Re: Netconsole in hardened kernel? (was Re: [gentoo-hardened] PAX: General protection fault, where logged?)

[David C. Manuelda]

Aren't those messages logged in /var/log/messages despite the crash? I can see 
them when I have a crash like that and can't start my system.

On Tuesday 22 July 2008 04:24:42 Brian A. Davis wrote:
> Netconsole doesn't seem to be available int he hardened kernel. Am I
> missing something?
>
> flagg src # ls -lt
> total 16
> drwxr-xr-x 21 root root 4096 Jul 21 22:23 linux-2.6.25.9
> drwxr-xr-x 22 root root 4096 Jul 21 22:21 linux-2.6.24-hardened-r3
> drwxr-xr-x 21 root root 4096 Jul  7 23:04 linux-2.6.23-hardened-r12
> lrwxrwxrwx  1 root root   24 Jul  7 15:19 linux -> linux-2.6.24-hardened-r3
> drwxr-xr-x 20 root root 4096 Jun 30 22:18 linux-2.6.23-hardened-r13
> flagg src # cd linux
> flagg linux # pwd
> /usr/src/linux
> flagg linux # grep NETCONSOLE .config
> flagg linux #
>
> Thanks,
> Brian
>
> Will Keaney wrote:
> > Brian A. Davis wrote:
> >> I'm getting a PAX General protection fault, which outputs a stack
> >> trace to the console (monitor), but there's no way for me to get it
> >> since the machine is crashed at this point.
> >>
> >> Where would this be getting logged? grep PAX * in /var/log doesn't
> >> turn up anything.
> >>
> >> Thanks,
> >> Brian
> >
> > There are a couple of ways to get the trace from this.  One is to
> > attach a serial console to the machine in question and log the crash
> > from another computer (see
> > /usr/src/linux/Documentation/serial-console.txt).
> > Another is to configure netconsole, which will allow you to capture
> > kernel messages from another machine over ethernet.  See
> > /usr/src/linux/Documentation/networking/netconsole.txt for
> > instructions on this.
> > If you have a digital camera, you can take a picture of the stack trace.
> > Finally, you can transcribe it by hand.  This is veeeery tedious.
> >
> > Hope this helps.
> >
> > Will