Re: [Crash-utility] crash: invalid kernel virtual address: 0 type: "memory section"

On Mon, Jan 5, 2015 at 7:02 PM, Ilya Dryomov <idryomov(a)redhat.com&gt; wrote: > On Mon, Jan 5, 2015 at 6:49 PM, Dave Anderson <anderson(a)redhat.com&gt; wrote: >> >> >> Just for sanity's sake, try this: >> >> $ ./crash --minimal ../ddeb/usr/lib/debug/boot/vmlinux-3.13.0-39-generic >> ../dump.201412280256 >> >> and see if you can read the linux_banner string successfully. For >> example, using >> my sample 3.13 kernel: >> >> $ crash --minimal 3.13.0-0.rc1.git2.1.fc20_SLAB/vmlinux.gz >> 3.13.0-0.rc1.git2.1.fc20_SLAB/vmcore_c_d31 >> >> crash 7.0.9 >> Copyright (C) 2002-2014 Red Hat, Inc. >> Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation >> Copyright (C) 1999-2006 Hewlett-Packard Co >> Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited >> Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. >> Copyright (C) 2005, 2011 NEC Corporation >> Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. >> Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. >> This program 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. Enter "help copying" to see the conditions. >> This program has absolutely no warranty. Enter "help warranty" for >> details. >> >> GNU gdb (GDB) 7.6 >> Copyright (C) 2013 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later >> <http://gnu.org/licenses/gpl.html> >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. Type "show >> copying" >> and "show warranty" for details. >> This GDB was configured as "x86_64-unknown-linux-gnu"... >> >> NOTE: minimal mode commands: log, dis, rd, sym, eval, set, extend and >> exit >> >> crash> rd -a linux_banner >> ffffffff818000c0: Linux version 3.13.0-0.rc1.git2.1.fc20.x86_64 >> (root@hp-xw455 >> ffffffff818000fc: 0-02.ml3.eng.bos.redhat.com) (gcc version 4.8.1 >> 20130814 (Re >> ffffffff81800138: d Hat 4.8.1-6) (GCC) ) #1 SMP Tue Nov 26 14:42:45 EST >> 2013 >> crash> >> >> And then try reading other stuff, most notably the __per_cpu_offset[] >> array, >> like this: >> >> crash> rd __per_cpu_offset 256 > > Attached - __per_cpu_offset seems busted. OK, so the banner read with crash is ffffffff818000a0: Linux version 3.13.0-39-generic (buildd@brownie) (gcc versio ffffffff818000dc: n 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #66~precise1-Ubuntu ffffffff81800118: SMP Wed Oct 29 09:56:49 UTC 2014 (Ubuntu 3.13.0-39.66~preci ffffffff81800154: se1-generic 3.13.11.8) whereas the banner from vmlinux-3.13.0-39-generic is 0a000a0: 4c69 6e75 7820 7665 7273 696f 6e20 332e Linux version 3. 0a000b0: 3133 2e30 2d33 392d 6765 6e65 7269 6320 13.0-39-generic 0a000c0: 2862 7569 6c64 6440 746f 796f 6c29 2028 (buildd@toyol) ( 0a000d0: 6763 6320 7665 7273 696f 6e20 342e 382e gcc version 4.8. 0a000e0: 3220 2855 6275 6e74 7520 342e 382e 322d 2 (Ubuntu 4.8.2- 0a000f0: 3139 7562 756e 7475 3129 2029 2023 3636 19ubuntu1) ) #66 0a00100: 2d55 6275 6e74 7520 534d 5020 5475 6520 -Ubuntu SMP Tue 0a00110: 4f63 7420 3238 2031 333a 3330 3a32 3720 Oct 28 13:30:27 0a00120: 5554 4320 3230 3134 2028 5562 756e 7475 UTC 2014 (Ubuntu 0a00130: 2033 2e31 332e 302d 3339 2e36 362d 6765 3.13.0-39.66-ge 0a00140: 6e65 7269 6320 332e 3133 2e31 312e 3829 neric 3.13.11.8) I guess I need to try to hunt down that exact vmlinux. Sigh. Thanks, Ilya -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility