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/6.0/sys/kern/kern_shutdown.c 151007 2005-10-06 17:53:46Z ups $");
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 <sys/signalvar.h>
72
73 #ifndef PANIC_REBOOT_WAIT_TIME
74 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
75 #endif
76
77 /*
78 * Note that stdarg.h and the ANSI style va_start macro is used for both
79 * ANSI and traditional C compilers.
80 */
81 #include <machine/stdarg.h>
82
83 #ifdef KDB
84 #ifdef KDB_UNATTENDED
85 int debugger_on_panic = 0;
86 #else
87 int debugger_on_panic = 1;
88 #endif
89 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
90 &debugger_on_panic, 0, "Run debugger on kernel panic");
91
92 #ifdef KDB_TRACE
93 int trace_on_panic = 1;
94 #else
95 int trace_on_panic = 0;
96 #endif
97 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
98 &trace_on_panic, 0, "Print stack trace on kernel panic");
99 #endif /* KDB */
100
101 int sync_on_panic = 0;
102 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
103 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
104
105 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
106
107 /*
108 * Variable panicstr contains argument to first call to panic; used as flag
109 * to indicate that the kernel has already called panic.
110 */
111 const char *panicstr;
112
113 int dumping; /* system is dumping */
114 static struct dumperinfo dumper; /* our selected dumper */
115
116 /* Context information for dump-debuggers. */
117 static struct pcb dumppcb; /* Registers. */
118 static lwpid_t dumptid; /* Thread ID. */
119
120 static void boot(int) __dead2;
121 static void poweroff_wait(void *, int);
122 static void shutdown_halt(void *junk, int howto);
123 static void shutdown_panic(void *junk, int howto);
124 static void shutdown_reset(void *junk, int howto);
125
126 /* register various local shutdown events */
127 static void
128 shutdown_conf(void *unused)
129 {
130
131 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
132 SHUTDOWN_PRI_FIRST);
133 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
134 SHUTDOWN_PRI_LAST + 100);
135 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
136 SHUTDOWN_PRI_LAST + 100);
137 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
138 SHUTDOWN_PRI_LAST + 200);
139 }
140
141 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
142
143 /*
144 * The system call that results in a reboot
145 *
146 * MPSAFE
147 */
148 /* ARGSUSED */
149 int
150 reboot(struct thread *td, struct reboot_args *uap)
151 {
152 int error;
153
154 error = 0;
155 #ifdef MAC
156 error = mac_check_system_reboot(td->td_ucred, uap->opt);
157 #endif
158 if (error == 0)
159 error = suser(td);
160 if (error == 0) {
161 mtx_lock(&Giant);
162 boot(uap->opt);
163 mtx_unlock(&Giant);
164 }
165 return (error);
166 }
167
168 /*
169 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
170 */
171 static int shutdown_howto = 0;
172
173 void
174 shutdown_nice(int howto)
175 {
176
177 shutdown_howto = howto;
178
179 /* Send a signal to init(8) and have it shutdown the world */
180 if (initproc != NULL) {
181 PROC_LOCK(initproc);
182 psignal(initproc, SIGINT);
183 PROC_UNLOCK(initproc);
184 } else {
185 /* No init(8) running, so simply reboot */
186 boot(RB_NOSYNC);
187 }
188 return;
189 }
190 static int waittime = -1;
191
192 static void
193 print_uptime(void)
194 {
195 int f;
196 struct timespec ts;
197
198 getnanouptime(&ts);
199 printf("Uptime: ");
200 f = 0;
201 if (ts.tv_sec >= 86400) {
202 printf("%ldd", (long)ts.tv_sec / 86400);
203 ts.tv_sec %= 86400;
204 f = 1;
205 }
206 if (f || ts.tv_sec >= 3600) {
207 printf("%ldh", (long)ts.tv_sec / 3600);
208 ts.tv_sec %= 3600;
209 f = 1;
210 }
211 if (f || ts.tv_sec >= 60) {
212 printf("%ldm", (long)ts.tv_sec / 60);
213 ts.tv_sec %= 60;
214 f = 1;
215 }
216 printf("%lds\n", (long)ts.tv_sec);
217 }
218
219 static void
220 doadump(void)
221 {
222
223 /*
224 * Sometimes people have to call this from the kernel debugger.
225 * (if 'panic' can not dump)
226 * Give them a clue as to why they can't dump.
227 */
228 if (dumper.dumper == NULL) {
229 printf("Cannot dump. No dump device defined.\n");
230 return;
231 }
232
233 savectx(&dumppcb);
234 dumptid = curthread->td_tid;
235 dumping++;
236 dumpsys(&dumper);
237 }
238
239 static int
240 isbufbusy(struct buf *bp)
241 {
242 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
243 BUF_REFCNT(bp) > 0) ||
244 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
245 return (1);
246 return (0);
247 }
248
249 /*
250 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
251 */
252 static void
253 boot(int howto)
254 {
255 static int first_buf_printf = 1;
256
257 #if defined(SMP)
258 /*
259 * Bind us to CPU 0 so that all shutdown code runs there. Some
260 * systems don't shutdown properly (i.e., ACPI power off) if we
261 * run on another processor.
262 */
263 mtx_lock_spin(&sched_lock);
264 sched_bind(curthread, 0);
265 mtx_unlock_spin(&sched_lock);
266 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
267 #endif
268
269 /* collect extra flags that shutdown_nice might have set */
270 howto |= shutdown_howto;
271
272 /* We are out of the debugger now. */
273 kdb_active = 0;
274
275 /*
276 * Do any callouts that should be done BEFORE syncing the filesystems.
277 */
278 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
279
280 /*
281 * Now sync filesystems
282 */
283 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
284 register struct buf *bp;
285 int iter, nbusy, pbusy;
286 #ifndef PREEMPTION
287 int subiter;
288 #endif
289
290 waittime = 0;
291
292 sync(curthread, NULL);
293
294 /*
295 * With soft updates, some buffers that are
296 * written will be remarked as dirty until other
297 * buffers are written.
298 */
299 for (iter = pbusy = 0; iter < 20; iter++) {
300 nbusy = 0;
301 for (bp = &buf[nbuf]; --bp >= buf; )
302 if (isbufbusy(bp))
303 nbusy++;
304 if (nbusy == 0) {
305 if (first_buf_printf)
306 printf("All buffers synced.");
307 break;
308 }
309 if (first_buf_printf) {
310 printf("Syncing disks, buffers remaining... ");
311 first_buf_printf = 0;
312 }
313 printf("%d ", nbusy);
314 if (nbusy < pbusy)
315 iter = 0;
316 pbusy = nbusy;
317 sync(curthread, NULL);
318
319 #ifdef PREEMPTION
320 /*
321 * Drop Giant and spin for a while to allow
322 * interrupt threads to run.
323 */
324 DROP_GIANT();
325 DELAY(50000 * iter);
326 PICKUP_GIANT();
327 #else
328 /*
329 * Drop Giant and context switch several times to
330 * allow interrupt threads to run.
331 */
332 DROP_GIANT();
333 for (subiter = 0; subiter < 50 * iter; subiter++) {
334 mtx_lock_spin(&sched_lock);
335 mi_switch(SW_VOL, NULL);
336 mtx_unlock_spin(&sched_lock);
337 DELAY(1000);
338 }
339 PICKUP_GIANT();
340 #endif
341 }
342 printf("\n");
343 /*
344 * Count only busy local buffers to prevent forcing
345 * a fsck if we're just a client of a wedged NFS server
346 */
347 nbusy = 0;
348 for (bp = &buf[nbuf]; --bp >= buf; ) {
349 if (isbufbusy(bp)) {
350 #if 0
351 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */
352 if (bp->b_dev == NULL) {
353 TAILQ_REMOVE(&mountlist,
354 bp->b_vp->v_mount, mnt_list);
355 continue;
356 }
357 #endif
358 nbusy++;
359 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
360 printf(
361 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n",
362 nbusy, bp->b_bufobj,
363 bp->b_flags, (long)bp->b_blkno,
364 (long)bp->b_lblkno);
365 #endif
366 }
367 }
368 if (nbusy) {
369 /*
370 * Failed to sync all blocks. Indicate this and don't
371 * unmount filesystems (thus forcing an fsck on reboot).
372 */
373 printf("Giving up on %d buffers\n", nbusy);
374 DELAY(5000000); /* 5 seconds */
375 } else {
376 if (!first_buf_printf)
377 printf("Final sync complete\n");
378 /*
379 * Unmount filesystems
380 */
381 if (panicstr == 0)
382 vfs_unmountall();
383 }
384 DELAY(100000); /* wait for console output to finish */
385 }
386
387 print_uptime();
388
389 /*
390 * Ok, now do things that assume all filesystem activity has
391 * been completed.
392 */
393 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
394
395 /* XXX This doesn't disable interrupts any more. Reconsider? */
396 splhigh();
397
398 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
399 doadump();
400
401 /* Now that we're going to really halt the system... */
402 EVENTHANDLER_INVOKE(shutdown_final, howto);
403
404 for(;;) ; /* safety against shutdown_reset not working */
405 /* NOTREACHED */
406 }
407
408 /*
409 * If the shutdown was a clean halt, behave accordingly.
410 */
411 static void
412 shutdown_halt(void *junk, int howto)
413 {
414
415 if (howto & RB_HALT) {
416 printf("\n");
417 printf("The operating system has halted.\n");
418 printf("Please press any key to reboot.\n\n");
419 switch (cngetc()) {
420 case -1: /* No console, just die */
421 cpu_halt();
422 /* NOTREACHED */
423 default:
424 howto &= ~RB_HALT;
425 break;
426 }
427 }
428 }
429
430 /*
431 * Check to see if the system paniced, pause and then reboot
432 * according to the specified delay.
433 */
434 static void
435 shutdown_panic(void *junk, int howto)
436 {
437 int loop;
438
439 if (howto & RB_DUMP) {
440 if (PANIC_REBOOT_WAIT_TIME != 0) {
441 if (PANIC_REBOOT_WAIT_TIME != -1) {
442 printf("Automatic reboot in %d seconds - "
443 "press a key on the console to abort\n",
444 PANIC_REBOOT_WAIT_TIME);
445 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
446 loop > 0; --loop) {
447 DELAY(1000 * 100); /* 1/10th second */
448 /* Did user type a key? */
449 if (cncheckc() != -1)
450 break;
451 }
452 if (!loop)
453 return;
454 }
455 } else { /* zero time specified - reboot NOW */
456 return;
457 }
458 printf("--> Press a key on the console to reboot,\n");
459 printf("--> or switch off the system now.\n");
460 cngetc();
461 }
462 }
463
464 /*
465 * Everything done, now reset
466 */
467 static void
468 shutdown_reset(void *junk, int howto)
469 {
470
471 printf("Rebooting...\n");
472 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
473 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
474 cpu_reset();
475 /* NOTREACHED */ /* assuming reset worked */
476 }
477
478 #ifdef SMP
479 static u_int panic_cpu = NOCPU;
480 #endif
481
482 /*
483 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
484 * and then reboots. If we are called twice, then we avoid trying to sync
485 * the disks as this often leads to recursive panics.
486 *
487 * MPSAFE
488 */
489 void
490 panic(const char *fmt, ...)
491 {
492 struct thread *td = curthread;
493 int bootopt, newpanic;
494 va_list ap;
495 static char buf[256];
496
497 #ifdef SMP
498 /*
499 * We don't want multiple CPU's to panic at the same time, so we
500 * use panic_cpu as a simple spinlock. We have to keep checking
501 * panic_cpu if we are spinning in case the panic on the first
502 * CPU is canceled.
503 */
504 if (panic_cpu != PCPU_GET(cpuid))
505 while (atomic_cmpset_int(&panic_cpu, NOCPU,
506 PCPU_GET(cpuid)) == 0)
507 while (panic_cpu != NOCPU)
508 ; /* nothing */
509 #endif
510
511 bootopt = RB_AUTOBOOT | RB_DUMP;
512 newpanic = 0;
513 if (panicstr)
514 bootopt |= RB_NOSYNC;
515 else {
516 panicstr = fmt;
517 newpanic = 1;
518 }
519
520 va_start(ap, fmt);
521 if (newpanic) {
522 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
523 panicstr = buf;
524 printf("panic: %s\n", buf);
525 } else {
526 printf("panic: ");
527 vprintf(fmt, ap);
528 printf("\n");
529 }
530 va_end(ap);
531 #ifdef SMP
532 printf("cpuid = %d\n", PCPU_GET(cpuid));
533 #endif
534
535 #ifdef KDB
536 if (newpanic && trace_on_panic)
537 kdb_backtrace();
538 if (debugger_on_panic)
539 kdb_enter("panic");
540 #ifdef RESTARTABLE_PANICS
541 /* See if the user aborted the panic, in which case we continue. */
542 if (panicstr == NULL) {
543 #ifdef SMP
544 atomic_store_rel_int(&panic_cpu, NOCPU);
545 #endif
546 return;
547 }
548 #endif
549 #endif
550 mtx_lock_spin(&sched_lock);
551 td->td_flags |= TDF_INPANIC;
552 mtx_unlock_spin(&sched_lock);
553 if (!sync_on_panic)
554 bootopt |= RB_NOSYNC;
555 boot(bootopt);
556 }
557
558 /*
559 * Support for poweroff delay.
560 */
561 #ifndef POWEROFF_DELAY
562 # define POWEROFF_DELAY 5000
563 #endif
564 static int poweroff_delay = POWEROFF_DELAY;
565
566 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
567 &poweroff_delay, 0, "");
568
569 static void
570 poweroff_wait(void *junk, int howto)
571 {
572
573 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
574 return;
575 DELAY(poweroff_delay * 1000);
576 }
577
578 /*
579 * Some system processes (e.g. syncer) need to be stopped at appropriate
580 * points in their main loops prior to a system shutdown, so that they
581 * won't interfere with the shutdown process (e.g. by holding a disk buf
582 * to cause sync to fail). For each of these system processes, register
583 * shutdown_kproc() as a handler for one of shutdown events.
584 */
585 static int kproc_shutdown_wait = 60;
586 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
587 &kproc_shutdown_wait, 0, "");
588
589 void
590 kproc_shutdown(void *arg, int howto)
591 {
592 struct proc *p;
593 char procname[MAXCOMLEN + 1];
594 int error;
595
596 if (panicstr)
597 return;
598
599 p = (struct proc *)arg;
600 strlcpy(procname, p->p_comm, sizeof(procname));
601 printf("Waiting (max %d seconds) for system process `%s' to stop...",
602 kproc_shutdown_wait, procname);
603 error = kthread_suspend(p, kproc_shutdown_wait * hz);
604
605 if (error == EWOULDBLOCK)
606 printf("timed out\n");
607 else
608 printf("done\n");
609 }
610
611 /* Registration of dumpers */
612 int
613 set_dumper(struct dumperinfo *di)
614 {
615
616 if (di == NULL) {
617 bzero(&dumper, sizeof dumper);
618 return (0);
619 }
620 if (dumper.dumper != NULL)
621 return (EBUSY);
622 dumper = *di;
623 return (0);
624 }
625
626 #if defined(__powerpc__)
627 void
628 dumpsys(struct dumperinfo *di __unused)
629 {
630
631 printf("Kernel dumps not implemented on this architecture\n");
632 }
633 #endif
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