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/11.0/sys/kern/sys_generic.c 297493 2016-04-01 18:29:38Z jhb $");
39
40 #include "opt_capsicum.h"
41 #include "opt_compat.h"
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
47 #include <sys/capsicum.h>
48 #include <sys/filedesc.h>
49 #include <sys/filio.h>
50 #include <sys/fcntl.h>
51 #include <sys/file.h>
52 #include <sys/lock.h>
53 #include <sys/proc.h>
54 #include <sys/signalvar.h>
55 #include <sys/socketvar.h>
56 #include <sys/uio.h>
57 #include <sys/kernel.h>
58 #include <sys/ktr.h>
59 #include <sys/limits.h>
60 #include <sys/malloc.h>
61 #include <sys/poll.h>
62 #include <sys/resourcevar.h>
63 #include <sys/selinfo.h>
64 #include <sys/sleepqueue.h>
65 #include <sys/syscallsubr.h>
66 #include <sys/sysctl.h>
67 #include <sys/sysent.h>
68 #include <sys/vnode.h>
69 #include <sys/bio.h>
70 #include <sys/buf.h>
71 #include <sys/condvar.h>
72 #ifdef KTRACE
73 #include <sys/ktrace.h>
74 #endif
75
76 #include <security/audit/audit.h>
77
78 /*
79 * The following macro defines how many bytes will be allocated from
80 * the stack instead of memory allocated when passing the IOCTL data
81 * structures from userspace and to the kernel. Some IOCTLs having
82 * small data structures are used very frequently and this small
83 * buffer on the stack gives a significant speedup improvement for
84 * those requests. The value of this define should be greater or equal
85 * to 64 bytes and should also be power of two. The data structure is
86 * currently hard-aligned to a 8-byte boundary on the stack. This
87 * should currently be sufficient for all supported platforms.
88 */
89 #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */
90 #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */
91
92 #ifdef __LP64__
93 static int iosize_max_clamp = 0;
94 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW,
95 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX");
96 static int devfs_iosize_max_clamp = 1;
97 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW,
98 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices");
99 #endif
100
101 /*
102 * Assert that the return value of read(2) and write(2) syscalls fits
103 * into a register. If not, an architecture will need to provide the
104 * usermode wrappers to reconstruct the result.
105 */
106 CTASSERT(sizeof(register_t) >= sizeof(size_t));
107
108 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
109 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
110 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
111
112 static int pollout(struct thread *, struct pollfd *, struct pollfd *,
113 u_int);
114 static int pollscan(struct thread *, struct pollfd *, u_int);
115 static int pollrescan(struct thread *);
116 static int selscan(struct thread *, fd_mask **, fd_mask **, int);
117 static int selrescan(struct thread *, fd_mask **, fd_mask **);
118 static void selfdalloc(struct thread *, void *);
119 static void selfdfree(struct seltd *, struct selfd *);
120 static int dofileread(struct thread *, int, struct file *, struct uio *,
121 off_t, int);
122 static int dofilewrite(struct thread *, int, struct file *, struct uio *,
123 off_t, int);
124 static void doselwakeup(struct selinfo *, int);
125 static void seltdinit(struct thread *);
126 static int seltdwait(struct thread *, sbintime_t, sbintime_t);
127 static void seltdclear(struct thread *);
128
129 /*
130 * One seltd per-thread allocated on demand as needed.
131 *
132 * t - protected by st_mtx
133 * k - Only accessed by curthread or read-only
134 */
135 struct seltd {
136 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */
137 struct selfd *st_free1; /* (k) free fd for read set. */
138 struct selfd *st_free2; /* (k) free fd for write set. */
139 struct mtx st_mtx; /* Protects struct seltd */
140 struct cv st_wait; /* (t) Wait channel. */
141 int st_flags; /* (t) SELTD_ flags. */
142 };
143
144 #define SELTD_PENDING 0x0001 /* We have pending events. */
145 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */
146
147 /*
148 * One selfd allocated per-thread per-file-descriptor.
149 * f - protected by sf_mtx
150 */
151 struct selfd {
152 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */
153 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */
154 struct selinfo *sf_si; /* (f) selinfo when linked. */
155 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */
156 struct seltd *sf_td; /* (k) owning seltd. */
157 void *sf_cookie; /* (k) fd or pollfd. */
158 u_int sf_refs;
159 };
160
161 static uma_zone_t selfd_zone;
162 static struct mtx_pool *mtxpool_select;
163
164 #ifdef __LP64__
165 size_t
166 devfs_iosize_max(void)
167 {
168
169 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
170 INT_MAX : SSIZE_MAX);
171 }
172
173 size_t
174 iosize_max(void)
175 {
176
177 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
178 INT_MAX : SSIZE_MAX);
179 }
180 #endif
181
182 #ifndef _SYS_SYSPROTO_H_
183 struct read_args {
184 int fd;
185 void *buf;
186 size_t nbyte;
187 };
188 #endif
189 int
190 sys_read(td, uap)
191 struct thread *td;
192 struct read_args *uap;
193 {
194 struct uio auio;
195 struct iovec aiov;
196 int error;
197
198 if (uap->nbyte > IOSIZE_MAX)
199 return (EINVAL);
200 aiov.iov_base = uap->buf;
201 aiov.iov_len = uap->nbyte;
202 auio.uio_iov = &aiov;
203 auio.uio_iovcnt = 1;
204 auio.uio_resid = uap->nbyte;
205 auio.uio_segflg = UIO_USERSPACE;
206 error = kern_readv(td, uap->fd, &auio);
207 return(error);
208 }
209
210 /*
211 * Positioned read system call
212 */
213 #ifndef _SYS_SYSPROTO_H_
214 struct pread_args {
215 int fd;
216 void *buf;
217 size_t nbyte;
218 int pad;
219 off_t offset;
220 };
221 #endif
222 int
223 sys_pread(td, uap)
224 struct thread *td;
225 struct pread_args *uap;
226 {
227 struct uio auio;
228 struct iovec aiov;
229 int error;
230
231 if (uap->nbyte > IOSIZE_MAX)
232 return (EINVAL);
233 aiov.iov_base = uap->buf;
234 aiov.iov_len = uap->nbyte;
235 auio.uio_iov = &aiov;
236 auio.uio_iovcnt = 1;
237 auio.uio_resid = uap->nbyte;
238 auio.uio_segflg = UIO_USERSPACE;
239 error = kern_preadv(td, uap->fd, &auio, uap->offset);
240 return(error);
241 }
242
243 #if defined(COMPAT_FREEBSD6)
244 int
245 freebsd6_pread(td, uap)
246 struct thread *td;
247 struct freebsd6_pread_args *uap;
248 {
249 struct pread_args oargs;
250
251 oargs.fd = uap->fd;
252 oargs.buf = uap->buf;
253 oargs.nbyte = uap->nbyte;
254 oargs.offset = uap->offset;
255 return (sys_pread(td, &oargs));
256 }
257 #endif
258
259 /*
260 * Scatter read system call.
261 */
262 #ifndef _SYS_SYSPROTO_H_
263 struct readv_args {
264 int fd;
265 struct iovec *iovp;
266 u_int iovcnt;
267 };
268 #endif
269 int
270 sys_readv(struct thread *td, struct readv_args *uap)
271 {
272 struct uio *auio;
273 int error;
274
275 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
276 if (error)
277 return (error);
278 error = kern_readv(td, uap->fd, auio);
279 free(auio, M_IOV);
280 return (error);
281 }
282
283 int
284 kern_readv(struct thread *td, int fd, struct uio *auio)
285 {
286 struct file *fp;
287 cap_rights_t rights;
288 int error;
289
290 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
291 if (error)
292 return (error);
293 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
294 fdrop(fp, td);
295 return (error);
296 }
297
298 /*
299 * Scatter positioned read system call.
300 */
301 #ifndef _SYS_SYSPROTO_H_
302 struct preadv_args {
303 int fd;
304 struct iovec *iovp;
305 u_int iovcnt;
306 off_t offset;
307 };
308 #endif
309 int
310 sys_preadv(struct thread *td, struct preadv_args *uap)
311 {
312 struct uio *auio;
313 int error;
314
315 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
316 if (error)
317 return (error);
318 error = kern_preadv(td, uap->fd, auio, uap->offset);
319 free(auio, M_IOV);
320 return (error);
321 }
322
323 int
324 kern_preadv(td, fd, auio, offset)
325 struct thread *td;
326 int fd;
327 struct uio *auio;
328 off_t offset;
329 {
330 struct file *fp;
331 cap_rights_t rights;
332 int error;
333
334 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp);
335 if (error)
336 return (error);
337 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
338 error = ESPIPE;
339 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
340 error = EINVAL;
341 else
342 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
343 fdrop(fp, td);
344 return (error);
345 }
346
347 /*
348 * Common code for readv and preadv that reads data in
349 * from a file using the passed in uio, offset, and flags.
350 */
351 static int
352 dofileread(td, fd, fp, auio, offset, flags)
353 struct thread *td;
354 int fd;
355 struct file *fp;
356 struct uio *auio;
357 off_t offset;
358 int flags;
359 {
360 ssize_t cnt;
361 int error;
362 #ifdef KTRACE
363 struct uio *ktruio = NULL;
364 #endif
365
366 /* Finish zero length reads right here */
367 if (auio->uio_resid == 0) {
368 td->td_retval[0] = 0;
369 return(0);
370 }
371 auio->uio_rw = UIO_READ;
372 auio->uio_offset = offset;
373 auio->uio_td = td;
374 #ifdef KTRACE
375 if (KTRPOINT(td, KTR_GENIO))
376 ktruio = cloneuio(auio);
377 #endif
378 cnt = auio->uio_resid;
379 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
380 if (auio->uio_resid != cnt && (error == ERESTART ||
381 error == EINTR || error == EWOULDBLOCK))
382 error = 0;
383 }
384 cnt -= auio->uio_resid;
385 #ifdef KTRACE
386 if (ktruio != NULL) {
387 ktruio->uio_resid = cnt;
388 ktrgenio(fd, UIO_READ, ktruio, error);
389 }
390 #endif
391 td->td_retval[0] = cnt;
392 return (error);
393 }
394
395 #ifndef _SYS_SYSPROTO_H_
396 struct write_args {
397 int fd;
398 const void *buf;
399 size_t nbyte;
400 };
401 #endif
402 int
403 sys_write(td, uap)
404 struct thread *td;
405 struct write_args *uap;
406 {
407 struct uio auio;
408 struct iovec aiov;
409 int error;
410
411 if (uap->nbyte > IOSIZE_MAX)
412 return (EINVAL);
413 aiov.iov_base = (void *)(uintptr_t)uap->buf;
414 aiov.iov_len = uap->nbyte;
415 auio.uio_iov = &aiov;
416 auio.uio_iovcnt = 1;
417 auio.uio_resid = uap->nbyte;
418 auio.uio_segflg = UIO_USERSPACE;
419 error = kern_writev(td, uap->fd, &auio);
420 return(error);
421 }
422
423 /*
424 * Positioned write system call.
425 */
426 #ifndef _SYS_SYSPROTO_H_
427 struct pwrite_args {
428 int fd;
429 const void *buf;
430 size_t nbyte;
431 int pad;
432 off_t offset;
433 };
434 #endif
435 int
436 sys_pwrite(td, uap)
437 struct thread *td;
438 struct pwrite_args *uap;
439 {
440 struct uio auio;
441 struct iovec aiov;
442 int error;
443
444 if (uap->nbyte > IOSIZE_MAX)
445 return (EINVAL);
446 aiov.iov_base = (void *)(uintptr_t)uap->buf;
447 aiov.iov_len = uap->nbyte;
448 auio.uio_iov = &aiov;
449 auio.uio_iovcnt = 1;
450 auio.uio_resid = uap->nbyte;
451 auio.uio_segflg = UIO_USERSPACE;
452 error = kern_pwritev(td, uap->fd, &auio, uap->offset);
453 return(error);
454 }
455
456 #if defined(COMPAT_FREEBSD6)
457 int
458 freebsd6_pwrite(td, uap)
459 struct thread *td;
460 struct freebsd6_pwrite_args *uap;
461 {
462 struct pwrite_args oargs;
463
464 oargs.fd = uap->fd;
465 oargs.buf = uap->buf;
466 oargs.nbyte = uap->nbyte;
467 oargs.offset = uap->offset;
468 return (sys_pwrite(td, &oargs));
469 }
470 #endif
471
472 /*
473 * Gather write system call.
474 */
475 #ifndef _SYS_SYSPROTO_H_
476 struct writev_args {
477 int fd;
478 struct iovec *iovp;
479 u_int iovcnt;
480 };
481 #endif
482 int
483 sys_writev(struct thread *td, struct writev_args *uap)
484 {
485 struct uio *auio;
486 int error;
487
488 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
489 if (error)
490 return (error);
491 error = kern_writev(td, uap->fd, auio);
492 free(auio, M_IOV);
493 return (error);
494 }
495
496 int
497 kern_writev(struct thread *td, int fd, struct uio *auio)
498 {
499 struct file *fp;
500 cap_rights_t rights;
501 int error;
502
503 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp);
504 if (error)
505 return (error);
506 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
507 fdrop(fp, td);
508 return (error);
509 }
510
511 /*
512 * Gather positioned write system call.
513 */
514 #ifndef _SYS_SYSPROTO_H_
515 struct pwritev_args {
516 int fd;
517 struct iovec *iovp;
518 u_int iovcnt;
519 off_t offset;
520 };
521 #endif
522 int
523 sys_pwritev(struct thread *td, struct pwritev_args *uap)
524 {
525 struct uio *auio;
526 int error;
527
528 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
529 if (error)
530 return (error);
531 error = kern_pwritev(td, uap->fd, auio, uap->offset);
532 free(auio, M_IOV);
533 return (error);
534 }
535
536 int
537 kern_pwritev(td, fd, auio, offset)
538 struct thread *td;
539 struct uio *auio;
540 int fd;
541 off_t offset;
542 {
543 struct file *fp;
544 cap_rights_t rights;
545 int error;
546
547 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
548 if (error)
549 return (error);
550 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
551 error = ESPIPE;
552 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
553 error = EINVAL;
554 else
555 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
556 fdrop(fp, td);
557 return (error);
558 }
559
560 /*
561 * Common code for writev and pwritev that writes data to
562 * a file using the passed in uio, offset, and flags.
563 */
564 static int
565 dofilewrite(td, fd, fp, auio, offset, flags)
566 struct thread *td;
567 int fd;
568 struct file *fp;
569 struct uio *auio;
570 off_t offset;
571 int flags;
572 {
573 ssize_t cnt;
574 int error;
575 #ifdef KTRACE
576 struct uio *ktruio = NULL;
577 #endif
578
579 auio->uio_rw = UIO_WRITE;
580 auio->uio_td = td;
581 auio->uio_offset = offset;
582 #ifdef KTRACE
583 if (KTRPOINT(td, KTR_GENIO))
584 ktruio = cloneuio(auio);
585 #endif
586 cnt = auio->uio_resid;
587 if (fp->f_type == DTYPE_VNODE &&
588 (fp->f_vnread_flags & FDEVFS_VNODE) == 0)
589 bwillwrite();
590 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
591 if (auio->uio_resid != cnt && (error == ERESTART ||
592 error == EINTR || error == EWOULDBLOCK))
593 error = 0;
594 /* Socket layer is responsible for issuing SIGPIPE. */
595 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
596 PROC_LOCK(td->td_proc);
597 tdsignal(td, SIGPIPE);
598 PROC_UNLOCK(td->td_proc);
599 }
600 }
601 cnt -= auio->uio_resid;
602 #ifdef KTRACE
603 if (ktruio != NULL) {
604 ktruio->uio_resid = cnt;
605 ktrgenio(fd, UIO_WRITE, ktruio, error);
606 }
607 #endif
608 td->td_retval[0] = cnt;
609 return (error);
610 }
611
612 /*
613 * Truncate a file given a file descriptor.
614 *
615 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
616 * descriptor isn't writable.
617 */
618 int
619 kern_ftruncate(td, fd, length)
620 struct thread *td;
621 int fd;
622 off_t length;
623 {
624 struct file *fp;
625 cap_rights_t rights;
626 int error;
627
628 AUDIT_ARG_FD(fd);
629 if (length < 0)
630 return (EINVAL);
631 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp);
632 if (error)
633 return (error);
634 AUDIT_ARG_FILE(td->td_proc, fp);
635 if (!(fp->f_flag & FWRITE)) {
636 fdrop(fp, td);
637 return (EINVAL);
638 }
639 error = fo_truncate(fp, length, td->td_ucred, td);
640 fdrop(fp, td);
641 return (error);
642 }
643
644 #ifndef _SYS_SYSPROTO_H_
645 struct ftruncate_args {
646 int fd;
647 int pad;
648 off_t length;
649 };
650 #endif
651 int
652 sys_ftruncate(td, uap)
653 struct thread *td;
654 struct ftruncate_args *uap;
655 {
656
657 return (kern_ftruncate(td, uap->fd, uap->length));
658 }
659
660 #if defined(COMPAT_43)
661 #ifndef _SYS_SYSPROTO_H_
662 struct oftruncate_args {
663 int fd;
664 long length;
665 };
666 #endif
667 int
668 oftruncate(td, uap)
669 struct thread *td;
670 struct oftruncate_args *uap;
671 {
672
673 return (kern_ftruncate(td, uap->fd, uap->length));
674 }
675 #endif /* COMPAT_43 */
676
677 #ifndef _SYS_SYSPROTO_H_
678 struct ioctl_args {
679 int fd;
680 u_long com;
681 caddr_t data;
682 };
683 #endif
684 /* ARGSUSED */
685 int
686 sys_ioctl(struct thread *td, struct ioctl_args *uap)
687 {
688 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
689 u_long com;
690 int arg, error;
691 u_int size;
692 caddr_t data;
693
694 if (uap->com > 0xffffffff) {
695 printf(
696 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
697 td->td_proc->p_pid, td->td_name, uap->com);
698 uap->com &= 0xffffffff;
699 }
700 com = uap->com;
701
702 /*
703 * Interpret high order word to find amount of data to be
704 * copied to/from the user's address space.
705 */
706 size = IOCPARM_LEN(com);
707 if ((size > IOCPARM_MAX) ||
708 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
709 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
710 ((com & IOC_OUT) && size == 0) ||
711 #else
712 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
713 #endif
714 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
715 return (ENOTTY);
716
717 if (size > 0) {
718 if (com & IOC_VOID) {
719 /* Integer argument. */
720 arg = (intptr_t)uap->data;
721 data = (void *)&arg;
722 size = 0;
723 } else {
724 if (size > SYS_IOCTL_SMALL_SIZE)
725 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
726 else
727 data = smalldata;
728 }
729 } else
730 data = (void *)&uap->data;
731 if (com & IOC_IN) {
732 error = copyin(uap->data, data, (u_int)size);
733 if (error != 0)
734 goto out;
735 } else if (com & IOC_OUT) {
736 /*
737 * Zero the buffer so the user always
738 * gets back something deterministic.
739 */
740 bzero(data, size);
741 }
742
743 error = kern_ioctl(td, uap->fd, com, data);
744
745 if (error == 0 && (com & IOC_OUT))
746 error = copyout(data, uap->data, (u_int)size);
747
748 out:
749 if (size > SYS_IOCTL_SMALL_SIZE)
750 free(data, M_IOCTLOPS);
751 return (error);
752 }
753
754 int
755 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
756 {
757 struct file *fp;
758 struct filedesc *fdp;
759 #ifndef CAPABILITIES
760 cap_rights_t rights;
761 #endif
762 int error, tmp, locked;
763
764 AUDIT_ARG_FD(fd);
765 AUDIT_ARG_CMD(com);
766
767 fdp = td->td_proc->p_fd;
768
769 switch (com) {
770 case FIONCLEX:
771 case FIOCLEX:
772 FILEDESC_XLOCK(fdp);
773 locked = LA_XLOCKED;
774 break;
775 default:
776 #ifdef CAPABILITIES
777 FILEDESC_SLOCK(fdp);
778 locked = LA_SLOCKED;
779 #else
780 locked = LA_UNLOCKED;
781 #endif
782 break;
783 }
784
785 #ifdef CAPABILITIES
786 if ((fp = fget_locked(fdp, fd)) == NULL) {
787 error = EBADF;
788 goto out;
789 }
790 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
791 fp = NULL; /* fhold() was not called yet */
792 goto out;
793 }
794 fhold(fp);
795 if (locked == LA_SLOCKED) {
796 FILEDESC_SUNLOCK(fdp);
797 locked = LA_UNLOCKED;
798 }
799 #else
800 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
801 if (error != 0) {
802 fp = NULL;
803 goto out;
804 }
805 #endif
806 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
807 error = EBADF;
808 goto out;
809 }
810
811 switch (com) {
812 case FIONCLEX:
813 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
814 goto out;
815 case FIOCLEX:
816 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
817 goto out;
818 case FIONBIO:
819 if ((tmp = *(int *)data))
820 atomic_set_int(&fp->f_flag, FNONBLOCK);
821 else
822 atomic_clear_int(&fp->f_flag, FNONBLOCK);
823 data = (void *)&tmp;
824 break;
825 case FIOASYNC:
826 if ((tmp = *(int *)data))
827 atomic_set_int(&fp->f_flag, FASYNC);
828 else
829 atomic_clear_int(&fp->f_flag, FASYNC);
830 data = (void *)&tmp;
831 break;
832 }
833
834 error = fo_ioctl(fp, com, data, td->td_ucred, td);
835 out:
836 switch (locked) {
837 case LA_XLOCKED:
838 FILEDESC_XUNLOCK(fdp);
839 break;
840 #ifdef CAPABILITIES
841 case LA_SLOCKED:
842 FILEDESC_SUNLOCK(fdp);
843 break;
844 #endif
845 default:
846 FILEDESC_UNLOCK_ASSERT(fdp);
847 break;
848 }
849 if (fp != NULL)
850 fdrop(fp, td);
851 return (error);
852 }
853
854 int
855 poll_no_poll(int events)
856 {
857 /*
858 * Return true for read/write. If the user asked for something
859 * special, return POLLNVAL, so that clients have a way of
860 * determining reliably whether or not the extended
861 * functionality is present without hard-coding knowledge
862 * of specific filesystem implementations.
863 */
864 if (events & ~POLLSTANDARD)
865 return (POLLNVAL);
866
867 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
868 }
869
870 int
871 sys_pselect(struct thread *td, struct pselect_args *uap)
872 {
873 struct timespec ts;
874 struct timeval tv, *tvp;
875 sigset_t set, *uset;
876 int error;
877
878 if (uap->ts != NULL) {
879 error = copyin(uap->ts, &ts, sizeof(ts));
880 if (error != 0)
881 return (error);
882 TIMESPEC_TO_TIMEVAL(&tv, &ts);
883 tvp = &tv;
884 } else
885 tvp = NULL;
886 if (uap->sm != NULL) {
887 error = copyin(uap->sm, &set, sizeof(set));
888 if (error != 0)
889 return (error);
890 uset = &set;
891 } else
892 uset = NULL;
893 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
894 uset, NFDBITS));
895 }
896
897 int
898 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
899 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
900 {
901 int error;
902
903 if (uset != NULL) {
904 error = kern_sigprocmask(td, SIG_SETMASK, uset,
905 &td->td_oldsigmask, 0);
906 if (error != 0)
907 return (error);
908 td->td_pflags |= TDP_OLDMASK;
909 /*
910 * Make sure that ast() is called on return to
911 * usermode and TDP_OLDMASK is cleared, restoring old
912 * sigmask.
913 */
914 thread_lock(td);
915 td->td_flags |= TDF_ASTPENDING;
916 thread_unlock(td);
917 }
918 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
919 return (error);
920 }
921
922 #ifndef _SYS_SYSPROTO_H_
923 struct select_args {
924 int nd;
925 fd_set *in, *ou, *ex;
926 struct timeval *tv;
927 };
928 #endif
929 int
930 sys_select(struct thread *td, struct select_args *uap)
931 {
932 struct timeval tv, *tvp;
933 int error;
934
935 if (uap->tv != NULL) {
936 error = copyin(uap->tv, &tv, sizeof(tv));
937 if (error)
938 return (error);
939 tvp = &tv;
940 } else
941 tvp = NULL;
942
943 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
944 NFDBITS));
945 }
946
947 /*
948 * In the unlikely case when user specified n greater then the last
949 * open file descriptor, check that no bits are set after the last
950 * valid fd. We must return EBADF if any is set.
951 *
952 * There are applications that rely on the behaviour.
953 *
954 * nd is fd_lastfile + 1.
955 */
956 static int
957 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
958 {
959 char *addr, *oaddr;
960 int b, i, res;
961 uint8_t bits;
962
963 if (nd >= ndu || fd_in == NULL)
964 return (0);
965
966 oaddr = NULL;
967 bits = 0; /* silence gcc */
968 for (i = nd; i < ndu; i++) {
969 b = i / NBBY;
970 #if BYTE_ORDER == LITTLE_ENDIAN
971 addr = (char *)fd_in + b;
972 #else
973 addr = (char *)fd_in;
974 if (abi_nfdbits == NFDBITS) {
975 addr += rounddown(b, sizeof(fd_mask)) +
976 sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
977 } else {
978 addr += rounddown(b, sizeof(uint32_t)) +
979 sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
980 }
981 #endif
982 if (addr != oaddr) {
983 res = fubyte(addr);
984 if (res == -1)
985 return (EFAULT);
986 oaddr = addr;
987 bits = res;
988 }
989 if ((bits & (1 << (i % NBBY))) != 0)
990 return (EBADF);
991 }
992 return (0);
993 }
994
995 int
996 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
997 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
998 {
999 struct filedesc *fdp;
1000 /*
1001 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
1002 * infds with the new FD_SETSIZE of 1024, and more than enough for
1003 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
1004 * of 256.
1005 */
1006 fd_mask s_selbits[howmany(2048, NFDBITS)];
1007 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
1008 struct timeval rtv;
1009 sbintime_t asbt, precision, rsbt;
1010 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
1011 int error, lf, ndu;
1012
1013 if (nd < 0)
1014 return (EINVAL);
1015 fdp = td->td_proc->p_fd;
1016 ndu = nd;
1017 lf = fdp->fd_lastfile;
1018 if (nd > lf + 1)
1019 nd = lf + 1;
1020
1021 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
1022 if (error != 0)
1023 return (error);
1024 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
1025 if (error != 0)
1026 return (error);
1027 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
1028 if (error != 0)
1029 return (error);
1030
1031 /*
1032 * Allocate just enough bits for the non-null fd_sets. Use the
1033 * preallocated auto buffer if possible.
1034 */
1035 nfdbits = roundup(nd, NFDBITS);
1036 ncpbytes = nfdbits / NBBY;
1037 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
1038 nbufbytes = 0;
1039 if (fd_in != NULL)
1040 nbufbytes += 2 * ncpbytes;
1041 if (fd_ou != NULL)
1042 nbufbytes += 2 * ncpbytes;
1043 if (fd_ex != NULL)
1044 nbufbytes += 2 * ncpbytes;
1045 if (nbufbytes <= sizeof s_selbits)
1046 selbits = &s_selbits[0];
1047 else
1048 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
1049
1050 /*
1051 * Assign pointers into the bit buffers and fetch the input bits.
1052 * Put the output buffers together so that they can be bzeroed
1053 * together.
1054 */
1055 sbp = selbits;
1056 #define getbits(name, x) \
1057 do { \
1058 if (name == NULL) { \
1059 ibits[x] = NULL; \
1060 obits[x] = NULL; \
1061 } else { \
1062 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
1063 obits[x] = sbp; \
1064 sbp += ncpbytes / sizeof *sbp; \
1065 error = copyin(name, ibits[x], ncpubytes); \
1066 if (error != 0) \
1067 goto done; \
1068 bzero((char *)ibits[x] + ncpubytes, \
1069 ncpbytes - ncpubytes); \
1070 } \
1071 } while (0)
1072 getbits(fd_in, 0);
1073 getbits(fd_ou, 1);
1074 getbits(fd_ex, 2);
1075 #undef getbits
1076
1077 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
1078 /*
1079 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
1080 * we are running under 32-bit emulation. This should be more
1081 * generic.
1082 */
1083 #define swizzle_fdset(bits) \
1084 if (abi_nfdbits != NFDBITS && bits != NULL) { \
1085 int i; \
1086 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
1087 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
1088 }
1089 #else
1090 #define swizzle_fdset(bits)
1091 #endif
1092
1093 /* Make sure the bit order makes it through an ABI transition */
1094 swizzle_fdset(ibits[0]);
1095 swizzle_fdset(ibits[1]);
1096 swizzle_fdset(ibits[2]);
1097
1098 if (nbufbytes != 0)
1099 bzero(selbits, nbufbytes / 2);
1100
1101 precision = 0;
1102 if (tvp != NULL) {
1103 rtv = *tvp;
1104 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1105 rtv.tv_usec >= 1000000) {
1106 error = EINVAL;
1107 goto done;
1108 }
1109 if (!timevalisset(&rtv))
1110 asbt = 0;
1111 else if (rtv.tv_sec <= INT32_MAX) {
1112 rsbt = tvtosbt(rtv);
1113 precision = rsbt;
1114 precision >>= tc_precexp;
1115 if (TIMESEL(&asbt, rsbt))
1116 asbt += tc_tick_sbt;
1117 if (asbt <= SBT_MAX - rsbt)
1118 asbt += rsbt;
1119 else
1120 asbt = -1;
1121 } else
1122 asbt = -1;
1123 } else
1124 asbt = -1;
1125 seltdinit(td);
1126 /* Iterate until the timeout expires or descriptors become ready. */
1127 for (;;) {
1128 error = selscan(td, ibits, obits, nd);
1129 if (error || td->td_retval[0] != 0)
1130 break;
1131 error = seltdwait(td, asbt, precision);
1132 if (error)
1133 break;
1134 error = selrescan(td, ibits, obits);
1135 if (error || td->td_retval[0] != 0)
1136 break;
1137 }
1138 seltdclear(td);
1139
1140 done:
1141 /* select is not restarted after signals... */
1142 if (error == ERESTART)
1143 error = EINTR;
1144 if (error == EWOULDBLOCK)
1145 error = 0;
1146
1147 /* swizzle bit order back, if necessary */
1148 swizzle_fdset(obits[0]);
1149 swizzle_fdset(obits[1]);
1150 swizzle_fdset(obits[2]);
1151 #undef swizzle_fdset
1152
1153 #define putbits(name, x) \
1154 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
1155 error = error2;
1156 if (error == 0) {
1157 int error2;
1158
1159 putbits(fd_in, 0);
1160 putbits(fd_ou, 1);
1161 putbits(fd_ex, 2);
1162 #undef putbits
1163 }
1164 if (selbits != &s_selbits[0])
1165 free(selbits, M_SELECT);
1166
1167 return (error);
1168 }
1169 /*
1170 * Convert a select bit set to poll flags.
1171 *
1172 * The backend always returns POLLHUP/POLLERR if appropriate and we
1173 * return this as a set bit in any set.
1174 */
1175 static int select_flags[3] = {
1176 POLLRDNORM | POLLHUP | POLLERR,
1177 POLLWRNORM | POLLHUP | POLLERR,
1178 POLLRDBAND | POLLERR
1179 };
1180
1181 /*
1182 * Compute the fo_poll flags required for a fd given by the index and
1183 * bit position in the fd_mask array.
1184 */
1185 static __inline int
1186 selflags(fd_mask **ibits, int idx, fd_mask bit)
1187 {
1188 int flags;
1189 int msk;
1190
1191 flags = 0;
1192 for (msk = 0; msk < 3; msk++) {
1193 if (ibits[msk] == NULL)
1194 continue;
1195 if ((ibits[msk][idx] & bit) == 0)
1196 continue;
1197 flags |= select_flags[msk];
1198 }
1199 return (flags);
1200 }
1201
1202 /*
1203 * Set the appropriate output bits given a mask of fired events and the
1204 * input bits originally requested.
1205 */
1206 static __inline int
1207 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1208 {
1209 int msk;
1210 int n;
1211
1212 n = 0;
1213 for (msk = 0; msk < 3; msk++) {
1214 if ((events & select_flags[msk]) == 0)
1215 continue;
1216 if (ibits[msk] == NULL)
1217 continue;
1218 if ((ibits[msk][idx] & bit) == 0)
1219 continue;
1220 /*
1221 * XXX Check for a duplicate set. This can occur because a
1222 * socket calls selrecord() twice for each poll() call
1223 * resulting in two selfds per real fd. selrescan() will
1224 * call selsetbits twice as a result.
1225 */
1226 if ((obits[msk][idx] & bit) != 0)
1227 continue;
1228 obits[msk][idx] |= bit;
1229 n++;
1230 }
1231
1232 return (n);
1233 }
1234
1235 static __inline int
1236 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp)
1237 {
1238 cap_rights_t rights;
1239
1240 cap_rights_init(&rights, CAP_EVENT);
1241
1242 return (fget_unlocked(fdp, fd, &rights, fpp, NULL));
1243 }
1244
1245 /*
1246 * Traverse the list of fds attached to this thread's seltd and check for
1247 * completion.
1248 */
1249 static int
1250 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1251 {
1252 struct filedesc *fdp;
1253 struct selinfo *si;
1254 struct seltd *stp;
1255 struct selfd *sfp;
1256 struct selfd *sfn;
1257 struct file *fp;
1258 fd_mask bit;
1259 int fd, ev, n, idx;
1260 int error;
1261
1262 fdp = td->td_proc->p_fd;
1263 stp = td->td_sel;
1264 n = 0;
1265 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1266 fd = (int)(uintptr_t)sfp->sf_cookie;
1267 si = sfp->sf_si;
1268 selfdfree(stp, sfp);
1269 /* If the selinfo wasn't cleared the event didn't fire. */
1270 if (si != NULL)
1271 continue;
1272 error = getselfd_cap(fdp, fd, &fp);
1273 if (error)
1274 return (error);
1275 idx = fd / NFDBITS;
1276 bit = (fd_mask)1 << (fd % NFDBITS);
1277 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1278 fdrop(fp, td);
1279 if (ev != 0)
1280 n += selsetbits(ibits, obits, idx, bit, ev);
1281 }
1282 stp->st_flags = 0;
1283 td->td_retval[0] = n;
1284 return (0);
1285 }
1286
1287 /*
1288 * Perform the initial filedescriptor scan and register ourselves with
1289 * each selinfo.
1290 */
1291 static int
1292 selscan(td, ibits, obits, nfd)
1293 struct thread *td;
1294 fd_mask **ibits, **obits;
1295 int nfd;
1296 {
1297 struct filedesc *fdp;
1298 struct file *fp;
1299 fd_mask bit;
1300 int ev, flags, end, fd;
1301 int n, idx;
1302 int error;
1303
1304 fdp = td->td_proc->p_fd;
1305 n = 0;
1306 for (idx = 0, fd = 0; fd < nfd; idx++) {
1307 end = imin(fd + NFDBITS, nfd);
1308 for (bit = 1; fd < end; bit <<= 1, fd++) {
1309 /* Compute the list of events we're interested in. */
1310 flags = selflags(ibits, idx, bit);
1311 if (flags == 0)
1312 continue;
1313 error = getselfd_cap(fdp, fd, &fp);
1314 if (error)
1315 return (error);
1316 selfdalloc(td, (void *)(uintptr_t)fd);
1317 ev = fo_poll(fp, flags, td->td_ucred, td);
1318 fdrop(fp, td);
1319 if (ev != 0)
1320 n += selsetbits(ibits, obits, idx, bit, ev);
1321 }
1322 }
1323
1324 td->td_retval[0] = n;
1325 return (0);
1326 }
1327
1328 int
1329 sys_poll(struct thread *td, struct poll_args *uap)
1330 {
1331 struct timespec ts, *tsp;
1332
1333 if (uap->timeout != INFTIM) {
1334 if (uap->timeout < 0)
1335 return (EINVAL);
1336 ts.tv_sec = uap->timeout / 1000;
1337 ts.tv_nsec = (uap->timeout % 1000) * 1000000;
1338 tsp = &ts;
1339 } else
1340 tsp = NULL;
1341
1342 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL));
1343 }
1344
1345 int
1346 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds,
1347 struct timespec *tsp, sigset_t *uset)
1348 {
1349 struct pollfd *bits;
1350 struct pollfd smallbits[32];
1351 sbintime_t sbt, precision, tmp;
1352 time_t over;
1353 struct timespec ts;
1354 int error;
1355 size_t ni;
1356
1357 precision = 0;
1358 if (tsp != NULL) {
1359 if (tsp->tv_sec < 0)
1360 return (EINVAL);
1361 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000)
1362 return (EINVAL);
1363 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
1364 sbt = 0;
1365 else {
1366 ts = *tsp;
1367 if (ts.tv_sec > INT32_MAX / 2) {
1368 over = ts.tv_sec - INT32_MAX / 2;
1369 ts.tv_sec -= over;
1370 } else
1371 over = 0;
1372 tmp = tstosbt(ts);
1373 precision = tmp;
1374 precision >>= tc_precexp;
1375 if (TIMESEL(&sbt, tmp))
1376 sbt += tc_tick_sbt;
1377 sbt += tmp;
1378 }
1379 } else
1380 sbt = -1;
1381
1382 if (nfds > maxfilesperproc && nfds > FD_SETSIZE)
1383 return (EINVAL);
1384 ni = nfds * sizeof(struct pollfd);
1385 if (ni > sizeof(smallbits))
1386 bits = malloc(ni, M_TEMP, M_WAITOK);
1387 else
1388 bits = smallbits;
1389 error = copyin(fds, bits, ni);
1390 if (error)
1391 goto done;
1392
1393 if (uset != NULL) {
1394 error = kern_sigprocmask(td, SIG_SETMASK, uset,
1395 &td->td_oldsigmask, 0);
1396 if (error)
1397 goto done;
1398 td->td_pflags |= TDP_OLDMASK;
1399 /*
1400 * Make sure that ast() is called on return to
1401 * usermode and TDP_OLDMASK is cleared, restoring old
1402 * sigmask.
1403 */
1404 thread_lock(td);
1405 td->td_flags |= TDF_ASTPENDING;
1406 thread_unlock(td);
1407 }
1408
1409 seltdinit(td);
1410 /* Iterate until the timeout expires or descriptors become ready. */
1411 for (;;) {
1412 error = pollscan(td, bits, nfds);
1413 if (error || td->td_retval[0] != 0)
1414 break;
1415 error = seltdwait(td, sbt, precision);
1416 if (error)
1417 break;
1418 error = pollrescan(td);
1419 if (error || td->td_retval[0] != 0)
1420 break;
1421 }
1422 seltdclear(td);
1423
1424 done:
1425 /* poll is not restarted after signals... */
1426 if (error == ERESTART)
1427 error = EINTR;
1428 if (error == EWOULDBLOCK)
1429 error = 0;
1430 if (error == 0) {
1431 error = pollout(td, bits, fds, nfds);
1432 if (error)
1433 goto out;
1434 }
1435 out:
1436 if (ni > sizeof(smallbits))
1437 free(bits, M_TEMP);
1438 return (error);
1439 }
1440
1441 int
1442 sys_ppoll(struct thread *td, struct ppoll_args *uap)
1443 {
1444 struct timespec ts, *tsp;
1445 sigset_t set, *ssp;
1446 int error;
1447
1448 if (uap->ts != NULL) {
1449 error = copyin(uap->ts, &ts, sizeof(ts));
1450 if (error)
1451 return (error);
1452 tsp = &ts;
1453 } else
1454 tsp = NULL;
1455 if (uap->set != NULL) {
1456 error = copyin(uap->set, &set, sizeof(set));
1457 if (error)
1458 return (error);
1459 ssp = &set;
1460 } else
1461 ssp = NULL;
1462 /*
1463 * fds is still a pointer to user space. kern_poll() will
1464 * take care of copyin that array to the kernel space.
1465 */
1466
1467 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp));
1468 }
1469
1470 static int
1471 pollrescan(struct thread *td)
1472 {
1473 struct seltd *stp;
1474 struct selfd *sfp;
1475 struct selfd *sfn;
1476 struct selinfo *si;
1477 struct filedesc *fdp;
1478 struct file *fp;
1479 struct pollfd *fd;
1480 #ifdef CAPABILITIES
1481 cap_rights_t rights;
1482 #endif
1483 int n;
1484
1485 n = 0;
1486 fdp = td->td_proc->p_fd;
1487 stp = td->td_sel;
1488 FILEDESC_SLOCK(fdp);
1489 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1490 fd = (struct pollfd *)sfp->sf_cookie;
1491 si = sfp->sf_si;
1492 selfdfree(stp, sfp);
1493 /* If the selinfo wasn't cleared the event didn't fire. */
1494 if (si != NULL)
1495 continue;
1496 fp = fdp->fd_ofiles[fd->fd].fde_file;
1497 #ifdef CAPABILITIES
1498 if (fp == NULL ||
1499 cap_check(cap_rights(fdp, fd->fd),
1500 cap_rights_init(&rights, CAP_EVENT)) != 0)
1501 #else
1502 if (fp == NULL)
1503 #endif
1504 {
1505 fd->revents = POLLNVAL;
1506 n++;
1507 continue;
1508 }
1509
1510 /*
1511 * Note: backend also returns POLLHUP and
1512 * POLLERR if appropriate.
1513 */
1514 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1515 if (fd->revents != 0)
1516 n++;
1517 }
1518 FILEDESC_SUNLOCK(fdp);
1519 stp->st_flags = 0;
1520 td->td_retval[0] = n;
1521 return (0);
1522 }
1523
1524
1525 static int
1526 pollout(td, fds, ufds, nfd)
1527 struct thread *td;
1528 struct pollfd *fds;
1529 struct pollfd *ufds;
1530 u_int nfd;
1531 {
1532 int error = 0;
1533 u_int i = 0;
1534 u_int n = 0;
1535
1536 for (i = 0; i < nfd; i++) {
1537 error = copyout(&fds->revents, &ufds->revents,
1538 sizeof(ufds->revents));
1539 if (error)
1540 return (error);
1541 if (fds->revents != 0)
1542 n++;
1543 fds++;
1544 ufds++;
1545 }
1546 td->td_retval[0] = n;
1547 return (0);
1548 }
1549
1550 static int
1551 pollscan(td, fds, nfd)
1552 struct thread *td;
1553 struct pollfd *fds;
1554 u_int nfd;
1555 {
1556 struct filedesc *fdp = td->td_proc->p_fd;
1557 struct file *fp;
1558 #ifdef CAPABILITIES
1559 cap_rights_t rights;
1560 #endif
1561 int i, n = 0;
1562
1563 FILEDESC_SLOCK(fdp);
1564 for (i = 0; i < nfd; i++, fds++) {
1565 if (fds->fd > fdp->fd_lastfile) {
1566 fds->revents = POLLNVAL;
1567 n++;
1568 } else if (fds->fd < 0) {
1569 fds->revents = 0;
1570 } else {
1571 fp = fdp->fd_ofiles[fds->fd].fde_file;
1572 #ifdef CAPABILITIES
1573 if (fp == NULL ||
1574 cap_check(cap_rights(fdp, fds->fd),
1575 cap_rights_init(&rights, CAP_EVENT)) != 0)
1576 #else
1577 if (fp == NULL)
1578 #endif
1579 {
1580 fds->revents = POLLNVAL;
1581 n++;
1582 } else {
1583 /*
1584 * Note: backend also returns POLLHUP and
1585 * POLLERR if appropriate.
1586 */
1587 selfdalloc(td, fds);
1588 fds->revents = fo_poll(fp, fds->events,
1589 td->td_ucred, td);
1590 /*
1591 * POSIX requires POLLOUT to be never
1592 * set simultaneously with POLLHUP.
1593 */
1594 if ((fds->revents & POLLHUP) != 0)
1595 fds->revents &= ~POLLOUT;
1596
1597 if (fds->revents != 0)
1598 n++;
1599 }
1600 }
1601 }
1602 FILEDESC_SUNLOCK(fdp);
1603 td->td_retval[0] = n;
1604 return (0);
1605 }
1606
1607 /*
1608 * OpenBSD poll system call.
1609 *
1610 * XXX this isn't quite a true representation.. OpenBSD uses select ops.
1611 */
1612 #ifndef _SYS_SYSPROTO_H_
1613 struct openbsd_poll_args {
1614 struct pollfd *fds;
1615 u_int nfds;
1616 int timeout;
1617 };
1618 #endif
1619 int
1620 sys_openbsd_poll(td, uap)
1621 register struct thread *td;
1622 register struct openbsd_poll_args *uap;
1623 {
1624 return (sys_poll(td, (struct poll_args *)uap));
1625 }
1626
1627 /*
1628 * XXX This was created specifically to support netncp and netsmb. This
1629 * allows the caller to specify a socket to wait for events on. It returns
1630 * 0 if any events matched and an error otherwise. There is no way to
1631 * determine which events fired.
1632 */
1633 int
1634 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1635 {
1636 struct timeval rtv;
1637 sbintime_t asbt, precision, rsbt;
1638 int error;
1639
1640 precision = 0; /* stupid gcc! */
1641 if (tvp != NULL) {
1642 rtv = *tvp;
1643 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1644 rtv.tv_usec >= 1000000)
1645 return (EINVAL);
1646 if (!timevalisset(&rtv))
1647 asbt = 0;
1648 else if (rtv.tv_sec <= INT32_MAX) {
1649 rsbt = tvtosbt(rtv);
1650 precision = rsbt;
1651 precision >>= tc_precexp;
1652 if (TIMESEL(&asbt, rsbt))
1653 asbt += tc_tick_sbt;
1654 if (asbt <= SBT_MAX - rsbt)
1655 asbt += rsbt;
1656 else
1657 asbt = -1;
1658 } else
1659 asbt = -1;
1660 } else
1661 asbt = -1;
1662 seltdinit(td);
1663 /*
1664 * Iterate until the timeout expires or the socket becomes ready.
1665 */
1666 for (;;) {
1667 selfdalloc(td, NULL);
1668 error = sopoll(so, events, NULL, td);
1669 /* error here is actually the ready events. */
1670 if (error)
1671 return (0);
1672 error = seltdwait(td, asbt, precision);
1673 if (error)
1674 break;
1675 }
1676 seltdclear(td);
1677 /* XXX Duplicates ncp/smb behavior. */
1678 if (error == ERESTART)
1679 error = 0;
1680 return (error);
1681 }
1682
1683 /*
1684 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1685 * have two select sets, one for read and another for write.
1686 */
1687 static void
1688 selfdalloc(struct thread *td, void *cookie)
1689 {
1690 struct seltd *stp;
1691
1692 stp = td->td_sel;
1693 if (stp->st_free1 == NULL)
1694 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1695 stp->st_free1->sf_td = stp;
1696 stp->st_free1->sf_cookie = cookie;
1697 if (stp->st_free2 == NULL)
1698 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1699 stp->st_free2->sf_td = stp;
1700 stp->st_free2->sf_cookie = cookie;
1701 }
1702
1703 static void
1704 selfdfree(struct seltd *stp, struct selfd *sfp)
1705 {
1706 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1707 if (sfp->sf_si != NULL) {
1708 mtx_lock(sfp->sf_mtx);
1709 if (sfp->sf_si != NULL) {
1710 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1711 refcount_release(&sfp->sf_refs);
1712 }
1713 mtx_unlock(sfp->sf_mtx);
1714 }
1715 if (refcount_release(&sfp->sf_refs))
1716 uma_zfree(selfd_zone, sfp);
1717 }
1718
1719 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
1720 void
1721 seldrain(sip)
1722 struct selinfo *sip;
1723 {
1724
1725 /*
1726 * This feature is already provided by doselwakeup(), thus it is
1727 * enough to go for it.
1728 * Eventually, the context, should take care to avoid races
1729 * between thread calling select()/poll() and file descriptor
1730 * detaching, but, again, the races are just the same as
1731 * selwakeup().
1732 */
1733 doselwakeup(sip, -1);
1734 }
1735
1736 /*
1737 * Record a select request.
1738 */
1739 void
1740 selrecord(selector, sip)
1741 struct thread *selector;
1742 struct selinfo *sip;
1743 {
1744 struct selfd *sfp;
1745 struct seltd *stp;
1746 struct mtx *mtxp;
1747
1748 stp = selector->td_sel;
1749 /*
1750 * Don't record when doing a rescan.
1751 */
1752 if (stp->st_flags & SELTD_RESCAN)
1753 return;
1754 /*
1755 * Grab one of the preallocated descriptors.
1756 */
1757 sfp = NULL;
1758 if ((sfp = stp->st_free1) != NULL)
1759 stp->st_free1 = NULL;
1760 else if ((sfp = stp->st_free2) != NULL)
1761 stp->st_free2 = NULL;
1762 else
1763 panic("selrecord: No free selfd on selq");
1764 mtxp = sip->si_mtx;
1765 if (mtxp == NULL)
1766 mtxp = mtx_pool_find(mtxpool_select, sip);
1767 /*
1768 * Initialize the sfp and queue it in the thread.
1769 */
1770 sfp->sf_si = sip;
1771 sfp->sf_mtx = mtxp;
1772 refcount_init(&sfp->sf_refs, 2);
1773 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1774 /*
1775 * Now that we've locked the sip, check for initialization.
1776 */
1777 mtx_lock(mtxp);
1778 if (sip->si_mtx == NULL) {
1779 sip->si_mtx = mtxp;
1780 TAILQ_INIT(&sip->si_tdlist);
1781 }
1782 /*
1783 * Add this thread to the list of selfds listening on this selinfo.
1784 */
1785 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1786 mtx_unlock(sip->si_mtx);
1787 }
1788
1789 /* Wake up a selecting thread. */
1790 void
1791 selwakeup(sip)
1792 struct selinfo *sip;
1793 {
1794 doselwakeup(sip, -1);
1795 }
1796
1797 /* Wake up a selecting thread, and set its priority. */
1798 void
1799 selwakeuppri(sip, pri)
1800 struct selinfo *sip;
1801 int pri;
1802 {
1803 doselwakeup(sip, pri);
1804 }
1805
1806 /*
1807 * Do a wakeup when a selectable event occurs.
1808 */
1809 static void
1810 doselwakeup(sip, pri)
1811 struct selinfo *sip;
1812 int pri;
1813 {
1814 struct selfd *sfp;
1815 struct selfd *sfn;
1816 struct seltd *stp;
1817
1818 /* If it's not initialized there can't be any waiters. */
1819 if (sip->si_mtx == NULL)
1820 return;
1821 /*
1822 * Locking the selinfo locks all selfds associated with it.
1823 */
1824 mtx_lock(sip->si_mtx);
1825 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1826 /*
1827 * Once we remove this sfp from the list and clear the
1828 * sf_si seltdclear will know to ignore this si.
1829 */
1830 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1831 sfp->sf_si = NULL;
1832 stp = sfp->sf_td;
1833 mtx_lock(&stp->st_mtx);
1834 stp->st_flags |= SELTD_PENDING;
1835 cv_broadcastpri(&stp->st_wait, pri);
1836 mtx_unlock(&stp->st_mtx);
1837 if (refcount_release(&sfp->sf_refs))
1838 uma_zfree(selfd_zone, sfp);
1839 }
1840 mtx_unlock(sip->si_mtx);
1841 }
1842
1843 static void
1844 seltdinit(struct thread *td)
1845 {
1846 struct seltd *stp;
1847
1848 if ((stp = td->td_sel) != NULL)
1849 goto out;
1850 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1851 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1852 cv_init(&stp->st_wait, "select");
1853 out:
1854 stp->st_flags = 0;
1855 STAILQ_INIT(&stp->st_selq);
1856 }
1857
1858 static int
1859 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision)
1860 {
1861 struct seltd *stp;
1862 int error;
1863
1864 stp = td->td_sel;
1865 /*
1866 * An event of interest may occur while we do not hold the seltd
1867 * locked so check the pending flag before we sleep.
1868 */
1869 mtx_lock(&stp->st_mtx);
1870 /*
1871 * Any further calls to selrecord will be a rescan.
1872 */
1873 stp->st_flags |= SELTD_RESCAN;
1874 if (stp->st_flags & SELTD_PENDING) {
1875 mtx_unlock(&stp->st_mtx);
1876 return (0);
1877 }
1878 if (sbt == 0)
1879 error = EWOULDBLOCK;
1880 else if (sbt != -1)
1881 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx,
1882 sbt, precision, C_ABSOLUTE);
1883 else
1884 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
1885 mtx_unlock(&stp->st_mtx);
1886
1887 return (error);
1888 }
1889
1890 void
1891 seltdfini(struct thread *td)
1892 {
1893 struct seltd *stp;
1894
1895 stp = td->td_sel;
1896 if (stp == NULL)
1897 return;
1898 if (stp->st_free1)
1899 uma_zfree(selfd_zone, stp->st_free1);
1900 if (stp->st_free2)
1901 uma_zfree(selfd_zone, stp->st_free2);
1902 td->td_sel = NULL;
1903 free(stp, M_SELECT);
1904 }
1905
1906 /*
1907 * Remove the references to the thread from all of the objects we were
1908 * polling.
1909 */
1910 static void
1911 seltdclear(struct thread *td)
1912 {
1913 struct seltd *stp;
1914 struct selfd *sfp;
1915 struct selfd *sfn;
1916
1917 stp = td->td_sel;
1918 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
1919 selfdfree(stp, sfp);
1920 stp->st_flags = 0;
1921 }
1922
1923 static void selectinit(void *);
1924 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
1925 static void
1926 selectinit(void *dummy __unused)
1927 {
1928
1929 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
1930 NULL, NULL, UMA_ALIGN_PTR, 0);
1931 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
1932 }
1933
1934 /*
1935 * Set up a syscall return value that follows the convention specified for
1936 * posix_* functions.
1937 */
1938 int
1939 kern_posix_error(struct thread *td, int error)
1940 {
1941
1942 if (error <= 0)
1943 return (error);
1944 td->td_errno = error;
1945 td->td_pflags |= TDP_NERRNO;
1946 td->td_retval[0] = error;
1947 return (0);
1948 }
Cache object: 30720027b3f577b400ad191c51753527
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