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_mac.h" 43 #include "opt_panic.h" 44 #include "opt_show_busybufs.h" 45 #include "opt_sched.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/cons.h> 53 #include <sys/eventhandler.h> 54 #include <sys/kdb.h> 55 #include <sys/kernel.h> 56 #include <sys/kthread.h> 57 #include <sys/malloc.h> 58 #include <sys/mount.h> 59 #include <sys/priv.h> 60 #include <sys/proc.h> 61 #include <sys/reboot.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sched.h> 64 #include <sys/smp.h> /* smp_active */ 65 #include <sys/sysctl.h> 66 #include <sys/sysproto.h> 67 68 #include <ddb/ddb.h> 69 70 #include <machine/cpu.h> 71 #include <machine/pcb.h> 72 #include <machine/smp.h> 73 74 #include <security/mac/mac_framework.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_object.h> 78 #include <vm/vm_page.h> 79 #include <vm/vm_pager.h> 80 #include <vm/swap_pager.h> 81 82 #include <sys/signalvar.h> 83 84 #ifndef PANIC_REBOOT_WAIT_TIME 85 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */ 86 #endif 87 88 /* 89 * Note that stdarg.h and the ANSI style va_start macro is used for both 90 * ANSI and traditional C compilers. 91 */ 92 #include <machine/stdarg.h> 93 94 #ifdef KDB 95 #ifdef KDB_UNATTENDED 96 int debugger_on_panic = 0; 97 #else 98 int debugger_on_panic = 1; 99 #endif 100 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW, 101 &debugger_on_panic, 0, "Run debugger on kernel panic"); 102 103 #ifdef KDB_TRACE 104 int trace_on_panic = 1; 105 #else 106 int trace_on_panic = 0; 107 #endif 108 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW, 109 &trace_on_panic, 0, "Print stack trace on kernel panic"); 110 #endif /* KDB */ 111 112 int sync_on_panic = 0; 113 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW, 114 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 115 116 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment"); 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 */ 122 const char *panicstr; 123 124 int dumping; /* system is dumping */ 125 int rebooting; /* system is rebooting */ 126 static struct dumperinfo dumper; /* our selected dumper */ 127 128 /* Context information for dump-debuggers. */ 129 static struct pcb dumppcb; /* Registers. */ 130 static lwpid_t dumptid; /* Thread ID. */ 131 132 static void boot(int) __dead2; 133 static void poweroff_wait(void *, int); 134 static void shutdown_halt(void *junk, int howto); 135 static void shutdown_panic(void *junk, int howto); 136 static void shutdown_reset(void *junk, int howto); 137 138 /* register various local shutdown events */ 139 static void 140 shutdown_conf(void *unused) 141 { 142 143 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, 144 SHUTDOWN_PRI_FIRST); 145 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, 146 SHUTDOWN_PRI_LAST + 100); 147 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, 148 SHUTDOWN_PRI_LAST + 100); 149 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, 150 SHUTDOWN_PRI_LAST + 200); 151 } 152 153 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL) 154 155 /* 156 * The system call that results in a reboot. 157 */ 158 /* ARGSUSED */ 159 int 160 reboot(struct thread *td, struct reboot_args *uap) 161 { 162 int error; 163 164 error = 0; 165 #ifdef MAC 166 error = mac_system_check_reboot(td->td_ucred, uap->opt); 167 #endif 168 if (error == 0) 169 error = priv_check(td, PRIV_REBOOT); 170 if (error == 0) { 171 mtx_lock(&Giant); 172 boot(uap->opt); 173 mtx_unlock(&Giant); 174 } 175 return (error); 176 } 177 178 /* 179 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC 180 */ 181 static int shutdown_howto = 0; 182 183 void 184 shutdown_nice(int howto) 185 { 186 187 shutdown_howto = howto; 188 189 /* Send a signal to init(8) and have it shutdown the world */ 190 if (initproc != NULL) { 191 PROC_LOCK(initproc); 192 psignal(initproc, SIGINT); 193 PROC_UNLOCK(initproc); 194 } else { 195 /* No init(8) running, so simply reboot */ 196 boot(RB_NOSYNC); 197 } 198 return; 199 } 200 static int waittime = -1; 201 202 static void 203 print_uptime(void) 204 { 205 int f; 206 struct timespec ts; 207 208 getnanouptime(&ts); 209 printf("Uptime: "); 210 f = 0; 211 if (ts.tv_sec >= 86400) { 212 printf("%ldd", (long)ts.tv_sec / 86400); 213 ts.tv_sec %= 86400; 214 f = 1; 215 } 216 if (f || ts.tv_sec >= 3600) { 217 printf("%ldh", (long)ts.tv_sec / 3600); 218 ts.tv_sec %= 3600; 219 f = 1; 220 } 221 if (f || ts.tv_sec >= 60) { 222 printf("%ldm", (long)ts.tv_sec / 60); 223 ts.tv_sec %= 60; 224 f = 1; 225 } 226 printf("%lds\n", (long)ts.tv_sec); 227 } 228 229 static void 230 doadump(void) 231 { 232 233 /* 234 * Sometimes people have to call this from the kernel debugger. 235 * (if 'panic' can not dump) 236 * Give them a clue as to why they can't dump. 237 */ 238 if (dumper.dumper == NULL) { 239 printf("Cannot dump. No dump device defined.\n"); 240 return; 241 } 242 243 savectx(&dumppcb); 244 dumptid = curthread->td_tid; 245 dumping++; 246 #ifdef DDB 247 if (textdump_pending) 248 textdump_dumpsys(&dumper); 249 else 250 #endif 251 dumpsys(&dumper); 252 } 253 254 static int 255 isbufbusy(struct buf *bp) 256 { 257 if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 && 258 BUF_REFCNT(bp) > 0) || 259 ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI)) 260 return (1); 261 return (0); 262 } 263 264 /* 265 * Shutdown the system cleanly to prepare for reboot, halt, or power off. 266 */ 267 static void 268 boot(int howto) 269 { 270 static int first_buf_printf = 1; 271 272 #if defined(SMP) 273 /* 274 * Bind us to CPU 0 so that all shutdown code runs there. Some 275 * systems don't shutdown properly (i.e., ACPI power off) if we 276 * run on another processor. 277 */ 278 thread_lock(curthread); 279 sched_bind(curthread, 0); 280 thread_unlock(curthread); 281 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0")); 282 #endif 283 /* We're in the process of rebooting. */ 284 rebooting = 1; 285 286 /* collect extra flags that shutdown_nice might have set */ 287 howto |= shutdown_howto; 288 289 /* We are out of the debugger now. */ 290 kdb_active = 0; 291 292 /* 293 * Do any callouts that should be done BEFORE syncing the filesystems. 294 */ 295 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 296 297 /* 298 * Now sync filesystems 299 */ 300 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) { 301 register struct buf *bp; 302 int iter, nbusy, pbusy; 303 #ifndef PREEMPTION 304 int subiter; 305 #endif 306 307 waittime = 0; 308 309 sync(curthread, NULL); 310 311 /* 312 * With soft updates, some buffers that are 313 * written will be remarked as dirty until other 314 * buffers are written. 315 */ 316 for (iter = pbusy = 0; iter < 20; iter++) { 317 nbusy = 0; 318 for (bp = &buf[nbuf]; --bp >= buf; ) 319 if (isbufbusy(bp)) 320 nbusy++; 321 if (nbusy == 0) { 322 if (first_buf_printf) 323 printf("All buffers synced."); 324 break; 325 } 326 if (first_buf_printf) { 327 printf("Syncing disks, buffers remaining... "); 328 first_buf_printf = 0; 329 } 330 printf("%d ", nbusy); 331 if (nbusy < pbusy) 332 iter = 0; 333 pbusy = nbusy; 334 sync(curthread, NULL); 335 336 #ifdef PREEMPTION 337 /* 338 * Drop Giant and spin for a while to allow 339 * interrupt threads to run. 340 */ 341 DROP_GIANT(); 342 DELAY(50000 * iter); 343 PICKUP_GIANT(); 344 #else 345 /* 346 * Drop Giant and context switch several times to 347 * allow interrupt threads to run. 348 */ 349 DROP_GIANT(); 350 for (subiter = 0; subiter < 50 * iter; subiter++) { 351 thread_lock(curthread); 352 mi_switch(SW_VOL, NULL); 353 thread_unlock(curthread); 354 DELAY(1000); 355 } 356 PICKUP_GIANT(); 357 #endif 358 } 359 printf("\n"); 360 /* 361 * Count only busy local buffers to prevent forcing 362 * a fsck if we're just a client of a wedged NFS server 363 */ 364 nbusy = 0; 365 for (bp = &buf[nbuf]; --bp >= buf; ) { 366 if (isbufbusy(bp)) { 367 #if 0 368 /* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */ 369 if (bp->b_dev == NULL) { 370 TAILQ_REMOVE(&mountlist, 371 bp->b_vp->v_mount, mnt_list); 372 continue; 373 } 374 #endif 375 nbusy++; 376 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC) 377 printf( 378 "%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n", 379 nbusy, bp->b_bufobj, 380 bp->b_flags, (long)bp->b_blkno, 381 (long)bp->b_lblkno); 382 #endif 383 } 384 } 385 if (nbusy) { 386 /* 387 * Failed to sync all blocks. Indicate this and don't 388 * unmount filesystems (thus forcing an fsck on reboot). 389 */ 390 printf("Giving up on %d buffers\n", nbusy); 391 DELAY(5000000); /* 5 seconds */ 392 } else { 393 if (!first_buf_printf) 394 printf("Final sync complete\n"); 395 /* 396 * Unmount filesystems 397 */ 398 if (panicstr == 0) 399 vfs_unmountall(); 400 } 401 swapoff_all(); 402 DELAY(100000); /* wait for console output to finish */ 403 } 404 405 print_uptime(); 406 407 /* 408 * Ok, now do things that assume all filesystem activity has 409 * been completed. 410 */ 411 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 412 413 /* XXX This doesn't disable interrupts any more. Reconsider? */ 414 splhigh(); 415 416 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping) 417 doadump(); 418 419 /* Now that we're going to really halt the system... */ 420 EVENTHANDLER_INVOKE(shutdown_final, howto); 421 422 for(;;) ; /* safety against shutdown_reset not working */ 423 /* NOTREACHED */ 424 } 425 426 /* 427 * If the shutdown was a clean halt, behave accordingly. 428 */ 429 static void 430 shutdown_halt(void *junk, int howto) 431 { 432 433 if (howto & RB_HALT) { 434 printf("\n"); 435 printf("The operating system has halted.\n"); 436 printf("Please press any key to reboot.\n\n"); 437 switch (cngetc()) { 438 case -1: /* No console, just die */ 439 cpu_halt(); 440 /* NOTREACHED */ 441 default: 442 howto &= ~RB_HALT; 443 break; 444 } 445 } 446 } 447 448 /* 449 * Check to see if the system paniced, pause and then reboot 450 * according to the specified delay. 451 */ 452 static void 453 shutdown_panic(void *junk, int howto) 454 { 455 int loop; 456 457 if (howto & RB_DUMP) { 458 if (PANIC_REBOOT_WAIT_TIME != 0) { 459 if (PANIC_REBOOT_WAIT_TIME != -1) { 460 printf("Automatic reboot in %d seconds - " 461 "press a key on the console to abort\n", 462 PANIC_REBOOT_WAIT_TIME); 463 for (loop = PANIC_REBOOT_WAIT_TIME * 10; 464 loop > 0; --loop) { 465 DELAY(1000 * 100); /* 1/10th second */ 466 /* Did user type a key? */ 467 if (cncheckc() != -1) 468 break; 469 } 470 if (!loop) 471 return; 472 } 473 } else { /* zero time specified - reboot NOW */ 474 return; 475 } 476 printf("--> Press a key on the console to reboot,\n"); 477 printf("--> or switch off the system now.\n"); 478 cngetc(); 479 } 480 } 481 482 /* 483 * Everything done, now reset 484 */ 485 static void 486 shutdown_reset(void *junk, int howto) 487 { 488 489 printf("Rebooting...\n"); 490 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */ 491 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 492 cpu_reset(); 493 /* NOTREACHED */ /* assuming reset worked */ 494 } 495 496 #ifdef SMP 497 static u_int panic_cpu = NOCPU; 498 #endif 499 500 /* 501 * Panic is called on unresolvable fatal errors. It prints "panic: mesg", 502 * and then reboots. If we are called twice, then we avoid trying to sync 503 * the disks as this often leads to recursive panics. 504 */ 505 void 506 panic(const char *fmt, ...) 507 { 508 struct thread *td = curthread; 509 int bootopt, newpanic; 510 va_list ap; 511 static char buf[256]; 512 513 #ifdef SMP 514 /* 515 * We don't want multiple CPU's to panic at the same time, so we 516 * use panic_cpu as a simple spinlock. We have to keep checking 517 * panic_cpu if we are spinning in case the panic on the first 518 * CPU is canceled. 519 */ 520 if (panic_cpu != PCPU_GET(cpuid)) 521 while (atomic_cmpset_int(&panic_cpu, NOCPU, 522 PCPU_GET(cpuid)) == 0) 523 while (panic_cpu != NOCPU) 524 ; /* nothing */ 525 #endif 526 527 bootopt = RB_AUTOBOOT | RB_DUMP; 528 newpanic = 0; 529 if (panicstr) 530 bootopt |= RB_NOSYNC; 531 else { 532 panicstr = fmt; 533 newpanic = 1; 534 } 535 536 va_start(ap, fmt); 537 if (newpanic) { 538 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 539 panicstr = buf; 540 printf("panic: %s\n", buf); 541 } else { 542 printf("panic: "); 543 vprintf(fmt, ap); 544 printf("\n"); 545 } 546 va_end(ap); 547 #ifdef SMP 548 printf("cpuid = %d\n", PCPU_GET(cpuid)); 549 #endif 550 551 #ifdef KDB 552 if (newpanic && trace_on_panic) 553 kdb_backtrace(); 554 if (debugger_on_panic) 555 kdb_enter(KDB_WHY_PANIC, "panic"); 556 #ifdef RESTARTABLE_PANICS 557 /* See if the user aborted the panic, in which case we continue. */ 558 if (panicstr == NULL) { 559 #ifdef SMP 560 atomic_store_rel_int(&panic_cpu, NOCPU); 561 #endif 562 return; 563 } 564 #endif 565 #endif 566 /*thread_lock(td); */ 567 td->td_flags |= TDF_INPANIC; 568 /* thread_unlock(td); */ 569 if (!sync_on_panic) 570 bootopt |= RB_NOSYNC; 571 boot(bootopt); 572 } 573 574 /* 575 * Support for poweroff delay. 576 */ 577 #ifndef POWEROFF_DELAY 578 # define POWEROFF_DELAY 5000 579 #endif 580 static int poweroff_delay = POWEROFF_DELAY; 581 582 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 583 &poweroff_delay, 0, ""); 584 585 static void 586 poweroff_wait(void *junk, int howto) 587 { 588 589 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0) 590 return; 591 DELAY(poweroff_delay * 1000); 592 } 593 594 /* 595 * Some system processes (e.g. syncer) need to be stopped at appropriate 596 * points in their main loops prior to a system shutdown, so that they 597 * won't interfere with the shutdown process (e.g. by holding a disk buf 598 * to cause sync to fail). For each of these system processes, register 599 * shutdown_kproc() as a handler for one of shutdown events. 600 */ 601 static int kproc_shutdown_wait = 60; 602 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 603 &kproc_shutdown_wait, 0, ""); 604 605 void 606 kproc_shutdown(void *arg, int howto) 607 { 608 struct proc *p; 609 char procname[MAXCOMLEN + 1]; 610 int error; 611 612 if (panicstr) 613 return; 614 615 p = (struct proc *)arg; 616 strlcpy(procname, p->p_comm, sizeof(procname)); 617 printf("Waiting (max %d seconds) for system process `%s' to stop...", 618 kproc_shutdown_wait, procname); 619 error = kproc_suspend(p, kproc_shutdown_wait * hz); 620 621 if (error == EWOULDBLOCK) 622 printf("timed out\n"); 623 else 624 printf("done\n"); 625 } 626 627 void 628 kthread_shutdown(void *arg, int howto) 629 { 630 struct thread *td; 631 char procname[MAXCOMLEN + 1]; 632 int error; 633 634 if (panicstr) 635 return; 636 637 td = (struct thread *)arg; 638 strlcpy(procname, td->td_name, sizeof(procname)); 639 printf("Waiting (max %d seconds) for system thread `%s' to stop...", 640 kproc_shutdown_wait, procname); 641 error = kthread_suspend(td, kproc_shutdown_wait * hz); 642 643 if (error == EWOULDBLOCK) 644 printf("timed out\n"); 645 else 646 printf("done\n"); 647 } 648 649 /* Registration of dumpers */ 650 int 651 set_dumper(struct dumperinfo *di) 652 { 653 654 if (di == NULL) { 655 bzero(&dumper, sizeof dumper); 656 return (0); 657 } 658 if (dumper.dumper != NULL) 659 return (EBUSY); 660 dumper = *di; 661 return (0); 662 } 663 664 #if defined(__powerpc__) 665 void 666 dumpsys(struct dumperinfo *di __unused) 667 { 668 669 printf("Kernel dumps not implemented on this architecture\n"); 670 } 671 #endif 672