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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22E87C433F5 for ; Wed, 15 Dec 2021 14:13:03 +0000 (UTC) Received: from localhost ([::1]:56902 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mxV1h-00050Q-Rv for qemu-devel@archiver.kernel.org; Wed, 15 Dec 2021 09:13:01 -0500 Received: from eggs.gnu.org ([209.51.188.92]:35668) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mxUSI-0008VA-O2 for qemu-devel@nongnu.org; Wed, 15 Dec 2021 08:36:26 -0500 Received: from [2a00:1450:4864:20::32e] (port=42750 helo=mail-wm1-x32e.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mxUSB-0007fg-Jq for qemu-devel@nongnu.org; Wed, 15 Dec 2021 08:36:26 -0500 Received: by mail-wm1-x32e.google.com with SMTP id a83-20020a1c9856000000b00344731e044bso3073733wme.1 for ; Wed, 15 Dec 2021 05:36:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=EPRwErRmLGlIXg9dNaURh+XfvKs8o+o7Xh6lQ5YpXno=; b=CvfJNV4NpSVfPDB/A/BcqI6jcvy6pFq8vdv/yMG+LpPbtGujvFldMnQKQd5PVc2j8K Q3CKTPOnrWQyTQFg45gF7mymG8V1nG52qoiBz0SxtDKneF8ObdiYcTjlEQ8paYzH1Axm Meboyf7wgi9bfyFJvbs6YtY5fuoP0ghd+e9X10qv9uHM9u2kneXdjbiWi/oCn1IMql8c rqdshNta7PrVk1JeDVg5bGedK+/mKBS+fUsFlygKA3XedGxp9Qt5+yFXphovmpPObSip dXjO8TjyN7rjeU6ClYPkFQoH5dPqerJnbYiKAXmkY9MlQyotDvJRmBlduabNAlQCykIZ P87g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=EPRwErRmLGlIXg9dNaURh+XfvKs8o+o7Xh6lQ5YpXno=; b=aiFb4Ma74tE06ll6SmEL2jajlCOhQLc6Cdh9Y8hyG3mGTskesrf09VAR11m6VhJJ52 LJpj8QPUnfjwqIn5jPWH4YK7AxwrQ0dCcM+G1+eCE44gMmxmpPlmvxiknyVTvYL3Fmn2 3PCXfIerfPIzc683aDEnBJMJYv0fK0UKKiIzsNmYg2I05VYNIjo06qDQPiqayYjddNUD Ur2tfW3ON5GegtGWWRO+Wd4SWjCzThWpjZpoubkybg2SK6NNkJCvlmUhLkC8q6JchuIU evS8q2eFsPXnhfMlMstnt/3TlvE+lP9QgFbvngfhbQQyMKTzirLb9bo7jDqRC2Cov38T laLg== X-Gm-Message-State: AOAM531XxuUtp/2QcJwlW06Wku6x9/dgf0T1uneUVjOJKiZfqBDPfdTr OcwLwPY+P9SP3qQ+/VLM/Ow68Lt5q/GbNREJJWNV/A== X-Google-Smtp-Source: ABdhPJyBNwpWvWLaiOwupqrNTPHD1uhZZxOIjVGnTG1x8JlyeST3A3COxBy3iDaf77o48d0C0FiocB43hsU049UY0Vw= X-Received: by 2002:a05:600c:3486:: with SMTP id a6mr4602176wmq.32.1639575378070; Wed, 15 Dec 2021 05:36:18 -0800 (PST) MIME-Version: 1.0 References: <20211215120926.1696302-1-alex.bennee@linaro.org> In-Reply-To: <20211215120926.1696302-1-alex.bennee@linaro.org> From: Peter Maydell Date: Wed, 15 Dec 2021 13:36:07 +0000 Message-ID: Subject: Re: [PATCH] hw/arm: add control knob to disable kaslr_seed via DTB To: =?UTF-8?B?QWxleCBCZW5uw6ll?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::32e (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::32e; envelope-from=peter.maydell@linaro.org; helo=mail-wm1-x32e.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ilias Apalodimas , qemu-arm@nongnu.org, Jerome Forissier , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 15 Dec 2021 at 12:09, Alex Benn=C3=A9e wro= te: > > Generally a guest needs an external source of randomness to properly > enable things like address space randomisation. However in a trusted > boot environment where the firmware will cryptographically verify > components having random data in the DTB will cause verification to > fail. Add a control knob so we can prevent this being added to the > system DTB. Given that the DTB is automatically generated for the virt board, firmware has no way to guarantee that it's the same every time anyway, surely ? -- PMM