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 * Well-known bootloader identifiers: 549 * 1. LILO/Grub pass "BOOT_IMAGE=..."; 550 * 2. kexec/kdump (kexec-tools) pass "kexec". 551 */ 552 const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL }; 553 554 /* Handle params aliased to sysctls */ 555 if (sysctl_is_alias(param)) 556 return 0; 557 558 repair_env_string(param, val); 559 560 /* Handle bootloader identifier */ 561 for (int i = 0; bootloader[i]; i++) { 562 if (strstarts(param, bootloader[i])) 563 return 0; 564 } 565 566 /* Handle obsolete-style parameters */ 567 if (obsolete_checksetup(param)) 568 return 0; 569 570 /* Unused module parameter. */ 571 if (strnchr(param, len, '.')) 572 return 0; 573 574 if (panic_later) 575 return 0; 576 577 if (val) { 578 /* Environment option */ 579 unsigned int i; 580 for (i = 0; envp_init[i]; i++) { 581 if (i == MAX_INIT_ENVS) { 582 panic_later = "env"; 583 panic_param = param; 584 } 585 if (!strncmp(param, envp_init[i], len+1)) 586 break; 587 } 588 envp_init[i] = param; 589 } else { 590 /* Command line option */ 591 unsigned int i; 592 for (i = 0; argv_init[i]; i++) { 593 if (i == MAX_INIT_ARGS) { 594 panic_later = "init"; 595 panic_param = param; 596 } 597 } 598 argv_init[i] = param; 599 } 600 return 0; 601 } 602 603 static int __init init_setup(char *str) 604 { 605 unsigned int i; 606 607 execute_command = str; 608 /* 609 * In case LILO is going to boot us with default command line, 610 * it prepends "auto" before the whole cmdline which makes 611 * the shell think it should execute a script with such name. 612 * So we ignore all arguments entered _before_ init=... [MJ] 613 */ 614 for (i = 1; i < MAX_INIT_ARGS; i++) 615 argv_init[i] = NULL; 616 return 1; 617 } 618 __setup("init=", init_setup); 619 620 static int __init rdinit_setup(char *str) 621 { 622 unsigned int i; 623 624 ramdisk_execute_command = str; 625 /* See "auto" comment in init_setup */ 626 for (i = 1; i < MAX_INIT_ARGS; i++) 627 argv_init[i] = NULL; 628 return 1; 629 } 630 __setup("rdinit=", rdinit_setup); 631 632 #ifndef CONFIG_SMP 633 static inline void setup_nr_cpu_ids(void) { } 634 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 635 #endif 636 637 /* 638 * We need to store the untouched command line for future reference. 639 * We also need to store the touched command line since the parameter 640 * parsing is performed in place, and we should allow a component to 641 * store reference of name/value for future reference. 642 */ 643 static void __init setup_command_line(char *command_line) 644 { 645 size_t len, xlen = 0, ilen = 0; 646 647 if (extra_command_line) 648 xlen = strlen(extra_command_line); 649 if (extra_init_args) { 650 extra_init_args = strim(extra_init_args); /* remove trailing space */ 651 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 652 } 653 654 len = xlen + strlen(boot_command_line) + ilen + 1; 655 656 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 657 658 len = xlen + strlen(command_line) + 1; 659 660 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 661 662 if (xlen) { 663 /* 664 * We have to put extra_command_line before boot command 665 * lines because there could be dashes (separator of init 666 * command line) in the command lines. 667 */ 668 strcpy(saved_command_line, extra_command_line); 669 strcpy(static_command_line, extra_command_line); 670 } 671 strcpy(saved_command_line + xlen, boot_command_line); 672 strcpy(static_command_line + xlen, command_line); 673 674 if (ilen) { 675 /* 676 * Append supplemental init boot args to saved_command_line 677 * so that user can check what command line options passed 678 * to init. 679 * The order should always be 680 * " -- "[bootconfig init-param][cmdline init-param] 681 */ 682 if (initargs_offs) { 683 len = xlen + initargs_offs; 684 strcpy(saved_command_line + len, extra_init_args); 685 len += ilen - 4; /* strlen(extra_init_args) */ 686 strcpy(saved_command_line + len, 687 boot_command_line + initargs_offs - 1); 688 } else { 689 len = strlen(saved_command_line); 690 strcpy(saved_command_line + len, " -- "); 691 len += 4; 692 strcpy(saved_command_line + len, extra_init_args); 693 } 694 } 695 696 saved_command_line_len = strlen(saved_command_line); 697 } 698 699 /* 700 * We need to finalize in a non-__init function or else race conditions 701 * between the root thread and the init thread may cause start_kernel to 702 * be reaped by free_initmem before the root thread has proceeded to 703 * cpu_idle. 704 * 705 * gcc-3.4 accidentally inlines this function, so use noinline. 706 */ 707 708 static __initdata DECLARE_COMPLETION(kthreadd_done); 709 710 static noinline void __ref __noreturn rest_init(void) 711 { 712 struct task_struct *tsk; 713 int pid; 714 715 rcu_scheduler_starting(); 716 /* 717 * We need to spawn init first so that it obtains pid 1, however 718 * the init task will end up wanting to create kthreads, which, if 719 * we schedule it before we create kthreadd, will OOPS. 720 */ 721 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 722 /* 723 * Pin init on the boot CPU. Task migration is not properly working 724 * until sched_init_smp() has been run. It will set the allowed 725 * CPUs for init to the non isolated CPUs. 726 */ 727 rcu_read_lock(); 728 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 729 tsk->flags |= PF_NO_SETAFFINITY; 730 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 731 rcu_read_unlock(); 732 733 numa_default_policy(); 734 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 735 rcu_read_lock(); 736 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 737 rcu_read_unlock(); 738 739 /* 740 * Enable might_sleep() and smp_processor_id() checks. 741 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 742 * kernel_thread() would trigger might_sleep() splats. With 743 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 744 * already, but it's stuck on the kthreadd_done completion. 745 */ 746 system_state = SYSTEM_SCHEDULING; 747 748 complete(&kthreadd_done); 749 750 /* 751 * The boot idle thread must execute schedule() 752 * at least once to get things moving: 753 */ 754 schedule_preempt_disabled(); 755 /* Call into cpu_idle with preempt disabled */ 756 cpu_startup_entry(CPUHP_ONLINE); 757 } 758 759 /* Check for early params. */ 760 static int __init do_early_param(char *param, char *val, 761 const char *unused, void *arg) 762 { 763 const struct obs_kernel_param *p; 764 765 for (p = __setup_start; p < __setup_end; p++) { 766 if (p->early && parameq(param, p->str)) { 767 if (p->setup_func(val) != 0) 768 pr_warn("Malformed early option '%s'\n", param); 769 } 770 } 771 /* We accept everything at this stage. */ 772 return 0; 773 } 774 775 void __init parse_early_options(char *cmdline) 776 { 777 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 778 do_early_param); 779 } 780 781 /* Arch code calls this early on, or if not, just before other parsing. */ 782 void __init parse_early_param(void) 783 { 784 static int done __initdata; 785 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 786 787 if (done) 788 return; 789 790 /* All fall through to do_early_param. */ 791 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 792 parse_early_options(tmp_cmdline); 793 done = 1; 794 } 795 796 void __init __weak arch_post_acpi_subsys_init(void) { } 797 798 void __init __weak smp_setup_processor_id(void) 799 { 800 } 801 802 void __init __weak smp_prepare_boot_cpu(void) 803 { 804 } 805 806 # if THREAD_SIZE >= PAGE_SIZE 807 void __init __weak thread_stack_cache_init(void) 808 { 809 } 810 #endif 811 812 void __init __weak poking_init(void) { } 813 814 void __init __weak pgtable_cache_init(void) { } 815 816 void __init __weak trap_init(void) { } 817 818 bool initcall_debug; 819 core_param(initcall_debug, initcall_debug, bool, 0644); 820 821 #ifdef TRACEPOINTS_ENABLED 822 static void __init initcall_debug_enable(void); 823 #else 824 static inline void initcall_debug_enable(void) 825 { 826 } 827 #endif 828 829 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 830 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 831 randomize_kstack_offset); 832 DEFINE_PER_CPU(u32, kstack_offset); 833 834 static int __init early_randomize_kstack_offset(char *buf) 835 { 836 int ret; 837 bool bool_result; 838 839 ret = kstrtobool(buf, &bool_result); 840 if (ret) 841 return ret; 842 843 if (bool_result) 844 static_branch_enable(&randomize_kstack_offset); 845 else 846 static_branch_disable(&randomize_kstack_offset); 847 return 0; 848 } 849 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 850 #endif 851 852 static void __init print_unknown_bootoptions(void) 853 { 854 char *unknown_options; 855 char *end; 856 const char *const *p; 857 size_t len; 858 859 if (panic_later || (!argv_init[1] && !envp_init[2])) 860 return; 861 862 /* 863 * Determine how many options we have to print out, plus a space 864 * before each 865 */ 866 len = 1; /* null terminator */ 867 for (p = &argv_init[1]; *p; p++) { 868 len++; 869 len += strlen(*p); 870 } 871 for (p = &envp_init[2]; *p; p++) { 872 len++; 873 len += strlen(*p); 874 } 875 876 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 877 if (!unknown_options) { 878 pr_err("%s: Failed to allocate %zu bytes\n", 879 __func__, len); 880 return; 881 } 882 end = unknown_options; 883 884 for (p = &argv_init[1]; *p; p++) 885 end += sprintf(end, " %s", *p); 886 for (p = &envp_init[2]; *p; p++) 887 end += sprintf(end, " %s", *p); 888 889 /* Start at unknown_options[1] to skip the initial space */ 890 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 891 &unknown_options[1]); 892 memblock_free(unknown_options, len); 893 } 894 895 static void __init early_numa_node_init(void) 896 { 897 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 898 #ifndef cpu_to_node 899 int cpu; 900 901 /* The early_cpu_to_node() should be ready here. */ 902 for_each_possible_cpu(cpu) 903 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 904 #endif 905 #endif 906 } 907 908 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 909 void start_kernel(void) 910 { 911 char *command_line; 912 char *after_dashes; 913 914 set_task_stack_end_magic(&init_task); 915 smp_setup_processor_id(); 916 debug_objects_early_init(); 917 init_vmlinux_build_id(); 918 919 cgroup_init_early(); 920 921 local_irq_disable(); 922 early_boot_irqs_disabled = true; 923 924 /* 925 * Interrupts are still disabled. Do necessary setups, then 926 * enable them. 927 */ 928 boot_cpu_init(); 929 page_address_init(); 930 pr_notice("%s", linux_banner); 931 setup_arch(&command_line); 932 /* Static keys and static calls are needed by LSMs */ 933 jump_label_init(); 934 static_call_init(); 935 early_security_init(); 936 setup_boot_config(); 937 setup_command_line(command_line); 938 setup_nr_cpu_ids(); 939 setup_per_cpu_areas(); 940 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 941 early_numa_node_init(); 942 boot_cpu_hotplug_init(); 943 944 pr_notice("Kernel command line: %s\n", saved_command_line); 945 /* parameters may set static keys */ 946 parse_early_param(); 947 after_dashes = parse_args("Booting kernel", 948 static_command_line, __start___param, 949 __stop___param - __start___param, 950 -1, -1, NULL, &unknown_bootoption); 951 print_unknown_bootoptions(); 952 if (!IS_ERR_OR_NULL(after_dashes)) 953 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 954 NULL, set_init_arg); 955 if (extra_init_args) 956 parse_args("Setting extra init args", extra_init_args, 957 NULL, 0, -1, -1, NULL, set_init_arg); 958 959 /* Architectural and non-timekeeping rng init, before allocator init */ 960 random_init_early(command_line); 961 962 /* 963 * These use large bootmem allocations and must precede 964 * initalization of page allocator 965 */ 966 setup_log_buf(0); 967 vfs_caches_init_early(); 968 sort_main_extable(); 969 trap_init(); 970 mm_core_init(); 971 poking_init(); 972 ftrace_init(); 973 974 /* trace_printk can be enabled here */ 975 early_trace_init(); 976 977 /* 978 * Set up the scheduler prior starting any interrupts (such as the 979 * timer interrupt). Full topology setup happens at smp_init() 980 * time - but meanwhile we still have a functioning scheduler. 981 */ 982 sched_init(); 983 984 if (WARN(!irqs_disabled(), 985 "Interrupts were enabled *very* early, fixing it\n")) 986 local_irq_disable(); 987 radix_tree_init(); 988 maple_tree_init(); 989 990 /* 991 * Set up housekeeping before setting up workqueues to allow the unbound 992 * workqueue to take non-housekeeping into account. 993 */ 994 housekeeping_init(); 995 996 /* 997 * Allow workqueue creation and work item queueing/cancelling 998 * early. Work item execution depends on kthreads and starts after 999 * workqueue_init(). 1000 */ 1001 workqueue_init_early(); 1002 1003 rcu_init(); 1004 kvfree_rcu_init(); 1005 1006 /* Trace events are available after this */ 1007 trace_init(); 1008 1009 if (initcall_debug) 1010 initcall_debug_enable(); 1011 1012 context_tracking_init(); 1013 /* init some links before init_ISA_irqs() */ 1014 early_irq_init(); 1015 init_IRQ(); 1016 tick_init(); 1017 rcu_init_nohz(); 1018 timers_init(); 1019 srcu_init(); 1020 hrtimers_init(); 1021 softirq_init(); 1022 timekeeping_init(); 1023 time_init(); 1024 1025 /* This must be after timekeeping is initialized */ 1026 random_init(); 1027 1028 /* These make use of the fully initialized rng */ 1029 kfence_init(); 1030 boot_init_stack_canary(); 1031 1032 perf_event_init(); 1033 profile_init(); 1034 call_function_init(); 1035 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1036 1037 early_boot_irqs_disabled = false; 1038 local_irq_enable(); 1039 1040 kmem_cache_init_late(); 1041 1042 /* 1043 * HACK ALERT! This is early. We're enabling the console before 1044 * we've done PCI setups etc, and console_init() must be aware of 1045 * this. But we do want output early, in case something goes wrong. 1046 */ 1047 console_init(); 1048 if (panic_later) 1049 panic("Too many boot %s vars at `%s'", panic_later, 1050 panic_param); 1051 1052 lockdep_init(); 1053 1054 /* 1055 * Need to run this when irqs are enabled, because it wants 1056 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1057 * too: 1058 */ 1059 locking_selftest(); 1060 1061 #ifdef CONFIG_BLK_DEV_INITRD 1062 if (initrd_start && !initrd_below_start_ok && 1063 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1064 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1065 page_to_pfn(virt_to_page((void *)initrd_start)), 1066 min_low_pfn); 1067 initrd_start = 0; 1068 } 1069 #endif 1070 setup_per_cpu_pageset(); 1071 numa_policy_init(); 1072 acpi_early_init(); 1073 if (late_time_init) 1074 late_time_init(); 1075 sched_clock_init(); 1076 calibrate_delay(); 1077 1078 arch_cpu_finalize_init(); 1079 1080 pid_idr_init(); 1081 anon_vma_init(); 1082 thread_stack_cache_init(); 1083 cred_init(); 1084 fork_init(); 1085 proc_caches_init(); 1086 uts_ns_init(); 1087 key_init(); 1088 security_init(); 1089 dbg_late_init(); 1090 net_ns_init(); 1091 vfs_caches_init(); 1092 pagecache_init(); 1093 signals_init(); 1094 seq_file_init(); 1095 proc_root_init(); 1096 nsfs_init(); 1097 pidfs_init(); 1098 cpuset_init(); 1099 mem_cgroup_init(); 1100 cgroup_init(); 1101 taskstats_init_early(); 1102 delayacct_init(); 1103 1104 acpi_subsystem_init(); 1105 arch_post_acpi_subsys_init(); 1106 kcsan_init(); 1107 1108 /* Do the rest non-__init'ed, we're now alive */ 1109 rest_init(); 1110 1111 /* 1112 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1113 * and older. 1114 */ 1115 #if !__has_attribute(__no_stack_protector__) 1116 prevent_tail_call_optimization(); 1117 #endif 1118 } 1119 1120 /* Call all constructor functions linked into the kernel. */ 1121 static void __init do_ctors(void) 1122 { 1123 /* 1124 * For UML, the constructors have already been called by the 1125 * normal setup code as it's just a normal ELF binary, so we 1126 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1127 * even on UML for modules. 1128 */ 1129 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1130 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1131 1132 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1133 (*fn)(); 1134 #endif 1135 } 1136 1137 #ifdef CONFIG_KALLSYMS 1138 struct blacklist_entry { 1139 struct list_head next; 1140 char *buf; 1141 }; 1142 1143 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1144 1145 static int __init initcall_blacklist(char *str) 1146 { 1147 char *str_entry; 1148 struct blacklist_entry *entry; 1149 1150 /* str argument is a comma-separated list of functions */ 1151 do { 1152 str_entry = strsep(&str, ","); 1153 if (str_entry) { 1154 pr_debug("blacklisting initcall %s\n", str_entry); 1155 entry = memblock_alloc_or_panic(sizeof(*entry), 1156 SMP_CACHE_BYTES); 1157 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1158 SMP_CACHE_BYTES); 1159 strcpy(entry->buf, str_entry); 1160 list_add(&entry->next, &blacklisted_initcalls); 1161 } 1162 } while (str_entry); 1163 1164 return 1; 1165 } 1166 1167 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1168 { 1169 struct blacklist_entry *entry; 1170 char fn_name[KSYM_SYMBOL_LEN]; 1171 unsigned long addr; 1172 1173 if (list_empty(&blacklisted_initcalls)) 1174 return false; 1175 1176 addr = (unsigned long) dereference_function_descriptor(fn); 1177 sprint_symbol_no_offset(fn_name, addr); 1178 1179 /* 1180 * fn will be "function_name [module_name]" where [module_name] is not 1181 * displayed for built-in init functions. Strip off the [module_name]. 1182 */ 1183 strreplace(fn_name, ' ', '\0'); 1184 1185 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1186 if (!strcmp(fn_name, entry->buf)) { 1187 pr_debug("initcall %s blacklisted\n", fn_name); 1188 return true; 1189 } 1190 } 1191 1192 return false; 1193 } 1194 #else 1195 static int __init initcall_blacklist(char *str) 1196 { 1197 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1198 return 0; 1199 } 1200 1201 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1202 { 1203 return false; 1204 } 1205 #endif 1206 __setup("initcall_blacklist=", initcall_blacklist); 1207 1208 static __init_or_module void 1209 trace_initcall_start_cb(void *data, initcall_t fn) 1210 { 1211 ktime_t *calltime = data; 1212 1213 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1214 *calltime = ktime_get(); 1215 } 1216 1217 static __init_or_module void 1218 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1219 { 1220 ktime_t rettime, *calltime = data; 1221 1222 rettime = ktime_get(); 1223 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1224 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1225 } 1226 1227 static __init_or_module void 1228 trace_initcall_level_cb(void *data, const char *level) 1229 { 1230 printk(KERN_DEBUG "entering initcall level: %s\n", level); 1231 } 1232 1233 static ktime_t initcall_calltime; 1234 1235 #ifdef TRACEPOINTS_ENABLED 1236 static void __init initcall_debug_enable(void) 1237 { 1238 int ret; 1239 1240 ret = register_trace_initcall_start(trace_initcall_start_cb, 1241 &initcall_calltime); 1242 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1243 &initcall_calltime); 1244 ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL); 1245 WARN(ret, "Failed to register initcall tracepoints\n"); 1246 } 1247 # define do_trace_initcall_start trace_initcall_start 1248 # define do_trace_initcall_finish trace_initcall_finish 1249 # define do_trace_initcall_level trace_initcall_level 1250 #else 1251 static inline void do_trace_initcall_start(initcall_t fn) 1252 { 1253 if (!initcall_debug) 1254 return; 1255 trace_initcall_start_cb(&initcall_calltime, fn); 1256 } 1257 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1258 { 1259 if (!initcall_debug) 1260 return; 1261 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1262 } 1263 static inline void do_trace_initcall_level(const char *level) 1264 { 1265 if (!initcall_debug) 1266 return; 1267 trace_initcall_level_cb(NULL, level); 1268 } 1269 #endif /* !TRACEPOINTS_ENABLED */ 1270 1271 int __init_or_module do_one_initcall(initcall_t fn) 1272 { 1273 int count = preempt_count(); 1274 char msgbuf[64]; 1275 int ret; 1276 1277 if (initcall_blacklisted(fn)) 1278 return -EPERM; 1279 1280 do_trace_initcall_start(fn); 1281 ret = fn(); 1282 do_trace_initcall_finish(fn, ret); 1283 1284 msgbuf[0] = 0; 1285 1286 if (preempt_count() != count) { 1287 sprintf(msgbuf, "preemption imbalance "); 1288 preempt_count_set(count); 1289 } 1290 if (irqs_disabled()) { 1291 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1292 local_irq_enable(); 1293 } 1294 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1295 1296 add_latent_entropy(); 1297 return ret; 1298 } 1299 1300 1301 static initcall_entry_t *initcall_levels[] __initdata = { 1302 __initcall0_start, 1303 __initcall1_start, 1304 __initcall2_start, 1305 __initcall3_start, 1306 __initcall4_start, 1307 __initcall5_start, 1308 __initcall6_start, 1309 __initcall7_start, 1310 __initcall_end, 1311 }; 1312 1313 /* Keep these in sync with initcalls in include/linux/init.h */ 1314 static const char *initcall_level_names[] __initdata = { 1315 "pure", 1316 "core", 1317 "postcore", 1318 "arch", 1319 "subsys", 1320 "fs", 1321 "device", 1322 "late", 1323 }; 1324 1325 static int __init ignore_unknown_bootoption(char *param, char *val, 1326 const char *unused, void *arg) 1327 { 1328 return 0; 1329 } 1330 1331 static void __init do_initcall_level(int level, char *command_line) 1332 { 1333 initcall_entry_t *fn; 1334 1335 parse_args(initcall_level_names[level], 1336 command_line, __start___param, 1337 __stop___param - __start___param, 1338 level, level, 1339 NULL, ignore_unknown_bootoption); 1340 1341 do_trace_initcall_level(initcall_level_names[level]); 1342 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1343 do_one_initcall(initcall_from_entry(fn)); 1344 } 1345 1346 static void __init do_initcalls(void) 1347 { 1348 int level; 1349 size_t len = saved_command_line_len + 1; 1350 char *command_line; 1351 1352 command_line = kzalloc(len, GFP_KERNEL); 1353 if (!command_line) 1354 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1355 1356 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1357 /* Parser modifies command_line, restore it each time */ 1358 strcpy(command_line, saved_command_line); 1359 do_initcall_level(level, command_line); 1360 } 1361 1362 kfree(command_line); 1363 } 1364 1365 /* 1366 * Ok, the machine is now initialized. None of the devices 1367 * have been touched yet, but the CPU subsystem is up and 1368 * running, and memory and process management works. 1369 * 1370 * Now we can finally start doing some real work.. 1371 */ 1372 static void __init do_basic_setup(void) 1373 { 1374 cpuset_init_smp(); 1375 driver_init(); 1376 init_irq_proc(); 1377 do_ctors(); 1378 do_initcalls(); 1379 } 1380 1381 static void __init do_pre_smp_initcalls(void) 1382 { 1383 initcall_entry_t *fn; 1384 1385 do_trace_initcall_level("early"); 1386 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1387 do_one_initcall(initcall_from_entry(fn)); 1388 } 1389 1390 static int run_init_process(const char *init_filename) 1391 { 1392 const char *const *p; 1393 1394 argv_init[0] = init_filename; 1395 pr_info("Run %s as init process\n", init_filename); 1396 pr_debug(" with arguments:\n"); 1397 for (p = argv_init; *p; p++) 1398 pr_debug(" %s\n", *p); 1399 pr_debug(" with environment:\n"); 1400 for (p = envp_init; *p; p++) 1401 pr_debug(" %s\n", *p); 1402 return kernel_execve(init_filename, argv_init, envp_init); 1403 } 1404 1405 static int try_to_run_init_process(const char *init_filename) 1406 { 1407 int ret; 1408 1409 ret = run_init_process(init_filename); 1410 1411 if (ret && ret != -ENOENT) { 1412 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1413 init_filename, ret); 1414 } 1415 1416 return ret; 1417 } 1418 1419 static noinline void __init kernel_init_freeable(void); 1420 1421 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1422 bool rodata_enabled __ro_after_init = true; 1423 1424 #ifndef arch_parse_debug_rodata 1425 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1426 #endif 1427 1428 static int __init set_debug_rodata(char *str) 1429 { 1430 if (arch_parse_debug_rodata(str)) 1431 return 0; 1432 1433 if (str && !strcmp(str, "on")) 1434 rodata_enabled = true; 1435 else if (str && !strcmp(str, "off")) 1436 rodata_enabled = false; 1437 else 1438 pr_warn("Invalid option string for rodata: '%s'\n", str); 1439 return 0; 1440 } 1441 early_param("rodata", set_debug_rodata); 1442 #endif 1443 1444 static void mark_readonly(void) 1445 { 1446 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1447 /* 1448 * load_module() results in W+X mappings, which are cleaned 1449 * up with init_free_wq. Let's make sure that queued work is 1450 * flushed so that we don't hit false positives looking for 1451 * insecure pages which are W+X. 1452 */ 1453 flush_module_init_free_work(); 1454 jump_label_init_ro(); 1455 mark_rodata_ro(); 1456 debug_checkwx(); 1457 rodata_test(); 1458 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1459 pr_info("Kernel memory protection disabled.\n"); 1460 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1461 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1462 } else { 1463 pr_warn("This architecture does not have kernel memory protection.\n"); 1464 } 1465 } 1466 1467 void __weak free_initmem(void) 1468 { 1469 free_initmem_default(POISON_FREE_INITMEM); 1470 } 1471 1472 static int __ref kernel_init(void *unused) 1473 { 1474 int ret; 1475 1476 /* 1477 * Wait until kthreadd is all set-up. 1478 */ 1479 wait_for_completion(&kthreadd_done); 1480 1481 kernel_init_freeable(); 1482 /* need to finish all async __init code before freeing the memory */ 1483 async_synchronize_full(); 1484 1485 system_state = SYSTEM_FREEING_INITMEM; 1486 kprobe_free_init_mem(); 1487 ftrace_free_init_mem(); 1488 kgdb_free_init_mem(); 1489 exit_boot_config(); 1490 free_initmem(); 1491 mark_readonly(); 1492 1493 /* 1494 * Kernel mappings are now finalized - update the userspace page-table 1495 * to finalize PTI. 1496 */ 1497 pti_finalize(); 1498 1499 system_state = SYSTEM_RUNNING; 1500 numa_default_policy(); 1501 1502 rcu_end_inkernel_boot(); 1503 1504 do_sysctl_args(); 1505 1506 if (ramdisk_execute_command) { 1507 ret = run_init_process(ramdisk_execute_command); 1508 if (!ret) 1509 return 0; 1510 pr_err("Failed to execute %s (error %d)\n", 1511 ramdisk_execute_command, ret); 1512 } 1513 1514 /* 1515 * We try each of these until one succeeds. 1516 * 1517 * The Bourne shell can be used instead of init if we are 1518 * trying to recover a really broken machine. 1519 */ 1520 if (execute_command) { 1521 ret = run_init_process(execute_command); 1522 if (!ret) 1523 return 0; 1524 panic("Requested init %s failed (error %d).", 1525 execute_command, ret); 1526 } 1527 1528 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1529 ret = run_init_process(CONFIG_DEFAULT_INIT); 1530 if (ret) 1531 pr_err("Default init %s failed (error %d)\n", 1532 CONFIG_DEFAULT_INIT, ret); 1533 else 1534 return 0; 1535 } 1536 1537 if (!try_to_run_init_process("/sbin/init") || 1538 !try_to_run_init_process("/etc/init") || 1539 !try_to_run_init_process("/bin/init") || 1540 !try_to_run_init_process("/bin/sh")) 1541 return 0; 1542 1543 panic("No working init found. Try passing init= option to kernel. " 1544 "See Linux Documentation/admin-guide/init.rst for guidance."); 1545 } 1546 1547 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1548 void __init console_on_rootfs(void) 1549 { 1550 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1551 1552 if (IS_ERR(file)) { 1553 pr_err("Warning: unable to open an initial console.\n"); 1554 return; 1555 } 1556 init_dup(file); 1557 init_dup(file); 1558 init_dup(file); 1559 fput(file); 1560 } 1561 1562 static noinline void __init kernel_init_freeable(void) 1563 { 1564 /* Now the scheduler is fully set up and can do blocking allocations */ 1565 gfp_allowed_mask = __GFP_BITS_MASK; 1566 1567 /* 1568 * init can allocate pages on any node 1569 */ 1570 set_mems_allowed(node_states[N_MEMORY]); 1571 1572 cad_pid = get_pid(task_pid(current)); 1573 1574 smp_prepare_cpus(setup_max_cpus); 1575 1576 workqueue_init(); 1577 1578 init_mm_internals(); 1579 1580 do_pre_smp_initcalls(); 1581 lockup_detector_init(); 1582 1583 smp_init(); 1584 sched_init_smp(); 1585 1586 workqueue_init_topology(); 1587 async_init(); 1588 padata_init(); 1589 page_alloc_init_late(); 1590 1591 do_basic_setup(); 1592 1593 kunit_run_all_tests(); 1594 1595 wait_for_initramfs(); 1596 console_on_rootfs(); 1597 1598 /* 1599 * check if there is an early userspace init. If yes, let it do all 1600 * the work 1601 */ 1602 int ramdisk_command_access; 1603 ramdisk_command_access = init_eaccess(ramdisk_execute_command); 1604 if (ramdisk_command_access != 0) { 1605 pr_warn("check access for rdinit=%s failed: %i, ignoring\n", 1606 ramdisk_execute_command, ramdisk_command_access); 1607 ramdisk_execute_command = NULL; 1608 prepare_namespace(); 1609 } 1610 1611 /* 1612 * Ok, we have completed the initial bootup, and 1613 * we're essentially up and running. Get rid of the 1614 * initmem segments and start the user-mode stuff.. 1615 * 1616 * rootfs is available now, try loading the public keys 1617 * and default modules 1618 */ 1619 1620 integrity_load_keys(); 1621 } 1622