1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * kexec_file for arm64 4 * 5 * Copyright (C) 2018 Linaro Limited 6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> 7 * 8 * Most code is derived from arm64 port of kexec-tools 9 */ 10 11 #define pr_fmt(fmt) "kexec_file: " fmt 12 13 #include <linux/ioport.h> 14 #include <linux/kernel.h> 15 #include <linux/kexec.h> 16 #include <linux/libfdt.h> 17 #include <linux/memblock.h> 18 #include <linux/of.h> 19 #include <linux/of_fdt.h> 20 #include <linux/slab.h> 21 #include <linux/string.h> 22 #include <linux/types.h> 23 #include <linux/vmalloc.h> 24 25 const struct kexec_file_ops * const kexec_file_loaders[] = { 26 &kexec_image_ops, 27 NULL 28 }; 29 arch_kimage_file_post_load_cleanup(struct kimage * image)30 int arch_kimage_file_post_load_cleanup(struct kimage *image) 31 { 32 kvfree(image->arch.dtb); 33 image->arch.dtb = NULL; 34 35 vfree(image->elf_headers); 36 image->elf_headers = NULL; 37 image->elf_headers_sz = 0; 38 39 return kexec_image_post_load_cleanup_default(image); 40 } 41 prepare_elf_headers(void ** addr,unsigned long * sz)42 static int prepare_elf_headers(void **addr, unsigned long *sz) 43 { 44 struct crash_mem *cmem; 45 unsigned int nr_ranges; 46 int ret; 47 u64 i; 48 phys_addr_t start, end; 49 50 nr_ranges = 2; /* for exclusion of crashkernel region */ 51 for_each_mem_range(i, &start, &end) 52 nr_ranges++; 53 54 cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); 55 if (!cmem) 56 return -ENOMEM; 57 58 cmem->max_nr_ranges = nr_ranges; 59 cmem->nr_ranges = 0; 60 for_each_mem_range(i, &start, &end) { 61 cmem->ranges[cmem->nr_ranges].start = start; 62 cmem->ranges[cmem->nr_ranges].end = end - 1; 63 cmem->nr_ranges++; 64 } 65 66 /* Exclude crashkernel region */ 67 ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); 68 if (ret) 69 goto out; 70 71 if (crashk_low_res.end) { 72 ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); 73 if (ret) 74 goto out; 75 } 76 77 ret = crash_prepare_elf64_headers(cmem, true, addr, sz); 78 79 out: 80 kfree(cmem); 81 return ret; 82 } 83 84 /* 85 * Tries to add the initrd and DTB to the image. If it is not possible to find 86 * valid locations, this function will undo changes to the image and return non 87 * zero. 88 */ load_other_segments(struct kimage * image,unsigned long kernel_load_addr,unsigned long kernel_size,char * initrd,unsigned long initrd_len,char * cmdline)89 int load_other_segments(struct kimage *image, 90 unsigned long kernel_load_addr, 91 unsigned long kernel_size, 92 char *initrd, unsigned long initrd_len, 93 char *cmdline) 94 { 95 struct kexec_buf kbuf; 96 void *headers, *dtb = NULL; 97 unsigned long headers_sz, initrd_load_addr = 0, dtb_len, 98 orig_segments = image->nr_segments; 99 int ret = 0; 100 101 kbuf.image = image; 102 /* not allocate anything below the kernel */ 103 kbuf.buf_min = kernel_load_addr + kernel_size; 104 105 /* load elf core header */ 106 if (image->type == KEXEC_TYPE_CRASH) { 107 ret = prepare_elf_headers(&headers, &headers_sz); 108 if (ret) { 109 pr_err("Preparing elf core header failed\n"); 110 goto out_err; 111 } 112 113 kbuf.buffer = headers; 114 kbuf.bufsz = headers_sz; 115 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 116 kbuf.memsz = headers_sz; 117 kbuf.buf_align = SZ_64K; /* largest supported page size */ 118 kbuf.buf_max = ULONG_MAX; 119 kbuf.top_down = true; 120 121 ret = kexec_add_buffer(&kbuf); 122 if (ret) { 123 vfree(headers); 124 goto out_err; 125 } 126 image->elf_headers = headers; 127 image->elf_load_addr = kbuf.mem; 128 image->elf_headers_sz = headers_sz; 129 130 pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 131 image->elf_load_addr, kbuf.bufsz, kbuf.memsz); 132 } 133 134 /* load initrd */ 135 if (initrd) { 136 kbuf.buffer = initrd; 137 kbuf.bufsz = initrd_len; 138 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 139 kbuf.memsz = initrd_len; 140 kbuf.buf_align = 0; 141 /* within 1GB-aligned window of up to 32GB in size */ 142 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G) 143 + (unsigned long)SZ_1G * 32; 144 kbuf.top_down = false; 145 146 ret = kexec_add_buffer(&kbuf); 147 if (ret) 148 goto out_err; 149 initrd_load_addr = kbuf.mem; 150 151 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 152 initrd_load_addr, kbuf.bufsz, kbuf.memsz); 153 } 154 155 /* load dtb */ 156 dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr, 157 initrd_len, cmdline, 0); 158 if (!dtb) { 159 pr_err("Preparing for new dtb failed\n"); 160 ret = -EINVAL; 161 goto out_err; 162 } 163 164 /* trim it */ 165 fdt_pack(dtb); 166 dtb_len = fdt_totalsize(dtb); 167 kbuf.buffer = dtb; 168 kbuf.bufsz = dtb_len; 169 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 170 kbuf.memsz = dtb_len; 171 /* not across 2MB boundary */ 172 kbuf.buf_align = SZ_2M; 173 kbuf.buf_max = ULONG_MAX; 174 kbuf.top_down = true; 175 176 ret = kexec_add_buffer(&kbuf); 177 if (ret) 178 goto out_err; 179 image->arch.dtb = dtb; 180 image->arch.dtb_mem = kbuf.mem; 181 182 pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 183 kbuf.mem, kbuf.bufsz, kbuf.memsz); 184 185 return 0; 186 187 out_err: 188 image->nr_segments = orig_segments; 189 kvfree(dtb); 190 return ret; 191 } 192