From: Herbert Xu Subject: Re: [PATCH v2 0/2] crypto hwrng consider quality value, remember user choice Date: Tue, 18 Jul 2017 18:39:51 +0800 Message-ID: <20170718103951.GU6479@gondor.apana.org.au> References: <1499758583-14626-1-git-send-email-freude@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-crypto@vger.kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org, prasannatsmkumar@gmail.com, schwidefsky@de.ibm.com To: Harald Freudenberger Return-path: Received: from orcrist.hmeau.com ([104.223.48.154]:33364 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182AbdGRKkS (ORCPT ); Tue, 18 Jul 2017 06:40:18 -0400 Content-Disposition: inline In-Reply-To: <1499758583-14626-1-git-send-email-freude@linux.vnet.ibm.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Tue, Jul 11, 2017 at 09:36:21AM +0200, Harald Freudenberger wrote: > The hwrng core implementation currently doesn't consider the > quality field of the struct hwrng. So the first registered rng > is the winner and further rng sources even with much better > quality are ignored. > > The behavior should be that always the best rng with the highest > quality rate should be used as current rng source. Only if the > user explicitly chooses a rng source (via writing a rng name > to /sys/class/misc/hw_random/rng_current) the decision for the > best quality should be suppressed. > > This two patches make hwrng always hold a list of registered > rng sources sorted decreasing by quality. On registration of a new > hwrng source the list is updated and if the current rng source was > not chosen by user and the new rng provides better quality set as > new current rng source. Similar on unregistration of an rng, if it > was the current used rng source the one with the next highest quality > is used. If a rng source has been set via sysfs from userland as > long as this one doesn't unregister it is kept as current rng > regardless of registration of 'better' rng sources. > > Patch 1 introduces the sorted list of registered rngs and the > always use the best quality behavior. > > Patch 2 makes hwrng remember that the user has selected an > rng via echo to /sys/class/misc/hw_random/rng_current and > adds a new sysfs attribute file 'rng_selected' to the rng core. > > Harald Freudenberger (2): > crypto: hwrng use rng source with best quality > crypto: hwrng remember rng chosen by user All patches applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt