[Crash-utility] crash bug on 2.6.27.8

[Dave Anderson]

----- "Jun Koi" <junkoi2004 at gmail.com> wrote:

> On Mon, Feb 9, 2009 at 11:51 PM, Dave Anderson <anderson at redhat.com>
> wrote:
> >
> > ----- "Jun Koi" <junkoi2004 at gmail.com> wrote:
> >
> >> Hi,
> >>
> >> When using the latest crash on 2.6.27.14 to analyze live memory
> >> (running crash without any option), I got a bug like below. How can
> I
> >> fix that?
> >>
> >> (A similar problem is also seen on 2.6.27.8)
> >>
> >> Thanks,
> >> Jun
> >
> > The "read error" indications are most likely due to your kernel
> > being configured with CONFIG_STRICT_DEVMEM, which restricts
> > /dev/mem access to the first 256 pages of physical memory,
> > which makes it useless for the crash utility.
> 
> Thanks a lot for the information - I can fix the kernel here.
> 
> But perhaps it is better to give some hints when we have such a error
> report, so users know that they should turn off the above
> configuration? I am sure that many people will have this problem, as
> the option may be ON by default.
> 
> Thanks,
> Jun

Good idea -- I'll put something in place for the next release.

I'll also look into creating a web page with a "canned answer"
for this issue, including directions for going the crash-module-build
or kprobe routes for those who cannot rebuild their kernels.

Thanks,
  Dave