ACK: [Oneiric/SRU][PATCH] UBUNTU: SAUCE: (no-up) Reinstate missing hunk from nx emulation

[Stefan Bader]

On 05.04.2012 02:15, Herton R. Krzesinski wrote:
> From: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
> 
> Recently with kernel 3.0.0-18.31, we started to get several bug reports
> of userspace crashes on launchpad, happening on i386 installs. After
> reproducing the issue and doing a bisect, we detected that the breakage
> started with commit 1d43fea ("i387: do not preload FPU state at task
> switch time").
> 
> Looking at that commit, turns out that our application of that change
> accidentaly removed one piece of i386 NX emulation patch, added with
> commit 775e6e8 ("UBUNTU: ubuntu: nx-emu - i386: NX emulation").
> 
> This adds back the section of code wrongly removed, verified here it
> fixes the bug as well.
> 
> BugLink: http://bugs.launchpad.net/bugs/972821
> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
> ---
>  arch/x86/kernel/process_32.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
> index 98f78e8..2d73f7d 100644
> --- a/arch/x86/kernel/process_32.c
> +++ b/arch/x86/kernel/process_32.c
> @@ -307,6 +307,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
>  
>  	fpu = switch_fpu_prepare(prev_p, next_p);
>  
> +	if (next_p->mm)
> +		load_user_cs_desc(cpu, next_p->mm);
> +
>  	/*
>  	 * Reload esp0.
>  	 */
Testing successful and looks to have been in there as described.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 900 bytes
Desc: OpenPGP digital signature
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20120405/679edc9a/attachment.sig>