Date: Wed, 19 Feb 2003 10:18:08 -0500 From: Mike Tancsa <mike@sentex.net> To: Dag-Erling Smorgrav <des@ofug.org> Cc: freebsd-hackers@freebsd.org Subject: Re: debugging a repeating panic that does not produce a dump Message-ID: <5.2.0.9.0.20030219101029.041d18d8@marble.sentex.ca> In-Reply-To: <xzpisvi4ryo.fsf@flood.ping.uio.no> References: <5.2.0.9.0.20030217135903.064d7378@marble.sentex.ca> <5.2.0.9.0.20030217091242.05b184b0@marble.sentex.ca> <5.2.0.9.0.20030217091242.05b184b0@marble.sentex.ca> <5.2.0.9.0.20030217135903.064d7378@marble.sentex.ca>
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At 08:39 PM 17/02/2003 +0100, Dag-Erling Smorgrav wrote:
>Mike Tancsa <mike@sentex.net> writes:
> > ns4# nm /kernel | grep \^c0174 | sort
> > [...]
> > c01747d4 T makedev
> > c01748f4 T freedev
>
>This is it (makedev)
>
> > Does this actually show the location ?
> > ns4# gdb -k kernel.debug
> > [...]
> > (kgdb) list *0xc0174830
> > 0xc0174830 is in makedev (/usr/src/sys/kern/kern_conf.c:208).
> > 203 if (x == umajor(NOUDEV) && y == uminor(NOUDEV))
> > 204 Debugger("makedev of NOUDEV");
> > 205 udev = (x << 8) | y;
> > 206 hash = udev % DEVT_HASH;
> > 207 LIST_FOREACH(si, &dev_hash[hash], si_hash) {
> > 208 if (si->si_udev == udev)
> > 209 return (si);
> > 210 }
> > 211 if (stashed >= DEVT_STASH) {
> > 212 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT,
> > (kgdb)
>
>Yep. Looks like si is garbage:
>
> > fault virtual address = 0x211e6d36
>
>is most likely the value of si at the time of the crash. It's nowhere
>near kernel memory (which starts at 0xc0000000).
>
>If / when you get a dump, show me the backtrace and the value of x, y
>and udev (as reported by gdb operating on the recovered core)
OK, got it today.
ns4# gdb -k /usr/obj/usr/src/sys/smp/kernel.debug vmcore.0
GNU gdb 4.18 (FreeBSD)
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd"...Deprecated bfd_read
called at
/usr/src/gnu/usr.bin/binutils/gdb/../../../../contrib/gdb/gdb/dbxread.c
line 2627 in elfstab_build_psymtabs
Deprecated bfd_read called at
/usr/src/gnu/usr.bin/binutils/gdb/../../../../contrib/gdb/gdb/dbxread.c
line 933 in fill_symbuf
SMP 2 cpus
IdlePTD at phsyical address 0x003d4000
initial pcb at physical address 0x0032ebc0
panicstr: page fault
panic messages:
---
Fatal trap 12: page fault while in kernel mode
mp_lock = 00000002; cpuid = 0; lapic.id = 01000000
fault virtual address = 0xc6efa8e8
fault code = supervisor read, page not present
instruction pointer = 0x8:0xc0174830
stack pointer = 0x10:0xdef1dc4c
frame pointer = 0x10:0xdef1dc58
code segment = base 0x0, limit 0xfffff, type 0x1b
= DPL 0, pres 1, def32 1, gran 1
processor eflags = interrupt enabled, resume, IOPL = 0
current process = 91300 (find)
interrupt mask = none <- SMP: XXX
trap number = 12
panic: page fault
mp_lock = 00000002; cpuid = 0; lapic.id = 01000000
boot() called on cpu#0
syncing disks... 2 2
done
Uptime: 1d22h58m21s
dumping to dev #twed/1, offset 524312
dump 767 766 765 764 763 762 761 760 759 758 757 756 755 754 753 752 751
750 749 748 747 746 745 744 743 742 741 740 739 738 737 736 735 734 733 732
731 730 729 728 727 726 725 724 723 722 721 720 719 718 717 716 715 714 713
712 711 710 709 708 707 706 705 704 703 702 701 700 699 698 697 696 695 694
693 692 691 690 689 688 687 686 685 684 683 682 681 680 679 678 677 676 675
674 673 672 671 670 669 668 667 666 665 664 663 662 661 660 659 658 657 656
655 654 653 652 651 650 649 648 647 646 645 644 643 642 641 640 639 638 637
636 635 634 633 632 631 630 629 628 627 626 625 624 623 622 621 620 619 618
617 616 615 614 613 612 611 610 609 608 607 606 605 604 603 602 601 600 599
598 597 596 595 594 593 592 591 590 589 588 587 586 585 584 583 582 581 580
579 578 577 576 575 574 573 572 571 570 569 568 567 566 565 564 563 562 561
560 559 558 557 556 555 554 553 552 551 550 549 548 547 546 545 544 543 542
541 540 539 538 537 536 535 534 533 532 531 530 529 528 527 526 525 524 523
522 521 520 519 518 517 516 515 514 513 512 511 510 509 508 507 506 505 504
503 502 501 500 499 498 497 496 495 494 493 492 491 490 489 488 487 486 485
484 483 482 481 480 479 478 477 476 475 474 473 472 471 470 469 468 467 466
465 464 463 462 461 460 459 458 457 456 455 454 453 452 451 450 449 448 447
446 445 444 443 442 441 440 439 438 437 436 435 434 433 432 431 430 429 428
427 426 425 424 423 422 421 420 419 418 417 416 415 414 413 412 411 410 409
408 407 406 405 404 403 402 401 400 399 398 397 396 395 394 393 392 391 390
389 388 387 386 385 384 383 382 381 380 379 378 377 376 375 374 373 372 371
370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352
351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 333
332 331 330 329 328 327 326 325 324 323 322 321 320 319 318 317 316 315 314
313 312 311 310 309 308 307 306 305 304 303 302 301 300 299 298 297 296 295
294 293 292 291 290 289 288 287 286 285 284 283 282 281 280 279 278 277 276
275 274 273 272 271 270 269 268 267 266 265 264 263 262 261 260 259 258 257
256 255 254 253 252 251 250 249 248 247 246 245 244 243 242 241 240 239 238
237 236 235 234 233 232 231 230 229 228 227 226 225 224 223 222 221 220 219
218 217 216 215 214 213 212 211 210 209 208 207 206 205 204 203 202 201 200
199 198 197 196 195 194 193 192 191 190 189 188 187 186 185 184 183 182 181
180 179 178 177 176 175 174 173 172 171 170 169 168 167 166 165 164 163 162
161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144 143
142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124
123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105
104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82
81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57
56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5
4 3 2 1 0
---
#0 dumpsys () at /usr/src/sys/kern/kern_shutdown.c:487
487 if (dumping++) {
(kgdb) bt
#0 dumpsys () at /usr/src/sys/kern/kern_shutdown.c:487
#1 0xc018071c in boot (howto=256) at /usr/src/sys/kern/kern_shutdown.c:316
#2 0xc0180b84 in poweroff_wait (junk=0xc02fd4d9, howto=-1070608465) at
/usr/src/sys/kern/kern_shutdown.c:595
#3 0xc02b2b51 in trap_fatal (frame=0xdef1dc0c, eva=3337595112) at
/usr/src/sys/i386/i386/trap.c:974
#4 0xc02b27c9 in trap_pfault (frame=0xdef1dc0c, usermode=0,
eva=3337595112) at /usr/src/sys/i386/i386/trap.c:867
#5 0xc02b2327 in trap (frame={tf_fs = -554631144, tf_es = -1072234480,
tf_ds = -818348016, tf_edi = 7328, tf_esi = 24,
tf_ebp = -554574760, tf_isp = -554574792, tf_ebx = -957372188,
tf_edx = 1412, tf_ecx = -1028930048, tf_eax = 7304,
tf_trapno = 12, tf_err = 0, tf_eip = -1072216016, tf_cs = 8,
tf_eflags = 66182, tf_esp = 7328, tf_ss = -1015177472})
at /usr/src/sys/i386/i386/trap.c:466
#6 0xc0174830 in makedev (x=28, y=160) at /usr/src/sys/kern/kern_conf.c:207
#7 0xc01749ce in udev2dev (x=7328, b=0) at /usr/src/sys/kern/kern_conf.c:264
#8 0xc01afbf0 in addaliasu (nvp=0xdda80dc0, nvp_rdev=7328) at
/usr/src/sys/kern/vfs_subr.c:1465
#9 0xc0273f47 in ufs_vinit (mntp=0xc2abc600, specops=0xc2a7b200,
fifoops=0xc2b08700, vpp=0xdef1dcdc)
at /usr/src/sys/ufs/ufs/ufs_vnops.c:2024
#10 0xc026c153 in ffs_vget (mp=0xc2abc600, ino=19399, vpp=0xdef1dd48) at
/usr/src/sys/ufs/ffs/ffs_vfsops.c:1174
#11 0xc026f8a3 in ufs_lookup (ap=0xdef1dda8) at
/usr/src/sys/ufs/ufs/ufs_lookup.c:611
#12 0xc0274331 in ufs_vnoperate (ap=0xdef1dda8) at
/usr/src/sys/ufs/ufs/ufs_vnops.c:2376
#13 0xc01aabee in vfs_cache_lookup (ap=0xdef1de00) at vnode_if.h:77
#14 0xc0274331 in ufs_vnoperate (ap=0xdef1de00) at
/usr/src/sys/ufs/ufs/ufs_vnops.c:2376
#15 0xc01adc81 in lookup (ndp=0xdef1de7c) at vnode_if.h:52
#16 0xc01ad76c in namei (ndp=0xdef1de7c) at /usr/src/sys/kern/vfs_lookup.c:153
#17 0xc01b3b15 in lstat (p=0xdeee8dc0, uap=0xdef1df80) at
/usr/src/sys/kern/vfs_syscalls.c:1823
#18 0xc02b2e95 in syscall2 (frame={tf_fs = 47, tf_es = 47, tf_ds = 47,
tf_edi = 134658816, tf_esi = 134658888,
tf_ebp = -1077937420, tf_isp = -554573868, tf_ebx = 672089228,
tf_edx = 2, tf_ecx = 134658880, tf_eax = 190, tf_trapno = 12,
tf_err = 2, tf_eip = 671764272, tf_cs = 31, tf_eflags = 663, tf_esp
= -1077937560, tf_ss = 47})
at /usr/src/sys/i386/i386/trap.c:1175
#19 0xc029ce8b in Xint0x80_syscall ()
#20 0x280a1591 in ?? ()
#21 0x280a0e0e in ?? ()
#22 0x8049732 in ?? ()
#23 0x804b9f8 in ?? ()
#24 0x80493ce in ?? ()
(kgdb)
(kgdb) up 6
#6 0xc0174830 in makedev (x=28, y=160) at /usr/src/sys/kern/kern_conf.c:207
207 LIST_FOREACH(si, &dev_hash[hash], si_hash) {
(kgdb) list
202
203 if (x == umajor(NOUDEV) && y == uminor(NOUDEV))
204 Debugger("makedev of NOUDEV");
205 udev = (x << 8) | y;
206 hash = udev % DEVT_HASH;
207 LIST_FOREACH(si, &dev_hash[hash], si_hash) {
208 if (si->si_udev == udev)
209 return (si);
210 }
211 if (stashed >= DEVT_STASH) {
(kgdb) p udev
$1 = 7328
(kgdb)
> > > How do you build your kernels - 'make buildkernel' or manually?
> > Always make buildkernel. I have a debug kernel built as well
> > (makeoptions DEBUG=-g)
>
>That's what I wanted to know.
>
>DES
>--
>Dag-Erling Smorgrav - des@ofug.org
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