From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20CD0C3A5A1 for ; Thu, 22 Aug 2019 16:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDFC8233A0 for ; Thu, 22 Aug 2019 16:06:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389726AbfHVQG2 (ORCPT ); Thu, 22 Aug 2019 12:06:28 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:52434 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731346AbfHVQG2 (ORCPT ); Thu, 22 Aug 2019 12:06:28 -0400 Received: from callcc.thunk.org (guestnat-104-133-0-111.corp.google.com [104.133.0.111] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id x7MG3r9U010677 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Aug 2019 12:03:55 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id CF95A42049E; Thu, 22 Aug 2019 12:03:52 -0400 (EDT) Date: Thu, 22 Aug 2019 12:03:52 -0400 From: "Theodore Y. Ts'o" To: Hsin-Yi Wang Cc: linux-arm-kernel@lists.infradead.org, Russell King , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , "Paul E . McKenney" , Kate Stewart , "David S . Miller" , Viresh Kumar , Marek Szyprowski , Arnd Bergmann , Marc Zyngier , Julien Thierry , Greg Kroah-Hartman , Wei Li , Anders Roxell , Rob Herring , Aaro Koskinen , Daniel Thompson , Tim Chen , Rik van Riel , Waiman Long , Marcelo Tosatti , Peter Zijlstra , Armijn Hemel , Grzegorz Halat , Len Brown , Shaokun Zhang , Mike Rapoport , Kees Cook , Stephen Boyd , Guenter Roeck , Andrew Morton , Mathieu Desnoyers , Alexey Dobriyan , Yury Norov , Josh Poimboeuf , Jiri Kosina , Mukesh Ojha , linux-kernel@vger.kernel.org Subject: Re: [PATCH v9 2/3] fdt: add support for rng-seed Message-ID: <20190822160352.GA17783@mit.edu> Mail-Followup-To: "Theodore Y. Ts'o" , Hsin-Yi Wang , linux-arm-kernel@lists.infradead.org, Russell King , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , "Paul E . McKenney" , Kate Stewart , "David S . Miller" , Viresh Kumar , Marek Szyprowski , Arnd Bergmann , Marc Zyngier , Julien Thierry , Greg Kroah-Hartman , Wei Li , Anders Roxell , Rob Herring , Aaro Koskinen , Daniel Thompson , Tim Chen , Rik van Riel , Waiman Long , Marcelo Tosatti , Peter Zijlstra , Armijn Hemel , Grzegorz Halat , Len Brown , Shaokun Zhang , Mike Rapoport , Kees Cook , Stephen Boyd , Guenter Roeck , Andrew Morton , Mathieu Desnoyers , Alexey Dobriyan , Yury Norov , Josh Poimboeuf , Jiri Kosina , Mukesh Ojha , linux-kernel@vger.kernel.org References: <20190822071522.143986-1-hsinyi@chromium.org> <20190822071522.143986-3-hsinyi@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190822071522.143986-3-hsinyi@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 22, 2019 at 03:15:22PM +0800, Hsin-Yi Wang wrote: > Introducing a chosen node, rng-seed, which is an entropy that can be > passed to kernel called very early to increase initial device > randomness. Bootloader should provide this entropy and the value is > read from /chosen/rng-seed in DT. > > Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(), > since early_init_dt_scan_chosen() would modify fdt to erase rng-seed. > > Add a new interface add_bootloader_randomness() for rng-seed use case. > Depends on whether the seed is trustworthy, rng seed would be passed to > add_hwgenerator_randomness(). Otherwise it would be passed to > add_device_randomness(). Decision is controlled by kernel config > RANDOM_TRUST_BOOTLOADER. > > Signed-off-by: Hsin-Yi Wang > Reviewed-by: Stephen Boyd > Reviewed-by: Rob Herring For the changes to drivers/char/random.c: Reviewed-by: Theodore Ts'o