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/srcu.h> 46 #include <linux/moduleparam.h> 47 #include <linux/kallsyms.h> 48 #include <linux/buildid.h> 49 #include <linux/writeback.h> 50 #include <linux/cpu.h> 51 #include <linux/cpuset.h> 52 #include <linux/cgroup.h> 53 #include <linux/efi.h> 54 #include <linux/tick.h> 55 #include <linux/sched/isolation.h> 56 #include <linux/interrupt.h> 57 #include <linux/taskstats_kern.h> 58 #include <linux/delayacct.h> 59 #include <linux/unistd.h> 60 #include <linux/utsname.h> 61 #include <linux/rmap.h> 62 #include <linux/mempolicy.h> 63 #include <linux/key.h> 64 #include <linux/page_ext.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/elevator.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/list.h> 93 #include <linux/integrity.h> 94 #include <linux/proc_ns.h> 95 #include <linux/io.h> 96 #include <linux/cache.h> 97 #include <linux/rodata_test.h> 98 #include <linux/jump_label.h> 99 #include <linux/mem_encrypt.h> 100 #include <linux/kcsan.h> 101 #include <linux/init_syscalls.h> 102 #include <linux/stackdepot.h> 103 104 #include <asm/io.h> 105 #include <asm/bugs.h> 106 #include <asm/setup.h> 107 #include <asm/sections.h> 108 #include <asm/cacheflush.h> 109 110 #define CREATE_TRACE_POINTS 111 #include <trace/events/initcall.h> 112 113 #include <kunit/test.h> 114 115 static int kernel_init(void *); 116 117 extern void init_IRQ(void); 118 extern void radix_tree_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 extern void time_init(void); 139 /* Default late time init is NULL. archs can override this later. */ 140 void (*__initdata late_time_init)(void); 141 142 /* Untouched command line saved by arch-specific code. */ 143 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 144 /* Untouched saved command line (eg. for /proc) */ 145 char *saved_command_line; 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 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 197 198 static bool __init obsolete_checksetup(char *line) 199 { 200 const struct obs_kernel_param *p; 201 bool had_early_param = false; 202 203 p = __setup_start; 204 do { 205 int n = strlen(p->str); 206 if (parameqn(line, p->str, n)) { 207 if (p->early) { 208 /* Already done in parse_early_param? 209 * (Needs exact match on param part). 210 * Keep iterating, as we can have early 211 * params and __setups of same names 8( */ 212 if (line[n] == '\0' || line[n] == '=') 213 had_early_param = true; 214 } else if (!p->setup_func) { 215 pr_warn("Parameter %s is obsolete, ignored\n", 216 p->str); 217 return true; 218 } else if (p->setup_func(line + n)) 219 return true; 220 } 221 p++; 222 } while (p < __setup_end); 223 224 return had_early_param; 225 } 226 227 /* 228 * This should be approx 2 Bo*oMips to start (note initial shift), and will 229 * still work even if initially too large, it will just take slightly longer 230 */ 231 unsigned long loops_per_jiffy = (1<<12); 232 EXPORT_SYMBOL(loops_per_jiffy); 233 234 static int __init debug_kernel(char *str) 235 { 236 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 237 return 0; 238 } 239 240 static int __init quiet_kernel(char *str) 241 { 242 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 243 return 0; 244 } 245 246 early_param("debug", debug_kernel); 247 early_param("quiet", quiet_kernel); 248 249 static int __init loglevel(char *str) 250 { 251 int newlevel; 252 253 /* 254 * Only update loglevel value when a correct setting was passed, 255 * to prevent blind crashes (when loglevel being set to 0) that 256 * are quite hard to debug 257 */ 258 if (get_option(&str, &newlevel)) { 259 console_loglevel = newlevel; 260 return 0; 261 } 262 263 return -EINVAL; 264 } 265 266 early_param("loglevel", loglevel); 267 268 #ifdef CONFIG_BLK_DEV_INITRD 269 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) 270 { 271 u32 size, csum; 272 char *data; 273 u32 *hdr; 274 int i; 275 276 if (!initrd_end) 277 return NULL; 278 279 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 280 /* 281 * Since Grub may align the size of initrd to 4, we must 282 * check the preceding 3 bytes as well. 283 */ 284 for (i = 0; i < 4; i++) { 285 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 286 goto found; 287 data--; 288 } 289 return NULL; 290 291 found: 292 hdr = (u32 *)(data - 8); 293 size = le32_to_cpu(hdr[0]); 294 csum = le32_to_cpu(hdr[1]); 295 296 data = ((void *)hdr) - size; 297 if ((unsigned long)data < initrd_start) { 298 pr_err("bootconfig size %d is greater than initrd size %ld\n", 299 size, initrd_end - initrd_start); 300 return NULL; 301 } 302 303 /* Remove bootconfig from initramfs/initrd */ 304 initrd_end = (unsigned long)data; 305 if (_size) 306 *_size = size; 307 if (_csum) 308 *_csum = csum; 309 310 return data; 311 } 312 #else 313 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) 314 { 315 return NULL; 316 } 317 #endif 318 319 #ifdef CONFIG_BOOT_CONFIG 320 321 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 322 323 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 324 325 static int __init xbc_snprint_cmdline(char *buf, size_t size, 326 struct xbc_node *root) 327 { 328 struct xbc_node *knode, *vnode; 329 char *end = buf + size; 330 const char *val; 331 int ret; 332 333 xbc_node_for_each_key_value(root, knode, val) { 334 ret = xbc_node_compose_key_after(root, knode, 335 xbc_namebuf, XBC_KEYLEN_MAX); 336 if (ret < 0) 337 return ret; 338 339 vnode = xbc_node_get_child(knode); 340 if (!vnode) { 341 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 342 if (ret < 0) 343 return ret; 344 buf += ret; 345 continue; 346 } 347 xbc_array_for_each_value(vnode, val) { 348 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ", 349 xbc_namebuf, val); 350 if (ret < 0) 351 return ret; 352 buf += ret; 353 } 354 } 355 356 return buf - (end - size); 357 } 358 #undef rest 359 360 /* Make an extra command line under given key word */ 361 static char * __init xbc_make_cmdline(const char *key) 362 { 363 struct xbc_node *root; 364 char *new_cmdline; 365 int ret, len = 0; 366 367 root = xbc_find_node(key); 368 if (!root) 369 return NULL; 370 371 /* Count required buffer size */ 372 len = xbc_snprint_cmdline(NULL, 0, root); 373 if (len <= 0) 374 return NULL; 375 376 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 377 if (!new_cmdline) { 378 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 379 return NULL; 380 } 381 382 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 383 if (ret < 0 || ret > len) { 384 pr_err("Failed to print extra kernel cmdline.\n"); 385 memblock_free_ptr(new_cmdline, len + 1); 386 return NULL; 387 } 388 389 return new_cmdline; 390 } 391 392 static int __init bootconfig_params(char *param, char *val, 393 const char *unused, void *arg) 394 { 395 if (strcmp(param, "bootconfig") == 0) { 396 bootconfig_found = true; 397 } 398 return 0; 399 } 400 401 static int __init warn_bootconfig(char *str) 402 { 403 /* The 'bootconfig' has been handled by bootconfig_params(). */ 404 return 0; 405 } 406 407 static void __init setup_boot_config(void) 408 { 409 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 410 const char *msg; 411 int pos; 412 u32 size, csum; 413 char *data, *copy, *err; 414 int ret; 415 416 /* Cut out the bootconfig data even if we have no bootconfig option */ 417 data = get_boot_config_from_initrd(&size, &csum); 418 419 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 420 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 421 bootconfig_params); 422 423 if (IS_ERR(err) || !bootconfig_found) 424 return; 425 426 /* parse_args() stops at the next param of '--' and returns an address */ 427 if (err) 428 initargs_offs = err - tmp_cmdline; 429 430 if (!data) { 431 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 432 return; 433 } 434 435 if (size >= XBC_DATA_MAX) { 436 pr_err("bootconfig size %d greater than max size %d\n", 437 size, XBC_DATA_MAX); 438 return; 439 } 440 441 if (xbc_calc_checksum(data, size) != csum) { 442 pr_err("bootconfig checksum failed\n"); 443 return; 444 } 445 446 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES); 447 if (!copy) { 448 pr_err("Failed to allocate memory for bootconfig\n"); 449 return; 450 } 451 452 memcpy(copy, data, size); 453 copy[size] = '\0'; 454 455 ret = xbc_init(copy, &msg, &pos); 456 if (ret < 0) { 457 if (pos < 0) 458 pr_err("Failed to init bootconfig: %s.\n", msg); 459 else 460 pr_err("Failed to parse bootconfig: %s at %d.\n", 461 msg, pos); 462 } else { 463 pr_info("Load bootconfig: %d bytes %d nodes\n", 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_destroy_all(); 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, 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 /* Change NUL term back to "=", to make "param" the whole string. */ 498 static void __init repair_env_string(char *param, char *val) 499 { 500 if (val) { 501 /* param=val or param="val"? */ 502 if (val == param+strlen(param)+1) 503 val[-1] = '='; 504 else if (val == param+strlen(param)+2) { 505 val[-2] = '='; 506 memmove(val-1, val, strlen(val)+1); 507 } else 508 BUG(); 509 } 510 } 511 512 /* Anything after -- gets handed straight to init. */ 513 static int __init set_init_arg(char *param, char *val, 514 const char *unused, void *arg) 515 { 516 unsigned int i; 517 518 if (panic_later) 519 return 0; 520 521 repair_env_string(param, val); 522 523 for (i = 0; argv_init[i]; i++) { 524 if (i == MAX_INIT_ARGS) { 525 panic_later = "init"; 526 panic_param = param; 527 return 0; 528 } 529 } 530 argv_init[i] = param; 531 return 0; 532 } 533 534 /* 535 * Unknown boot options get handed to init, unless they look like 536 * unused parameters (modprobe will find them in /proc/cmdline). 537 */ 538 static int __init unknown_bootoption(char *param, char *val, 539 const char *unused, void *arg) 540 { 541 size_t len = strlen(param); 542 543 repair_env_string(param, val); 544 545 /* Handle obsolete-style parameters */ 546 if (obsolete_checksetup(param)) 547 return 0; 548 549 /* Unused module parameter. */ 550 if (strnchr(param, len, '.')) 551 return 0; 552 553 if (panic_later) 554 return 0; 555 556 if (val) { 557 /* Environment option */ 558 unsigned int i; 559 for (i = 0; envp_init[i]; i++) { 560 if (i == MAX_INIT_ENVS) { 561 panic_later = "env"; 562 panic_param = param; 563 } 564 if (!strncmp(param, envp_init[i], len+1)) 565 break; 566 } 567 envp_init[i] = param; 568 } else { 569 /* Command line option */ 570 unsigned int i; 571 for (i = 0; argv_init[i]; i++) { 572 if (i == MAX_INIT_ARGS) { 573 panic_later = "init"; 574 panic_param = param; 575 } 576 } 577 argv_init[i] = param; 578 } 579 return 0; 580 } 581 582 static int __init init_setup(char *str) 583 { 584 unsigned int i; 585 586 execute_command = str; 587 /* 588 * In case LILO is going to boot us with default command line, 589 * it prepends "auto" before the whole cmdline which makes 590 * the shell think it should execute a script with such name. 591 * So we ignore all arguments entered _before_ init=... [MJ] 592 */ 593 for (i = 1; i < MAX_INIT_ARGS; i++) 594 argv_init[i] = NULL; 595 return 1; 596 } 597 __setup("init=", init_setup); 598 599 static int __init rdinit_setup(char *str) 600 { 601 unsigned int i; 602 603 ramdisk_execute_command = str; 604 /* See "auto" comment in init_setup */ 605 for (i = 1; i < MAX_INIT_ARGS; i++) 606 argv_init[i] = NULL; 607 return 1; 608 } 609 __setup("rdinit=", rdinit_setup); 610 611 #ifndef CONFIG_SMP 612 static const unsigned int setup_max_cpus = NR_CPUS; 613 static inline void setup_nr_cpu_ids(void) { } 614 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 615 #endif 616 617 /* 618 * We need to store the untouched command line for future reference. 619 * We also need to store the touched command line since the parameter 620 * parsing is performed in place, and we should allow a component to 621 * store reference of name/value for future reference. 622 */ 623 static void __init setup_command_line(char *command_line) 624 { 625 size_t len, xlen = 0, ilen = 0; 626 627 if (extra_command_line) 628 xlen = strlen(extra_command_line); 629 if (extra_init_args) 630 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 631 632 len = xlen + strlen(boot_command_line) + 1; 633 634 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); 635 if (!saved_command_line) 636 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); 637 638 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 639 if (!static_command_line) 640 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 641 642 if (xlen) { 643 /* 644 * We have to put extra_command_line before boot command 645 * lines because there could be dashes (separator of init 646 * command line) in the command lines. 647 */ 648 strcpy(saved_command_line, extra_command_line); 649 strcpy(static_command_line, extra_command_line); 650 } 651 strcpy(saved_command_line + xlen, boot_command_line); 652 strcpy(static_command_line + xlen, command_line); 653 654 if (ilen) { 655 /* 656 * Append supplemental init boot args to saved_command_line 657 * so that user can check what command line options passed 658 * to init. 659 * The order should always be 660 * " -- "[bootconfig init-param][cmdline init-param] 661 */ 662 if (initargs_offs) { 663 len = xlen + initargs_offs; 664 strcpy(saved_command_line + len, extra_init_args); 665 len += ilen - 4; /* strlen(extra_init_args) */ 666 strcpy(saved_command_line + len, 667 boot_command_line + initargs_offs - 1); 668 } else { 669 len = strlen(saved_command_line); 670 strcpy(saved_command_line + len, " -- "); 671 len += 4; 672 strcpy(saved_command_line + len, extra_init_args); 673 } 674 } 675 } 676 677 /* 678 * We need to finalize in a non-__init function or else race conditions 679 * between the root thread and the init thread may cause start_kernel to 680 * be reaped by free_initmem before the root thread has proceeded to 681 * cpu_idle. 682 * 683 * gcc-3.4 accidentally inlines this function, so use noinline. 684 */ 685 686 static __initdata DECLARE_COMPLETION(kthreadd_done); 687 688 noinline void __ref rest_init(void) 689 { 690 struct task_struct *tsk; 691 int pid; 692 693 rcu_scheduler_starting(); 694 /* 695 * We need to spawn init first so that it obtains pid 1, however 696 * the init task will end up wanting to create kthreads, which, if 697 * we schedule it before we create kthreadd, will OOPS. 698 */ 699 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 700 /* 701 * Pin init on the boot CPU. Task migration is not properly working 702 * until sched_init_smp() has been run. It will set the allowed 703 * CPUs for init to the non isolated CPUs. 704 */ 705 rcu_read_lock(); 706 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 707 tsk->flags |= PF_NO_SETAFFINITY; 708 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 709 rcu_read_unlock(); 710 711 numa_default_policy(); 712 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 713 rcu_read_lock(); 714 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 715 rcu_read_unlock(); 716 717 /* 718 * Enable might_sleep() and smp_processor_id() checks. 719 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 720 * kernel_thread() would trigger might_sleep() splats. With 721 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 722 * already, but it's stuck on the kthreadd_done completion. 723 */ 724 system_state = SYSTEM_SCHEDULING; 725 726 complete(&kthreadd_done); 727 728 /* 729 * The boot idle thread must execute schedule() 730 * at least once to get things moving: 731 */ 732 schedule_preempt_disabled(); 733 /* Call into cpu_idle with preempt disabled */ 734 cpu_startup_entry(CPUHP_ONLINE); 735 } 736 737 /* Check for early params. */ 738 static int __init do_early_param(char *param, char *val, 739 const char *unused, void *arg) 740 { 741 const struct obs_kernel_param *p; 742 743 for (p = __setup_start; p < __setup_end; p++) { 744 if ((p->early && parameq(param, p->str)) || 745 (strcmp(param, "console") == 0 && 746 strcmp(p->str, "earlycon") == 0) 747 ) { 748 if (p->setup_func(val) != 0) 749 pr_warn("Malformed early option '%s'\n", param); 750 } 751 } 752 /* We accept everything at this stage. */ 753 return 0; 754 } 755 756 void __init parse_early_options(char *cmdline) 757 { 758 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 759 do_early_param); 760 } 761 762 /* Arch code calls this early on, or if not, just before other parsing. */ 763 void __init parse_early_param(void) 764 { 765 static int done __initdata; 766 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 767 768 if (done) 769 return; 770 771 /* All fall through to do_early_param. */ 772 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 773 parse_early_options(tmp_cmdline); 774 done = 1; 775 } 776 777 void __init __weak arch_post_acpi_subsys_init(void) { } 778 779 void __init __weak smp_setup_processor_id(void) 780 { 781 } 782 783 # if THREAD_SIZE >= PAGE_SIZE 784 void __init __weak thread_stack_cache_init(void) 785 { 786 } 787 #endif 788 789 void __init __weak mem_encrypt_init(void) { } 790 791 void __init __weak poking_init(void) { } 792 793 void __init __weak pgtable_cache_init(void) { } 794 795 void __init __weak trap_init(void) { } 796 797 bool initcall_debug; 798 core_param(initcall_debug, initcall_debug, bool, 0644); 799 800 #ifdef TRACEPOINTS_ENABLED 801 static void __init initcall_debug_enable(void); 802 #else 803 static inline void initcall_debug_enable(void) 804 { 805 } 806 #endif 807 808 /* Report memory auto-initialization states for this boot. */ 809 static void __init report_meminit(void) 810 { 811 const char *stack; 812 813 if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN)) 814 stack = "all(pattern)"; 815 else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO)) 816 stack = "all(zero)"; 817 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) 818 stack = "byref_all(zero)"; 819 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) 820 stack = "byref(zero)"; 821 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) 822 stack = "__user(zero)"; 823 else 824 stack = "off"; 825 826 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", 827 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", 828 want_init_on_free() ? "on" : "off"); 829 if (want_init_on_free()) 830 pr_info("mem auto-init: clearing system memory may take some time...\n"); 831 } 832 833 /* 834 * Set up kernel memory allocators 835 */ 836 static void __init mm_init(void) 837 { 838 /* 839 * page_ext requires contiguous pages, 840 * bigger than MAX_ORDER unless SPARSEMEM. 841 */ 842 page_ext_init_flatmem(); 843 init_mem_debugging_and_hardening(); 844 kfence_alloc_pool(); 845 report_meminit(); 846 stack_depot_init(); 847 mem_init(); 848 mem_init_print_info(); 849 /* page_owner must be initialized after buddy is ready */ 850 page_ext_init_flatmem_late(); 851 kmem_cache_init(); 852 kmemleak_init(); 853 pgtable_init(); 854 debug_objects_mem_init(); 855 vmalloc_init(); 856 /* Should be run before the first non-init thread is created */ 857 init_espfix_bsp(); 858 /* Should be run after espfix64 is set up. */ 859 pti_init(); 860 } 861 862 #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 863 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 864 randomize_kstack_offset); 865 DEFINE_PER_CPU(u32, kstack_offset); 866 867 static int __init early_randomize_kstack_offset(char *buf) 868 { 869 int ret; 870 bool bool_result; 871 872 ret = kstrtobool(buf, &bool_result); 873 if (ret) 874 return ret; 875 876 if (bool_result) 877 static_branch_enable(&randomize_kstack_offset); 878 else 879 static_branch_disable(&randomize_kstack_offset); 880 return 0; 881 } 882 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 883 #endif 884 885 void __init __weak arch_call_rest_init(void) 886 { 887 rest_init(); 888 } 889 890 static void __init print_unknown_bootoptions(void) 891 { 892 char *unknown_options; 893 char *end; 894 const char *const *p; 895 size_t len; 896 897 if (panic_later || (!argv_init[1] && !envp_init[2])) 898 return; 899 900 /* 901 * Determine how many options we have to print out, plus a space 902 * before each 903 */ 904 len = 1; /* null terminator */ 905 for (p = &argv_init[1]; *p; p++) { 906 len++; 907 len += strlen(*p); 908 } 909 for (p = &envp_init[2]; *p; p++) { 910 len++; 911 len += strlen(*p); 912 } 913 914 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 915 if (!unknown_options) { 916 pr_err("%s: Failed to allocate %zu bytes\n", 917 __func__, len); 918 return; 919 } 920 end = unknown_options; 921 922 for (p = &argv_init[1]; *p; p++) 923 end += sprintf(end, " %s", *p); 924 for (p = &envp_init[2]; *p; p++) 925 end += sprintf(end, " %s", *p); 926 927 pr_notice("Unknown command line parameters:%s\n", unknown_options); 928 memblock_free_ptr(unknown_options, len); 929 } 930 931 asmlinkage __visible void __init __no_sanitize_address start_kernel(void) 932 { 933 char *command_line; 934 char *after_dashes; 935 936 set_task_stack_end_magic(&init_task); 937 smp_setup_processor_id(); 938 debug_objects_early_init(); 939 init_vmlinux_build_id(); 940 941 cgroup_init_early(); 942 943 local_irq_disable(); 944 early_boot_irqs_disabled = true; 945 946 /* 947 * Interrupts are still disabled. Do necessary setups, then 948 * enable them. 949 */ 950 boot_cpu_init(); 951 page_address_init(); 952 pr_notice("%s", linux_banner); 953 early_security_init(); 954 setup_arch(&command_line); 955 setup_boot_config(); 956 setup_command_line(command_line); 957 setup_nr_cpu_ids(); 958 setup_per_cpu_areas(); 959 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 960 boot_cpu_hotplug_init(); 961 962 build_all_zonelists(NULL); 963 page_alloc_init(); 964 965 pr_notice("Kernel command line: %s\n", saved_command_line); 966 /* parameters may set static keys */ 967 jump_label_init(); 968 parse_early_param(); 969 after_dashes = parse_args("Booting kernel", 970 static_command_line, __start___param, 971 __stop___param - __start___param, 972 -1, -1, NULL, &unknown_bootoption); 973 print_unknown_bootoptions(); 974 if (!IS_ERR_OR_NULL(after_dashes)) 975 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 976 NULL, set_init_arg); 977 if (extra_init_args) 978 parse_args("Setting extra init args", extra_init_args, 979 NULL, 0, -1, -1, NULL, set_init_arg); 980 981 /* 982 * These use large bootmem allocations and must precede 983 * kmem_cache_init() 984 */ 985 setup_log_buf(0); 986 vfs_caches_init_early(); 987 sort_main_extable(); 988 trap_init(); 989 mm_init(); 990 991 ftrace_init(); 992 993 /* trace_printk can be enabled here */ 994 early_trace_init(); 995 996 /* 997 * Set up the scheduler prior starting any interrupts (such as the 998 * timer interrupt). Full topology setup happens at smp_init() 999 * time - but meanwhile we still have a functioning scheduler. 1000 */ 1001 sched_init(); 1002 1003 if (WARN(!irqs_disabled(), 1004 "Interrupts were enabled *very* early, fixing it\n")) 1005 local_irq_disable(); 1006 radix_tree_init(); 1007 1008 /* 1009 * Set up housekeeping before setting up workqueues to allow the unbound 1010 * workqueue to take non-housekeeping into account. 1011 */ 1012 housekeeping_init(); 1013 1014 /* 1015 * Allow workqueue creation and work item queueing/cancelling 1016 * early. Work item execution depends on kthreads and starts after 1017 * workqueue_init(). 1018 */ 1019 workqueue_init_early(); 1020 1021 rcu_init(); 1022 1023 /* Trace events are available after this */ 1024 trace_init(); 1025 1026 if (initcall_debug) 1027 initcall_debug_enable(); 1028 1029 context_tracking_init(); 1030 /* init some links before init_ISA_irqs() */ 1031 early_irq_init(); 1032 init_IRQ(); 1033 tick_init(); 1034 rcu_init_nohz(); 1035 init_timers(); 1036 srcu_init(); 1037 hrtimers_init(); 1038 softirq_init(); 1039 timekeeping_init(); 1040 kfence_init(); 1041 1042 /* 1043 * For best initial stack canary entropy, prepare it after: 1044 * - setup_arch() for any UEFI RNG entropy and boot cmdline access 1045 * - timekeeping_init() for ktime entropy used in rand_initialize() 1046 * - rand_initialize() to get any arch-specific entropy like RDRAND 1047 * - add_latent_entropy() to get any latent entropy 1048 * - adding command line entropy 1049 */ 1050 rand_initialize(); 1051 add_latent_entropy(); 1052 add_device_randomness(command_line, strlen(command_line)); 1053 boot_init_stack_canary(); 1054 1055 time_init(); 1056 perf_event_init(); 1057 profile_init(); 1058 call_function_init(); 1059 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1060 1061 early_boot_irqs_disabled = false; 1062 local_irq_enable(); 1063 1064 kmem_cache_init_late(); 1065 1066 /* 1067 * HACK ALERT! This is early. We're enabling the console before 1068 * we've done PCI setups etc, and console_init() must be aware of 1069 * this. But we do want output early, in case something goes wrong. 1070 */ 1071 console_init(); 1072 if (panic_later) 1073 panic("Too many boot %s vars at `%s'", panic_later, 1074 panic_param); 1075 1076 lockdep_init(); 1077 1078 /* 1079 * Need to run this when irqs are enabled, because it wants 1080 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1081 * too: 1082 */ 1083 locking_selftest(); 1084 1085 /* 1086 * This needs to be called before any devices perform DMA 1087 * operations that might use the SWIOTLB bounce buffers. It will 1088 * mark the bounce buffers as decrypted so that their usage will 1089 * not cause "plain-text" data to be decrypted when accessed. 1090 */ 1091 mem_encrypt_init(); 1092 1093 #ifdef CONFIG_BLK_DEV_INITRD 1094 if (initrd_start && !initrd_below_start_ok && 1095 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1096 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1097 page_to_pfn(virt_to_page((void *)initrd_start)), 1098 min_low_pfn); 1099 initrd_start = 0; 1100 } 1101 #endif 1102 setup_per_cpu_pageset(); 1103 numa_policy_init(); 1104 acpi_early_init(); 1105 if (late_time_init) 1106 late_time_init(); 1107 sched_clock_init(); 1108 calibrate_delay(); 1109 pid_idr_init(); 1110 anon_vma_init(); 1111 #ifdef CONFIG_X86 1112 if (efi_enabled(EFI_RUNTIME_SERVICES)) 1113 efi_enter_virtual_mode(); 1114 #endif 1115 thread_stack_cache_init(); 1116 cred_init(); 1117 fork_init(); 1118 proc_caches_init(); 1119 uts_ns_init(); 1120 key_init(); 1121 security_init(); 1122 dbg_late_init(); 1123 vfs_caches_init(); 1124 pagecache_init(); 1125 signals_init(); 1126 seq_file_init(); 1127 proc_root_init(); 1128 nsfs_init(); 1129 cpuset_init(); 1130 cgroup_init(); 1131 taskstats_init_early(); 1132 delayacct_init(); 1133 1134 poking_init(); 1135 check_bugs(); 1136 1137 acpi_subsystem_init(); 1138 arch_post_acpi_subsys_init(); 1139 kcsan_init(); 1140 1141 /* Do the rest non-__init'ed, we're now alive */ 1142 arch_call_rest_init(); 1143 1144 prevent_tail_call_optimization(); 1145 } 1146 1147 /* Call all constructor functions linked into the kernel. */ 1148 static void __init do_ctors(void) 1149 { 1150 /* 1151 * For UML, the constructors have already been called by the 1152 * normal setup code as it's just a normal ELF binary, so we 1153 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1154 * even on UML for modules. 1155 */ 1156 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1157 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1158 1159 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1160 (*fn)(); 1161 #endif 1162 } 1163 1164 #ifdef CONFIG_KALLSYMS 1165 struct blacklist_entry { 1166 struct list_head next; 1167 char *buf; 1168 }; 1169 1170 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1171 1172 static int __init initcall_blacklist(char *str) 1173 { 1174 char *str_entry; 1175 struct blacklist_entry *entry; 1176 1177 /* str argument is a comma-separated list of functions */ 1178 do { 1179 str_entry = strsep(&str, ","); 1180 if (str_entry) { 1181 pr_debug("blacklisting initcall %s\n", str_entry); 1182 entry = memblock_alloc(sizeof(*entry), 1183 SMP_CACHE_BYTES); 1184 if (!entry) 1185 panic("%s: Failed to allocate %zu bytes\n", 1186 __func__, sizeof(*entry)); 1187 entry->buf = memblock_alloc(strlen(str_entry) + 1, 1188 SMP_CACHE_BYTES); 1189 if (!entry->buf) 1190 panic("%s: Failed to allocate %zu bytes\n", 1191 __func__, strlen(str_entry) + 1); 1192 strcpy(entry->buf, str_entry); 1193 list_add(&entry->next, &blacklisted_initcalls); 1194 } 1195 } while (str_entry); 1196 1197 return 0; 1198 } 1199 1200 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1201 { 1202 struct blacklist_entry *entry; 1203 char fn_name[KSYM_SYMBOL_LEN]; 1204 unsigned long addr; 1205 1206 if (list_empty(&blacklisted_initcalls)) 1207 return false; 1208 1209 addr = (unsigned long) dereference_function_descriptor(fn); 1210 sprint_symbol_no_offset(fn_name, addr); 1211 1212 /* 1213 * fn will be "function_name [module_name]" where [module_name] is not 1214 * displayed for built-in init functions. Strip off the [module_name]. 1215 */ 1216 strreplace(fn_name, ' ', '\0'); 1217 1218 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1219 if (!strcmp(fn_name, entry->buf)) { 1220 pr_debug("initcall %s blacklisted\n", fn_name); 1221 return true; 1222 } 1223 } 1224 1225 return false; 1226 } 1227 #else 1228 static int __init initcall_blacklist(char *str) 1229 { 1230 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1231 return 0; 1232 } 1233 1234 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1235 { 1236 return false; 1237 } 1238 #endif 1239 __setup("initcall_blacklist=", initcall_blacklist); 1240 1241 static __init_or_module void 1242 trace_initcall_start_cb(void *data, initcall_t fn) 1243 { 1244 ktime_t *calltime = (ktime_t *)data; 1245 1246 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1247 *calltime = ktime_get(); 1248 } 1249 1250 static __init_or_module void 1251 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1252 { 1253 ktime_t *calltime = (ktime_t *)data; 1254 ktime_t delta, rettime; 1255 unsigned long long duration; 1256 1257 rettime = ktime_get(); 1258 delta = ktime_sub(rettime, *calltime); 1259 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 1260 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1261 fn, ret, duration); 1262 } 1263 1264 static ktime_t initcall_calltime; 1265 1266 #ifdef TRACEPOINTS_ENABLED 1267 static void __init initcall_debug_enable(void) 1268 { 1269 int ret; 1270 1271 ret = register_trace_initcall_start(trace_initcall_start_cb, 1272 &initcall_calltime); 1273 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1274 &initcall_calltime); 1275 WARN(ret, "Failed to register initcall tracepoints\n"); 1276 } 1277 # define do_trace_initcall_start trace_initcall_start 1278 # define do_trace_initcall_finish trace_initcall_finish 1279 #else 1280 static inline void do_trace_initcall_start(initcall_t fn) 1281 { 1282 if (!initcall_debug) 1283 return; 1284 trace_initcall_start_cb(&initcall_calltime, fn); 1285 } 1286 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1287 { 1288 if (!initcall_debug) 1289 return; 1290 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1291 } 1292 #endif /* !TRACEPOINTS_ENABLED */ 1293 1294 int __init_or_module do_one_initcall(initcall_t fn) 1295 { 1296 int count = preempt_count(); 1297 char msgbuf[64]; 1298 int ret; 1299 1300 if (initcall_blacklisted(fn)) 1301 return -EPERM; 1302 1303 do_trace_initcall_start(fn); 1304 ret = fn(); 1305 do_trace_initcall_finish(fn, ret); 1306 1307 msgbuf[0] = 0; 1308 1309 if (preempt_count() != count) { 1310 sprintf(msgbuf, "preemption imbalance "); 1311 preempt_count_set(count); 1312 } 1313 if (irqs_disabled()) { 1314 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1315 local_irq_enable(); 1316 } 1317 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1318 1319 add_latent_entropy(); 1320 return ret; 1321 } 1322 1323 1324 extern initcall_entry_t __initcall_start[]; 1325 extern initcall_entry_t __initcall0_start[]; 1326 extern initcall_entry_t __initcall1_start[]; 1327 extern initcall_entry_t __initcall2_start[]; 1328 extern initcall_entry_t __initcall3_start[]; 1329 extern initcall_entry_t __initcall4_start[]; 1330 extern initcall_entry_t __initcall5_start[]; 1331 extern initcall_entry_t __initcall6_start[]; 1332 extern initcall_entry_t __initcall7_start[]; 1333 extern initcall_entry_t __initcall_end[]; 1334 1335 static initcall_entry_t *initcall_levels[] __initdata = { 1336 __initcall0_start, 1337 __initcall1_start, 1338 __initcall2_start, 1339 __initcall3_start, 1340 __initcall4_start, 1341 __initcall5_start, 1342 __initcall6_start, 1343 __initcall7_start, 1344 __initcall_end, 1345 }; 1346 1347 /* Keep these in sync with initcalls in include/linux/init.h */ 1348 static const char *initcall_level_names[] __initdata = { 1349 "pure", 1350 "core", 1351 "postcore", 1352 "arch", 1353 "subsys", 1354 "fs", 1355 "device", 1356 "late", 1357 }; 1358 1359 static int __init ignore_unknown_bootoption(char *param, char *val, 1360 const char *unused, void *arg) 1361 { 1362 return 0; 1363 } 1364 1365 static void __init do_initcall_level(int level, char *command_line) 1366 { 1367 initcall_entry_t *fn; 1368 1369 parse_args(initcall_level_names[level], 1370 command_line, __start___param, 1371 __stop___param - __start___param, 1372 level, level, 1373 NULL, ignore_unknown_bootoption); 1374 1375 trace_initcall_level(initcall_level_names[level]); 1376 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1377 do_one_initcall(initcall_from_entry(fn)); 1378 } 1379 1380 static void __init do_initcalls(void) 1381 { 1382 int level; 1383 size_t len = strlen(saved_command_line) + 1; 1384 char *command_line; 1385 1386 command_line = kzalloc(len, GFP_KERNEL); 1387 if (!command_line) 1388 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1389 1390 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1391 /* Parser modifies command_line, restore it each time */ 1392 strcpy(command_line, saved_command_line); 1393 do_initcall_level(level, command_line); 1394 } 1395 1396 kfree(command_line); 1397 } 1398 1399 /* 1400 * Ok, the machine is now initialized. None of the devices 1401 * have been touched yet, but the CPU subsystem is up and 1402 * running, and memory and process management works. 1403 * 1404 * Now we can finally start doing some real work.. 1405 */ 1406 static void __init do_basic_setup(void) 1407 { 1408 cpuset_init_smp(); 1409 driver_init(); 1410 init_irq_proc(); 1411 do_ctors(); 1412 do_initcalls(); 1413 } 1414 1415 static void __init do_pre_smp_initcalls(void) 1416 { 1417 initcall_entry_t *fn; 1418 1419 trace_initcall_level("early"); 1420 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1421 do_one_initcall(initcall_from_entry(fn)); 1422 } 1423 1424 static int run_init_process(const char *init_filename) 1425 { 1426 const char *const *p; 1427 1428 argv_init[0] = init_filename; 1429 pr_info("Run %s as init process\n", init_filename); 1430 pr_debug(" with arguments:\n"); 1431 for (p = argv_init; *p; p++) 1432 pr_debug(" %s\n", *p); 1433 pr_debug(" with environment:\n"); 1434 for (p = envp_init; *p; p++) 1435 pr_debug(" %s\n", *p); 1436 return kernel_execve(init_filename, argv_init, envp_init); 1437 } 1438 1439 static int try_to_run_init_process(const char *init_filename) 1440 { 1441 int ret; 1442 1443 ret = run_init_process(init_filename); 1444 1445 if (ret && ret != -ENOENT) { 1446 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1447 init_filename, ret); 1448 } 1449 1450 return ret; 1451 } 1452 1453 static noinline void __init kernel_init_freeable(void); 1454 1455 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1456 bool rodata_enabled __ro_after_init = true; 1457 static int __init set_debug_rodata(char *str) 1458 { 1459 return strtobool(str, &rodata_enabled); 1460 } 1461 __setup("rodata=", set_debug_rodata); 1462 #endif 1463 1464 #ifdef CONFIG_STRICT_KERNEL_RWX 1465 static void mark_readonly(void) 1466 { 1467 if (rodata_enabled) { 1468 /* 1469 * load_module() results in W+X mappings, which are cleaned 1470 * up with call_rcu(). Let's make sure that queued work is 1471 * flushed so that we don't hit false positives looking for 1472 * insecure pages which are W+X. 1473 */ 1474 rcu_barrier(); 1475 mark_rodata_ro(); 1476 rodata_test(); 1477 } else 1478 pr_info("Kernel memory protection disabled.\n"); 1479 } 1480 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX) 1481 static inline void mark_readonly(void) 1482 { 1483 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1484 } 1485 #else 1486 static inline void mark_readonly(void) 1487 { 1488 pr_warn("This architecture does not have kernel memory protection.\n"); 1489 } 1490 #endif 1491 1492 void __weak free_initmem(void) 1493 { 1494 free_initmem_default(POISON_FREE_INITMEM); 1495 } 1496 1497 static int __ref kernel_init(void *unused) 1498 { 1499 int ret; 1500 1501 /* 1502 * Wait until kthreadd is all set-up. 1503 */ 1504 wait_for_completion(&kthreadd_done); 1505 1506 kernel_init_freeable(); 1507 /* need to finish all async __init code before freeing the memory */ 1508 async_synchronize_full(); 1509 kprobe_free_init_mem(); 1510 ftrace_free_init_mem(); 1511 kgdb_free_init_mem(); 1512 exit_boot_config(); 1513 free_initmem(); 1514 mark_readonly(); 1515 1516 /* 1517 * Kernel mappings are now finalized - update the userspace page-table 1518 * to finalize PTI. 1519 */ 1520 pti_finalize(); 1521 1522 system_state = SYSTEM_RUNNING; 1523 numa_default_policy(); 1524 1525 rcu_end_inkernel_boot(); 1526 1527 do_sysctl_args(); 1528 1529 if (ramdisk_execute_command) { 1530 ret = run_init_process(ramdisk_execute_command); 1531 if (!ret) 1532 return 0; 1533 pr_err("Failed to execute %s (error %d)\n", 1534 ramdisk_execute_command, ret); 1535 } 1536 1537 /* 1538 * We try each of these until one succeeds. 1539 * 1540 * The Bourne shell can be used instead of init if we are 1541 * trying to recover a really broken machine. 1542 */ 1543 if (execute_command) { 1544 ret = run_init_process(execute_command); 1545 if (!ret) 1546 return 0; 1547 panic("Requested init %s failed (error %d).", 1548 execute_command, ret); 1549 } 1550 1551 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1552 ret = run_init_process(CONFIG_DEFAULT_INIT); 1553 if (ret) 1554 pr_err("Default init %s failed (error %d)\n", 1555 CONFIG_DEFAULT_INIT, ret); 1556 else 1557 return 0; 1558 } 1559 1560 if (!try_to_run_init_process("/sbin/init") || 1561 !try_to_run_init_process("/etc/init") || 1562 !try_to_run_init_process("/bin/init") || 1563 !try_to_run_init_process("/bin/sh")) 1564 return 0; 1565 1566 panic("No working init found. Try passing init= option to kernel. " 1567 "See Linux Documentation/admin-guide/init.rst for guidance."); 1568 } 1569 1570 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1571 void __init console_on_rootfs(void) 1572 { 1573 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1574 1575 if (IS_ERR(file)) { 1576 pr_err("Warning: unable to open an initial console.\n"); 1577 return; 1578 } 1579 init_dup(file); 1580 init_dup(file); 1581 init_dup(file); 1582 fput(file); 1583 } 1584 1585 static noinline void __init kernel_init_freeable(void) 1586 { 1587 /* Now the scheduler is fully set up and can do blocking allocations */ 1588 gfp_allowed_mask = __GFP_BITS_MASK; 1589 1590 /* 1591 * init can allocate pages on any node 1592 */ 1593 set_mems_allowed(node_states[N_MEMORY]); 1594 1595 cad_pid = get_pid(task_pid(current)); 1596 1597 smp_prepare_cpus(setup_max_cpus); 1598 1599 workqueue_init(); 1600 1601 init_mm_internals(); 1602 1603 rcu_init_tasks_generic(); 1604 do_pre_smp_initcalls(); 1605 lockup_detector_init(); 1606 1607 smp_init(); 1608 sched_init_smp(); 1609 1610 padata_init(); 1611 page_alloc_init_late(); 1612 /* Initialize page ext after all struct pages are initialized. */ 1613 page_ext_init(); 1614 1615 do_basic_setup(); 1616 1617 kunit_run_all_tests(); 1618 1619 wait_for_initramfs(); 1620 console_on_rootfs(); 1621 1622 /* 1623 * check if there is an early userspace init. If yes, let it do all 1624 * the work 1625 */ 1626 if (init_eaccess(ramdisk_execute_command) != 0) { 1627 ramdisk_execute_command = NULL; 1628 prepare_namespace(); 1629 } 1630 1631 /* 1632 * Ok, we have completed the initial bootup, and 1633 * we're essentially up and running. Get rid of the 1634 * initmem segments and start the user-mode stuff.. 1635 * 1636 * rootfs is available now, try loading the public keys 1637 * and default modules 1638 */ 1639 1640 integrity_load_keys(); 1641 } 1642