From patchwork Sun Oct 25 13:49:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 285502 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, 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 07D32C55178 for ; Sun, 25 Oct 2020 13:50:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B69662225E for ; Sun, 25 Oct 2020 13:50:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732354AbgJYNuF (ORCPT ); Sun, 25 Oct 2020 09:50:05 -0400 Received: from foss.arm.com ([217.140.110.172]:46350 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1416433AbgJYNuF (ORCPT ); Sun, 25 Oct 2020 09:50:05 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 556F2143B; Sun, 25 Oct 2020 06:50:04 -0700 (PDT) Received: from e123331-lin.nice.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 391153F68F; Sun, 25 Oct 2020 06:50:03 -0700 (PDT) From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: Ard Biesheuvel , grub-devel@gnu.org, daniel.kiper@oracle.com, leif@nuviainc.com Subject: [PATCH v2 7/8] efi: implement LoadFile2 initrd loading protocol for Linux Date: Sun, 25 Oct 2020 14:49:40 +0100 Message-Id: <20201025134941.4805-8-ard.biesheuvel@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201025134941.4805-1-ard.biesheuvel@arm.com> References: <20201025134941.4805-1-ard.biesheuvel@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Recent Linux kernels will invoke the LoadFile2 protocol installed on a well-known vendor media devicepath to load the initrd if it is exposed by the firmware. Using this method is preferred for two reasons: - the Linux kernel is in charge of allocating the memory, and so it can implement any placement policy it wants (given that these tend to change between kernel versions), - it is no longer necessary to modify the device tree provided by the firmware. So let's install this protocol when handling the 'initrd' command if such a recent kernel was detected (based on the PE/COFF image version), and defer loading the initrd contents until the point where the kernel invokes the LoadFile2 protocol. Signed-off-by: Ard Biesheuvel --- grub-core/loader/arm64/linux.c | 109 +++++++++++++++++++- 1 file changed, 108 insertions(+), 1 deletion(-) diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c index 28ff8584a3b5..c6a95e1f0c43 100644 --- a/grub-core/loader/arm64/linux.c +++ b/grub-core/loader/arm64/linux.c @@ -48,6 +48,10 @@ static grub_uint32_t cmdline_size; static grub_addr_t initrd_start; static grub_addr_t initrd_end; +static struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; +static grub_efi_handle_t initrd_lf2_handle; +static int initrd_use_loadfile2; + grub_err_t grub_arch_efi_linux_load_image_header (grub_file_t file, struct linux_arch_kernel_header * lh) @@ -81,6 +85,18 @@ grub_arch_efi_linux_load_image_header (grub_file_t file, return grub_error(GRUB_ERR_FILE_READ_ERROR, "failed to read COFF image header"); } + /* + * Linux kernels built for any architecture are guaranteed to support the + * LoadFile2 based initrd loading protocol if the image version is >= 1. + */ + if (lh->coff_image_header.optional_header.major_image_version >= 1) + initrd_use_loadfile2 = 1; + else + initrd_use_loadfile2 = 0; + + grub_dprintf ("linux", "LoadFile2 initrd loading %sabled\n", + initrd_use_loadfile2 ? "en" : "dis"); + return GRUB_ERR_NONE; } @@ -250,13 +266,86 @@ allocate_initrd_mem (int initrd_pages) GRUB_EFI_LOADER_DATA); } +struct initrd_media_device_path { + grub_efi_vendor_media_device_path_t vendor; + grub_efi_device_path_t end; +} GRUB_PACKED; + +#define LINUX_EFI_INITRD_MEDIA_GUID \ + { 0x5568e427, 0x68fc, 0x4f3d, \ + { 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68 } \ + } + +static struct initrd_media_device_path initrd_lf2_device_path = { + { + { + GRUB_EFI_MEDIA_DEVICE_PATH_TYPE, + GRUB_EFI_VENDOR_MEDIA_DEVICE_PATH_SUBTYPE, + sizeof(grub_efi_vendor_media_device_path_t), + }, + LINUX_EFI_INITRD_MEDIA_GUID + }, { + GRUB_EFI_END_DEVICE_PATH_TYPE, + GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE, + sizeof(grub_efi_device_path_t) + } +}; + +static grub_efi_status_t initrd_load_file2(grub_efi_load_file2_t *this, + grub_efi_device_path_t *device_path, + grub_efi_boolean_t boot_policy, + grub_efi_uintn_t *buffer_size, + void *buffer); + +static grub_efi_load_file2_t initrd_lf2 = { + initrd_load_file2 +}; + +static grub_efi_status_t initrd_load_file2(grub_efi_load_file2_t *this, + grub_efi_device_path_t *device_path, + grub_efi_boolean_t boot_policy, + grub_efi_uintn_t *buffer_size, + void *buffer) +{ + grub_efi_status_t status = GRUB_EFI_SUCCESS; + grub_efi_uintn_t initrd_size; + + if (!this || this != &initrd_lf2 || !buffer_size) + return GRUB_EFI_INVALID_PARAMETER; + + if (device_path->type != GRUB_EFI_END_DEVICE_PATH_TYPE || + device_path->subtype != GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE) + return GRUB_EFI_NOT_FOUND; + + if (boot_policy) + return GRUB_EFI_UNSUPPORTED; + + initrd_size = grub_get_initrd_size (&initrd_ctx); + if (!buffer || *buffer_size < initrd_size) + { + *buffer_size = initrd_size; + return GRUB_EFI_BUFFER_TOO_SMALL; + } + + grub_dprintf ("linux", "Loading initrd via LOAD_FILE2_PROTOCOL\n"); + + if (grub_initrd_load (&initrd_ctx, NULL, buffer)) + status = GRUB_EFI_LOAD_ERROR; + + grub_initrd_close (&initrd_ctx); + return status; +} + static grub_err_t grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[]) { - struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; int initrd_size, initrd_pages; void *initrd_mem = NULL; + grub_efi_guid_t load_file2_guid = GRUB_EFI_LOAD_FILE2_PROTOCOL_GUID; + grub_efi_guid_t device_path_guid = GRUB_EFI_DEVICE_PATH_GUID; + grub_efi_boot_services_t *b; + grub_efi_status_t status; if (argc == 0) { @@ -274,6 +363,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), if (grub_initrd_init (argc, argv, &initrd_ctx)) goto fail; + if (initrd_use_loadfile2) + { + b = grub_efi_system_table->boot_services; + status = b->install_multiple_protocol_interfaces (&initrd_lf2_handle, + &load_file2_guid, + &initrd_lf2, + &device_path_guid, + &initrd_lf2_device_path, + NULL); + if (status == GRUB_EFI_OUT_OF_RESOURCES) + { + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + return grub_errno; + } + grub_dprintf ("linux", "LoadFile2 initrd loading protocol installed\n"); + return GRUB_ERR_NONE; + } + initrd_size = grub_get_initrd_size (&initrd_ctx); grub_dprintf ("linux", "Loading initrd\n");