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_fdt.h>
23#include <linux/slab.h>
24#include <linux/types.h>
25
26static void *elf64_load(struct kimage *image, char *kernel_buf,
27			unsigned long kernel_len, char *initrd,
28			unsigned long initrd_len, char *cmdline,
29			unsigned long cmdline_len)
30{
31	int ret;
32	unsigned int fdt_size;
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		goto out;
49
50	if (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	pr_debug("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	pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);
71
72	/* Load additional segments needed for panic kernel */
73	if (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		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
103	}
104
105	fdt_size = kexec_fdt_totalsize_ppc64(image);
106	fdt = kmalloc(fdt_size, GFP_KERNEL);
107	if (!fdt) {
108		pr_err("Not enough memory for the device tree.\n");
109		ret = -ENOMEM;
110		goto out;
111	}
112	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
113	if (ret < 0) {
114		pr_err("Error setting up the new device tree.\n");
115		ret = -EINVAL;
116		goto out;
117	}
118
119	ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
120				  initrd_len, cmdline);
121	if (ret)
122		goto out;
123
124	fdt_pack(fdt);
125
126	kbuf.buffer = fdt;
127	kbuf.bufsz = kbuf.memsz = fdt_size;
128	kbuf.buf_align = PAGE_SIZE;
129	kbuf.top_down = true;
130	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
131	ret = kexec_add_buffer(&kbuf);
132	if (ret)
133		goto out;
134	fdt_load_addr = kbuf.mem;
135
136	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
137
138	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
139	ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
140				    fdt_load_addr);
141	if (ret)
142		pr_err("Error setting up the purgatory.\n");
143
144out:
145	kfree(modified_cmdline);
146	kexec_free_elf_info(&elf_info);
147
148	/* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
149	return ret ? ERR_PTR(ret) : fdt;
150}
151
152const struct kexec_file_ops kexec_elf64_ops = {
153	.probe = kexec_elf_probe,
154	.load = elf64_load,
155};
156