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("$FreeBSD$");
39
40 #include "opt_ddb.h"
41 #include "opt_kdb.h"
42 #include "opt_panic.h"
43 #include "opt_sched.h"
44 #include "opt_watchdog.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/filedesc.h>
54 #include <sys/jail.h>
55 #include <sys/kdb.h>
56 #include <sys/kernel.h>
57 #include <sys/kerneldump.h>
58 #include <sys/kthread.h>
59 #include <sys/ktr.h>
60 #include <sys/malloc.h>
61 #include <sys/mount.h>
62 #include <sys/priv.h>
63 #include <sys/proc.h>
64 #include <sys/reboot.h>
65 #include <sys/resourcevar.h>
66 #include <sys/rwlock.h>
67 #include <sys/sched.h>
68 #include <sys/smp.h>
69 #include <sys/sysctl.h>
70 #include <sys/sysproto.h>
71 #include <sys/vnode.h>
72 #include <sys/watchdog.h>
73
74 #include <ddb/ddb.h>
75
76 #include <machine/cpu.h>
77 #include <machine/dump.h>
78 #include <machine/pcb.h>
79 #include <machine/smp.h>
80
81 #include <security/mac/mac_framework.h>
82
83 #include <vm/vm.h>
84 #include <vm/vm_object.h>
85 #include <vm/vm_page.h>
86 #include <vm/vm_pager.h>
87 #include <vm/swap_pager.h>
88
89 #include <sys/signalvar.h>
90
91 #ifndef PANIC_REBOOT_WAIT_TIME
92 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
93 #endif
94 static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME;
95 SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN,
96 &panic_reboot_wait_time, 0,
97 "Seconds to wait before rebooting after a panic");
98
99 /*
100 * Note that stdarg.h and the ANSI style va_start macro is used for both
101 * ANSI and traditional C compilers.
102 */
103 #include <machine/stdarg.h>
104
105 #ifdef KDB
106 #ifdef KDB_UNATTENDED
107 int debugger_on_panic = 0;
108 #else
109 int debugger_on_panic = 1;
110 #endif
111 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic,
112 CTLFLAG_RWTUN | CTLFLAG_SECURE,
113 &debugger_on_panic, 0, "Run debugger on kernel panic");
114
115 #ifdef KDB_TRACE
116 static int trace_on_panic = 1;
117 #else
118 static int trace_on_panic = 0;
119 #endif
120 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic,
121 CTLFLAG_RWTUN | CTLFLAG_SECURE,
122 &trace_on_panic, 0, "Print stack trace on kernel panic");
123 #endif /* KDB */
124
125 static int sync_on_panic = 0;
126 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN,
127 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
128
129 static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0,
130 "Shutdown environment");
131
132 #ifndef DIAGNOSTIC
133 static int show_busybufs;
134 #else
135 static int show_busybufs = 1;
136 #endif
137 SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
138 &show_busybufs, 0, "");
139
140 int suspend_blocked = 0;
141 SYSCTL_INT(_kern, OID_AUTO, suspend_blocked, CTLFLAG_RW,
142 &suspend_blocked, 0, "Block suspend due to a pending shutdown");
143
144 /*
145 * Variable panicstr contains argument to first call to panic; used as flag
146 * to indicate that the kernel has already called panic.
147 */
148 const char *panicstr;
149
150 int dumping; /* system is dumping */
151 int rebooting; /* system is rebooting */
152 static struct dumperinfo dumper; /* our selected dumper */
153
154 /* Context information for dump-debuggers. */
155 static struct pcb dumppcb; /* Registers. */
156 lwpid_t dumptid; /* Thread ID. */
157
158 static struct cdevsw reroot_cdevsw = {
159 .d_version = D_VERSION,
160 .d_name = "reroot",
161 };
162
163 static void poweroff_wait(void *, int);
164 static void shutdown_halt(void *junk, int howto);
165 static void shutdown_panic(void *junk, int howto);
166 static void shutdown_reset(void *junk, int howto);
167 static int kern_reroot(void);
168
169 /* register various local shutdown events */
170 static void
shutdown_conf(void * unused)171 shutdown_conf(void *unused)
172 {
173
174 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
175 SHUTDOWN_PRI_FIRST);
176 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
177 SHUTDOWN_PRI_LAST + 100);
178 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
179 SHUTDOWN_PRI_LAST + 100);
180 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
181 SHUTDOWN_PRI_LAST + 200);
182 }
183
184 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
185
186 /*
187 * The only reason this exists is to create the /dev/reroot/ directory,
188 * used by reroot code in init(8) as a mountpoint for tmpfs.
189 */
190 static void
reroot_conf(void * unused)191 reroot_conf(void *unused)
192 {
193 int error;
194 struct cdev *cdev;
195
196 error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &cdev,
197 &reroot_cdevsw, NULL, UID_ROOT, GID_WHEEL, 0600, "reroot/reroot");
198 if (error != 0) {
199 printf("%s: failed to create device node, error %d",
200 __func__, error);
201 }
202 }
203
204 SYSINIT(reroot_conf, SI_SUB_DEVFS, SI_ORDER_ANY, reroot_conf, NULL);
205
206 /*
207 * The system call that results in a reboot.
208 */
209 /* ARGSUSED */
210 int
sys_reboot(struct thread * td,struct reboot_args * uap)211 sys_reboot(struct thread *td, struct reboot_args *uap)
212 {
213 int error;
214
215 error = 0;
216 #ifdef MAC
217 error = mac_system_check_reboot(td->td_ucred, uap->opt);
218 #endif
219 if (error == 0)
220 error = priv_check(td, PRIV_REBOOT);
221 if (error == 0) {
222 if (uap->opt & RB_REROOT) {
223 error = kern_reroot();
224 } else {
225 mtx_lock(&Giant);
226 kern_reboot(uap->opt);
227 mtx_unlock(&Giant);
228 }
229 }
230 return (error);
231 }
232
233 /*
234 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
235 */
236 void
shutdown_nice(int howto)237 shutdown_nice(int howto)
238 {
239
240 if (initproc != NULL) {
241 /* Send a signal to init(8) and have it shutdown the world. */
242 PROC_LOCK(initproc);
243 if (howto & RB_POWEROFF)
244 kern_psignal(initproc, SIGUSR2);
245 else if (howto & RB_HALT)
246 kern_psignal(initproc, SIGUSR1);
247 else
248 kern_psignal(initproc, SIGINT);
249 PROC_UNLOCK(initproc);
250 } else {
251 /* No init(8) running, so simply reboot. */
252 kern_reboot(howto | RB_NOSYNC);
253 }
254 }
255
256 static void
print_uptime(void)257 print_uptime(void)
258 {
259 int f;
260 struct timespec ts;
261
262 getnanouptime(&ts);
263 printf("Uptime: ");
264 f = 0;
265 if (ts.tv_sec >= 86400) {
266 printf("%ldd", (long)ts.tv_sec / 86400);
267 ts.tv_sec %= 86400;
268 f = 1;
269 }
270 if (f || ts.tv_sec >= 3600) {
271 printf("%ldh", (long)ts.tv_sec / 3600);
272 ts.tv_sec %= 3600;
273 f = 1;
274 }
275 if (f || ts.tv_sec >= 60) {
276 printf("%ldm", (long)ts.tv_sec / 60);
277 ts.tv_sec %= 60;
278 f = 1;
279 }
280 printf("%lds\n", (long)ts.tv_sec);
281 }
282
283 int
doadump(boolean_t textdump)284 doadump(boolean_t textdump)
285 {
286 boolean_t coredump;
287 int error;
288
289 error = 0;
290 if (dumping)
291 return (EBUSY);
292 if (dumper.dumper == NULL)
293 return (ENXIO);
294
295 savectx(&dumppcb);
296 dumptid = curthread->td_tid;
297 dumping++;
298
299 coredump = TRUE;
300 #ifdef DDB
301 if (textdump && textdump_pending) {
302 coredump = FALSE;
303 textdump_dumpsys(&dumper);
304 }
305 #endif
306 if (coredump)
307 error = dumpsys(&dumper);
308
309 dumping--;
310 return (error);
311 }
312
313 /*
314 * Shutdown the system cleanly to prepare for reboot, halt, or power off.
315 */
316 void
kern_reboot(int howto)317 kern_reboot(int howto)
318 {
319 static int once = 0;
320
321 #if defined(SMP)
322 /*
323 * Bind us to CPU 0 so that all shutdown code runs there. Some
324 * systems don't shutdown properly (i.e., ACPI power off) if we
325 * run on another processor.
326 */
327 if (!SCHEDULER_STOPPED()) {
328 thread_lock(curthread);
329 sched_bind(curthread, 0);
330 thread_unlock(curthread);
331 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
332 }
333 #endif
334 /* We're in the process of rebooting. */
335 rebooting = 1;
336
337 /* We are out of the debugger now. */
338 kdb_active = 0;
339
340 /*
341 * Do any callouts that should be done BEFORE syncing the filesystems.
342 */
343 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
344
345 /*
346 * Now sync filesystems
347 */
348 if (!cold && (howto & RB_NOSYNC) == 0 && once == 0) {
349 once = 1;
350 bufshutdown(show_busybufs);
351 }
352
353 print_uptime();
354
355 cngrab();
356
357 /*
358 * Ok, now do things that assume all filesystem activity has
359 * been completed.
360 */
361 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
362
363 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
364 doadump(TRUE);
365
366 /* Now that we're going to really halt the system... */
367 EVENTHANDLER_INVOKE(shutdown_final, howto);
368
369 for(;;) ; /* safety against shutdown_reset not working */
370 /* NOTREACHED */
371 }
372
373 /*
374 * The system call that results in changing the rootfs.
375 */
376 static int
kern_reroot(void)377 kern_reroot(void)
378 {
379 struct vnode *oldrootvnode, *vp;
380 struct mount *mp, *devmp;
381 int error;
382
383 if (curproc != initproc)
384 return (EPERM);
385
386 /*
387 * Mark the filesystem containing currently-running executable
388 * (the temporary copy of init(8)) busy.
389 */
390 vp = curproc->p_textvp;
391 error = vn_lock(vp, LK_SHARED);
392 if (error != 0)
393 return (error);
394 mp = vp->v_mount;
395 error = vfs_busy(mp, MBF_NOWAIT);
396 if (error != 0) {
397 vfs_ref(mp);
398 VOP_UNLOCK(vp, 0);
399 error = vfs_busy(mp, 0);
400 vn_lock(vp, LK_SHARED | LK_RETRY);
401 vfs_rel(mp);
402 if (error != 0) {
403 VOP_UNLOCK(vp, 0);
404 return (ENOENT);
405 }
406 if (vp->v_iflag & VI_DOOMED) {
407 VOP_UNLOCK(vp, 0);
408 vfs_unbusy(mp);
409 return (ENOENT);
410 }
411 }
412 VOP_UNLOCK(vp, 0);
413
414 /*
415 * Remove the filesystem containing currently-running executable
416 * from the mount list, to prevent it from being unmounted
417 * by vfs_unmountall(), and to avoid confusing vfs_mountroot().
418 *
419 * Also preserve /dev - forcibly unmounting it could cause driver
420 * reinitialization.
421 */
422
423 vfs_ref(rootdevmp);
424 devmp = rootdevmp;
425 rootdevmp = NULL;
426
427 mtx_lock(&mountlist_mtx);
428 TAILQ_REMOVE(&mountlist, mp, mnt_list);
429 TAILQ_REMOVE(&mountlist, devmp, mnt_list);
430 mtx_unlock(&mountlist_mtx);
431
432 oldrootvnode = rootvnode;
433
434 /*
435 * Unmount everything except for the two filesystems preserved above.
436 */
437 vfs_unmountall();
438
439 /*
440 * Add /dev back; vfs_mountroot() will move it into its new place.
441 */
442 mtx_lock(&mountlist_mtx);
443 TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list);
444 mtx_unlock(&mountlist_mtx);
445 rootdevmp = devmp;
446 vfs_rel(rootdevmp);
447
448 /*
449 * Mount the new rootfs.
450 */
451 vfs_mountroot();
452
453 /*
454 * Update all references to the old rootvnode.
455 */
456 mountcheckdirs(oldrootvnode, rootvnode);
457
458 /*
459 * Add the temporary filesystem back and unbusy it.
460 */
461 mtx_lock(&mountlist_mtx);
462 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
463 mtx_unlock(&mountlist_mtx);
464 vfs_unbusy(mp);
465
466 return (0);
467 }
468
469 /*
470 * If the shutdown was a clean halt, behave accordingly.
471 */
472 static void
shutdown_halt(void * junk,int howto)473 shutdown_halt(void *junk, int howto)
474 {
475
476 if (howto & RB_HALT) {
477 printf("\n");
478 printf("The operating system has halted.\n");
479 printf("Please press any key to reboot.\n\n");
480 switch (cngetc()) {
481 case -1: /* No console, just die */
482 cpu_halt();
483 /* NOTREACHED */
484 default:
485 howto &= ~RB_HALT;
486 break;
487 }
488 }
489 }
490
491 /*
492 * Check to see if the system paniced, pause and then reboot
493 * according to the specified delay.
494 */
495 static void
shutdown_panic(void * junk,int howto)496 shutdown_panic(void *junk, int howto)
497 {
498 int loop;
499
500 if (howto & RB_DUMP) {
501 if (panic_reboot_wait_time != 0) {
502 if (panic_reboot_wait_time != -1) {
503 printf("Automatic reboot in %d seconds - "
504 "press a key on the console to abort\n",
505 panic_reboot_wait_time);
506 for (loop = panic_reboot_wait_time * 10;
507 loop > 0; --loop) {
508 DELAY(1000 * 100); /* 1/10th second */
509 /* Did user type a key? */
510 if (cncheckc() != -1)
511 break;
512 }
513 if (!loop)
514 return;
515 }
516 } else { /* zero time specified - reboot NOW */
517 return;
518 }
519 printf("--> Press a key on the console to reboot,\n");
520 printf("--> or switch off the system now.\n");
521 cngetc();
522 }
523 }
524
525 /*
526 * Everything done, now reset
527 */
528 static void
shutdown_reset(void * junk,int howto)529 shutdown_reset(void *junk, int howto)
530 {
531
532 printf("Rebooting...\n");
533 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
534
535 /*
536 * Acquiring smp_ipi_mtx here has a double effect:
537 * - it disables interrupts avoiding CPU0 preemption
538 * by fast handlers (thus deadlocking against other CPUs)
539 * - it avoids deadlocks against smp_rendezvous() or, more
540 * generally, threads busy-waiting, with this spinlock held,
541 * and waiting for responses by threads on other CPUs
542 * (ie. smp_tlb_shootdown()).
543 *
544 * For the !SMP case it just needs to handle the former problem.
545 */
546 #ifdef SMP
547 mtx_lock_spin(&smp_ipi_mtx);
548 #else
549 spinlock_enter();
550 #endif
551
552 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
553 cpu_reset();
554 /* NOTREACHED */ /* assuming reset worked */
555 }
556
557 #if defined(WITNESS) || defined(INVARIANTS)
558 static int kassert_warn_only = 0;
559 #ifdef KDB
560 static int kassert_do_kdb = 0;
561 #endif
562 #ifdef KTR
563 static int kassert_do_ktr = 0;
564 #endif
565 static int kassert_do_log = 1;
566 static int kassert_log_pps_limit = 4;
567 static int kassert_log_mute_at = 0;
568 static int kassert_log_panic_at = 0;
569 static int kassert_warnings = 0;
570
571 SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options");
572
573 SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RWTUN,
574 &kassert_warn_only, 0,
575 "KASSERT triggers a panic (1) or just a warning (0)");
576
577 #ifdef KDB
578 SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RWTUN,
579 &kassert_do_kdb, 0, "KASSERT will enter the debugger");
580 #endif
581
582 #ifdef KTR
583 SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RWTUN,
584 &kassert_do_ktr, 0,
585 "KASSERT does a KTR, set this to the KTRMASK you want");
586 #endif
587
588 SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RWTUN,
589 &kassert_do_log, 0, "KASSERT triggers a panic (1) or just a warning (0)");
590
591 SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RWTUN,
592 &kassert_warnings, 0, "number of KASSERTs that have been triggered");
593
594 SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RWTUN,
595 &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic");
596
597 SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RWTUN,
598 &kassert_log_pps_limit, 0, "limit number of log messages per second");
599
600 SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RWTUN,
601 &kassert_log_mute_at, 0, "max number of KASSERTS to log");
602
603 static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS);
604
605 SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert,
606 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, NULL, 0,
607 kassert_sysctl_kassert, "I", "set to trigger a test kassert");
608
609 static int
kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)610 kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)
611 {
612 int error, i;
613
614 error = sysctl_wire_old_buffer(req, sizeof(int));
615 if (error == 0) {
616 i = 0;
617 error = sysctl_handle_int(oidp, &i, 0, req);
618 }
619 if (error != 0 || req->newptr == NULL)
620 return (error);
621 KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i));
622 return (0);
623 }
624
625 /*
626 * Called by KASSERT, this decides if we will panic
627 * or if we will log via printf and/or ktr.
628 */
629 void
kassert_panic(const char * fmt,...)630 kassert_panic(const char *fmt, ...)
631 {
632 static char buf[256];
633 va_list ap;
634
635 va_start(ap, fmt);
636 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
637 va_end(ap);
638
639 /*
640 * panic if we're not just warning, or if we've exceeded
641 * kassert_log_panic_at warnings.
642 */
643 if (!kassert_warn_only ||
644 (kassert_log_panic_at > 0 &&
645 kassert_warnings >= kassert_log_panic_at)) {
646 va_start(ap, fmt);
647 vpanic(fmt, ap);
648 /* NORETURN */
649 }
650 #ifdef KTR
651 if (kassert_do_ktr)
652 CTR0(ktr_mask, buf);
653 #endif /* KTR */
654 /*
655 * log if we've not yet met the mute limit.
656 */
657 if (kassert_do_log &&
658 (kassert_log_mute_at == 0 ||
659 kassert_warnings < kassert_log_mute_at)) {
660 static struct timeval lasterr;
661 static int curerr;
662
663 if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) {
664 printf("KASSERT failed: %s\n", buf);
665 kdb_backtrace();
666 }
667 }
668 #ifdef KDB
669 if (kassert_do_kdb) {
670 kdb_enter(KDB_WHY_KASSERT, buf);
671 }
672 #endif
673 atomic_add_int(&kassert_warnings, 1);
674 }
675 #endif
676
677 /*
678 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
679 * and then reboots. If we are called twice, then we avoid trying to sync
680 * the disks as this often leads to recursive panics.
681 */
682 void
panic(const char * fmt,...)683 panic(const char *fmt, ...)
684 {
685 va_list ap;
686
687 va_start(ap, fmt);
688 vpanic(fmt, ap);
689 }
690
691 void
vpanic(const char * fmt,va_list ap)692 vpanic(const char *fmt, va_list ap)
693 {
694 #ifdef SMP
695 cpuset_t other_cpus;
696 #endif
697 struct thread *td = curthread;
698 int bootopt, newpanic;
699 static char buf[256];
700
701 spinlock_enter();
702
703 #ifdef SMP
704 /*
705 * stop_cpus_hard(other_cpus) should prevent multiple CPUs from
706 * concurrently entering panic. Only the winner will proceed
707 * further.
708 */
709 if (panicstr == NULL && !kdb_active) {
710 other_cpus = all_cpus;
711 CPU_CLR(PCPU_GET(cpuid), &other_cpus);
712 stop_cpus_hard(other_cpus);
713 }
714
715 /*
716 * Ensure that the scheduler is stopped while panicking, even if panic
717 * has been entered from kdb.
718 */
719 td->td_stopsched = 1;
720 #endif
721
722 bootopt = RB_AUTOBOOT;
723 newpanic = 0;
724 if (panicstr)
725 bootopt |= RB_NOSYNC;
726 else {
727 bootopt |= RB_DUMP;
728 panicstr = fmt;
729 newpanic = 1;
730 }
731
732 if (newpanic) {
733 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
734 panicstr = buf;
735 cngrab();
736 printf("panic: %s\n", buf);
737 } else {
738 printf("panic: ");
739 vprintf(fmt, ap);
740 printf("\n");
741 }
742 #ifdef SMP
743 printf("cpuid = %d\n", PCPU_GET(cpuid));
744 #endif
745
746 #ifdef KDB
747 if (newpanic && trace_on_panic)
748 kdb_backtrace();
749 if (debugger_on_panic)
750 kdb_enter(KDB_WHY_PANIC, "panic");
751 #endif
752 /*thread_lock(td); */
753 td->td_flags |= TDF_INPANIC;
754 /* thread_unlock(td); */
755 if (!sync_on_panic)
756 bootopt |= RB_NOSYNC;
757 kern_reboot(bootopt);
758 }
759
760 /*
761 * Support for poweroff delay.
762 *
763 * Please note that setting this delay too short might power off your machine
764 * before the write cache on your hard disk has been flushed, leading to
765 * soft-updates inconsistencies.
766 */
767 #ifndef POWEROFF_DELAY
768 # define POWEROFF_DELAY 5000
769 #endif
770 static int poweroff_delay = POWEROFF_DELAY;
771
772 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
773 &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)");
774
775 static void
poweroff_wait(void * junk,int howto)776 poweroff_wait(void *junk, int howto)
777 {
778
779 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
780 return;
781 DELAY(poweroff_delay * 1000);
782 }
783
784 /*
785 * Some system processes (e.g. syncer) need to be stopped at appropriate
786 * points in their main loops prior to a system shutdown, so that they
787 * won't interfere with the shutdown process (e.g. by holding a disk buf
788 * to cause sync to fail). For each of these system processes, register
789 * shutdown_kproc() as a handler for one of shutdown events.
790 */
791 static int kproc_shutdown_wait = 60;
792 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
793 &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process");
794
795 void
kproc_shutdown(void * arg,int howto)796 kproc_shutdown(void *arg, int howto)
797 {
798 struct proc *p;
799 int error;
800
801 if (panicstr)
802 return;
803
804 p = (struct proc *)arg;
805 printf("Waiting (max %d seconds) for system process `%s' to stop...",
806 kproc_shutdown_wait, p->p_comm);
807 error = kproc_suspend(p, kproc_shutdown_wait * hz);
808
809 if (error == EWOULDBLOCK)
810 printf("timed out\n");
811 else
812 printf("done\n");
813 }
814
815 void
kthread_shutdown(void * arg,int howto)816 kthread_shutdown(void *arg, int howto)
817 {
818 struct thread *td;
819 int error;
820
821 if (panicstr)
822 return;
823
824 td = (struct thread *)arg;
825 printf("Waiting (max %d seconds) for system thread `%s' to stop...",
826 kproc_shutdown_wait, td->td_name);
827 error = kthread_suspend(td, kproc_shutdown_wait * hz);
828
829 if (error == EWOULDBLOCK)
830 printf("timed out\n");
831 else
832 printf("done\n");
833 }
834
835 static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)];
836 SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD,
837 dumpdevname, 0, "Device for kernel dumps");
838
839 /* Registration of dumpers */
840 int
set_dumper(struct dumperinfo * di,const char * devname,struct thread * td)841 set_dumper(struct dumperinfo *di, const char *devname, struct thread *td)
842 {
843 size_t wantcopy;
844 int error;
845
846 error = priv_check(td, PRIV_SETDUMPER);
847 if (error != 0)
848 return (error);
849
850 if (di == NULL) {
851 bzero(&dumper, sizeof dumper);
852 dumpdevname[0] = '\0';
853 return (0);
854 }
855 if (dumper.dumper != NULL)
856 return (EBUSY);
857 dumper = *di;
858 wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname));
859 if (wantcopy >= sizeof(dumpdevname)) {
860 printf("set_dumper: device name truncated from '%s' -> '%s'\n",
861 devname, dumpdevname);
862 }
863 return (0);
864 }
865
866 /* Call dumper with bounds checking. */
867 int
dump_write(struct dumperinfo * di,void * virtual,vm_offset_t physical,off_t offset,size_t length)868 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
869 off_t offset, size_t length)
870 {
871
872 if (length != 0 && (offset < di->mediaoffset ||
873 offset - di->mediaoffset + length > di->mediasize)) {
874 printf("Attempt to write outside dump device boundaries.\n"
875 "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
876 (intmax_t)offset, (intmax_t)di->mediaoffset,
877 (uintmax_t)length, (intmax_t)di->mediasize);
878 return (ENOSPC);
879 }
880 return (di->dumper(di->priv, virtual, physical, offset, length));
881 }
882
883 void
mkdumpheader(struct kerneldumpheader * kdh,char * magic,uint32_t archver,uint64_t dumplen,uint32_t blksz)884 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
885 uint64_t dumplen, uint32_t blksz)
886 {
887
888 bzero(kdh, sizeof(*kdh));
889 strlcpy(kdh->magic, magic, sizeof(kdh->magic));
890 strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
891 kdh->version = htod32(KERNELDUMPVERSION);
892 kdh->architectureversion = htod32(archver);
893 kdh->dumplength = htod64(dumplen);
894 kdh->dumptime = htod64(time_second);
895 kdh->blocksize = htod32(blksz);
896 strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
897 strlcpy(kdh->versionstring, version, sizeof(kdh->versionstring));
898 if (panicstr != NULL)
899 strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
900 kdh->parity = kerneldump_parity(kdh);
901 }
902