arch/powerpc/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.h>
  23 #include <linux/of_fdt.h>
  24 #include <linux/slab.h>
  25 #include <linux/types.h>
  26
  27 static 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                 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 = 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;
 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;
 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 out:
 144         kfree(modified_cmdline);
 145         kexec_free_elf_info(&elf_info);
 146
 147         /*
 148          * Once FDT buffer has been successfully passed to kexec_add_buffer(),
 149          * the FDT buffer address is saved in image->arch.fdt. In that case,
 150          * the memory cannot be freed here in case of any other error.
 151          */
 152         if (ret && !image->arch.fdt)
 153                 kvfree(fdt);
 154
 155         return ret ? ERR_PTR(ret) : NULL;
 156 }
 157
 158 const struct kexec_file_ops kexec_elf64_ops = {
 159         .probe = kexec_elf_probe,
 160         .load = elf64_load,
 161 };