From owner-svn-src-all@FreeBSD.ORG Tue Nov 4 14:22:57 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id BB37ED81; Tue, 4 Nov 2014 14:22:57 +0000 (UTC) Received: from elvis.mu.org (elvis.mu.org [IPv6:2001:470:1f05:b76::196]) by mx1.freebsd.org (Postfix) with ESMTP id A604BAD3; Tue, 4 Nov 2014 14:22:57 +0000 (UTC) Received: from [172.16.1.27] (50-206-19-250-static.hfc.comcastbusiness.net [50.206.19.250]) by elvis.mu.org (Postfix) with ESMTPSA id 5FA8D341F83D; Tue, 4 Nov 2014 06:22:57 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (1.0) Subject: Re: svn commit: r274017 - head/sys/kern From: Alfred Perlstein X-Mailer: iPhone Mail (12B411) In-Reply-To: <20141104092558.GP53947@kib.kiev.ua> Date: Tue, 4 Nov 2014 06:22:56 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: <88CC9FA2-D677-484A-8D6B-9DA66D8479AE@mu.org> References: <201411030746.sA37kpPu037113@svn.freebsd.org> <5457F771.3010509@freebsd.org> <20141104092558.GP53947@kib.kiev.ua> To: Konstantin Belousov Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , Alfred Perlstein , "src-committers@freebsd.org" , Mateusz Guzik X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Nov 2014 14:22:57 -0000 > On Nov 4, 2014, at 1:25 AM, Konstantin Belousov wrot= e: >=20 >> On Mon, Nov 03, 2014 at 01:45:21PM -0800, Alfred Perlstein wrote: >> Isn't there a problem where the stack can be swapped out? >>=20 >> I seem to recall a problem where a swapped out process was causing=20 >> problems due to a buffer passed being stack allocated and that process=20= >> being swapped out... >>=20 >> If this is not the case then please disregard. >=20 > Sure, stack can be swapped out, but buffer passing is usually not a proble= m. > At least, I am not aware of cases. >=20 > In fact, many compat layers do exactly this, allocate the native-ABI > structure on the stack, copyin the foreighn-ABI structure in pieces > into the native-ABI one, and pass native to kern_foo() implementations. >=20 > So I think you worries are not realized. >=20 Ok then as long as system will not pass this buffer as Dma target down to dr= iver we are ok. =20=