1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 2018 Linaro Limited
6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
8 * Most code is derived from arm64 port of kexec-tools
11 #define pr_fmt(fmt) "kexec_file: " fmt
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_fdt.h>
19 #include <linux/random.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/types.h>
23 #include <linux/vmalloc.h>
24 #include <asm/byteorder.h>
26 /* relevant device tree properties */
27 #define FDT_PROP_KEXEC_ELFHDR "linux,elfcorehdr"
28 #define FDT_PROP_MEM_RANGE "linux,usable-memory-range"
29 #define FDT_PROP_INITRD_START "linux,initrd-start"
30 #define FDT_PROP_INITRD_END "linux,initrd-end"
31 #define FDT_PROP_BOOTARGS "bootargs"
32 #define FDT_PROP_KASLR_SEED "kaslr-seed"
33 #define FDT_PROP_RNG_SEED "rng-seed"
34 #define RNG_SEED_SIZE 128
36 const struct kexec_file_ops * const kexec_file_loaders[] = {
41 int arch_kimage_file_post_load_cleanup(struct kimage *image)
43 vfree(image->arch.dtb);
44 image->arch.dtb = NULL;
46 vfree(image->arch.elf_headers);
47 image->arch.elf_headers = NULL;
48 image->arch.elf_headers_sz = 0;
50 return kexec_image_post_load_cleanup_default(image);
53 static int setup_dtb(struct kimage *image,
54 unsigned long initrd_load_addr, unsigned long initrd_len,
55 char *cmdline, void *dtb)
59 ret = fdt_path_offset(dtb, "/chosen");
65 ret = fdt_delprop(dtb, off, FDT_PROP_KEXEC_ELFHDR);
66 if (ret && ret != -FDT_ERR_NOTFOUND)
68 ret = fdt_delprop(dtb, off, FDT_PROP_MEM_RANGE);
69 if (ret && ret != -FDT_ERR_NOTFOUND)
72 if (image->type == KEXEC_TYPE_CRASH) {
73 /* add linux,elfcorehdr */
74 ret = fdt_appendprop_addrrange(dtb, 0, off,
75 FDT_PROP_KEXEC_ELFHDR,
76 image->arch.elf_headers_mem,
77 image->arch.elf_headers_sz);
79 return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
81 /* add linux,usable-memory-range */
82 ret = fdt_appendprop_addrrange(dtb, 0, off,
85 crashk_res.end - crashk_res.start + 1);
87 return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
92 ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline);
96 ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS);
97 if (ret && (ret != -FDT_ERR_NOTFOUND))
102 if (initrd_load_addr) {
103 ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START,
108 ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END,
109 initrd_load_addr + initrd_len);
113 ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START);
114 if (ret && (ret != -FDT_ERR_NOTFOUND))
117 ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END);
118 if (ret && (ret != -FDT_ERR_NOTFOUND))
123 ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED);
124 if (ret == -FDT_ERR_NOTFOUND)
129 if (rng_is_initialized()) {
130 u64 seed = get_random_u64();
131 ret = fdt_setprop_u64(dtb, off, FDT_PROP_KASLR_SEED, seed);
135 pr_notice("RNG is not initialised: omitting \"%s\" property\n",
136 FDT_PROP_KASLR_SEED);
140 if (rng_is_initialized()) {
142 ret = fdt_setprop_placeholder(dtb, off, FDT_PROP_RNG_SEED,
143 RNG_SEED_SIZE, &rng_seed);
146 get_random_bytes(rng_seed, RNG_SEED_SIZE);
148 pr_notice("RNG is not initialised: omitting \"%s\" property\n",
154 return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
160 * More space needed so that we can add initrd, bootargs, kaslr-seed,
161 * rng-seed, userable-memory-range and elfcorehdr.
163 #define DTB_EXTRA_SPACE 0x1000
165 static int create_dtb(struct kimage *image,
166 unsigned long initrd_load_addr, unsigned long initrd_len,
167 char *cmdline, void **dtb)
174 cmdline_len = cmdline ? strlen(cmdline) : 0;
175 buf_size = fdt_totalsize(initial_boot_params)
176 + cmdline_len + DTB_EXTRA_SPACE;
179 buf = vmalloc(buf_size);
183 /* duplicate a device tree blob */
184 ret = fdt_open_into(initial_boot_params, buf, buf_size);
188 ret = setup_dtb(image, initrd_load_addr, initrd_len,
192 if (ret == -ENOMEM) {
193 /* unlikely, but just in case */
194 buf_size += DTB_EXTRA_SPACE;
209 static int prepare_elf_headers(void **addr, unsigned long *sz)
211 struct crash_mem *cmem;
212 unsigned int nr_ranges;
215 phys_addr_t start, end;
217 nr_ranges = 1; /* for exclusion of crashkernel region */
218 for_each_mem_range(i, &start, &end)
221 cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
225 cmem->max_nr_ranges = nr_ranges;
227 for_each_mem_range(i, &start, &end) {
228 cmem->ranges[cmem->nr_ranges].start = start;
229 cmem->ranges[cmem->nr_ranges].end = end - 1;
233 /* Exclude crashkernel region */
234 ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
237 ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
244 * Tries to add the initrd and DTB to the image. If it is not possible to find
245 * valid locations, this function will undo changes to the image and return non
248 int load_other_segments(struct kimage *image,
249 unsigned long kernel_load_addr,
250 unsigned long kernel_size,
251 char *initrd, unsigned long initrd_len,
254 struct kexec_buf kbuf;
255 void *headers, *dtb = NULL;
256 unsigned long headers_sz, initrd_load_addr = 0, dtb_len,
257 orig_segments = image->nr_segments;
261 /* not allocate anything below the kernel */
262 kbuf.buf_min = kernel_load_addr + kernel_size;
264 /* load elf core header */
265 if (image->type == KEXEC_TYPE_CRASH) {
266 ret = prepare_elf_headers(&headers, &headers_sz);
268 pr_err("Preparing elf core header failed\n");
272 kbuf.buffer = headers;
273 kbuf.bufsz = headers_sz;
274 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
275 kbuf.memsz = headers_sz;
276 kbuf.buf_align = SZ_64K; /* largest supported page size */
277 kbuf.buf_max = ULONG_MAX;
278 kbuf.top_down = true;
280 ret = kexec_add_buffer(&kbuf);
285 image->arch.elf_headers = headers;
286 image->arch.elf_headers_mem = kbuf.mem;
287 image->arch.elf_headers_sz = headers_sz;
289 pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
290 image->arch.elf_headers_mem, kbuf.bufsz, kbuf.memsz);
295 kbuf.buffer = initrd;
296 kbuf.bufsz = initrd_len;
297 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
298 kbuf.memsz = initrd_len;
300 /* within 1GB-aligned window of up to 32GB in size */
301 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
302 + (unsigned long)SZ_1G * 32;
303 kbuf.top_down = false;
305 ret = kexec_add_buffer(&kbuf);
308 initrd_load_addr = kbuf.mem;
310 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
311 initrd_load_addr, kbuf.bufsz, kbuf.memsz);
315 ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb);
317 pr_err("Preparing for new dtb failed\n");
321 dtb_len = fdt_totalsize(dtb);
323 kbuf.bufsz = dtb_len;
324 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
325 kbuf.memsz = dtb_len;
326 /* not across 2MB boundary */
327 kbuf.buf_align = SZ_2M;
328 kbuf.buf_max = ULONG_MAX;
329 kbuf.top_down = true;
331 ret = kexec_add_buffer(&kbuf);
334 image->arch.dtb = dtb;
335 image->arch.dtb_mem = kbuf.mem;
337 pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
338 kbuf.mem, kbuf.bufsz, kbuf.memsz);
343 image->nr_segments = orig_segments;