kgdb and vmcore.0 cannot access memory at 0x252d1
dhaneshkk at hotmail.com
Tue May 10 17:29:54 UTC 2011
I am new to kernel debugging, I compiled a new kernel with options KDB and DDB in addition to the GENERIC config and booted with the new kernel.( Goal is to debug the coredumps in my laptops /var/crash/vmcore files and try to find and fix the panic/situation which produce these coredumps)
I tried to analyze all of the vmcore files in my /var/crash/vmcore.x core dumps
after booting into the new kernel
# cd /usr/obj/usr/src/sys/MYCUSTORMKERNEL
#kgdb kernel.debug /var/crash/vmcore.0
kgdb kernel.debug /var/crash/vmcore.0
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 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-marcel-freebsd"...
Cannot access memory at address 0x252d1
For all the vmcore files I am getting this output.. Cannot access memory at address 0x252d1, how can I proceed from here,
How to debug what is happening, what makes the kernel to dump these vmcores and fix the issue by using further debugging..
what are the next steps , if there a message in kgdb "Cannot access memory at address 0x252d1 or any address"
Please share your suggestion and hints to debug more from this point. I am stuck here..
Thanks in advance
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