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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 EF0E9C3A5A2 for ; Fri, 23 Aug 2019 06:28:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C27622070B for ; Fri, 23 Aug 2019 06:28:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kYR339iH"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="XWLQMu9+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C27622070B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0cG5SIILyBliR0qBBlTEJjRmh4lzK10oEXPwAw9CQhE=; b=kYR339iHHnfH7+ 9NSEy57QYobO/vm60JsMSep6hRUW5gqZ/aK9ifa8dcqRTqIVpqcSnEIMHw15bDtx9NKKxFQuRpMxf bkDQxw1Vl4LAGIRLK8SVPt0vgL04wVfMpxwAisavdRIvhp4kL7MVSeWv3TI8tcmc7l8IGA9oLmCiG ccDu+zTgxnPq8yWp9rjJ5aDRpWmowa2fPueERMCj4vXQrTwoDG8IT5BTrmJbmLR8Cc7qJZZCqQb6U ak2C6eW3ogCtSDk0E0k/cPY6lg8+1u4UORoos9OJZOzdSg19ZqV7RmCiFLMhdVdln6UQm9SfxwNwh 4IoFsPhcrGguPWXVgGXQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i133K-0002rr-76; Fri, 23 Aug 2019 06:28:02 +0000 Received: from mail-pf1-x444.google.com ([2607:f8b0:4864:20::444]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i132t-0002RC-3e for linux-arm-kernel@lists.infradead.org; Fri, 23 Aug 2019 06:27:36 +0000 Received: by mail-pf1-x444.google.com with SMTP id w26so5750991pfq.12 for ; Thu, 22 Aug 2019 23:27:35 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=0pVReU3L4xNNWo9+KatKn65E5Ld718QqqaoOMK1fJHQ=; b=XWLQMu9+3h/iiKrPiQ+ZajD1bYKREAVWGm/oN5kfGiIkOsaUVYdGD9oABeJ9b7IO95 wRhqWd249jRsuQlRX40CtosYmC+jw3LZvtQL8AMXe8oqmHGDPyr2fP3Cm+1a0czCyU35 v0Pu4/ZcYMgi0gTjwMpbG7TgTOb7IRXYbkvOs= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=0pVReU3L4xNNWo9+KatKn65E5Ld718QqqaoOMK1fJHQ=; b=cm9zvAJSxsZ9MBWNqRSMU92i50uio/i/VQ/ks8qYiGIigki3it6VvbJY7XXn9mTh+7 k5PbxgujtudplV1k26Np+Dr0PqufVSzlghsGFA1Yxm4TGll89mG/zKCqr8NDwl5DnJ8m NINVKXnkQFkaohwQIuAnXDPWIHfz6CEiiPP4iI52iKKgvpW59CYWjImpDbSyO8o0jdGj 3exM24jCgeljsv3ENuAnDPwzp9av7Z6OKzfTM05ewTDlYjtcRmMuKMFqGWmJXBVfIKHD G75u3JRS72Kz56Ni02cXgqH++XK17ibuVce41dcgGuqG+ZtqjpD6G+zE0iPSMI05/ONP mIWg== X-Gm-Message-State: APjAAAWdWqyZnzRlsferXb6gbdJwFB8VdqeQkR1yNoM4oXZXVcMl9iUz ShoQ6zw8ClHoWs0tTxjuWuG6ULEMdiE= X-Google-Smtp-Source: APXvYqz0Nb4vLW/Rppgb80/OXeYgQhAO9pkk8UoujB6MiOthueFuVt1sTRT03Pr+UQuClClNGMHy1w== X-Received: by 2002:a17:90a:bf0e:: with SMTP id c14mr3519541pjs.140.1566541654373; Thu, 22 Aug 2019 23:27:34 -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 q13sm2139671pfl.124.2019.08.22.23.27.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 22 Aug 2019 23:27:33 -0700 (PDT) From: Hsin-Yi Wang To: linux-arm-kernel@lists.infradead.org, "Theodore Y . Ts'o" Subject: [PATCH v10 2/3] fdt: add support for rng-seed Date: Fri, 23 Aug 2019 14:24:51 +0800 Message-Id: <20190823062452.127528-3-hsinyi@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190823062452.127528-1-hsinyi@chromium.org> References: <20190823062452.127528-1-hsinyi@chromium.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190822_232735_235285_D27B8387 X-CRM114-Status: GOOD ( 20.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , Peter Zijlstra , Catalin Marinas , Mukesh Ojha , Grzegorz Halat , "H . Peter Anvin" , Guenter Roeck , Will Deacon , Marek Szyprowski , Rob Herring , Daniel Thompson , Anders Roxell , Yury Norov , Marc Zyngier , Russell King , Aaro Koskinen , Ingo Molnar , Viresh Kumar , Waiman Long , "Paul E . McKenney" , Wei Li , Alexey Dobriyan , Julien Thierry , Len Brown , Kees Cook , Arnd Bergmann , Rik van Riel , Stephen Boyd , Shaokun Zhang , Mike Rapoport , Borislav Petkov , Josh Poimboeuf , Thomas Gleixner , Greg Kroah-Hartman , Marcelo Tosatti , linux-kernel@vger.kernel.org, Armijn Hemel , Jiri Kosina , Mathieu Desnoyers , Andrew Morton , Tim Chen , "David S . Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.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. 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 --- Change from v9: * reword kconfig * use IS_ENABLED for config --- drivers/char/Kconfig | 9 +++++++++ drivers/char/random.c | 14 ++++++++++++++ drivers/of/fdt.c | 14 ++++++++++++-- include/linux/random.h | 1 + 4 files changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 96156c729a31..df0fc997dc3e 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -551,3 +551,12 @@ config RANDOM_TRUST_CPU has not installed a hidden back door to compromise the CPU's random number generation facilities. This can also be configured at boot with "random.trust_cpu=on/off". + +config RANDOM_TRUST_BOOTLOADER + bool "Trust the bootloader to initialize Linux's CRNG" + help + Some bootloaders can provide entropy to increase the kernel's initial + device randomness. Say Y here to assume the entropy provided by the + booloader is trustworthy so it will be added to the kernel's entropy + pool. Otherwise, say N here so it will be regarded as device input that + only mixes the entropy pool. \ No newline at end of file diff --git a/drivers/char/random.c b/drivers/char/random.c index 5d5ea4ce1442..566922df4b7b 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -2445,3 +2445,17 @@ void add_hwgenerator_randomness(const char *buffer, size_t count, credit_entropy_bits(poolp, entropy); } EXPORT_SYMBOL_GPL(add_hwgenerator_randomness); + +/* Handle random seed passed by bootloader. + * If the seed is trustworthy, it would be regarded as hardware RNGs. Otherwise + * it would be regarded as device data. + * The decision is controlled by CONFIG_RANDOM_TRUST_BOOTLOADER. + */ +void add_bootloader_randomness(const void *buf, unsigned int size) +{ + if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER)) + add_hwgenerator_randomness(buf, size, size * 8); + else + add_device_randomness(buf, size); +} +EXPORT_SYMBOL_GPL(add_bootloader_randomness); \ No newline at end of file diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 9cdf14b9aaab..7d97ab6d0e31 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 @@ -1044,6 +1045,7 @@ 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); @@ -1078,6 +1080,14 @@ 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) { + add_bootloader_randomness(rng_seed, l); + + /* try to clear seed so it won't be found. */ + fdt_nop_property(initial_boot_params, node, "rng-seed"); + } + /* break now */ return 1; } @@ -1166,8 +1176,6 @@ bool __init early_init_dt_verify(void *params) /* Setup flat device-tree pointer */ initial_boot_params = params; - of_fdt_crc32 = crc32_be(~0, initial_boot_params, - fdt_totalsize(initial_boot_params)); return true; } @@ -1197,6 +1205,8 @@ bool __init early_init_dt_scan(void *params) return false; early_init_dt_scan_nodes(); + of_fdt_crc32 = crc32_be(~0, initial_boot_params, + fdt_totalsize(initial_boot_params)); return true; } diff --git a/include/linux/random.h b/include/linux/random.h index 1f7dced2bba6..f189c927fdea 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -19,6 +19,7 @@ struct random_ready_callback { }; extern void add_device_randomness(const void *, unsigned int); +extern void add_bootloader_randomness(const void *, unsigned int); #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) static inline void add_latent_entropy(void) -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel