Hello,
I am trying to analyse the dump created by the kdump utility. This is what I did
I took 2.6.25.14 vanilla version of kernel and made two copies of the kernel named vmlinuz-2.6.25.14-main (Production kernel) and vmlinuz-2.6.25.14-kdump (Crash kernel) by following the procedure mentioned in the following website
http://www.dedoimedo.com/computers/kdump.html
When I run crash utility using the following command
crash /usr/src/linux-2.6.25.14-main/vmlinux /var/crash/2009-08-08-23:32/vmcore
I get the following error
crash /usr/src/linux-2.6.25.14-main/vmlinux /var/crash/2009-08-08-23:32/vmcore
crash 4.0-6.0.5
Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
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GNU gdb 6.1
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
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This GDB was configured as "i686-pc-linux-gnu"...
crash: read error: kernel virtual address: c1399f10 type: "xtime"
I checked for the error and found this link which mentions few work-around/fixes for the issue with reading of /dev/mem
http://www.mail-archive.com/crash-utility@redhat.com/msg01553.html
I tried adding CONFIG_STRICT_DEVMEM to the .config file (This parameter was not already present in the config file)
I got the following error while compiling the kernel
scripts/kconfig/mconf arch/x86/Kconfig
.config:3869:warning: trying to assign nonexistent symbol STRICT_DEVMEM
I tried to create the kretprobe module, it works fine for do_fork() but when I give devmem_is_allowed() as the functioin name I get the following error
[root@buzzsaw kprobes]# insmod kretprobe_devmem.ko
insmod: error inserting 'kretprobe_devmem.ko': -1 Operation not permitted
I am new to the area of kernel debugging. Please let me know how I can solve this issue. Thanks
--
Regards,
Mani