From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753105AbcDCNvx (ORCPT ); Sun, 3 Apr 2016 09:51:53 -0400 Received: from mail-ig0-f195.google.com ([209.85.213.195]:36071 "EHLO mail-ig0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752135AbcDCNvw (ORCPT ); Sun, 3 Apr 2016 09:51:52 -0400 MIME-Version: 1.0 In-Reply-To: <20160403080737.GA19007@pd.tnic> References: <20fc047d926150cb08cb9b9f2923519b07ec1a15.1459605520.git.luto@kernel.org> <20160402185227.GB2538@pd.tnic> <20160402205248.GD2538@pd.tnic> <20160403080737.GA19007@pd.tnic> Date: Sun, 3 Apr 2016 08:51:50 -0500 X-Google-Sender-Auth: sgjDVbWm3PxQNL98OLFHeiUJj8s Message-ID: Subject: Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early From: Linus Torvalds To: Borislav Petkov Cc: Andy Lutomirski , "H. Peter Anvin" , Andy Lutomirski , X86 ML , Paolo Bonzini , Peter Zijlstra , KVM list , Arjan van de Ven , xen-devel , "linux-kernel@vger.kernel.org" , Andrew Morton Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 3, 2016 at 3:07 AM, Borislav Petkov wrote: > > I'm wondering whether making it try to EFAULT correctly is the right > thing to do... We're certainly more conservative if we panic and not > allow some silently failed attempt at recovery which looks successful, > to continue. No, please don't fail at early boot. Early boot is just about the *worst* situation to try to debug odd failures, exactly since things like printk may not be reliable, and things won't get logged etc. So particularly during early boot we should try as hard as possible not to crash - even if it means not being able to log about a problem. At least that way you have a hopefully working machine and can *maybe* debug things. Linus