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8#include <linux/syscalls.h>
9#include <linux/init.h>
10#include <linux/mm.h>
11#include <linux/sched/task.h>
12#include <linux/fs.h>
13#include <linux/file.h>
14#include <linux/fdtable.h>
15#include <linux/capability.h>
16#include <linux/dnotify.h>
17#include <linux/slab.h>
18#include <linux/module.h>
19#include <linux/pipe_fs_i.h>
20#include <linux/security.h>
21#include <linux/ptrace.h>
22#include <linux/signal.h>
23#include <linux/rcupdate.h>
24#include <linux/pid_namespace.h>
25#include <linux/user_namespace.h>
26#include <linux/memfd.h>
27#include <linux/compat.h>
28#include <linux/mount.h>
29
30#include <linux/poll.h>
31#include <asm/siginfo.h>
32#include <linux/uaccess.h>
33
34#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
35
36static int setfl(int fd, struct file * filp, unsigned long arg)
37{
38 struct inode * inode = file_inode(filp);
39 int error = 0;
40
41
42
43
44
45 if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode))
46 return -EPERM;
47
48
49 if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
50 if (!inode_owner_or_capable(file_mnt_user_ns(filp), inode))
51 return -EPERM;
52
53
54 if (O_NONBLOCK != O_NDELAY)
55 if (arg & O_NDELAY)
56 arg |= O_NONBLOCK;
57
58
59 if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) {
60 if (!filp->f_mapping || !filp->f_mapping->a_ops ||
61 !filp->f_mapping->a_ops->direct_IO)
62 return -EINVAL;
63 }
64
65 if (filp->f_op->check_flags)
66 error = filp->f_op->check_flags(arg);
67 if (error)
68 return error;
69
70
71
72
73 if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) {
74 error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
75 if (error < 0)
76 goto out;
77 if (error > 0)
78 error = 0;
79 }
80 spin_lock(&filp->f_lock);
81 filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
82 spin_unlock(&filp->f_lock);
83
84 out:
85 return error;
86}
87
88static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
89 int force)
90{
91 write_lock_irq(&filp->f_owner.lock);
92 if (force || !filp->f_owner.pid) {
93 put_pid(filp->f_owner.pid);
94 filp->f_owner.pid = get_pid(pid);
95 filp->f_owner.pid_type = type;
96
97 if (pid) {
98 const struct cred *cred = current_cred();
99 filp->f_owner.uid = cred->uid;
100 filp->f_owner.euid = cred->euid;
101 }
102 }
103 write_unlock_irq(&filp->f_owner.lock);
104}
105
106void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
107 int force)
108{
109 security_file_set_fowner(filp);
110 f_modown(filp, pid, type, force);
111}
112EXPORT_SYMBOL(__f_setown);
113
114int f_setown(struct file *filp, unsigned long arg, int force)
115{
116 enum pid_type type;
117 struct pid *pid = NULL;
118 int who = arg, ret = 0;
119
120 type = PIDTYPE_TGID;
121 if (who < 0) {
122
123 if (who == INT_MIN)
124 return -EINVAL;
125
126 type = PIDTYPE_PGID;
127 who = -who;
128 }
129
130 rcu_read_lock();
131 if (who) {
132 pid = find_vpid(who);
133 if (!pid)
134 ret = -ESRCH;
135 }
136
137 if (!ret)
138 __f_setown(filp, pid, type, force);
139 rcu_read_unlock();
140
141 return ret;
142}
143EXPORT_SYMBOL(f_setown);
144
145void f_delown(struct file *filp)
146{
147 f_modown(filp, NULL, PIDTYPE_TGID, 1);
148}
149
150pid_t f_getown(struct file *filp)
151{
152 pid_t pid = 0;
153
154 read_lock_irq(&filp->f_owner.lock);
155 rcu_read_lock();
156 if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) {
157 pid = pid_vnr(filp->f_owner.pid);
158 if (filp->f_owner.pid_type == PIDTYPE_PGID)
159 pid = -pid;
160 }
161 rcu_read_unlock();
162 read_unlock_irq(&filp->f_owner.lock);
163 return pid;
164}
165
166static int f_setown_ex(struct file *filp, unsigned long arg)
167{
168 struct f_owner_ex __user *owner_p = (void __user *)arg;
169 struct f_owner_ex owner;
170 struct pid *pid;
171 int type;
172 int ret;
173
174 ret = copy_from_user(&owner, owner_p, sizeof(owner));
175 if (ret)
176 return -EFAULT;
177
178 switch (owner.type) {
179 case F_OWNER_TID:
180 type = PIDTYPE_PID;
181 break;
182
183 case F_OWNER_PID:
184 type = PIDTYPE_TGID;
185 break;
186
187 case F_OWNER_PGRP:
188 type = PIDTYPE_PGID;
189 break;
190
191 default:
192 return -EINVAL;
193 }
194
195 rcu_read_lock();
196 pid = find_vpid(owner.pid);
197 if (owner.pid && !pid)
198 ret = -ESRCH;
199 else
200 __f_setown(filp, pid, type, 1);
201 rcu_read_unlock();
202
203 return ret;
204}
205
206static int f_getown_ex(struct file *filp, unsigned long arg)
207{
208 struct f_owner_ex __user *owner_p = (void __user *)arg;
209 struct f_owner_ex owner = {};
210 int ret = 0;
211
212 read_lock_irq(&filp->f_owner.lock);
213 rcu_read_lock();
214 if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type))
215 owner.pid = pid_vnr(filp->f_owner.pid);
216 rcu_read_unlock();
217 switch (filp->f_owner.pid_type) {
218 case PIDTYPE_PID:
219 owner.type = F_OWNER_TID;
220 break;
221
222 case PIDTYPE_TGID:
223 owner.type = F_OWNER_PID;
224 break;
225
226 case PIDTYPE_PGID:
227 owner.type = F_OWNER_PGRP;
228 break;
229
230 default:
231 WARN_ON(1);
232 ret = -EINVAL;
233 break;
234 }
235 read_unlock_irq(&filp->f_owner.lock);
236
237 if (!ret) {
238 ret = copy_to_user(owner_p, &owner, sizeof(owner));
239 if (ret)
240 ret = -EFAULT;
241 }
242 return ret;
243}
244
245#ifdef CONFIG_CHECKPOINT_RESTORE
246static int f_getowner_uids(struct file *filp, unsigned long arg)
247{
248 struct user_namespace *user_ns = current_user_ns();
249 uid_t __user *dst = (void __user *)arg;
250 uid_t src[2];
251 int err;
252
253 read_lock_irq(&filp->f_owner.lock);
254 src[0] = from_kuid(user_ns, filp->f_owner.uid);
255 src[1] = from_kuid(user_ns, filp->f_owner.euid);
256 read_unlock_irq(&filp->f_owner.lock);
257
258 err = put_user(src[0], &dst[0]);
259 err |= put_user(src[1], &dst[1]);
260
261 return err;
262}
263#else
264static int f_getowner_uids(struct file *filp, unsigned long arg)
265{
266 return -EINVAL;
267}
268#endif
269
270static bool rw_hint_valid(enum rw_hint hint)
271{
272 switch (hint) {
273 case RWH_WRITE_LIFE_NOT_SET:
274 case RWH_WRITE_LIFE_NONE:
275 case RWH_WRITE_LIFE_SHORT:
276 case RWH_WRITE_LIFE_MEDIUM:
277 case RWH_WRITE_LIFE_LONG:
278 case RWH_WRITE_LIFE_EXTREME:
279 return true;
280 default:
281 return false;
282 }
283}
284
285static long fcntl_rw_hint(struct file *file, unsigned int cmd,
286 unsigned long arg)
287{
288 struct inode *inode = file_inode(file);
289 u64 __user *argp = (u64 __user *)arg;
290 enum rw_hint hint;
291 u64 h;
292
293 switch (cmd) {
294 case F_GET_FILE_RW_HINT:
295 h = file_write_hint(file);
296 if (copy_to_user(argp, &h, sizeof(*argp)))
297 return -EFAULT;
298 return 0;
299 case F_SET_FILE_RW_HINT:
300 if (copy_from_user(&h, argp, sizeof(h)))
301 return -EFAULT;
302 hint = (enum rw_hint) h;
303 if (!rw_hint_valid(hint))
304 return -EINVAL;
305
306 spin_lock(&file->f_lock);
307 file->f_write_hint = hint;
308 spin_unlock(&file->f_lock);
309 return 0;
310 case F_GET_RW_HINT:
311 h = inode->i_write_hint;
312 if (copy_to_user(argp, &h, sizeof(*argp)))
313 return -EFAULT;
314 return 0;
315 case F_SET_RW_HINT:
316 if (copy_from_user(&h, argp, sizeof(h)))
317 return -EFAULT;
318 hint = (enum rw_hint) h;
319 if (!rw_hint_valid(hint))
320 return -EINVAL;
321
322 inode_lock(inode);
323 inode->i_write_hint = hint;
324 inode_unlock(inode);
325 return 0;
326 default:
327 return -EINVAL;
328 }
329}
330
331static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
332 struct file *filp)
333{
334 void __user *argp = (void __user *)arg;
335 struct flock flock;
336 long err = -EINVAL;
337
338 switch (cmd) {
339 case F_DUPFD:
340 err = f_dupfd(arg, filp, 0);
341 break;
342 case F_DUPFD_CLOEXEC:
343 err = f_dupfd(arg, filp, O_CLOEXEC);
344 break;
345 case F_GETFD:
346 err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
347 break;
348 case F_SETFD:
349 err = 0;
350 set_close_on_exec(fd, arg & FD_CLOEXEC);
351 break;
352 case F_GETFL:
353 err = filp->f_flags;
354 break;
355 case F_SETFL:
356 err = setfl(fd, filp, arg);
357 break;
358#if BITS_PER_LONG != 32
359
360 case F_OFD_GETLK:
361#endif
362 case F_GETLK:
363 if (copy_from_user(&flock, argp, sizeof(flock)))
364 return -EFAULT;
365 err = fcntl_getlk(filp, cmd, &flock);
366 if (!err && copy_to_user(argp, &flock, sizeof(flock)))
367 return -EFAULT;
368 break;
369#if BITS_PER_LONG != 32
370
371 case F_OFD_SETLK:
372 case F_OFD_SETLKW:
373 fallthrough;
374#endif
375 case F_SETLK:
376 case F_SETLKW:
377 if (copy_from_user(&flock, argp, sizeof(flock)))
378 return -EFAULT;
379 err = fcntl_setlk(fd, filp, cmd, &flock);
380 break;
381 case F_GETOWN:
382
383
384
385
386
387
388
389 err = f_getown(filp);
390 force_successful_syscall_return();
391 break;
392 case F_SETOWN:
393 err = f_setown(filp, arg, 1);
394 break;
395 case F_GETOWN_EX:
396 err = f_getown_ex(filp, arg);
397 break;
398 case F_SETOWN_EX:
399 err = f_setown_ex(filp, arg);
400 break;
401 case F_GETOWNER_UIDS:
402 err = f_getowner_uids(filp, arg);
403 break;
404 case F_GETSIG:
405 err = filp->f_owner.signum;
406 break;
407 case F_SETSIG:
408
409 if (!valid_signal(arg)) {
410 break;
411 }
412 err = 0;
413 filp->f_owner.signum = arg;
414 break;
415 case F_GETLEASE:
416 err = fcntl_getlease(filp);
417 break;
418 case F_SETLEASE:
419 err = fcntl_setlease(fd, filp, arg);
420 break;
421 case F_NOTIFY:
422 err = fcntl_dirnotify(fd, filp, arg);
423 break;
424 case F_SETPIPE_SZ:
425 case F_GETPIPE_SZ:
426 err = pipe_fcntl(filp, cmd, arg);
427 break;
428 case F_ADD_SEALS:
429 case F_GET_SEALS:
430 err = memfd_fcntl(filp, cmd, arg);
431 break;
432 case F_GET_RW_HINT:
433 case F_SET_RW_HINT:
434 case F_GET_FILE_RW_HINT:
435 case F_SET_FILE_RW_HINT:
436 err = fcntl_rw_hint(filp, cmd, arg);
437 break;
438 default:
439 break;
440 }
441 return err;
442}
443
444static int check_fcntl_cmd(unsigned cmd)
445{
446 switch (cmd) {
447 case F_DUPFD:
448 case F_DUPFD_CLOEXEC:
449 case F_GETFD:
450 case F_SETFD:
451 case F_GETFL:
452 return 1;
453 }
454 return 0;
455}
456
457SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
458{
459 struct fd f = fdget_raw(fd);
460 long err = -EBADF;
461
462 if (!f.file)
463 goto out;
464
465 if (unlikely(f.file->f_mode & FMODE_PATH)) {
466 if (!check_fcntl_cmd(cmd))
467 goto out1;
468 }
469
470 err = security_file_fcntl(f.file, cmd, arg);
471 if (!err)
472 err = do_fcntl(fd, cmd, arg, f.file);
473
474out1:
475 fdput(f);
476out:
477 return err;
478}
479
480#if BITS_PER_LONG == 32
481SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
482 unsigned long, arg)
483{
484 void __user *argp = (void __user *)arg;
485 struct fd f = fdget_raw(fd);
486 struct flock64 flock;
487 long err = -EBADF;
488
489 if (!f.file)
490 goto out;
491
492 if (unlikely(f.file->f_mode & FMODE_PATH)) {
493 if (!check_fcntl_cmd(cmd))
494 goto out1;
495 }
496
497 err = security_file_fcntl(f.file, cmd, arg);
498 if (err)
499 goto out1;
500
501 switch (cmd) {
502 case F_GETLK64:
503 case F_OFD_GETLK:
504 err = -EFAULT;
505 if (copy_from_user(&flock, argp, sizeof(flock)))
506 break;
507 err = fcntl_getlk64(f.file, cmd, &flock);
508 if (!err && copy_to_user(argp, &flock, sizeof(flock)))
509 err = -EFAULT;
510 break;
511 case F_SETLK64:
512 case F_SETLKW64:
513 case F_OFD_SETLK:
514 case F_OFD_SETLKW:
515 err = -EFAULT;
516 if (copy_from_user(&flock, argp, sizeof(flock)))
517 break;
518 err = fcntl_setlk64(fd, f.file, cmd, &flock);
519 break;
520 default:
521 err = do_fcntl(fd, cmd, arg, f.file);
522 break;
523 }
524out1:
525 fdput(f);
526out:
527 return err;
528}
529#endif
530
531#ifdef CONFIG_COMPAT
532
533#define copy_flock_fields(dst, src) \
534 (dst)->l_type = (src)->l_type; \
535 (dst)->l_whence = (src)->l_whence; \
536 (dst)->l_start = (src)->l_start; \
537 (dst)->l_len = (src)->l_len; \
538 (dst)->l_pid = (src)->l_pid;
539
540static int get_compat_flock(struct flock *kfl, const struct compat_flock __user *ufl)
541{
542 struct compat_flock fl;
543
544 if (copy_from_user(&fl, ufl, sizeof(struct compat_flock)))
545 return -EFAULT;
546 copy_flock_fields(kfl, &fl);
547 return 0;
548}
549
550static int get_compat_flock64(struct flock *kfl, const struct compat_flock64 __user *ufl)
551{
552 struct compat_flock64 fl;
553
554 if (copy_from_user(&fl, ufl, sizeof(struct compat_flock64)))
555 return -EFAULT;
556 copy_flock_fields(kfl, &fl);
557 return 0;
558}
559
560static int put_compat_flock(const struct flock *kfl, struct compat_flock __user *ufl)
561{
562 struct compat_flock fl;
563
564 memset(&fl, 0, sizeof(struct compat_flock));
565 copy_flock_fields(&fl, kfl);
566 if (copy_to_user(ufl, &fl, sizeof(struct compat_flock)))
567 return -EFAULT;
568 return 0;
569}
570
571static int put_compat_flock64(const struct flock *kfl, struct compat_flock64 __user *ufl)
572{
573 struct compat_flock64 fl;
574
575 BUILD_BUG_ON(sizeof(kfl->l_start) > sizeof(ufl->l_start));
576 BUILD_BUG_ON(sizeof(kfl->l_len) > sizeof(ufl->l_len));
577
578 memset(&fl, 0, sizeof(struct compat_flock64));
579 copy_flock_fields(&fl, kfl);
580 if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64)))
581 return -EFAULT;
582 return 0;
583}
584#undef copy_flock_fields
585
586static unsigned int
587convert_fcntl_cmd(unsigned int cmd)
588{
589 switch (cmd) {
590 case F_GETLK64:
591 return F_GETLK;
592 case F_SETLK64:
593 return F_SETLK;
594 case F_SETLKW64:
595 return F_SETLKW;
596 }
597
598 return cmd;
599}
600
601
602
603
604
605
606
607
608
609
610static int fixup_compat_flock(struct flock *flock)
611{
612 if (flock->l_start > COMPAT_OFF_T_MAX)
613 return -EOVERFLOW;
614 if (flock->l_len > COMPAT_OFF_T_MAX)
615 flock->l_len = COMPAT_OFF_T_MAX;
616 return 0;
617}
618
619static long do_compat_fcntl64(unsigned int fd, unsigned int cmd,
620 compat_ulong_t arg)
621{
622 struct fd f = fdget_raw(fd);
623 struct flock flock;
624 long err = -EBADF;
625
626 if (!f.file)
627 return err;
628
629 if (unlikely(f.file->f_mode & FMODE_PATH)) {
630 if (!check_fcntl_cmd(cmd))
631 goto out_put;
632 }
633
634 err = security_file_fcntl(f.file, cmd, arg);
635 if (err)
636 goto out_put;
637
638 switch (cmd) {
639 case F_GETLK:
640 err = get_compat_flock(&flock, compat_ptr(arg));
641 if (err)
642 break;
643 err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock);
644 if (err)
645 break;
646 err = fixup_compat_flock(&flock);
647 if (!err)
648 err = put_compat_flock(&flock, compat_ptr(arg));
649 break;
650 case F_GETLK64:
651 case F_OFD_GETLK:
652 err = get_compat_flock64(&flock, compat_ptr(arg));
653 if (err)
654 break;
655 err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock);
656 if (!err)
657 err = put_compat_flock64(&flock, compat_ptr(arg));
658 break;
659 case F_SETLK:
660 case F_SETLKW:
661 err = get_compat_flock(&flock, compat_ptr(arg));
662 if (err)
663 break;
664 err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock);
665 break;
666 case F_SETLK64:
667 case F_SETLKW64:
668 case F_OFD_SETLK:
669 case F_OFD_SETLKW:
670 err = get_compat_flock64(&flock, compat_ptr(arg));
671 if (err)
672 break;
673 err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock);
674 break;
675 default:
676 err = do_fcntl(fd, cmd, arg, f.file);
677 break;
678 }
679out_put:
680 fdput(f);
681 return err;
682}
683
684COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
685 compat_ulong_t, arg)
686{
687 return do_compat_fcntl64(fd, cmd, arg);
688}
689
690COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
691 compat_ulong_t, arg)
692{
693 switch (cmd) {
694 case F_GETLK64:
695 case F_SETLK64:
696 case F_SETLKW64:
697 case F_OFD_GETLK:
698 case F_OFD_SETLK:
699 case F_OFD_SETLKW:
700 return -EINVAL;
701 }
702 return do_compat_fcntl64(fd, cmd, arg);
703}
704#endif
705
706
707
708static const __poll_t band_table[NSIGPOLL] = {
709 EPOLLIN | EPOLLRDNORM,
710 EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND,
711 EPOLLIN | EPOLLRDNORM | EPOLLMSG,
712 EPOLLERR,
713 EPOLLPRI | EPOLLRDBAND,
714 EPOLLHUP | EPOLLERR
715};
716
717static inline int sigio_perm(struct task_struct *p,
718 struct fown_struct *fown, int sig)
719{
720 const struct cred *cred;
721 int ret;
722
723 rcu_read_lock();
724 cred = __task_cred(p);
725 ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) ||
726 uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) ||
727 uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) &&
728 !security_file_send_sigiotask(p, fown, sig));
729 rcu_read_unlock();
730 return ret;
731}
732
733static void send_sigio_to_task(struct task_struct *p,
734 struct fown_struct *fown,
735 int fd, int reason, enum pid_type type)
736{
737
738
739
740
741 int signum = READ_ONCE(fown->signum);
742
743 if (!sigio_perm(p, fown, signum))
744 return;
745
746 switch (signum) {
747 default: {
748 kernel_siginfo_t si;
749
750
751
752
753
754
755
756 clear_siginfo(&si);
757 si.si_signo = signum;
758 si.si_errno = 0;
759 si.si_code = reason;
760
761
762
763
764
765
766
767
768 if ((signum != SIGPOLL) && sig_specific_sicodes(signum))
769 si.si_code = SI_SIGIO;
770
771
772
773
774 BUG_ON((reason < POLL_IN) || ((reason - POLL_IN) >= NSIGPOLL));
775 if (reason - POLL_IN >= NSIGPOLL)
776 si.si_band = ~0L;
777 else
778 si.si_band = mangle_poll(band_table[reason - POLL_IN]);
779 si.si_fd = fd;
780 if (!do_send_sig_info(signum, &si, p, type))
781 break;
782 }
783 fallthrough;
784 case 0:
785 do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, type);
786 }
787}
788
789void send_sigio(struct fown_struct *fown, int fd, int band)
790{
791 struct task_struct *p;
792 enum pid_type type;
793 unsigned long flags;
794 struct pid *pid;
795
796 read_lock_irqsave(&fown->lock, flags);
797
798 type = fown->pid_type;
799 pid = fown->pid;
800 if (!pid)
801 goto out_unlock_fown;
802
803 if (type <= PIDTYPE_TGID) {
804 rcu_read_lock();
805 p = pid_task(pid, PIDTYPE_PID);
806 if (p)
807 send_sigio_to_task(p, fown, fd, band, type);
808 rcu_read_unlock();
809 } else {
810 read_lock(&tasklist_lock);
811 do_each_pid_task(pid, type, p) {
812 send_sigio_to_task(p, fown, fd, band, type);
813 } while_each_pid_task(pid, type, p);
814 read_unlock(&tasklist_lock);
815 }
816 out_unlock_fown:
817 read_unlock_irqrestore(&fown->lock, flags);
818}
819
820static void send_sigurg_to_task(struct task_struct *p,
821 struct fown_struct *fown, enum pid_type type)
822{
823 if (sigio_perm(p, fown, SIGURG))
824 do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, type);
825}
826
827int send_sigurg(struct fown_struct *fown)
828{
829 struct task_struct *p;
830 enum pid_type type;
831 struct pid *pid;
832 unsigned long flags;
833 int ret = 0;
834
835 read_lock_irqsave(&fown->lock, flags);
836
837 type = fown->pid_type;
838 pid = fown->pid;
839 if (!pid)
840 goto out_unlock_fown;
841
842 ret = 1;
843
844 if (type <= PIDTYPE_TGID) {
845 rcu_read_lock();
846 p = pid_task(pid, PIDTYPE_PID);
847 if (p)
848 send_sigurg_to_task(p, fown, type);
849 rcu_read_unlock();
850 } else {
851 read_lock(&tasklist_lock);
852 do_each_pid_task(pid, type, p) {
853 send_sigurg_to_task(p, fown, type);
854 } while_each_pid_task(pid, type, p);
855 read_unlock(&tasklist_lock);
856 }
857 out_unlock_fown:
858 read_unlock_irqrestore(&fown->lock, flags);
859 return ret;
860}
861
862static DEFINE_SPINLOCK(fasync_lock);
863static struct kmem_cache *fasync_cache __read_mostly;
864
865static void fasync_free_rcu(struct rcu_head *head)
866{
867 kmem_cache_free(fasync_cache,
868 container_of(head, struct fasync_struct, fa_rcu));
869}
870
871
872
873
874
875
876
877
878
879
880int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
881{
882 struct fasync_struct *fa, **fp;
883 int result = 0;
884
885 spin_lock(&filp->f_lock);
886 spin_lock(&fasync_lock);
887 for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
888 if (fa->fa_file != filp)
889 continue;
890
891 write_lock_irq(&fa->fa_lock);
892 fa->fa_file = NULL;
893 write_unlock_irq(&fa->fa_lock);
894
895 *fp = fa->fa_next;
896 call_rcu(&fa->fa_rcu, fasync_free_rcu);
897 filp->f_flags &= ~FASYNC;
898 result = 1;
899 break;
900 }
901 spin_unlock(&fasync_lock);
902 spin_unlock(&filp->f_lock);
903 return result;
904}
905
906struct fasync_struct *fasync_alloc(void)
907{
908 return kmem_cache_alloc(fasync_cache, GFP_KERNEL);
909}
910
911
912
913
914
915
916void fasync_free(struct fasync_struct *new)
917{
918 kmem_cache_free(fasync_cache, new);
919}
920
921
922
923
924
925
926
927
928struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new)
929{
930 struct fasync_struct *fa, **fp;
931
932 spin_lock(&filp->f_lock);
933 spin_lock(&fasync_lock);
934 for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
935 if (fa->fa_file != filp)
936 continue;
937
938 write_lock_irq(&fa->fa_lock);
939 fa->fa_fd = fd;
940 write_unlock_irq(&fa->fa_lock);
941 goto out;
942 }
943
944 rwlock_init(&new->fa_lock);
945 new->magic = FASYNC_MAGIC;
946 new->fa_file = filp;
947 new->fa_fd = fd;
948 new->fa_next = *fapp;
949 rcu_assign_pointer(*fapp, new);
950 filp->f_flags |= FASYNC;
951
952out:
953 spin_unlock(&fasync_lock);
954 spin_unlock(&filp->f_lock);
955 return fa;
956}
957
958
959
960
961
962static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
963{
964 struct fasync_struct *new;
965
966 new = fasync_alloc();
967 if (!new)
968 return -ENOMEM;
969
970
971
972
973
974
975
976
977 if (fasync_insert_entry(fd, filp, fapp, new)) {
978 fasync_free(new);
979 return 0;
980 }
981
982 return 1;
983}
984
985
986
987
988
989
990
991int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
992{
993 if (!on)
994 return fasync_remove_entry(filp, fapp);
995 return fasync_add_entry(fd, filp, fapp);
996}
997
998EXPORT_SYMBOL(fasync_helper);
999
1000
1001
1002
1003static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
1004{
1005 while (fa) {
1006 struct fown_struct *fown;
1007 unsigned long flags;
1008
1009 if (fa->magic != FASYNC_MAGIC) {
1010 printk(KERN_ERR "kill_fasync: bad magic number in "
1011 "fasync_struct!\n");
1012 return;
1013 }
1014 read_lock_irqsave(&fa->fa_lock, flags);
1015 if (fa->fa_file) {
1016 fown = &fa->fa_file->f_owner;
1017
1018
1019
1020 if (!(sig == SIGURG && fown->signum == 0))
1021 send_sigio(fown, fa->fa_fd, band);
1022 }
1023 read_unlock_irqrestore(&fa->fa_lock, flags);
1024 fa = rcu_dereference(fa->fa_next);
1025 }
1026}
1027
1028void kill_fasync(struct fasync_struct **fp, int sig, int band)
1029{
1030
1031
1032
1033 if (*fp) {
1034 rcu_read_lock();
1035 kill_fasync_rcu(rcu_dereference(*fp), sig, band);
1036 rcu_read_unlock();
1037 }
1038}
1039EXPORT_SYMBOL(kill_fasync);
1040
1041static int __init fcntl_init(void)
1042{
1043
1044
1045
1046
1047
1048 BUILD_BUG_ON(21 - 1 !=
1049 HWEIGHT32(
1050 (VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) |
1051 __FMODE_EXEC | __FMODE_NONOTIFY));
1052
1053 fasync_cache = kmem_cache_create("fasync_cache",
1054 sizeof(struct fasync_struct), 0,
1055 SLAB_PANIC | SLAB_ACCOUNT, NULL);
1056 return 0;
1057}
1058
1059module_init(fcntl_init)
1060