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