1 /* 2 * Kexec bzImage loader 3 * 4 * Copyright (C) 2014 Red Hat Inc. 5 * Authors: 6 * Vivek Goyal <vgoyal@redhat.com> 7 * 8 * This source code is licensed under the GNU General Public License, 9 * Version 2. See the file COPYING for more details. 10 */ 11 12 #define pr_fmt(fmt) "kexec-bzImage64: " fmt 13 14 #include <linux/string.h> 15 #include <linux/printk.h> 16 #include <linux/errno.h> 17 #include <linux/slab.h> 18 #include <linux/kexec.h> 19 #include <linux/kernel.h> 20 #include <linux/mm.h> 21 #include <linux/efi.h> 22 #include <linux/verification.h> 23 24 #include <asm/bootparam.h> 25 #include <asm/setup.h> 26 #include <asm/crash.h> 27 #include <asm/efi.h> 28 #include <asm/e820/api.h> 29 #include <asm/kexec-bzimage64.h> 30 31 #define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */ 32 33 /* 34 * Defines lowest physical address for various segments. Not sure where 35 * exactly these limits came from. Current bzimage64 loader in kexec-tools 36 * uses these so I am retaining it. It can be changed over time as we gain 37 * more insight. 38 */ 39 #define MIN_PURGATORY_ADDR 0x3000 40 #define MIN_BOOTPARAM_ADDR 0x3000 41 #define MIN_KERNEL_LOAD_ADDR 0x100000 42 #define MIN_INITRD_LOAD_ADDR 0x1000000 43 44 /* 45 * This is a place holder for all boot loader specific data structure which 46 * gets allocated in one call but gets freed much later during cleanup 47 * time. Right now there is only one field but it can grow as need be. 48 */ 49 struct bzimage64_data { 50 /* 51 * Temporary buffer to hold bootparams buffer. This should be 52 * freed once the bootparam segment has been loaded. 53 */ 54 void *bootparams_buf; 55 }; 56 57 static int setup_initrd(struct boot_params *params, 58 unsigned long initrd_load_addr, unsigned long initrd_len) 59 { 60 params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL; 61 params->hdr.ramdisk_size = initrd_len & 0xffffffffUL; 62 63 params->ext_ramdisk_image = initrd_load_addr >> 32; 64 params->ext_ramdisk_size = initrd_len >> 32; 65 66 return 0; 67 } 68 69 static int setup_cmdline(struct kimage *image, struct boot_params *params, 70 unsigned long bootparams_load_addr, 71 unsigned long cmdline_offset, char *cmdline, 72 unsigned long cmdline_len) 73 { 74 char *cmdline_ptr = ((char *)params) + cmdline_offset; 75 unsigned long cmdline_ptr_phys, len = 0; 76 uint32_t cmdline_low_32, cmdline_ext_32; 77 78 if (image->type == KEXEC_TYPE_CRASH) { 79 len = sprintf(cmdline_ptr, 80 "elfcorehdr=0x%lx ", image->arch.elf_load_addr); 81 } 82 memcpy(cmdline_ptr + len, cmdline, cmdline_len); 83 cmdline_len += len; 84 85 cmdline_ptr[cmdline_len - 1] = '\0'; 86 87 pr_debug("Final command line is: %s\n", cmdline_ptr); 88 cmdline_ptr_phys = bootparams_load_addr + cmdline_offset; 89 cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL; 90 cmdline_ext_32 = cmdline_ptr_phys >> 32; 91 92 params->hdr.cmd_line_ptr = cmdline_low_32; 93 if (cmdline_ext_32) 94 params->ext_cmd_line_ptr = cmdline_ext_32; 95 96 return 0; 97 } 98 99 static int setup_e820_entries(struct boot_params *params) 100 { 101 unsigned int nr_e820_entries; 102 103 nr_e820_entries = e820_table_kexec->nr_entries; 104 105 /* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */ 106 if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE) 107 nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE; 108 109 params->e820_entries = nr_e820_entries; 110 memcpy(¶ms->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry)); 111 112 return 0; 113 } 114 115 #ifdef CONFIG_EFI 116 static int setup_efi_info_memmap(struct boot_params *params, 117 unsigned long params_load_addr, 118 unsigned int efi_map_offset, 119 unsigned int efi_map_sz) 120 { 121 void *efi_map = (void *)params + efi_map_offset; 122 unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset; 123 struct efi_info *ei = ¶ms->efi_info; 124 125 if (!efi_map_sz) 126 return 0; 127 128 efi_runtime_map_copy(efi_map, efi_map_sz); 129 130 ei->efi_memmap = efi_map_phys_addr & 0xffffffff; 131 ei->efi_memmap_hi = efi_map_phys_addr >> 32; 132 ei->efi_memmap_size = efi_map_sz; 133 134 return 0; 135 } 136 137 static int 138 prepare_add_efi_setup_data(struct boot_params *params, 139 unsigned long params_load_addr, 140 unsigned int efi_setup_data_offset) 141 { 142 unsigned long setup_data_phys; 143 struct setup_data *sd = (void *)params + efi_setup_data_offset; 144 struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data); 145 146 esd->fw_vendor = efi.fw_vendor; 147 esd->runtime = efi.runtime; 148 esd->tables = efi.config_table; 149 esd->smbios = efi.smbios; 150 151 sd->type = SETUP_EFI; 152 sd->len = sizeof(struct efi_setup_data); 153 154 /* Add setup data */ 155 setup_data_phys = params_load_addr + efi_setup_data_offset; 156 sd->next = params->hdr.setup_data; 157 params->hdr.setup_data = setup_data_phys; 158 159 return 0; 160 } 161 162 static int 163 setup_efi_state(struct boot_params *params, unsigned long params_load_addr, 164 unsigned int efi_map_offset, unsigned int efi_map_sz, 165 unsigned int efi_setup_data_offset) 166 { 167 struct efi_info *current_ei = &boot_params.efi_info; 168 struct efi_info *ei = ¶ms->efi_info; 169 170 if (!efi_enabled(EFI_RUNTIME_SERVICES)) 171 return 0; 172 173 if (!current_ei->efi_memmap_size) 174 return 0; 175 176 /* 177 * If 1:1 mapping is not enabled, second kernel can not setup EFI 178 * and use EFI run time services. User space will have to pass 179 * acpi_rsdp=<addr> on kernel command line to make second kernel boot 180 * without efi. 181 */ 182 if (efi_enabled(EFI_OLD_MEMMAP)) 183 return 0; 184 185 ei->efi_loader_signature = current_ei->efi_loader_signature; 186 ei->efi_systab = current_ei->efi_systab; 187 ei->efi_systab_hi = current_ei->efi_systab_hi; 188 189 ei->efi_memdesc_version = current_ei->efi_memdesc_version; 190 ei->efi_memdesc_size = efi_get_runtime_map_desc_size(); 191 192 setup_efi_info_memmap(params, params_load_addr, efi_map_offset, 193 efi_map_sz); 194 prepare_add_efi_setup_data(params, params_load_addr, 195 efi_setup_data_offset); 196 return 0; 197 } 198 #endif /* CONFIG_EFI */ 199 200 static int 201 setup_boot_parameters(struct kimage *image, struct boot_params *params, 202 unsigned long params_load_addr, 203 unsigned int efi_map_offset, unsigned int efi_map_sz, 204 unsigned int efi_setup_data_offset) 205 { 206 unsigned int nr_e820_entries; 207 unsigned long long mem_k, start, end; 208 int i, ret = 0; 209 210 /* Get subarch from existing bootparams */ 211 params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; 212 213 /* Copying screen_info will do? */ 214 memcpy(¶ms->screen_info, &boot_params.screen_info, 215 sizeof(struct screen_info)); 216 217 /* Fill in memsize later */ 218 params->screen_info.ext_mem_k = 0; 219 params->alt_mem_k = 0; 220 221 /* Always fill in RSDP: it is either 0 or a valid value */ 222 params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr; 223 224 /* Default APM info */ 225 memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info)); 226 227 /* Default drive info */ 228 memset(¶ms->hd0_info, 0, sizeof(params->hd0_info)); 229 memset(¶ms->hd1_info, 0, sizeof(params->hd1_info)); 230 231 if (image->type == KEXEC_TYPE_CRASH) { 232 ret = crash_setup_memmap_entries(image, params); 233 if (ret) 234 return ret; 235 } else 236 setup_e820_entries(params); 237 238 nr_e820_entries = params->e820_entries; 239 240 for (i = 0; i < nr_e820_entries; i++) { 241 if (params->e820_table[i].type != E820_TYPE_RAM) 242 continue; 243 start = params->e820_table[i].addr; 244 end = params->e820_table[i].addr + params->e820_table[i].size - 1; 245 246 if ((start <= 0x100000) && end > 0x100000) { 247 mem_k = (end >> 10) - (0x100000 >> 10); 248 params->screen_info.ext_mem_k = mem_k; 249 params->alt_mem_k = mem_k; 250 if (mem_k > 0xfc00) 251 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/ 252 if (mem_k > 0xffffffff) 253 params->alt_mem_k = 0xffffffff; 254 } 255 } 256 257 #ifdef CONFIG_EFI 258 /* Setup EFI state */ 259 setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, 260 efi_setup_data_offset); 261 #endif 262 /* Setup EDD info */ 263 memcpy(params->eddbuf, boot_params.eddbuf, 264 EDDMAXNR * sizeof(struct edd_info)); 265 params->eddbuf_entries = boot_params.eddbuf_entries; 266 267 memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer, 268 EDD_MBR_SIG_MAX * sizeof(unsigned int)); 269 270 return ret; 271 } 272 273 static int bzImage64_probe(const char *buf, unsigned long len) 274 { 275 int ret = -ENOEXEC; 276 struct setup_header *header; 277 278 /* kernel should be at least two sectors long */ 279 if (len < 2 * 512) { 280 pr_err("File is too short to be a bzImage\n"); 281 return ret; 282 } 283 284 header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr)); 285 if (memcmp((char *)&header->header, "HdrS", 4) != 0) { 286 pr_err("Not a bzImage\n"); 287 return ret; 288 } 289 290 if (header->boot_flag != 0xAA55) { 291 pr_err("No x86 boot sector present\n"); 292 return ret; 293 } 294 295 if (header->version < 0x020C) { 296 pr_err("Must be at least protocol version 2.12\n"); 297 return ret; 298 } 299 300 if (!(header->loadflags & LOADED_HIGH)) { 301 pr_err("zImage not a bzImage\n"); 302 return ret; 303 } 304 305 if (!(header->xloadflags & XLF_KERNEL_64)) { 306 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n"); 307 return ret; 308 } 309 310 if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) { 311 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n"); 312 return ret; 313 } 314 315 /* 316 * Can't handle 32bit EFI as it does not allow loading kernel 317 * above 4G. This should be handled by 32bit bzImage loader 318 */ 319 if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) { 320 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n"); 321 return ret; 322 } 323 324 /* I've got a bzImage */ 325 pr_debug("It's a relocatable bzImage64\n"); 326 ret = 0; 327 328 return ret; 329 } 330 331 static void *bzImage64_load(struct kimage *image, char *kernel, 332 unsigned long kernel_len, char *initrd, 333 unsigned long initrd_len, char *cmdline, 334 unsigned long cmdline_len) 335 { 336 337 struct setup_header *header; 338 int setup_sects, kern16_size, ret = 0; 339 unsigned long setup_header_size, params_cmdline_sz; 340 struct boot_params *params; 341 unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; 342 struct bzimage64_data *ldata; 343 struct kexec_entry64_regs regs64; 344 void *stack; 345 unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr); 346 unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; 347 struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, 348 .top_down = true }; 349 struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR, 350 .buf_max = ULONG_MAX, .top_down = true }; 351 352 header = (struct setup_header *)(kernel + setup_hdr_offset); 353 setup_sects = header->setup_sects; 354 if (setup_sects == 0) 355 setup_sects = 4; 356 357 kern16_size = (setup_sects + 1) * 512; 358 if (kernel_len < kern16_size) { 359 pr_err("bzImage truncated\n"); 360 return ERR_PTR(-ENOEXEC); 361 } 362 363 if (cmdline_len > header->cmdline_size) { 364 pr_err("Kernel command line too long\n"); 365 return ERR_PTR(-EINVAL); 366 } 367 368 /* 369 * In case of crash dump, we will append elfcorehdr=<addr> to 370 * command line. Make sure it does not overflow 371 */ 372 if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) { 373 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n"); 374 return ERR_PTR(-EINVAL); 375 } 376 377 /* Allocate and load backup region */ 378 if (image->type == KEXEC_TYPE_CRASH) { 379 ret = crash_load_segments(image); 380 if (ret) 381 return ERR_PTR(ret); 382 } 383 384 /* 385 * Load purgatory. For 64bit entry point, purgatory code can be 386 * anywhere. 387 */ 388 ret = kexec_load_purgatory(image, &pbuf); 389 if (ret) { 390 pr_err("Loading purgatory failed\n"); 391 return ERR_PTR(ret); 392 } 393 394 pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); 395 396 397 /* 398 * Load Bootparams and cmdline and space for efi stuff. 399 * 400 * Allocate memory together for multiple data structures so 401 * that they all can go in single area/segment and we don't 402 * have to create separate segment for each. Keeps things 403 * little bit simple 404 */ 405 efi_map_sz = efi_get_runtime_map_size(); 406 params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + 407 MAX_ELFCOREHDR_STR_LEN; 408 params_cmdline_sz = ALIGN(params_cmdline_sz, 16); 409 kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) + 410 sizeof(struct setup_data) + 411 sizeof(struct efi_setup_data); 412 413 params = kzalloc(kbuf.bufsz, GFP_KERNEL); 414 if (!params) 415 return ERR_PTR(-ENOMEM); 416 efi_map_offset = params_cmdline_sz; 417 efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16); 418 419 /* Copy setup header onto bootparams. Documentation/x86/boot.txt */ 420 setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset; 421 422 /* Is there a limit on setup header size? */ 423 memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size); 424 425 kbuf.buffer = params; 426 kbuf.memsz = kbuf.bufsz; 427 kbuf.buf_align = 16; 428 kbuf.buf_min = MIN_BOOTPARAM_ADDR; 429 ret = kexec_add_buffer(&kbuf); 430 if (ret) 431 goto out_free_params; 432 bootparam_load_addr = kbuf.mem; 433 pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 434 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz); 435 436 /* Load kernel */ 437 kbuf.buffer = kernel + kern16_size; 438 kbuf.bufsz = kernel_len - kern16_size; 439 kbuf.memsz = PAGE_ALIGN(header->init_size); 440 kbuf.buf_align = header->kernel_alignment; 441 kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; 442 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 443 ret = kexec_add_buffer(&kbuf); 444 if (ret) 445 goto out_free_params; 446 kernel_load_addr = kbuf.mem; 447 448 pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 449 kernel_load_addr, kbuf.bufsz, kbuf.memsz); 450 451 /* Load initrd high */ 452 if (initrd) { 453 kbuf.buffer = initrd; 454 kbuf.bufsz = kbuf.memsz = initrd_len; 455 kbuf.buf_align = PAGE_SIZE; 456 kbuf.buf_min = MIN_INITRD_LOAD_ADDR; 457 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 458 ret = kexec_add_buffer(&kbuf); 459 if (ret) 460 goto out_free_params; 461 initrd_load_addr = kbuf.mem; 462 463 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 464 initrd_load_addr, initrd_len, initrd_len); 465 466 setup_initrd(params, initrd_load_addr, initrd_len); 467 } 468 469 setup_cmdline(image, params, bootparam_load_addr, 470 sizeof(struct boot_params), cmdline, cmdline_len); 471 472 /* bootloader info. Do we need a separate ID for kexec kernel loader? */ 473 params->hdr.type_of_loader = 0x0D << 4; 474 params->hdr.loadflags = 0; 475 476 /* Setup purgatory regs for entry */ 477 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 478 sizeof(regs64), 1); 479 if (ret) 480 goto out_free_params; 481 482 regs64.rbx = 0; /* Bootstrap Processor */ 483 regs64.rsi = bootparam_load_addr; 484 regs64.rip = kernel_load_addr + 0x200; 485 stack = kexec_purgatory_get_symbol_addr(image, "stack_end"); 486 if (IS_ERR(stack)) { 487 pr_err("Could not find address of symbol stack_end\n"); 488 ret = -EINVAL; 489 goto out_free_params; 490 } 491 492 regs64.rsp = (unsigned long)stack; 493 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 494 sizeof(regs64), 0); 495 if (ret) 496 goto out_free_params; 497 498 ret = setup_boot_parameters(image, params, bootparam_load_addr, 499 efi_map_offset, efi_map_sz, 500 efi_setup_data_offset); 501 if (ret) 502 goto out_free_params; 503 504 /* Allocate loader specific data */ 505 ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL); 506 if (!ldata) { 507 ret = -ENOMEM; 508 goto out_free_params; 509 } 510 511 /* 512 * Store pointer to params so that it could be freed after loading 513 * params segment has been loaded and contents have been copied 514 * somewhere else. 515 */ 516 ldata->bootparams_buf = params; 517 return ldata; 518 519 out_free_params: 520 kfree(params); 521 return ERR_PTR(ret); 522 } 523 524 /* This cleanup function is called after various segments have been loaded */ 525 static int bzImage64_cleanup(void *loader_data) 526 { 527 struct bzimage64_data *ldata = loader_data; 528 529 if (!ldata) 530 return 0; 531 532 kfree(ldata->bootparams_buf); 533 ldata->bootparams_buf = NULL; 534 535 return 0; 536 } 537 538 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG 539 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) 540 { 541 int ret; 542 543 ret = verify_pefile_signature(kernel, kernel_len, 544 VERIFY_USE_SECONDARY_KEYRING, 545 VERIFYING_KEXEC_PE_SIGNATURE); 546 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { 547 ret = verify_pefile_signature(kernel, kernel_len, 548 VERIFY_USE_PLATFORM_KEYRING, 549 VERIFYING_KEXEC_PE_SIGNATURE); 550 } 551 return ret; 552 } 553 #endif 554 555 const struct kexec_file_ops kexec_bzImage64_ops = { 556 .probe = bzImage64_probe, 557 .load = bzImage64_load, 558 .cleanup = bzImage64_cleanup, 559 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG 560 .verify_sig = bzImage64_verify_sig, 561 #endif 562 }; 563