Re: [Linuxsampler-devel] [PATCH] Fix endianness and memory alignment issues for big-endian architectures (s390x)

[Christian S. <sch...@li...>]

On Thursday, 13 August 2026 15:38:38 CEST Christian Schoenebeck wrote:
> On Tuesday, 11 August 2026 11:19:03 CEST Pranav P wrote:
> > Hi Christian and the LinuxSampler team,
> > I have put together a patch to port libgig to big-endian architectures
> > (testing happend on s390x). This was based on the bug report in Debian:
> > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1116657 While the
> > existing code works well on little-endian systems (like x86_64), it
> > contained several assumptions that caused data corruption, CRC mismatches,
> > and crashes (due to unaligned memory access) on big-endian systems.
> > Changes
> 
> > made in this patch:
> Hi Pranav,
> 
> thanks for pointing this out and for the patch.
> 
> I made a quick test with QEMU s390x user mode emulation and was able to
> reproduce these BE issues.
> 
> Give me some time. I am thinking about a cleaner approach to fix these.

I have split your fixes up into separate commits.

For the following fixes I chose a different, cleaner approach:

https://svn.linuxsampler.org/cgi-bin/viewvc.cgi?view=revision&revision=4651
https://svn.linuxsampler.org/cgi-bin/viewvc.cgi?view=revision&revision=4652

For the following fix I picked your solution, just brought back comments that 
your dropped:

https://svn.linuxsampler.org/cgi-bin/viewvc.cgi?view=revision&revision=4653

All existing tests already pass for s390x here for me. However there is still 
one fix in your patch that I have not addressed in SVN yet: your BE changes 
for calling __calculateCRC(). How did you hit this issue, given that all tests 
already succeed for me with current SVN r4653?

/Christian