Re: RFH: SIGBUS in buildd but not in porterbox

[David Daney <ddaney@caviumnetworks.com>]

On 02/17/2014 01:28 PM, Andreas Barth wrote:
> * Felipe Sateler (fsateler@gmail.com) [140217 20:33]:
> > The package liblo runs a test suite at build time. This test suite
> > failed in mipsel (but not mips)[1]. I tried to reproduce the issue in
> > eder.d.o but it passed.
> >
> > Liblo does use unaligned access (liblo had to be removed from sparc
> > for this reason).
> > But I'm confused as to why does the buildd error out and the porterbox
> > doesn't. Is it possible to (programatically) instruct the kernel to
> > not raise a SIGBUS?
> >
> >
> > [1] https://buildd.debian.org/status/fetch.php?pkg=liblo&arch=mipsel&ver=0.28-3&stamp=1392064303
>
> rem and eder are different hardware.

Yes, Some MIPS CPUs (like OCTEON) can be, and are, configured to handle 
unaligned accesses.  Others cannot.

The kernel may be able to emulate unaligned accesses for integer loads 
and stores, but I think the problem may be that the FPU emulator cannot 
do unaligned accesses.

Really the application that is doing this should be fixed.

David Daney


> Also are you sure your package
> builds with /bin/sh=bash (just asking because I have seen that issue
> with another package recently)?
>
>
> Andi