Comment 12 for bug 659422

I bisected the problem down to this change:

commit 4f797709f4c0f61368c2f0f989cefc805fed0c9e
Author: Brad Figg <email address hidden>
Date: Fri Aug 27 09:10:55 2010 -0700

    mm: make the vma list be doubly linked

    BugLink: http://bugs.launchpad.net/bugs/625392

    commit 297c5eee372478fc32fec5fe8eed711eedb13f3d upstream.

    It's a really simple list, and several of the users want to go backwards
    in it to find the previous vma. So rather than have to look up the
    previous entry with 'find_vma_prev()' or something similar, just make it
    doubly linked instead.

    Tested-by: Ian Campbell <email address hidden>
    Signed-off-by: Linus Torvalds <email address hidden>
    Signed-off-by: Greg Kroah-Hartman <email address hidden>
    Acked-by: Steve Conklin <email address hidden>
    Acked-by: Stefan Bader <email address hidden>
    Acked-by: Brad Figg <email address hidden>
    Signed-off-by: Brad Figg <email address hidden>

 include/linux/mm_types.h | 2 +-
 kernel/fork.c | 7 +++++--
 mm/mmap.c | 39 +++++++++++++++++++++++++--------------
 mm/nommu.c | 7 +++++--
 4 files changed, 36 insertions(+), 19 deletions(-)

Reverting allows me to boot the VM. However if I compile mainline or stable 2.6.32.21 that has this commit as well then I am able to boot just fine.

I expect we are witnessing incompatibility of the patch with Ubuntu "sauce". I suspect it might be this one:

commit 59b35f3ba2cba40bd260ad19dbf4cf445714044f
Author: Kees Cook <email address hidden>
Date: Thu Apr 30 12:47:47 2009 -0700

    UBUNTU: SAUCE: [x86] implement cs-limit nx-emulation for ia32

but it is too tangled up with other changes to be reverted cleanly to test this theory.