arch/powerpc/kernel/kexec_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_fdt.h>
  23 #include <linux/slab.h>
  24 #include <linux/types.h>
  25
  26 static 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
 115 out:
 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
 122 const struct kexec_file_ops kexec_elf64_ops = {
 123         .probe = kexec_elf_probe,
 124         .load = elf64_load,
 125 };