[PATCH 2/3] ARM: compressed/misc.c: simplify decompress_kernel()

[Nicolas Pitre]

On Wed, 27 Apr 2011, Russell King - ARM Linux wrote:

> On Wed, Apr 20, 2011 at 12:15:03AM -0400, Nicolas Pitre wrote:
> > The return value for decompress_kernel() is no longer used.  Furthermore,
> > this was obtained and stored in a variable called output_ptr which is
> > a complete misnomer for what is actually the size of the decompressed
> > kernel image.  Let's get rid of it.
> > 
> > Signed-off-by: Nicolas Pitre <nicolas.pitre at linaro.org>
> > ---
> > 
> > BTW, I've yet to understand why, but this patch makes CONFIG_KERNEL_LZMA
> > work for me.
> 
> Hmm.  I've switched almost entirely to LZMA since it was introduced and it
> works for me on all my platforms.  I haven't tested kernels rigorously since
> your patches to the decompressor, so maybe there's a regression in there
> somewhere.
> 
> Can you try LZMA with your various patches over the last four months
> reverted?

Yes I did, and the issue turned up to be about the stack alignment wich 
was not enforced to a 64 bit boundary.  Depending on the size of the 
code and compressed kernel data, the stack would end up properly aligned 
with a 50% probability.  And this was a problem only if your gcc version 
emited LDRD/STRD type accesses to the stack.

I'm about to send you a pull request with all those fixes.


Nicolas