kern_shutdown.c revision 131927
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: head/sys/kern/kern_shutdown.c 131927 2004-07-10 21:36:01Z marcel $"); 39 40#include "opt_kdb.h" 41#include "opt_hw_wdog.h" 42#include "opt_mac.h" 43#include "opt_panic.h" 44#include "opt_show_busybufs.h" 45 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/smp.h> /* smp_active */ 63#include <sys/sysctl.h> 64#include <sys/sysproto.h> 65#include <sys/vnode.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 85int debugger_on_panic = 0; 86#else 87int debugger_on_panic = 1; 88#endif 89SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW, 90 &debugger_on_panic, 0, "Run debugger on kernel panic"); 91 92#ifdef KDB_TRACE 93int trace_on_panic = 1; 94#else 95int trace_on_panic = 0; 96#endif 97SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW, 98 &trace_on_panic, 0, "Print stack trace on kernel panic"); 99#endif /* KDB */ 100 101int sync_on_panic = 1; 102SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW, 103 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 104 105SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment"); 106 107#ifdef HW_WDOG 108/* 109 * If there is a hardware watchdog, point this at the function needed to 110 * hold it off. 111 * It's needed when the kernel needs to do some lengthy operations. 112 * e.g. in wd.c when dumping core.. It's most annoying to have 113 * your precious core-dump only half written because the wdog kicked in. 114 */ 115watchdog_tickle_fn wdog_tickler = NULL; 116#endif /* HW_WDOG */ 117 118/* 119 * Variable panicstr contains argument to first call to panic; used as flag 120 * to indicate that the kernel has already called panic. 121 */ 122const char *panicstr; 123 124int dumping; /* system is dumping */ 125static struct dumperinfo dumper; /* our selected dumper */ 126 127/* Context information for dump-debuggers. */ 128static struct pcb dumppcb; /* Registers. */ 129static lwpid_t dumptid; /* Thread ID. */ 130 131static void boot(int) __dead2; 132static void poweroff_wait(void *, int); 133static void shutdown_halt(void *junk, int howto); 134static void shutdown_panic(void *junk, int howto); 135static void shutdown_reset(void *junk, int howto); 136 137/* register various local shutdown events */ 138static void 139shutdown_conf(void *unused) 140{ 141 142 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, 143 SHUTDOWN_PRI_FIRST); 144 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, 145 SHUTDOWN_PRI_LAST + 100); 146 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, 147 SHUTDOWN_PRI_LAST + 100); 148 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, 149 SHUTDOWN_PRI_LAST + 200); 150} 151 152SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL) 153 154/* 155 * The system call that results in a reboot 156 * 157 * MPSAFE 158 */ 159/* ARGSUSED */ 160int 161reboot(struct thread *td, struct reboot_args *uap) 162{ 163 int error; 164 165 error = 0; 166#ifdef MAC 167 error = mac_check_system_reboot(td->td_ucred, uap->opt); 168#endif 169 if (error == 0) 170 error = suser(td); 171 if (error == 0) { 172 mtx_lock(&Giant); 173 boot(uap->opt); 174 mtx_unlock(&Giant); 175 } 176 return (error); 177} 178 179/* 180 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC 181 */ 182static int shutdown_howto = 0; 183 184void 185shutdown_nice(int howto) 186{ 187 188 shutdown_howto = howto; 189 190 /* Send a signal to init(8) and have it shutdown the world */ 191 if (initproc != NULL) { 192 PROC_LOCK(initproc); 193 psignal(initproc, SIGINT); 194 PROC_UNLOCK(initproc); 195 } else { 196 /* No init(8) running, so simply reboot */ 197 boot(RB_NOSYNC); 198 } 199 return; 200} 201static int waittime = -1; 202 203static void 204print_uptime(void) 205{ 206 int f; 207 struct timespec ts; 208 209 getnanouptime(&ts); 210 printf("Uptime: "); 211 f = 0; 212 if (ts.tv_sec >= 86400) { 213 printf("%ldd", (long)ts.tv_sec / 86400); 214 ts.tv_sec %= 86400; 215 f = 1; 216 } 217 if (f || ts.tv_sec >= 3600) { 218 printf("%ldh", (long)ts.tv_sec / 3600); 219 ts.tv_sec %= 3600; 220 f = 1; 221 } 222 if (f || ts.tv_sec >= 60) { 223 printf("%ldm", (long)ts.tv_sec / 60); 224 ts.tv_sec %= 60; 225 f = 1; 226 } 227 printf("%lds\n", (long)ts.tv_sec); 228} 229 230static void 231doadump(void) 232{ 233 234 savectx(&dumppcb); 235 dumptid = curthread->td_tid; 236 dumping++; 237 dumpsys(&dumper); 238} 239 240/* 241 * Go through the rigmarole of shutting down.. 242 * this used to be in machdep.c but I'll be dammned if I could see 243 * anything machine dependant in it. 244 */ 245static void 246boot(int howto) 247{ 248 249 /* collect extra flags that shutdown_nice might have set */ 250 howto |= shutdown_howto; 251 252 /* We are out of the debugger now. */ 253 kdb_active = 0; 254 255#ifdef SMP 256 if (smp_active) 257 printf("boot() called on cpu#%d\n", PCPU_GET(cpuid)); 258#endif 259 /* 260 * Do any callouts that should be done BEFORE syncing the filesystems. 261 */ 262 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 263 264 /* 265 * Now sync filesystems 266 */ 267 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) { 268 register struct buf *bp; 269 int iter, nbusy, pbusy; 270#ifndef PREEMPTION 271 int subiter; 272#endif 273 274 waittime = 0; 275 printf("\nsyncing disks, buffers remaining... "); 276 277 sync(&thread0, NULL); 278 279 /* 280 * With soft updates, some buffers that are 281 * written will be remarked as dirty until other 282 * buffers are written. 283 */ 284 for (iter = pbusy = 0; iter < 20; iter++) { 285 nbusy = 0; 286 for (bp = &buf[nbuf]; --bp >= buf; ) { 287 if ((bp->b_flags & B_INVAL) == 0 && 288 BUF_REFCNT(bp) > 0) { 289 nbusy++; 290 } else if ((bp->b_flags & (B_DELWRI | B_INVAL)) 291 == B_DELWRI) { 292 /* bawrite(bp);*/ 293 nbusy++; 294 } 295 } 296 if (nbusy == 0) 297 break; 298 printf("%d ", nbusy); 299 if (nbusy < pbusy) 300 iter = 0; 301 pbusy = nbusy; 302 sync(&thread0, NULL); 303 304#ifdef PREEMPTION 305 /* 306 * Drop Giant and spin for a while to allow 307 * interrupt threads to run. 308 */ 309 DROP_GIANT(); 310 DELAY(50000 * iter); 311 PICKUP_GIANT(); 312#else 313 /* 314 * Drop Giant and context switch several times to 315 * allow interrupt threads to run. 316 */ 317 DROP_GIANT(); 318 for (subiter = 0; subiter < 50 * iter; subiter++) { 319 mtx_lock_spin(&sched_lock); 320 mi_switch(SW_VOL, NULL); 321 mtx_unlock_spin(&sched_lock); 322 DELAY(1000); 323 } 324 PICKUP_GIANT(); 325#endif 326 } 327 printf("\n"); 328 /* 329 * Count only busy local buffers to prevent forcing 330 * a fsck if we're just a client of a wedged NFS server 331 */ 332 nbusy = 0; 333 for (bp = &buf[nbuf]; --bp >= buf; ) { 334 if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) || 335 ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) { 336 if (bp->b_dev == NULL) { 337 TAILQ_REMOVE(&mountlist, 338 bp->b_vp->v_mount, mnt_list); 339 continue; 340 } 341 nbusy++; 342#if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC) 343 printf( 344 "%d: dev:%s, flags:%0x, blkno:%ld, lblkno:%ld\n", 345 nbusy, devtoname(bp->b_dev), 346 bp->b_flags, (long)bp->b_blkno, 347 (long)bp->b_lblkno); 348#endif 349 } 350 } 351 if (nbusy) { 352 /* 353 * Failed to sync all blocks. Indicate this and don't 354 * unmount filesystems (thus forcing an fsck on reboot). 355 */ 356 printf("giving up on %d buffers\n", nbusy); 357 DELAY(5000000); /* 5 seconds */ 358 } else { 359 printf("done\n"); 360 /* 361 * Unmount filesystems 362 */ 363 if (panicstr == 0) 364 vfs_unmountall(); 365 } 366 DELAY(100000); /* wait for console output to finish */ 367 } 368 369 print_uptime(); 370 371 /* 372 * Ok, now do things that assume all filesystem activity has 373 * been completed. 374 */ 375 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 376 splhigh(); 377 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && 378 !cold && dumper.dumper != NULL && !dumping) 379 doadump(); 380 381 /* Now that we're going to really halt the system... */ 382 EVENTHANDLER_INVOKE(shutdown_final, howto); 383 384 for(;;) ; /* safety against shutdown_reset not working */ 385 /* NOTREACHED */ 386} 387 388/* 389 * If the shutdown was a clean halt, behave accordingly. 390 */ 391static void 392shutdown_halt(void *junk, int howto) 393{ 394 395 if (howto & RB_HALT) { 396 printf("\n"); 397 printf("The operating system has halted.\n"); 398 printf("Please press any key to reboot.\n\n"); 399 switch (cngetc()) { 400 case -1: /* No console, just die */ 401 cpu_halt(); 402 /* NOTREACHED */ 403 default: 404 howto &= ~RB_HALT; 405 break; 406 } 407 } 408} 409 410/* 411 * Check to see if the system paniced, pause and then reboot 412 * according to the specified delay. 413 */ 414static void 415shutdown_panic(void *junk, int howto) 416{ 417 int loop; 418 419 if (howto & RB_DUMP) { 420 if (PANIC_REBOOT_WAIT_TIME != 0) { 421 if (PANIC_REBOOT_WAIT_TIME != -1) { 422 printf("Automatic reboot in %d seconds - " 423 "press a key on the console to abort\n", 424 PANIC_REBOOT_WAIT_TIME); 425 for (loop = PANIC_REBOOT_WAIT_TIME * 10; 426 loop > 0; --loop) { 427 DELAY(1000 * 100); /* 1/10th second */ 428 /* Did user type a key? */ 429 if (cncheckc() != -1) 430 break; 431 } 432 if (!loop) 433 return; 434 } 435 } else { /* zero time specified - reboot NOW */ 436 return; 437 } 438 printf("--> Press a key on the console to reboot,\n"); 439 printf("--> or switch off the system now.\n"); 440 cngetc(); 441 } 442} 443 444/* 445 * Everything done, now reset 446 */ 447static void 448shutdown_reset(void *junk, int howto) 449{ 450 451 printf("Rebooting...\n"); 452 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */ 453 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 454 cpu_reset(); 455 /* NOTREACHED */ /* assuming reset worked */ 456} 457 458#ifdef SMP 459static u_int panic_cpu = NOCPU; 460#endif 461 462/* 463 * Panic is called on unresolvable fatal errors. It prints "panic: mesg", 464 * and then reboots. If we are called twice, then we avoid trying to sync 465 * the disks as this often leads to recursive panics. 466 * 467 * MPSAFE 468 */ 469void 470panic(const char *fmt, ...) 471{ 472 struct thread *td = curthread; 473 int bootopt, newpanic; 474 va_list ap; 475 static char buf[256]; 476 477#ifdef SMP 478 /* 479 * We don't want multiple CPU's to panic at the same time, so we 480 * use panic_cpu as a simple spinlock. We have to keep checking 481 * panic_cpu if we are spinning in case the panic on the first 482 * CPU is canceled. 483 */ 484 if (panic_cpu != PCPU_GET(cpuid)) 485 while (atomic_cmpset_int(&panic_cpu, NOCPU, 486 PCPU_GET(cpuid)) == 0) 487 while (panic_cpu != NOCPU) 488 ; /* nothing */ 489#endif 490 491 bootopt = RB_AUTOBOOT | RB_DUMP; 492 newpanic = 0; 493 if (panicstr) 494 bootopt |= RB_NOSYNC; 495 else { 496 panicstr = fmt; 497 newpanic = 1; 498 } 499 500 va_start(ap, fmt); 501 if (newpanic) { 502 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 503 panicstr = buf; 504 printf("panic: %s\n", buf); 505 } else { 506 printf("panic: "); 507 vprintf(fmt, ap); 508 printf("\n"); 509 } 510 va_end(ap); 511#ifdef SMP 512 /* two separate prints in case of an unmapped page and trap */ 513 printf("cpuid = %d; ", PCPU_GET(cpuid)); 514#ifdef APIC_IO 515 printf("lapic.id = %08x\n", lapic.id); 516#else 517 printf("\n"); 518#endif 519#endif 520 521#ifdef KDB 522 if (newpanic && trace_on_panic) 523 kdb_backtrace(); 524 if (debugger_on_panic) 525 kdb_enter("panic"); 526#ifdef RESTARTABLE_PANICS 527 /* See if the user aborted the panic, in which case we continue. */ 528 if (panicstr == NULL) { 529#ifdef SMP 530 atomic_store_rel_int(&panic_cpu, NOCPU); 531#endif 532 return; 533 } 534#endif 535#endif 536 mtx_lock_spin(&sched_lock); 537 td->td_flags |= TDF_INPANIC; 538 mtx_unlock_spin(&sched_lock); 539 if (!sync_on_panic) 540 bootopt |= RB_NOSYNC; 541 boot(bootopt); 542} 543 544/* 545 * Support for poweroff delay. 546 */ 547#ifndef POWEROFF_DELAY 548# define POWEROFF_DELAY 5000 549#endif 550static int poweroff_delay = POWEROFF_DELAY; 551 552SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 553 &poweroff_delay, 0, ""); 554 555static void 556poweroff_wait(void *junk, int howto) 557{ 558 559 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0) 560 return; 561 DELAY(poweroff_delay * 1000); 562} 563 564/* 565 * Some system processes (e.g. syncer) need to be stopped at appropriate 566 * points in their main loops prior to a system shutdown, so that they 567 * won't interfere with the shutdown process (e.g. by holding a disk buf 568 * to cause sync to fail). For each of these system processes, register 569 * shutdown_kproc() as a handler for one of shutdown events. 570 */ 571static int kproc_shutdown_wait = 60; 572SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 573 &kproc_shutdown_wait, 0, ""); 574 575void 576kproc_shutdown(void *arg, int howto) 577{ 578 struct proc *p; 579 int error; 580 581 if (panicstr) 582 return; 583 584 p = (struct proc *)arg; 585 printf("Waiting (max %d seconds) for system process `%s' to stop...", 586 kproc_shutdown_wait, p->p_comm); 587 error = kthread_suspend(p, kproc_shutdown_wait * hz); 588 589 if (error == EWOULDBLOCK) 590 printf("timed out\n"); 591 else 592 printf("stopped\n"); 593} 594 595/* Registration of dumpers */ 596int 597set_dumper(struct dumperinfo *di) 598{ 599 600 if (di == NULL) { 601 bzero(&dumper, sizeof dumper); 602 return (0); 603 } 604 if (dumper.dumper != NULL) 605 return (EBUSY); 606 dumper = *di; 607 return (0); 608} 609 610#if defined(__powerpc__) 611void 612dumpsys(struct dumperinfo *di __unused) 613{ 614 615 printf("Kernel dumps not implemented on this architecture\n"); 616} 617#endif 618