Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751794AbdIOK6t (ORCPT ); Fri, 15 Sep 2017 06:58:49 -0400 Received: from mail-pf0-f176.google.com ([209.85.192.176]:49830 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758AbdIOK6p (ORCPT ); Fri, 15 Sep 2017 06:58:45 -0400 X-Google-Smtp-Source: ADKCNb5m0GqTByqV3J2qUH51l278Lpv3wMo6Q4lfmorwKqil+YWVkV9WBVbk0BVqg9Nt03u9iGbdXQ== From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro Subject: [PATCH v3 10/10] arm64: kexec_file: add Image format support Date: Fri, 15 Sep 2017 19:59:32 +0900 Message-Id: <20170915105932.25338-11-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170915105932.25338-1-takahiro.akashi@linaro.org> References: <20170915105932.25338-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7746 Lines: 260 The "Image" binary will be loaded at the offset of TEXT_OFFSET from the start of system memory. TEXT_OFFSET is determined from the header of the image. Regarding kernel signature verification, it will be done through verify_pefile_signature() as arm64's "Image" binary can be seen as in PE format. This approach is consistent with x86 implementation. we can sign an image with sbsign command. Signed-off-by: AKASHI Takahiro Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/Kconfig | 7 +++ arch/arm64/include/asm/kexec.h | 66 +++++++++++++++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/kexec_image.c | 105 +++++++++++++++++++++++++++++++++ arch/arm64/kernel/machine_kexec_file.c | 3 + 5 files changed, 182 insertions(+) create mode 100644 arch/arm64/kernel/kexec_image.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index fa7299f08cc6..b7f1a760434a 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -769,10 +769,17 @@ config KEXEC_FILE In addition to this option, you need to enable a specific type of image support. +config KEXEC_FILE_IMAGE_FMT + bool "Enable Image support" + depends on KEXEC_FILE + ---help--- + Select this option to enable 'Image' kernel loading. + config KEXEC_VERIFY_SIG bool "Verify kernel signature during kexec_file_load() syscall" depends on KEXEC_FILE select SYSTEM_DATA_VERIFICATION + select SIGNED_PE_FILE_VERIFICATION if KEXEC_FILE_IMAGE_FMT ---help--- Select this option to verify a signature with loaded kernel image. If configured, any attempt of loading a image without diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index edb702e64a8a..7ec529e11a8b 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -104,6 +104,72 @@ struct kimage_arch { unsigned long elf_load_addr; }; +/** + * struct arm64_image_header - arm64 kernel image header + * + * @pe_sig: Optional PE format 'MZ' signature + * @branch_code: Instruction to branch to stext + * @text_offset: Image load offset, little endian + * @image_size: Effective image size, little endian + * @flags: + * Bit 0: Kernel endianness. 0=little endian, 1=big endian + * @reserved: Reserved + * @magic: Magic number, "ARM\x64" + * @pe_header: Optional offset to a PE format header + **/ + +struct arm64_image_header { + u8 pe_sig[2]; + u8 pad[2]; + u32 branch_code; + u64 text_offset; + u64 image_size; + u64 flags; + u64 reserved[3]; + u8 magic[4]; + u32 pe_header; +}; + +static const u8 arm64_image_magic[4] = {'A', 'R', 'M', 0x64U}; +static const u8 arm64_image_pe_sig[2] = {'M', 'Z'}; + +/** + * arm64_header_check_magic - Helper to check the arm64 image header. + * + * Returns non-zero if header is OK. + */ + +static inline int arm64_header_check_magic(const struct arm64_image_header *h) +{ + if (!h) + return 0; + + if (!h->text_offset) + return 0; + + return (h->magic[0] == arm64_image_magic[0] + && h->magic[1] == arm64_image_magic[1] + && h->magic[2] == arm64_image_magic[2] + && h->magic[3] == arm64_image_magic[3]); +} + +/** + * arm64_header_check_pe_sig - Helper to check the arm64 image header. + * + * Returns non-zero if 'MZ' signature is found. + */ + +static inline int arm64_header_check_pe_sig(const struct arm64_image_header *h) +{ + if (!h) + return 0; + + return (h->pe_sig[0] == arm64_image_pe_sig[0] + && h->pe_sig[1] == arm64_image_pe_sig[1]); +} + +extern struct kexec_file_ops kexec_image_ops; + struct kimage; #define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 5df003d6157c..a1161bab6810 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -51,6 +51,7 @@ arm64-obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o arm64-obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o \ cpu-reset.o arm64-obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o +arm64-obj-$(CONFIG_KEXEC_FILE_IMAGE_FMT) += kexec_image.o arm64-obj-$(CONFIG_ARM64_RELOC_TEST) += arm64-reloc-test.o arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c new file mode 100644 index 000000000000..b19538af2f3d --- /dev/null +++ b/arch/arm64/kernel/kexec_image.c @@ -0,0 +1,105 @@ +/* + * Kexec image loader + + * Copyright (C) 2017 Linaro Limited + * Author: AKASHI Takahiro + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) "kexec_file(Image): " fmt + +#include +#include +#include +#include +#include +#include +#include + +static int image_probe(const char *kernel_buf, unsigned long kernel_len) +{ + const struct arm64_image_header *h; + + h = (const struct arm64_image_header *)(kernel_buf); + + if ((kernel_len < sizeof(*h)) || !arm64_header_check_magic(h)) + return -EINVAL; + + pr_debug("PE format: %s\n", + (arm64_header_check_pe_sig(h) ? "yes" : "no")); + + return 0; +} + +static void *image_load(struct kimage *image, char *kernel, + unsigned long kernel_len, char *initrd, + unsigned long initrd_len, char *cmdline, + unsigned long cmdline_len) +{ + struct kexec_buf kbuf; + struct arm64_image_header *h = (struct arm64_image_header *)kernel; + unsigned long text_offset, kernel_load_addr; + int ret; + + /* Create elf core header segment */ + ret = load_crashdump_segments(image); + if (ret) + goto out; + + /* Load the kernel */ + kbuf.image = image; + if (image->type == KEXEC_TYPE_CRASH) { + kbuf.buf_min = crashk_res.start; + kbuf.buf_max = crashk_res.end + 1; + } else { + kbuf.buf_min = 0; + kbuf.buf_max = ULONG_MAX; + } + kbuf.top_down = 0; + + kbuf.buffer = kernel; + kbuf.bufsz = kernel_len; + kbuf.memsz = le64_to_cpu(h->image_size); + text_offset = le64_to_cpu(h->text_offset); + kbuf.buf_align = SZ_2M; + + /* Adjust kernel segment with TEXT_OFFSET */ + kbuf.memsz += text_offset; + + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out; + + image->segment[image->nr_segments - 1].mem += text_offset; + image->segment[image->nr_segments - 1].memsz -= text_offset; + kernel_load_addr = kbuf.mem + text_offset; + + pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kernel_load_addr, kbuf.bufsz, kbuf.memsz); + + /* Load additional data */ + ret = load_other_segments(image, kernel_load_addr, + initrd, initrd_len, cmdline, cmdline_len); + +out: + return ERR_PTR(ret); +} + +#ifdef CONFIG_KEXEC_VERIFY_SIG +static int image_verify_sig(const char *kernel, unsigned long kernel_len) +{ + return verify_pefile_signature(kernel, kernel_len, NULL, + VERIFYING_KEXEC_PE_SIGNATURE); +} +#endif + +struct kexec_file_ops kexec_image_ops = { + .probe = image_probe, + .load = image_load, +#ifdef CONFIG_KEXEC_VERIFY_SIG + .verify_sig = image_verify_sig, +#endif +}; diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index e4671610fb12..fbf1cb4b58df 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -24,6 +24,9 @@ static int __dt_root_addr_cells; static int __dt_root_size_cells; struct kexec_file_ops *kexec_file_loaders[] = { +#ifdef CONFIG_KEXEC_FILE_IMAGE_FMT + &kexec_image_ops, +#endif NULL }; -- 2.14.1