Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753223AbaGJJxq (ORCPT ); Thu, 10 Jul 2014 05:53:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38572 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103AbaGJJxo (ORCPT ); Thu, 10 Jul 2014 05:53:44 -0400 Date: Thu, 10 Jul 2014 15:23:11 +0530 From: Amit Shah To: Herbert Xu Cc: Jason Cooper , linux-kernel@vger.kernel.org, Virtualization List , Rusty Russell , keescook@chromium.org, stable@vger.kernel.org Subject: Re: [PATCH v2 2/2] virtio: rng: ensure reads happen after successful probe Message-ID: <20140710095311.GH3375@grmbl.mre> References: <20140709161836.GQ13433@titan.lakedaemon.net> <20140710084514.GA15418@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140710084514.GA15418@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (Thu) 10 Jul 2014 [16:45:14], Herbert Xu wrote: > On Wed, Jul 09, 2014 at 12:18:36PM -0400, Jason Cooper wrote: > > On Sat, Jul 05, 2014 at 11:04:53AM +0530, Amit Shah wrote: > > > The hwrng core asks for random data in the hwrng_register() call itself > > > from commit d9e7972619. This doesn't play well with virtio -- the > > > DRIVER_OK bit is only set by virtio core on a successful probe, and > > > we're not yet out of our probe routine when this call is made. This > > > causes the host to not acknowledge any requests we put in the virtqueue, > > > and the insmod or kernel boot process just waits for data to arrive from > > > the host, which never happens. > > > > > > CC: Kees Cook > > > CC: Jason Cooper > > > CC: Herbert Xu > > > CC: # For v3.15+ > > > Signed-off-by: Amit Shah > > > --- > > > drivers/char/hw_random/core.c | 6 ++++++ > > > drivers/char/hw_random/virtio-rng.c | 10 ++++++++++ > > > 2 files changed, 16 insertions(+) > > > > Yeah, I don't think there's any viable way to get random data out of > > virtio-rng at probe time... :-( > > > > Reviewed-by: Jason Cooper > > OK, if there are no more objections I will take these two patches. Please wait for the v3 -- I like that one better as it doesn't have the init weirdness that Kees pointed out. I'm sending that out in a few mins. Thanks! Amit -- 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/