kern_shutdown.c revision 21776 
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 21776 1997-01-16 15:58:32Z bde $
40 */
41
42#include "opt_ddb.h"
43
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/reboot.h>
47#include <sys/msgbuf.h>
48#include <sys/proc.h>
49#include <sys/vnode.h>
50#include <sys/tty.h>
51#include <sys/tprintf.h>
52#include <sys/syslog.h>
53#include <sys/malloc.h>
54#include <sys/kernel.h>
55#include <sys/mount.h>
56#include <sys/sysctl.h>
57#include <sys/conf.h>
58#include <sys/sysproto.h>
59
60#include <machine/pcb.h>
61#include <machine/clock.h>
62#include <machine/cons.h>
63#include <machine/md_var.h>
64
65#include <sys/utsname.h>
66#include <sys/signalvar.h>
67
68#ifndef PANIC_REBOOT_WAIT_TIME
69#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
70#endif
71
72/*
73 * Note that stdarg.h and the ANSI style va_start macro is used for both
74 * ANSI and traditional C compilers.
75 */
76#include <machine/stdarg.h>
77
78#if defined(DDB)
79#ifdef DDB_UNATTENDED
80	static int debugger_on_panic = 0;
81#else
82	static int debugger_on_panic = 1;
83#endif
84
85SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
86	&debugger_on_panic, 0, "");
87#endif
88
89
90/*
91 * Variable panicstr contains argument to first call to panic; used as flag
92 * to indicate that the kernel has already called panic.
93 */
94const char *panicstr;
95
96/*
97 * callout list for things to do a shutdown
98 */
99typedef struct shutdown_list_element {
100	struct shutdown_list_element *next;
101	bootlist_fn function;
102	void *arg;
103} *sle_p;
104
105/*
106 * there are two shutdown lists. Some things need to be shut down
107 * Earlier than others.
108 */
109static sle_p shutdown_list1;
110static sle_p shutdown_list2;
111
112
113static void dumpsys(void);
114
115#ifndef _SYS_SYSPROTO_H_
116struct reboot_args {
117	int	opt;
118};
119#endif
120/* ARGSUSED */
121
122/*
123 * The system call that results in a reboot
124 */
125int
126reboot(p, uap, retval)
127	struct proc *p;
128	struct reboot_args *uap;
129	int *retval;
130{
131	int error;
132
133	if ((error = suser(p->p_ucred, &p->p_acflag)))
134		return (error);
135
136	boot(uap->opt);
137	return (0);
138}
139
140/*
141 * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
142 */
143void
144shutdown_nice(void)
145{
146	/* Send a signal to init(8) and have it shutdown the world */
147	if (initproc != NULL) {
148		psignal(initproc, SIGINT);
149	} else {
150		/* No init(8) running, so simply reboot */
151		boot(RB_NOSYNC);
152	}
153	return;
154}
155static int	waittime = -1;
156static struct pcb dumppcb;
157
158/*
159 *  Go through the rigmarole of shutting down..
160 * this used to be in machdep.c but I'll be dammned if I could see
161 * anything machine dependant in it.
162 */
163void
164boot(howto)
165	int howto;
166{
167	sle_p ep;
168
169	ep = shutdown_list1;
170	while (ep) {
171		shutdown_list1 = ep->next;
172		(*ep->function)(howto, ep->arg);
173		ep = ep->next;
174	}
175	if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
176		register struct buf *bp;
177		int iter, nbusy;
178
179		waittime = 0;
180		printf("\nsyncing disks... ");
181
182		sync(&proc0, NULL, NULL);
183
184		for (iter = 0; iter < 20; iter++) {
185			nbusy = 0;
186			for (bp = &buf[nbuf]; --bp >= buf; ) {
187				if ((bp->b_flags & (B_BUSY | B_INVAL)) == B_BUSY) {
188					nbusy++;
189				}
190			}
191			if (nbusy == 0)
192				break;
193			printf("%d ", nbusy);
194			DELAY(40000 * iter);
195		}
196		if (nbusy) {
197			/*
198			 * Failed to sync all blocks. Indicate this and don't
199			 * unmount filesystems (thus forcing an fsck on reboot).
200			 */
201			printf("giving up\n");
202#ifdef SHOW_BUSYBUFS
203			nbusy = 0;
204			for (bp = &buf[nbuf]; --bp >= buf; ) {
205				if ((bp->b_flags & (B_BUSY | B_INVAL)) == B_BUSY) {
206					nbusy++;
207					printf("%d: dev:%08x, flags:%08x, blkno:%d, lblkno:%d\n", nbusy, bp->b_dev, bp->b_flags, bp->b_blkno, bp->b_lblkno);
208				}
209			}
210			DELAY(5000000);	/* 5 seconds */
211#endif
212		} else {
213			printf("done\n");
214			/*
215			 * Unmount filesystems
216			 */
217			if (panicstr == 0)
218				vfs_unmountall();
219		}
220		DELAY(100000);			/* wait for console output to finish */
221	}
222	ep = shutdown_list2;
223	while (ep) {
224		shutdown_list2 = ep->next;
225		(*ep->function)(howto, ep->arg);
226		ep = ep->next;
227	}
228	splhigh();
229	if (howto & RB_HALT) {
230		printf("\n");
231		printf("The operating system has halted.\n");
232		printf("Please press any key to reboot.\n\n");
233		switch (cngetc()) {
234		case -1:		/* No console, just die */
235			cpu_halt();
236			/* NOTREACHED */
237		default:
238			break;
239		}
240	} else {
241		if (howto & RB_DUMP) {
242			if (!cold) {
243				savectx(&dumppcb);
244				dumppcb.pcb_cr3 = rcr3();
245				dumpsys();
246			}
247
248			if (PANIC_REBOOT_WAIT_TIME != 0) {
249				if (PANIC_REBOOT_WAIT_TIME != -1) {
250					int loop;
251					printf("Automatic reboot in %d seconds - press a key on the console to abort\n",
252						PANIC_REBOOT_WAIT_TIME);
253					for (loop = PANIC_REBOOT_WAIT_TIME * 10; loop > 0; --loop) {
254						DELAY(1000 * 100); /* 1/10th second */
255						/* Did user type a key? */
256						if (cncheckc() != -1)
257							break;
258					}
259					if (!loop)
260						goto die;
261				}
262			} else { /* zero time specified - reboot NOW */
263				goto die;
264			}
265			printf("--> Press a key on the console to reboot <--\n");
266			cngetc();
267		}
268	}
269die:
270	printf("Rebooting...\n");
271	DELAY(1000000);	/* wait 1 sec for printf's to complete and be read */
272	/* cpu_boot(howto); */ /* doesn't do anything at the moment */
273	cpu_reset();
274	for(;;) ;
275	/* NOTREACHED */
276}
277
278/*
279 * Magic number for savecore
280 *
281 * exported (symorder) and used at least by savecore(8)
282 *
283 */
284static u_long const	dumpmag = 0x8fca0101UL;
285
286static int	dumpsize = 0;		/* also for savecore */
287
288static int	dodump = 1;
289SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW, &dodump, 0, "");
290
291/*
292 * Doadump comes here after turning off memory management and
293 * getting on the dump stack, either when called above, or by
294 * the auto-restart code.
295 */
296static void
297dumpsys(void)
298{
299
300	if (!dodump)
301		return;
302	if (dumpdev == NODEV)
303		return;
304	if ((minor(dumpdev)&07) != 1)
305		return;
306	if (!(bdevsw[major(dumpdev)]))
307		return;
308	if (!(bdevsw[major(dumpdev)]->d_dump))
309		return;
310	dumpsize = Maxmem;
311	printf("\ndumping to dev %lx, offset %ld\n", dumpdev, dumplo);
312	printf("dump ");
313	switch ((*bdevsw[major(dumpdev)]->d_dump)(dumpdev)) {
314
315	case ENXIO:
316		printf("device bad\n");
317		break;
318
319	case EFAULT:
320		printf("device not ready\n");
321		break;
322
323	case EINVAL:
324		printf("area improper\n");
325		break;
326
327	case EIO:
328		printf("i/o error\n");
329		break;
330
331	case EINTR:
332		printf("aborted from console\n");
333		break;
334
335	default:
336		printf("succeeded\n");
337		break;
338	}
339}
340
341/*
342 * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
343 * and then reboots.  If we are called twice, then we avoid trying to sync
344 * the disks as this often leads to recursive panics.
345 */
346void
347panic(const char *fmt, ...)
348{
349	int bootopt;
350	va_list ap;
351
352	bootopt = RB_AUTOBOOT | RB_DUMP;
353	if (panicstr)
354		bootopt |= RB_NOSYNC;
355	else
356		panicstr = fmt;
357
358	printf("panic: ");
359	va_start(ap, fmt);
360	vprintf(fmt, ap);
361	va_end(ap);
362	printf("\n");
363
364#if defined(DDB)
365	if (debugger_on_panic)
366		Debugger ("panic");
367#endif
368	boot(bootopt);
369}
370
371/*
372 * Two routines to handle adding/deleting items on the
373 * shutdown callout lists
374 *
375 * at_shutdown():
376 * Take the arguments given and put them onto the shutdown callout list.
377 * However first make sure that it's not already there.
378 * returns 0 on success.
379 */
380int
381at_shutdown(bootlist_fn function, void *arg, int position)
382{
383	sle_p ep, *epp;
384
385	switch(position) {
386	case SHUTDOWN_PRE_SYNC:
387		epp = &shutdown_list1;
388		break;
389	case SHUTDOWN_POST_SYNC:
390		epp = &shutdown_list2;
391		break;
392	default:
393		printf("bad exit callout list specified\n");
394		return (EINVAL);
395	}
396	if (rm_at_shutdown(function, arg))
397		printf("exit callout entry already present\n");
398	ep = malloc(sizeof(*ep), M_TEMP, M_NOWAIT);
399	if (ep == NULL)
400		return (ENOMEM);
401	ep->next = *epp;
402	ep->function = function;
403	ep->arg = arg;
404	*epp = ep;
405	return (0);
406}
407
408/*
409 * Scan the exit callout lists for the given items and remove them.
410 * Returns the number of items removed.
411 */
412int
413rm_at_shutdown(bootlist_fn function, void *arg)
414{
415	sle_p *epp, ep;
416	int count;
417
418	count = 0;
419	epp = &shutdown_list1;
420	ep = *epp;
421	while (ep) {
422		if ((ep->function == function) && (ep->arg == arg)) {
423			*epp = ep->next;
424			free(ep, M_TEMP);
425			count++;
426		} else {
427			epp = &ep->next;
428		}
429		ep = *epp;
430	}
431	epp = &shutdown_list2;
432	ep = *epp;
433	while (ep) {
434		if ((ep->function == function) && (ep->arg == arg)) {
435			*epp = ep->next;
436			free(ep, M_TEMP);
437			count++;
438		} else {
439			epp = &ep->next;
440		}
441		ep = *epp;
442	}
443	return (count);
444}
445
446