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_kdb.h" 41 #include "opt_mac.h" 42 #include "opt_panic.h" 43 #include "opt_show_busybufs.h" 44 #include "opt_sched.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/bio.h> 49 #include <sys/buf.h> 50 #include <sys/conf.h> 51 #include <sys/cons.h> 52 #include <sys/eventhandler.h> 53 #include <sys/kdb.h> 54 #include <sys/kernel.h> 55 #include <sys/kthread.h> 56 #include <sys/malloc.h> 57 #include <sys/mount.h> 58 #include <sys/proc.h> 59 #include <sys/reboot.h> 60 #include <sys/resourcevar.h> 61 #include <sys/sched.h> 62 #include <sys/smp.h> /* smp_active */ 63 #include <sys/sysctl.h> 64 #include <sys/sysproto.h> 65 66 #include <machine/cpu.h> 67 #include <machine/pcb.h> 68 #include <machine/smp.h> 69 70 #include <security/mac/mac_framework.h> 71 72 #include <vm/vm.h> 73 #include <vm/vm_object.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_pager.h> 76 #include <vm/swap_pager.h> 77 78 #include <sys/signalvar.h> 79 80 #ifndef PANIC_REBOOT_WAIT_TIME 81 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */ 82 #endif 83 84 /* 85 * Note that stdarg.h and the ANSI style va_start macro is used for both 86 * ANSI and traditional C compilers. 87 */ 88 #include <machine/stdarg.h> 89 90 #ifdef KDB 91 #ifdef KDB_UNATTENDED 92 int debugger_on_panic = 0; 93 #else 94 int debugger_on_panic = 1; 95 #endif 96 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW, 97 &debugger_on_panic, 0, "Run debugger on kernel panic"); 98 99 #ifdef KDB_TRACE 100 int trace_on_panic = 1; 101 #else 102 int trace_on_panic = 0; 103 #endif 104 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW, 105 &trace_on_panic, 0, "Print stack trace on kernel panic"); 106 #endif /* KDB */ 107 108 int sync_on_panic = 0; 109 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW, 110 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 111 112 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment"); 113 114 /* 115 * Variable panicstr contains argument to first call to panic; used as flag 116 * to indicate that the kernel has already called panic. 117 */ 118 const char *panicstr; 119 120 int dumping; /* system is dumping */ 121 int rebooting; /* system is rebooting */ 122 static struct dumperinfo dumper; /* our selected dumper */ 123 124 /* Context information for dump-debuggers. */ 125 static struct pcb dumppcb; /* Registers. */ 126 static lwpid_t dumptid; /* Thread ID. */ 127 128 static void boot(int) __dead2; 129 static void poweroff_wait(void *, int); 130 static void shutdown_halt(void *junk, int howto); 131 static void shutdown_panic(void *junk, int howto); 132 static void shutdown_reset(void *junk, int howto); 133 134 /* register various local shutdown events */ 135 static void 136 shutdown_conf(void *unused) 137 { 138 139 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, 140 SHUTDOWN_PRI_FIRST); 141 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, 142 SHUTDOWN_PRI_LAST + 100); 143 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, 144 SHUTDOWN_PRI_LAST + 100); 145 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, 146 SHUTDOWN_PRI_LAST + 200); 147 } 148 149 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL) 150 151 /* 152 * The system call that results in a reboot 153 * 154 * MPSAFE 155 */ 156 /* ARGSUSED */ 157 int 158 reboot(struct thread *td, struct reboot_args *uap) 159 { 160 int error; 161 162 error = 0; 163 #ifdef MAC 164 error = mac_check_system_reboot(td->td_ucred, uap->opt); 165 #endif 166 if (error == 0) 167 error = suser(td); 168 if (error == 0) { 169 mtx_lock(&Giant); 170 boot(uap->opt); 171 mtx_unlock(&Giant); 172 } 173 return (error); 174 } 175 176 /* 177 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC 178 */ 179 static int shutdown_howto = 0; 180 181 void 182 shutdown_nice(int howto) 183 { 184 185 shutdown_howto = howto; 186 187 /* Send a signal to init(8) and have it shutdown the world */ 188 if (initproc != NULL) { 189 PROC_LOCK(initproc); 190 psignal(initproc, SIGINT); 191 PROC_UNLOCK(initproc); 192 } else { 193 /* No init(8) running, so simply reboot */ 194 boot(RB_NOSYNC); 195 } 196 return; 197 } 198 static int waittime = -1; 199 200 static void 201 print_uptime(void) 202 { 203 int f; 204 struct timespec ts; 205 206 getnanouptime(&ts); 207 printf("Uptime: "); 208 f = 0; 209 if (ts.tv_sec >= 86400) { 210 printf("%ldd", (long)ts.tv_sec / 86400); 211 ts.tv_sec %= 86400; 212 f = 1; 213 } 214 if (f || ts.tv_sec >= 3600) { 215 printf("%ldh", (long)ts.tv_sec / 3600); 216 ts.tv_sec %= 3600; 217 f = 1; 218 } 219 if (f || ts.tv_sec >= 60) { 220 printf("%ldm", (long)ts.tv_sec / 60); 221 ts.tv_sec %= 60; 222 f = 1; 223 } 224 printf("%lds\n", (long)ts.tv_sec); 225 } 226 227 static void 228 doadump(void) 229 { 230 231 /* 232 * Sometimes people have to call this from the kernel debugger. 233 * (if 'panic' can not dump) 234 * Give them a clue as to why they can't dump. 235 */ 236 if (dumper.dumper == NULL) { 237 printf("Cannot dump. No dump device defined.\n"); 238 return; 239 } 240 241 savectx(&dumppcb); 242 dumptid = curthread->td_tid; 243 dumping++; 244 dumpsys(&dumper); 245 } 246 247 static int 248 isbufbusy(struct buf *bp) 249 { 250 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 && 251 BUF_REFCNT(bp) > 0) || 252 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI)) 253 return (1); 254 return (0); 255 } 256 257 /* 258 * Shutdown the system cleanly to prepare for reboot, halt, or power off. 259 */ 260 static void 261 boot(int howto) 262 { 263 static int first_buf_printf = 1; 264 265 #if defined(SMP) 266 /* 267 * Bind us to CPU 0 so that all shutdown code runs there. Some 268 * systems don't shutdown properly (i.e., ACPI power off) if we 269 * run on another processor. 270 */ 271 mtx_lock_spin(&sched_lock); 272 sched_bind(curthread, 0); 273 mtx_unlock_spin(&sched_lock); 274 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0")); 275 #endif 276 /* We're in the process of rebooting. */ 277 rebooting = 1; 278 279 /* collect extra flags that shutdown_nice might have set */ 280 howto |= shutdown_howto; 281 282 /* We are out of the debugger now. */ 283 kdb_active = 0; 284 285 /* 286 * Do any callouts that should be done BEFORE syncing the filesystems. 287 */ 288 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 289 290 /* 291 * Now sync filesystems 292 */ 293 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) { 294 register struct buf *bp; 295 int iter, nbusy, pbusy; 296 #ifndef PREEMPTION 297 int subiter; 298 #endif 299 300 waittime = 0; 301 302 sync(curthread, NULL); 303 304 /* 305 * With soft updates, some buffers that are 306 * written will be remarked as dirty until other 307 * buffers are written. 308 */ 309 for (iter = pbusy = 0; iter < 20; iter++) { 310 nbusy = 0; 311 for (bp = &buf[nbuf]; --bp >= buf; ) 312 if (isbufbusy(bp)) 313 nbusy++; 314 if (nbusy == 0) { 315 if (first_buf_printf) 316 printf("All buffers synced."); 317 break; 318 } 319 if (first_buf_printf) { 320 printf("Syncing disks, buffers remaining... "); 321 first_buf_printf = 0; 322 } 323 printf("%d ", nbusy); 324 if (nbusy < pbusy) 325 iter = 0; 326 pbusy = nbusy; 327 sync(curthread, NULL); 328 329 #ifdef PREEMPTION 330 /* 331 * Drop Giant and spin for a while to allow 332 * interrupt threads to run. 333 */ 334 DROP_GIANT(); 335 DELAY(50000 * iter); 336 PICKUP_GIANT(); 337 #else 338 /* 339 * Drop Giant and context switch several times to 340 * allow interrupt threads to run. 341 */ 342 DROP_GIANT(); 343 for (subiter = 0; subiter < 50 * iter; subiter++) { 344 mtx_lock_spin(&sched_lock); 345 mi_switch(SW_VOL, NULL); 346 mtx_unlock_spin(&sched_lock); 347 DELAY(1000); 348 } 349 PICKUP_GIANT(); 350 #endif 351 } 352 printf("\n"); 353 /* 354 * Count only busy local buffers to prevent forcing 355 * a fsck if we're just a client of a wedged NFS server 356 */ 357 nbusy = 0; 358 for (bp = &buf[nbuf]; --bp >= buf; ) { 359 if (isbufbusy(bp)) { 360 #if 0 361 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */ 362 if (bp->b_dev == NULL) { 363 TAILQ_REMOVE(&mountlist, 364 bp->b_vp->v_mount, mnt_list); 365 continue; 366 } 367 #endif 368 nbusy++; 369 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC) 370 printf( 371 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n", 372 nbusy, bp->b_bufobj, 373 bp->b_flags, (long)bp->b_blkno, 374 (long)bp->b_lblkno); 375 #endif 376 } 377 } 378 if (nbusy) { 379 /* 380 * Failed to sync all blocks. Indicate this and don't 381 * unmount filesystems (thus forcing an fsck on reboot). 382 */ 383 printf("Giving up on %d buffers\n", nbusy); 384 DELAY(5000000); /* 5 seconds */ 385 } else { 386 if (!first_buf_printf) 387 printf("Final sync complete\n"); 388 /* 389 * Unmount filesystems 390 */ 391 if (panicstr == 0) 392 vfs_unmountall(); 393 } 394 swapoff_all(); 395 DELAY(100000); /* wait for console output to finish */ 396 } 397 398 print_uptime(); 399 400 /* 401 * Ok, now do things that assume all filesystem activity has 402 * been completed. 403 */ 404 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 405 406 /* XXX This doesn't disable interrupts any more. Reconsider? */ 407 splhigh(); 408 409 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping) 410 doadump(); 411 412 /* Now that we're going to really halt the system... */ 413 EVENTHANDLER_INVOKE(shutdown_final, howto); 414 415 for(;;) ; /* safety against shutdown_reset not working */ 416 /* NOTREACHED */ 417 } 418 419 /* 420 * If the shutdown was a clean halt, behave accordingly. 421 */ 422 static void 423 shutdown_halt(void *junk, int howto) 424 { 425 426 if (howto & RB_HALT) { 427 printf("\n"); 428 printf("The operating system has halted.\n"); 429 printf("Please press any key to reboot.\n\n"); 430 switch (cngetc()) { 431 case -1: /* No console, just die */ 432 cpu_halt(); 433 /* NOTREACHED */ 434 default: 435 howto &= ~RB_HALT; 436 break; 437 } 438 } 439 } 440 441 /* 442 * Check to see if the system paniced, pause and then reboot 443 * according to the specified delay. 444 */ 445 static void 446 shutdown_panic(void *junk, int howto) 447 { 448 int loop; 449 450 if (howto & RB_DUMP) { 451 if (PANIC_REBOOT_WAIT_TIME != 0) { 452 if (PANIC_REBOOT_WAIT_TIME != -1) { 453 printf("Automatic reboot in %d seconds - " 454 "press a key on the console to abort\n", 455 PANIC_REBOOT_WAIT_TIME); 456 for (loop = PANIC_REBOOT_WAIT_TIME * 10; 457 loop > 0; --loop) { 458 DELAY(1000 * 100); /* 1/10th second */ 459 /* Did user type a key? */ 460 if (cncheckc() != -1) 461 break; 462 } 463 if (!loop) 464 return; 465 } 466 } else { /* zero time specified - reboot NOW */ 467 return; 468 } 469 printf("--> Press a key on the console to reboot,\n"); 470 printf("--> or switch off the system now.\n"); 471 cngetc(); 472 } 473 } 474 475 /* 476 * Everything done, now reset 477 */ 478 static void 479 shutdown_reset(void *junk, int howto) 480 { 481 482 printf("Rebooting...\n"); 483 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */ 484 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 485 cpu_reset(); 486 /* NOTREACHED */ /* assuming reset worked */ 487 } 488 489 #ifdef SMP 490 static u_int panic_cpu = NOCPU; 491 #endif 492 493 /* 494 * Panic is called on unresolvable fatal errors. It prints "panic: mesg", 495 * and then reboots. If we are called twice, then we avoid trying to sync 496 * the disks as this often leads to recursive panics. 497 * 498 * MPSAFE 499 */ 500 void 501 panic(const char *fmt, ...) 502 { 503 struct thread *td = curthread; 504 int bootopt, newpanic; 505 va_list ap; 506 static char buf[256]; 507 508 #ifdef SMP 509 /* 510 * We don't want multiple CPU's to panic at the same time, so we 511 * use panic_cpu as a simple spinlock. We have to keep checking 512 * panic_cpu if we are spinning in case the panic on the first 513 * CPU is canceled. 514 */ 515 if (panic_cpu != PCPU_GET(cpuid)) 516 while (atomic_cmpset_int(&panic_cpu, NOCPU, 517 PCPU_GET(cpuid)) == 0) 518 while (panic_cpu != NOCPU) 519 ; /* nothing */ 520 #endif 521 522 bootopt = RB_AUTOBOOT | RB_DUMP; 523 newpanic = 0; 524 if (panicstr) 525 bootopt |= RB_NOSYNC; 526 else { 527 panicstr = fmt; 528 newpanic = 1; 529 } 530 531 va_start(ap, fmt); 532 if (newpanic) { 533 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 534 panicstr = buf; 535 printf("panic: %s\n", buf); 536 } else { 537 printf("panic: "); 538 vprintf(fmt, ap); 539 printf("\n"); 540 } 541 va_end(ap); 542 #ifdef SMP 543 printf("cpuid = %d\n", PCPU_GET(cpuid)); 544 #endif 545 546 #ifdef KDB 547 if (newpanic && trace_on_panic) 548 kdb_backtrace(); 549 if (debugger_on_panic) 550 kdb_enter("panic"); 551 #ifdef RESTARTABLE_PANICS 552 /* See if the user aborted the panic, in which case we continue. */ 553 if (panicstr == NULL) { 554 #ifdef SMP 555 atomic_store_rel_int(&panic_cpu, NOCPU); 556 #endif 557 return; 558 } 559 #endif 560 #endif 561 mtx_lock_spin(&sched_lock); 562 td->td_flags |= TDF_INPANIC; 563 mtx_unlock_spin(&sched_lock); 564 if (!sync_on_panic) 565 bootopt |= RB_NOSYNC; 566 boot(bootopt); 567 } 568 569 /* 570 * Support for poweroff delay. 571 */ 572 #ifndef POWEROFF_DELAY 573 # define POWEROFF_DELAY 5000 574 #endif 575 static int poweroff_delay = POWEROFF_DELAY; 576 577 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 578 &poweroff_delay, 0, ""); 579 580 static void 581 poweroff_wait(void *junk, int howto) 582 { 583 584 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0) 585 return; 586 DELAY(poweroff_delay * 1000); 587 } 588 589 /* 590 * Some system processes (e.g. syncer) need to be stopped at appropriate 591 * points in their main loops prior to a system shutdown, so that they 592 * won't interfere with the shutdown process (e.g. by holding a disk buf 593 * to cause sync to fail). For each of these system processes, register 594 * shutdown_kproc() as a handler for one of shutdown events. 595 */ 596 static int kproc_shutdown_wait = 60; 597 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 598 &kproc_shutdown_wait, 0, ""); 599 600 void 601 kproc_shutdown(void *arg, int howto) 602 { 603 struct proc *p; 604 char procname[MAXCOMLEN + 1]; 605 int error; 606 607 if (panicstr) 608 return; 609 610 p = (struct proc *)arg; 611 strlcpy(procname, p->p_comm, sizeof(procname)); 612 printf("Waiting (max %d seconds) for system process `%s' to stop...", 613 kproc_shutdown_wait, procname); 614 error = kthread_suspend(p, kproc_shutdown_wait * hz); 615 616 if (error == EWOULDBLOCK) 617 printf("timed out\n"); 618 else 619 printf("done\n"); 620 } 621 622 /* Registration of dumpers */ 623 int 624 set_dumper(struct dumperinfo *di) 625 { 626 627 if (di == NULL) { 628 bzero(&dumper, sizeof dumper); 629 return (0); 630 } 631 if (dumper.dumper != NULL) 632 return (EBUSY); 633 dumper = *di; 634 return (0); 635 } 636 637 #if defined(__powerpc__) 638 void 639 dumpsys(struct dumperinfo *di __unused) 640 { 641 642 printf("Kernel dumps not implemented on this architecture\n"); 643 } 644 #endif 645