elf_64.c

  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#include <asm/kexec_ranges.h>
 27
 28static void *elf64_load(struct kimage *image, char *kernel_buf,
 29			unsigned long kernel_len, char *initrd,
 30			unsigned long initrd_len, char *cmdline,
 31			unsigned long cmdline_len)
 32{
 33	int ret;
 34	unsigned long kernel_load_addr;
 35	unsigned long initrd_load_addr = 0, fdt_load_addr;
 36	void *fdt;
 37	const void *slave_code;
 38	struct elfhdr ehdr;
 39	char *modified_cmdline = NULL;
 40	struct crash_mem *rmem = NULL;
 41	struct kexec_elf_info elf_info;
 42	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
 43				  .buf_max = ppc64_rma_size };
 44	struct kexec_buf pbuf = { .image = image, .buf_min = 0,
 45				  .buf_max = ppc64_rma_size, .top_down = true,
 46				  .mem = KEXEC_BUF_MEM_UNKNOWN };
 47
 48	ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
 49	if (ret)
 50		return ERR_PTR(ret);
 51
 52	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
 53		/* min & max buffer values for kdump case */
 54		kbuf.buf_min = pbuf.buf_min = crashk_res.start;
 55		kbuf.buf_max = pbuf.buf_max =
 56				((crashk_res.end < ppc64_rma_size) ?
 57				 crashk_res.end : (ppc64_rma_size - 1));
 58	}
 59
 60	ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
 61	if (ret)
 62		goto out;
 63
 64	kexec_dprintk("Loaded the kernel at 0x%lx\n", kernel_load_addr);
 65
 66	ret = kexec_load_purgatory(image, &pbuf);
 67	if (ret) {
 68		pr_err("Loading purgatory failed.\n");
 69		goto out;
 70	}
 71
 72	kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
 73
 74	/* Load additional segments needed for panic kernel */
 75	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
 76		ret = load_crashdump_segments_ppc64(image, &kbuf);
 77		if (ret) {
 78			pr_err("Failed to load kdump kernel segments\n");
 79			goto out;
 80		}
 81
 82		/* Setup cmdline for kdump kernel case */
 83		modified_cmdline = setup_kdump_cmdline(image, cmdline,
 84						       cmdline_len);
 85		if (!modified_cmdline) {
 86			pr_err("Setting up cmdline for kdump kernel failed\n");
 87			ret = -EINVAL;
 88			goto out;
 89		}
 90		cmdline = modified_cmdline;
 91	}
 92
 93	if (initrd != NULL) {
 94		kbuf.buffer = initrd;
 95		kbuf.bufsz = kbuf.memsz = initrd_len;
 96		kbuf.buf_align = PAGE_SIZE;
 97		kbuf.top_down = false;
 98		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 99		ret = kexec_add_buffer(&kbuf);
100		if (ret)
101			goto out;
102		initrd_load_addr = kbuf.mem;
103
104		kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_load_addr);
105	}
106
107	ret = get_reserved_memory_ranges(&rmem);
108	if (ret)
109		goto out;
110
111	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
112					   initrd_len, cmdline,
113					   kexec_extra_fdt_size_ppc64(image, rmem));
114	if (!fdt) {
115		pr_err("Error setting up the new device tree.\n");
116		ret = -EINVAL;
117		goto out;
118	}
119
120	ret = setup_new_fdt_ppc64(image, fdt, rmem);
121	if (ret)
122		goto out_free_fdt;
123
124	if (!IS_ENABLED(CONFIG_CRASH_HOTPLUG) || image->type != KEXEC_TYPE_CRASH)
125		fdt_pack(fdt);
126
127	kbuf.buffer = fdt;
128	kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
129	kbuf.buf_align = PAGE_SIZE;
130	kbuf.top_down = true;
131	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
132	ret = kexec_add_buffer(&kbuf);
133	if (ret)
134		goto out_free_fdt;
135
136	/* FDT will be freed in arch_kimage_file_post_load_cleanup */
137	image->arch.fdt = fdt;
138
139	fdt_load_addr = kbuf.mem;
140
141	kexec_dprintk("Loaded device tree at 0x%lx\n", fdt_load_addr);
142
143	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
144	ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
145				    fdt_load_addr);
146	if (ret)
147		pr_err("Error setting up the purgatory.\n");
148
149	goto out;
150
151out_free_fdt:
152	kvfree(fdt);
153out:
154	kfree(rmem);
155	kfree(modified_cmdline);
156	kexec_free_elf_info(&elf_info);
157
158	return ret ? ERR_PTR(ret) : NULL;
159}
160
161const struct kexec_file_ops kexec_elf64_ops = {
162	.probe = kexec_elf_probe,
163	.load = elf64_load,
164};