kern_shutdown.c revision 48431 
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	@(#)kern_shutdown.c	8.3 (Berkeley) 1/21/94
39 * $Id: kern_shutdown.c,v 1.53 1999/06/26 02:46:02 mckusick Exp $
40 */
41
42#include "opt_ddb.h"
43#include "opt_hw_wdog.h"
44#include "opt_panic.h"
45#include "opt_show_busybufs.h"
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/buf.h>
50#include <sys/reboot.h>
51#include <sys/proc.h>
52#include <sys/vnode.h>
53#include <sys/malloc.h>
54#include <sys/kernel.h>
55#include <sys/mount.h>
56#include <sys/queue.h>
57#include <sys/sysctl.h>
58#include <sys/conf.h>
59#include <sys/sysproto.h>
60
61#include <machine/pcb.h>
62#include <machine/clock.h>
63#include <machine/cons.h>
64#include <machine/md_var.h>
65#ifdef SMP
66#include <machine/smp.h>		/* smp_active, cpuid */
67#endif
68
69#include <sys/signalvar.h>
70
71#ifndef PANIC_REBOOT_WAIT_TIME
72#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
73#endif
74
75/*
76 * Note that stdarg.h and the ANSI style va_start macro is used for both
77 * ANSI and traditional C compilers.
78 */
79#include <machine/stdarg.h>
80
81#ifdef DDB
82#ifdef DDB_UNATTENDED
83int debugger_on_panic = 0;
84#else
85int debugger_on_panic = 1;
86#endif
87SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
88	&debugger_on_panic, 0, "Run debugger on kernel panic");
89#endif
90
91SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
92
93#ifdef	HW_WDOG
94/*
95 * If there is a hardware watchdog, point this at the function needed to
96 * hold it off.
97 * It's needed when the kernel needs to do some lengthy operations.
98 * e.g. in wd.c when dumping core.. It's most annoying to have
99 * your precious core-dump only half written because the wdog kicked in.
100 */
101watchdog_tickle_fn wdog_tickler = NULL;
102#endif	/* HW_WDOG */
103
104/*
105 * Variable panicstr contains argument to first call to panic; used as flag
106 * to indicate that the kernel has already called panic.
107 */
108const char *panicstr;
109
110/*
111 * callout list for things to do a shutdown
112 */
113typedef struct shutdown_list_element {
114	LIST_ENTRY(shutdown_list_element) links;
115	bootlist_fn function;
116	void *arg;
117	int priority;
118} *sle_p;
119
120/*
121 * There are three shutdown lists. Some things need to be shut down
122 * earlier than others.
123 */
124LIST_HEAD(shutdown_list, shutdown_list_element);
125
126static struct shutdown_list shutdown_lists[SHUTDOWN_FINAL + 1];
127
128static void boot __P((int)) __dead2;
129static void dumpsys __P((void));
130
131#ifndef _SYS_SYSPROTO_H_
132struct reboot_args {
133	int	opt;
134};
135#endif
136/* ARGSUSED */
137
138/*
139 * The system call that results in a reboot
140 */
141int
142reboot(p, uap)
143	struct proc *p;
144	struct reboot_args *uap;
145{
146	int error;
147
148	if ((error = suser(p)))
149		return (error);
150
151	boot(uap->opt);
152	return (0);
153}
154
155/*
156 * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
157 */
158void
159shutdown_nice()
160{
161	/* Send a signal to init(8) and have it shutdown the world */
162	if (initproc != NULL) {
163		psignal(initproc, SIGINT);
164	} else {
165		/* No init(8) running, so simply reboot */
166		boot(RB_NOSYNC);
167	}
168	return;
169}
170static int	waittime = -1;
171static struct pcb dumppcb;
172
173/*
174 *  Go through the rigmarole of shutting down..
175 * this used to be in machdep.c but I'll be dammned if I could see
176 * anything machine dependant in it.
177 */
178static void
179boot(howto)
180	int howto;
181{
182	sle_p ep;
183
184#ifdef SMP
185	if (smp_active) {
186		printf("boot() called on cpu#%d\n", cpuid);
187	}
188#endif
189	/*
190	 * Do any callouts that should be done BEFORE syncing the filesystems.
191	 */
192	LIST_FOREACH(ep, &shutdown_lists[SHUTDOWN_PRE_SYNC], links)
193		(*ep->function)(howto, ep->arg);
194
195	/*
196	 * Now sync filesystems
197	 */
198	if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
199		register struct buf *bp;
200		int iter, nbusy;
201
202		waittime = 0;
203		printf("\nsyncing disks... ");
204
205		sync(&proc0, NULL);
206
207		/*
208		 * With soft updates, some buffers that are
209		 * written will be remarked as dirty until other
210		 * buffers are written.
211		 */
212		for (iter = 0; iter < 20; iter++) {
213			nbusy = 0;
214			for (bp = &buf[nbuf]; --bp >= buf; ) {
215				if ((bp->b_flags & B_INVAL) == 0 &&
216				    BUF_REFCNT(bp) > 0) {
217					nbusy++;
218				} else if ((bp->b_flags & (B_DELWRI | B_INVAL))
219						== B_DELWRI) {
220					/* bawrite(bp);*/
221					nbusy++;
222				}
223			}
224			if (nbusy == 0)
225				break;
226			printf("%d ", nbusy);
227			sync(&proc0, NULL);
228			DELAY(50000 * iter);
229		}
230		/*
231		 * Count only busy local buffers to prevent forcing
232		 * a fsck if we're just a client of a wedged NFS server
233		 */
234		nbusy = 0;
235		for (bp = &buf[nbuf]; --bp >= buf; ) {
236			if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
237			    ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
238				if (bp->b_dev == NODEV)
239					CIRCLEQ_REMOVE(&mountlist,
240					    bp->b_vp->v_mount, mnt_list);
241				else
242					nbusy++;
243			}
244
245
246		}
247		if (nbusy) {
248			/*
249			 * Failed to sync all blocks. Indicate this and don't
250			 * unmount filesystems (thus forcing an fsck on reboot).
251			 */
252			printf("giving up\n");
253#ifdef SHOW_BUSYBUFS
254			nbusy = 0;
255			for (bp = &buf[nbuf]; --bp >= buf; ) {
256				if ((bp->b_flags & B_INVAL) == 0 &&
257				    BUF_REFCNT(bp) > 0) {
258					nbusy++;
259					printf(
260			"%d: dev:%08lx, flags:%08lx, blkno:%ld, lblkno:%ld\n",
261					    nbusy, (u_long)bp->b_dev,
262					    bp->b_flags, (long)bp->b_blkno,
263					    (long)bp->b_lblkno);
264				}
265			}
266			DELAY(5000000);	/* 5 seconds */
267#endif
268		} else {
269			printf("done\n");
270			/*
271			 * Unmount filesystems
272			 */
273			if (panicstr == 0)
274				vfs_unmountall();
275		}
276		DELAY(100000);		/* wait for console output to finish */
277	}
278
279	/*
280	 * Ok, now do things that assume all filesystem activity has
281	 * been completed.
282	 */
283	LIST_FOREACH(ep, &shutdown_lists[SHUTDOWN_POST_SYNC], links)
284		(*ep->function)(howto, ep->arg);
285	splhigh();
286	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold) {
287		savectx(&dumppcb);
288#ifdef __i386__
289		dumppcb.pcb_cr3 = rcr3();
290#endif
291		dumpsys();
292	}
293
294	/* Now that we're going to really halt the system... */
295	LIST_FOREACH(ep, &shutdown_lists[SHUTDOWN_FINAL], links)
296		(*ep->function)(howto, ep->arg);
297
298	if (howto & RB_HALT) {
299		printf("\n");
300		printf("The operating system has halted.\n");
301		printf("Please press any key to reboot.\n\n");
302		switch (cngetc()) {
303		case -1:		/* No console, just die */
304			cpu_halt();
305			/* NOTREACHED */
306		default:
307			howto &= ~RB_HALT;
308			break;
309		}
310	} else if (howto & RB_DUMP) {
311		/* System Paniced */
312
313		if (PANIC_REBOOT_WAIT_TIME != 0) {
314			if (PANIC_REBOOT_WAIT_TIME != -1) {
315				int loop;
316				printf("Automatic reboot in %d seconds - "
317				       "press a key on the console to abort\n",
318					PANIC_REBOOT_WAIT_TIME);
319				for (loop = PANIC_REBOOT_WAIT_TIME * 10;
320				     loop > 0; --loop) {
321					DELAY(1000 * 100); /* 1/10th second */
322					/* Did user type a key? */
323					if (cncheckc() != -1)
324						break;
325				}
326				if (!loop)
327					goto die;
328			}
329		} else { /* zero time specified - reboot NOW */
330			goto die;
331		}
332		printf("--> Press a key on the console to reboot <--\n");
333		cngetc();
334	}
335die:
336	printf("Rebooting...\n");
337	DELAY(1000000);	/* wait 1 sec for printf's to complete and be read */
338	/* cpu_boot(howto); */ /* doesn't do anything at the moment */
339	cpu_reset();
340	for(;;) ;
341	/* NOTREACHED */
342}
343
344/*
345 * Magic number for savecore
346 *
347 * exported (symorder) and used at least by savecore(8)
348 *
349 */
350static u_long const	dumpmag = 0x8fca0101UL;
351
352static int	dumpsize = 0;		/* also for savecore */
353
354static int	dodump = 1;
355SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW,
356    &dodump, 0, "Do coredump on kernel panic");
357
358/* ARGSUSED */
359static void dump_conf __P((void *dummy));
360static void
361dump_conf(dummy)
362	void *dummy;
363{
364	cpu_dumpconf();
365}
366SYSINIT(dump_conf, SI_SUB_DUMP_CONF, SI_ORDER_FIRST, dump_conf, NULL)
367
368/*
369 * Doadump comes here after turning off memory management and
370 * getting on the dump stack, either when called above, or by
371 * the auto-restart code.
372 */
373static void
374dumpsys(void)
375{
376
377	if (!dodump)
378		return;
379	if (dumpdev == NODEV)
380		return;
381	if (!(bdevsw(dumpdev)))
382		return;
383	if (!(bdevsw(dumpdev)->d_dump))
384		return;
385	dumpsize = Maxmem;
386	printf("\ndumping to dev (%d,%d), offset %ld\n",
387		major(dumpdev), minor(dumpdev), dumplo);
388	printf("dump ");
389	switch ((*bdevsw(dumpdev)->d_dump)(dumpdev)) {
390
391	case ENXIO:
392		printf("device bad\n");
393		break;
394
395	case EFAULT:
396		printf("device not ready\n");
397		break;
398
399	case EINVAL:
400		printf("area improper\n");
401		break;
402
403	case EIO:
404		printf("i/o error\n");
405		break;
406
407	case EINTR:
408		printf("aborted from console\n");
409		break;
410
411	default:
412		printf("succeeded\n");
413		break;
414	}
415}
416
417/*
418 * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
419 * and then reboots.  If we are called twice, then we avoid trying to sync
420 * the disks as this often leads to recursive panics.
421 */
422void
423panic(const char *fmt, ...)
424{
425	int bootopt;
426	va_list ap;
427	static char buf[256];
428
429	bootopt = RB_AUTOBOOT | RB_DUMP;
430	if (panicstr)
431		bootopt |= RB_NOSYNC;
432	else
433		panicstr = fmt;
434
435	va_start(ap, fmt);
436	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
437	if (panicstr == fmt)
438		panicstr = buf;
439	va_end(ap);
440	printf("panic: %s\n", buf);
441#ifdef SMP
442	/* three seperate prints in case of an unmapped page and trap */
443	printf("mp_lock = %08x; ", mp_lock);
444	printf("cpuid = %d; ", cpuid);
445	printf("lapic.id = %08x\n", lapic.id);
446#endif
447
448#if defined(DDB)
449	if (debugger_on_panic)
450		Debugger ("panic");
451#endif
452	boot(bootopt);
453}
454
455/*
456 * Three routines to handle adding/deleting items on the
457 * shutdown callout lists
458 *
459 * at_shutdown():
460 * Take the arguments given and put them onto the shutdown callout list.
461 * However first make sure that it's not already there.
462 * returns 0 on success.
463 */
464int
465at_shutdown(bootlist_fn function, void *arg, int queue)
466{
467	return(at_shutdown_pri(function, arg, queue, SHUTDOWN_PRI_DEFAULT));
468}
469
470/*
471 * at_shutdown_pri():
472 * Take the arguments given and put them onto the shutdown callout list
473 * with the given execution priority.
474 * returns 0 on success.
475 */
476int
477at_shutdown_pri(bootlist_fn function, void *arg, int queue, int pri)
478{
479	sle_p op, ep, ip;
480
481	op = NULL;		/* shut up gcc */
482	if (queue < SHUTDOWN_PRE_SYNC
483	 || queue > SHUTDOWN_FINAL) {
484		printf("at_shutdown: bad exit callout queue %d specified\n",
485		       queue);
486		return (EINVAL);
487	}
488	if (rm_at_shutdown(function, arg))
489		printf("at_shutdown: exit callout entry was already present\n");
490	ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT);
491	if (ep == NULL)
492		return (ENOMEM);
493	ep->function = function;
494	ep->arg = arg;
495	ep->priority = pri;
496
497	/* Sort into list of items on this queue */
498	ip = LIST_FIRST(&shutdown_lists[queue]);
499	if (ip == NULL) {
500		LIST_INSERT_HEAD(&shutdown_lists[queue], ep, links);
501	} else {
502		for (; ip != NULL; op = ip, ip = LIST_NEXT(ip, links)) {
503			if (ep->priority < ip->priority) {
504				LIST_INSERT_BEFORE(ip, ep, links);
505				ep = NULL;
506				break;
507			}
508		}
509		if (ep != NULL)
510			LIST_INSERT_AFTER(op, ep, links);
511	}
512	return (0);
513}
514
515/*
516 * Scan the exit callout lists for the given items and remove them.
517 * Returns the number of items removed.
518 */
519int
520rm_at_shutdown(bootlist_fn function, void *arg)
521{
522	sle_p ep;
523	int   count;
524	int   queue;
525
526	count = 0;
527	for (queue = SHUTDOWN_PRE_SYNC; queue < SHUTDOWN_FINAL; queue++) {
528		LIST_FOREACH(ep, &shutdown_lists[queue], links) {
529			if ((ep->function == function) && (ep->arg == arg)) {
530				LIST_REMOVE(ep, links);
531				free(ep, M_TEMP);
532				count++;
533			}
534		}
535	}
536	return (count);
537}
538
539/*
540 * Support for poweroff delay.
541 */
542static int poweroff_delay = 0;
543SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
544	&poweroff_delay, 0, "");
545
546static void poweroff_wait(int howto, void *unused)
547{
548	if(!(howto & RB_POWEROFF) || poweroff_delay <= 0)
549		return;
550	DELAY(poweroff_delay * 1000);
551}
552
553/*
554 * XXX OK? This implies I know SHUTDOWN_PRI_LAST > SHUTDOWN_PRI_FIRST
555 */
556static void poweroff_conf(void *unused)
557{
558	at_shutdown_pri(poweroff_wait, NULL, SHUTDOWN_FINAL, SHUTDOWN_PRI_FIRST);
559}
560
561SYSINIT(poweroff_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, poweroff_conf, NULL)
562