Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754589AbdC2S5B (ORCPT ); Wed, 29 Mar 2017 14:57:01 -0400 Received: from mail-io0-f180.google.com ([209.85.223.180]:35086 "EHLO mail-io0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752592AbdC2S45 (ORCPT ); Wed, 29 Mar 2017 14:56:57 -0400 MIME-Version: 1.0 In-Reply-To: <20170329185041.GA24806@redhat.com> References: <20170328145413.GA3164@redhat.com> <20170329163335.GA23977@redhat.com> <20170329165554.GA24250@redhat.com> <20170329170442.GA24342@redhat.com> <20170329185041.GA24806@redhat.com> From: Linus Torvalds Date: Wed, 29 Mar 2017 11:56:55 -0700 X-Google-Sender-Auth: CuKkyRnAJRWi7qPTAen8DVYwKrk Message-ID: Subject: Re: syscall_get_error() && TS_ checks To: Oleg Nesterov Cc: Andrew Morton , Andy Lutomirski , Denys Vlasenko , "H. Peter Anvin" , Ingo Molnar , Jan Kratochvil , Pedro Alves , Thomas Gleixner , "the arch/x86 maintainers" , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 812 Lines: 21 On Wed, Mar 29, 2017 at 11:50 AM, Oleg Nesterov wrote: > > Again, afaics we only need these compat checks because regs->ax could be > changed by 32-bit debugger without sign-extension. You don't explain how you were planning on *fixing* that code. You know why it exists, but then you just say "let's remove it", without any explanation of what you'd replace it with. If your suggestion is just that "let's remove it, breaking the known reason it's there", I really really don't see the upside. It may be hacky, but it *works*. You seem to be advocating replacing it with something simpler - "cleaner, but broken". I really don't see the point of "cleaner, but broken". The fact is, reality is not "clean". But reality trumps :I wish" and "make-believe" every single time. Linus