xref: /freebsd/sys/kern/kern_shutdown.c (revision 3fe401a500cdfc73d8c066da3c577c4b9f0aa953)
1 /*-
2  * Copyright (c) 1986, 1988, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)kern_shutdown.c	8.3 (Berkeley) 1/21/94
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_ddb.h"
41 #include "opt_kdb.h"
42 #include "opt_panic.h"
43 #include "opt_sched.h"
44 #include "opt_watchdog.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/bio.h>
49 #include <sys/buf.h>
50 #include <sys/conf.h>
51 #include <sys/cons.h>
52 #include <sys/eventhandler.h>
53 #include <sys/jail.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/kerneldump.h>
57 #include <sys/kthread.h>
58 #include <sys/ktr.h>
59 #include <sys/malloc.h>
60 #include <sys/mount.h>
61 #include <sys/priv.h>
62 #include <sys/proc.h>
63 #include <sys/reboot.h>
64 #include <sys/resourcevar.h>
65 #include <sys/rwlock.h>
66 #include <sys/sched.h>
67 #include <sys/smp.h>
68 #include <sys/sysctl.h>
69 #include <sys/sysproto.h>
70 #include <sys/vnode.h>
71 #include <sys/watchdog.h>
72 
73 #include <ddb/ddb.h>
74 
75 #include <machine/cpu.h>
76 #include <machine/dump.h>
77 #include <machine/pcb.h>
78 #include <machine/smp.h>
79 
80 #include <security/mac/mac_framework.h>
81 
82 #include <vm/vm.h>
83 #include <vm/vm_object.h>
84 #include <vm/vm_page.h>
85 #include <vm/vm_pager.h>
86 #include <vm/swap_pager.h>
87 
88 #include <sys/signalvar.h>
89 
90 #ifndef PANIC_REBOOT_WAIT_TIME
91 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
92 #endif
93 static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME;
94 SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN,
95     &panic_reboot_wait_time, 0,
96     "Seconds to wait before rebooting after a panic");
97 
98 /*
99  * Note that stdarg.h and the ANSI style va_start macro is used for both
100  * ANSI and traditional C compilers.
101  */
102 #include <machine/stdarg.h>
103 
104 #ifdef KDB
105 #ifdef KDB_UNATTENDED
106 int debugger_on_panic = 0;
107 #else
108 int debugger_on_panic = 1;
109 #endif
110 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic,
111     CTLFLAG_RWTUN | CTLFLAG_SECURE,
112     &debugger_on_panic, 0, "Run debugger on kernel panic");
113 
114 #ifdef KDB_TRACE
115 static int trace_on_panic = 1;
116 #else
117 static int trace_on_panic = 0;
118 #endif
119 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic,
120     CTLFLAG_RWTUN | CTLFLAG_SECURE,
121     &trace_on_panic, 0, "Print stack trace on kernel panic");
122 #endif /* KDB */
123 
124 static int sync_on_panic = 0;
125 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN,
126 	&sync_on_panic, 0, "Do a sync before rebooting from a panic");
127 
128 static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0,
129     "Shutdown environment");
130 
131 #ifndef DIAGNOSTIC
132 static int show_busybufs;
133 #else
134 static int show_busybufs = 1;
135 #endif
136 SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
137 	&show_busybufs, 0, "");
138 
139 /*
140  * Variable panicstr contains argument to first call to panic; used as flag
141  * to indicate that the kernel has already called panic.
142  */
143 const char *panicstr;
144 
145 int dumping;				/* system is dumping */
146 int rebooting;				/* system is rebooting */
147 static struct dumperinfo dumper;	/* our selected dumper */
148 
149 /* Context information for dump-debuggers. */
150 static struct pcb dumppcb;		/* Registers. */
151 lwpid_t dumptid;			/* Thread ID. */
152 
153 static void poweroff_wait(void *, int);
154 static void shutdown_halt(void *junk, int howto);
155 static void shutdown_panic(void *junk, int howto);
156 static void shutdown_reset(void *junk, int howto);
157 
158 /* register various local shutdown events */
159 static void
160 shutdown_conf(void *unused)
161 {
162 
163 	EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
164 	    SHUTDOWN_PRI_FIRST);
165 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
166 	    SHUTDOWN_PRI_LAST + 100);
167 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
168 	    SHUTDOWN_PRI_LAST + 100);
169 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
170 	    SHUTDOWN_PRI_LAST + 200);
171 }
172 
173 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
174 
175 /*
176  * The system call that results in a reboot.
177  */
178 /* ARGSUSED */
179 int
180 sys_reboot(struct thread *td, struct reboot_args *uap)
181 {
182 	int error;
183 
184 	error = 0;
185 #ifdef MAC
186 	error = mac_system_check_reboot(td->td_ucred, uap->opt);
187 #endif
188 	if (error == 0)
189 		error = priv_check(td, PRIV_REBOOT);
190 	if (error == 0) {
191 		mtx_lock(&Giant);
192 		kern_reboot(uap->opt);
193 		mtx_unlock(&Giant);
194 	}
195 	return (error);
196 }
197 
198 /*
199  * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
200  */
201 void
202 shutdown_nice(int howto)
203 {
204 
205 	if (initproc != NULL) {
206 		/* Send a signal to init(8) and have it shutdown the world. */
207 		PROC_LOCK(initproc);
208 		if (howto & RB_POWEROFF)
209 			kern_psignal(initproc, SIGUSR2);
210 		else if (howto & RB_HALT)
211 			kern_psignal(initproc, SIGUSR1);
212 		else
213 			kern_psignal(initproc, SIGINT);
214 		PROC_UNLOCK(initproc);
215 	} else {
216 		/* No init(8) running, so simply reboot. */
217 		kern_reboot(howto | RB_NOSYNC);
218 	}
219 }
220 
221 static void
222 print_uptime(void)
223 {
224 	int f;
225 	struct timespec ts;
226 
227 	getnanouptime(&ts);
228 	printf("Uptime: ");
229 	f = 0;
230 	if (ts.tv_sec >= 86400) {
231 		printf("%ldd", (long)ts.tv_sec / 86400);
232 		ts.tv_sec %= 86400;
233 		f = 1;
234 	}
235 	if (f || ts.tv_sec >= 3600) {
236 		printf("%ldh", (long)ts.tv_sec / 3600);
237 		ts.tv_sec %= 3600;
238 		f = 1;
239 	}
240 	if (f || ts.tv_sec >= 60) {
241 		printf("%ldm", (long)ts.tv_sec / 60);
242 		ts.tv_sec %= 60;
243 		f = 1;
244 	}
245 	printf("%lds\n", (long)ts.tv_sec);
246 }
247 
248 int
249 doadump(boolean_t textdump)
250 {
251 	boolean_t coredump;
252 	int error;
253 
254 	error = 0;
255 	if (dumping)
256 		return (EBUSY);
257 	if (dumper.dumper == NULL)
258 		return (ENXIO);
259 
260 	savectx(&dumppcb);
261 	dumptid = curthread->td_tid;
262 	dumping++;
263 
264 	coredump = TRUE;
265 #ifdef DDB
266 	if (textdump && textdump_pending) {
267 		coredump = FALSE;
268 		textdump_dumpsys(&dumper);
269 	}
270 #endif
271 	if (coredump)
272 		error = dumpsys(&dumper);
273 
274 	dumping--;
275 	return (error);
276 }
277 
278 /*
279  * Shutdown the system cleanly to prepare for reboot, halt, or power off.
280  */
281 void
282 kern_reboot(int howto)
283 {
284 	static int once = 0;
285 
286 #if defined(SMP)
287 	/*
288 	 * Bind us to CPU 0 so that all shutdown code runs there.  Some
289 	 * systems don't shutdown properly (i.e., ACPI power off) if we
290 	 * run on another processor.
291 	 */
292 	if (!SCHEDULER_STOPPED()) {
293 		thread_lock(curthread);
294 		sched_bind(curthread, 0);
295 		thread_unlock(curthread);
296 		KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
297 	}
298 #endif
299 	/* We're in the process of rebooting. */
300 	rebooting = 1;
301 
302 	/* We are out of the debugger now. */
303 	kdb_active = 0;
304 
305 	/*
306 	 * Do any callouts that should be done BEFORE syncing the filesystems.
307 	 */
308 	EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
309 
310 	/*
311 	 * Now sync filesystems
312 	 */
313 	if (!cold && (howto & RB_NOSYNC) == 0 && once == 0) {
314 		once = 1;
315 		bufshutdown(show_busybufs);
316 	}
317 
318 	print_uptime();
319 
320 	cngrab();
321 
322 	/*
323 	 * Ok, now do things that assume all filesystem activity has
324 	 * been completed.
325 	 */
326 	EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
327 
328 	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
329 		doadump(TRUE);
330 
331 	/* Now that we're going to really halt the system... */
332 	EVENTHANDLER_INVOKE(shutdown_final, howto);
333 
334 	for(;;) ;	/* safety against shutdown_reset not working */
335 	/* NOTREACHED */
336 }
337 
338 /*
339  * If the shutdown was a clean halt, behave accordingly.
340  */
341 static void
342 shutdown_halt(void *junk, int howto)
343 {
344 
345 	if (howto & RB_HALT) {
346 		printf("\n");
347 		printf("The operating system has halted.\n");
348 		printf("Please press any key to reboot.\n\n");
349 		switch (cngetc()) {
350 		case -1:		/* No console, just die */
351 			cpu_halt();
352 			/* NOTREACHED */
353 		default:
354 			howto &= ~RB_HALT;
355 			break;
356 		}
357 	}
358 }
359 
360 /*
361  * Check to see if the system paniced, pause and then reboot
362  * according to the specified delay.
363  */
364 static void
365 shutdown_panic(void *junk, int howto)
366 {
367 	int loop;
368 
369 	if (howto & RB_DUMP) {
370 		if (panic_reboot_wait_time != 0) {
371 			if (panic_reboot_wait_time != -1) {
372 				printf("Automatic reboot in %d seconds - "
373 				       "press a key on the console to abort\n",
374 					panic_reboot_wait_time);
375 				for (loop = panic_reboot_wait_time * 10;
376 				     loop > 0; --loop) {
377 					DELAY(1000 * 100); /* 1/10th second */
378 					/* Did user type a key? */
379 					if (cncheckc() != -1)
380 						break;
381 				}
382 				if (!loop)
383 					return;
384 			}
385 		} else { /* zero time specified - reboot NOW */
386 			return;
387 		}
388 		printf("--> Press a key on the console to reboot,\n");
389 		printf("--> or switch off the system now.\n");
390 		cngetc();
391 	}
392 }
393 
394 /*
395  * Everything done, now reset
396  */
397 static void
398 shutdown_reset(void *junk, int howto)
399 {
400 
401 	printf("Rebooting...\n");
402 	DELAY(1000000);	/* wait 1 sec for printf's to complete and be read */
403 
404 	/*
405 	 * Acquiring smp_ipi_mtx here has a double effect:
406 	 * - it disables interrupts avoiding CPU0 preemption
407 	 *   by fast handlers (thus deadlocking  against other CPUs)
408 	 * - it avoids deadlocks against smp_rendezvous() or, more
409 	 *   generally, threads busy-waiting, with this spinlock held,
410 	 *   and waiting for responses by threads on other CPUs
411 	 *   (ie. smp_tlb_shootdown()).
412 	 *
413 	 * For the !SMP case it just needs to handle the former problem.
414 	 */
415 #ifdef SMP
416 	mtx_lock_spin(&smp_ipi_mtx);
417 #else
418 	spinlock_enter();
419 #endif
420 
421 	/* cpu_boot(howto); */ /* doesn't do anything at the moment */
422 	cpu_reset();
423 	/* NOTREACHED */ /* assuming reset worked */
424 }
425 
426 #if defined(WITNESS) || defined(INVARIANTS)
427 static int kassert_warn_only = 0;
428 #ifdef KDB
429 static int kassert_do_kdb = 0;
430 #endif
431 #ifdef KTR
432 static int kassert_do_ktr = 0;
433 #endif
434 static int kassert_do_log = 1;
435 static int kassert_log_pps_limit = 4;
436 static int kassert_log_mute_at = 0;
437 static int kassert_log_panic_at = 0;
438 static int kassert_warnings = 0;
439 
440 SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options");
441 
442 SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RWTUN,
443     &kassert_warn_only, 0,
444     "KASSERT triggers a panic (1) or just a warning (0)");
445 
446 #ifdef KDB
447 SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RWTUN,
448     &kassert_do_kdb, 0, "KASSERT will enter the debugger");
449 #endif
450 
451 #ifdef KTR
452 SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RWTUN,
453     &kassert_do_ktr, 0,
454     "KASSERT does a KTR, set this to the KTRMASK you want");
455 #endif
456 
457 SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RWTUN,
458     &kassert_do_log, 0, "KASSERT triggers a panic (1) or just a warning (0)");
459 
460 SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RWTUN,
461     &kassert_warnings, 0, "number of KASSERTs that have been triggered");
462 
463 SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RWTUN,
464     &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic");
465 
466 SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RWTUN,
467     &kassert_log_pps_limit, 0, "limit number of log messages per second");
468 
469 SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RWTUN,
470     &kassert_log_mute_at, 0, "max number of KASSERTS to log");
471 
472 static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS);
473 
474 SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert,
475     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, NULL, 0,
476     kassert_sysctl_kassert, "I", "set to trigger a test kassert");
477 
478 static int
479 kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)
480 {
481 	int error, i;
482 
483 	error = sysctl_wire_old_buffer(req, sizeof(int));
484 	if (error == 0) {
485 		i = 0;
486 		error = sysctl_handle_int(oidp, &i, 0, req);
487 	}
488 	if (error != 0 || req->newptr == NULL)
489 		return (error);
490 	KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i));
491 	return (0);
492 }
493 
494 /*
495  * Called by KASSERT, this decides if we will panic
496  * or if we will log via printf and/or ktr.
497  */
498 void
499 kassert_panic(const char *fmt, ...)
500 {
501 	static char buf[256];
502 	va_list ap;
503 
504 	va_start(ap, fmt);
505 	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
506 	va_end(ap);
507 
508 	/*
509 	 * panic if we're not just warning, or if we've exceeded
510 	 * kassert_log_panic_at warnings.
511 	 */
512 	if (!kassert_warn_only ||
513 	    (kassert_log_panic_at > 0 &&
514 	     kassert_warnings >= kassert_log_panic_at)) {
515 		va_start(ap, fmt);
516 		vpanic(fmt, ap);
517 		/* NORETURN */
518 	}
519 #ifdef KTR
520 	if (kassert_do_ktr)
521 		CTR0(ktr_mask, buf);
522 #endif /* KTR */
523 	/*
524 	 * log if we've not yet met the mute limit.
525 	 */
526 	if (kassert_do_log &&
527 	    (kassert_log_mute_at == 0 ||
528 	     kassert_warnings < kassert_log_mute_at)) {
529 		static  struct timeval lasterr;
530 		static  int curerr;
531 
532 		if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) {
533 			printf("KASSERT failed: %s\n", buf);
534 			kdb_backtrace();
535 		}
536 	}
537 #ifdef KDB
538 	if (kassert_do_kdb) {
539 		kdb_enter(KDB_WHY_KASSERT, buf);
540 	}
541 #endif
542 	atomic_add_int(&kassert_warnings, 1);
543 }
544 #endif
545 
546 /*
547  * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
548  * and then reboots.  If we are called twice, then we avoid trying to sync
549  * the disks as this often leads to recursive panics.
550  */
551 void
552 panic(const char *fmt, ...)
553 {
554 	va_list ap;
555 
556 	va_start(ap, fmt);
557 	vpanic(fmt, ap);
558 }
559 
560 void
561 vpanic(const char *fmt, va_list ap)
562 {
563 #ifdef SMP
564 	cpuset_t other_cpus;
565 #endif
566 	struct thread *td = curthread;
567 	int bootopt, newpanic;
568 	static char buf[256];
569 
570 	spinlock_enter();
571 
572 #ifdef SMP
573 	/*
574 	 * stop_cpus_hard(other_cpus) should prevent multiple CPUs from
575 	 * concurrently entering panic.  Only the winner will proceed
576 	 * further.
577 	 */
578 	if (panicstr == NULL && !kdb_active) {
579 		other_cpus = all_cpus;
580 		CPU_CLR(PCPU_GET(cpuid), &other_cpus);
581 		stop_cpus_hard(other_cpus);
582 	}
583 
584 	/*
585 	 * Ensure that the scheduler is stopped while panicking, even if panic
586 	 * has been entered from kdb.
587 	 */
588 	td->td_stopsched = 1;
589 #endif
590 
591 	bootopt = RB_AUTOBOOT;
592 	newpanic = 0;
593 	if (panicstr)
594 		bootopt |= RB_NOSYNC;
595 	else {
596 		bootopt |= RB_DUMP;
597 		panicstr = fmt;
598 		newpanic = 1;
599 	}
600 
601 	if (newpanic) {
602 		(void)vsnprintf(buf, sizeof(buf), fmt, ap);
603 		panicstr = buf;
604 		cngrab();
605 		printf("panic: %s\n", buf);
606 	} else {
607 		printf("panic: ");
608 		vprintf(fmt, ap);
609 		printf("\n");
610 	}
611 #ifdef SMP
612 	printf("cpuid = %d\n", PCPU_GET(cpuid));
613 #endif
614 
615 #ifdef KDB
616 	if (newpanic && trace_on_panic)
617 		kdb_backtrace();
618 	if (debugger_on_panic)
619 		kdb_enter(KDB_WHY_PANIC, "panic");
620 #endif
621 	/*thread_lock(td); */
622 	td->td_flags |= TDF_INPANIC;
623 	/* thread_unlock(td); */
624 	if (!sync_on_panic)
625 		bootopt |= RB_NOSYNC;
626 	kern_reboot(bootopt);
627 }
628 
629 /*
630  * Support for poweroff delay.
631  *
632  * Please note that setting this delay too short might power off your machine
633  * before the write cache on your hard disk has been flushed, leading to
634  * soft-updates inconsistencies.
635  */
636 #ifndef POWEROFF_DELAY
637 # define POWEROFF_DELAY 5000
638 #endif
639 static int poweroff_delay = POWEROFF_DELAY;
640 
641 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
642     &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)");
643 
644 static void
645 poweroff_wait(void *junk, int howto)
646 {
647 
648 	if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
649 		return;
650 	DELAY(poweroff_delay * 1000);
651 }
652 
653 /*
654  * Some system processes (e.g. syncer) need to be stopped at appropriate
655  * points in their main loops prior to a system shutdown, so that they
656  * won't interfere with the shutdown process (e.g. by holding a disk buf
657  * to cause sync to fail).  For each of these system processes, register
658  * shutdown_kproc() as a handler for one of shutdown events.
659  */
660 static int kproc_shutdown_wait = 60;
661 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
662     &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process");
663 
664 void
665 kproc_shutdown(void *arg, int howto)
666 {
667 	struct proc *p;
668 	int error;
669 
670 	if (panicstr)
671 		return;
672 
673 	p = (struct proc *)arg;
674 	printf("Waiting (max %d seconds) for system process `%s' to stop...",
675 	    kproc_shutdown_wait, p->p_comm);
676 	error = kproc_suspend(p, kproc_shutdown_wait * hz);
677 
678 	if (error == EWOULDBLOCK)
679 		printf("timed out\n");
680 	else
681 		printf("done\n");
682 }
683 
684 void
685 kthread_shutdown(void *arg, int howto)
686 {
687 	struct thread *td;
688 	int error;
689 
690 	if (panicstr)
691 		return;
692 
693 	td = (struct thread *)arg;
694 	printf("Waiting (max %d seconds) for system thread `%s' to stop...",
695 	    kproc_shutdown_wait, td->td_name);
696 	error = kthread_suspend(td, kproc_shutdown_wait * hz);
697 
698 	if (error == EWOULDBLOCK)
699 		printf("timed out\n");
700 	else
701 		printf("done\n");
702 }
703 
704 static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)];
705 SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD,
706     dumpdevname, 0, "Device for kernel dumps");
707 
708 /* Registration of dumpers */
709 int
710 set_dumper(struct dumperinfo *di, const char *devname, struct thread *td)
711 {
712 	size_t wantcopy;
713 	int error;
714 
715 	error = priv_check(td, PRIV_SETDUMPER);
716 	if (error != 0)
717 		return (error);
718 
719 	if (di == NULL) {
720 		bzero(&dumper, sizeof dumper);
721 		dumpdevname[0] = '\0';
722 		return (0);
723 	}
724 	if (dumper.dumper != NULL)
725 		return (EBUSY);
726 	dumper = *di;
727 	wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname));
728 	if (wantcopy >= sizeof(dumpdevname)) {
729 		printf("set_dumper: device name truncated from '%s' -> '%s'\n",
730 			devname, dumpdevname);
731 	}
732 	return (0);
733 }
734 
735 /* Call dumper with bounds checking. */
736 int
737 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
738     off_t offset, size_t length)
739 {
740 
741 	if (length != 0 && (offset < di->mediaoffset ||
742 	    offset - di->mediaoffset + length > di->mediasize)) {
743 		printf("Attempt to write outside dump device boundaries.\n"
744 	    "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
745 		    (intmax_t)offset, (intmax_t)di->mediaoffset,
746 		    (uintmax_t)length, (intmax_t)di->mediasize);
747 		return (ENOSPC);
748 	}
749 	return (di->dumper(di->priv, virtual, physical, offset, length));
750 }
751 
752 void
753 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
754     uint64_t dumplen, uint32_t blksz)
755 {
756 
757 	bzero(kdh, sizeof(*kdh));
758 	strlcpy(kdh->magic, magic, sizeof(kdh->magic));
759 	strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
760 	kdh->version = htod32(KERNELDUMPVERSION);
761 	kdh->architectureversion = htod32(archver);
762 	kdh->dumplength = htod64(dumplen);
763 	kdh->dumptime = htod64(time_second);
764 	kdh->blocksize = htod32(blksz);
765 	strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
766 	strlcpy(kdh->versionstring, version, sizeof(kdh->versionstring));
767 	if (panicstr != NULL)
768 		strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
769 	kdh->parity = kerneldump_parity(kdh);
770 }
771