makedumpfile --dump-dmesg option broken on 3.5 kernels and later

[Atsushi Kumagai]

Hello Louis,

On Tue, 22 Jan 2013 14:52:09 +0100
Bouchard Louis <louis.bouchard at canonical.com> wrote:

> Hello Kumagai-san,
> 
> Following a suggestion from Dave Anderson, I have tested the
> makedumpfile --dump-dmesg option. After some research, I realized that
> the option was no longer working on 3.5 kernel and later. Here is an
> example of the result (on Ubuntu Quantal) :
> 
> # makedumpfile --dump-dmesg /proc/vmcore /tmp/dmesg
> dump_dmesg: Can't find some symbols for log_buf.
> 
> makedumpfile Failed.
> 
> On 3.5 kernel and later, the log_end symbol no longer exists.
> 
> This is caused by the change from byte-buffer structure to
> variable-length record buffer of the kernel log buffer introduced by
> this commit :
> 	http://goo.gl/NCgLI
> 
> I am curious to know if you were aware of this change and if you had
> done some work on modifying dump_dmesg() accordingly ? Just so I don't
> go off and try to work on something that you have already solved.

Thanks for your report.
I haven't been aware of this, so could I ask you to help me ?


Thanks
Atsushi Kumagai

> Kind regards,
> 
> ...Louis
> -- 
> Louis Bouchard
> Backline Support Analyst
> Canonical Ltd
> Ubuntu support: http://landscape.canonical.com