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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | // SPDX-License-Identifier: GPL-2.0 /* * ELF loader for kexec_file_load system call. * * Copyright IBM Corp. 2018 * * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> */ #include <linux/errno.h> #include <linux/kernel.h> #include <linux/kexec.h> #include <asm/setup.h> static int kexec_file_add_elf_kernel(struct kimage *image, struct s390_load_data *data, char *kernel, unsigned long kernel_len) { struct kexec_buf buf; const Elf_Ehdr *ehdr; const Elf_Phdr *phdr; Elf_Addr entry; int i, ret; ehdr = (Elf_Ehdr *)kernel; buf.image = image; if (image->type == KEXEC_TYPE_CRASH) entry = STARTUP_KDUMP_OFFSET; else entry = ehdr->e_entry; phdr = (void *)ehdr + ehdr->e_phoff; for (i = 0; i < ehdr->e_phnum; i++, phdr++) { if (phdr->p_type != PT_LOAD) continue; buf.buffer = kernel + phdr->p_offset; buf.bufsz = phdr->p_filesz; buf.mem = ALIGN(phdr->p_paddr, phdr->p_align); buf.memsz = phdr->p_memsz; if (entry - phdr->p_paddr < phdr->p_memsz) { data->kernel_buf = buf.buffer; data->memsz += STARTUP_NORMAL_OFFSET; buf.buffer += STARTUP_NORMAL_OFFSET; buf.bufsz -= STARTUP_NORMAL_OFFSET; buf.mem += STARTUP_NORMAL_OFFSET; buf.memsz -= STARTUP_NORMAL_OFFSET; } if (image->type == KEXEC_TYPE_CRASH) buf.mem += crashk_res.start; ret = kexec_add_buffer(&buf); if (ret) return ret; data->memsz = ALIGN(data->memsz, phdr->p_align) + buf.memsz; } return 0; } static void *s390_elf_load(struct kimage *image, char *kernel, unsigned long kernel_len, char *initrd, unsigned long initrd_len, char *cmdline, unsigned long cmdline_len) { struct s390_load_data data = {0}; const Elf_Ehdr *ehdr; const Elf_Phdr *phdr; size_t size; int i, ret; /* image->fobs->probe already checked for valid ELF magic number. */ ehdr = (Elf_Ehdr *)kernel; if (ehdr->e_type != ET_EXEC || ehdr->e_ident[EI_CLASS] != ELFCLASS64 || !elf_check_arch(ehdr)) return ERR_PTR(-EINVAL); if (!ehdr->e_phnum || ehdr->e_phentsize != sizeof(Elf_Phdr)) return ERR_PTR(-EINVAL); size = ehdr->e_ehsize + ehdr->e_phoff; size += ehdr->e_phentsize * ehdr->e_phnum; if (size > kernel_len) return ERR_PTR(-EINVAL); phdr = (void *)ehdr + ehdr->e_phoff; size = ALIGN(size, phdr->p_align); for (i = 0; i < ehdr->e_phnum; i++, phdr++) { if (phdr->p_type == PT_INTERP) return ERR_PTR(-EINVAL); if (phdr->p_offset > kernel_len) return ERR_PTR(-EINVAL); size += ALIGN(phdr->p_filesz, phdr->p_align); } if (size > kernel_len) return ERR_PTR(-EINVAL); ret = kexec_file_add_elf_kernel(image, &data, kernel, kernel_len); if (ret) return ERR_PTR(ret); if (!data.memsz) return ERR_PTR(-EINVAL); if (initrd) { ret = kexec_file_add_initrd(image, &data, initrd, initrd_len); if (ret) return ERR_PTR(ret); } ret = kexec_file_add_purgatory(image, &data); if (ret) return ERR_PTR(ret); return kexec_file_update_kernel(image, &data); } static int s390_elf_probe(const char *buf, unsigned long len) { const Elf_Ehdr *ehdr; if (len < sizeof(Elf_Ehdr)) return -ENOEXEC; ehdr = (Elf_Ehdr *)buf; /* Only check the ELF magic number here and do proper validity check * in the loader. Any check here that fails would send the erroneous * ELF file to the image loader that does not care what it gets. * (Most likely) causing behavior not intended by the user. */ if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) return -ENOEXEC; return 0; } const struct kexec_file_ops s390_kexec_elf_ops = { .probe = s390_elf_probe, .load = s390_elf_load, }; |