From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758218AbcBXUTG (ORCPT ); Wed, 24 Feb 2016 15:19:06 -0500 Received: from mail.kernel.org ([198.145.29.136]:48280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753992AbcBXUTD (ORCPT ); Wed, 24 Feb 2016 15:19:03 -0500 From: Andy Lutomirski To: x86@kernel.org Cc: Brian Gerst , "linux-kernel@vger.kernel.org" , Borislav Petkov , Andy Lutomirski , stable@vger.kernel.org Subject: [PATCH] x86/entry/compat: Add missing CLAC to entry_INT80_32 Date: Wed, 24 Feb 2016 12:18:49 -0800 Message-Id: X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This doesn't seem to fix a regression -- I don't think the CLAC was ever there. I double-checked in a debugger: entries through the int80 gate do not automatically clear AC. Stable maintainers: I can provide a backport to 4.3 and earlier if needed. This needs to be backported all the way to 3.10. Reported-by: Brian Gerst Cc: stable@vger.kernel.org Fixes: 63bcff2a307b ("x86, smap: Add STAC and CLAC instructions to control user space access") Signed-off-by: Andy Lutomirski --- arch/x86/entry/entry_64_compat.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 5e887ee35662..41fbb3389a2f 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -261,6 +261,7 @@ ENTRY(entry_INT80_compat) * Interrupts are off on entry. */ PARAVIRT_ADJUST_EXCEPTION_FRAME + ASM_CLAC /* Do this early to minimize exposure */ SWAPGS /* -- 2.5.0