[3.16.y-ckt stable] Patch "x86, microcode: Update BSPs microcode on resume" has been added to staging queue

[Borislav Petkov]

Hey Luis,

please drop this patch for now as it breaks 32-bit suspend to ram. I'll
have a full list of patches for stable once the whole issue has been
sorted out properly.

Thanks.

On Mon, Dec 01, 2014 at 10:19:51AM +0000, Luis Henriques wrote:
> This is a note to let you know that I have just added a patch titled
> 
>     x86, microcode: Update BSPs microcode on resume
> 
> to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
> which can be found at:
> 
>  http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue
> 
> This patch is scheduled to be released in version 3.16.7-ckt3.
> 
> If you, or anyone else, feels it should not be added to this tree, please 
> reply to this email.
> 
> For more information about the 3.16.y-ckt tree, see
> https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
> 
> Thanks.
> -Luis
> 
> ------
> 
> From 76c27f3e62e96a4e4a4591fb3861048ec171b006 Mon Sep 17 00:00:00 2001
> From: Borislav Petkov <bp at suse.de>
> Date: Tue, 18 Nov 2014 10:46:57 +0100
> Subject: x86, microcode: Update BSPs microcode on resume
> 
> commit fb86b97300d930b57471068720c52bfa8622eab7 upstream.
> 
> In the situation when we apply early microcode but do *not* apply late
> microcode, we fail to update the BSP's microcode on resume because we
> haven't initialized the uci->mc microcode pointer. So, in order to
> alleviate that, we go and dig out the stashed microcode patch during
> early boot. It is basically the same thing that is done on the APs early
> during boot so do that too here.
> 
> Tested-by: alex.schnaidt at gmail.com
> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=88001
> Cc: Henrique de Moraes Holschuh <hmh at hmh.eng.br>
> Cc: Fenghua Yu <fenghua.yu at intel.com>
> Signed-off-by: Borislav Petkov <bp at suse.de>
> Link: http://lkml.kernel.org/r/20141118094657.GA6635@pd.tnic
> Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
> Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
> ---
>  arch/x86/kernel/cpu/microcode/core.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
> index dd9d6190b08d..2ce9051174e6 100644
> --- a/arch/x86/kernel/cpu/microcode/core.c
> +++ b/arch/x86/kernel/cpu/microcode/core.c
> @@ -465,6 +465,14 @@ static void mc_bp_resume(void)
> 
>  	if (uci->valid && uci->mc)
>  		microcode_ops->apply_microcode(cpu);
> +	else if (!uci->mc)
> +		/*
> +		 * We might resume and not have applied late microcode but still
> +		 * have a newer patch stashed from the early loader. We don't
> +		 * have it in uci->mc so we have to load it the same way we're
> +		 * applying patches early on the APs.
> +		 */
> +		load_ucode_ap();
>  }
> 
>  static struct syscore_ops mc_syscore_ops = {
> --
> 2.1.0
> 

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--