xref: /xnu-8796.141.3/bsd/kern/sys_generic.c (revision 1b191cb58250d0705d8a51287127505aa4bc0789)
1 /*
2  * Copyright (c) 2000-2021 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1982, 1986, 1989, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  * (c) UNIX System Laboratories, Inc.
33  * All or some portions of this file are derived from material licensed
34  * to the University of California by American Telephone and Telegraph
35  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
36  * the permission of UNIX System Laboratories, Inc.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)sys_generic.c	8.9 (Berkeley) 2/14/95
67  */
68 /*
69  * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
70  * support for mandatory and extensible security protections.  This notice
71  * is included in support of clause 2.2 (b) of the Apple Public License,
72  * Version 2.0.
73  */
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/filedesc.h>
78 #include <sys/ioctl.h>
79 #include <sys/file_internal.h>
80 #include <sys/proc_internal.h>
81 #include <sys/socketvar.h>
82 #include <sys/uio_internal.h>
83 #include <sys/kernel.h>
84 #include <sys/guarded.h>
85 #include <sys/stat.h>
86 #include <sys/malloc.h>
87 #include <sys/sysproto.h>
88 
89 #include <sys/mount_internal.h>
90 #include <sys/protosw.h>
91 #include <sys/ev.h>
92 #include <sys/user.h>
93 #include <sys/kdebug.h>
94 #include <sys/poll.h>
95 #include <sys/event.h>
96 #include <sys/eventvar.h>
97 #include <sys/proc.h>
98 #include <sys/kauth.h>
99 
100 #include <machine/smp.h>
101 #include <mach/mach_types.h>
102 #include <kern/kern_types.h>
103 #include <kern/assert.h>
104 #include <kern/kalloc.h>
105 #include <kern/thread.h>
106 #include <kern/clock.h>
107 #include <kern/ledger.h>
108 #include <kern/monotonic.h>
109 #include <kern/task.h>
110 #include <kern/telemetry.h>
111 #include <kern/waitq.h>
112 #include <kern/sched_hygiene.h>
113 #include <kern/sched_prim.h>
114 #include <kern/mpsc_queue.h>
115 #include <kern/debug.h>
116 
117 #include <sys/mbuf.h>
118 #include <sys/domain.h>
119 #include <sys/socket.h>
120 #include <sys/socketvar.h>
121 #include <sys/errno.h>
122 #include <sys/syscall.h>
123 #include <sys/pipe.h>
124 
125 #include <security/audit/audit.h>
126 
127 #include <net/if.h>
128 #include <net/route.h>
129 
130 #include <netinet/in.h>
131 #include <netinet/in_systm.h>
132 #include <netinet/ip.h>
133 #include <netinet/in_pcb.h>
134 #include <netinet/ip_var.h>
135 #include <netinet/ip6.h>
136 #include <netinet/tcp.h>
137 #include <netinet/tcp_fsm.h>
138 #include <netinet/tcp_seq.h>
139 #include <netinet/tcp_timer.h>
140 #include <netinet/tcp_var.h>
141 #include <netinet/tcpip.h>
142 #include <netinet/tcp_debug.h>
143 /* for wait queue based select */
144 #include <kern/waitq.h>
145 #include <sys/vnode_internal.h>
146 /* for remote time api*/
147 #include <kern/remote_time.h>
148 #include <os/log.h>
149 #include <sys/log_data.h>
150 
151 #if CONFIG_MACF
152 #include <security/mac_framework.h>
153 #endif
154 
155 #ifdef CONFIG_KDP_INTERACTIVE_DEBUGGING
156 #include <mach_debug/mach_debug_types.h>
157 #endif
158 
159 #if MONOTONIC
160 #include <machine/monotonic.h>
161 #endif /* MONOTONIC */
162 
163 /* for entitlement check */
164 #include <IOKit/IOBSD.h>
165 
166 /* XXX should be in a header file somewhere */
167 extern kern_return_t IOBSDGetPlatformUUID(__darwin_uuid_t uuid, mach_timespec_t timeoutp);
168 
169 int do_uiowrite(struct proc *p, struct fileproc *fp, uio_t uio, int flags, user_ssize_t *retval);
170 __private_extern__ int  dofileread(vfs_context_t ctx, struct fileproc *fp,
171     user_addr_t bufp, user_size_t nbyte,
172     off_t offset, int flags, user_ssize_t *retval);
173 __private_extern__ int  dofilewrite(vfs_context_t ctx, struct fileproc *fp,
174     user_addr_t bufp, user_size_t nbyte,
175     off_t offset, int flags, user_ssize_t *retval);
176 static int preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_vnode);
177 
178 /* needed by guarded_writev, etc. */
179 int write_internal(struct proc *p, int fd, user_addr_t buf, user_size_t nbyte,
180     off_t offset, int flags, guardid_t *puguard, user_ssize_t *retval);
181 int writev_uio(struct proc *p, int fd, user_addr_t user_iovp, int iovcnt, off_t offset, int flags,
182     guardid_t *puguard, user_ssize_t *retval);
183 
184 #define f_flag fp_glob->fg_flag
185 #define f_type fp_glob->fg_ops->fo_type
186 #define f_cred fp_glob->fg_cred
187 #define f_ops fp_glob->fg_ops
188 
189 /*
190  * Validate if the file can be used for random access (pread, pwrite, etc).
191  *
192  * Conditions:
193  *		proc_fdlock is held
194  *
195  * Returns:    0                       Success
196  *             ESPIPE
197  *             ENXIO
198  */
199 static int
valid_for_random_access(struct fileproc * fp)200 valid_for_random_access(struct fileproc *fp)
201 {
202 	if (__improbable(fp->f_type != DTYPE_VNODE)) {
203 		return ESPIPE;
204 	}
205 
206 	vnode_t vp = (struct vnode *)fp_get_data(fp);
207 	if (__improbable(vnode_isfifo(vp))) {
208 		return ESPIPE;
209 	}
210 
211 	if (__improbable(vp->v_flag & VISTTY)) {
212 		return ENXIO;
213 	}
214 
215 	return 0;
216 }
217 
218 /*
219  * Returns:	0			Success
220  *		EBADF
221  *		ESPIPE
222  *		ENXIO
223  *	fp_lookup:EBADF
224  *  valid_for_random_access:ESPIPE
225  *  valid_for_random_access:ENXIO
226  */
227 static int
preparefileread(struct proc * p,struct fileproc ** fp_ret,int fd,int check_for_pread)228 preparefileread(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pread)
229 {
230 	int     error;
231 	struct fileproc *fp;
232 
233 	AUDIT_ARG(fd, fd);
234 
235 	proc_fdlock_spin(p);
236 
237 	error = fp_lookup(p, fd, &fp, 1);
238 
239 	if (error) {
240 		proc_fdunlock(p);
241 		return error;
242 	}
243 	if ((fp->f_flag & FREAD) == 0) {
244 		error = EBADF;
245 		goto out;
246 	}
247 	if (check_for_pread) {
248 		if ((error = valid_for_random_access(fp))) {
249 			goto out;
250 		}
251 	}
252 
253 	*fp_ret = fp;
254 
255 	proc_fdunlock(p);
256 	return 0;
257 
258 out:
259 	fp_drop(p, fd, fp, 1);
260 	proc_fdunlock(p);
261 	return error;
262 }
263 
264 static int
fp_readv(vfs_context_t ctx,struct fileproc * fp,uio_t uio,int flags,user_ssize_t * retval)265 fp_readv(vfs_context_t ctx, struct fileproc *fp, uio_t uio, int flags,
266     user_ssize_t *retval)
267 {
268 	int error;
269 	user_ssize_t count;
270 
271 	if ((error = uio_calculateresid(uio))) {
272 		*retval = 0;
273 		return error;
274 	}
275 
276 	count = uio_resid(uio);
277 	error = fo_read(fp, uio, flags, ctx);
278 
279 	switch (error) {
280 	case ERESTART:
281 	case EINTR:
282 	case EWOULDBLOCK:
283 		if (uio_resid(uio) != count) {
284 			error = 0;
285 		}
286 		break;
287 
288 	default:
289 		break;
290 	}
291 
292 	*retval = count - uio_resid(uio);
293 	return error;
294 }
295 
296 /*
297  * Returns:	0			Success
298  *		EINVAL
299  *	fo_read:???
300  */
301 __private_extern__ int
dofileread(vfs_context_t ctx,struct fileproc * fp,user_addr_t bufp,user_size_t nbyte,off_t offset,int flags,user_ssize_t * retval)302 dofileread(vfs_context_t ctx, struct fileproc *fp,
303     user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
304     user_ssize_t *retval)
305 {
306 	uio_stackbuf_t uio_buf[UIO_SIZEOF(1)];
307 	uio_t uio;
308 	int spacetype;
309 
310 	if (nbyte > INT_MAX) {
311 		*retval = 0;
312 		return EINVAL;
313 	}
314 
315 	spacetype = vfs_context_is64bit(ctx) ? UIO_USERSPACE64 : UIO_USERSPACE32;
316 	uio = uio_createwithbuffer(1, offset, spacetype, UIO_READ, &uio_buf[0],
317 	    sizeof(uio_buf));
318 
319 	if (uio_addiov(uio, bufp, nbyte) != 0) {
320 		*retval = 0;
321 		return EINVAL;
322 	}
323 
324 	return fp_readv(ctx, fp, uio, flags, retval);
325 }
326 
327 static int
readv_internal(struct proc * p,int fd,uio_t uio,int flags,user_ssize_t * retval)328 readv_internal(struct proc *p, int fd, uio_t uio, int flags,
329     user_ssize_t *retval)
330 {
331 	struct fileproc *fp = NULL;
332 	struct vfs_context context;
333 	int error;
334 
335 	if ((error = preparefileread(p, &fp, fd, flags & FOF_OFFSET))) {
336 		*retval = 0;
337 		return error;
338 	}
339 
340 	context = *(vfs_context_current());
341 	context.vc_ucred = fp->fp_glob->fg_cred;
342 
343 	error = fp_readv(&context, fp, uio, flags, retval);
344 
345 	fp_drop(p, fd, fp, 0);
346 	return error;
347 }
348 
349 static int
read_internal(struct proc * p,int fd,user_addr_t buf,user_size_t nbyte,off_t offset,int flags,user_ssize_t * retval)350 read_internal(struct proc *p, int fd, user_addr_t buf, user_size_t nbyte,
351     off_t offset, int flags, user_ssize_t *retval)
352 {
353 	uio_stackbuf_t uio_buf[UIO_SIZEOF(1)];
354 	uio_t uio;
355 	int spacetype = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;
356 
357 	if (nbyte > INT_MAX) {
358 		*retval = 0;
359 		return EINVAL;
360 	}
361 
362 	uio = uio_createwithbuffer(1, offset, spacetype, UIO_READ,
363 	    &uio_buf[0], sizeof(uio_buf));
364 
365 	if (uio_addiov(uio, buf, nbyte) != 0) {
366 		*retval = 0;
367 		return EINVAL;
368 	}
369 
370 	return readv_internal(p, fd, uio, flags, retval);
371 }
372 
373 int
read_nocancel(struct proc * p,struct read_nocancel_args * uap,user_ssize_t * retval)374 read_nocancel(struct proc *p, struct read_nocancel_args *uap, user_ssize_t *retval)
375 {
376 	return read_internal(p, uap->fd, uap->cbuf, uap->nbyte, (off_t)-1, 0,
377 	           retval);
378 }
379 
380 /*
381  * Read system call.
382  *
383  * Returns:	0			Success
384  *	preparefileread:EBADF
385  *	preparefileread:ESPIPE
386  *	preparefileread:ENXIO
387  *	preparefileread:EBADF
388  *	dofileread:???
389  */
390 int
read(struct proc * p,struct read_args * uap,user_ssize_t * retval)391 read(struct proc *p, struct read_args *uap, user_ssize_t *retval)
392 {
393 	__pthread_testcancel(1);
394 	return read_nocancel(p, (struct read_nocancel_args *)uap, retval);
395 }
396 
397 int
pread_nocancel(struct proc * p,struct pread_nocancel_args * uap,user_ssize_t * retval)398 pread_nocancel(struct proc *p, struct pread_nocancel_args *uap, user_ssize_t *retval)
399 {
400 	KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pread) | DBG_FUNC_NONE),
401 	    uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
402 
403 	return read_internal(p, uap->fd, uap->buf, uap->nbyte, uap->offset,
404 	           FOF_OFFSET, retval);
405 }
406 
407 /*
408  * Pread system call
409  *
410  * Returns:	0			Success
411  *	preparefileread:EBADF
412  *	preparefileread:ESPIPE
413  *	preparefileread:ENXIO
414  *	preparefileread:EBADF
415  *	dofileread:???
416  */
417 int
pread(struct proc * p,struct pread_args * uap,user_ssize_t * retval)418 pread(struct proc *p, struct pread_args *uap, user_ssize_t *retval)
419 {
420 	__pthread_testcancel(1);
421 	return pread_nocancel(p, (struct pread_nocancel_args *)uap, retval);
422 }
423 
424 /*
425  * Vector read.
426  *
427  * Returns:    0                       Success
428  *             EINVAL
429  *             ENOMEM
430  *     preparefileread:EBADF
431  *     preparefileread:ESPIPE
432  *     preparefileread:ENXIO
433  *     preparefileread:EBADF
434  *     copyin:EFAULT
435  *     rd_uio:???
436  */
437 static int
readv_uio(struct proc * p,int fd,user_addr_t user_iovp,int iovcnt,off_t offset,int flags,user_ssize_t * retval)438 readv_uio(struct proc *p, int fd,
439     user_addr_t user_iovp, int iovcnt, off_t offset, int flags,
440     user_ssize_t *retval)
441 {
442 	uio_t uio = NULL;
443 	int error;
444 	struct user_iovec *iovp;
445 
446 	if (iovcnt <= 0 || iovcnt > UIO_MAXIOV) {
447 		error = EINVAL;
448 		goto out;
449 	}
450 
451 	uio = uio_create(iovcnt, offset,
452 	    (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
453 	    UIO_READ);
454 
455 	iovp = uio_iovsaddr(uio);
456 	if (iovp == NULL) {
457 		error = ENOMEM;
458 		goto out;
459 	}
460 
461 	error = copyin_user_iovec_array(user_iovp,
462 	    IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
463 	    iovcnt, iovp);
464 
465 	if (error) {
466 		goto out;
467 	}
468 
469 	error = readv_internal(p, fd, uio, flags, retval);
470 
471 out:
472 	if (uio != NULL) {
473 		uio_free(uio);
474 	}
475 
476 	return error;
477 }
478 
479 int
readv_nocancel(struct proc * p,struct readv_nocancel_args * uap,user_ssize_t * retval)480 readv_nocancel(struct proc *p, struct readv_nocancel_args *uap, user_ssize_t *retval)
481 {
482 	return readv_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, retval);
483 }
484 
485 /*
486  * Scatter read system call.
487  */
488 int
readv(struct proc * p,struct readv_args * uap,user_ssize_t * retval)489 readv(struct proc *p, struct readv_args *uap, user_ssize_t *retval)
490 {
491 	__pthread_testcancel(1);
492 	return readv_nocancel(p, (struct readv_nocancel_args *)uap, retval);
493 }
494 
495 int
sys_preadv_nocancel(struct proc * p,struct preadv_nocancel_args * uap,user_ssize_t * retval)496 sys_preadv_nocancel(struct proc *p, struct preadv_nocancel_args *uap, user_ssize_t *retval)
497 {
498 	return readv_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset,
499 	           FOF_OFFSET, retval);
500 }
501 
502 /*
503  * Preadv system call
504  */
505 int
sys_preadv(struct proc * p,struct preadv_args * uap,user_ssize_t * retval)506 sys_preadv(struct proc *p, struct preadv_args *uap, user_ssize_t *retval)
507 {
508 	__pthread_testcancel(1);
509 	return sys_preadv_nocancel(p, (struct preadv_nocancel_args *)uap, retval);
510 }
511 
512 /*
513  * Returns:	0			Success
514  *		EBADF
515  *		ESPIPE
516  *		ENXIO
517  *	fp_lookup:EBADF
518  *	fp_guard_exception:???
519  *  valid_for_random_access:ESPIPE
520  *  valid_for_random_access:ENXIO
521  */
522 static int
preparefilewrite(struct proc * p,struct fileproc ** fp_ret,int fd,int check_for_pwrite,guardid_t * puguard)523 preparefilewrite(struct proc *p, struct fileproc **fp_ret, int fd, int check_for_pwrite,
524     guardid_t *puguard)
525 {
526 	int error;
527 	struct fileproc *fp;
528 
529 	AUDIT_ARG(fd, fd);
530 
531 	proc_fdlock_spin(p);
532 
533 	if (puguard) {
534 		error = fp_lookup_guarded(p, fd, *puguard, &fp, 1);
535 		if (error) {
536 			proc_fdunlock(p);
537 			return error;
538 		}
539 
540 		if ((fp->f_flag & FWRITE) == 0) {
541 			error = EBADF;
542 			goto out;
543 		}
544 	} else {
545 		error = fp_lookup(p, fd, &fp, 1);
546 		if (error) {
547 			proc_fdunlock(p);
548 			return error;
549 		}
550 
551 		/* Allow EBADF first. */
552 		if ((fp->f_flag & FWRITE) == 0) {
553 			error = EBADF;
554 			goto out;
555 		}
556 
557 		if (fp_isguarded(fp, GUARD_WRITE)) {
558 			error = fp_guard_exception(p, fd, fp, kGUARD_EXC_WRITE);
559 			goto out;
560 		}
561 	}
562 
563 	if (check_for_pwrite) {
564 		if ((error = valid_for_random_access(fp))) {
565 			goto out;
566 		}
567 	}
568 
569 	*fp_ret = fp;
570 
571 	proc_fdunlock(p);
572 	return 0;
573 
574 out:
575 	fp_drop(p, fd, fp, 1);
576 	proc_fdunlock(p);
577 	return error;
578 }
579 
580 static int
fp_writev(vfs_context_t ctx,struct fileproc * fp,uio_t uio,int flags,user_ssize_t * retval)581 fp_writev(vfs_context_t ctx, struct fileproc *fp, uio_t uio, int flags,
582     user_ssize_t *retval)
583 {
584 	int error;
585 	user_ssize_t count;
586 
587 	if ((error = uio_calculateresid(uio))) {
588 		*retval = 0;
589 		return error;
590 	}
591 
592 	count = uio_resid(uio);
593 	error = fo_write(fp, uio, flags, ctx);
594 
595 	switch (error) {
596 	case ERESTART:
597 	case EINTR:
598 	case EWOULDBLOCK:
599 		if (uio_resid(uio) != count) {
600 			error = 0;
601 		}
602 		break;
603 
604 	case EPIPE:
605 		if (fp->f_type != DTYPE_SOCKET &&
606 		    (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) == 0) {
607 			/* XXX Raise the signal on the thread? */
608 			psignal(vfs_context_proc(ctx), SIGPIPE);
609 		}
610 		break;
611 
612 	default:
613 		break;
614 	}
615 
616 	if ((*retval = count - uio_resid(uio))) {
617 		os_atomic_or(&fp->fp_glob->fg_flag, FWASWRITTEN, relaxed);
618 	}
619 
620 	return error;
621 }
622 
623 /*
624  * Returns:	0			Success
625  *		EINVAL
626  *	<fo_write>:EPIPE
627  *	<fo_write>:???			[indirect through struct fileops]
628  */
629 __private_extern__ int
dofilewrite(vfs_context_t ctx,struct fileproc * fp,user_addr_t bufp,user_size_t nbyte,off_t offset,int flags,user_ssize_t * retval)630 dofilewrite(vfs_context_t ctx, struct fileproc *fp,
631     user_addr_t bufp, user_size_t nbyte, off_t offset, int flags,
632     user_ssize_t *retval)
633 {
634 	uio_stackbuf_t uio_buf[UIO_SIZEOF(1)];
635 	uio_t uio;
636 	int spacetype;
637 
638 	if (nbyte > INT_MAX) {
639 		*retval = 0;
640 		return EINVAL;
641 	}
642 
643 	spacetype = vfs_context_is64bit(ctx) ? UIO_USERSPACE64 : UIO_USERSPACE32;
644 	uio = uio_createwithbuffer(1, offset, spacetype, UIO_WRITE, &uio_buf[0],
645 	    sizeof(uio_buf));
646 
647 	if (uio_addiov(uio, bufp, nbyte) != 0) {
648 		*retval = 0;
649 		return EINVAL;
650 	}
651 
652 	return fp_writev(ctx, fp, uio, flags, retval);
653 }
654 
655 static int
writev_internal(struct proc * p,int fd,uio_t uio,int flags,guardid_t * puguard,user_ssize_t * retval)656 writev_internal(struct proc *p, int fd, uio_t uio, int flags,
657     guardid_t *puguard, user_ssize_t *retval)
658 {
659 	struct fileproc *fp = NULL;
660 	struct vfs_context context;
661 	int error;
662 
663 	if ((error = preparefilewrite(p, &fp, fd, flags & FOF_OFFSET, puguard))) {
664 		*retval = 0;
665 		return error;
666 	}
667 
668 	context = *(vfs_context_current());
669 	context.vc_ucred = fp->fp_glob->fg_cred;
670 
671 	error = fp_writev(&context, fp, uio, flags, retval);
672 
673 	fp_drop(p, fd, fp, 0);
674 	return error;
675 }
676 
677 int
write_internal(struct proc * p,int fd,user_addr_t buf,user_size_t nbyte,off_t offset,int flags,guardid_t * puguard,user_ssize_t * retval)678 write_internal(struct proc *p, int fd, user_addr_t buf, user_size_t nbyte,
679     off_t offset, int flags, guardid_t *puguard, user_ssize_t *retval)
680 {
681 	uio_stackbuf_t uio_buf[UIO_SIZEOF(1)];
682 	uio_t uio;
683 	int spacetype = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;
684 
685 	if (nbyte > INT_MAX) {
686 		*retval = 0;
687 		return EINVAL;
688 	}
689 
690 	uio = uio_createwithbuffer(1, offset, spacetype, UIO_WRITE,
691 	    &uio_buf[0], sizeof(uio_buf));
692 
693 	if (uio_addiov(uio, buf, nbyte) != 0) {
694 		*retval = 0;
695 		return EINVAL;
696 	}
697 
698 	return writev_internal(p, fd, uio, flags, puguard, retval);
699 }
700 
701 int
write_nocancel(struct proc * p,struct write_nocancel_args * uap,user_ssize_t * retval)702 write_nocancel(struct proc *p, struct write_nocancel_args *uap, user_ssize_t *retval)
703 {
704 	return write_internal(p, uap->fd, uap->cbuf, uap->nbyte, (off_t)-1, 0,
705 	           NULL, retval);
706 }
707 
708 /*
709  * Write system call
710  *
711  * Returns:	0			Success
712  *		EBADF
713  *	fp_lookup:EBADF
714  *	dofilewrite:???
715  */
716 int
write(struct proc * p,struct write_args * uap,user_ssize_t * retval)717 write(struct proc *p, struct write_args *uap, user_ssize_t *retval)
718 {
719 	__pthread_testcancel(1);
720 	return write_nocancel(p, (struct write_nocancel_args *)uap, retval);
721 }
722 
723 int
pwrite_nocancel(struct proc * p,struct pwrite_nocancel_args * uap,user_ssize_t * retval)724 pwrite_nocancel(struct proc *p, struct pwrite_nocancel_args *uap, user_ssize_t *retval)
725 {
726 	KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_SC_EXTENDED_INFO, SYS_pwrite) | DBG_FUNC_NONE),
727 	    uap->fd, uap->nbyte, (unsigned int)((uap->offset >> 32)), (unsigned int)(uap->offset), 0);
728 
729 	/* XXX: Should be < 0 instead? (See man page + pwritev) */
730 	if (uap->offset == (off_t)-1) {
731 		return EINVAL;
732 	}
733 
734 	return write_internal(p, uap->fd, uap->buf, uap->nbyte, uap->offset,
735 	           FOF_OFFSET, NULL, retval);
736 }
737 
738 /*
739  * pwrite system call
740  *
741  * Returns:	0			Success
742  *		EBADF
743  *		ESPIPE
744  *		ENXIO
745  *		EINVAL
746  *	fp_lookup:EBADF
747  *	dofilewrite:???
748  */
749 int
pwrite(struct proc * p,struct pwrite_args * uap,user_ssize_t * retval)750 pwrite(struct proc *p, struct pwrite_args *uap, user_ssize_t *retval)
751 {
752 	__pthread_testcancel(1);
753 	return pwrite_nocancel(p, (struct pwrite_nocancel_args *)uap, retval);
754 }
755 
756 int
writev_uio(struct proc * p,int fd,user_addr_t user_iovp,int iovcnt,off_t offset,int flags,guardid_t * puguard,user_ssize_t * retval)757 writev_uio(struct proc *p, int fd,
758     user_addr_t user_iovp, int iovcnt, off_t offset, int flags,
759     guardid_t *puguard, user_ssize_t *retval)
760 {
761 	uio_t uio = NULL;
762 	int error;
763 	struct user_iovec *iovp;
764 
765 	if (iovcnt <= 0 || iovcnt > UIO_MAXIOV || offset < 0) {
766 		error = EINVAL;
767 		goto out;
768 	}
769 
770 	uio = uio_create(iovcnt, offset,
771 	    (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
772 	    UIO_WRITE);
773 
774 	iovp = uio_iovsaddr(uio);
775 	if (iovp == NULL) {
776 		error = ENOMEM;
777 		goto out;
778 	}
779 
780 	error = copyin_user_iovec_array(user_iovp,
781 	    IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32,
782 	    iovcnt, iovp);
783 
784 	if (error) {
785 		goto out;
786 	}
787 
788 	error = writev_internal(p, fd, uio, flags, puguard, retval);
789 
790 out:
791 	if (uio != NULL) {
792 		uio_free(uio);
793 	}
794 
795 	return error;
796 }
797 
798 int
writev_nocancel(struct proc * p,struct writev_nocancel_args * uap,user_ssize_t * retval)799 writev_nocancel(struct proc *p, struct writev_nocancel_args *uap, user_ssize_t *retval)
800 {
801 	return writev_uio(p, uap->fd, uap->iovp, uap->iovcnt, 0, 0, NULL, retval);
802 }
803 
804 /*
805  * Gather write system call
806  */
807 int
writev(struct proc * p,struct writev_args * uap,user_ssize_t * retval)808 writev(struct proc *p, struct writev_args *uap, user_ssize_t *retval)
809 {
810 	__pthread_testcancel(1);
811 	return writev_nocancel(p, (struct writev_nocancel_args *)uap, retval);
812 }
813 
814 int
sys_pwritev_nocancel(struct proc * p,struct pwritev_nocancel_args * uap,user_ssize_t * retval)815 sys_pwritev_nocancel(struct proc *p, struct pwritev_nocancel_args *uap, user_ssize_t *retval)
816 {
817 	return writev_uio(p, uap->fd, uap->iovp, uap->iovcnt, uap->offset,
818 	           FOF_OFFSET, NULL, retval);
819 }
820 
821 /*
822  * Pwritev system call
823  */
824 int
sys_pwritev(struct proc * p,struct pwritev_args * uap,user_ssize_t * retval)825 sys_pwritev(struct proc *p, struct pwritev_args *uap, user_ssize_t *retval)
826 {
827 	__pthread_testcancel(1);
828 	return sys_pwritev_nocancel(p, (struct pwritev_nocancel_args *)uap, retval);
829 }
830 
831 /*
832  * Ioctl system call
833  *
834  * Returns:	0			Success
835  *		EBADF
836  *		ENOTTY
837  *		ENOMEM
838  *		ESRCH
839  *	copyin:EFAULT
840  *	copyoutEFAULT
841  *	fp_lookup:EBADF			Bad file descriptor
842  *	fo_ioctl:???
843  */
844 int
ioctl(struct proc * p,struct ioctl_args * uap,__unused int32_t * retval)845 ioctl(struct proc *p, struct ioctl_args *uap, __unused int32_t *retval)
846 {
847 	struct fileproc *fp = NULL;
848 	int error = 0;
849 	u_int size = 0;
850 	caddr_t datap = NULL, memp = NULL;
851 	boolean_t is64bit = FALSE;
852 	int tmp = 0;
853 #define STK_PARAMS      128
854 	char stkbuf[STK_PARAMS] = {};
855 	int fd = uap->fd;
856 	u_long com = uap->com;
857 	struct vfs_context context = *vfs_context_current();
858 
859 	AUDIT_ARG(fd, uap->fd);
860 	AUDIT_ARG(addr, uap->data);
861 
862 	is64bit = proc_is64bit(p);
863 #if CONFIG_AUDIT
864 	if (is64bit) {
865 		AUDIT_ARG(value64, com);
866 	} else {
867 		AUDIT_ARG(cmd, CAST_DOWN_EXPLICIT(int, com));
868 	}
869 #endif /* CONFIG_AUDIT */
870 
871 	/*
872 	 * Interpret high order word to find amount of data to be
873 	 * copied to/from the user's address space.
874 	 */
875 	size = IOCPARM_LEN(com);
876 	if (size > IOCPARM_MAX) {
877 		return ENOTTY;
878 	}
879 	if (size > sizeof(stkbuf)) {
880 		memp = (caddr_t)kalloc_data(size, Z_WAITOK);
881 		if (memp == 0) {
882 			return ENOMEM;
883 		}
884 		datap = memp;
885 	} else {
886 		datap = &stkbuf[0];
887 	}
888 	if (com & IOC_IN) {
889 		if (size) {
890 			error = copyin(uap->data, datap, size);
891 			if (error) {
892 				goto out_nofp;
893 			}
894 		} else {
895 			/* XXX - IOC_IN and no size?  we should proably return an error here!! */
896 			if (is64bit) {
897 				*(user_addr_t *)datap = uap->data;
898 			} else {
899 				*(uint32_t *)datap = (uint32_t)uap->data;
900 			}
901 		}
902 	} else if ((com & IOC_OUT) && size) {
903 		/*
904 		 * Zero the buffer so the user always
905 		 * gets back something deterministic.
906 		 */
907 		bzero(datap, size);
908 	} else if (com & IOC_VOID) {
909 		/* XXX - this is odd since IOC_VOID means no parameters */
910 		if (is64bit) {
911 			*(user_addr_t *)datap = uap->data;
912 		} else {
913 			*(uint32_t *)datap = (uint32_t)uap->data;
914 		}
915 	}
916 
917 	proc_fdlock(p);
918 	error = fp_lookup(p, fd, &fp, 1);
919 	if (error) {
920 		proc_fdunlock(p);
921 		goto out_nofp;
922 	}
923 
924 	AUDIT_ARG(file, p, fp);
925 
926 	if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
927 		error = EBADF;
928 		goto out;
929 	}
930 
931 	context.vc_ucred = fp->fp_glob->fg_cred;
932 
933 #if CONFIG_MACF
934 	error = mac_file_check_ioctl(context.vc_ucred, fp->fp_glob, com);
935 	if (error) {
936 		goto out;
937 	}
938 #endif
939 
940 	switch (com) {
941 	case FIONCLEX:
942 		fp->fp_flags &= ~FP_CLOEXEC;
943 		break;
944 
945 	case FIOCLEX:
946 		fp->fp_flags |= FP_CLOEXEC;
947 		break;
948 
949 	case FIONBIO:
950 		// FIXME (rdar://54898652)
951 		//
952 		// this code is broken if fnctl(F_SETFL), ioctl() are
953 		// called concurrently for the same fileglob.
954 		if ((tmp = *(int *)datap)) {
955 			os_atomic_or(&fp->f_flag, FNONBLOCK, relaxed);
956 		} else {
957 			os_atomic_andnot(&fp->f_flag, FNONBLOCK, relaxed);
958 		}
959 		error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
960 		break;
961 
962 	case FIOASYNC:
963 		// FIXME (rdar://54898652)
964 		//
965 		// this code is broken if fnctl(F_SETFL), ioctl() are
966 		// called concurrently for the same fileglob.
967 		if ((tmp = *(int *)datap)) {
968 			os_atomic_or(&fp->f_flag, FASYNC, relaxed);
969 		} else {
970 			os_atomic_andnot(&fp->f_flag, FASYNC, relaxed);
971 		}
972 		error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, &context);
973 		break;
974 
975 	case FIOSETOWN:
976 		tmp = *(int *)datap;
977 		if (fp->f_type == DTYPE_SOCKET) {
978 			((struct socket *)fp_get_data(fp))->so_pgid = tmp;
979 			break;
980 		}
981 		if (fp->f_type == DTYPE_PIPE) {
982 			error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
983 			break;
984 		}
985 		if (tmp <= 0) {
986 			tmp = -tmp;
987 		} else {
988 			struct proc *p1 = proc_find(tmp);
989 			if (p1 == 0) {
990 				error = ESRCH;
991 				break;
992 			}
993 			tmp = p1->p_pgrpid;
994 			proc_rele(p1);
995 		}
996 		error = fo_ioctl(fp, TIOCSPGRP, (caddr_t)&tmp, &context);
997 		break;
998 
999 	case FIOGETOWN:
1000 		if (fp->f_type == DTYPE_SOCKET) {
1001 			*(int *)datap = ((struct socket *)fp_get_data(fp))->so_pgid;
1002 			break;
1003 		}
1004 		error = fo_ioctl(fp, TIOCGPGRP, datap, &context);
1005 		*(int *)datap = -*(int *)datap;
1006 		break;
1007 
1008 	default:
1009 		error = fo_ioctl(fp, com, datap, &context);
1010 		/*
1011 		 * Copy any data to user, size was
1012 		 * already set and checked above.
1013 		 */
1014 		if (error == 0 && (com & IOC_OUT) && size) {
1015 			error = copyout(datap, uap->data, (u_int)size);
1016 		}
1017 		break;
1018 	}
1019 out:
1020 	fp_drop(p, fd, fp, 1);
1021 	proc_fdunlock(p);
1022 
1023 out_nofp:
1024 	if (memp) {
1025 		kfree_data(memp, size);
1026 	}
1027 	return error;
1028 }
1029 
1030 int     selwait;
1031 #define SEL_FIRSTPASS 1
1032 #define SEL_SECONDPASS 2
1033 static int selprocess(struct proc *p, int error, int sel_pass);
1034 static int selscan(struct proc *p, struct _select * sel, struct _select_data * seldata,
1035     int nfd, int32_t *retval, int sel_pass, struct select_set *selset);
1036 static int selcount(struct proc *p, u_int32_t *ibits, int nfd, int *count);
1037 static int seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup);
1038 static int seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim);
1039 static int select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval);
1040 
1041 /*
1042  * This is used for the special device nodes that do not implement
1043  * a proper kevent filter (see filt_specattach).
1044  *
1045  * In order to enable kevents on those, the spec_filtops will pretend
1046  * to call select, and try to sniff the selrecord(), if it observes one,
1047  * the knote is attached, which pairs with selwakeup() or selthreadclear().
1048  *
1049  * The last issue remaining, is that we need to serialize filt_specdetach()
1050  * with this, but it really can't know the "selinfo" or any locking domain.
1051  * To make up for this, We protect knote list operations with a global lock,
1052  * which give us a safe shared locking domain.
1053  *
1054  * Note: It is a little distasteful, but we really have very few of those.
1055  *       The big problem here is that sharing a lock domain without
1056  *       any kind of shared knowledge is a little complicated.
1057  *
1058  *       1. filters can really implement their own kqueue integration
1059  *          to side step this,
1060  *
1061  *       2. There's an opportunity to pick a private lock in selspec_attach()
1062  *          because both the selinfo and the knote are locked at that time.
1063  *          The cleanup story is however a little complicated.
1064  */
1065 static LCK_GRP_DECLARE(selspec_grp, "spec_filtops");
1066 static LCK_SPIN_DECLARE(selspec_lock, &selspec_grp);
1067 
1068 /*
1069  * The "primitive" lock is held.
1070  * The knote lock is held.
1071  */
1072 void
selspec_attach(struct knote * kn,struct selinfo * si)1073 selspec_attach(struct knote *kn, struct selinfo *si)
1074 {
1075 	struct selinfo *cur = os_atomic_load(&kn->kn_hook, relaxed);
1076 
1077 	if (cur == NULL) {
1078 		si->si_flags |= SI_SELSPEC;
1079 		lck_spin_lock(&selspec_lock);
1080 		kn->kn_hook = si;
1081 		KNOTE_ATTACH(&si->si_note, kn);
1082 		lck_spin_unlock(&selspec_lock);
1083 	} else {
1084 		/*
1085 		 * selspec_attach() can be called from e.g. filt_spectouch()
1086 		 * which might be called before any event was dequeued.
1087 		 *
1088 		 * It is hence not impossible for the knote already be hooked.
1089 		 *
1090 		 * Note that selwakeup_internal() could possibly
1091 		 * already have cleared this pointer. This is a race
1092 		 * that filt_specprocess will debounce.
1093 		 */
1094 		assert(si->si_flags & SI_SELSPEC);
1095 		assert(cur == si);
1096 	}
1097 }
1098 
1099 /*
1100  * The "primitive" lock is _not_ held.
1101  *
1102  * knote "lock" is held
1103  */
1104 void
selspec_detach(struct knote * kn)1105 selspec_detach(struct knote *kn)
1106 {
1107 	lck_spin_lock(&selspec_lock);
1108 
1109 	if (!KNOTE_IS_AUTODETACHED(kn)) {
1110 		if (kn->kn_hook) {
1111 			struct selinfo *sip = kn->kn_hook;
1112 
1113 			KNOTE_DETACH(&sip->si_note, kn);
1114 		}
1115 	}
1116 
1117 	kn->kn_hook = NULL;
1118 
1119 	lck_spin_unlock(&selspec_lock);
1120 }
1121 
1122 /*
1123  * Select system call.
1124  *
1125  * Returns:	0			Success
1126  *		EINVAL			Invalid argument
1127  *		EAGAIN			Nonconformant error if allocation fails
1128  */
1129 int
select(struct proc * p,struct select_args * uap,int32_t * retval)1130 select(struct proc *p, struct select_args *uap, int32_t *retval)
1131 {
1132 	__pthread_testcancel(1);
1133 	return select_nocancel(p, (struct select_nocancel_args *)uap, retval);
1134 }
1135 
1136 int
select_nocancel(struct proc * p,struct select_nocancel_args * uap,int32_t * retval)1137 select_nocancel(struct proc *p, struct select_nocancel_args *uap, int32_t *retval)
1138 {
1139 	uint64_t timeout = 0;
1140 
1141 	if (uap->tv) {
1142 		int err;
1143 		struct timeval atv;
1144 		if (IS_64BIT_PROCESS(p)) {
1145 			struct user64_timeval atv64;
1146 			err = copyin(uap->tv, (caddr_t)&atv64, sizeof(atv64));
1147 			/* Loses resolution - assume timeout < 68 years */
1148 			atv.tv_sec = (__darwin_time_t)atv64.tv_sec;
1149 			atv.tv_usec = atv64.tv_usec;
1150 		} else {
1151 			struct user32_timeval atv32;
1152 			err = copyin(uap->tv, (caddr_t)&atv32, sizeof(atv32));
1153 			atv.tv_sec = atv32.tv_sec;
1154 			atv.tv_usec = atv32.tv_usec;
1155 		}
1156 		if (err) {
1157 			return err;
1158 		}
1159 
1160 		if (itimerfix(&atv)) {
1161 			err = EINVAL;
1162 			return err;
1163 		}
1164 
1165 		clock_absolutetime_interval_to_deadline(tvtoabstime(&atv), &timeout);
1166 	}
1167 
1168 	return select_internal(p, uap, timeout, retval);
1169 }
1170 
1171 int
pselect(struct proc * p,struct pselect_args * uap,int32_t * retval)1172 pselect(struct proc *p, struct pselect_args *uap, int32_t *retval)
1173 {
1174 	__pthread_testcancel(1);
1175 	return pselect_nocancel(p, (struct pselect_nocancel_args *)uap, retval);
1176 }
1177 
1178 int
pselect_nocancel(struct proc * p,struct pselect_nocancel_args * uap,int32_t * retval)1179 pselect_nocancel(struct proc *p, struct pselect_nocancel_args *uap, int32_t *retval)
1180 {
1181 	int err;
1182 	struct uthread *ut;
1183 	uint64_t timeout = 0;
1184 
1185 	if (uap->ts) {
1186 		struct timespec ts;
1187 
1188 		if (IS_64BIT_PROCESS(p)) {
1189 			struct user64_timespec ts64;
1190 			err = copyin(uap->ts, (caddr_t)&ts64, sizeof(ts64));
1191 			ts.tv_sec = (__darwin_time_t)ts64.tv_sec;
1192 			ts.tv_nsec = (long)ts64.tv_nsec;
1193 		} else {
1194 			struct user32_timespec ts32;
1195 			err = copyin(uap->ts, (caddr_t)&ts32, sizeof(ts32));
1196 			ts.tv_sec = ts32.tv_sec;
1197 			ts.tv_nsec = ts32.tv_nsec;
1198 		}
1199 		if (err) {
1200 			return err;
1201 		}
1202 
1203 		if (!timespec_is_valid(&ts)) {
1204 			return EINVAL;
1205 		}
1206 		clock_absolutetime_interval_to_deadline(tstoabstime(&ts), &timeout);
1207 	}
1208 
1209 	ut = current_uthread();
1210 
1211 	if (uap->mask != USER_ADDR_NULL) {
1212 		/* save current mask, then copyin and set new mask */
1213 		sigset_t newset;
1214 		err = copyin(uap->mask, &newset, sizeof(sigset_t));
1215 		if (err) {
1216 			return err;
1217 		}
1218 		ut->uu_oldmask = ut->uu_sigmask;
1219 		ut->uu_flag |= UT_SAS_OLDMASK;
1220 		ut->uu_sigmask = (newset & ~sigcantmask);
1221 	}
1222 
1223 	err = select_internal(p, (struct select_nocancel_args *)uap, timeout, retval);
1224 
1225 	if (err != EINTR && ut->uu_flag & UT_SAS_OLDMASK) {
1226 		/*
1227 		 * Restore old mask (direct return case). NOTE: EINTR can also be returned
1228 		 * if the thread is cancelled. In that case, we don't reset the signal
1229 		 * mask to its original value (which usually happens in the signal
1230 		 * delivery path). This behavior is permitted by POSIX.
1231 		 */
1232 		ut->uu_sigmask = ut->uu_oldmask;
1233 		ut->uu_oldmask = 0;
1234 		ut->uu_flag &= ~UT_SAS_OLDMASK;
1235 	}
1236 
1237 	return err;
1238 }
1239 
1240 void
select_cleanup_uthread(struct _select * sel)1241 select_cleanup_uthread(struct _select *sel)
1242 {
1243 	kfree_data(sel->ibits, 2 * sel->nbytes);
1244 	sel->ibits = sel->obits = NULL;
1245 	sel->nbytes = 0;
1246 }
1247 
1248 static int
select_grow_uthread_cache(struct _select * sel,uint32_t nbytes)1249 select_grow_uthread_cache(struct _select *sel, uint32_t nbytes)
1250 {
1251 	uint32_t *buf;
1252 
1253 	buf = kalloc_data(2 * nbytes, Z_WAITOK | Z_ZERO);
1254 	if (buf) {
1255 		select_cleanup_uthread(sel);
1256 		sel->ibits = buf;
1257 		sel->obits = buf + nbytes / sizeof(uint32_t);
1258 		sel->nbytes = nbytes;
1259 		return true;
1260 	}
1261 	return false;
1262 }
1263 
1264 static void
select_bzero_uthread_cache(struct _select * sel)1265 select_bzero_uthread_cache(struct _select *sel)
1266 {
1267 	bzero(sel->ibits, sel->nbytes * 2);
1268 }
1269 
1270 /*
1271  * Generic implementation of {,p}select. Care: we type-pun uap across the two
1272  * syscalls, which differ slightly. The first 4 arguments (nfds and the fd sets)
1273  * are identical. The 5th (timeout) argument points to different types, so we
1274  * unpack in the syscall-specific code, but the generic code still does a null
1275  * check on this argument to determine if a timeout was specified.
1276  */
1277 static int
select_internal(struct proc * p,struct select_nocancel_args * uap,uint64_t timeout,int32_t * retval)1278 select_internal(struct proc *p, struct select_nocancel_args *uap, uint64_t timeout, int32_t *retval)
1279 {
1280 	struct uthread *uth = current_uthread();
1281 	struct _select *sel = &uth->uu_select;
1282 	struct _select_data *seldata = &uth->uu_save.uus_select_data;
1283 	int error = 0;
1284 	u_int ni, nw;
1285 
1286 	*retval = 0;
1287 
1288 	seldata->abstime = timeout;
1289 	seldata->args = uap;
1290 	seldata->retval = retval;
1291 	seldata->count = 0;
1292 
1293 	if (uap->nd < 0) {
1294 		return EINVAL;
1295 	}
1296 
1297 	if (uap->nd > p->p_fd.fd_nfiles) {
1298 		uap->nd = p->p_fd.fd_nfiles; /* forgiving; slightly wrong */
1299 	}
1300 	nw = howmany(uap->nd, NFDBITS);
1301 	ni = nw * sizeof(fd_mask);
1302 
1303 	/*
1304 	 * if the previously allocated space for the bits is smaller than
1305 	 * what is requested or no space has yet been allocated for this
1306 	 * thread, allocate enough space now.
1307 	 *
1308 	 * Note: If this process fails, select() will return EAGAIN; this
1309 	 * is the same thing pool() returns in a no-memory situation, but
1310 	 * it is not a POSIX compliant error code for select().
1311 	 */
1312 	if (sel->nbytes >= (3 * ni)) {
1313 		select_bzero_uthread_cache(sel);
1314 	} else if (!select_grow_uthread_cache(sel, 3 * ni)) {
1315 		return EAGAIN;
1316 	}
1317 
1318 	/*
1319 	 * get the bits from the user address space
1320 	 */
1321 #define getbits(name, x) \
1322 	(uap->name ? copyin(uap->name, &sel->ibits[(x) * nw], ni) : 0)
1323 
1324 	if ((error = getbits(in, 0))) {
1325 		return error;
1326 	}
1327 	if ((error = getbits(ou, 1))) {
1328 		return error;
1329 	}
1330 	if ((error = getbits(ex, 2))) {
1331 		return error;
1332 	}
1333 #undef  getbits
1334 
1335 	if ((error = selcount(p, sel->ibits, uap->nd, &seldata->count))) {
1336 		return error;
1337 	}
1338 
1339 	if (uth->uu_selset == NULL) {
1340 		uth->uu_selset = select_set_alloc();
1341 	}
1342 	return selprocess(p, 0, SEL_FIRSTPASS);
1343 }
1344 
1345 static int
selcontinue(int error)1346 selcontinue(int error)
1347 {
1348 	return selprocess(current_proc(), error, SEL_SECONDPASS);
1349 }
1350 
1351 
1352 /*
1353  * selprocess
1354  *
1355  * Parameters:	error			The error code from our caller
1356  *		sel_pass		The pass we are on
1357  */
1358 int
selprocess(struct proc * p,int error,int sel_pass)1359 selprocess(struct proc *p, int error, int sel_pass)
1360 {
1361 	struct uthread *uth = current_uthread();
1362 	struct _select *sel = &uth->uu_select;
1363 	struct _select_data *seldata = &uth->uu_save.uus_select_data;
1364 	struct select_nocancel_args *uap = seldata->args;
1365 	int *retval = seldata->retval;
1366 
1367 	int unwind = 1;
1368 	int prepost = 0;
1369 	int somewakeup = 0;
1370 	int doretry = 0;
1371 	wait_result_t wait_result;
1372 
1373 	if ((error != 0) && (sel_pass == SEL_FIRSTPASS)) {
1374 		unwind = 0;
1375 	}
1376 	if (seldata->count == 0) {
1377 		unwind = 0;
1378 	}
1379 retry:
1380 	if (error != 0) {
1381 		goto done;
1382 	}
1383 
1384 	OSBitOrAtomic(P_SELECT, &p->p_flag);
1385 
1386 	/* skip scans if the select is just for timeouts */
1387 	if (seldata->count) {
1388 		error = selscan(p, sel, seldata, uap->nd, retval, sel_pass,
1389 		    uth->uu_selset);
1390 		if (error || *retval) {
1391 			goto done;
1392 		}
1393 		if (prepost || somewakeup) {
1394 			/*
1395 			 * if the select of log, then we can wakeup and
1396 			 * discover some one else already read the data;
1397 			 * go to select again if time permits
1398 			 */
1399 			prepost = 0;
1400 			somewakeup = 0;
1401 			doretry = 1;
1402 		}
1403 	}
1404 
1405 	if (uap->tv) {
1406 		uint64_t        now;
1407 
1408 		clock_get_uptime(&now);
1409 		if (now >= seldata->abstime) {
1410 			goto done;
1411 		}
1412 	}
1413 
1414 	if (doretry) {
1415 		/* cleanup obits and try again */
1416 		doretry = 0;
1417 		sel_pass = SEL_FIRSTPASS;
1418 		goto retry;
1419 	}
1420 
1421 	/*
1422 	 * To effect a poll, the timeout argument should be
1423 	 * non-nil, pointing to a zero-valued timeval structure.
1424 	 */
1425 	if (uap->tv && seldata->abstime == 0) {
1426 		goto done;
1427 	}
1428 
1429 	/* No spurious wakeups due to colls,no need to check for them */
1430 	if ((sel_pass == SEL_SECONDPASS) || ((p->p_flag & P_SELECT) == 0)) {
1431 		sel_pass = SEL_FIRSTPASS;
1432 		goto retry;
1433 	}
1434 
1435 	OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
1436 
1437 	/* if the select is just for timeout skip check */
1438 	if (seldata->count && (sel_pass == SEL_SECONDPASS)) {
1439 		panic("selprocess: 2nd pass assertwaiting");
1440 	}
1441 
1442 	wait_result = waitq_assert_wait64_leeway(uth->uu_selset,
1443 	    NO_EVENT64, THREAD_ABORTSAFE,
1444 	    TIMEOUT_URGENCY_USER_NORMAL,
1445 	    seldata->abstime,
1446 	    TIMEOUT_NO_LEEWAY);
1447 	if (wait_result != THREAD_AWAKENED) {
1448 		/* there are no preposted events */
1449 		error = tsleep1(NULL, PSOCK | PCATCH,
1450 		    "select", 0, selcontinue);
1451 	} else {
1452 		prepost = 1;
1453 		error = 0;
1454 	}
1455 
1456 	if (error == 0) {
1457 		sel_pass = SEL_SECONDPASS;
1458 		if (!prepost) {
1459 			somewakeup = 1;
1460 		}
1461 		goto retry;
1462 	}
1463 done:
1464 	if (unwind) {
1465 		seldrop(p, sel->ibits, uap->nd, seldata->count);
1466 		select_set_reset(uth->uu_selset);
1467 	}
1468 	OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
1469 	/* select is not restarted after signals... */
1470 	if (error == ERESTART) {
1471 		error = EINTR;
1472 	}
1473 	if (error == EWOULDBLOCK) {
1474 		error = 0;
1475 	}
1476 
1477 	if (error == 0) {
1478 		uint32_t nw = howmany(uap->nd, NFDBITS);
1479 		uint32_t ni = nw * sizeof(fd_mask);
1480 
1481 #define putbits(name, x) \
1482 	(uap->name ? copyout(&sel->obits[(x) * nw], uap->name, ni) : 0)
1483 		int e0 = putbits(in, 0);
1484 		int e1 = putbits(ou, 1);
1485 		int e2 = putbits(ex, 2);
1486 
1487 		error = e0 ?: e1 ?: e2;
1488 #undef putbits
1489 	}
1490 
1491 	if (error != EINTR && sel_pass == SEL_SECONDPASS && uth->uu_flag & UT_SAS_OLDMASK) {
1492 		/* restore signal mask - continuation case */
1493 		uth->uu_sigmask = uth->uu_oldmask;
1494 		uth->uu_oldmask = 0;
1495 		uth->uu_flag &= ~UT_SAS_OLDMASK;
1496 	}
1497 
1498 	return error;
1499 }
1500 
1501 
1502 /**
1503  * remove the fileproc's underlying waitq from the supplied waitq set;
1504  * clear FP_INSELECT when appropriate
1505  *
1506  * Parameters:
1507  *		fp	File proc that is potentially currently in select
1508  *		selset	Waitq set to which the fileproc may belong
1509  *			(usually this is the thread's private waitq set)
1510  * Conditions:
1511  *		proc_fdlock is held
1512  */
1513 static void
selunlinkfp(struct fileproc * fp,struct select_set * selset)1514 selunlinkfp(struct fileproc *fp, struct select_set *selset)
1515 {
1516 	if (fp->fp_flags & FP_INSELECT) {
1517 		if (fp->fp_guard_attrs) {
1518 			if (fp->fp_guard->fpg_wset == selset) {
1519 				fp->fp_guard->fpg_wset = NULL;
1520 				fp->fp_flags &= ~FP_INSELECT;
1521 			}
1522 		} else {
1523 			if (fp->fp_wset == selset) {
1524 				fp->fp_wset = NULL;
1525 				fp->fp_flags &= ~FP_INSELECT;
1526 			}
1527 		}
1528 	}
1529 }
1530 
1531 /**
1532  * connect a fileproc to the given selset, potentially bridging to a waitq
1533  * pointed to indirectly by wq_data
1534  *
1535  * Parameters:
1536  *		fp	File proc potentially currently in select
1537  *		selset	Waitq set to which the fileproc should now belong
1538  *			(usually this is the thread's private waitq set)
1539  *
1540  * Conditions:
1541  *		proc_fdlock is held
1542  */
1543 static void
sellinkfp(struct fileproc * fp,struct select_set * selset,waitq_link_t * linkp)1544 sellinkfp(struct fileproc *fp, struct select_set *selset, waitq_link_t *linkp)
1545 {
1546 	if ((fp->fp_flags & FP_INSELECT) == 0) {
1547 		if (fp->fp_guard_attrs) {
1548 			fp->fp_guard->fpg_wset = selset;
1549 		} else {
1550 			fp->fp_wset = selset;
1551 		}
1552 		fp->fp_flags |= FP_INSELECT;
1553 	} else {
1554 		fp->fp_flags |= FP_SELCONFLICT;
1555 		if (linkp->wqlh == NULL) {
1556 			*linkp = waitq_link_alloc(WQT_SELECT_SET);
1557 		}
1558 		select_set_link(&select_conflict_queue, selset, linkp);
1559 	}
1560 }
1561 
1562 
1563 /*
1564  * selscan
1565  *
1566  * Parameters:	p			Process performing the select
1567  *		sel			The per-thread select context structure
1568  *		nfd			The number of file descriptors to scan
1569  *		retval			The per thread system call return area
1570  *		sel_pass		Which pass this is; allowed values are
1571  *						SEL_FIRSTPASS and SEL_SECONDPASS
1572  *		selset			The per thread wait queue set
1573  *
1574  * Returns:	0			Success
1575  *		EIO			Invalid p->p_fd field XXX Obsolete?
1576  *		EBADF			One of the files in the bit vector is
1577  *						invalid.
1578  */
1579 static int
selscan(struct proc * p,struct _select * sel,struct _select_data * seldata,int nfd,int32_t * retval,int sel_pass,struct select_set * selset)1580 selscan(struct proc *p, struct _select *sel, struct _select_data * seldata,
1581     int nfd, int32_t *retval, int sel_pass, struct select_set *selset)
1582 {
1583 	int msk, i, j, fd;
1584 	u_int32_t bits;
1585 	struct fileproc *fp;
1586 	int n = 0;              /* count of bits */
1587 	int nc = 0;             /* bit vector offset (nc'th bit) */
1588 	static int flag[3] = { FREAD, FWRITE, 0 };
1589 	u_int32_t *iptr, *optr;
1590 	u_int nw;
1591 	u_int32_t *ibits, *obits;
1592 	int count;
1593 	struct vfs_context context = {
1594 		.vc_thread = current_thread(),
1595 	};
1596 	waitq_link_t link = WQL_NULL;
1597 	void *s_data;
1598 
1599 	ibits = sel->ibits;
1600 	obits = sel->obits;
1601 
1602 	nw = howmany(nfd, NFDBITS);
1603 
1604 	count = seldata->count;
1605 
1606 	nc = 0;
1607 	if (!count) {
1608 		*retval = 0;
1609 		return 0;
1610 	}
1611 
1612 	if (sel_pass == SEL_FIRSTPASS) {
1613 		/*
1614 		 * Make sure the waitq-set is all clean:
1615 		 *
1616 		 * select loops until it finds at least one event, however it
1617 		 * doesn't mean that the event that woke up select is still
1618 		 * fired by the time the second pass runs, and then
1619 		 * select_internal will loop back to a first pass.
1620 		 */
1621 		select_set_reset(selset);
1622 		s_data = &link;
1623 	} else {
1624 		s_data = NULL;
1625 	}
1626 
1627 	proc_fdlock(p);
1628 	for (msk = 0; msk < 3; msk++) {
1629 		iptr = (u_int32_t *)&ibits[msk * nw];
1630 		optr = (u_int32_t *)&obits[msk * nw];
1631 
1632 		for (i = 0; i < nfd; i += NFDBITS) {
1633 			bits = iptr[i / NFDBITS];
1634 
1635 			while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
1636 				bits &= ~(1U << j);
1637 
1638 				fp = fp_get_noref_locked(p, fd);
1639 				if (fp == NULL) {
1640 					/*
1641 					 * If we abort because of a bad
1642 					 * fd, let the caller unwind...
1643 					 */
1644 					proc_fdunlock(p);
1645 					return EBADF;
1646 				}
1647 				if (sel_pass == SEL_SECONDPASS) {
1648 					selunlinkfp(fp, selset);
1649 				} else if (link.wqlh == NULL) {
1650 					link = waitq_link_alloc(WQT_SELECT_SET);
1651 				}
1652 
1653 				context.vc_ucred = fp->f_cred;
1654 
1655 				/* The select; set the bit, if true */
1656 				if (fo_select(fp, flag[msk], s_data, &context)) {
1657 					optr[fd / NFDBITS] |= (1U << (fd % NFDBITS));
1658 					n++;
1659 				}
1660 				if (sel_pass == SEL_FIRSTPASS) {
1661 					/*
1662 					 * Hook up the thread's waitq set either to
1663 					 * the fileproc structure, or to the global
1664 					 * conflict queue: but only on the first
1665 					 * select pass.
1666 					 */
1667 					sellinkfp(fp, selset, &link);
1668 				}
1669 				nc++;
1670 			}
1671 		}
1672 	}
1673 	proc_fdunlock(p);
1674 
1675 	if (link.wqlh) {
1676 		waitq_link_free(WQT_SELECT_SET, link);
1677 	}
1678 
1679 	*retval = n;
1680 	return 0;
1681 }
1682 
1683 static int poll_callback(struct kevent_qos_s *, kevent_ctx_t);
1684 
1685 int
poll(struct proc * p,struct poll_args * uap,int32_t * retval)1686 poll(struct proc *p, struct poll_args *uap, int32_t *retval)
1687 {
1688 	__pthread_testcancel(1);
1689 	return poll_nocancel(p, (struct poll_nocancel_args *)uap, retval);
1690 }
1691 
1692 
1693 int
poll_nocancel(struct proc * p,struct poll_nocancel_args * uap,int32_t * retval)1694 poll_nocancel(struct proc *p, struct poll_nocancel_args *uap, int32_t *retval)
1695 {
1696 	struct pollfd *fds = NULL;
1697 	struct kqueue *kq = NULL;
1698 	int error = 0;
1699 	u_int nfds = uap->nfds;
1700 	u_int rfds = 0;
1701 	rlim_t nofile = proc_limitgetcur(p, RLIMIT_NOFILE);
1702 	size_t ni = nfds * sizeof(struct pollfd);
1703 
1704 	/*
1705 	 * This is kinda bogus.  We have fd limits, but that is not
1706 	 * really related to the size of the pollfd array.  Make sure
1707 	 * we let the process use at least FD_SETSIZE entries and at
1708 	 * least enough for the current limits.  We want to be reasonably
1709 	 * safe, but not overly restrictive.
1710 	 */
1711 	if (nfds > OPEN_MAX ||
1712 	    (nfds > nofile && (proc_suser(p) || nfds > FD_SETSIZE))) {
1713 		return EINVAL;
1714 	}
1715 
1716 	kq = kqueue_alloc(p);
1717 	if (kq == NULL) {
1718 		return EAGAIN;
1719 	}
1720 
1721 	if (nfds) {
1722 		fds = (struct pollfd *)kalloc_data(ni, Z_WAITOK);
1723 		if (NULL == fds) {
1724 			error = EAGAIN;
1725 			goto out;
1726 		}
1727 
1728 		error = copyin(uap->fds, fds, nfds * sizeof(struct pollfd));
1729 		if (error) {
1730 			goto out;
1731 		}
1732 	}
1733 
1734 	/* JMM - all this P_SELECT stuff is bogus */
1735 	OSBitOrAtomic(P_SELECT, &p->p_flag);
1736 	for (u_int i = 0; i < nfds; i++) {
1737 		short events = fds[i].events;
1738 		__assert_only int rc;
1739 
1740 		/* per spec, ignore fd values below zero */
1741 		if (fds[i].fd < 0) {
1742 			fds[i].revents = 0;
1743 			continue;
1744 		}
1745 
1746 		/* convert the poll event into a kqueue kevent */
1747 		struct kevent_qos_s kev = {
1748 			.ident = fds[i].fd,
1749 			.flags = EV_ADD | EV_ONESHOT | EV_POLL,
1750 			.udata = i, /* Index into pollfd array */
1751 		};
1752 
1753 		/* Handle input events */
1754 		if (events & (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND | POLLHUP)) {
1755 			kev.filter = EVFILT_READ;
1756 			if (events & (POLLPRI | POLLRDBAND)) {
1757 				kev.flags |= EV_OOBAND;
1758 			}
1759 			rc = kevent_register(kq, &kev, NULL);
1760 			assert((rc & FILTER_REGISTER_WAIT) == 0);
1761 		}
1762 
1763 		/* Handle output events */
1764 		if ((kev.flags & EV_ERROR) == 0 &&
1765 		    (events & (POLLOUT | POLLWRNORM | POLLWRBAND))) {
1766 			kev.filter = EVFILT_WRITE;
1767 			rc = kevent_register(kq, &kev, NULL);
1768 			assert((rc & FILTER_REGISTER_WAIT) == 0);
1769 		}
1770 
1771 		/* Handle BSD extension vnode events */
1772 		if ((kev.flags & EV_ERROR) == 0 &&
1773 		    (events & (POLLEXTEND | POLLATTRIB | POLLNLINK | POLLWRITE))) {
1774 			kev.filter = EVFILT_VNODE;
1775 			kev.fflags = 0;
1776 			if (events & POLLEXTEND) {
1777 				kev.fflags |= NOTE_EXTEND;
1778 			}
1779 			if (events & POLLATTRIB) {
1780 				kev.fflags |= NOTE_ATTRIB;
1781 			}
1782 			if (events & POLLNLINK) {
1783 				kev.fflags |= NOTE_LINK;
1784 			}
1785 			if (events & POLLWRITE) {
1786 				kev.fflags |= NOTE_WRITE;
1787 			}
1788 			rc = kevent_register(kq, &kev, NULL);
1789 			assert((rc & FILTER_REGISTER_WAIT) == 0);
1790 		}
1791 
1792 		if (kev.flags & EV_ERROR) {
1793 			fds[i].revents = POLLNVAL;
1794 			rfds++;
1795 		} else {
1796 			fds[i].revents = 0;
1797 		}
1798 	}
1799 
1800 	/*
1801 	 * Did we have any trouble registering?
1802 	 * If user space passed 0 FDs, then respect any timeout value passed.
1803 	 * This is an extremely inefficient sleep. If user space passed one or
1804 	 * more FDs, and we had trouble registering _all_ of them, then bail
1805 	 * out. If a subset of the provided FDs failed to register, then we
1806 	 * will still call the kqueue_scan function.
1807 	 */
1808 	if (nfds && (rfds == nfds)) {
1809 		goto done;
1810 	}
1811 
1812 	/* scan for, and possibly wait for, the kevents to trigger */
1813 	kevent_ctx_t kectx = kevent_get_context(current_thread());
1814 	*kectx = (struct kevent_ctx_s){
1815 		.kec_process_noutputs = rfds,
1816 		.kec_process_flags    = KEVENT_FLAG_POLL,
1817 		.kec_deadline         = 0, /* wait forever */
1818 		.kec_poll_fds         = fds,
1819 	};
1820 
1821 	/*
1822 	 * If any events have trouble registering, an event has fired and we
1823 	 * shouldn't wait for events in kqueue_scan.
1824 	 */
1825 	if (rfds) {
1826 		kectx->kec_process_flags |= KEVENT_FLAG_IMMEDIATE;
1827 	} else if (uap->timeout != -1) {
1828 		clock_interval_to_deadline(uap->timeout, NSEC_PER_MSEC,
1829 		    &kectx->kec_deadline);
1830 	}
1831 
1832 	error = kqueue_scan(kq, kectx->kec_process_flags, kectx, poll_callback);
1833 	rfds = kectx->kec_process_noutputs;
1834 
1835 done:
1836 	OSBitAndAtomic(~((uint32_t)P_SELECT), &p->p_flag);
1837 	/* poll is not restarted after signals... */
1838 	if (error == ERESTART) {
1839 		error = EINTR;
1840 	}
1841 	if (error == 0) {
1842 		error = copyout(fds, uap->fds, nfds * sizeof(struct pollfd));
1843 		*retval = rfds;
1844 	}
1845 
1846 out:
1847 	kfree_data(fds, ni);
1848 
1849 	kqueue_dealloc(kq);
1850 	return error;
1851 }
1852 
1853 static int
poll_callback(struct kevent_qos_s * kevp,kevent_ctx_t kectx)1854 poll_callback(struct kevent_qos_s *kevp, kevent_ctx_t kectx)
1855 {
1856 	assert(kectx->kec_process_flags & KEVENT_FLAG_POLL);
1857 	struct pollfd *fds = &kectx->kec_poll_fds[kevp->udata];
1858 
1859 	short prev_revents = fds->revents;
1860 	short mask = 0;
1861 
1862 	/* convert the results back into revents */
1863 	if (kevp->flags & EV_EOF) {
1864 		fds->revents |= POLLHUP;
1865 	}
1866 	if (kevp->flags & EV_ERROR) {
1867 		fds->revents |= POLLERR;
1868 	}
1869 
1870 	switch (kevp->filter) {
1871 	case EVFILT_READ:
1872 		if (fds->revents & POLLHUP) {
1873 			mask = (POLLIN | POLLRDNORM | POLLPRI | POLLRDBAND);
1874 		} else {
1875 			mask = (POLLIN | POLLRDNORM);
1876 			if (kevp->flags & EV_OOBAND) {
1877 				mask |= (POLLPRI | POLLRDBAND);
1878 			}
1879 		}
1880 		fds->revents |= (fds->events & mask);
1881 		break;
1882 
1883 	case EVFILT_WRITE:
1884 		if (!(fds->revents & POLLHUP)) {
1885 			fds->revents |= (fds->events & (POLLOUT | POLLWRNORM | POLLWRBAND));
1886 		}
1887 		break;
1888 
1889 	case EVFILT_VNODE:
1890 		if (kevp->fflags & NOTE_EXTEND) {
1891 			fds->revents |= (fds->events & POLLEXTEND);
1892 		}
1893 		if (kevp->fflags & NOTE_ATTRIB) {
1894 			fds->revents |= (fds->events & POLLATTRIB);
1895 		}
1896 		if (kevp->fflags & NOTE_LINK) {
1897 			fds->revents |= (fds->events & POLLNLINK);
1898 		}
1899 		if (kevp->fflags & NOTE_WRITE) {
1900 			fds->revents |= (fds->events & POLLWRITE);
1901 		}
1902 		break;
1903 	}
1904 
1905 	if (fds->revents != 0 && prev_revents == 0) {
1906 		kectx->kec_process_noutputs++;
1907 	}
1908 
1909 	return 0;
1910 }
1911 
1912 int
seltrue(__unused dev_t dev,__unused int flag,__unused struct proc * p)1913 seltrue(__unused dev_t dev, __unused int flag, __unused struct proc *p)
1914 {
1915 	return 1;
1916 }
1917 
1918 /*
1919  * selcount
1920  *
1921  * Count the number of bits set in the input bit vector, and establish an
1922  * outstanding fp->fp_iocount for each of the descriptors which will be in
1923  * use in the select operation.
1924  *
1925  * Parameters:	p			The process doing the select
1926  *		ibits			The input bit vector
1927  *		nfd			The number of fd's in the vector
1928  *		countp			Pointer to where to store the bit count
1929  *
1930  * Returns:	0			Success
1931  *		EIO			Bad per process open file table
1932  *		EBADF			One of the bits in the input bit vector
1933  *						references an invalid fd
1934  *
1935  * Implicit:	*countp (modified)	Count of fd's
1936  *
1937  * Notes:	This function is the first pass under the proc_fdlock() that
1938  *		permits us to recognize invalid descriptors in the bit vector;
1939  *		the may, however, not remain valid through the drop and
1940  *		later reacquisition of the proc_fdlock().
1941  */
1942 static int
selcount(struct proc * p,u_int32_t * ibits,int nfd,int * countp)1943 selcount(struct proc *p, u_int32_t *ibits, int nfd, int *countp)
1944 {
1945 	int msk, i, j, fd;
1946 	u_int32_t bits;
1947 	struct fileproc *fp;
1948 	int n = 0;
1949 	u_int32_t *iptr;
1950 	u_int nw;
1951 	int error = 0;
1952 	int need_wakeup = 0;
1953 
1954 	nw = howmany(nfd, NFDBITS);
1955 
1956 	proc_fdlock(p);
1957 	for (msk = 0; msk < 3; msk++) {
1958 		iptr = (u_int32_t *)&ibits[msk * nw];
1959 		for (i = 0; i < nfd; i += NFDBITS) {
1960 			bits = iptr[i / NFDBITS];
1961 			while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
1962 				bits &= ~(1U << j);
1963 
1964 				fp = fp_get_noref_locked(p, fd);
1965 				if (fp == NULL) {
1966 					*countp = 0;
1967 					error = EBADF;
1968 					goto bad;
1969 				}
1970 				os_ref_retain_locked(&fp->fp_iocount);
1971 				n++;
1972 			}
1973 		}
1974 	}
1975 	proc_fdunlock(p);
1976 
1977 	*countp = n;
1978 	return 0;
1979 
1980 bad:
1981 	if (n == 0) {
1982 		goto out;
1983 	}
1984 	/* Ignore error return; it's already EBADF */
1985 	(void)seldrop_locked(p, ibits, nfd, n, &need_wakeup);
1986 
1987 out:
1988 	proc_fdunlock(p);
1989 	if (need_wakeup) {
1990 		wakeup(&p->p_fd.fd_fpdrainwait);
1991 	}
1992 	return error;
1993 }
1994 
1995 
1996 /*
1997  * seldrop_locked
1998  *
1999  * Drop outstanding wait queue references set up during selscan(); drop the
2000  * outstanding per fileproc fp_iocount picked up during the selcount().
2001  *
2002  * Parameters:	p			Process performing the select
2003  *		ibits			Input bit bector of fd's
2004  *		nfd			Number of fd's
2005  *		lim			Limit to number of vector entries to
2006  *						consider, or -1 for "all"
2007  *		inselect		True if
2008  *		need_wakeup		Pointer to flag to set to do a wakeup
2009  *					if f_iocont on any descriptor goes to 0
2010  *
2011  * Returns:	0			Success
2012  *		EBADF			One or more fds in the bit vector
2013  *						were invalid, but the rest
2014  *						were successfully dropped
2015  *
2016  * Notes:	An fd make become bad while the proc_fdlock() is not held,
2017  *		if a multithreaded application closes the fd out from under
2018  *		the in progress select.  In this case, we still have to
2019  *		clean up after the set up on the remaining fds.
2020  */
2021 static int
seldrop_locked(struct proc * p,u_int32_t * ibits,int nfd,int lim,int * need_wakeup)2022 seldrop_locked(struct proc *p, u_int32_t *ibits, int nfd, int lim, int *need_wakeup)
2023 {
2024 	int msk, i, j, nc, fd;
2025 	u_int32_t bits;
2026 	struct fileproc *fp;
2027 	u_int32_t *iptr;
2028 	u_int nw;
2029 	int error = 0;
2030 	uthread_t uth = current_uthread();
2031 	struct _select_data *seldata;
2032 
2033 	*need_wakeup = 0;
2034 
2035 	nw = howmany(nfd, NFDBITS);
2036 	seldata = &uth->uu_save.uus_select_data;
2037 
2038 	nc = 0;
2039 	for (msk = 0; msk < 3; msk++) {
2040 		iptr = (u_int32_t *)&ibits[msk * nw];
2041 		for (i = 0; i < nfd; i += NFDBITS) {
2042 			bits = iptr[i / NFDBITS];
2043 			while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
2044 				bits &= ~(1U << j);
2045 				/*
2046 				 * If we've already dropped as many as were
2047 				 * counted/scanned, then we are done.
2048 				 */
2049 				if (nc >= lim) {
2050 					goto done;
2051 				}
2052 
2053 				/*
2054 				 * We took an I/O reference in selcount,
2055 				 * so the fp can't possibly be NULL.
2056 				 */
2057 				fp = fp_get_noref_locked_with_iocount(p, fd);
2058 				selunlinkfp(fp, uth->uu_selset);
2059 
2060 				nc++;
2061 
2062 				const os_ref_count_t refc = os_ref_release_locked(&fp->fp_iocount);
2063 				if (0 == refc) {
2064 					panic("fp_iocount overdecrement!");
2065 				}
2066 
2067 				if (1 == refc) {
2068 					/*
2069 					 * The last iocount is responsible for clearing
2070 					 * selconfict flag - even if we didn't set it -
2071 					 * and is also responsible for waking up anyone
2072 					 * waiting on iocounts to drain.
2073 					 */
2074 					if (fp->fp_flags & FP_SELCONFLICT) {
2075 						fp->fp_flags &= ~FP_SELCONFLICT;
2076 					}
2077 					if (p->p_fd.fd_fpdrainwait) {
2078 						p->p_fd.fd_fpdrainwait = 0;
2079 						*need_wakeup = 1;
2080 					}
2081 				}
2082 			}
2083 		}
2084 	}
2085 done:
2086 	return error;
2087 }
2088 
2089 
2090 static int
seldrop(struct proc * p,u_int32_t * ibits,int nfd,int lim)2091 seldrop(struct proc *p, u_int32_t *ibits, int nfd, int lim)
2092 {
2093 	int error;
2094 	int need_wakeup = 0;
2095 
2096 	proc_fdlock(p);
2097 	error = seldrop_locked(p, ibits, nfd, lim, &need_wakeup);
2098 	proc_fdunlock(p);
2099 	if (need_wakeup) {
2100 		wakeup(&p->p_fd.fd_fpdrainwait);
2101 	}
2102 	return error;
2103 }
2104 
2105 /*
2106  * Record a select request.
2107  */
2108 void
selrecord(__unused struct proc * selector,struct selinfo * sip,void * s_data)2109 selrecord(__unused struct proc *selector, struct selinfo *sip, void *s_data)
2110 {
2111 	struct select_set *selset = current_uthread()->uu_selset;
2112 
2113 	/* do not record if this is second pass of select */
2114 	if (!s_data) {
2115 		return;
2116 	}
2117 
2118 	if (selset == SELSPEC_RECORD_MARKER) {
2119 		/*
2120 		 * The kevent subsystem is trying to sniff
2121 		 * the selinfo::si_note to attach to.
2122 		 */
2123 		((selspec_record_hook_t)s_data)(sip);
2124 	} else {
2125 		waitq_link_t *linkp = s_data;
2126 
2127 		if (!waitq_is_valid(&sip->si_waitq)) {
2128 			waitq_init(&sip->si_waitq, WQT_SELECT, SYNC_POLICY_FIFO);
2129 		}
2130 
2131 		/* note: this checks for pre-existing linkage */
2132 		select_set_link(&sip->si_waitq, selset, linkp);
2133 	}
2134 }
2135 
2136 static void
selwakeup_internal(struct selinfo * sip,long hint,wait_result_t wr)2137 selwakeup_internal(struct selinfo *sip, long hint, wait_result_t wr)
2138 {
2139 	if (sip->si_flags & SI_SELSPEC) {
2140 		/*
2141 		 * The "primitive" lock is held.
2142 		 * The knote lock is not held.
2143 		 *
2144 		 * All knotes will transition their kn_hook to NULL and we will
2145 		 * reeinitialize the primitive's klist
2146 		 */
2147 		lck_spin_lock(&selspec_lock);
2148 		knote(&sip->si_note, hint, /*autodetach=*/ true);
2149 		lck_spin_unlock(&selspec_lock);
2150 		sip->si_flags &= ~SI_SELSPEC;
2151 	}
2152 
2153 	/*
2154 	 * After selrecord() has been called, selinfo owners must call
2155 	 * at least one of selwakeup() or selthreadclear().
2156 	 *
2157 	 * Use this opportunity to deinit the waitq
2158 	 * so that all linkages are garbage collected
2159 	 * in a combined wakeup-all + unlink + deinit call.
2160 	 */
2161 	select_waitq_wakeup_and_deinit(&sip->si_waitq, NO_EVENT64, wr);
2162 }
2163 
2164 
2165 void
selwakeup(struct selinfo * sip)2166 selwakeup(struct selinfo *sip)
2167 {
2168 	selwakeup_internal(sip, 0, THREAD_AWAKENED);
2169 }
2170 
2171 void
selthreadclear(struct selinfo * sip)2172 selthreadclear(struct selinfo *sip)
2173 {
2174 	selwakeup_internal(sip, NOTE_REVOKE, THREAD_RESTART);
2175 }
2176 
2177 
2178 /*
2179  * gethostuuid
2180  *
2181  * Description:	Get the host UUID from IOKit and return it to user space.
2182  *
2183  * Parameters:	uuid_buf		Pointer to buffer to receive UUID
2184  *		timeout			Timespec for timout
2185  *
2186  * Returns:	0			Success
2187  *		EWOULDBLOCK		Timeout is too short
2188  *		copyout:EFAULT		Bad user buffer
2189  *		mac_system_check_info:EPERM		Client not allowed to perform this operation
2190  *
2191  * Notes:	A timeout seems redundant, since if it's tolerable to not
2192  *		have a system UUID in hand, then why ask for one?
2193  */
2194 int
gethostuuid(struct proc * p,struct gethostuuid_args * uap,__unused int32_t * retval)2195 gethostuuid(struct proc *p, struct gethostuuid_args *uap, __unused int32_t *retval)
2196 {
2197 	kern_return_t kret;
2198 	int error;
2199 	mach_timespec_t mach_ts;        /* for IOKit call */
2200 	__darwin_uuid_t uuid_kern = {}; /* for IOKit call */
2201 
2202 	/* Check entitlement */
2203 	if (!IOCurrentTaskHasEntitlement("com.apple.private.getprivatesysid")) {
2204 #if !defined(XNU_TARGET_OS_OSX)
2205 #if CONFIG_MACF
2206 		if ((error = mac_system_check_info(kauth_cred_get(), "hw.uuid")) != 0) {
2207 			/* EPERM invokes userspace upcall if present */
2208 			return error;
2209 		}
2210 #endif
2211 #endif
2212 	}
2213 
2214 	/* Convert the 32/64 bit timespec into a mach_timespec_t */
2215 	if (proc_is64bit(p)) {
2216 		struct user64_timespec ts;
2217 		error = copyin(uap->timeoutp, &ts, sizeof(ts));
2218 		if (error) {
2219 			return error;
2220 		}
2221 		mach_ts.tv_sec = (unsigned int)ts.tv_sec;
2222 		mach_ts.tv_nsec = (clock_res_t)ts.tv_nsec;
2223 	} else {
2224 		struct user32_timespec ts;
2225 		error = copyin(uap->timeoutp, &ts, sizeof(ts));
2226 		if (error) {
2227 			return error;
2228 		}
2229 		mach_ts.tv_sec = ts.tv_sec;
2230 		mach_ts.tv_nsec = ts.tv_nsec;
2231 	}
2232 
2233 	/* Call IOKit with the stack buffer to get the UUID */
2234 	kret = IOBSDGetPlatformUUID(uuid_kern, mach_ts);
2235 
2236 	/*
2237 	 * If we get it, copy out the data to the user buffer; note that a
2238 	 * uuid_t is an array of characters, so this is size invariant for
2239 	 * 32 vs. 64 bit.
2240 	 */
2241 	if (kret == KERN_SUCCESS) {
2242 		error = copyout(uuid_kern, uap->uuid_buf, sizeof(uuid_kern));
2243 	} else {
2244 		error = EWOULDBLOCK;
2245 	}
2246 
2247 	return error;
2248 }
2249 
2250 /*
2251  * ledger
2252  *
2253  * Description:	Omnibus system call for ledger operations
2254  */
2255 int
ledger(struct proc * p,struct ledger_args * args,__unused int32_t * retval)2256 ledger(struct proc *p, struct ledger_args *args, __unused int32_t *retval)
2257 {
2258 #if !CONFIG_MACF
2259 #pragma unused(p)
2260 #endif
2261 	int rval, pid, len, error;
2262 #ifdef LEDGER_DEBUG
2263 	struct ledger_limit_args lla;
2264 #endif
2265 	task_t task;
2266 	proc_t proc;
2267 
2268 	/* Finish copying in the necessary args before taking the proc lock */
2269 	error = 0;
2270 	len = 0;
2271 	if (args->cmd == LEDGER_ENTRY_INFO) {
2272 		error = copyin(args->arg3, (char *)&len, sizeof(len));
2273 	} else if (args->cmd == LEDGER_TEMPLATE_INFO) {
2274 		error = copyin(args->arg2, (char *)&len, sizeof(len));
2275 	} else if (args->cmd == LEDGER_LIMIT)
2276 #ifdef LEDGER_DEBUG
2277 	{ error = copyin(args->arg2, (char *)&lla, sizeof(lla));}
2278 #else
2279 	{ return EINVAL; }
2280 #endif
2281 	else if ((args->cmd < 0) || (args->cmd > LEDGER_MAX_CMD)) {
2282 		return EINVAL;
2283 	}
2284 
2285 	if (error) {
2286 		return error;
2287 	}
2288 	if (len < 0) {
2289 		return EINVAL;
2290 	}
2291 
2292 	rval = 0;
2293 	if (args->cmd != LEDGER_TEMPLATE_INFO) {
2294 		pid = (int)args->arg1;
2295 		proc = proc_find(pid);
2296 		if (proc == NULL) {
2297 			return ESRCH;
2298 		}
2299 
2300 #if CONFIG_MACF
2301 		error = mac_proc_check_ledger(p, proc, args->cmd);
2302 		if (error) {
2303 			proc_rele(proc);
2304 			return error;
2305 		}
2306 #endif
2307 
2308 		task = proc_task(proc);
2309 	}
2310 
2311 	switch (args->cmd) {
2312 #ifdef LEDGER_DEBUG
2313 	case LEDGER_LIMIT: {
2314 		if (!kauth_cred_issuser(kauth_cred_get())) {
2315 			rval = EPERM;
2316 		}
2317 		rval = ledger_limit(task, &lla);
2318 		proc_rele(proc);
2319 		break;
2320 	}
2321 #endif
2322 	case LEDGER_INFO: {
2323 		struct ledger_info info = {};
2324 
2325 		rval = ledger_info(task, &info);
2326 		proc_rele(proc);
2327 		if (rval == 0) {
2328 			rval = copyout(&info, args->arg2,
2329 			    sizeof(info));
2330 		}
2331 		break;
2332 	}
2333 
2334 	case LEDGER_ENTRY_INFO: {
2335 		void *buf;
2336 		int sz;
2337 
2338 #if CONFIG_MEMORYSTATUS
2339 		task_ledger_settle_dirty_time(task);
2340 #endif /* CONFIG_MEMORYSTATUS */
2341 
2342 		rval = ledger_get_task_entry_info_multiple(task, &buf, &len);
2343 		proc_rele(proc);
2344 		if ((rval == 0) && (len >= 0)) {
2345 			sz = len * sizeof(struct ledger_entry_info);
2346 			rval = copyout(buf, args->arg2, sz);
2347 			kfree_data(buf, sz);
2348 		}
2349 		if (rval == 0) {
2350 			rval = copyout(&len, args->arg3, sizeof(len));
2351 		}
2352 		break;
2353 	}
2354 
2355 	case LEDGER_TEMPLATE_INFO: {
2356 		void *buf;
2357 		int sz;
2358 
2359 		rval = ledger_template_info(&buf, &len);
2360 		if ((rval == 0) && (len >= 0)) {
2361 			sz = len * sizeof(struct ledger_template_info);
2362 			rval = copyout(buf, args->arg1, sz);
2363 			kfree_data(buf, sz);
2364 		}
2365 		if (rval == 0) {
2366 			rval = copyout(&len, args->arg2, sizeof(len));
2367 		}
2368 		break;
2369 	}
2370 
2371 	default:
2372 		panic("ledger syscall logic error -- command type %d", args->cmd);
2373 		proc_rele(proc);
2374 		rval = EINVAL;
2375 	}
2376 
2377 	return rval;
2378 }
2379 
2380 int
telemetry(__unused struct proc * p,struct telemetry_args * args,__unused int32_t * retval)2381 telemetry(__unused struct proc *p, struct telemetry_args *args, __unused int32_t *retval)
2382 {
2383 	int error = 0;
2384 
2385 	switch (args->cmd) {
2386 #if CONFIG_TELEMETRY
2387 	case TELEMETRY_CMD_TIMER_EVENT:
2388 		error = telemetry_timer_event(args->deadline, args->interval, args->leeway);
2389 		break;
2390 	case TELEMETRY_CMD_PMI_SETUP:
2391 		error = telemetry_pmi_setup((enum telemetry_pmi)args->deadline, args->interval);
2392 		break;
2393 #endif /* CONFIG_TELEMETRY */
2394 	case TELEMETRY_CMD_VOUCHER_NAME:
2395 		if (thread_set_voucher_name((mach_port_name_t)args->deadline)) {
2396 			error = EINVAL;
2397 		}
2398 		break;
2399 
2400 	default:
2401 		error = EINVAL;
2402 		break;
2403 	}
2404 
2405 	return error;
2406 }
2407 
2408 /*
2409  * Logging
2410  *
2411  * Description: syscall to access kernel logging from userspace
2412  *
2413  * Args:
2414  *	tag - used for syncing with userspace on the version.
2415  *	flags - flags used by the syscall.
2416  *	buffer - userspace address of string to copy.
2417  *	size - size of buffer.
2418  */
2419 int
log_data(__unused struct proc * p,struct log_data_args * args,int * retval)2420 log_data(__unused struct proc *p, struct log_data_args *args, int *retval)
2421 {
2422 	unsigned int tag = args->tag;
2423 	unsigned int flags = args->flags;
2424 	user_addr_t buffer = args->buffer;
2425 	unsigned int size = args->size;
2426 	int ret = 0;
2427 	*retval = 0;
2428 
2429 	/* Only DEXTs are suppose to use this syscall. */
2430 	if (!task_is_driver(current_task())) {
2431 		return EPERM;
2432 	}
2433 
2434 	/*
2435 	 * Tag synchronize the syscall version with userspace.
2436 	 * Tag == 0 => flags == OS_LOG_TYPE
2437 	 */
2438 	if (tag != 0) {
2439 		return EINVAL;
2440 	}
2441 
2442 	/*
2443 	 * OS_LOG_TYPE are defined in libkern/os/log.h
2444 	 * In userspace they are defined in libtrace/os/log.h
2445 	 */
2446 	if (flags != OS_LOG_TYPE_DEFAULT &&
2447 	    flags != OS_LOG_TYPE_INFO &&
2448 	    flags != OS_LOG_TYPE_DEBUG &&
2449 	    flags != OS_LOG_TYPE_ERROR &&
2450 	    flags != OS_LOG_TYPE_FAULT) {
2451 		return EINVAL;
2452 	}
2453 
2454 	if (size == 0) {
2455 		return EINVAL;
2456 	}
2457 
2458 	/* truncate to OS_LOG_DATA_MAX_SIZE */
2459 	if (size > OS_LOG_DATA_MAX_SIZE) {
2460 		printf("%s: WARNING msg is going to be truncated from %u to %u\n",
2461 		    __func__, size, OS_LOG_DATA_MAX_SIZE);
2462 		size = OS_LOG_DATA_MAX_SIZE;
2463 	}
2464 
2465 	char *log_msg = (char *)kalloc_data(size, Z_WAITOK);
2466 	if (!log_msg) {
2467 		return ENOMEM;
2468 	}
2469 
2470 	if (copyin(buffer, log_msg, size) != 0) {
2471 		ret = EFAULT;
2472 		goto out;
2473 	}
2474 	log_msg[size - 1] = '\0';
2475 
2476 	/*
2477 	 * This will log to dmesg and logd.
2478 	 * The call will fail if the current
2479 	 * process is not a driverKit process.
2480 	 */
2481 	os_log_driverKit(&ret, OS_LOG_DEFAULT, (os_log_type_t)flags, "%s", log_msg);
2482 
2483 out:
2484 	if (log_msg != NULL) {
2485 		kfree_data(log_msg, size);
2486 	}
2487 
2488 	return ret;
2489 }
2490 
2491 #if DEVELOPMENT || DEBUG
2492 
2493 static int
2494 sysctl_mpsc_test_pingpong SYSCTL_HANDLER_ARGS
2495 {
2496 #pragma unused(oidp, arg1, arg2)
2497 	uint64_t value = 0;
2498 	int error;
2499 
2500 	error = SYSCTL_IN(req, &value, sizeof(value));
2501 	if (error) {
2502 		return error;
2503 	}
2504 
2505 	if (error == 0 && req->newptr) {
2506 		error = mpsc_test_pingpong(value, &value);
2507 		if (error == 0) {
2508 			error = SYSCTL_OUT(req, &value, sizeof(value));
2509 		}
2510 	}
2511 
2512 	return error;
2513 }
2514 SYSCTL_PROC(_kern, OID_AUTO, mpsc_test_pingpong, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
2515     0, 0, sysctl_mpsc_test_pingpong, "Q", "MPSC tests: pingpong");
2516 
2517 #endif /* DEVELOPMENT || DEBUG */
2518 
2519 /* Telemetry, microstackshots */
2520 
2521 SYSCTL_NODE(_kern, OID_AUTO, microstackshot, CTLFLAG_RD | CTLFLAG_LOCKED, 0,
2522     "microstackshot info");
2523 
2524 extern uint32_t telemetry_sample_rate;
2525 SYSCTL_UINT(_kern_microstackshot, OID_AUTO, interrupt_sample_rate,
2526     CTLFLAG_RD | CTLFLAG_LOCKED, &telemetry_sample_rate, 0,
2527     "interrupt-based sampling rate in Hz");
2528 
2529 #if defined(MT_CORE_INSTRS) && defined(MT_CORE_CYCLES)
2530 
2531 extern uint64_t mt_microstackshot_period;
2532 SYSCTL_QUAD(_kern_microstackshot, OID_AUTO, pmi_sample_period,
2533     CTLFLAG_RD | CTLFLAG_LOCKED, &mt_microstackshot_period,
2534     "PMI sampling rate");
2535 extern unsigned int mt_microstackshot_ctr;
2536 SYSCTL_UINT(_kern_microstackshot, OID_AUTO, pmi_sample_counter,
2537     CTLFLAG_RD | CTLFLAG_LOCKED, &mt_microstackshot_ctr, 0,
2538     "PMI counter");
2539 
2540 #endif /* defined(MT_CORE_INSTRS) && defined(MT_CORE_CYCLES) */
2541 
2542 /*Remote Time api*/
2543 SYSCTL_NODE(_machdep, OID_AUTO, remotetime, CTLFLAG_RD | CTLFLAG_LOCKED, 0, "Remote time api");
2544 
2545 #if DEVELOPMENT || DEBUG
2546 #if CONFIG_MACH_BRIDGE_SEND_TIME
2547 extern _Atomic uint32_t bt_init_flag;
2548 extern uint32_t mach_bridge_timer_enable(uint32_t, int);
2549 
2550 SYSCTL_INT(_machdep_remotetime, OID_AUTO, bridge_timer_init_flag,
2551     CTLFLAG_RD | CTLFLAG_LOCKED, &bt_init_flag, 0, "");
2552 
2553 static int sysctl_mach_bridge_timer_enable SYSCTL_HANDLER_ARGS
2554 {
2555 #pragma unused(oidp, arg1, arg2)
2556 	uint32_t value = 0;
2557 	int error = 0;
2558 	/* User is querying buffer size */
2559 	if (req->oldptr == USER_ADDR_NULL && req->newptr == USER_ADDR_NULL) {
2560 		req->oldidx = sizeof(value);
2561 		return 0;
2562 	}
2563 	if (os_atomic_load(&bt_init_flag, acquire)) {
2564 		if (req->newptr) {
2565 			int new_value = 0;
2566 			error = SYSCTL_IN(req, &new_value, sizeof(new_value));
2567 			if (error) {
2568 				return error;
2569 			}
2570 			if (new_value == 0 || new_value == 1) {
2571 				value = mach_bridge_timer_enable(new_value, 1);
2572 			} else {
2573 				return EPERM;
2574 			}
2575 		} else {
2576 			value = mach_bridge_timer_enable(0, 0);
2577 		}
2578 	}
2579 	error = SYSCTL_OUT(req, &value, sizeof(value));
2580 	return error;
2581 }
2582 
2583 SYSCTL_PROC(_machdep_remotetime, OID_AUTO, bridge_timer_enable,
2584     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
2585     0, 0, sysctl_mach_bridge_timer_enable, "I", "");
2586 
2587 #endif /* CONFIG_MACH_BRIDGE_SEND_TIME */
2588 
2589 static int sysctl_mach_bridge_remote_time SYSCTL_HANDLER_ARGS
2590 {
2591 #pragma unused(oidp, arg1, arg2)
2592 	uint64_t ltime = 0, rtime = 0;
2593 	if (req->oldptr == USER_ADDR_NULL) {
2594 		req->oldidx = sizeof(rtime);
2595 		return 0;
2596 	}
2597 	if (req->newptr) {
2598 		int error = SYSCTL_IN(req, &ltime, sizeof(ltime));
2599 		if (error) {
2600 			return error;
2601 		}
2602 	}
2603 	rtime = mach_bridge_remote_time(ltime);
2604 	return SYSCTL_OUT(req, &rtime, sizeof(rtime));
2605 }
2606 SYSCTL_PROC(_machdep_remotetime, OID_AUTO, mach_bridge_remote_time,
2607     CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED,
2608     0, 0, sysctl_mach_bridge_remote_time, "Q", "");
2609 
2610 #endif /* DEVELOPMENT || DEBUG */
2611 
2612 #if CONFIG_MACH_BRIDGE_RECV_TIME
2613 extern struct bt_params bt_params_get_latest(void);
2614 
2615 static int sysctl_mach_bridge_conversion_params SYSCTL_HANDLER_ARGS
2616 {
2617 #pragma unused(oidp, arg1, arg2)
2618 	struct bt_params params = {};
2619 	if (req->oldptr == USER_ADDR_NULL) {
2620 		req->oldidx = sizeof(struct bt_params);
2621 		return 0;
2622 	}
2623 	if (req->newptr) {
2624 		return EPERM;
2625 	}
2626 	params = bt_params_get_latest();
2627 	return SYSCTL_OUT(req, &params, MIN(sizeof(params), req->oldlen));
2628 }
2629 
2630 SYSCTL_PROC(_machdep_remotetime, OID_AUTO, conversion_params,
2631     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0,
2632     0, sysctl_mach_bridge_conversion_params, "S,bt_params", "");
2633 
2634 #endif /* CONFIG_MACH_BRIDGE_RECV_TIME */
2635 
2636 #if DEVELOPMENT || DEBUG
2637 
2638 #include <pexpert/pexpert.h>
2639 extern int32_t sysctl_get_bound_cpuid(void);
2640 extern kern_return_t sysctl_thread_bind_cpuid(int32_t cpuid);
2641 static int
2642 sysctl_kern_sched_thread_bind_cpu SYSCTL_HANDLER_ARGS
2643 {
2644 #pragma unused(oidp, arg1, arg2)
2645 
2646 	/*
2647 	 * DO NOT remove this bootarg guard or make this non-development.
2648 	 * This kind of binding should only be used for tests and
2649 	 * experiments in a custom configuration, never shipping code.
2650 	 */
2651 
2652 	if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
2653 		return ENOENT;
2654 	}
2655 
2656 	int32_t cpuid = sysctl_get_bound_cpuid();
2657 
2658 	int32_t new_value;
2659 	int changed;
2660 	int error = sysctl_io_number(req, cpuid, sizeof cpuid, &new_value, &changed);
2661 	if (error) {
2662 		return error;
2663 	}
2664 
2665 	if (changed) {
2666 		kern_return_t kr = sysctl_thread_bind_cpuid(new_value);
2667 
2668 		if (kr == KERN_NOT_SUPPORTED) {
2669 			return ENOTSUP;
2670 		}
2671 
2672 		if (kr == KERN_INVALID_VALUE) {
2673 			return ERANGE;
2674 		}
2675 	}
2676 
2677 	return error;
2678 }
2679 
2680 SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cpu, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
2681     0, 0, sysctl_kern_sched_thread_bind_cpu, "I", "");
2682 
2683 #if __AMP__
2684 extern char sysctl_get_bound_cluster_type(void);
2685 extern void sysctl_thread_bind_cluster_type(char cluster_type);
2686 static int
2687 sysctl_kern_sched_thread_bind_cluster_type SYSCTL_HANDLER_ARGS
2688 {
2689 #pragma unused(oidp, arg1, arg2)
2690 	char buff[4];
2691 
2692 	if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
2693 		return ENOENT;
2694 	}
2695 
2696 	int error = SYSCTL_IN(req, buff, 1);
2697 	if (error) {
2698 		return error;
2699 	}
2700 	char cluster_type = buff[0];
2701 
2702 	if (!req->newptr) {
2703 		goto out;
2704 	}
2705 
2706 	sysctl_thread_bind_cluster_type(cluster_type);
2707 out:
2708 	cluster_type = sysctl_get_bound_cluster_type();
2709 	buff[0] = cluster_type;
2710 
2711 	return SYSCTL_OUT(req, buff, 1);
2712 }
2713 
2714 SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
2715     0, 0, sysctl_kern_sched_thread_bind_cluster_type, "A", "");
2716 
2717 extern char sysctl_get_task_cluster_type(void);
2718 extern void sysctl_task_set_cluster_type(char cluster_type);
2719 static int
2720 sysctl_kern_sched_task_set_cluster_type SYSCTL_HANDLER_ARGS
2721 {
2722 #pragma unused(oidp, arg1, arg2)
2723 	char buff[4];
2724 
2725 	if (!PE_parse_boot_argn("enable_skstsct", NULL, 0)) {
2726 		return ENOENT;
2727 	}
2728 
2729 	int error = SYSCTL_IN(req, buff, 1);
2730 	if (error) {
2731 		return error;
2732 	}
2733 	char cluster_type = buff[0];
2734 
2735 	if (!req->newptr) {
2736 		goto out;
2737 	}
2738 
2739 	sysctl_task_set_cluster_type(cluster_type);
2740 out:
2741 	cluster_type = sysctl_get_task_cluster_type();
2742 	buff[0] = cluster_type;
2743 
2744 	return SYSCTL_OUT(req, buff, 1);
2745 }
2746 
2747 SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_cluster_type, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED,
2748     0, 0, sysctl_kern_sched_task_set_cluster_type, "A", "");
2749 
2750 extern kern_return_t thread_bind_cluster_id(thread_t thread, uint32_t cluster_id, thread_bind_option_t options);
2751 extern uint32_t thread_bound_cluster_id(thread_t);
2752 static int
2753 sysctl_kern_sched_thread_bind_cluster_id SYSCTL_HANDLER_ARGS
2754 {
2755 #pragma unused(oidp, arg1, arg2)
2756 	if (!PE_parse_boot_argn("enable_skstb", NULL, 0)) {
2757 		return ENOENT;
2758 	}
2759 
2760 	thread_t self = current_thread();
2761 	uint32_t old_value = thread_bound_cluster_id(self);
2762 	uint32_t new_value;
2763 
2764 	int error = SYSCTL_IN(req, &new_value, sizeof(new_value));
2765 	if (error) {
2766 		return error;
2767 	}
2768 	if (new_value != old_value) {
2769 		/*
2770 		 * This sysctl binds the thread to the cluster without any flags,
2771 		 * which means it will be hard bound and not check eligibility.
2772 		 */
2773 		thread_bind_cluster_id(self, new_value, 0);
2774 	}
2775 	return SYSCTL_OUT(req, &old_value, sizeof(old_value));
2776 }
2777 
2778 SYSCTL_PROC(_kern, OID_AUTO, sched_thread_bind_cluster_id, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
2779     0, 0, sysctl_kern_sched_thread_bind_cluster_id, "I", "");
2780 
2781 #if CONFIG_SCHED_EDGE
2782 
2783 extern int sched_edge_restrict_ut;
2784 SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_ut, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict UT Threads");
2785 extern int sched_edge_restrict_bg;
2786 SYSCTL_INT(_kern, OID_AUTO, sched_edge_restrict_bg, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_restrict_ut, 0, "Edge Scheduler Restrict BG Threads");
2787 extern int sched_edge_migrate_ipi_immediate;
2788 SYSCTL_INT(_kern, OID_AUTO, sched_edge_migrate_ipi_immediate, CTLFLAG_RW | CTLFLAG_LOCKED, &sched_edge_migrate_ipi_immediate, 0, "Edge Scheduler uses immediate IPIs for migration event based on execution latency");
2789 
2790 #endif /* CONFIG_SCHED_EDGE */
2791 
2792 #endif /* __AMP__ */
2793 
2794 #if SCHED_HYGIENE_DEBUG
2795 
2796 SYSCTL_QUAD(_kern, OID_AUTO, interrupt_masked_threshold_mt, CTLFLAG_RW | CTLFLAG_LOCKED,
2797     &interrupt_masked_timeout,
2798     "Interrupt masked duration after which a tracepoint is emitted or the device panics (in mach timebase units)");
2799 
2800 SYSCTL_INT(_kern, OID_AUTO, interrupt_masked_debug_mode, CTLFLAG_RW | CTLFLAG_LOCKED,
2801     &interrupt_masked_debug_mode, 0,
2802     "Enable interrupt masked tracing or panic (0: off, 1: trace, 2: panic)");
2803 
2804 SYSCTL_QUAD(_kern, OID_AUTO, sched_preemption_disable_threshold_mt, CTLFLAG_RW | CTLFLAG_LOCKED,
2805     &sched_preemption_disable_threshold_mt,
2806     "Preemption disablement duration after which a tracepoint is emitted or the device panics (in mach timebase units)");
2807 
2808 SYSCTL_INT(_kern, OID_AUTO, sched_preemption_disable_debug_mode, CTLFLAG_RW | CTLFLAG_LOCKED,
2809     &sched_preemption_disable_debug_mode, 0,
2810     "Enable preemption disablement tracing or panic (0: off, 1: trace, 2: panic)");
2811 
2812 PERCPU_DECL(uint64_t _Atomic, preemption_disable_max_mt);
2813 
2814 static int
sysctl_sched_preemption_disable_stats(__unused struct sysctl_oid * oidp,__unused void * arg1,__unused int arg2,struct sysctl_req * req)2815 sysctl_sched_preemption_disable_stats(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
2816 {
2817 	uint64_t stats[MAX_CPUS]; // maximum per CPU
2818 
2819 	/*
2820 	 * No synchronization here. The individual values are pretty much
2821 	 * independent, and reading/writing them is atomic.
2822 	 */
2823 
2824 	int cpu = 0;
2825 	percpu_foreach(max_stat, preemption_disable_max_mt) {
2826 		stats[cpu++] = os_atomic_load(max_stat, relaxed);
2827 	}
2828 
2829 	if (req->newlen > 0) {
2830 		// writing just resets all stats.
2831 		percpu_foreach(max_stat, preemption_disable_max_mt) {
2832 			os_atomic_store(max_stat, 0, relaxed);
2833 		}
2834 	}
2835 
2836 	return sysctl_io_opaque(req, stats, cpu * sizeof(uint64_t), NULL);
2837 }
2838 
2839 SYSCTL_PROC(_kern, OID_AUTO, sched_preemption_disable_stats,
2840     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED,
2841     0, 0, sysctl_sched_preemption_disable_stats, "I", "Preemption disablement statistics");
2842 
2843 #endif /* SCHED_HYGIENE_DEBUG */
2844 
2845 /* used for testing by exception_tests */
2846 extern uint32_t ipc_control_port_options;
2847 SYSCTL_INT(_kern, OID_AUTO, ipc_control_port_options,
2848     CTLFLAG_RD | CTLFLAG_LOCKED, &ipc_control_port_options, 0, "");
2849 
2850 #endif /* DEVELOPMENT || DEBUG */
2851 
2852 extern uint32_t task_exc_guard_default;
2853 
2854 SYSCTL_INT(_kern, OID_AUTO, task_exc_guard_default,
2855     CTLFLAG_RD | CTLFLAG_LOCKED, &task_exc_guard_default, 0, "");
2856 
2857 
2858 static int
2859 sysctl_kern_tcsm_available SYSCTL_HANDLER_ARGS
2860 {
2861 #pragma unused(oidp, arg1, arg2)
2862 	uint32_t value = machine_csv(CPUVN_CI) ? 1 : 0;
2863 
2864 	if (req->newptr) {
2865 		return EINVAL;
2866 	}
2867 
2868 	return SYSCTL_OUT(req, &value, sizeof(value));
2869 }
2870 SYSCTL_PROC(_kern, OID_AUTO, tcsm_available,
2871     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
2872     0, 0, sysctl_kern_tcsm_available, "I", "");
2873 
2874 
2875 static int
2876 sysctl_kern_tcsm_enable SYSCTL_HANDLER_ARGS
2877 {
2878 #pragma unused(oidp, arg1, arg2)
2879 	uint32_t soflags = 0;
2880 	uint32_t old_value = thread_get_no_smt() ? 1 : 0;
2881 
2882 	int error = SYSCTL_IN(req, &soflags, sizeof(soflags));
2883 	if (error) {
2884 		return error;
2885 	}
2886 
2887 	if (soflags && machine_csv(CPUVN_CI)) {
2888 		thread_set_no_smt(true);
2889 		machine_tecs(current_thread());
2890 	}
2891 
2892 	return SYSCTL_OUT(req, &old_value, sizeof(old_value));
2893 }
2894 SYSCTL_PROC(_kern, OID_AUTO, tcsm_enable,
2895     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
2896     0, 0, sysctl_kern_tcsm_enable, "I", "");
2897 
2898 static int
2899 sysctl_kern_debug_get_preoslog SYSCTL_HANDLER_ARGS
2900 {
2901 #pragma unused(oidp, arg1, arg2)
2902 	static bool oneshot_executed = false;
2903 	size_t preoslog_size = 0;
2904 	const char *preoslog = NULL;
2905 	int ret = 0;
2906 
2907 	// DumpPanic passes a non-zero write value when it needs oneshot behaviour
2908 	if (req->newptr != USER_ADDR_NULL) {
2909 		uint8_t oneshot = 0;
2910 		int error = SYSCTL_IN(req, &oneshot, sizeof(oneshot));
2911 		if (error) {
2912 			return error;
2913 		}
2914 
2915 		if (oneshot) {
2916 			if (!os_atomic_cmpxchg(&oneshot_executed, false, true, acq_rel)) {
2917 				return EPERM;
2918 			}
2919 		}
2920 	}
2921 
2922 	preoslog = sysctl_debug_get_preoslog(&preoslog_size);
2923 	if (preoslog != NULL && preoslog_size == 0) {
2924 		sysctl_debug_free_preoslog();
2925 		return 0;
2926 	}
2927 
2928 	if (preoslog == NULL || preoslog_size == 0) {
2929 		return 0;
2930 	}
2931 
2932 	if (req->oldptr == USER_ADDR_NULL) {
2933 		req->oldidx = preoslog_size;
2934 		return 0;
2935 	}
2936 
2937 	ret = SYSCTL_OUT(req, preoslog, preoslog_size);
2938 	sysctl_debug_free_preoslog();
2939 	return ret;
2940 }
2941 
2942 SYSCTL_PROC(_kern, OID_AUTO, preoslog, CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED,
2943     0, 0, sysctl_kern_debug_get_preoslog, "-", "");
2944 
2945 #if DEVELOPMENT || DEBUG
2946 extern void sysctl_task_set_no_smt(char no_smt);
2947 extern char sysctl_task_get_no_smt(void);
2948 
2949 static int
2950 sysctl_kern_sched_task_set_no_smt SYSCTL_HANDLER_ARGS
2951 {
2952 #pragma unused(oidp, arg1, arg2)
2953 	char buff[4];
2954 
2955 	int error = SYSCTL_IN(req, buff, 1);
2956 	if (error) {
2957 		return error;
2958 	}
2959 	char no_smt = buff[0];
2960 
2961 	if (!req->newptr) {
2962 		goto out;
2963 	}
2964 
2965 	sysctl_task_set_no_smt(no_smt);
2966 out:
2967 	no_smt = sysctl_task_get_no_smt();
2968 	buff[0] = no_smt;
2969 
2970 	return SYSCTL_OUT(req, buff, 1);
2971 }
2972 
2973 SYSCTL_PROC(_kern, OID_AUTO, sched_task_set_no_smt, CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
2974     0, 0, sysctl_kern_sched_task_set_no_smt, "A", "");
2975 
2976 static int
sysctl_kern_sched_thread_set_no_smt(__unused struct sysctl_oid * oidp,__unused void * arg1,__unused int arg2,struct sysctl_req * req)2977 sysctl_kern_sched_thread_set_no_smt(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
2978 {
2979 	int new_value, changed;
2980 	int old_value = thread_get_no_smt() ? 1 : 0;
2981 	int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);
2982 
2983 	if (changed) {
2984 		thread_set_no_smt(!!new_value);
2985 	}
2986 
2987 	return error;
2988 }
2989 
2990 SYSCTL_PROC(_kern, OID_AUTO, sched_thread_set_no_smt,
2991     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
2992     0, 0, sysctl_kern_sched_thread_set_no_smt, "I", "");
2993 
2994 #if CONFIG_SCHED_RT_ALLOW
2995 
2996 #if DEVELOPMENT || DEBUG
2997 #define RT_ALLOW_CTLFLAGS CTLFLAG_RW
2998 #else
2999 #define RT_ALLOW_CTLFLAGS CTLFLAG_RD
3000 #endif /* DEVELOPMENT || DEBUG */
3001 
3002 static int
sysctl_kern_rt_allow_limit_percent(__unused struct sysctl_oid * oidp,__unused void * arg1,__unused int arg2,struct sysctl_req * req)3003 sysctl_kern_rt_allow_limit_percent(__unused struct sysctl_oid *oidp,
3004     __unused void *arg1, __unused int arg2, struct sysctl_req *req)
3005 {
3006 	extern uint8_t rt_allow_limit_percent;
3007 
3008 	int new_value = 0;
3009 	int old_value = rt_allow_limit_percent;
3010 	int changed = 0;
3011 
3012 	int error = sysctl_io_number(req, old_value, sizeof(old_value),
3013 	    &new_value, &changed);
3014 	if (error != 0) {
3015 		return error;
3016 	}
3017 
3018 	/* Only accept a percentage between 1 and 99 inclusive. */
3019 	if (changed) {
3020 		if (new_value >= 100 || new_value <= 0) {
3021 			return EINVAL;
3022 		}
3023 
3024 		rt_allow_limit_percent = (uint8_t)new_value;
3025 	}
3026 
3027 	return 0;
3028 }
3029 
3030 SYSCTL_PROC(_kern, OID_AUTO, rt_allow_limit_percent,
3031     RT_ALLOW_CTLFLAGS | CTLTYPE_INT | CTLFLAG_LOCKED,
3032     0, 0, sysctl_kern_rt_allow_limit_percent, "I", "");
3033 
3034 static int
sysctl_kern_rt_allow_limit_interval_ms(__unused struct sysctl_oid * oidp,__unused void * arg1,__unused int arg2,struct sysctl_req * req)3035 sysctl_kern_rt_allow_limit_interval_ms(__unused struct sysctl_oid *oidp,
3036     __unused void *arg1, __unused int arg2, struct sysctl_req *req)
3037 {
3038 	extern uint16_t rt_allow_limit_interval_ms;
3039 
3040 	uint64_t new_value = 0;
3041 	uint64_t old_value = rt_allow_limit_interval_ms;
3042 	int changed = 0;
3043 
3044 	int error = sysctl_io_number(req, old_value, sizeof(old_value),
3045 	    &new_value, &changed);
3046 	if (error != 0) {
3047 		return error;
3048 	}
3049 
3050 	/* Value is in ns. Must be at least 1ms. */
3051 	if (changed) {
3052 		if (new_value < 1 || new_value > UINT16_MAX) {
3053 			return EINVAL;
3054 		}
3055 
3056 		rt_allow_limit_interval_ms = (uint16_t)new_value;
3057 	}
3058 
3059 	return 0;
3060 }
3061 
3062 SYSCTL_PROC(_kern, OID_AUTO, rt_allow_limit_interval_ms,
3063     RT_ALLOW_CTLFLAGS | CTLTYPE_QUAD | CTLFLAG_LOCKED,
3064     0, 0, sysctl_kern_rt_allow_limit_interval_ms, "Q", "");
3065 
3066 #endif /* CONFIG_SCHED_RT_ALLOW */
3067 
3068 
3069 static int
3070 sysctl_kern_task_set_filter_msg_flag SYSCTL_HANDLER_ARGS
3071 {
3072 #pragma unused(oidp, arg1, arg2)
3073 	int new_value, changed;
3074 	int old_value = task_get_filter_msg_flag(current_task()) ? 1 : 0;
3075 	int error = sysctl_io_number(req, old_value, sizeof(int), &new_value, &changed);
3076 
3077 	if (changed) {
3078 		task_set_filter_msg_flag(current_task(), !!new_value);
3079 	}
3080 
3081 	return error;
3082 }
3083 
3084 SYSCTL_PROC(_kern, OID_AUTO, task_set_filter_msg_flag, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
3085     0, 0, sysctl_kern_task_set_filter_msg_flag, "I", "");
3086 
3087 #if CONFIG_PROC_RESOURCE_LIMITS
3088 
3089 extern mach_port_name_t current_task_get_fatal_port_name(void);
3090 
3091 static int
3092 sysctl_kern_task_get_fatal_port SYSCTL_HANDLER_ARGS
3093 {
3094 #pragma unused(oidp, arg1, arg2)
3095 	int port = 0;
3096 	int flag = 0;
3097 
3098 	if (req->oldptr == USER_ADDR_NULL) {
3099 		req->oldidx = sizeof(mach_port_t);
3100 		return 0;
3101 	}
3102 
3103 	int error = SYSCTL_IN(req, &flag, sizeof(flag));
3104 	if (error) {
3105 		return error;
3106 	}
3107 
3108 	if (flag == 1) {
3109 		port = (int)current_task_get_fatal_port_name();
3110 	}
3111 	return SYSCTL_OUT(req, &port, sizeof(port));
3112 }
3113 
3114 SYSCTL_PROC(_machdep, OID_AUTO, task_get_fatal_port, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
3115     0, 0, sysctl_kern_task_get_fatal_port, "I", "");
3116 
3117 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
3118 
3119 extern unsigned int ipc_entry_table_count_max(void);
3120 
3121 static int
3122 sysctl_mach_max_port_table_size SYSCTL_HANDLER_ARGS
3123 {
3124 #pragma unused(oidp, arg1, arg2)
3125 	int old_value = ipc_entry_table_count_max();
3126 	int error = sysctl_io_number(req, old_value, sizeof(int), NULL, NULL);
3127 
3128 	return error;
3129 }
3130 
3131 SYSCTL_PROC(_machdep, OID_AUTO, max_port_table_size, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
3132     0, 0, sysctl_mach_max_port_table_size, "I", "");
3133 
3134 #endif /* DEVELOPMENT || DEBUG */
3135 
3136 #if defined(CONFIG_KDP_INTERACTIVE_DEBUGGING) && defined(CONFIG_KDP_COREDUMP_ENCRYPTION)
3137 
3138 #define COREDUMP_ENCRYPTION_KEY_ENTITLEMENT "com.apple.private.coredump-encryption-key"
3139 
3140 static int
3141 sysctl_coredump_encryption_key_update SYSCTL_HANDLER_ARGS
3142 {
3143 	kern_return_t ret = KERN_SUCCESS;
3144 	int error = 0;
3145 	struct kdp_core_encryption_key_descriptor key_descriptor = {
3146 		.kcekd_format = MACH_CORE_FILEHEADER_V2_FLAG_NEXT_COREFILE_KEY_FORMAT_NIST_P256,
3147 	};
3148 
3149 	/* Need to be root and have entitlement */
3150 	if (!kauth_cred_issuser(kauth_cred_get()) && !IOCurrentTaskHasEntitlement(COREDUMP_ENCRYPTION_KEY_ENTITLEMENT)) {
3151 		return EPERM;
3152 	}
3153 
3154 	// Sanity-check the given key length
3155 	if (req->newlen > UINT16_MAX) {
3156 		return EINVAL;
3157 	}
3158 
3159 	// It is allowed for the caller to pass in a NULL buffer.
3160 	// This indicates that they want us to forget about any public key we might have.
3161 	if (req->newptr) {
3162 		key_descriptor.kcekd_size = (uint16_t) req->newlen;
3163 		key_descriptor.kcekd_key = kalloc_data(key_descriptor.kcekd_size, Z_WAITOK);
3164 
3165 		if (key_descriptor.kcekd_key == NULL) {
3166 			return ENOMEM;
3167 		}
3168 
3169 		error = SYSCTL_IN(req, key_descriptor.kcekd_key, key_descriptor.kcekd_size);
3170 		if (error) {
3171 			goto out;
3172 		}
3173 	}
3174 
3175 	ret = IOProvideCoreFileAccess(kdp_core_handle_new_encryption_key, (void *)&key_descriptor);
3176 	if (KERN_SUCCESS != ret) {
3177 		printf("Failed to handle the new encryption key. Error 0x%x", ret);
3178 		error = EFAULT;
3179 	}
3180 
3181 out:
3182 	kfree_data(key_descriptor.kcekd_key, key_descriptor.kcekd_size);
3183 	return 0;
3184 }
3185 
3186 SYSCTL_PROC(_kern, OID_AUTO, coredump_encryption_key, CTLTYPE_OPAQUE | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
3187     0, 0, &sysctl_coredump_encryption_key_update, "-", "Set a new encryption key for coredumps");
3188 
3189 #endif /* CONFIG_KDP_INTERACTIVE_DEBUGGING && CONFIG_KDP_COREDUMP_ENCRYPTION*/
3190