Bug#397616: /proc/cpu/alignment should default to warn and fixup on arm
I think this should be pushed via upstream. In the following
thread, it seems to be concluded that 1) fixups should be default
2) warnings can cause bad side-effects (imagine a unaligned
error in sysklogd..)
http://thread.gmane.org/gmane.linux.ports.arm.kernel/34044
On Fri, Apr 25, 2008 at 03:12:08PM +0700, Martin Michlmayr wrote:
> I'd like to hear Riku's opinion on this.
>
> But I'm inclined not to move away from the upstream default, although
> I must admit that Sjoerd has good arguments for changing it.
>
> Maybe you could ask upstream whether it's time to change the default
> to a warning?
>
>
> * Sjoerd Simons <sjoerd@debian.org> [2006-11-08 14:02]:
> > Package: linux-2.6
> > Severity: normal
> >
> > Hi,
> >
> > By default the ARM kernel just ignores unaligned accesses from
> > userspace and can just accesses another address then actually
> > specified. This can cause strange behaviour by userspace programs.
> > While i agree that these programs are somewhat buggy, but doing
> > something undefined and not telling anyone doesn't seem like a good
> > strategy :)
> >
> > Some discussion on #debian-arm indicates that it the current default
> > made some sense in the old days. Where some programs actually relied
> > on the behaviour and the amount of buggy programs was so big that it
> > actually caused a flood of warnings.
> >
> > Times have changed though, no applications in debian should depend on
> > this behaviour and turning on warn+fixup doesn't seem cause a flood
> > anymore. Most problemeatic should have been fixed by now, as on Sparc
> > you'll get a sigbus on unaligned access and iirc Alpha gives a warning
> > about it.
> >
> > For reference, i discovered this issue because powerdns on my arm was
> > giving out weird SOA records. So enabling fixup does solves real
> > problems or at least shows where they are :) (Yes i've already patched
> > pdns and will be sending the patch out after some more testing)
> >
> > Sjoerd
> >
> > -- System Information:
> > Debian Release: testing/unstable
> > APT prefers testing
> > APT policy: (500, 'testing'), (101, 'unstable')
> > Architecture: arm (armv5tel)
> > Shell: /bin/sh linked to /bin/bash
> > Kernel: Linux 2.6.18-1-iop32x
> > Locale: LANG=C, LC_CTYPE=nl_NL (charmap=ISO-8859-1)
> >
> >
> > --
> > To UNSUBSCRIBE, email to debian-arm-REQUEST@lists.debian.org
> > with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
>
> --
> Martin Michlmayr
> http://www.cyrius.com/
--
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