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1191cf49 SS |
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 | pr_debug("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 | pr_debug("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 | pr_debug("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 | }; |