projects / mirror_ubuntu-hirsute-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| f3b70e50 AT |
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/string.h> | |
| 16 | #include <asm/byteorder.h> | |
| 17 | #include <asm/cpufeature.h> | |
| 18 | #include <asm/image.h> | |
| 19 | #include <asm/memory.h> | |
| 20 | ||
| 21 | static int image_probe(const char *kernel_buf, unsigned long kernel_len) | |
| 22 | { | |
| 23 | const struct arm64_image_header *h; | |
| 24 | ||
| 25 | h = (const struct arm64_image_header *)(kernel_buf); | |
| 26 | ||
| 27 | if (!h || (kernel_len < sizeof(*h)) || | |
| 28 | memcmp(&h->magic, ARM64_IMAGE_MAGIC, | |
| 29 | sizeof(h->magic))) | |
| 30 | return -EINVAL; | |
| 31 | ||
| 32 | return 0; | |
| 33 | } | |
| 34 | ||
| 35 | static void *image_load(struct kimage *image, | |
| 36 | char *kernel, unsigned long kernel_len, | |
| 37 | char *initrd, unsigned long initrd_len, | |
| 38 | char *cmdline, unsigned long cmdline_len) | |
| 39 | { | |
| 40 | struct arm64_image_header *h; | |
| 41 | u64 flags, value; | |
| 42 | bool be_image, be_kernel; | |
| 43 | struct kexec_buf kbuf; | |
| 44 | unsigned long text_offset; | |
| 45 | struct kexec_segment *kernel_segment; | |
| 46 | int ret; | |
| 47 | ||
| 48 | /* | |
| 49 | * We require a kernel with an unambiguous Image header. Per | |
| 50 | * Documentation/booting.txt, this is the case when image_size | |
| 51 | * is non-zero (practically speaking, since v3.17). | |
| 52 | */ | |
| 53 | h = (struct arm64_image_header *)kernel; | |
| 54 | if (!h->image_size) | |
| 55 | return ERR_PTR(-EINVAL); | |
| 56 | ||
| 57 | /* Check cpu features */ | |
| 58 | flags = le64_to_cpu(h->flags); | |
| 59 | be_image = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_BE); | |
| 60 | be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN); | |
| 61 | if ((be_image != be_kernel) && !system_supports_mixed_endian()) | |
| 62 | return ERR_PTR(-EINVAL); | |
| 63 | ||
| 64 | value = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_PAGE_SIZE); | |
| 65 | if (((value == ARM64_IMAGE_FLAG_PAGE_SIZE_4K) && | |
| 66 | !system_supports_4kb_granule()) || | |
| 67 | ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_64K) && | |
| 68 | !system_supports_64kb_granule()) || | |
| 69 | ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_16K) && | |
| 70 | !system_supports_16kb_granule())) | |
| 71 | return ERR_PTR(-EINVAL); | |
| 72 | ||
| 73 | /* Load the kernel */ | |
| 74 | kbuf.image = image; | |
| 75 | kbuf.buf_min = 0; | |
| 76 | kbuf.buf_max = ULONG_MAX; | |
| 77 | kbuf.top_down = false; | |
| 78 | ||
| 79 | kbuf.buffer = kernel; | |
| 80 | kbuf.bufsz = kernel_len; | |
| 81 | kbuf.mem = 0; | |
| 82 | kbuf.memsz = le64_to_cpu(h->image_size); | |
| 83 | text_offset = le64_to_cpu(h->text_offset); | |
| 84 | kbuf.buf_align = MIN_KIMG_ALIGN; | |
| 85 | ||
| 86 | /* Adjust kernel segment with TEXT_OFFSET */ | |
| 87 | kbuf.memsz += text_offset; | |
| 88 | ||
| 89 | ret = kexec_add_buffer(&kbuf); | |
| 90 | if (ret) | |
| 91 | return ERR_PTR(ret); | |
| 92 | ||
| 93 | kernel_segment = &image->segment[image->nr_segments - 1]; | |
| 94 | kernel_segment->mem += text_offset; | |
| 95 | kernel_segment->memsz -= text_offset; | |
| 96 | image->start = kernel_segment->mem; | |
| 97 | ||
| 98 | pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", | |
| 99 | kernel_segment->mem, kbuf.bufsz, | |
| 100 | kernel_segment->memsz); | |
| 101 | ||
| 102 | /* Load additional data */ | |
| 103 | ret = load_other_segments(image, | |
| 104 | kernel_segment->mem, kernel_segment->memsz, | |
| 105 | initrd, initrd_len, cmdline); | |
| 106 | ||
| 107 | return ERR_PTR(ret); | |
| 108 | } | |
| 109 | ||
| 110 | const struct kexec_file_ops kexec_image_ops = { | |
| 111 | .probe = image_probe, | |
| 112 | .load = image_load, | |
| 113 | }; |