1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/init/main.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * GK 2/5/95 - Changed to support mounting root fs via NFS 8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 10 * Simplified starting of init: Michael A. Griffith <grif@acm.org> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/extable.h> 17 #include <linux/module.h> 18 #include <linux/proc_fs.h> 19 #include <linux/binfmts.h> 20 #include <linux/kernel.h> 21 #include <linux/syscalls.h> 22 #include <linux/stackprotector.h> 23 #include <linux/string.h> 24 #include <linux/ctype.h> 25 #include <linux/delay.h> 26 #include <linux/ioport.h> 27 #include <linux/init.h> 28 #include <linux/initrd.h> 29 #include <linux/memblock.h> 30 #include <linux/acpi.h> 31 #include <linux/bootconfig.h> 32 #include <linux/console.h> 33 #include <linux/nmi.h> 34 #include <linux/percpu.h> 35 #include <linux/kmod.h> 36 #include <linux/vmalloc.h> 37 #include <linux/kernel_stat.h> 38 #include <linux/start_kernel.h> 39 #include <linux/security.h> 40 #include <linux/smp.h> 41 #include <linux/profile.h> 42 #include <linux/rcupdate.h> 43 #include <linux/moduleparam.h> 44 #include <linux/kallsyms.h> 45 #include <linux/writeback.h> 46 #include <linux/cpu.h> 47 #include <linux/cpuset.h> 48 #include <linux/cgroup.h> 49 #include <linux/efi.h> 50 #include <linux/tick.h> 51 #include <linux/sched/isolation.h> 52 #include <linux/interrupt.h> 53 #include <linux/taskstats_kern.h> 54 #include <linux/delayacct.h> 55 #include <linux/unistd.h> 56 #include <linux/utsname.h> 57 #include <linux/rmap.h> 58 #include <linux/mempolicy.h> 59 #include <linux/key.h> 60 #include <linux/buffer_head.h> 61 #include <linux/page_ext.h> 62 #include <linux/debug_locks.h> 63 #include <linux/debugobjects.h> 64 #include <linux/lockdep.h> 65 #include <linux/kmemleak.h> 66 #include <linux/pid_namespace.h> 67 #include <linux/device.h> 68 #include <linux/kthread.h> 69 #include <linux/sched.h> 70 #include <linux/sched/init.h> 71 #include <linux/signal.h> 72 #include <linux/idr.h> 73 #include <linux/kgdb.h> 74 #include <linux/ftrace.h> 75 #include <linux/async.h> 76 #include <linux/sfi.h> 77 #include <linux/shmem_fs.h> 78 #include <linux/slab.h> 79 #include <linux/perf_event.h> 80 #include <linux/ptrace.h> 81 #include <linux/pti.h> 82 #include <linux/blkdev.h> 83 #include <linux/elevator.h> 84 #include <linux/sched/clock.h> 85 #include <linux/sched/task.h> 86 #include <linux/sched/task_stack.h> 87 #include <linux/context_tracking.h> 88 #include <linux/random.h> 89 #include <linux/list.h> 90 #include <linux/integrity.h> 91 #include <linux/proc_ns.h> 92 #include <linux/io.h> 93 #include <linux/cache.h> 94 #include <linux/rodata_test.h> 95 #include <linux/jump_label.h> 96 #include <linux/mem_encrypt.h> 97 98 #include <asm/io.h> 99 #include <asm/bugs.h> 100 #include <asm/setup.h> 101 #include <asm/sections.h> 102 #include <asm/cacheflush.h> 103 104 #define CREATE_TRACE_POINTS 105 #include <trace/events/initcall.h> 106 107 static int kernel_init(void *); 108 109 extern void init_IRQ(void); 110 extern void radix_tree_init(void); 111 112 /* 113 * Debug helper: via this flag we know that we are in 'early bootup code' 114 * where only the boot processor is running with IRQ disabled. This means 115 * two things - IRQ must not be enabled before the flag is cleared and some 116 * operations which are not allowed with IRQ disabled are allowed while the 117 * flag is set. 118 */ 119 bool early_boot_irqs_disabled __read_mostly; 120 121 enum system_states system_state __read_mostly; 122 EXPORT_SYMBOL(system_state); 123 124 /* 125 * Boot command-line arguments 126 */ 127 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 128 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 129 130 extern void time_init(void); 131 /* Default late time init is NULL. archs can override this later. */ 132 void (*__initdata late_time_init)(void); 133 134 /* Untouched command line saved by arch-specific code. */ 135 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 136 /* Untouched saved command line (eg. for /proc) */ 137 char *saved_command_line; 138 /* Command line for parameter parsing */ 139 static char *static_command_line; 140 /* Untouched extra command line */ 141 static char *extra_command_line; 142 /* Extra init arguments */ 143 static char *extra_init_args; 144 145 #ifdef CONFIG_BOOT_CONFIG 146 /* Is bootconfig on command line? */ 147 static bool bootconfig_found; 148 static bool initargs_found; 149 #else 150 # define bootconfig_found false 151 # define initargs_found false 152 #endif 153 154 static char *execute_command; 155 static char *ramdisk_execute_command; 156 157 /* 158 * Used to generate warnings if static_key manipulation functions are used 159 * before jump_label_init is called. 160 */ 161 bool static_key_initialized __read_mostly; 162 EXPORT_SYMBOL_GPL(static_key_initialized); 163 164 /* 165 * If set, this is an indication to the drivers that reset the underlying 166 * device before going ahead with the initialization otherwise driver might 167 * rely on the BIOS and skip the reset operation. 168 * 169 * This is useful if kernel is booting in an unreliable environment. 170 * For ex. kdump situation where previous kernel has crashed, BIOS has been 171 * skipped and devices will be in unknown state. 172 */ 173 unsigned int reset_devices; 174 EXPORT_SYMBOL(reset_devices); 175 176 static int __init set_reset_devices(char *str) 177 { 178 reset_devices = 1; 179 return 1; 180 } 181 182 __setup("reset_devices", set_reset_devices); 183 184 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 185 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 186 static const char *panic_later, *panic_param; 187 188 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 189 190 static bool __init obsolete_checksetup(char *line) 191 { 192 const struct obs_kernel_param *p; 193 bool had_early_param = false; 194 195 p = __setup_start; 196 do { 197 int n = strlen(p->str); 198 if (parameqn(line, p->str, n)) { 199 if (p->early) { 200 /* Already done in parse_early_param? 201 * (Needs exact match on param part). 202 * Keep iterating, as we can have early 203 * params and __setups of same names 8( */ 204 if (line[n] == '\0' || line[n] == '=') 205 had_early_param = true; 206 } else if (!p->setup_func) { 207 pr_warn("Parameter %s is obsolete, ignored\n", 208 p->str); 209 return true; 210 } else if (p->setup_func(line + n)) 211 return true; 212 } 213 p++; 214 } while (p < __setup_end); 215 216 return had_early_param; 217 } 218 219 /* 220 * This should be approx 2 Bo*oMips to start (note initial shift), and will 221 * still work even if initially too large, it will just take slightly longer 222 */ 223 unsigned long loops_per_jiffy = (1<<12); 224 EXPORT_SYMBOL(loops_per_jiffy); 225 226 static int __init debug_kernel(char *str) 227 { 228 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 229 return 0; 230 } 231 232 static int __init quiet_kernel(char *str) 233 { 234 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 235 return 0; 236 } 237 238 early_param("debug", debug_kernel); 239 early_param("quiet", quiet_kernel); 240 241 static int __init loglevel(char *str) 242 { 243 int newlevel; 244 245 /* 246 * Only update loglevel value when a correct setting was passed, 247 * to prevent blind crashes (when loglevel being set to 0) that 248 * are quite hard to debug 249 */ 250 if (get_option(&str, &newlevel)) { 251 console_loglevel = newlevel; 252 return 0; 253 } 254 255 return -EINVAL; 256 } 257 258 early_param("loglevel", loglevel); 259 260 #ifdef CONFIG_BOOT_CONFIG 261 262 char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 263 264 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 265 266 static int __init xbc_snprint_cmdline(char *buf, size_t size, 267 struct xbc_node *root) 268 { 269 struct xbc_node *knode, *vnode; 270 char *end = buf + size; 271 char c = '\"'; 272 const char *val; 273 int ret; 274 275 xbc_node_for_each_key_value(root, knode, val) { 276 ret = xbc_node_compose_key_after(root, knode, 277 xbc_namebuf, XBC_KEYLEN_MAX); 278 if (ret < 0) 279 return ret; 280 281 vnode = xbc_node_get_child(knode); 282 ret = snprintf(buf, rest(buf, end), "%s%c", xbc_namebuf, 283 vnode ? '=' : ' '); 284 if (ret < 0) 285 return ret; 286 buf += ret; 287 if (!vnode) 288 continue; 289 290 c = '\"'; 291 xbc_array_for_each_value(vnode, val) { 292 ret = snprintf(buf, rest(buf, end), "%c%s", c, val); 293 if (ret < 0) 294 return ret; 295 buf += ret; 296 c = ','; 297 } 298 if (rest(buf, end) > 2) 299 strcpy(buf, "\" "); 300 buf += 2; 301 } 302 303 return buf - (end - size); 304 } 305 #undef rest 306 307 /* Make an extra command line under given key word */ 308 static char * __init xbc_make_cmdline(const char *key) 309 { 310 struct xbc_node *root; 311 char *new_cmdline; 312 int ret, len = 0; 313 314 root = xbc_find_node(key); 315 if (!root) 316 return NULL; 317 318 /* Count required buffer size */ 319 len = xbc_snprint_cmdline(NULL, 0, root); 320 if (len <= 0) 321 return NULL; 322 323 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 324 if (!new_cmdline) { 325 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 326 return NULL; 327 } 328 329 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 330 if (ret < 0 || ret > len) { 331 pr_err("Failed to print extra kernel cmdline.\n"); 332 return NULL; 333 } 334 335 return new_cmdline; 336 } 337 338 u32 boot_config_checksum(unsigned char *p, u32 size) 339 { 340 u32 ret = 0; 341 342 while (size--) 343 ret += *p++; 344 345 return ret; 346 } 347 348 static int __init bootconfig_params(char *param, char *val, 349 const char *unused, void *arg) 350 { 351 if (strcmp(param, "bootconfig") == 0) { 352 bootconfig_found = true; 353 } else if (strcmp(param, "--") == 0) { 354 initargs_found = true; 355 } 356 return 0; 357 } 358 359 static void __init setup_boot_config(const char *cmdline) 360 { 361 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 362 u32 size, csum; 363 char *data, *copy; 364 u32 *hdr; 365 int ret; 366 367 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 368 parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 369 bootconfig_params); 370 371 if (!bootconfig_found) 372 return; 373 374 if (!initrd_end) 375 goto not_found; 376 377 hdr = (u32 *)(initrd_end - 8); 378 size = hdr[0]; 379 csum = hdr[1]; 380 381 if (size >= XBC_DATA_MAX) { 382 pr_err("bootconfig size %d greater than max size %d\n", 383 size, XBC_DATA_MAX); 384 return; 385 } 386 387 data = ((void *)hdr) - size; 388 if ((unsigned long)data < initrd_start) 389 goto not_found; 390 391 if (boot_config_checksum((unsigned char *)data, size) != csum) { 392 pr_err("bootconfig checksum failed\n"); 393 return; 394 } 395 396 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES); 397 if (!copy) { 398 pr_err("Failed to allocate memory for bootconfig\n"); 399 return; 400 } 401 402 memcpy(copy, data, size); 403 copy[size] = '\0'; 404 405 ret = xbc_init(copy); 406 if (ret < 0) 407 pr_err("Failed to parse bootconfig\n"); 408 else { 409 pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret); 410 /* keys starting with "kernel." are passed via cmdline */ 411 extra_command_line = xbc_make_cmdline("kernel"); 412 /* Also, "init." keys are init arguments */ 413 extra_init_args = xbc_make_cmdline("init"); 414 } 415 return; 416 not_found: 417 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 418 } 419 #else 420 #define setup_boot_config(cmdline) do { } while (0) 421 #endif 422 423 /* Change NUL term back to "=", to make "param" the whole string. */ 424 static int __init repair_env_string(char *param, char *val, 425 const char *unused, void *arg) 426 { 427 if (val) { 428 /* param=val or param="val"? */ 429 if (val == param+strlen(param)+1) 430 val[-1] = '='; 431 else if (val == param+strlen(param)+2) { 432 val[-2] = '='; 433 memmove(val-1, val, strlen(val)+1); 434 val--; 435 } else 436 BUG(); 437 } 438 return 0; 439 } 440 441 /* Anything after -- gets handed straight to init. */ 442 static int __init set_init_arg(char *param, char *val, 443 const char *unused, void *arg) 444 { 445 unsigned int i; 446 447 if (panic_later) 448 return 0; 449 450 repair_env_string(param, val, unused, NULL); 451 452 for (i = 0; argv_init[i]; i++) { 453 if (i == MAX_INIT_ARGS) { 454 panic_later = "init"; 455 panic_param = param; 456 return 0; 457 } 458 } 459 argv_init[i] = param; 460 return 0; 461 } 462 463 /* 464 * Unknown boot options get handed to init, unless they look like 465 * unused parameters (modprobe will find them in /proc/cmdline). 466 */ 467 static int __init unknown_bootoption(char *param, char *val, 468 const char *unused, void *arg) 469 { 470 repair_env_string(param, val, unused, NULL); 471 472 /* Handle obsolete-style parameters */ 473 if (obsolete_checksetup(param)) 474 return 0; 475 476 /* Unused module parameter. */ 477 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 478 return 0; 479 480 if (panic_later) 481 return 0; 482 483 if (val) { 484 /* Environment option */ 485 unsigned int i; 486 for (i = 0; envp_init[i]; i++) { 487 if (i == MAX_INIT_ENVS) { 488 panic_later = "env"; 489 panic_param = param; 490 } 491 if (!strncmp(param, envp_init[i], val - param)) 492 break; 493 } 494 envp_init[i] = param; 495 } else { 496 /* Command line option */ 497 unsigned int i; 498 for (i = 0; argv_init[i]; i++) { 499 if (i == MAX_INIT_ARGS) { 500 panic_later = "init"; 501 panic_param = param; 502 } 503 } 504 argv_init[i] = param; 505 } 506 return 0; 507 } 508 509 static int __init init_setup(char *str) 510 { 511 unsigned int i; 512 513 execute_command = str; 514 /* 515 * In case LILO is going to boot us with default command line, 516 * it prepends "auto" before the whole cmdline which makes 517 * the shell think it should execute a script with such name. 518 * So we ignore all arguments entered _before_ init=... [MJ] 519 */ 520 for (i = 1; i < MAX_INIT_ARGS; i++) 521 argv_init[i] = NULL; 522 return 1; 523 } 524 __setup("init=", init_setup); 525 526 static int __init rdinit_setup(char *str) 527 { 528 unsigned int i; 529 530 ramdisk_execute_command = str; 531 /* See "auto" comment in init_setup */ 532 for (i = 1; i < MAX_INIT_ARGS; i++) 533 argv_init[i] = NULL; 534 return 1; 535 } 536 __setup("rdinit=", rdinit_setup); 537 538 #ifndef CONFIG_SMP 539 static const unsigned int setup_max_cpus = NR_CPUS; 540 static inline void setup_nr_cpu_ids(void) { } 541 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 542 #endif 543 544 /* 545 * We need to store the untouched command line for future reference. 546 * We also need to store the touched command line since the parameter 547 * parsing is performed in place, and we should allow a component to 548 * store reference of name/value for future reference. 549 */ 550 static void __init setup_command_line(char *command_line) 551 { 552 size_t len, xlen = 0, ilen = 0; 553 554 if (extra_command_line) 555 xlen = strlen(extra_command_line); 556 if (extra_init_args) 557 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 558 559 len = xlen + strlen(boot_command_line) + 1; 560 561 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); 562 if (!saved_command_line) 563 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); 564 565 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 566 if (!static_command_line) 567 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 568 569 if (xlen) { 570 /* 571 * We have to put extra_command_line before boot command 572 * lines because there could be dashes (separator of init 573 * command line) in the command lines. 574 */ 575 strcpy(saved_command_line, extra_command_line); 576 strcpy(static_command_line, extra_command_line); 577 } 578 strcpy(saved_command_line + xlen, boot_command_line); 579 strcpy(static_command_line + xlen, command_line); 580 581 if (ilen) { 582 /* 583 * Append supplemental init boot args to saved_command_line 584 * so that user can check what command line options passed 585 * to init. 586 */ 587 len = strlen(saved_command_line); 588 if (initargs_found) { 589 saved_command_line[len++] = ' '; 590 } else { 591 strcpy(saved_command_line + len, " -- "); 592 len += 4; 593 } 594 595 strcpy(saved_command_line + len, extra_init_args); 596 } 597 } 598 599 /* 600 * We need to finalize in a non-__init function or else race conditions 601 * between the root thread and the init thread may cause start_kernel to 602 * be reaped by free_initmem before the root thread has proceeded to 603 * cpu_idle. 604 * 605 * gcc-3.4 accidentally inlines this function, so use noinline. 606 */ 607 608 static __initdata DECLARE_COMPLETION(kthreadd_done); 609 610 noinline void __ref rest_init(void) 611 { 612 struct task_struct *tsk; 613 int pid; 614 615 rcu_scheduler_starting(); 616 /* 617 * We need to spawn init first so that it obtains pid 1, however 618 * the init task will end up wanting to create kthreads, which, if 619 * we schedule it before we create kthreadd, will OOPS. 620 */ 621 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 622 /* 623 * Pin init on the boot CPU. Task migration is not properly working 624 * until sched_init_smp() has been run. It will set the allowed 625 * CPUs for init to the non isolated CPUs. 626 */ 627 rcu_read_lock(); 628 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 629 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 630 rcu_read_unlock(); 631 632 numa_default_policy(); 633 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 634 rcu_read_lock(); 635 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 636 rcu_read_unlock(); 637 638 /* 639 * Enable might_sleep() and smp_processor_id() checks. 640 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 641 * kernel_thread() would trigger might_sleep() splats. With 642 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 643 * already, but it's stuck on the kthreadd_done completion. 644 */ 645 system_state = SYSTEM_SCHEDULING; 646 647 complete(&kthreadd_done); 648 649 /* 650 * The boot idle thread must execute schedule() 651 * at least once to get things moving: 652 */ 653 schedule_preempt_disabled(); 654 /* Call into cpu_idle with preempt disabled */ 655 cpu_startup_entry(CPUHP_ONLINE); 656 } 657 658 /* Check for early params. */ 659 static int __init do_early_param(char *param, char *val, 660 const char *unused, void *arg) 661 { 662 const struct obs_kernel_param *p; 663 664 for (p = __setup_start; p < __setup_end; p++) { 665 if ((p->early && parameq(param, p->str)) || 666 (strcmp(param, "console") == 0 && 667 strcmp(p->str, "earlycon") == 0) 668 ) { 669 if (p->setup_func(val) != 0) 670 pr_warn("Malformed early option '%s'\n", param); 671 } 672 } 673 /* We accept everything at this stage. */ 674 return 0; 675 } 676 677 void __init parse_early_options(char *cmdline) 678 { 679 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 680 do_early_param); 681 } 682 683 /* Arch code calls this early on, or if not, just before other parsing. */ 684 void __init parse_early_param(void) 685 { 686 static int done __initdata; 687 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 688 689 if (done) 690 return; 691 692 /* All fall through to do_early_param. */ 693 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 694 parse_early_options(tmp_cmdline); 695 done = 1; 696 } 697 698 void __init __weak arch_post_acpi_subsys_init(void) { } 699 700 void __init __weak smp_setup_processor_id(void) 701 { 702 } 703 704 # if THREAD_SIZE >= PAGE_SIZE 705 void __init __weak thread_stack_cache_init(void) 706 { 707 } 708 #endif 709 710 void __init __weak mem_encrypt_init(void) { } 711 712 void __init __weak poking_init(void) { } 713 714 void __init __weak pgtable_cache_init(void) { } 715 716 bool initcall_debug; 717 core_param(initcall_debug, initcall_debug, bool, 0644); 718 719 #ifdef TRACEPOINTS_ENABLED 720 static void __init initcall_debug_enable(void); 721 #else 722 static inline void initcall_debug_enable(void) 723 { 724 } 725 #endif 726 727 /* Report memory auto-initialization states for this boot. */ 728 static void __init report_meminit(void) 729 { 730 const char *stack; 731 732 if (IS_ENABLED(CONFIG_INIT_STACK_ALL)) 733 stack = "all"; 734 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) 735 stack = "byref_all"; 736 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) 737 stack = "byref"; 738 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) 739 stack = "__user"; 740 else 741 stack = "off"; 742 743 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", 744 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", 745 want_init_on_free() ? "on" : "off"); 746 if (want_init_on_free()) 747 pr_info("mem auto-init: clearing system memory may take some time...\n"); 748 } 749 750 /* 751 * Set up kernel memory allocators 752 */ 753 static void __init mm_init(void) 754 { 755 /* 756 * page_ext requires contiguous pages, 757 * bigger than MAX_ORDER unless SPARSEMEM. 758 */ 759 page_ext_init_flatmem(); 760 report_meminit(); 761 mem_init(); 762 kmem_cache_init(); 763 kmemleak_init(); 764 pgtable_init(); 765 debug_objects_mem_init(); 766 vmalloc_init(); 767 ioremap_huge_init(); 768 /* Should be run before the first non-init thread is created */ 769 init_espfix_bsp(); 770 /* Should be run after espfix64 is set up. */ 771 pti_init(); 772 } 773 774 void __init __weak arch_call_rest_init(void) 775 { 776 rest_init(); 777 } 778 779 asmlinkage __visible void __init start_kernel(void) 780 { 781 char *command_line; 782 char *after_dashes; 783 784 set_task_stack_end_magic(&init_task); 785 smp_setup_processor_id(); 786 debug_objects_early_init(); 787 788 cgroup_init_early(); 789 790 local_irq_disable(); 791 early_boot_irqs_disabled = true; 792 793 /* 794 * Interrupts are still disabled. Do necessary setups, then 795 * enable them. 796 */ 797 boot_cpu_init(); 798 page_address_init(); 799 pr_notice("%s", linux_banner); 800 early_security_init(); 801 setup_arch(&command_line); 802 setup_boot_config(command_line); 803 setup_command_line(command_line); 804 setup_nr_cpu_ids(); 805 setup_per_cpu_areas(); 806 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 807 boot_cpu_hotplug_init(); 808 809 build_all_zonelists(NULL); 810 page_alloc_init(); 811 812 pr_notice("Kernel command line: %s\n", saved_command_line); 813 /* parameters may set static keys */ 814 jump_label_init(); 815 parse_early_param(); 816 after_dashes = parse_args("Booting kernel", 817 static_command_line, __start___param, 818 __stop___param - __start___param, 819 -1, -1, NULL, &unknown_bootoption); 820 if (!IS_ERR_OR_NULL(after_dashes)) 821 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 822 NULL, set_init_arg); 823 if (extra_init_args) 824 parse_args("Setting extra init args", extra_init_args, 825 NULL, 0, -1, -1, NULL, set_init_arg); 826 827 /* 828 * These use large bootmem allocations and must precede 829 * kmem_cache_init() 830 */ 831 setup_log_buf(0); 832 vfs_caches_init_early(); 833 sort_main_extable(); 834 trap_init(); 835 mm_init(); 836 837 ftrace_init(); 838 839 /* trace_printk can be enabled here */ 840 early_trace_init(); 841 842 /* 843 * Set up the scheduler prior starting any interrupts (such as the 844 * timer interrupt). Full topology setup happens at smp_init() 845 * time - but meanwhile we still have a functioning scheduler. 846 */ 847 sched_init(); 848 /* 849 * Disable preemption - early bootup scheduling is extremely 850 * fragile until we cpu_idle() for the first time. 851 */ 852 preempt_disable(); 853 if (WARN(!irqs_disabled(), 854 "Interrupts were enabled *very* early, fixing it\n")) 855 local_irq_disable(); 856 radix_tree_init(); 857 858 /* 859 * Set up housekeeping before setting up workqueues to allow the unbound 860 * workqueue to take non-housekeeping into account. 861 */ 862 housekeeping_init(); 863 864 /* 865 * Allow workqueue creation and work item queueing/cancelling 866 * early. Work item execution depends on kthreads and starts after 867 * workqueue_init(). 868 */ 869 workqueue_init_early(); 870 871 rcu_init(); 872 873 /* Trace events are available after this */ 874 trace_init(); 875 876 if (initcall_debug) 877 initcall_debug_enable(); 878 879 context_tracking_init(); 880 /* init some links before init_ISA_irqs() */ 881 early_irq_init(); 882 init_IRQ(); 883 tick_init(); 884 rcu_init_nohz(); 885 init_timers(); 886 hrtimers_init(); 887 softirq_init(); 888 timekeeping_init(); 889 890 /* 891 * For best initial stack canary entropy, prepare it after: 892 * - setup_arch() for any UEFI RNG entropy and boot cmdline access 893 * - timekeeping_init() for ktime entropy used in rand_initialize() 894 * - rand_initialize() to get any arch-specific entropy like RDRAND 895 * - add_latent_entropy() to get any latent entropy 896 * - adding command line entropy 897 */ 898 rand_initialize(); 899 add_latent_entropy(); 900 add_device_randomness(command_line, strlen(command_line)); 901 boot_init_stack_canary(); 902 903 time_init(); 904 printk_safe_init(); 905 perf_event_init(); 906 profile_init(); 907 call_function_init(); 908 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 909 910 early_boot_irqs_disabled = false; 911 local_irq_enable(); 912 913 kmem_cache_init_late(); 914 915 /* 916 * HACK ALERT! This is early. We're enabling the console before 917 * we've done PCI setups etc, and console_init() must be aware of 918 * this. But we do want output early, in case something goes wrong. 919 */ 920 console_init(); 921 if (panic_later) 922 panic("Too many boot %s vars at `%s'", panic_later, 923 panic_param); 924 925 lockdep_init(); 926 927 /* 928 * Need to run this when irqs are enabled, because it wants 929 * to self-test [hard/soft]-irqs on/off lock inversion bugs 930 * too: 931 */ 932 locking_selftest(); 933 934 /* 935 * This needs to be called before any devices perform DMA 936 * operations that might use the SWIOTLB bounce buffers. It will 937 * mark the bounce buffers as decrypted so that their usage will 938 * not cause "plain-text" data to be decrypted when accessed. 939 */ 940 mem_encrypt_init(); 941 942 #ifdef CONFIG_BLK_DEV_INITRD 943 if (initrd_start && !initrd_below_start_ok && 944 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 945 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 946 page_to_pfn(virt_to_page((void *)initrd_start)), 947 min_low_pfn); 948 initrd_start = 0; 949 } 950 #endif 951 setup_per_cpu_pageset(); 952 numa_policy_init(); 953 acpi_early_init(); 954 if (late_time_init) 955 late_time_init(); 956 sched_clock_init(); 957 calibrate_delay(); 958 pid_idr_init(); 959 anon_vma_init(); 960 #ifdef CONFIG_X86 961 if (efi_enabled(EFI_RUNTIME_SERVICES)) 962 efi_enter_virtual_mode(); 963 #endif 964 thread_stack_cache_init(); 965 cred_init(); 966 fork_init(); 967 proc_caches_init(); 968 uts_ns_init(); 969 buffer_init(); 970 key_init(); 971 security_init(); 972 dbg_late_init(); 973 vfs_caches_init(); 974 pagecache_init(); 975 signals_init(); 976 seq_file_init(); 977 proc_root_init(); 978 nsfs_init(); 979 cpuset_init(); 980 cgroup_init(); 981 taskstats_init_early(); 982 delayacct_init(); 983 984 poking_init(); 985 check_bugs(); 986 987 acpi_subsystem_init(); 988 arch_post_acpi_subsys_init(); 989 sfi_init_late(); 990 991 /* Do the rest non-__init'ed, we're now alive */ 992 arch_call_rest_init(); 993 } 994 995 /* Call all constructor functions linked into the kernel. */ 996 static void __init do_ctors(void) 997 { 998 #ifdef CONFIG_CONSTRUCTORS 999 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1000 1001 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1002 (*fn)(); 1003 #endif 1004 } 1005 1006 #ifdef CONFIG_KALLSYMS 1007 struct blacklist_entry { 1008 struct list_head next; 1009 char *buf; 1010 }; 1011 1012 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1013 1014 static int __init initcall_blacklist(char *str) 1015 { 1016 char *str_entry; 1017 struct blacklist_entry *entry; 1018 1019 /* str argument is a comma-separated list of functions */ 1020 do { 1021 str_entry = strsep(&str, ","); 1022 if (str_entry) { 1023 pr_debug("blacklisting initcall %s\n", str_entry); 1024 entry = memblock_alloc(sizeof(*entry), 1025 SMP_CACHE_BYTES); 1026 if (!entry) 1027 panic("%s: Failed to allocate %zu bytes\n", 1028 __func__, sizeof(*entry)); 1029 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1030 SMP_CACHE_BYTES); 1031 if (!entry->buf) 1032 panic("%s: Failed to allocate %zu bytes\n", 1033 __func__, strlen(str_entry) + 1); 1034 strcpy(entry->buf, str_entry); 1035 list_add(&entry->next, &blacklisted_initcalls); 1036 } 1037 } while (str_entry); 1038 1039 return 0; 1040 } 1041 1042 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1043 { 1044 struct blacklist_entry *entry; 1045 char fn_name[KSYM_SYMBOL_LEN]; 1046 unsigned long addr; 1047 1048 if (list_empty(&blacklisted_initcalls)) 1049 return false; 1050 1051 addr = (unsigned long) dereference_function_descriptor(fn); 1052 sprint_symbol_no_offset(fn_name, addr); 1053 1054 /* 1055 * fn will be "function_name [module_name]" where [module_name] is not 1056 * displayed for built-in init functions. Strip off the [module_name]. 1057 */ 1058 strreplace(fn_name, ' ', '\0'); 1059 1060 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1061 if (!strcmp(fn_name, entry->buf)) { 1062 pr_debug("initcall %s blacklisted\n", fn_name); 1063 return true; 1064 } 1065 } 1066 1067 return false; 1068 } 1069 #else 1070 static int __init initcall_blacklist(char *str) 1071 { 1072 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1073 return 0; 1074 } 1075 1076 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1077 { 1078 return false; 1079 } 1080 #endif 1081 __setup("initcall_blacklist=", initcall_blacklist); 1082 1083 static __init_or_module void 1084 trace_initcall_start_cb(void *data, initcall_t fn) 1085 { 1086 ktime_t *calltime = (ktime_t *)data; 1087 1088 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1089 *calltime = ktime_get(); 1090 } 1091 1092 static __init_or_module void 1093 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1094 { 1095 ktime_t *calltime = (ktime_t *)data; 1096 ktime_t delta, rettime; 1097 unsigned long long duration; 1098 1099 rettime = ktime_get(); 1100 delta = ktime_sub(rettime, *calltime); 1101 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 1102 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1103 fn, ret, duration); 1104 } 1105 1106 static ktime_t initcall_calltime; 1107 1108 #ifdef TRACEPOINTS_ENABLED 1109 static void __init initcall_debug_enable(void) 1110 { 1111 int ret; 1112 1113 ret = register_trace_initcall_start(trace_initcall_start_cb, 1114 &initcall_calltime); 1115 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1116 &initcall_calltime); 1117 WARN(ret, "Failed to register initcall tracepoints\n"); 1118 } 1119 # define do_trace_initcall_start trace_initcall_start 1120 # define do_trace_initcall_finish trace_initcall_finish 1121 #else 1122 static inline void do_trace_initcall_start(initcall_t fn) 1123 { 1124 if (!initcall_debug) 1125 return; 1126 trace_initcall_start_cb(&initcall_calltime, fn); 1127 } 1128 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1129 { 1130 if (!initcall_debug) 1131 return; 1132 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1133 } 1134 #endif /* !TRACEPOINTS_ENABLED */ 1135 1136 int __init_or_module do_one_initcall(initcall_t fn) 1137 { 1138 int count = preempt_count(); 1139 char msgbuf[64]; 1140 int ret; 1141 1142 if (initcall_blacklisted(fn)) 1143 return -EPERM; 1144 1145 do_trace_initcall_start(fn); 1146 ret = fn(); 1147 do_trace_initcall_finish(fn, ret); 1148 1149 msgbuf[0] = 0; 1150 1151 if (preempt_count() != count) { 1152 sprintf(msgbuf, "preemption imbalance "); 1153 preempt_count_set(count); 1154 } 1155 if (irqs_disabled()) { 1156 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1157 local_irq_enable(); 1158 } 1159 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1160 1161 add_latent_entropy(); 1162 return ret; 1163 } 1164 1165 1166 extern initcall_entry_t __initcall_start[]; 1167 extern initcall_entry_t __initcall0_start[]; 1168 extern initcall_entry_t __initcall1_start[]; 1169 extern initcall_entry_t __initcall2_start[]; 1170 extern initcall_entry_t __initcall3_start[]; 1171 extern initcall_entry_t __initcall4_start[]; 1172 extern initcall_entry_t __initcall5_start[]; 1173 extern initcall_entry_t __initcall6_start[]; 1174 extern initcall_entry_t __initcall7_start[]; 1175 extern initcall_entry_t __initcall_end[]; 1176 1177 static initcall_entry_t *initcall_levels[] __initdata = { 1178 __initcall0_start, 1179 __initcall1_start, 1180 __initcall2_start, 1181 __initcall3_start, 1182 __initcall4_start, 1183 __initcall5_start, 1184 __initcall6_start, 1185 __initcall7_start, 1186 __initcall_end, 1187 }; 1188 1189 /* Keep these in sync with initcalls in include/linux/init.h */ 1190 static const char *initcall_level_names[] __initdata = { 1191 "pure", 1192 "core", 1193 "postcore", 1194 "arch", 1195 "subsys", 1196 "fs", 1197 "device", 1198 "late", 1199 }; 1200 1201 static void __init do_initcall_level(int level, char *command_line) 1202 { 1203 initcall_entry_t *fn; 1204 1205 parse_args(initcall_level_names[level], 1206 command_line, __start___param, 1207 __stop___param - __start___param, 1208 level, level, 1209 NULL, &repair_env_string); 1210 1211 trace_initcall_level(initcall_level_names[level]); 1212 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1213 do_one_initcall(initcall_from_entry(fn)); 1214 } 1215 1216 static void __init do_initcalls(void) 1217 { 1218 int level; 1219 size_t len = strlen(saved_command_line) + 1; 1220 char *command_line; 1221 1222 command_line = kzalloc(len, GFP_KERNEL); 1223 if (!command_line) 1224 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1225 1226 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1227 /* Parser modifies command_line, restore it each time */ 1228 strcpy(command_line, saved_command_line); 1229 do_initcall_level(level, command_line); 1230 } 1231 1232 kfree(command_line); 1233 } 1234 1235 /* 1236 * Ok, the machine is now initialized. None of the devices 1237 * have been touched yet, but the CPU subsystem is up and 1238 * running, and memory and process management works. 1239 * 1240 * Now we can finally start doing some real work.. 1241 */ 1242 static void __init do_basic_setup(void) 1243 { 1244 cpuset_init_smp(); 1245 driver_init(); 1246 init_irq_proc(); 1247 do_ctors(); 1248 usermodehelper_enable(); 1249 do_initcalls(); 1250 } 1251 1252 static void __init do_pre_smp_initcalls(void) 1253 { 1254 initcall_entry_t *fn; 1255 1256 trace_initcall_level("early"); 1257 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1258 do_one_initcall(initcall_from_entry(fn)); 1259 } 1260 1261 static int run_init_process(const char *init_filename) 1262 { 1263 argv_init[0] = init_filename; 1264 pr_info("Run %s as init process\n", init_filename); 1265 return do_execve(getname_kernel(init_filename), 1266 (const char __user *const __user *)argv_init, 1267 (const char __user *const __user *)envp_init); 1268 } 1269 1270 static int try_to_run_init_process(const char *init_filename) 1271 { 1272 int ret; 1273 1274 ret = run_init_process(init_filename); 1275 1276 if (ret && ret != -ENOENT) { 1277 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1278 init_filename, ret); 1279 } 1280 1281 return ret; 1282 } 1283 1284 static noinline void __init kernel_init_freeable(void); 1285 1286 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1287 bool rodata_enabled __ro_after_init = true; 1288 static int __init set_debug_rodata(char *str) 1289 { 1290 return strtobool(str, &rodata_enabled); 1291 } 1292 __setup("rodata=", set_debug_rodata); 1293 #endif 1294 1295 #ifdef CONFIG_STRICT_KERNEL_RWX 1296 static void mark_readonly(void) 1297 { 1298 if (rodata_enabled) { 1299 /* 1300 * load_module() results in W+X mappings, which are cleaned 1301 * up with call_rcu(). Let's make sure that queued work is 1302 * flushed so that we don't hit false positives looking for 1303 * insecure pages which are W+X. 1304 */ 1305 rcu_barrier(); 1306 mark_rodata_ro(); 1307 rodata_test(); 1308 } else 1309 pr_info("Kernel memory protection disabled.\n"); 1310 } 1311 #else 1312 static inline void mark_readonly(void) 1313 { 1314 pr_warn("This architecture does not have kernel memory protection.\n"); 1315 } 1316 #endif 1317 1318 void __weak free_initmem(void) 1319 { 1320 free_initmem_default(POISON_FREE_INITMEM); 1321 } 1322 1323 static int __ref kernel_init(void *unused) 1324 { 1325 int ret; 1326 1327 kernel_init_freeable(); 1328 /* need to finish all async __init code before freeing the memory */ 1329 async_synchronize_full(); 1330 ftrace_free_init_mem(); 1331 free_initmem(); 1332 mark_readonly(); 1333 1334 /* 1335 * Kernel mappings are now finalized - update the userspace page-table 1336 * to finalize PTI. 1337 */ 1338 pti_finalize(); 1339 1340 system_state = SYSTEM_RUNNING; 1341 numa_default_policy(); 1342 1343 rcu_end_inkernel_boot(); 1344 1345 if (ramdisk_execute_command) { 1346 ret = run_init_process(ramdisk_execute_command); 1347 if (!ret) 1348 return 0; 1349 pr_err("Failed to execute %s (error %d)\n", 1350 ramdisk_execute_command, ret); 1351 } 1352 1353 /* 1354 * We try each of these until one succeeds. 1355 * 1356 * The Bourne shell can be used instead of init if we are 1357 * trying to recover a really broken machine. 1358 */ 1359 if (execute_command) { 1360 ret = run_init_process(execute_command); 1361 if (!ret) 1362 return 0; 1363 panic("Requested init %s failed (error %d).", 1364 execute_command, ret); 1365 } 1366 if (!try_to_run_init_process("/sbin/init") || 1367 !try_to_run_init_process("/etc/init") || 1368 !try_to_run_init_process("/bin/init") || 1369 !try_to_run_init_process("/bin/sh")) 1370 return 0; 1371 1372 panic("No working init found. Try passing init= option to kernel. " 1373 "See Linux Documentation/admin-guide/init.rst for guidance."); 1374 } 1375 1376 void console_on_rootfs(void) 1377 { 1378 /* Open the /dev/console as stdin, this should never fail */ 1379 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 1380 pr_err("Warning: unable to open an initial console.\n"); 1381 1382 /* create stdout/stderr */ 1383 (void) ksys_dup(0); 1384 (void) ksys_dup(0); 1385 } 1386 1387 static noinline void __init kernel_init_freeable(void) 1388 { 1389 /* 1390 * Wait until kthreadd is all set-up. 1391 */ 1392 wait_for_completion(&kthreadd_done); 1393 1394 /* Now the scheduler is fully set up and can do blocking allocations */ 1395 gfp_allowed_mask = __GFP_BITS_MASK; 1396 1397 /* 1398 * init can allocate pages on any node 1399 */ 1400 set_mems_allowed(node_states[N_MEMORY]); 1401 1402 cad_pid = task_pid(current); 1403 1404 smp_prepare_cpus(setup_max_cpus); 1405 1406 workqueue_init(); 1407 1408 init_mm_internals(); 1409 1410 do_pre_smp_initcalls(); 1411 lockup_detector_init(); 1412 1413 smp_init(); 1414 sched_init_smp(); 1415 1416 page_alloc_init_late(); 1417 /* Initialize page ext after all struct pages are initialized. */ 1418 page_ext_init(); 1419 1420 do_basic_setup(); 1421 1422 console_on_rootfs(); 1423 1424 /* 1425 * check if there is an early userspace init. If yes, let it do all 1426 * the work 1427 */ 1428 1429 if (!ramdisk_execute_command) 1430 ramdisk_execute_command = "/init"; 1431 1432 if (ksys_access((const char __user *) 1433 ramdisk_execute_command, 0) != 0) { 1434 ramdisk_execute_command = NULL; 1435 prepare_namespace(); 1436 } 1437 1438 /* 1439 * Ok, we have completed the initial bootup, and 1440 * we're essentially up and running. Get rid of the 1441 * initmem segments and start the user-mode stuff.. 1442 * 1443 * rootfs is available now, try loading the public keys 1444 * and default modules 1445 */ 1446 1447 integrity_load_keys(); 1448 } 1449