1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/8.1/sys/kern/sys_generic.c 208801 2010-06-04 14:06:59Z kib $");
39
40 #include "opt_compat.h"
41 #include "opt_ktrace.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysproto.h>
46 #include <sys/filedesc.h>
47 #include <sys/filio.h>
48 #include <sys/fcntl.h>
49 #include <sys/file.h>
50 #include <sys/proc.h>
51 #include <sys/signalvar.h>
52 #include <sys/socketvar.h>
53 #include <sys/uio.h>
54 #include <sys/kernel.h>
55 #include <sys/ktr.h>
56 #include <sys/limits.h>
57 #include <sys/malloc.h>
58 #include <sys/poll.h>
59 #include <sys/resourcevar.h>
60 #include <sys/selinfo.h>
61 #include <sys/sleepqueue.h>
62 #include <sys/syscallsubr.h>
63 #include <sys/sysctl.h>
64 #include <sys/sysent.h>
65 #include <sys/vnode.h>
66 #include <sys/bio.h>
67 #include <sys/buf.h>
68 #include <sys/condvar.h>
69 #ifdef KTRACE
70 #include <sys/ktrace.h>
71 #endif
72
73 #include <security/audit/audit.h>
74
75 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
76 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
77 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
78
79 static int pollout(struct pollfd *, struct pollfd *, u_int);
80 static int pollscan(struct thread *, struct pollfd *, u_int);
81 static int pollrescan(struct thread *);
82 static int selscan(struct thread *, fd_mask **, fd_mask **, int);
83 static int selrescan(struct thread *, fd_mask **, fd_mask **);
84 static void selfdalloc(struct thread *, void *);
85 static void selfdfree(struct seltd *, struct selfd *);
86 static int dofileread(struct thread *, int, struct file *, struct uio *,
87 off_t, int);
88 static int dofilewrite(struct thread *, int, struct file *, struct uio *,
89 off_t, int);
90 static void doselwakeup(struct selinfo *, int);
91 static void seltdinit(struct thread *);
92 static int seltdwait(struct thread *, int);
93 static void seltdclear(struct thread *);
94
95 /*
96 * One seltd per-thread allocated on demand as needed.
97 *
98 * t - protected by st_mtx
99 * k - Only accessed by curthread or read-only
100 */
101 struct seltd {
102 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */
103 struct selfd *st_free1; /* (k) free fd for read set. */
104 struct selfd *st_free2; /* (k) free fd for write set. */
105 struct mtx st_mtx; /* Protects struct seltd */
106 struct cv st_wait; /* (t) Wait channel. */
107 int st_flags; /* (t) SELTD_ flags. */
108 };
109
110 #define SELTD_PENDING 0x0001 /* We have pending events. */
111 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */
112
113 /*
114 * One selfd allocated per-thread per-file-descriptor.
115 * f - protected by sf_mtx
116 */
117 struct selfd {
118 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */
119 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */
120 struct selinfo *sf_si; /* (f) selinfo when linked. */
121 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */
122 struct seltd *sf_td; /* (k) owning seltd. */
123 void *sf_cookie; /* (k) fd or pollfd. */
124 };
125
126 static uma_zone_t selfd_zone;
127 static struct mtx_pool *mtxpool_select;
128
129 #ifndef _SYS_SYSPROTO_H_
130 struct read_args {
131 int fd;
132 void *buf;
133 size_t nbyte;
134 };
135 #endif
136 int
137 read(td, uap)
138 struct thread *td;
139 struct read_args *uap;
140 {
141 struct uio auio;
142 struct iovec aiov;
143 int error;
144
145 if (uap->nbyte > INT_MAX)
146 return (EINVAL);
147 aiov.iov_base = uap->buf;
148 aiov.iov_len = uap->nbyte;
149 auio.uio_iov = &aiov;
150 auio.uio_iovcnt = 1;
151 auio.uio_resid = uap->nbyte;
152 auio.uio_segflg = UIO_USERSPACE;
153 error = kern_readv(td, uap->fd, &auio);
154 return(error);
155 }
156
157 /*
158 * Positioned read system call
159 */
160 #ifndef _SYS_SYSPROTO_H_
161 struct pread_args {
162 int fd;
163 void *buf;
164 size_t nbyte;
165 int pad;
166 off_t offset;
167 };
168 #endif
169 int
170 pread(td, uap)
171 struct thread *td;
172 struct pread_args *uap;
173 {
174 struct uio auio;
175 struct iovec aiov;
176 int error;
177
178 if (uap->nbyte > INT_MAX)
179 return (EINVAL);
180 aiov.iov_base = uap->buf;
181 aiov.iov_len = uap->nbyte;
182 auio.uio_iov = &aiov;
183 auio.uio_iovcnt = 1;
184 auio.uio_resid = uap->nbyte;
185 auio.uio_segflg = UIO_USERSPACE;
186 error = kern_preadv(td, uap->fd, &auio, uap->offset);
187 return(error);
188 }
189
190 int
191 freebsd6_pread(td, uap)
192 struct thread *td;
193 struct freebsd6_pread_args *uap;
194 {
195 struct pread_args oargs;
196
197 oargs.fd = uap->fd;
198 oargs.buf = uap->buf;
199 oargs.nbyte = uap->nbyte;
200 oargs.offset = uap->offset;
201 return (pread(td, &oargs));
202 }
203
204 /*
205 * Scatter read system call.
206 */
207 #ifndef _SYS_SYSPROTO_H_
208 struct readv_args {
209 int fd;
210 struct iovec *iovp;
211 u_int iovcnt;
212 };
213 #endif
214 int
215 readv(struct thread *td, struct readv_args *uap)
216 {
217 struct uio *auio;
218 int error;
219
220 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
221 if (error)
222 return (error);
223 error = kern_readv(td, uap->fd, auio);
224 free(auio, M_IOV);
225 return (error);
226 }
227
228 int
229 kern_readv(struct thread *td, int fd, struct uio *auio)
230 {
231 struct file *fp;
232 int error;
233
234 error = fget_read(td, fd, &fp);
235 if (error)
236 return (error);
237 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
238 fdrop(fp, td);
239 return (error);
240 }
241
242 /*
243 * Scatter positioned read system call.
244 */
245 #ifndef _SYS_SYSPROTO_H_
246 struct preadv_args {
247 int fd;
248 struct iovec *iovp;
249 u_int iovcnt;
250 off_t offset;
251 };
252 #endif
253 int
254 preadv(struct thread *td, struct preadv_args *uap)
255 {
256 struct uio *auio;
257 int error;
258
259 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
260 if (error)
261 return (error);
262 error = kern_preadv(td, uap->fd, auio, uap->offset);
263 free(auio, M_IOV);
264 return (error);
265 }
266
267 int
268 kern_preadv(td, fd, auio, offset)
269 struct thread *td;
270 int fd;
271 struct uio *auio;
272 off_t offset;
273 {
274 struct file *fp;
275 int error;
276
277 error = fget_read(td, fd, &fp);
278 if (error)
279 return (error);
280 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
281 error = ESPIPE;
282 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
283 error = EINVAL;
284 else
285 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
286 fdrop(fp, td);
287 return (error);
288 }
289
290 /*
291 * Common code for readv and preadv that reads data in
292 * from a file using the passed in uio, offset, and flags.
293 */
294 static int
295 dofileread(td, fd, fp, auio, offset, flags)
296 struct thread *td;
297 int fd;
298 struct file *fp;
299 struct uio *auio;
300 off_t offset;
301 int flags;
302 {
303 ssize_t cnt;
304 int error;
305 #ifdef KTRACE
306 struct uio *ktruio = NULL;
307 #endif
308
309 /* Finish zero length reads right here */
310 if (auio->uio_resid == 0) {
311 td->td_retval[0] = 0;
312 return(0);
313 }
314 auio->uio_rw = UIO_READ;
315 auio->uio_offset = offset;
316 auio->uio_td = td;
317 #ifdef KTRACE
318 if (KTRPOINT(td, KTR_GENIO))
319 ktruio = cloneuio(auio);
320 #endif
321 cnt = auio->uio_resid;
322 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
323 if (auio->uio_resid != cnt && (error == ERESTART ||
324 error == EINTR || error == EWOULDBLOCK))
325 error = 0;
326 }
327 cnt -= auio->uio_resid;
328 #ifdef KTRACE
329 if (ktruio != NULL) {
330 ktruio->uio_resid = cnt;
331 ktrgenio(fd, UIO_READ, ktruio, error);
332 }
333 #endif
334 td->td_retval[0] = cnt;
335 return (error);
336 }
337
338 #ifndef _SYS_SYSPROTO_H_
339 struct write_args {
340 int fd;
341 const void *buf;
342 size_t nbyte;
343 };
344 #endif
345 int
346 write(td, uap)
347 struct thread *td;
348 struct write_args *uap;
349 {
350 struct uio auio;
351 struct iovec aiov;
352 int error;
353
354 if (uap->nbyte > INT_MAX)
355 return (EINVAL);
356 aiov.iov_base = (void *)(uintptr_t)uap->buf;
357 aiov.iov_len = uap->nbyte;
358 auio.uio_iov = &aiov;
359 auio.uio_iovcnt = 1;
360 auio.uio_resid = uap->nbyte;
361 auio.uio_segflg = UIO_USERSPACE;
362 error = kern_writev(td, uap->fd, &auio);
363 return(error);
364 }
365
366 /*
367 * Positioned write system call.
368 */
369 #ifndef _SYS_SYSPROTO_H_
370 struct pwrite_args {
371 int fd;
372 const void *buf;
373 size_t nbyte;
374 int pad;
375 off_t offset;
376 };
377 #endif
378 int
379 pwrite(td, uap)
380 struct thread *td;
381 struct pwrite_args *uap;
382 {
383 struct uio auio;
384 struct iovec aiov;
385 int error;
386
387 if (uap->nbyte > INT_MAX)
388 return (EINVAL);
389 aiov.iov_base = (void *)(uintptr_t)uap->buf;
390 aiov.iov_len = uap->nbyte;
391 auio.uio_iov = &aiov;
392 auio.uio_iovcnt = 1;
393 auio.uio_resid = uap->nbyte;
394 auio.uio_segflg = UIO_USERSPACE;
395 error = kern_pwritev(td, uap->fd, &auio, uap->offset);
396 return(error);
397 }
398
399 int
400 freebsd6_pwrite(td, uap)
401 struct thread *td;
402 struct freebsd6_pwrite_args *uap;
403 {
404 struct pwrite_args oargs;
405
406 oargs.fd = uap->fd;
407 oargs.buf = uap->buf;
408 oargs.nbyte = uap->nbyte;
409 oargs.offset = uap->offset;
410 return (pwrite(td, &oargs));
411 }
412
413 /*
414 * Gather write system call.
415 */
416 #ifndef _SYS_SYSPROTO_H_
417 struct writev_args {
418 int fd;
419 struct iovec *iovp;
420 u_int iovcnt;
421 };
422 #endif
423 int
424 writev(struct thread *td, struct writev_args *uap)
425 {
426 struct uio *auio;
427 int error;
428
429 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
430 if (error)
431 return (error);
432 error = kern_writev(td, uap->fd, auio);
433 free(auio, M_IOV);
434 return (error);
435 }
436
437 int
438 kern_writev(struct thread *td, int fd, struct uio *auio)
439 {
440 struct file *fp;
441 int error;
442
443 error = fget_write(td, fd, &fp);
444 if (error)
445 return (error);
446 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
447 fdrop(fp, td);
448 return (error);
449 }
450
451 /*
452 * Gather positioned write system call.
453 */
454 #ifndef _SYS_SYSPROTO_H_
455 struct pwritev_args {
456 int fd;
457 struct iovec *iovp;
458 u_int iovcnt;
459 off_t offset;
460 };
461 #endif
462 int
463 pwritev(struct thread *td, struct pwritev_args *uap)
464 {
465 struct uio *auio;
466 int error;
467
468 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
469 if (error)
470 return (error);
471 error = kern_pwritev(td, uap->fd, auio, uap->offset);
472 free(auio, M_IOV);
473 return (error);
474 }
475
476 int
477 kern_pwritev(td, fd, auio, offset)
478 struct thread *td;
479 struct uio *auio;
480 int fd;
481 off_t offset;
482 {
483 struct file *fp;
484 int error;
485
486 error = fget_write(td, fd, &fp);
487 if (error)
488 return (error);
489 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
490 error = ESPIPE;
491 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
492 error = EINVAL;
493 else
494 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
495 fdrop(fp, td);
496 return (error);
497 }
498
499 /*
500 * Common code for writev and pwritev that writes data to
501 * a file using the passed in uio, offset, and flags.
502 */
503 static int
504 dofilewrite(td, fd, fp, auio, offset, flags)
505 struct thread *td;
506 int fd;
507 struct file *fp;
508 struct uio *auio;
509 off_t offset;
510 int flags;
511 {
512 ssize_t cnt;
513 int error;
514 #ifdef KTRACE
515 struct uio *ktruio = NULL;
516 #endif
517
518 auio->uio_rw = UIO_WRITE;
519 auio->uio_td = td;
520 auio->uio_offset = offset;
521 #ifdef KTRACE
522 if (KTRPOINT(td, KTR_GENIO))
523 ktruio = cloneuio(auio);
524 #endif
525 cnt = auio->uio_resid;
526 if (fp->f_type == DTYPE_VNODE)
527 bwillwrite();
528 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
529 if (auio->uio_resid != cnt && (error == ERESTART ||
530 error == EINTR || error == EWOULDBLOCK))
531 error = 0;
532 /* Socket layer is responsible for issuing SIGPIPE. */
533 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
534 PROC_LOCK(td->td_proc);
535 psignal(td->td_proc, SIGPIPE);
536 PROC_UNLOCK(td->td_proc);
537 }
538 }
539 cnt -= auio->uio_resid;
540 #ifdef KTRACE
541 if (ktruio != NULL) {
542 ktruio->uio_resid = cnt;
543 ktrgenio(fd, UIO_WRITE, ktruio, error);
544 }
545 #endif
546 td->td_retval[0] = cnt;
547 return (error);
548 }
549
550 /*
551 * Truncate a file given a file descriptor.
552 *
553 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
554 * descriptor isn't writable.
555 */
556 int
557 kern_ftruncate(td, fd, length)
558 struct thread *td;
559 int fd;
560 off_t length;
561 {
562 struct file *fp;
563 int error;
564
565 AUDIT_ARG_FD(fd);
566 if (length < 0)
567 return (EINVAL);
568 error = fget(td, fd, &fp);
569 if (error)
570 return (error);
571 AUDIT_ARG_FILE(td->td_proc, fp);
572 if (!(fp->f_flag & FWRITE)) {
573 fdrop(fp, td);
574 return (EINVAL);
575 }
576 error = fo_truncate(fp, length, td->td_ucred, td);
577 fdrop(fp, td);
578 return (error);
579 }
580
581 #ifndef _SYS_SYSPROTO_H_
582 struct ftruncate_args {
583 int fd;
584 int pad;
585 off_t length;
586 };
587 #endif
588 int
589 ftruncate(td, uap)
590 struct thread *td;
591 struct ftruncate_args *uap;
592 {
593
594 return (kern_ftruncate(td, uap->fd, uap->length));
595 }
596
597 #if defined(COMPAT_43)
598 #ifndef _SYS_SYSPROTO_H_
599 struct oftruncate_args {
600 int fd;
601 long length;
602 };
603 #endif
604 int
605 oftruncate(td, uap)
606 struct thread *td;
607 struct oftruncate_args *uap;
608 {
609
610 return (kern_ftruncate(td, uap->fd, uap->length));
611 }
612 #endif /* COMPAT_43 */
613
614 #ifndef _SYS_SYSPROTO_H_
615 struct ioctl_args {
616 int fd;
617 u_long com;
618 caddr_t data;
619 };
620 #endif
621 /* ARGSUSED */
622 int
623 ioctl(struct thread *td, struct ioctl_args *uap)
624 {
625 u_long com;
626 int arg, error;
627 u_int size;
628 caddr_t data;
629
630 if (uap->com > 0xffffffff) {
631 printf(
632 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
633 td->td_proc->p_pid, td->td_name, uap->com);
634 uap->com &= 0xffffffff;
635 }
636 com = uap->com;
637
638 /*
639 * Interpret high order word to find amount of data to be
640 * copied to/from the user's address space.
641 */
642 size = IOCPARM_LEN(com);
643 if ((size > IOCPARM_MAX) ||
644 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
645 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
646 ((com & IOC_OUT) && size == 0) ||
647 #else
648 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
649 #endif
650 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
651 return (ENOTTY);
652
653 if (size > 0) {
654 if (com & IOC_VOID) {
655 /* Integer argument. */
656 arg = (intptr_t)uap->data;
657 data = (void *)&arg;
658 size = 0;
659 } else
660 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
661 } else
662 data = (void *)&uap->data;
663 if (com & IOC_IN) {
664 error = copyin(uap->data, data, (u_int)size);
665 if (error) {
666 if (size > 0)
667 free(data, M_IOCTLOPS);
668 return (error);
669 }
670 } else if (com & IOC_OUT) {
671 /*
672 * Zero the buffer so the user always
673 * gets back something deterministic.
674 */
675 bzero(data, size);
676 }
677
678 error = kern_ioctl(td, uap->fd, com, data);
679
680 if (error == 0 && (com & IOC_OUT))
681 error = copyout(data, uap->data, (u_int)size);
682
683 if (size > 0)
684 free(data, M_IOCTLOPS);
685 return (error);
686 }
687
688 int
689 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
690 {
691 struct file *fp;
692 struct filedesc *fdp;
693 int error;
694 int tmp;
695
696 AUDIT_ARG_FD(fd);
697 AUDIT_ARG_CMD(com);
698 if ((error = fget(td, fd, &fp)) != 0)
699 return (error);
700 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
701 fdrop(fp, td);
702 return (EBADF);
703 }
704 fdp = td->td_proc->p_fd;
705 switch (com) {
706 case FIONCLEX:
707 FILEDESC_XLOCK(fdp);
708 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
709 FILEDESC_XUNLOCK(fdp);
710 goto out;
711 case FIOCLEX:
712 FILEDESC_XLOCK(fdp);
713 fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
714 FILEDESC_XUNLOCK(fdp);
715 goto out;
716 case FIONBIO:
717 if ((tmp = *(int *)data))
718 atomic_set_int(&fp->f_flag, FNONBLOCK);
719 else
720 atomic_clear_int(&fp->f_flag, FNONBLOCK);
721 data = (void *)&tmp;
722 break;
723 case FIOASYNC:
724 if ((tmp = *(int *)data))
725 atomic_set_int(&fp->f_flag, FASYNC);
726 else
727 atomic_clear_int(&fp->f_flag, FASYNC);
728 data = (void *)&tmp;
729 break;
730 }
731
732 error = fo_ioctl(fp, com, data, td->td_ucred, td);
733 out:
734 fdrop(fp, td);
735 return (error);
736 }
737
738 int
739 poll_no_poll(int events)
740 {
741 /*
742 * Return true for read/write. If the user asked for something
743 * special, return POLLNVAL, so that clients have a way of
744 * determining reliably whether or not the extended
745 * functionality is present without hard-coding knowledge
746 * of specific filesystem implementations.
747 */
748 if (events & ~POLLSTANDARD)
749 return (POLLNVAL);
750
751 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
752 }
753
754 int
755 pselect(struct thread *td, struct pselect_args *uap)
756 {
757 struct timespec ts;
758 struct timeval tv, *tvp;
759 sigset_t set, *uset;
760 int error;
761
762 if (uap->ts != NULL) {
763 error = copyin(uap->ts, &ts, sizeof(ts));
764 if (error != 0)
765 return (error);
766 TIMESPEC_TO_TIMEVAL(&tv, &ts);
767 tvp = &tv;
768 } else
769 tvp = NULL;
770 if (uap->sm != NULL) {
771 error = copyin(uap->sm, &set, sizeof(set));
772 if (error != 0)
773 return (error);
774 uset = &set;
775 } else
776 uset = NULL;
777 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
778 uset, NFDBITS));
779 }
780
781 int
782 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
783 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
784 {
785 int error;
786
787 if (uset != NULL) {
788 error = kern_sigprocmask(td, SIG_SETMASK, uset,
789 &td->td_oldsigmask, 0);
790 if (error != 0)
791 return (error);
792 td->td_pflags |= TDP_OLDMASK;
793 /*
794 * Make sure that ast() is called on return to
795 * usermode and TDP_OLDMASK is cleared, restoring old
796 * sigmask.
797 */
798 thread_lock(td);
799 td->td_flags |= TDF_ASTPENDING;
800 thread_unlock(td);
801 }
802 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
803 return (error);
804 }
805
806 #ifndef _SYS_SYSPROTO_H_
807 struct select_args {
808 int nd;
809 fd_set *in, *ou, *ex;
810 struct timeval *tv;
811 };
812 #endif
813 int
814 select(struct thread *td, struct select_args *uap)
815 {
816 struct timeval tv, *tvp;
817 int error;
818
819 if (uap->tv != NULL) {
820 error = copyin(uap->tv, &tv, sizeof(tv));
821 if (error)
822 return (error);
823 tvp = &tv;
824 } else
825 tvp = NULL;
826
827 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
828 NFDBITS));
829 }
830
831 int
832 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
833 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
834 {
835 struct filedesc *fdp;
836 /*
837 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
838 * infds with the new FD_SETSIZE of 1024, and more than enough for
839 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
840 * of 256.
841 */
842 fd_mask s_selbits[howmany(2048, NFDBITS)];
843 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
844 struct timeval atv, rtv, ttv;
845 int error, timo;
846 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
847
848 if (nd < 0)
849 return (EINVAL);
850 fdp = td->td_proc->p_fd;
851 if (nd > fdp->fd_lastfile + 1)
852 nd = fdp->fd_lastfile + 1;
853
854 /*
855 * Allocate just enough bits for the non-null fd_sets. Use the
856 * preallocated auto buffer if possible.
857 */
858 nfdbits = roundup(nd, NFDBITS);
859 ncpbytes = nfdbits / NBBY;
860 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
861 nbufbytes = 0;
862 if (fd_in != NULL)
863 nbufbytes += 2 * ncpbytes;
864 if (fd_ou != NULL)
865 nbufbytes += 2 * ncpbytes;
866 if (fd_ex != NULL)
867 nbufbytes += 2 * ncpbytes;
868 if (nbufbytes <= sizeof s_selbits)
869 selbits = &s_selbits[0];
870 else
871 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
872
873 /*
874 * Assign pointers into the bit buffers and fetch the input bits.
875 * Put the output buffers together so that they can be bzeroed
876 * together.
877 */
878 sbp = selbits;
879 #define getbits(name, x) \
880 do { \
881 if (name == NULL) { \
882 ibits[x] = NULL; \
883 obits[x] = NULL; \
884 } else { \
885 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
886 obits[x] = sbp; \
887 sbp += ncpbytes / sizeof *sbp; \
888 error = copyin(name, ibits[x], ncpubytes); \
889 if (error != 0) \
890 goto done; \
891 bzero((char *)ibits[x] + ncpubytes, \
892 ncpbytes - ncpubytes); \
893 } \
894 } while (0)
895 getbits(fd_in, 0);
896 getbits(fd_ou, 1);
897 getbits(fd_ex, 2);
898 #undef getbits
899
900 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
901 /*
902 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
903 * we are running under 32-bit emulation. This should be more
904 * generic.
905 */
906 #define swizzle_fdset(bits) \
907 if (abi_nfdbits != NFDBITS && bits != NULL) { \
908 int i; \
909 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
910 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
911 }
912 #else
913 #define swizzle_fdset(bits)
914 #endif
915
916 /* Make sure the bit order makes it through an ABI transition */
917 swizzle_fdset(ibits[0]);
918 swizzle_fdset(ibits[1]);
919 swizzle_fdset(ibits[2]);
920
921 if (nbufbytes != 0)
922 bzero(selbits, nbufbytes / 2);
923
924 if (tvp != NULL) {
925 atv = *tvp;
926 if (itimerfix(&atv)) {
927 error = EINVAL;
928 goto done;
929 }
930 getmicrouptime(&rtv);
931 timevaladd(&atv, &rtv);
932 } else {
933 atv.tv_sec = 0;
934 atv.tv_usec = 0;
935 }
936 timo = 0;
937 seltdinit(td);
938 /* Iterate until the timeout expires or descriptors become ready. */
939 for (;;) {
940 error = selscan(td, ibits, obits, nd);
941 if (error || td->td_retval[0] != 0)
942 break;
943 if (atv.tv_sec || atv.tv_usec) {
944 getmicrouptime(&rtv);
945 if (timevalcmp(&rtv, &atv, >=))
946 break;
947 ttv = atv;
948 timevalsub(&ttv, &rtv);
949 timo = ttv.tv_sec > 24 * 60 * 60 ?
950 24 * 60 * 60 * hz : tvtohz(&ttv);
951 }
952 error = seltdwait(td, timo);
953 if (error)
954 break;
955 error = selrescan(td, ibits, obits);
956 if (error || td->td_retval[0] != 0)
957 break;
958 }
959 seltdclear(td);
960
961 done:
962 /* select is not restarted after signals... */
963 if (error == ERESTART)
964 error = EINTR;
965 if (error == EWOULDBLOCK)
966 error = 0;
967
968 /* swizzle bit order back, if necessary */
969 swizzle_fdset(obits[0]);
970 swizzle_fdset(obits[1]);
971 swizzle_fdset(obits[2]);
972 #undef swizzle_fdset
973
974 #define putbits(name, x) \
975 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
976 error = error2;
977 if (error == 0) {
978 int error2;
979
980 putbits(fd_in, 0);
981 putbits(fd_ou, 1);
982 putbits(fd_ex, 2);
983 #undef putbits
984 }
985 if (selbits != &s_selbits[0])
986 free(selbits, M_SELECT);
987
988 return (error);
989 }
990 /*
991 * Convert a select bit set to poll flags.
992 *
993 * The backend always returns POLLHUP/POLLERR if appropriate and we
994 * return this as a set bit in any set.
995 */
996 static int select_flags[3] = {
997 POLLRDNORM | POLLHUP | POLLERR,
998 POLLWRNORM | POLLHUP | POLLERR,
999 POLLRDBAND | POLLERR
1000 };
1001
1002 /*
1003 * Compute the fo_poll flags required for a fd given by the index and
1004 * bit position in the fd_mask array.
1005 */
1006 static __inline int
1007 selflags(fd_mask **ibits, int idx, fd_mask bit)
1008 {
1009 int flags;
1010 int msk;
1011
1012 flags = 0;
1013 for (msk = 0; msk < 3; msk++) {
1014 if (ibits[msk] == NULL)
1015 continue;
1016 if ((ibits[msk][idx] & bit) == 0)
1017 continue;
1018 flags |= select_flags[msk];
1019 }
1020 return (flags);
1021 }
1022
1023 /*
1024 * Set the appropriate output bits given a mask of fired events and the
1025 * input bits originally requested.
1026 */
1027 static __inline int
1028 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1029 {
1030 int msk;
1031 int n;
1032
1033 n = 0;
1034 for (msk = 0; msk < 3; msk++) {
1035 if ((events & select_flags[msk]) == 0)
1036 continue;
1037 if (ibits[msk] == NULL)
1038 continue;
1039 if ((ibits[msk][idx] & bit) == 0)
1040 continue;
1041 /*
1042 * XXX Check for a duplicate set. This can occur because a
1043 * socket calls selrecord() twice for each poll() call
1044 * resulting in two selfds per real fd. selrescan() will
1045 * call selsetbits twice as a result.
1046 */
1047 if ((obits[msk][idx] & bit) != 0)
1048 continue;
1049 obits[msk][idx] |= bit;
1050 n++;
1051 }
1052
1053 return (n);
1054 }
1055
1056 /*
1057 * Traverse the list of fds attached to this thread's seltd and check for
1058 * completion.
1059 */
1060 static int
1061 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1062 {
1063 struct filedesc *fdp;
1064 struct selinfo *si;
1065 struct seltd *stp;
1066 struct selfd *sfp;
1067 struct selfd *sfn;
1068 struct file *fp;
1069 fd_mask bit;
1070 int fd, ev, n, idx;
1071
1072 fdp = td->td_proc->p_fd;
1073 stp = td->td_sel;
1074 n = 0;
1075 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1076 fd = (int)(uintptr_t)sfp->sf_cookie;
1077 si = sfp->sf_si;
1078 selfdfree(stp, sfp);
1079 /* If the selinfo wasn't cleared the event didn't fire. */
1080 if (si != NULL)
1081 continue;
1082 if ((fp = fget_unlocked(fdp, fd)) == NULL)
1083 return (EBADF);
1084 idx = fd / NFDBITS;
1085 bit = (fd_mask)1 << (fd % NFDBITS);
1086 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1087 fdrop(fp, td);
1088 if (ev != 0)
1089 n += selsetbits(ibits, obits, idx, bit, ev);
1090 }
1091 stp->st_flags = 0;
1092 td->td_retval[0] = n;
1093 return (0);
1094 }
1095
1096 /*
1097 * Perform the initial filedescriptor scan and register ourselves with
1098 * each selinfo.
1099 */
1100 static int
1101 selscan(td, ibits, obits, nfd)
1102 struct thread *td;
1103 fd_mask **ibits, **obits;
1104 int nfd;
1105 {
1106 struct filedesc *fdp;
1107 struct file *fp;
1108 fd_mask bit;
1109 int ev, flags, end, fd;
1110 int n, idx;
1111
1112 fdp = td->td_proc->p_fd;
1113 n = 0;
1114 for (idx = 0, fd = 0; fd < nfd; idx++) {
1115 end = imin(fd + NFDBITS, nfd);
1116 for (bit = 1; fd < end; bit <<= 1, fd++) {
1117 /* Compute the list of events we're interested in. */
1118 flags = selflags(ibits, idx, bit);
1119 if (flags == 0)
1120 continue;
1121 if ((fp = fget_unlocked(fdp, fd)) == NULL)
1122 return (EBADF);
1123 selfdalloc(td, (void *)(uintptr_t)fd);
1124 ev = fo_poll(fp, flags, td->td_ucred, td);
1125 fdrop(fp, td);
1126 if (ev != 0)
1127 n += selsetbits(ibits, obits, idx, bit, ev);
1128 }
1129 }
1130
1131 td->td_retval[0] = n;
1132 return (0);
1133 }
1134
1135 #ifndef _SYS_SYSPROTO_H_
1136 struct poll_args {
1137 struct pollfd *fds;
1138 u_int nfds;
1139 int timeout;
1140 };
1141 #endif
1142 int
1143 poll(td, uap)
1144 struct thread *td;
1145 struct poll_args *uap;
1146 {
1147 struct pollfd *bits;
1148 struct pollfd smallbits[32];
1149 struct timeval atv, rtv, ttv;
1150 int error = 0, timo;
1151 u_int nfds;
1152 size_t ni;
1153
1154 nfds = uap->nfds;
1155 if (nfds > maxfilesperproc && nfds > FD_SETSIZE)
1156 return (EINVAL);
1157 ni = nfds * sizeof(struct pollfd);
1158 if (ni > sizeof(smallbits))
1159 bits = malloc(ni, M_TEMP, M_WAITOK);
1160 else
1161 bits = smallbits;
1162 error = copyin(uap->fds, bits, ni);
1163 if (error)
1164 goto done;
1165 if (uap->timeout != INFTIM) {
1166 atv.tv_sec = uap->timeout / 1000;
1167 atv.tv_usec = (uap->timeout % 1000) * 1000;
1168 if (itimerfix(&atv)) {
1169 error = EINVAL;
1170 goto done;
1171 }
1172 getmicrouptime(&rtv);
1173 timevaladd(&atv, &rtv);
1174 } else {
1175 atv.tv_sec = 0;
1176 atv.tv_usec = 0;
1177 }
1178 timo = 0;
1179 seltdinit(td);
1180 /* Iterate until the timeout expires or descriptors become ready. */
1181 for (;;) {
1182 error = pollscan(td, bits, nfds);
1183 if (error || td->td_retval[0] != 0)
1184 break;
1185 if (atv.tv_sec || atv.tv_usec) {
1186 getmicrouptime(&rtv);
1187 if (timevalcmp(&rtv, &atv, >=))
1188 break;
1189 ttv = atv;
1190 timevalsub(&ttv, &rtv);
1191 timo = ttv.tv_sec > 24 * 60 * 60 ?
1192 24 * 60 * 60 * hz : tvtohz(&ttv);
1193 }
1194 error = seltdwait(td, timo);
1195 if (error)
1196 break;
1197 error = pollrescan(td);
1198 if (error || td->td_retval[0] != 0)
1199 break;
1200 }
1201 seltdclear(td);
1202
1203 done:
1204 /* poll is not restarted after signals... */
1205 if (error == ERESTART)
1206 error = EINTR;
1207 if (error == EWOULDBLOCK)
1208 error = 0;
1209 if (error == 0) {
1210 error = pollout(bits, uap->fds, nfds);
1211 if (error)
1212 goto out;
1213 }
1214 out:
1215 if (ni > sizeof(smallbits))
1216 free(bits, M_TEMP);
1217 return (error);
1218 }
1219
1220 static int
1221 pollrescan(struct thread *td)
1222 {
1223 struct seltd *stp;
1224 struct selfd *sfp;
1225 struct selfd *sfn;
1226 struct selinfo *si;
1227 struct filedesc *fdp;
1228 struct file *fp;
1229 struct pollfd *fd;
1230 int n;
1231
1232 n = 0;
1233 fdp = td->td_proc->p_fd;
1234 stp = td->td_sel;
1235 FILEDESC_SLOCK(fdp);
1236 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1237 fd = (struct pollfd *)sfp->sf_cookie;
1238 si = sfp->sf_si;
1239 selfdfree(stp, sfp);
1240 /* If the selinfo wasn't cleared the event didn't fire. */
1241 if (si != NULL)
1242 continue;
1243 fp = fdp->fd_ofiles[fd->fd];
1244 if (fp == NULL) {
1245 fd->revents = POLLNVAL;
1246 n++;
1247 continue;
1248 }
1249 /*
1250 * Note: backend also returns POLLHUP and
1251 * POLLERR if appropriate.
1252 */
1253 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1254 if (fd->revents != 0)
1255 n++;
1256 }
1257 FILEDESC_SUNLOCK(fdp);
1258 stp->st_flags = 0;
1259 td->td_retval[0] = n;
1260 return (0);
1261 }
1262
1263
1264 static int
1265 pollout(fds, ufds, nfd)
1266 struct pollfd *fds;
1267 struct pollfd *ufds;
1268 u_int nfd;
1269 {
1270 int error = 0;
1271 u_int i = 0;
1272
1273 for (i = 0; i < nfd; i++) {
1274 error = copyout(&fds->revents, &ufds->revents,
1275 sizeof(ufds->revents));
1276 if (error)
1277 return (error);
1278 fds++;
1279 ufds++;
1280 }
1281 return (0);
1282 }
1283
1284 static int
1285 pollscan(td, fds, nfd)
1286 struct thread *td;
1287 struct pollfd *fds;
1288 u_int nfd;
1289 {
1290 struct filedesc *fdp = td->td_proc->p_fd;
1291 int i;
1292 struct file *fp;
1293 int n = 0;
1294
1295 FILEDESC_SLOCK(fdp);
1296 for (i = 0; i < nfd; i++, fds++) {
1297 if (fds->fd >= fdp->fd_nfiles) {
1298 fds->revents = POLLNVAL;
1299 n++;
1300 } else if (fds->fd < 0) {
1301 fds->revents = 0;
1302 } else {
1303 fp = fdp->fd_ofiles[fds->fd];
1304 if (fp == NULL) {
1305 fds->revents = POLLNVAL;
1306 n++;
1307 } else {
1308 /*
1309 * Note: backend also returns POLLHUP and
1310 * POLLERR if appropriate.
1311 */
1312 selfdalloc(td, fds);
1313 fds->revents = fo_poll(fp, fds->events,
1314 td->td_ucred, td);
1315 /*
1316 * POSIX requires POLLOUT to be never
1317 * set simultaneously with POLLHUP.
1318 */
1319 if ((fds->revents & POLLHUP) != 0)
1320 fds->revents &= ~POLLOUT;
1321
1322 if (fds->revents != 0)
1323 n++;
1324 }
1325 }
1326 }
1327 FILEDESC_SUNLOCK(fdp);
1328 td->td_retval[0] = n;
1329 return (0);
1330 }
1331
1332 /*
1333 * OpenBSD poll system call.
1334 *
1335 * XXX this isn't quite a true representation.. OpenBSD uses select ops.
1336 */
1337 #ifndef _SYS_SYSPROTO_H_
1338 struct openbsd_poll_args {
1339 struct pollfd *fds;
1340 u_int nfds;
1341 int timeout;
1342 };
1343 #endif
1344 int
1345 openbsd_poll(td, uap)
1346 register struct thread *td;
1347 register struct openbsd_poll_args *uap;
1348 {
1349 return (poll(td, (struct poll_args *)uap));
1350 }
1351
1352 /*
1353 * XXX This was created specifically to support netncp and netsmb. This
1354 * allows the caller to specify a socket to wait for events on. It returns
1355 * 0 if any events matched and an error otherwise. There is no way to
1356 * determine which events fired.
1357 */
1358 int
1359 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1360 {
1361 struct timeval atv, rtv, ttv;
1362 int error, timo;
1363
1364 if (tvp != NULL) {
1365 atv = *tvp;
1366 if (itimerfix(&atv))
1367 return (EINVAL);
1368 getmicrouptime(&rtv);
1369 timevaladd(&atv, &rtv);
1370 } else {
1371 atv.tv_sec = 0;
1372 atv.tv_usec = 0;
1373 }
1374
1375 timo = 0;
1376 seltdinit(td);
1377 /*
1378 * Iterate until the timeout expires or the socket becomes ready.
1379 */
1380 for (;;) {
1381 selfdalloc(td, NULL);
1382 error = sopoll(so, events, NULL, td);
1383 /* error here is actually the ready events. */
1384 if (error)
1385 return (0);
1386 if (atv.tv_sec || atv.tv_usec) {
1387 getmicrouptime(&rtv);
1388 if (timevalcmp(&rtv, &atv, >=)) {
1389 seltdclear(td);
1390 return (EWOULDBLOCK);
1391 }
1392 ttv = atv;
1393 timevalsub(&ttv, &rtv);
1394 timo = ttv.tv_sec > 24 * 60 * 60 ?
1395 24 * 60 * 60 * hz : tvtohz(&ttv);
1396 }
1397 error = seltdwait(td, timo);
1398 seltdclear(td);
1399 if (error)
1400 break;
1401 }
1402 /* XXX Duplicates ncp/smb behavior. */
1403 if (error == ERESTART)
1404 error = 0;
1405 return (error);
1406 }
1407
1408 /*
1409 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1410 * have two select sets, one for read and another for write.
1411 */
1412 static void
1413 selfdalloc(struct thread *td, void *cookie)
1414 {
1415 struct seltd *stp;
1416
1417 stp = td->td_sel;
1418 if (stp->st_free1 == NULL)
1419 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1420 stp->st_free1->sf_td = stp;
1421 stp->st_free1->sf_cookie = cookie;
1422 if (stp->st_free2 == NULL)
1423 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1424 stp->st_free2->sf_td = stp;
1425 stp->st_free2->sf_cookie = cookie;
1426 }
1427
1428 static void
1429 selfdfree(struct seltd *stp, struct selfd *sfp)
1430 {
1431 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1432 mtx_lock(sfp->sf_mtx);
1433 if (sfp->sf_si)
1434 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1435 mtx_unlock(sfp->sf_mtx);
1436 uma_zfree(selfd_zone, sfp);
1437 }
1438
1439 /*
1440 * Record a select request.
1441 */
1442 void
1443 selrecord(selector, sip)
1444 struct thread *selector;
1445 struct selinfo *sip;
1446 {
1447 struct selfd *sfp;
1448 struct seltd *stp;
1449 struct mtx *mtxp;
1450
1451 stp = selector->td_sel;
1452 /*
1453 * Don't record when doing a rescan.
1454 */
1455 if (stp->st_flags & SELTD_RESCAN)
1456 return;
1457 /*
1458 * Grab one of the preallocated descriptors.
1459 */
1460 sfp = NULL;
1461 if ((sfp = stp->st_free1) != NULL)
1462 stp->st_free1 = NULL;
1463 else if ((sfp = stp->st_free2) != NULL)
1464 stp->st_free2 = NULL;
1465 else
1466 panic("selrecord: No free selfd on selq");
1467 mtxp = sip->si_mtx;
1468 if (mtxp == NULL)
1469 mtxp = mtx_pool_find(mtxpool_select, sip);
1470 /*
1471 * Initialize the sfp and queue it in the thread.
1472 */
1473 sfp->sf_si = sip;
1474 sfp->sf_mtx = mtxp;
1475 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1476 /*
1477 * Now that we've locked the sip, check for initialization.
1478 */
1479 mtx_lock(mtxp);
1480 if (sip->si_mtx == NULL) {
1481 sip->si_mtx = mtxp;
1482 TAILQ_INIT(&sip->si_tdlist);
1483 }
1484 /*
1485 * Add this thread to the list of selfds listening on this selinfo.
1486 */
1487 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1488 mtx_unlock(sip->si_mtx);
1489 }
1490
1491 /* Wake up a selecting thread. */
1492 void
1493 selwakeup(sip)
1494 struct selinfo *sip;
1495 {
1496 doselwakeup(sip, -1);
1497 }
1498
1499 /* Wake up a selecting thread, and set its priority. */
1500 void
1501 selwakeuppri(sip, pri)
1502 struct selinfo *sip;
1503 int pri;
1504 {
1505 doselwakeup(sip, pri);
1506 }
1507
1508 /*
1509 * Do a wakeup when a selectable event occurs.
1510 */
1511 static void
1512 doselwakeup(sip, pri)
1513 struct selinfo *sip;
1514 int pri;
1515 {
1516 struct selfd *sfp;
1517 struct selfd *sfn;
1518 struct seltd *stp;
1519
1520 /* If it's not initialized there can't be any waiters. */
1521 if (sip->si_mtx == NULL)
1522 return;
1523 /*
1524 * Locking the selinfo locks all selfds associated with it.
1525 */
1526 mtx_lock(sip->si_mtx);
1527 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1528 /*
1529 * Once we remove this sfp from the list and clear the
1530 * sf_si seltdclear will know to ignore this si.
1531 */
1532 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1533 sfp->sf_si = NULL;
1534 stp = sfp->sf_td;
1535 mtx_lock(&stp->st_mtx);
1536 stp->st_flags |= SELTD_PENDING;
1537 cv_broadcastpri(&stp->st_wait, pri);
1538 mtx_unlock(&stp->st_mtx);
1539 }
1540 mtx_unlock(sip->si_mtx);
1541 }
1542
1543 static void
1544 seltdinit(struct thread *td)
1545 {
1546 struct seltd *stp;
1547
1548 if ((stp = td->td_sel) != NULL)
1549 goto out;
1550 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1551 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1552 cv_init(&stp->st_wait, "select");
1553 out:
1554 stp->st_flags = 0;
1555 STAILQ_INIT(&stp->st_selq);
1556 }
1557
1558 static int
1559 seltdwait(struct thread *td, int timo)
1560 {
1561 struct seltd *stp;
1562 int error;
1563
1564 stp = td->td_sel;
1565 /*
1566 * An event of interest may occur while we do not hold the seltd
1567 * locked so check the pending flag before we sleep.
1568 */
1569 mtx_lock(&stp->st_mtx);
1570 /*
1571 * Any further calls to selrecord will be a rescan.
1572 */
1573 stp->st_flags |= SELTD_RESCAN;
1574 if (stp->st_flags & SELTD_PENDING) {
1575 mtx_unlock(&stp->st_mtx);
1576 return (0);
1577 }
1578 if (timo > 0)
1579 error = cv_timedwait_sig(&stp->st_wait, &stp->st_mtx, timo);
1580 else
1581 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
1582 mtx_unlock(&stp->st_mtx);
1583
1584 return (error);
1585 }
1586
1587 void
1588 seltdfini(struct thread *td)
1589 {
1590 struct seltd *stp;
1591
1592 stp = td->td_sel;
1593 if (stp == NULL)
1594 return;
1595 if (stp->st_free1)
1596 uma_zfree(selfd_zone, stp->st_free1);
1597 if (stp->st_free2)
1598 uma_zfree(selfd_zone, stp->st_free2);
1599 td->td_sel = NULL;
1600 free(stp, M_SELECT);
1601 }
1602
1603 /*
1604 * Remove the references to the thread from all of the objects we were
1605 * polling.
1606 */
1607 static void
1608 seltdclear(struct thread *td)
1609 {
1610 struct seltd *stp;
1611 struct selfd *sfp;
1612 struct selfd *sfn;
1613
1614 stp = td->td_sel;
1615 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
1616 selfdfree(stp, sfp);
1617 stp->st_flags = 0;
1618 }
1619
1620 static void selectinit(void *);
1621 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
1622 static void
1623 selectinit(void *dummy __unused)
1624 {
1625
1626 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
1627 NULL, NULL, UMA_ALIGN_PTR, 0);
1628 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
1629 }
Cache object: 1875666b1971ae260be100bee9f301dc
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