From patchwork Wed Jul 11 09:40:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 141708 Delivered-To: patch@linaro.org Received: by 2002:a2e:9754:0:0:0:0:0 with SMTP id f20-v6csp69804ljj; Wed, 11 Jul 2018 02:41:02 -0700 (PDT) X-Google-Smtp-Source: AAOMgpf44YGcKoH2tJhC+38V+2MOpQ1ICYeSK4L0w3vdfQNDBAW6OfKGNBrhWhanWnkkPXjTXoXl X-Received: by 2002:a17:902:264:: with SMTP id 91-v6mr27433692plc.341.1531302062119; Wed, 11 Jul 2018 02:41:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531302062; cv=none; d=google.com; s=arc-20160816; b=LSz9ZfWxCTI8IfiwWoN68llsXgogTgOxCCx4cRVIW0j4OW31irhoaaPrywKZQeDm3d WMS5LO8EuituJNGJz8FEQ31M0l19yDl+w8jKstyva0s8c7gi07WJ9VsgqYVj+WLZ2+Zr BWyreGOB9VDeUW6bCjCTqgU/ux4WouQNSsZP0uQXXk9Co4hCq3Ox4oeJw6Hw1KzId0Lu pNg6sMp3xWpuW+fFv9projXdcekTFeE7epkhzZ4ZlOcCdyEAvIk3NRT7RMbq1JIqg7ZN QmkPc0swZZRVnykDgjkZzO8wZyiqJvenYYnWDdTk2zWFSUbuui6VBXL3oks9Brd+Di7w drbQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=semFZDZ5nZhcHHAbVFoDCVNYOqmDtPeCRsqInWmd32A=; b=KIyRAs0ESGhE0RqlF1C8ZyfCGvz1r7Xy4KHt5c+J9UvT3ZCelmCu2XB2omIm0CP8ph o+dO3jgGNyus8WUpX74NuD454C295ZVZKSIvqoDCOYD8GuKnH55GZiYu/OK127lYfZlO AO9V0XP5j/ioSw8A9m916bt+8GKrjTCh4Kwo7SaTnGKsTrAt4MF5VxFQe7/jNt3+eN8w Bgv3pqkNls3I+m2jWd0pZF93vQoW0S/bGxQcAeJk/T5fbem9ZCx/N6br4drDcmIX4UZO 3pyfsxDKzt0jucL0IuB1eYSJoFLKG+P4rjccQwi/onQmhzUqjRZ/qIT5AgADF25KOgBH bY7Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b="BWjg/fqT"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o1-v6si18610527plb.279.2018.07.11.02.41.01; Wed, 11 Jul 2018 02:41:02 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b="BWjg/fqT"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732708AbeGKJoZ (ORCPT + 22 others); Wed, 11 Jul 2018 05:44:25 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35790 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732628AbeGKJoY (ORCPT ); Wed, 11 Jul 2018 05:44:24 -0400 Received: by mail-wm0-f66.google.com with SMTP id v3-v6so1840740wmh.0 for ; Wed, 11 Jul 2018 02:40:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=semFZDZ5nZhcHHAbVFoDCVNYOqmDtPeCRsqInWmd32A=; b=BWjg/fqTgl5cNpg7yim7h3iQMkc7YJV61kg5WOiBg59yZZtM5yxShPo9dWI5gdVMD3 2PIpjqvI9zVgj/I4osdj8UDv5ayb9uYhnRhy631Lam2Mlw/9V3SQWlF7R0B4f1E4+iNU a0AxXPVMWUvChd3jRy3/0Tnq3yXEEBFqN/Ui0= 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; bh=semFZDZ5nZhcHHAbVFoDCVNYOqmDtPeCRsqInWmd32A=; b=nFYFjxLdvXGcikh6rM7C0QQmGeVTT8OdkppEHSbSqa/iz+A4QqqRRmkMsYnbDzwkd+ sM0JrF3lxiYzZSswaYwnd5A/XRV7AH6SmxN9lXs+950yosE3lHCiHkrO9Uf7OmpEQ1Zb t7FVcV1jISz9Z0nAI26Jtz8ReUDdC9kVjzR6MP+NM9VqbeK2wewlFpmuN9aGy91JYUj9 SYFoNBaBbMKqIvIgqM79PmHVJAS+adGEs9wc98XXD1vOvPidZln/O6E73Sm2AYKc4zgl dhoC56p9tKrn4kluOwI5Aeojb4LwqmqEqH15T8ZJUPD7Shu2kqmj2bpW4pUhW50qmT/X bCFw== X-Gm-Message-State: APt69E3Y7DB/H3LP9y7MR1mW3DGIp1SFSqFjcPA/Flm4zB78rgvX1w7n XiRFFmVdVVilEYNCCWpMvb1ozw== X-Received: by 2002:a1c:8d0a:: with SMTP id p10-v6mr17760280wmd.121.1531302056988; Wed, 11 Jul 2018 02:40:56 -0700 (PDT) Received: from localhost.localdomain (33.153.69.91.rev.sfr.net. [91.69.153.33]) by smtp.gmail.com with ESMTPSA id t124-v6sm1641311wmt.29.2018.07.11.02.40.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Jul 2018 02:40:56 -0700 (PDT) From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org Subject: [PATCH 6/8] efi/libstub/arm: add opt-in Kconfig option for the DTB loader Date: Wed, 11 Jul 2018 11:40:38 +0200 Message-Id: <20180711094040.12506-7-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180711094040.12506-1-ard.biesheuvel@linaro.org> References: <20180711094040.12506-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are various ways a platform can provide a device tree binary to the kernel, with different levels of sophistication: - ideally, the UEFI firmware, which is tightly coupled with the platform, provides a device tree image directly as a UEFI configuration table, and typically permits the contents to be manipulated either via menu options or via UEFI environment variables that specify a replacement image, - GRUB for ARM has a 'devicetree' directive which allows a device tree image to be loaded from any location accessible to GRUB, and supersede the one provided by the firmware, - the EFI stub implements a dtb= command line option that allows a device tree image to be loaded from a file residing in the same file system as the one the kernel image was loaded from. The dtb= command line option was never intended to be more than a development feature, to allow the other options to be implemented in parallel. So let's make it an opt-in feature that is disabled by default, but can be re-enabled at will. Note that we already disable the dtb= command line option when we detect that we are running with UEFI Secure Boot enabled. Acked-by: Leif Lindholm Reviewed-by: Alexander Graf Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/Kconfig | 12 ++++++++++++ drivers/firmware/efi/libstub/arm-stub.c | 7 ++++--- 2 files changed, 16 insertions(+), 3 deletions(-) -- 2.17.1 diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 781a4a337557..fc1cb2961d5b 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -87,6 +87,18 @@ config EFI_RUNTIME_WRAPPERS config EFI_ARMSTUB bool +config EFI_ARMSTUB_DTB_LOADER + bool "Enable the DTB loader" + depends on EFI_ARMSTUB + help + Select this config option to add support for the dtb= command + line parameter, allowing a device tree blob to be loaded into + memory from the EFI System Partition by the stub. + + The device tree is typically provided by the platform or by + the bootloader, and so this option is mostly for development + purposes only. + config EFI_BOOTLOADER_CONTROL tristate "EFI Bootloader Control" depends on EFI_VARS diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 01a9d78ee415..c98b1856fc3d 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -202,9 +202,10 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure * boot is enabled if we can't determine its state. */ - if (secure_boot != efi_secureboot_mode_disabled && - strstr(cmdline_ptr, "dtb=")) { - pr_efi(sys_table, "Ignoring DTB from command line.\n"); + if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || + secure_boot != efi_secureboot_mode_disabled) { + if (strstr(cmdline_ptr, "dtb=")) + pr_efi(sys_table, "Ignoring DTB from command line.\n"); } else { status = handle_cmdline_files(sys_table, image, cmdline_ptr, "dtb=",