md5sum makes unaligned word accesses...

Mike Frysinger vapier at gentoo.org
Wed May 10 05:25:05 UTC 2006


On Wednesday 10 May 2006 00:57, Andre wrote:
> --- Mike Frysinger <vapier at gentoo.org> wrote:
> > On Tuesday 09 May 2006 23:56, Andre wrote:
> > > (This is ARM specific and ensures that userspace alignment faults
> > > don't cause silent data corruption... which unfortunately is the
> > > default behaviour).
> >
> > i'm pretty sure the kernel handles this stuff sanely ... it would
> > either fixup the unaligned access or kill the process, not let
> > "silent data corruption" happen ...
>
> Unfortunately not. For historical reasons (of which I'm not 100%
> clear) the default value in /proc/cpu/alignment on ARM is 0 (no
> fixup, no warning). Here's hoping the default can be changed along
> with the switch to EABI...

what kernel version ?  arm/oldabi linux-2.6.14.2 works fine for me (even after 
setting /proc/cpu/alignment to 5):
busybox dd if=/dev/zero | busybox md5sum

then again, the two warnings in libbb/md5.c:md5_end() are probably the source 
of the trouble
-mike



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