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: releng/6.2/sys/kern/kern_shutdown.c 164286 2006-11-14 20:42:41Z cvs2svn $");
39
40 #include "opt_kdb.h"
41 #include "opt_mac.h"
42 #include "opt_panic.h"
43 #include "opt_show_busybufs.h"
44 #include "opt_sched.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/kdb.h>
54 #include <sys/kernel.h>
55 #include <sys/kthread.h>
56 #include <sys/mac.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/proc.h>
60 #include <sys/reboot.h>
61 #include <sys/resourcevar.h>
62 #include <sys/sched.h>
63 #include <sys/smp.h> /* smp_active */
64 #include <sys/sysctl.h>
65 #include <sys/sysproto.h>
66
67 #include <machine/cpu.h>
68 #include <machine/pcb.h>
69 #include <machine/smp.h>
70
71 #include <vm/vm.h>
72 #include <vm/vm_object.h>
73 #include <vm/vm_page.h>
74 #include <vm/vm_pager.h>
75 #include <vm/swap_pager.h>
76
77 #include <sys/signalvar.h>
78
79 #ifndef PANIC_REBOOT_WAIT_TIME
80 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
81 #endif
82
83 /*
84 * Note that stdarg.h and the ANSI style va_start macro is used for both
85 * ANSI and traditional C compilers.
86 */
87 #include <machine/stdarg.h>
88
89 #ifdef KDB
90 #ifdef KDB_UNATTENDED
91 int debugger_on_panic = 0;
92 #else
93 int debugger_on_panic = 1;
94 #endif
95 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
96 &debugger_on_panic, 0, "Run debugger on kernel panic");
97
98 #ifdef KDB_TRACE
99 int trace_on_panic = 1;
100 #else
101 int trace_on_panic = 0;
102 #endif
103 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
104 &trace_on_panic, 0, "Print stack trace on kernel panic");
105 #endif /* KDB */
106
107 int sync_on_panic = 0;
108 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
109 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
110
111 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
112
113 /*
114 * Variable panicstr contains argument to first call to panic; used as flag
115 * to indicate that the kernel has already called panic.
116 */
117 const char *panicstr;
118
119 int dumping; /* system is dumping */
120 int rebooting; /* system is rebooting */
121 static struct dumperinfo dumper; /* our selected dumper */
122
123 /* Context information for dump-debuggers. */
124 static struct pcb dumppcb; /* Registers. */
125 static lwpid_t dumptid; /* Thread ID. */
126
127 static void boot(int) __dead2;
128 static void poweroff_wait(void *, int);
129 static void shutdown_halt(void *junk, int howto);
130 static void shutdown_panic(void *junk, int howto);
131 static void shutdown_reset(void *junk, int howto);
132
133 /* register various local shutdown events */
134 static void
135 shutdown_conf(void *unused)
136 {
137
138 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
139 SHUTDOWN_PRI_FIRST);
140 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
141 SHUTDOWN_PRI_LAST + 100);
142 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
143 SHUTDOWN_PRI_LAST + 100);
144 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
145 SHUTDOWN_PRI_LAST + 200);
146 }
147
148 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
149
150 /*
151 * The system call that results in a reboot
152 *
153 * MPSAFE
154 */
155 /* ARGSUSED */
156 int
157 reboot(struct thread *td, struct reboot_args *uap)
158 {
159 int error;
160
161 error = 0;
162 #ifdef MAC
163 error = mac_check_system_reboot(td->td_ucred, uap->opt);
164 #endif
165 if (error == 0)
166 error = suser(td);
167 if (error == 0) {
168 mtx_lock(&Giant);
169 boot(uap->opt);
170 mtx_unlock(&Giant);
171 }
172 return (error);
173 }
174
175 /*
176 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
177 */
178 static int shutdown_howto = 0;
179
180 void
181 shutdown_nice(int howto)
182 {
183
184 shutdown_howto = howto;
185
186 /* Send a signal to init(8) and have it shutdown the world */
187 if (initproc != NULL) {
188 PROC_LOCK(initproc);
189 psignal(initproc, SIGINT);
190 PROC_UNLOCK(initproc);
191 } else {
192 /* No init(8) running, so simply reboot */
193 boot(RB_NOSYNC);
194 }
195 return;
196 }
197 static int waittime = -1;
198
199 static void
200 print_uptime(void)
201 {
202 int f;
203 struct timespec ts;
204
205 getnanouptime(&ts);
206 printf("Uptime: ");
207 f = 0;
208 if (ts.tv_sec >= 86400) {
209 printf("%ldd", (long)ts.tv_sec / 86400);
210 ts.tv_sec %= 86400;
211 f = 1;
212 }
213 if (f || ts.tv_sec >= 3600) {
214 printf("%ldh", (long)ts.tv_sec / 3600);
215 ts.tv_sec %= 3600;
216 f = 1;
217 }
218 if (f || ts.tv_sec >= 60) {
219 printf("%ldm", (long)ts.tv_sec / 60);
220 ts.tv_sec %= 60;
221 f = 1;
222 }
223 printf("%lds\n", (long)ts.tv_sec);
224 }
225
226 static void
227 doadump(void)
228 {
229
230 /*
231 * Sometimes people have to call this from the kernel debugger.
232 * (if 'panic' can not dump)
233 * Give them a clue as to why they can't dump.
234 */
235 if (dumper.dumper == NULL) {
236 printf("Cannot dump. No dump device defined.\n");
237 return;
238 }
239
240 savectx(&dumppcb);
241 dumptid = curthread->td_tid;
242 dumping++;
243 dumpsys(&dumper);
244 }
245
246 static int
247 isbufbusy(struct buf *bp)
248 {
249 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
250 BUF_REFCNT(bp) > 0) ||
251 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
252 return (1);
253 return (0);
254 }
255
256 /*
257 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
258 */
259 static void
260 boot(int howto)
261 {
262 static int first_buf_printf = 1;
263
264 #if defined(SMP)
265 /*
266 * Bind us to CPU 0 so that all shutdown code runs there. Some
267 * systems don't shutdown properly (i.e., ACPI power off) if we
268 * run on another processor.
269 */
270 mtx_lock_spin(&sched_lock);
271 sched_bind(curthread, 0);
272 mtx_unlock_spin(&sched_lock);
273 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
274 #endif
275 /* We're in the process of rebooting. */
276 rebooting = 1;
277
278 /* collect extra flags that shutdown_nice might have set */
279 howto |= shutdown_howto;
280
281 /* We are out of the debugger now. */
282 kdb_active = 0;
283
284 /*
285 * Do any callouts that should be done BEFORE syncing the filesystems.
286 */
287 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
288
289 /*
290 * Now sync filesystems
291 */
292 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
293 register struct buf *bp;
294 int iter, nbusy, pbusy;
295 #ifndef PREEMPTION
296 int subiter;
297 #endif
298
299 waittime = 0;
300
301 sync(curthread, NULL);
302
303 /*
304 * With soft updates, some buffers that are
305 * written will be remarked as dirty until other
306 * buffers are written.
307 */
308 for (iter = pbusy = 0; iter < 20; iter++) {
309 nbusy = 0;
310 for (bp = &buf[nbuf]; --bp >= buf; )
311 if (isbufbusy(bp))
312 nbusy++;
313 if (nbusy == 0) {
314 if (first_buf_printf)
315 printf("All buffers synced.");
316 break;
317 }
318 if (first_buf_printf) {
319 printf("Syncing disks, buffers remaining... ");
320 first_buf_printf = 0;
321 }
322 printf("%d ", nbusy);
323 if (nbusy < pbusy)
324 iter = 0;
325 pbusy = nbusy;
326 sync(curthread, NULL);
327
328 #ifdef PREEMPTION
329 /*
330 * Drop Giant and spin for a while to allow
331 * interrupt threads to run.
332 */
333 DROP_GIANT();
334 DELAY(50000 * iter);
335 PICKUP_GIANT();
336 #else
337 /*
338 * Drop Giant and context switch several times to
339 * allow interrupt threads to run.
340 */
341 DROP_GIANT();
342 for (subiter = 0; subiter < 50 * iter; subiter++) {
343 mtx_lock_spin(&sched_lock);
344 mi_switch(SW_VOL, NULL);
345 mtx_unlock_spin(&sched_lock);
346 DELAY(1000);
347 }
348 PICKUP_GIANT();
349 #endif
350 }
351 printf("\n");
352 /*
353 * Count only busy local buffers to prevent forcing
354 * a fsck if we're just a client of a wedged NFS server
355 */
356 nbusy = 0;
357 for (bp = &buf[nbuf]; --bp >= buf; ) {
358 if (isbufbusy(bp)) {
359 #if 0
360 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */
361 if (bp->b_dev == NULL) {
362 TAILQ_REMOVE(&mountlist,
363 bp->b_vp->v_mount, mnt_list);
364 continue;
365 }
366 #endif
367 nbusy++;
368 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
369 printf(
370 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n",
371 nbusy, bp->b_bufobj,
372 bp->b_flags, (long)bp->b_blkno,
373 (long)bp->b_lblkno);
374 #endif
375 }
376 }
377 if (nbusy) {
378 /*
379 * Failed to sync all blocks. Indicate this and don't
380 * unmount filesystems (thus forcing an fsck on reboot).
381 */
382 printf("Giving up on %d buffers\n", nbusy);
383 DELAY(5000000); /* 5 seconds */
384 } else {
385 if (!first_buf_printf)
386 printf("Final sync complete\n");
387 /*
388 * Unmount filesystems
389 */
390 if (panicstr == 0)
391 vfs_unmountall();
392 }
393 swapoff_all();
394 DELAY(100000); /* wait for console output to finish */
395 }
396
397 print_uptime();
398
399 /*
400 * Ok, now do things that assume all filesystem activity has
401 * been completed.
402 */
403 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
404
405 /* XXX This doesn't disable interrupts any more. Reconsider? */
406 splhigh();
407
408 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
409 doadump();
410
411 /* Now that we're going to really halt the system... */
412 EVENTHANDLER_INVOKE(shutdown_final, howto);
413
414 for(;;) ; /* safety against shutdown_reset not working */
415 /* NOTREACHED */
416 }
417
418 /*
419 * If the shutdown was a clean halt, behave accordingly.
420 */
421 static void
422 shutdown_halt(void *junk, int howto)
423 {
424
425 if (howto & RB_HALT) {
426 printf("\n");
427 printf("The operating system has halted.\n");
428 printf("Please press any key to reboot.\n\n");
429 switch (cngetc()) {
430 case -1: /* No console, just die */
431 cpu_halt();
432 /* NOTREACHED */
433 default:
434 howto &= ~RB_HALT;
435 break;
436 }
437 }
438 }
439
440 /*
441 * Check to see if the system paniced, pause and then reboot
442 * according to the specified delay.
443 */
444 static void
445 shutdown_panic(void *junk, int howto)
446 {
447 int loop;
448
449 if (howto & RB_DUMP) {
450 if (PANIC_REBOOT_WAIT_TIME != 0) {
451 if (PANIC_REBOOT_WAIT_TIME != -1) {
452 printf("Automatic reboot in %d seconds - "
453 "press a key on the console to abort\n",
454 PANIC_REBOOT_WAIT_TIME);
455 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
456 loop > 0; --loop) {
457 DELAY(1000 * 100); /* 1/10th second */
458 /* Did user type a key? */
459 if (cncheckc() != -1)
460 break;
461 }
462 if (!loop)
463 return;
464 }
465 } else { /* zero time specified - reboot NOW */
466 return;
467 }
468 printf("--> Press a key on the console to reboot,\n");
469 printf("--> or switch off the system now.\n");
470 cngetc();
471 }
472 }
473
474 /*
475 * Everything done, now reset
476 */
477 static void
478 shutdown_reset(void *junk, int howto)
479 {
480
481 printf("Rebooting...\n");
482 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
483 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
484 cpu_reset();
485 /* NOTREACHED */ /* assuming reset worked */
486 }
487
488 #ifdef SMP
489 static u_int panic_cpu = NOCPU;
490 #endif
491
492 /*
493 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
494 * and then reboots. If we are called twice, then we avoid trying to sync
495 * the disks as this often leads to recursive panics.
496 *
497 * MPSAFE
498 */
499 void
500 panic(const char *fmt, ...)
501 {
502 struct thread *td = curthread;
503 int bootopt, newpanic;
504 va_list ap;
505 static char buf[256];
506
507 #ifdef SMP
508 /*
509 * We don't want multiple CPU's to panic at the same time, so we
510 * use panic_cpu as a simple spinlock. We have to keep checking
511 * panic_cpu if we are spinning in case the panic on the first
512 * CPU is canceled.
513 */
514 if (panic_cpu != PCPU_GET(cpuid))
515 while (atomic_cmpset_int(&panic_cpu, NOCPU,
516 PCPU_GET(cpuid)) == 0)
517 while (panic_cpu != NOCPU)
518 ; /* nothing */
519 #endif
520
521 bootopt = RB_AUTOBOOT | RB_DUMP;
522 newpanic = 0;
523 if (panicstr)
524 bootopt |= RB_NOSYNC;
525 else {
526 panicstr = fmt;
527 newpanic = 1;
528 }
529
530 va_start(ap, fmt);
531 if (newpanic) {
532 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
533 panicstr = buf;
534 printf("panic: %s\n", buf);
535 } else {
536 printf("panic: ");
537 vprintf(fmt, ap);
538 printf("\n");
539 }
540 va_end(ap);
541 #ifdef SMP
542 printf("cpuid = %d\n", PCPU_GET(cpuid));
543 #endif
544
545 #ifdef KDB
546 if (newpanic && trace_on_panic)
547 kdb_backtrace();
548 if (debugger_on_panic)
549 kdb_enter("panic");
550 #ifdef RESTARTABLE_PANICS
551 /* See if the user aborted the panic, in which case we continue. */
552 if (panicstr == NULL) {
553 #ifdef SMP
554 atomic_store_rel_int(&panic_cpu, NOCPU);
555 #endif
556 return;
557 }
558 #endif
559 #endif
560 mtx_lock_spin(&sched_lock);
561 td->td_flags |= TDF_INPANIC;
562 mtx_unlock_spin(&sched_lock);
563 if (!sync_on_panic)
564 bootopt |= RB_NOSYNC;
565 boot(bootopt);
566 }
567
568 /*
569 * Support for poweroff delay.
570 */
571 #ifndef POWEROFF_DELAY
572 # define POWEROFF_DELAY 5000
573 #endif
574 static int poweroff_delay = POWEROFF_DELAY;
575
576 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
577 &poweroff_delay, 0, "");
578
579 static void
580 poweroff_wait(void *junk, int howto)
581 {
582
583 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
584 return;
585 DELAY(poweroff_delay * 1000);
586 }
587
588 /*
589 * Some system processes (e.g. syncer) need to be stopped at appropriate
590 * points in their main loops prior to a system shutdown, so that they
591 * won't interfere with the shutdown process (e.g. by holding a disk buf
592 * to cause sync to fail). For each of these system processes, register
593 * shutdown_kproc() as a handler for one of shutdown events.
594 */
595 static int kproc_shutdown_wait = 60;
596 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
597 &kproc_shutdown_wait, 0, "");
598
599 void
600 kproc_shutdown(void *arg, int howto)
601 {
602 struct proc *p;
603 char procname[MAXCOMLEN + 1];
604 int error;
605
606 if (panicstr)
607 return;
608
609 p = (struct proc *)arg;
610 strlcpy(procname, p->p_comm, sizeof(procname));
611 printf("Waiting (max %d seconds) for system process `%s' to stop...",
612 kproc_shutdown_wait, procname);
613 error = kthread_suspend(p, kproc_shutdown_wait * hz);
614
615 if (error == EWOULDBLOCK)
616 printf("timed out\n");
617 else
618 printf("done\n");
619 }
620
621 /* Registration of dumpers */
622 int
623 set_dumper(struct dumperinfo *di)
624 {
625
626 if (di == NULL) {
627 bzero(&dumper, sizeof dumper);
628 return (0);
629 }
630 if (dumper.dumper != NULL)
631 return (EBUSY);
632 dumper = *di;
633 return (0);
634 }
635
636 #if defined(__powerpc__)
637 void
638 dumpsys(struct dumperinfo *di __unused)
639 {
640
641 printf("Kernel dumps not implemented on this architecture\n");
642 }
643 #endif
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