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/random.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 */ 47struct 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 55static 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 67static 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->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 kexec_dprintk("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 97static 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 113enum { RNG_SEED_LENGTH = 32 }; 114 115static void 116setup_rng_seed(struct boot_params *params, unsigned long params_load_addr, 117 unsigned int rng_seed_setup_data_offset) 118{ 119 struct setup_data *sd = (void *)params + rng_seed_setup_data_offset; 120 unsigned long setup_data_phys; 121 122 if (!rng_is_initialized()) 123 return; 124 125 sd->type = SETUP_RNG_SEED; 126 sd->len = RNG_SEED_LENGTH; 127 get_random_bytes(sd->data, RNG_SEED_LENGTH); 128 setup_data_phys = params_load_addr + rng_seed_setup_data_offset; 129 sd->next = params->hdr.setup_data; 130 params->hdr.setup_data = setup_data_phys; 131} 132 133#ifdef CONFIG_EFI 134static int setup_efi_info_memmap(struct boot_params *params, 135 unsigned long params_load_addr, 136 unsigned int efi_map_offset, 137 unsigned int efi_map_sz) 138{ 139 void *efi_map = (void *)params + efi_map_offset; 140 unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset; 141 struct efi_info *ei = ¶ms->efi_info; 142 143 if (!efi_map_sz) 144 return 0; 145 146 efi_runtime_map_copy(efi_map, efi_map_sz); 147 148 ei->efi_memmap = efi_map_phys_addr & 0xffffffff; 149 ei->efi_memmap_hi = efi_map_phys_addr >> 32; 150 ei->efi_memmap_size = efi_map_sz; 151 152 return 0; 153} 154 155static int 156prepare_add_efi_setup_data(struct boot_params *params, 157 unsigned long params_load_addr, 158 unsigned int efi_setup_data_offset) 159{ 160 unsigned long setup_data_phys; 161 struct setup_data *sd = (void *)params + efi_setup_data_offset; 162 struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data); 163 164 esd->fw_vendor = efi_fw_vendor; 165 esd->tables = efi_config_table; 166 esd->smbios = efi.smbios; 167 168 sd->type = SETUP_EFI; 169 sd->len = sizeof(struct efi_setup_data); 170 171 /* Add setup data */ 172 setup_data_phys = params_load_addr + efi_setup_data_offset; 173 sd->next = params->hdr.setup_data; 174 params->hdr.setup_data = setup_data_phys; 175 176 return 0; 177} 178 179static int 180setup_efi_state(struct boot_params *params, unsigned long params_load_addr, 181 unsigned int efi_map_offset, unsigned int efi_map_sz, 182 unsigned int efi_setup_data_offset) 183{ 184 struct efi_info *current_ei = &boot_params.efi_info; 185 struct efi_info *ei = ¶ms->efi_info; 186 187 if (!efi_enabled(EFI_RUNTIME_SERVICES)) 188 return 0; 189 190 if (!current_ei->efi_memmap_size) 191 return 0; 192 193 params->secure_boot = boot_params.secure_boot; 194 ei->efi_loader_signature = current_ei->efi_loader_signature; 195 ei->efi_systab = current_ei->efi_systab; 196 ei->efi_systab_hi = current_ei->efi_systab_hi; 197 198 ei->efi_memdesc_version = current_ei->efi_memdesc_version; 199 ei->efi_memdesc_size = efi_get_runtime_map_desc_size(); 200 201 setup_efi_info_memmap(params, params_load_addr, efi_map_offset, 202 efi_map_sz); 203 prepare_add_efi_setup_data(params, params_load_addr, 204 efi_setup_data_offset); 205 return 0; 206} 207#endif /* CONFIG_EFI */ 208 209static void 210setup_ima_state(const struct kimage *image, struct boot_params *params, 211 unsigned long params_load_addr, 212 unsigned int ima_setup_data_offset) 213{ 214#ifdef CONFIG_IMA_KEXEC 215 struct setup_data *sd = (void *)params + ima_setup_data_offset; 216 unsigned long setup_data_phys; 217 struct ima_setup_data *ima; 218 219 if (!image->ima_buffer_size) 220 return; 221 222 sd->type = SETUP_IMA; 223 sd->len = sizeof(*ima); 224 225 ima = (void *)sd + sizeof(struct setup_data); 226 ima->addr = image->ima_buffer_addr; 227 ima->size = image->ima_buffer_size; 228 229 /* Add setup data */ 230 setup_data_phys = params_load_addr + ima_setup_data_offset; 231 sd->next = params->hdr.setup_data; 232 params->hdr.setup_data = setup_data_phys; 233#endif /* CONFIG_IMA_KEXEC */ 234} 235 236static int 237setup_boot_parameters(struct kimage *image, struct boot_params *params, 238 unsigned long params_load_addr, 239 unsigned int efi_map_offset, unsigned int efi_map_sz, 240 unsigned int setup_data_offset) 241{ 242 unsigned int nr_e820_entries; 243 unsigned long long mem_k, start, end; 244 int i, ret = 0; 245 246 /* Get subarch from existing bootparams */ 247 params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; 248 249 /* Copying screen_info will do? */ 250 memcpy(¶ms->screen_info, &screen_info, sizeof(struct screen_info)); 251 252 /* Fill in memsize later */ 253 params->screen_info.ext_mem_k = 0; 254 params->alt_mem_k = 0; 255 256 /* Always fill in RSDP: it is either 0 or a valid value */ 257 params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr; 258 259 /* Default APM info */ 260 memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info)); 261 262 /* Default drive info */ 263 memset(¶ms->hd0_info, 0, sizeof(params->hd0_info)); 264 memset(¶ms->hd1_info, 0, sizeof(params->hd1_info)); 265 266#ifdef CONFIG_CRASH_DUMP 267 if (image->type == KEXEC_TYPE_CRASH) { 268 ret = crash_setup_memmap_entries(image, params); 269 if (ret) 270 return ret; 271 } else 272#endif 273 setup_e820_entries(params); 274 275 nr_e820_entries = params->e820_entries; 276 277 kexec_dprintk("E820 memmap:\n"); 278 for (i = 0; i < nr_e820_entries; i++) { 279 kexec_dprintk("%016llx-%016llx (%d)\n", 280 params->e820_table[i].addr, 281 params->e820_table[i].addr + params->e820_table[i].size - 1, 282 params->e820_table[i].type); 283 if (params->e820_table[i].type != E820_TYPE_RAM) 284 continue; 285 start = params->e820_table[i].addr; 286 end = params->e820_table[i].addr + params->e820_table[i].size - 1; 287 288 if ((start <= 0x100000) && end > 0x100000) { 289 mem_k = (end >> 10) - (0x100000 >> 10); 290 params->screen_info.ext_mem_k = mem_k; 291 params->alt_mem_k = mem_k; 292 if (mem_k > 0xfc00) 293 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/ 294 if (mem_k > 0xffffffff) 295 params->alt_mem_k = 0xffffffff; 296 } 297 } 298 299#ifdef CONFIG_EFI 300 /* Setup EFI state */ 301 setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, 302 setup_data_offset); 303 setup_data_offset += sizeof(struct setup_data) + 304 sizeof(struct efi_setup_data); 305#endif 306 307 if (IS_ENABLED(CONFIG_IMA_KEXEC)) { 308 /* Setup IMA log buffer state */ 309 setup_ima_state(image, params, params_load_addr, 310 setup_data_offset); 311 setup_data_offset += sizeof(struct setup_data) + 312 sizeof(struct ima_setup_data); 313 } 314 315 /* Setup RNG seed */ 316 setup_rng_seed(params, params_load_addr, setup_data_offset); 317 318 /* Setup EDD info */ 319 memcpy(params->eddbuf, boot_params.eddbuf, 320 EDDMAXNR * sizeof(struct edd_info)); 321 params->eddbuf_entries = boot_params.eddbuf_entries; 322 323 memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer, 324 EDD_MBR_SIG_MAX * sizeof(unsigned int)); 325 326 return ret; 327} 328 329static int bzImage64_probe(const char *buf, unsigned long len) 330{ 331 int ret = -ENOEXEC; 332 struct setup_header *header; 333 334 /* kernel should be at least two sectors long */ 335 if (len < 2 * 512) { 336 pr_err("File is too short to be a bzImage\n"); 337 return ret; 338 } 339 340 header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr)); 341 if (memcmp((char *)&header->header, "HdrS", 4) != 0) { 342 pr_err("Not a bzImage\n"); 343 return ret; 344 } 345 346 if (header->boot_flag != 0xAA55) { 347 pr_err("No x86 boot sector present\n"); 348 return ret; 349 } 350 351 if (header->version < 0x020C) { 352 pr_err("Must be at least protocol version 2.12\n"); 353 return ret; 354 } 355 356 if (!(header->loadflags & LOADED_HIGH)) { 357 pr_err("zImage not a bzImage\n"); 358 return ret; 359 } 360 361 if (!(header->xloadflags & XLF_KERNEL_64)) { 362 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n"); 363 return ret; 364 } 365 366 if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) { 367 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n"); 368 return ret; 369 } 370 371 /* 372 * Can't handle 32bit EFI as it does not allow loading kernel 373 * above 4G. This should be handled by 32bit bzImage loader 374 */ 375 if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) { 376 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n"); 377 return ret; 378 } 379 380 if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) { 381 pr_err("bzImage cannot handle 5-level paging mode.\n"); 382 return ret; 383 } 384 385 /* I've got a bzImage */ 386 pr_debug("It's a relocatable bzImage64\n"); 387 ret = 0; 388 389 return ret; 390} 391 392static void *bzImage64_load(struct kimage *image, char *kernel, 393 unsigned long kernel_len, char *initrd, 394 unsigned long initrd_len, char *cmdline, 395 unsigned long cmdline_len) 396{ 397 398 struct setup_header *header; 399 int setup_sects, kern16_size, ret = 0; 400 unsigned long setup_header_size, params_cmdline_sz; 401 struct boot_params *params; 402 unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; 403 struct bzimage64_data *ldata; 404 struct kexec_entry64_regs regs64; 405 void *stack; 406 unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr); 407 unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; 408 struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, 409 .top_down = true }; 410 struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR, 411 .buf_max = ULONG_MAX, .top_down = true }; 412 413 header = (struct setup_header *)(kernel + setup_hdr_offset); 414 setup_sects = header->setup_sects; 415 if (setup_sects == 0) 416 setup_sects = 4; 417 418 kern16_size = (setup_sects + 1) * 512; 419 if (kernel_len < kern16_size) { 420 pr_err("bzImage truncated\n"); 421 return ERR_PTR(-ENOEXEC); 422 } 423 424 if (cmdline_len > header->cmdline_size) { 425 pr_err("Kernel command line too long\n"); 426 return ERR_PTR(-EINVAL); 427 } 428 429 /* 430 * In case of crash dump, we will append elfcorehdr=<addr> to 431 * command line. Make sure it does not overflow 432 */ 433 if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) { 434 pr_err("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n"); 435 return ERR_PTR(-EINVAL); 436 } 437 438#ifdef CONFIG_CRASH_DUMP 439 /* Allocate and load backup region */ 440 if (image->type == KEXEC_TYPE_CRASH) { 441 ret = crash_load_segments(image); 442 if (ret) 443 return ERR_PTR(ret); 444 } 445#endif 446 447 /* 448 * Load purgatory. For 64bit entry point, purgatory code can be 449 * anywhere. 450 */ 451 ret = kexec_load_purgatory(image, &pbuf); 452 if (ret) { 453 pr_err("Loading purgatory failed\n"); 454 return ERR_PTR(ret); 455 } 456 457 kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem); 458 459 460 /* 461 * Load Bootparams and cmdline and space for efi stuff. 462 * 463 * Allocate memory together for multiple data structures so 464 * that they all can go in single area/segment and we don't 465 * have to create separate segment for each. Keeps things 466 * little bit simple 467 */ 468 efi_map_sz = efi_get_runtime_map_size(); 469 params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + 470 MAX_ELFCOREHDR_STR_LEN; 471 params_cmdline_sz = ALIGN(params_cmdline_sz, 16); 472 kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) + 473 sizeof(struct setup_data) + 474 sizeof(struct efi_setup_data) + 475 sizeof(struct setup_data) + 476 RNG_SEED_LENGTH; 477 478 if (IS_ENABLED(CONFIG_IMA_KEXEC)) 479 kbuf.bufsz += sizeof(struct setup_data) + 480 sizeof(struct ima_setup_data); 481 482 params = kzalloc(kbuf.bufsz, GFP_KERNEL); 483 if (!params) 484 return ERR_PTR(-ENOMEM); 485 efi_map_offset = params_cmdline_sz; 486 efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16); 487 488 /* Copy setup header onto bootparams. Documentation/arch/x86/boot.rst */ 489 setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset; 490 491 /* Is there a limit on setup header size? */ 492 memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size); 493 494 kbuf.buffer = params; 495 kbuf.memsz = kbuf.bufsz; 496 kbuf.buf_align = 16; 497 kbuf.buf_min = MIN_BOOTPARAM_ADDR; 498 ret = kexec_add_buffer(&kbuf); 499 if (ret) 500 goto out_free_params; 501 bootparam_load_addr = kbuf.mem; 502 kexec_dprintk("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 503 bootparam_load_addr, kbuf.bufsz, kbuf.memsz); 504 505 /* Load kernel */ 506 kbuf.buffer = kernel + kern16_size; 507 kbuf.bufsz = kernel_len - kern16_size; 508 kbuf.memsz = PAGE_ALIGN(header->init_size); 509 kbuf.buf_align = header->kernel_alignment; 510 if (header->pref_address < MIN_KERNEL_LOAD_ADDR) 511 kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; 512 else 513 kbuf.buf_min = header->pref_address; 514 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 515 ret = kexec_add_buffer(&kbuf); 516 if (ret) 517 goto out_free_params; 518 kernel_load_addr = kbuf.mem; 519 520 kexec_dprintk("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 521 kernel_load_addr, kbuf.bufsz, kbuf.memsz); 522 523 /* Load initrd high */ 524 if (initrd) { 525 kbuf.buffer = initrd; 526 kbuf.bufsz = kbuf.memsz = initrd_len; 527 kbuf.buf_align = PAGE_SIZE; 528 kbuf.buf_min = MIN_INITRD_LOAD_ADDR; 529 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; 530 ret = kexec_add_buffer(&kbuf); 531 if (ret) 532 goto out_free_params; 533 initrd_load_addr = kbuf.mem; 534 535 kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", 536 initrd_load_addr, initrd_len, initrd_len); 537 538 setup_initrd(params, initrd_load_addr, initrd_len); 539 } 540 541 setup_cmdline(image, params, bootparam_load_addr, 542 sizeof(struct boot_params), cmdline, cmdline_len); 543 544 /* bootloader info. Do we need a separate ID for kexec kernel loader? */ 545 params->hdr.type_of_loader = 0x0D << 4; 546 params->hdr.loadflags = 0; 547 548 /* Setup purgatory regs for entry */ 549 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 550 sizeof(regs64), 1); 551 if (ret) 552 goto out_free_params; 553 554 regs64.rbx = 0; /* Bootstrap Processor */ 555 regs64.rsi = bootparam_load_addr; 556 regs64.rip = kernel_load_addr + 0x200; 557 stack = kexec_purgatory_get_symbol_addr(image, "stack_end"); 558 if (IS_ERR(stack)) { 559 pr_err("Could not find address of symbol stack_end\n"); 560 ret = -EINVAL; 561 goto out_free_params; 562 } 563 564 regs64.rsp = (unsigned long)stack; 565 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64, 566 sizeof(regs64), 0); 567 if (ret) 568 goto out_free_params; 569 570 ret = setup_boot_parameters(image, params, bootparam_load_addr, 571 efi_map_offset, efi_map_sz, 572 efi_setup_data_offset); 573 if (ret) 574 goto out_free_params; 575 576 /* Allocate loader specific data */ 577 ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL); 578 if (!ldata) { 579 ret = -ENOMEM; 580 goto out_free_params; 581 } 582 583 /* 584 * Store pointer to params so that it could be freed after loading 585 * params segment has been loaded and contents have been copied 586 * somewhere else. 587 */ 588 ldata->bootparams_buf = params; 589 return ldata; 590 591out_free_params: 592 kfree(params); 593 return ERR_PTR(ret); 594} 595 596/* This cleanup function is called after various segments have been loaded */ 597static int bzImage64_cleanup(void *loader_data) 598{ 599 struct bzimage64_data *ldata = loader_data; 600 601 if (!ldata) 602 return 0; 603 604 kfree(ldata->bootparams_buf); 605 ldata->bootparams_buf = NULL; 606 607 return 0; 608} 609 610const struct kexec_file_ops kexec_bzImage64_ops = { 611 .probe = bzImage64_probe, 612 .load = bzImage64_load, 613 .cleanup = bzImage64_cleanup, 614#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG 615 .verify_sig = kexec_kernel_verify_pe_sig, 616#endif 617}; 618