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