378 |
break; case F_SETLK64: case F_SETLKW64: |
2903ff019
|
379 |
err = fcntl_setlk64(fd, f.file, cmd, |
c293621bb
|
380 |
(struct flock64 __user *) arg); |
1da177e4c
|
381 382 |
break; default: |
2903ff019
|
383 |
err = do_fcntl(fd, cmd, arg, f.file); |
1da177e4c
|
384 385 |
break; } |
545ec2c79
|
386 |
out1: |
2903ff019
|
387 |
fdput(f); |
1da177e4c
|
388 389 390 391 392 393 |
out: return err; } #endif /* Table to convert sigio signal codes into poll band bitmaps */ |
fa3536cc1
|
394 |
static const long band_table[NSIGPOLL] = { |
1da177e4c
|
395 396 397 398 399 400 401 402 403 404 405 |
POLLIN | POLLRDNORM, /* POLL_IN */ POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ POLLERR, /* POLL_ERR */ POLLPRI | POLLRDBAND, /* POLL_PRI */ POLLHUP | POLLERR /* POLL_HUP */ }; static inline int sigio_perm(struct task_struct *p, struct fown_struct *fown, int sig) { |
c69e8d9c0
|
406 407 408 409 410 |
const struct cred *cred; int ret; rcu_read_lock(); cred = __task_cred(p); |
8e96e3b7b
|
411 412 413 |
ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) || uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) || uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) && |
c69e8d9c0
|
414 415 416 |
!security_file_send_sigiotask(p, fown, sig)); rcu_read_unlock(); return ret; |
1da177e4c
|
417 418 419 |
} static void send_sigio_to_task(struct task_struct *p, |
8eeee4e2f
|
420 |
struct fown_struct *fown, |
ba0a6c9f6
|
421 |
int fd, int reason, int group) |
1da177e4c
|
422 |
{ |
8eeee4e2f
|
423 424 425 426 427 428 429 |
/* * F_SETSIG can change ->signum lockless in parallel, make * sure we read it once and use the same value throughout. */ int signum = ACCESS_ONCE(fown->signum); if (!sigio_perm(p, fown, signum)) |
1da177e4c
|
430 |
return; |
8eeee4e2f
|
431 |
switch (signum) { |
1da177e4c
|
432 433 434 435 436 437 438 439 |
siginfo_t si; default: /* Queue a rt signal with the appropriate fd as its value. We use SI_SIGIO as the source, not SI_KERNEL, since kernel signals always get delivered even if we can't queue. Failure to queue in this case _should_ be reported; we fall back to SIGIO in that case. --sct */ |
8eeee4e2f
|
440 |
si.si_signo = signum; |
1da177e4c
|
441 442 443 444 445 |
si.si_errno = 0; si.si_code = reason; /* Make sure we are called with one of the POLL_* reasons, otherwise we could leak kernel stack into userspace. */ |
f6298aab2
|
446 |
BUG_ON((reason & __SI_MASK) != __SI_POLL); |
1da177e4c
|
447 448 449 450 451 |
if (reason - POLL_IN >= NSIGPOLL) si.si_band = ~0L; else si.si_band = band_table[reason - POLL_IN]; si.si_fd = fd; |
ba0a6c9f6
|
452 |
if (!do_send_sig_info(signum, &si, p, group)) |
1da177e4c
|
453 454 455 |
break; /* fall-through: fall back on the old plain SIGIO signal */ case 0: |
ba0a6c9f6
|
456 |
do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group); |
1da177e4c
|
457 458 459 460 461 462 |
} } void send_sigio(struct fown_struct *fown, int fd, int band) { struct task_struct *p; |
609d7fa95
|
463 464 |
enum pid_type type; struct pid *pid; |
ba0a6c9f6
|
465 |
int group = 1; |
1da177e4c
|
466 467 |
read_lock(&fown->lock); |
ba0a6c9f6
|
468 |
|
609d7fa95
|
469 |
type = fown->pid_type; |
ba0a6c9f6
|
470 471 472 473 |
if (type == PIDTYPE_MAX) { group = 0; type = PIDTYPE_PID; } |
1da177e4c
|
474 475 476 477 478 |
pid = fown->pid; if (!pid) goto out_unlock_fown; read_lock(&tasklist_lock); |
609d7fa95
|
479 |
do_each_pid_task(pid, type, p) { |
ba0a6c9f6
|
480 |
send_sigio_to_task(p, fown, fd, band, group); |
609d7fa95
|
481 |
} while_each_pid_task(pid, type, p); |
1da177e4c
|
482 483 484 485 486 487 |
read_unlock(&tasklist_lock); out_unlock_fown: read_unlock(&fown->lock); } static void send_sigurg_to_task(struct task_struct *p, |
ba0a6c9f6
|
488 |
struct fown_struct *fown, int group) |
1da177e4c
|
489 490 |
{ if (sigio_perm(p, fown, SIGURG)) |
ba0a6c9f6
|
491 |
do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group); |
1da177e4c
|
492 493 494 495 496 |
} int send_sigurg(struct fown_struct *fown) { struct task_struct *p; |
609d7fa95
|
497 498 |
enum pid_type type; struct pid *pid; |
ba0a6c9f6
|
499 |
int group = 1; |
609d7fa95
|
500 |
int ret = 0; |
1da177e4c
|
501 502 |
read_lock(&fown->lock); |
ba0a6c9f6
|
503 |
|
609d7fa95
|
504 |
type = fown->pid_type; |
ba0a6c9f6
|
505 506 507 508 |
if (type == PIDTYPE_MAX) { group = 0; type = PIDTYPE_PID; } |
1da177e4c
|
509 510 511 512 513 514 515 |
pid = fown->pid; if (!pid) goto out_unlock_fown; ret = 1; read_lock(&tasklist_lock); |
609d7fa95
|
516 |
do_each_pid_task(pid, type, p) { |
ba0a6c9f6
|
517 |
send_sigurg_to_task(p, fown, group); |
609d7fa95
|
518 |
} while_each_pid_task(pid, type, p); |
1da177e4c
|
519 520 521 522 523 |
read_unlock(&tasklist_lock); out_unlock_fown: read_unlock(&fown->lock); return ret; } |
989a29792
|
524 |
static DEFINE_SPINLOCK(fasync_lock); |
e18b890bb
|
525 |
static struct kmem_cache *fasync_cache __read_mostly; |
1da177e4c
|
526 |
|
989a29792
|
527 528 529 530 531 |
static void fasync_free_rcu(struct rcu_head *head) { kmem_cache_free(fasync_cache, container_of(head, struct fasync_struct, fa_rcu)); } |
1da177e4c
|
532 |
/* |
53281b6d3
|
533 534 535 536 537 538 539 |
* Remove a fasync entry. If successfully removed, return * positive and clear the FASYNC flag. If no entry exists, * do nothing and return 0. * * NOTE! It is very important that the FASYNC flag always * match the state "is the filp on a fasync list". * |
1da177e4c
|
540 |
*/ |
f7347ce4e
|
541 |
int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp) |
1da177e4c
|
542 543 |
{ struct fasync_struct *fa, **fp; |
1da177e4c
|
544 |
int result = 0; |
53281b6d3
|
545 |
spin_lock(&filp->f_lock); |
989a29792
|
546 |
spin_lock(&fasync_lock); |
53281b6d3
|
547 548 549 |
for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { if (fa->fa_file != filp) continue; |
989a29792
|
550 551 552 553 |
spin_lock_irq(&fa->fa_lock); fa->fa_file = NULL; spin_unlock_irq(&fa->fa_lock); |
53281b6d3
|
554 |
*fp = fa->fa_next; |
989a29792
|
555 |
call_rcu(&fa->fa_rcu, fasync_free_rcu); |
53281b6d3
|
556 557 558 |
filp->f_flags &= ~FASYNC; result = 1; break; |
1da177e4c
|
559 |
} |
989a29792
|
560 |
spin_unlock(&fasync_lock); |
53281b6d3
|
561 562 563 |
spin_unlock(&filp->f_lock); return result; } |
f7347ce4e
|
564 565 566 567 |
struct fasync_struct *fasync_alloc(void) { return kmem_cache_alloc(fasync_cache, GFP_KERNEL); } |
53281b6d3
|
568 |
/* |
f7347ce4e
|
569 570 571 |
* NOTE! This can be used only for unused fasync entries: * entries that actually got inserted on the fasync list * need to be released by rcu - see fasync_remove_entry. |
53281b6d3
|
572 |
*/ |
f7347ce4e
|
573 |
void fasync_free(struct fasync_struct *new) |
53281b6d3
|
574 |
{ |
f7347ce4e
|
575 576 |
kmem_cache_free(fasync_cache, new); } |
53281b6d3
|
577 |
|
f7347ce4e
|
578 579 580 |
/* * Insert a new entry into the fasync list. Return the pointer to the * old one if we didn't use the new one. |
55f335a88
|
581 582 583 |
* * NOTE! It is very important that the FASYNC flag always * match the state "is the filp on a fasync list". |
f7347ce4e
|
584 585 586 587 |
*/ struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new) { struct fasync_struct *fa, **fp; |
4a6a44996
|
588 |
|
4a6a44996
|
589 |
spin_lock(&filp->f_lock); |
989a29792
|
590 |
spin_lock(&fasync_lock); |
1da177e4c
|
591 |
for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { |
53281b6d3
|
592 593 |
if (fa->fa_file != filp) continue; |
989a29792
|
594 595 |
spin_lock_irq(&fa->fa_lock); |
53281b6d3
|
596 |
fa->fa_fd = fd; |
989a29792
|
597 |
spin_unlock_irq(&fa->fa_lock); |
53281b6d3
|
598 |
goto out; |
1da177e4c
|
599 |
} |
989a29792
|
600 |
spin_lock_init(&new->fa_lock); |
53281b6d3
|
601 602 603 604 |
new->magic = FASYNC_MAGIC; new->fa_file = filp; new->fa_fd = fd; new->fa_next = *fapp; |
989a29792
|
605 |
rcu_assign_pointer(*fapp, new); |
53281b6d3
|
606 |
filp->f_flags |= FASYNC; |
1da177e4c
|
607 |
out: |
989a29792
|
608 |
spin_unlock(&fasync_lock); |
4a6a44996
|
609 |
spin_unlock(&filp->f_lock); |
f7347ce4e
|
610 611 612 613 614 615 |
return fa; } /* * Add a fasync entry. Return negative on error, positive if * added, and zero if did nothing but change an existing one. |
f7347ce4e
|
616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 |
*/ static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp) { struct fasync_struct *new; new = fasync_alloc(); if (!new) return -ENOMEM; /* * fasync_insert_entry() returns the old (update) entry if * it existed. * * So free the (unused) new entry and return 0 to let the * caller know that we didn't add any new fasync entries. */ if (fasync_insert_entry(fd, filp, fapp, new)) { fasync_free(new); return 0; } return 1; |
1da177e4c
|
638 |
} |
53281b6d3
|
639 640 641 642 643 644 645 646 647 648 649 650 |
/* * fasync_helper() is used by almost all character device drivers * to set up the fasync queue, and for regular files by the file * lease code. It returns negative on error, 0 if it did no changes * and positive if it added/deleted the entry. */ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp) { if (!on) return fasync_remove_entry(filp, fapp); return fasync_add_entry(fd, filp, fapp); } |
1da177e4c
|
651 |
EXPORT_SYMBOL(fasync_helper); |
989a29792
|
652 653 654 655 |
/* * rcu_read_lock() is held */ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) |
1da177e4c
|
656 657 |
{ while (fa) { |
989a29792
|
658 |
struct fown_struct *fown; |
f4985dc71
|
659 |
unsigned long flags; |
1da177e4c
|
660 661 662 663 664 665 |
if (fa->magic != FASYNC_MAGIC) { printk(KERN_ERR "kill_fasync: bad magic number in " "fasync_struct! "); return; } |
f4985dc71
|
666 |
spin_lock_irqsave(&fa->fa_lock, flags); |
989a29792
|
667 668 669 670 671 672 673 674 |
if (fa->fa_file) { fown = &fa->fa_file->f_owner; /* Don't send SIGURG to processes which have not set a queued signum: SIGURG has its own default signalling mechanism. */ if (!(sig == SIGURG && fown->signum == 0)) send_sigio(fown, fa->fa_fd, band); } |
f4985dc71
|
675 |
spin_unlock_irqrestore(&fa->fa_lock, flags); |
989a29792
|
676 |
fa = rcu_dereference(fa->fa_next); |
1da177e4c
|
677 678 |
} } |
1da177e4c
|
679 680 681 682 683 684 |
void kill_fasync(struct fasync_struct **fp, int sig, int band) { /* First a quick test without locking: usually * the list is empty. */ if (*fp) { |
989a29792
|
685 686 687 |
rcu_read_lock(); kill_fasync_rcu(rcu_dereference(*fp), sig, band); rcu_read_unlock(); |
1da177e4c
|
688 689 690 |
} } EXPORT_SYMBOL(kill_fasync); |
454eedb89
|
691 |
static int __init fcntl_init(void) |
1da177e4c
|
692 |
{ |
3ab04d5cf
|
693 694 695 696 697 |
/* * Please add new bits here to ensure allocation uniqueness. * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY * is defined as O_NONBLOCK on some platforms and not on others. */ |
1abf0c718
|
698 |
BUILD_BUG_ON(19 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32( |
454eedb89
|
699 700 |
O_RDONLY | O_WRONLY | O_RDWR | O_CREAT | O_EXCL | O_NOCTTY | |
3ab04d5cf
|
701 |
O_TRUNC | O_APPEND | /* O_NONBLOCK | */ |
454eedb89
|
702 703 704 |
__O_SYNC | O_DSYNC | FASYNC | O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | O_NOATIME | O_CLOEXEC | |
1abf0c718
|
705 |
__FMODE_EXEC | O_PATH |
454eedb89
|
706 |
)); |
1da177e4c
|
707 |
fasync_cache = kmem_cache_create("fasync_cache", |
20c2df83d
|
708 |
sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); |
1da177e4c
|
709 710 |
return 0; } |
454eedb89
|
711 |
module_init(fcntl_init) |