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 __noreturn 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, 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 __noreturn 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 __init __no_sanitize_address __noreturn __no_stack_protector 881 void start_kernel(void) 882 { 883 char *command_line; 884 char *after_dashes; 885 886 set_task_stack_end_magic(&init_task); 887 smp_setup_processor_id(); 888 debug_objects_early_init(); 889 init_vmlinux_build_id(); 890 891 cgroup_init_early(); 892 893 local_irq_disable(); 894 early_boot_irqs_disabled = true; 895 896 /* 897 * Interrupts are still disabled. Do necessary setups, then 898 * enable them. 899 */ 900 boot_cpu_init(); 901 page_address_init(); 902 pr_notice("%s", linux_banner); 903 early_security_init(); 904 setup_arch(&command_line); 905 setup_boot_config(); 906 setup_command_line(command_line); 907 setup_nr_cpu_ids(); 908 setup_per_cpu_areas(); 909 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 910 boot_cpu_hotplug_init(); 911 912 pr_notice("Kernel command line: %s\n", saved_command_line); 913 /* parameters may set static keys */ 914 jump_label_init(); 915 parse_early_param(); 916 after_dashes = parse_args("Booting kernel", 917 static_command_line, __start___param, 918 __stop___param - __start___param, 919 -1, -1, NULL, &unknown_bootoption); 920 print_unknown_bootoptions(); 921 if (!IS_ERR_OR_NULL(after_dashes)) 922 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 923 NULL, set_init_arg); 924 if (extra_init_args) 925 parse_args("Setting extra init args", extra_init_args, 926 NULL, 0, -1, -1, NULL, set_init_arg); 927 928 /* Architectural and non-timekeeping rng init, before allocator init */ 929 random_init_early(command_line); 930 931 /* 932 * These use large bootmem allocations and must precede 933 * initalization of page allocator 934 */ 935 setup_log_buf(0); 936 vfs_caches_init_early(); 937 sort_main_extable(); 938 trap_init(); 939 mm_core_init(); 940 poking_init(); 941 ftrace_init(); 942 943 /* trace_printk can be enabled here */ 944 early_trace_init(); 945 946 /* 947 * Set up the scheduler prior starting any interrupts (such as the 948 * timer interrupt). Full topology setup happens at smp_init() 949 * time - but meanwhile we still have a functioning scheduler. 950 */ 951 sched_init(); 952 953 if (WARN(!irqs_disabled(), 954 "Interrupts were enabled *very* early, fixing it\n")) 955 local_irq_disable(); 956 radix_tree_init(); 957 maple_tree_init(); 958 959 /* 960 * Set up housekeeping before setting up workqueues to allow the unbound 961 * workqueue to take non-housekeeping into account. 962 */ 963 housekeeping_init(); 964 965 /* 966 * Allow workqueue creation and work item queueing/cancelling 967 * early. Work item execution depends on kthreads and starts after 968 * workqueue_init(). 969 */ 970 workqueue_init_early(); 971 972 rcu_init(); 973 974 /* Trace events are available after this */ 975 trace_init(); 976 977 if (initcall_debug) 978 initcall_debug_enable(); 979 980 context_tracking_init(); 981 /* init some links before init_ISA_irqs() */ 982 early_irq_init(); 983 init_IRQ(); 984 tick_init(); 985 rcu_init_nohz(); 986 init_timers(); 987 srcu_init(); 988 hrtimers_init(); 989 softirq_init(); 990 timekeeping_init(); 991 time_init(); 992 993 /* This must be after timekeeping is initialized */ 994 random_init(); 995 996 /* These make use of the fully initialized rng */ 997 kfence_init(); 998 boot_init_stack_canary(); 999 1000 perf_event_init(); 1001 profile_init(); 1002 call_function_init(); 1003 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1004 1005 early_boot_irqs_disabled = false; 1006 local_irq_enable(); 1007 1008 kmem_cache_init_late(); 1009 1010 /* 1011 * HACK ALERT! This is early. We're enabling the console before 1012 * we've done PCI setups etc, and console_init() must be aware of 1013 * this. But we do want output early, in case something goes wrong. 1014 */ 1015 console_init(); 1016 if (panic_later) 1017 panic("Too many boot %s vars at `%s'", panic_later, 1018 panic_param); 1019 1020 lockdep_init(); 1021 1022 /* 1023 * Need to run this when irqs are enabled, because it wants 1024 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1025 * too: 1026 */ 1027 locking_selftest(); 1028 1029 #ifdef CONFIG_BLK_DEV_INITRD 1030 if (initrd_start && !initrd_below_start_ok && 1031 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1032 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1033 page_to_pfn(virt_to_page((void *)initrd_start)), 1034 min_low_pfn); 1035 initrd_start = 0; 1036 } 1037 #endif 1038 setup_per_cpu_pageset(); 1039 numa_policy_init(); 1040 acpi_early_init(); 1041 if (late_time_init) 1042 late_time_init(); 1043 sched_clock_init(); 1044 calibrate_delay(); 1045 1046 /* 1047 * This needs to be called before any devices perform DMA 1048 * operations that might use the SWIOTLB bounce buffers. It will 1049 * mark the bounce buffers as decrypted so that their usage will 1050 * not cause "plain-text" data to be decrypted when accessed. It 1051 * must be called after late_time_init() so that Hyper-V x86/x64 1052 * hypercalls work when the SWIOTLB bounce buffers are decrypted. 1053 */ 1054 mem_encrypt_init(); 1055 1056 pid_idr_init(); 1057 anon_vma_init(); 1058 #ifdef CONFIG_X86 1059 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1060 efi_enter_virtual_mode(); 1061 #endif 1062 thread_stack_cache_init(); 1063 cred_init(); 1064 fork_init(); 1065 proc_caches_init(); 1066 uts_ns_init(); 1067 key_init(); 1068 security_init(); 1069 dbg_late_init(); 1070 net_ns_init(); 1071 vfs_caches_init(); 1072 pagecache_init(); 1073 signals_init(); 1074 seq_file_init(); 1075 proc_root_init(); 1076 nsfs_init(); 1077 cpuset_init(); 1078 cgroup_init(); 1079 taskstats_init_early(); 1080 delayacct_init(); 1081 1082 check_bugs(); 1083 1084 acpi_subsystem_init(); 1085 arch_post_acpi_subsys_init(); 1086 kcsan_init(); 1087 1088 /* Do the rest non-__init'ed, we're now alive */ 1089 arch_call_rest_init(); 1090 1091 /* 1092 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1093 * and older. 1094 */ 1095 #if !__has_attribute(__no_stack_protector__) 1096 prevent_tail_call_optimization(); 1097 #endif 1098 } 1099 1100 /* Call all constructor functions linked into the kernel. */ 1101 static void __init do_ctors(void) 1102 { 1103 /* 1104 * For UML, the constructors have already been called by the 1105 * normal setup code as it's just a normal ELF binary, so we 1106 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1107 * even on UML for modules. 1108 */ 1109 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1110 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1111 1112 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1113 (*fn)(); 1114 #endif 1115 } 1116 1117 #ifdef CONFIG_KALLSYMS 1118 struct blacklist_entry { 1119 struct list_head next; 1120 char *buf; 1121 }; 1122 1123 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1124 1125 static int __init initcall_blacklist(char *str) 1126 { 1127 char *str_entry; 1128 struct blacklist_entry *entry; 1129 1130 /* str argument is a comma-separated list of functions */ 1131 do { 1132 str_entry = strsep(&str, ","); 1133 if (str_entry) { 1134 pr_debug("blacklisting initcall %s\n", str_entry); 1135 entry = memblock_alloc(sizeof(*entry), 1136 SMP_CACHE_BYTES); 1137 if (!entry) 1138 panic("%s: Failed to allocate %zu bytes\n", 1139 __func__, sizeof(*entry)); 1140 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1141 SMP_CACHE_BYTES); 1142 if (!entry->buf) 1143 panic("%s: Failed to allocate %zu bytes\n", 1144 __func__, strlen(str_entry) + 1); 1145 strcpy(entry->buf, str_entry); 1146 list_add(&entry->next, &blacklisted_initcalls); 1147 } 1148 } while (str_entry); 1149 1150 return 1; 1151 } 1152 1153 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1154 { 1155 struct blacklist_entry *entry; 1156 char fn_name[KSYM_SYMBOL_LEN]; 1157 unsigned long addr; 1158 1159 if (list_empty(&blacklisted_initcalls)) 1160 return false; 1161 1162 addr = (unsigned long) dereference_function_descriptor(fn); 1163 sprint_symbol_no_offset(fn_name, addr); 1164 1165 /* 1166 * fn will be "function_name [module_name]" where [module_name] is not 1167 * displayed for built-in init functions. Strip off the [module_name]. 1168 */ 1169 strreplace(fn_name, ' ', '\0'); 1170 1171 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1172 if (!strcmp(fn_name, entry->buf)) { 1173 pr_debug("initcall %s blacklisted\n", fn_name); 1174 return true; 1175 } 1176 } 1177 1178 return false; 1179 } 1180 #else 1181 static int __init initcall_blacklist(char *str) 1182 { 1183 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1184 return 0; 1185 } 1186 1187 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1188 { 1189 return false; 1190 } 1191 #endif 1192 __setup("initcall_blacklist=", initcall_blacklist); 1193 1194 static __init_or_module void 1195 trace_initcall_start_cb(void *data, initcall_t fn) 1196 { 1197 ktime_t *calltime = data; 1198 1199 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1200 *calltime = ktime_get(); 1201 } 1202 1203 static __init_or_module void 1204 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1205 { 1206 ktime_t rettime, *calltime = data; 1207 1208 rettime = ktime_get(); 1209 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1210 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1211 } 1212 1213 static ktime_t initcall_calltime; 1214 1215 #ifdef TRACEPOINTS_ENABLED 1216 static void __init initcall_debug_enable(void) 1217 { 1218 int ret; 1219 1220 ret = register_trace_initcall_start(trace_initcall_start_cb, 1221 &initcall_calltime); 1222 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1223 &initcall_calltime); 1224 WARN(ret, "Failed to register initcall tracepoints\n"); 1225 } 1226 # define do_trace_initcall_start trace_initcall_start 1227 # define do_trace_initcall_finish trace_initcall_finish 1228 #else 1229 static inline void do_trace_initcall_start(initcall_t fn) 1230 { 1231 if (!initcall_debug) 1232 return; 1233 trace_initcall_start_cb(&initcall_calltime, fn); 1234 } 1235 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1236 { 1237 if (!initcall_debug) 1238 return; 1239 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1240 } 1241 #endif /* !TRACEPOINTS_ENABLED */ 1242 1243 int __init_or_module do_one_initcall(initcall_t fn) 1244 { 1245 int count = preempt_count(); 1246 char msgbuf[64]; 1247 int ret; 1248 1249 if (initcall_blacklisted(fn)) 1250 return -EPERM; 1251 1252 do_trace_initcall_start(fn); 1253 ret = fn(); 1254 do_trace_initcall_finish(fn, ret); 1255 1256 msgbuf[0] = 0; 1257 1258 if (preempt_count() != count) { 1259 sprintf(msgbuf, "preemption imbalance "); 1260 preempt_count_set(count); 1261 } 1262 if (irqs_disabled()) { 1263 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1264 local_irq_enable(); 1265 } 1266 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1267 1268 add_latent_entropy(); 1269 return ret; 1270 } 1271 1272 1273 extern initcall_entry_t __initcall_start[]; 1274 extern initcall_entry_t __initcall0_start[]; 1275 extern initcall_entry_t __initcall1_start[]; 1276 extern initcall_entry_t __initcall2_start[]; 1277 extern initcall_entry_t __initcall3_start[]; 1278 extern initcall_entry_t __initcall4_start[]; 1279 extern initcall_entry_t __initcall5_start[]; 1280 extern initcall_entry_t __initcall6_start[]; 1281 extern initcall_entry_t __initcall7_start[]; 1282 extern initcall_entry_t __initcall_end[]; 1283 1284 static initcall_entry_t *initcall_levels[] __initdata = { 1285 __initcall0_start, 1286 __initcall1_start, 1287 __initcall2_start, 1288 __initcall3_start, 1289 __initcall4_start, 1290 __initcall5_start, 1291 __initcall6_start, 1292 __initcall7_start, 1293 __initcall_end, 1294 }; 1295 1296 /* Keep these in sync with initcalls in include/linux/init.h */ 1297 static const char *initcall_level_names[] __initdata = { 1298 "pure", 1299 "core", 1300 "postcore", 1301 "arch", 1302 "subsys", 1303 "fs", 1304 "device", 1305 "late", 1306 }; 1307 1308 static int __init ignore_unknown_bootoption(char *param, char *val, 1309 const char *unused, void *arg) 1310 { 1311 return 0; 1312 } 1313 1314 static void __init do_initcall_level(int level, char *command_line) 1315 { 1316 initcall_entry_t *fn; 1317 1318 parse_args(initcall_level_names[level], 1319 command_line, __start___param, 1320 __stop___param - __start___param, 1321 level, level, 1322 NULL, ignore_unknown_bootoption); 1323 1324 trace_initcall_level(initcall_level_names[level]); 1325 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1326 do_one_initcall(initcall_from_entry(fn)); 1327 } 1328 1329 static void __init do_initcalls(void) 1330 { 1331 int level; 1332 size_t len = saved_command_line_len + 1; 1333 char *command_line; 1334 1335 command_line = kzalloc(len, GFP_KERNEL); 1336 if (!command_line) 1337 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1338 1339 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1340 /* Parser modifies command_line, restore it each time */ 1341 strcpy(command_line, saved_command_line); 1342 do_initcall_level(level, command_line); 1343 } 1344 1345 kfree(command_line); 1346 } 1347 1348 /* 1349 * Ok, the machine is now initialized. None of the devices 1350 * have been touched yet, but the CPU subsystem is up and 1351 * running, and memory and process management works. 1352 * 1353 * Now we can finally start doing some real work.. 1354 */ 1355 static void __init do_basic_setup(void) 1356 { 1357 cpuset_init_smp(); 1358 driver_init(); 1359 init_irq_proc(); 1360 do_ctors(); 1361 do_initcalls(); 1362 } 1363 1364 static void __init do_pre_smp_initcalls(void) 1365 { 1366 initcall_entry_t *fn; 1367 1368 trace_initcall_level("early"); 1369 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1370 do_one_initcall(initcall_from_entry(fn)); 1371 } 1372 1373 static int run_init_process(const char *init_filename) 1374 { 1375 const char *const *p; 1376 1377 argv_init[0] = init_filename; 1378 pr_info("Run %s as init process\n", init_filename); 1379 pr_debug(" with arguments:\n"); 1380 for (p = argv_init; *p; p++) 1381 pr_debug(" %s\n", *p); 1382 pr_debug(" with environment:\n"); 1383 for (p = envp_init; *p; p++) 1384 pr_debug(" %s\n", *p); 1385 return kernel_execve(init_filename, argv_init, envp_init); 1386 } 1387 1388 static int try_to_run_init_process(const char *init_filename) 1389 { 1390 int ret; 1391 1392 ret = run_init_process(init_filename); 1393 1394 if (ret && ret != -ENOENT) { 1395 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1396 init_filename, ret); 1397 } 1398 1399 return ret; 1400 } 1401 1402 static noinline void __init kernel_init_freeable(void); 1403 1404 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1405 bool rodata_enabled __ro_after_init = true; 1406 1407 #ifndef arch_parse_debug_rodata 1408 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1409 #endif 1410 1411 static int __init set_debug_rodata(char *str) 1412 { 1413 if (arch_parse_debug_rodata(str)) 1414 return 0; 1415 1416 if (str && !strcmp(str, "on")) 1417 rodata_enabled = true; 1418 else if (str && !strcmp(str, "off")) 1419 rodata_enabled = false; 1420 else 1421 pr_warn("Invalid option string for rodata: '%s'\n", str); 1422 return 0; 1423 } 1424 early_param("rodata", set_debug_rodata); 1425 #endif 1426 1427 #ifdef CONFIG_STRICT_KERNEL_RWX 1428 static void mark_readonly(void) 1429 { 1430 if (rodata_enabled) { 1431 /* 1432 * load_module() results in W+X mappings, which are cleaned 1433 * up with call_rcu(). Let's make sure that queued work is 1434 * flushed so that we don't hit false positives looking for 1435 * insecure pages which are W+X. 1436 */ 1437 rcu_barrier(); 1438 mark_rodata_ro(); 1439 rodata_test(); 1440 } else 1441 pr_info("Kernel memory protection disabled.\n"); 1442 } 1443 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX) 1444 static inline void mark_readonly(void) 1445 { 1446 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1447 } 1448 #else 1449 static inline void mark_readonly(void) 1450 { 1451 pr_warn("This architecture does not have kernel memory protection.\n"); 1452 } 1453 #endif 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 padata_init(); 1576 page_alloc_init_late(); 1577 1578 do_basic_setup(); 1579 1580 kunit_run_all_tests(); 1581 1582 wait_for_initramfs(); 1583 console_on_rootfs(); 1584 1585 /* 1586 * check if there is an early userspace init. If yes, let it do all 1587 * the work 1588 */ 1589 if (init_eaccess(ramdisk_execute_command) != 0) { 1590 ramdisk_execute_command = NULL; 1591 prepare_namespace(); 1592 } 1593 1594 /* 1595 * Ok, we have completed the initial bootup, and 1596 * we're essentially up and running. Get rid of the 1597 * initmem segments and start the user-mode stuff.. 1598 * 1599 * rootfs is available now, try loading the public keys 1600 * and default modules 1601 */ 1602 1603 integrity_load_keys(); 1604 } 1605