[Crash-utility] dis command not correct in crash

[Per Fransson]

On Wed, Mar 6, 2013 at 4:00 AM, Lei Wen <adrian.wenl at gmail.com> wrote:
> Per,
>
> [snip..]
>>
>> What do you get when you do:
>>
>> $ nm vmlinux | grep linux_banner
>>
>> $ readelf -l <dumpfile>
>>
>> $ strings -a -t x <dumpfile> | grep "Linux version"
>
> Here is the result:
> nm vmlinux | grep linux_banner
> c05bc06b R linux_banner
>
> readelf -l 2013-01-18
>
> Elf file type is CORE (Core file)
> Entry point 0x0
> There are 2 program headers, starting at offset 52
>
> Program Headers:
>   Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
>   NOTE           0x000074 0x00000000 0x00000000 0x00000 0x00000     0
>   LOAD           0x000074 0xc0000000 0x00000000 0x20000000 0x20000000 RWE 0
>
>
> strings -a -t x 2013-01-18 | grep "Linux version"
>  5bc0df Linux version 3.4.5+ (1 at 2) (gcc version 4.6.x-google 20120106
> (prerelease) (GCC) ) #1 SMP PREEMPT Tue Jan 15 15:51:59 CST 2013
>

So, the placement in the file seems ok:

0xc0000000+0x5bc0df-0x000074 == 0xc05bc06b

The only alternative I see is that there are overwrites in .text. You
could use dd to pull out that part of both the dump and the vmlinux
and diff them. Beware that there could be some valid reasons for
differences between them though...

/Per

> Thanks,
> Lei