From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935043AbcATKuv (ORCPT ); Wed, 20 Jan 2016 05:50:51 -0500 Received: from mx2.suse.de ([195.135.220.15]:33930 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932979AbcATKut (ORCPT ); Wed, 20 Jan 2016 05:50:49 -0500 Date: Wed, 20 Jan 2016 11:50:18 +0100 From: Borislav Petkov To: "H. Peter Anvin" Cc: Brian Gerst , the arch/x86 maintainers , Linux Kernel Mailing List , Ingo Molnar , Denys Vlasenko , Andy Lutomirski , Linus Torvalds Subject: Re: [PATCH] x86: static_cpu_has_safe: discard dynamic check after init Message-ID: <20160120105018.GB23350@pd.tnic> References: <20160117103337.GC8549@pd.tnic> <20160118181457.GG12651@pd.tnic> <20160118185107.GI12651@pd.tnic> <20160119011026.GA12911@pd.tnic> <20160119092213.GA15071@pd.tnic> <569F06B9.4060903@zytor.com> <569F1022.6040709@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <569F1022.6040709@zytor.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 19, 2016 at 08:42:10PM -0800, H. Peter Anvin wrote: > Right. I wish we could tag reference call sites as clean, not sources > or targets. Sigh. I was thinking about something like this: From: Borislav Petkov Date: Wed, 20 Jan 2016 11:45:36 +0100 Subject: [PATCH] x86/alternatives: Add an auxilary section Add .altinstr_aux for additional instructions which will be used before and/or during patching. All stuff which needs more sophisticated patching should go there. See next patch. Signed-off-by: Borislav Petkov --- arch/x86/kernel/vmlinux.lds.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 74e4bf11f562..35868bf529b9 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -244,6 +244,11 @@ SECTIONS */ .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { *(.altinstr_replacement) + /* + * Auxiliary section for misc instruction patching tasks. See + * static_cpu_has(), for an example. + */ + *(.altinstr_aux) } /* -- 2.3.5 SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --