From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [PATCH 3/8] random: trigger random_ready callback upon crng_init == 1 Date: Tue, 17 Jan 2017 23:12:50 -0500 Message-ID: <20170118041250.x7wszcasd4dplj3h@thunk.org> References: <3254875.f5A5oHPdxF@positron.chronox.de> <3576149.HSfW5KObBF@positron.chronox.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org To: Stephan =?iso-8859-1?Q?M=FCller?= Return-path: Received: from imap.thunk.org ([74.207.234.97]:55818 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbdAREPi (ORCPT ); Tue, 17 Jan 2017 23:15:38 -0500 Content-Disposition: inline In-Reply-To: <3576149.HSfW5KObBF@positron.chronox.de> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Tue, Dec 27, 2016 at 11:39:57PM +0100, Stephan Müller wrote: > The random_ready callback mechanism is intended to replicate the > getrandom system call behavior to in-kernel users. As the getrandom > system call unblocks with crng_init == 1, trigger the random_ready > wakeup call at the same time. It was deliberate that random_ready would only get triggered with crng_init==2. In general I'm assuming kernel callers really want real randomness (as opposed to using prandom), where as there's a lot of b.s. userspace users of kernel randomness (for things that really don't require cryptographic randomness, e.g., for salting Python dictionaries, systemd/udev using /dev/urandom for non-cryptographic, non-security applications etc.) - Ted