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/11.1/sys/kern/sys_generic.c 315553 2017-03-19 14:46:40Z trasz $");
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(struct thread *td, struct pread_args *uap)
224 {
225
226 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
227 }
228
229 int
230 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset)
231 {
232 struct uio auio;
233 struct iovec aiov;
234 int error;
235
236 if (nbyte > IOSIZE_MAX)
237 return (EINVAL);
238 aiov.iov_base = buf;
239 aiov.iov_len = nbyte;
240 auio.uio_iov = &aiov;
241 auio.uio_iovcnt = 1;
242 auio.uio_resid = nbyte;
243 auio.uio_segflg = UIO_USERSPACE;
244 error = kern_preadv(td, fd, &auio, offset);
245 return (error);
246 }
247
248 #if defined(COMPAT_FREEBSD6)
249 int
250 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap)
251 {
252
253 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
254 }
255 #endif
256
257 /*
258 * Scatter read system call.
259 */
260 #ifndef _SYS_SYSPROTO_H_
261 struct readv_args {
262 int fd;
263 struct iovec *iovp;
264 u_int iovcnt;
265 };
266 #endif
267 int
268 sys_readv(struct thread *td, struct readv_args *uap)
269 {
270 struct uio *auio;
271 int error;
272
273 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
274 if (error)
275 return (error);
276 error = kern_readv(td, uap->fd, auio);
277 free(auio, M_IOV);
278 return (error);
279 }
280
281 int
282 kern_readv(struct thread *td, int fd, struct uio *auio)
283 {
284 struct file *fp;
285 cap_rights_t rights;
286 int error;
287
288 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
289 if (error)
290 return (error);
291 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
292 fdrop(fp, td);
293 return (error);
294 }
295
296 /*
297 * Scatter positioned read system call.
298 */
299 #ifndef _SYS_SYSPROTO_H_
300 struct preadv_args {
301 int fd;
302 struct iovec *iovp;
303 u_int iovcnt;
304 off_t offset;
305 };
306 #endif
307 int
308 sys_preadv(struct thread *td, struct preadv_args *uap)
309 {
310 struct uio *auio;
311 int error;
312
313 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
314 if (error)
315 return (error);
316 error = kern_preadv(td, uap->fd, auio, uap->offset);
317 free(auio, M_IOV);
318 return (error);
319 }
320
321 int
322 kern_preadv(td, fd, auio, offset)
323 struct thread *td;
324 int fd;
325 struct uio *auio;
326 off_t offset;
327 {
328 struct file *fp;
329 cap_rights_t rights;
330 int error;
331
332 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp);
333 if (error)
334 return (error);
335 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
336 error = ESPIPE;
337 else if (offset < 0 &&
338 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR))
339 error = EINVAL;
340 else
341 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
342 fdrop(fp, td);
343 return (error);
344 }
345
346 /*
347 * Common code for readv and preadv that reads data in
348 * from a file using the passed in uio, offset, and flags.
349 */
350 static int
351 dofileread(td, fd, fp, auio, offset, flags)
352 struct thread *td;
353 int fd;
354 struct file *fp;
355 struct uio *auio;
356 off_t offset;
357 int flags;
358 {
359 ssize_t cnt;
360 int error;
361 #ifdef KTRACE
362 struct uio *ktruio = NULL;
363 #endif
364
365 AUDIT_ARG_FD(fd);
366
367 /* Finish zero length reads right here */
368 if (auio->uio_resid == 0) {
369 td->td_retval[0] = 0;
370 return(0);
371 }
372 auio->uio_rw = UIO_READ;
373 auio->uio_offset = offset;
374 auio->uio_td = td;
375 #ifdef KTRACE
376 if (KTRPOINT(td, KTR_GENIO))
377 ktruio = cloneuio(auio);
378 #endif
379 cnt = auio->uio_resid;
380 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
381 if (auio->uio_resid != cnt && (error == ERESTART ||
382 error == EINTR || error == EWOULDBLOCK))
383 error = 0;
384 }
385 cnt -= auio->uio_resid;
386 #ifdef KTRACE
387 if (ktruio != NULL) {
388 ktruio->uio_resid = cnt;
389 ktrgenio(fd, UIO_READ, ktruio, error);
390 }
391 #endif
392 td->td_retval[0] = cnt;
393 return (error);
394 }
395
396 #ifndef _SYS_SYSPROTO_H_
397 struct write_args {
398 int fd;
399 const void *buf;
400 size_t nbyte;
401 };
402 #endif
403 int
404 sys_write(td, uap)
405 struct thread *td;
406 struct write_args *uap;
407 {
408 struct uio auio;
409 struct iovec aiov;
410 int error;
411
412 if (uap->nbyte > IOSIZE_MAX)
413 return (EINVAL);
414 aiov.iov_base = (void *)(uintptr_t)uap->buf;
415 aiov.iov_len = uap->nbyte;
416 auio.uio_iov = &aiov;
417 auio.uio_iovcnt = 1;
418 auio.uio_resid = uap->nbyte;
419 auio.uio_segflg = UIO_USERSPACE;
420 error = kern_writev(td, uap->fd, &auio);
421 return(error);
422 }
423
424 /*
425 * Positioned write system call.
426 */
427 #ifndef _SYS_SYSPROTO_H_
428 struct pwrite_args {
429 int fd;
430 const void *buf;
431 size_t nbyte;
432 int pad;
433 off_t offset;
434 };
435 #endif
436 int
437 sys_pwrite(struct thread *td, struct pwrite_args *uap)
438 {
439
440 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
441 }
442
443 int
444 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte,
445 off_t offset)
446 {
447 struct uio auio;
448 struct iovec aiov;
449 int error;
450
451 if (nbyte > IOSIZE_MAX)
452 return (EINVAL);
453 aiov.iov_base = (void *)(uintptr_t)buf;
454 aiov.iov_len = nbyte;
455 auio.uio_iov = &aiov;
456 auio.uio_iovcnt = 1;
457 auio.uio_resid = nbyte;
458 auio.uio_segflg = UIO_USERSPACE;
459 error = kern_pwritev(td, fd, &auio, offset);
460 return(error);
461 }
462
463 #if defined(COMPAT_FREEBSD6)
464 int
465 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap)
466 {
467
468 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
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 &&
553 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR))
554 error = EINVAL;
555 else
556 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
557 fdrop(fp, td);
558 return (error);
559 }
560
561 /*
562 * Common code for writev and pwritev that writes data to
563 * a file using the passed in uio, offset, and flags.
564 */
565 static int
566 dofilewrite(td, fd, fp, auio, offset, flags)
567 struct thread *td;
568 int fd;
569 struct file *fp;
570 struct uio *auio;
571 off_t offset;
572 int flags;
573 {
574 ssize_t cnt;
575 int error;
576 #ifdef KTRACE
577 struct uio *ktruio = NULL;
578 #endif
579
580 AUDIT_ARG_FD(fd);
581 auio->uio_rw = UIO_WRITE;
582 auio->uio_td = td;
583 auio->uio_offset = offset;
584 #ifdef KTRACE
585 if (KTRPOINT(td, KTR_GENIO))
586 ktruio = cloneuio(auio);
587 #endif
588 cnt = auio->uio_resid;
589 if (fp->f_type == DTYPE_VNODE &&
590 (fp->f_vnread_flags & FDEVFS_VNODE) == 0)
591 bwillwrite();
592 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
593 if (auio->uio_resid != cnt && (error == ERESTART ||
594 error == EINTR || error == EWOULDBLOCK))
595 error = 0;
596 /* Socket layer is responsible for issuing SIGPIPE. */
597 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
598 PROC_LOCK(td->td_proc);
599 tdsignal(td, SIGPIPE);
600 PROC_UNLOCK(td->td_proc);
601 }
602 }
603 cnt -= auio->uio_resid;
604 #ifdef KTRACE
605 if (ktruio != NULL) {
606 ktruio->uio_resid = cnt;
607 ktrgenio(fd, UIO_WRITE, ktruio, error);
608 }
609 #endif
610 td->td_retval[0] = cnt;
611 return (error);
612 }
613
614 /*
615 * Truncate a file given a file descriptor.
616 *
617 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
618 * descriptor isn't writable.
619 */
620 int
621 kern_ftruncate(td, fd, length)
622 struct thread *td;
623 int fd;
624 off_t length;
625 {
626 struct file *fp;
627 cap_rights_t rights;
628 int error;
629
630 AUDIT_ARG_FD(fd);
631 if (length < 0)
632 return (EINVAL);
633 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp);
634 if (error)
635 return (error);
636 AUDIT_ARG_FILE(td->td_proc, fp);
637 if (!(fp->f_flag & FWRITE)) {
638 fdrop(fp, td);
639 return (EINVAL);
640 }
641 error = fo_truncate(fp, length, td->td_ucred, td);
642 fdrop(fp, td);
643 return (error);
644 }
645
646 #ifndef _SYS_SYSPROTO_H_
647 struct ftruncate_args {
648 int fd;
649 int pad;
650 off_t length;
651 };
652 #endif
653 int
654 sys_ftruncate(td, uap)
655 struct thread *td;
656 struct ftruncate_args *uap;
657 {
658
659 return (kern_ftruncate(td, uap->fd, uap->length));
660 }
661
662 #if defined(COMPAT_43)
663 #ifndef _SYS_SYSPROTO_H_
664 struct oftruncate_args {
665 int fd;
666 long length;
667 };
668 #endif
669 int
670 oftruncate(td, uap)
671 struct thread *td;
672 struct oftruncate_args *uap;
673 {
674
675 return (kern_ftruncate(td, uap->fd, uap->length));
676 }
677 #endif /* COMPAT_43 */
678
679 #ifndef _SYS_SYSPROTO_H_
680 struct ioctl_args {
681 int fd;
682 u_long com;
683 caddr_t data;
684 };
685 #endif
686 /* ARGSUSED */
687 int
688 sys_ioctl(struct thread *td, struct ioctl_args *uap)
689 {
690 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
691 u_long com;
692 int arg, error;
693 u_int size;
694 caddr_t data;
695
696 if (uap->com > 0xffffffff) {
697 printf(
698 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
699 td->td_proc->p_pid, td->td_name, uap->com);
700 uap->com &= 0xffffffff;
701 }
702 com = uap->com;
703
704 /*
705 * Interpret high order word to find amount of data to be
706 * copied to/from the user's address space.
707 */
708 size = IOCPARM_LEN(com);
709 if ((size > IOCPARM_MAX) ||
710 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
711 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
712 ((com & IOC_OUT) && size == 0) ||
713 #else
714 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
715 #endif
716 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
717 return (ENOTTY);
718
719 if (size > 0) {
720 if (com & IOC_VOID) {
721 /* Integer argument. */
722 arg = (intptr_t)uap->data;
723 data = (void *)&arg;
724 size = 0;
725 } else {
726 if (size > SYS_IOCTL_SMALL_SIZE)
727 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
728 else
729 data = smalldata;
730 }
731 } else
732 data = (void *)&uap->data;
733 if (com & IOC_IN) {
734 error = copyin(uap->data, data, (u_int)size);
735 if (error != 0)
736 goto out;
737 } else if (com & IOC_OUT) {
738 /*
739 * Zero the buffer so the user always
740 * gets back something deterministic.
741 */
742 bzero(data, size);
743 }
744
745 error = kern_ioctl(td, uap->fd, com, data);
746
747 if (error == 0 && (com & IOC_OUT))
748 error = copyout(data, uap->data, (u_int)size);
749
750 out:
751 if (size > SYS_IOCTL_SMALL_SIZE)
752 free(data, M_IOCTLOPS);
753 return (error);
754 }
755
756 int
757 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
758 {
759 struct file *fp;
760 struct filedesc *fdp;
761 #ifndef CAPABILITIES
762 cap_rights_t rights;
763 #endif
764 int error, tmp, locked;
765
766 AUDIT_ARG_FD(fd);
767 AUDIT_ARG_CMD(com);
768
769 fdp = td->td_proc->p_fd;
770
771 switch (com) {
772 case FIONCLEX:
773 case FIOCLEX:
774 FILEDESC_XLOCK(fdp);
775 locked = LA_XLOCKED;
776 break;
777 default:
778 #ifdef CAPABILITIES
779 FILEDESC_SLOCK(fdp);
780 locked = LA_SLOCKED;
781 #else
782 locked = LA_UNLOCKED;
783 #endif
784 break;
785 }
786
787 #ifdef CAPABILITIES
788 if ((fp = fget_locked(fdp, fd)) == NULL) {
789 error = EBADF;
790 goto out;
791 }
792 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
793 fp = NULL; /* fhold() was not called yet */
794 goto out;
795 }
796 fhold(fp);
797 if (locked == LA_SLOCKED) {
798 FILEDESC_SUNLOCK(fdp);
799 locked = LA_UNLOCKED;
800 }
801 #else
802 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
803 if (error != 0) {
804 fp = NULL;
805 goto out;
806 }
807 #endif
808 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
809 error = EBADF;
810 goto out;
811 }
812
813 switch (com) {
814 case FIONCLEX:
815 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
816 goto out;
817 case FIOCLEX:
818 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
819 goto out;
820 case FIONBIO:
821 if ((tmp = *(int *)data))
822 atomic_set_int(&fp->f_flag, FNONBLOCK);
823 else
824 atomic_clear_int(&fp->f_flag, FNONBLOCK);
825 data = (void *)&tmp;
826 break;
827 case FIOASYNC:
828 if ((tmp = *(int *)data))
829 atomic_set_int(&fp->f_flag, FASYNC);
830 else
831 atomic_clear_int(&fp->f_flag, FASYNC);
832 data = (void *)&tmp;
833 break;
834 }
835
836 error = fo_ioctl(fp, com, data, td->td_ucred, td);
837 out:
838 switch (locked) {
839 case LA_XLOCKED:
840 FILEDESC_XUNLOCK(fdp);
841 break;
842 #ifdef CAPABILITIES
843 case LA_SLOCKED:
844 FILEDESC_SUNLOCK(fdp);
845 break;
846 #endif
847 default:
848 FILEDESC_UNLOCK_ASSERT(fdp);
849 break;
850 }
851 if (fp != NULL)
852 fdrop(fp, td);
853 return (error);
854 }
855
856 int
857 poll_no_poll(int events)
858 {
859 /*
860 * Return true for read/write. If the user asked for something
861 * special, return POLLNVAL, so that clients have a way of
862 * determining reliably whether or not the extended
863 * functionality is present without hard-coding knowledge
864 * of specific filesystem implementations.
865 */
866 if (events & ~POLLSTANDARD)
867 return (POLLNVAL);
868
869 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
870 }
871
872 int
873 sys_pselect(struct thread *td, struct pselect_args *uap)
874 {
875 struct timespec ts;
876 struct timeval tv, *tvp;
877 sigset_t set, *uset;
878 int error;
879
880 if (uap->ts != NULL) {
881 error = copyin(uap->ts, &ts, sizeof(ts));
882 if (error != 0)
883 return (error);
884 TIMESPEC_TO_TIMEVAL(&tv, &ts);
885 tvp = &tv;
886 } else
887 tvp = NULL;
888 if (uap->sm != NULL) {
889 error = copyin(uap->sm, &set, sizeof(set));
890 if (error != 0)
891 return (error);
892 uset = &set;
893 } else
894 uset = NULL;
895 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
896 uset, NFDBITS));
897 }
898
899 int
900 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
901 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
902 {
903 int error;
904
905 if (uset != NULL) {
906 error = kern_sigprocmask(td, SIG_SETMASK, uset,
907 &td->td_oldsigmask, 0);
908 if (error != 0)
909 return (error);
910 td->td_pflags |= TDP_OLDMASK;
911 /*
912 * Make sure that ast() is called on return to
913 * usermode and TDP_OLDMASK is cleared, restoring old
914 * sigmask.
915 */
916 thread_lock(td);
917 td->td_flags |= TDF_ASTPENDING;
918 thread_unlock(td);
919 }
920 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
921 return (error);
922 }
923
924 #ifndef _SYS_SYSPROTO_H_
925 struct select_args {
926 int nd;
927 fd_set *in, *ou, *ex;
928 struct timeval *tv;
929 };
930 #endif
931 int
932 sys_select(struct thread *td, struct select_args *uap)
933 {
934 struct timeval tv, *tvp;
935 int error;
936
937 if (uap->tv != NULL) {
938 error = copyin(uap->tv, &tv, sizeof(tv));
939 if (error)
940 return (error);
941 tvp = &tv;
942 } else
943 tvp = NULL;
944
945 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
946 NFDBITS));
947 }
948
949 /*
950 * In the unlikely case when user specified n greater then the last
951 * open file descriptor, check that no bits are set after the last
952 * valid fd. We must return EBADF if any is set.
953 *
954 * There are applications that rely on the behaviour.
955 *
956 * nd is fd_lastfile + 1.
957 */
958 static int
959 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
960 {
961 char *addr, *oaddr;
962 int b, i, res;
963 uint8_t bits;
964
965 if (nd >= ndu || fd_in == NULL)
966 return (0);
967
968 oaddr = NULL;
969 bits = 0; /* silence gcc */
970 for (i = nd; i < ndu; i++) {
971 b = i / NBBY;
972 #if BYTE_ORDER == LITTLE_ENDIAN
973 addr = (char *)fd_in + b;
974 #else
975 addr = (char *)fd_in;
976 if (abi_nfdbits == NFDBITS) {
977 addr += rounddown(b, sizeof(fd_mask)) +
978 sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
979 } else {
980 addr += rounddown(b, sizeof(uint32_t)) +
981 sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
982 }
983 #endif
984 if (addr != oaddr) {
985 res = fubyte(addr);
986 if (res == -1)
987 return (EFAULT);
988 oaddr = addr;
989 bits = res;
990 }
991 if ((bits & (1 << (i % NBBY))) != 0)
992 return (EBADF);
993 }
994 return (0);
995 }
996
997 int
998 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
999 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
1000 {
1001 struct filedesc *fdp;
1002 /*
1003 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
1004 * infds with the new FD_SETSIZE of 1024, and more than enough for
1005 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
1006 * of 256.
1007 */
1008 fd_mask s_selbits[howmany(2048, NFDBITS)];
1009 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
1010 struct timeval rtv;
1011 sbintime_t asbt, precision, rsbt;
1012 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
1013 int error, lf, ndu;
1014
1015 if (nd < 0)
1016 return (EINVAL);
1017 fdp = td->td_proc->p_fd;
1018 ndu = nd;
1019 lf = fdp->fd_lastfile;
1020 if (nd > lf + 1)
1021 nd = lf + 1;
1022
1023 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
1024 if (error != 0)
1025 return (error);
1026 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
1027 if (error != 0)
1028 return (error);
1029 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
1030 if (error != 0)
1031 return (error);
1032
1033 /*
1034 * Allocate just enough bits for the non-null fd_sets. Use the
1035 * preallocated auto buffer if possible.
1036 */
1037 nfdbits = roundup(nd, NFDBITS);
1038 ncpbytes = nfdbits / NBBY;
1039 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
1040 nbufbytes = 0;
1041 if (fd_in != NULL)
1042 nbufbytes += 2 * ncpbytes;
1043 if (fd_ou != NULL)
1044 nbufbytes += 2 * ncpbytes;
1045 if (fd_ex != NULL)
1046 nbufbytes += 2 * ncpbytes;
1047 if (nbufbytes <= sizeof s_selbits)
1048 selbits = &s_selbits[0];
1049 else
1050 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
1051
1052 /*
1053 * Assign pointers into the bit buffers and fetch the input bits.
1054 * Put the output buffers together so that they can be bzeroed
1055 * together.
1056 */
1057 sbp = selbits;
1058 #define getbits(name, x) \
1059 do { \
1060 if (name == NULL) { \
1061 ibits[x] = NULL; \
1062 obits[x] = NULL; \
1063 } else { \
1064 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
1065 obits[x] = sbp; \
1066 sbp += ncpbytes / sizeof *sbp; \
1067 error = copyin(name, ibits[x], ncpubytes); \
1068 if (error != 0) \
1069 goto done; \
1070 bzero((char *)ibits[x] + ncpubytes, \
1071 ncpbytes - ncpubytes); \
1072 } \
1073 } while (0)
1074 getbits(fd_in, 0);
1075 getbits(fd_ou, 1);
1076 getbits(fd_ex, 2);
1077 #undef getbits
1078
1079 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
1080 /*
1081 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
1082 * we are running under 32-bit emulation. This should be more
1083 * generic.
1084 */
1085 #define swizzle_fdset(bits) \
1086 if (abi_nfdbits != NFDBITS && bits != NULL) { \
1087 int i; \
1088 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
1089 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
1090 }
1091 #else
1092 #define swizzle_fdset(bits)
1093 #endif
1094
1095 /* Make sure the bit order makes it through an ABI transition */
1096 swizzle_fdset(ibits[0]);
1097 swizzle_fdset(ibits[1]);
1098 swizzle_fdset(ibits[2]);
1099
1100 if (nbufbytes != 0)
1101 bzero(selbits, nbufbytes / 2);
1102
1103 precision = 0;
1104 if (tvp != NULL) {
1105 rtv = *tvp;
1106 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1107 rtv.tv_usec >= 1000000) {
1108 error = EINVAL;
1109 goto done;
1110 }
1111 if (!timevalisset(&rtv))
1112 asbt = 0;
1113 else if (rtv.tv_sec <= INT32_MAX) {
1114 rsbt = tvtosbt(rtv);
1115 precision = rsbt;
1116 precision >>= tc_precexp;
1117 if (TIMESEL(&asbt, rsbt))
1118 asbt += tc_tick_sbt;
1119 if (asbt <= SBT_MAX - rsbt)
1120 asbt += rsbt;
1121 else
1122 asbt = -1;
1123 } else
1124 asbt = -1;
1125 } else
1126 asbt = -1;
1127 seltdinit(td);
1128 /* Iterate until the timeout expires or descriptors become ready. */
1129 for (;;) {
1130 error = selscan(td, ibits, obits, nd);
1131 if (error || td->td_retval[0] != 0)
1132 break;
1133 error = seltdwait(td, asbt, precision);
1134 if (error)
1135 break;
1136 error = selrescan(td, ibits, obits);
1137 if (error || td->td_retval[0] != 0)
1138 break;
1139 }
1140 seltdclear(td);
1141
1142 done:
1143 /* select is not restarted after signals... */
1144 if (error == ERESTART)
1145 error = EINTR;
1146 if (error == EWOULDBLOCK)
1147 error = 0;
1148
1149 /* swizzle bit order back, if necessary */
1150 swizzle_fdset(obits[0]);
1151 swizzle_fdset(obits[1]);
1152 swizzle_fdset(obits[2]);
1153 #undef swizzle_fdset
1154
1155 #define putbits(name, x) \
1156 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
1157 error = error2;
1158 if (error == 0) {
1159 int error2;
1160
1161 putbits(fd_in, 0);
1162 putbits(fd_ou, 1);
1163 putbits(fd_ex, 2);
1164 #undef putbits
1165 }
1166 if (selbits != &s_selbits[0])
1167 free(selbits, M_SELECT);
1168
1169 return (error);
1170 }
1171 /*
1172 * Convert a select bit set to poll flags.
1173 *
1174 * The backend always returns POLLHUP/POLLERR if appropriate and we
1175 * return this as a set bit in any set.
1176 */
1177 static int select_flags[3] = {
1178 POLLRDNORM | POLLHUP | POLLERR,
1179 POLLWRNORM | POLLHUP | POLLERR,
1180 POLLRDBAND | POLLERR
1181 };
1182
1183 /*
1184 * Compute the fo_poll flags required for a fd given by the index and
1185 * bit position in the fd_mask array.
1186 */
1187 static __inline int
1188 selflags(fd_mask **ibits, int idx, fd_mask bit)
1189 {
1190 int flags;
1191 int msk;
1192
1193 flags = 0;
1194 for (msk = 0; msk < 3; msk++) {
1195 if (ibits[msk] == NULL)
1196 continue;
1197 if ((ibits[msk][idx] & bit) == 0)
1198 continue;
1199 flags |= select_flags[msk];
1200 }
1201 return (flags);
1202 }
1203
1204 /*
1205 * Set the appropriate output bits given a mask of fired events and the
1206 * input bits originally requested.
1207 */
1208 static __inline int
1209 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1210 {
1211 int msk;
1212 int n;
1213
1214 n = 0;
1215 for (msk = 0; msk < 3; msk++) {
1216 if ((events & select_flags[msk]) == 0)
1217 continue;
1218 if (ibits[msk] == NULL)
1219 continue;
1220 if ((ibits[msk][idx] & bit) == 0)
1221 continue;
1222 /*
1223 * XXX Check for a duplicate set. This can occur because a
1224 * socket calls selrecord() twice for each poll() call
1225 * resulting in two selfds per real fd. selrescan() will
1226 * call selsetbits twice as a result.
1227 */
1228 if ((obits[msk][idx] & bit) != 0)
1229 continue;
1230 obits[msk][idx] |= bit;
1231 n++;
1232 }
1233
1234 return (n);
1235 }
1236
1237 static __inline int
1238 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp)
1239 {
1240 cap_rights_t rights;
1241
1242 cap_rights_init(&rights, CAP_EVENT);
1243
1244 return (fget_unlocked(fdp, fd, &rights, fpp, NULL));
1245 }
1246
1247 /*
1248 * Traverse the list of fds attached to this thread's seltd and check for
1249 * completion.
1250 */
1251 static int
1252 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1253 {
1254 struct filedesc *fdp;
1255 struct selinfo *si;
1256 struct seltd *stp;
1257 struct selfd *sfp;
1258 struct selfd *sfn;
1259 struct file *fp;
1260 fd_mask bit;
1261 int fd, ev, n, idx;
1262 int error;
1263
1264 fdp = td->td_proc->p_fd;
1265 stp = td->td_sel;
1266 n = 0;
1267 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1268 fd = (int)(uintptr_t)sfp->sf_cookie;
1269 si = sfp->sf_si;
1270 selfdfree(stp, sfp);
1271 /* If the selinfo wasn't cleared the event didn't fire. */
1272 if (si != NULL)
1273 continue;
1274 error = getselfd_cap(fdp, fd, &fp);
1275 if (error)
1276 return (error);
1277 idx = fd / NFDBITS;
1278 bit = (fd_mask)1 << (fd % NFDBITS);
1279 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1280 fdrop(fp, td);
1281 if (ev != 0)
1282 n += selsetbits(ibits, obits, idx, bit, ev);
1283 }
1284 stp->st_flags = 0;
1285 td->td_retval[0] = n;
1286 return (0);
1287 }
1288
1289 /*
1290 * Perform the initial filedescriptor scan and register ourselves with
1291 * each selinfo.
1292 */
1293 static int
1294 selscan(td, ibits, obits, nfd)
1295 struct thread *td;
1296 fd_mask **ibits, **obits;
1297 int nfd;
1298 {
1299 struct filedesc *fdp;
1300 struct file *fp;
1301 fd_mask bit;
1302 int ev, flags, end, fd;
1303 int n, idx;
1304 int error;
1305
1306 fdp = td->td_proc->p_fd;
1307 n = 0;
1308 for (idx = 0, fd = 0; fd < nfd; idx++) {
1309 end = imin(fd + NFDBITS, nfd);
1310 for (bit = 1; fd < end; bit <<= 1, fd++) {
1311 /* Compute the list of events we're interested in. */
1312 flags = selflags(ibits, idx, bit);
1313 if (flags == 0)
1314 continue;
1315 error = getselfd_cap(fdp, fd, &fp);
1316 if (error)
1317 return (error);
1318 selfdalloc(td, (void *)(uintptr_t)fd);
1319 ev = fo_poll(fp, flags, td->td_ucred, td);
1320 fdrop(fp, td);
1321 if (ev != 0)
1322 n += selsetbits(ibits, obits, idx, bit, ev);
1323 }
1324 }
1325
1326 td->td_retval[0] = n;
1327 return (0);
1328 }
1329
1330 int
1331 sys_poll(struct thread *td, struct poll_args *uap)
1332 {
1333 struct timespec ts, *tsp;
1334
1335 if (uap->timeout != INFTIM) {
1336 if (uap->timeout < 0)
1337 return (EINVAL);
1338 ts.tv_sec = uap->timeout / 1000;
1339 ts.tv_nsec = (uap->timeout % 1000) * 1000000;
1340 tsp = &ts;
1341 } else
1342 tsp = NULL;
1343
1344 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL));
1345 }
1346
1347 int
1348 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds,
1349 struct timespec *tsp, sigset_t *uset)
1350 {
1351 struct pollfd *bits;
1352 struct pollfd smallbits[32];
1353 sbintime_t sbt, precision, tmp;
1354 time_t over;
1355 struct timespec ts;
1356 int error;
1357 size_t ni;
1358
1359 precision = 0;
1360 if (tsp != NULL) {
1361 if (tsp->tv_sec < 0)
1362 return (EINVAL);
1363 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000)
1364 return (EINVAL);
1365 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
1366 sbt = 0;
1367 else {
1368 ts = *tsp;
1369 if (ts.tv_sec > INT32_MAX / 2) {
1370 over = ts.tv_sec - INT32_MAX / 2;
1371 ts.tv_sec -= over;
1372 } else
1373 over = 0;
1374 tmp = tstosbt(ts);
1375 precision = tmp;
1376 precision >>= tc_precexp;
1377 if (TIMESEL(&sbt, tmp))
1378 sbt += tc_tick_sbt;
1379 sbt += tmp;
1380 }
1381 } else
1382 sbt = -1;
1383
1384 if (nfds > maxfilesperproc && nfds > FD_SETSIZE)
1385 return (EINVAL);
1386 ni = nfds * sizeof(struct pollfd);
1387 if (ni > sizeof(smallbits))
1388 bits = malloc(ni, M_TEMP, M_WAITOK);
1389 else
1390 bits = smallbits;
1391 error = copyin(fds, bits, ni);
1392 if (error)
1393 goto done;
1394
1395 if (uset != NULL) {
1396 error = kern_sigprocmask(td, SIG_SETMASK, uset,
1397 &td->td_oldsigmask, 0);
1398 if (error)
1399 goto done;
1400 td->td_pflags |= TDP_OLDMASK;
1401 /*
1402 * Make sure that ast() is called on return to
1403 * usermode and TDP_OLDMASK is cleared, restoring old
1404 * sigmask.
1405 */
1406 thread_lock(td);
1407 td->td_flags |= TDF_ASTPENDING;
1408 thread_unlock(td);
1409 }
1410
1411 seltdinit(td);
1412 /* Iterate until the timeout expires or descriptors become ready. */
1413 for (;;) {
1414 error = pollscan(td, bits, nfds);
1415 if (error || td->td_retval[0] != 0)
1416 break;
1417 error = seltdwait(td, sbt, precision);
1418 if (error)
1419 break;
1420 error = pollrescan(td);
1421 if (error || td->td_retval[0] != 0)
1422 break;
1423 }
1424 seltdclear(td);
1425
1426 done:
1427 /* poll is not restarted after signals... */
1428 if (error == ERESTART)
1429 error = EINTR;
1430 if (error == EWOULDBLOCK)
1431 error = 0;
1432 if (error == 0) {
1433 error = pollout(td, bits, fds, nfds);
1434 if (error)
1435 goto out;
1436 }
1437 out:
1438 if (ni > sizeof(smallbits))
1439 free(bits, M_TEMP);
1440 return (error);
1441 }
1442
1443 int
1444 sys_ppoll(struct thread *td, struct ppoll_args *uap)
1445 {
1446 struct timespec ts, *tsp;
1447 sigset_t set, *ssp;
1448 int error;
1449
1450 if (uap->ts != NULL) {
1451 error = copyin(uap->ts, &ts, sizeof(ts));
1452 if (error)
1453 return (error);
1454 tsp = &ts;
1455 } else
1456 tsp = NULL;
1457 if (uap->set != NULL) {
1458 error = copyin(uap->set, &set, sizeof(set));
1459 if (error)
1460 return (error);
1461 ssp = &set;
1462 } else
1463 ssp = NULL;
1464 /*
1465 * fds is still a pointer to user space. kern_poll() will
1466 * take care of copyin that array to the kernel space.
1467 */
1468
1469 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp));
1470 }
1471
1472 static int
1473 pollrescan(struct thread *td)
1474 {
1475 struct seltd *stp;
1476 struct selfd *sfp;
1477 struct selfd *sfn;
1478 struct selinfo *si;
1479 struct filedesc *fdp;
1480 struct file *fp;
1481 struct pollfd *fd;
1482 #ifdef CAPABILITIES
1483 cap_rights_t rights;
1484 #endif
1485 int n;
1486
1487 n = 0;
1488 fdp = td->td_proc->p_fd;
1489 stp = td->td_sel;
1490 FILEDESC_SLOCK(fdp);
1491 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1492 fd = (struct pollfd *)sfp->sf_cookie;
1493 si = sfp->sf_si;
1494 selfdfree(stp, sfp);
1495 /* If the selinfo wasn't cleared the event didn't fire. */
1496 if (si != NULL)
1497 continue;
1498 fp = fdp->fd_ofiles[fd->fd].fde_file;
1499 #ifdef CAPABILITIES
1500 if (fp == NULL ||
1501 cap_check(cap_rights(fdp, fd->fd),
1502 cap_rights_init(&rights, CAP_EVENT)) != 0)
1503 #else
1504 if (fp == NULL)
1505 #endif
1506 {
1507 fd->revents = POLLNVAL;
1508 n++;
1509 continue;
1510 }
1511
1512 /*
1513 * Note: backend also returns POLLHUP and
1514 * POLLERR if appropriate.
1515 */
1516 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1517 if (fd->revents != 0)
1518 n++;
1519 }
1520 FILEDESC_SUNLOCK(fdp);
1521 stp->st_flags = 0;
1522 td->td_retval[0] = n;
1523 return (0);
1524 }
1525
1526
1527 static int
1528 pollout(td, fds, ufds, nfd)
1529 struct thread *td;
1530 struct pollfd *fds;
1531 struct pollfd *ufds;
1532 u_int nfd;
1533 {
1534 int error = 0;
1535 u_int i = 0;
1536 u_int n = 0;
1537
1538 for (i = 0; i < nfd; i++) {
1539 error = copyout(&fds->revents, &ufds->revents,
1540 sizeof(ufds->revents));
1541 if (error)
1542 return (error);
1543 if (fds->revents != 0)
1544 n++;
1545 fds++;
1546 ufds++;
1547 }
1548 td->td_retval[0] = n;
1549 return (0);
1550 }
1551
1552 static int
1553 pollscan(td, fds, nfd)
1554 struct thread *td;
1555 struct pollfd *fds;
1556 u_int nfd;
1557 {
1558 struct filedesc *fdp = td->td_proc->p_fd;
1559 struct file *fp;
1560 #ifdef CAPABILITIES
1561 cap_rights_t rights;
1562 #endif
1563 int i, n = 0;
1564
1565 FILEDESC_SLOCK(fdp);
1566 for (i = 0; i < nfd; i++, fds++) {
1567 if (fds->fd > fdp->fd_lastfile) {
1568 fds->revents = POLLNVAL;
1569 n++;
1570 } else if (fds->fd < 0) {
1571 fds->revents = 0;
1572 } else {
1573 fp = fdp->fd_ofiles[fds->fd].fde_file;
1574 #ifdef CAPABILITIES
1575 if (fp == NULL ||
1576 cap_check(cap_rights(fdp, fds->fd),
1577 cap_rights_init(&rights, CAP_EVENT)) != 0)
1578 #else
1579 if (fp == NULL)
1580 #endif
1581 {
1582 fds->revents = POLLNVAL;
1583 n++;
1584 } else {
1585 /*
1586 * Note: backend also returns POLLHUP and
1587 * POLLERR if appropriate.
1588 */
1589 selfdalloc(td, fds);
1590 fds->revents = fo_poll(fp, fds->events,
1591 td->td_ucred, td);
1592 /*
1593 * POSIX requires POLLOUT to be never
1594 * set simultaneously with POLLHUP.
1595 */
1596 if ((fds->revents & POLLHUP) != 0)
1597 fds->revents &= ~POLLOUT;
1598
1599 if (fds->revents != 0)
1600 n++;
1601 }
1602 }
1603 }
1604 FILEDESC_SUNLOCK(fdp);
1605 td->td_retval[0] = n;
1606 return (0);
1607 }
1608
1609 /*
1610 * OpenBSD poll system call.
1611 *
1612 * XXX this isn't quite a true representation.. OpenBSD uses select ops.
1613 */
1614 #ifndef _SYS_SYSPROTO_H_
1615 struct openbsd_poll_args {
1616 struct pollfd *fds;
1617 u_int nfds;
1618 int timeout;
1619 };
1620 #endif
1621 int
1622 sys_openbsd_poll(td, uap)
1623 register struct thread *td;
1624 register struct openbsd_poll_args *uap;
1625 {
1626 return (sys_poll(td, (struct poll_args *)uap));
1627 }
1628
1629 /*
1630 * XXX This was created specifically to support netncp and netsmb. This
1631 * allows the caller to specify a socket to wait for events on. It returns
1632 * 0 if any events matched and an error otherwise. There is no way to
1633 * determine which events fired.
1634 */
1635 int
1636 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1637 {
1638 struct timeval rtv;
1639 sbintime_t asbt, precision, rsbt;
1640 int error;
1641
1642 precision = 0; /* stupid gcc! */
1643 if (tvp != NULL) {
1644 rtv = *tvp;
1645 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1646 rtv.tv_usec >= 1000000)
1647 return (EINVAL);
1648 if (!timevalisset(&rtv))
1649 asbt = 0;
1650 else if (rtv.tv_sec <= INT32_MAX) {
1651 rsbt = tvtosbt(rtv);
1652 precision = rsbt;
1653 precision >>= tc_precexp;
1654 if (TIMESEL(&asbt, rsbt))
1655 asbt += tc_tick_sbt;
1656 if (asbt <= SBT_MAX - rsbt)
1657 asbt += rsbt;
1658 else
1659 asbt = -1;
1660 } else
1661 asbt = -1;
1662 } else
1663 asbt = -1;
1664 seltdinit(td);
1665 /*
1666 * Iterate until the timeout expires or the socket becomes ready.
1667 */
1668 for (;;) {
1669 selfdalloc(td, NULL);
1670 error = sopoll(so, events, NULL, td);
1671 /* error here is actually the ready events. */
1672 if (error)
1673 return (0);
1674 error = seltdwait(td, asbt, precision);
1675 if (error)
1676 break;
1677 }
1678 seltdclear(td);
1679 /* XXX Duplicates ncp/smb behavior. */
1680 if (error == ERESTART)
1681 error = 0;
1682 return (error);
1683 }
1684
1685 /*
1686 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1687 * have two select sets, one for read and another for write.
1688 */
1689 static void
1690 selfdalloc(struct thread *td, void *cookie)
1691 {
1692 struct seltd *stp;
1693
1694 stp = td->td_sel;
1695 if (stp->st_free1 == NULL)
1696 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1697 stp->st_free1->sf_td = stp;
1698 stp->st_free1->sf_cookie = cookie;
1699 if (stp->st_free2 == NULL)
1700 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1701 stp->st_free2->sf_td = stp;
1702 stp->st_free2->sf_cookie = cookie;
1703 }
1704
1705 static void
1706 selfdfree(struct seltd *stp, struct selfd *sfp)
1707 {
1708 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1709 if (sfp->sf_si != NULL) {
1710 mtx_lock(sfp->sf_mtx);
1711 if (sfp->sf_si != NULL) {
1712 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1713 refcount_release(&sfp->sf_refs);
1714 }
1715 mtx_unlock(sfp->sf_mtx);
1716 }
1717 if (refcount_release(&sfp->sf_refs))
1718 uma_zfree(selfd_zone, sfp);
1719 }
1720
1721 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
1722 void
1723 seldrain(sip)
1724 struct selinfo *sip;
1725 {
1726
1727 /*
1728 * This feature is already provided by doselwakeup(), thus it is
1729 * enough to go for it.
1730 * Eventually, the context, should take care to avoid races
1731 * between thread calling select()/poll() and file descriptor
1732 * detaching, but, again, the races are just the same as
1733 * selwakeup().
1734 */
1735 doselwakeup(sip, -1);
1736 }
1737
1738 /*
1739 * Record a select request.
1740 */
1741 void
1742 selrecord(selector, sip)
1743 struct thread *selector;
1744 struct selinfo *sip;
1745 {
1746 struct selfd *sfp;
1747 struct seltd *stp;
1748 struct mtx *mtxp;
1749
1750 stp = selector->td_sel;
1751 /*
1752 * Don't record when doing a rescan.
1753 */
1754 if (stp->st_flags & SELTD_RESCAN)
1755 return;
1756 /*
1757 * Grab one of the preallocated descriptors.
1758 */
1759 sfp = NULL;
1760 if ((sfp = stp->st_free1) != NULL)
1761 stp->st_free1 = NULL;
1762 else if ((sfp = stp->st_free2) != NULL)
1763 stp->st_free2 = NULL;
1764 else
1765 panic("selrecord: No free selfd on selq");
1766 mtxp = sip->si_mtx;
1767 if (mtxp == NULL)
1768 mtxp = mtx_pool_find(mtxpool_select, sip);
1769 /*
1770 * Initialize the sfp and queue it in the thread.
1771 */
1772 sfp->sf_si = sip;
1773 sfp->sf_mtx = mtxp;
1774 refcount_init(&sfp->sf_refs, 2);
1775 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1776 /*
1777 * Now that we've locked the sip, check for initialization.
1778 */
1779 mtx_lock(mtxp);
1780 if (sip->si_mtx == NULL) {
1781 sip->si_mtx = mtxp;
1782 TAILQ_INIT(&sip->si_tdlist);
1783 }
1784 /*
1785 * Add this thread to the list of selfds listening on this selinfo.
1786 */
1787 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1788 mtx_unlock(sip->si_mtx);
1789 }
1790
1791 /* Wake up a selecting thread. */
1792 void
1793 selwakeup(sip)
1794 struct selinfo *sip;
1795 {
1796 doselwakeup(sip, -1);
1797 }
1798
1799 /* Wake up a selecting thread, and set its priority. */
1800 void
1801 selwakeuppri(sip, pri)
1802 struct selinfo *sip;
1803 int pri;
1804 {
1805 doselwakeup(sip, pri);
1806 }
1807
1808 /*
1809 * Do a wakeup when a selectable event occurs.
1810 */
1811 static void
1812 doselwakeup(sip, pri)
1813 struct selinfo *sip;
1814 int pri;
1815 {
1816 struct selfd *sfp;
1817 struct selfd *sfn;
1818 struct seltd *stp;
1819
1820 /* If it's not initialized there can't be any waiters. */
1821 if (sip->si_mtx == NULL)
1822 return;
1823 /*
1824 * Locking the selinfo locks all selfds associated with it.
1825 */
1826 mtx_lock(sip->si_mtx);
1827 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1828 /*
1829 * Once we remove this sfp from the list and clear the
1830 * sf_si seltdclear will know to ignore this si.
1831 */
1832 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1833 sfp->sf_si = NULL;
1834 stp = sfp->sf_td;
1835 mtx_lock(&stp->st_mtx);
1836 stp->st_flags |= SELTD_PENDING;
1837 cv_broadcastpri(&stp->st_wait, pri);
1838 mtx_unlock(&stp->st_mtx);
1839 if (refcount_release(&sfp->sf_refs))
1840 uma_zfree(selfd_zone, sfp);
1841 }
1842 mtx_unlock(sip->si_mtx);
1843 }
1844
1845 static void
1846 seltdinit(struct thread *td)
1847 {
1848 struct seltd *stp;
1849
1850 if ((stp = td->td_sel) != NULL)
1851 goto out;
1852 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1853 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1854 cv_init(&stp->st_wait, "select");
1855 out:
1856 stp->st_flags = 0;
1857 STAILQ_INIT(&stp->st_selq);
1858 }
1859
1860 static int
1861 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision)
1862 {
1863 struct seltd *stp;
1864 int error;
1865
1866 stp = td->td_sel;
1867 /*
1868 * An event of interest may occur while we do not hold the seltd
1869 * locked so check the pending flag before we sleep.
1870 */
1871 mtx_lock(&stp->st_mtx);
1872 /*
1873 * Any further calls to selrecord will be a rescan.
1874 */
1875 stp->st_flags |= SELTD_RESCAN;
1876 if (stp->st_flags & SELTD_PENDING) {
1877 mtx_unlock(&stp->st_mtx);
1878 return (0);
1879 }
1880 if (sbt == 0)
1881 error = EWOULDBLOCK;
1882 else if (sbt != -1)
1883 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx,
1884 sbt, precision, C_ABSOLUTE);
1885 else
1886 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
1887 mtx_unlock(&stp->st_mtx);
1888
1889 return (error);
1890 }
1891
1892 void
1893 seltdfini(struct thread *td)
1894 {
1895 struct seltd *stp;
1896
1897 stp = td->td_sel;
1898 if (stp == NULL)
1899 return;
1900 if (stp->st_free1)
1901 uma_zfree(selfd_zone, stp->st_free1);
1902 if (stp->st_free2)
1903 uma_zfree(selfd_zone, stp->st_free2);
1904 td->td_sel = NULL;
1905 free(stp, M_SELECT);
1906 }
1907
1908 /*
1909 * Remove the references to the thread from all of the objects we were
1910 * polling.
1911 */
1912 static void
1913 seltdclear(struct thread *td)
1914 {
1915 struct seltd *stp;
1916 struct selfd *sfp;
1917 struct selfd *sfn;
1918
1919 stp = td->td_sel;
1920 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
1921 selfdfree(stp, sfp);
1922 stp->st_flags = 0;
1923 }
1924
1925 static void selectinit(void *);
1926 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
1927 static void
1928 selectinit(void *dummy __unused)
1929 {
1930
1931 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
1932 NULL, NULL, UMA_ALIGN_PTR, 0);
1933 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
1934 }
1935
1936 /*
1937 * Set up a syscall return value that follows the convention specified for
1938 * posix_* functions.
1939 */
1940 int
1941 kern_posix_error(struct thread *td, int error)
1942 {
1943
1944 if (error <= 0)
1945 return (error);
1946 td->td_errno = error;
1947 td->td_pflags |= TDP_NERRNO;
1948 td->td_retval[0] = error;
1949 return (0);
1950 }
Cache object: 820046e9819834df148f973fff9b3778
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