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 static int prepare_elf_headers(void **addr, unsigned long *sz)
  43 {
  44         struct crash_mem *cmem;
  45         unsigned int nr_ranges;
  46         int ret;
  47         u64 i;
  48         phys_addr_t start, end;
  49
  50         nr_ranges = 2; /* for exclusion of crashkernel region */
  51         for_each_mem_range(i, &start, &end)
  52                 nr_ranges++;
  53
  54         cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
  55         if (!cmem)
  56                 return -ENOMEM;
  57
  58         cmem->max_nr_ranges = nr_ranges;
  59         cmem->nr_ranges = 0;
  60         for_each_mem_range(i, &start, &end) {
  61                 cmem->ranges[cmem->nr_ranges].start = start;
  62                 cmem->ranges[cmem->nr_ranges].end = end - 1;
  63                 cmem->nr_ranges++;
  64         }
  65
  66         /* Exclude crashkernel region */
  67         ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
  68         if (ret)
  69                 goto out;
  70
  71         if (crashk_low_res.end) {
  72                 ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
  73                 if (ret)
  74                         goto out;
  75         }
  76
  77         ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
  78
  79 out:
  80         kfree(cmem);
  81         return ret;
  82 }
  83
  84 /*
  85  * Tries to add the initrd and DTB to the image. If it is not possible to find
  86  * valid locations, this function will undo changes to the image and return non
  87  * zero.
  88  */
  89 int load_other_segments(struct kimage *image,
  90                         unsigned long kernel_load_addr,
  91                         unsigned long kernel_size,
  92                         char *initrd, unsigned long initrd_len,
  93                         char *cmdline)
  94 {
  95         struct kexec_buf kbuf;
  96         void *headers, *dtb = NULL;
  97         unsigned long headers_sz, initrd_load_addr = 0, dtb_len,
  98                       orig_segments = image->nr_segments;
  99         int ret = 0;
 100
 101         kbuf.image = image;
 102         /* not allocate anything below the kernel */
 103         kbuf.buf_min = kernel_load_addr + kernel_size;
 104
 105         /* load elf core header */
 106         if (image->type == KEXEC_TYPE_CRASH) {
 107                 ret = prepare_elf_headers(&headers, &headers_sz);
 108                 if (ret) {
 109                         pr_err("Preparing elf core header failed\n");
 110                         goto out_err;
 111                 }
 112
 113                 kbuf.buffer = headers;
 114                 kbuf.bufsz = headers_sz;
 115                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 116                 kbuf.memsz = headers_sz;
 117                 kbuf.buf_align = SZ_64K; /* largest supported page size */
 118                 kbuf.buf_max = ULONG_MAX;
 119                 kbuf.top_down = true;
 120
 121                 ret = kexec_add_buffer(&kbuf);
 122                 if (ret) {
 123                         vfree(headers);
 124                         goto out_err;
 125                 }
 126                 image->elf_headers = headers;
 127                 image->elf_load_addr = kbuf.mem;
 128                 image->elf_headers_sz = headers_sz;
 129
 130                 pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 131                          image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
 132         }
 133
 134         /* load initrd */
 135         if (initrd) {
 136                 kbuf.buffer = initrd;
 137                 kbuf.bufsz = initrd_len;
 138                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 139                 kbuf.memsz = initrd_len;
 140                 kbuf.buf_align = 0;
 141                 /* within 1GB-aligned window of up to 32GB in size */
 142                 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
 143                                                 + (unsigned long)SZ_1G * 32;
 144                 kbuf.top_down = false;
 145
 146                 ret = kexec_add_buffer(&kbuf);
 147                 if (ret)
 148                         goto out_err;
 149                 initrd_load_addr = kbuf.mem;
 150
 151                 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 152                                 initrd_load_addr, kbuf.bufsz, kbuf.memsz);
 153         }
 154
 155         /* load dtb */
 156         dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
 157                                            initrd_len, cmdline, 0);
 158         if (!dtb) {
 159                 pr_err("Preparing for new dtb failed\n");
 160                 ret = -EINVAL;
 161                 goto out_err;
 162         }
 163
 164         /* trim it */
 165         fdt_pack(dtb);
 166         dtb_len = fdt_totalsize(dtb);
 167         kbuf.buffer = dtb;
 168         kbuf.bufsz = dtb_len;
 169         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 170         kbuf.memsz = dtb_len;
 171         /* not across 2MB boundary */
 172         kbuf.buf_align = SZ_2M;
 173         kbuf.buf_max = ULONG_MAX;
 174         kbuf.top_down = true;
 175
 176         ret = kexec_add_buffer(&kbuf);
 177         if (ret)
 178                 goto out_err;
 179         image->arch.dtb = dtb;
 180         image->arch.dtb_mem = kbuf.mem;
 181
 182         pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 183                         kbuf.mem, kbuf.bufsz, kbuf.memsz);
 184
 185         return 0;
 186
 187 out_err:
 188         image->nr_segments = orig_segments;
 189         kvfree(dtb);
 190         return ret;
 191 }