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 }; 87