LXR linux/arch/powerpc/kexec/elf

   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