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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 29DDDC04A6B for ; Mon, 13 May 2019 00:39:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC6B0208CB for ; Mon, 13 May 2019 00:39:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="PAJDB8sd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727230AbfEMAjH (ORCPT ); Sun, 12 May 2019 20:39:07 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:45927 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727047AbfEMAjH (ORCPT ); Sun, 12 May 2019 20:39:07 -0400 Received: by mail-pg1-f195.google.com with SMTP id i21so5819299pgi.12 for ; Sun, 12 May 2019 17:39:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=IgOJ9QLzOUW01yLV2OfG7YkSkZvw2ViCiy6aBBS6YFQ=; b=PAJDB8sdHVi0D44H/07DcJs+vX7Cb6MzLOV7JTtIBdbHIYzaIGW6owURsu25tGJfP9 Y8tm7gC8gBtob9CnxVZrElnfLEKoMkVic3khHAFKYDIS4xHKxMSValMptyH9vg4JGMsA cd04NRnP/ULXmIzpZPHml84TD4lCSO7ftc7/U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=IgOJ9QLzOUW01yLV2OfG7YkSkZvw2ViCiy6aBBS6YFQ=; b=Yq3tAaL3zaE0zFSZ5Ld0HwdOBPypBFhXyCo/IiePOc93CUGiz0PHDueGr0bYh9MzhD Cs/MWsMf+h19HlOZswp/7Tm+7TLNwa1JsVWQ4fgUtpPy6aFRwwyP1Pe2budmWbzhlXCc HK5VU4zrZf9mP1EmGlgWMHGcXbJ0OyuV2WZGk/KAiyElCWConlQLbLIHgrwmBPLN4erZ gOfBnaNrh4kENm+CTKBs5Eior5HmIsfngNyTdT6jMSxkLZMS+jZnqNT28ugQu+LuhzJI D2oyMYyXz9jIk2JPfzg2MzAYBTdYnG5ZuPcrqHtcUUM40NwdFurDjvEsgObUqPBWVUGa +Z+w== X-Gm-Message-State: APjAAAWMU3qSK+pS270pd7fCBKfzG0EL/7hg91D2kLQ6NzwqddWS/Dhg kuSuI9dahDpmFn0YbmiX2LwCaw== X-Google-Smtp-Source: APXvYqx8VoaPUnB/vcidvsLO44Gv71Rvn/n97EeuUINg+y35uX61qP9+WW9jO9KRmilThstyUVqPNw== X-Received: by 2002:a62:36c1:: with SMTP id d184mr7952363pfa.49.1557707946437; Sun, 12 May 2019 17:39:06 -0700 (PDT) Received: from hsinyi-z840.tpe.corp.google.com ([2401:fa00:1:10:b852:bd51:9305:4261]) by smtp.gmail.com with ESMTPSA id a9sm14619577pgw.72.2019.05.12.17.39.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 12 May 2019 17:39:05 -0700 (PDT) From: Hsin-Yi Wang To: linux-arm-kernel@lists.infradead.org Cc: Rob Herring , Mark Rutland , Frank Rowand , Hsin-Yi Wang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Stephen Boyd , Kees Cook , Rasmus Villemoes , boot-architecture@lists.linaro.org, Catalin Marinas , Will Deacon , Andrew Morton , Mike Rapoport , Michal Hocko , Ard Biesheuvel , Miles Chen , James Morse , Andrew Murray Subject: [PATCH v2 1/2] fdt: add support for rng-seed Date: Mon, 13 May 2019 08:38:18 +0800 Message-Id: <20190513003819.356-1-hsinyi@chromium.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Hsin-Yi Wang --- change log: v1->v2: * call function in early_init_dt_scan_chosen * will add doc to devicetree-org/dt-schema on github if this is accepted --- Documentation/devicetree/bindings/chosen.txt | 14 ++++++++++++++ drivers/of/fdt.c | 11 +++++++++++ 2 files changed, 25 insertions(+) diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 45e79172a646..fef5c82672dc 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -28,6 +28,20 @@ mode) when EFI_RNG_PROTOCOL is supported, it will be overwritten by the Linux EFI stub (which will populate the property itself, using EFI_RNG_PROTOCOL). +rng-seed +----------- + +This property served as an entropy to add device randomness. It is parsed +as a byte array, e.g. + +/ { + chosen { + rng-seed = <0x31 0x95 0x1b 0x3c 0xc9 0xfa 0xb3 ...>; + }; +}; + +This random value should be provided by bootloader. + stdout-path ----------- diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index de893c9616a1..96ea5eba9dd5 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -24,6 +24,7 @@ #include #include #include +#include #include /* for COMMAND_LINE_SIZE */ #include @@ -1079,6 +1080,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, { int l; const char *p; + const void *rng_seed; pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); @@ -1113,6 +1115,15 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, pr_debug("Command line is: %s\n", (char*)data); + rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); + if (!rng_seed || l == 0) + return 1; + + /* try to clear seed so it won't be found. */ + fdt_nop_property(initial_boot_params, node, "rng-seed"); + + add_device_randomness(rng_seed, l); + /* break now */ return 1; } -- 2.20.1