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

[Kamal Mostafa]

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-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 2e25f406c1d7f18c4ed16c8b522bb6fabe696a86 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: Kamal Mostafa <kamal at canonical.com>
---
 arch/x86/kernel/microcode_core.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index 15c9876..1354282 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -462,6 +462,14 @@ 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 = {
--
1.9.1