From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:58384 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752058AbcCGKRo (ORCPT ); Mon, 7 Mar 2016 05:17:44 -0500 Date: Mon, 7 Mar 2016 10:17:38 +0000 From: Luis Henriques To: Kamal Mostafa Cc: Greg Kroah-Hartman , Sasha Levin , Jiri Slaby , stable@vger.kernel.org, Andy Lutomirski , Ingo Molnar Subject: Re: [3.xx-stable backport] x86/entry/compat: Add missing CLAC to entry_INT80_32 Message-ID: <20160307101738.GA3081@ares> References: <1457117182-27061-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1457117182-27061-1-git-send-email-kamal@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: On Fri, Mar 04, 2016 at 10:46:22AM -0800, Kamal Mostafa wrote: > 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 > Cc: # v3.10 and later > 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 ] Thanks Kamal, I'll queue it for the 3.16 kernel. Cheers, -- Lu�s > Signed-off-by: Kamal Mostafa > --- > 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 82e8a1d..164f541 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 > -- > 2.7.0 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html