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/7.3/sys/kern/kern_shutdown.c 183619 2008-10-05 09:13:27Z kib $");
39
40 #include "opt_ddb.h"
41 #include "opt_kdb.h"
42 #include "opt_mac.h"
43 #include "opt_panic.h"
44 #include "opt_show_busybufs.h"
45 #include "opt_sched.h"
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/bio.h>
50 #include <sys/buf.h>
51 #include <sys/conf.h>
52 #include <sys/cons.h>
53 #include <sys/eventhandler.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/kthread.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/priv.h>
60 #include <sys/proc.h>
61 #include <sys/reboot.h>
62 #include <sys/resourcevar.h>
63 #include <sys/sched.h>
64 #include <sys/smp.h> /* smp_active */
65 #include <sys/sysctl.h>
66 #include <sys/sysproto.h>
67
68 #include <ddb/ddb.h>
69
70 #include <machine/cpu.h>
71 #include <machine/pcb.h>
72 #include <machine/smp.h>
73
74 #include <security/mac/mac_framework.h>
75
76 #include <vm/vm.h>
77 #include <vm/vm_object.h>
78 #include <vm/vm_page.h>
79 #include <vm/vm_pager.h>
80 #include <vm/swap_pager.h>
81
82 #include <sys/signalvar.h>
83
84 #ifndef PANIC_REBOOT_WAIT_TIME
85 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
86 #endif
87
88 /*
89 * Note that stdarg.h and the ANSI style va_start macro is used for both
90 * ANSI and traditional C compilers.
91 */
92 #include <machine/stdarg.h>
93
94 #ifdef KDB
95 #ifdef KDB_UNATTENDED
96 int debugger_on_panic = 0;
97 #else
98 int debugger_on_panic = 1;
99 #endif
100 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
101 &debugger_on_panic, 0, "Run debugger on kernel panic");
102
103 #ifdef KDB_TRACE
104 int trace_on_panic = 1;
105 #else
106 int trace_on_panic = 0;
107 #endif
108 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
109 &trace_on_panic, 0, "Print stack trace on kernel panic");
110 #endif /* KDB */
111
112 int sync_on_panic = 0;
113 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
114 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
115
116 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
117
118 /*
119 * Variable panicstr contains argument to first call to panic; used as flag
120 * to indicate that the kernel has already called panic.
121 */
122 const char *panicstr;
123
124 int dumping; /* system is dumping */
125 int rebooting; /* system is rebooting */
126 static struct dumperinfo dumper; /* our selected dumper */
127
128 /* Context information for dump-debuggers. */
129 static struct pcb dumppcb; /* Registers. */
130 static lwpid_t dumptid; /* Thread ID. */
131
132 static void boot(int) __dead2;
133 static void poweroff_wait(void *, int);
134 static void shutdown_halt(void *junk, int howto);
135 static void shutdown_panic(void *junk, int howto);
136 static void shutdown_reset(void *junk, int howto);
137
138 /* register various local shutdown events */
139 static void
140 shutdown_conf(void *unused)
141 {
142
143 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
144 SHUTDOWN_PRI_FIRST);
145 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
146 SHUTDOWN_PRI_LAST + 100);
147 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
148 SHUTDOWN_PRI_LAST + 100);
149 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
150 SHUTDOWN_PRI_LAST + 200);
151 }
152
153 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
154
155 /*
156 * The system call that results in a reboot.
157 */
158 /* ARGSUSED */
159 int
160 reboot(struct thread *td, struct reboot_args *uap)
161 {
162 int error;
163
164 error = 0;
165 #ifdef MAC
166 error = mac_check_system_reboot(td->td_ucred, uap->opt);
167 #endif
168 if (error == 0)
169 error = priv_check(td, PRIV_REBOOT);
170 if (error == 0) {
171 mtx_lock(&Giant);
172 boot(uap->opt);
173 mtx_unlock(&Giant);
174 }
175 return (error);
176 }
177
178 /*
179 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
180 */
181 static int shutdown_howto = 0;
182
183 void
184 shutdown_nice(int howto)
185 {
186
187 shutdown_howto = howto;
188
189 /* Send a signal to init(8) and have it shutdown the world */
190 if (initproc != NULL) {
191 PROC_LOCK(initproc);
192 psignal(initproc, SIGINT);
193 PROC_UNLOCK(initproc);
194 } else {
195 /* No init(8) running, so simply reboot */
196 boot(RB_NOSYNC);
197 }
198 return;
199 }
200 static int waittime = -1;
201
202 static void
203 print_uptime(void)
204 {
205 int f;
206 struct timespec ts;
207
208 getnanouptime(&ts);
209 printf("Uptime: ");
210 f = 0;
211 if (ts.tv_sec >= 86400) {
212 printf("%ldd", (long)ts.tv_sec / 86400);
213 ts.tv_sec %= 86400;
214 f = 1;
215 }
216 if (f || ts.tv_sec >= 3600) {
217 printf("%ldh", (long)ts.tv_sec / 3600);
218 ts.tv_sec %= 3600;
219 f = 1;
220 }
221 if (f || ts.tv_sec >= 60) {
222 printf("%ldm", (long)ts.tv_sec / 60);
223 ts.tv_sec %= 60;
224 f = 1;
225 }
226 printf("%lds\n", (long)ts.tv_sec);
227 }
228
229 static void
230 doadump(void)
231 {
232
233 /*
234 * Sometimes people have to call this from the kernel debugger.
235 * (if 'panic' can not dump)
236 * Give them a clue as to why they can't dump.
237 */
238 if (dumper.dumper == NULL) {
239 printf("Cannot dump. No dump device defined.\n");
240 return;
241 }
242
243 savectx(&dumppcb);
244 dumptid = curthread->td_tid;
245 dumping++;
246 #ifdef DDB
247 if (textdump_pending)
248 textdump_dumpsys(&dumper);
249 else
250 #endif
251 dumpsys(&dumper);
252 dumping--;
253 }
254
255 static int
256 isbufbusy(struct buf *bp)
257 {
258 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
259 BUF_REFCNT(bp) > 0) ||
260 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
261 return (1);
262 return (0);
263 }
264
265 /*
266 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
267 */
268 static void
269 boot(int howto)
270 {
271 static int first_buf_printf = 1;
272
273 #if defined(SMP)
274 /*
275 * Bind us to CPU 0 so that all shutdown code runs there. Some
276 * systems don't shutdown properly (i.e., ACPI power off) if we
277 * run on another processor.
278 */
279 thread_lock(curthread);
280 sched_bind(curthread, 0);
281 thread_unlock(curthread);
282 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
283 #endif
284 /* We're in the process of rebooting. */
285 rebooting = 1;
286
287 /* collect extra flags that shutdown_nice might have set */
288 howto |= shutdown_howto;
289
290 /* We are out of the debugger now. */
291 kdb_active = 0;
292
293 /*
294 * Do any callouts that should be done BEFORE syncing the filesystems.
295 */
296 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
297
298 /*
299 * Now sync filesystems
300 */
301 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
302 register struct buf *bp;
303 int iter, nbusy, pbusy;
304 #ifndef PREEMPTION
305 int subiter;
306 #endif
307
308 waittime = 0;
309
310 sync(curthread, NULL);
311
312 /*
313 * With soft updates, some buffers that are
314 * written will be remarked as dirty until other
315 * buffers are written.
316 */
317 for (iter = pbusy = 0; iter < 20; iter++) {
318 nbusy = 0;
319 for (bp = &buf[nbuf]; --bp >= buf; )
320 if (isbufbusy(bp))
321 nbusy++;
322 if (nbusy == 0) {
323 if (first_buf_printf)
324 printf("All buffers synced.");
325 break;
326 }
327 if (first_buf_printf) {
328 printf("Syncing disks, buffers remaining... ");
329 first_buf_printf = 0;
330 }
331 printf("%d ", nbusy);
332 if (nbusy < pbusy)
333 iter = 0;
334 pbusy = nbusy;
335 sync(curthread, NULL);
336
337 #ifdef PREEMPTION
338 /*
339 * Drop Giant and spin for a while to allow
340 * interrupt threads to run.
341 */
342 DROP_GIANT();
343 DELAY(50000 * iter);
344 PICKUP_GIANT();
345 #else
346 /*
347 * Drop Giant and context switch several times to
348 * allow interrupt threads to run.
349 */
350 DROP_GIANT();
351 for (subiter = 0; subiter < 50 * iter; subiter++) {
352 thread_lock(curthread);
353 mi_switch(SW_VOL, NULL);
354 thread_unlock(curthread);
355 DELAY(1000);
356 }
357 PICKUP_GIANT();
358 #endif
359 }
360 printf("\n");
361 /*
362 * Count only busy local buffers to prevent forcing
363 * a fsck if we're just a client of a wedged NFS server
364 */
365 nbusy = 0;
366 for (bp = &buf[nbuf]; --bp >= buf; ) {
367 if (isbufbusy(bp)) {
368 #if 0
369 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */
370 if (bp->b_dev == NULL) {
371 TAILQ_REMOVE(&mountlist,
372 bp->b_vp->v_mount, mnt_list);
373 continue;
374 }
375 #endif
376 nbusy++;
377 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
378 printf(
379 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n",
380 nbusy, bp->b_bufobj,
381 bp->b_flags, (long)bp->b_blkno,
382 (long)bp->b_lblkno);
383 #endif
384 }
385 }
386 if (nbusy) {
387 /*
388 * Failed to sync all blocks. Indicate this and don't
389 * unmount filesystems (thus forcing an fsck on reboot).
390 */
391 printf("Giving up on %d buffers\n", nbusy);
392 DELAY(5000000); /* 5 seconds */
393 } else {
394 if (!first_buf_printf)
395 printf("Final sync complete\n");
396 /*
397 * Unmount filesystems
398 */
399 if (panicstr == 0)
400 vfs_unmountall();
401 }
402 swapoff_all();
403 DELAY(100000); /* wait for console output to finish */
404 }
405
406 print_uptime();
407
408 /*
409 * Ok, now do things that assume all filesystem activity has
410 * been completed.
411 */
412 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
413
414 /* XXX This doesn't disable interrupts any more. Reconsider? */
415 splhigh();
416
417 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
418 doadump();
419
420 /* Now that we're going to really halt the system... */
421 EVENTHANDLER_INVOKE(shutdown_final, howto);
422
423 for(;;) ; /* safety against shutdown_reset not working */
424 /* NOTREACHED */
425 }
426
427 /*
428 * If the shutdown was a clean halt, behave accordingly.
429 */
430 static void
431 shutdown_halt(void *junk, int howto)
432 {
433
434 if (howto & RB_HALT) {
435 printf("\n");
436 printf("The operating system has halted.\n");
437 printf("Please press any key to reboot.\n\n");
438 switch (cngetc()) {
439 case -1: /* No console, just die */
440 cpu_halt();
441 /* NOTREACHED */
442 default:
443 howto &= ~RB_HALT;
444 break;
445 }
446 }
447 }
448
449 /*
450 * Check to see if the system paniced, pause and then reboot
451 * according to the specified delay.
452 */
453 static void
454 shutdown_panic(void *junk, int howto)
455 {
456 int loop;
457
458 if (howto & RB_DUMP) {
459 if (PANIC_REBOOT_WAIT_TIME != 0) {
460 if (PANIC_REBOOT_WAIT_TIME != -1) {
461 printf("Automatic reboot in %d seconds - "
462 "press a key on the console to abort\n",
463 PANIC_REBOOT_WAIT_TIME);
464 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
465 loop > 0; --loop) {
466 DELAY(1000 * 100); /* 1/10th second */
467 /* Did user type a key? */
468 if (cncheckc() != -1)
469 break;
470 }
471 if (!loop)
472 return;
473 }
474 } else { /* zero time specified - reboot NOW */
475 return;
476 }
477 printf("--> Press a key on the console to reboot,\n");
478 printf("--> or switch off the system now.\n");
479 cngetc();
480 }
481 }
482
483 /*
484 * Everything done, now reset
485 */
486 static void
487 shutdown_reset(void *junk, int howto)
488 {
489
490 printf("Rebooting...\n");
491 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
492 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
493 cpu_reset();
494 /* NOTREACHED */ /* assuming reset worked */
495 }
496
497 #ifdef SMP
498 static u_int panic_cpu = NOCPU;
499 #endif
500
501 /*
502 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
503 * and then reboots. If we are called twice, then we avoid trying to sync
504 * the disks as this often leads to recursive panics.
505 */
506 void
507 panic(const char *fmt, ...)
508 {
509 struct thread *td = curthread;
510 int bootopt, newpanic;
511 va_list ap;
512 static char buf[256];
513
514 critical_enter();
515 #ifdef SMP
516 /*
517 * We don't want multiple CPU's to panic at the same time, so we
518 * use panic_cpu as a simple spinlock. We have to keep checking
519 * panic_cpu if we are spinning in case the panic on the first
520 * CPU is canceled.
521 */
522 if (panic_cpu != PCPU_GET(cpuid))
523 while (atomic_cmpset_int(&panic_cpu, NOCPU,
524 PCPU_GET(cpuid)) == 0)
525 while (panic_cpu != NOCPU)
526 ; /* nothing */
527 #endif
528
529 bootopt = RB_AUTOBOOT | RB_DUMP;
530 newpanic = 0;
531 if (panicstr)
532 bootopt |= RB_NOSYNC;
533 else {
534 panicstr = fmt;
535 newpanic = 1;
536 }
537
538 va_start(ap, fmt);
539 if (newpanic) {
540 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
541 panicstr = buf;
542 printf("panic: %s\n", buf);
543 } else {
544 printf("panic: ");
545 vprintf(fmt, ap);
546 printf("\n");
547 }
548 va_end(ap);
549 #ifdef SMP
550 printf("cpuid = %d\n", PCPU_GET(cpuid));
551 #endif
552
553 #ifdef KDB
554 if (newpanic && trace_on_panic)
555 kdb_backtrace();
556 if (debugger_on_panic)
557 kdb_enter_why(KDB_WHY_PANIC, "panic");
558 #ifdef RESTARTABLE_PANICS
559 /* See if the user aborted the panic, in which case we continue. */
560 if (panicstr == NULL) {
561 #ifdef SMP
562 atomic_store_rel_int(&panic_cpu, NOCPU);
563 #endif
564 return;
565 }
566 #endif
567 #endif
568 /*thread_lock(td); */
569 td->td_flags |= TDF_INPANIC;
570 /* thread_unlock(td); */
571 if (!sync_on_panic)
572 bootopt |= RB_NOSYNC;
573 critical_exit();
574 boot(bootopt);
575 }
576
577 /*
578 * Support for poweroff delay.
579 */
580 #ifndef POWEROFF_DELAY
581 # define POWEROFF_DELAY 5000
582 #endif
583 static int poweroff_delay = POWEROFF_DELAY;
584
585 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
586 &poweroff_delay, 0, "");
587
588 static void
589 poweroff_wait(void *junk, int howto)
590 {
591
592 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
593 return;
594 DELAY(poweroff_delay * 1000);
595 }
596
597 /*
598 * Some system processes (e.g. syncer) need to be stopped at appropriate
599 * points in their main loops prior to a system shutdown, so that they
600 * won't interfere with the shutdown process (e.g. by holding a disk buf
601 * to cause sync to fail). For each of these system processes, register
602 * shutdown_kproc() as a handler for one of shutdown events.
603 */
604 static int kproc_shutdown_wait = 60;
605 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
606 &kproc_shutdown_wait, 0, "");
607
608 void
609 kproc_shutdown(void *arg, int howto)
610 {
611 struct proc *p;
612 char procname[MAXCOMLEN + 1];
613 int error;
614
615 if (panicstr)
616 return;
617
618 p = (struct proc *)arg;
619 strlcpy(procname, p->p_comm, sizeof(procname));
620 printf("Waiting (max %d seconds) for system process `%s' to stop...",
621 kproc_shutdown_wait, procname);
622 error = kthread_suspend(p, kproc_shutdown_wait * hz);
623
624 if (error == EWOULDBLOCK)
625 printf("timed out\n");
626 else
627 printf("done\n");
628 }
629
630 /* Registration of dumpers */
631 int
632 set_dumper(struct dumperinfo *di)
633 {
634
635 if (di == NULL) {
636 bzero(&dumper, sizeof dumper);
637 return (0);
638 }
639 if (dumper.dumper != NULL)
640 return (EBUSY);
641 dumper = *di;
642 return (0);
643 }
644
645 /* Call dumper with bounds checking. */
646 int
647 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
648 off_t offset, size_t length)
649 {
650
651 if (length != 0 && (offset < di->mediaoffset ||
652 offset - di->mediaoffset + length > di->mediasize)) {
653 printf("Attempt to write outside dump device boundaries.\n");
654 return (ENXIO);
655 }
656 return (di->dumper(di->priv, virtual, physical, offset, length));
657 }
658
659 #if defined(__powerpc__)
660 void
661 dumpsys(struct dumperinfo *di __unused)
662 {
663
664 printf("Kernel dumps not implemented on this architecture\n");
665 }
666 #endif
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