From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752167AbaK3N0o (ORCPT ); Sun, 30 Nov 2014 08:26:44 -0500 Received: from mail.skyhub.de ([78.46.96.112]:54520 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751614AbaK3N0n (ORCPT ); Sun, 30 Nov 2014 08:26:43 -0500 From: Borislav Petkov To: X86 ML Cc: LKML Subject: [PATCH] x86, microcode: Limit the microcode reloading to 64-bit for now Date: Sun, 30 Nov 2014 14:26:39 +0100 Message-Id: <1417353999-32236-1-git-send-email-bp@alien8.de> X-Mailer: git-send-email 2.0.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov First, there was this: https://bugzilla.kernel.org/show_bug.cgi?id=88001 The problem there was that microcode patches are not being reapplied after suspend-to-ram. It was important to reapply them, though, because of for example Haswell's TSX erratum which disabled TSX instructions with a microcode patch. A simple fix was fb86b97300d9 ("x86, microcode: Update BSPs microcode on resume") but, as it is often the case, simple fixes are too simple. This one causes 32-bit resume to fail: https://bugzilla.kernel.org/show_bug.cgi?id=88391 Properly fixing this would require more involved changes for which it is too late now, before the merge window. Thus, limit this to 64-bit only temporarily. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/microcode/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 2ce9051174e6..08fe6e8a726e 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -465,6 +465,7 @@ static void mc_bp_resume(void) if (uci->valid && uci->mc) microcode_ops->apply_microcode(cpu); +#ifdef CONFIG_X86_64 else if (!uci->mc) /* * We might resume and not have applied late microcode but still @@ -473,6 +474,7 @@ static void mc_bp_resume(void) * applying patches early on the APs. */ load_ucode_ap(); +#endif } static struct syscore_ops mc_syscore_ops = { -- 2.0.0