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/5.4/sys/kern/kern_shutdown.c 145335 2005-04-20 19:11:07Z cvs2svn $");
39
40 #include "opt_kdb.h"
41 #include "opt_hw_wdog.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/mac.h>
58 #include <sys/malloc.h>
59 #include <sys/mount.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 #include <sys/vnode.h>
68
69 #include <machine/cpu.h>
70 #include <machine/pcb.h>
71 #include <machine/smp.h>
72
73 #include <sys/signalvar.h>
74
75 #ifndef PANIC_REBOOT_WAIT_TIME
76 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
77 #endif
78
79 /*
80 * Note that stdarg.h and the ANSI style va_start macro is used for both
81 * ANSI and traditional C compilers.
82 */
83 #include <machine/stdarg.h>
84
85 #ifdef KDB
86 #ifdef KDB_UNATTENDED
87 int debugger_on_panic = 0;
88 #else
89 int debugger_on_panic = 1;
90 #endif
91 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
92 &debugger_on_panic, 0, "Run debugger on kernel panic");
93
94 #ifdef KDB_TRACE
95 int trace_on_panic = 1;
96 #else
97 int trace_on_panic = 0;
98 #endif
99 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
100 &trace_on_panic, 0, "Print stack trace on kernel panic");
101 #endif /* KDB */
102
103 int sync_on_panic = 0;
104 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
105 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
106
107 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
108
109 #ifdef HW_WDOG
110 /*
111 * If there is a hardware watchdog, point this at the function needed to
112 * hold it off.
113 * It's needed when the kernel needs to do some lengthy operations.
114 * e.g. in wd.c when dumping core.. It's most annoying to have
115 * your precious core-dump only half written because the wdog kicked in.
116 */
117 watchdog_tickle_fn wdog_tickler = NULL;
118 #endif /* HW_WDOG */
119
120 /*
121 * Variable panicstr contains argument to first call to panic; used as flag
122 * to indicate that the kernel has already called panic.
123 */
124 const char *panicstr;
125
126 int dumping; /* system is dumping */
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 * MPSAFE
160 */
161 /* ARGSUSED */
162 int
163 reboot(struct thread *td, struct reboot_args *uap)
164 {
165 int error;
166
167 error = 0;
168 #ifdef MAC
169 error = mac_check_system_reboot(td->td_ucred, uap->opt);
170 #endif
171 if (error == 0)
172 error = suser(td);
173 if (error == 0) {
174 mtx_lock(&Giant);
175 boot(uap->opt);
176 mtx_unlock(&Giant);
177 }
178 return (error);
179 }
180
181 /*
182 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
183 */
184 static int shutdown_howto = 0;
185
186 void
187 shutdown_nice(int howto)
188 {
189
190 shutdown_howto = howto;
191
192 /* Send a signal to init(8) and have it shutdown the world */
193 if (initproc != NULL) {
194 PROC_LOCK(initproc);
195 psignal(initproc, SIGINT);
196 PROC_UNLOCK(initproc);
197 } else {
198 /* No init(8) running, so simply reboot */
199 boot(RB_NOSYNC);
200 }
201 return;
202 }
203 static int waittime = -1;
204
205 static void
206 print_uptime(void)
207 {
208 int f;
209 struct timespec ts;
210
211 getnanouptime(&ts);
212 printf("Uptime: ");
213 f = 0;
214 if (ts.tv_sec >= 86400) {
215 printf("%ldd", (long)ts.tv_sec / 86400);
216 ts.tv_sec %= 86400;
217 f = 1;
218 }
219 if (f || ts.tv_sec >= 3600) {
220 printf("%ldh", (long)ts.tv_sec / 3600);
221 ts.tv_sec %= 3600;
222 f = 1;
223 }
224 if (f || ts.tv_sec >= 60) {
225 printf("%ldm", (long)ts.tv_sec / 60);
226 ts.tv_sec %= 60;
227 f = 1;
228 }
229 printf("%lds\n", (long)ts.tv_sec);
230 }
231
232 static void
233 doadump(void)
234 {
235
236 /*
237 * Sometimes people have to call this from the kernel debugger.
238 * (if 'panic' can not dump)
239 * Give them a clue as to why they can't dump.
240 */
241 if (dumper.dumper == NULL) {
242 printf("Cannot dump. No dump device defined.\n");
243 return;
244 }
245
246 savectx(&dumppcb);
247 dumptid = curthread->td_tid;
248 dumping++;
249 dumpsys(&dumper);
250 }
251
252 /*
253 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
254 */
255 static void
256 boot(int howto)
257 {
258 static int first_buf_printf = 1;
259
260 #if defined(SMP)
261 /*
262 * Bind us to CPU 0 so that all shutdown code runs there. Some
263 * systems don't shutdown properly (i.e., ACPI power off) if we
264 * run on another processor.
265 */
266 mtx_lock_spin(&sched_lock);
267 sched_bind(curthread, 0);
268 mtx_unlock_spin(&sched_lock);
269 #endif
270
271 /* collect extra flags that shutdown_nice might have set */
272 howto |= shutdown_howto;
273
274 /* We are out of the debugger now. */
275 kdb_active = 0;
276
277 #ifdef SMP
278 if (smp_active)
279 printf("boot() called on cpu#%d\n", PCPU_GET(cpuid));
280 #endif
281 /*
282 * Do any callouts that should be done BEFORE syncing the filesystems.
283 */
284 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
285
286 /*
287 * Now sync filesystems
288 */
289 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
290 register struct buf *bp;
291 int iter, nbusy, pbusy;
292 #ifndef PREEMPTION
293 int subiter;
294 #endif
295
296 waittime = 0;
297
298 sync(&thread0, NULL);
299
300 /*
301 * With soft updates, some buffers that are
302 * written will be remarked as dirty until other
303 * buffers are written.
304 */
305 for (iter = pbusy = 0; iter < 20; iter++) {
306 nbusy = 0;
307 for (bp = &buf[nbuf]; --bp >= buf; ) {
308 if ((bp->b_flags & B_INVAL) == 0 &&
309 BUF_REFCNT(bp) > 0) {
310 nbusy++;
311 } else if ((bp->b_flags & (B_DELWRI | B_INVAL))
312 == B_DELWRI) {
313 /* bawrite(bp);*/
314 nbusy++;
315 }
316 }
317 if (nbusy == 0) {
318 if (first_buf_printf)
319 printf("No buffers busy after final sync");
320 break;
321 }
322 if (first_buf_printf) {
323 printf("Syncing disks, buffers remaining... ");
324 first_buf_printf = 0;
325 }
326 printf("%d ", nbusy);
327 if (nbusy < pbusy)
328 iter = 0;
329 pbusy = nbusy;
330 sync(&thread0, NULL);
331
332 #ifdef PREEMPTION
333 /*
334 * Drop Giant and spin for a while to allow
335 * interrupt threads to run.
336 */
337 DROP_GIANT();
338 DELAY(50000 * iter);
339 PICKUP_GIANT();
340 #else
341 /*
342 * Drop Giant and context switch several times to
343 * allow interrupt threads to run.
344 */
345 DROP_GIANT();
346 for (subiter = 0; subiter < 50 * iter; subiter++) {
347 mtx_lock_spin(&sched_lock);
348 mi_switch(SW_VOL, NULL);
349 mtx_unlock_spin(&sched_lock);
350 DELAY(1000);
351 }
352 PICKUP_GIANT();
353 #endif
354 }
355 printf("\n");
356 /*
357 * Count only busy local buffers to prevent forcing
358 * a fsck if we're just a client of a wedged NFS server
359 */
360 nbusy = 0;
361 for (bp = &buf[nbuf]; --bp >= buf; ) {
362 if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
363 ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
364 if (bp->b_dev == NULL) {
365 TAILQ_REMOVE(&mountlist,
366 bp->b_vp->v_mount, mnt_list);
367 continue;
368 }
369 nbusy++;
370 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
371 printf(
372 "%d: dev:%s, flags:%0x, blkno:%ld, lblkno:%ld\n",
373 nbusy, devtoname(bp->b_dev),
374 bp->b_flags, (long)bp->b_blkno,
375 (long)bp->b_lblkno);
376 #endif
377 }
378 }
379 if (nbusy) {
380 /*
381 * Failed to sync all blocks. Indicate this and don't
382 * unmount filesystems (thus forcing an fsck on reboot).
383 */
384 printf("Giving up on %d buffers\n", nbusy);
385 DELAY(5000000); /* 5 seconds */
386 } else {
387 if (!first_buf_printf)
388 printf("Final sync complete\n");
389 /*
390 * Unmount filesystems
391 */
392 if (panicstr == 0)
393 vfs_unmountall();
394 }
395 DELAY(100000); /* wait for console output to finish */
396 }
397
398 print_uptime();
399
400 /*
401 * Ok, now do things that assume all filesystem activity has
402 * been completed.
403 */
404 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
405
406 /* XXX This doesn't disable interrupts any more. Reconsider? */
407 splhigh();
408
409 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
410 doadump();
411
412 /* Now that we're going to really halt the system... */
413 EVENTHANDLER_INVOKE(shutdown_final, howto);
414
415 for(;;) ; /* safety against shutdown_reset not working */
416 /* NOTREACHED */
417 }
418
419 /*
420 * If the shutdown was a clean halt, behave accordingly.
421 */
422 static void
423 shutdown_halt(void *junk, int howto)
424 {
425
426 if (howto & RB_HALT) {
427 printf("\n");
428 printf("The operating system has halted.\n");
429 printf("Please press any key to reboot.\n\n");
430 switch (cngetc()) {
431 case -1: /* No console, just die */
432 cpu_halt();
433 /* NOTREACHED */
434 default:
435 howto &= ~RB_HALT;
436 break;
437 }
438 }
439 }
440
441 /*
442 * Check to see if the system paniced, pause and then reboot
443 * according to the specified delay.
444 */
445 static void
446 shutdown_panic(void *junk, int howto)
447 {
448 int loop;
449
450 if (howto & RB_DUMP) {
451 if (PANIC_REBOOT_WAIT_TIME != 0) {
452 if (PANIC_REBOOT_WAIT_TIME != -1) {
453 printf("Automatic reboot in %d seconds - "
454 "press a key on the console to abort\n",
455 PANIC_REBOOT_WAIT_TIME);
456 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
457 loop > 0; --loop) {
458 DELAY(1000 * 100); /* 1/10th second */
459 /* Did user type a key? */
460 if (cncheckc() != -1)
461 break;
462 }
463 if (!loop)
464 return;
465 }
466 } else { /* zero time specified - reboot NOW */
467 return;
468 }
469 printf("--> Press a key on the console to reboot,\n");
470 printf("--> or switch off the system now.\n");
471 cngetc();
472 }
473 }
474
475 /*
476 * Everything done, now reset
477 */
478 static void
479 shutdown_reset(void *junk, int howto)
480 {
481
482 printf("Rebooting...\n");
483 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
484 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
485 cpu_reset();
486 /* NOTREACHED */ /* assuming reset worked */
487 }
488
489 #ifdef SMP
490 static u_int panic_cpu = NOCPU;
491 #endif
492
493 /*
494 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
495 * and then reboots. If we are called twice, then we avoid trying to sync
496 * the disks as this often leads to recursive panics.
497 *
498 * MPSAFE
499 */
500 void
501 panic(const char *fmt, ...)
502 {
503 struct thread *td = curthread;
504 int bootopt, newpanic;
505 va_list ap;
506 static char buf[256];
507
508 #ifdef SMP
509 /*
510 * We don't want multiple CPU's to panic at the same time, so we
511 * use panic_cpu as a simple spinlock. We have to keep checking
512 * panic_cpu if we are spinning in case the panic on the first
513 * CPU is canceled.
514 */
515 if (panic_cpu != PCPU_GET(cpuid))
516 while (atomic_cmpset_int(&panic_cpu, NOCPU,
517 PCPU_GET(cpuid)) == 0)
518 while (panic_cpu != NOCPU)
519 ; /* nothing */
520 #endif
521
522 bootopt = RB_AUTOBOOT | RB_DUMP;
523 newpanic = 0;
524 if (panicstr)
525 bootopt |= RB_NOSYNC;
526 else {
527 panicstr = fmt;
528 newpanic = 1;
529 }
530
531 va_start(ap, fmt);
532 if (newpanic) {
533 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
534 panicstr = buf;
535 printf("panic: %s\n", buf);
536 } else {
537 printf("panic: ");
538 vprintf(fmt, ap);
539 printf("\n");
540 }
541 va_end(ap);
542 #ifdef SMP
543 printf("cpuid = %d\n", PCPU_GET(cpuid));
544 #endif
545
546 #ifdef KDB
547 if (newpanic && trace_on_panic)
548 kdb_backtrace();
549 if (debugger_on_panic)
550 kdb_enter("panic");
551 #ifdef RESTARTABLE_PANICS
552 /* See if the user aborted the panic, in which case we continue. */
553 if (panicstr == NULL) {
554 #ifdef SMP
555 atomic_store_rel_int(&panic_cpu, NOCPU);
556 #endif
557 return;
558 }
559 #endif
560 #endif
561 mtx_lock_spin(&sched_lock);
562 td->td_flags |= TDF_INPANIC;
563 mtx_unlock_spin(&sched_lock);
564 if (!sync_on_panic)
565 bootopt |= RB_NOSYNC;
566 boot(bootopt);
567 }
568
569 /*
570 * Support for poweroff delay.
571 */
572 #ifndef POWEROFF_DELAY
573 # define POWEROFF_DELAY 5000
574 #endif
575 static int poweroff_delay = POWEROFF_DELAY;
576
577 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
578 &poweroff_delay, 0, "");
579
580 static void
581 poweroff_wait(void *junk, int howto)
582 {
583
584 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
585 return;
586 DELAY(poweroff_delay * 1000);
587 }
588
589 /*
590 * Some system processes (e.g. syncer) need to be stopped at appropriate
591 * points in their main loops prior to a system shutdown, so that they
592 * won't interfere with the shutdown process (e.g. by holding a disk buf
593 * to cause sync to fail). For each of these system processes, register
594 * shutdown_kproc() as a handler for one of shutdown events.
595 */
596 static int kproc_shutdown_wait = 60;
597 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
598 &kproc_shutdown_wait, 0, "");
599
600 void
601 kproc_shutdown(void *arg, int howto)
602 {
603 struct proc *p;
604 char procname[MAXCOMLEN + 1];
605 int error;
606
607 if (panicstr)
608 return;
609
610 p = (struct proc *)arg;
611 strlcpy(procname, p->p_comm, sizeof(procname));
612 printf("Waiting (max %d seconds) for system process `%s' to stop...",
613 kproc_shutdown_wait, procname);
614 error = kthread_suspend(p, kproc_shutdown_wait * hz);
615
616 if (error == EWOULDBLOCK)
617 printf("timed out\n");
618 else
619 printf("done\n");
620 }
621
622 /* Registration of dumpers */
623 int
624 set_dumper(struct dumperinfo *di)
625 {
626
627 if (di == NULL) {
628 bzero(&dumper, sizeof dumper);
629 return (0);
630 }
631 if (dumper.dumper != NULL)
632 return (EBUSY);
633 dumper = *di;
634 return (0);
635 }
636
637 #if defined(__powerpc__)
638 void
639 dumpsys(struct dumperinfo *di __unused)
640 {
641
642 printf("Kernel dumps not implemented on this architecture\n");
643 }
644 #endif
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