> On 30.01.21 19:53, Roman Shaposhnik wrote: > > On Fri, Jan 29, 2021 at 11:28 PM Jürgen Groß <jgr...@suse.com> wrote: > >> > >> On 29.01.21 21:12, Roman Shaposhnik wrote: > >>> Hi! > >>> > >>> I'm trying to see how much mileage I can get out of > >>> crash(1) 7.2.8 (based on gdb 7.6) when it comes to analyzing crash > >>> dumps taken via xl dump-core (this is all on x86_64 with stock Xen > >>> v. 4.14). > >>> > >>> The good news is that the image actually does load up but it throws > >>> the following WARNINGs in the process: > >>> > >>> WARNING: cannot access vmalloc'd module memory > >>> crash: read error: kernel virtual address: ffffffff93613480 type: > >>> "fill_task_struct" > >>> WARNING: active task ffffffff93613480 on cpu 0 not found in PID hash > >>> crash: read error: kernel virtual address: ffffffff93613480 type: > >>> "fill_task_struct" > >>> WARNING: cannot read log_buf contents > >>> > >>> And then the info that it gives me around basic things like ps, mod, > >>> log, etc. is really super limited (and I am now suspecting may even > >>> be wrong). > >>> > >>> Since I was primarily after dmesg/log initially, I tried: > >>> crash> log > >>> log: WARNING: cannot read log_buf contents > >>> > >>> Then I tried taking an xl dump-core from the domU that was still > >>> very much alive and happy and got similar results -- so it clearly > >>> doesn't seem to be related to the state domU is in. > >>> > >>> As matter of fact, I actually got to the desired dmesg output by > >>> simply running strings(1) on the core file -- so the info is > >>> definitely there -- but I guess some kind of index/reference maybe > >>> broken. > >>> > >>> With all that in mind, if there's anyone on this ML who has recently > >>> done Xen DomU crash dump analysis -- I would definitely appreciate > >>> the pointers! > >> > >> For me it just works (openSUSE). > > > > Can you please run: > > > > crash --version and readelf -a XXXX (on the xl dump-core output) and > > post the results? > > # crash --version > > crash 7.2.1
I tried to build this version but I still get the following while trying to open a dump file produced by "xl dump-core": [root@lcy2-dt92 crash]# ./crash ../vmlinux-5.8.0-44-generic ../xxx.dmp crash 7.2.1 Copyright (C) 2002-2017 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"... crash: cannot determine base kernel version crash: ../vmlinux-5.8.0-44-generic and ../xxx.dmp do not match! Am I doing something wrong? How do I need to use crash for it to work? Igor
