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/list.h> 92 #include <linux/integrity.h> 93 #include <linux/proc_ns.h> 94 #include <linux/io.h> 95 #include <linux/cache.h> 96 #include <linux/rodata_test.h> 97 #include <linux/jump_label.h> 98 #include <linux/mem_encrypt.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 <net/net_namespace.h> 104 105 #include <asm/io.h> 106 #include <asm/bugs.h> 107 #include <asm/setup.h> 108 #include <asm/sections.h> 109 #include <asm/cacheflush.h> 110 111 #define CREATE_TRACE_POINTS 112 #include <trace/events/initcall.h> 113 114 #include <kunit/test.h> 115 116 static int kernel_init(void *); 117 118 extern void init_IRQ(void); 119 extern void radix_tree_init(void); 120 extern void maple_tree_init(void); 121 122 /* 123 * Debug helper: via this flag we know that we are in 'early bootup code' 124 * where only the boot processor is running with IRQ disabled. This means 125 * two things - IRQ must not be enabled before the flag is cleared and some 126 * operations which are not allowed with IRQ disabled are allowed while the 127 * flag is set. 128 */ 129 bool early_boot_irqs_disabled __read_mostly; 130 131 enum system_states system_state __read_mostly; 132 EXPORT_SYMBOL(system_state); 133 134 /* 135 * Boot command-line arguments 136 */ 137 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 138 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 139 140 extern void time_init(void); 141 /* Default late time init is NULL. archs can override this later. */ 142 void (*__initdata late_time_init)(void); 143 144 /* Untouched command line saved by arch-specific code. */ 145 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 146 /* Untouched saved command line (eg. for /proc) */ 147 char *saved_command_line __ro_after_init; 148 unsigned int saved_command_line_len __ro_after_init; 149 /* Command line for parameter parsing */ 150 static char *static_command_line; 151 /* Untouched extra command line */ 152 static char *extra_command_line; 153 /* Extra init arguments */ 154 static char *extra_init_args; 155 156 #ifdef CONFIG_BOOT_CONFIG 157 /* Is bootconfig on command line? */ 158 static bool bootconfig_found; 159 static size_t initargs_offs; 160 #else 161 # define bootconfig_found false 162 # define initargs_offs 0 163 #endif 164 165 static char *execute_command; 166 static char *ramdisk_execute_command = "/init"; 167 168 /* 169 * Used to generate warnings if static_key manipulation functions are used 170 * before jump_label_init is called. 171 */ 172 bool static_key_initialized __read_mostly; 173 EXPORT_SYMBOL_GPL(static_key_initialized); 174 175 /* 176 * If set, this is an indication to the drivers that reset the underlying 177 * device before going ahead with the initialization otherwise driver might 178 * rely on the BIOS and skip the reset operation. 179 * 180 * This is useful if kernel is booting in an unreliable environment. 181 * For ex. kdump situation where previous kernel has crashed, BIOS has been 182 * skipped and devices will be in unknown state. 183 */ 184 unsigned int reset_devices; 185 EXPORT_SYMBOL(reset_devices); 186 187 static int __init set_reset_devices(char *str) 188 { 189 reset_devices = 1; 190 return 1; 191 } 192 193 __setup("reset_devices", set_reset_devices); 194 195 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 196 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 197 static const char *panic_later, *panic_param; 198 199 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 200 201 static bool __init obsolete_checksetup(char *line) 202 { 203 const struct obs_kernel_param *p; 204 bool had_early_param = false; 205 206 p = __setup_start; 207 do { 208 int n = strlen(p->str); 209 if (parameqn(line, p->str, n)) { 210 if (p->early) { 211 /* Already done in parse_early_param? 212 * (Needs exact match on param part). 213 * Keep iterating, as we can have early 214 * params and __setups of same names 8( */ 215 if (line[n] == '\0' || line[n] == '=') 216 had_early_param = true; 217 } else if (!p->setup_func) { 218 pr_warn("Parameter %s is obsolete, ignored\n", 219 p->str); 220 return true; 221 } else if (p->setup_func(line + n)) 222 return true; 223 } 224 p++; 225 } while (p < __setup_end); 226 227 return had_early_param; 228 } 229 230 /* 231 * This should be approx 2 Bo*oMips to start (note initial shift), and will 232 * still work even if initially too large, it will just take slightly longer 233 */ 234 unsigned long loops_per_jiffy = (1<<12); 235 EXPORT_SYMBOL(loops_per_jiffy); 236 237 static int __init debug_kernel(char *str) 238 { 239 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 240 return 0; 241 } 242 243 static int __init quiet_kernel(char *str) 244 { 245 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 246 return 0; 247 } 248 249 early_param("debug", debug_kernel); 250 early_param("quiet", quiet_kernel); 251 252 static int __init loglevel(char *str) 253 { 254 int newlevel; 255 256 /* 257 * Only update loglevel value when a correct setting was passed, 258 * to prevent blind crashes (when loglevel being set to 0) that 259 * are quite hard to debug 260 */ 261 if (get_option(&str, &newlevel)) { 262 console_loglevel = newlevel; 263 return 0; 264 } 265 266 return -EINVAL; 267 } 268 269 early_param("loglevel", loglevel); 270 271 #ifdef CONFIG_BLK_DEV_INITRD 272 static void * __init get_boot_config_from_initrd(size_t *_size) 273 { 274 u32 size, csum; 275 char *data; 276 u32 *hdr; 277 int i; 278 279 if (!initrd_end) 280 return NULL; 281 282 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 283 /* 284 * Since Grub may align the size of initrd to 4, we must 285 * check the preceding 3 bytes as well. 286 */ 287 for (i = 0; i < 4; i++) { 288 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 289 goto found; 290 data--; 291 } 292 return NULL; 293 294 found: 295 hdr = (u32 *)(data - 8); 296 size = le32_to_cpu(hdr[0]); 297 csum = le32_to_cpu(hdr[1]); 298 299 data = ((void *)hdr) - size; 300 if ((unsigned long)data < initrd_start) { 301 pr_err("bootconfig size %d is greater than initrd size %ld\n", 302 size, initrd_end - initrd_start); 303 return NULL; 304 } 305 306 if (xbc_calc_checksum(data, size) != csum) { 307 pr_err("bootconfig checksum failed\n"); 308 return NULL; 309 } 310 311 /* Remove bootconfig from initramfs/initrd */ 312 initrd_end = (unsigned long)data; 313 if (_size) 314 *_size = size; 315 316 return data; 317 } 318 #else 319 static void * __init get_boot_config_from_initrd(size_t *_size) 320 { 321 return NULL; 322 } 323 #endif 324 325 #ifdef CONFIG_BOOT_CONFIG 326 327 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 328 329 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 330 331 static int __init xbc_snprint_cmdline(char *buf, size_t size, 332 struct xbc_node *root) 333 { 334 struct xbc_node *knode, *vnode; 335 char *end = buf + size; 336 const char *val; 337 int ret; 338 339 xbc_node_for_each_key_value(root, knode, val) { 340 ret = xbc_node_compose_key_after(root, knode, 341 xbc_namebuf, XBC_KEYLEN_MAX); 342 if (ret < 0) 343 return ret; 344 345 vnode = xbc_node_get_child(knode); 346 if (!vnode) { 347 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 348 if (ret < 0) 349 return ret; 350 buf += ret; 351 continue; 352 } 353 xbc_array_for_each_value(vnode, val) { 354 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ", 355 xbc_namebuf, val); 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 /* Change NUL term back to "=", to make "param" the whole string. */ 497 static void __init repair_env_string(char *param, char *val) 498 { 499 if (val) { 500 /* param=val or param="val"? */ 501 if (val == param+strlen(param)+1) 502 val[-1] = '='; 503 else if (val == param+strlen(param)+2) { 504 val[-2] = '='; 505 memmove(val-1, val, strlen(val)+1); 506 } else 507 BUG(); 508 } 509 } 510 511 /* Anything after -- gets handed straight to init. */ 512 static int __init set_init_arg(char *param, char *val, 513 const char *unused, void *arg) 514 { 515 unsigned int i; 516 517 if (panic_later) 518 return 0; 519 520 repair_env_string(param, val); 521 522 for (i = 0; argv_init[i]; i++) { 523 if (i == MAX_INIT_ARGS) { 524 panic_later = "init"; 525 panic_param = param; 526 return 0; 527 } 528 } 529 argv_init[i] = param; 530 return 0; 531 } 532 533 /* 534 * Unknown boot options get handed to init, unless they look like 535 * unused parameters (modprobe will find them in /proc/cmdline). 536 */ 537 static int __init unknown_bootoption(char *param, char *val, 538 const char *unused, void *arg) 539 { 540 size_t len = strlen(param); 541 542 repair_env_string(param, val); 543 544 /* Handle obsolete-style parameters */ 545 if (obsolete_checksetup(param)) 546 return 0; 547 548 /* Unused module parameter. */ 549 if (strnchr(param, len, '.')) 550 return 0; 551 552 if (panic_later) 553 return 0; 554 555 if (val) { 556 /* Environment option */ 557 unsigned int i; 558 for (i = 0; envp_init[i]; i++) { 559 if (i == MAX_INIT_ENVS) { 560 panic_later = "env"; 561 panic_param = param; 562 } 563 if (!strncmp(param, envp_init[i], len+1)) 564 break; 565 } 566 envp_init[i] = param; 567 } else { 568 /* Command line option */ 569 unsigned int i; 570 for (i = 0; argv_init[i]; i++) { 571 if (i == MAX_INIT_ARGS) { 572 panic_later = "init"; 573 panic_param = param; 574 } 575 } 576 argv_init[i] = param; 577 } 578 return 0; 579 } 580 581 static int __init init_setup(char *str) 582 { 583 unsigned int i; 584 585 execute_command = str; 586 /* 587 * In case LILO is going to boot us with default command line, 588 * it prepends "auto" before the whole cmdline which makes 589 * the shell think it should execute a script with such name. 590 * So we ignore all arguments entered _before_ init=... [MJ] 591 */ 592 for (i = 1; i < MAX_INIT_ARGS; i++) 593 argv_init[i] = NULL; 594 return 1; 595 } 596 __setup("init=", init_setup); 597 598 static int __init rdinit_setup(char *str) 599 { 600 unsigned int i; 601 602 ramdisk_execute_command = str; 603 /* See "auto" comment in init_setup */ 604 for (i = 1; i < MAX_INIT_ARGS; i++) 605 argv_init[i] = NULL; 606 return 1; 607 } 608 __setup("rdinit=", rdinit_setup); 609 610 #ifndef CONFIG_SMP 611 static const unsigned int setup_max_cpus = NR_CPUS; 612 static inline void setup_nr_cpu_ids(void) { } 613 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 614 #endif 615 616 /* 617 * We need to store the untouched command line for future reference. 618 * We also need to store the touched command line since the parameter 619 * parsing is performed in place, and we should allow a component to 620 * store reference of name/value for future reference. 621 */ 622 static void __init setup_command_line(char *command_line) 623 { 624 size_t len, xlen = 0, ilen = 0; 625 626 if (extra_command_line) 627 xlen = strlen(extra_command_line); 628 if (extra_init_args) 629 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 630 631 len = xlen + strlen(boot_command_line) + 1; 632 633 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); 634 if (!saved_command_line) 635 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); 636 637 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 638 if (!static_command_line) 639 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 640 641 if (xlen) { 642 /* 643 * We have to put extra_command_line before boot command 644 * lines because there could be dashes (separator of init 645 * command line) in the command lines. 646 */ 647 strcpy(saved_command_line, extra_command_line); 648 strcpy(static_command_line, extra_command_line); 649 } 650 strcpy(saved_command_line + xlen, boot_command_line); 651 strcpy(static_command_line + xlen, command_line); 652 653 if (ilen) { 654 /* 655 * Append supplemental init boot args to saved_command_line 656 * so that user can check what command line options passed 657 * to init. 658 * The order should always be 659 * " -- "[bootconfig init-param][cmdline init-param] 660 */ 661 if (initargs_offs) { 662 len = xlen + initargs_offs; 663 strcpy(saved_command_line + len, extra_init_args); 664 len += ilen - 4; /* strlen(extra_init_args) */ 665 strcpy(saved_command_line + len, 666 boot_command_line + initargs_offs - 1); 667 } else { 668 len = strlen(saved_command_line); 669 strcpy(saved_command_line + len, " -- "); 670 len += 4; 671 strcpy(saved_command_line + len, extra_init_args); 672 } 673 } 674 675 saved_command_line_len = strlen(saved_command_line); 676 } 677 678 /* 679 * We need to finalize in a non-__init function or else race conditions 680 * between the root thread and the init thread may cause start_kernel to 681 * be reaped by free_initmem before the root thread has proceeded to 682 * cpu_idle. 683 * 684 * gcc-3.4 accidentally inlines this function, so use noinline. 685 */ 686 687 static __initdata DECLARE_COMPLETION(kthreadd_done); 688 689 noinline void __ref rest_init(void) 690 { 691 struct task_struct *tsk; 692 int pid; 693 694 rcu_scheduler_starting(); 695 /* 696 * We need to spawn init first so that it obtains pid 1, however 697 * the init task will end up wanting to create kthreads, which, if 698 * we schedule it before we create kthreadd, will OOPS. 699 */ 700 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 701 /* 702 * Pin init on the boot CPU. Task migration is not properly working 703 * until sched_init_smp() has been run. It will set the allowed 704 * CPUs for init to the non isolated CPUs. 705 */ 706 rcu_read_lock(); 707 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 708 tsk->flags |= PF_NO_SETAFFINITY; 709 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 710 rcu_read_unlock(); 711 712 numa_default_policy(); 713 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 714 rcu_read_lock(); 715 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 716 rcu_read_unlock(); 717 718 /* 719 * Enable might_sleep() and smp_processor_id() checks. 720 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 721 * kernel_thread() would trigger might_sleep() splats. With 722 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 723 * already, but it's stuck on the kthreadd_done completion. 724 */ 725 system_state = SYSTEM_SCHEDULING; 726 727 complete(&kthreadd_done); 728 729 /* 730 * The boot idle thread must execute schedule() 731 * at least once to get things moving: 732 */ 733 schedule_preempt_disabled(); 734 /* Call into cpu_idle with preempt disabled */ 735 cpu_startup_entry(CPUHP_ONLINE); 736 } 737 738 /* Check for early params. */ 739 static int __init do_early_param(char *param, char *val, 740 const char *unused, void *arg) 741 { 742 const struct obs_kernel_param *p; 743 744 for (p = __setup_start; p < __setup_end; p++) { 745 if ((p->early && parameq(param, p->str)) || 746 (strcmp(param, "console") == 0 && 747 strcmp(p->str, "earlycon") == 0) 748 ) { 749 if (p->setup_func(val) != 0) 750 pr_warn("Malformed early option '%s'\n", param); 751 } 752 } 753 /* We accept everything at this stage. */ 754 return 0; 755 } 756 757 void __init parse_early_options(char *cmdline) 758 { 759 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 760 do_early_param); 761 } 762 763 /* Arch code calls this early on, or if not, just before other parsing. */ 764 void __init parse_early_param(void) 765 { 766 static int done __initdata; 767 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 768 769 if (done) 770 return; 771 772 /* All fall through to do_early_param. */ 773 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 774 parse_early_options(tmp_cmdline); 775 done = 1; 776 } 777 778 void __init __weak arch_post_acpi_subsys_init(void) { } 779 780 void __init __weak smp_setup_processor_id(void) 781 { 782 } 783 784 # if THREAD_SIZE >= PAGE_SIZE 785 void __init __weak thread_stack_cache_init(void) 786 { 787 } 788 #endif 789 790 void __init __weak mem_encrypt_init(void) { } 791 792 void __init __weak poking_init(void) { } 793 794 void __init __weak pgtable_cache_init(void) { } 795 796 void __init __weak trap_init(void) { } 797 798 bool initcall_debug; 799 core_param(initcall_debug, initcall_debug, bool, 0644); 800 801 #ifdef TRACEPOINTS_ENABLED 802 static void __init initcall_debug_enable(void); 803 #else 804 static inline void initcall_debug_enable(void) 805 { 806 } 807 #endif 808 809 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 810 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 811 randomize_kstack_offset); 812 DEFINE_PER_CPU(u32, kstack_offset); 813 814 static int __init early_randomize_kstack_offset(char *buf) 815 { 816 int ret; 817 bool bool_result; 818 819 ret = kstrtobool(buf, &bool_result); 820 if (ret) 821 return ret; 822 823 if (bool_result) 824 static_branch_enable(&randomize_kstack_offset); 825 else 826 static_branch_disable(&randomize_kstack_offset); 827 return 0; 828 } 829 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 830 #endif 831 832 void __init __weak arch_call_rest_init(void) 833 { 834 rest_init(); 835 } 836 837 static void __init print_unknown_bootoptions(void) 838 { 839 char *unknown_options; 840 char *end; 841 const char *const *p; 842 size_t len; 843 844 if (panic_later || (!argv_init[1] && !envp_init[2])) 845 return; 846 847 /* 848 * Determine how many options we have to print out, plus a space 849 * before each 850 */ 851 len = 1; /* null terminator */ 852 for (p = &argv_init[1]; *p; p++) { 853 len++; 854 len += strlen(*p); 855 } 856 for (p = &envp_init[2]; *p; p++) { 857 len++; 858 len += strlen(*p); 859 } 860 861 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 862 if (!unknown_options) { 863 pr_err("%s: Failed to allocate %zu bytes\n", 864 __func__, len); 865 return; 866 } 867 end = unknown_options; 868 869 for (p = &argv_init[1]; *p; p++) 870 end += sprintf(end, " %s", *p); 871 for (p = &envp_init[2]; *p; p++) 872 end += sprintf(end, " %s", *p); 873 874 /* Start at unknown_options[1] to skip the initial space */ 875 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 876 &unknown_options[1]); 877 memblock_free(unknown_options, len); 878 } 879 880 asmlinkage __visible void __init __no_sanitize_address start_kernel(void) 881 { 882 char *command_line; 883 char *after_dashes; 884 885 set_task_stack_end_magic(&init_task); 886 smp_setup_processor_id(); 887 debug_objects_early_init(); 888 init_vmlinux_build_id(); 889 890 cgroup_init_early(); 891 892 local_irq_disable(); 893 early_boot_irqs_disabled = true; 894 895 /* 896 * Interrupts are still disabled. Do necessary setups, then 897 * enable them. 898 */ 899 boot_cpu_init(); 900 page_address_init(); 901 pr_notice("%s", linux_banner); 902 early_security_init(); 903 setup_arch(&command_line); 904 setup_boot_config(); 905 setup_command_line(command_line); 906 setup_nr_cpu_ids(); 907 setup_per_cpu_areas(); 908 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 909 boot_cpu_hotplug_init(); 910 911 pr_notice("Kernel command line: %s\n", saved_command_line); 912 /* parameters may set static keys */ 913 jump_label_init(); 914 parse_early_param(); 915 after_dashes = parse_args("Booting kernel", 916 static_command_line, __start___param, 917 __stop___param - __start___param, 918 -1, -1, NULL, &unknown_bootoption); 919 print_unknown_bootoptions(); 920 if (!IS_ERR_OR_NULL(after_dashes)) 921 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 922 NULL, set_init_arg); 923 if (extra_init_args) 924 parse_args("Setting extra init args", extra_init_args, 925 NULL, 0, -1, -1, NULL, set_init_arg); 926 927 /* Architectural and non-timekeeping rng init, before allocator init */ 928 random_init_early(command_line); 929 930 /* 931 * These use large bootmem allocations and must precede 932 * initalization of page allocator 933 */ 934 setup_log_buf(0); 935 vfs_caches_init_early(); 936 sort_main_extable(); 937 trap_init(); 938 mm_core_init(); 939 poking_init(); 940 ftrace_init(); 941 942 /* trace_printk can be enabled here */ 943 early_trace_init(); 944 945 /* 946 * Set up the scheduler prior starting any interrupts (such as the 947 * timer interrupt). Full topology setup happens at smp_init() 948 * time - but meanwhile we still have a functioning scheduler. 949 */ 950 sched_init(); 951 952 if (WARN(!irqs_disabled(), 953 "Interrupts were enabled *very* early, fixing it\n")) 954 local_irq_disable(); 955 radix_tree_init(); 956 maple_tree_init(); 957 958 /* 959 * Set up housekeeping before setting up workqueues to allow the unbound 960 * workqueue to take non-housekeeping into account. 961 */ 962 housekeeping_init(); 963 964 /* 965 * Allow workqueue creation and work item queueing/cancelling 966 * early. Work item execution depends on kthreads and starts after 967 * workqueue_init(). 968 */ 969 workqueue_init_early(); 970 971 rcu_init(); 972 973 /* Trace events are available after this */ 974 trace_init(); 975 976 if (initcall_debug) 977 initcall_debug_enable(); 978 979 context_tracking_init(); 980 /* init some links before init_ISA_irqs() */ 981 early_irq_init(); 982 init_IRQ(); 983 tick_init(); 984 rcu_init_nohz(); 985 init_timers(); 986 srcu_init(); 987 hrtimers_init(); 988 softirq_init(); 989 timekeeping_init(); 990 time_init(); 991 992 /* This must be after timekeeping is initialized */ 993 random_init(); 994 995 /* These make use of the fully initialized rng */ 996 kfence_init(); 997 boot_init_stack_canary(); 998 999 perf_event_init(); 1000 profile_init(); 1001 call_function_init(); 1002 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1003 1004 early_boot_irqs_disabled = false; 1005 local_irq_enable(); 1006 1007 kmem_cache_init_late(); 1008 1009 /* 1010 * HACK ALERT! This is early. We're enabling the console before 1011 * we've done PCI setups etc, and console_init() must be aware of 1012 * this. But we do want output early, in case something goes wrong. 1013 */ 1014 console_init(); 1015 if (panic_later) 1016 panic("Too many boot %s vars at `%s'", panic_later, 1017 panic_param); 1018 1019 lockdep_init(); 1020 1021 /* 1022 * Need to run this when irqs are enabled, because it wants 1023 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1024 * too: 1025 */ 1026 locking_selftest(); 1027 1028 /* 1029 * This needs to be called before any devices perform DMA 1030 * operations that might use the SWIOTLB bounce buffers. It will 1031 * mark the bounce buffers as decrypted so that their usage will 1032 * not cause "plain-text" data to be decrypted when accessed. 1033 */ 1034 mem_encrypt_init(); 1035 1036 #ifdef CONFIG_BLK_DEV_INITRD 1037 if (initrd_start && !initrd_below_start_ok && 1038 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1039 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1040 page_to_pfn(virt_to_page((void *)initrd_start)), 1041 min_low_pfn); 1042 initrd_start = 0; 1043 } 1044 #endif 1045 setup_per_cpu_pageset(); 1046 numa_policy_init(); 1047 acpi_early_init(); 1048 if (late_time_init) 1049 late_time_init(); 1050 sched_clock_init(); 1051 calibrate_delay(); 1052 pid_idr_init(); 1053 anon_vma_init(); 1054 #ifdef CONFIG_X86 1055 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1056 efi_enter_virtual_mode(); 1057 #endif 1058 thread_stack_cache_init(); 1059 cred_init(); 1060 fork_init(); 1061 proc_caches_init(); 1062 uts_ns_init(); 1063 key_init(); 1064 security_init(); 1065 dbg_late_init(); 1066 net_ns_init(); 1067 vfs_caches_init(); 1068 pagecache_init(); 1069 signals_init(); 1070 seq_file_init(); 1071 proc_root_init(); 1072 nsfs_init(); 1073 cpuset_init(); 1074 cgroup_init(); 1075 taskstats_init_early(); 1076 delayacct_init(); 1077 1078 check_bugs(); 1079 1080 acpi_subsystem_init(); 1081 arch_post_acpi_subsys_init(); 1082 kcsan_init(); 1083 1084 /* Do the rest non-__init'ed, we're now alive */ 1085 arch_call_rest_init(); 1086 1087 prevent_tail_call_optimization(); 1088 } 1089 1090 /* Call all constructor functions linked into the kernel. */ 1091 static void __init do_ctors(void) 1092 { 1093 /* 1094 * For UML, the constructors have already been called by the 1095 * normal setup code as it's just a normal ELF binary, so we 1096 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1097 * even on UML for modules. 1098 */ 1099 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1100 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1101 1102 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1103 (*fn)(); 1104 #endif 1105 } 1106 1107 #ifdef CONFIG_KALLSYMS 1108 struct blacklist_entry { 1109 struct list_head next; 1110 char *buf; 1111 }; 1112 1113 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1114 1115 static int __init initcall_blacklist(char *str) 1116 { 1117 char *str_entry; 1118 struct blacklist_entry *entry; 1119 1120 /* str argument is a comma-separated list of functions */ 1121 do { 1122 str_entry = strsep(&str, ","); 1123 if (str_entry) { 1124 pr_debug("blacklisting initcall %s\n", str_entry); 1125 entry = memblock_alloc(sizeof(*entry), 1126 SMP_CACHE_BYTES); 1127 if (!entry) 1128 panic("%s: Failed to allocate %zu bytes\n", 1129 __func__, sizeof(*entry)); 1130 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1131 SMP_CACHE_BYTES); 1132 if (!entry->buf) 1133 panic("%s: Failed to allocate %zu bytes\n", 1134 __func__, strlen(str_entry) + 1); 1135 strcpy(entry->buf, str_entry); 1136 list_add(&entry->next, &blacklisted_initcalls); 1137 } 1138 } while (str_entry); 1139 1140 return 1; 1141 } 1142 1143 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1144 { 1145 struct blacklist_entry *entry; 1146 char fn_name[KSYM_SYMBOL_LEN]; 1147 unsigned long addr; 1148 1149 if (list_empty(&blacklisted_initcalls)) 1150 return false; 1151 1152 addr = (unsigned long) dereference_function_descriptor(fn); 1153 sprint_symbol_no_offset(fn_name, addr); 1154 1155 /* 1156 * fn will be "function_name [module_name]" where [module_name] is not 1157 * displayed for built-in init functions. Strip off the [module_name]. 1158 */ 1159 strreplace(fn_name, ' ', '\0'); 1160 1161 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1162 if (!strcmp(fn_name, entry->buf)) { 1163 pr_debug("initcall %s blacklisted\n", fn_name); 1164 return true; 1165 } 1166 } 1167 1168 return false; 1169 } 1170 #else 1171 static int __init initcall_blacklist(char *str) 1172 { 1173 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1174 return 0; 1175 } 1176 1177 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1178 { 1179 return false; 1180 } 1181 #endif 1182 __setup("initcall_blacklist=", initcall_blacklist); 1183 1184 static __init_or_module void 1185 trace_initcall_start_cb(void *data, initcall_t fn) 1186 { 1187 ktime_t *calltime = data; 1188 1189 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1190 *calltime = ktime_get(); 1191 } 1192 1193 static __init_or_module void 1194 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1195 { 1196 ktime_t rettime, *calltime = data; 1197 1198 rettime = ktime_get(); 1199 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1200 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1201 } 1202 1203 static ktime_t initcall_calltime; 1204 1205 #ifdef TRACEPOINTS_ENABLED 1206 static void __init initcall_debug_enable(void) 1207 { 1208 int ret; 1209 1210 ret = register_trace_initcall_start(trace_initcall_start_cb, 1211 &initcall_calltime); 1212 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1213 &initcall_calltime); 1214 WARN(ret, "Failed to register initcall tracepoints\n"); 1215 } 1216 # define do_trace_initcall_start trace_initcall_start 1217 # define do_trace_initcall_finish trace_initcall_finish 1218 #else 1219 static inline void do_trace_initcall_start(initcall_t fn) 1220 { 1221 if (!initcall_debug) 1222 return; 1223 trace_initcall_start_cb(&initcall_calltime, fn); 1224 } 1225 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1226 { 1227 if (!initcall_debug) 1228 return; 1229 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1230 } 1231 #endif /* !TRACEPOINTS_ENABLED */ 1232 1233 int __init_or_module do_one_initcall(initcall_t fn) 1234 { 1235 int count = preempt_count(); 1236 char msgbuf[64]; 1237 int ret; 1238 1239 if (initcall_blacklisted(fn)) 1240 return -EPERM; 1241 1242 do_trace_initcall_start(fn); 1243 ret = fn(); 1244 do_trace_initcall_finish(fn, ret); 1245 1246 msgbuf[0] = 0; 1247 1248 if (preempt_count() != count) { 1249 sprintf(msgbuf, "preemption imbalance "); 1250 preempt_count_set(count); 1251 } 1252 if (irqs_disabled()) { 1253 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1254 local_irq_enable(); 1255 } 1256 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1257 1258 add_latent_entropy(); 1259 return ret; 1260 } 1261 1262 1263 extern initcall_entry_t __initcall_start[]; 1264 extern initcall_entry_t __initcall0_start[]; 1265 extern initcall_entry_t __initcall1_start[]; 1266 extern initcall_entry_t __initcall2_start[]; 1267 extern initcall_entry_t __initcall3_start[]; 1268 extern initcall_entry_t __initcall4_start[]; 1269 extern initcall_entry_t __initcall5_start[]; 1270 extern initcall_entry_t __initcall6_start[]; 1271 extern initcall_entry_t __initcall7_start[]; 1272 extern initcall_entry_t __initcall_end[]; 1273 1274 static initcall_entry_t *initcall_levels[] __initdata = { 1275 __initcall0_start, 1276 __initcall1_start, 1277 __initcall2_start, 1278 __initcall3_start, 1279 __initcall4_start, 1280 __initcall5_start, 1281 __initcall6_start, 1282 __initcall7_start, 1283 __initcall_end, 1284 }; 1285 1286 /* Keep these in sync with initcalls in include/linux/init.h */ 1287 static const char *initcall_level_names[] __initdata = { 1288 "pure", 1289 "core", 1290 "postcore", 1291 "arch", 1292 "subsys", 1293 "fs", 1294 "device", 1295 "late", 1296 }; 1297 1298 static int __init ignore_unknown_bootoption(char *param, char *val, 1299 const char *unused, void *arg) 1300 { 1301 return 0; 1302 } 1303 1304 static void __init do_initcall_level(int level, char *command_line) 1305 { 1306 initcall_entry_t *fn; 1307 1308 parse_args(initcall_level_names[level], 1309 command_line, __start___param, 1310 __stop___param - __start___param, 1311 level, level, 1312 NULL, ignore_unknown_bootoption); 1313 1314 trace_initcall_level(initcall_level_names[level]); 1315 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1316 do_one_initcall(initcall_from_entry(fn)); 1317 } 1318 1319 static void __init do_initcalls(void) 1320 { 1321 int level; 1322 size_t len = saved_command_line_len + 1; 1323 char *command_line; 1324 1325 command_line = kzalloc(len, GFP_KERNEL); 1326 if (!command_line) 1327 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1328 1329 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1330 /* Parser modifies command_line, restore it each time */ 1331 strcpy(command_line, saved_command_line); 1332 do_initcall_level(level, command_line); 1333 } 1334 1335 kfree(command_line); 1336 } 1337 1338 /* 1339 * Ok, the machine is now initialized. None of the devices 1340 * have been touched yet, but the CPU subsystem is up and 1341 * running, and memory and process management works. 1342 * 1343 * Now we can finally start doing some real work.. 1344 */ 1345 static void __init do_basic_setup(void) 1346 { 1347 cpuset_init_smp(); 1348 driver_init(); 1349 init_irq_proc(); 1350 do_ctors(); 1351 do_initcalls(); 1352 } 1353 1354 static void __init do_pre_smp_initcalls(void) 1355 { 1356 initcall_entry_t *fn; 1357 1358 trace_initcall_level("early"); 1359 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1360 do_one_initcall(initcall_from_entry(fn)); 1361 } 1362 1363 static int run_init_process(const char *init_filename) 1364 { 1365 const char *const *p; 1366 1367 argv_init[0] = init_filename; 1368 pr_info("Run %s as init process\n", init_filename); 1369 pr_debug(" with arguments:\n"); 1370 for (p = argv_init; *p; p++) 1371 pr_debug(" %s\n", *p); 1372 pr_debug(" with environment:\n"); 1373 for (p = envp_init; *p; p++) 1374 pr_debug(" %s\n", *p); 1375 return kernel_execve(init_filename, argv_init, envp_init); 1376 } 1377 1378 static int try_to_run_init_process(const char *init_filename) 1379 { 1380 int ret; 1381 1382 ret = run_init_process(init_filename); 1383 1384 if (ret && ret != -ENOENT) { 1385 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1386 init_filename, ret); 1387 } 1388 1389 return ret; 1390 } 1391 1392 static noinline void __init kernel_init_freeable(void); 1393 1394 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1395 bool rodata_enabled __ro_after_init = true; 1396 1397 #ifndef arch_parse_debug_rodata 1398 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1399 #endif 1400 1401 static int __init set_debug_rodata(char *str) 1402 { 1403 if (arch_parse_debug_rodata(str)) 1404 return 0; 1405 1406 if (str && !strcmp(str, "on")) 1407 rodata_enabled = true; 1408 else if (str && !strcmp(str, "off")) 1409 rodata_enabled = false; 1410 else 1411 pr_warn("Invalid option string for rodata: '%s'\n", str); 1412 return 0; 1413 } 1414 early_param("rodata", set_debug_rodata); 1415 #endif 1416 1417 #ifdef CONFIG_STRICT_KERNEL_RWX 1418 static void mark_readonly(void) 1419 { 1420 if (rodata_enabled) { 1421 /* 1422 * load_module() results in W+X mappings, which are cleaned 1423 * up with call_rcu(). Let's make sure that queued work is 1424 * flushed so that we don't hit false positives looking for 1425 * insecure pages which are W+X. 1426 */ 1427 rcu_barrier(); 1428 mark_rodata_ro(); 1429 rodata_test(); 1430 } else 1431 pr_info("Kernel memory protection disabled.\n"); 1432 } 1433 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX) 1434 static inline void mark_readonly(void) 1435 { 1436 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1437 } 1438 #else 1439 static inline void mark_readonly(void) 1440 { 1441 pr_warn("This architecture does not have kernel memory protection.\n"); 1442 } 1443 #endif 1444 1445 void __weak free_initmem(void) 1446 { 1447 free_initmem_default(POISON_FREE_INITMEM); 1448 } 1449 1450 static int __ref kernel_init(void *unused) 1451 { 1452 int ret; 1453 1454 /* 1455 * Wait until kthreadd is all set-up. 1456 */ 1457 wait_for_completion(&kthreadd_done); 1458 1459 kernel_init_freeable(); 1460 /* need to finish all async __init code before freeing the memory */ 1461 async_synchronize_full(); 1462 1463 system_state = SYSTEM_FREEING_INITMEM; 1464 kprobe_free_init_mem(); 1465 ftrace_free_init_mem(); 1466 kgdb_free_init_mem(); 1467 exit_boot_config(); 1468 free_initmem(); 1469 mark_readonly(); 1470 1471 /* 1472 * Kernel mappings are now finalized - update the userspace page-table 1473 * to finalize PTI. 1474 */ 1475 pti_finalize(); 1476 1477 system_state = SYSTEM_RUNNING; 1478 numa_default_policy(); 1479 1480 rcu_end_inkernel_boot(); 1481 1482 do_sysctl_args(); 1483 1484 if (ramdisk_execute_command) { 1485 ret = run_init_process(ramdisk_execute_command); 1486 if (!ret) 1487 return 0; 1488 pr_err("Failed to execute %s (error %d)\n", 1489 ramdisk_execute_command, ret); 1490 } 1491 1492 /* 1493 * We try each of these until one succeeds. 1494 * 1495 * The Bourne shell can be used instead of init if we are 1496 * trying to recover a really broken machine. 1497 */ 1498 if (execute_command) { 1499 ret = run_init_process(execute_command); 1500 if (!ret) 1501 return 0; 1502 panic("Requested init %s failed (error %d).", 1503 execute_command, ret); 1504 } 1505 1506 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1507 ret = run_init_process(CONFIG_DEFAULT_INIT); 1508 if (ret) 1509 pr_err("Default init %s failed (error %d)\n", 1510 CONFIG_DEFAULT_INIT, ret); 1511 else 1512 return 0; 1513 } 1514 1515 if (!try_to_run_init_process("/sbin/init") || 1516 !try_to_run_init_process("/etc/init") || 1517 !try_to_run_init_process("/bin/init") || 1518 !try_to_run_init_process("/bin/sh")) 1519 return 0; 1520 1521 panic("No working init found. Try passing init= option to kernel. " 1522 "See Linux Documentation/admin-guide/init.rst for guidance."); 1523 } 1524 1525 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1526 void __init console_on_rootfs(void) 1527 { 1528 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1529 1530 if (IS_ERR(file)) { 1531 pr_err("Warning: unable to open an initial console.\n"); 1532 return; 1533 } 1534 init_dup(file); 1535 init_dup(file); 1536 init_dup(file); 1537 fput(file); 1538 } 1539 1540 static noinline void __init kernel_init_freeable(void) 1541 { 1542 /* Now the scheduler is fully set up and can do blocking allocations */ 1543 gfp_allowed_mask = __GFP_BITS_MASK; 1544 1545 /* 1546 * init can allocate pages on any node 1547 */ 1548 set_mems_allowed(node_states[N_MEMORY]); 1549 1550 cad_pid = get_pid(task_pid(current)); 1551 1552 smp_prepare_cpus(setup_max_cpus); 1553 1554 workqueue_init(); 1555 1556 init_mm_internals(); 1557 1558 rcu_init_tasks_generic(); 1559 do_pre_smp_initcalls(); 1560 lockup_detector_init(); 1561 1562 smp_init(); 1563 sched_init_smp(); 1564 1565 padata_init(); 1566 page_alloc_init_late(); 1567 1568 do_basic_setup(); 1569 1570 kunit_run_all_tests(); 1571 1572 wait_for_initramfs(); 1573 console_on_rootfs(); 1574 1575 /* 1576 * check if there is an early userspace init. If yes, let it do all 1577 * the work 1578 */ 1579 if (init_eaccess(ramdisk_execute_command) != 0) { 1580 ramdisk_execute_command = NULL; 1581 prepare_namespace(); 1582 } 1583 1584 /* 1585 * Ok, we have completed the initial bootup, and 1586 * we're essentially up and running. Get rid of the 1587 * initmem segments and start the user-mode stuff.. 1588 * 1589 * rootfs is available now, try loading the public keys 1590 * and default modules 1591 */ 1592 1593 integrity_load_keys(); 1594 } 1595