xref: /openbmc/linux/fs/fcntl.c (revision 6774def6) 
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>
12 #include <linux/fdtable.h>
13 #include <linux/capability.h>
14 #include <linux/dnotify.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/pipe_fs_i.h>
18 #include <linux/security.h>
19 #include <linux/ptrace.h>
20 #include <linux/signal.h>
21 #include <linux/rcupdate.h>
22 #include <linux/pid_namespace.h>
23 #include <linux/user_namespace.h>
24 #include <linux/shmem_fs.h>
25 
26 #include <asm/poll.h>
27 #include <asm/siginfo.h>
28 #include <asm/uaccess.h>
29 
30 #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
31 
32 static int setfl(int fd, struct file * filp, unsigned long arg)
33 {
34 	struct inode * inode = file_inode(filp);
35 	int error = 0;
36 
37 	/*
38 	 * O_APPEND cannot be cleared if the file is marked as append-only
39 	 * and the file is open for write.
40 	 */
41 	if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode))
42 		return -EPERM;
43 
44 	/* O_NOATIME can only be set by the owner or superuser */
45 	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
46 		if (!inode_owner_or_capable(inode))
47 			return -EPERM;
48 
49 	/* required for strict SunOS emulation */
50 	if (O_NONBLOCK != O_NDELAY)
51 	       if (arg & O_NDELAY)
52 		   arg |= O_NONBLOCK;
53 
54 	if (arg & O_DIRECT) {
55 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
56 			!filp->f_mapping->a_ops->direct_IO)
57 				return -EINVAL;
58 	}
59 
60 	if (filp->f_op->check_flags)
61 		error = filp->f_op->check_flags(arg);
62 	if (error)
63 		return error;
64 
65 	/*
66 	 * ->fasync() is responsible for setting the FASYNC bit.
67 	 */
68 	if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) {
69 		error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
70 		if (error < 0)
71 			goto out;
72 		if (error > 0)
73 			error = 0;
74 	}
75 	spin_lock(&filp->f_lock);
76 	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
77 	spin_unlock(&filp->f_lock);
78 
79  out:
80 	return error;
81 }
82 
83 static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
84                      int force)
85 {
86 	write_lock_irq(&filp->f_owner.lock);
87 	if (force || !filp->f_owner.pid) {
88 		put_pid(filp->f_owner.pid);
89 		filp->f_owner.pid = get_pid(pid);
90 		filp->f_owner.pid_type = type;
91 
92 		if (pid) {
93 			const struct cred *cred = current_cred();
94 			filp->f_owner.uid = cred->uid;
95 			filp->f_owner.euid = cred->euid;
96 		}
97 	}
98 	write_unlock_irq(&filp->f_owner.lock);
99 }
100 
101 void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
102 		int force)
103 {
104 	security_file_set_fowner(filp);
105 	f_modown(filp, pid, type, force);
106 }
107 EXPORT_SYMBOL(__f_setown);
108 
109 void f_setown(struct file *filp, unsigned long arg, int force)
110 {
111 	enum pid_type type;
112 	struct pid *pid;
113 	int who = arg;
114 	type = PIDTYPE_PID;
115 	if (who < 0) {
116 		type = PIDTYPE_PGID;
117 		who = -who;
118 	}
119 	rcu_read_lock();
120 	pid = find_vpid(who);
121 	__f_setown(filp, pid, type, force);
122 	rcu_read_unlock();
123 }
124 EXPORT_SYMBOL(f_setown);
125 
126 void f_delown(struct file *filp)
127 {
128 	f_modown(filp, NULL, PIDTYPE_PID, 1);
129 }
130 
131 pid_t f_getown(struct file *filp)
132 {
133 	pid_t pid;
134 	read_lock(&filp->f_owner.lock);
135 	pid = pid_vnr(filp->f_owner.pid);
136 	if (filp->f_owner.pid_type == PIDTYPE_PGID)
137 		pid = -pid;
138 	read_unlock(&filp->f_owner.lock);
139 	return pid;
140 }
141 
142 static int f_setown_ex(struct file *filp, unsigned long arg)
143 {
144 	struct f_owner_ex __user *owner_p = (void __user *)arg;
145 	struct f_owner_ex owner;
146 	struct pid *pid;
147 	int type;
148 	int ret;
149 
150 	ret = copy_from_user(&owner, owner_p, sizeof(owner));
151 	if (ret)
152 		return -EFAULT;
153 
154 	switch (owner.type) {
155 	case F_OWNER_TID:
156 		type = PIDTYPE_MAX;
157 		break;
158 
159 	case F_OWNER_PID:
160 		type = PIDTYPE_PID;
161 		break;
162 
163 	case F_OWNER_PGRP:
164 		type = PIDTYPE_PGID;
165 		break;
166 
167 	default:
168 		return -EINVAL;
169 	}
170 
171 	rcu_read_lock();
172 	pid = find_vpid(owner.pid);
173 	if (owner.pid && !pid)
174 		ret = -ESRCH;
175 	else
176 		 __f_setown(filp, pid, type, 1);
177 	rcu_read_unlock();
178 
179 	return ret;
180 }
181 
182 static int f_getown_ex(struct file *filp, unsigned long arg)
183 {
184 	struct f_owner_ex __user *owner_p = (void __user *)arg;
185 	struct f_owner_ex owner;
186 	int ret = 0;
187 
188 	read_lock(&filp->f_owner.lock);
189 	owner.pid = pid_vnr(filp->f_owner.pid);
190 	switch (filp->f_owner.pid_type) {
191 	case PIDTYPE_MAX:
192 		owner.type = F_OWNER_TID;
193 		break;
194 
195 	case PIDTYPE_PID:
196 		owner.type = F_OWNER_PID;
197 		break;
198 
199 	case PIDTYPE_PGID:
200 		owner.type = F_OWNER_PGRP;
201 		break;
202 
203 	default:
204 		WARN_ON(1);
205 		ret = -EINVAL;
206 		break;
207 	}
208 	read_unlock(&filp->f_owner.lock);
209 
210 	if (!ret) {
211 		ret = copy_to_user(owner_p, &owner, sizeof(owner));
212 		if (ret)
213 			ret = -EFAULT;
214 	}
215 	return ret;
216 }
217 
218 #ifdef CONFIG_CHECKPOINT_RESTORE
219 static int f_getowner_uids(struct file *filp, unsigned long arg)
220 {
221 	struct user_namespace *user_ns = current_user_ns();
222 	uid_t __user *dst = (void __user *)arg;
223 	uid_t src[2];
224 	int err;
225 
226 	read_lock(&filp->f_owner.lock);
227 	src[0] = from_kuid(user_ns, filp->f_owner.uid);
228 	src[1] = from_kuid(user_ns, filp->f_owner.euid);
229 	read_unlock(&filp->f_owner.lock);
230 
231 	err  = put_user(src[0], &dst[0]);
232 	err |= put_user(src[1], &dst[1]);
233 
234 	return err;
235 }
236 #else
237 static int f_getowner_uids(struct file *filp, unsigned long arg)
238 {
239 	return -EINVAL;
240 }
241 #endif
242 
243 static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
244 		struct file *filp)
245 {
246 	long err = -EINVAL;
247 
248 	switch (cmd) {
249 	case F_DUPFD:
250 		err = f_dupfd(arg, filp, 0);
251 		break;
252 	case F_DUPFD_CLOEXEC:
253 		err = f_dupfd(arg, filp, O_CLOEXEC);
254 		break;
255 	case F_GETFD:
256 		err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
257 		break;
258 	case F_SETFD:
259 		err = 0;
260 		set_close_on_exec(fd, arg & FD_CLOEXEC);
261 		break;
262 	case F_GETFL:
263 		err = filp->f_flags;
264 		break;
265 	case F_SETFL:
266 		err = setfl(fd, filp, arg);
267 		break;
268 #if BITS_PER_LONG != 32
269 	/* 32-bit arches must use fcntl64() */
270 	case F_OFD_GETLK:
271 #endif
272 	case F_GETLK:
273 		err = fcntl_getlk(filp, cmd, (struct flock __user *) arg);
274 		break;
275 #if BITS_PER_LONG != 32
276 	/* 32-bit arches must use fcntl64() */
277 	case F_OFD_SETLK:
278 	case F_OFD_SETLKW:
279 #endif
280 		/* Fallthrough */
281 	case F_SETLK:
282 	case F_SETLKW:
283 		err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
284 		break;
285 	case F_GETOWN:
286 		/*
287 		 * XXX If f_owner is a process group, the
288 		 * negative return value will get converted
289 		 * into an error.  Oops.  If we keep the
290 		 * current syscall conventions, the only way
291 		 * to fix this will be in libc.
292 		 */
293 		err = f_getown(filp);
294 		force_successful_syscall_return();
295 		break;
296 	case F_SETOWN:
297 		f_setown(filp, arg, 1);
298 		err = 0;
299 		break;
300 	case F_GETOWN_EX:
301 		err = f_getown_ex(filp, arg);
302 		break;
303 	case F_SETOWN_EX:
304 		err = f_setown_ex(filp, arg);
305 		break;
306 	case F_GETOWNER_UIDS:
307 		err = f_getowner_uids(filp, arg);
308 		break;
309 	case F_GETSIG:
310 		err = filp->f_owner.signum;
311 		break;
312 	case F_SETSIG:
313 		/* arg == 0 restores default behaviour. */
314 		if (!valid_signal(arg)) {
315 			break;
316 		}
317 		err = 0;
318 		filp->f_owner.signum = arg;
319 		break;
320 	case F_GETLEASE:
321 		err = fcntl_getlease(filp);
322 		break;
323 	case F_SETLEASE:
324 		err = fcntl_setlease(fd, filp, arg);
325 		break;
326 	case F_NOTIFY:
327 		err = fcntl_dirnotify(fd, filp, arg);
328 		break;
329 	case F_SETPIPE_SZ:
330 	case F_GETPIPE_SZ:
331 		err = pipe_fcntl(filp, cmd, arg);
332 		break;
333 	case F_ADD_SEALS:
334 	case F_GET_SEALS:
335 		err = shmem_fcntl(filp, cmd, arg);
336 		break;
337 	default:
338 		break;
339 	}
340 	return err;
341 }
342 
343 static int check_fcntl_cmd(unsigned cmd)
344 {
345 	switch (cmd) {
346 	case F_DUPFD:
347 	case F_DUPFD_CLOEXEC:
348 	case F_GETFD:
349 	case F_SETFD:
350 	case F_GETFL:
351 		return 1;
352 	}
353 	return 0;
354 }
355 
356 SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
357 {
358 	struct fd f = fdget_raw(fd);
359 	long err = -EBADF;
360 
361 	if (!f.file)
362 		goto out;
363 
364 	if (unlikely(f.file->f_mode & FMODE_PATH)) {
365 		if (!check_fcntl_cmd(cmd))
366 			goto out1;
367 	}
368 
369 	err = security_file_fcntl(f.file, cmd, arg);
370 	if (!err)
371 		err = do_fcntl(fd, cmd, arg, f.file);
372 
373 out1:
374  	fdput(f);
375 out:
376 	return err;
377 }
378 
379 #if BITS_PER_LONG == 32
380 SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
381 		unsigned long, arg)
382 {
383 	struct fd f = fdget_raw(fd);
384 	long err = -EBADF;
385 
386 	if (!f.file)
387 		goto out;
388 
389 	if (unlikely(f.file->f_mode & FMODE_PATH)) {
390 		if (!check_fcntl_cmd(cmd))
391 			goto out1;
392 	}
393 
394 	err = security_file_fcntl(f.file, cmd, arg);
395 	if (err)
396 		goto out1;
397 
398 	switch (cmd) {
399 	case F_GETLK64:
400 	case F_OFD_GETLK:
401 		err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg);
402 		break;
403 	case F_SETLK64:
404 	case F_SETLKW64:
405 	case F_OFD_SETLK:
406 	case F_OFD_SETLKW:
407 		err = fcntl_setlk64(fd, f.file, cmd,
408 				(struct flock64 __user *) arg);
409 		break;
410 	default:
411 		err = do_fcntl(fd, cmd, arg, f.file);
412 		break;
413 	}
414 out1:
415 	fdput(f);
416 out:
417 	return err;
418 }
419 #endif
420 
421 /* Table to convert sigio signal codes into poll band bitmaps */
422 
423 static const long band_table[NSIGPOLL] = {
424 	POLLIN | POLLRDNORM,			/* POLL_IN */
425 	POLLOUT | POLLWRNORM | POLLWRBAND,	/* POLL_OUT */
426 	POLLIN | POLLRDNORM | POLLMSG,		/* POLL_MSG */
427 	POLLERR,				/* POLL_ERR */
428 	POLLPRI | POLLRDBAND,			/* POLL_PRI */
429 	POLLHUP | POLLERR			/* POLL_HUP */
430 };
431 
432 static inline int sigio_perm(struct task_struct *p,
433                              struct fown_struct *fown, int sig)
434 {
435 	const struct cred *cred;
436 	int ret;
437 
438 	rcu_read_lock();
439 	cred = __task_cred(p);
440 	ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) ||
441 		uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) ||
442 		uid_eq(fown->uid,  cred->suid) || uid_eq(fown->uid,  cred->uid)) &&
443 	       !security_file_send_sigiotask(p, fown, sig));
444 	rcu_read_unlock();
445 	return ret;
446 }
447 
448 static void send_sigio_to_task(struct task_struct *p,
449 			       struct fown_struct *fown,
450 			       int fd, int reason, int group)
451 {
452 	/*
453 	 * F_SETSIG can change ->signum lockless in parallel, make
454 	 * sure we read it once and use the same value throughout.
455 	 */
456 	int signum = ACCESS_ONCE(fown->signum);
457 
458 	if (!sigio_perm(p, fown, signum))
459 		return;
460 
461 	switch (signum) {
462 		siginfo_t si;
463 		default:
464 			/* Queue a rt signal with the appropriate fd as its
465 			   value.  We use SI_SIGIO as the source, not
466 			   SI_KERNEL, since kernel signals always get
467 			   delivered even if we can't queue.  Failure to
468 			   queue in this case _should_ be reported; we fall
469 			   back to SIGIO in that case. --sct */
470 			si.si_signo = signum;
471 			si.si_errno = 0;
472 		        si.si_code  = reason;
473 			/* Make sure we are called with one of the POLL_*
474 			   reasons, otherwise we could leak kernel stack into
475 			   userspace.  */
476 			BUG_ON((reason & __SI_MASK) != __SI_POLL);
477 			if (reason - POLL_IN >= NSIGPOLL)
478 				si.si_band  = ~0L;
479 			else
480 				si.si_band = band_table[reason - POLL_IN];
481 			si.si_fd    = fd;
482 			if (!do_send_sig_info(signum, &si, p, group))
483 				break;
484 		/* fall-through: fall back on the old plain SIGIO signal */
485 		case 0:
486 			do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group);
487 	}
488 }
489 
490 void send_sigio(struct fown_struct *fown, int fd, int band)
491 {
492 	struct task_struct *p;
493 	enum pid_type type;
494 	struct pid *pid;
495 	int group = 1;
496 
497 	read_lock(&fown->lock);
498 
499 	type = fown->pid_type;
500 	if (type == PIDTYPE_MAX) {
501 		group = 0;
502 		type = PIDTYPE_PID;
503 	}
504 
505 	pid = fown->pid;
506 	if (!pid)
507 		goto out_unlock_fown;
508 
509 	read_lock(&tasklist_lock);
510 	do_each_pid_task(pid, type, p) {
511 		send_sigio_to_task(p, fown, fd, band, group);
512 	} while_each_pid_task(pid, type, p);
513 	read_unlock(&tasklist_lock);
514  out_unlock_fown:
515 	read_unlock(&fown->lock);
516 }
517 
518 static void send_sigurg_to_task(struct task_struct *p,
519 				struct fown_struct *fown, int group)
520 {
521 	if (sigio_perm(p, fown, SIGURG))
522 		do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group);
523 }
524 
525 int send_sigurg(struct fown_struct *fown)
526 {
527 	struct task_struct *p;
528 	enum pid_type type;
529 	struct pid *pid;
530 	int group = 1;
531 	int ret = 0;
532 
533 	read_lock(&fown->lock);
534 
535 	type = fown->pid_type;
536 	if (type == PIDTYPE_MAX) {
537 		group = 0;
538 		type = PIDTYPE_PID;
539 	}
540 
541 	pid = fown->pid;
542 	if (!pid)
543 		goto out_unlock_fown;
544 
545 	ret = 1;
546 
547 	read_lock(&tasklist_lock);
548 	do_each_pid_task(pid, type, p) {
549 		send_sigurg_to_task(p, fown, group);
550 	} while_each_pid_task(pid, type, p);
551 	read_unlock(&tasklist_lock);
552  out_unlock_fown:
553 	read_unlock(&fown->lock);
554 	return ret;
555 }
556 
557 static DEFINE_SPINLOCK(fasync_lock);
558 static struct kmem_cache *fasync_cache __read_mostly;
559 
560 static void fasync_free_rcu(struct rcu_head *head)
561 {
562 	kmem_cache_free(fasync_cache,
563 			container_of(head, struct fasync_struct, fa_rcu));
564 }
565 
566 /*
567  * Remove a fasync entry. If successfully removed, return
568  * positive and clear the FASYNC flag. If no entry exists,
569  * do nothing and return 0.
570  *
571  * NOTE! It is very important that the FASYNC flag always
572  * match the state "is the filp on a fasync list".
573  *
574  */
575 int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
576 {
577 	struct fasync_struct *fa, **fp;
578 	int result = 0;
579 
580 	spin_lock(&filp->f_lock);
581 	spin_lock(&fasync_lock);
582 	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
583 		if (fa->fa_file != filp)
584 			continue;
585 
586 		spin_lock_irq(&fa->fa_lock);
587 		fa->fa_file = NULL;
588 		spin_unlock_irq(&fa->fa_lock);
589 
590 		*fp = fa->fa_next;
591 		call_rcu(&fa->fa_rcu, fasync_free_rcu);
592 		filp->f_flags &= ~FASYNC;
593 		result = 1;
594 		break;
595 	}
596 	spin_unlock(&fasync_lock);
597 	spin_unlock(&filp->f_lock);
598 	return result;
599 }
600 
601 struct fasync_struct *fasync_alloc(void)
602 {
603 	return kmem_cache_alloc(fasync_cache, GFP_KERNEL);
604 }
605 
606 /*
607  * NOTE! This can be used only for unused fasync entries:
608  * entries that actually got inserted on the fasync list
609  * need to be released by rcu - see fasync_remove_entry.
610  */
611 void fasync_free(struct fasync_struct *new)
612 {
613 	kmem_cache_free(fasync_cache, new);
614 }
615 
616 /*
617  * Insert a new entry into the fasync list.  Return the pointer to the
618  * old one if we didn't use the new one.
619  *
620  * NOTE! It is very important that the FASYNC flag always
621  * match the state "is the filp on a fasync list".
622  */
623 struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new)
624 {
625         struct fasync_struct *fa, **fp;
626 
627 	spin_lock(&filp->f_lock);
628 	spin_lock(&fasync_lock);
629 	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
630 		if (fa->fa_file != filp)
631 			continue;
632 
633 		spin_lock_irq(&fa->fa_lock);
634 		fa->fa_fd = fd;
635 		spin_unlock_irq(&fa->fa_lock);
636 		goto out;
637 	}
638 
639 	spin_lock_init(&new->fa_lock);
640 	new->magic = FASYNC_MAGIC;
641 	new->fa_file = filp;
642 	new->fa_fd = fd;
643 	new->fa_next = *fapp;
644 	rcu_assign_pointer(*fapp, new);
645 	filp->f_flags |= FASYNC;
646 
647 out:
648 	spin_unlock(&fasync_lock);
649 	spin_unlock(&filp->f_lock);
650 	return fa;
651 }
652 
653 /*
654  * Add a fasync entry. Return negative on error, positive if
655  * added, and zero if did nothing but change an existing one.
656  */
657 static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
658 {
659 	struct fasync_struct *new;
660 
661 	new = fasync_alloc();
662 	if (!new)
663 		return -ENOMEM;
664 
665 	/*
666 	 * fasync_insert_entry() returns the old (update) entry if
667 	 * it existed.
668 	 *
669 	 * So free the (unused) new entry and return 0 to let the
670 	 * caller know that we didn't add any new fasync entries.
671 	 */
672 	if (fasync_insert_entry(fd, filp, fapp, new)) {
673 		fasync_free(new);
674 		return 0;
675 	}
676 
677 	return 1;
678 }
679 
680 /*
681  * fasync_helper() is used by almost all character device drivers
682  * to set up the fasync queue, and for regular files by the file
683  * lease code. It returns negative on error, 0 if it did no changes
684  * and positive if it added/deleted the entry.
685  */
686 int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
687 {
688 	if (!on)
689 		return fasync_remove_entry(filp, fapp);
690 	return fasync_add_entry(fd, filp, fapp);
691 }
692 
693 EXPORT_SYMBOL(fasync_helper);
694 
695 /*
696  * rcu_read_lock() is held
697  */
698 static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
699 {
700 	while (fa) {
701 		struct fown_struct *fown;
702 		unsigned long flags;
703 
704 		if (fa->magic != FASYNC_MAGIC) {
705 			printk(KERN_ERR "kill_fasync: bad magic number in "
706 			       "fasync_struct!\n");
707 			return;
708 		}
709 		spin_lock_irqsave(&fa->fa_lock, flags);
710 		if (fa->fa_file) {
711 			fown = &fa->fa_file->f_owner;
712 			/* Don't send SIGURG to processes which have not set a
713 			   queued signum: SIGURG has its own default signalling
714 			   mechanism. */
715 			if (!(sig == SIGURG && fown->signum == 0))
716 				send_sigio(fown, fa->fa_fd, band);
717 		}
718 		spin_unlock_irqrestore(&fa->fa_lock, flags);
719 		fa = rcu_dereference(fa->fa_next);
720 	}
721 }
722 
723 void kill_fasync(struct fasync_struct **fp, int sig, int band)
724 {
725 	/* First a quick test without locking: usually
726 	 * the list is empty.
727 	 */
728 	if (*fp) {
729 		rcu_read_lock();
730 		kill_fasync_rcu(rcu_dereference(*fp), sig, band);
731 		rcu_read_unlock();
732 	}
733 }
734 EXPORT_SYMBOL(kill_fasync);
735 
736 static int __init fcntl_init(void)
737 {
738 	/*
739 	 * Please add new bits here to ensure allocation uniqueness.
740 	 * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
741 	 * is defined as O_NONBLOCK on some platforms and not on others.
742 	 */
743 	BUILD_BUG_ON(20 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
744 		O_RDONLY	| O_WRONLY	| O_RDWR	|
745 		O_CREAT		| O_EXCL	| O_NOCTTY	|
746 		O_TRUNC		| O_APPEND	| /* O_NONBLOCK	| */
747 		__O_SYNC	| O_DSYNC	| FASYNC	|
748 		O_DIRECT	| O_LARGEFILE	| O_DIRECTORY	|
749 		O_NOFOLLOW	| O_NOATIME	| O_CLOEXEC	|
750 		__FMODE_EXEC	| O_PATH	| __O_TMPFILE
751 		));
752 
753 	fasync_cache = kmem_cache_create("fasync_cache",
754 		sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL);
755 	return 0;
756 }
757 
758 module_init(fcntl_init)
759