1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Kexec image loader 4 5 * Copyright (C) 2018 Linaro Limited 6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> 7 */ 8 9 #define pr_fmt(fmt) "kexec_file(Image): " fmt 10 11 #include <linux/err.h> 12 #include <linux/errno.h> 13 #include <linux/kernel.h> 14 #include <linux/kexec.h> 15 #include <linux/pe.h> 16 #include <linux/string.h> 17 #include <linux/verification.h> 18 #include <asm/byteorder.h> 19 #include <asm/cpufeature.h> 20 #include <asm/image.h> 21 #include <asm/memory.h> 22 23 static int image_probe(const char *kernel_buf, unsigned long kernel_len) 24 { 25 const struct arm64_image_header *h = 26 (const struct arm64_image_header *)(kernel_buf); 27 28 if (!h || (kernel_len < sizeof(*h))) 29 return -EINVAL; 30 31 if (memcmp(&h->magic, ARM64_IMAGE_MAGIC, sizeof(h->magic))) 32 return -EINVAL; 33 34 return 0; 35 } 36 37 static void *image_load(struct kimage *image, 38 char *kernel, unsigned long kernel_len, 39 char *initrd, unsigned long initrd_len, 40 char *cmdline, unsigned long cmdline_len) 41 { 42 struct arm64_image_header *h; 43 u64 flags, value; 44 bool be_image, be_kernel; 45 struct kexec_buf kbuf; 46 unsigned long text_offset; 47 struct kexec_segment *kernel_segment; 48 int ret; 49 50 /* 51 * We require a kernel with an unambiguous Image header. Per 52 * Documentation/arm64/booting.rst, this is the case when image_size 53 * is non-zero (practically speaking, since v3.17). 54 */ 55 h = (struct arm64_image_header *)kernel; 56 if (!h->image_size) 57 return ERR_PTR(-EINVAL); 58 59 /* Check cpu features */ 60 flags = le64_to_cpu(h->flags); 61 be_image = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_BE); 62 be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN); 63 if ((be_image != be_kernel) && !system_supports_mixed_endian()) 64 return ERR_PTR(-EINVAL); 65 66 value = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_PAGE_SIZE); 67 if (((value == ARM64_IMAGE_FLAG_PAGE_SIZE_4K) && 68 !system_supports_4kb_granule()) || 69 ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_64K) && 70 !system_supports_64kb_granule()) || 71 ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_16K) && 72 !system_supports_16kb_granule())) 73 return ERR_PTR(-EINVAL); 74 75 /* Load the kernel */ 76 kbuf.image = image; 77 kbuf.buf_min = 0; 78 kbuf.buf_max = ULONG_MAX; 79 kbuf.top_down = false; 80 81 kbuf.buffer = kernel; 82 kbuf.bufsz = kernel_len; 83 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 84 kbuf.memsz = le64_to_cpu(h->image_size); 85 text_offset = le64_to_cpu(h->text_offset); 86 kbuf.buf_align = MIN_KIMG_ALIGN; 87 88 /* Adjust kernel segment with TEXT_OFFSET */ 89 kbuf.memsz += text_offset; 90 91 ret = kexec_add_buffer(&kbuf); 92 if (ret) 93 return ERR_PTR(ret); 94 95 kernel_segment = &image->segment[image->nr_segments - 1]; 96 kernel_segment->mem += text_offset; 97 kernel_segment->memsz -= text_offset; 98 image->start = kernel_segment->mem; 99 100 pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 101 kernel_segment->mem, kbuf.bufsz, 102 kernel_segment->memsz); 103 104 /* Load additional data */ 105 ret = load_other_segments(image, 106 kernel_segment->mem, kernel_segment->memsz, 107 initrd, initrd_len, cmdline); 108 109 return ERR_PTR(ret); 110 } 111 112 #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG 113 static int image_verify_sig(const char *kernel, unsigned long kernel_len) 114 { 115 return verify_pefile_signature(kernel, kernel_len, NULL, 116 VERIFYING_KEXEC_PE_SIGNATURE); 117 } 118 #endif 119 120 const struct kexec_file_ops kexec_image_ops = { 121 .probe = image_probe, 122 .load = image_load, 123 #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG 124 .verify_sig = image_verify_sig, 125 #endif 126 }; 127