Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753520AbaBCWBX (ORCPT ); Mon, 3 Feb 2014 17:01:23 -0500 Received: from eddie.linux-mips.org ([78.24.191.182]:53052 "EHLO cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751864AbaBCWBW (ORCPT ); Mon, 3 Feb 2014 17:01:22 -0500 X-Greylist: delayed 418 seconds by postgrey-1.27 at vger.kernel.org; Mon, 03 Feb 2014 17:01:22 EST Date: Mon, 3 Feb 2014 21:54:22 +0000 (GMT) From: "Maciej W. Rozycki" To: "Theodore Ts'o" cc: =?ISO-8859-15?Q?J=F6rn_Engel?= , "H. Peter Anvin" , Linux Kernel Developers List , Ralf Baechle , dave.taht@gmail.com, blogic@openwrt.org, andrewmcgr@gmail.com, smueller@chronox.de, Geert Uytterhoeven , tg@mirbsd.de Subject: Re: [PATCH,RFC] random: collect cpu randomness In-Reply-To: <20140203163729.GA13634@thunk.org> Message-ID: References: <20140202203617.GA9499@logfs.org> <20140203155042.GD9499@logfs.org> <20140203163729.GA13634@thunk.org> User-Agent: Alpine 2.10 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 3 Feb 2014, Theodore Ts'o wrote: > > How about taking the saved registers from the interrupted CPU, xor'ing > > them all and calling the result random_get_entropy() on systems > > lacking a good cycles-counter? > > So we could take the struct pt_regs which we get from get_irq_regs(), > XOR them together and use them to feed into input[2] amd input[3] in > add_interrupt_randomness(). Or some other way of distributing the > values of all of the irq registers into the __u32 input[4] array. Can we be sure we don't leak information this way? Just being paranoid... Maciej -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/