From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick Simmons Subject: Re: [PATCH] Add IRQF_SAMPLE_RANDOM Flag to forcedeth Date: Sat, 09 Oct 2010 21:23:01 -0600 Message-ID: <4CB13195.2070007@netscape.net> References: <4CB0FEA6.3030206@netscape.net> <20101010010924.GB15074@solarflare.com> <20101009.201501.214209347.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: bhutchings@solarflare.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from imr-da01.mx.aol.com ([205.188.105.143]:51010 "EHLO imr-da01.mx.aol.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756724Ab0JJDXL (ORCPT ); Sat, 9 Oct 2010 23:23:11 -0400 In-Reply-To: <20101009.201501.214209347.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 10/09/10 21:15, David Miller wrote: > From: Ben Hutchings > Date: Sun, 10 Oct 2010 02:09:24 +0100 > >> Patrick Simmons wrote: >>> This patch adds the IRQF_SAMPLE_RANDOM flag to the forcedeth driver, >>> allowing the interrupt timing for forcedeth to be used for entropy >>> generation. This should help /dev/random generate more secure random >>> numbers on machines using this driver. >> [...] >> >> We don't enable this for network drivers any more because: >> >> 1. At high packet rates, interrupt moderation makes interrupts very >> regular. >> 2. At low packet rates, a malicious sender can control the interrupt >> timing. > > Agreed on all counts, I'm not applying this patch. It's enabled for other network drivers, which is where I got the idea from. Has anyone actually done an experiment to see whether these two concerns are valid? --Patrick -- If I'm not here, I've gone out to find myself. If I get back before I return, please keep me here.