[Hardy] SRU: Disable COMPAT_VDSO for custom xen i386 builds

SRU Justification:

Impact: The COMPAT_VDSO option will cause the VDSO segment (32bit) to appear
also at its old, non-randomized place. It is only required for older libc
versions. 10.04 already is at a newer level and the generic build has it turned off.

Fix: Turn the option off for the custom-binary-xen (i386) build as well.

Testcase: QA regression testing will fail with this option turned on. Verified
it is running successfully in a Hardy VM using the -xen kernel in dom0, as well
as running it as domU on EC2 (m1.small).

-Stefan

On Thu, Jun 09, 2011 at 02:01:15PM +0200, Stefan Bader wrote:
> SRU Justification:
> 
> Impact: The COMPAT_VDSO option will cause the VDSO segment (32bit) to appear
> also at its old, non-randomized place. It is only required for older libc
> versions. 10.04 already is at a newer level and the generic build has it turned off.
> 
> Fix: Turn the option off for the custom-binary-xen (i386) build as well.
> 
> Testcase: QA regression testing will fail with this option turned on. Verified
> it is running successfully in a Hardy VM using the -xen kernel in dom0, as well
> as running it as domU on EC2 (m1.small).
> 
> -Stefan

> From a24326982bdf55584b1a1c119dbd26bc5979877e Mon Sep 17 00:00:00 2001
> From: Stefan Bader <stefan.bader@canonical.com>
> Date: Thu, 9 Jun 2011 13:53:58 +0200
> Subject: [PATCH] UBUNTU: (config) Disable COMPAT_VDSO for i386 Xen kernels
> 
> BugLink: http://bugs.launchpad.net/bugs/794715
> 
> This option is already disabled for generic i386 kernels as it
> practically renders randomization of the VDSO location useless.
> According to the description of this option it only is needed for
> older (<2.3.3) versions of libc. As the Hardy version is newer
> than that, it makes no sense to keep it enabled.
> 
> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
> ---
>  debian/binary-custom.d/xen/config.i386 |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/debian/binary-custom.d/xen/config.i386 b/debian/binary-custom.d/xen/config.i386
> index c387aa5..72758e9 100644
> --- a/debian/binary-custom.d/xen/config.i386
> +++ b/debian/binary-custom.d/xen/config.i386
> @@ -241,7 +241,7 @@ CONFIG_CRASH_DUMP=y
>  CONFIG_PHYSICAL_START=0x100000
>  CONFIG_PHYSICAL_ALIGN=0x100000
>  CONFIG_HOTPLUG_CPU=y
> -CONFIG_COMPAT_VDSO=y
> +# CONFIG_COMPAT_VDSO is not set
>  CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y
>  
>  #

Seems appropriate to me, makes it consistent with all other flavours.

Acked-by: Andy Whitcroft <apw@canonical.com>

-apw

On 06/09/2011 06:01 AM, Stefan Bader wrote:
> SRU Justification:
>
> Impact: The COMPAT_VDSO option will cause the VDSO segment (32bit) to appear
> also at its old, non-randomized place. It is only required for older libc
> versions. 10.04 already is at a newer level and the generic build has it turned off.
>
> Fix: Turn the option off for the custom-binary-xen (i386) build as well.
>
> Testcase: QA regression testing will fail with this option turned on. Verified
> it is running successfully in a Hardy VM using the -xen kernel in dom0, as well
> as running it as domU on EC2 (m1.small).
>
> -Stefan
>

Acked-by: Tim Gardner <tim.gardner@canonical.com>

Applied and pushed to hardy master-next