From owner-freebsd-current@FreeBSD.ORG Mon Oct 13 11:29:54 2014 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id D8DDD594 for ; Mon, 13 Oct 2014 11:29:54 +0000 (UTC) Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "vps1.elischer.org", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 9406C640 for ; Mon, 13 Oct 2014 11:29:54 +0000 (UTC) Received: from Julian-MBP3.local (50-196-156-133-static.hfc.comcastbusiness.net [50.196.156.133]) (authenticated bits=0) by vps1.elischer.org (8.14.9/8.14.9) with ESMTP id s9DBTnfY024882 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Mon, 13 Oct 2014 04:29:52 -0700 (PDT) (envelope-from julian@freebsd.org) Message-ID: <543BB7A7.9080709@freebsd.org> Date: Mon, 13 Oct 2014 19:29:43 +0800 From: Julian Elischer User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: FreeBSD Current Subject: number of args in a syscall Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Oct 2014 11:29:54 -0000 I'm faced with porting some code that has patched the 8.0 kernel to accept up to 16 args in a syscall. It makes my skin crawl a bit but if I can't give a good reason to suggest that they do things differently in 10 (pass a pointer to a struct maybe) then I'll just take the easy path and s/8/16/ in the appropriate line in amd64/include/proc.h and get on with life. I initially thought it may confuse things like ktrace or truss but I haven't seen any problems.. allocating more space on the stack is another thing but you only ever do one syscall at a time. Julian