1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Load ELF vmlinux file for the kexec_file_load syscall.
4 *
5 * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
6 *
7 */
8 #include <linux/elf.h>
9 #include <linux/kexec.h>
10 #include <linux/libfdt.h>
11 #include <linux/module.h>
12 #include <linux/of_fdt.h>
13 #include <linux/slab.h>
14 #include <linux/types.h>
15
16 static void *elf_load(struct kimage *image, char *kernel_buf,
17 unsigned long kernel_len, char *initrd,
18 unsigned long initrd_len, char *cmdline,
19 unsigned long cmdline_len)
20 {
21 int ret, i;
22 unsigned long kernel_load_addr;
23 struct elfhdr ehdr;
24 struct kexec_elf_info elf_info;
25 struct kexec_buf kbuf = { .image = image, .buf_min = 0,
26 .buf_max = -1UL, };
27
28 ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
29 if (ret)
30 goto out;
31
32 ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
33 if (ret)
34 goto out;
35
36 image->start = __pa(elf_info.ehdr->e_entry);
37
38 for (i = 0; i < image->nr_segments; i++)
39 image->segment[i].mem = __pa(image->segment[i].mem);
40
41 kexec_dprintk("Loaded the kernel at 0x%lx, entry at 0x%lx\n",
42 kernel_load_addr, image->start);
43
44 if (initrd != NULL) {
45 kbuf.buffer = initrd;
46 kbuf.bufsz = kbuf.memsz = initrd_len;
47 kbuf.buf_align = PAGE_SIZE;
48 kbuf.top_down = false;
49 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
50 ret = kexec_add_buffer(&kbuf);
51 if (ret)
52 goto out;
53
54 kexec_dprintk("Loaded initrd at 0x%lx\n", kbuf.mem);
55 image->arch.initrd_start = kbuf.mem;
56 image->arch.initrd_end = kbuf.mem + initrd_len;
57 }
58
59 if (cmdline != NULL) {
60 kbuf.buffer = cmdline;
61 kbuf.bufsz = kbuf.memsz = ALIGN(cmdline_len, 8);
62 kbuf.buf_align = PAGE_SIZE;
63 kbuf.top_down = false;
64 kbuf.buf_min = PAGE0->mem_free + PAGE_SIZE;
65 kbuf.buf_max = kernel_load_addr;
66 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
67 ret = kexec_add_buffer(&kbuf);
68 if (ret)
69 goto out;
70
71 kexec_dprintk("Loaded cmdline at 0x%lx\n", kbuf.mem);
72 image->arch.cmdline = kbuf.mem;
73 }
74 out:
75 return NULL;
76 }
77
78 const struct kexec_file_ops kexec_elf_ops = {
79 .probe = kexec_elf_probe,
80 .load = elf_load,
81 };
82
83 const struct kexec_file_ops * const kexec_file_loaders[] = {
84 &kexec_elf_ops,
85 NULL
86 };
87
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