Re: initrd change breaks binary compatibility

[Anthony Liguori <aliguori@us.ibm.com>]

John Levon wrote:
> This change in 3.0.3-testing-rc3:
> 
> changeset:   11728:30f13007be3f
> user:        kfraser@localhost.localdomain
> date:        Mon Oct 09 13:50:00 2006 +0100
> files:       tools/libxc/xc_linux_build.c
> description:
> [XEND] No need to decompress the initrd when building a domain.
> 
> breaks binary compatibility. In particular, it breaks Solaris, which
> expects both grub and xen to uncompress the initrd for us. And it does
> seem odd to differ from grub's behaviour needlessly.
> 
> I don't know what causes the broken Linux initrd's that the commit
> message refers to, but it seems they need to be fixed another way.

I suspect that we're actually broken here.  I think the way we determine 
the uncompressed size (by reading the last couple bytes) is not 
something that can, in generally, be safely relied upon.

We could work around this by decompressing the initrd and dynamically 
expanding the buffer we're decompressing to as needed.

Regards,

Anthony Liguori

> regards,
> john