xref: /freebsd/sys/kern/kern_shutdown.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
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/filedesc.h>
54 #include <sys/jail.h>
55 #include <sys/kdb.h>
56 #include <sys/kernel.h>
57 #include <sys/kerneldump.h>
58 #include <sys/kthread.h>
59 #include <sys/ktr.h>
60 #include <sys/malloc.h>
61 #include <sys/mount.h>
62 #include <sys/priv.h>
63 #include <sys/proc.h>
64 #include <sys/reboot.h>
65 #include <sys/resourcevar.h>
66 #include <sys/rwlock.h>
67 #include <sys/sched.h>
68 #include <sys/smp.h>
69 #include <sys/sysctl.h>
70 #include <sys/sysproto.h>
71 #include <sys/vnode.h>
72 #include <sys/watchdog.h>
73 
74 #include <ddb/ddb.h>
75 
76 #include <machine/cpu.h>
77 #include <machine/dump.h>
78 #include <machine/pcb.h>
79 #include <machine/smp.h>
80 
81 #include <security/mac/mac_framework.h>
82 
83 #include <vm/vm.h>
84 #include <vm/vm_object.h>
85 #include <vm/vm_page.h>
86 #include <vm/vm_pager.h>
87 #include <vm/swap_pager.h>
88 
89 #include <sys/signalvar.h>
90 
91 static MALLOC_DEFINE(M_DUMPER, "dumper", "dumper block buffer");
92 
93 #ifndef PANIC_REBOOT_WAIT_TIME
94 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
95 #endif
96 static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME;
97 SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN,
98     &panic_reboot_wait_time, 0,
99     "Seconds to wait before rebooting after a panic");
100 
101 /*
102  * Note that stdarg.h and the ANSI style va_start macro is used for both
103  * ANSI and traditional C compilers.
104  */
105 #include <machine/stdarg.h>
106 
107 #ifdef KDB
108 #ifdef KDB_UNATTENDED
109 int debugger_on_panic = 0;
110 #else
111 int debugger_on_panic = 1;
112 #endif
113 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic,
114     CTLFLAG_RWTUN | CTLFLAG_SECURE,
115     &debugger_on_panic, 0, "Run debugger on kernel panic");
116 
117 #ifdef KDB_TRACE
118 static int trace_on_panic = 1;
119 #else
120 static int trace_on_panic = 0;
121 #endif
122 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic,
123     CTLFLAG_RWTUN | CTLFLAG_SECURE,
124     &trace_on_panic, 0, "Print stack trace on kernel panic");
125 #endif /* KDB */
126 
127 static int sync_on_panic = 0;
128 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN,
129 	&sync_on_panic, 0, "Do a sync before rebooting from a panic");
130 
131 static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0,
132     "Shutdown environment");
133 
134 #ifndef DIAGNOSTIC
135 static int show_busybufs;
136 #else
137 static int show_busybufs = 1;
138 #endif
139 SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
140 	&show_busybufs, 0, "");
141 
142 int suspend_blocked = 0;
143 SYSCTL_INT(_kern, OID_AUTO, suspend_blocked, CTLFLAG_RW,
144 	&suspend_blocked, 0, "Block suspend due to a pending shutdown");
145 
146 /*
147  * Variable panicstr contains argument to first call to panic; used as flag
148  * to indicate that the kernel has already called panic.
149  */
150 const char *panicstr;
151 
152 int dumping;				/* system is dumping */
153 int rebooting;				/* system is rebooting */
154 static struct dumperinfo dumper;	/* our selected dumper */
155 
156 /* Context information for dump-debuggers. */
157 static struct pcb dumppcb;		/* Registers. */
158 lwpid_t dumptid;			/* Thread ID. */
159 
160 static struct cdevsw reroot_cdevsw = {
161      .d_version = D_VERSION,
162      .d_name    = "reroot",
163 };
164 
165 static void poweroff_wait(void *, int);
166 static void shutdown_halt(void *junk, int howto);
167 static void shutdown_panic(void *junk, int howto);
168 static void shutdown_reset(void *junk, int howto);
169 static int kern_reroot(void);
170 
171 /* register various local shutdown events */
172 static void
173 shutdown_conf(void *unused)
174 {
175 
176 	EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
177 	    SHUTDOWN_PRI_FIRST);
178 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
179 	    SHUTDOWN_PRI_LAST + 100);
180 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
181 	    SHUTDOWN_PRI_LAST + 100);
182 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
183 	    SHUTDOWN_PRI_LAST + 200);
184 }
185 
186 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
187 
188 /*
189  * The only reason this exists is to create the /dev/reroot/ directory,
190  * used by reroot code in init(8) as a mountpoint for tmpfs.
191  */
192 static void
193 reroot_conf(void *unused)
194 {
195 	int error;
196 	struct cdev *cdev;
197 
198 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &cdev,
199 	    &reroot_cdevsw, NULL, UID_ROOT, GID_WHEEL, 0600, "reroot/reroot");
200 	if (error != 0) {
201 		printf("%s: failed to create device node, error %d",
202 		    __func__, error);
203 	}
204 }
205 
206 SYSINIT(reroot_conf, SI_SUB_DEVFS, SI_ORDER_ANY, reroot_conf, NULL);
207 
208 /*
209  * The system call that results in a reboot.
210  */
211 /* ARGSUSED */
212 int
213 sys_reboot(struct thread *td, struct reboot_args *uap)
214 {
215 	int error;
216 
217 	error = 0;
218 #ifdef MAC
219 	error = mac_system_check_reboot(td->td_ucred, uap->opt);
220 #endif
221 	if (error == 0)
222 		error = priv_check(td, PRIV_REBOOT);
223 	if (error == 0) {
224 		if (uap->opt & RB_REROOT) {
225 			error = kern_reroot();
226 		} else {
227 			mtx_lock(&Giant);
228 			kern_reboot(uap->opt);
229 			mtx_unlock(&Giant);
230 		}
231 	}
232 	return (error);
233 }
234 
235 /*
236  * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
237  */
238 void
239 shutdown_nice(int howto)
240 {
241 
242 	if (initproc != NULL) {
243 		/* Send a signal to init(8) and have it shutdown the world. */
244 		PROC_LOCK(initproc);
245 		if (howto & RB_POWEROFF)
246 			kern_psignal(initproc, SIGUSR2);
247 		else if (howto & RB_HALT)
248 			kern_psignal(initproc, SIGUSR1);
249 		else
250 			kern_psignal(initproc, SIGINT);
251 		PROC_UNLOCK(initproc);
252 	} else {
253 		/* No init(8) running, so simply reboot. */
254 		kern_reboot(howto | RB_NOSYNC);
255 	}
256 }
257 
258 static void
259 print_uptime(void)
260 {
261 	int f;
262 	struct timespec ts;
263 
264 	getnanouptime(&ts);
265 	printf("Uptime: ");
266 	f = 0;
267 	if (ts.tv_sec >= 86400) {
268 		printf("%ldd", (long)ts.tv_sec / 86400);
269 		ts.tv_sec %= 86400;
270 		f = 1;
271 	}
272 	if (f || ts.tv_sec >= 3600) {
273 		printf("%ldh", (long)ts.tv_sec / 3600);
274 		ts.tv_sec %= 3600;
275 		f = 1;
276 	}
277 	if (f || ts.tv_sec >= 60) {
278 		printf("%ldm", (long)ts.tv_sec / 60);
279 		ts.tv_sec %= 60;
280 		f = 1;
281 	}
282 	printf("%lds\n", (long)ts.tv_sec);
283 }
284 
285 int
286 doadump(boolean_t textdump)
287 {
288 	boolean_t coredump;
289 	int error;
290 
291 	error = 0;
292 	if (dumping)
293 		return (EBUSY);
294 	if (dumper.dumper == NULL)
295 		return (ENXIO);
296 
297 	savectx(&dumppcb);
298 	dumptid = curthread->td_tid;
299 	dumping++;
300 
301 	coredump = TRUE;
302 #ifdef DDB
303 	if (textdump && textdump_pending) {
304 		coredump = FALSE;
305 		textdump_dumpsys(&dumper);
306 	}
307 #endif
308 	if (coredump)
309 		error = dumpsys(&dumper);
310 
311 	dumping--;
312 	return (error);
313 }
314 
315 /*
316  * Shutdown the system cleanly to prepare for reboot, halt, or power off.
317  */
318 void
319 kern_reboot(int howto)
320 {
321 	static int once = 0;
322 
323 #if defined(SMP)
324 	/*
325 	 * Bind us to CPU 0 so that all shutdown code runs there.  Some
326 	 * systems don't shutdown properly (i.e., ACPI power off) if we
327 	 * run on another processor.
328 	 */
329 	if (!SCHEDULER_STOPPED()) {
330 		thread_lock(curthread);
331 		sched_bind(curthread, 0);
332 		thread_unlock(curthread);
333 		KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
334 	}
335 #endif
336 	/* We're in the process of rebooting. */
337 	rebooting = 1;
338 
339 	/* We are out of the debugger now. */
340 	kdb_active = 0;
341 
342 	/*
343 	 * Do any callouts that should be done BEFORE syncing the filesystems.
344 	 */
345 	EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
346 
347 	/*
348 	 * Now sync filesystems
349 	 */
350 	if (!cold && (howto & RB_NOSYNC) == 0 && once == 0) {
351 		once = 1;
352 		bufshutdown(show_busybufs);
353 	}
354 
355 	print_uptime();
356 
357 	cngrab();
358 
359 	/*
360 	 * Ok, now do things that assume all filesystem activity has
361 	 * been completed.
362 	 */
363 	EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
364 
365 	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
366 		doadump(TRUE);
367 
368 	/* Now that we're going to really halt the system... */
369 	EVENTHANDLER_INVOKE(shutdown_final, howto);
370 
371 	for(;;) ;	/* safety against shutdown_reset not working */
372 	/* NOTREACHED */
373 }
374 
375 /*
376  * The system call that results in changing the rootfs.
377  */
378 static int
379 kern_reroot(void)
380 {
381 	struct vnode *oldrootvnode, *vp;
382 	struct mount *mp, *devmp;
383 	int error;
384 
385 	if (curproc != initproc)
386 		return (EPERM);
387 
388 	/*
389 	 * Mark the filesystem containing currently-running executable
390 	 * (the temporary copy of init(8)) busy.
391 	 */
392 	vp = curproc->p_textvp;
393 	error = vn_lock(vp, LK_SHARED);
394 	if (error != 0)
395 		return (error);
396 	mp = vp->v_mount;
397 	error = vfs_busy(mp, MBF_NOWAIT);
398 	if (error != 0) {
399 		vfs_ref(mp);
400 		VOP_UNLOCK(vp, 0);
401 		error = vfs_busy(mp, 0);
402 		vn_lock(vp, LK_SHARED | LK_RETRY);
403 		vfs_rel(mp);
404 		if (error != 0) {
405 			VOP_UNLOCK(vp, 0);
406 			return (ENOENT);
407 		}
408 		if (vp->v_iflag & VI_DOOMED) {
409 			VOP_UNLOCK(vp, 0);
410 			vfs_unbusy(mp);
411 			return (ENOENT);
412 		}
413 	}
414 	VOP_UNLOCK(vp, 0);
415 
416 	/*
417 	 * Remove the filesystem containing currently-running executable
418 	 * from the mount list, to prevent it from being unmounted
419 	 * by vfs_unmountall(), and to avoid confusing vfs_mountroot().
420 	 *
421 	 * Also preserve /dev - forcibly unmounting it could cause driver
422 	 * reinitialization.
423 	 */
424 
425 	vfs_ref(rootdevmp);
426 	devmp = rootdevmp;
427 	rootdevmp = NULL;
428 
429 	mtx_lock(&mountlist_mtx);
430 	TAILQ_REMOVE(&mountlist, mp, mnt_list);
431 	TAILQ_REMOVE(&mountlist, devmp, mnt_list);
432 	mtx_unlock(&mountlist_mtx);
433 
434 	oldrootvnode = rootvnode;
435 
436 	/*
437 	 * Unmount everything except for the two filesystems preserved above.
438 	 */
439 	vfs_unmountall();
440 
441 	/*
442 	 * Add /dev back; vfs_mountroot() will move it into its new place.
443 	 */
444 	mtx_lock(&mountlist_mtx);
445 	TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list);
446 	mtx_unlock(&mountlist_mtx);
447 	rootdevmp = devmp;
448 	vfs_rel(rootdevmp);
449 
450 	/*
451 	 * Mount the new rootfs.
452 	 */
453 	vfs_mountroot();
454 
455 	/*
456 	 * Update all references to the old rootvnode.
457 	 */
458 	mountcheckdirs(oldrootvnode, rootvnode);
459 
460 	/*
461 	 * Add the temporary filesystem back and unbusy it.
462 	 */
463 	mtx_lock(&mountlist_mtx);
464 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
465 	mtx_unlock(&mountlist_mtx);
466 	vfs_unbusy(mp);
467 
468 	return (0);
469 }
470 
471 /*
472  * If the shutdown was a clean halt, behave accordingly.
473  */
474 static void
475 shutdown_halt(void *junk, int howto)
476 {
477 
478 	if (howto & RB_HALT) {
479 		printf("\n");
480 		printf("The operating system has halted.\n");
481 		printf("Please press any key to reboot.\n\n");
482 		switch (cngetc()) {
483 		case -1:		/* No console, just die */
484 			cpu_halt();
485 			/* NOTREACHED */
486 		default:
487 			howto &= ~RB_HALT;
488 			break;
489 		}
490 	}
491 }
492 
493 /*
494  * Check to see if the system paniced, pause and then reboot
495  * according to the specified delay.
496  */
497 static void
498 shutdown_panic(void *junk, int howto)
499 {
500 	int loop;
501 
502 	if (howto & RB_DUMP) {
503 		if (panic_reboot_wait_time != 0) {
504 			if (panic_reboot_wait_time != -1) {
505 				printf("Automatic reboot in %d seconds - "
506 				       "press a key on the console to abort\n",
507 					panic_reboot_wait_time);
508 				for (loop = panic_reboot_wait_time * 10;
509 				     loop > 0; --loop) {
510 					DELAY(1000 * 100); /* 1/10th second */
511 					/* Did user type a key? */
512 					if (cncheckc() != -1)
513 						break;
514 				}
515 				if (!loop)
516 					return;
517 			}
518 		} else { /* zero time specified - reboot NOW */
519 			return;
520 		}
521 		printf("--> Press a key on the console to reboot,\n");
522 		printf("--> or switch off the system now.\n");
523 		cngetc();
524 	}
525 }
526 
527 /*
528  * Everything done, now reset
529  */
530 static void
531 shutdown_reset(void *junk, int howto)
532 {
533 
534 	printf("Rebooting...\n");
535 	DELAY(1000000);	/* wait 1 sec for printf's to complete and be read */
536 
537 	/*
538 	 * Acquiring smp_ipi_mtx here has a double effect:
539 	 * - it disables interrupts avoiding CPU0 preemption
540 	 *   by fast handlers (thus deadlocking  against other CPUs)
541 	 * - it avoids deadlocks against smp_rendezvous() or, more
542 	 *   generally, threads busy-waiting, with this spinlock held,
543 	 *   and waiting for responses by threads on other CPUs
544 	 *   (ie. smp_tlb_shootdown()).
545 	 *
546 	 * For the !SMP case it just needs to handle the former problem.
547 	 */
548 #ifdef SMP
549 	mtx_lock_spin(&smp_ipi_mtx);
550 #else
551 	spinlock_enter();
552 #endif
553 
554 	/* cpu_boot(howto); */ /* doesn't do anything at the moment */
555 	cpu_reset();
556 	/* NOTREACHED */ /* assuming reset worked */
557 }
558 
559 #if defined(WITNESS) || defined(INVARIANT_SUPPORT)
560 static int kassert_warn_only = 0;
561 #ifdef KDB
562 static int kassert_do_kdb = 0;
563 #endif
564 #ifdef KTR
565 static int kassert_do_ktr = 0;
566 #endif
567 static int kassert_do_log = 1;
568 static int kassert_log_pps_limit = 4;
569 static int kassert_log_mute_at = 0;
570 static int kassert_log_panic_at = 0;
571 static int kassert_warnings = 0;
572 
573 SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options");
574 
575 SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RWTUN,
576     &kassert_warn_only, 0,
577     "KASSERT triggers a panic (1) or just a warning (0)");
578 
579 #ifdef KDB
580 SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RWTUN,
581     &kassert_do_kdb, 0, "KASSERT will enter the debugger");
582 #endif
583 
584 #ifdef KTR
585 SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RWTUN,
586     &kassert_do_ktr, 0,
587     "KASSERT does a KTR, set this to the KTRMASK you want");
588 #endif
589 
590 SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RWTUN,
591     &kassert_do_log, 0, "KASSERT triggers a panic (1) or just a warning (0)");
592 
593 SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RWTUN,
594     &kassert_warnings, 0, "number of KASSERTs that have been triggered");
595 
596 SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RWTUN,
597     &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic");
598 
599 SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RWTUN,
600     &kassert_log_pps_limit, 0, "limit number of log messages per second");
601 
602 SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RWTUN,
603     &kassert_log_mute_at, 0, "max number of KASSERTS to log");
604 
605 static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS);
606 
607 SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert,
608     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, NULL, 0,
609     kassert_sysctl_kassert, "I", "set to trigger a test kassert");
610 
611 static int
612 kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)
613 {
614 	int error, i;
615 
616 	error = sysctl_wire_old_buffer(req, sizeof(int));
617 	if (error == 0) {
618 		i = 0;
619 		error = sysctl_handle_int(oidp, &i, 0, req);
620 	}
621 	if (error != 0 || req->newptr == NULL)
622 		return (error);
623 	KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i));
624 	return (0);
625 }
626 
627 /*
628  * Called by KASSERT, this decides if we will panic
629  * or if we will log via printf and/or ktr.
630  */
631 void
632 kassert_panic(const char *fmt, ...)
633 {
634 	static char buf[256];
635 	va_list ap;
636 
637 	va_start(ap, fmt);
638 	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
639 	va_end(ap);
640 
641 	/*
642 	 * panic if we're not just warning, or if we've exceeded
643 	 * kassert_log_panic_at warnings.
644 	 */
645 	if (!kassert_warn_only ||
646 	    (kassert_log_panic_at > 0 &&
647 	     kassert_warnings >= kassert_log_panic_at)) {
648 		va_start(ap, fmt);
649 		vpanic(fmt, ap);
650 		/* NORETURN */
651 	}
652 #ifdef KTR
653 	if (kassert_do_ktr)
654 		CTR0(ktr_mask, buf);
655 #endif /* KTR */
656 	/*
657 	 * log if we've not yet met the mute limit.
658 	 */
659 	if (kassert_do_log &&
660 	    (kassert_log_mute_at == 0 ||
661 	     kassert_warnings < kassert_log_mute_at)) {
662 		static  struct timeval lasterr;
663 		static  int curerr;
664 
665 		if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) {
666 			printf("KASSERT failed: %s\n", buf);
667 			kdb_backtrace();
668 		}
669 	}
670 #ifdef KDB
671 	if (kassert_do_kdb) {
672 		kdb_enter(KDB_WHY_KASSERT, buf);
673 	}
674 #endif
675 	atomic_add_int(&kassert_warnings, 1);
676 }
677 #endif
678 
679 /*
680  * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
681  * and then reboots.  If we are called twice, then we avoid trying to sync
682  * the disks as this often leads to recursive panics.
683  */
684 void
685 panic(const char *fmt, ...)
686 {
687 	va_list ap;
688 
689 	va_start(ap, fmt);
690 	vpanic(fmt, ap);
691 }
692 
693 void
694 vpanic(const char *fmt, va_list ap)
695 {
696 #ifdef SMP
697 	cpuset_t other_cpus;
698 #endif
699 	struct thread *td = curthread;
700 	int bootopt, newpanic;
701 	static char buf[256];
702 
703 	spinlock_enter();
704 
705 #ifdef SMP
706 	/*
707 	 * stop_cpus_hard(other_cpus) should prevent multiple CPUs from
708 	 * concurrently entering panic.  Only the winner will proceed
709 	 * further.
710 	 */
711 	if (panicstr == NULL && !kdb_active) {
712 		other_cpus = all_cpus;
713 		CPU_CLR(PCPU_GET(cpuid), &other_cpus);
714 		stop_cpus_hard(other_cpus);
715 	}
716 
717 	/*
718 	 * Ensure that the scheduler is stopped while panicking, even if panic
719 	 * has been entered from kdb.
720 	 */
721 	td->td_stopsched = 1;
722 #endif
723 
724 	bootopt = RB_AUTOBOOT;
725 	newpanic = 0;
726 	if (panicstr)
727 		bootopt |= RB_NOSYNC;
728 	else {
729 		bootopt |= RB_DUMP;
730 		panicstr = fmt;
731 		newpanic = 1;
732 	}
733 
734 	if (newpanic) {
735 		(void)vsnprintf(buf, sizeof(buf), fmt, ap);
736 		panicstr = buf;
737 		cngrab();
738 		printf("panic: %s\n", buf);
739 	} else {
740 		printf("panic: ");
741 		vprintf(fmt, ap);
742 		printf("\n");
743 	}
744 #ifdef SMP
745 	printf("cpuid = %d\n", PCPU_GET(cpuid));
746 #endif
747 
748 #ifdef KDB
749 	if (newpanic && trace_on_panic)
750 		kdb_backtrace();
751 	if (debugger_on_panic)
752 		kdb_enter(KDB_WHY_PANIC, "panic");
753 #endif
754 	/*thread_lock(td); */
755 	td->td_flags |= TDF_INPANIC;
756 	/* thread_unlock(td); */
757 	if (!sync_on_panic)
758 		bootopt |= RB_NOSYNC;
759 	kern_reboot(bootopt);
760 }
761 
762 /*
763  * Support for poweroff delay.
764  *
765  * Please note that setting this delay too short might power off your machine
766  * before the write cache on your hard disk has been flushed, leading to
767  * soft-updates inconsistencies.
768  */
769 #ifndef POWEROFF_DELAY
770 # define POWEROFF_DELAY 5000
771 #endif
772 static int poweroff_delay = POWEROFF_DELAY;
773 
774 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
775     &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)");
776 
777 static void
778 poweroff_wait(void *junk, int howto)
779 {
780 
781 	if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
782 		return;
783 	DELAY(poweroff_delay * 1000);
784 }
785 
786 /*
787  * Some system processes (e.g. syncer) need to be stopped at appropriate
788  * points in their main loops prior to a system shutdown, so that they
789  * won't interfere with the shutdown process (e.g. by holding a disk buf
790  * to cause sync to fail).  For each of these system processes, register
791  * shutdown_kproc() as a handler for one of shutdown events.
792  */
793 static int kproc_shutdown_wait = 60;
794 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
795     &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process");
796 
797 void
798 kproc_shutdown(void *arg, int howto)
799 {
800 	struct proc *p;
801 	int error;
802 
803 	if (panicstr)
804 		return;
805 
806 	p = (struct proc *)arg;
807 	printf("Waiting (max %d seconds) for system process `%s' to stop... ",
808 	    kproc_shutdown_wait, p->p_comm);
809 	error = kproc_suspend(p, kproc_shutdown_wait * hz);
810 
811 	if (error == EWOULDBLOCK)
812 		printf("timed out\n");
813 	else
814 		printf("done\n");
815 }
816 
817 void
818 kthread_shutdown(void *arg, int howto)
819 {
820 	struct thread *td;
821 	int error;
822 
823 	if (panicstr)
824 		return;
825 
826 	td = (struct thread *)arg;
827 	printf("Waiting (max %d seconds) for system thread `%s' to stop... ",
828 	    kproc_shutdown_wait, td->td_name);
829 	error = kthread_suspend(td, kproc_shutdown_wait * hz);
830 
831 	if (error == EWOULDBLOCK)
832 		printf("timed out\n");
833 	else
834 		printf("done\n");
835 }
836 
837 static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)];
838 SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD,
839     dumpdevname, 0, "Device for kernel dumps");
840 
841 /* Registration of dumpers */
842 int
843 set_dumper(struct dumperinfo *di, const char *devname, struct thread *td)
844 {
845 	size_t wantcopy;
846 	int error;
847 
848 	error = priv_check(td, PRIV_SETDUMPER);
849 	if (error != 0)
850 		return (error);
851 
852 	if (di == NULL) {
853 		if (dumper.blockbuf != NULL)
854 			free(dumper.blockbuf, M_DUMPER);
855 		bzero(&dumper, sizeof(dumper));
856 		dumpdevname[0] = '\0';
857 		return (0);
858 	}
859 	if (dumper.dumper != NULL)
860 		return (EBUSY);
861 	dumper = *di;
862 	wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname));
863 	if (wantcopy >= sizeof(dumpdevname)) {
864 		printf("set_dumper: device name truncated from '%s' -> '%s'\n",
865 			devname, dumpdevname);
866 	}
867 	dumper.blockbuf = malloc(di->blocksize, M_DUMPER, M_WAITOK | M_ZERO);
868 	return (0);
869 }
870 
871 /* Call dumper with bounds checking. */
872 int
873 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
874     off_t offset, size_t length)
875 {
876 
877 	if (length != 0 && (offset < di->mediaoffset ||
878 	    offset - di->mediaoffset + length > di->mediasize)) {
879 		printf("Attempt to write outside dump device boundaries.\n"
880 	    "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
881 		    (intmax_t)offset, (intmax_t)di->mediaoffset,
882 		    (uintmax_t)length, (intmax_t)di->mediasize);
883 		return (ENOSPC);
884 	}
885 	return (di->dumper(di->priv, virtual, physical, offset, length));
886 }
887 
888 /* Call dumper with bounds checking. */
889 int
890 dump_write_pad(struct dumperinfo *di, void *virtual, vm_offset_t physical,
891     off_t offset, size_t length, size_t *size)
892 {
893 	char *temp;
894 	int ret;
895 
896 	if (length > di->blocksize)
897 		return (ENOMEM);
898 
899 	*size = di->blocksize;
900 	if (length == di->blocksize)
901 		temp = virtual;
902 	else {
903 		temp = di->blockbuf;
904 		memset(temp + length, 0, di->blocksize - length);
905 		memcpy(temp, virtual, length);
906 	}
907 	ret = dump_write(di, temp, physical, offset, *size);
908 
909 	return (ret);
910 }
911 
912 
913 void
914 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
915     uint64_t dumplen, uint32_t blksz)
916 {
917 
918 	bzero(kdh, sizeof(*kdh));
919 	strlcpy(kdh->magic, magic, sizeof(kdh->magic));
920 	strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
921 	kdh->version = htod32(KERNELDUMPVERSION);
922 	kdh->architectureversion = htod32(archver);
923 	kdh->dumplength = htod64(dumplen);
924 	kdh->dumptime = htod64(time_second);
925 	kdh->blocksize = htod32(blksz);
926 	strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
927 	strlcpy(kdh->versionstring, version, sizeof(kdh->versionstring));
928 	if (panicstr != NULL)
929 		strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
930 	kdh->parity = kerneldump_parity(kdh);
931 }
932 
933 #ifdef DDB
934 DB_SHOW_COMMAND(panic, db_show_panic)
935 {
936 
937 	if (panicstr == NULL)
938 		db_printf("panicstr not set\n");
939 	else
940 		db_printf("panic: %s\n", panicstr);
941 }
942 #endif
943