Panic from vesa_configure()

[Cy Schubert]

In message <201601080107.u0817kDw078603 at slippy.cwsent.com>, Cy Schubert 
writes:
> In message <CAJ-VmonGOs2f+rzciEcV=VuaNrZt0hqNePQx4LZDWu6BxuR9NQ at mail.gmail.c
> om>
> , Adrian Chadd writes:
> > Ok,
> > 
> > So try adding this check:
> > 
> > vmbuf = x86bios_alloc(&offs, sizeof(*buf), M_WAITOK);
> > if (vmbuf == NULL) {
> >     printf("%s: x86bios_alloc failed!\n", __func__);
> >     goto fail;
> > }
> > 
> > ... that call shouldn't be failing, but if it's truely failing on the
> > bcopy(), the only reason is because vmbuf is NULL.
> 
> Thanks. I'll try this.
> 
> vesa.c hasn't changed for a while so I suspect the root cuase may be 
> somewhere else (we're probably treating the symptom here). Nice thing about 
> using the same mobo and cpu combination on all my machines (except 
> laptops), failures are completely reproducible. Might be a good idea to put 
> in a dtrace probe too.

Hi Adrian,

Your patch fixed the issue. I've included a dtrace probe. I suspect the 
error may be BIOS specific and the dtrace probe should help in tracking it 
down. Does this look good to commit?


-- 
Cheers,
Cy Schubert <Cy.Schubert at komquats.com> or <Cy.Schubert at cschubert.com>
FreeBSD UNIX:  <cy at FreeBSD.org>   Web:  http://www.FreeBSD.org

	The need of the many outweighs the greed of the few.