From owner-freebsd-hackers@FreeBSD.ORG Thu Sep 4 15:56:08 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 998713D2; Thu, 4 Sep 2014 15:56:08 +0000 (UTC) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6F7BD1CEF; Thu, 4 Sep 2014 15:56:08 +0000 (UTC) Received: from ralph.baldwin.cx (pool-173-70-85-31.nwrknj.fios.verizon.net [173.70.85.31]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 5FC20B995; Thu, 4 Sep 2014 11:56:07 -0400 (EDT) From: John Baldwin To: freebsd-hackers@freebsd.org Subject: Re: Can anyone help clarify details about the FreeBSD system call interface? Date: Thu, 04 Sep 2014 10:06:08 -0400 Message-ID: <2041449.H6lUHcsTDl@ralph.baldwin.cx> User-Agent: KMail/4.10.5 (FreeBSD/10.0-STABLE; KDE/4.10.5; amd64; ; ) In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Thu, 04 Sep 2014 11:56:07 -0400 (EDT) Cc: Benjamin Kaduk , kib@freebsd.org, Steven Stewart-Gallus X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Sep 2014 15:56:08 -0000 On Wednesday, September 03, 2014 05:30:01 PM Benjamin Kaduk wrote: > On Thu, 28 Aug 2014, Steven Stewart-Gallus wrote: > > > svn blame says that the whole implementation dates from r1541. > > > Looks like > > > it was never implemented. Some googling indicates that it was a > > > plannedroutine to set the stack size, which was never implemented, > > > anywhere. > > > > > > The locking comments were added in r79224, but the implementation is > > > otherwise from r1541, i.e., it was never implemented. > > > > Alright, so sys/kern/syscalls.master can be patched somewhat like so > > and I won't need to document them? > > > > -72 AUE_O_VADVISE STD { int ovadvise(int anom); } vadvise \ > > - ovadvise_args int > > +72 AUE_NULL OBSOL ovadvise > > > > -70 AUE_SSTK STD { int sstk(int incr); } > > +70 AUE_SSTK OBSOL sstk > > I don't think so; I think that would be a regression. > > We do currently provide implementations for these syscalls, that just > happen to always return failure. I think that the OBSOL annotation > corresponds to a complete lack of implementation. Perhaps it would be > acceptable at a major release boundary, but this is not my area of > expertise. For these two calls, I doubt anything is actually using them. They've been stubs since the Mach VM was imported into BSD in 1990. We don't ship a system call for creat() anymore either. In this particular case, I think it would be more of a feature if those symbols disappeared from libc and caused link errors. -- John Baldwin