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(len, SMP_CACHE_BYTES); 644 if (!saved_command_line) 645 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 646 647 len = xlen + strlen(command_line) + 1; 648 649 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 650 if (!static_command_line) 651 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 652 653 if (xlen) { 654 /* 655 * We have to put extra_command_line before boot command 656 * lines because there could be dashes (separator of init 657 * command line) in the command lines. 658 */ 659 strcpy(saved_command_line, extra_command_line); 660 strcpy(static_command_line, extra_command_line); 661 } 662 strcpy(saved_command_line + xlen, boot_command_line); 663 strcpy(static_command_line + xlen, command_line); 664 665 if (ilen) { 666 /* 667 * Append supplemental init boot args to saved_command_line 668 * so that user can check what command line options passed 669 * to init. 670 * The order should always be 671 * " -- "[bootconfig init-param][cmdline init-param] 672 */ 673 if (initargs_offs) { 674 len = xlen + initargs_offs; 675 strcpy(saved_command_line + len, extra_init_args); 676 len += ilen - 4; /* strlen(extra_init_args) */ 677 strcpy(saved_command_line + len, 678 boot_command_line + initargs_offs - 1); 679 } else { 680 len = strlen(saved_command_line); 681 strcpy(saved_command_line + len, " -- "); 682 len += 4; 683 strcpy(saved_command_line + len, extra_init_args); 684 } 685 } 686 687 saved_command_line_len = strlen(saved_command_line); 688 } 689 690 /* 691 * We need to finalize in a non-__init function or else race conditions 692 * between the root thread and the init thread may cause start_kernel to 693 * be reaped by free_initmem before the root thread has proceeded to 694 * cpu_idle. 695 * 696 * gcc-3.4 accidentally inlines this function, so use noinline. 697 */ 698 699 static __initdata DECLARE_COMPLETION(kthreadd_done); 700 701 static noinline void __ref __noreturn rest_init(void) 702 { 703 struct task_struct *tsk; 704 int pid; 705 706 rcu_scheduler_starting(); 707 /* 708 * We need to spawn init first so that it obtains pid 1, however 709 * the init task will end up wanting to create kthreads, which, if 710 * we schedule it before we create kthreadd, will OOPS. 711 */ 712 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 713 /* 714 * Pin init on the boot CPU. Task migration is not properly working 715 * until sched_init_smp() has been run. It will set the allowed 716 * CPUs for init to the non isolated CPUs. 717 */ 718 rcu_read_lock(); 719 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 720 tsk->flags |= PF_NO_SETAFFINITY; 721 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 722 rcu_read_unlock(); 723 724 numa_default_policy(); 725 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 726 rcu_read_lock(); 727 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 728 rcu_read_unlock(); 729 730 /* 731 * Enable might_sleep() and smp_processor_id() checks. 732 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 733 * kernel_thread() would trigger might_sleep() splats. With 734 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 735 * already, but it's stuck on the kthreadd_done completion. 736 */ 737 system_state = SYSTEM_SCHEDULING; 738 739 complete(&kthreadd_done); 740 741 /* 742 * The boot idle thread must execute schedule() 743 * at least once to get things moving: 744 */ 745 schedule_preempt_disabled(); 746 /* Call into cpu_idle with preempt disabled */ 747 cpu_startup_entry(CPUHP_ONLINE); 748 } 749 750 /* Check for early params. */ 751 static int __init do_early_param(char *param, char *val, 752 const char *unused, void *arg) 753 { 754 const struct obs_kernel_param *p; 755 756 for (p = __setup_start; p < __setup_end; p++) { 757 if ((p->early && parameq(param, p->str)) || 758 (strcmp(param, "console") == 0 && 759 strcmp(p->str, "earlycon") == 0) 760 ) { 761 if (p->setup_func(val) != 0) 762 pr_warn("Malformed early option '%s'\n", param); 763 } 764 } 765 /* We accept everything at this stage. */ 766 return 0; 767 } 768 769 void __init parse_early_options(char *cmdline) 770 { 771 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 772 do_early_param); 773 } 774 775 /* Arch code calls this early on, or if not, just before other parsing. */ 776 void __init parse_early_param(void) 777 { 778 static int done __initdata; 779 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 780 781 if (done) 782 return; 783 784 /* All fall through to do_early_param. */ 785 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 786 parse_early_options(tmp_cmdline); 787 done = 1; 788 } 789 790 void __init __weak arch_post_acpi_subsys_init(void) { } 791 792 void __init __weak smp_setup_processor_id(void) 793 { 794 } 795 796 void __init __weak smp_prepare_boot_cpu(void) 797 { 798 } 799 800 # if THREAD_SIZE >= PAGE_SIZE 801 void __init __weak thread_stack_cache_init(void) 802 { 803 } 804 #endif 805 806 void __init __weak poking_init(void) { } 807 808 void __init __weak pgtable_cache_init(void) { } 809 810 void __init __weak trap_init(void) { } 811 812 bool initcall_debug; 813 core_param(initcall_debug, initcall_debug, bool, 0644); 814 815 #ifdef TRACEPOINTS_ENABLED 816 static void __init initcall_debug_enable(void); 817 #else 818 static inline void initcall_debug_enable(void) 819 { 820 } 821 #endif 822 823 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 824 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 825 randomize_kstack_offset); 826 DEFINE_PER_CPU(u32, kstack_offset); 827 828 static int __init early_randomize_kstack_offset(char *buf) 829 { 830 int ret; 831 bool bool_result; 832 833 ret = kstrtobool(buf, &bool_result); 834 if (ret) 835 return ret; 836 837 if (bool_result) 838 static_branch_enable(&randomize_kstack_offset); 839 else 840 static_branch_disable(&randomize_kstack_offset); 841 return 0; 842 } 843 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 844 #endif 845 846 static void __init print_unknown_bootoptions(void) 847 { 848 char *unknown_options; 849 char *end; 850 const char *const *p; 851 size_t len; 852 853 if (panic_later || (!argv_init[1] && !envp_init[2])) 854 return; 855 856 /* 857 * Determine how many options we have to print out, plus a space 858 * before each 859 */ 860 len = 1; /* null terminator */ 861 for (p = &argv_init[1]; *p; p++) { 862 len++; 863 len += strlen(*p); 864 } 865 for (p = &envp_init[2]; *p; p++) { 866 len++; 867 len += strlen(*p); 868 } 869 870 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 871 if (!unknown_options) { 872 pr_err("%s: Failed to allocate %zu bytes\n", 873 __func__, len); 874 return; 875 } 876 end = unknown_options; 877 878 for (p = &argv_init[1]; *p; p++) 879 end += sprintf(end, " %s", *p); 880 for (p = &envp_init[2]; *p; p++) 881 end += sprintf(end, " %s", *p); 882 883 /* Start at unknown_options[1] to skip the initial space */ 884 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 885 &unknown_options[1]); 886 memblock_free(unknown_options, len); 887 } 888 889 static void __init early_numa_node_init(void) 890 { 891 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 892 #ifndef cpu_to_node 893 int cpu; 894 895 /* The early_cpu_to_node() should be ready here. */ 896 for_each_possible_cpu(cpu) 897 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 898 #endif 899 #endif 900 } 901 902 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 903 void start_kernel(void) 904 { 905 char *command_line; 906 char *after_dashes; 907 908 set_task_stack_end_magic(&init_task); 909 smp_setup_processor_id(); 910 debug_objects_early_init(); 911 init_vmlinux_build_id(); 912 913 cgroup_init_early(); 914 915 local_irq_disable(); 916 early_boot_irqs_disabled = true; 917 918 /* 919 * Interrupts are still disabled. Do necessary setups, then 920 * enable them. 921 */ 922 boot_cpu_init(); 923 page_address_init(); 924 pr_notice("%s", linux_banner); 925 setup_arch(&command_line); 926 /* Static keys and static calls are needed by LSMs */ 927 jump_label_init(); 928 static_call_init(); 929 early_security_init(); 930 setup_boot_config(); 931 setup_command_line(command_line); 932 setup_nr_cpu_ids(); 933 setup_per_cpu_areas(); 934 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 935 early_numa_node_init(); 936 boot_cpu_hotplug_init(); 937 938 pr_notice("Kernel command line: %s\n", saved_command_line); 939 /* parameters may set static keys */ 940 parse_early_param(); 941 after_dashes = parse_args("Booting kernel", 942 static_command_line, __start___param, 943 __stop___param - __start___param, 944 -1, -1, NULL, &unknown_bootoption); 945 print_unknown_bootoptions(); 946 if (!IS_ERR_OR_NULL(after_dashes)) 947 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 948 NULL, set_init_arg); 949 if (extra_init_args) 950 parse_args("Setting extra init args", extra_init_args, 951 NULL, 0, -1, -1, NULL, set_init_arg); 952 953 /* Architectural and non-timekeeping rng init, before allocator init */ 954 random_init_early(command_line); 955 956 /* 957 * These use large bootmem allocations and must precede 958 * initalization of page allocator 959 */ 960 setup_log_buf(0); 961 vfs_caches_init_early(); 962 sort_main_extable(); 963 trap_init(); 964 mm_core_init(); 965 poking_init(); 966 ftrace_init(); 967 968 /* trace_printk can be enabled here */ 969 early_trace_init(); 970 971 /* 972 * Set up the scheduler prior starting any interrupts (such as the 973 * timer interrupt). Full topology setup happens at smp_init() 974 * time - but meanwhile we still have a functioning scheduler. 975 */ 976 sched_init(); 977 978 if (WARN(!irqs_disabled(), 979 "Interrupts were enabled *very* early, fixing it\n")) 980 local_irq_disable(); 981 radix_tree_init(); 982 maple_tree_init(); 983 984 /* 985 * Set up housekeeping before setting up workqueues to allow the unbound 986 * workqueue to take non-housekeeping into account. 987 */ 988 housekeeping_init(); 989 990 /* 991 * Allow workqueue creation and work item queueing/cancelling 992 * early. Work item execution depends on kthreads and starts after 993 * workqueue_init(). 994 */ 995 workqueue_init_early(); 996 997 rcu_init(); 998 999 /* Trace events are available after this */ 1000 trace_init(); 1001 1002 if (initcall_debug) 1003 initcall_debug_enable(); 1004 1005 context_tracking_init(); 1006 /* init some links before init_ISA_irqs() */ 1007 early_irq_init(); 1008 init_IRQ(); 1009 tick_init(); 1010 rcu_init_nohz(); 1011 init_timers(); 1012 srcu_init(); 1013 hrtimers_init(); 1014 softirq_init(); 1015 timekeeping_init(); 1016 time_init(); 1017 1018 /* This must be after timekeeping is initialized */ 1019 random_init(); 1020 1021 /* These make use of the fully initialized rng */ 1022 kfence_init(); 1023 boot_init_stack_canary(); 1024 1025 perf_event_init(); 1026 profile_init(); 1027 call_function_init(); 1028 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1029 1030 early_boot_irqs_disabled = false; 1031 local_irq_enable(); 1032 1033 kmem_cache_init_late(); 1034 1035 /* 1036 * HACK ALERT! This is early. We're enabling the console before 1037 * we've done PCI setups etc, and console_init() must be aware of 1038 * this. But we do want output early, in case something goes wrong. 1039 */ 1040 console_init(); 1041 if (panic_later) 1042 panic("Too many boot %s vars at `%s'", panic_later, 1043 panic_param); 1044 1045 lockdep_init(); 1046 1047 /* 1048 * Need to run this when irqs are enabled, because it wants 1049 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1050 * too: 1051 */ 1052 locking_selftest(); 1053 1054 #ifdef CONFIG_BLK_DEV_INITRD 1055 if (initrd_start && !initrd_below_start_ok && 1056 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1057 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1058 page_to_pfn(virt_to_page((void *)initrd_start)), 1059 min_low_pfn); 1060 initrd_start = 0; 1061 } 1062 #endif 1063 setup_per_cpu_pageset(); 1064 numa_policy_init(); 1065 acpi_early_init(); 1066 if (late_time_init) 1067 late_time_init(); 1068 sched_clock_init(); 1069 calibrate_delay(); 1070 1071 arch_cpu_finalize_init(); 1072 1073 pid_idr_init(); 1074 anon_vma_init(); 1075 #ifdef CONFIG_X86 1076 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1077 efi_enter_virtual_mode(); 1078 #endif 1079 thread_stack_cache_init(); 1080 cred_init(); 1081 fork_init(); 1082 proc_caches_init(); 1083 uts_ns_init(); 1084 key_init(); 1085 security_init(); 1086 dbg_late_init(); 1087 net_ns_init(); 1088 vfs_caches_init(); 1089 pagecache_init(); 1090 signals_init(); 1091 seq_file_init(); 1092 proc_root_init(); 1093 nsfs_init(); 1094 pidfs_init(); 1095 cpuset_init(); 1096 cgroup_init(); 1097 taskstats_init_early(); 1098 delayacct_init(); 1099 1100 acpi_subsystem_init(); 1101 arch_post_acpi_subsys_init(); 1102 kcsan_init(); 1103 1104 /* Do the rest non-__init'ed, we're now alive */ 1105 rest_init(); 1106 1107 /* 1108 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1109 * and older. 1110 */ 1111 #if !__has_attribute(__no_stack_protector__) 1112 prevent_tail_call_optimization(); 1113 #endif 1114 } 1115 1116 /* Call all constructor functions linked into the kernel. */ 1117 static void __init do_ctors(void) 1118 { 1119 /* 1120 * For UML, the constructors have already been called by the 1121 * normal setup code as it's just a normal ELF binary, so we 1122 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1123 * even on UML for modules. 1124 */ 1125 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1126 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1127 1128 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1129 (*fn)(); 1130 #endif 1131 } 1132 1133 #ifdef CONFIG_KALLSYMS 1134 struct blacklist_entry { 1135 struct list_head next; 1136 char *buf; 1137 }; 1138 1139 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1140 1141 static int __init initcall_blacklist(char *str) 1142 { 1143 char *str_entry; 1144 struct blacklist_entry *entry; 1145 1146 /* str argument is a comma-separated list of functions */ 1147 do { 1148 str_entry = strsep(&str, ","); 1149 if (str_entry) { 1150 pr_debug("blacklisting initcall %s\n", str_entry); 1151 entry = memblock_alloc(sizeof(*entry), 1152 SMP_CACHE_BYTES); 1153 if (!entry) 1154 panic("%s: Failed to allocate %zu bytes\n", 1155 __func__, sizeof(*entry)); 1156 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1157 SMP_CACHE_BYTES); 1158 if (!entry->buf) 1159 panic("%s: Failed to allocate %zu bytes\n", 1160 __func__, strlen(str_entry) + 1); 1161 strcpy(entry->buf, str_entry); 1162 list_add(&entry->next, &blacklisted_initcalls); 1163 } 1164 } while (str_entry); 1165 1166 return 1; 1167 } 1168 1169 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1170 { 1171 struct blacklist_entry *entry; 1172 char fn_name[KSYM_SYMBOL_LEN]; 1173 unsigned long addr; 1174 1175 if (list_empty(&blacklisted_initcalls)) 1176 return false; 1177 1178 addr = (unsigned long) dereference_function_descriptor(fn); 1179 sprint_symbol_no_offset(fn_name, addr); 1180 1181 /* 1182 * fn will be "function_name [module_name]" where [module_name] is not 1183 * displayed for built-in init functions. Strip off the [module_name]. 1184 */ 1185 strreplace(fn_name, ' ', '\0'); 1186 1187 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1188 if (!strcmp(fn_name, entry->buf)) { 1189 pr_debug("initcall %s blacklisted\n", fn_name); 1190 return true; 1191 } 1192 } 1193 1194 return false; 1195 } 1196 #else 1197 static int __init initcall_blacklist(char *str) 1198 { 1199 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1200 return 0; 1201 } 1202 1203 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1204 { 1205 return false; 1206 } 1207 #endif 1208 __setup("initcall_blacklist=", initcall_blacklist); 1209 1210 static __init_or_module void 1211 trace_initcall_start_cb(void *data, initcall_t fn) 1212 { 1213 ktime_t *calltime = data; 1214 1215 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1216 *calltime = ktime_get(); 1217 } 1218 1219 static __init_or_module void 1220 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1221 { 1222 ktime_t rettime, *calltime = data; 1223 1224 rettime = ktime_get(); 1225 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1226 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1227 } 1228 1229 static ktime_t initcall_calltime; 1230 1231 #ifdef TRACEPOINTS_ENABLED 1232 static void __init initcall_debug_enable(void) 1233 { 1234 int ret; 1235 1236 ret = register_trace_initcall_start(trace_initcall_start_cb, 1237 &initcall_calltime); 1238 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1239 &initcall_calltime); 1240 WARN(ret, "Failed to register initcall tracepoints\n"); 1241 } 1242 # define do_trace_initcall_start trace_initcall_start 1243 # define do_trace_initcall_finish trace_initcall_finish 1244 #else 1245 static inline void do_trace_initcall_start(initcall_t fn) 1246 { 1247 if (!initcall_debug) 1248 return; 1249 trace_initcall_start_cb(&initcall_calltime, fn); 1250 } 1251 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1252 { 1253 if (!initcall_debug) 1254 return; 1255 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 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 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 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 rcu_init_tasks_generic(); 1569 do_pre_smp_initcalls(); 1570 lockup_detector_init(); 1571 1572 smp_init(); 1573 sched_init_smp(); 1574 1575 workqueue_init_topology(); 1576 async_init(); 1577 padata_init(); 1578 page_alloc_init_late(); 1579 1580 do_basic_setup(); 1581 1582 kunit_run_all_tests(); 1583 1584 wait_for_initramfs(); 1585 console_on_rootfs(); 1586 1587 /* 1588 * check if there is an early userspace init. If yes, let it do all 1589 * the work 1590 */ 1591 if (init_eaccess(ramdisk_execute_command) != 0) { 1592 ramdisk_execute_command = NULL; 1593 prepare_namespace(); 1594 } 1595 1596 /* 1597 * Ok, we have completed the initial bootup, and 1598 * we're essentially up and running. Get rid of the 1599 * initmem segments and start the user-mode stuff.. 1600 * 1601 * rootfs is available now, try loading the public keys 1602 * and default modules 1603 */ 1604 1605 integrity_load_keys(); 1606 } 1607