[petsc-users] Bus Error

[Matthew Knepley]

On Mon, Aug 24, 2020 at 1:46 PM Barry Smith <bsmith at petsc.dev> wrote:

>
>
> > On Aug 24, 2020, at 12:39 PM, Jed Brown <jed at jedbrown.org> wrote:
> >
> > Barry Smith <bsmith at petsc.dev> writes:
> >
> >>> On Aug 24, 2020, at 12:31 PM, Jed Brown <jed at jedbrown.org> wrote:
> >>>
> >>> Barry Smith <bsmith at petsc.dev> writes:
> >>>
> >>>> So if a BLAS errors with SIGBUS then it is always an input error of
> just not proper double/complex alignment? Or some other very strange thing?
> >>>
> >>> I would suspect memory corruption.
> >>
> >>
> >>  Corruption meaning what specifically?
> >>
> >>  The routines crashing are dgemv which only take double precision
> arrays, regardless of what garbage is in those arrays i don't think there
> can be BUS errors resulting. They don't take integer arrays whose
> corruption could result in bad indexing and then BUS errors.
> >>
> >>  So then it can only be corruption of the pointers passed in, correct?
> >
> > Such as those pointers pointing into data on the stack with incorrect
> sizes.
>
> But won't incorrect sizes "usually" lead to SEGV not SEGBUS?
>

My understanding was that roughly memory errors in the heap are SEGV and
memory errors on the stack are SIGBUS. Is that not true?

   Matt

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20200824/d1ff87a3/attachment.html>