From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754566AbaDNQCU (ORCPT ); Mon, 14 Apr 2014 12:02:20 -0400 Received: from verein.lst.de ([213.95.11.211]:49449 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754393AbaDNQCQ (ORCPT ); Mon, 14 Apr 2014 12:02:16 -0400 Date: Mon, 14 Apr 2014 18:02:11 +0200 From: Torsten Duwe To: "H. Peter Anvin" Cc: Andy Lutomirski , "Theodore Ts'o" , Greg Kroah-Hartman , Andrew Morton , Matt Mackall , Herbert Xu , Arnd Bergmann , Rusty Russell , Satoru Takeuchi , ingo.tuchscherer@de.ibm.com, linux-kernel@vger.kernel.org, Hans-Georg Markgraf , Gerald Schaefer , Martin Schwidefsky , Heiko Carstens , Joe Perches Subject: [PATCH v3 00/03]: hwrng: an in-kernel rngd Message-ID: <20140414160211.GE711@lst.de> References: <20140321142950.GI1763@lst.de> <20140321143342.GK1763@lst.de> <533375C1.5060904@mit.edu> <158d2776-1ea4-4f32-a9e9-0488047e6b70@email.android.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <158d2776-1ea4-4f32-a9e9-0488047e6b70@email.android.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org More or less a resend of v2. On Wed, Mar 26, 2014 at 06:03:37PM -0700, H. Peter Anvin wrote: > I'm wondering more about the default. We default to 50% for arch_get_random_seed, and this is supposed to be the default for in effect unverified hwrngs... Done. 50% is now the default, that's the only change from v2. Andy: the printk you pointed out already limits itself to 1/10s, which is half the default rate limit. Also, as Peter already wrote, we're dealing with true HWRNGs here; if such a device does not produce a single byte within 10 seconds something _is_ severely broken and, like a dying disk, worth to be logged. Here's one of the better circuits I found: http://www.maximintegrated.com/app-notes/index.mvp/id/3469 or offline: http://pdfserv.maximintegrated.com/en/an/AN3469.pdf Disclaimer: I'm not endorsing Maxim, it's just that paper that hits the spot IMHO. Anything wrong with feeding those bits into the input pool? Any other comments on the code? Torsten