From owner-svn-src-all@FreeBSD.ORG Fri Dec 3 14:41:24 2010 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 886391065670; Fri, 3 Dec 2010 14:41:24 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.cran.org.uk (muon.cran.org.uk [IPv6:2a01:348:0:15:5d59:5c40:0:1]) by mx1.freebsd.org (Postfix) with ESMTP id 104598FC17; Fri, 3 Dec 2010 14:41:24 +0000 (UTC) Received: from muon.cran.org.uk (localhost [127.0.0.1]) by muon.cran.org.uk (Postfix) with ESMTP id 3A685E7167; Fri, 3 Dec 2010 14:41:23 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cran.org.uk; h=date:from :to:cc:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; s=mail; bh=ZssQ//EKEAYT 2kMp41HOLQ8ZiV8=; b=qeDrYzrwWYDlJaLBYB/Mt3YH2wzXvJ5gP5tBFFTd0Huu IXYImLOl36H+F7HmvfZplaMu80NMrvoN+kWqsADD2n8MrCIevMTh/TvUwim2+Mmp cA/KlsxllQKn5iWWZmAhyr/jsSaON0ryRPF64Ynwhn3R4H9fGUQqQ5AHhYdbvOE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=cran.org.uk; h=date:from:to :cc:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; q=dns; s=mail; b=BDLQO0 NCanFt9I5IjGyn362YNiFFkAL4L1/iVrxsPx47rEZR6qfFPFfFo91fCTruxXfUQR iep8GBrbZkzysKLRHA4n/wYzxdd6Xo7vITNE/dzIbNd9zmIBaDssbLit5XXlCcMt gddAwa+iBMP3TjUBHUszsShL18tlNw8GYh5XE= Received: from unknown (client-86-31-8-12.midd.adsl.virginmedia.com [86.31.8.12]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by muon.cran.org.uk (Postfix) with ESMTPSA id A992CE60D0; Fri, 3 Dec 2010 14:41:22 +0000 (GMT) Date: Fri, 3 Dec 2010 14:41:03 +0000 From: Bruce Cran To: Ivan Voras Message-ID: <20101203144103.00005a78@unknown> In-Reply-To: References: <201012022219.oB2MJUx5031472@svn.freebsd.org> <20101203201705.O2228@besplex.bde.org> <20101203101651.7461ced0@core.draftnet> <201012030746.44967.jhb@freebsd.org> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.16.0; i586-pc-mingw32msvc) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: src-committers@freebsd.org, John Baldwin , svn-src-all@freebsd.org, Bruce Evans , Bruce Cran , svn-src-head@freebsd.org Subject: Re: svn commit: r216134 - in head: share/man/man9 sys/amd64/include sys/arm/include sys/i386/include sys/ia64/include sys/mips/include sys/pc98/include sys/powerpc/include sys/sparc64/include sys/sun4v... X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 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: Fri, 03 Dec 2010 14:41:24 -0000 On Fri, 3 Dec 2010 15:27:13 +0100 Ivan Voras wrote: > I'd say it depends on if the "specific case that hps raised a few > years ago" sentence part refers to an actual problem; i.e. did it > happen in practice? If yes, leaving KASSERTs looks like the best > option. I've found hps's original email thread, which is at http://lists.freebsd.org/pipermail/freebsd-hackers/2005-June/012342.html . The argument for allowing zero-length reads/writes is at http://lists.freebsd.org/pipermail/freebsd-hackers/2005-June/012348.html . I suspect the mistake occurred due to a misunderstanding of the API. NetBSD have documented it in their man page but not added asserts in the code: "Functions which take a count of bytes have undefined results if the specified count is zero." -- Bruce Cran