1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Kexec bzImage loader 4 * 5 * Copyright (C) 2014 Red Hat Inc. 6 * Authors: 7 * Vivek Goyal <vgoyal@redhat.com> 8 */ 9 10 #define pr_fmt(fmt) "kexec-bzImage64: " fmt 11 12 #include <linux/string.h> 13 #include <linux/printk.h> 14 #include <linux/errno.h> 15 #include <linux/slab.h> 16 #include <linux/kexec.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/efi.h> 20 #include <linux/verification.h> 21 22 #include <asm/bootparam.h> 23 #include <asm/setup.h> 24 #include <asm/crash.h> 25 #include <asm/efi.h> 26 #include <asm/e820/api.h> 27 #include <asm/kexec-bzimage64.h> 28 29 #define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */ 30 31 /* 32 * Defines lowest physical address for various segments. Not sure where 33 * exactly these limits came from. Current bzimage64 loader in kexec-tools 34 * uses these so I am retaining it. It can be changed over time as we gain 35 * more insight. 36 */ 37 #define MIN_PURGATORY_ADDR 0x3000 38 #define MIN_BOOTPARAM_ADDR 0x3000 39 #define MIN_KERNEL_LOAD_ADDR 0x100000 40 #define MIN_INITRD_LOAD_ADDR 0x1000000 41 42 /* 43 * This is a place holder for all boot loader specific data structure which 44 * gets allocated in one call but gets freed much later during cleanup 45 * time. Right now there is only one field but it can grow as need be. 46 */ 47 struct bzimage64_data { 48 /* 49 * Temporary buffer to hold bootparams buffer. This should be 50 * freed once the bootparam segment has been loaded. 51 */ 52 void *bootparams_buf; 53 }; 54 55 static int setup_initrd(struct boot_params *params, 56 unsigned long initrd_load_addr, unsigned long initrd_len) 57 { 58 params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL; 59 params->hdr.ramdisk_size = initrd_len & 0xffffffffUL; 60 61 params->ext_ramdisk_image = initrd_load_addr >> 32; 62 params->ext_ramdisk_size = initrd_len >> 32; 63 64 return 0; 65 } 66 67 static int setup_cmdline(struct kimage *image, struct boot_params *params, 68 unsigned long bootparams_load_addr, 69 unsigned long cmdline_offset, char *cmdline, 70 unsigned long cmdline_len) 71 { 72 char *cmdline_ptr = ((char *)params) + cmdline_offset; 73 unsigned long cmdline_ptr_phys, len = 0; 74 uint32_t cmdline_low_32, cmdline_ext_32; 75 76 if (image->type == KEXEC_TYPE_CRASH) { 77 len = sprintf(cmdline_ptr, 78 "elfcorehdr=0x%lx ", image->arch.elf_load_addr); 79 } 80 memcpy(cmdline_ptr + len, cmdline, cmdline_len); 81 cmdline_len += len; 82 83 cmdline_ptr[cmdline_len - 1] = '\0'; 84 85 pr_debug("Final command line is: %s\n", cmdline_ptr); 86 cmdline_ptr_phys = bootparams_load_addr + cmdline_offset; 87 cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL; 88 cmdline_ext_32 = cmdline_ptr_phys >> 32; 89 90 params->hdr.cmd_line_ptr = cmdline_low_32; 91 if (cmdline_ext_32) 92 params->ext_cmd_line_ptr = cmdline_ext_32; 93 94 return 0; 95 } 96 97 static int setup_e820_entries(struct boot_params *params) 98 { 99 unsigned int nr_e820_entries; 100 101 nr_e820_entries = e820_table_kexec->nr_entries; 102 103 /* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */ 104 if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE) 105 nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE; 106 107 params->e820_entries = nr_e820_entries; 108 memcpy(¶ms->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry)); 109 110 return 0; 111 } 112 113 #ifdef CONFIG_EFI 114 static int setup_efi_info_memmap(struct boot_params *params, 115 unsigned long params_load_addr, 116 unsigned int efi_map_offset, 117 unsigned int efi_map_sz) 118 { 119 void *efi_map = (void *)params + efi_map_offset; 120 unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset; 121 struct efi_info *ei = ¶ms->efi_info; 122 123 if (!efi_map_sz) 124 return 0; 125 126 efi_runtime_map_copy(efi_map, efi_map_sz); 127 128 ei->efi_memmap = efi_map_phys_addr & 0xffffffff; 129 ei->efi_memmap_hi = efi_map_phys_addr >> 32; 130 ei->efi_memmap_size = efi_map_sz; 131 132 return 0; 133 } 134 135 static int 136 prepare_add_efi_setup_data(struct boot_params *params, 137 unsigned long params_load_addr, 138 unsigned int efi_setup_data_offset) 139 { 140 unsigned long setup_data_phys; 141 struct setup_data *sd = (void *)params + efi_setup_data_offset; 142 struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data); 143 144 esd->fw_vendor = efi_fw_vendor; 145 esd->tables = efi_config_table; 146 esd->smbios = efi.smbios; 147 148 sd->type = SETUP_EFI; 149 sd->len = sizeof(struct efi_setup_data); 150 151 /* Add setup data */ 152 setup_data_phys = params_load_addr + efi_setup_data_offset; 153 sd->next = params->hdr.setup_data; 154 params->hdr.setup_data = setup_data_phys; 155 156 return 0; 157 } 158 159 static int 160 setup_efi_state(struct boot_params *params, unsigned long params_load_addr, 161 unsigned int efi_map_offset, unsigned int efi_map_sz, 162 unsigned int efi_setup_data_offset) 163 { 164 struct efi_info *current_ei = &boot_params.efi_info; 165 struct efi_info *ei = ¶ms->efi_info; 166 167 if (!efi_enabled(EFI_RUNTIME_SERVICES)) 168 return 0; 169 170 if (!current_ei->efi_memmap_size) 171 return 0; 172 173 params->secure_boot = boot_params.secure_boot; 174 ei->efi_loader_signature = current_ei->efi_loader_signature; 175 ei->efi_systab = current_ei->efi_systab; 176 ei->efi_systab_hi = current_ei->efi_systab_hi; 177 178 ei->efi_memdesc_version = current_ei->efi_memdesc_version; 179 ei->efi_memdesc_size = efi_get_runtime_map_desc_size(); 180 181 setup_efi_info_memmap(params, params_load_addr, efi_map_offset, 182 efi_map_sz); 183 prepare_add_efi_setup_data(params, params_load_addr, 184 efi_setup_data_offset); 185 return 0; 186 } 187 #endif /* CONFIG_EFI */ 188 189 static int 190 setup_boot_parameters(struct kimage *image, struct boot_params *params, 191 unsigned long params_load_addr, 192 unsigned int efi_map_offset, unsigned int efi_map_sz, 193 unsigned int efi_setup_data_offset) 194 { 195 unsigned int nr_e820_entries; 196 unsigned long long mem_k, start, end; 197 int i, ret = 0; 198 199 /* Get subarch from existing bootparams */ 200 params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; 201 202 /* Copying screen_info will do? */ 203 memcpy(¶ms->screen_info, &screen_info, sizeof(struct screen_info)); 204 205 /* Fill in memsize later */ 206 params->screen_info.ext_mem_k = 0; 207 params->alt_mem_k = 0; 208 209 /* Always fill in RSDP: it is either 0 or a valid value */ 210 params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr; 211 212 /* Default APM info */ 213 memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info)); 214 215 /* Default drive info */ 216 memset(¶ms->hd0_info, 0, sizeof(params->hd0_info)); 217 memset(¶ms->hd1_info, 0, sizeof(params->hd1_info)); 218 219 if (image->type == KEXEC_TYPE_CRASH) { 220 ret = crash_setup_memmap_entries(image, params); 221 if (ret) 222 return ret; 223 } else 224 setup_e820_entries(params); 225 226 nr_e820_entries = params->e820_entries; 227 228 for (i = 0; i < nr_e820_entries; i++) { 229 if (params->e820_table[i].type != E820_TYPE_RAM) 230 continue; 231 start = params->e820_table[i].addr; 232 end = params->e820_table[i].addr + params->e820_table[i].size - 1; 233 234 if ((start <= 0x100000) && end > 0x100000) { 235 mem_k = (end >> 10) - (0x100000 >> 10); 236 params->screen_info.ext_mem_k = mem_k; 237 params->alt_mem_k = mem_k; 238 if (mem_k > 0xfc00) 239 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/ 240 if (mem_k > 0xffffffff) 241 params->alt_mem_k = 0xffffffff; 242 } 243 } 244 245 #ifdef CONFIG_EFI 246 /* Setup EFI state */ 247 setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, 248 efi_setup_data_offset); 249 #endif 250 /* Setup EDD info */ 251 memcpy(params->eddbuf, boot_params.eddbuf, 252 EDDMAXNR * sizeof(struct edd_info)); 253 params->eddbuf_entries = boot_params.eddbuf_entries; 254 255 memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer, 256 EDD_MBR_SIG_MAX * sizeof(unsigned int)); 257 258 return ret; 259 } 260 261 static int bzImage64_probe(const char *buf, unsigned long len) 262 { 263 int ret = -ENOEXEC; 264 struct setup_header *header; 265 266 /* kernel should be at least two sectors long */ 267 if (len < 2 * 512) { 268 pr_err("File is too short to be a bzImage\n"); 269 return ret; 270 } 271 272 header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr)); 273 if (memcmp((char *)&header->header, "HdrS", 4) != 0) { 274 pr_err("Not a bzImage\n"); 275 return ret; 276 } 277 278 if (header->boot_flag != 0xAA55) { 279 pr_err("No x86 boot sector present\n"); 280 return ret; 281 } 282 283 if (header->version < 0x020C) { 284 pr_err("Must be at least protocol version 2.12\n"); 285 return ret; 286 } 287 288 if (!(header->loadflags & LOADED_HIGH)) { 289 pr_err("zImage not a bzImage\n"); 290 return ret; 291 } 292 293 if (!(header->xloadflags & XLF_KERNEL_64)) { 294 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n"); 295 return ret; 296 } 297 298 if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) { 299 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n"); 300 return ret; 301 } 302 303 /* 304 * Can't handle 32bit EFI as it does not allow loading kernel 305 * above 4G. This should be handled by 32bit bzImage loader 306 */ 307 if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) { 308 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n"); 309 return ret; 310 } 311 312 if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) { 313 pr_err("bzImage cannot handle 5-level paging mode.\n"); 314 return ret; 315 } 316 317 /* I've got a bzImage */ 318 pr_debug("It's a relocatable bzImage64\n"); 319 ret = 0; 320 321 return ret; 322 } 323 324 static void *bzImage64_load(struct kimage *image, char *kernel, 325 unsigned long kernel_len, char *initrd, 326 unsigned long initrd_len, char *cmdline, 327 unsigned long cmdline_len) 328 { 329 330 struct setup_header *header; 331 int setup_sects, kern16_size, ret = 0; 332 unsigned long setup_header_size, params_cmdline_sz; 333 struct boot_params *params; 334 unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; 335 struct bzimage64_data *ldata; 336 struct kexec_entry64_regs regs64; 337 void *stack; 338 unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr); 339 unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; 340 struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, 341 .top_down = true }; 342 struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR, 343 .buf_max = ULONG_MAX, .top_down = true }; 344 345 header = (struct setup_header *)(kernel + setup_hdr_offset); 346 setup_sects = header->setup_sects; 347 if (setup_sects == 0) 348 setup_sects = 4; 349 350 kern16_size = (setup_sects + 1) * 512; 351 if (kernel_len < kern16_size) { 352 pr_err("bzImage truncated\n"); 353 return ERR_PTR(-ENOEXEC); 354 } 355 356 if (cmdline_len > header->cmdline_size) { 357 pr_err("Kernel command line too long\n"); 358 return ERR_PTR(-EINVAL); 359 } 360 361 /* 362 * In case of crash dump, we will append elfcorehdr=<addr> to 363 * command line. Make sure it does not overflow 364 */ 365 if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) { 366 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n"); 367 return ERR_PTR(-EINVAL); 368 } 369 370 /* Allocate and load backup region */ 371 if (image->type == KEXEC_TYPE_CRASH) { 372 ret = crash_load_segments(image); 373 if (ret) 374 return ERR_PTR(ret); 375 } 376 377 /* 378 * Load purgatory. For 64bit entry point, purgatory code can be 379 * anywhere. 380 */ 381 ret = kexec_load_purgatory(image, &pbuf); 382 if (ret) { 383 pr_err("Loading purgatory failed\n"); 384 return ERR_PTR(ret); 385 } 386 387 pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); 388 389 390 /* 391 * Load Bootparams and cmdline and space for efi stuff. 392 * 393 * Allocate memory together for multiple data structures so 394 * that they all can go in single area/segment and we don't 395 * have to create separate segment for each. Keeps things 396 * little bit simple 397 */ 398 efi_map_sz = efi_get_runtime_map_size(); 399 params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + 400 MAX_ELFCOREHDR_STR_LEN; 401 params_cmdline_sz = ALIGN(params_cmdline_sz, 16); 402 kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) + 403 sizeof(struct setup_data) + 404 sizeof(struct efi_setup_data); 405 406 params = kzalloc(kbuf.bufsz, GFP_KERNEL); 407 if (!params) 408 return ERR_PTR(-ENOMEM); 409 efi_map_offset = params_cmdline_sz; 410 efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16); 411 412 /* Copy setup header onto bootparams. Documentation/x86/boot.rst */ 413 setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset; 414 415 /* Is there a limit on setup header size? */ 416 memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size); 417 418 kbuf.buffer = params; 419 kbuf.memsz = kbuf.bufsz; 420 kbuf.buf_align = 16; 421 kbuf.buf_min = MIN_BOOTPARAM_ADDR; 422 ret = kexec_add_buffer(&kbuf); 423 if (ret) 424 goto out_free_params; 425 bootparam_load_addr = kbuf.mem; 426 pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 427 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz); 428 429 /* Load kernel */ 430 kbuf.buffer = kernel + kern16_size; 431 kbuf.bufsz = kernel_len - kern16_size; 432 kbuf.memsz = PAGE_ALIGN(header->init_size); 433 kbuf.buf_align = header->kernel_alignment; 434 kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; 435 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 436 ret = kexec_add_buffer(&kbuf); 437 if (ret) 438 goto out_free_params; 439 kernel_load_addr = kbuf.mem; 440 441 pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 442 kernel_load_addr, kbuf.bufsz, kbuf.memsz); 443 444 /* Load initrd high */ 445 if (initrd) { 446 kbuf.buffer = initrd; 447 kbuf.bufsz = kbuf.memsz = initrd_len; 448 kbuf.buf_align = PAGE_SIZE; 449 kbuf.buf_min = MIN_INITRD_LOAD_ADDR; 450 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 451 ret = kexec_add_buffer(&kbuf); 452 if (ret) 453 goto out_free_params; 454 initrd_load_addr = kbuf.mem; 455 456 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 457 initrd_load_addr, initrd_len, initrd_len); 458 459 setup_initrd(params, initrd_load_addr, initrd_len); 460 } 461 462 setup_cmdline(image, params, bootparam_load_addr, 463 sizeof(struct boot_params), cmdline, cmdline_len); 464 465 /* bootloader info. Do we need a separate ID for kexec kernel loader? */ 466 params->hdr.type_of_loader = 0x0D << 4; 467 params->hdr.loadflags = 0; 468 469 /* Setup purgatory regs for entry */ 470 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 471 sizeof(regs64), 1); 472 if (ret) 473 goto out_free_params; 474 475 regs64.rbx = 0; /* Bootstrap Processor */ 476 regs64.rsi = bootparam_load_addr; 477 regs64.rip = kernel_load_addr + 0x200; 478 stack = kexec_purgatory_get_symbol_addr(image, "stack_end"); 479 if (IS_ERR(stack)) { 480 pr_err("Could not find address of symbol stack_end\n"); 481 ret = -EINVAL; 482 goto out_free_params; 483 } 484 485 regs64.rsp = (unsigned long)stack; 486 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 487 sizeof(regs64), 0); 488 if (ret) 489 goto out_free_params; 490 491 ret = setup_boot_parameters(image, params, bootparam_load_addr, 492 efi_map_offset, efi_map_sz, 493 efi_setup_data_offset); 494 if (ret) 495 goto out_free_params; 496 497 /* Allocate loader specific data */ 498 ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL); 499 if (!ldata) { 500 ret = -ENOMEM; 501 goto out_free_params; 502 } 503 504 /* 505 * Store pointer to params so that it could be freed after loading 506 * params segment has been loaded and contents have been copied 507 * somewhere else. 508 */ 509 ldata->bootparams_buf = params; 510 return ldata; 511 512 out_free_params: 513 kfree(params); 514 return ERR_PTR(ret); 515 } 516 517 /* This cleanup function is called after various segments have been loaded */ 518 static int bzImage64_cleanup(void *loader_data) 519 { 520 struct bzimage64_data *ldata = loader_data; 521 522 if (!ldata) 523 return 0; 524 525 kfree(ldata->bootparams_buf); 526 ldata->bootparams_buf = NULL; 527 528 return 0; 529 } 530 531 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG 532 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) 533 { 534 int ret; 535 536 ret = verify_pefile_signature(kernel, kernel_len, 537 VERIFY_USE_SECONDARY_KEYRING, 538 VERIFYING_KEXEC_PE_SIGNATURE); 539 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { 540 ret = verify_pefile_signature(kernel, kernel_len, 541 VERIFY_USE_PLATFORM_KEYRING, 542 VERIFYING_KEXEC_PE_SIGNATURE); 543 } 544 return ret; 545 } 546 #endif 547 548 const struct kexec_file_ops kexec_bzImage64_ops = { 549 .probe = bzImage64_probe, 550 .load = bzImage64_load, 551 .cleanup = bzImage64_cleanup, 552 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG 553 .verify_sig = bzImage64_verify_sig, 554 #endif 555 }; 556