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

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Submitter Stefan Bader
Date June 9, 2011, 12:01 p.m.
Message ID <4DF0B60B.1050508@canonical.com>
Download mbox | patch
Permalink /patch/99739/
State New
Headers show

Comments

Stefan Bader - June 9, 2011, 12:01 p.m.
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
Andy Whitcroft - June 9, 2011, 12:29 p.m.
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
Tim Gardner - June 9, 2011, 12:46 p.m.
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>
Stefan Bader - June 9, 2011, 12:50 p.m.
Applied and pushed to hardy master-next

Patch

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
 
 #
-- 
1.7.4.1