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	struct kexec_elf_info elf_info;
 39	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
 40				  .buf_max = ppc64_rma_size };
 41	struct kexec_buf pbuf = { .image = image, .buf_min = 0,
 42				  .buf_max = ppc64_rma_size, .top_down = true,
 43				  .mem = KEXEC_BUF_MEM_UNKNOWN };
 44
 45	ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
 46	if (ret)
 47		goto out;
 48
 49	ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
 50	if (ret)
 51		goto out;
 52
 53	pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr);
 54
 55	ret = kexec_load_purgatory(image, &pbuf);
 56	if (ret) {
 57		pr_err("Loading purgatory failed.\n");
 58		goto out;
 59	}
 60
 61	pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);
 62
 63	if (initrd != NULL) {
 64		kbuf.buffer = initrd;
 65		kbuf.bufsz = kbuf.memsz = initrd_len;
 66		kbuf.buf_align = PAGE_SIZE;
 67		kbuf.top_down = false;
 68		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 69		ret = kexec_add_buffer(&kbuf);
 70		if (ret)
 71			goto out;
 72		initrd_load_addr = kbuf.mem;
 73
 74		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
 75	}
 76
 77	fdt_size = fdt_totalsize(initial_boot_params) * 2;
 78	fdt = kmalloc(fdt_size, GFP_KERNEL);
 79	if (!fdt) {
 80		pr_err("Not enough memory for the device tree.\n");
 81		ret = -ENOMEM;
 82		goto out;
 83	}
 84	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
 85	if (ret < 0) {
 86		pr_err("Error setting up the new device tree.\n");
 87		ret = -EINVAL;
 88		goto out;
 89	}
 90
 91	ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
 92	if (ret)
 93		goto out;
 94
 95	fdt_pack(fdt);
 96
 97	kbuf.buffer = fdt;
 98	kbuf.bufsz = kbuf.memsz = fdt_size;
 99	kbuf.buf_align = PAGE_SIZE;
100	kbuf.top_down = true;
101	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
102	ret = kexec_add_buffer(&kbuf);
103	if (ret)
104		goto out;
105	fdt_load_addr = kbuf.mem;
106
107	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
108
109	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
110	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
111			      fdt_load_addr);
112	if (ret)
113		pr_err("Error setting up the purgatory.\n");
114
115out:
116	kexec_free_elf_info(&elf_info);
117
118	/* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
119	return ret ? ERR_PTR(ret) : fdt;
120}
121
122const struct kexec_file_ops kexec_elf64_ops = {
123	.probe = kexec_elf_probe,
124	.load = elf64_load,
125};