From: "Ilya Dryomov" <idryomov@redhat.com>
To: crash-utility@redhat.com
Cc: "Castillon de la Cruz, Eddy Gonzalo" <ecastillon@axcess-financial.com>
Sent: Monday, January 5, 2015 9:16:09 AM
Subject: crash: invalid kernel virtual address: 0 type: "memory section"
Hello,
I have a couple dumps generated on Ubuntu Trusty LTS (3.13.0-39-generic
kernel) which crash fails on.
$ ./crash ../ddeb/usr/lib/debug/boot/vmlinux-3.13.0-39-generic
../dump.201412280256
crash 7.0.9
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Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
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Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
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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.
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This GDB was configured as "x86_64-unknown-linux-gnu"...
crash: cannot determine thread return address
please wait... (gathering kmem slab cache data)
crash: invalid kernel virtual address: 1c type: "kmem_cache
objsize/object_size"
crash: failed to read pageflag_names entry
please wait... (gathering module symbol data)
WARNING: invalid kernel module size: 0
crash: cannot determine idle task addresses from init_tasks[] or runqueues[]
crash: cannot resolve "init_task_union"
vmlinux-3.13.0-39-generic was extracted from Ubuntu ddeb:
$ file ../ddeb/usr/lib/debug/boot/vmlinux-3.13.0-39-generic
../ddeb/usr/lib/debug/boot/vmlinux-3.13.0-39-generic: ELF 64-bit LSB
executable, x86-64, version 1 (SYSV), statically linked,
BuildID[sha1]=c4fa631d2cc34a0b2628a5de01a04e81a0667555, not stripped
With -d8 I get:
...
<read_diskdump: addr: ffffffffffffffff paddr: 7fffffff cnt: 1>
read_diskdump: paddr/pfn: 7fffffff/7ffff -> cache physical page: 7ffff000
crash: invalid kernel virtual address: 0 type: "memory section"
The entire -d8 output is attached.
Bogus "base kernel version" stands out immediately and I'm pretty sure
I've seen "0.0.0" in there a couple times with exactly the same dump.
From a quick look, the base kernel version code in kernel.c is not safe
against kt->utsname.release being all zeroes.
Eddy Gonzalo (CC'ed) can probably provide access to the dumps if
needed.
Thanks,
Ilya