cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

elf_64.c (4134B)

      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 (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 = 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	pr_debug("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};