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=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 5279FC65BAE for ; Thu, 13 Dec 2018 12:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 237BD20851 for ; Thu, 13 Dec 2018 12:12:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 237BD20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=guarana.org 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 S1728886AbeLMMMT (ORCPT ); Thu, 13 Dec 2018 07:12:19 -0500 Received: from aws.guarana.org ([13.237.110.252]:56270 "EHLO aws.guarana.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728767AbeLMMMS (ORCPT ); Thu, 13 Dec 2018 07:12:18 -0500 Received: by aws.guarana.org (Postfix, from userid 1006) id D9D63A18AC; Thu, 13 Dec 2018 12:12:13 +0000 (UTC) Date: Thu, 13 Dec 2018 12:12:13 +0000 From: Kevin Easton To: Richard Weinberger Cc: glaubitz@physik.fu-berlin.de, Andy Lutomirski , x86@kernel.org, LKML , "open list:ABI/API" , "H. Peter Anvin" , Peter Zijlstra , Borislav Petkov , fweimer@redhat.com, Mike Frysinger , "H.J. Lu" , dalias@libc.org, x32@buildd.debian.org, Arnd Bergmann , Will Deacon , Catalin Marinas , Linus Torvalds Subject: Re: Can we drop upstream Linux x32 support? Message-ID: <20181213121213.GA28833@ip-172-31-15-78> References: <70bb54b2-8ed3-b5ee-c02d-6ef66c4f27eb@physik.fu-berlin.de> <20181213050313.GA21201@ip-172-31-15-78> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 13, 2018 at 10:05:14AM +0100, Richard Weinberger wrote: > On Thu, Dec 13, 2018 at 6:03 AM Kevin Easton wrote: > > > > On Tue, Dec 11, 2018 at 11:29:14AM +0100, John Paul Adrian Glaubitz wrote: > > ... > > > I can't say anything about the syscall interface. However, what I do know > > > is that the weird combination of a 32-bit userland with a 64-bit kernel > > > interface is sometimes causing issues. For example, application code usually > > > expects things like time_t to be 32-bit on a 32-bit system. However, this > > > isn't the case for x32 which is why code fails to build. > > > > OpenBSD and NetBSD both have 64-bit time_t on 32-bit systems and have > > had for four or five years at this point. > > They can also do flag-day changes and break existing applications, Linux not. Sure, but the point is that most widely-used software has probably by now come in to contact with systems where time_t is bigger than long. - Kevin