kern_shutdown.c revision 260431
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: stable/10/sys/kern/kern_shutdown.c 260431 2014-01-08 02:19:39Z cperciva $"); 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/jail.h> 54#include <sys/kdb.h> 55#include <sys/kernel.h> 56#include <sys/kerneldump.h> 57#include <sys/kthread.h> 58#include <sys/ktr.h> 59#include <sys/malloc.h> 60#include <sys/mount.h> 61#include <sys/priv.h> 62#include <sys/proc.h> 63#include <sys/reboot.h> 64#include <sys/resourcevar.h> 65#include <sys/rwlock.h> 66#include <sys/sched.h> 67#include <sys/smp.h> 68#include <sys/sysctl.h> 69#include <sys/sysproto.h> 70#include <sys/vnode.h> 71#include <sys/watchdog.h> 72 73#include <ddb/ddb.h> 74 75#include <machine/cpu.h> 76#include <machine/pcb.h> 77#include <machine/smp.h> 78 79#include <security/mac/mac_framework.h> 80 81#include <vm/vm.h> 82#include <vm/vm_object.h> 83#include <vm/vm_page.h> 84#include <vm/vm_pager.h> 85#include <vm/swap_pager.h> 86 87#include <sys/signalvar.h> 88 89#ifndef PANIC_REBOOT_WAIT_TIME 90#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */ 91#endif 92static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME; 93SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RW | CTLFLAG_TUN, 94 &panic_reboot_wait_time, 0, 95 "Seconds to wait before rebooting after a panic"); 96TUNABLE_INT("kern.panic_reboot_wait_time", &panic_reboot_wait_time); 97 98/* 99 * Note that stdarg.h and the ANSI style va_start macro is used for both 100 * ANSI and traditional C compilers. 101 */ 102#include <machine/stdarg.h> 103 104#ifdef KDB 105#ifdef KDB_UNATTENDED 106int debugger_on_panic = 0; 107#else 108int debugger_on_panic = 1; 109#endif 110SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, 111 CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_TUN, 112 &debugger_on_panic, 0, "Run debugger on kernel panic"); 113TUNABLE_INT("debug.debugger_on_panic", &debugger_on_panic); 114 115#ifdef KDB_TRACE 116static int trace_on_panic = 1; 117#else 118static int trace_on_panic = 0; 119#endif 120SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, 121 CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_TUN, 122 &trace_on_panic, 0, "Print stack trace on kernel panic"); 123TUNABLE_INT("debug.trace_on_panic", &trace_on_panic); 124#endif /* KDB */ 125 126static int sync_on_panic = 0; 127SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW | CTLFLAG_TUN, 128 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 129TUNABLE_INT("kern.sync_on_panic", &sync_on_panic); 130 131static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, 132 "Shutdown environment"); 133 134#ifndef DIAGNOSTIC 135static int show_busybufs; 136#else 137static int show_busybufs = 1; 138#endif 139SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW, 140 &show_busybufs, 0, ""); 141 142/* 143 * Variable panicstr contains argument to first call to panic; used as flag 144 * to indicate that the kernel has already called panic. 145 */ 146const char *panicstr; 147 148int dumping; /* system is dumping */ 149int rebooting; /* system is rebooting */ 150static struct dumperinfo dumper; /* our selected dumper */ 151 152/* Context information for dump-debuggers. */ 153static struct pcb dumppcb; /* Registers. */ 154lwpid_t dumptid; /* Thread ID. */ 155 156static void poweroff_wait(void *, int); 157static void shutdown_halt(void *junk, int howto); 158static void shutdown_panic(void *junk, int howto); 159static void shutdown_reset(void *junk, int howto); 160static void vpanic(const char *fmt, va_list ap) __dead2; 161 162/* register various local shutdown events */ 163static void 164shutdown_conf(void *unused) 165{ 166 167 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, 168 SHUTDOWN_PRI_FIRST); 169 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, 170 SHUTDOWN_PRI_LAST + 100); 171 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, 172 SHUTDOWN_PRI_LAST + 100); 173 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, 174 SHUTDOWN_PRI_LAST + 200); 175} 176 177SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL); 178 179/* 180 * The system call that results in a reboot. 181 */ 182/* ARGSUSED */ 183int 184sys_reboot(struct thread *td, struct reboot_args *uap) 185{ 186 int error; 187 188 error = 0; 189#ifdef MAC 190 error = mac_system_check_reboot(td->td_ucred, uap->opt); 191#endif 192 if (error == 0) 193 error = priv_check(td, PRIV_REBOOT); 194 if (error == 0) { 195 mtx_lock(&Giant); 196 kern_reboot(uap->opt); 197 mtx_unlock(&Giant); 198 } 199 return (error); 200} 201 202/* 203 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC 204 */ 205static int shutdown_howto = 0; 206 207void 208shutdown_nice(int howto) 209{ 210 211 shutdown_howto = howto; 212 213 /* Send a signal to init(8) and have it shutdown the world */ 214 if (initproc != NULL) { 215 PROC_LOCK(initproc); 216 kern_psignal(initproc, SIGINT); 217 PROC_UNLOCK(initproc); 218 } else { 219 /* No init(8) running, so simply reboot */ 220 kern_reboot(RB_NOSYNC); 221 } 222 return; 223} 224static int waittime = -1; 225 226static void 227print_uptime(void) 228{ 229 int f; 230 struct timespec ts; 231 232 getnanouptime(&ts); 233 printf("Uptime: "); 234 f = 0; 235 if (ts.tv_sec >= 86400) { 236 printf("%ldd", (long)ts.tv_sec / 86400); 237 ts.tv_sec %= 86400; 238 f = 1; 239 } 240 if (f || ts.tv_sec >= 3600) { 241 printf("%ldh", (long)ts.tv_sec / 3600); 242 ts.tv_sec %= 3600; 243 f = 1; 244 } 245 if (f || ts.tv_sec >= 60) { 246 printf("%ldm", (long)ts.tv_sec / 60); 247 ts.tv_sec %= 60; 248 f = 1; 249 } 250 printf("%lds\n", (long)ts.tv_sec); 251} 252 253int 254doadump(boolean_t textdump) 255{ 256 boolean_t coredump; 257 258 if (dumping) 259 return (EBUSY); 260 if (dumper.dumper == NULL) 261 return (ENXIO); 262 263 savectx(&dumppcb); 264 dumptid = curthread->td_tid; 265 dumping++; 266 267 coredump = TRUE; 268#ifdef DDB 269 if (textdump && textdump_pending) { 270 coredump = FALSE; 271 textdump_dumpsys(&dumper); 272 } 273#endif 274 if (coredump) 275 dumpsys(&dumper); 276 277 dumping--; 278 return (0); 279} 280 281static int 282isbufbusy(struct buf *bp) 283{ 284 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 && 285 BUF_ISLOCKED(bp)) || 286 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI)) 287 return (1); 288 return (0); 289} 290 291/* 292 * Shutdown the system cleanly to prepare for reboot, halt, or power off. 293 */ 294void 295kern_reboot(int howto) 296{ 297 static int first_buf_printf = 1; 298 299#if defined(SMP) 300 /* 301 * Bind us to CPU 0 so that all shutdown code runs there. Some 302 * systems don't shutdown properly (i.e., ACPI power off) if we 303 * run on another processor. 304 */ 305 if (!SCHEDULER_STOPPED()) { 306 thread_lock(curthread); 307 sched_bind(curthread, 0); 308 thread_unlock(curthread); 309 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0")); 310 } 311#endif 312 /* We're in the process of rebooting. */ 313 rebooting = 1; 314 315 /* collect extra flags that shutdown_nice might have set */ 316 howto |= shutdown_howto; 317 318 /* We are out of the debugger now. */ 319 kdb_active = 0; 320 321 /* 322 * Do any callouts that should be done BEFORE syncing the filesystems. 323 */ 324 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 325 326 /* 327 * Now sync filesystems 328 */ 329 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) { 330 register struct buf *bp; 331 int iter, nbusy, pbusy; 332#ifndef PREEMPTION 333 int subiter; 334#endif 335 336 waittime = 0; 337 338 wdog_kern_pat(WD_LASTVAL); 339 sys_sync(curthread, NULL); 340 341 /* 342 * With soft updates, some buffers that are 343 * written will be remarked as dirty until other 344 * buffers are written. 345 */ 346 for (iter = pbusy = 0; iter < 20; iter++) { 347 nbusy = 0; 348 for (bp = &buf[nbuf]; --bp >= buf; ) 349 if (isbufbusy(bp)) 350 nbusy++; 351 if (nbusy == 0) { 352 if (first_buf_printf) 353 printf("All buffers synced."); 354 break; 355 } 356 if (first_buf_printf) { 357 printf("Syncing disks, buffers remaining... "); 358 first_buf_printf = 0; 359 } 360 printf("%d ", nbusy); 361 if (nbusy < pbusy) 362 iter = 0; 363 pbusy = nbusy; 364 365 wdog_kern_pat(WD_LASTVAL); 366 sys_sync(curthread, NULL); 367 368#ifdef PREEMPTION 369 /* 370 * Drop Giant and spin for a while to allow 371 * interrupt threads to run. 372 */ 373 DROP_GIANT(); 374 DELAY(50000 * iter); 375 PICKUP_GIANT(); 376#else 377 /* 378 * Drop Giant and context switch several times to 379 * allow interrupt threads to run. 380 */ 381 DROP_GIANT(); 382 for (subiter = 0; subiter < 50 * iter; subiter++) { 383 thread_lock(curthread); 384 mi_switch(SW_VOL, NULL); 385 thread_unlock(curthread); 386 DELAY(1000); 387 } 388 PICKUP_GIANT(); 389#endif 390 } 391 printf("\n"); 392 /* 393 * Count only busy local buffers to prevent forcing 394 * a fsck if we're just a client of a wedged NFS server 395 */ 396 nbusy = 0; 397 for (bp = &buf[nbuf]; --bp >= buf; ) { 398 if (isbufbusy(bp)) { 399#if 0 400/* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */ 401 if (bp->b_dev == NULL) { 402 TAILQ_REMOVE(&mountlist, 403 bp->b_vp->v_mount, mnt_list); 404 continue; 405 } 406#endif 407 nbusy++; 408 if (show_busybufs > 0) { 409 printf( 410 "%d: buf:%p, vnode:%p, flags:%0x, blkno:%jd, lblkno:%jd, buflock:", 411 nbusy, bp, bp->b_vp, bp->b_flags, 412 (intmax_t)bp->b_blkno, 413 (intmax_t)bp->b_lblkno); 414 BUF_LOCKPRINTINFO(bp); 415 if (show_busybufs > 1) 416 vn_printf(bp->b_vp, 417 "vnode content: "); 418 } 419 } 420 } 421 if (nbusy) { 422 /* 423 * Failed to sync all blocks. Indicate this and don't 424 * unmount filesystems (thus forcing an fsck on reboot). 425 */ 426 printf("Giving up on %d buffers\n", nbusy); 427 DELAY(5000000); /* 5 seconds */ 428 } else { 429 if (!first_buf_printf) 430 printf("Final sync complete\n"); 431 /* 432 * Unmount filesystems 433 */ 434 if (panicstr == 0) 435 vfs_unmountall(); 436 } 437 swapoff_all(); 438 DELAY(100000); /* wait for console output to finish */ 439 } 440 441 print_uptime(); 442 443 cngrab(); 444 445 /* 446 * Ok, now do things that assume all filesystem activity has 447 * been completed. 448 */ 449 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 450 451 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping) 452 doadump(TRUE); 453 454 /* Now that we're going to really halt the system... */ 455 EVENTHANDLER_INVOKE(shutdown_final, howto); 456 457 for(;;) ; /* safety against shutdown_reset not working */ 458 /* NOTREACHED */ 459} 460 461/* 462 * If the shutdown was a clean halt, behave accordingly. 463 */ 464static void 465shutdown_halt(void *junk, int howto) 466{ 467 468 if (howto & RB_HALT) { 469 printf("\n"); 470 printf("The operating system has halted.\n"); 471 printf("Please press any key to reboot.\n\n"); 472 switch (cngetc()) { 473 case -1: /* No console, just die */ 474 cpu_halt(); 475 /* NOTREACHED */ 476 default: 477 howto &= ~RB_HALT; 478 break; 479 } 480 } 481} 482 483/* 484 * Check to see if the system paniced, pause and then reboot 485 * according to the specified delay. 486 */ 487static void 488shutdown_panic(void *junk, int howto) 489{ 490 int loop; 491 492 if (howto & RB_DUMP) { 493 if (panic_reboot_wait_time != 0) { 494 if (panic_reboot_wait_time != -1) { 495 printf("Automatic reboot in %d seconds - " 496 "press a key on the console to abort\n", 497 panic_reboot_wait_time); 498 for (loop = panic_reboot_wait_time * 10; 499 loop > 0; --loop) { 500 DELAY(1000 * 100); /* 1/10th second */ 501 /* Did user type a key? */ 502 if (cncheckc() != -1) 503 break; 504 } 505 if (!loop) 506 return; 507 } 508 } else { /* zero time specified - reboot NOW */ 509 return; 510 } 511 printf("--> Press a key on the console to reboot,\n"); 512 printf("--> or switch off the system now.\n"); 513 cngetc(); 514 } 515} 516 517/* 518 * Everything done, now reset 519 */ 520static void 521shutdown_reset(void *junk, int howto) 522{ 523 524 printf("Rebooting...\n"); 525 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */ 526 527 /* 528 * Acquiring smp_ipi_mtx here has a double effect: 529 * - it disables interrupts avoiding CPU0 preemption 530 * by fast handlers (thus deadlocking against other CPUs) 531 * - it avoids deadlocks against smp_rendezvous() or, more 532 * generally, threads busy-waiting, with this spinlock held, 533 * and waiting for responses by threads on other CPUs 534 * (ie. smp_tlb_shootdown()). 535 * 536 * For the !SMP case it just needs to handle the former problem. 537 */ 538#ifdef SMP 539 mtx_lock_spin(&smp_ipi_mtx); 540#else 541 spinlock_enter(); 542#endif 543 544 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 545 cpu_reset(); 546 /* NOTREACHED */ /* assuming reset worked */ 547} 548 549#if defined(WITNESS) || defined(INVARIANTS) 550static int kassert_warn_only = 0; 551#ifdef KDB 552static int kassert_do_kdb = 0; 553#endif 554#ifdef KTR 555static int kassert_do_ktr = 0; 556#endif 557static int kassert_do_log = 1; 558static int kassert_log_pps_limit = 4; 559static int kassert_log_mute_at = 0; 560static int kassert_log_panic_at = 0; 561static int kassert_warnings = 0; 562 563SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options"); 564 565SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RW | CTLFLAG_TUN, 566 &kassert_warn_only, 0, 567 "KASSERT triggers a panic (1) or just a warning (0)"); 568TUNABLE_INT("debug.kassert.warn_only", &kassert_warn_only); 569 570#ifdef KDB 571SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RW | CTLFLAG_TUN, 572 &kassert_do_kdb, 0, "KASSERT will enter the debugger"); 573TUNABLE_INT("debug.kassert.do_kdb", &kassert_do_kdb); 574#endif 575 576#ifdef KTR 577SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RW | CTLFLAG_TUN, 578 &kassert_do_ktr, 0, 579 "KASSERT does a KTR, set this to the KTRMASK you want"); 580TUNABLE_INT("debug.kassert.do_ktr", &kassert_do_ktr); 581#endif 582 583SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RW | CTLFLAG_TUN, 584 &kassert_do_log, 0, "KASSERT triggers a panic (1) or just a warning (0)"); 585TUNABLE_INT("debug.kassert.do_log", &kassert_do_log); 586 587SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RW | CTLFLAG_TUN, 588 &kassert_warnings, 0, "number of KASSERTs that have been triggered"); 589TUNABLE_INT("debug.kassert.warnings", &kassert_warnings); 590 591SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RW | CTLFLAG_TUN, 592 &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic"); 593TUNABLE_INT("debug.kassert.log_panic_at", &kassert_log_panic_at); 594 595SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RW | CTLFLAG_TUN, 596 &kassert_log_pps_limit, 0, "limit number of log messages per second"); 597TUNABLE_INT("debug.kassert.log_pps_limit", &kassert_log_pps_limit); 598 599SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RW | CTLFLAG_TUN, 600 &kassert_log_mute_at, 0, "max number of KASSERTS to log"); 601TUNABLE_INT("debug.kassert.log_mute_at", &kassert_log_mute_at); 602 603static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS); 604 605SYSCTL_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 609static int 610kassert_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 */ 629void 630kassert_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 */ 682void 683panic(const char *fmt, ...) 684{ 685 va_list ap; 686 687 va_start(ap, fmt); 688 vpanic(fmt, ap); 689} 690 691static void 692vpanic(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 * We set stop_scheduler here and not in the block above, 717 * because we want to ensure that if panic has been called and 718 * stop_scheduler_on_panic is true, then stop_scheduler will 719 * always be set. Even if panic has been entered from kdb. 720 */ 721 td->td_stopsched = 1; 722#endif 723 724 bootopt = RB_AUTOBOOT; 725 newpanic = 0; 726 if (panicstr) 727 bootopt |= RB_NOSYNC; 728 else { 729 bootopt |= RB_DUMP; 730 panicstr = fmt; 731 newpanic = 1; 732 } 733 734 if (newpanic) { 735 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 736 panicstr = buf; 737 cngrab(); 738 printf("panic: %s\n", buf); 739 } else { 740 printf("panic: "); 741 vprintf(fmt, ap); 742 printf("\n"); 743 } 744#ifdef SMP 745 printf("cpuid = %d\n", PCPU_GET(cpuid)); 746#endif 747 748#ifdef KDB 749 if (newpanic && trace_on_panic) 750 kdb_backtrace(); 751 if (debugger_on_panic) 752 kdb_enter(KDB_WHY_PANIC, "panic"); 753#endif 754 /*thread_lock(td); */ 755 td->td_flags |= TDF_INPANIC; 756 /* thread_unlock(td); */ 757 if (!sync_on_panic) 758 bootopt |= RB_NOSYNC; 759 kern_reboot(bootopt); 760} 761 762/* 763 * Support for poweroff delay. 764 * 765 * Please note that setting this delay too short might power off your machine 766 * before the write cache on your hard disk has been flushed, leading to 767 * soft-updates inconsistencies. 768 */ 769#ifndef POWEROFF_DELAY 770# define POWEROFF_DELAY 5000 771#endif 772static int poweroff_delay = POWEROFF_DELAY; 773 774SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 775 &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)"); 776 777static void 778poweroff_wait(void *junk, int howto) 779{ 780 781 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0) 782 return; 783 DELAY(poweroff_delay * 1000); 784} 785 786/* 787 * Some system processes (e.g. syncer) need to be stopped at appropriate 788 * points in their main loops prior to a system shutdown, so that they 789 * won't interfere with the shutdown process (e.g. by holding a disk buf 790 * to cause sync to fail). For each of these system processes, register 791 * shutdown_kproc() as a handler for one of shutdown events. 792 */ 793static int kproc_shutdown_wait = 60; 794SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 795 &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process"); 796 797void 798kproc_shutdown(void *arg, int howto) 799{ 800 struct proc *p; 801 int error; 802 803 if (panicstr) 804 return; 805 806 p = (struct proc *)arg; 807 printf("Waiting (max %d seconds) for system process `%s' to stop...", 808 kproc_shutdown_wait, p->p_comm); 809 error = kproc_suspend(p, kproc_shutdown_wait * hz); 810 811 if (error == EWOULDBLOCK) 812 printf("timed out\n"); 813 else 814 printf("done\n"); 815} 816 817void 818kthread_shutdown(void *arg, int howto) 819{ 820 struct thread *td; 821 int error; 822 823 if (panicstr) 824 return; 825 826 td = (struct thread *)arg; 827 printf("Waiting (max %d seconds) for system thread `%s' to stop...", 828 kproc_shutdown_wait, td->td_name); 829 error = kthread_suspend(td, kproc_shutdown_wait * hz); 830 831 if (error == EWOULDBLOCK) 832 printf("timed out\n"); 833 else 834 printf("done\n"); 835} 836 837static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)]; 838SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD, 839 dumpdevname, 0, "Device for kernel dumps"); 840 841/* Registration of dumpers */ 842int 843set_dumper(struct dumperinfo *di, const char *devname) 844{ 845 size_t wantcopy; 846 847 if (di == NULL) { 848 bzero(&dumper, sizeof dumper); 849 dumpdevname[0] = '\0'; 850 return (0); 851 } 852 if (dumper.dumper != NULL) 853 return (EBUSY); 854 dumper = *di; 855 wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname)); 856 if (wantcopy >= sizeof(dumpdevname)) { 857 printf("set_dumper: device name truncated from '%s' -> '%s'\n", 858 devname, dumpdevname); 859 } 860 return (0); 861} 862 863/* Call dumper with bounds checking. */ 864int 865dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical, 866 off_t offset, size_t length) 867{ 868 869 if (length != 0 && (offset < di->mediaoffset || 870 offset - di->mediaoffset + length > di->mediasize)) { 871 printf("Attempt to write outside dump device boundaries.\n" 872 "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n", 873 (intmax_t)offset, (intmax_t)di->mediaoffset, 874 (uintmax_t)length, (intmax_t)di->mediasize); 875 return (ENOSPC); 876 } 877 return (di->dumper(di->priv, virtual, physical, offset, length)); 878} 879 880void 881mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver, 882 uint64_t dumplen, uint32_t blksz) 883{ 884 885 bzero(kdh, sizeof(*kdh)); 886 strncpy(kdh->magic, magic, sizeof(kdh->magic)); 887 strncpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture)); 888 kdh->version = htod32(KERNELDUMPVERSION); 889 kdh->architectureversion = htod32(archver); 890 kdh->dumplength = htod64(dumplen); 891 kdh->dumptime = htod64(time_second); 892 kdh->blocksize = htod32(blksz); 893 strncpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname)); 894 strncpy(kdh->versionstring, version, sizeof(kdh->versionstring)); 895 if (panicstr != NULL) 896 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring)); 897 kdh->parity = kerneldump_parity(kdh); 898} 899