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/vmalloc.h> 38 #include <linux/kernel_stat.h> 39 #include <linux/start_kernel.h> 40 #include <linux/security.h> 41 #include <linux/smp.h> 42 #include <linux/profile.h> 43 #include <linux/kfence.h> 44 #include <linux/rcupdate.h> 45 #include <linux/moduleparam.h> 46 #include <linux/kallsyms.h> 47 #include <linux/writeback.h> 48 #include <linux/cpu.h> 49 #include <linux/cpuset.h> 50 #include <linux/cgroup.h> 51 #include <linux/efi.h> 52 #include <linux/tick.h> 53 #include <linux/sched/isolation.h> 54 #include <linux/interrupt.h> 55 #include <linux/taskstats_kern.h> 56 #include <linux/delayacct.h> 57 #include <linux/unistd.h> 58 #include <linux/utsname.h> 59 #include <linux/rmap.h> 60 #include <linux/mempolicy.h> 61 #include <linux/key.h> 62 #include <linux/page_ext.h> 63 #include <linux/debug_locks.h> 64 #include <linux/debugobjects.h> 65 #include <linux/lockdep.h> 66 #include <linux/kmemleak.h> 67 #include <linux/padata.h> 68 #include <linux/pid_namespace.h> 69 #include <linux/device/driver.h> 70 #include <linux/kthread.h> 71 #include <linux/sched.h> 72 #include <linux/sched/init.h> 73 #include <linux/signal.h> 74 #include <linux/idr.h> 75 #include <linux/kgdb.h> 76 #include <linux/ftrace.h> 77 #include <linux/async.h> 78 #include <linux/shmem_fs.h> 79 #include <linux/slab.h> 80 #include <linux/perf_event.h> 81 #include <linux/ptrace.h> 82 #include <linux/pti.h> 83 #include <linux/blkdev.h> 84 #include <linux/elevator.h> 85 #include <linux/sched/clock.h> 86 #include <linux/sched/task.h> 87 #include <linux/sched/task_stack.h> 88 #include <linux/context_tracking.h> 89 #include <linux/random.h> 90 #include <linux/list.h> 91 #include <linux/integrity.h> 92 #include <linux/proc_ns.h> 93 #include <linux/io.h> 94 #include <linux/cache.h> 95 #include <linux/rodata_test.h> 96 #include <linux/jump_label.h> 97 #include <linux/mem_encrypt.h> 98 #include <linux/kcsan.h> 99 #include <linux/init_syscalls.h> 100 #include <linux/stackdepot.h> 101 102 #include <asm/io.h> 103 #include <asm/bugs.h> 104 #include <asm/setup.h> 105 #include <asm/sections.h> 106 #include <asm/cacheflush.h> 107 108 #define CREATE_TRACE_POINTS 109 #include <trace/events/initcall.h> 110 111 #include <kunit/test.h> 112 113 static int kernel_init(void *); 114 115 extern void init_IRQ(void); 116 extern void radix_tree_init(void); 117 118 /* 119 * Debug helper: via this flag we know that we are in 'early bootup code' 120 * where only the boot processor is running with IRQ disabled. This means 121 * two things - IRQ must not be enabled before the flag is cleared and some 122 * operations which are not allowed with IRQ disabled are allowed while the 123 * flag is set. 124 */ 125 bool early_boot_irqs_disabled __read_mostly; 126 127 enum system_states system_state __read_mostly; 128 EXPORT_SYMBOL(system_state); 129 130 /* 131 * Boot command-line arguments 132 */ 133 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 134 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 135 136 extern void time_init(void); 137 /* Default late time init is NULL. archs can override this later. */ 138 void (*__initdata late_time_init)(void); 139 140 /* Untouched command line saved by arch-specific code. */ 141 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 142 /* Untouched saved command line (eg. for /proc) */ 143 char *saved_command_line; 144 /* Command line for parameter parsing */ 145 static char *static_command_line; 146 /* Untouched extra command line */ 147 static char *extra_command_line; 148 /* Extra init arguments */ 149 static char *extra_init_args; 150 151 #ifdef CONFIG_BOOT_CONFIG 152 /* Is bootconfig on command line? */ 153 static bool bootconfig_found; 154 static bool initargs_found; 155 #else 156 # define bootconfig_found false 157 # define initargs_found false 158 #endif 159 160 static char *execute_command; 161 static char *ramdisk_execute_command = "/init"; 162 163 /* 164 * Used to generate warnings if static_key manipulation functions are used 165 * before jump_label_init is called. 166 */ 167 bool static_key_initialized __read_mostly; 168 EXPORT_SYMBOL_GPL(static_key_initialized); 169 170 /* 171 * If set, this is an indication to the drivers that reset the underlying 172 * device before going ahead with the initialization otherwise driver might 173 * rely on the BIOS and skip the reset operation. 174 * 175 * This is useful if kernel is booting in an unreliable environment. 176 * For ex. kdump situation where previous kernel has crashed, BIOS has been 177 * skipped and devices will be in unknown state. 178 */ 179 unsigned int reset_devices; 180 EXPORT_SYMBOL(reset_devices); 181 182 static int __init set_reset_devices(char *str) 183 { 184 reset_devices = 1; 185 return 1; 186 } 187 188 __setup("reset_devices", set_reset_devices); 189 190 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 191 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 192 static const char *panic_later, *panic_param; 193 194 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 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(u32 *_size, u32 *_csum) 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 /* Remove bootconfig from initramfs/initrd */ 302 initrd_end = (unsigned long)data; 303 if (_size) 304 *_size = size; 305 if (_csum) 306 *_csum = csum; 307 308 return data; 309 } 310 #else 311 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) 312 { 313 return NULL; 314 } 315 #endif 316 317 #ifdef CONFIG_BOOT_CONFIG 318 319 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 320 321 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 322 323 static int __init xbc_snprint_cmdline(char *buf, size_t size, 324 struct xbc_node *root) 325 { 326 struct xbc_node *knode, *vnode; 327 char *end = buf + size; 328 const char *val; 329 int ret; 330 331 xbc_node_for_each_key_value(root, knode, val) { 332 ret = xbc_node_compose_key_after(root, knode, 333 xbc_namebuf, XBC_KEYLEN_MAX); 334 if (ret < 0) 335 return ret; 336 337 vnode = xbc_node_get_child(knode); 338 if (!vnode) { 339 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 340 if (ret < 0) 341 return ret; 342 buf += ret; 343 continue; 344 } 345 xbc_array_for_each_value(vnode, val) { 346 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ", 347 xbc_namebuf, val); 348 if (ret < 0) 349 return ret; 350 buf += ret; 351 } 352 } 353 354 return buf - (end - size); 355 } 356 #undef rest 357 358 /* Make an extra command line under given key word */ 359 static char * __init xbc_make_cmdline(const char *key) 360 { 361 struct xbc_node *root; 362 char *new_cmdline; 363 int ret, len = 0; 364 365 root = xbc_find_node(key); 366 if (!root) 367 return NULL; 368 369 /* Count required buffer size */ 370 len = xbc_snprint_cmdline(NULL, 0, root); 371 if (len <= 0) 372 return NULL; 373 374 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 375 if (!new_cmdline) { 376 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 377 return NULL; 378 } 379 380 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 381 if (ret < 0 || ret > len) { 382 pr_err("Failed to print extra kernel cmdline.\n"); 383 return NULL; 384 } 385 386 return new_cmdline; 387 } 388 389 static u32 boot_config_checksum(unsigned char *p, u32 size) 390 { 391 u32 ret = 0; 392 393 while (size--) 394 ret += *p++; 395 396 return ret; 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 void __init setup_boot_config(const char *cmdline) 409 { 410 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 411 const char *msg; 412 int pos; 413 u32 size, csum; 414 char *data, *copy, *err; 415 int ret; 416 417 /* Cut out the bootconfig data even if we have no bootconfig option */ 418 data = get_boot_config_from_initrd(&size, &csum); 419 420 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 421 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 422 bootconfig_params); 423 424 if (IS_ERR(err) || !bootconfig_found) 425 return; 426 427 /* parse_args() stops at '--' and returns an address */ 428 if (err) 429 initargs_found = true; 430 431 if (!data) { 432 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 433 return; 434 } 435 436 if (size >= XBC_DATA_MAX) { 437 pr_err("bootconfig size %d greater than max size %d\n", 438 size, XBC_DATA_MAX); 439 return; 440 } 441 442 if (boot_config_checksum((unsigned char *)data, size) != csum) { 443 pr_err("bootconfig checksum failed\n"); 444 return; 445 } 446 447 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES); 448 if (!copy) { 449 pr_err("Failed to allocate memory for bootconfig\n"); 450 return; 451 } 452 453 memcpy(copy, data, size); 454 copy[size] = '\0'; 455 456 ret = xbc_init(copy, &msg, &pos); 457 if (ret < 0) { 458 if (pos < 0) 459 pr_err("Failed to init bootconfig: %s.\n", msg); 460 else 461 pr_err("Failed to parse bootconfig: %s at %d.\n", 462 msg, pos); 463 } else { 464 pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret); 465 /* keys starting with "kernel." are passed via cmdline */ 466 extra_command_line = xbc_make_cmdline("kernel"); 467 /* Also, "init." keys are init arguments */ 468 extra_init_args = xbc_make_cmdline("init"); 469 } 470 return; 471 } 472 473 #else 474 475 static void __init setup_boot_config(const char *cmdline) 476 { 477 /* Remove bootconfig data from initrd */ 478 get_boot_config_from_initrd(NULL, NULL); 479 } 480 481 static int __init warn_bootconfig(char *str) 482 { 483 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 484 return 0; 485 } 486 early_param("bootconfig", warn_bootconfig); 487 488 #endif 489 490 /* Change NUL term back to "=", to make "param" the whole string. */ 491 static void __init repair_env_string(char *param, char *val) 492 { 493 if (val) { 494 /* param=val or param="val"? */ 495 if (val == param+strlen(param)+1) 496 val[-1] = '='; 497 else if (val == param+strlen(param)+2) { 498 val[-2] = '='; 499 memmove(val-1, val, strlen(val)+1); 500 } else 501 BUG(); 502 } 503 } 504 505 /* Anything after -- gets handed straight to init. */ 506 static int __init set_init_arg(char *param, char *val, 507 const char *unused, void *arg) 508 { 509 unsigned int i; 510 511 if (panic_later) 512 return 0; 513 514 repair_env_string(param, val); 515 516 for (i = 0; argv_init[i]; i++) { 517 if (i == MAX_INIT_ARGS) { 518 panic_later = "init"; 519 panic_param = param; 520 return 0; 521 } 522 } 523 argv_init[i] = param; 524 return 0; 525 } 526 527 /* 528 * Unknown boot options get handed to init, unless they look like 529 * unused parameters (modprobe will find them in /proc/cmdline). 530 */ 531 static int __init unknown_bootoption(char *param, char *val, 532 const char *unused, void *arg) 533 { 534 size_t len = strlen(param); 535 536 repair_env_string(param, val); 537 538 /* Handle obsolete-style parameters */ 539 if (obsolete_checksetup(param)) 540 return 0; 541 542 /* Unused module parameter. */ 543 if (strnchr(param, len, '.')) 544 return 0; 545 546 if (panic_later) 547 return 0; 548 549 if (val) { 550 /* Environment option */ 551 unsigned int i; 552 for (i = 0; envp_init[i]; i++) { 553 if (i == MAX_INIT_ENVS) { 554 panic_later = "env"; 555 panic_param = param; 556 } 557 if (!strncmp(param, envp_init[i], len+1)) 558 break; 559 } 560 envp_init[i] = param; 561 } else { 562 /* Command line option */ 563 unsigned int i; 564 for (i = 0; argv_init[i]; i++) { 565 if (i == MAX_INIT_ARGS) { 566 panic_later = "init"; 567 panic_param = param; 568 } 569 } 570 argv_init[i] = param; 571 } 572 return 0; 573 } 574 575 static int __init init_setup(char *str) 576 { 577 unsigned int i; 578 579 execute_command = str; 580 /* 581 * In case LILO is going to boot us with default command line, 582 * it prepends "auto" before the whole cmdline which makes 583 * the shell think it should execute a script with such name. 584 * So we ignore all arguments entered _before_ init=... [MJ] 585 */ 586 for (i = 1; i < MAX_INIT_ARGS; i++) 587 argv_init[i] = NULL; 588 return 1; 589 } 590 __setup("init=", init_setup); 591 592 static int __init rdinit_setup(char *str) 593 { 594 unsigned int i; 595 596 ramdisk_execute_command = str; 597 /* See "auto" comment in init_setup */ 598 for (i = 1; i < MAX_INIT_ARGS; i++) 599 argv_init[i] = NULL; 600 return 1; 601 } 602 __setup("rdinit=", rdinit_setup); 603 604 #ifndef CONFIG_SMP 605 static const unsigned int setup_max_cpus = NR_CPUS; 606 static inline void setup_nr_cpu_ids(void) { } 607 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 608 #endif 609 610 /* 611 * We need to store the untouched command line for future reference. 612 * We also need to store the touched command line since the parameter 613 * parsing is performed in place, and we should allow a component to 614 * store reference of name/value for future reference. 615 */ 616 static void __init setup_command_line(char *command_line) 617 { 618 size_t len, xlen = 0, ilen = 0; 619 620 if (extra_command_line) 621 xlen = strlen(extra_command_line); 622 if (extra_init_args) 623 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 624 625 len = xlen + strlen(boot_command_line) + 1; 626 627 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); 628 if (!saved_command_line) 629 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); 630 631 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 632 if (!static_command_line) 633 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 634 635 if (xlen) { 636 /* 637 * We have to put extra_command_line before boot command 638 * lines because there could be dashes (separator of init 639 * command line) in the command lines. 640 */ 641 strcpy(saved_command_line, extra_command_line); 642 strcpy(static_command_line, extra_command_line); 643 } 644 strcpy(saved_command_line + xlen, boot_command_line); 645 strcpy(static_command_line + xlen, command_line); 646 647 if (ilen) { 648 /* 649 * Append supplemental init boot args to saved_command_line 650 * so that user can check what command line options passed 651 * to init. 652 */ 653 len = strlen(saved_command_line); 654 if (initargs_found) { 655 saved_command_line[len++] = ' '; 656 } else { 657 strcpy(saved_command_line + len, " -- "); 658 len += 4; 659 } 660 661 strcpy(saved_command_line + len, extra_init_args); 662 } 663 } 664 665 /* 666 * We need to finalize in a non-__init function or else race conditions 667 * between the root thread and the init thread may cause start_kernel to 668 * be reaped by free_initmem before the root thread has proceeded to 669 * cpu_idle. 670 * 671 * gcc-3.4 accidentally inlines this function, so use noinline. 672 */ 673 674 static __initdata DECLARE_COMPLETION(kthreadd_done); 675 676 noinline void __ref rest_init(void) 677 { 678 struct task_struct *tsk; 679 int pid; 680 681 rcu_scheduler_starting(); 682 /* 683 * We need to spawn init first so that it obtains pid 1, however 684 * the init task will end up wanting to create kthreads, which, if 685 * we schedule it before we create kthreadd, will OOPS. 686 */ 687 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 688 /* 689 * Pin init on the boot CPU. Task migration is not properly working 690 * until sched_init_smp() has been run. It will set the allowed 691 * CPUs for init to the non isolated CPUs. 692 */ 693 rcu_read_lock(); 694 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 695 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 696 rcu_read_unlock(); 697 698 numa_default_policy(); 699 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 700 rcu_read_lock(); 701 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 702 rcu_read_unlock(); 703 704 /* 705 * Enable might_sleep() and smp_processor_id() checks. 706 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 707 * kernel_thread() would trigger might_sleep() splats. With 708 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 709 * already, but it's stuck on the kthreadd_done completion. 710 */ 711 system_state = SYSTEM_SCHEDULING; 712 713 complete(&kthreadd_done); 714 715 /* 716 * The boot idle thread must execute schedule() 717 * at least once to get things moving: 718 */ 719 schedule_preempt_disabled(); 720 /* Call into cpu_idle with preempt disabled */ 721 cpu_startup_entry(CPUHP_ONLINE); 722 } 723 724 /* Check for early params. */ 725 static int __init do_early_param(char *param, char *val, 726 const char *unused, void *arg) 727 { 728 const struct obs_kernel_param *p; 729 730 for (p = __setup_start; p < __setup_end; p++) { 731 if ((p->early && parameq(param, p->str)) || 732 (strcmp(param, "console") == 0 && 733 strcmp(p->str, "earlycon") == 0) 734 ) { 735 if (p->setup_func(val) != 0) 736 pr_warn("Malformed early option '%s'\n", param); 737 } 738 } 739 /* We accept everything at this stage. */ 740 return 0; 741 } 742 743 void __init parse_early_options(char *cmdline) 744 { 745 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 746 do_early_param); 747 } 748 749 /* Arch code calls this early on, or if not, just before other parsing. */ 750 void __init parse_early_param(void) 751 { 752 static int done __initdata; 753 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 754 755 if (done) 756 return; 757 758 /* All fall through to do_early_param. */ 759 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 760 parse_early_options(tmp_cmdline); 761 done = 1; 762 } 763 764 void __init __weak arch_post_acpi_subsys_init(void) { } 765 766 void __init __weak smp_setup_processor_id(void) 767 { 768 } 769 770 # if THREAD_SIZE >= PAGE_SIZE 771 void __init __weak thread_stack_cache_init(void) 772 { 773 } 774 #endif 775 776 void __init __weak mem_encrypt_init(void) { } 777 778 void __init __weak poking_init(void) { } 779 780 void __init __weak pgtable_cache_init(void) { } 781 782 bool initcall_debug; 783 core_param(initcall_debug, initcall_debug, bool, 0644); 784 785 #ifdef TRACEPOINTS_ENABLED 786 static void __init initcall_debug_enable(void); 787 #else 788 static inline void initcall_debug_enable(void) 789 { 790 } 791 #endif 792 793 /* Report memory auto-initialization states for this boot. */ 794 static void __init report_meminit(void) 795 { 796 const char *stack; 797 798 if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN)) 799 stack = "all(pattern)"; 800 else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO)) 801 stack = "all(zero)"; 802 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) 803 stack = "byref_all(zero)"; 804 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) 805 stack = "byref(zero)"; 806 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) 807 stack = "__user(zero)"; 808 else 809 stack = "off"; 810 811 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", 812 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", 813 want_init_on_free() ? "on" : "off"); 814 if (want_init_on_free()) 815 pr_info("mem auto-init: clearing system memory may take some time...\n"); 816 } 817 818 /* 819 * Set up kernel memory allocators 820 */ 821 static void __init mm_init(void) 822 { 823 /* 824 * page_ext requires contiguous pages, 825 * bigger than MAX_ORDER unless SPARSEMEM. 826 */ 827 page_ext_init_flatmem(); 828 init_mem_debugging_and_hardening(); 829 kfence_alloc_pool(); 830 report_meminit(); 831 stack_depot_init(); 832 mem_init(); 833 mem_init_print_info(); 834 /* page_owner must be initialized after buddy is ready */ 835 page_ext_init_flatmem_late(); 836 kmem_cache_init(); 837 kmemleak_init(); 838 pgtable_init(); 839 debug_objects_mem_init(); 840 vmalloc_init(); 841 /* Should be run before the first non-init thread is created */ 842 init_espfix_bsp(); 843 /* Should be run after espfix64 is set up. */ 844 pti_init(); 845 } 846 847 #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 848 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 849 randomize_kstack_offset); 850 DEFINE_PER_CPU(u32, kstack_offset); 851 852 static int __init early_randomize_kstack_offset(char *buf) 853 { 854 int ret; 855 bool bool_result; 856 857 ret = kstrtobool(buf, &bool_result); 858 if (ret) 859 return ret; 860 861 if (bool_result) 862 static_branch_enable(&randomize_kstack_offset); 863 else 864 static_branch_disable(&randomize_kstack_offset); 865 return 0; 866 } 867 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 868 #endif 869 870 void __init __weak arch_call_rest_init(void) 871 { 872 rest_init(); 873 } 874 875 asmlinkage __visible void __init __no_sanitize_address start_kernel(void) 876 { 877 char *command_line; 878 char *after_dashes; 879 880 set_task_stack_end_magic(&init_task); 881 smp_setup_processor_id(); 882 debug_objects_early_init(); 883 884 cgroup_init_early(); 885 886 local_irq_disable(); 887 early_boot_irqs_disabled = true; 888 889 /* 890 * Interrupts are still disabled. Do necessary setups, then 891 * enable them. 892 */ 893 boot_cpu_init(); 894 page_address_init(); 895 pr_notice("%s", linux_banner); 896 early_security_init(); 897 setup_arch(&command_line); 898 setup_boot_config(command_line); 899 setup_command_line(command_line); 900 setup_nr_cpu_ids(); 901 setup_per_cpu_areas(); 902 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 903 boot_cpu_hotplug_init(); 904 905 build_all_zonelists(NULL); 906 page_alloc_init(); 907 908 pr_notice("Kernel command line: %s\n", saved_command_line); 909 /* parameters may set static keys */ 910 jump_label_init(); 911 parse_early_param(); 912 after_dashes = parse_args("Booting kernel", 913 static_command_line, __start___param, 914 __stop___param - __start___param, 915 -1, -1, NULL, &unknown_bootoption); 916 if (!IS_ERR_OR_NULL(after_dashes)) 917 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 918 NULL, set_init_arg); 919 if (extra_init_args) 920 parse_args("Setting extra init args", extra_init_args, 921 NULL, 0, -1, -1, NULL, set_init_arg); 922 923 /* 924 * These use large bootmem allocations and must precede 925 * kmem_cache_init() 926 */ 927 setup_log_buf(0); 928 vfs_caches_init_early(); 929 sort_main_extable(); 930 trap_init(); 931 mm_init(); 932 933 ftrace_init(); 934 935 /* trace_printk can be enabled here */ 936 early_trace_init(); 937 938 /* 939 * Set up the scheduler prior starting any interrupts (such as the 940 * timer interrupt). Full topology setup happens at smp_init() 941 * time - but meanwhile we still have a functioning scheduler. 942 */ 943 sched_init(); 944 /* 945 * Disable preemption - early bootup scheduling is extremely 946 * fragile until we cpu_idle() for the first time. 947 */ 948 preempt_disable(); 949 if (WARN(!irqs_disabled(), 950 "Interrupts were enabled *very* early, fixing it\n")) 951 local_irq_disable(); 952 radix_tree_init(); 953 954 /* 955 * Set up housekeeping before setting up workqueues to allow the unbound 956 * workqueue to take non-housekeeping into account. 957 */ 958 housekeeping_init(); 959 960 /* 961 * Allow workqueue creation and work item queueing/cancelling 962 * early. Work item execution depends on kthreads and starts after 963 * workqueue_init(). 964 */ 965 workqueue_init_early(); 966 967 rcu_init(); 968 969 /* Trace events are available after this */ 970 trace_init(); 971 972 if (initcall_debug) 973 initcall_debug_enable(); 974 975 context_tracking_init(); 976 /* init some links before init_ISA_irqs() */ 977 early_irq_init(); 978 init_IRQ(); 979 tick_init(); 980 rcu_init_nohz(); 981 init_timers(); 982 hrtimers_init(); 983 softirq_init(); 984 timekeeping_init(); 985 kfence_init(); 986 987 /* 988 * For best initial stack canary entropy, prepare it after: 989 * - setup_arch() for any UEFI RNG entropy and boot cmdline access 990 * - timekeeping_init() for ktime entropy used in rand_initialize() 991 * - rand_initialize() to get any arch-specific entropy like RDRAND 992 * - add_latent_entropy() to get any latent entropy 993 * - adding command line entropy 994 */ 995 rand_initialize(); 996 add_latent_entropy(); 997 add_device_randomness(command_line, strlen(command_line)); 998 boot_init_stack_canary(); 999 1000 time_init(); 1001 perf_event_init(); 1002 profile_init(); 1003 call_function_init(); 1004 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1005 1006 early_boot_irqs_disabled = false; 1007 local_irq_enable(); 1008 1009 kmem_cache_init_late(); 1010 1011 /* 1012 * HACK ALERT! This is early. We're enabling the console before 1013 * we've done PCI setups etc, and console_init() must be aware of 1014 * this. But we do want output early, in case something goes wrong. 1015 */ 1016 console_init(); 1017 if (panic_later) 1018 panic("Too many boot %s vars at `%s'", panic_later, 1019 panic_param); 1020 1021 lockdep_init(); 1022 1023 /* 1024 * Need to run this when irqs are enabled, because it wants 1025 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1026 * too: 1027 */ 1028 locking_selftest(); 1029 1030 /* 1031 * This needs to be called before any devices perform DMA 1032 * operations that might use the SWIOTLB bounce buffers. It will 1033 * mark the bounce buffers as decrypted so that their usage will 1034 * not cause "plain-text" data to be decrypted when accessed. 1035 */ 1036 mem_encrypt_init(); 1037 1038 #ifdef CONFIG_BLK_DEV_INITRD 1039 if (initrd_start && !initrd_below_start_ok && 1040 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1041 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1042 page_to_pfn(virt_to_page((void *)initrd_start)), 1043 min_low_pfn); 1044 initrd_start = 0; 1045 } 1046 #endif 1047 setup_per_cpu_pageset(); 1048 numa_policy_init(); 1049 acpi_early_init(); 1050 if (late_time_init) 1051 late_time_init(); 1052 sched_clock_init(); 1053 calibrate_delay(); 1054 pid_idr_init(); 1055 anon_vma_init(); 1056 #ifdef CONFIG_X86 1057 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1058 efi_enter_virtual_mode(); 1059 #endif 1060 thread_stack_cache_init(); 1061 cred_init(); 1062 fork_init(); 1063 proc_caches_init(); 1064 uts_ns_init(); 1065 key_init(); 1066 security_init(); 1067 dbg_late_init(); 1068 vfs_caches_init(); 1069 pagecache_init(); 1070 signals_init(); 1071 seq_file_init(); 1072 proc_root_init(); 1073 nsfs_init(); 1074 cpuset_init(); 1075 cgroup_init(); 1076 taskstats_init_early(); 1077 delayacct_init(); 1078 1079 poking_init(); 1080 check_bugs(); 1081 1082 acpi_subsystem_init(); 1083 arch_post_acpi_subsys_init(); 1084 kcsan_init(); 1085 1086 /* Do the rest non-__init'ed, we're now alive */ 1087 arch_call_rest_init(); 1088 1089 prevent_tail_call_optimization(); 1090 } 1091 1092 /* Call all constructor functions linked into the kernel. */ 1093 static void __init do_ctors(void) 1094 { 1095 /* 1096 * For UML, the constructors have already been called by the 1097 * normal setup code as it's just a normal ELF binary, so we 1098 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1099 * even on UML for modules. 1100 */ 1101 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1102 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1103 1104 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1105 (*fn)(); 1106 #endif 1107 } 1108 1109 #ifdef CONFIG_KALLSYMS 1110 struct blacklist_entry { 1111 struct list_head next; 1112 char *buf; 1113 }; 1114 1115 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1116 1117 static int __init initcall_blacklist(char *str) 1118 { 1119 char *str_entry; 1120 struct blacklist_entry *entry; 1121 1122 /* str argument is a comma-separated list of functions */ 1123 do { 1124 str_entry = strsep(&str, ","); 1125 if (str_entry) { 1126 pr_debug("blacklisting initcall %s\n", str_entry); 1127 entry = memblock_alloc(sizeof(*entry), 1128 SMP_CACHE_BYTES); 1129 if (!entry) 1130 panic("%s: Failed to allocate %zu bytes\n", 1131 __func__, sizeof(*entry)); 1132 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1133 SMP_CACHE_BYTES); 1134 if (!entry->buf) 1135 panic("%s: Failed to allocate %zu bytes\n", 1136 __func__, strlen(str_entry) + 1); 1137 strcpy(entry->buf, str_entry); 1138 list_add(&entry->next, &blacklisted_initcalls); 1139 } 1140 } while (str_entry); 1141 1142 return 0; 1143 } 1144 1145 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1146 { 1147 struct blacklist_entry *entry; 1148 char fn_name[KSYM_SYMBOL_LEN]; 1149 unsigned long addr; 1150 1151 if (list_empty(&blacklisted_initcalls)) 1152 return false; 1153 1154 addr = (unsigned long) dereference_function_descriptor(fn); 1155 sprint_symbol_no_offset(fn_name, addr); 1156 1157 /* 1158 * fn will be "function_name [module_name]" where [module_name] is not 1159 * displayed for built-in init functions. Strip off the [module_name]. 1160 */ 1161 strreplace(fn_name, ' ', '\0'); 1162 1163 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1164 if (!strcmp(fn_name, entry->buf)) { 1165 pr_debug("initcall %s blacklisted\n", fn_name); 1166 return true; 1167 } 1168 } 1169 1170 return false; 1171 } 1172 #else 1173 static int __init initcall_blacklist(char *str) 1174 { 1175 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1176 return 0; 1177 } 1178 1179 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1180 { 1181 return false; 1182 } 1183 #endif 1184 __setup("initcall_blacklist=", initcall_blacklist); 1185 1186 static __init_or_module void 1187 trace_initcall_start_cb(void *data, initcall_t fn) 1188 { 1189 ktime_t *calltime = (ktime_t *)data; 1190 1191 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1192 *calltime = ktime_get(); 1193 } 1194 1195 static __init_or_module void 1196 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1197 { 1198 ktime_t *calltime = (ktime_t *)data; 1199 ktime_t delta, rettime; 1200 unsigned long long duration; 1201 1202 rettime = ktime_get(); 1203 delta = ktime_sub(rettime, *calltime); 1204 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 1205 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1206 fn, ret, duration); 1207 } 1208 1209 static ktime_t initcall_calltime; 1210 1211 #ifdef TRACEPOINTS_ENABLED 1212 static void __init initcall_debug_enable(void) 1213 { 1214 int ret; 1215 1216 ret = register_trace_initcall_start(trace_initcall_start_cb, 1217 &initcall_calltime); 1218 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1219 &initcall_calltime); 1220 WARN(ret, "Failed to register initcall tracepoints\n"); 1221 } 1222 # define do_trace_initcall_start trace_initcall_start 1223 # define do_trace_initcall_finish trace_initcall_finish 1224 #else 1225 static inline void do_trace_initcall_start(initcall_t fn) 1226 { 1227 if (!initcall_debug) 1228 return; 1229 trace_initcall_start_cb(&initcall_calltime, fn); 1230 } 1231 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1232 { 1233 if (!initcall_debug) 1234 return; 1235 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1236 } 1237 #endif /* !TRACEPOINTS_ENABLED */ 1238 1239 int __init_or_module do_one_initcall(initcall_t fn) 1240 { 1241 int count = preempt_count(); 1242 char msgbuf[64]; 1243 int ret; 1244 1245 if (initcall_blacklisted(fn)) 1246 return -EPERM; 1247 1248 do_trace_initcall_start(fn); 1249 ret = fn(); 1250 do_trace_initcall_finish(fn, ret); 1251 1252 msgbuf[0] = 0; 1253 1254 if (preempt_count() != count) { 1255 sprintf(msgbuf, "preemption imbalance "); 1256 preempt_count_set(count); 1257 } 1258 if (irqs_disabled()) { 1259 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1260 local_irq_enable(); 1261 } 1262 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1263 1264 add_latent_entropy(); 1265 return ret; 1266 } 1267 1268 1269 extern initcall_entry_t __initcall_start[]; 1270 extern initcall_entry_t __initcall0_start[]; 1271 extern initcall_entry_t __initcall1_start[]; 1272 extern initcall_entry_t __initcall2_start[]; 1273 extern initcall_entry_t __initcall3_start[]; 1274 extern initcall_entry_t __initcall4_start[]; 1275 extern initcall_entry_t __initcall5_start[]; 1276 extern initcall_entry_t __initcall6_start[]; 1277 extern initcall_entry_t __initcall7_start[]; 1278 extern initcall_entry_t __initcall_end[]; 1279 1280 static initcall_entry_t *initcall_levels[] __initdata = { 1281 __initcall0_start, 1282 __initcall1_start, 1283 __initcall2_start, 1284 __initcall3_start, 1285 __initcall4_start, 1286 __initcall5_start, 1287 __initcall6_start, 1288 __initcall7_start, 1289 __initcall_end, 1290 }; 1291 1292 /* Keep these in sync with initcalls in include/linux/init.h */ 1293 static const char *initcall_level_names[] __initdata = { 1294 "pure", 1295 "core", 1296 "postcore", 1297 "arch", 1298 "subsys", 1299 "fs", 1300 "device", 1301 "late", 1302 }; 1303 1304 static int __init ignore_unknown_bootoption(char *param, char *val, 1305 const char *unused, void *arg) 1306 { 1307 return 0; 1308 } 1309 1310 static void __init do_initcall_level(int level, char *command_line) 1311 { 1312 initcall_entry_t *fn; 1313 1314 parse_args(initcall_level_names[level], 1315 command_line, __start___param, 1316 __stop___param - __start___param, 1317 level, level, 1318 NULL, ignore_unknown_bootoption); 1319 1320 trace_initcall_level(initcall_level_names[level]); 1321 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1322 do_one_initcall(initcall_from_entry(fn)); 1323 } 1324 1325 static void __init do_initcalls(void) 1326 { 1327 int level; 1328 size_t len = strlen(saved_command_line) + 1; 1329 char *command_line; 1330 1331 command_line = kzalloc(len, GFP_KERNEL); 1332 if (!command_line) 1333 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1334 1335 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1336 /* Parser modifies command_line, restore it each time */ 1337 strcpy(command_line, saved_command_line); 1338 do_initcall_level(level, command_line); 1339 } 1340 1341 kfree(command_line); 1342 } 1343 1344 /* 1345 * Ok, the machine is now initialized. None of the devices 1346 * have been touched yet, but the CPU subsystem is up and 1347 * running, and memory and process management works. 1348 * 1349 * Now we can finally start doing some real work.. 1350 */ 1351 static void __init do_basic_setup(void) 1352 { 1353 cpuset_init_smp(); 1354 driver_init(); 1355 init_irq_proc(); 1356 do_ctors(); 1357 usermodehelper_enable(); 1358 do_initcalls(); 1359 } 1360 1361 static void __init do_pre_smp_initcalls(void) 1362 { 1363 initcall_entry_t *fn; 1364 1365 trace_initcall_level("early"); 1366 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1367 do_one_initcall(initcall_from_entry(fn)); 1368 } 1369 1370 static int run_init_process(const char *init_filename) 1371 { 1372 const char *const *p; 1373 1374 argv_init[0] = init_filename; 1375 pr_info("Run %s as init process\n", init_filename); 1376 pr_debug(" with arguments:\n"); 1377 for (p = argv_init; *p; p++) 1378 pr_debug(" %s\n", *p); 1379 pr_debug(" with environment:\n"); 1380 for (p = envp_init; *p; p++) 1381 pr_debug(" %s\n", *p); 1382 return kernel_execve(init_filename, argv_init, envp_init); 1383 } 1384 1385 static int try_to_run_init_process(const char *init_filename) 1386 { 1387 int ret; 1388 1389 ret = run_init_process(init_filename); 1390 1391 if (ret && ret != -ENOENT) { 1392 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1393 init_filename, ret); 1394 } 1395 1396 return ret; 1397 } 1398 1399 static noinline void __init kernel_init_freeable(void); 1400 1401 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1402 bool rodata_enabled __ro_after_init = true; 1403 static int __init set_debug_rodata(char *str) 1404 { 1405 return strtobool(str, &rodata_enabled); 1406 } 1407 __setup("rodata=", set_debug_rodata); 1408 #endif 1409 1410 #ifdef CONFIG_STRICT_KERNEL_RWX 1411 static void mark_readonly(void) 1412 { 1413 if (rodata_enabled) { 1414 /* 1415 * load_module() results in W+X mappings, which are cleaned 1416 * up with call_rcu(). Let's make sure that queued work is 1417 * flushed so that we don't hit false positives looking for 1418 * insecure pages which are W+X. 1419 */ 1420 rcu_barrier(); 1421 mark_rodata_ro(); 1422 rodata_test(); 1423 } else 1424 pr_info("Kernel memory protection disabled.\n"); 1425 } 1426 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX) 1427 static inline void mark_readonly(void) 1428 { 1429 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1430 } 1431 #else 1432 static inline void mark_readonly(void) 1433 { 1434 pr_warn("This architecture does not have kernel memory protection.\n"); 1435 } 1436 #endif 1437 1438 void __weak free_initmem(void) 1439 { 1440 free_initmem_default(POISON_FREE_INITMEM); 1441 } 1442 1443 static int __ref kernel_init(void *unused) 1444 { 1445 int ret; 1446 1447 kernel_init_freeable(); 1448 /* need to finish all async __init code before freeing the memory */ 1449 async_synchronize_full(); 1450 kprobe_free_init_mem(); 1451 ftrace_free_init_mem(); 1452 kgdb_free_init_mem(); 1453 free_initmem(); 1454 mark_readonly(); 1455 1456 /* 1457 * Kernel mappings are now finalized - update the userspace page-table 1458 * to finalize PTI. 1459 */ 1460 pti_finalize(); 1461 1462 system_state = SYSTEM_RUNNING; 1463 numa_default_policy(); 1464 1465 rcu_end_inkernel_boot(); 1466 1467 do_sysctl_args(); 1468 1469 if (ramdisk_execute_command) { 1470 ret = run_init_process(ramdisk_execute_command); 1471 if (!ret) 1472 return 0; 1473 pr_err("Failed to execute %s (error %d)\n", 1474 ramdisk_execute_command, ret); 1475 } 1476 1477 /* 1478 * We try each of these until one succeeds. 1479 * 1480 * The Bourne shell can be used instead of init if we are 1481 * trying to recover a really broken machine. 1482 */ 1483 if (execute_command) { 1484 ret = run_init_process(execute_command); 1485 if (!ret) 1486 return 0; 1487 panic("Requested init %s failed (error %d).", 1488 execute_command, ret); 1489 } 1490 1491 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1492 ret = run_init_process(CONFIG_DEFAULT_INIT); 1493 if (ret) 1494 pr_err("Default init %s failed (error %d)\n", 1495 CONFIG_DEFAULT_INIT, ret); 1496 else 1497 return 0; 1498 } 1499 1500 if (!try_to_run_init_process("/sbin/init") || 1501 !try_to_run_init_process("/etc/init") || 1502 !try_to_run_init_process("/bin/init") || 1503 !try_to_run_init_process("/bin/sh")) 1504 return 0; 1505 1506 panic("No working init found. Try passing init= option to kernel. " 1507 "See Linux Documentation/admin-guide/init.rst for guidance."); 1508 } 1509 1510 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1511 void __init console_on_rootfs(void) 1512 { 1513 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1514 1515 if (IS_ERR(file)) { 1516 pr_err("Warning: unable to open an initial console.\n"); 1517 return; 1518 } 1519 init_dup(file); 1520 init_dup(file); 1521 init_dup(file); 1522 fput(file); 1523 } 1524 1525 static noinline void __init kernel_init_freeable(void) 1526 { 1527 /* 1528 * Wait until kthreadd is all set-up. 1529 */ 1530 wait_for_completion(&kthreadd_done); 1531 1532 /* Now the scheduler is fully set up and can do blocking allocations */ 1533 gfp_allowed_mask = __GFP_BITS_MASK; 1534 1535 /* 1536 * init can allocate pages on any node 1537 */ 1538 set_mems_allowed(node_states[N_MEMORY]); 1539 1540 cad_pid = task_pid(current); 1541 1542 smp_prepare_cpus(setup_max_cpus); 1543 1544 workqueue_init(); 1545 1546 init_mm_internals(); 1547 1548 rcu_init_tasks_generic(); 1549 do_pre_smp_initcalls(); 1550 lockup_detector_init(); 1551 1552 smp_init(); 1553 sched_init_smp(); 1554 1555 padata_init(); 1556 page_alloc_init_late(); 1557 /* Initialize page ext after all struct pages are initialized. */ 1558 page_ext_init(); 1559 1560 do_basic_setup(); 1561 1562 kunit_run_all_tests(); 1563 1564 console_on_rootfs(); 1565 1566 /* 1567 * check if there is an early userspace init. If yes, let it do all 1568 * the work 1569 */ 1570 if (init_eaccess(ramdisk_execute_command) != 0) { 1571 ramdisk_execute_command = NULL; 1572 prepare_namespace(); 1573 } 1574 1575 /* 1576 * Ok, we have completed the initial bootup, and 1577 * we're essentially up and running. Get rid of the 1578 * initmem segments and start the user-mode stuff.. 1579 * 1580 * rootfs is available now, try loading the public keys 1581 * and default modules 1582 */ 1583 1584 integrity_load_keys(); 1585 } 1586