1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Load ELF vmlinux file for the kexec_file_load syscall.
4 *
5 * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
6 * Copyright (C) 2004  IBM Corp.
7 * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
8 * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
9 * Copyright (C) 2016  IBM Corporation
10 *
11 * Based on kexec-tools' kexec-elf-exec.c and kexec-elf-ppc64.c.
12 * Heavily modified for the kernel by
13 * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
14 */
15
16#define pr_fmt(fmt)	"kexec_elf: " fmt
17
18#include <linux/elf.h>
19#include <linux/kexec.h>
20#include <linux/libfdt.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/of_fdt.h>
24#include <linux/slab.h>
25#include <linux/types.h>
26
27static void *elf64_load(struct kimage *image, char *kernel_buf,
28			unsigned long kernel_len, char *initrd,
29			unsigned long initrd_len, char *cmdline,
30			unsigned long cmdline_len)
31{
32	int ret;
33	unsigned long kernel_load_addr;
34	unsigned long initrd_load_addr = 0, fdt_load_addr;
35	void *fdt;
36	const void *slave_code;
37	struct elfhdr ehdr;
38	char *modified_cmdline = NULL;
39	struct kexec_elf_info elf_info;
40	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
41				  .buf_max = ppc64_rma_size };
42	struct kexec_buf pbuf = { .image = image, .buf_min = 0,
43				  .buf_max = ppc64_rma_size, .top_down = true,
44				  .mem = KEXEC_BUF_MEM_UNKNOWN };
45
46	ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
47	if (ret)
48		return ERR_PTR(ret);
49
50	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
51		/* min & max buffer values for kdump case */
52		kbuf.buf_min = pbuf.buf_min = crashk_res.start;
53		kbuf.buf_max = pbuf.buf_max =
54				((crashk_res.end < ppc64_rma_size) ?
55				 crashk_res.end : (ppc64_rma_size - 1));
56	}
57
58	ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
59	if (ret)
60		goto out;
61
62	kexec_dprintk("Loaded the kernel at 0x%lx\n", kernel_load_addr);
63
64	ret = kexec_load_purgatory(image, &pbuf);
65	if (ret) {
66		pr_err("Loading purgatory failed.\n");
67		goto out;
68	}
69
70	kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
71
72	/* Load additional segments needed for panic kernel */
73	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
74		ret = load_crashdump_segments_ppc64(image, &kbuf);
75		if (ret) {
76			pr_err("Failed to load kdump kernel segments\n");
77			goto out;
78		}
79
80		/* Setup cmdline for kdump kernel case */
81		modified_cmdline = setup_kdump_cmdline(image, cmdline,
82						       cmdline_len);
83		if (!modified_cmdline) {
84			pr_err("Setting up cmdline for kdump kernel failed\n");
85			ret = -EINVAL;
86			goto out;
87		}
88		cmdline = modified_cmdline;
89	}
90
91	if (initrd != NULL) {
92		kbuf.buffer = initrd;
93		kbuf.bufsz = kbuf.memsz = initrd_len;
94		kbuf.buf_align = PAGE_SIZE;
95		kbuf.top_down = false;
96		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
97		ret = kexec_add_buffer(&kbuf);
98		if (ret)
99			goto out;
100		initrd_load_addr = kbuf.mem;
101
102		kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_load_addr);
103	}
104
105	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
106					   initrd_len, cmdline,
107					   kexec_extra_fdt_size_ppc64(image));
108	if (!fdt) {
109		pr_err("Error setting up the new device tree.\n");
110		ret = -EINVAL;
111		goto out;
112	}
113
114	ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
115				  initrd_len, cmdline);
116	if (ret)
117		goto out_free_fdt;
118
119	fdt_pack(fdt);
120
121	kbuf.buffer = fdt;
122	kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
123	kbuf.buf_align = PAGE_SIZE;
124	kbuf.top_down = true;
125	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
126	ret = kexec_add_buffer(&kbuf);
127	if (ret)
128		goto out_free_fdt;
129
130	/* FDT will be freed in arch_kimage_file_post_load_cleanup */
131	image->arch.fdt = fdt;
132
133	fdt_load_addr = kbuf.mem;
134
135	kexec_dprintk("Loaded device tree at 0x%lx\n", fdt_load_addr);
136
137	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
138	ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
139				    fdt_load_addr);
140	if (ret)
141		pr_err("Error setting up the purgatory.\n");
142
143	goto out;
144
145out_free_fdt:
146	kvfree(fdt);
147out:
148	kfree(modified_cmdline);
149	kexec_free_elf_info(&elf_info);
150
151	return ret ? ERR_PTR(ret) : NULL;
152}
153
154const struct kexec_file_ops kexec_elf64_ops = {
155	.probe = kexec_elf_probe,
156	.load = elf64_load,
157};
158