Re: [patch -v2] flat: fix data sections alignment

[Paul Mundt <lethal@linux-sh.org>]

On Fri, May 29, 2009 at 10:01:51AM +1000, John Williams wrote:
> Hi,
> 
> On Wed, Mar 4, 2009 at 11:51 PM, Johannes Weiner <jw@emlix.com> wrote:
> > From: Oskar Schirmer <os@emlix.com>
> >
> > The flat loader uses an architecture's flat_stack_align() to align the
> > stack but assumes word-alignment is enough for the data sections.
> >
> > However, on the Xtensa S6000 we have registers up to 128bit width
> > which can be used from userspace and therefor need userspace stack and
> > data-section alignment of at least this size.
> >
> > This patch drops flat_stack_align() and uses the same alignment that
> > is required for slab caches, ARCH_SLAB_MINALIGN, or wordsize if it's
> > not defined by the architecture.
> >
> > It also fixes m32r which was obviously kaput, aligning an
> > uninitialized stack entry instead of the stack pointer.
> >
> 
> > ---
> > ?arch/arm/include/asm/flat.h ? ? ?| ? ?3 ---
> > ?arch/blackfin/include/asm/flat.h | ? ?1 -
> > ?arch/h8300/include/asm/flat.h ? ?| ? ?1 -
> > ?arch/m68k/include/asm/flat.h ? ? | ? ?1 -
> > ?arch/sh/include/asm/flat.h ? ? ? | ? ?1 -
> > ?fs/binfmt_flat.c ? ? ? ? ? ? ? ? | ? 37 ++++++++++++++++++++++---------------
> > ?include/asm-m32r/flat.h ? ? ? ? ?| ? ?1 -
> > ?7 files changed, 22 insertions(+), 23 deletions(-)
> 
> Can you please cross-check this patch for MicroBlaze as well, we are
> another active nommu architecture.
> 
I already did, see http://lkml.org/lkml/2009/5/27/753

You just need to kill off your flat_stack_align(), as it doesn't do
anything presently it is harmless one way or the other.