kern_shutdown.c revision 70063 
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 * $FreeBSD: head/sys/kern/kern_shutdown.c 70063 2000-12-15 20:08:20Z jhb $
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/eventhandler.h>
50#include <sys/bio.h>
51#include <sys/buf.h>
52#include <sys/reboot.h>
53#include <sys/proc.h>
54#include <sys/vnode.h>
55#include <sys/kernel.h>
56#include <sys/kthread.h>
57#include <sys/mount.h>
58#include <sys/mutex.h>
59#include <sys/queue.h>
60#include <sys/sysctl.h>
61#include <sys/conf.h>
62#include <sys/sysproto.h>
63#include <sys/cons.h>
64
65#include <machine/pcb.h>
66#include <machine/lock.h>
67#include <machine/md_var.h>
68#include <machine/smp.h>		/* smp_active, cpuid */
69
70#include <sys/signalvar.h>
71
72#ifndef PANIC_REBOOT_WAIT_TIME
73#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
74#endif
75
76/*
77 * Note that stdarg.h and the ANSI style va_start macro is used for both
78 * ANSI and traditional C compilers.
79 */
80#include <machine/stdarg.h>
81
82#ifdef DDB
83#ifdef DDB_UNATTENDED
84int debugger_on_panic = 0;
85#else
86int debugger_on_panic = 1;
87#endif
88SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
89	&debugger_on_panic, 0, "Run debugger on kernel panic");
90#endif
91
92SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
93
94#ifdef	HW_WDOG
95/*
96 * If there is a hardware watchdog, point this at the function needed to
97 * hold it off.
98 * It's needed when the kernel needs to do some lengthy operations.
99 * e.g. in wd.c when dumping core.. It's most annoying to have
100 * your precious core-dump only half written because the wdog kicked in.
101 */
102watchdog_tickle_fn wdog_tickler = NULL;
103#endif	/* HW_WDOG */
104
105/*
106 * Variable panicstr contains argument to first call to panic; used as flag
107 * to indicate that the kernel has already called panic.
108 */
109const char *panicstr;
110
111int dumping;				 /* system is dumping */
112
113static void boot(int) __dead2;
114static void dumpsys(void);
115static void poweroff_wait(void *, int);
116static void shutdown_halt(void *junk, int howto);
117static void shutdown_panic(void *junk, int howto);
118static void shutdown_reset(void *junk, int howto);
119
120/* register various local shutdown events */
121static void
122shutdown_conf(void *unused)
123{
124	EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, SHUTDOWN_PRI_FIRST);
125	EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, SHUTDOWN_PRI_LAST + 100);
126	EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, SHUTDOWN_PRI_LAST + 100);
127	EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, SHUTDOWN_PRI_LAST + 200);
128}
129
130SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
131
132/* ARGSUSED */
133
134/*
135 * The system call that results in a reboot
136 */
137int
138reboot(struct proc *p, struct reboot_args *uap)
139{
140	int error;
141
142	if ((error = suser(p)))
143		return (error);
144
145	boot(uap->opt);
146	return (0);
147}
148
149/*
150 * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
151 */
152static int shutdown_howto = 0;
153
154void
155shutdown_nice(int howto)
156{
157	shutdown_howto = howto;
158
159	/* Send a signal to init(8) and have it shutdown the world */
160	if (initproc != NULL) {
161		psignal(initproc, SIGINT);
162	} else {
163		/* No init(8) running, so simply reboot */
164		boot(RB_NOSYNC);
165	}
166	return;
167}
168static int	waittime = -1;
169static struct pcb dumppcb;
170
171static void
172print_uptime(void)
173{
174	int f;
175	struct timespec ts;
176
177	getnanouptime(&ts);
178	printf("Uptime: ");
179	f = 0;
180	if (ts.tv_sec >= 86400) {
181		printf("%ldd", (long)ts.tv_sec / 86400);
182		ts.tv_sec %= 86400;
183		f = 1;
184	}
185	if (f || ts.tv_sec >= 3600) {
186		printf("%ldh", (long)ts.tv_sec / 3600);
187		ts.tv_sec %= 3600;
188		f = 1;
189	}
190	if (f || ts.tv_sec >= 60) {
191		printf("%ldm", (long)ts.tv_sec / 60);
192		ts.tv_sec %= 60;
193		f = 1;
194	}
195	printf("%lds\n", (long)ts.tv_sec);
196}
197
198/*
199 *  Go through the rigmarole of shutting down..
200 * this used to be in machdep.c but I'll be dammned if I could see
201 * anything machine dependant in it.
202 */
203static void
204boot(int howto)
205{
206
207	/* collect extra flags that shutdown_nice might have set */
208	howto |= shutdown_howto;
209
210#ifdef SMP
211	if (smp_active)
212		printf("boot() called on cpu#%d\n", cpuid);
213#endif
214	/*
215	 * Do any callouts that should be done BEFORE syncing the filesystems.
216	 */
217	EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
218
219	/*
220	 * Now sync filesystems
221	 */
222	if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
223		register struct buf *bp;
224		int iter, nbusy, pbusy;
225		int subiter;
226
227		waittime = 0;
228		printf("\nsyncing disks... ");
229
230		sync(&proc0, NULL);
231
232		/*
233		 * With soft updates, some buffers that are
234		 * written will be remarked as dirty until other
235		 * buffers are written.
236		 */
237		for (iter = pbusy = 0; iter < 20; iter++) {
238			nbusy = 0;
239			for (bp = &buf[nbuf]; --bp >= buf; ) {
240				if ((bp->b_flags & B_INVAL) == 0 &&
241				    BUF_REFCNT(bp) > 0) {
242					nbusy++;
243				} else if ((bp->b_flags & (B_DELWRI | B_INVAL))
244						== B_DELWRI) {
245					/* bawrite(bp);*/
246					nbusy++;
247				}
248			}
249			if (nbusy == 0)
250				break;
251			printf("%d ", nbusy);
252			if (nbusy < pbusy)
253				iter = 0;
254			pbusy = nbusy;
255			sync(&proc0, NULL);
256 			if (curproc != NULL) {
257				DROP_GIANT_NOSWITCH();
258   				for (subiter = 0; subiter < 50 * iter; subiter++) {
259     					mtx_enter(&sched_lock, MTX_SPIN);
260     					setrunqueue(curproc);
261     					mi_switch(); /* Allow interrupt threads to run */
262     					mtx_exit(&sched_lock, MTX_SPIN);
263     					DELAY(1000);
264   				}
265				PICKUP_GIANT();
266 			} else
267			DELAY(50000 * iter);
268		}
269		printf("\n");
270		/*
271		 * Count only busy local buffers to prevent forcing
272		 * a fsck if we're just a client of a wedged NFS server
273		 */
274		nbusy = 0;
275		for (bp = &buf[nbuf]; --bp >= buf; ) {
276			if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
277			    ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
278				if (bp->b_dev == NODEV) {
279					TAILQ_REMOVE(&mountlist,
280					    bp->b_vp->v_mount, mnt_list);
281					continue;
282				}
283				nbusy++;
284#if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
285				printf(
286			    "%d: dev:%s, flags:%08lx, blkno:%ld, lblkno:%ld\n",
287				    nbusy, devtoname(bp->b_dev),
288				    bp->b_flags, (long)bp->b_blkno,
289				    (long)bp->b_lblkno);
290#endif
291			}
292		}
293		if (nbusy) {
294			/*
295			 * Failed to sync all blocks. Indicate this and don't
296			 * unmount filesystems (thus forcing an fsck on reboot).
297			 */
298			printf("giving up on %d buffers\n", nbusy);
299			DELAY(5000000);	/* 5 seconds */
300		} else {
301			printf("done\n");
302			/*
303			 * Unmount filesystems
304			 */
305			if (panicstr == 0)
306				vfs_unmountall();
307		}
308		DELAY(100000);		/* wait for console output to finish */
309	}
310
311	print_uptime();
312
313	/*
314	 * Ok, now do things that assume all filesystem activity has
315	 * been completed.
316	 */
317	EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
318	splhigh();
319	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold)
320		dumpsys();
321
322	/* Now that we're going to really halt the system... */
323	EVENTHANDLER_INVOKE(shutdown_final, howto);
324
325	for(;;) ;	/* safety against shutdown_reset not working */
326	/* NOTREACHED */
327}
328
329/*
330 * If the shutdown was a clean halt, behave accordingly.
331 */
332static void
333shutdown_halt(void *junk, int howto)
334{
335	if (howto & RB_HALT) {
336		printf("\n");
337		printf("The operating system has halted.\n");
338		printf("Please press any key to reboot.\n\n");
339		switch (cngetc()) {
340		case -1:		/* No console, just die */
341			cpu_halt();
342			/* NOTREACHED */
343		default:
344			howto &= ~RB_HALT;
345			break;
346		}
347	}
348}
349
350/*
351 * Check to see if the system paniced, pause and then reboot
352 * according to the specified delay.
353 */
354static void
355shutdown_panic(void *junk, int howto)
356{
357	int loop;
358
359	if (howto & RB_DUMP) {
360		if (PANIC_REBOOT_WAIT_TIME != 0) {
361			if (PANIC_REBOOT_WAIT_TIME != -1) {
362				printf("Automatic reboot in %d seconds - "
363				       "press a key on the console to abort\n",
364					PANIC_REBOOT_WAIT_TIME);
365				for (loop = PANIC_REBOOT_WAIT_TIME * 10;
366				     loop > 0; --loop) {
367					DELAY(1000 * 100); /* 1/10th second */
368					/* Did user type a key? */
369					if (cncheckc() != -1)
370						break;
371				}
372				if (!loop)
373					return;
374			}
375		} else { /* zero time specified - reboot NOW */
376			return;
377		}
378		printf("--> Press a key on the console to reboot <--\n");
379		cngetc();
380	}
381}
382
383/*
384 * Everything done, now reset
385 */
386static void
387shutdown_reset(void *junk, int howto)
388{
389	printf("Rebooting...\n");
390	DELAY(1000000);	/* wait 1 sec for printf's to complete and be read */
391	/* cpu_boot(howto); */ /* doesn't do anything at the moment */
392	cpu_reset();
393	/* NOTREACHED */ /* assuming reset worked */
394}
395
396/*
397 * Magic number for savecore
398 *
399 * exported (symorder) and used at least by savecore(8)
400 *
401 */
402static u_long const	dumpmag = 0x8fca0101UL;
403
404static int	dumpsize = 0;		/* also for savecore */
405
406static int	dodump = 1;
407
408SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW, &dodump, 0,
409    "Try to perform coredump on kernel panic");
410
411static int
412setdumpdev(dev_t dev)
413{
414	int psize;
415	long newdumplo;
416
417	if (dev == NODEV) {
418		dumpdev = dev;
419		return (0);
420	}
421	if (devsw(dev) == NULL)
422		return (ENXIO);		/* XXX is this right? */
423	if (devsw(dev)->d_psize == NULL)
424		return (ENXIO);		/* XXX should be ENODEV ? */
425	psize = devsw(dev)->d_psize(dev);
426	if (psize == -1)
427		return (ENXIO);		/* XXX should be ENODEV ? */
428	/*
429	 * XXX should clean up checking in dumpsys() to be more like this.
430	 */
431	newdumplo = psize - Maxmem * PAGE_SIZE / DEV_BSIZE;
432	if (newdumplo < 0)
433		return (ENOSPC);
434	dumpdev = dev;
435	dumplo = newdumplo;
436	return (0);
437}
438
439
440/* ARGSUSED */
441static void
442dump_conf(void *dummy)
443{
444	if (setdumpdev(dumpdev) != 0)
445		dumpdev = NODEV;
446}
447
448SYSINIT(dump_conf, SI_SUB_DUMP_CONF, SI_ORDER_FIRST, dump_conf, NULL)
449
450static int
451sysctl_kern_dumpdev(SYSCTL_HANDLER_ARGS)
452{
453	int error;
454	udev_t ndumpdev;
455
456	ndumpdev = dev2udev(dumpdev);
457	error = sysctl_handle_opaque(oidp, &ndumpdev, sizeof ndumpdev, req);
458	if (error == 0 && req->newptr != NULL)
459		error = setdumpdev(udev2dev(ndumpdev, 0));
460	return (error);
461}
462
463SYSCTL_PROC(_kern, KERN_DUMPDEV, dumpdev, CTLTYPE_OPAQUE|CTLFLAG_RW,
464	0, sizeof dumpdev, sysctl_kern_dumpdev, "T,dev_t", "");
465
466/*
467 * Doadump comes here after turning off memory management and
468 * getting on the dump stack, either when called above, or by
469 * the auto-restart code.
470 */
471static void
472dumpsys(void)
473{
474	int	error;
475
476	savectx(&dumppcb);
477	if (dumping++) {
478		printf("Dump already in progress, bailing...\n");
479		return;
480	}
481	if (!dodump)
482		return;
483	if (dumpdev == NODEV)
484		return;
485	if (!(devsw(dumpdev)))
486		return;
487	if (!(devsw(dumpdev)->d_dump))
488		return;
489	dumpsize = Maxmem;
490	printf("\ndumping to dev %s, offset %ld\n", devtoname(dumpdev), dumplo);
491	printf("dump ");
492	error = (*devsw(dumpdev)->d_dump)(dumpdev);
493	if (error == 0) {
494		printf("succeeded\n");
495		return;
496	}
497	printf("failed, reason: ");
498	switch (error) {
499	case ENODEV:
500		printf("device doesn't support a dump routine\n");
501		break;
502
503	case ENXIO:
504		printf("device bad\n");
505		break;
506
507	case EFAULT:
508		printf("device not ready\n");
509		break;
510
511	case EINVAL:
512		printf("area improper\n");
513		break;
514
515	case EIO:
516		printf("i/o error\n");
517		break;
518
519	case EINTR:
520		printf("aborted from console\n");
521		break;
522
523	default:
524		printf("unknown, error = %d\n", error);
525		break;
526	}
527}
528
529/*
530 * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
531 * and then reboots.  If we are called twice, then we avoid trying to sync
532 * the disks as this often leads to recursive panics.
533 */
534void
535panic(const char *fmt, ...)
536{
537	int bootopt;
538	va_list ap;
539	static char buf[256];
540
541#ifdef SMP
542	/* Only 1 CPU can panic at a time */
543	s_lock(&panic_lock);
544#endif
545
546	bootopt = RB_AUTOBOOT | RB_DUMP;
547	if (panicstr)
548		bootopt |= RB_NOSYNC;
549	else
550		panicstr = fmt;
551
552	va_start(ap, fmt);
553	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
554	if (panicstr == fmt)
555		panicstr = buf;
556	va_end(ap);
557	printf("panic: %s\n", buf);
558#ifdef SMP
559	/* two seperate prints in case of an unmapped page and trap */
560	printf("cpuid = %d; ", cpuid);
561#ifdef APIC_IO
562	printf("lapic.id = %08x\n", lapic.id);
563#endif
564#endif
565
566#if defined(DDB)
567	if (debugger_on_panic)
568		Debugger ("panic");
569#endif
570	boot(bootopt);
571}
572
573/*
574 * Support for poweroff delay.
575 */
576#ifndef POWEROFF_DELAY
577# define POWEROFF_DELAY 5000
578#endif
579static int poweroff_delay = POWEROFF_DELAY;
580
581SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
582	&poweroff_delay, 0, "");
583
584static void
585poweroff_wait(void *junk, int howto)
586{
587	if(!(howto & RB_POWEROFF) || poweroff_delay <= 0)
588		return;
589	DELAY(poweroff_delay * 1000);
590}
591
592/*
593 * Some system processes (e.g. syncer) need to be stopped at appropriate
594 * points in their main loops prior to a system shutdown, so that they
595 * won't interfere with the shutdown process (e.g. by holding a disk buf
596 * to cause sync to fail).  For each of these system processes, register
597 * shutdown_kproc() as a handler for one of shutdown events.
598 */
599static int kproc_shutdown_wait = 60;
600SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
601    &kproc_shutdown_wait, 0, "");
602
603void
604kproc_shutdown(void *arg, int howto)
605{
606	struct proc *p;
607	int error;
608
609	if (panicstr)
610		return;
611
612	p = (struct proc *)arg;
613	printf("Waiting (max %d seconds) for system process `%s' to stop...",
614	    kproc_shutdown_wait, p->p_comm);
615	error = kthread_suspend(p, kproc_shutdown_wait * hz);
616
617	if (error == EWOULDBLOCK)
618		printf("timed out\n");
619	else
620		printf("stopped\n");
621}
622