Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758872AbcCVLAI (ORCPT ); Tue, 22 Mar 2016 07:00:08 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56809 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758824AbcCVKmm (ORCPT ); Tue, 22 Mar 2016 06:42:42 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Andy Lutomirski , Andy Lutomirski , Borislav Petkov , Denys Vlasenko , "H. Peter Anvin" , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Kamal Mostafa , Luis Henriques Subject: [PATCH 3.16.y-ckt 025/142] x86/entry/compat: Add missing CLAC to entry_INT80_32 Date: Tue, 22 Mar 2016 10:39:14 +0000 Message-Id: <1458643271-4227-26-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1867 Lines: 48 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Andy Lutomirski commit 3d44d51bd339766f0178f0cf2e8d048b4a4872aa upstream. 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 Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: 63bcff2a307b ("x86, smap: Add STAC and CLAC instructions to control user space access") Link: http://lkml.kernel.org/r/b02b7e71ae54074be01fc171cbd4b72517055c0e.1456345086.git.luto@kernel.org Signed-off-by: Ingo Molnar [ kamal: backport to 3.10 through 3.19-stable: file rename; context ] Signed-off-by: Kamal Mostafa Signed-off-by: Luis Henriques --- arch/x86/ia32/ia32entry.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 92a2e9333620..b74ac9c5710b 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -422,6 +422,7 @@ ENTRY(ia32_syscall) /*CFI_REL_OFFSET cs,CS-RIP*/ CFI_REL_OFFSET rip,RIP-RIP PARAVIRT_ADJUST_EXCEPTION_FRAME + ASM_CLAC /* Do this early to minimize exposure */ SWAPGS /* * No need to follow this irqs on/off section: the syscall