Bug#397616: /proc/cpu/alignment should default to warn and fixup on arm

[Sjoerd Simons <sjoerd@debian.org>]

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)