From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 669A1C0044C for ; Thu, 1 Nov 2018 12:18:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2451520657 for ; Thu, 1 Nov 2018 12:18:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2451520657 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728539AbeKAVUq (ORCPT ); Thu, 1 Nov 2018 17:20:46 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:57361 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728085AbeKAVUq (ORCPT ); Thu, 1 Nov 2018 17:20:46 -0400 Received: from p5492fe24.dip0.t-ipconnect.de ([84.146.254.36] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gIBvC-0003h3-Oq; Thu, 01 Nov 2018 13:17:58 +0100 Date: Thu, 1 Nov 2018 13:17:58 +0100 (CET) From: Thomas Gleixner To: "Woodhouse, David" cc: "mingo@kernel.org" , "zhenzhong.duan@oracle.com" , "linux-kernel@vger.kernel.org" , "daniel@iogearbox.net" , "peterz@infradead.org" , "bp@suse.de" , "srinivas.eeda@oracle.com" , "konrad.wilk@oracle.com" , "michal.lkml@markovi.net" , "hpa@zytor.com" , "mingo@redhat.com" , "yamada.masahiro@socionext.com" , "luto@kernel.org" Subject: Re: [PATCH v2 1/2] retpolines: Only enable retpoline support when compiler support it In-Reply-To: <90a9eed724b28d5af57a71694a95b4cd92728ccc.camel@amazon.co.uk> Message-ID: References: <991cbe9b-1e31-4b12-b572-91fde5c79699@default> <20181101095002.GA118944@gmail.com> <90a9eed724b28d5af57a71694a95b4cd92728ccc.camel@amazon.co.uk> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 1 Nov 2018, Woodhouse, David wrote: > On Thu, 2018-11-01 at 10:50 +0100, Ingo Molnar wrote: > > * Zhenzhong Duan wrote: > > > > > Since retpoline capable compilers are widely available, make > > > CONFIG_RETPOLINE hard depend on it. > > > > > > The check of RETPOLINE is changed to CONFIG_RETPOLINE. > > > > > > This change is based on suggestion in https://lkml.org/lkml/2018/9/18/1016 > > > > > > Signed-off-by: Zhenzhong Duan > > > Cc: Thomas Gleixner > > > Cc: Peter Zijlstra > > > > Please turn such 'based on suggestions' into proper tags as well, i.e. > > something like: > > > > Suggested-by: David Woodhouse > > I think the suggestion came from PeterZ; I just acked it. > > Although on furthe reflection, I think I'd prefer a build break if > retpoline is enabled in the kernel config and the compiler doesn't > support it. This patch would make it silently fail to be secure. Agreed. Thanks, tglx