arch/parisc/kernel/kexec_file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Load ELF vmlinux file for the kexec_file_load syscall.
   4  *
   5  * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
   6  *
   7  */
   8 #include <linux/elf.h>
   9 #include <linux/kexec.h>
  10 #include <linux/libfdt.h>
  11 #include <linux/module.h>
  12 #include <linux/of_fdt.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15
  16 static void *elf_load(struct kimage *image, char *kernel_buf,
  17                         unsigned long kernel_len, char *initrd,
  18                         unsigned long initrd_len, char *cmdline,
  19                         unsigned long cmdline_len)
  20 {
  21         int ret, i;
  22         unsigned long kernel_load_addr;
  23         struct elfhdr ehdr;
  24         struct kexec_elf_info elf_info;
  25         struct kexec_buf kbuf = { .image = image, .buf_min = 0,
  26                                   .buf_max = -1UL, };
  27
  28         ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
  29         if (ret)
  30                 goto out;
  31
  32         ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
  33         if (ret)
  34                 goto out;
  35
  36         image->start = __pa(elf_info.ehdr->e_entry);
  37
  38         for (i = 0; i < image->nr_segments; i++)
  39                 image->segment[i].mem = __pa(image->segment[i].mem);
  40
  41         pr_debug("Loaded the kernel at 0x%lx, entry at 0x%lx\n",
  42                  kernel_load_addr, image->start);
  43
  44         if (initrd != NULL) {
  45                 kbuf.buffer = initrd;
  46                 kbuf.bufsz = kbuf.memsz = initrd_len;
  47                 kbuf.buf_align = PAGE_SIZE;
  48                 kbuf.top_down = false;
  49                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
  50                 ret = kexec_add_buffer(&kbuf);
  51                 if (ret)
  52                         goto out;
  53
  54                 pr_debug("Loaded initrd at 0x%lx\n", kbuf.mem);
  55                 image->arch.initrd_start = kbuf.mem;
  56                 image->arch.initrd_end = kbuf.mem + initrd_len;
  57         }
  58
  59         if (cmdline != NULL) {
  60                 kbuf.buffer = cmdline;
  61                 kbuf.bufsz = kbuf.memsz = ALIGN(cmdline_len, 8);
  62                 kbuf.buf_align = PAGE_SIZE;
  63                 kbuf.top_down = false;
  64                 kbuf.buf_min = PAGE0->mem_free + PAGE_SIZE;
  65                 kbuf.buf_max = kernel_load_addr;
  66                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
  67                 ret = kexec_add_buffer(&kbuf);
  68                 if (ret)
  69                         goto out;
  70
  71                 pr_debug("Loaded cmdline at 0x%lx\n", kbuf.mem);
  72                 image->arch.cmdline = kbuf.mem;
  73         }
  74 out:
  75         return NULL;
  76 }
  77
  78 const struct kexec_file_ops kexec_elf_ops = {
  79         .probe = kexec_elf_probe,
  80         .load = elf_load,
  81 };
  82
  83 const struct kexec_file_ops * const kexec_file_loaders[] = {
  84         &kexec_elf_ops,
  85         NULL
  86 };