freebsd stable - Oct 2018 - loader lsdev crashes loader (Was: head -r338804 boots threadripper 1950X fine; head -r338810+ do not; -r338807 seems implicated)

> On 23 Oct 2018, at 13:53, Lev Serebryakov <lev at FreeBSD.org> wrote:
> 
> On 22.10.2018 12:27, Toomas Soome wrote:
> 
>> It would help to get output from loader lsdev -v command.
> current loader crashes on "lsdev" for me:
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232483 (it is not
> threadripper-related, my hardware is Intel Atom).
> 
> -- 
> // Lev Serebryakov
> 
That error means something is corrupting the memory, it is hard to guess what
exactly and debugging it is nasty - it means we would need to track down what
was allocated before this memory block (guard1 is marker inserted in front of
the allocated memory block).

Fortunately the code to print the partition table is in stand/common/disk.c and
the partition code is just next to it and so it should be relatively easy to
find the guilty one? I will try to see if I can replicate the issue.

rgds,
toomas

On Tue, Oct 23, 2018 at 5:54 AM Toomas Soome <tsoome at me.com> wrote:
>
> > On 23 Oct 2018, at 13:53, Lev Serebryakov <lev at FreeBSD.org>
wrote:
> >
> > On 22.10.2018 12:27, Toomas Soome wrote:
> >
> >> It would help to get output from loader lsdev -v command.
> > current loader crashes on "lsdev" for me:
> > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232483 (it is not
> > threadripper-related, my hardware is Intel Atom).
> >
> > --
> > // Lev Serebryakov
> >
>
> That error means something is corrupting the memory, it is hard to guess
> what exactly and debugging it is nasty - it means we would need to track
> down what was allocated before this memory block (guard1 is marker inserted
> in front of the allocated memory block).
>
> Fortunately the code to print the partition table is in
> stand/common/disk.c and the partition code is just next to it and so it
> should be relatively easy to find the guilty one? I will try to see if I
> can replicate the issue.
>
We've had reports of other systems mysteriously hanging on boot with the
new boot loader, but not older ones. It isn't limited to new AMD boxes, but
it's been seen on other Intel boxes of various flavors. When we crash, it
seems like we don't have a good recovery like we do with BTX. Maybe they
are related?

Warner