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 * 3. 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 * $FreeBSD: src/sys/kern/kern_shutdown.c,v 1.72.2.12 2002/02/21 19:15:10 dillon Exp $
36 */
37
38 #include "opt_ddb.h"
39 #include "opt_ddb_trace.h"
40 #include "opt_panic.h"
41 #include "opt_show_busybufs.h"
42 #include "use_gpio.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/eventhandler.h>
47 #include <sys/buf.h>
48 #include <sys/disk.h>
49 #include <sys/diskslice.h>
50 #include <sys/reboot.h>
51 #include <sys/proc.h>
52 #include <sys/priv.h>
53 #include <sys/fcntl.h> /* FREAD */
54 #include <sys/stat.h> /* S_IFCHR */
55 #include <sys/vnode.h>
56 #include <sys/kernel.h>
57 #include <sys/kerneldump.h>
58 #include <sys/kthread.h>
59 #include <sys/malloc.h>
60 #include <sys/mount.h>
61 #include <sys/queue.h>
62 #include <sys/sysctl.h>
63 #include <sys/vkernel.h>
64 #include <sys/conf.h>
65 #include <sys/sysproto.h>
66 #include <sys/device.h>
67 #include <sys/cons.h>
68 #include <sys/shm.h>
69 #include <sys/kern_syscall.h>
70 #include <vm/vm_map.h>
71 #include <vm/pmap.h>
72
73 #include <sys/thread2.h>
74 #include <sys/buf2.h>
75 #include <sys/mplock2.h>
76
77 #include <machine/cpu.h>
78 #include <machine/clock.h>
79 #include <machine/md_var.h>
80 #include <machine/smp.h> /* smp_active_mask, cpuid */
81 #include <machine/vmparam.h>
82 #include <machine/thread.h>
83
84 #include <sys/signalvar.h>
85
86 #include <sys/wdog.h>
87 #include <dev/misc/gpio/gpio.h>
88
89 #ifndef PANIC_REBOOT_WAIT_TIME
90 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
91 #endif
92
93 /*
94 * Note that stdarg.h and the ANSI style va_start macro is used for both
95 * ANSI and traditional C compilers. We use the machine version to stay
96 * within the confines of the kernel header files.
97 */
98 #include <machine/stdarg.h>
99
100 #ifdef DDB
101 #include <ddb/ddb.h>
102 #ifdef DDB_UNATTENDED
103 int debugger_on_panic = 0;
104 #else
105 int debugger_on_panic = 1;
106 #endif
107 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
108 &debugger_on_panic, 0, "Run debugger on kernel panic");
109
110 #ifdef DDB_TRACE
111 int trace_on_panic = 1;
112 #else
113 int trace_on_panic = 0;
114 #endif
115 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
116 &trace_on_panic, 0, "Print stack trace on kernel panic");
117 #endif
118
119 static int sync_on_panic = 0;
120 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
121 &sync_on_panic, 0, "Do a sync before rebooting from a panic");
122
123 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
124
125 /*
126 * Variable panicstr contains argument to first call to panic; used as flag
127 * to indicate that the kernel has already called panic.
128 */
129 const char *panicstr;
130
131 int dumping; /* system is dumping */
132 static struct dumperinfo dumper; /* selected dumper */
133
134 globaldata_t panic_cpu_gd; /* which cpu took the panic */
135 struct lwkt_tokref panic_tokens[LWKT_MAXTOKENS];
136 int panic_tokens_count;
137
138 int bootverbose = 0; /* note: assignment to force non-bss */
139 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW,
140 &bootverbose, 0, "Verbose kernel messages");
141
142 int cold = 1; /* note: assignment to force non-bss */
143 int dumplo; /* OBSOLETE - savecore compat */
144 u_int64_t dumplo64;
145
146 static void boot (int) __dead2;
147 static int setdumpdev (cdev_t dev);
148 static void poweroff_wait (void *, int);
149 static void print_uptime (void);
150 static void shutdown_halt (void *junk, int howto);
151 static void shutdown_panic (void *junk, int howto);
152 static void shutdown_reset (void *junk, int howto);
153 static int shutdown_busycount1(struct buf *bp, void *info);
154 static int shutdown_busycount2(struct buf *bp, void *info);
155 static void shutdown_cleanup_proc(struct proc *p);
156
157 /* register various local shutdown events */
158 static void
159 shutdown_conf(void *unused)
160 {
161 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, SHUTDOWN_PRI_FIRST);
162 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, SHUTDOWN_PRI_LAST + 100);
163 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, SHUTDOWN_PRI_LAST + 100);
164 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, SHUTDOWN_PRI_LAST + 200);
165 }
166
167 SYSINIT(shutdown_conf, SI_BOOT2_MACHDEP, SI_ORDER_ANY, shutdown_conf, NULL)
168
169 /* ARGSUSED */
170
171 /*
172 * The system call that results in a reboot
173 *
174 * MPALMOSTSAFE
175 */
176 int
177 sys_reboot(struct reboot_args *uap)
178 {
179 struct thread *td = curthread;
180 int error;
181
182 if ((error = priv_check(td, PRIV_REBOOT)))
183 return (error);
184
185 get_mplock();
186 boot(uap->opt);
187 rel_mplock();
188 return (0);
189 }
190
191 /*
192 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
193 */
194 static int shutdown_howto = 0;
195
196 void
197 shutdown_nice(int howto)
198 {
199 shutdown_howto = howto;
200
201 /* Send a signal to init(8) and have it shutdown the world */
202 if (initproc != NULL) {
203 ksignal(initproc, SIGINT);
204 } else {
205 /* No init(8) running, so simply reboot */
206 boot(RB_NOSYNC);
207 }
208 return;
209 }
210 static int waittime = -1;
211 struct pcb dumppcb;
212 struct thread *dumpthread;
213
214 static void
215 print_uptime(void)
216 {
217 int f;
218 struct timespec ts;
219
220 getnanouptime(&ts);
221 kprintf("Uptime: ");
222 f = 0;
223 if (ts.tv_sec >= 86400) {
224 kprintf("%ldd", ts.tv_sec / 86400);
225 ts.tv_sec %= 86400;
226 f = 1;
227 }
228 if (f || ts.tv_sec >= 3600) {
229 kprintf("%ldh", ts.tv_sec / 3600);
230 ts.tv_sec %= 3600;
231 f = 1;
232 }
233 if (f || ts.tv_sec >= 60) {
234 kprintf("%ldm", ts.tv_sec / 60);
235 ts.tv_sec %= 60;
236 f = 1;
237 }
238 kprintf("%lds\n", ts.tv_sec);
239 }
240
241 /*
242 * Go through the rigmarole of shutting down..
243 * this used to be in machdep.c but I'll be dammned if I could see
244 * anything machine dependant in it.
245 */
246 static void
247 boot(int howto)
248 {
249 /*
250 * Get rid of any user scheduler baggage and then give
251 * us a high priority.
252 */
253 if (curthread->td_release)
254 curthread->td_release(curthread);
255 lwkt_setpri_self(TDPRI_MAX);
256
257 /* collect extra flags that shutdown_nice might have set */
258 howto |= shutdown_howto;
259
260 /*
261 * We really want to shutdown on the BSP. Subsystems such as ACPI
262 * can't power-down the box otherwise.
263 */
264 if (smp_active_mask > 1) {
265 kprintf("boot() called on cpu#%d\n", mycpu->gd_cpuid);
266 }
267 if (panicstr == NULL && mycpu->gd_cpuid != 0) {
268 kprintf("Switching to cpu #0 for shutdown\n");
269 lwkt_setcpu_self(globaldata_find(0));
270 }
271 /*
272 * Do any callouts that should be done BEFORE syncing the filesystems.
273 */
274 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
275
276 /*
277 * Try to get rid of any remaining FS references. The calling
278 * process, proc0, and init may still hold references. The
279 * VFS cache subsystem may still hold a root reference to root.
280 *
281 * XXX this needs work. We really need to SIGSTOP all remaining
282 * processes in order to avoid blowups due to proc0's filesystem
283 * references going away. For now just make sure that the init
284 * process is stopped.
285 */
286 if (panicstr == NULL) {
287 shutdown_cleanup_proc(curproc);
288 shutdown_cleanup_proc(&proc0);
289 if (initproc) {
290 if (initproc != curproc) {
291 ksignal(initproc, SIGSTOP);
292 tsleep(boot, 0, "shutdn", hz / 20);
293 }
294 shutdown_cleanup_proc(initproc);
295 }
296 vfs_cache_setroot(NULL, NULL);
297 }
298
299 /*
300 * Now sync filesystems
301 */
302 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
303 int iter, nbusy, pbusy;
304
305 waittime = 0;
306 kprintf("\nsyncing disks... ");
307
308 sys_sync(NULL); /* YYY was sync(&proc0, NULL). why proc0 ? */
309
310 /*
311 * With soft updates, some buffers that are
312 * written will be remarked as dirty until other
313 * buffers are written.
314 */
315 for (iter = pbusy = 0; iter < 20; iter++) {
316 nbusy = scan_all_buffers(shutdown_busycount1, NULL);
317 if (nbusy == 0)
318 break;
319 kprintf("%d ", nbusy);
320 if (nbusy < pbusy)
321 iter = 0;
322 pbusy = nbusy;
323 /*
324 * XXX:
325 * Process soft update work queue if buffers don't sync
326 * after 6 iterations by permitting the syncer to run.
327 */
328 if (iter > 5)
329 bio_ops_sync(NULL);
330
331 sys_sync(NULL); /* YYY was sync(&proc0, NULL). why proc0 ? */
332 tsleep(boot, 0, "shutdn", hz * iter / 20 + 1);
333 }
334 kprintf("\n");
335 /*
336 * Count only busy local buffers to prevent forcing
337 * a fsck if we're just a client of a wedged NFS server
338 */
339 nbusy = scan_all_buffers(shutdown_busycount2, NULL);
340 if (nbusy) {
341 /*
342 * Failed to sync all blocks. Indicate this and don't
343 * unmount filesystems (thus forcing an fsck on reboot).
344 */
345 kprintf("giving up on %d buffers\n", nbusy);
346 #ifdef DDB
347 if (debugger_on_panic)
348 Debugger("busy buffer problem");
349 #endif /* DDB */
350 tsleep(boot, 0, "shutdn", hz * 5 + 1);
351 } else {
352 kprintf("done\n");
353 /*
354 * Unmount filesystems
355 */
356 if (panicstr == NULL)
357 vfs_unmountall();
358 }
359 tsleep(boot, 0, "shutdn", hz / 10 + 1);
360 }
361
362 print_uptime();
363
364 /*
365 * Dump before doing post_sync shutdown ops
366 */
367 crit_enter();
368 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold) {
369 dumpsys();
370 }
371
372 /*
373 * Ok, now do things that assume all filesystem activity has
374 * been completed. This will also call the device shutdown
375 * methods.
376 */
377 EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
378
379 /* Now that we're going to really halt the system... */
380 EVENTHANDLER_INVOKE(shutdown_final, howto);
381
382 for(;;) ; /* safety against shutdown_reset not working */
383 /* NOTREACHED */
384 }
385
386 /*
387 * Pass 1 - Figure out if there are any busy or dirty buffers still present.
388 *
389 * We ignore TMPFS mounts in this pass.
390 */
391 static int
392 shutdown_busycount1(struct buf *bp, void *info)
393 {
394 struct vnode *vp;
395
396 if ((vp = bp->b_vp) != NULL && vp->v_tag == VT_TMPFS)
397 return (0);
398 if ((bp->b_flags & B_INVAL) == 0 && BUF_REFCNT(bp) > 0)
399 return(1);
400 if ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI)
401 return (1);
402 return (0);
403 }
404
405 /*
406 * Pass 2 - only run after pass 1 has completed or has given up
407 *
408 * We ignore TMPFS, NFS, MFS, and SMBFS mounts in this pass.
409 */
410 static int
411 shutdown_busycount2(struct buf *bp, void *info)
412 {
413 struct vnode *vp;
414
415 /*
416 * Ignore tmpfs and nfs mounts
417 */
418 if ((vp = bp->b_vp) != NULL) {
419 if (vp->v_tag == VT_TMPFS)
420 return (0);
421 if (vp->v_tag == VT_NFS)
422 return (0);
423 if (vp->v_tag == VT_MFS)
424 return (0);
425 if (vp->v_tag == VT_SMBFS)
426 return (0);
427 }
428
429 /*
430 * Only count buffers stuck on I/O, ignore everything else
431 */
432 if (((bp->b_flags & B_INVAL) == 0 && BUF_REFCNT(bp)) ||
433 ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
434 /*
435 * Only count buffers undergoing write I/O
436 * on the related vnode.
437 */
438 if (bp->b_vp == NULL ||
439 bio_track_active(&bp->b_vp->v_track_write) == 0) {
440 return (0);
441 }
442 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
443 kprintf(
444 "%p dev:?, flags:%08x, loffset:%jd, doffset:%jd\n",
445 bp,
446 bp->b_flags, (intmax_t)bp->b_loffset,
447 (intmax_t)bp->b_bio2.bio_offset);
448 #endif
449 return(1);
450 }
451 return(0);
452 }
453
454 /*
455 * If the shutdown was a clean halt, behave accordingly.
456 */
457 static void
458 shutdown_halt(void *junk, int howto)
459 {
460 if (howto & RB_HALT) {
461 kprintf("\n");
462 kprintf("The operating system has halted.\n");
463 #ifdef _KERNEL_VIRTUAL
464 cpu_halt();
465 #else
466 kprintf("Please press any key to reboot.\n\n");
467 switch (cngetc()) {
468 case -1: /* No console, just die */
469 cpu_halt();
470 /* NOTREACHED */
471 default:
472 howto &= ~RB_HALT;
473 break;
474 }
475 #endif
476 }
477 }
478
479 /*
480 * Check to see if the system paniced, pause and then reboot
481 * according to the specified delay.
482 */
483 static void
484 shutdown_panic(void *junk, int howto)
485 {
486 int loop;
487
488 if (howto & RB_DUMP) {
489 if (PANIC_REBOOT_WAIT_TIME != 0) {
490 if (PANIC_REBOOT_WAIT_TIME != -1) {
491 kprintf("Automatic reboot in %d seconds - "
492 "press a key on the console to abort\n",
493 PANIC_REBOOT_WAIT_TIME);
494 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
495 loop > 0; --loop) {
496 DELAY(1000 * 100); /* 1/10th second */
497 /* Did user type a key? */
498 if (cncheckc() != -1)
499 break;
500 }
501 if (!loop)
502 return;
503 }
504 } else { /* zero time specified - reboot NOW */
505 return;
506 }
507 kprintf("--> Press a key on the console to reboot,\n");
508 kprintf("--> or switch off the system now.\n");
509 cngetc();
510 }
511 }
512
513 /*
514 * Everything done, now reset
515 */
516 static void
517 shutdown_reset(void *junk, int howto)
518 {
519 kprintf("Rebooting...\n");
520 DELAY(1000000); /* wait 1 sec for kprintf's to complete and be read */
521 /* cpu_boot(howto); */ /* doesn't do anything at the moment */
522 cpu_reset();
523 /* NOTREACHED */ /* assuming reset worked */
524 }
525
526 /*
527 * Try to remove FS references in the specified process. This function
528 * is used during shutdown
529 */
530 static
531 void
532 shutdown_cleanup_proc(struct proc *p)
533 {
534 struct filedesc *fdp;
535 struct vmspace *vm;
536
537 if (p == NULL)
538 return;
539 if ((fdp = p->p_fd) != NULL) {
540 kern_closefrom(0);
541 if (fdp->fd_cdir) {
542 cache_drop(&fdp->fd_ncdir);
543 vrele(fdp->fd_cdir);
544 fdp->fd_cdir = NULL;
545 }
546 if (fdp->fd_rdir) {
547 cache_drop(&fdp->fd_nrdir);
548 vrele(fdp->fd_rdir);
549 fdp->fd_rdir = NULL;
550 }
551 if (fdp->fd_jdir) {
552 cache_drop(&fdp->fd_njdir);
553 vrele(fdp->fd_jdir);
554 fdp->fd_jdir = NULL;
555 }
556 }
557 if (p->p_vkernel)
558 vkernel_exit(p);
559 if (p->p_textvp) {
560 vrele(p->p_textvp);
561 p->p_textvp = NULL;
562 }
563 vm = p->p_vmspace;
564 if (vm != NULL) {
565 pmap_remove_pages(vmspace_pmap(vm),
566 VM_MIN_USER_ADDRESS,
567 VM_MAX_USER_ADDRESS);
568 vm_map_remove(&vm->vm_map,
569 VM_MIN_USER_ADDRESS,
570 VM_MAX_USER_ADDRESS);
571 }
572 }
573
574 /*
575 * Magic number for savecore
576 *
577 * exported (symorder) and used at least by savecore(8)
578 *
579 * Mark it as used so that gcc doesn't optimize it away.
580 */
581 __attribute__((__used__))
582 static u_long const dumpmag = 0x8fca0101UL;
583
584 __attribute__((__used__))
585 static int dumpsize = 0; /* also for savecore */
586
587 static int dodump = 1;
588
589 SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW, &dodump, 0,
590 "Try to perform coredump on kernel panic");
591
592 void
593 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
594 uint64_t dumplen, uint32_t blksz)
595 {
596 bzero(kdh, sizeof(*kdh));
597 strncpy(kdh->magic, magic, sizeof(kdh->magic));
598 strncpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
599 kdh->version = htod32(KERNELDUMPVERSION);
600 kdh->architectureversion = htod32(archver);
601 kdh->dumplength = htod64(dumplen);
602 kdh->dumptime = htod64(time_second);
603 kdh->blocksize = htod32(blksz);
604 strncpy(kdh->hostname, hostname, sizeof(kdh->hostname));
605 strncpy(kdh->versionstring, version, sizeof(kdh->versionstring));
606 if (panicstr != NULL)
607 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
608 kdh->parity = kerneldump_parity(kdh);
609 }
610
611 static int
612 setdumpdev(cdev_t dev)
613 {
614 int error;
615 int doopen;
616
617 if (dev == NULL) {
618 disk_dumpconf(NULL, 0/*off*/);
619 return (0);
620 }
621
622 /*
623 * We have to open the device before we can perform ioctls on it,
624 * or the slice/label data may not be present. Device opens are
625 * usually tracked by specfs, but the dump device can be set in
626 * early boot and may not be open so this is somewhat of a hack.
627 */
628 doopen = (dev->si_sysref.refcnt == 1);
629 if (doopen) {
630 error = dev_dopen(dev, FREAD, S_IFCHR, proc0.p_ucred);
631 if (error)
632 return (error);
633 }
634 error = disk_dumpconf(dev, 1/*on*/);
635
636 return error;
637 }
638
639 /* ARGSUSED */
640 static void dump_conf (void *dummy);
641 static void
642 dump_conf(void *dummy)
643 {
644 char *path;
645 cdev_t dev;
646 int _dummy;
647
648 path = kmalloc(MNAMELEN, M_TEMP, M_WAITOK);
649 if (TUNABLE_STR_FETCH("dumpdev", path, MNAMELEN) != 0) {
650 /*
651 * Make sure all disk devices created so far have also been
652 * probed, and also make sure that the newly created device
653 * nodes for probed disks are ready, too.
654 *
655 * XXX - Delay an additional 2 seconds to help drivers which
656 * pickup devices asynchronously and are not caught by
657 * CAM's initial probe.
658 */
659 sync_devs();
660 tsleep(&_dummy, 0, "syncer", hz*2);
661
662 dev = kgetdiskbyname(path);
663 if (dev != NULL)
664 dumpdev = dev;
665 }
666 kfree(path, M_TEMP);
667 if (setdumpdev(dumpdev) != 0)
668 dumpdev = NULL;
669 }
670
671 SYSINIT(dump_conf, SI_SUB_DUMP_CONF, SI_ORDER_FIRST, dump_conf, NULL)
672
673 static int
674 sysctl_kern_dumpdev(SYSCTL_HANDLER_ARGS)
675 {
676 int error;
677 udev_t ndumpdev;
678
679 ndumpdev = dev2udev(dumpdev);
680 error = sysctl_handle_opaque(oidp, &ndumpdev, sizeof ndumpdev, req);
681 if (error == 0 && req->newptr != NULL)
682 error = setdumpdev(udev2dev(ndumpdev, 0));
683 return (error);
684 }
685
686 SYSCTL_PROC(_kern, KERN_DUMPDEV, dumpdev, CTLTYPE_OPAQUE|CTLFLAG_RW,
687 0, sizeof dumpdev, sysctl_kern_dumpdev, "T,udev_t", "");
688
689 /*
690 * Panic is called on unresolvable fatal errors. It prints "panic: mesg",
691 * and then reboots. If we are called twice, then we avoid trying to sync
692 * the disks as this often leads to recursive panics.
693 */
694 void
695 panic(const char *fmt, ...)
696 {
697 int bootopt, newpanic;
698 globaldata_t gd = mycpu;
699 thread_t td = gd->gd_curthread;
700 __va_list ap;
701 static char buf[256];
702
703 /*
704 * If a panic occurs on multiple cpus before the first is able to
705 * halt the other cpus, only one cpu is allowed to take the panic.
706 * Attempt to be verbose about this situation but if the kprintf()
707 * itself panics don't let us overrun the kernel stack.
708 *
709 * Be very nasty about descheduling our thread at the lowest
710 * level possible in an attempt to freeze the thread without
711 * inducing further panics.
712 *
713 * Bumping gd_trap_nesting_level will also bypass assertions in
714 * lwkt_switch() and allow us to switch away even if we are a
715 * FAST interrupt or IPI.
716 *
717 * The setting of panic_cpu_gd also determines how kprintf()
718 * spin-locks itself. DDB can set panic_cpu_gd as well.
719 */
720 for (;;) {
721 globaldata_t xgd = panic_cpu_gd;
722
723 /*
724 * Someone else got the panic cpu
725 */
726 if (xgd && xgd != gd) {
727 crit_enter();
728 ++mycpu->gd_trap_nesting_level;
729 if (mycpu->gd_trap_nesting_level < 25) {
730 kprintf("SECONDARY PANIC ON CPU %d THREAD %p\n",
731 mycpu->gd_cpuid, td);
732 }
733 td->td_release = NULL; /* be a grinch */
734 for (;;) {
735 lwkt_deschedule_self(td);
736 lwkt_switch();
737 }
738 /* NOT REACHED */
739 /* --mycpu->gd_trap_nesting_level */
740 /* crit_exit() */
741 }
742
743 /*
744 * Reentrant panic
745 */
746 if (xgd && xgd == gd)
747 break;
748
749 /*
750 * We got it
751 */
752 if (atomic_cmpset_ptr(&panic_cpu_gd, NULL, gd))
753 break;
754 }
755 /*
756 * Try to get the system into a working state. Save information
757 * we are about to destroy.
758 */
759 kvcreinitspin();
760 if (panicstr == NULL) {
761 bcopy(td->td_toks_array, panic_tokens, sizeof(panic_tokens));
762 panic_tokens_count = td->td_toks_stop - &td->td_toks_base;
763 }
764 lwkt_relalltokens(td);
765 td->td_toks_stop = &td->td_toks_base;
766 if (gd->gd_spinlocks)
767 kprintf("panic with %d spinlocks held\n", gd->gd_spinlocks);
768 gd->gd_spinlocks = 0;
769
770 /*
771 * Setup
772 */
773 bootopt = RB_AUTOBOOT | RB_DUMP;
774 if (sync_on_panic == 0)
775 bootopt |= RB_NOSYNC;
776 newpanic = 0;
777 if (panicstr) {
778 bootopt |= RB_NOSYNC;
779 } else {
780 panicstr = fmt;
781 newpanic = 1;
782 }
783
784 /*
785 * Format the panic string.
786 */
787 __va_start(ap, fmt);
788 kvsnprintf(buf, sizeof(buf), fmt, ap);
789 if (panicstr == fmt)
790 panicstr = buf;
791 __va_end(ap);
792 kprintf("panic: %s\n", buf);
793 /* two separate prints in case of an unmapped page and trap */
794 kprintf("cpuid = %d\n", mycpu->gd_cpuid);
795
796 #if (NGPIO > 0) && defined(ERROR_LED_ON_PANIC)
797 led_switch("error", 1);
798 #endif
799
800 #if defined(WDOG_DISABLE_ON_PANIC)
801 wdog_disable();
802 #endif
803
804 /*
805 * Enter the debugger or fall through & dump. Entering the
806 * debugger will stop cpus. If not entering the debugger stop
807 * cpus here.
808 */
809 #if defined(DDB)
810 if (newpanic && trace_on_panic)
811 print_backtrace(-1);
812 if (debugger_on_panic)
813 Debugger("panic");
814 else
815 #endif
816 if (newpanic)
817 stop_cpus(mycpu->gd_other_cpus);
818 boot(bootopt);
819 }
820
821 /*
822 * Support for poweroff delay.
823 */
824 #ifndef POWEROFF_DELAY
825 # define POWEROFF_DELAY 5000
826 #endif
827 static int poweroff_delay = POWEROFF_DELAY;
828
829 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
830 &poweroff_delay, 0, "");
831
832 static void
833 poweroff_wait(void *junk, int howto)
834 {
835 if(!(howto & RB_POWEROFF) || poweroff_delay <= 0)
836 return;
837 DELAY(poweroff_delay * 1000);
838 }
839
840 /*
841 * Some system processes (e.g. syncer) need to be stopped at appropriate
842 * points in their main loops prior to a system shutdown, so that they
843 * won't interfere with the shutdown process (e.g. by holding a disk buf
844 * to cause sync to fail). For each of these system processes, register
845 * shutdown_kproc() as a handler for one of shutdown events.
846 */
847 static int kproc_shutdown_wait = 60;
848 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
849 &kproc_shutdown_wait, 0, "");
850
851 void
852 shutdown_kproc(void *arg, int howto)
853 {
854 struct thread *td;
855 struct proc *p;
856 int error;
857
858 if (panicstr)
859 return;
860
861 td = (struct thread *)arg;
862 if ((p = td->td_proc) != NULL) {
863 kprintf("Waiting (max %d seconds) for system process `%s' to stop...",
864 kproc_shutdown_wait, p->p_comm);
865 } else {
866 kprintf("Waiting (max %d seconds) for system thread %s to stop...",
867 kproc_shutdown_wait, td->td_comm);
868 }
869 error = suspend_kproc(td, kproc_shutdown_wait * hz);
870
871 if (error == EWOULDBLOCK)
872 kprintf("timed out\n");
873 else
874 kprintf("stopped\n");
875 }
876
877 /* Registration of dumpers */
878 int
879 set_dumper(struct dumperinfo *di)
880 {
881 if (di == NULL) {
882 bzero(&dumper, sizeof(dumper));
883 return 0;
884 }
885
886 if (dumper.dumper != NULL)
887 return (EBUSY);
888
889 dumper = *di;
890 return 0;
891 }
892
893 void
894 dumpsys(void)
895 {
896 #if defined (_KERNEL_VIRTUAL)
897 /* VKERNELs don't support dumps */
898 kprintf("VKERNEL doesn't support dumps\n");
899 return;
900 #endif
901 /*
902 * If there is a dumper registered and we aren't dumping already, call
903 * the machine dependent dumpsys (md_dumpsys) to do the hard work.
904 *
905 * XXX: while right now the md_dumpsys() of x86 and x86_64 could be
906 * factored out completely into here, I rather keep them machine
907 * dependent in case we ever add a platform which does not share
908 * the same dumpsys() code, such as arm.
909 */
910 if (dumper.dumper != NULL && !dumping) {
911 dumping++;
912 md_dumpsys(&dumper);
913 }
914 }
915
916 int dump_stop_usertds = 0;
917
918 static
919 void
920 need_user_resched_remote(void *dummy)
921 {
922 need_user_resched();
923 }
924
925 void
926 dump_reactivate_cpus(void)
927 {
928 globaldata_t gd;
929 int cpu, seq;
930
931 dump_stop_usertds = 1;
932
933 need_user_resched();
934
935 for (cpu = 0; cpu < ncpus; cpu++) {
936 gd = globaldata_find(cpu);
937 seq = lwkt_send_ipiq(gd, need_user_resched_remote, NULL);
938 lwkt_wait_ipiq(gd, seq);
939 }
940
941 restart_cpus(stopped_cpus);
942 }
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