Re: selftests: Linux Kernel Dump Test Module output

Kees Cook
2020-02-21T00:16:06Z

On Wed, Feb 19, 2020 at 09:16:03AM -0700, shuah wrote:
> On 2/17/20 8:36 AM, Cristian Marussi wrote:
> > Hi
> >
> > n 17/02/2020 11:09, Naresh Kamboju wrote:
> > > The selftest lkdtm test failed on x86_64 and arm64.
> > > am I missing any pre-requisite?
> > >
> > > Boot log:
> > > [ 3.297812] lkdtm: No crash points registered, enable through debugfs
> > >
> >
> > from your logs I cannot deduce anything useful, but in our CI I've got similar issues
> > since the 10/12th of Feb...
> >
> > TAP version 13
> > 1..71
> > # selftests: lkdtm: PANIC.sh
> > # Cannot find /sys/kernel/debug/provoke-crash/DIRECT (missing CONFIG_LKDTM?)
> > not ok 1 selftests: lkdtm: PANIC.sh # SKIP
> > # selftests: lkdtm: BUG.sh
> > # Cannot find /sys/kernel/debug/provoke-crash/DIRECT (missing CONFIG_LKDTM?)
> >
> > so I suppose this and a bunch of other (probably new) tests are simply
> > missing a bit of CONFIGs... (but I have still to look into this properly)
> > (not sure if this also is your case either...)
> >
> > Regards
> >
> > Cristian
> >
>
> Hi Kees,
>
> Any ideas on what this is about? Missing config or something else?

In the first case, I'm not sure what's happening -- the logs don't seem
to show anything, but the lkdtm should be available (from the boot log).

In the second case, yes, it looks like missing CONFIG_LKDTM (the test
even has a "config" file). Either CONFIG_LKDTM=y or CONFIG_LKDTM=m will
work (the test running will attempt to load the lkdtm module if it's
missing).

A final option is that either the debug filesystem isn't mounted, or is
mounted somewhere "non-standard"? (I'd expect a lot of things to fail...)

-Kees

--
Kees Cook