arch/arm64/kernel/machine_kexec_file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * kexec_file for arm64
   4  *
   5  * Copyright (C) 2018 Linaro Limited
   6  * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
   7  *
   8  * Most code is derived from arm64 port of kexec-tools
   9  */
  10
  11 #define pr_fmt(fmt) "kexec_file: " fmt
  12
  13 #include <linux/ioport.h>
  14 #include <linux/kernel.h>
  15 #include <linux/kexec.h>
  16 #include <linux/libfdt.h>
  17 #include <linux/memblock.h>
  18 #include <linux/of.h>
  19 #include <linux/of_fdt.h>
  20 #include <linux/slab.h>
  21 #include <linux/string.h>
  22 #include <linux/types.h>
  23 #include <linux/vmalloc.h>
  24
  25 const struct kexec_file_ops * const kexec_file_loaders[] = {
  26         &kexec_image_ops,
  27         NULL
  28 };
  29
  30 int arch_kimage_file_post_load_cleanup(struct kimage *image)
  31 {
  32         kvfree(image->arch.dtb);
  33         image->arch.dtb = NULL;
  34
  35         vfree(image->elf_headers);
  36         image->elf_headers = NULL;
  37         image->elf_headers_sz = 0;
  38
  39         return kexec_image_post_load_cleanup_default(image);
  40 }
  41
  42 #ifdef CONFIG_CRASH_DUMP
  43 static int prepare_elf_headers(void **addr, unsigned long *sz)
  44 {
  45         struct crash_mem *cmem;
  46         unsigned int nr_ranges;
  47         int ret;
  48         u64 i;
  49         phys_addr_t start, end;
  50
  51         nr_ranges = 2; /* for exclusion of crashkernel region */
  52         for_each_mem_range(i, &start, &end)
  53                 nr_ranges++;
  54
  55         cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
  56         if (!cmem)
  57                 return -ENOMEM;
  58
  59         cmem->max_nr_ranges = nr_ranges;
  60         cmem->nr_ranges = 0;
  61         for_each_mem_range(i, &start, &end) {
  62                 cmem->ranges[cmem->nr_ranges].start = start;
  63                 cmem->ranges[cmem->nr_ranges].end = end - 1;
  64                 cmem->nr_ranges++;
  65         }
  66
  67         /* Exclude crashkernel region */
  68         ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
  69         if (ret)
  70                 goto out;
  71
  72         if (crashk_low_res.end) {
  73                 ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
  74                 if (ret)
  75                         goto out;
  76         }
  77
  78         ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
  79
  80 out:
  81         kfree(cmem);
  82         return ret;
  83 }
  84 #endif
  85
  86 /*
  87  * Tries to add the initrd and DTB to the image. If it is not possible to find
  88  * valid locations, this function will undo changes to the image and return non
  89  * zero.
  90  */
  91 int load_other_segments(struct kimage *image,
  92                         unsigned long kernel_load_addr,
  93                         unsigned long kernel_size,
  94                         char *initrd, unsigned long initrd_len,
  95                         char *cmdline)
  96 {
  97         struct kexec_buf kbuf;
  98         void *dtb = NULL;
  99         unsigned long initrd_load_addr = 0, dtb_len,
 100                       orig_segments = image->nr_segments;
 101         int ret = 0;
 102
 103         kbuf.image = image;
 104         /* not allocate anything below the kernel */
 105         kbuf.buf_min = kernel_load_addr + kernel_size;
 106
 107 #ifdef CONFIG_CRASH_DUMP
 108         /* load elf core header */
 109         void *headers;
 110         unsigned long headers_sz;
 111         if (image->type == KEXEC_TYPE_CRASH) {
 112                 ret = prepare_elf_headers(&headers, &headers_sz);
 113                 if (ret) {
 114                         pr_err("Preparing elf core header failed\n");
 115                         goto out_err;
 116                 }
 117
 118                 kbuf.buffer = headers;
 119                 kbuf.bufsz = headers_sz;
 120                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 121                 kbuf.memsz = headers_sz;
 122                 kbuf.buf_align = SZ_64K; /* largest supported page size */
 123                 kbuf.buf_max = ULONG_MAX;
 124                 kbuf.top_down = true;
 125
 126                 ret = kexec_add_buffer(&kbuf);
 127                 if (ret) {
 128                         vfree(headers);
 129                         goto out_err;
 130                 }
 131                 image->elf_headers = headers;
 132                 image->elf_load_addr = kbuf.mem;
 133                 image->elf_headers_sz = headers_sz;
 134
 135                 kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 136                               image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
 137         }
 138 #endif
 139
 140         /* load initrd */
 141         if (initrd) {
 142                 kbuf.buffer = initrd;
 143                 kbuf.bufsz = initrd_len;
 144                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 145                 kbuf.memsz = initrd_len;
 146                 kbuf.buf_align = 0;
 147                 /* within 1GB-aligned window of up to 32GB in size */
 148                 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
 149                                                 + (unsigned long)SZ_1G * 32;
 150                 kbuf.top_down = false;
 151
 152                 ret = kexec_add_buffer(&kbuf);
 153                 if (ret)
 154                         goto out_err;
 155                 initrd_load_addr = kbuf.mem;
 156
 157                 kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 158                               initrd_load_addr, kbuf.bufsz, kbuf.memsz);
 159         }
 160
 161         /* load dtb */
 162         dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
 163                                            initrd_len, cmdline, 0);
 164         if (!dtb) {
 165                 pr_err("Preparing for new dtb failed\n");
 166                 ret = -EINVAL;
 167                 goto out_err;
 168         }
 169
 170         /* trim it */
 171         fdt_pack(dtb);
 172         dtb_len = fdt_totalsize(dtb);
 173         kbuf.buffer = dtb;
 174         kbuf.bufsz = dtb_len;
 175         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 176         kbuf.memsz = dtb_len;
 177         /* not across 2MB boundary */
 178         kbuf.buf_align = SZ_2M;
 179         kbuf.buf_max = ULONG_MAX;
 180         kbuf.top_down = true;
 181
 182         ret = kexec_add_buffer(&kbuf);
 183         if (ret)
 184                 goto out_err;
 185         image->arch.dtb = dtb;
 186         image->arch.dtb_mem = kbuf.mem;
 187
 188         kexec_dprintk("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 189                       kbuf.mem, kbuf.bufsz, kbuf.memsz);
 190
 191         return 0;
 192
 193 out_err:
 194         image->nr_segments = orig_segments;
 195         kvfree(dtb);
 196         return ret;
 197 }