Re: [Crash-utility] Crash, won't read my vmcore "crash: page excluded: kernel virtual address:"
A couple other things I should have mentioned with respect to
your validity tests:
----- Original Message -----
[root@kvm7 127.0.0.1-2014-02-07-19:17:09]# crash
/boot/System.map-2.6.32-220.el6.x86_64.debug
/usr/lib/debug/lib/modules/2.6.32-220.el6.x86_64.debug/vmlinux vmcore
crash 5.1.8-1.el6
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This GDB was configured as "x86_64-unknown-linux-gnu"...
crash: page excluded: kernel virtual address: ffffffff81542000 type:
"cpu_possible_mask"
I can go into minimal,
Yes, but you didn't indicate whether data that is readable in the --minimal mode
is meaningful. The best way to do that is to verify that you can read the
linux_banner string at the advertised address, for example:
crash> rd -a linux_banner 100
ffffffff81600020: Linux version 2.6.32-313.el6.x86_64 (mockbuild(a)x86-022.build
ffffffff8160005c: .eng.bos.redhat.com) (gcc version 4.4.6
crash>
If the command above doesn't show the "Linux ..." string lined up,
you've got the
wrong vmlinux.
nm -Bn /usr/lib/debug/lib/modules/2.6.32-220.el6.x86_64.debug/vmlinux | grep _stext
ffffffff81000198 T _stext
cat /proc/kallsyms | grep _stext
ffffffff81000198 T _stext
That's not a valid test. The "_stext" symbol for both the standard kernel
and
the debug kernel variant both have the same "_stext" offset, but the symbols
become rapidly out of sync afterwards.
This is from the standard kernel's vmlinux file:
$ nm -Bn vmlinux | grep -e _stext -e linux_banner
ffffffff81000198 T _stext
ffffffff81600020 R linux_banner
$
as compared to the debug variant's vmlinux file:
$ nm -Bn vmlinux.debug | grep -e _stext -e linux_banner
ffffffff81000198 T _stext
ffffffff8152e020 R linux_banner
$
Dave