From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753300AbdLDC4Q (ORCPT ); Sun, 3 Dec 2017 21:56:16 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:35153 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753189AbdLDCzW (ORCPT ); Sun, 3 Dec 2017 21:55:22 -0500 X-Google-Smtp-Source: AGs4zMaorn7DGNdzsm+tZurk00xE6hAbK6Wj48oIt9MBfr6RHYsFFRH7R4otSb4C2MBwjUWc0eRZ5Q== 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, julien.thierry@arm.com Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro Subject: [PATCH v7 09/11] arm64: kexec_file: add Image format support Date: Mon, 4 Dec 2017 11:57:59 +0900 Message-Id: <20171204025801.12161-10-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171204025801.12161-1-takahiro.akashi@linaro.org> References: <20171204025801.12161-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. This patch doesn't have CONFIG_KEXEC_VERIFY_SIG support. Nevertherless kernel verification will be supported by enabling IMA security subsystem. See more details about IMA here: https://sourceforge.net/p/linux-ima/wiki/Home/ You can sign(label) a kernel image binary to be kexec-ed on target filesystem with: $ evmctl ima_sign --key /path/to/private_key.pem Image On live system, you must have IMA enforced with, at least, the following security policy: "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig" Signed-off-by: AKASHI Takahiro Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/Kconfig | 7 +++ arch/arm64/include/asm/kexec.h | 50 +++++++++++++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/kexec_image.c | 90 ++++++++++++++++++++++++++++++++++ arch/arm64/kernel/machine_kexec_file.c | 3 ++ 5 files changed, 151 insertions(+) create mode 100644 arch/arm64/kernel/kexec_image.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 865d110809f9..c0b021736c10 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -807,6 +807,13 @@ 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" + default y + depends on KEXEC_FILE + ---help--- + Select this option to enable 'Image' kernel loading. + config CRASH_DUMP bool "Build kdump crash kernel" help diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index edb702e64a8a..b6469bc64a89 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -104,6 +104,56 @@ 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}; + +/** + * 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]); +} + +extern const 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 2cd982b779b9..17906a62d795 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -50,6 +50,7 @@ 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..1c106237901d --- /dev/null +++ b/arch/arm64/kernel/kexec_image.c @@ -0,0 +1,90 @@ +/* + * 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 + +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; + + 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); +} + +const struct kexec_file_ops kexec_image_ops = { + .probe = image_probe, + .load = image_load, +}; diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 012b2af4e27b..2b6d9164df8a 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -25,6 +25,9 @@ static int __dt_root_addr_cells; static int __dt_root_size_cells; const struct kexec_file_ops * const kexec_file_loaders[] = { +#ifdef CONFIG_KEXEC_FILE_IMAGE_FMT + &kexec_image_ops, +#endif NULL }; -- 2.14.1