From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262165AbVANVLk (ORCPT ); Fri, 14 Jan 2005 16:11:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262106AbVANVJO (ORCPT ); Fri, 14 Jan 2005 16:09:14 -0500 Received: from mx1.redhat.com ([66.187.233.31]:48603 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262169AbVANVHo (ORCPT ); Fri, 14 Jan 2005 16:07:44 -0500 Message-ID: <41E833F4.8090800@redhat.com> Date: Fri, 14 Jan 2005 13:04:52 -0800 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla Thunderbird (X11/20041216) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Theodore Ts'o" CC: Linux Kernel Subject: Re: short read from /dev/urandom References: <41E7509E.4030802@redhat.com> <20050114191056.GB17481@thunk.org> In-Reply-To: <20050114191056.GB17481@thunk.org> X-Enigmail-Version: 0.89.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig0B40E8DA58C5C1E721BBF375" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig0B40E8DA58C5C1E721BBF375 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Theodore Ts'o wrote: > What do you think? Does gcc -pg calls sigaction with SA_RESTART, to > avoid changing the behaviour of the programs that it is profiling? Profiling certainly uses SA_RESTART. But this was just one possible problem case. I'm concerned that there is isgnificant code out there relying on the no-short-read promise. And perhaps more importantly, other implementations promise the same. The code in question comes from a crypto library which is in wide use (http://www.cryptopp.com) and it is using urandom under this assumption. I fear there is quite a bit more code like this out there. Changing the ABI after the fact is no good and dangerous in this case. I know this is making the device special, but I really think the no-short-reads property should be perserved for urandom. -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖ --------------enig0B40E8DA58C5C1E721BBF375 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFB6DP12ijCOnn/RHQRArhGAKCntucrVd6mrfqVbZX7ERKHevasYQCgsZ3c i7a3WS+dsthMNyZsCTm17sI= =1Ofs -----END PGP SIGNATURE----- --------------enig0B40E8DA58C5C1E721BBF375--