Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752547AbdHXIU1 (ORCPT ); Thu, 24 Aug 2017 04:20:27 -0400 Received: from mail-pg0-f47.google.com ([74.125.83.47]:34984 "EHLO mail-pg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbdHXITP (ORCPT ); Thu, 24 Aug 2017 04:19:15 -0400 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 13/14] arm64: kexec_file: add Image format support Date: Thu, 24 Aug 2017 17:18:10 +0900 Message-Id: <20170824081811.19299-14-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170824081811.19299-1-takahiro.akashi@linaro.org> References: <20170824081811.19299-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8699 Lines: 291 The "Image" binary will be loaded at the offset of TEXT_OFFSET from the start of system memory. TEXT_OFFSET is basically determined from the header of the image. Regarding kernel 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 it with sbsign command. Signed-off-by: AKASHI Takahiro Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/Kconfig | 11 ++-- arch/arm64/include/asm/kexec_file.h | 83 ++++++++++++++++++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/kexec_image.c | 112 +++++++++++++++++++++++++++++++++ arch/arm64/kernel/machine_kexec_file.c | 6 +- 5 files changed, 208 insertions(+), 5 deletions(-) create mode 100644 arch/arm64/include/asm/kexec_file.h create mode 100644 arch/arm64/kernel/kexec_image.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index cf10bc720d9e..c8f603700bdd 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -766,18 +766,21 @@ config KEXEC_FILE for kernel and initramfs as opposed to list of segments as accepted by previous system call. +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--- This option makes kernel signature verification mandatory for the kexec_file_load() syscall. - In addition to that option, you need to enable signature - verification for the corresponding kernel image type being - loaded in order for this to work. - config CRASH_DUMP bool "Build kdump crash kernel" help diff --git a/arch/arm64/include/asm/kexec_file.h b/arch/arm64/include/asm/kexec_file.h new file mode 100644 index 000000000000..5df899aa0d2e --- /dev/null +++ b/arch/arm64/include/asm/kexec_file.h @@ -0,0 +1,83 @@ +#ifndef _ASM_KEXEC_FILE_H +#define _ASM_KEXEC_FILE_H + +extern struct kexec_file_ops kexec_image_ops; + +/** + * struct arm64_image_header - arm64 kernel image header. + * + * @pe_sig: Optional PE format 'MZ' signature. + * @branch_code: Reserved for instructions to branch to stext. + * @text_offset: The image load offset in LSB byte order. + * @image_size: An estimated size of the memory image size in LSB byte order. + * @flags: Bit flags: + * Bit 7.0: Image byte order, 1=MSB. + * @reserved_1: Reserved. + * @magic: Magic number, "ARM\x64". + * @pe_header: Optional offset to a PE format header. + **/ + +struct arm64_image_header { + u8 pe_sig[2]; + u16 branch_code[3]; + u64 text_offset; + u64 image_size; + u8 flags[8]; + u64 reserved_1[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'}; +static const u64 arm64_image_flag_7_be = 0x01U; + +/** + * 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]); +} + +/** + * arm64_header_check_msb - Helper to check the arm64 image header. + * + * Returns non-zero if the image was built as big endian. + */ + +static inline int arm64_header_check_msb(const struct arm64_image_header *h) +{ + if (!h) + return 0; + + return !!(h->flags[7] & arm64_image_flag_7_be); +} +#endif /* _ASM_KEXE_FILE_H */ 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..db4aa1379fec --- /dev/null +++ b/arch/arm64/kernel/kexec_image.c @@ -0,0 +1,112 @@ +/* + * Kexec image loader + + * Copyright (C) 2017 Linaro Limited + * Authors: 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 +#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("%s: PE format: %s\n", __func__, + (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; + if (h->image_size) { + kbuf.memsz = le64_to_cpu(h->image_size); + text_offset = le64_to_cpu(h->text_offset); + } else { + /* v3.16 or older */ + kbuf.memsz = kbuf.bufsz; /* NOTE: not including BSS */ + text_offset = 0x80000; + } + 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 012063307001..ab3b19d51727 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -27,7 +27,11 @@ static int __dt_root_addr_cells; static int __dt_root_size_cells; -static struct kexec_file_ops *kexec_file_loaders[0]; +static struct kexec_file_ops *kexec_file_loaders[] = { +#ifdef CONFIG_KEXEC_FILE_IMAGE_FMT + &kexec_image_ops, +#endif +}; int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) -- 2.14.1