개념 설명 전체 · v6.18.37 / init/main.c
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 <[email protected]> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/export.h> 17 #include <linux/extable.h> 18 #include <linux/module.h> 19 #include <linux/proc_fs.h> 20 #include <linux/binfmts.h> 21 #include <linux/kernel.h> 22 #include <linux/syscalls.h> 23 #include <linux/stackprotector.h> 24 #include <linux/string.h> 25 #include <linux/ctype.h> 26 #include <linux/delay.h> 27 #include <linux/ioport.h> 28 #include <linux/init.h> 29 #include <linux/initrd.h> 30 #include <linux/memblock.h> 31 #include <linux/acpi.h> 32 #include <linux/bootconfig.h> 33 #include <linux/console.h> 34 #include <linux/nmi.h> 35 #include <linux/percpu.h> 36 #include <linux/kmod.h> 37 #include <linux/kprobes.h> 38 #include <linux/kmsan.h> 39 #include <linux/vmalloc.h> 40 #include <linux/kernel_stat.h> 41 #include <linux/start_kernel.h> 42 #include <linux/security.h> 43 #include <linux/smp.h> 44 #include <linux/profile.h> 45 #include <linux/kfence.h> 46 #include <linux/rcupdate.h> 47 #include <linux/srcu.h> 48 #include <linux/moduleparam.h> 49 #include <linux/kallsyms.h> 50 #include <linux/buildid.h> 51 #include <linux/writeback.h> 52 #include <linux/cpu.h> 53 #include <linux/cpuset.h> 54 #include <linux/memcontrol.h> 55 #include <linux/cgroup.h> 56 #include <linux/tick.h> 57 #include <linux/sched/isolation.h> 58 #include <linux/interrupt.h> 59 #include <linux/taskstats_kern.h> 60 #include <linux/delayacct.h> 61 #include <linux/unistd.h> 62 #include <linux/utsname.h> 63 #include <linux/rmap.h> 64 #include <linux/mempolicy.h> 65 #include <linux/key.h> 66 #include <linux/debug_locks.h> 67 #include <linux/debugobjects.h> 68 #include <linux/lockdep.h> 69 #include <linux/kmemleak.h> 70 #include <linux/padata.h> 71 #include <linux/pid_namespace.h> 72 #include <linux/device/driver.h> 73 #include <linux/kthread.h> 74 #include <linux/sched.h> 75 #include <linux/sched/init.h> 76 #include <linux/signal.h> 77 #include <linux/idr.h> 78 #include <linux/kgdb.h> 79 #include <linux/ftrace.h> 80 #include <linux/async.h> 81 #include <linux/shmem_fs.h> 82 #include <linux/slab.h> 83 #include <linux/perf_event.h> 84 #include <linux/ptrace.h> 85 #include <linux/pti.h> 86 #include <linux/blkdev.h> 87 #include <linux/sched/clock.h> 88 #include <linux/sched/task.h> 89 #include <linux/sched/task_stack.h> 90 #include <linux/context_tracking.h> 91 #include <linux/random.h> 92 #include <linux/moduleloader.h> 93 #include <linux/list.h> 94 #include <linux/integrity.h> 95 #include <linux/proc_ns.h> 96 #include <linux/io.h> 97 #include <linux/cache.h> 98 #include <linux/rodata_test.h> 99 #include <linux/jump_label.h> 100 #include <linux/kcsan.h> 101 #include <linux/init_syscalls.h> 102 #include <linux/stackdepot.h> 103 #include <linux/randomize_kstack.h> 104 #include <linux/pidfs.h> 105 #include <linux/ptdump.h> 106 #include <linux/time_namespace.h> 107 #include <net/net_namespace.h> 108 109 #include <asm/io.h> 110 #include <asm/setup.h> 111 #include <asm/sections.h> 112 #include <asm/cacheflush.h> 113 114 #define CREATE_TRACE_POINTS 115 #include <trace/events/initcall.h> 116 117 #include <kunit/test.h> 118 119 static int kernel_init(void *); 120 121 /* 122 * Debug helper: via this flag we know that we are in 'early bootup code' 123 * where only the boot processor is running with IRQ disabled. This means 124 * two things - IRQ must not be enabled before the flag is cleared and some 125 * operations which are not allowed with IRQ disabled are allowed while the 126 * flag is set. 127 */ 128 bool early_boot_irqs_disabled __read_mostly; 129 130 enum system_states system_state __read_mostly; 131 EXPORT_SYMBOL(system_state); 132 133 /* 134 * Boot command-line arguments 135 */ 136 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 137 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 138 139 /* Default late time init is NULL. archs can override this later. */ 140 void (*__initdata late_time_init)(void); 141 142 /* Untouched command line saved by arch-specific code. */ 143 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 144 /* Untouched saved command line (eg. for /proc) */ 145 char *saved_command_line __ro_after_init; 146 unsigned int saved_command_line_len __ro_after_init; 147 /* Command line for parameter parsing */ 148 static char *static_command_line; 149 /* Untouched extra command line */ 150 static char *extra_command_line; 151 /* Extra init arguments */ 152 static char *extra_init_args; 153 154 #ifdef CONFIG_BOOT_CONFIG 155 /* Is bootconfig on command line? */ 156 static bool bootconfig_found; 157 static size_t initargs_offs; 158 #else 159 # define bootconfig_found false 160 # define initargs_offs 0 161 #endif 162 163 static char *execute_command; 164 static char *ramdisk_execute_command = "/init"; 165 166 /* 167 * Used to generate warnings if static_key manipulation functions are used 168 * before jump_label_init is called. 169 */ 170 bool static_key_initialized __read_mostly; 171 EXPORT_SYMBOL_GPL(static_key_initialized); 172 173 /* 174 * If set, this is an indication to the drivers that reset the underlying 175 * device before going ahead with the initialization otherwise driver might 176 * rely on the BIOS and skip the reset operation. 177 * 178 * This is useful if kernel is booting in an unreliable environment. 179 * For ex. kdump situation where previous kernel has crashed, BIOS has been 180 * skipped and devices will be in unknown state. 181 */ 182 unsigned int reset_devices; 183 EXPORT_SYMBOL(reset_devices); 184 185 static int __init set_reset_devices(char *str) 186 { 187 reset_devices = 1; 188 return 1; 189 } 190 191 __setup("reset_devices", set_reset_devices); 192 193 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 194 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 195 static const char *panic_later, *panic_param; 196 197 static bool __init obsolete_checksetup(char *line) 198 { 199 const struct obs_kernel_param *p; 200 bool had_early_param = false; 201 202 p = __setup_start; 203 do { 204 int n = strlen(p->str); 205 if (parameqn(line, p->str, n)) { 206 if (p->early) { 207 /* Already done in parse_early_param? 208 * (Needs exact match on param part). 209 * Keep iterating, as we can have early 210 * params and __setups of same names 8( */ 211 if (line[n] == '\0' || line[n] == '=') 212 had_early_param = true; 213 } else if (!p->setup_func) { 214 pr_warn("Parameter %s is obsolete, ignored\n", 215 p->str); 216 return true; 217 } else if (p->setup_func(line + n)) 218 return true; 219 } 220 p++; 221 } while (p < __setup_end); 222 223 return had_early_param; 224 } 225 226 /* 227 * This should be approx 2 Bo*oMips to start (note initial shift), and will 228 * still work even if initially too large, it will just take slightly longer 229 */ 230 unsigned long loops_per_jiffy = (1<<12); 231 EXPORT_SYMBOL(loops_per_jiffy); 232 233 static int __init debug_kernel(char *str) 234 { 235 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 236 return 0; 237 } 238 239 static int __init quiet_kernel(char *str) 240 { 241 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 242 return 0; 243 } 244 245 early_param("debug", debug_kernel); 246 early_param("quiet", quiet_kernel); 247 248 static int __init loglevel(char *str) 249 { 250 int newlevel; 251 252 /* 253 * Only update loglevel value when a correct setting was passed, 254 * to prevent blind crashes (when loglevel being set to 0) that 255 * are quite hard to debug 256 */ 257 if (get_option(&str, &newlevel)) { 258 console_loglevel = newlevel; 259 return 0; 260 } 261 262 return -EINVAL; 263 } 264 265 early_param("loglevel", loglevel); 266 267 #ifdef CONFIG_BLK_DEV_INITRD 268 static void * __init get_boot_config_from_initrd(size_t *_size) 269 { 270 u32 size, csum; 271 char *data; 272 u32 *hdr; 273 int i; 274 275 if (!initrd_end) 276 return NULL; 277 278 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 279 /* 280 * Since Grub may align the size of initrd to 4, we must 281 * check the preceding 3 bytes as well. 282 */ 283 for (i = 0; i < 4; i++) { 284 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 285 goto found; 286 data--; 287 } 288 return NULL; 289 290 found: 291 hdr = (u32 *)(data - 8); 292 size = le32_to_cpu(hdr[0]); 293 csum = le32_to_cpu(hdr[1]); 294 295 data = ((void *)hdr) - size; 296 if ((unsigned long)data < initrd_start) { 297 pr_err("bootconfig size %d is greater than initrd size %ld\n", 298 size, initrd_end - initrd_start); 299 return NULL; 300 } 301 302 if (xbc_calc_checksum(data, size) != csum) { 303 pr_err("bootconfig checksum failed\n"); 304 return NULL; 305 } 306 307 /* Remove bootconfig from initramfs/initrd */ 308 initrd_end = (unsigned long)data; 309 if (_size) 310 *_size = size; 311 312 return data; 313 } 314 #else 315 static void * __init get_boot_config_from_initrd(size_t *_size) 316 { 317 return NULL; 318 } 319 #endif 320 321 #ifdef CONFIG_BOOT_CONFIG 322 323 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 324 325 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 326 327 static int __init xbc_snprint_cmdline(char *buf, size_t size, 328 struct xbc_node *root) 329 { 330 struct xbc_node *knode, *vnode; 331 char *end = buf + size; 332 const char *val, *q; 333 int ret; 334 335 xbc_node_for_each_key_value(root, knode, val) { 336 ret = xbc_node_compose_key_after(root, knode, 337 xbc_namebuf, XBC_KEYLEN_MAX); 338 if (ret < 0) 339 return ret; 340 341 vnode = xbc_node_get_child(knode); 342 if (!vnode) { 343 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 344 if (ret < 0) 345 return ret; 346 buf += ret; 347 continue; 348 } 349 xbc_array_for_each_value(vnode, val) { 350 /* 351 * For prettier and more readable /proc/cmdline, only 352 * quote the value when necessary, i.e. when it contains 353 * whitespace. 354 */ 355 q = strpbrk(val, " \t\r\n") ? "\"" : ""; 356 ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ", 357 xbc_namebuf, q, val, q); 358 if (ret < 0) 359 return ret; 360 buf += ret; 361 } 362 } 363 364 return buf - (end - size); 365 } 366 #undef rest 367 368 /* Make an extra command line under given key word */ 369 static char * __init xbc_make_cmdline(const char *key) 370 { 371 struct xbc_node *root; 372 char *new_cmdline; 373 int ret, len = 0; 374 375 root = xbc_find_node(key); 376 if (!root) 377 return NULL; 378 379 /* Count required buffer size */ 380 len = xbc_snprint_cmdline(NULL, 0, root); 381 if (len <= 0) 382 return NULL; 383 384 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 385 if (!new_cmdline) { 386 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 387 return NULL; 388 } 389 390 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 391 if (ret < 0 || ret > len) { 392 pr_err("Failed to print extra kernel cmdline.\n"); 393 memblock_free(new_cmdline, len + 1); 394 return NULL; 395 } 396 397 return new_cmdline; 398 } 399 400 static int __init bootconfig_params(char *param, char *val, 401 const char *unused, void *arg) 402 { 403 if (strcmp(param, "bootconfig") == 0) { 404 bootconfig_found = true; 405 } 406 return 0; 407 } 408 409 static int __init warn_bootconfig(char *str) 410 { 411 /* The 'bootconfig' has been handled by bootconfig_params(). */ 412 return 0; 413 } 414 415 static void __init setup_boot_config(void) 416 { 417 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 418 const char *msg, *data; 419 int pos, ret; 420 size_t size; 421 char *err; 422 423 /* Cut out the bootconfig data even if we have no bootconfig option */ 424 data = get_boot_config_from_initrd(&size); 425 /* If there is no bootconfig in initrd, try embedded one. */ 426 if (!data) 427 data = xbc_get_embedded_bootconfig(&size); 428 429 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 430 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 431 bootconfig_params); 432 433 if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE))) 434 return; 435 436 /* parse_args() stops at the next param of '--' and returns an address */ 437 if (err) 438 initargs_offs = err - tmp_cmdline; 439 440 if (!data) { 441 /* If user intended to use bootconfig, show an error level message */ 442 if (bootconfig_found) 443 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 444 else 445 pr_info("No bootconfig data provided, so skipping bootconfig"); 446 return; 447 } 448 449 if (size >= XBC_DATA_MAX) { 450 pr_err("bootconfig size %ld greater than max size %d\n", 451 (long)size, XBC_DATA_MAX); 452 return; 453 } 454 455 ret = xbc_init(data, size, &msg, &pos); 456 if (ret < 0) { 457 if (pos < 0) 458 pr_err("Failed to init bootconfig: %s.\n", msg); 459 else 460 pr_err("Failed to parse bootconfig: %s at %d.\n", 461 msg, pos); 462 } else { 463 xbc_get_info(&ret, NULL); 464 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); 465 /* keys starting with "kernel." are passed via cmdline */ 466 extra_command_line = xbc_make_cmdline("kernel"); 467 /* Also, "init." keys are init arguments */ 468 extra_init_args = xbc_make_cmdline("init"); 469 } 470 return; 471 } 472 473 static void __init exit_boot_config(void) 474 { 475 xbc_exit(); 476 } 477 478 #else /* !CONFIG_BOOT_CONFIG */ 479 480 static void __init setup_boot_config(void) 481 { 482 /* Remove bootconfig data from initrd */ 483 get_boot_config_from_initrd(NULL); 484 } 485 486 static int __init warn_bootconfig(char *str) 487 { 488 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 489 return 0; 490 } 491 492 #define exit_boot_config() do {} while (0) 493 494 #endif /* CONFIG_BOOT_CONFIG */ 495 496 early_param("bootconfig", warn_bootconfig); 497 498 bool __init cmdline_has_extra_options(void) 499 { 500 return extra_command_line || extra_init_args; 501 } 502 503 /* Change NUL term back to "=", to make "param" the whole string. */ 504 static void __init repair_env_string(char *param, char *val) 505 { 506 if (val) { 507 /* param=val or param="val"? */ 508 if (val == param+strlen(param)+1) 509 val[-1] = '='; 510 else if (val == param+strlen(param)+2) { 511 val[-2] = '='; 512 memmove(val-1, val, strlen(val)+1); 513 } else 514 BUG(); 515 } 516 } 517 518 /* Anything after -- gets handed straight to init. */ 519 static int __init set_init_arg(char *param, char *val, 520 const char *unused, void *arg) 521 { 522 unsigned int i; 523 524 if (panic_later) 525 return 0; 526 527 repair_env_string(param, val); 528 529 for (i = 0; argv_init[i]; i++) { 530 if (i == MAX_INIT_ARGS) { 531 panic_later = "init"; 532 panic_param = param; 533 return 0; 534 } 535 } 536 argv_init[i] = param; 537 return 0; 538 } 539 540 /* 541 * Unknown boot options get handed to init, unless they look like 542 * unused parameters (modprobe will find them in /proc/cmdline). 543 */ 544 static int __init unknown_bootoption(char *param, char *val, 545 const char *unused, void *arg) 546 { 547 size_t len = strlen(param); 548 /* 549 * Well-known bootloader identifiers: 550 * 1. LILO/Grub pass "BOOT_IMAGE=..."; 551 * 2. kexec/kdump (kexec-tools) pass "kexec". 552 */ 553 const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL }; 554 555 /* Handle params aliased to sysctls */ 556 if (sysctl_is_alias(param)) 557 return 0; 558 559 repair_env_string(param, val); 560 561 /* Handle bootloader identifier */ 562 for (int i = 0; bootloader[i]; i++) { 563 if (strstarts(param, bootloader[i])) 564 return 0; 565 } 566 567 /* Handle obsolete-style parameters */ 568 if (obsolete_checksetup(param)) 569 return 0; 570 571 /* Unused module parameter. */ 572 if (strnchr(param, len, '.')) 573 return 0; 574 575 if (panic_later) 576 return 0; 577 578 if (val) { 579 /* Environment option */ 580 unsigned int i; 581 for (i = 0; envp_init[i]; i++) { 582 if (i == MAX_INIT_ENVS) { 583 panic_later = "env"; 584 panic_param = param; 585 } 586 if (!strncmp(param, envp_init[i], len+1)) 587 break; 588 } 589 envp_init[i] = param; 590 } else { 591 /* Command line option */ 592 unsigned int i; 593 for (i = 0; argv_init[i]; i++) { 594 if (i == MAX_INIT_ARGS) { 595 panic_later = "init"; 596 panic_param = param; 597 } 598 } 599 argv_init[i] = param; 600 } 601 return 0; 602 } 603 604 static int __init init_setup(char *str) 605 { 606 unsigned int i; 607 608 execute_command = str; 609 /* 610 * In case LILO is going to boot us with default command line, 611 * it prepends "auto" before the whole cmdline which makes 612 * the shell think it should execute a script with such name. 613 * So we ignore all arguments entered _before_ init=... [MJ] 614 */ 615 for (i = 1; i < MAX_INIT_ARGS; i++) 616 argv_init[i] = NULL; 617 return 1; 618 } 619 __setup("init=", init_setup); 620 621 static int __init rdinit_setup(char *str) 622 { 623 unsigned int i; 624 625 ramdisk_execute_command = str; 626 /* See "auto" comment in init_setup */ 627 for (i = 1; i < MAX_INIT_ARGS; i++) 628 argv_init[i] = NULL; 629 return 1; 630 } 631 __setup("rdinit=", rdinit_setup); 632 633 #ifndef CONFIG_SMP 634 static inline void setup_nr_cpu_ids(void) { } 635 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 636 #endif 637 638 /* 639 * We need to store the untouched command line for future reference. 640 * We also need to store the touched command line since the parameter 641 * parsing is performed in place, and we should allow a component to 642 * store reference of name/value for future reference. 643 */ 644 static void __init setup_command_line(char *command_line) 645 { 646 size_t len, xlen = 0, ilen = 0; 647 648 if (extra_command_line) 649 xlen = strlen(extra_command_line); 650 if (extra_init_args) { 651 extra_init_args = strim(extra_init_args); /* remove trailing space */ 652 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 653 } 654 655 len = xlen + strlen(boot_command_line) + ilen + 1; 656 657 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 658 659 len = xlen + strlen(command_line) + 1; 660 661 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 662 663 if (xlen) { 664 /* 665 * We have to put extra_command_line before boot command 666 * lines because there could be dashes (separator of init 667 * command line) in the command lines. 668 */ 669 strcpy(saved_command_line, extra_command_line); 670 strcpy(static_command_line, extra_command_line); 671 } 672 strcpy(saved_command_line + xlen, boot_command_line); 673 strcpy(static_command_line + xlen, command_line); 674 675 if (ilen) { 676 /* 677 * Append supplemental init boot args to saved_command_line 678 * so that user can check what command line options passed 679 * to init. 680 * The order should always be 681 * " -- "[bootconfig init-param][cmdline init-param] 682 */ 683 if (initargs_offs) { 684 len = xlen + initargs_offs; 685 strcpy(saved_command_line + len, extra_init_args); 686 len += ilen - 4; /* strlen(extra_init_args) */ 687 strcpy(saved_command_line + len, 688 boot_command_line + initargs_offs - 1); 689 } else { 690 len = strlen(saved_command_line); 691 strcpy(saved_command_line + len, " -- "); 692 len += 4; 693 strcpy(saved_command_line + len, extra_init_args); 694 } 695 } 696 697 saved_command_line_len = strlen(saved_command_line); 698 } 699 700 /* 701 * We need to finalize in a non-__init function or else race conditions 702 * between the root thread and the init thread may cause start_kernel to 703 * be reaped by free_initmem before the root thread has proceeded to 704 * cpu_idle. 705 * 706 * gcc-3.4 accidentally inlines this function, so use noinline. 707 */ 708 709 static __initdata DECLARE_COMPLETION(kthreadd_done); 710 711 static noinline void __ref __noreturn rest_init(void) 712 { 713 struct task_struct *tsk; 714 int pid; 715 716 rcu_scheduler_starting(); 717 /* 718 * We need to spawn init first so that it obtains pid 1, however 719 * the init task will end up wanting to create kthreads, which, if 720 * we schedule it before we create kthreadd, will OOPS. 721 */ 722 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 723 /* 724 * Pin init on the boot CPU. Task migration is not properly working 725 * until sched_init_smp() has been run. It will set the allowed 726 * CPUs for init to the non isolated CPUs. 727 */ 728 rcu_read_lock(); 729 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 730 tsk->flags |= PF_NO_SETAFFINITY; 731 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 732 rcu_read_unlock(); 733 734 numa_default_policy(); 735 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 736 rcu_read_lock(); 737 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 738 rcu_read_unlock(); 739 740 /* 741 * Enable might_sleep() and smp_processor_id() checks. 742 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 743 * kernel_thread() would trigger might_sleep() splats. With 744 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 745 * already, but it's stuck on the kthreadd_done completion. 746 */ 747 system_state = SYSTEM_SCHEDULING; 748 749 complete(&kthreadd_done); 750 751 /* 752 * The boot idle thread must execute schedule() 753 * at least once to get things moving: 754 */ 755 schedule_preempt_disabled(); 756 /* Call into cpu_idle with preempt disabled */ 757 cpu_startup_entry(CPUHP_ONLINE); 758 } 759 760 /* Check for early params. */ 761 static int __init do_early_param(char *param, char *val, 762 const char *unused, void *arg) 763 { 764 const struct obs_kernel_param *p; 765 766 for (p = __setup_start; p < __setup_end; p++) { 767 if (p->early && parameq(param, p->str)) { 768 if (p->setup_func(val) != 0) 769 pr_warn("Malformed early option '%s'\n", param); 770 } 771 } 772 /* We accept everything at this stage. */ 773 return 0; 774 } 775 776 void __init parse_early_options(char *cmdline) 777 { 778 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 779 do_early_param); 780 } 781 782 /* Arch code calls this early on, or if not, just before other parsing. */ 783 void __init parse_early_param(void) 784 { 785 static int done __initdata; 786 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 787 788 if (done) 789 return; 790 791 /* All fall through to do_early_param. */ 792 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 793 parse_early_options(tmp_cmdline); 794 done = 1; 795 } 796 797 void __init __weak arch_post_acpi_subsys_init(void) { } 798 799 void __init __weak smp_setup_processor_id(void) 800 { 801 } 802 803 void __init __weak smp_prepare_boot_cpu(void) 804 { 805 } 806 807 # if THREAD_SIZE >= PAGE_SIZE 808 void __init __weak thread_stack_cache_init(void) 809 { 810 } 811 #endif 812 813 void __init __weak poking_init(void) { } 814 815 void __init __weak pgtable_cache_init(void) { } 816 817 void __init __weak trap_init(void) { } 818 819 bool initcall_debug; 820 core_param(initcall_debug, initcall_debug, bool, 0644); 821 822 #ifdef TRACEPOINTS_ENABLED 823 static void __init initcall_debug_enable(void); 824 #else 825 static inline void initcall_debug_enable(void) 826 { 827 } 828 #endif 829 830 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 831 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 832 randomize_kstack_offset); 833 834 static int __init early_randomize_kstack_offset(char *buf) 835 { 836 int ret; 837 bool bool_result; 838 839 ret = kstrtobool(buf, &bool_result); 840 if (ret) 841 return ret; 842 843 if (bool_result) 844 static_branch_enable(&randomize_kstack_offset); 845 else 846 static_branch_disable(&randomize_kstack_offset); 847 return 0; 848 } 849 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 850 #endif 851 852 static void __init print_unknown_bootoptions(void) 853 { 854 char *unknown_options; 855 char *end; 856 const char *const *p; 857 size_t len; 858 859 if (panic_later || (!argv_init[1] && !envp_init[2])) 860 return; 861 862 /* 863 * Determine how many options we have to print out, plus a space 864 * before each 865 */ 866 len = 1; /* null terminator */ 867 for (p = &argv_init[1]; *p; p++) { 868 len++; 869 len += strlen(*p); 870 } 871 for (p = &envp_init[2]; *p; p++) { 872 len++; 873 len += strlen(*p); 874 } 875 876 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 877 if (!unknown_options) { 878 pr_err("%s: Failed to allocate %zu bytes\n", 879 __func__, len); 880 return; 881 } 882 end = unknown_options; 883 884 for (p = &argv_init[1]; *p; p++) 885 end += sprintf(end, " %s", *p); 886 for (p = &envp_init[2]; *p; p++) 887 end += sprintf(end, " %s", *p); 888 889 /* Start at unknown_options[1] to skip the initial space */ 890 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 891 &unknown_options[1]); 892 memblock_free(unknown_options, len); 893 } 894 895 static void __init early_numa_node_init(void) 896 { 897 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 898 #ifndef cpu_to_node 899 int cpu; 900 901 /* The early_cpu_to_node() should be ready here. */ 902 for_each_possible_cpu(cpu) 903 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 904 #endif 905 #endif 906 } 907 908 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 909 void start_kernel(void) 910 { 911 char *command_line; 912 char *after_dashes; 913 914 set_task_stack_end_magic(&init_task); 915 smp_setup_processor_id(); 916 debug_objects_early_init(); 917 init_vmlinux_build_id(); 918 919 cgroup_init_early(); 920 921 local_irq_disable(); 922 early_boot_irqs_disabled = true; 923 924 /* 925 * Interrupts are still disabled. Do necessary setups, then 926 * enable them. 927 */ 928 boot_cpu_init(); 929 page_address_init(); 930 pr_notice("%s", linux_banner); 931 setup_arch(&command_line); 932 /* Static keys and static calls are needed by LSMs */ 933 jump_label_init(); 934 static_call_init(); 935 early_security_init(); 936 setup_boot_config(); 937 setup_command_line(command_line); 938 setup_nr_cpu_ids(); 939 setup_per_cpu_areas(); 940 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 941 early_numa_node_init(); 942 boot_cpu_hotplug_init(); 943 944 pr_notice("Kernel command line: %s\n", saved_command_line); 945 /* parameters may set static keys */ 946 parse_early_param(); 947 after_dashes = parse_args("Booting kernel", 948 static_command_line, __start___param, 949 __stop___param - __start___param, 950 -1, -1, NULL, &unknown_bootoption); 951 print_unknown_bootoptions(); 952 if (!IS_ERR_OR_NULL(after_dashes)) 953 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 954 NULL, set_init_arg); 955 if (extra_init_args) 956 parse_args("Setting extra init args", extra_init_args, 957 NULL, 0, -1, -1, NULL, set_init_arg); 958 959 /* Architectural and non-timekeeping rng init, before allocator init */ 960 random_init_early(command_line); 961 962 /* 963 * These use large bootmem allocations and must precede 964 * initalization of page allocator 965 */ 966 setup_log_buf(0); 967 vfs_caches_init_early(); 968 sort_main_extable(); 969 trap_init(); 970 mm_core_init(); 971 maple_tree_init(); 972 poking_init(); 973 ftrace_init(); 974 975 /* trace_printk can be enabled here */ 976 early_trace_init(); 977 978 /* 979 * Set up the scheduler prior starting any interrupts (such as the 980 * timer interrupt). Full topology setup happens at smp_init() 981 * time - but meanwhile we still have a functioning scheduler. 982 */ 983 sched_init(); 984 985 if (WARN(!irqs_disabled(), 986 "Interrupts were enabled *very* early, fixing it\n")) 987 local_irq_disable(); 988 radix_tree_init(); 989 990 /* 991 * Set up housekeeping before setting up workqueues to allow the unbound 992 * workqueue to take non-housekeeping into account. 993 */ 994 housekeeping_init(); 995 996 /* 997 * Allow workqueue creation and work item queueing/cancelling 998 * early. Work item execution depends on kthreads and starts after 999 * workqueue_init(). 1000 */ 1001 workqueue_init_early(); 1002 1003 rcu_init(); 1004 kvfree_rcu_init(); 1005 1006 /* Trace events are available after this */ 1007 trace_init(); 1008 1009 if (initcall_debug) 1010 initcall_debug_enable(); 1011 1012 context_tracking_init(); 1013 /* init some links before init_ISA_irqs() */ 1014 early_irq_init(); 1015 init_IRQ(); 1016 tick_init(); 1017 rcu_init_nohz(); 1018 timers_init(); 1019 srcu_init(); 1020 hrtimers_init(); 1021 softirq_init(); 1022 timekeeping_init(); 1023 time_init(); 1024 1025 /* This must be after timekeeping is initialized */ 1026 random_init(); 1027 1028 /* These make use of the fully initialized rng */ 1029 kfence_init(); 1030 boot_init_stack_canary(); 1031 1032 perf_event_init(); 1033 profile_init(); 1034 call_function_init(); 1035 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1036 1037 early_boot_irqs_disabled = false; 1038 local_irq_enable(); 1039 1040 kmem_cache_init_late(); 1041 1042 /* 1043 * HACK ALERT! This is early. We're enabling the console before 1044 * we've done PCI setups etc, and console_init() must be aware of 1045 * this. But we do want output early, in case something goes wrong. 1046 */ 1047 console_init(); 1048 if (panic_later) 1049 panic("Too many boot %s vars at `%s'", panic_later, 1050 panic_param); 1051 1052 lockdep_init(); 1053 1054 /* 1055 * Need to run this when irqs are enabled, because it wants 1056 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1057 * too: 1058 */ 1059 locking_selftest(); 1060 1061 #ifdef CONFIG_BLK_DEV_INITRD 1062 if (initrd_start && !initrd_below_start_ok && 1063 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1064 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1065 page_to_pfn(virt_to_page((void *)initrd_start)), 1066 min_low_pfn); 1067 initrd_start = 0; 1068 } 1069 #endif 1070 setup_per_cpu_pageset(); 1071 numa_policy_init(); 1072 acpi_early_init(); 1073 if (late_time_init) 1074 late_time_init(); 1075 sched_clock_init(); 1076 calibrate_delay(); 1077 1078 arch_cpu_finalize_init(); 1079 1080 pid_idr_init(); 1081 anon_vma_init(); 1082 thread_stack_cache_init(); 1083 cred_init(); 1084 fork_init(); 1085 proc_caches_init(); 1086 uts_ns_init(); 1087 time_ns_init(); 1088 key_init(); 1089 security_init(); 1090 dbg_late_init(); 1091 net_ns_init(); 1092 vfs_caches_init(); 1093 pagecache_init(); 1094 signals_init(); 1095 seq_file_init(); 1096 proc_root_init(); 1097 nsfs_init(); 1098 pidfs_init(); 1099 cpuset_init(); 1100 mem_cgroup_init(); 1101 cgroup_init(); 1102 taskstats_init_early(); 1103 delayacct_init(); 1104 1105 acpi_subsystem_init(); 1106 arch_post_acpi_subsys_init(); 1107 kcsan_init(); 1108 1109 /* Do the rest non-__init'ed, we're now alive */ 1110 rest_init(); 1111 1112 /* 1113 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1114 * and older. 1115 */ 1116 #if !__has_attribute(__no_stack_protector__) 1117 prevent_tail_call_optimization(); 1118 #endif 1119 } 1120 1121 /* Call all constructor functions linked into the kernel. */ 1122 static void __init do_ctors(void) 1123 { 1124 /* 1125 * For UML, the constructors have already been called by the 1126 * normal setup code as it's just a normal ELF binary, so we 1127 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1128 * even on UML for modules. 1129 */ 1130 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1131 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1132 1133 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1134 (*fn)(); 1135 #endif 1136 } 1137 1138 #ifdef CONFIG_KALLSYMS 1139 struct blacklist_entry { 1140 struct list_head next; 1141 char *buf; 1142 }; 1143 1144 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1145 1146 static int __init initcall_blacklist(char *str) 1147 { 1148 char *str_entry; 1149 struct blacklist_entry *entry; 1150 1151 /* str argument is a comma-separated list of functions */ 1152 do { 1153 str_entry = strsep(&str, ","); 1154 if (str_entry) { 1155 pr_debug("blacklisting initcall %s\n", str_entry); 1156 entry = memblock_alloc_or_panic(sizeof(*entry), 1157 SMP_CACHE_BYTES); 1158 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1159 SMP_CACHE_BYTES); 1160 strcpy(entry->buf, str_entry); 1161 list_add(&entry->next, &blacklisted_initcalls); 1162 } 1163 } while (str_entry); 1164 1165 return 1; 1166 } 1167 1168 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1169 { 1170 struct blacklist_entry *entry; 1171 char fn_name[KSYM_SYMBOL_LEN]; 1172 unsigned long addr; 1173 1174 if (list_empty(&blacklisted_initcalls)) 1175 return false; 1176 1177 addr = (unsigned long) dereference_function_descriptor(fn); 1178 sprint_symbol_no_offset(fn_name, addr); 1179 1180 /* 1181 * fn will be "function_name [module_name]" where [module_name] is not 1182 * displayed for built-in init functions. Strip off the [module_name]. 1183 */ 1184 strreplace(fn_name, ' ', '\0'); 1185 1186 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1187 if (!strcmp(fn_name, entry->buf)) { 1188 pr_debug("initcall %s blacklisted\n", fn_name); 1189 return true; 1190 } 1191 } 1192 1193 return false; 1194 } 1195 #else 1196 static int __init initcall_blacklist(char *str) 1197 { 1198 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1199 return 0; 1200 } 1201 1202 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1203 { 1204 return false; 1205 } 1206 #endif 1207 __setup("initcall_blacklist=", initcall_blacklist); 1208 1209 static __init_or_module void 1210 trace_initcall_start_cb(void *data, initcall_t fn) 1211 { 1212 ktime_t *calltime = data; 1213 1214 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1215 *calltime = ktime_get(); 1216 } 1217 1218 static __init_or_module void 1219 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1220 { 1221 ktime_t rettime, *calltime = data; 1222 1223 rettime = ktime_get(); 1224 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1225 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1226 } 1227 1228 static __init_or_module void 1229 trace_initcall_level_cb(void *data, const char *level) 1230 { 1231 printk(KERN_DEBUG "entering initcall level: %s\n", level); 1232 } 1233 1234 static ktime_t initcall_calltime; 1235 1236 #ifdef TRACEPOINTS_ENABLED 1237 static void __init initcall_debug_enable(void) 1238 { 1239 int ret; 1240 1241 ret = register_trace_initcall_start(trace_initcall_start_cb, 1242 &initcall_calltime); 1243 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1244 &initcall_calltime); 1245 ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL); 1246 WARN(ret, "Failed to register initcall tracepoints\n"); 1247 } 1248 # define do_trace_initcall_start trace_initcall_start 1249 # define do_trace_initcall_finish trace_initcall_finish 1250 # define do_trace_initcall_level trace_initcall_level 1251 #else 1252 static inline void do_trace_initcall_start(initcall_t fn) 1253 { 1254 if (!initcall_debug) 1255 return; 1256 trace_initcall_start_cb(&initcall_calltime, fn); 1257 } 1258 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1259 { 1260 if (!initcall_debug) 1261 return; 1262 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1263 } 1264 static inline void do_trace_initcall_level(const char *level) 1265 { 1266 if (!initcall_debug) 1267 return; 1268 trace_initcall_level_cb(NULL, level); 1269 } 1270 #endif /* !TRACEPOINTS_ENABLED */ 1271 1272 int __init_or_module do_one_initcall(initcall_t fn) 1273 { 1274 int count = preempt_count(); 1275 char msgbuf[64]; 1276 int ret; 1277 1278 if (initcall_blacklisted(fn)) 1279 return -EPERM; 1280 1281 do_trace_initcall_start(fn); 1282 ret = fn(); 1283 do_trace_initcall_finish(fn, ret); 1284 1285 msgbuf[0] = 0; 1286 1287 if (preempt_count() != count) { 1288 sprintf(msgbuf, "preemption imbalance "); 1289 preempt_count_set(count); 1290 } 1291 if (irqs_disabled()) { 1292 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1293 local_irq_enable(); 1294 } 1295 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1296 1297 add_latent_entropy(); 1298 return ret; 1299 } 1300 1301 1302 static initcall_entry_t *initcall_levels[] __initdata = { 1303 __initcall0_start, 1304 __initcall1_start, 1305 __initcall2_start, 1306 __initcall3_start, 1307 __initcall4_start, 1308 __initcall5_start, 1309 __initcall6_start, 1310 __initcall7_start, 1311 __initcall_end, 1312 }; 1313 1314 /* Keep these in sync with initcalls in include/linux/init.h */ 1315 static const char *initcall_level_names[] __initdata = { 1316 "pure", 1317 "core", 1318 "postcore", 1319 "arch", 1320 "subsys", 1321 "fs", 1322 "device", 1323 "late", 1324 }; 1325 1326 static int __init ignore_unknown_bootoption(char *param, char *val, 1327 const char *unused, void *arg) 1328 { 1329 return 0; 1330 } 1331 1332 static void __init do_initcall_level(int level, char *command_line) 1333 { 1334 initcall_entry_t *fn; 1335 1336 parse_args(initcall_level_names[level], 1337 command_line, __start___param, 1338 __stop___param - __start___param, 1339 level, level, 1340 NULL, ignore_unknown_bootoption); 1341 1342 do_trace_initcall_level(initcall_level_names[level]); 1343 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1344 do_one_initcall(initcall_from_entry(fn)); 1345 } 1346 1347 static void __init do_initcalls(void) 1348 { 1349 int level; 1350 size_t len = saved_command_line_len + 1; 1351 char *command_line; 1352 1353 command_line = kzalloc(len, GFP_KERNEL); 1354 if (!command_line) 1355 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1356 1357 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1358 /* Parser modifies command_line, restore it each time */ 1359 strcpy(command_line, saved_command_line); 1360 do_initcall_level(level, command_line); 1361 } 1362 1363 kfree(command_line); 1364 } 1365 1366 /* 1367 * Ok, the machine is now initialized. None of the devices 1368 * have been touched yet, but the CPU subsystem is up and 1369 * running, and memory and process management works. 1370 * 1371 * Now we can finally start doing some real work.. 1372 */ 1373 static void __init do_basic_setup(void) 1374 { 1375 cpuset_init_smp(); 1376 driver_init(); 1377 init_irq_proc(); 1378 do_ctors(); 1379 do_initcalls(); 1380 } 1381 1382 static void __init do_pre_smp_initcalls(void) 1383 { 1384 initcall_entry_t *fn; 1385 1386 do_trace_initcall_level("early"); 1387 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1388 do_one_initcall(initcall_from_entry(fn)); 1389 } 1390 1391 static int run_init_process(const char *init_filename) 1392 { 1393 const char *const *p; 1394 1395 argv_init[0] = init_filename; 1396 pr_info("Run %s as init process\n", init_filename); 1397 pr_debug(" with arguments:\n"); 1398 for (p = argv_init; *p; p++) 1399 pr_debug(" %s\n", *p); 1400 pr_debug(" with environment:\n"); 1401 for (p = envp_init; *p; p++) 1402 pr_debug(" %s\n", *p); 1403 return kernel_execve(init_filename, argv_init, envp_init); 1404 } 1405 1406 static int try_to_run_init_process(const char *init_filename) 1407 { 1408 int ret; 1409 1410 ret = run_init_process(init_filename); 1411 1412 if (ret && ret != -ENOENT) { 1413 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1414 init_filename, ret); 1415 } 1416 1417 return ret; 1418 } 1419 1420 static noinline void __init kernel_init_freeable(void); 1421 1422 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1423 bool rodata_enabled __ro_after_init = true; 1424 1425 #ifndef arch_parse_debug_rodata 1426 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1427 #endif 1428 1429 static int __init set_debug_rodata(char *str) 1430 { 1431 if (arch_parse_debug_rodata(str)) 1432 return 0; 1433 1434 if (str && !strcmp(str, "on")) 1435 rodata_enabled = true; 1436 else if (str && !strcmp(str, "off")) 1437 rodata_enabled = false; 1438 else 1439 pr_warn("Invalid option string for rodata: '%s'\n", str); 1440 return 0; 1441 } 1442 early_param("rodata", set_debug_rodata); 1443 #endif 1444 1445 static void mark_readonly(void) 1446 { 1447 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1448 /* 1449 * load_module() results in W+X mappings, which are cleaned 1450 * up with init_free_wq. Let's make sure that queued work is 1451 * flushed so that we don't hit false positives looking for 1452 * insecure pages which are W+X. 1453 */ 1454 flush_module_init_free_work(); 1455 jump_label_init_ro(); 1456 mark_rodata_ro(); 1457 debug_checkwx(); 1458 rodata_test(); 1459 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1460 pr_info("Kernel memory protection disabled.\n"); 1461 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1462 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1463 } else { 1464 pr_warn("This architecture does not have kernel memory protection.\n"); 1465 } 1466 } 1467 1468 void __weak free_initmem(void) 1469 { 1470 free_initmem_default(POISON_FREE_INITMEM); 1471 } 1472 1473 static int __ref kernel_init(void *unused) 1474 { 1475 int ret; 1476 1477 /* 1478 * Wait until kthreadd is all set-up. 1479 */ 1480 wait_for_completion(&kthreadd_done); 1481 1482 kernel_init_freeable(); 1483 /* need to finish all async __init code before freeing the memory */ 1484 async_synchronize_full(); 1485 1486 system_state = SYSTEM_FREEING_INITMEM; 1487 kprobe_free_init_mem(); 1488 ftrace_free_init_mem(); 1489 kgdb_free_init_mem(); 1490 exit_boot_config(); 1491 free_initmem(); 1492 mark_readonly(); 1493 1494 /* 1495 * Kernel mappings are now finalized - update the userspace page-table 1496 * to finalize PTI. 1497 */ 1498 pti_finalize(); 1499 1500 system_state = SYSTEM_RUNNING; 1501 numa_default_policy(); 1502 1503 rcu_end_inkernel_boot(); 1504 1505 do_sysctl_args(); 1506 1507 if (ramdisk_execute_command) { 1508 ret = run_init_process(ramdisk_execute_command); 1509 if (!ret) 1510 return 0; 1511 pr_err("Failed to execute %s (error %d)\n", 1512 ramdisk_execute_command, ret); 1513 } 1514 1515 /* 1516 * We try each of these until one succeeds. 1517 * 1518 * The Bourne shell can be used instead of init if we are 1519 * trying to recover a really broken machine. 1520 */ 1521 if (execute_command) { 1522 ret = run_init_process(execute_command); 1523 if (!ret) 1524 return 0; 1525 panic("Requested init %s failed (error %d).", 1526 execute_command, ret); 1527 } 1528 1529 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1530 ret = run_init_process(CONFIG_DEFAULT_INIT); 1531 if (ret) 1532 pr_err("Default init %s failed (error %d)\n", 1533 CONFIG_DEFAULT_INIT, ret); 1534 else 1535 return 0; 1536 } 1537 1538 if (!try_to_run_init_process("/sbin/init") || 1539 !try_to_run_init_process("/etc/init") || 1540 !try_to_run_init_process("/bin/init") || 1541 !try_to_run_init_process("/bin/sh")) 1542 return 0; 1543 1544 panic("No working init found. Try passing init= option to kernel. " 1545 "See Linux Documentation/admin-guide/init.rst for guidance."); 1546 } 1547 1548 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1549 void __init console_on_rootfs(void) 1550 { 1551 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1552 1553 if (IS_ERR(file)) { 1554 pr_err("Warning: unable to open an initial console.\n"); 1555 return; 1556 } 1557 init_dup(file); 1558 init_dup(file); 1559 init_dup(file); 1560 fput(file); 1561 } 1562 1563 static noinline void __init kernel_init_freeable(void) 1564 { 1565 /* Now the scheduler is fully set up and can do blocking allocations */ 1566 gfp_allowed_mask = __GFP_BITS_MASK; 1567 1568 /* 1569 * init can allocate pages on any node 1570 */ 1571 set_mems_allowed(node_states[N_MEMORY]); 1572 1573 cad_pid = get_pid(task_pid(current)); 1574 1575 smp_prepare_cpus(setup_max_cpus); 1576 1577 workqueue_init(); 1578 1579 init_mm_internals(); 1580 1581 do_pre_smp_initcalls(); 1582 lockup_detector_init(); 1583 1584 smp_init(); 1585 sched_init_smp(); 1586 1587 workqueue_init_topology(); 1588 async_init(); 1589 padata_init(); 1590 page_alloc_init_late(); 1591 1592 do_basic_setup(); 1593 1594 kunit_run_all_tests(); 1595 1596 wait_for_initramfs(); 1597 console_on_rootfs(); 1598 1599 /* 1600 * check if there is an early userspace init. If yes, let it do all 1601 * the work 1602 */ 1603 int ramdisk_command_access; 1604 ramdisk_command_access = init_eaccess(ramdisk_execute_command); 1605 if (ramdisk_command_access != 0) { 1606 pr_warn("check access for rdinit=%s failed: %i, ignoring\n", 1607 ramdisk_execute_command, ramdisk_command_access); 1608 ramdisk_execute_command = NULL; 1609 prepare_namespace(); 1610 } 1611 1612 /* 1613 * Ok, we have completed the initial bootup, and 1614 * we're essentially up and running. Get rid of the 1615 * initmem segments and start the user-mode stuff.. 1616 * 1617 * rootfs is available now, try loading the public keys 1618 * and default modules 1619 */ 1620 1621 integrity_load_keys(); 1622 }