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/8.0/sys/kern/kern_shutdown.c 196198 2009-08-13 17:54:11Z attilio $");
39
40 #include "opt_ddb.h"
41 #include "opt_kdb.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/jail.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/kerneldump.h>
57 #include <sys/kthread.h>
58 #include <sys/malloc.h>
59 #include <sys/mount.h>
60 #include <sys/priv.h>
61 #include <sys/proc.h>
62 #include <sys/reboot.h>
63 #include <sys/resourcevar.h>
64 #include <sys/sched.h>
65 #include <sys/smp.h> /* smp_active */
66 #include <sys/sysctl.h>
67 #include <sys/sysproto.h>
68
69 #include <ddb/ddb.h>
70
71 #include <machine/cpu.h>
72 #include <machine/pcb.h>
73 #include <machine/smp.h>
74
75 #include <security/mac/mac_framework.h>
76
77 #include <vm/vm.h>
78 #include <vm/vm_object.h>
79 #include <vm/vm_page.h>
80 #include <vm/vm_pager.h>
81 #include <vm/swap_pager.h>
82
83 #include <sys/signalvar.h>
84
85 #ifndef PANIC_REBOOT_WAIT_TIME
86 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
87 #endif
88
89 /*
90 * Note that stdarg.h and the ANSI style va_start macro is used for both
91 * ANSI and traditional C compilers.
92 */
93 #include <machine/stdarg.h>
94
95 #ifdef KDB
96 #ifdef KDB_UNATTENDED
97 int debugger_on_panic = 0;
98 #else
99 int debugger_on_panic = 1;
100 #endif
101 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
102 &debugger_on_panic, 0, "Run debugger on kernel panic");
103
104 #ifdef KDB_TRACE
105 int trace_on_panic = 1;
106 #else
107 int trace_on_panic = 0;
108 #endif
109 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
110 &trace_on_panic, 0, "Print stack trace on kernel panic");
111 #endif /* KDB */
112
113 int sync_on_panic = 0;
114 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
115 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
116
117 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
118
119 /*
120 * Variable panicstr contains argument to first call to panic; used as flag
121 * to indicate that the kernel has already called panic.
122 */
123 const char *panicstr;
124
125 int dumping; /* system is dumping */
126 int rebooting; /* system is rebooting */
127 static struct dumperinfo dumper; /* our selected dumper */
128
129 /* Context information for dump-debuggers. */
130 static struct pcb dumppcb; /* Registers. */
131 static lwpid_t dumptid; /* Thread ID. */
132
133 static void boot(int) __dead2;
134 static void poweroff_wait(void *, int);
135 static void shutdown_halt(void *junk, int howto);
136 static void shutdown_panic(void *junk, int howto);
137 static void shutdown_reset(void *junk, int howto);
138
139 /* register various local shutdown events */
140 static void
141 shutdown_conf(void *unused)
142 {
143
144 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
145 SHUTDOWN_PRI_FIRST);
146 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
147 SHUTDOWN_PRI_LAST + 100);
148 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
149 SHUTDOWN_PRI_LAST + 100);
150 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
151 SHUTDOWN_PRI_LAST + 200);
152 }
153
154 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
155
156 /*
157 * The system call that results in a reboot.
158 */
159 /* ARGSUSED */
160 int
161 reboot(struct thread *td, struct reboot_args *uap)
162 {
163 int error;
164
165 error = 0;
166 #ifdef MAC
167 error = mac_system_check_reboot(td->td_ucred, uap->opt);
168 #endif
169 if (error == 0)
170 error = priv_check(td, PRIV_REBOOT);
171 if (error == 0) {
172 mtx_lock(&Giant);
173 boot(uap->opt);
174 mtx_unlock(&Giant);
175 }
176 return (error);
177 }
178
179 /*
180 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
181 */
182 static int shutdown_howto = 0;
183
184 void
185 shutdown_nice(int howto)
186 {
187
188 shutdown_howto = howto;
189
190 /* Send a signal to init(8) and have it shutdown the world */
191 if (initproc != NULL) {
192 PROC_LOCK(initproc);
193 psignal(initproc, SIGINT);
194 PROC_UNLOCK(initproc);
195 } else {
196 /* No init(8) running, so simply reboot */
197 boot(RB_NOSYNC);
198 }
199 return;
200 }
201 static int waittime = -1;
202
203 static void
204 print_uptime(void)
205 {
206 int f;
207 struct timespec ts;
208
209 getnanouptime(&ts);
210 printf("Uptime: ");
211 f = 0;
212 if (ts.tv_sec >= 86400) {
213 printf("%ldd", (long)ts.tv_sec / 86400);
214 ts.tv_sec %= 86400;
215 f = 1;
216 }
217 if (f || ts.tv_sec >= 3600) {
218 printf("%ldh", (long)ts.tv_sec / 3600);
219 ts.tv_sec %= 3600;
220 f = 1;
221 }
222 if (f || ts.tv_sec >= 60) {
223 printf("%ldm", (long)ts.tv_sec / 60);
224 ts.tv_sec %= 60;
225 f = 1;
226 }
227 printf("%lds\n", (long)ts.tv_sec);
228 }
229
230 static void
231 doadump(void)
232 {
233
234 /*
235 * Sometimes people have to call this from the kernel debugger.
236 * (if 'panic' can not dump)
237 * Give them a clue as to why they can't dump.
238 */
239 if (dumper.dumper == NULL) {
240 printf("Cannot dump. Device not defined or unavailable.\n");
241 return;
242 }
243
244 savectx(&dumppcb);
245 dumptid = curthread->td_tid;
246 dumping++;
247 #ifdef DDB
248 if (textdump_pending)
249 textdump_dumpsys(&dumper);
250 else
251 #endif
252 dumpsys(&dumper);
253 dumping--;
254 }
255
256 static int
257 isbufbusy(struct buf *bp)
258 {
259 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
260 BUF_ISLOCKED(bp)) ||
261 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
262 return (1);
263 return (0);
264 }
265
266 /*
267 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
268 */
269 static void
270 boot(int howto)
271 {
272 static int first_buf_printf = 1;
273
274 #if defined(SMP)
275 /*
276 * Bind us to CPU 0 so that all shutdown code runs there. Some
277 * systems don't shutdown properly (i.e., ACPI power off) if we
278 * run on another processor.
279 */
280 thread_lock(curthread);
281 sched_bind(curthread, 0);
282 thread_unlock(curthread);
283 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
284 #endif
285 /* We're in the process of rebooting. */
286 rebooting = 1;
287
288 /* collect extra flags that shutdown_nice might have set */
289 howto |= shutdown_howto;
290
291 /* We are out of the debugger now. */
292 kdb_active = 0;
293
294 /*
295 * Do any callouts that should be done BEFORE syncing the filesystems.
296 */
297 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
298
299 /*
300 * Now sync filesystems
301 */
302 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
303 register struct buf *bp;
304 int iter, nbusy, pbusy;
305 #ifndef PREEMPTION
306 int subiter;
307 #endif
308
309 waittime = 0;
310
311 sync(curthread, NULL);
312
313 /*
314 * With soft updates, some buffers that are
315 * written will be remarked as dirty until other
316 * buffers are written.
317 */
318 for (iter = pbusy = 0; iter < 20; iter++) {
319 nbusy = 0;
320 for (bp = &buf[nbuf]; --bp >= buf; )
321 if (isbufbusy(bp))
322 nbusy++;
323 if (nbusy == 0) {
324 if (first_buf_printf)
325 printf("All buffers synced.");
326 break;
327 }
328 if (first_buf_printf) {
329 printf("Syncing disks, buffers remaining... ");
330 first_buf_printf = 0;
331 }
332 printf("%d ", nbusy);
333 if (nbusy < pbusy)
334 iter = 0;
335 pbusy = nbusy;
336 sync(curthread, NULL);
337
338 #ifdef PREEMPTION
339 /*
340 * Drop Giant and spin for a while to allow
341 * interrupt threads to run.
342 */
343 DROP_GIANT();
344 DELAY(50000 * iter);
345 PICKUP_GIANT();
346 #else
347 /*
348 * Drop Giant and context switch several times to
349 * allow interrupt threads to run.
350 */
351 DROP_GIANT();
352 for (subiter = 0; subiter < 50 * iter; subiter++) {
353 thread_lock(curthread);
354 mi_switch(SW_VOL, NULL);
355 thread_unlock(curthread);
356 DELAY(1000);
357 }
358 PICKUP_GIANT();
359 #endif
360 }
361 printf("\n");
362 /*
363 * Count only busy local buffers to prevent forcing
364 * a fsck if we're just a client of a wedged NFS server
365 */
366 nbusy = 0;
367 for (bp = &buf[nbuf]; --bp >= buf; ) {
368 if (isbufbusy(bp)) {
369 #if 0
370 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */
371 if (bp->b_dev == NULL) {
372 TAILQ_REMOVE(&mountlist,
373 bp->b_vp->v_mount, mnt_list);
374 continue;
375 }
376 #endif
377 nbusy++;
378 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
379 printf(
380 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n",
381 nbusy, bp->b_bufobj,
382 bp->b_flags, (long)bp->b_blkno,
383 (long)bp->b_lblkno);
384 #endif
385 }
386 }
387 if (nbusy) {
388 /*
389 * Failed to sync all blocks. Indicate this and don't
390 * unmount filesystems (thus forcing an fsck on reboot).
391 */
392 printf("Giving up on %d buffers\n", nbusy);
393 DELAY(5000000); /* 5 seconds */
394 } else {
395 if (!first_buf_printf)
396 printf("Final sync complete\n");
397 /*
398 * Unmount filesystems
399 */
400 if (panicstr == 0)
401 vfs_unmountall();
402 }
403 swapoff_all();
404 DELAY(100000); /* wait for console output to finish */
405 }
406
407 print_uptime();
408
409 /*
410 * Ok, now do things that assume all filesystem activity has
411 * been completed.
412 */
413 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
414
415 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
416 doadump();
417
418 /* Now that we're going to really halt the system... */
419 EVENTHANDLER_INVOKE(shutdown_final, howto);
420
421 for(;;) ; /* safety against shutdown_reset not working */
422 /* NOTREACHED */
423 }
424
425 /*
426 * If the shutdown was a clean halt, behave accordingly.
427 */
428 static void
429 shutdown_halt(void *junk, int howto)
430 {
431
432 if (howto & RB_HALT) {
433 printf("\n");
434 printf("The operating system has halted.\n");
435 printf("Please press any key to reboot.\n\n");
436 switch (cngetc()) {
437 case -1: /* No console, just die */
438 cpu_halt();
439 /* NOTREACHED */
440 default:
441 howto &= ~RB_HALT;
442 break;
443 }
444 }
445 }
446
447 /*
448 * Check to see if the system paniced, pause and then reboot
449 * according to the specified delay.
450 */
451 static void
452 shutdown_panic(void *junk, int howto)
453 {
454 int loop;
455
456 if (howto & RB_DUMP) {
457 if (PANIC_REBOOT_WAIT_TIME != 0) {
458 if (PANIC_REBOOT_WAIT_TIME != -1) {
459 printf("Automatic reboot in %d seconds - "
460 "press a key on the console to abort\n",
461 PANIC_REBOOT_WAIT_TIME);
462 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
463 loop > 0; --loop) {
464 DELAY(1000 * 100); /* 1/10th second */
465 /* Did user type a key? */
466 if (cncheckc() != -1)
467 break;
468 }
469 if (!loop)
470 return;
471 }
472 } else { /* zero time specified - reboot NOW */
473 return;
474 }
475 printf("--> Press a key on the console to reboot,\n");
476 printf("--> or switch off the system now.\n");
477 cngetc();
478 }
479 }
480
481 /*
482 * Everything done, now reset
483 */
484 static void
485 shutdown_reset(void *junk, int howto)
486 {
487
488 /*
489 * Disable interrupts on CPU0 in order to avoid fast handlers
490 * to preempt the stopping process and to deadlock against other
491 * CPUs.
492 */
493 spinlock_enter();
494
495 printf("Rebooting...\n");
496 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
497 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
498 cpu_reset();
499 /* NOTREACHED */ /* assuming reset worked */
500 }
501
502 #ifdef SMP
503 static u_int panic_cpu = NOCPU;
504 #endif
505
506 /*
507 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
508 * and then reboots. If we are called twice, then we avoid trying to sync
509 * the disks as this often leads to recursive panics.
510 */
511 void
512 panic(const char *fmt, ...)
513 {
514 struct thread *td = curthread;
515 int bootopt, newpanic;
516 va_list ap;
517 static char buf[256];
518
519 critical_enter();
520 #ifdef SMP
521 /*
522 * We don't want multiple CPU's to panic at the same time, so we
523 * use panic_cpu as a simple spinlock. We have to keep checking
524 * panic_cpu if we are spinning in case the panic on the first
525 * CPU is canceled.
526 */
527 if (panic_cpu != PCPU_GET(cpuid))
528 while (atomic_cmpset_int(&panic_cpu, NOCPU,
529 PCPU_GET(cpuid)) == 0)
530 while (panic_cpu != NOCPU)
531 ; /* nothing */
532 #endif
533
534 bootopt = RB_AUTOBOOT | RB_DUMP;
535 newpanic = 0;
536 if (panicstr)
537 bootopt |= RB_NOSYNC;
538 else {
539 panicstr = fmt;
540 newpanic = 1;
541 }
542
543 va_start(ap, fmt);
544 if (newpanic) {
545 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
546 panicstr = buf;
547 printf("panic: %s\n", buf);
548 } else {
549 printf("panic: ");
550 vprintf(fmt, ap);
551 printf("\n");
552 }
553 va_end(ap);
554 #ifdef SMP
555 printf("cpuid = %d\n", PCPU_GET(cpuid));
556 #endif
557
558 #ifdef KDB
559 if (newpanic && trace_on_panic)
560 kdb_backtrace();
561 if (debugger_on_panic)
562 kdb_enter(KDB_WHY_PANIC, "panic");
563 #ifdef RESTARTABLE_PANICS
564 /* See if the user aborted the panic, in which case we continue. */
565 if (panicstr == NULL) {
566 #ifdef SMP
567 atomic_store_rel_int(&panic_cpu, NOCPU);
568 #endif
569 return;
570 }
571 #endif
572 #endif
573 /*thread_lock(td); */
574 td->td_flags |= TDF_INPANIC;
575 /* thread_unlock(td); */
576 if (!sync_on_panic)
577 bootopt |= RB_NOSYNC;
578 critical_exit();
579 boot(bootopt);
580 }
581
582 /*
583 * Support for poweroff delay.
584 */
585 #ifndef POWEROFF_DELAY
586 # define POWEROFF_DELAY 5000
587 #endif
588 static int poweroff_delay = POWEROFF_DELAY;
589
590 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
591 &poweroff_delay, 0, "");
592
593 static void
594 poweroff_wait(void *junk, int howto)
595 {
596
597 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
598 return;
599 DELAY(poweroff_delay * 1000);
600 }
601
602 /*
603 * Some system processes (e.g. syncer) need to be stopped at appropriate
604 * points in their main loops prior to a system shutdown, so that they
605 * won't interfere with the shutdown process (e.g. by holding a disk buf
606 * to cause sync to fail). For each of these system processes, register
607 * shutdown_kproc() as a handler for one of shutdown events.
608 */
609 static int kproc_shutdown_wait = 60;
610 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
611 &kproc_shutdown_wait, 0, "");
612
613 void
614 kproc_shutdown(void *arg, int howto)
615 {
616 struct proc *p;
617 char procname[MAXCOMLEN + 1];
618 int error;
619
620 if (panicstr)
621 return;
622
623 p = (struct proc *)arg;
624 strlcpy(procname, p->p_comm, sizeof(procname));
625 printf("Waiting (max %d seconds) for system process `%s' to stop...",
626 kproc_shutdown_wait, procname);
627 error = kproc_suspend(p, kproc_shutdown_wait * hz);
628
629 if (error == EWOULDBLOCK)
630 printf("timed out\n");
631 else
632 printf("done\n");
633 }
634
635 void
636 kthread_shutdown(void *arg, int howto)
637 {
638 struct thread *td;
639 char procname[MAXCOMLEN + 1];
640 int error;
641
642 if (panicstr)
643 return;
644
645 td = (struct thread *)arg;
646 strlcpy(procname, td->td_name, sizeof(procname));
647 printf("Waiting (max %d seconds) for system thread `%s' to stop...",
648 kproc_shutdown_wait, procname);
649 error = kthread_suspend(td, kproc_shutdown_wait * hz);
650
651 if (error == EWOULDBLOCK)
652 printf("timed out\n");
653 else
654 printf("done\n");
655 }
656
657 /* Registration of dumpers */
658 int
659 set_dumper(struct dumperinfo *di)
660 {
661
662 if (di == NULL) {
663 bzero(&dumper, sizeof dumper);
664 return (0);
665 }
666 if (dumper.dumper != NULL)
667 return (EBUSY);
668 dumper = *di;
669 return (0);
670 }
671
672 /* Call dumper with bounds checking. */
673 int
674 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
675 off_t offset, size_t length)
676 {
677
678 if (length != 0 && (offset < di->mediaoffset ||
679 offset - di->mediaoffset + length > di->mediasize)) {
680 printf("Attempt to write outside dump device boundaries.\n");
681 return (ENXIO);
682 }
683 return (di->dumper(di->priv, virtual, physical, offset, length));
684 }
685
686 void
687 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
688 uint64_t dumplen, uint32_t blksz)
689 {
690
691 bzero(kdh, sizeof(*kdh));
692 strncpy(kdh->magic, magic, sizeof(kdh->magic));
693 strncpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
694 kdh->version = htod32(KERNELDUMPVERSION);
695 kdh->architectureversion = htod32(archver);
696 kdh->dumplength = htod64(dumplen);
697 kdh->dumptime = htod64(time_second);
698 kdh->blocksize = htod32(blksz);
699 strncpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
700 strncpy(kdh->versionstring, version, sizeof(kdh->versionstring));
701 if (panicstr != NULL)
702 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
703 kdh->parity = kerneldump_parity(kdh);
704 }
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