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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_shutdown.c 8.3 (Berkeley) 1/21/94 39 * $FreeBSD: src/sys/kern/kern_shutdown.c,v 1.72.2.12 2002/02/21 19:15:10 dillon Exp $ 40 * $DragonFly: src/sys/kern/kern_shutdown.c,v 1.53 2007/05/19 07:05:25 dillon Exp $ 41 */ 42 43 #include "opt_ddb.h" 44 #include "opt_ddb_trace.h" 45 #include "opt_hw_wdog.h" 46 #include "opt_panic.h" 47 #include "opt_show_busybufs.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/eventhandler.h> 52 #include <sys/buf.h> 53 #include <sys/diskslice.h> 54 #include <sys/reboot.h> 55 #include <sys/proc.h> 56 #include <sys/vnode.h> 57 #include <sys/kernel.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 76 #include <machine/pcb.h> 77 #include <machine/clock.h> 78 #include <machine/md_var.h> 79 #include <machine/smp.h> /* smp_active_mask, cpuid */ 80 #include <machine/vmparam.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. We use the machine version to stay 91 * within the confines of the kernel header files. 92 */ 93 #include <machine/stdarg.h> 94 95 #ifdef DDB 96 #ifdef DDB_UNATTENDED 97 int debugger_on_panic = 0; 98 #else 99 int debugger_on_panic = 1; 100 #endif 101 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW, 102 &debugger_on_panic, 0, "Run debugger on kernel panic"); 103 104 extern void db_print_backtrace(void); 105 106 #ifdef DDB_TRACE 107 int trace_on_panic = 1; 108 #else 109 int trace_on_panic = 0; 110 #endif 111 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW, 112 &trace_on_panic, 0, "Print stack trace on kernel panic"); 113 #endif 114 115 static int sync_on_panic = 1; 116 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW, 117 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 118 119 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment"); 120 121 #ifdef HW_WDOG 122 /* 123 * If there is a hardware watchdog, point this at the function needed to 124 * hold it off. 125 * It's needed when the kernel needs to do some lengthy operations. 126 * e.g. in wd.c when dumping core.. It's most annoying to have 127 * your precious core-dump only half written because the wdog kicked in. 128 */ 129 watchdog_tickle_fn wdog_tickler = NULL; 130 #endif /* HW_WDOG */ 131 132 /* 133 * Variable panicstr contains argument to first call to panic; used as flag 134 * to indicate that the kernel has already called panic. 135 */ 136 const char *panicstr; 137 138 int dumping; /* system is dumping */ 139 #ifdef SMP 140 u_int panic_cpu_interlock; /* panic interlock */ 141 globaldata_t panic_cpu_gd; /* which cpu took the panic */ 142 #endif 143 144 int bootverbose = 0; /* note: assignment to force non-bss */ 145 int cold = 1; /* note: assignment to force non-bss */ 146 int dumplo; /* OBSOLETE - savecore compat */ 147 u_int64_t dumplo64; 148 149 static void boot (int) __dead2; 150 static void dumpsys (void); 151 static int setdumpdev (cdev_t dev); 152 static void poweroff_wait (void *, int); 153 static void print_uptime (void); 154 static void shutdown_halt (void *junk, int howto); 155 static void shutdown_panic (void *junk, int howto); 156 static void shutdown_reset (void *junk, int howto); 157 static int shutdown_busycount1(struct buf *bp, void *info); 158 static int shutdown_busycount2(struct buf *bp, void *info); 159 static void shutdown_cleanup_proc(struct proc *p); 160 161 /* register various local shutdown events */ 162 static void 163 shutdown_conf(void *unused) 164 { 165 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, SHUTDOWN_PRI_FIRST); 166 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, SHUTDOWN_PRI_LAST + 100); 167 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, SHUTDOWN_PRI_LAST + 100); 168 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, SHUTDOWN_PRI_LAST + 200); 169 } 170 171 SYSINIT(shutdown_conf, SI_BOOT2_MACHDEP, SI_ORDER_ANY, shutdown_conf, NULL) 172 173 /* ARGSUSED */ 174 175 /* 176 * The system call that results in a reboot 177 */ 178 int 179 sys_reboot(struct reboot_args *uap) 180 { 181 struct thread *td = curthread; 182 int error; 183 184 if ((error = suser(td))) 185 return (error); 186 187 boot(uap->opt); 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 static struct thread *dumpthread; 212 static struct pcb dumppcb; 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 #ifdef SMP 261 /* 262 * We really want to shutdown on the BSP. Subsystems such as ACPI 263 * can't power-down the box otherwise. 264 */ 265 if (smp_active_mask > 1) { 266 kprintf("boot() called on cpu#%d\n", mycpu->gd_cpuid); 267 } 268 if (panicstr == NULL && mycpu->gd_cpuid != 0) { 269 kprintf("Switching to cpu #0 for shutdown\n"); 270 lwkt_setcpu_self(globaldata_find(0)); 271 } 272 #endif 273 /* 274 * Do any callouts that should be done BEFORE syncing the filesystems. 275 */ 276 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 277 278 /* 279 * Try to get rid of any remaining FS references. The calling 280 * process, proc0, and init may still hold references. The 281 * VFS cache subsystem may still hold a root reference to root. 282 * 283 * XXX this needs work. We really need to SIGSTOP all remaining 284 * processes in order to avoid blowups due to proc0's filesystem 285 * references going away. For now just make sure that the init 286 * process is stopped. 287 */ 288 if (panicstr == NULL) { 289 shutdown_cleanup_proc(curproc); 290 shutdown_cleanup_proc(&proc0); 291 if (initproc) { 292 if (initproc != curproc) { 293 ksignal(initproc, SIGSTOP); 294 tsleep(boot, 0, "shutdn", hz / 20); 295 } 296 shutdown_cleanup_proc(initproc); 297 } 298 vfs_cache_setroot(NULL, NULL); 299 } 300 301 /* 302 * Now sync filesystems 303 */ 304 if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) { 305 int iter, nbusy, pbusy; 306 307 waittime = 0; 308 kprintf("\nsyncing disks... "); 309 310 sys_sync(NULL); /* YYY was sync(&proc0, NULL). why proc0 ? */ 311 312 /* 313 * With soft updates, some buffers that are 314 * written will be remarked as dirty until other 315 * buffers are written. 316 */ 317 for (iter = pbusy = 0; iter < 20; iter++) { 318 nbusy = scan_all_buffers(shutdown_busycount1, NULL); 319 if (nbusy == 0) 320 break; 321 kprintf("%d ", nbusy); 322 if (nbusy < pbusy) 323 iter = 0; 324 pbusy = nbusy; 325 /* 326 * XXX: 327 * Process soft update work queue if buffers don't sync 328 * after 6 iterations by permitting the syncer to run. 329 */ 330 if (iter > 5 && bioops.io_sync) 331 (*bioops.io_sync)(NULL); 332 sys_sync(NULL); /* YYY was sync(&proc0, NULL). why proc0 ? */ 333 tsleep(boot, 0, "shutdn", hz * iter / 20 + 1); 334 } 335 kprintf("\n"); 336 /* 337 * Count only busy local buffers to prevent forcing 338 * a fsck if we're just a client of a wedged NFS server 339 */ 340 nbusy = scan_all_buffers(shutdown_busycount2, NULL); 341 if (nbusy) { 342 /* 343 * Failed to sync all blocks. Indicate this and don't 344 * unmount filesystems (thus forcing an fsck on reboot). 345 */ 346 kprintf("giving up on %d buffers\n", nbusy); 347 #ifdef DDB 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 * Ok, now do things that assume all filesystem activity has 366 * been completed. 367 */ 368 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 369 crit_enter(); 370 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold) 371 dumpsys(); 372 373 /* Now that we're going to really halt the system... */ 374 EVENTHANDLER_INVOKE(shutdown_final, howto); 375 376 for(;;) ; /* safety against shutdown_reset not working */ 377 /* NOTREACHED */ 378 } 379 380 static int 381 shutdown_busycount1(struct buf *bp, void *info) 382 { 383 if ((bp->b_flags & B_INVAL) == 0 && BUF_REFCNT(bp) > 0) 384 return(1); 385 if ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) 386 return (1); 387 return (0); 388 } 389 390 static int 391 shutdown_busycount2(struct buf *bp, void *info) 392 { 393 if (((bp->b_flags & B_INVAL) == 0 && BUF_REFCNT(bp)) || 394 ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) { 395 /* 396 * Only count buffers undergoing write I/O 397 * on the related vnode. 398 */ 399 if (bp->b_vp == NULL || 400 bp->b_vp->v_track_write.bk_active == 0) { 401 return (0); 402 } 403 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC) 404 kprintf( 405 "%p dev:?, flags:%08x, loffset:%lld, doffset:%lld\n", 406 bp, 407 bp->b_flags, bp->b_loffset, 408 bp->b_bio2.bio_offset); 409 #endif 410 return(1); 411 } 412 return(0); 413 } 414 415 /* 416 * If the shutdown was a clean halt, behave accordingly. 417 */ 418 static void 419 shutdown_halt(void *junk, int howto) 420 { 421 if (howto & RB_HALT) { 422 kprintf("\n"); 423 kprintf("The operating system has halted.\n"); 424 kprintf("Please press any key to reboot.\n\n"); 425 switch (cngetc()) { 426 case -1: /* No console, just die */ 427 cpu_halt(); 428 /* NOTREACHED */ 429 default: 430 howto &= ~RB_HALT; 431 break; 432 } 433 } 434 } 435 436 /* 437 * Check to see if the system paniced, pause and then reboot 438 * according to the specified delay. 439 */ 440 static void 441 shutdown_panic(void *junk, int howto) 442 { 443 int loop; 444 445 if (howto & RB_DUMP) { 446 if (PANIC_REBOOT_WAIT_TIME != 0) { 447 if (PANIC_REBOOT_WAIT_TIME != -1) { 448 kprintf("Automatic reboot in %d seconds - " 449 "press a key on the console to abort\n", 450 PANIC_REBOOT_WAIT_TIME); 451 for (loop = PANIC_REBOOT_WAIT_TIME * 10; 452 loop > 0; --loop) { 453 DELAY(1000 * 100); /* 1/10th second */ 454 /* Did user type a key? */ 455 if (cncheckc() != -1) 456 break; 457 } 458 if (!loop) 459 return; 460 } 461 } else { /* zero time specified - reboot NOW */ 462 return; 463 } 464 kprintf("--> Press a key on the console to reboot,\n"); 465 kprintf("--> or switch off the system now.\n"); 466 cngetc(); 467 } 468 } 469 470 /* 471 * Everything done, now reset 472 */ 473 static void 474 shutdown_reset(void *junk, int howto) 475 { 476 kprintf("Rebooting...\n"); 477 DELAY(1000000); /* wait 1 sec for kprintf's to complete and be read */ 478 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 479 cpu_reset(); 480 /* NOTREACHED */ /* assuming reset worked */ 481 } 482 483 /* 484 * Try to remove FS references in the specified process. This function 485 * is used during shutdown 486 */ 487 static 488 void 489 shutdown_cleanup_proc(struct proc *p) 490 { 491 struct filedesc *fdp; 492 struct vmspace *vm; 493 494 if (p == NULL) 495 return; 496 if ((fdp = p->p_fd) != NULL) { 497 kern_closefrom(0); 498 if (fdp->fd_cdir) { 499 cache_drop(&fdp->fd_ncdir); 500 vrele(fdp->fd_cdir); 501 fdp->fd_cdir = NULL; 502 } 503 if (fdp->fd_rdir) { 504 cache_drop(&fdp->fd_nrdir); 505 vrele(fdp->fd_rdir); 506 fdp->fd_rdir = NULL; 507 } 508 if (fdp->fd_jdir) { 509 cache_drop(&fdp->fd_njdir); 510 vrele(fdp->fd_jdir); 511 fdp->fd_jdir = NULL; 512 } 513 } 514 if (p->p_vkernel) 515 vkernel_exit(p); 516 if (p->p_textvp) { 517 vrele(p->p_textvp); 518 p->p_textvp = NULL; 519 } 520 vm = p->p_vmspace; 521 if (vm != NULL) { 522 pmap_remove_pages(vmspace_pmap(vm), 523 VM_MIN_USER_ADDRESS, 524 VM_MAX_USER_ADDRESS); 525 vm_map_remove(&vm->vm_map, 526 VM_MIN_USER_ADDRESS, 527 VM_MAX_USER_ADDRESS); 528 } 529 } 530 531 /* 532 * Magic number for savecore 533 * 534 * exported (symorder) and used at least by savecore(8) 535 * 536 * Mark it as used so that gcc doesn't optimize it away. 537 */ 538 __attribute__((__used__)) 539 static u_long const dumpmag = 0x8fca0101UL; 540 541 static int dumpsize = 0; /* also for savecore */ 542 543 static int dodump = 1; 544 545 SYSCTL_INT(_machdep, OID_AUTO, do_dump, CTLFLAG_RW, &dodump, 0, 546 "Try to perform coredump on kernel panic"); 547 548 static int 549 setdumpdev(cdev_t dev) 550 { 551 struct partinfo pinfo; 552 u_int64_t newdumplo; 553 int error; 554 555 if (dev == NULL) { 556 dumpdev = dev; 557 return (0); 558 } 559 bzero(&pinfo, sizeof(pinfo)); 560 error = dev_dioctl(dev, DIOCGPART, (void *)&pinfo, 0, proc0.p_ucred); 561 if (error || pinfo.media_blocks == 0 || pinfo.media_blksize == 0) 562 return (ENXIO); 563 564 newdumplo = pinfo.media_blocks - 565 ((u_int64_t)Maxmem * PAGE_SIZE / DEV_BSIZE); 566 if ((int64_t)newdumplo < (int64_t)pinfo.skip_bsdlabel) 567 return (ENOSPC); 568 dumpdev = dev; 569 dumplo64 = newdumplo; 570 return (0); 571 } 572 573 574 /* ARGSUSED */ 575 static void dump_conf (void *dummy); 576 static void 577 dump_conf(void *dummy) 578 { 579 char *path; 580 cdev_t dev; 581 582 path = kmalloc(MNAMELEN, M_TEMP, M_WAITOK); 583 if (TUNABLE_STR_FETCH("dumpdev", path, MNAMELEN) != 0) { 584 dev = kgetdiskbyname(path); 585 if (dev != NULL) 586 dumpdev = dev; 587 } 588 kfree(path, M_TEMP); 589 if (setdumpdev(dumpdev) != 0) 590 dumpdev = NULL; 591 } 592 593 SYSINIT(dump_conf, SI_SUB_DUMP_CONF, SI_ORDER_FIRST, dump_conf, NULL) 594 595 static int 596 sysctl_kern_dumpdev(SYSCTL_HANDLER_ARGS) 597 { 598 int error; 599 udev_t ndumpdev; 600 601 ndumpdev = dev2udev(dumpdev); 602 error = sysctl_handle_opaque(oidp, &ndumpdev, sizeof ndumpdev, req); 603 if (error == 0 && req->newptr != NULL) 604 error = setdumpdev(udev2dev(ndumpdev, 0)); 605 return (error); 606 } 607 608 SYSCTL_PROC(_kern, KERN_DUMPDEV, dumpdev, CTLTYPE_OPAQUE|CTLFLAG_RW, 609 0, sizeof dumpdev, sysctl_kern_dumpdev, "T,udev_t", ""); 610 611 /* 612 * Doadump comes here after turning off memory management and 613 * getting on the dump stack, either when called above, or by 614 * the auto-restart code. 615 */ 616 static void 617 dumpsys(void) 618 { 619 int error; 620 621 savectx(&dumppcb); 622 dumpthread = curthread; 623 if (dumping++) { 624 kprintf("Dump already in progress, bailing...\n"); 625 return; 626 } 627 if (!dodump) 628 return; 629 if (dumpdev == NULL) 630 return; 631 dumpsize = Maxmem; 632 kprintf("\ndumping to dev %s, blockno %lld\n", 633 devtoname(dumpdev), dumplo64); 634 kprintf("dump "); 635 error = dev_ddump(dumpdev); 636 if (error == 0) { 637 kprintf("succeeded\n"); 638 return; 639 } 640 kprintf("failed, reason: "); 641 switch (error) { 642 case ENOSYS: 643 case ENODEV: 644 kprintf("device doesn't support a dump routine\n"); 645 break; 646 647 case ENXIO: 648 kprintf("device bad\n"); 649 break; 650 651 case EFAULT: 652 kprintf("device not ready\n"); 653 break; 654 655 case EINVAL: 656 kprintf("area improper\n"); 657 break; 658 659 case EIO: 660 kprintf("i/o error\n"); 661 break; 662 663 case EINTR: 664 kprintf("aborted from console\n"); 665 break; 666 667 default: 668 kprintf("unknown, error = %d\n", error); 669 break; 670 } 671 } 672 673 int 674 dumpstatus(vm_offset_t addr, off_t count) 675 { 676 int c; 677 678 if (addr % (1024 * 1024) == 0) { 679 #ifdef HW_WDOG 680 if (wdog_tickler) 681 (*wdog_tickler)(); 682 #endif 683 kprintf("%ld ", (long)(count / (1024 * 1024))); 684 } 685 686 if ((c = cncheckc()) == 0x03) 687 return -1; 688 else if (c != -1) 689 kprintf("[CTRL-C to abort] "); 690 691 return 0; 692 } 693 694 /* 695 * Panic is called on unresolvable fatal errors. It prints "panic: mesg", 696 * and then reboots. If we are called twice, then we avoid trying to sync 697 * the disks as this often leads to recursive panics. 698 */ 699 void 700 panic(const char *fmt, ...) 701 { 702 int bootopt, newpanic; 703 __va_list ap; 704 static char buf[256]; 705 706 #ifdef SMP 707 /* 708 * If a panic occurs on multiple cpus before the first is able to 709 * halt the other cpus, only one cpu is allowed to take the panic. 710 * Attempt to be verbose about this situation but if the kprintf() 711 * itself panics don't let us overrun the kernel stack. 712 * 713 * Be very nasty about descheduling our thread at the lowest 714 * level possible in an attempt to freeze the thread without 715 * inducing further panics. 716 * 717 * Bumping gd_trap_nesting_level will also bypass assertions in 718 * lwkt_switch() and allow us to switch away even if we are a 719 * FAST interrupt or IPI. 720 */ 721 if (atomic_poll_acquire_int(&panic_cpu_interlock)) { 722 panic_cpu_gd = mycpu; 723 } else if (panic_cpu_gd != mycpu) { 724 crit_enter(); 725 ++mycpu->gd_trap_nesting_level; 726 if (mycpu->gd_trap_nesting_level < 25) { 727 kprintf("SECONDARY PANIC ON CPU %d THREAD %p\n", 728 mycpu->gd_cpuid, curthread); 729 } 730 curthread->td_release = NULL; /* be a grinch */ 731 for (;;) { 732 lwkt_deschedule_self(curthread); 733 lwkt_switch(); 734 } 735 /* NOT REACHED */ 736 /* --mycpu->gd_trap_nesting_level */ 737 /* crit_exit() */ 738 } 739 #endif 740 bootopt = RB_AUTOBOOT | RB_DUMP; 741 if (sync_on_panic == 0) 742 bootopt |= RB_NOSYNC; 743 newpanic = 0; 744 if (panicstr) 745 bootopt |= RB_NOSYNC; 746 else { 747 panicstr = fmt; 748 newpanic = 1; 749 } 750 751 __va_start(ap, fmt); 752 kvsnprintf(buf, sizeof(buf), fmt, ap); 753 if (panicstr == fmt) 754 panicstr = buf; 755 __va_end(ap); 756 kprintf("panic: %s\n", buf); 757 #ifdef SMP 758 /* three separate prints in case of an unmapped page and trap */ 759 kprintf("mp_lock = %08x; ", mp_lock); 760 kprintf("cpuid = %d; ", mycpu->gd_cpuid); 761 kprintf("lapic.id = %08x\n", lapic.id); 762 #endif 763 764 #if defined(DDB) 765 if (newpanic && trace_on_panic) 766 db_print_backtrace(); 767 if (debugger_on_panic) 768 Debugger ("panic"); 769 #endif 770 boot(bootopt); 771 } 772 773 /* 774 * Support for poweroff delay. 775 */ 776 #ifndef POWEROFF_DELAY 777 # define POWEROFF_DELAY 5000 778 #endif 779 static int poweroff_delay = POWEROFF_DELAY; 780 781 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 782 &poweroff_delay, 0, ""); 783 784 static void 785 poweroff_wait(void *junk, int howto) 786 { 787 if(!(howto & RB_POWEROFF) || poweroff_delay <= 0) 788 return; 789 DELAY(poweroff_delay * 1000); 790 } 791 792 /* 793 * Some system processes (e.g. syncer) need to be stopped at appropriate 794 * points in their main loops prior to a system shutdown, so that they 795 * won't interfere with the shutdown process (e.g. by holding a disk buf 796 * to cause sync to fail). For each of these system processes, register 797 * shutdown_kproc() as a handler for one of shutdown events. 798 */ 799 static int kproc_shutdown_wait = 60; 800 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 801 &kproc_shutdown_wait, 0, ""); 802 803 void 804 shutdown_kproc(void *arg, int howto) 805 { 806 struct thread *td; 807 struct proc *p; 808 int error; 809 810 if (panicstr) 811 return; 812 813 td = (struct thread *)arg; 814 if ((p = td->td_proc) != NULL) { 815 kprintf("Waiting (max %d seconds) for system process `%s' to stop...", 816 kproc_shutdown_wait, p->p_comm); 817 } else { 818 kprintf("Waiting (max %d seconds) for system thread %s to stop...", 819 kproc_shutdown_wait, td->td_comm); 820 } 821 error = suspend_kproc(td, kproc_shutdown_wait * hz); 822 823 if (error == EWOULDBLOCK) 824 kprintf("timed out\n"); 825 else 826 kprintf("stopped\n"); 827 } 828