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 ([email protected])
   6  * Copyright (C) 2004  IBM Corp.
   7  * Copyright (C) 2005  R Sharada ([email protected])
   8  * Copyright (C) 2006  Mohan Kumar M ([email protected])
   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 <[email protected]>.
  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 #include <asm/kexec_ranges.h>
  27
  28 static void *elf64_load(struct kimage *image, char *kernel_buf,
  29                         unsigned long kernel_len, char *initrd,
  30                         unsigned long initrd_len, char *cmdline,
  31                         unsigned long cmdline_len)
  32 {
  33         int ret;
  34         unsigned long kernel_load_addr;
  35         unsigned long initrd_load_addr = 0, fdt_load_addr;
  36         void *fdt;
  37         const void *slave_code;
  38         struct elfhdr ehdr;
  39         char *modified_cmdline = NULL;
  40         struct crash_mem *rmem = NULL;
  41         struct kexec_elf_info elf_info;
  42         struct kexec_buf kbuf = { .image = image, .buf_min = 0,
  43                                   .buf_max = ppc64_rma_size };
  44         struct kexec_buf pbuf = { .image = image, .buf_min = 0,
  45                                   .buf_max = ppc64_rma_size, .top_down = true,
  46                                   .mem = KEXEC_BUF_MEM_UNKNOWN };
  47
  48         ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
  49         if (ret)
  50                 return ERR_PTR(ret);
  51
  52         if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
  53                 /* min & max buffer values for kdump case */
  54                 kbuf.buf_min = pbuf.buf_min = crashk_res.start;
  55                 kbuf.buf_max = pbuf.buf_max =
  56                                 ((crashk_res.end < ppc64_rma_size) ?
  57                                  crashk_res.end : (ppc64_rma_size - 1));
  58         }
  59
  60         ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
  61         if (ret)
  62                 goto out;
  63
  64         kexec_dprintk("Loaded the kernel at 0x%lx\n", kernel_load_addr);
  65
  66         ret = kexec_load_purgatory(image, &pbuf);
  67         if (ret) {
  68                 pr_err("Loading purgatory failed.\n");
  69                 goto out;
  70         }
  71
  72         kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
  73
  74         /* Load additional segments needed for panic kernel */
  75         if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
  76                 ret = load_crashdump_segments_ppc64(image, &kbuf);
  77                 if (ret) {
  78                         pr_err("Failed to load kdump kernel segments\n");
  79                         goto out;
  80                 }
  81
  82                 /* Setup cmdline for kdump kernel case */
  83                 modified_cmdline = setup_kdump_cmdline(image, cmdline,
  84                                                        cmdline_len);
  85                 if (!modified_cmdline) {
  86                         pr_err("Setting up cmdline for kdump kernel failed\n");
  87                         ret = -EINVAL;
  88                         goto out;
  89                 }
  90                 cmdline = modified_cmdline;
  91         }
  92
  93         if (initrd != NULL) {
  94                 kbuf.buffer = initrd;
  95                 kbuf.bufsz = kbuf.memsz = initrd_len;
  96                 kbuf.buf_align = PAGE_SIZE;
  97                 kbuf.top_down = false;
  98                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
  99                 ret = kexec_add_buffer(&kbuf);
 100                 if (ret)
 101                         goto out;
 102                 initrd_load_addr = kbuf.mem;
 103
 104                 kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_load_addr);
 105         }
 106
 107         ret = get_reserved_memory_ranges(&rmem);
 108         if (ret)
 109                 goto out;
 110
 111         fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
 112                                            initrd_len, cmdline,
 113                                            kexec_extra_fdt_size_ppc64(image, rmem));
 114         if (!fdt) {
 115                 pr_err("Error setting up the new device tree.\n");
 116                 ret = -EINVAL;
 117                 goto out;
 118         }
 119
 120         ret = setup_new_fdt_ppc64(image, fdt, rmem);
 121         if (ret)
 122                 goto out_free_fdt;
 123
 124         if (!IS_ENABLED(CONFIG_CRASH_HOTPLUG) || image->type != KEXEC_TYPE_CRASH)
 125                 fdt_pack(fdt);
 126
 127         kbuf.buffer = fdt;
 128         kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
 129         kbuf.buf_align = PAGE_SIZE;
 130         kbuf.top_down = true;
 131         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 132         ret = kexec_add_buffer(&kbuf);
 133         if (ret)
 134                 goto out_free_fdt;
 135
 136         /* FDT will be freed in arch_kimage_file_post_load_cleanup */
 137         image->arch.fdt = fdt;
 138
 139         fdt_load_addr = kbuf.mem;
 140
 141         kexec_dprintk("Loaded device tree at 0x%lx\n", fdt_load_addr);
 142
 143         slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
 144         ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
 145                                     fdt_load_addr);
 146         if (ret)
 147                 pr_err("Error setting up the purgatory.\n");
 148
 149         goto out;
 150
 151 out_free_fdt:
 152         kvfree(fdt);
 153 out:
 154         kfree(rmem);
 155         kfree(modified_cmdline);
 156         kexec_free_elf_info(&elf_info);
 157
 158         return ret ? ERR_PTR(ret) : NULL;
 159 }
 160
 161 const struct kexec_file_ops kexec_elf64_ops = {
 162         .probe = kexec_elf_probe,
 163         .load = elf64_load,
 164 };