Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp2148122imu; Wed, 12 Dec 2018 10:16:16 -0800 (PST) X-Google-Smtp-Source: AFSGD/Vjucxi6bq2inBtcIsw2zuP9avj8xJkr0wbenaVUCZx+BMIj+LWebPEifLYGCbhOg1HbBQU X-Received: by 2002:a17:902:6b83:: with SMTP id p3mr20569571plk.118.1544638576875; Wed, 12 Dec 2018 10:16:16 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544638576; cv=none; d=google.com; s=arc-20160816; b=aKX9nDcBZCLgWT+1/BG4Ljd8LPeXH0HGA2o2bpyFC6Ry21LeQ+nXhs1Xl47vj5kdIb QtYkFf6fjPefeC4W4+zt13TUAfJZNdCK2hV0VF7w62zimc+10jOwhwoMRikUkmnMI6aM 7yC1sj89kdQAqlDWOsTLUdGUkZO9pTufhups+OwsUVfbHGXPmFnHfaL0swsr55fjy7EJ LW+1w8t/veKe/lOxF6HqkpsWc6DGTQM+v9U8UStgxxsek4hy0Oeis5CrB8MgPIjdtAlN /vCfMGHRXNqCok7hozlm4VOH/5JntfsWTqrO/ygS2tHVB2rX9Vk6L/MJ7SrIqtHUWo5Z tGCQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:user-agent:references :message-id:in-reply-to:subject:cc:to:from:date; bh=bURgEtjb5Fj51smLDBkOAGQo3UrMvUao37mLui8yJYY=; b=1CY+6WT1LG+LyEwy0fnmCjRJcUJK/7XwVdlQiAIctFqEBId9ZiXAGNAlVirKtVwlv3 maKlaoJHxSz/mtBPve+cqJQDsF4IGX9ryOtxUyjLIcGIoAOxqXCm1SiAnIgxEW75Lc/y y7N9YOqLe674/LX6MM9r6Fyfjuz+0gjlAgAFfQSzig6GbwD8EfkluNADczxsneV1wSJn Y3ASjZNj4xJVO534uuXr2eS1PCAsPZ6qH3EuEUQ+oXDahnpAkQbxBlnogn51m4WMO+6A 0WUHIS+heKeIWZLs2LamY44asQ2pdFv1D7qqDUBvC6T/OJo3FJVHSWmFag0Dm3/Zt55q kCVQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g71si14832371pgc.419.2018.12.12.10.16.00; Wed, 12 Dec 2018 10:16:16 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728207AbeLLSOW (ORCPT + 99 others); Wed, 12 Dec 2018 13:14:22 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:63393 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727990AbeLLSOU (ORCPT ); Wed, 12 Dec 2018 13:14:20 -0500 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=svr-ies-mbx-01.mgc.mentorg.com) by relay1.mentorg.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-SHA384:256) id 1gX91I-0005kK-LV from joseph_myers@mentor.com ; Wed, 12 Dec 2018 10:14:04 -0800 Received: from digraph.polyomino.org.uk (137.202.0.90) by svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Wed, 12 Dec 2018 18:14:01 +0000 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.90_1) (envelope-from ) id 1gX91E-0007Ah-I4; Wed, 12 Dec 2018 18:14:00 +0000 Date: Wed, 12 Dec 2018 18:14:00 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Arnd Bergmann CC: , Andy Lutomirski , Linus Torvalds , the arch/x86 maintainers , Linux Kernel Mailing List , Linux API , "H. Peter Anvin" , Peter Zijlstra , Borislav Petkov , Florian Weimer , , "H.J. Lu" , Rich Felker , , Will Deacon , Catalin Marinas Subject: Re: Can we drop upstream Linux x32 support? In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-08.mgc.mentorg.com (139.181.222.8) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 Dec 2018, Arnd Bergmann wrote: > > MIPS had o32, n32, n64 since like forever. > > o32 and n32 are practically the same, the only difference on the > syscall ABI that I can see are the actual syscall numbers, and > the 'struct sigcontext' definition. And for syscalls that have 64-bit arguments, n32 generally passes those in a single register (like n64), not pairs of registers (like o32). But, yes, userspace structure layout for n32 is generally much closer to o32 than to n64. -- Joseph S. Myers joseph@codesourcery.com