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[209.132.180.67]) by mx.google.com with ESMTP id cd11-v6si27947347plb.59.2018.11.14.10.33.07; Wed, 14 Nov 2018 10:33:33 -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 S1733202AbeKOEex (ORCPT + 99 others); Wed, 14 Nov 2018 23:34:53 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:53019 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727736AbeKOEex (ORCPT ); Wed, 14 Nov 2018 23:34:53 -0500 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-MBX-03.mgc.mentorg.com) by relay1.mentorg.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-SHA384:256) id 1gMzvr-0003eq-Ig from joseph_myers@mentor.com ; Wed, 14 Nov 2018 10:30:31 -0800 Received: from digraph.polyomino.org.uk (137.202.0.90) by SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Wed, 14 Nov 2018 18:30:28 +0000 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.90_1) (envelope-from ) id 1gMzvn-0005QZ-Kz; Wed, 14 Nov 2018 18:30:27 +0000 Date: Wed, 14 Nov 2018 18:30:27 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Arnd Bergmann CC: , Szabolcs Nagy , Dave Martin , , , Florian Weimer , Michael Kerrisk , Linux Kernel Mailing List , Joel Fernandes , Linux API , Willy Tarreau , Vlastimil Babka , GNU C Library , Firoz Khan Subject: Re: Official Linux system wrapper library? In-Reply-To: Message-ID: References: <877ehjx447.fsf@oldenburg.str.redhat.com> <875zx2vhpd.fsf@oldenburg.str.redhat.com> <20181113193859.GJ3505@e103592.cambridge.arm.com> <5853c297-9d84-86e5-dede-aa2957562c6b@arm.com> 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-05.mgc.mentorg.com (139.181.222.5) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 14 Nov 2018, Arnd Bergmann wrote: > Firoz Khan is in the process of doing part of this, by changing the > in-kernel per-architecture unistd.h and syscall.S files into a > architecture independent machine-readable format that is used to > generate the existing files. The format will be similar to what > we have on arm/s390/x86 in the syscall.tbl files already. Will this also mean the following are unable to occur in future (both have occurred in the past): * A syscall added to unistd.h for an architecture, but not added to the syscall table until sometime later? * A syscall added to the native syscall table for some ABI (e.g. 32-bit x86 or arm) but not added to the corresponding compat syscall table (e.g. 32-bit x86 binaries running on x86_64, 32-bit arm binaries running on arm64) until sometime later? Avoiding both of those complications is beneficial to libc (as is a third thing, avoiding a syscall being added to different architectures in different versions). -- Joseph S. Myers joseph@codesourcery.com