xref: /dflybsd-src/sys/kern/sys_generic.c (revision b287d64931f43a98750195e846e5681a1b90eb06)
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)sys_generic.c	8.5 (Berkeley) 1/21/94
39  * $FreeBSD: src/sys/kern/sys_generic.c,v 1.55.2.10 2001/03/17 10:39:32 peter Exp $
40  * $DragonFly: src/sys/kern/sys_generic.c,v 1.49 2008/05/05 22:09:44 dillon Exp $
41  */
42 
43 #include "opt_ktrace.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/event.h>
49 #include <sys/filedesc.h>
50 #include <sys/filio.h>
51 #include <sys/fcntl.h>
52 #include <sys/file.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/kern_syscall.h>
59 #include <sys/malloc.h>
60 #include <sys/mapped_ioctl.h>
61 #include <sys/poll.h>
62 #include <sys/queue.h>
63 #include <sys/resourcevar.h>
64 #include <sys/sysctl.h>
65 #include <sys/sysent.h>
66 #include <sys/buf.h>
67 #ifdef KTRACE
68 #include <sys/ktrace.h>
69 #endif
70 #include <vm/vm.h>
71 #include <vm/vm_page.h>
72 
73 #include <sys/file2.h>
74 #include <sys/mplock2.h>
75 
76 #include <machine/limits.h>
77 
78 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
79 static MALLOC_DEFINE(M_IOCTLMAP, "ioctlmap", "mapped ioctl handler buffer");
80 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
81 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
82 
83 typedef struct kfd_set {
84         fd_mask	fds_bits[2];
85 } kfd_set;
86 
87 enum select_copyin_states {
88     COPYIN_READ, COPYIN_WRITE, COPYIN_EXCEPT, COPYIN_DONE };
89 
90 struct select_kevent_copyin_args {
91 	kfd_set		*read_set;
92 	kfd_set		*write_set;
93 	kfd_set		*except_set;
94 	int		active_set;	/* One of select_copyin_states */
95 	struct lwp	*lwp;		/* Pointer to our lwp */
96 	int		num_fds;	/* Number of file descriptors (syscall arg) */
97 	int		proc_fds;	/* Processed fd's (wraps) */
98 	int		error;		/* Returned to userland */
99 };
100 
101 struct poll_kevent_copyin_args {
102 	struct lwp	*lwp;
103 	struct pollfd	*fds;
104 	int		nfds;
105 	int		pfds;
106 	int		error;
107 };
108 
109 static int 	doselect(int nd, fd_set *in, fd_set *ou, fd_set *ex,
110 			 struct timespec *ts, int *res);
111 static int	dopoll(int nfds, struct pollfd *fds, struct timespec *ts,
112 		       int *res);
113 static int	dofileread(int, struct file *, struct uio *, int, size_t *);
114 static int	dofilewrite(int, struct file *, struct uio *, int, size_t *);
115 
116 /*
117  * Read system call.
118  *
119  * MPSAFE
120  */
121 int
122 sys_read(struct read_args *uap)
123 {
124 	struct thread *td = curthread;
125 	struct uio auio;
126 	struct iovec aiov;
127 	int error;
128 
129 	if ((ssize_t)uap->nbyte < 0)
130 		error = EINVAL;
131 
132 	aiov.iov_base = uap->buf;
133 	aiov.iov_len = uap->nbyte;
134 	auio.uio_iov = &aiov;
135 	auio.uio_iovcnt = 1;
136 	auio.uio_offset = -1;
137 	auio.uio_resid = uap->nbyte;
138 	auio.uio_rw = UIO_READ;
139 	auio.uio_segflg = UIO_USERSPACE;
140 	auio.uio_td = td;
141 
142 	error = kern_preadv(uap->fd, &auio, 0, &uap->sysmsg_szresult);
143 	return(error);
144 }
145 
146 /*
147  * Positioned (Pread) read system call
148  *
149  * MPSAFE
150  */
151 int
152 sys_extpread(struct extpread_args *uap)
153 {
154 	struct thread *td = curthread;
155 	struct uio auio;
156 	struct iovec aiov;
157 	int error;
158 	int flags;
159 
160 	if ((ssize_t)uap->nbyte < 0)
161 		return(EINVAL);
162 
163 	aiov.iov_base = uap->buf;
164 	aiov.iov_len = uap->nbyte;
165 	auio.uio_iov = &aiov;
166 	auio.uio_iovcnt = 1;
167 	auio.uio_offset = uap->offset;
168 	auio.uio_resid = uap->nbyte;
169 	auio.uio_rw = UIO_READ;
170 	auio.uio_segflg = UIO_USERSPACE;
171 	auio.uio_td = td;
172 
173 	flags = uap->flags & O_FMASK;
174 	if (uap->offset != (off_t)-1)
175 		flags |= O_FOFFSET;
176 
177 	error = kern_preadv(uap->fd, &auio, flags, &uap->sysmsg_szresult);
178 	return(error);
179 }
180 
181 /*
182  * Scatter read system call.
183  *
184  * MPSAFE
185  */
186 int
187 sys_readv(struct readv_args *uap)
188 {
189 	struct thread *td = curthread;
190 	struct uio auio;
191 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
192 	int error;
193 
194 	error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt,
195 			     &auio.uio_resid);
196 	if (error)
197 		return (error);
198 	auio.uio_iov = iov;
199 	auio.uio_iovcnt = uap->iovcnt;
200 	auio.uio_offset = -1;
201 	auio.uio_rw = UIO_READ;
202 	auio.uio_segflg = UIO_USERSPACE;
203 	auio.uio_td = td;
204 
205 	error = kern_preadv(uap->fd, &auio, 0, &uap->sysmsg_szresult);
206 
207 	iovec_free(&iov, aiov);
208 	return (error);
209 }
210 
211 
212 /*
213  * Scatter positioned read system call.
214  *
215  * MPSAFE
216  */
217 int
218 sys_extpreadv(struct extpreadv_args *uap)
219 {
220 	struct thread *td = curthread;
221 	struct uio auio;
222 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
223 	int error;
224 	int flags;
225 
226 	error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt,
227 			     &auio.uio_resid);
228 	if (error)
229 		return (error);
230 	auio.uio_iov = iov;
231 	auio.uio_iovcnt = uap->iovcnt;
232 	auio.uio_offset = uap->offset;
233 	auio.uio_rw = UIO_READ;
234 	auio.uio_segflg = UIO_USERSPACE;
235 	auio.uio_td = td;
236 
237 	flags = uap->flags & O_FMASK;
238 	if (uap->offset != (off_t)-1)
239 		flags |= O_FOFFSET;
240 
241 	error = kern_preadv(uap->fd, &auio, flags, &uap->sysmsg_szresult);
242 
243 	iovec_free(&iov, aiov);
244 	return(error);
245 }
246 
247 /*
248  * MPSAFE
249  */
250 int
251 kern_preadv(int fd, struct uio *auio, int flags, size_t *res)
252 {
253 	struct thread *td = curthread;
254 	struct proc *p = td->td_proc;
255 	struct file *fp;
256 	int error;
257 
258 	KKASSERT(p);
259 
260 	fp = holdfp(p->p_fd, fd, FREAD);
261 	if (fp == NULL)
262 		return (EBADF);
263 	if (flags & O_FOFFSET && fp->f_type != DTYPE_VNODE) {
264 		error = ESPIPE;
265 	} else {
266 		error = dofileread(fd, fp, auio, flags, res);
267 	}
268 	fdrop(fp);
269 	return(error);
270 }
271 
272 /*
273  * Common code for readv and preadv that reads data in
274  * from a file using the passed in uio, offset, and flags.
275  *
276  * MPALMOSTSAFE - ktrace needs help
277  */
278 static int
279 dofileread(int fd, struct file *fp, struct uio *auio, int flags, size_t *res)
280 {
281 	int error;
282 	size_t len;
283 #ifdef KTRACE
284 	struct thread *td = curthread;
285 	struct iovec *ktriov = NULL;
286 	struct uio ktruio;
287 #endif
288 
289 #ifdef KTRACE
290 	/*
291 	 * if tracing, save a copy of iovec
292 	 */
293 	if (KTRPOINT(td, KTR_GENIO))  {
294 		int iovlen = auio->uio_iovcnt * sizeof(struct iovec);
295 
296 		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
297 		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
298 		ktruio = *auio;
299 	}
300 #endif
301 	len = auio->uio_resid;
302 	error = fo_read(fp, auio, fp->f_cred, flags);
303 	if (error) {
304 		if (auio->uio_resid != len && (error == ERESTART ||
305 		    error == EINTR || error == EWOULDBLOCK))
306 			error = 0;
307 	}
308 #ifdef KTRACE
309 	if (ktriov != NULL) {
310 		if (error == 0) {
311 			ktruio.uio_iov = ktriov;
312 			ktruio.uio_resid = len - auio->uio_resid;
313 			get_mplock();
314 			ktrgenio(td->td_lwp, fd, UIO_READ, &ktruio, error);
315 			rel_mplock();
316 		}
317 		FREE(ktriov, M_TEMP);
318 	}
319 #endif
320 	if (error == 0)
321 		*res = len - auio->uio_resid;
322 
323 	return(error);
324 }
325 
326 /*
327  * Write system call
328  *
329  * MPSAFE
330  */
331 int
332 sys_write(struct write_args *uap)
333 {
334 	struct thread *td = curthread;
335 	struct uio auio;
336 	struct iovec aiov;
337 	int error;
338 
339 	if ((ssize_t)uap->nbyte < 0)
340 		error = EINVAL;
341 
342 	aiov.iov_base = (void *)(uintptr_t)uap->buf;
343 	aiov.iov_len = uap->nbyte;
344 	auio.uio_iov = &aiov;
345 	auio.uio_iovcnt = 1;
346 	auio.uio_offset = -1;
347 	auio.uio_resid = uap->nbyte;
348 	auio.uio_rw = UIO_WRITE;
349 	auio.uio_segflg = UIO_USERSPACE;
350 	auio.uio_td = td;
351 
352 	error = kern_pwritev(uap->fd, &auio, 0, &uap->sysmsg_szresult);
353 
354 	return(error);
355 }
356 
357 /*
358  * Pwrite system call
359  *
360  * MPSAFE
361  */
362 int
363 sys_extpwrite(struct extpwrite_args *uap)
364 {
365 	struct thread *td = curthread;
366 	struct uio auio;
367 	struct iovec aiov;
368 	int error;
369 	int flags;
370 
371 	if ((ssize_t)uap->nbyte < 0)
372 		error = EINVAL;
373 
374 	aiov.iov_base = (void *)(uintptr_t)uap->buf;
375 	aiov.iov_len = uap->nbyte;
376 	auio.uio_iov = &aiov;
377 	auio.uio_iovcnt = 1;
378 	auio.uio_offset = uap->offset;
379 	auio.uio_resid = uap->nbyte;
380 	auio.uio_rw = UIO_WRITE;
381 	auio.uio_segflg = UIO_USERSPACE;
382 	auio.uio_td = td;
383 
384 	flags = uap->flags & O_FMASK;
385 	if (uap->offset != (off_t)-1)
386 		flags |= O_FOFFSET;
387 	error = kern_pwritev(uap->fd, &auio, flags, &uap->sysmsg_szresult);
388 	return(error);
389 }
390 
391 /*
392  * MPSAFE
393  */
394 int
395 sys_writev(struct writev_args *uap)
396 {
397 	struct thread *td = curthread;
398 	struct uio auio;
399 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
400 	int error;
401 
402 	error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt,
403 			     &auio.uio_resid);
404 	if (error)
405 		return (error);
406 	auio.uio_iov = iov;
407 	auio.uio_iovcnt = uap->iovcnt;
408 	auio.uio_offset = -1;
409 	auio.uio_rw = UIO_WRITE;
410 	auio.uio_segflg = UIO_USERSPACE;
411 	auio.uio_td = td;
412 
413 	error = kern_pwritev(uap->fd, &auio, 0, &uap->sysmsg_szresult);
414 
415 	iovec_free(&iov, aiov);
416 	return (error);
417 }
418 
419 
420 /*
421  * Gather positioned write system call
422  *
423  * MPSAFE
424  */
425 int
426 sys_extpwritev(struct extpwritev_args *uap)
427 {
428 	struct thread *td = curthread;
429 	struct uio auio;
430 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
431 	int error;
432 	int flags;
433 
434 	error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt,
435 			     &auio.uio_resid);
436 	if (error)
437 		return (error);
438 	auio.uio_iov = iov;
439 	auio.uio_iovcnt = uap->iovcnt;
440 	auio.uio_offset = uap->offset;
441 	auio.uio_rw = UIO_WRITE;
442 	auio.uio_segflg = UIO_USERSPACE;
443 	auio.uio_td = td;
444 
445 	flags = uap->flags & O_FMASK;
446 	if (uap->offset != (off_t)-1)
447 		flags |= O_FOFFSET;
448 
449 	error = kern_pwritev(uap->fd, &auio, flags, &uap->sysmsg_szresult);
450 
451 	iovec_free(&iov, aiov);
452 	return(error);
453 }
454 
455 /*
456  * MPSAFE
457  */
458 int
459 kern_pwritev(int fd, struct uio *auio, int flags, size_t *res)
460 {
461 	struct thread *td = curthread;
462 	struct proc *p = td->td_proc;
463 	struct file *fp;
464 	int error;
465 
466 	KKASSERT(p);
467 
468 	fp = holdfp(p->p_fd, fd, FWRITE);
469 	if (fp == NULL)
470 		return (EBADF);
471 	else if ((flags & O_FOFFSET) && fp->f_type != DTYPE_VNODE) {
472 		error = ESPIPE;
473 	} else {
474 		error = dofilewrite(fd, fp, auio, flags, res);
475 	}
476 
477 	fdrop(fp);
478 	return (error);
479 }
480 
481 /*
482  * Common code for writev and pwritev that writes data to
483  * a file using the passed in uio, offset, and flags.
484  *
485  * MPALMOSTSAFE - ktrace needs help
486  */
487 static int
488 dofilewrite(int fd, struct file *fp, struct uio *auio, int flags, size_t *res)
489 {
490 	struct thread *td = curthread;
491 	struct lwp *lp = td->td_lwp;
492 	int error;
493 	size_t len;
494 #ifdef KTRACE
495 	struct iovec *ktriov = NULL;
496 	struct uio ktruio;
497 #endif
498 
499 #ifdef KTRACE
500 	/*
501 	 * if tracing, save a copy of iovec and uio
502 	 */
503 	if (KTRPOINT(td, KTR_GENIO))  {
504 		int iovlen = auio->uio_iovcnt * sizeof(struct iovec);
505 
506 		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
507 		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
508 		ktruio = *auio;
509 	}
510 #endif
511 	len = auio->uio_resid;
512 	error = fo_write(fp, auio, fp->f_cred, flags);
513 	if (error) {
514 		if (auio->uio_resid != len && (error == ERESTART ||
515 		    error == EINTR || error == EWOULDBLOCK))
516 			error = 0;
517 		/* Socket layer is responsible for issuing SIGPIPE. */
518 		if (error == EPIPE) {
519 			get_mplock();
520 			lwpsignal(lp->lwp_proc, lp, SIGPIPE);
521 			rel_mplock();
522 		}
523 	}
524 #ifdef KTRACE
525 	if (ktriov != NULL) {
526 		if (error == 0) {
527 			ktruio.uio_iov = ktriov;
528 			ktruio.uio_resid = len - auio->uio_resid;
529 			get_mplock();
530 			ktrgenio(lp, fd, UIO_WRITE, &ktruio, error);
531 			rel_mplock();
532 		}
533 		FREE(ktriov, M_TEMP);
534 	}
535 #endif
536 	if (error == 0)
537 		*res = len - auio->uio_resid;
538 
539 	return(error);
540 }
541 
542 /*
543  * Ioctl system call
544  *
545  * MPALMOSTSAFE
546  */
547 int
548 sys_ioctl(struct ioctl_args *uap)
549 {
550 	int error;
551 
552 	get_mplock();
553 	error = mapped_ioctl(uap->fd, uap->com, uap->data, NULL, &uap->sysmsg);
554 	rel_mplock();
555 	return (error);
556 }
557 
558 struct ioctl_map_entry {
559 	const char *subsys;
560 	struct ioctl_map_range *cmd_ranges;
561 	LIST_ENTRY(ioctl_map_entry) entries;
562 };
563 
564 /*
565  * The true heart of all ioctl syscall handlers (native, emulation).
566  * If map != NULL, it will be searched for a matching entry for com,
567  * and appropriate conversions/conversion functions will be utilized.
568  */
569 int
570 mapped_ioctl(int fd, u_long com, caddr_t uspc_data, struct ioctl_map *map,
571 	     struct sysmsg *msg)
572 {
573 	struct thread *td = curthread;
574 	struct proc *p = td->td_proc;
575 	struct ucred *cred;
576 	struct file *fp;
577 	struct ioctl_map_range *iomc = NULL;
578 	int error;
579 	u_int size;
580 	u_long ocom = com;
581 	caddr_t data, memp;
582 	int tmp;
583 #define STK_PARAMS	128
584 	union {
585 	    char stkbuf[STK_PARAMS];
586 	    long align;
587 	} ubuf;
588 
589 	KKASSERT(p);
590 	cred = td->td_ucred;
591 
592 	fp = holdfp(p->p_fd, fd, FREAD|FWRITE);
593 	if (fp == NULL)
594 		return(EBADF);
595 
596 	if (map != NULL) {	/* obey translation map */
597 		u_long maskcmd;
598 		struct ioctl_map_entry *e;
599 
600 		maskcmd = com & map->mask;
601 
602 		LIST_FOREACH(e, &map->mapping, entries) {
603 			for (iomc = e->cmd_ranges; iomc->start != 0 ||
604 			     iomc->maptocmd != 0 || iomc->wrapfunc != NULL ||
605 			     iomc->mapfunc != NULL;
606 			     iomc++) {
607 				if (maskcmd >= iomc->start &&
608 				    maskcmd <= iomc->end)
609 					break;
610 			}
611 
612 			/* Did we find a match? */
613 			if (iomc->start != 0 || iomc->maptocmd != 0 ||
614 			    iomc->wrapfunc != NULL || iomc->mapfunc != NULL)
615 				break;
616 		}
617 
618 		if (iomc == NULL ||
619 		    (iomc->start == 0 && iomc->maptocmd == 0
620 		     && iomc->wrapfunc == NULL && iomc->mapfunc == NULL)) {
621 			kprintf("%s: 'ioctl' fd=%d, cmd=0x%lx ('%c',%d) not implemented\n",
622 			       map->sys, fd, maskcmd,
623 			       (int)((maskcmd >> 8) & 0xff),
624 			       (int)(maskcmd & 0xff));
625 			error = EINVAL;
626 			goto done;
627 		}
628 
629 		/*
630 		 * If it's a non-range one to one mapping, maptocmd should be
631 		 * correct. If it's a ranged one to one mapping, we pass the
632 		 * original value of com, and for a range mapped to a different
633 		 * range, we always need a mapping function to translate the
634 		 * ioctl to our native ioctl. Ex. 6500-65ff <-> 9500-95ff
635 		 */
636 		if (iomc->start == iomc->end && iomc->maptocmd == iomc->maptoend) {
637 			com = iomc->maptocmd;
638 		} else if (iomc->start == iomc->maptocmd && iomc->end == iomc->maptoend) {
639 			if (iomc->mapfunc != NULL)
640 				com = iomc->mapfunc(iomc->start, iomc->end,
641 						    iomc->start, iomc->end,
642 						    com, com);
643 		} else {
644 			if (iomc->mapfunc != NULL) {
645 				com = iomc->mapfunc(iomc->start, iomc->end,
646 						    iomc->maptocmd, iomc->maptoend,
647 						    com, ocom);
648 			} else {
649 				kprintf("%s: Invalid mapping for fd=%d, cmd=%#lx ('%c',%d)\n",
650 				       map->sys, fd, maskcmd,
651 				       (int)((maskcmd >> 8) & 0xff),
652 				       (int)(maskcmd & 0xff));
653 				error = EINVAL;
654 				goto done;
655 			}
656 		}
657 	}
658 
659 	switch (com) {
660 	case FIONCLEX:
661 		error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE);
662 		goto done;
663 	case FIOCLEX:
664 		error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE);
665 		goto done;
666 	}
667 
668 	/*
669 	 * Interpret high order word to find amount of data to be
670 	 * copied to/from the user's address space.
671 	 */
672 	size = IOCPARM_LEN(com);
673 	if (size > IOCPARM_MAX) {
674 		error = ENOTTY;
675 		goto done;
676 	}
677 
678 	memp = NULL;
679 	if (size > sizeof (ubuf.stkbuf)) {
680 		memp = kmalloc(size, M_IOCTLOPS, M_WAITOK);
681 		data = memp;
682 	} else {
683 		data = ubuf.stkbuf;
684 	}
685 	if ((com & IOC_IN) != 0) {
686 		if (size != 0) {
687 			error = copyin(uspc_data, data, (size_t)size);
688 			if (error) {
689 				if (memp != NULL)
690 					kfree(memp, M_IOCTLOPS);
691 				goto done;
692 			}
693 		} else {
694 			*(caddr_t *)data = uspc_data;
695 		}
696 	} else if ((com & IOC_OUT) != 0 && size) {
697 		/*
698 		 * Zero the buffer so the user always
699 		 * gets back something deterministic.
700 		 */
701 		bzero(data, (size_t)size);
702 	} else if ((com & IOC_VOID) != 0) {
703 		*(caddr_t *)data = uspc_data;
704 	}
705 
706 	switch (com) {
707 	case FIONBIO:
708 		if ((tmp = *(int *)data))
709 			fp->f_flag |= FNONBLOCK;
710 		else
711 			fp->f_flag &= ~FNONBLOCK;
712 		error = 0;
713 		break;
714 
715 	case FIOASYNC:
716 		if ((tmp = *(int *)data))
717 			fp->f_flag |= FASYNC;
718 		else
719 			fp->f_flag &= ~FASYNC;
720 		error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, cred, msg);
721 		break;
722 
723 	default:
724 		/*
725 		 *  If there is a override function,
726 		 *  call it instead of directly routing the call
727 		 */
728 		if (map != NULL && iomc->wrapfunc != NULL)
729 			error = iomc->wrapfunc(fp, com, ocom, data, cred);
730 		else
731 			error = fo_ioctl(fp, com, data, cred, msg);
732 		/*
733 		 * Copy any data to user, size was
734 		 * already set and checked above.
735 		 */
736 		if (error == 0 && (com & IOC_OUT) != 0 && size != 0)
737 			error = copyout(data, uspc_data, (size_t)size);
738 		break;
739 	}
740 	if (memp != NULL)
741 		kfree(memp, M_IOCTLOPS);
742 done:
743 	fdrop(fp);
744 	return(error);
745 }
746 
747 int
748 mapped_ioctl_register_handler(struct ioctl_map_handler *he)
749 {
750 	struct ioctl_map_entry *ne;
751 
752 	KKASSERT(he != NULL && he->map != NULL && he->cmd_ranges != NULL &&
753 		 he->subsys != NULL && *he->subsys != '\0');
754 
755 	ne = kmalloc(sizeof(struct ioctl_map_entry), M_IOCTLMAP, M_WAITOK);
756 
757 	ne->subsys = he->subsys;
758 	ne->cmd_ranges = he->cmd_ranges;
759 
760 	LIST_INSERT_HEAD(&he->map->mapping, ne, entries);
761 
762 	return(0);
763 }
764 
765 int
766 mapped_ioctl_unregister_handler(struct ioctl_map_handler *he)
767 {
768 	struct ioctl_map_entry *ne;
769 
770 	KKASSERT(he != NULL && he->map != NULL && he->cmd_ranges != NULL);
771 
772 	LIST_FOREACH(ne, &he->map->mapping, entries) {
773 		if (ne->cmd_ranges != he->cmd_ranges)
774 			continue;
775 		LIST_REMOVE(ne, entries);
776 		kfree(ne, M_IOCTLMAP);
777 		return(0);
778 	}
779 	return(EINVAL);
780 }
781 
782 static int	nselcoll;	/* Select collisions since boot */
783 int	selwait;
784 SYSCTL_INT(_kern, OID_AUTO, nselcoll, CTLFLAG_RD, &nselcoll, 0, "");
785 static int	nseldebug;
786 SYSCTL_INT(_kern, OID_AUTO, nseldebug, CTLFLAG_RW, &nseldebug, 0, "");
787 
788 /*
789  * Select system call.
790  *
791  * MPSAFE
792  */
793 int
794 sys_select(struct select_args *uap)
795 {
796 	struct timeval ktv;
797 	struct timespec *ktsp, kts;
798 	int error;
799 
800 	/*
801 	 * Get timeout if any.
802 	 */
803 	if (uap->tv != NULL) {
804 		error = copyin(uap->tv, &ktv, sizeof (ktv));
805 		if (error)
806 			return (error);
807 		TIMEVAL_TO_TIMESPEC(&ktv, &kts);
808 		ktsp = &kts;
809 	} else {
810 		ktsp = NULL;
811 	}
812 
813 	/*
814 	 * Do real work.
815 	 */
816 	error = doselect(uap->nd, uap->in, uap->ou, uap->ex, ktsp,
817 			 &uap->sysmsg_result);
818 
819 	return (error);
820 }
821 
822 
823 /*
824  * Pselect system call.
825  *
826  * MPALMOSTSAFE
827  */
828 int
829 sys_pselect(struct pselect_args *uap)
830 {
831 	struct thread *td = curthread;
832 	struct lwp *lp = td->td_lwp;
833 	struct timespec *ktsp, kts;
834 	sigset_t sigmask;
835 	int error;
836 
837 	/*
838 	 * Get timeout if any.
839 	 */
840 	if (uap->ts != NULL) {
841 		error = copyin(uap->ts, &kts, sizeof (kts));
842 		if (error)
843 			return (error);
844 		ktsp = &kts;
845 	} else {
846 		ktsp = NULL;
847 	}
848 
849 	/*
850 	 * Install temporary signal mask if any provided.
851 	 */
852 	if (uap->sigmask != NULL) {
853 		error = copyin(uap->sigmask, &sigmask, sizeof(sigmask));
854 		if (error)
855 			return (error);
856 		get_mplock();
857 		lp->lwp_oldsigmask = lp->lwp_sigmask;
858 		SIG_CANTMASK(sigmask);
859 		lp->lwp_sigmask = sigmask;
860 	} else {
861 		get_mplock();
862 	}
863 
864 	/*
865 	 * Do real job.
866 	 */
867 	error = doselect(uap->nd, uap->in, uap->ou, uap->ex, ktsp,
868 			 &uap->sysmsg_result);
869 
870 	if (uap->sigmask != NULL) {
871 		/* doselect() responsible for turning ERESTART into EINTR */
872 		KKASSERT(error != ERESTART);
873 		if (error == EINTR) {
874 			/*
875 			 * We can't restore the previous signal mask now
876 			 * because it could block the signal that interrupted
877 			 * us.  So make a note to restore it after executing
878 			 * the handler.
879 			 */
880 			lp->lwp_flag |= LWP_OLDMASK;
881 		} else {
882 			/*
883 			 * No handler to run. Restore previous mask immediately.
884 			 */
885 			lp->lwp_sigmask = lp->lwp_oldsigmask;
886 		}
887 	}
888 	rel_mplock();
889 
890 	return (error);
891 }
892 
893 static int
894 select_copyin(void *arg, struct kevent *kevp, int maxevents, int *events)
895 {
896 	struct select_kevent_copyin_args *skap = NULL;
897 	struct kevent *kev;
898 	int fd;
899 	kfd_set *fdp = NULL;
900 	short filter = 0;
901 	u_int fflags = 0;
902 
903 	skap = (struct select_kevent_copyin_args *)arg;
904 
905 	if (*events == maxevents)
906 		return (0);
907 
908 	while (skap->active_set < COPYIN_DONE) {
909 		switch (skap->active_set) {
910 		case COPYIN_READ:
911 			/*
912 			 * Register descriptors for the read filter
913 			 */
914 			fdp = skap->read_set;
915 			filter = EVFILT_READ;
916 			fflags = 0;
917 			if (fdp)
918 				break;
919 			++skap->active_set;
920 			skap->proc_fds = 0;
921 			/* fall through */
922 		case COPYIN_WRITE:
923 			/*
924 			 * Register descriptors for the write filter
925 			 */
926 			fdp = skap->write_set;
927 			filter = EVFILT_WRITE;
928 			fflags = 0;
929 			if (fdp)
930 				break;
931 			++skap->active_set;
932 			skap->proc_fds = 0;
933 			/* fall through */
934 		case COPYIN_EXCEPT:
935 			/*
936 			 * Register descriptors for the exception filter
937 			 */
938 			fdp = skap->except_set;
939 			filter = EVFILT_EXCEPT;
940 			fflags = NOTE_OOB;
941 			if (fdp)
942 				break;
943 			++skap->active_set;
944 			skap->proc_fds = 0;
945 			/* fall through */
946 		case COPYIN_DONE:
947 			/*
948 			 * Nothing left to register
949 			 */
950 			return(0);
951 			/* NOT REACHED */
952 		}
953 
954 		while (skap->proc_fds < skap->num_fds) {
955 			fd = skap->proc_fds;
956 			if (FD_ISSET(fd, fdp)) {
957 				kev = &kevp[*events];
958 				EV_SET(kev, fd, filter,
959 				       EV_ADD|EV_ENABLE,
960 				       fflags, 0,
961 				       (void *)skap->lwp->lwp_kqueue_serial);
962 				FD_CLR(fd, fdp);
963 				++*events;
964 			}
965 			++skap->proc_fds;
966 			if (*events == maxevents)
967 				return (0);
968 		}
969 		skap->active_set++;
970 		skap->proc_fds = 0;
971 	}
972 
973 	return (0);
974 }
975 
976 static int
977 select_copyout(void *arg, struct kevent *kevp, int count, int *res)
978 {
979 	struct select_kevent_copyin_args *skap;
980 	struct kevent kev;
981 	int i = 0;
982 
983 	skap = (struct select_kevent_copyin_args *)arg;
984 
985 	if (kevp[0].flags & EV_ERROR) {
986 		skap->error = kevp[0].data;
987 		return (0);
988 	}
989 
990 	for (i = 0; i < count; ++i) {
991 		if ((u_int)kevp[i].udata != skap->lwp->lwp_kqueue_serial) {
992 			kev = kevp[i];
993 			kev.flags = EV_DISABLE|EV_DELETE;
994 			kqueue_register(&skap->lwp->lwp_kqueue, &kev);
995 			continue;
996 		}
997 
998 		switch (kevp[i].filter) {
999 		case EVFILT_READ:
1000 			FD_SET(kevp[i].ident, skap->read_set);
1001 			break;
1002 		case EVFILT_WRITE:
1003 			FD_SET(kevp[i].ident, skap->write_set);
1004 			break;
1005 		case EVFILT_EXCEPT:
1006 			FD_SET(kevp[i].ident, skap->except_set);
1007 			break;
1008 		}
1009 
1010 		++*res;
1011 	}
1012 
1013 	return (0);
1014 }
1015 
1016 /*
1017  * Copy select bits in from userland.  Allocate kernel memory if the
1018  * set is large.
1019  */
1020 static int
1021 getbits(int bytes, fd_set *in_set, kfd_set **out_set, kfd_set *tmp_set)
1022 {
1023 	int error;
1024 
1025 	if (in_set) {
1026 		if (bytes < sizeof(*tmp_set))
1027 			*out_set = tmp_set;
1028 		else
1029 			*out_set = kmalloc(bytes, M_SELECT, M_WAITOK);
1030 		error = copyin(in_set, *out_set, bytes);
1031 	} else {
1032 		*out_set = NULL;
1033 		error = 0;
1034 	}
1035 	return (error);
1036 }
1037 
1038 /*
1039  * Copy returned select bits back out to userland.
1040  */
1041 static int
1042 putbits(int bytes, kfd_set *in_set, fd_set *out_set)
1043 {
1044 	int error;
1045 
1046 	if (in_set) {
1047 		error = copyout(in_set, out_set, bytes);
1048 	} else {
1049 		error = 0;
1050 	}
1051 	return (error);
1052 }
1053 
1054 /*
1055  * Common code for sys_select() and sys_pselect().
1056  *
1057  * in, out and ex are userland pointers.  ts must point to validated
1058  * kernel-side timeout value or NULL for infinite timeout.  res must
1059  * point to syscall return value.
1060  */
1061 static int
1062 doselect(int nd, fd_set *read, fd_set *write, fd_set *except,
1063 	 struct timespec *ts, int *res)
1064 {
1065 	struct proc *p = curproc;
1066 	struct select_kevent_copyin_args *kap, ka;
1067 	int bytes, error;
1068 	kfd_set read_tmp;
1069 	kfd_set write_tmp;
1070 	kfd_set except_tmp;
1071 
1072 	*res = 0;
1073 	if (nd < 0)
1074 		return (EINVAL);
1075 	if (nd > p->p_fd->fd_nfiles)		/* limit kmalloc */
1076 		nd = p->p_fd->fd_nfiles;
1077 
1078 	kap = &ka;
1079 	kap->lwp = curthread->td_lwp;
1080 	kap->num_fds = nd;
1081 	kap->proc_fds = 0;
1082 	kap->error = 0;
1083 	kap->active_set = COPYIN_READ;
1084 
1085 	/*
1086 	 * Calculate bytes based on the number of __fd_mask[] array entries
1087 	 * multiplied by the size of __fd_mask.
1088 	 */
1089 	bytes = howmany(nd, __NFDBITS) * sizeof(__fd_mask);
1090 
1091 	error = getbits(bytes, read, &kap->read_set, &read_tmp);
1092 	if (error == 0)
1093 		error = getbits(bytes, write, &kap->write_set, &write_tmp);
1094 	if (error == 0)
1095 		error = getbits(bytes, except, &kap->except_set, &except_tmp);
1096 	if (error)
1097 		goto done;
1098 
1099 	/*
1100 	 * NOTE: Make sure the max events passed to kern_kevent() is
1101 	 *	 effectively unlimited.  (nd * 3) accomplishes this.
1102 	 *
1103 	 *	 (*res) continues to increment as returned events are
1104 	 *	 loaded in.
1105 	 */
1106 	error = kern_kevent(&kap->lwp->lwp_kqueue, 0x7FFFFFFF, res, kap,
1107 			    select_copyin, select_copyout, ts);
1108 	if (error == 0)
1109 		error = putbits(bytes, kap->read_set, read);
1110 	if (error == 0)
1111 		error = putbits(bytes, kap->write_set, write);
1112 	if (error == 0)
1113 		error = putbits(bytes, kap->except_set, except);
1114 
1115 	/*
1116 	 * Cumulative error from individual events (EBADFD?)
1117 	 */
1118 	if (kap->error)
1119 		error = kap->error;
1120 
1121 	/*
1122 	 * Clean up.
1123 	 */
1124 done:
1125 	if (kap->read_set && kap->read_set != &read_tmp)
1126 		kfree(kap->read_set, M_SELECT);
1127 	if (kap->write_set && kap->write_set != &write_tmp)
1128 		kfree(kap->write_set, M_SELECT);
1129 	if (kap->except_set && kap->except_set != &except_tmp)
1130 		kfree(kap->except_set, M_SELECT);
1131 
1132 	kap->lwp->lwp_kqueue_serial++;
1133 
1134 	return (error);
1135 }
1136 
1137 /*
1138  * Poll system call.
1139  *
1140  * MPSAFE
1141  */
1142 int
1143 sys_poll(struct poll_args *uap)
1144 {
1145 	struct timespec ts, *tsp;
1146 	int error;
1147 
1148 	if (uap->timeout != INFTIM) {
1149 		ts.tv_sec = uap->timeout / 1000;
1150 		ts.tv_nsec = (uap->timeout % 1000) * 1000 * 1000;
1151 		tsp = &ts;
1152 	} else {
1153 		tsp = NULL;
1154 	}
1155 
1156 	error = dopoll(uap->nfds, uap->fds, tsp, &uap->sysmsg_result);
1157 
1158 	return (error);
1159 }
1160 
1161 static int
1162 poll_copyin(void *arg, struct kevent *kevp, int maxevents, int *events)
1163 {
1164 	struct poll_kevent_copyin_args *pkap;
1165 	struct pollfd *pfd;
1166 	struct kevent *kev;
1167 	int kev_count;
1168 
1169 	pkap = (struct poll_kevent_copyin_args *)arg;
1170 
1171 	while (pkap->pfds < pkap->nfds) {
1172 		pfd = &pkap->fds[pkap->pfds];
1173 
1174 		/* Clear return events */
1175 		pfd->revents = 0;
1176 
1177 		/* Do not check if fd is equal to -1 */
1178 		if (pfd->fd == -1) {
1179 			++pkap->pfds;
1180 			continue;
1181 		}
1182 
1183 		kev_count = 0;
1184 		if (pfd->events & (POLLIN | POLLRDNORM))
1185 			kev_count++;
1186 		if (pfd->events & (POLLOUT | POLLWRNORM))
1187 			kev_count++;
1188 		if (pfd->events & (POLLPRI | POLLRDBAND))
1189 			kev_count++;
1190 
1191 		if (*events + kev_count > maxevents)
1192 			return (0);
1193 
1194 		/*
1195 		 * NOTE: A combined serial number and poll array index is
1196 		 * stored in kev->udata.
1197 		 */
1198 		kev = &kevp[*events];
1199 		if (pfd->events & (POLLIN | POLLRDNORM)) {
1200 			EV_SET(kev++, pfd->fd, EVFILT_READ, EV_ADD|EV_ENABLE,
1201 			       0, 0, (void *)(pkap->lwp->lwp_kqueue_serial +
1202 					      pkap->pfds));
1203 		}
1204 		if (pfd->events & (POLLOUT | POLLWRNORM)) {
1205 			EV_SET(kev++, pfd->fd, EVFILT_WRITE, EV_ADD|EV_ENABLE,
1206 			       0, 0, (void *)(pkap->lwp->lwp_kqueue_serial +
1207 					      pkap->pfds));
1208 		}
1209 		if (pfd->events & (POLLPRI | POLLRDBAND)) {
1210 			EV_SET(kev++, pfd->fd, EVFILT_EXCEPT, EV_ADD|EV_ENABLE,
1211 			       NOTE_OOB, 0,
1212 			       (void *)(pkap->lwp->lwp_kqueue_serial +
1213 					pkap->pfds));
1214 		}
1215 
1216 		if (nseldebug) {
1217 			kprintf("poll index %d fd %d events %08x\n",
1218 				pkap->pfds, pfd->fd, pfd->events);
1219 		}
1220 
1221 		++pkap->pfds;
1222 		(*events) += kev_count;
1223 	}
1224 
1225 	return (0);
1226 }
1227 
1228 static int
1229 poll_copyout(void *arg, struct kevent *kevp, int count, int *res)
1230 {
1231 	struct poll_kevent_copyin_args *pkap;
1232 	struct pollfd *pfd;
1233 	struct kevent kev;
1234 	int i;
1235 	u_int pi;
1236 
1237 	pkap = (struct poll_kevent_copyin_args *)arg;
1238 
1239 	for (i = 0; i < count; ++i) {
1240 		/*
1241 		 * Extract the poll array index and delete spurious events.
1242 		 * We can easily tell if the serial number is incorrect
1243 		 * by checking whether the extracted index is out of range.
1244 		 */
1245 		pi = (u_int)kevp[i].udata - (u_int)pkap->lwp->lwp_kqueue_serial;
1246 
1247 		if (pi >= pkap->nfds) {
1248 			kev = kevp[i];
1249 			kev.flags = EV_DISABLE|EV_DELETE;
1250 			kqueue_register(&pkap->lwp->lwp_kqueue, &kev);
1251 			if (nseldebug)
1252 				kprintf("poll index %d out of range\n", pi);
1253 			continue;
1254 		}
1255 		pfd = &pkap->fds[pi];
1256 		if (kevp[i].ident == pfd->fd) {
1257 			if (kevp[i].flags & EV_ERROR) {
1258 				switch(kevp[i].data) {
1259 				case EOPNOTSUPP:
1260 					/*
1261 					 * Operation not supported.  Poll
1262 					 * does not return an error for
1263 					 * POLLPRI (OOB/urgent data) when
1264 					 * it is not supported by the device.
1265 					 */
1266 					if (kevp[i].filter != EVFILT_EXCEPT) {
1267 						pfd->revents |= POLLERR;
1268 						++*res;
1269 					}
1270 					break;
1271 				case EBADF:
1272 					/* Bad file descriptor */
1273 					pfd->revents |= POLLNVAL;
1274 					++*res;
1275 					break;
1276 				default:
1277 					pfd->revents |= POLLERR;
1278 					++*res;
1279 					break;
1280 				}
1281 				if (nseldebug)
1282 					kprintf("poll index %d fd %d filter %d error %d\n",
1283 						pi, pfd->fd,
1284 						kevp[i].filter, kevp[i].data);
1285 				continue;
1286 			}
1287 
1288 			if (kevp[i].flags & EV_EOF) {
1289 				pfd->revents |= POLLHUP;
1290 				++*res;
1291 				continue;
1292 			}
1293 
1294 			switch (kevp[i].filter) {
1295 			case EVFILT_READ:
1296 				pfd->revents |= (POLLIN | POLLRDNORM);
1297 				break;
1298 			case EVFILT_WRITE:
1299 				pfd->revents |= (POLLOUT | POLLWRNORM);
1300 				break;
1301 			case EVFILT_EXCEPT:
1302 				pfd->revents |= (POLLPRI | POLLRDBAND);
1303 				break;
1304 			}
1305 
1306 			if (nseldebug) {
1307 				kprintf("poll index %d fd %d revents %08x\n",
1308 					pi, pfd->fd, pfd->revents);
1309 			}
1310 
1311 			++*res;
1312 			continue;
1313 		} else {
1314 			if (nseldebug)
1315 				kprintf("poll index %d mismatch %d/%d\n",
1316 					pi, kevp[i].ident, pfd->fd);
1317 		}
1318 	}
1319 
1320 	return (0);
1321 }
1322 
1323 static int
1324 dopoll(int nfds, struct pollfd *fds, struct timespec *ts, int *res)
1325 {
1326 	struct poll_kevent_copyin_args ka;
1327 	struct pollfd sfds[64];
1328 	int bytes;
1329 	int error;
1330 
1331         *res = 0;
1332         if (nfds < 0)
1333                 return (EINVAL);
1334 
1335 	/*
1336 	 * This is a bit arbitrary but we need to limit internal kmallocs.
1337 	 */
1338         if (nfds > maxfilesperproc * 2)
1339                 nfds = maxfilesperproc * 2;
1340 	bytes = sizeof(struct pollfd) * nfds;
1341 
1342 	ka.lwp = curthread->td_lwp;
1343 	ka.nfds = nfds;
1344 	ka.pfds = 0;
1345 	ka.error = 0;
1346 
1347 	if (ka.nfds < 64)
1348 		ka.fds = sfds;
1349 	else
1350 		ka.fds = kmalloc(bytes, M_SELECT, M_WAITOK);
1351 
1352 	error = copyin(fds, ka.fds, bytes);
1353 	if (error == 0)
1354 		error = kern_kevent(&ka.lwp->lwp_kqueue, ka.nfds, res, &ka,
1355 				    poll_copyin, poll_copyout, ts);
1356 
1357 	if (error == 0)
1358 		error = copyout(ka.fds, fds, bytes);
1359 
1360 	if (ka.fds != sfds)
1361 		kfree(ka.fds, M_SELECT);
1362 
1363 	ka.lwp->lwp_kqueue_serial += nfds;
1364 
1365 	return (error);
1366 }
1367 
1368 /*
1369  * OpenBSD poll system call.
1370  * XXX this isn't quite a true representation..  OpenBSD uses select ops.
1371  *
1372  * MPSAFE
1373  */
1374 int
1375 sys_openbsd_poll(struct openbsd_poll_args *uap)
1376 {
1377 	return (sys_poll((struct poll_args *)uap));
1378 }
1379 
1380 /*ARGSUSED*/
1381 int
1382 seltrue(cdev_t dev, int events)
1383 {
1384 	return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
1385 }
1386 
1387 /*
1388  * Record a select request.  A global wait must be used since a process/thread
1389  * might go away after recording its request.
1390  */
1391 void
1392 selrecord(struct thread *selector, struct selinfo *sip)
1393 {
1394 	struct proc *p;
1395 	struct lwp *lp = NULL;
1396 
1397 	if (selector->td_lwp == NULL)
1398 		panic("selrecord: thread needs a process");
1399 
1400 	if (sip->si_pid == selector->td_proc->p_pid &&
1401 	    sip->si_tid == selector->td_lwp->lwp_tid)
1402 		return;
1403 	if (sip->si_pid && (p = pfind(sip->si_pid)))
1404 		lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, sip->si_tid);
1405 	if (lp != NULL && lp->lwp_wchan == (caddr_t)&selwait) {
1406 		sip->si_flags |= SI_COLL;
1407 	} else {
1408 		sip->si_pid = selector->td_proc->p_pid;
1409 		sip->si_tid = selector->td_lwp->lwp_tid;
1410 	}
1411 }
1412 
1413 /*
1414  * Do a wakeup when a selectable event occurs.
1415  */
1416 void
1417 selwakeup(struct selinfo *sip)
1418 {
1419 	struct proc *p;
1420 	struct lwp *lp = NULL;
1421 
1422 	if (sip->si_pid == 0)
1423 		return;
1424 	if (sip->si_flags & SI_COLL) {
1425 		nselcoll++;
1426 		sip->si_flags &= ~SI_COLL;
1427 		wakeup((caddr_t)&selwait);	/* YYY fixable */
1428 	}
1429 	p = pfind(sip->si_pid);
1430 	sip->si_pid = 0;
1431 	if (p == NULL)
1432 		return;
1433 	lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, sip->si_tid);
1434 	if (lp == NULL)
1435 		return;
1436 
1437 	/*
1438 	 * This is a temporary hack until the code can be rewritten.
1439 	 * Check LWP_SELECT before assuming we can setrunnable().
1440 	 * Otherwise we might catch the lwp before it actually goes to
1441 	 * sleep.
1442 	 */
1443 	crit_enter();
1444 	if (lp->lwp_flag & LWP_SELECT) {
1445 		lp->lwp_flag &= ~LWP_SELECT;
1446 	} else if (lp->lwp_wchan == (caddr_t)&selwait) {
1447 		/*
1448 		 * Flag the process to break the tsleep when
1449 		 * setrunnable is called, but only call setrunnable
1450 		 * here if the process is not in a stopped state.
1451 		 */
1452 		lp->lwp_flag |= LWP_BREAKTSLEEP;
1453 		if (p->p_stat != SSTOP)
1454 			setrunnable(lp);
1455 	}
1456 	crit_exit();
1457 
1458 	kqueue_wakeup(&lp->lwp_kqueue);
1459 }
1460 
1461