1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 #include "opt_capsicum.h"
39 #include "opt_ktrace.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/sysproto.h>
44 #include <sys/capsicum.h>
45 #include <sys/filedesc.h>
46 #include <sys/filio.h>
47 #include <sys/fcntl.h>
48 #include <sys/file.h>
49 #include <sys/lock.h>
50 #include <sys/proc.h>
51 #include <sys/signalvar.h>
52 #include <sys/socketvar.h>
53 #include <sys/uio.h>
54 #include <sys/eventfd.h>
55 #include <sys/kernel.h>
56 #include <sys/ktr.h>
57 #include <sys/limits.h>
58 #include <sys/malloc.h>
59 #include <sys/poll.h>
60 #include <sys/resourcevar.h>
61 #include <sys/selinfo.h>
62 #include <sys/sleepqueue.h>
63 #include <sys/specialfd.h>
64 #include <sys/syscallsubr.h>
65 #include <sys/sysctl.h>
66 #include <sys/sysent.h>
67 #include <sys/vnode.h>
68 #include <sys/unistd.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 };
159
160 MALLOC_DEFINE(M_SELFD, "selfd", "selfd");
161 static struct mtx_pool *mtxpool_select;
162
163 #ifdef __LP64__
164 size_t
devfs_iosize_max(void)165 devfs_iosize_max(void)
166 {
167
168 return (devfs_iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
169 INT_MAX : SSIZE_MAX);
170 }
171
172 size_t
iosize_max(void)173 iosize_max(void)
174 {
175
176 return (iosize_max_clamp || SV_CURPROC_FLAG(SV_ILP32) ?
177 INT_MAX : SSIZE_MAX);
178 }
179 #endif
180
181 #ifndef _SYS_SYSPROTO_H_
182 struct read_args {
183 int fd;
184 void *buf;
185 size_t nbyte;
186 };
187 #endif
188 int
sys_read(struct thread * td,struct read_args * uap)189 sys_read(struct thread *td, struct read_args *uap)
190 {
191 struct uio auio;
192 struct iovec aiov;
193 int error;
194
195 if (uap->nbyte > IOSIZE_MAX)
196 return (EINVAL);
197 aiov.iov_base = uap->buf;
198 aiov.iov_len = uap->nbyte;
199 auio.uio_iov = &aiov;
200 auio.uio_iovcnt = 1;
201 auio.uio_resid = uap->nbyte;
202 auio.uio_segflg = UIO_USERSPACE;
203 error = kern_readv(td, uap->fd, &auio);
204 return (error);
205 }
206
207 /*
208 * Positioned read system call
209 */
210 #ifndef _SYS_SYSPROTO_H_
211 struct pread_args {
212 int fd;
213 void *buf;
214 size_t nbyte;
215 int pad;
216 off_t offset;
217 };
218 #endif
219 int
sys_pread(struct thread * td,struct pread_args * uap)220 sys_pread(struct thread *td, struct pread_args *uap)
221 {
222
223 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
224 }
225
226 int
kern_pread(struct thread * td,int fd,void * buf,size_t nbyte,off_t offset)227 kern_pread(struct thread *td, int fd, void *buf, size_t nbyte, off_t offset)
228 {
229 struct uio auio;
230 struct iovec aiov;
231 int error;
232
233 if (nbyte > IOSIZE_MAX)
234 return (EINVAL);
235 aiov.iov_base = buf;
236 aiov.iov_len = nbyte;
237 auio.uio_iov = &aiov;
238 auio.uio_iovcnt = 1;
239 auio.uio_resid = nbyte;
240 auio.uio_segflg = UIO_USERSPACE;
241 error = kern_preadv(td, fd, &auio, offset);
242 return (error);
243 }
244
245 #if defined(COMPAT_FREEBSD6)
246 int
freebsd6_pread(struct thread * td,struct freebsd6_pread_args * uap)247 freebsd6_pread(struct thread *td, struct freebsd6_pread_args *uap)
248 {
249
250 return (kern_pread(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
251 }
252 #endif
253
254 /*
255 * Scatter read system call.
256 */
257 #ifndef _SYS_SYSPROTO_H_
258 struct readv_args {
259 int fd;
260 struct iovec *iovp;
261 u_int iovcnt;
262 };
263 #endif
264 int
sys_readv(struct thread * td,struct readv_args * uap)265 sys_readv(struct thread *td, struct readv_args *uap)
266 {
267 struct uio *auio;
268 int error;
269
270 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
271 if (error)
272 return (error);
273 error = kern_readv(td, uap->fd, auio);
274 freeuio(auio);
275 return (error);
276 }
277
278 int
kern_readv(struct thread * td,int fd,struct uio * auio)279 kern_readv(struct thread *td, int fd, struct uio *auio)
280 {
281 struct file *fp;
282 int error;
283
284 error = fget_read(td, fd, &cap_read_rights, &fp);
285 if (error)
286 return (error);
287 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
288 fdrop(fp, td);
289 return (error);
290 }
291
292 /*
293 * Scatter positioned read system call.
294 */
295 #ifndef _SYS_SYSPROTO_H_
296 struct preadv_args {
297 int fd;
298 struct iovec *iovp;
299 u_int iovcnt;
300 off_t offset;
301 };
302 #endif
303 int
sys_preadv(struct thread * td,struct preadv_args * uap)304 sys_preadv(struct thread *td, struct preadv_args *uap)
305 {
306 struct uio *auio;
307 int error;
308
309 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
310 if (error)
311 return (error);
312 error = kern_preadv(td, uap->fd, auio, uap->offset);
313 freeuio(auio);
314 return (error);
315 }
316
317 int
kern_preadv(struct thread * td,int fd,struct uio * auio,off_t offset)318 kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset)
319 {
320 struct file *fp;
321 int error;
322
323 error = fget_read(td, fd, &cap_pread_rights, &fp);
324 if (error)
325 return (error);
326 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
327 error = ESPIPE;
328 else if (offset < 0 &&
329 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR))
330 error = EINVAL;
331 else
332 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
333 fdrop(fp, td);
334 return (error);
335 }
336
337 /*
338 * Common code for readv and preadv that reads data in
339 * from a file using the passed in uio, offset, and flags.
340 */
341 static int
dofileread(struct thread * td,int fd,struct file * fp,struct uio * auio,off_t offset,int flags)342 dofileread(struct thread *td, int fd, struct file *fp, struct uio *auio,
343 off_t offset, int flags)
344 {
345 ssize_t cnt;
346 int error;
347 #ifdef KTRACE
348 struct uio *ktruio = NULL;
349 #endif
350
351 AUDIT_ARG_FD(fd);
352
353 /* Finish zero length reads right here */
354 if (auio->uio_resid == 0) {
355 td->td_retval[0] = 0;
356 return (0);
357 }
358 auio->uio_rw = UIO_READ;
359 auio->uio_offset = offset;
360 auio->uio_td = td;
361 #ifdef KTRACE
362 if (KTRPOINT(td, KTR_GENIO))
363 ktruio = cloneuio(auio);
364 #endif
365 cnt = auio->uio_resid;
366 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
367 if (auio->uio_resid != cnt && (error == ERESTART ||
368 error == EINTR || error == EWOULDBLOCK))
369 error = 0;
370 }
371 cnt -= auio->uio_resid;
372 #ifdef KTRACE
373 if (ktruio != NULL) {
374 ktruio->uio_resid = cnt;
375 ktrgenio(fd, UIO_READ, ktruio, error);
376 }
377 #endif
378 td->td_retval[0] = cnt;
379 return (error);
380 }
381
382 #ifndef _SYS_SYSPROTO_H_
383 struct write_args {
384 int fd;
385 const void *buf;
386 size_t nbyte;
387 };
388 #endif
389 int
sys_write(struct thread * td,struct write_args * uap)390 sys_write(struct thread *td, struct write_args *uap)
391 {
392 struct uio auio;
393 struct iovec aiov;
394 int error;
395
396 if (uap->nbyte > IOSIZE_MAX)
397 return (EINVAL);
398 aiov.iov_base = (void *)(uintptr_t)uap->buf;
399 aiov.iov_len = uap->nbyte;
400 auio.uio_iov = &aiov;
401 auio.uio_iovcnt = 1;
402 auio.uio_resid = uap->nbyte;
403 auio.uio_segflg = UIO_USERSPACE;
404 error = kern_writev(td, uap->fd, &auio);
405 return (error);
406 }
407
408 /*
409 * Positioned write system call.
410 */
411 #ifndef _SYS_SYSPROTO_H_
412 struct pwrite_args {
413 int fd;
414 const void *buf;
415 size_t nbyte;
416 int pad;
417 off_t offset;
418 };
419 #endif
420 int
sys_pwrite(struct thread * td,struct pwrite_args * uap)421 sys_pwrite(struct thread *td, struct pwrite_args *uap)
422 {
423
424 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
425 }
426
427 int
kern_pwrite(struct thread * td,int fd,const void * buf,size_t nbyte,off_t offset)428 kern_pwrite(struct thread *td, int fd, const void *buf, size_t nbyte,
429 off_t offset)
430 {
431 struct uio auio;
432 struct iovec aiov;
433 int error;
434
435 if (nbyte > IOSIZE_MAX)
436 return (EINVAL);
437 aiov.iov_base = (void *)(uintptr_t)buf;
438 aiov.iov_len = nbyte;
439 auio.uio_iov = &aiov;
440 auio.uio_iovcnt = 1;
441 auio.uio_resid = nbyte;
442 auio.uio_segflg = UIO_USERSPACE;
443 error = kern_pwritev(td, fd, &auio, offset);
444 return (error);
445 }
446
447 #if defined(COMPAT_FREEBSD6)
448 int
freebsd6_pwrite(struct thread * td,struct freebsd6_pwrite_args * uap)449 freebsd6_pwrite(struct thread *td, struct freebsd6_pwrite_args *uap)
450 {
451
452 return (kern_pwrite(td, uap->fd, uap->buf, uap->nbyte, uap->offset));
453 }
454 #endif
455
456 /*
457 * Gather write system call.
458 */
459 #ifndef _SYS_SYSPROTO_H_
460 struct writev_args {
461 int fd;
462 struct iovec *iovp;
463 u_int iovcnt;
464 };
465 #endif
466 int
sys_writev(struct thread * td,struct writev_args * uap)467 sys_writev(struct thread *td, struct writev_args *uap)
468 {
469 struct uio *auio;
470 int error;
471
472 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
473 if (error)
474 return (error);
475 error = kern_writev(td, uap->fd, auio);
476 freeuio(auio);
477 return (error);
478 }
479
480 int
kern_writev(struct thread * td,int fd,struct uio * auio)481 kern_writev(struct thread *td, int fd, struct uio *auio)
482 {
483 struct file *fp;
484 int error;
485
486 error = fget_write(td, fd, &cap_write_rights, &fp);
487 if (error)
488 return (error);
489 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
490 fdrop(fp, td);
491 return (error);
492 }
493
494 /*
495 * Gather positioned write system call.
496 */
497 #ifndef _SYS_SYSPROTO_H_
498 struct pwritev_args {
499 int fd;
500 struct iovec *iovp;
501 u_int iovcnt;
502 off_t offset;
503 };
504 #endif
505 int
sys_pwritev(struct thread * td,struct pwritev_args * uap)506 sys_pwritev(struct thread *td, struct pwritev_args *uap)
507 {
508 struct uio *auio;
509 int error;
510
511 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
512 if (error)
513 return (error);
514 error = kern_pwritev(td, uap->fd, auio, uap->offset);
515 freeuio(auio);
516 return (error);
517 }
518
519 int
kern_pwritev(struct thread * td,int fd,struct uio * auio,off_t offset)520 kern_pwritev(struct thread *td, int fd, struct uio *auio, off_t offset)
521 {
522 struct file *fp;
523 int error;
524
525 error = fget_write(td, fd, &cap_pwrite_rights, &fp);
526 if (error)
527 return (error);
528 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
529 error = ESPIPE;
530 else if (offset < 0 &&
531 (fp->f_vnode == NULL || fp->f_vnode->v_type != VCHR))
532 error = EINVAL;
533 else
534 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
535 fdrop(fp, td);
536 return (error);
537 }
538
539 /*
540 * Common code for writev and pwritev that writes data to
541 * a file using the passed in uio, offset, and flags.
542 */
543 static int
dofilewrite(struct thread * td,int fd,struct file * fp,struct uio * auio,off_t offset,int flags)544 dofilewrite(struct thread *td, int fd, struct file *fp, struct uio *auio,
545 off_t offset, int flags)
546 {
547 ssize_t cnt;
548 int error;
549 #ifdef KTRACE
550 struct uio *ktruio = NULL;
551 #endif
552
553 AUDIT_ARG_FD(fd);
554 auio->uio_rw = UIO_WRITE;
555 auio->uio_td = td;
556 auio->uio_offset = offset;
557 #ifdef KTRACE
558 if (KTRPOINT(td, KTR_GENIO))
559 ktruio = cloneuio(auio);
560 #endif
561 cnt = auio->uio_resid;
562 error = fo_write(fp, auio, td->td_ucred, flags, td);
563 /*
564 * Socket layer is responsible for special error handling,
565 * see sousrsend().
566 */
567 if (error != 0 && fp->f_type != DTYPE_SOCKET) {
568 if (auio->uio_resid != cnt && (error == ERESTART ||
569 error == EINTR || error == EWOULDBLOCK))
570 error = 0;
571 if (error == EPIPE) {
572 PROC_LOCK(td->td_proc);
573 tdsignal(td, SIGPIPE);
574 PROC_UNLOCK(td->td_proc);
575 }
576 }
577 cnt -= auio->uio_resid;
578 #ifdef KTRACE
579 if (ktruio != NULL) {
580 if (error == 0)
581 ktruio->uio_resid = cnt;
582 ktrgenio(fd, UIO_WRITE, ktruio, error);
583 }
584 #endif
585 td->td_retval[0] = cnt;
586 return (error);
587 }
588
589 /*
590 * Truncate a file given a file descriptor.
591 *
592 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
593 * descriptor isn't writable.
594 */
595 int
kern_ftruncate(struct thread * td,int fd,off_t length)596 kern_ftruncate(struct thread *td, int fd, off_t length)
597 {
598 struct file *fp;
599 int error;
600
601 AUDIT_ARG_FD(fd);
602 if (length < 0)
603 return (EINVAL);
604 error = fget(td, fd, &cap_ftruncate_rights, &fp);
605 if (error)
606 return (error);
607 AUDIT_ARG_FILE(td->td_proc, fp);
608 if (!(fp->f_flag & FWRITE)) {
609 fdrop(fp, td);
610 return (EINVAL);
611 }
612 error = fo_truncate(fp, length, td->td_ucred, td);
613 fdrop(fp, td);
614 return (error);
615 }
616
617 #ifndef _SYS_SYSPROTO_H_
618 struct ftruncate_args {
619 int fd;
620 int pad;
621 off_t length;
622 };
623 #endif
624 int
sys_ftruncate(struct thread * td,struct ftruncate_args * uap)625 sys_ftruncate(struct thread *td, struct ftruncate_args *uap)
626 {
627
628 return (kern_ftruncate(td, uap->fd, uap->length));
629 }
630
631 #if defined(COMPAT_43)
632 #ifndef _SYS_SYSPROTO_H_
633 struct oftruncate_args {
634 int fd;
635 long length;
636 };
637 #endif
638 int
oftruncate(struct thread * td,struct oftruncate_args * uap)639 oftruncate(struct thread *td, struct oftruncate_args *uap)
640 {
641
642 return (kern_ftruncate(td, uap->fd, uap->length));
643 }
644 #endif /* COMPAT_43 */
645
646 #ifndef _SYS_SYSPROTO_H_
647 struct ioctl_args {
648 int fd;
649 u_long com;
650 caddr_t data;
651 };
652 #endif
653 /* ARGSUSED */
654 int
sys_ioctl(struct thread * td,struct ioctl_args * uap)655 sys_ioctl(struct thread *td, struct ioctl_args *uap)
656 {
657 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
658 uint32_t com;
659 int arg, error;
660 u_int size;
661 caddr_t data;
662
663 #ifdef INVARIANTS
664 if (uap->com > 0xffffffff) {
665 printf(
666 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
667 td->td_proc->p_pid, td->td_name, uap->com);
668 }
669 #endif
670 com = (uint32_t)uap->com;
671
672 /*
673 * Interpret high order word to find amount of data to be
674 * copied to/from the user's address space.
675 */
676 size = IOCPARM_LEN(com);
677 if ((size > IOCPARM_MAX) ||
678 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
679 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
680 ((com & IOC_OUT) && size == 0) ||
681 #else
682 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
683 #endif
684 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
685 return (ENOTTY);
686
687 if (size > 0) {
688 if (com & IOC_VOID) {
689 /* Integer argument. */
690 arg = (intptr_t)uap->data;
691 data = (void *)&arg;
692 size = 0;
693 } else {
694 if (size > SYS_IOCTL_SMALL_SIZE)
695 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
696 else
697 data = smalldata;
698 }
699 } else
700 data = (void *)&uap->data;
701 if (com & IOC_IN) {
702 error = copyin(uap->data, data, (u_int)size);
703 if (error != 0)
704 goto out;
705 } else if (com & IOC_OUT) {
706 /*
707 * Zero the buffer so the user always
708 * gets back something deterministic.
709 */
710 bzero(data, size);
711 }
712
713 error = kern_ioctl(td, uap->fd, com, data);
714
715 if (error == 0 && (com & IOC_OUT))
716 error = copyout(data, uap->data, (u_int)size);
717
718 out:
719 if (size > SYS_IOCTL_SMALL_SIZE)
720 free(data, M_IOCTLOPS);
721 return (error);
722 }
723
724 int
kern_ioctl(struct thread * td,int fd,u_long com,caddr_t data)725 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
726 {
727 struct file *fp;
728 struct filedesc *fdp;
729 int error, tmp, locked;
730
731 AUDIT_ARG_FD(fd);
732 AUDIT_ARG_CMD(com);
733
734 fdp = td->td_proc->p_fd;
735
736 switch (com) {
737 case FIONCLEX:
738 case FIOCLEX:
739 FILEDESC_XLOCK(fdp);
740 locked = LA_XLOCKED;
741 break;
742 default:
743 #ifdef CAPABILITIES
744 FILEDESC_SLOCK(fdp);
745 locked = LA_SLOCKED;
746 #else
747 locked = LA_UNLOCKED;
748 #endif
749 break;
750 }
751
752 #ifdef CAPABILITIES
753 if ((fp = fget_noref(fdp, fd)) == NULL) {
754 error = EBADF;
755 goto out;
756 }
757 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
758 fp = NULL; /* fhold() was not called yet */
759 goto out;
760 }
761 if (!fhold(fp)) {
762 error = EBADF;
763 fp = NULL;
764 goto out;
765 }
766 if (locked == LA_SLOCKED) {
767 FILEDESC_SUNLOCK(fdp);
768 locked = LA_UNLOCKED;
769 }
770 #else
771 error = fget(td, fd, &cap_ioctl_rights, &fp);
772 if (error != 0) {
773 fp = NULL;
774 goto out;
775 }
776 #endif
777 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
778 error = EBADF;
779 goto out;
780 }
781
782 switch (com) {
783 case FIONCLEX:
784 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
785 goto out;
786 case FIOCLEX:
787 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
788 goto out;
789 case FIONBIO:
790 if ((tmp = *(int *)data))
791 atomic_set_int(&fp->f_flag, FNONBLOCK);
792 else
793 atomic_clear_int(&fp->f_flag, FNONBLOCK);
794 data = (void *)&tmp;
795 break;
796 case FIOASYNC:
797 if ((tmp = *(int *)data))
798 atomic_set_int(&fp->f_flag, FASYNC);
799 else
800 atomic_clear_int(&fp->f_flag, FASYNC);
801 data = (void *)&tmp;
802 break;
803 }
804
805 error = fo_ioctl(fp, com, data, td->td_ucred, td);
806 out:
807 switch (locked) {
808 case LA_XLOCKED:
809 FILEDESC_XUNLOCK(fdp);
810 break;
811 #ifdef CAPABILITIES
812 case LA_SLOCKED:
813 FILEDESC_SUNLOCK(fdp);
814 break;
815 #endif
816 default:
817 FILEDESC_UNLOCK_ASSERT(fdp);
818 break;
819 }
820 if (fp != NULL)
821 fdrop(fp, td);
822 return (error);
823 }
824
825 int
sys_posix_fallocate(struct thread * td,struct posix_fallocate_args * uap)826 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
827 {
828 int error;
829
830 error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
831 return (kern_posix_error(td, error));
832 }
833
834 int
kern_posix_fallocate(struct thread * td,int fd,off_t offset,off_t len)835 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len)
836 {
837 struct file *fp;
838 int error;
839
840 AUDIT_ARG_FD(fd);
841 if (offset < 0 || len <= 0)
842 return (EINVAL);
843 /* Check for wrap. */
844 if (offset > OFF_MAX - len)
845 return (EFBIG);
846 AUDIT_ARG_FD(fd);
847 error = fget(td, fd, &cap_pwrite_rights, &fp);
848 if (error != 0)
849 return (error);
850 AUDIT_ARG_FILE(td->td_proc, fp);
851 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
852 error = ESPIPE;
853 goto out;
854 }
855 if ((fp->f_flag & FWRITE) == 0) {
856 error = EBADF;
857 goto out;
858 }
859
860 error = fo_fallocate(fp, offset, len, td);
861 out:
862 fdrop(fp, td);
863 return (error);
864 }
865
866 int
sys_fspacectl(struct thread * td,struct fspacectl_args * uap)867 sys_fspacectl(struct thread *td, struct fspacectl_args *uap)
868 {
869 struct spacectl_range rqsr, rmsr;
870 int error, cerror;
871
872 error = copyin(uap->rqsr, &rqsr, sizeof(rqsr));
873 if (error != 0)
874 return (error);
875
876 error = kern_fspacectl(td, uap->fd, uap->cmd, &rqsr, uap->flags,
877 &rmsr);
878 if (uap->rmsr != NULL) {
879 cerror = copyout(&rmsr, uap->rmsr, sizeof(rmsr));
880 if (error == 0)
881 error = cerror;
882 }
883 return (error);
884 }
885
886 int
kern_fspacectl(struct thread * td,int fd,int cmd,const struct spacectl_range * rqsr,int flags,struct spacectl_range * rmsrp)887 kern_fspacectl(struct thread *td, int fd, int cmd,
888 const struct spacectl_range *rqsr, int flags, struct spacectl_range *rmsrp)
889 {
890 struct file *fp;
891 struct spacectl_range rmsr;
892 int error;
893
894 AUDIT_ARG_FD(fd);
895 AUDIT_ARG_CMD(cmd);
896 AUDIT_ARG_FFLAGS(flags);
897
898 if (rqsr == NULL)
899 return (EINVAL);
900 rmsr = *rqsr;
901 if (rmsrp != NULL)
902 *rmsrp = rmsr;
903
904 if (cmd != SPACECTL_DEALLOC ||
905 rqsr->r_offset < 0 || rqsr->r_len <= 0 ||
906 rqsr->r_offset > OFF_MAX - rqsr->r_len ||
907 (flags & ~SPACECTL_F_SUPPORTED) != 0)
908 return (EINVAL);
909
910 error = fget_write(td, fd, &cap_pwrite_rights, &fp);
911 if (error != 0)
912 return (error);
913 AUDIT_ARG_FILE(td->td_proc, fp);
914 if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
915 error = ESPIPE;
916 goto out;
917 }
918 if ((fp->f_flag & FWRITE) == 0) {
919 error = EBADF;
920 goto out;
921 }
922
923 error = fo_fspacectl(fp, cmd, &rmsr.r_offset, &rmsr.r_len, flags,
924 td->td_ucred, td);
925 /* fspacectl is not restarted after signals if the file is modified. */
926 if (rmsr.r_len != rqsr->r_len && (error == ERESTART ||
927 error == EINTR || error == EWOULDBLOCK))
928 error = 0;
929 if (rmsrp != NULL)
930 *rmsrp = rmsr;
931 out:
932 fdrop(fp, td);
933 return (error);
934 }
935
936 int
kern_specialfd(struct thread * td,int type,void * arg)937 kern_specialfd(struct thread *td, int type, void *arg)
938 {
939 struct file *fp;
940 struct specialfd_eventfd *ae;
941 int error, fd, fflags;
942
943 fflags = 0;
944 error = falloc_noinstall(td, &fp);
945 if (error != 0)
946 return (error);
947
948 switch (type) {
949 case SPECIALFD_EVENTFD:
950 ae = arg;
951 if ((ae->flags & EFD_CLOEXEC) != 0)
952 fflags |= O_CLOEXEC;
953 error = eventfd_create_file(td, fp, ae->initval, ae->flags);
954 break;
955 default:
956 error = EINVAL;
957 break;
958 }
959
960 if (error == 0)
961 error = finstall(td, fp, &fd, fflags, NULL);
962 fdrop(fp, td);
963 if (error == 0)
964 td->td_retval[0] = fd;
965 return (error);
966 }
967
968 int
sys___specialfd(struct thread * td,struct __specialfd_args * args)969 sys___specialfd(struct thread *td, struct __specialfd_args *args)
970 {
971 struct specialfd_eventfd ae;
972 int error;
973
974 switch (args->type) {
975 case SPECIALFD_EVENTFD:
976 if (args->len != sizeof(struct specialfd_eventfd)) {
977 error = EINVAL;
978 break;
979 }
980 error = copyin(args->req, &ae, sizeof(ae));
981 if (error != 0)
982 break;
983 if ((ae.flags & ~(EFD_CLOEXEC | EFD_NONBLOCK |
984 EFD_SEMAPHORE)) != 0) {
985 error = EINVAL;
986 break;
987 }
988 error = kern_specialfd(td, args->type, &ae);
989 break;
990 default:
991 error = EINVAL;
992 break;
993 }
994 return (error);
995 }
996
997 int
poll_no_poll(int events)998 poll_no_poll(int events)
999 {
1000 /*
1001 * Return true for read/write. If the user asked for something
1002 * special, return POLLNVAL, so that clients have a way of
1003 * determining reliably whether or not the extended
1004 * functionality is present without hard-coding knowledge
1005 * of specific filesystem implementations.
1006 */
1007 if (events & ~POLLSTANDARD)
1008 return (POLLNVAL);
1009
1010 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
1011 }
1012
1013 int
sys_pselect(struct thread * td,struct pselect_args * uap)1014 sys_pselect(struct thread *td, struct pselect_args *uap)
1015 {
1016 struct timespec ts;
1017 struct timeval tv, *tvp;
1018 sigset_t set, *uset;
1019 int error;
1020
1021 if (uap->ts != NULL) {
1022 error = copyin(uap->ts, &ts, sizeof(ts));
1023 if (error != 0)
1024 return (error);
1025 TIMESPEC_TO_TIMEVAL(&tv, &ts);
1026 tvp = &tv;
1027 } else
1028 tvp = NULL;
1029 if (uap->sm != NULL) {
1030 error = copyin(uap->sm, &set, sizeof(set));
1031 if (error != 0)
1032 return (error);
1033 uset = &set;
1034 } else
1035 uset = NULL;
1036 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
1037 uset, NFDBITS));
1038 }
1039
1040 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)1041 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
1042 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
1043 {
1044 int error;
1045
1046 if (uset != NULL) {
1047 error = kern_sigprocmask(td, SIG_SETMASK, uset,
1048 &td->td_oldsigmask, 0);
1049 if (error != 0)
1050 return (error);
1051 td->td_pflags |= TDP_OLDMASK;
1052 /*
1053 * Make sure that ast() is called on return to
1054 * usermode and TDP_OLDMASK is cleared, restoring old
1055 * sigmask.
1056 */
1057 ast_sched(td, TDA_SIGSUSPEND);
1058 }
1059 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
1060 return (error);
1061 }
1062
1063 #ifndef _SYS_SYSPROTO_H_
1064 struct select_args {
1065 int nd;
1066 fd_set *in, *ou, *ex;
1067 struct timeval *tv;
1068 };
1069 #endif
1070 int
sys_select(struct thread * td,struct select_args * uap)1071 sys_select(struct thread *td, struct select_args *uap)
1072 {
1073 struct timeval tv, *tvp;
1074 int error;
1075
1076 if (uap->tv != NULL) {
1077 error = copyin(uap->tv, &tv, sizeof(tv));
1078 if (error)
1079 return (error);
1080 tvp = &tv;
1081 } else
1082 tvp = NULL;
1083
1084 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
1085 NFDBITS));
1086 }
1087
1088 /*
1089 * In the unlikely case when user specified n greater then the last
1090 * open file descriptor, check that no bits are set after the last
1091 * valid fd. We must return EBADF if any is set.
1092 *
1093 * There are applications that rely on the behaviour.
1094 *
1095 * nd is fd_nfiles.
1096 */
1097 static int
select_check_badfd(fd_set * fd_in,int nd,int ndu,int abi_nfdbits)1098 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
1099 {
1100 char *addr, *oaddr;
1101 int b, i, res;
1102 uint8_t bits;
1103
1104 if (nd >= ndu || fd_in == NULL)
1105 return (0);
1106
1107 oaddr = NULL;
1108 bits = 0; /* silence gcc */
1109 for (i = nd; i < ndu; i++) {
1110 b = i / NBBY;
1111 #if BYTE_ORDER == LITTLE_ENDIAN
1112 addr = (char *)fd_in + b;
1113 #else
1114 addr = (char *)fd_in;
1115 if (abi_nfdbits == NFDBITS) {
1116 addr += rounddown(b, sizeof(fd_mask)) +
1117 sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
1118 } else {
1119 addr += rounddown(b, sizeof(uint32_t)) +
1120 sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
1121 }
1122 #endif
1123 if (addr != oaddr) {
1124 res = fubyte(addr);
1125 if (res == -1)
1126 return (EFAULT);
1127 oaddr = addr;
1128 bits = res;
1129 }
1130 if ((bits & (1 << (i % NBBY))) != 0)
1131 return (EBADF);
1132 }
1133 return (0);
1134 }
1135
1136 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)1137 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
1138 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
1139 {
1140 struct filedesc *fdp;
1141 /*
1142 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
1143 * infds with the new FD_SETSIZE of 1024, and more than enough for
1144 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
1145 * of 256.
1146 */
1147 fd_mask s_selbits[howmany(2048, NFDBITS)];
1148 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
1149 struct timeval rtv;
1150 sbintime_t asbt, precision, rsbt;
1151 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
1152 int error, lf, ndu;
1153
1154 if (nd < 0)
1155 return (EINVAL);
1156 fdp = td->td_proc->p_fd;
1157 ndu = nd;
1158 lf = fdp->fd_nfiles;
1159 if (nd > lf)
1160 nd = lf;
1161
1162 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
1163 if (error != 0)
1164 return (error);
1165 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
1166 if (error != 0)
1167 return (error);
1168 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
1169 if (error != 0)
1170 return (error);
1171
1172 /*
1173 * Allocate just enough bits for the non-null fd_sets. Use the
1174 * preallocated auto buffer if possible.
1175 */
1176 nfdbits = roundup(nd, NFDBITS);
1177 ncpbytes = nfdbits / NBBY;
1178 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
1179 nbufbytes = 0;
1180 if (fd_in != NULL)
1181 nbufbytes += 2 * ncpbytes;
1182 if (fd_ou != NULL)
1183 nbufbytes += 2 * ncpbytes;
1184 if (fd_ex != NULL)
1185 nbufbytes += 2 * ncpbytes;
1186 if (nbufbytes <= sizeof s_selbits)
1187 selbits = &s_selbits[0];
1188 else
1189 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
1190
1191 /*
1192 * Assign pointers into the bit buffers and fetch the input bits.
1193 * Put the output buffers together so that they can be bzeroed
1194 * together.
1195 */
1196 sbp = selbits;
1197 #define getbits(name, x) \
1198 do { \
1199 if (name == NULL) { \
1200 ibits[x] = NULL; \
1201 obits[x] = NULL; \
1202 } else { \
1203 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
1204 obits[x] = sbp; \
1205 sbp += ncpbytes / sizeof *sbp; \
1206 error = copyin(name, ibits[x], ncpubytes); \
1207 if (error != 0) \
1208 goto done; \
1209 if (ncpbytes != ncpubytes) \
1210 bzero((char *)ibits[x] + ncpubytes, \
1211 ncpbytes - ncpubytes); \
1212 } \
1213 } while (0)
1214 getbits(fd_in, 0);
1215 getbits(fd_ou, 1);
1216 getbits(fd_ex, 2);
1217 #undef getbits
1218
1219 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
1220 /*
1221 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
1222 * we are running under 32-bit emulation. This should be more
1223 * generic.
1224 */
1225 #define swizzle_fdset(bits) \
1226 if (abi_nfdbits != NFDBITS && bits != NULL) { \
1227 int i; \
1228 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
1229 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
1230 }
1231 #else
1232 #define swizzle_fdset(bits)
1233 #endif
1234
1235 /* Make sure the bit order makes it through an ABI transition */
1236 swizzle_fdset(ibits[0]);
1237 swizzle_fdset(ibits[1]);
1238 swizzle_fdset(ibits[2]);
1239
1240 if (nbufbytes != 0)
1241 bzero(selbits, nbufbytes / 2);
1242
1243 precision = 0;
1244 if (tvp != NULL) {
1245 rtv = *tvp;
1246 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1247 rtv.tv_usec >= 1000000) {
1248 error = EINVAL;
1249 goto done;
1250 }
1251 if (!timevalisset(&rtv))
1252 asbt = 0;
1253 else if (rtv.tv_sec <= INT32_MAX) {
1254 rsbt = tvtosbt(rtv);
1255 precision = rsbt;
1256 precision >>= tc_precexp;
1257 if (TIMESEL(&asbt, rsbt))
1258 asbt += tc_tick_sbt;
1259 if (asbt <= SBT_MAX - rsbt)
1260 asbt += rsbt;
1261 else
1262 asbt = -1;
1263 } else
1264 asbt = -1;
1265 } else
1266 asbt = -1;
1267 seltdinit(td);
1268 /* Iterate until the timeout expires or descriptors become ready. */
1269 for (;;) {
1270 error = selscan(td, ibits, obits, nd);
1271 if (error || td->td_retval[0] != 0)
1272 break;
1273 error = seltdwait(td, asbt, precision);
1274 if (error)
1275 break;
1276 error = selrescan(td, ibits, obits);
1277 if (error || td->td_retval[0] != 0)
1278 break;
1279 }
1280 seltdclear(td);
1281
1282 done:
1283 /* select is not restarted after signals... */
1284 if (error == ERESTART)
1285 error = EINTR;
1286 if (error == EWOULDBLOCK)
1287 error = 0;
1288
1289 /* swizzle bit order back, if necessary */
1290 swizzle_fdset(obits[0]);
1291 swizzle_fdset(obits[1]);
1292 swizzle_fdset(obits[2]);
1293 #undef swizzle_fdset
1294
1295 #define putbits(name, x) \
1296 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
1297 error = error2;
1298 if (error == 0) {
1299 int error2;
1300
1301 putbits(fd_in, 0);
1302 putbits(fd_ou, 1);
1303 putbits(fd_ex, 2);
1304 #undef putbits
1305 }
1306 if (selbits != &s_selbits[0])
1307 free(selbits, M_SELECT);
1308
1309 return (error);
1310 }
1311 /*
1312 * Convert a select bit set to poll flags.
1313 *
1314 * The backend always returns POLLHUP/POLLERR if appropriate and we
1315 * return this as a set bit in any set.
1316 */
1317 static const int select_flags[3] = {
1318 POLLRDNORM | POLLHUP | POLLERR,
1319 POLLWRNORM | POLLHUP | POLLERR,
1320 POLLRDBAND | POLLERR
1321 };
1322
1323 /*
1324 * Compute the fo_poll flags required for a fd given by the index and
1325 * bit position in the fd_mask array.
1326 */
1327 static __inline int
selflags(fd_mask ** ibits,int idx,fd_mask bit)1328 selflags(fd_mask **ibits, int idx, fd_mask bit)
1329 {
1330 int flags;
1331 int msk;
1332
1333 flags = 0;
1334 for (msk = 0; msk < 3; msk++) {
1335 if (ibits[msk] == NULL)
1336 continue;
1337 if ((ibits[msk][idx] & bit) == 0)
1338 continue;
1339 flags |= select_flags[msk];
1340 }
1341 return (flags);
1342 }
1343
1344 /*
1345 * Set the appropriate output bits given a mask of fired events and the
1346 * input bits originally requested.
1347 */
1348 static __inline int
selsetbits(fd_mask ** ibits,fd_mask ** obits,int idx,fd_mask bit,int events)1349 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1350 {
1351 int msk;
1352 int n;
1353
1354 n = 0;
1355 for (msk = 0; msk < 3; msk++) {
1356 if ((events & select_flags[msk]) == 0)
1357 continue;
1358 if (ibits[msk] == NULL)
1359 continue;
1360 if ((ibits[msk][idx] & bit) == 0)
1361 continue;
1362 /*
1363 * XXX Check for a duplicate set. This can occur because a
1364 * socket calls selrecord() twice for each poll() call
1365 * resulting in two selfds per real fd. selrescan() will
1366 * call selsetbits twice as a result.
1367 */
1368 if ((obits[msk][idx] & bit) != 0)
1369 continue;
1370 obits[msk][idx] |= bit;
1371 n++;
1372 }
1373
1374 return (n);
1375 }
1376
1377 /*
1378 * Traverse the list of fds attached to this thread's seltd and check for
1379 * completion.
1380 */
1381 static int
selrescan(struct thread * td,fd_mask ** ibits,fd_mask ** obits)1382 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1383 {
1384 struct filedesc *fdp;
1385 struct selinfo *si;
1386 struct seltd *stp;
1387 struct selfd *sfp;
1388 struct selfd *sfn;
1389 struct file *fp;
1390 fd_mask bit;
1391 int fd, ev, n, idx;
1392 int error;
1393 bool only_user;
1394
1395 fdp = td->td_proc->p_fd;
1396 stp = td->td_sel;
1397 n = 0;
1398 only_user = FILEDESC_IS_ONLY_USER(fdp);
1399 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1400 fd = (int)(uintptr_t)sfp->sf_cookie;
1401 si = sfp->sf_si;
1402 selfdfree(stp, sfp);
1403 /* If the selinfo wasn't cleared the event didn't fire. */
1404 if (si != NULL)
1405 continue;
1406 if (only_user)
1407 error = fget_only_user(fdp, fd, &cap_event_rights, &fp);
1408 else
1409 error = fget_unlocked(td, fd, &cap_event_rights, &fp);
1410 if (__predict_false(error != 0))
1411 return (error);
1412 idx = fd / NFDBITS;
1413 bit = (fd_mask)1 << (fd % NFDBITS);
1414 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1415 if (only_user)
1416 fput_only_user(fdp, fp);
1417 else
1418 fdrop(fp, td);
1419 if (ev != 0)
1420 n += selsetbits(ibits, obits, idx, bit, ev);
1421 }
1422 stp->st_flags = 0;
1423 td->td_retval[0] = n;
1424 return (0);
1425 }
1426
1427 /*
1428 * Perform the initial filedescriptor scan and register ourselves with
1429 * each selinfo.
1430 */
1431 static int
selscan(struct thread * td,fd_mask ** ibits,fd_mask ** obits,int nfd)1432 selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd)
1433 {
1434 struct filedesc *fdp;
1435 struct file *fp;
1436 fd_mask bit;
1437 int ev, flags, end, fd;
1438 int n, idx;
1439 int error;
1440 bool only_user;
1441
1442 fdp = td->td_proc->p_fd;
1443 n = 0;
1444 only_user = FILEDESC_IS_ONLY_USER(fdp);
1445 for (idx = 0, fd = 0; fd < nfd; idx++) {
1446 end = imin(fd + NFDBITS, nfd);
1447 for (bit = 1; fd < end; bit <<= 1, fd++) {
1448 /* Compute the list of events we're interested in. */
1449 flags = selflags(ibits, idx, bit);
1450 if (flags == 0)
1451 continue;
1452 if (only_user)
1453 error = fget_only_user(fdp, fd, &cap_event_rights, &fp);
1454 else
1455 error = fget_unlocked(td, fd, &cap_event_rights, &fp);
1456 if (__predict_false(error != 0))
1457 return (error);
1458 selfdalloc(td, (void *)(uintptr_t)fd);
1459 ev = fo_poll(fp, flags, td->td_ucred, td);
1460 if (only_user)
1461 fput_only_user(fdp, fp);
1462 else
1463 fdrop(fp, td);
1464 if (ev != 0)
1465 n += selsetbits(ibits, obits, idx, bit, ev);
1466 }
1467 }
1468
1469 td->td_retval[0] = n;
1470 return (0);
1471 }
1472
1473 int
sys_poll(struct thread * td,struct poll_args * uap)1474 sys_poll(struct thread *td, struct poll_args *uap)
1475 {
1476 struct timespec ts, *tsp;
1477
1478 if (uap->timeout != INFTIM) {
1479 if (uap->timeout < 0)
1480 return (EINVAL);
1481 ts.tv_sec = uap->timeout / 1000;
1482 ts.tv_nsec = (uap->timeout % 1000) * 1000000;
1483 tsp = &ts;
1484 } else
1485 tsp = NULL;
1486
1487 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL));
1488 }
1489
1490 /*
1491 * kfds points to an array in the kernel.
1492 */
1493 int
kern_poll_kfds(struct thread * td,struct pollfd * kfds,u_int nfds,struct timespec * tsp,sigset_t * uset)1494 kern_poll_kfds(struct thread *td, struct pollfd *kfds, u_int nfds,
1495 struct timespec *tsp, sigset_t *uset)
1496 {
1497 sbintime_t sbt, precision, tmp;
1498 time_t over;
1499 struct timespec ts;
1500 int error;
1501
1502 precision = 0;
1503 if (tsp != NULL) {
1504 if (!timespecvalid_interval(tsp))
1505 return (EINVAL);
1506 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
1507 sbt = 0;
1508 else {
1509 ts = *tsp;
1510 if (ts.tv_sec > INT32_MAX / 2) {
1511 over = ts.tv_sec - INT32_MAX / 2;
1512 ts.tv_sec -= over;
1513 } else
1514 over = 0;
1515 tmp = tstosbt(ts);
1516 precision = tmp;
1517 precision >>= tc_precexp;
1518 if (TIMESEL(&sbt, tmp))
1519 sbt += tc_tick_sbt;
1520 sbt += tmp;
1521 }
1522 } else
1523 sbt = -1;
1524
1525 if (uset != NULL) {
1526 error = kern_sigprocmask(td, SIG_SETMASK, uset,
1527 &td->td_oldsigmask, 0);
1528 if (error)
1529 return (error);
1530 td->td_pflags |= TDP_OLDMASK;
1531 /*
1532 * Make sure that ast() is called on return to
1533 * usermode and TDP_OLDMASK is cleared, restoring old
1534 * sigmask.
1535 */
1536 ast_sched(td, TDA_SIGSUSPEND);
1537 }
1538
1539 seltdinit(td);
1540 /* Iterate until the timeout expires or descriptors become ready. */
1541 for (;;) {
1542 error = pollscan(td, kfds, nfds);
1543 if (error || td->td_retval[0] != 0)
1544 break;
1545 error = seltdwait(td, sbt, precision);
1546 if (error)
1547 break;
1548 error = pollrescan(td);
1549 if (error || td->td_retval[0] != 0)
1550 break;
1551 }
1552 seltdclear(td);
1553
1554 /* poll is not restarted after signals... */
1555 if (error == ERESTART)
1556 error = EINTR;
1557 if (error == EWOULDBLOCK)
1558 error = 0;
1559 return (error);
1560 }
1561
1562 int
sys_ppoll(struct thread * td,struct ppoll_args * uap)1563 sys_ppoll(struct thread *td, struct ppoll_args *uap)
1564 {
1565 struct timespec ts, *tsp;
1566 sigset_t set, *ssp;
1567 int error;
1568
1569 if (uap->ts != NULL) {
1570 error = copyin(uap->ts, &ts, sizeof(ts));
1571 if (error)
1572 return (error);
1573 tsp = &ts;
1574 } else
1575 tsp = NULL;
1576 if (uap->set != NULL) {
1577 error = copyin(uap->set, &set, sizeof(set));
1578 if (error)
1579 return (error);
1580 ssp = &set;
1581 } else
1582 ssp = NULL;
1583 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp));
1584 }
1585
1586 /*
1587 * ufds points to an array in user space.
1588 */
1589 int
kern_poll(struct thread * td,struct pollfd * ufds,u_int nfds,struct timespec * tsp,sigset_t * set)1590 kern_poll(struct thread *td, struct pollfd *ufds, u_int nfds,
1591 struct timespec *tsp, sigset_t *set)
1592 {
1593 struct pollfd *kfds;
1594 struct pollfd stackfds[32];
1595 int error;
1596
1597 if (kern_poll_maxfds(nfds))
1598 return (EINVAL);
1599 if (nfds > nitems(stackfds))
1600 kfds = mallocarray(nfds, sizeof(*kfds), M_TEMP, M_WAITOK);
1601 else
1602 kfds = stackfds;
1603 error = copyin(ufds, kfds, nfds * sizeof(*kfds));
1604 if (error != 0)
1605 goto out;
1606
1607 error = kern_poll_kfds(td, kfds, nfds, tsp, set);
1608 if (error == 0)
1609 error = pollout(td, kfds, ufds, nfds);
1610 #ifdef KTRACE
1611 if (error == 0 && KTRPOINT(td, KTR_STRUCT_ARRAY))
1612 ktrstructarray("pollfd", UIO_USERSPACE, ufds, nfds,
1613 sizeof(*ufds));
1614 #endif
1615
1616 out:
1617 if (nfds > nitems(stackfds))
1618 free(kfds, M_TEMP);
1619 return (error);
1620 }
1621
1622 bool
kern_poll_maxfds(u_int nfds)1623 kern_poll_maxfds(u_int nfds)
1624 {
1625
1626 /*
1627 * This is kinda bogus. We have fd limits, but that is not
1628 * really related to the size of the pollfd array. Make sure
1629 * we let the process use at least FD_SETSIZE entries and at
1630 * least enough for the system-wide limits. We want to be reasonably
1631 * safe, but not overly restrictive.
1632 */
1633 return (nfds > maxfilesperproc && nfds > FD_SETSIZE);
1634 }
1635
1636 static int
pollrescan(struct thread * td)1637 pollrescan(struct thread *td)
1638 {
1639 struct seltd *stp;
1640 struct selfd *sfp;
1641 struct selfd *sfn;
1642 struct selinfo *si;
1643 struct filedesc *fdp;
1644 struct file *fp;
1645 struct pollfd *fd;
1646 int n, error;
1647 bool only_user;
1648
1649 n = 0;
1650 fdp = td->td_proc->p_fd;
1651 stp = td->td_sel;
1652 only_user = FILEDESC_IS_ONLY_USER(fdp);
1653 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1654 fd = (struct pollfd *)sfp->sf_cookie;
1655 si = sfp->sf_si;
1656 selfdfree(stp, sfp);
1657 /* If the selinfo wasn't cleared the event didn't fire. */
1658 if (si != NULL)
1659 continue;
1660 if (only_user)
1661 error = fget_only_user(fdp, fd->fd, &cap_event_rights, &fp);
1662 else
1663 error = fget_unlocked(td, fd->fd, &cap_event_rights, &fp);
1664 if (__predict_false(error != 0)) {
1665 fd->revents = POLLNVAL;
1666 n++;
1667 continue;
1668 }
1669 /*
1670 * Note: backend also returns POLLHUP and
1671 * POLLERR if appropriate.
1672 */
1673 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1674 if (only_user)
1675 fput_only_user(fdp, fp);
1676 else
1677 fdrop(fp, td);
1678 if (fd->revents != 0)
1679 n++;
1680 }
1681 stp->st_flags = 0;
1682 td->td_retval[0] = n;
1683 return (0);
1684 }
1685
1686 static int
pollout(struct thread * td,struct pollfd * fds,struct pollfd * ufds,u_int nfd)1687 pollout(struct thread *td, struct pollfd *fds, struct pollfd *ufds, u_int nfd)
1688 {
1689 int error = 0;
1690 u_int i = 0;
1691 u_int n = 0;
1692
1693 for (i = 0; i < nfd; i++) {
1694 error = copyout(&fds->revents, &ufds->revents,
1695 sizeof(ufds->revents));
1696 if (error)
1697 return (error);
1698 if (fds->revents != 0)
1699 n++;
1700 fds++;
1701 ufds++;
1702 }
1703 td->td_retval[0] = n;
1704 return (0);
1705 }
1706
1707 static int
pollscan(struct thread * td,struct pollfd * fds,u_int nfd)1708 pollscan(struct thread *td, struct pollfd *fds, u_int nfd)
1709 {
1710 struct filedesc *fdp;
1711 struct file *fp;
1712 int i, n, error;
1713 bool only_user;
1714
1715 n = 0;
1716 fdp = td->td_proc->p_fd;
1717 only_user = FILEDESC_IS_ONLY_USER(fdp);
1718 for (i = 0; i < nfd; i++, fds++) {
1719 if (fds->fd < 0) {
1720 fds->revents = 0;
1721 continue;
1722 }
1723 if (only_user)
1724 error = fget_only_user(fdp, fds->fd, &cap_event_rights, &fp);
1725 else
1726 error = fget_unlocked(td, fds->fd, &cap_event_rights, &fp);
1727 if (__predict_false(error != 0)) {
1728 fds->revents = POLLNVAL;
1729 n++;
1730 continue;
1731 }
1732 /*
1733 * Note: backend also returns POLLHUP and
1734 * POLLERR if appropriate.
1735 */
1736 selfdalloc(td, fds);
1737 fds->revents = fo_poll(fp, fds->events,
1738 td->td_ucred, td);
1739 if (only_user)
1740 fput_only_user(fdp, fp);
1741 else
1742 fdrop(fp, td);
1743 /*
1744 * POSIX requires POLLOUT to be never
1745 * set simultaneously with POLLHUP.
1746 */
1747 if ((fds->revents & POLLHUP) != 0)
1748 fds->revents &= ~POLLOUT;
1749
1750 if (fds->revents != 0)
1751 n++;
1752 }
1753 td->td_retval[0] = n;
1754 return (0);
1755 }
1756
1757 /*
1758 * XXX This was created specifically to support netncp and netsmb. This
1759 * allows the caller to specify a socket to wait for events on. It returns
1760 * 0 if any events matched and an error otherwise. There is no way to
1761 * determine which events fired.
1762 */
1763 int
selsocket(struct socket * so,int events,struct timeval * tvp,struct thread * td)1764 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1765 {
1766 struct timeval rtv;
1767 sbintime_t asbt, precision, rsbt;
1768 int error;
1769
1770 precision = 0; /* stupid gcc! */
1771 if (tvp != NULL) {
1772 rtv = *tvp;
1773 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1774 rtv.tv_usec >= 1000000)
1775 return (EINVAL);
1776 if (!timevalisset(&rtv))
1777 asbt = 0;
1778 else if (rtv.tv_sec <= INT32_MAX) {
1779 rsbt = tvtosbt(rtv);
1780 precision = rsbt;
1781 precision >>= tc_precexp;
1782 if (TIMESEL(&asbt, rsbt))
1783 asbt += tc_tick_sbt;
1784 if (asbt <= SBT_MAX - rsbt)
1785 asbt += rsbt;
1786 else
1787 asbt = -1;
1788 } else
1789 asbt = -1;
1790 } else
1791 asbt = -1;
1792 seltdinit(td);
1793 /*
1794 * Iterate until the timeout expires or the socket becomes ready.
1795 */
1796 for (;;) {
1797 selfdalloc(td, NULL);
1798 if (sopoll(so, events, NULL, td) != 0) {
1799 error = 0;
1800 break;
1801 }
1802 error = seltdwait(td, asbt, precision);
1803 if (error)
1804 break;
1805 }
1806 seltdclear(td);
1807 /* XXX Duplicates ncp/smb behavior. */
1808 if (error == ERESTART)
1809 error = 0;
1810 return (error);
1811 }
1812
1813 /*
1814 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1815 * have two select sets, one for read and another for write.
1816 */
1817 static void
selfdalloc(struct thread * td,void * cookie)1818 selfdalloc(struct thread *td, void *cookie)
1819 {
1820 struct seltd *stp;
1821
1822 stp = td->td_sel;
1823 if (stp->st_free1 == NULL)
1824 stp->st_free1 = malloc(sizeof(*stp->st_free1), M_SELFD, M_WAITOK|M_ZERO);
1825 stp->st_free1->sf_td = stp;
1826 stp->st_free1->sf_cookie = cookie;
1827 if (stp->st_free2 == NULL)
1828 stp->st_free2 = malloc(sizeof(*stp->st_free2), M_SELFD, M_WAITOK|M_ZERO);
1829 stp->st_free2->sf_td = stp;
1830 stp->st_free2->sf_cookie = cookie;
1831 }
1832
1833 static void
selfdfree(struct seltd * stp,struct selfd * sfp)1834 selfdfree(struct seltd *stp, struct selfd *sfp)
1835 {
1836 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1837 /*
1838 * Paired with doselwakeup.
1839 */
1840 if (atomic_load_acq_ptr((uintptr_t *)&sfp->sf_si) != (uintptr_t)NULL) {
1841 mtx_lock(sfp->sf_mtx);
1842 if (sfp->sf_si != NULL) {
1843 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1844 }
1845 mtx_unlock(sfp->sf_mtx);
1846 }
1847 free(sfp, M_SELFD);
1848 }
1849
1850 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
1851 void
seldrain(struct selinfo * sip)1852 seldrain(struct selinfo *sip)
1853 {
1854
1855 /*
1856 * This feature is already provided by doselwakeup(), thus it is
1857 * enough to go for it.
1858 * Eventually, the context, should take care to avoid races
1859 * between thread calling select()/poll() and file descriptor
1860 * detaching, but, again, the races are just the same as
1861 * selwakeup().
1862 */
1863 doselwakeup(sip, -1);
1864 }
1865
1866 /*
1867 * Record a select request.
1868 */
1869 void
selrecord(struct thread * selector,struct selinfo * sip)1870 selrecord(struct thread *selector, struct selinfo *sip)
1871 {
1872 struct selfd *sfp;
1873 struct seltd *stp;
1874 struct mtx *mtxp;
1875
1876 stp = selector->td_sel;
1877 /*
1878 * Don't record when doing a rescan.
1879 */
1880 if (stp->st_flags & SELTD_RESCAN)
1881 return;
1882 /*
1883 * Grab one of the preallocated descriptors.
1884 */
1885 sfp = NULL;
1886 if ((sfp = stp->st_free1) != NULL)
1887 stp->st_free1 = NULL;
1888 else if ((sfp = stp->st_free2) != NULL)
1889 stp->st_free2 = NULL;
1890 else
1891 panic("selrecord: No free selfd on selq");
1892 mtxp = sip->si_mtx;
1893 if (mtxp == NULL)
1894 mtxp = mtx_pool_find(mtxpool_select, sip);
1895 /*
1896 * Initialize the sfp and queue it in the thread.
1897 */
1898 sfp->sf_si = sip;
1899 sfp->sf_mtx = mtxp;
1900 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1901 /*
1902 * Now that we've locked the sip, check for initialization.
1903 */
1904 mtx_lock(mtxp);
1905 if (sip->si_mtx == NULL) {
1906 sip->si_mtx = mtxp;
1907 TAILQ_INIT(&sip->si_tdlist);
1908 }
1909 /*
1910 * Add this thread to the list of selfds listening on this selinfo.
1911 */
1912 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1913 mtx_unlock(sip->si_mtx);
1914 }
1915
1916 /* Wake up a selecting thread. */
1917 void
selwakeup(struct selinfo * sip)1918 selwakeup(struct selinfo *sip)
1919 {
1920 doselwakeup(sip, -1);
1921 }
1922
1923 /* Wake up a selecting thread, and set its priority. */
1924 void
selwakeuppri(struct selinfo * sip,int pri)1925 selwakeuppri(struct selinfo *sip, int pri)
1926 {
1927 doselwakeup(sip, pri);
1928 }
1929
1930 /*
1931 * Do a wakeup when a selectable event occurs.
1932 */
1933 static void
doselwakeup(struct selinfo * sip,int pri)1934 doselwakeup(struct selinfo *sip, int pri)
1935 {
1936 struct selfd *sfp;
1937 struct selfd *sfn;
1938 struct seltd *stp;
1939
1940 /* If it's not initialized there can't be any waiters. */
1941 if (sip->si_mtx == NULL)
1942 return;
1943 /*
1944 * Locking the selinfo locks all selfds associated with it.
1945 */
1946 mtx_lock(sip->si_mtx);
1947 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1948 /*
1949 * Once we remove this sfp from the list and clear the
1950 * sf_si seltdclear will know to ignore this si.
1951 */
1952 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1953 stp = sfp->sf_td;
1954 mtx_lock(&stp->st_mtx);
1955 stp->st_flags |= SELTD_PENDING;
1956 cv_broadcastpri(&stp->st_wait, pri);
1957 mtx_unlock(&stp->st_mtx);
1958 /*
1959 * Paired with selfdfree.
1960 *
1961 * Storing this only after the wakeup provides an invariant that
1962 * stp is not used after selfdfree returns.
1963 */
1964 atomic_store_rel_ptr((uintptr_t *)&sfp->sf_si, (uintptr_t)NULL);
1965 }
1966 mtx_unlock(sip->si_mtx);
1967 }
1968
1969 static void
seltdinit(struct thread * td)1970 seltdinit(struct thread *td)
1971 {
1972 struct seltd *stp;
1973
1974 stp = td->td_sel;
1975 if (stp != NULL) {
1976 MPASS(stp->st_flags == 0);
1977 MPASS(STAILQ_EMPTY(&stp->st_selq));
1978 return;
1979 }
1980 stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1981 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1982 cv_init(&stp->st_wait, "select");
1983 stp->st_flags = 0;
1984 STAILQ_INIT(&stp->st_selq);
1985 td->td_sel = stp;
1986 }
1987
1988 static int
seltdwait(struct thread * td,sbintime_t sbt,sbintime_t precision)1989 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision)
1990 {
1991 struct seltd *stp;
1992 int error;
1993
1994 stp = td->td_sel;
1995 /*
1996 * An event of interest may occur while we do not hold the seltd
1997 * locked so check the pending flag before we sleep.
1998 */
1999 mtx_lock(&stp->st_mtx);
2000 /*
2001 * Any further calls to selrecord will be a rescan.
2002 */
2003 stp->st_flags |= SELTD_RESCAN;
2004 if (stp->st_flags & SELTD_PENDING) {
2005 mtx_unlock(&stp->st_mtx);
2006 return (0);
2007 }
2008 if (sbt == 0)
2009 error = EWOULDBLOCK;
2010 else if (sbt != -1)
2011 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx,
2012 sbt, precision, C_ABSOLUTE);
2013 else
2014 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
2015 mtx_unlock(&stp->st_mtx);
2016
2017 return (error);
2018 }
2019
2020 void
seltdfini(struct thread * td)2021 seltdfini(struct thread *td)
2022 {
2023 struct seltd *stp;
2024
2025 stp = td->td_sel;
2026 if (stp == NULL)
2027 return;
2028 MPASS(stp->st_flags == 0);
2029 MPASS(STAILQ_EMPTY(&stp->st_selq));
2030 if (stp->st_free1)
2031 free(stp->st_free1, M_SELFD);
2032 if (stp->st_free2)
2033 free(stp->st_free2, M_SELFD);
2034 td->td_sel = NULL;
2035 cv_destroy(&stp->st_wait);
2036 mtx_destroy(&stp->st_mtx);
2037 free(stp, M_SELECT);
2038 }
2039
2040 /*
2041 * Remove the references to the thread from all of the objects we were
2042 * polling.
2043 */
2044 static void
seltdclear(struct thread * td)2045 seltdclear(struct thread *td)
2046 {
2047 struct seltd *stp;
2048 struct selfd *sfp;
2049 struct selfd *sfn;
2050
2051 stp = td->td_sel;
2052 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
2053 selfdfree(stp, sfp);
2054 stp->st_flags = 0;
2055 }
2056
2057 static void selectinit(void *);
2058 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
2059 static void
selectinit(void * dummy __unused)2060 selectinit(void *dummy __unused)
2061 {
2062
2063 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
2064 }
2065
2066 /*
2067 * Set up a syscall return value that follows the convention specified for
2068 * posix_* functions.
2069 */
2070 int
kern_posix_error(struct thread * td,int error)2071 kern_posix_error(struct thread *td, int error)
2072 {
2073
2074 if (error <= 0)
2075 return (error);
2076 td->td_errno = error;
2077 td->td_pflags |= TDP_NERRNO;
2078 td->td_retval[0] = error;
2079 return (0);
2080 }
2081
2082 int
kcmp_cmp(uintptr_t a,uintptr_t b)2083 kcmp_cmp(uintptr_t a, uintptr_t b)
2084 {
2085 if (a == b)
2086 return (0);
2087 else if (a < b)
2088 return (1);
2089 return (2);
2090 }
2091
2092 static int
kcmp_pget(struct thread * td,pid_t pid,struct proc ** pp)2093 kcmp_pget(struct thread *td, pid_t pid, struct proc **pp)
2094 {
2095 int error;
2096
2097 if (pid == td->td_proc->p_pid) {
2098 *pp = td->td_proc;
2099 return (0);
2100 }
2101 error = pget(pid, PGET_NOTID | PGET_CANDEBUG | PGET_NOTWEXIT |
2102 PGET_HOLD, pp);
2103 MPASS(*pp != td->td_proc);
2104 return (error);
2105 }
2106
2107 int
kern_kcmp(struct thread * td,pid_t pid1,pid_t pid2,int type,uintptr_t idx1,uintptr_t idx2)2108 kern_kcmp(struct thread *td, pid_t pid1, pid_t pid2, int type,
2109 uintptr_t idx1, uintptr_t idx2)
2110 {
2111 struct proc *p1, *p2;
2112 struct file *fp1, *fp2;
2113 int error, res;
2114
2115 res = -1;
2116 p1 = p2 = NULL;
2117 error = kcmp_pget(td, pid1, &p1);
2118 if (error == 0)
2119 error = kcmp_pget(td, pid2, &p2);
2120 if (error != 0)
2121 goto out;
2122
2123 switch (type) {
2124 case KCMP_FILE:
2125 case KCMP_FILEOBJ:
2126 error = fget_remote(td, p1, idx1, &fp1);
2127 if (error == 0) {
2128 error = fget_remote(td, p2, idx2, &fp2);
2129 if (error == 0) {
2130 if (type == KCMP_FILEOBJ)
2131 res = fo_cmp(fp1, fp2, td);
2132 else
2133 res = kcmp_cmp((uintptr_t)fp1,
2134 (uintptr_t)fp2);
2135 fdrop(fp2, td);
2136 }
2137 fdrop(fp1, td);
2138 }
2139 break;
2140 case KCMP_FILES:
2141 res = kcmp_cmp((uintptr_t)p1->p_fd, (uintptr_t)p2->p_fd);
2142 break;
2143 case KCMP_SIGHAND:
2144 res = kcmp_cmp((uintptr_t)p1->p_sigacts,
2145 (uintptr_t)p2->p_sigacts);
2146 break;
2147 case KCMP_VM:
2148 res = kcmp_cmp((uintptr_t)p1->p_vmspace,
2149 (uintptr_t)p2->p_vmspace);
2150 break;
2151 default:
2152 error = EINVAL;
2153 break;
2154 }
2155
2156 out:
2157 if (p1 != NULL && p1 != td->td_proc)
2158 PRELE(p1);
2159 if (p2 != NULL && p2 != td->td_proc)
2160 PRELE(p2);
2161
2162 td->td_retval[0] = res;
2163 return (error);
2164 }
2165
2166 int
sys_kcmp(struct thread * td,struct kcmp_args * uap)2167 sys_kcmp(struct thread *td, struct kcmp_args *uap)
2168 {
2169 return (kern_kcmp(td, uap->pid1, uap->pid2, uap->type,
2170 uap->idx1, uap->idx2));
2171 }
2172
2173 int
file_kcmp_generic(struct file * fp1,struct file * fp2,struct thread * td)2174 file_kcmp_generic(struct file *fp1, struct file *fp2, struct thread *td)
2175 {
2176 if (fp1->f_type != fp2->f_type)
2177 return (3);
2178 return (kcmp_cmp((uintptr_t)fp1->f_data, (uintptr_t)fp2->f_data));
2179 }
2180