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/kprobes.h> 37 #include <linux/kmsan.h> 38 #include <linux/vmalloc.h> 39 #include <linux/kernel_stat.h> 40 #include <linux/start_kernel.h> 41 #include <linux/security.h> 42 #include <linux/smp.h> 43 #include <linux/profile.h> 44 #include <linux/kfence.h> 45 #include <linux/rcupdate.h> 46 #include <linux/srcu.h> 47 #include <linux/moduleparam.h> 48 #include <linux/kallsyms.h> 49 #include <linux/buildid.h> 50 #include <linux/writeback.h> 51 #include <linux/cpu.h> 52 #include <linux/cpuset.h> 53 #include <linux/cgroup.h> 54 #include <linux/efi.h> 55 #include <linux/tick.h> 56 #include <linux/sched/isolation.h> 57 #include <linux/interrupt.h> 58 #include <linux/taskstats_kern.h> 59 #include <linux/delayacct.h> 60 #include <linux/unistd.h> 61 #include <linux/utsname.h> 62 #include <linux/rmap.h> 63 #include <linux/mempolicy.h> 64 #include <linux/key.h> 65 #include <linux/debug_locks.h> 66 #include <linux/debugobjects.h> 67 #include <linux/lockdep.h> 68 #include <linux/kmemleak.h> 69 #include <linux/padata.h> 70 #include <linux/pid_namespace.h> 71 #include <linux/device/driver.h> 72 #include <linux/kthread.h> 73 #include <linux/sched.h> 74 #include <linux/sched/init.h> 75 #include <linux/signal.h> 76 #include <linux/idr.h> 77 #include <linux/kgdb.h> 78 #include <linux/ftrace.h> 79 #include <linux/async.h> 80 #include <linux/shmem_fs.h> 81 #include <linux/slab.h> 82 #include <linux/perf_event.h> 83 #include <linux/ptrace.h> 84 #include <linux/pti.h> 85 #include <linux/blkdev.h> 86 #include <linux/sched/clock.h> 87 #include <linux/sched/task.h> 88 #include <linux/sched/task_stack.h> 89 #include <linux/context_tracking.h> 90 #include <linux/random.h> 91 #include <linux/moduleloader.h> 92 #include <linux/list.h> 93 #include <linux/integrity.h> 94 #include <linux/proc_ns.h> 95 #include <linux/io.h> 96 #include <linux/cache.h> 97 #include <linux/rodata_test.h> 98 #include <linux/jump_label.h> 99 #include <linux/kcsan.h> 100 #include <linux/init_syscalls.h> 101 #include <linux/stackdepot.h> 102 #include <linux/randomize_kstack.h> 103 #include <linux/pidfs.h> 104 #include <linux/ptdump.h> 105 #include <net/net_namespace.h> 106 107 #include <asm/io.h> 108 #include <asm/setup.h> 109 #include <asm/sections.h> 110 #include <asm/cacheflush.h> 111 112 #define CREATE_TRACE_POINTS 113 #include <trace/events/initcall.h> 114 115 #include <kunit/test.h> 116 117 static int kernel_init(void *); 118 119 /* 120 * Debug helper: via this flag we know that we are in 'early bootup code' 121 * where only the boot processor is running with IRQ disabled. This means 122 * two things - IRQ must not be enabled before the flag is cleared and some 123 * operations which are not allowed with IRQ disabled are allowed while the 124 * flag is set. 125 */ 126 bool early_boot_irqs_disabled __read_mostly; 127 128 enum system_states system_state __read_mostly; 129 EXPORT_SYMBOL(system_state); 130 131 /* 132 * Boot command-line arguments 133 */ 134 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 135 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 136 137 /* Default late time init is NULL. archs can override this later. */ 138 void (*__initdata late_time_init)(void); 139 140 /* Untouched command line saved by arch-specific code. */ 141 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 142 /* Untouched saved command line (eg. for /proc) */ 143 char *saved_command_line __ro_after_init; 144 unsigned int saved_command_line_len __ro_after_init; 145 /* Command line for parameter parsing */ 146 static char *static_command_line; 147 /* Untouched extra command line */ 148 static char *extra_command_line; 149 /* Extra init arguments */ 150 static char *extra_init_args; 151 152 #ifdef CONFIG_BOOT_CONFIG 153 /* Is bootconfig on command line? */ 154 static bool bootconfig_found; 155 static size_t initargs_offs; 156 #else 157 # define bootconfig_found false 158 # define initargs_offs 0 159 #endif 160 161 static char *execute_command; 162 static char *ramdisk_execute_command = "/init"; 163 164 /* 165 * Used to generate warnings if static_key manipulation functions are used 166 * before jump_label_init is called. 167 */ 168 bool static_key_initialized __read_mostly; 169 EXPORT_SYMBOL_GPL(static_key_initialized); 170 171 /* 172 * If set, this is an indication to the drivers that reset the underlying 173 * device before going ahead with the initialization otherwise driver might 174 * rely on the BIOS and skip the reset operation. 175 * 176 * This is useful if kernel is booting in an unreliable environment. 177 * For ex. kdump situation where previous kernel has crashed, BIOS has been 178 * skipped and devices will be in unknown state. 179 */ 180 unsigned int reset_devices; 181 EXPORT_SYMBOL(reset_devices); 182 183 static int __init set_reset_devices(char *str) 184 { 185 reset_devices = 1; 186 return 1; 187 } 188 189 __setup("reset_devices", set_reset_devices); 190 191 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 192 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 193 static const char *panic_later, *panic_param; 194 195 static bool __init obsolete_checksetup(char *line) 196 { 197 const struct obs_kernel_param *p; 198 bool had_early_param = false; 199 200 p = __setup_start; 201 do { 202 int n = strlen(p->str); 203 if (parameqn(line, p->str, n)) { 204 if (p->early) { 205 /* Already done in parse_early_param? 206 * (Needs exact match on param part). 207 * Keep iterating, as we can have early 208 * params and __setups of same names 8( */ 209 if (line[n] == '\0' || line[n] == '=') 210 had_early_param = true; 211 } else if (!p->setup_func) { 212 pr_warn("Parameter %s is obsolete, ignored\n", 213 p->str); 214 return true; 215 } else if (p->setup_func(line + n)) 216 return true; 217 } 218 p++; 219 } while (p < __setup_end); 220 221 return had_early_param; 222 } 223 224 /* 225 * This should be approx 2 Bo*oMips to start (note initial shift), and will 226 * still work even if initially too large, it will just take slightly longer 227 */ 228 unsigned long loops_per_jiffy = (1<<12); 229 EXPORT_SYMBOL(loops_per_jiffy); 230 231 static int __init debug_kernel(char *str) 232 { 233 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 234 return 0; 235 } 236 237 static int __init quiet_kernel(char *str) 238 { 239 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 240 return 0; 241 } 242 243 early_param("debug", debug_kernel); 244 early_param("quiet", quiet_kernel); 245 246 static int __init loglevel(char *str) 247 { 248 int newlevel; 249 250 /* 251 * Only update loglevel value when a correct setting was passed, 252 * to prevent blind crashes (when loglevel being set to 0) that 253 * are quite hard to debug 254 */ 255 if (get_option(&str, &newlevel)) { 256 console_loglevel = newlevel; 257 return 0; 258 } 259 260 return -EINVAL; 261 } 262 263 early_param("loglevel", loglevel); 264 265 #ifdef CONFIG_BLK_DEV_INITRD 266 static void * __init get_boot_config_from_initrd(size_t *_size) 267 { 268 u32 size, csum; 269 char *data; 270 u32 *hdr; 271 int i; 272 273 if (!initrd_end) 274 return NULL; 275 276 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 277 /* 278 * Since Grub may align the size of initrd to 4, we must 279 * check the preceding 3 bytes as well. 280 */ 281 for (i = 0; i < 4; i++) { 282 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 283 goto found; 284 data--; 285 } 286 return NULL; 287 288 found: 289 hdr = (u32 *)(data - 8); 290 size = le32_to_cpu(hdr[0]); 291 csum = le32_to_cpu(hdr[1]); 292 293 data = ((void *)hdr) - size; 294 if ((unsigned long)data < initrd_start) { 295 pr_err("bootconfig size %d is greater than initrd size %ld\n", 296 size, initrd_end - initrd_start); 297 return NULL; 298 } 299 300 if (xbc_calc_checksum(data, size) != csum) { 301 pr_err("bootconfig checksum failed\n"); 302 return NULL; 303 } 304 305 /* Remove bootconfig from initramfs/initrd */ 306 initrd_end = (unsigned long)data; 307 if (_size) 308 *_size = size; 309 310 return data; 311 } 312 #else 313 static void * __init get_boot_config_from_initrd(size_t *_size) 314 { 315 return NULL; 316 } 317 #endif 318 319 #ifdef CONFIG_BOOT_CONFIG 320 321 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 322 323 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 324 325 static int __init xbc_snprint_cmdline(char *buf, size_t size, 326 struct xbc_node *root) 327 { 328 struct xbc_node *knode, *vnode; 329 char *end = buf + size; 330 const char *val, *q; 331 int ret; 332 333 xbc_node_for_each_key_value(root, knode, val) { 334 ret = xbc_node_compose_key_after(root, knode, 335 xbc_namebuf, XBC_KEYLEN_MAX); 336 if (ret < 0) 337 return ret; 338 339 vnode = xbc_node_get_child(knode); 340 if (!vnode) { 341 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 342 if (ret < 0) 343 return ret; 344 buf += ret; 345 continue; 346 } 347 xbc_array_for_each_value(vnode, val) { 348 /* 349 * For prettier and more readable /proc/cmdline, only 350 * quote the value when necessary, i.e. when it contains 351 * whitespace. 352 */ 353 q = strpbrk(val, " \t\r\n") ? "\"" : ""; 354 ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ", 355 xbc_namebuf, q, val, q); 356 if (ret < 0) 357 return ret; 358 buf += ret; 359 } 360 } 361 362 return buf - (end - size); 363 } 364 #undef rest 365 366 /* Make an extra command line under given key word */ 367 static char * __init xbc_make_cmdline(const char *key) 368 { 369 struct xbc_node *root; 370 char *new_cmdline; 371 int ret, len = 0; 372 373 root = xbc_find_node(key); 374 if (!root) 375 return NULL; 376 377 /* Count required buffer size */ 378 len = xbc_snprint_cmdline(NULL, 0, root); 379 if (len <= 0) 380 return NULL; 381 382 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 383 if (!new_cmdline) { 384 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 385 return NULL; 386 } 387 388 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 389 if (ret < 0 || ret > len) { 390 pr_err("Failed to print extra kernel cmdline.\n"); 391 memblock_free(new_cmdline, len + 1); 392 return NULL; 393 } 394 395 return new_cmdline; 396 } 397 398 static int __init bootconfig_params(char *param, char *val, 399 const char *unused, void *arg) 400 { 401 if (strcmp(param, "bootconfig") == 0) { 402 bootconfig_found = true; 403 } 404 return 0; 405 } 406 407 static int __init warn_bootconfig(char *str) 408 { 409 /* The 'bootconfig' has been handled by bootconfig_params(). */ 410 return 0; 411 } 412 413 static void __init setup_boot_config(void) 414 { 415 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 416 const char *msg, *data; 417 int pos, ret; 418 size_t size; 419 char *err; 420 421 /* Cut out the bootconfig data even if we have no bootconfig option */ 422 data = get_boot_config_from_initrd(&size); 423 /* If there is no bootconfig in initrd, try embedded one. */ 424 if (!data) 425 data = xbc_get_embedded_bootconfig(&size); 426 427 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 428 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 429 bootconfig_params); 430 431 if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE))) 432 return; 433 434 /* parse_args() stops at the next param of '--' and returns an address */ 435 if (err) 436 initargs_offs = err - tmp_cmdline; 437 438 if (!data) { 439 /* If user intended to use bootconfig, show an error level message */ 440 if (bootconfig_found) 441 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 442 else 443 pr_info("No bootconfig data provided, so skipping bootconfig"); 444 return; 445 } 446 447 if (size >= XBC_DATA_MAX) { 448 pr_err("bootconfig size %ld greater than max size %d\n", 449 (long)size, XBC_DATA_MAX); 450 return; 451 } 452 453 ret = xbc_init(data, size, &msg, &pos); 454 if (ret < 0) { 455 if (pos < 0) 456 pr_err("Failed to init bootconfig: %s.\n", msg); 457 else 458 pr_err("Failed to parse bootconfig: %s at %d.\n", 459 msg, pos); 460 } else { 461 xbc_get_info(&ret, NULL); 462 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); 463 /* keys starting with "kernel." are passed via cmdline */ 464 extra_command_line = xbc_make_cmdline("kernel"); 465 /* Also, "init." keys are init arguments */ 466 extra_init_args = xbc_make_cmdline("init"); 467 } 468 return; 469 } 470 471 static void __init exit_boot_config(void) 472 { 473 xbc_exit(); 474 } 475 476 #else /* !CONFIG_BOOT_CONFIG */ 477 478 static void __init setup_boot_config(void) 479 { 480 /* Remove bootconfig data from initrd */ 481 get_boot_config_from_initrd(NULL); 482 } 483 484 static int __init warn_bootconfig(char *str) 485 { 486 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 487 return 0; 488 } 489 490 #define exit_boot_config() do {} while (0) 491 492 #endif /* CONFIG_BOOT_CONFIG */ 493 494 early_param("bootconfig", warn_bootconfig); 495 496 bool __init cmdline_has_extra_options(void) 497 { 498 return extra_command_line || extra_init_args; 499 } 500 501 /* Change NUL term back to "=", to make "param" the whole string. */ 502 static void __init repair_env_string(char *param, char *val) 503 { 504 if (val) { 505 /* param=val or param="val"? */ 506 if (val == param+strlen(param)+1) 507 val[-1] = '='; 508 else if (val == param+strlen(param)+2) { 509 val[-2] = '='; 510 memmove(val-1, val, strlen(val)+1); 511 } else 512 BUG(); 513 } 514 } 515 516 /* Anything after -- gets handed straight to init. */ 517 static int __init set_init_arg(char *param, char *val, 518 const char *unused, void *arg) 519 { 520 unsigned int i; 521 522 if (panic_later) 523 return 0; 524 525 repair_env_string(param, val); 526 527 for (i = 0; argv_init[i]; i++) { 528 if (i == MAX_INIT_ARGS) { 529 panic_later = "init"; 530 panic_param = param; 531 return 0; 532 } 533 } 534 argv_init[i] = param; 535 return 0; 536 } 537 538 /* 539 * Unknown boot options get handed to init, unless they look like 540 * unused parameters (modprobe will find them in /proc/cmdline). 541 */ 542 static int __init unknown_bootoption(char *param, char *val, 543 const char *unused, void *arg) 544 { 545 size_t len = strlen(param); 546 547 /* Handle params aliased to sysctls */ 548 if (sysctl_is_alias(param)) 549 return 0; 550 551 repair_env_string(param, val); 552 553 /* Handle obsolete-style parameters */ 554 if (obsolete_checksetup(param)) 555 return 0; 556 557 /* Unused module parameter. */ 558 if (strnchr(param, len, '.')) 559 return 0; 560 561 if (panic_later) 562 return 0; 563 564 if (val) { 565 /* Environment option */ 566 unsigned int i; 567 for (i = 0; envp_init[i]; i++) { 568 if (i == MAX_INIT_ENVS) { 569 panic_later = "env"; 570 panic_param = param; 571 } 572 if (!strncmp(param, envp_init[i], len+1)) 573 break; 574 } 575 envp_init[i] = param; 576 } else { 577 /* Command line option */ 578 unsigned int i; 579 for (i = 0; argv_init[i]; i++) { 580 if (i == MAX_INIT_ARGS) { 581 panic_later = "init"; 582 panic_param = param; 583 } 584 } 585 argv_init[i] = param; 586 } 587 return 0; 588 } 589 590 static int __init init_setup(char *str) 591 { 592 unsigned int i; 593 594 execute_command = str; 595 /* 596 * In case LILO is going to boot us with default command line, 597 * it prepends "auto" before the whole cmdline which makes 598 * the shell think it should execute a script with such name. 599 * So we ignore all arguments entered _before_ init=... [MJ] 600 */ 601 for (i = 1; i < MAX_INIT_ARGS; i++) 602 argv_init[i] = NULL; 603 return 1; 604 } 605 __setup("init=", init_setup); 606 607 static int __init rdinit_setup(char *str) 608 { 609 unsigned int i; 610 611 ramdisk_execute_command = str; 612 /* See "auto" comment in init_setup */ 613 for (i = 1; i < MAX_INIT_ARGS; i++) 614 argv_init[i] = NULL; 615 return 1; 616 } 617 __setup("rdinit=", rdinit_setup); 618 619 #ifndef CONFIG_SMP 620 static inline void setup_nr_cpu_ids(void) { } 621 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 622 #endif 623 624 /* 625 * We need to store the untouched command line for future reference. 626 * We also need to store the touched command line since the parameter 627 * parsing is performed in place, and we should allow a component to 628 * store reference of name/value for future reference. 629 */ 630 static void __init setup_command_line(char *command_line) 631 { 632 size_t len, xlen = 0, ilen = 0; 633 634 if (extra_command_line) 635 xlen = strlen(extra_command_line); 636 if (extra_init_args) { 637 extra_init_args = strim(extra_init_args); /* remove trailing space */ 638 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 639 } 640 641 len = xlen + strlen(boot_command_line) + ilen + 1; 642 643 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 644 645 len = xlen + strlen(command_line) + 1; 646 647 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 648 649 if (xlen) { 650 /* 651 * We have to put extra_command_line before boot command 652 * lines because there could be dashes (separator of init 653 * command line) in the command lines. 654 */ 655 strcpy(saved_command_line, extra_command_line); 656 strcpy(static_command_line, extra_command_line); 657 } 658 strcpy(saved_command_line + xlen, boot_command_line); 659 strcpy(static_command_line + xlen, command_line); 660 661 if (ilen) { 662 /* 663 * Append supplemental init boot args to saved_command_line 664 * so that user can check what command line options passed 665 * to init. 666 * The order should always be 667 * " -- "[bootconfig init-param][cmdline init-param] 668 */ 669 if (initargs_offs) { 670 len = xlen + initargs_offs; 671 strcpy(saved_command_line + len, extra_init_args); 672 len += ilen - 4; /* strlen(extra_init_args) */ 673 strcpy(saved_command_line + len, 674 boot_command_line + initargs_offs - 1); 675 } else { 676 len = strlen(saved_command_line); 677 strcpy(saved_command_line + len, " -- "); 678 len += 4; 679 strcpy(saved_command_line + len, extra_init_args); 680 } 681 } 682 683 saved_command_line_len = strlen(saved_command_line); 684 } 685 686 /* 687 * We need to finalize in a non-__init function or else race conditions 688 * between the root thread and the init thread may cause start_kernel to 689 * be reaped by free_initmem before the root thread has proceeded to 690 * cpu_idle. 691 * 692 * gcc-3.4 accidentally inlines this function, so use noinline. 693 */ 694 695 static __initdata DECLARE_COMPLETION(kthreadd_done); 696 697 static noinline void __ref __noreturn rest_init(void) 698 { 699 struct task_struct *tsk; 700 int pid; 701 702 rcu_scheduler_starting(); 703 /* 704 * We need to spawn init first so that it obtains pid 1, however 705 * the init task will end up wanting to create kthreads, which, if 706 * we schedule it before we create kthreadd, will OOPS. 707 */ 708 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 709 /* 710 * Pin init on the boot CPU. Task migration is not properly working 711 * until sched_init_smp() has been run. It will set the allowed 712 * CPUs for init to the non isolated CPUs. 713 */ 714 rcu_read_lock(); 715 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 716 tsk->flags |= PF_NO_SETAFFINITY; 717 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 718 rcu_read_unlock(); 719 720 numa_default_policy(); 721 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 722 rcu_read_lock(); 723 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 724 rcu_read_unlock(); 725 726 /* 727 * Enable might_sleep() and smp_processor_id() checks. 728 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 729 * kernel_thread() would trigger might_sleep() splats. With 730 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 731 * already, but it's stuck on the kthreadd_done completion. 732 */ 733 system_state = SYSTEM_SCHEDULING; 734 735 complete(&kthreadd_done); 736 737 /* 738 * The boot idle thread must execute schedule() 739 * at least once to get things moving: 740 */ 741 schedule_preempt_disabled(); 742 /* Call into cpu_idle with preempt disabled */ 743 cpu_startup_entry(CPUHP_ONLINE); 744 } 745 746 /* Check for early params. */ 747 static int __init do_early_param(char *param, char *val, 748 const char *unused, void *arg) 749 { 750 const struct obs_kernel_param *p; 751 752 for (p = __setup_start; p < __setup_end; p++) { 753 if (p->early && parameq(param, p->str)) { 754 if (p->setup_func(val) != 0) 755 pr_warn("Malformed early option '%s'\n", param); 756 } 757 } 758 /* We accept everything at this stage. */ 759 return 0; 760 } 761 762 void __init parse_early_options(char *cmdline) 763 { 764 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 765 do_early_param); 766 } 767 768 /* Arch code calls this early on, or if not, just before other parsing. */ 769 void __init parse_early_param(void) 770 { 771 static int done __initdata; 772 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 773 774 if (done) 775 return; 776 777 /* All fall through to do_early_param. */ 778 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 779 parse_early_options(tmp_cmdline); 780 done = 1; 781 } 782 783 void __init __weak arch_post_acpi_subsys_init(void) { } 784 785 void __init __weak smp_setup_processor_id(void) 786 { 787 } 788 789 void __init __weak smp_prepare_boot_cpu(void) 790 { 791 } 792 793 # if THREAD_SIZE >= PAGE_SIZE 794 void __init __weak thread_stack_cache_init(void) 795 { 796 } 797 #endif 798 799 void __init __weak poking_init(void) { } 800 801 void __init __weak pgtable_cache_init(void) { } 802 803 void __init __weak trap_init(void) { } 804 805 bool initcall_debug; 806 core_param(initcall_debug, initcall_debug, bool, 0644); 807 808 #ifdef TRACEPOINTS_ENABLED 809 static void __init initcall_debug_enable(void); 810 #else 811 static inline void initcall_debug_enable(void) 812 { 813 } 814 #endif 815 816 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 817 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 818 randomize_kstack_offset); 819 DEFINE_PER_CPU(u32, kstack_offset); 820 821 static int __init early_randomize_kstack_offset(char *buf) 822 { 823 int ret; 824 bool bool_result; 825 826 ret = kstrtobool(buf, &bool_result); 827 if (ret) 828 return ret; 829 830 if (bool_result) 831 static_branch_enable(&randomize_kstack_offset); 832 else 833 static_branch_disable(&randomize_kstack_offset); 834 return 0; 835 } 836 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 837 #endif 838 839 static void __init print_unknown_bootoptions(void) 840 { 841 char *unknown_options; 842 char *end; 843 const char *const *p; 844 size_t len; 845 846 if (panic_later || (!argv_init[1] && !envp_init[2])) 847 return; 848 849 /* 850 * Determine how many options we have to print out, plus a space 851 * before each 852 */ 853 len = 1; /* null terminator */ 854 for (p = &argv_init[1]; *p; p++) { 855 len++; 856 len += strlen(*p); 857 } 858 for (p = &envp_init[2]; *p; p++) { 859 len++; 860 len += strlen(*p); 861 } 862 863 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 864 if (!unknown_options) { 865 pr_err("%s: Failed to allocate %zu bytes\n", 866 __func__, len); 867 return; 868 } 869 end = unknown_options; 870 871 for (p = &argv_init[1]; *p; p++) 872 end += sprintf(end, " %s", *p); 873 for (p = &envp_init[2]; *p; p++) 874 end += sprintf(end, " %s", *p); 875 876 /* Start at unknown_options[1] to skip the initial space */ 877 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 878 &unknown_options[1]); 879 memblock_free(unknown_options, len); 880 } 881 882 static void __init early_numa_node_init(void) 883 { 884 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 885 #ifndef cpu_to_node 886 int cpu; 887 888 /* The early_cpu_to_node() should be ready here. */ 889 for_each_possible_cpu(cpu) 890 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 891 #endif 892 #endif 893 } 894 895 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 896 void start_kernel(void) 897 { 898 char *command_line; 899 char *after_dashes; 900 901 set_task_stack_end_magic(&init_task); 902 smp_setup_processor_id(); 903 debug_objects_early_init(); 904 init_vmlinux_build_id(); 905 906 cgroup_init_early(); 907 908 local_irq_disable(); 909 early_boot_irqs_disabled = true; 910 911 /* 912 * Interrupts are still disabled. Do necessary setups, then 913 * enable them. 914 */ 915 boot_cpu_init(); 916 page_address_init(); 917 pr_notice("%s", linux_banner); 918 setup_arch(&command_line); 919 /* Static keys and static calls are needed by LSMs */ 920 jump_label_init(); 921 static_call_init(); 922 early_security_init(); 923 setup_boot_config(); 924 setup_command_line(command_line); 925 setup_nr_cpu_ids(); 926 setup_per_cpu_areas(); 927 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 928 early_numa_node_init(); 929 boot_cpu_hotplug_init(); 930 931 pr_notice("Kernel command line: %s\n", saved_command_line); 932 /* parameters may set static keys */ 933 parse_early_param(); 934 after_dashes = parse_args("Booting kernel", 935 static_command_line, __start___param, 936 __stop___param - __start___param, 937 -1, -1, NULL, &unknown_bootoption); 938 print_unknown_bootoptions(); 939 if (!IS_ERR_OR_NULL(after_dashes)) 940 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 941 NULL, set_init_arg); 942 if (extra_init_args) 943 parse_args("Setting extra init args", extra_init_args, 944 NULL, 0, -1, -1, NULL, set_init_arg); 945 946 /* Architectural and non-timekeeping rng init, before allocator init */ 947 random_init_early(command_line); 948 949 /* 950 * These use large bootmem allocations and must precede 951 * initalization of page allocator 952 */ 953 setup_log_buf(0); 954 vfs_caches_init_early(); 955 sort_main_extable(); 956 trap_init(); 957 mm_core_init(); 958 poking_init(); 959 ftrace_init(); 960 961 /* trace_printk can be enabled here */ 962 early_trace_init(); 963 964 /* 965 * Set up the scheduler prior starting any interrupts (such as the 966 * timer interrupt). Full topology setup happens at smp_init() 967 * time - but meanwhile we still have a functioning scheduler. 968 */ 969 sched_init(); 970 971 if (WARN(!irqs_disabled(), 972 "Interrupts were enabled *very* early, fixing it\n")) 973 local_irq_disable(); 974 radix_tree_init(); 975 maple_tree_init(); 976 977 /* 978 * Set up housekeeping before setting up workqueues to allow the unbound 979 * workqueue to take non-housekeeping into account. 980 */ 981 housekeeping_init(); 982 983 /* 984 * Allow workqueue creation and work item queueing/cancelling 985 * early. Work item execution depends on kthreads and starts after 986 * workqueue_init(). 987 */ 988 workqueue_init_early(); 989 990 rcu_init(); 991 992 /* Trace events are available after this */ 993 trace_init(); 994 995 if (initcall_debug) 996 initcall_debug_enable(); 997 998 context_tracking_init(); 999 /* init some links before init_ISA_irqs() */ 1000 early_irq_init(); 1001 init_IRQ(); 1002 tick_init(); 1003 rcu_init_nohz(); 1004 init_timers(); 1005 srcu_init(); 1006 hrtimers_init(); 1007 softirq_init(); 1008 timekeeping_init(); 1009 time_init(); 1010 1011 /* This must be after timekeeping is initialized */ 1012 random_init(); 1013 1014 /* These make use of the fully initialized rng */ 1015 kfence_init(); 1016 boot_init_stack_canary(); 1017 1018 perf_event_init(); 1019 profile_init(); 1020 call_function_init(); 1021 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1022 1023 early_boot_irqs_disabled = false; 1024 local_irq_enable(); 1025 1026 kmem_cache_init_late(); 1027 1028 /* 1029 * HACK ALERT! This is early. We're enabling the console before 1030 * we've done PCI setups etc, and console_init() must be aware of 1031 * this. But we do want output early, in case something goes wrong. 1032 */ 1033 console_init(); 1034 if (panic_later) 1035 panic("Too many boot %s vars at `%s'", panic_later, 1036 panic_param); 1037 1038 lockdep_init(); 1039 1040 /* 1041 * Need to run this when irqs are enabled, because it wants 1042 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1043 * too: 1044 */ 1045 locking_selftest(); 1046 1047 #ifdef CONFIG_BLK_DEV_INITRD 1048 if (initrd_start && !initrd_below_start_ok && 1049 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1050 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1051 page_to_pfn(virt_to_page((void *)initrd_start)), 1052 min_low_pfn); 1053 initrd_start = 0; 1054 } 1055 #endif 1056 setup_per_cpu_pageset(); 1057 numa_policy_init(); 1058 acpi_early_init(); 1059 if (late_time_init) 1060 late_time_init(); 1061 sched_clock_init(); 1062 calibrate_delay(); 1063 1064 arch_cpu_finalize_init(); 1065 1066 pid_idr_init(); 1067 anon_vma_init(); 1068 #ifdef CONFIG_X86 1069 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1070 efi_enter_virtual_mode(); 1071 #endif 1072 thread_stack_cache_init(); 1073 cred_init(); 1074 fork_init(); 1075 proc_caches_init(); 1076 uts_ns_init(); 1077 key_init(); 1078 security_init(); 1079 dbg_late_init(); 1080 net_ns_init(); 1081 vfs_caches_init(); 1082 pagecache_init(); 1083 signals_init(); 1084 seq_file_init(); 1085 proc_root_init(); 1086 nsfs_init(); 1087 pidfs_init(); 1088 cpuset_init(); 1089 cgroup_init(); 1090 taskstats_init_early(); 1091 delayacct_init(); 1092 1093 acpi_subsystem_init(); 1094 arch_post_acpi_subsys_init(); 1095 kcsan_init(); 1096 1097 /* Do the rest non-__init'ed, we're now alive */ 1098 rest_init(); 1099 1100 /* 1101 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1102 * and older. 1103 */ 1104 #if !__has_attribute(__no_stack_protector__) 1105 prevent_tail_call_optimization(); 1106 #endif 1107 } 1108 1109 /* Call all constructor functions linked into the kernel. */ 1110 static void __init do_ctors(void) 1111 { 1112 /* 1113 * For UML, the constructors have already been called by the 1114 * normal setup code as it's just a normal ELF binary, so we 1115 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1116 * even on UML for modules. 1117 */ 1118 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1119 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1120 1121 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1122 (*fn)(); 1123 #endif 1124 } 1125 1126 #ifdef CONFIG_KALLSYMS 1127 struct blacklist_entry { 1128 struct list_head next; 1129 char *buf; 1130 }; 1131 1132 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1133 1134 static int __init initcall_blacklist(char *str) 1135 { 1136 char *str_entry; 1137 struct blacklist_entry *entry; 1138 1139 /* str argument is a comma-separated list of functions */ 1140 do { 1141 str_entry = strsep(&str, ","); 1142 if (str_entry) { 1143 pr_debug("blacklisting initcall %s\n", str_entry); 1144 entry = memblock_alloc_or_panic(sizeof(*entry), 1145 SMP_CACHE_BYTES); 1146 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1147 SMP_CACHE_BYTES); 1148 strcpy(entry->buf, str_entry); 1149 list_add(&entry->next, &blacklisted_initcalls); 1150 } 1151 } while (str_entry); 1152 1153 return 1; 1154 } 1155 1156 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1157 { 1158 struct blacklist_entry *entry; 1159 char fn_name[KSYM_SYMBOL_LEN]; 1160 unsigned long addr; 1161 1162 if (list_empty(&blacklisted_initcalls)) 1163 return false; 1164 1165 addr = (unsigned long) dereference_function_descriptor(fn); 1166 sprint_symbol_no_offset(fn_name, addr); 1167 1168 /* 1169 * fn will be "function_name [module_name]" where [module_name] is not 1170 * displayed for built-in init functions. Strip off the [module_name]. 1171 */ 1172 strreplace(fn_name, ' ', '\0'); 1173 1174 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1175 if (!strcmp(fn_name, entry->buf)) { 1176 pr_debug("initcall %s blacklisted\n", fn_name); 1177 return true; 1178 } 1179 } 1180 1181 return false; 1182 } 1183 #else 1184 static int __init initcall_blacklist(char *str) 1185 { 1186 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1187 return 0; 1188 } 1189 1190 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1191 { 1192 return false; 1193 } 1194 #endif 1195 __setup("initcall_blacklist=", initcall_blacklist); 1196 1197 static __init_or_module void 1198 trace_initcall_start_cb(void *data, initcall_t fn) 1199 { 1200 ktime_t *calltime = data; 1201 1202 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1203 *calltime = ktime_get(); 1204 } 1205 1206 static __init_or_module void 1207 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1208 { 1209 ktime_t rettime, *calltime = data; 1210 1211 rettime = ktime_get(); 1212 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1213 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1214 } 1215 1216 static ktime_t initcall_calltime; 1217 1218 #ifdef TRACEPOINTS_ENABLED 1219 static void __init initcall_debug_enable(void) 1220 { 1221 int ret; 1222 1223 ret = register_trace_initcall_start(trace_initcall_start_cb, 1224 &initcall_calltime); 1225 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1226 &initcall_calltime); 1227 WARN(ret, "Failed to register initcall tracepoints\n"); 1228 } 1229 # define do_trace_initcall_start trace_initcall_start 1230 # define do_trace_initcall_finish trace_initcall_finish 1231 #else 1232 static inline void do_trace_initcall_start(initcall_t fn) 1233 { 1234 if (!initcall_debug) 1235 return; 1236 trace_initcall_start_cb(&initcall_calltime, fn); 1237 } 1238 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1239 { 1240 if (!initcall_debug) 1241 return; 1242 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1243 } 1244 #endif /* !TRACEPOINTS_ENABLED */ 1245 1246 int __init_or_module do_one_initcall(initcall_t fn) 1247 { 1248 int count = preempt_count(); 1249 char msgbuf[64]; 1250 int ret; 1251 1252 if (initcall_blacklisted(fn)) 1253 return -EPERM; 1254 1255 do_trace_initcall_start(fn); 1256 ret = fn(); 1257 do_trace_initcall_finish(fn, ret); 1258 1259 msgbuf[0] = 0; 1260 1261 if (preempt_count() != count) { 1262 sprintf(msgbuf, "preemption imbalance "); 1263 preempt_count_set(count); 1264 } 1265 if (irqs_disabled()) { 1266 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1267 local_irq_enable(); 1268 } 1269 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1270 1271 add_latent_entropy(); 1272 return ret; 1273 } 1274 1275 1276 static initcall_entry_t *initcall_levels[] __initdata = { 1277 __initcall0_start, 1278 __initcall1_start, 1279 __initcall2_start, 1280 __initcall3_start, 1281 __initcall4_start, 1282 __initcall5_start, 1283 __initcall6_start, 1284 __initcall7_start, 1285 __initcall_end, 1286 }; 1287 1288 /* Keep these in sync with initcalls in include/linux/init.h */ 1289 static const char *initcall_level_names[] __initdata = { 1290 "pure", 1291 "core", 1292 "postcore", 1293 "arch", 1294 "subsys", 1295 "fs", 1296 "device", 1297 "late", 1298 }; 1299 1300 static int __init ignore_unknown_bootoption(char *param, char *val, 1301 const char *unused, void *arg) 1302 { 1303 return 0; 1304 } 1305 1306 static void __init do_initcall_level(int level, char *command_line) 1307 { 1308 initcall_entry_t *fn; 1309 1310 parse_args(initcall_level_names[level], 1311 command_line, __start___param, 1312 __stop___param - __start___param, 1313 level, level, 1314 NULL, ignore_unknown_bootoption); 1315 1316 trace_initcall_level(initcall_level_names[level]); 1317 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1318 do_one_initcall(initcall_from_entry(fn)); 1319 } 1320 1321 static void __init do_initcalls(void) 1322 { 1323 int level; 1324 size_t len = saved_command_line_len + 1; 1325 char *command_line; 1326 1327 command_line = kzalloc(len, GFP_KERNEL); 1328 if (!command_line) 1329 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1330 1331 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1332 /* Parser modifies command_line, restore it each time */ 1333 strcpy(command_line, saved_command_line); 1334 do_initcall_level(level, command_line); 1335 } 1336 1337 kfree(command_line); 1338 } 1339 1340 /* 1341 * Ok, the machine is now initialized. None of the devices 1342 * have been touched yet, but the CPU subsystem is up and 1343 * running, and memory and process management works. 1344 * 1345 * Now we can finally start doing some real work.. 1346 */ 1347 static void __init do_basic_setup(void) 1348 { 1349 cpuset_init_smp(); 1350 driver_init(); 1351 init_irq_proc(); 1352 do_ctors(); 1353 do_initcalls(); 1354 } 1355 1356 static void __init do_pre_smp_initcalls(void) 1357 { 1358 initcall_entry_t *fn; 1359 1360 trace_initcall_level("early"); 1361 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1362 do_one_initcall(initcall_from_entry(fn)); 1363 } 1364 1365 static int run_init_process(const char *init_filename) 1366 { 1367 const char *const *p; 1368 1369 argv_init[0] = init_filename; 1370 pr_info("Run %s as init process\n", init_filename); 1371 pr_debug(" with arguments:\n"); 1372 for (p = argv_init; *p; p++) 1373 pr_debug(" %s\n", *p); 1374 pr_debug(" with environment:\n"); 1375 for (p = envp_init; *p; p++) 1376 pr_debug(" %s\n", *p); 1377 return kernel_execve(init_filename, argv_init, envp_init); 1378 } 1379 1380 static int try_to_run_init_process(const char *init_filename) 1381 { 1382 int ret; 1383 1384 ret = run_init_process(init_filename); 1385 1386 if (ret && ret != -ENOENT) { 1387 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1388 init_filename, ret); 1389 } 1390 1391 return ret; 1392 } 1393 1394 static noinline void __init kernel_init_freeable(void); 1395 1396 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1397 bool rodata_enabled __ro_after_init = true; 1398 1399 #ifndef arch_parse_debug_rodata 1400 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1401 #endif 1402 1403 static int __init set_debug_rodata(char *str) 1404 { 1405 if (arch_parse_debug_rodata(str)) 1406 return 0; 1407 1408 if (str && !strcmp(str, "on")) 1409 rodata_enabled = true; 1410 else if (str && !strcmp(str, "off")) 1411 rodata_enabled = false; 1412 else 1413 pr_warn("Invalid option string for rodata: '%s'\n", str); 1414 return 0; 1415 } 1416 early_param("rodata", set_debug_rodata); 1417 #endif 1418 1419 static void mark_readonly(void) 1420 { 1421 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1422 /* 1423 * load_module() results in W+X mappings, which are cleaned 1424 * up with init_free_wq. Let's make sure that queued work is 1425 * flushed so that we don't hit false positives looking for 1426 * insecure pages which are W+X. 1427 */ 1428 flush_module_init_free_work(); 1429 jump_label_init_ro(); 1430 mark_rodata_ro(); 1431 debug_checkwx(); 1432 rodata_test(); 1433 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1434 pr_info("Kernel memory protection disabled.\n"); 1435 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1436 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1437 } else { 1438 pr_warn("This architecture does not have kernel memory protection.\n"); 1439 } 1440 } 1441 1442 void __weak free_initmem(void) 1443 { 1444 free_initmem_default(POISON_FREE_INITMEM); 1445 } 1446 1447 static int __ref kernel_init(void *unused) 1448 { 1449 int ret; 1450 1451 /* 1452 * Wait until kthreadd is all set-up. 1453 */ 1454 wait_for_completion(&kthreadd_done); 1455 1456 kernel_init_freeable(); 1457 /* need to finish all async __init code before freeing the memory */ 1458 async_synchronize_full(); 1459 1460 system_state = SYSTEM_FREEING_INITMEM; 1461 kprobe_free_init_mem(); 1462 ftrace_free_init_mem(); 1463 kgdb_free_init_mem(); 1464 exit_boot_config(); 1465 free_initmem(); 1466 mark_readonly(); 1467 1468 /* 1469 * Kernel mappings are now finalized - update the userspace page-table 1470 * to finalize PTI. 1471 */ 1472 pti_finalize(); 1473 1474 system_state = SYSTEM_RUNNING; 1475 numa_default_policy(); 1476 1477 rcu_end_inkernel_boot(); 1478 1479 do_sysctl_args(); 1480 1481 if (ramdisk_execute_command) { 1482 ret = run_init_process(ramdisk_execute_command); 1483 if (!ret) 1484 return 0; 1485 pr_err("Failed to execute %s (error %d)\n", 1486 ramdisk_execute_command, ret); 1487 } 1488 1489 /* 1490 * We try each of these until one succeeds. 1491 * 1492 * The Bourne shell can be used instead of init if we are 1493 * trying to recover a really broken machine. 1494 */ 1495 if (execute_command) { 1496 ret = run_init_process(execute_command); 1497 if (!ret) 1498 return 0; 1499 panic("Requested init %s failed (error %d).", 1500 execute_command, ret); 1501 } 1502 1503 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1504 ret = run_init_process(CONFIG_DEFAULT_INIT); 1505 if (ret) 1506 pr_err("Default init %s failed (error %d)\n", 1507 CONFIG_DEFAULT_INIT, ret); 1508 else 1509 return 0; 1510 } 1511 1512 if (!try_to_run_init_process("/sbin/init") || 1513 !try_to_run_init_process("/etc/init") || 1514 !try_to_run_init_process("/bin/init") || 1515 !try_to_run_init_process("/bin/sh")) 1516 return 0; 1517 1518 panic("No working init found. Try passing init= option to kernel. " 1519 "See Linux Documentation/admin-guide/init.rst for guidance."); 1520 } 1521 1522 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1523 void __init console_on_rootfs(void) 1524 { 1525 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1526 1527 if (IS_ERR(file)) { 1528 pr_err("Warning: unable to open an initial console.\n"); 1529 return; 1530 } 1531 init_dup(file); 1532 init_dup(file); 1533 init_dup(file); 1534 fput(file); 1535 } 1536 1537 static noinline void __init kernel_init_freeable(void) 1538 { 1539 /* Now the scheduler is fully set up and can do blocking allocations */ 1540 gfp_allowed_mask = __GFP_BITS_MASK; 1541 1542 /* 1543 * init can allocate pages on any node 1544 */ 1545 set_mems_allowed(node_states[N_MEMORY]); 1546 1547 cad_pid = get_pid(task_pid(current)); 1548 1549 smp_prepare_cpus(setup_max_cpus); 1550 1551 workqueue_init(); 1552 1553 init_mm_internals(); 1554 1555 rcu_init_tasks_generic(); 1556 do_pre_smp_initcalls(); 1557 lockup_detector_init(); 1558 1559 smp_init(); 1560 sched_init_smp(); 1561 1562 workqueue_init_topology(); 1563 async_init(); 1564 padata_init(); 1565 page_alloc_init_late(); 1566 1567 do_basic_setup(); 1568 1569 kunit_run_all_tests(); 1570 1571 wait_for_initramfs(); 1572 console_on_rootfs(); 1573 1574 /* 1575 * check if there is an early userspace init. If yes, let it do all 1576 * the work 1577 */ 1578 if (init_eaccess(ramdisk_execute_command) != 0) { 1579 ramdisk_execute_command = NULL; 1580 prepare_namespace(); 1581 } 1582 1583 /* 1584 * Ok, we have completed the initial bootup, and 1585 * we're essentially up and running. Get rid of the 1586 * initmem segments and start the user-mode stuff.. 1587 * 1588 * rootfs is available now, try loading the public keys 1589 * and default modules 1590 */ 1591 1592 integrity_load_keys(); 1593 } 1594