1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/init/main.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * GK 2/5/95 - Changed to support mounting root fs via NFS 8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 10 * Simplified starting of init: Michael A. Griffith <grif@acm.org> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/export.h> 17 #include <linux/extable.h> 18 #include <linux/module.h> 19 #include <linux/proc_fs.h> 20 #include <linux/binfmts.h> 21 #include <linux/kernel.h> 22 #include <linux/syscalls.h> 23 #include <linux/stackprotector.h> 24 #include <linux/string.h> 25 #include <linux/ctype.h> 26 #include <linux/delay.h> 27 #include <linux/ioport.h> 28 #include <linux/init.h> 29 #include <linux/initrd.h> 30 #include <linux/memblock.h> 31 #include <linux/acpi.h> 32 #include <linux/bootconfig.h> 33 #include <linux/console.h> 34 #include <linux/nmi.h> 35 #include <linux/percpu.h> 36 #include <linux/kmod.h> 37 #include <linux/kprobes.h> 38 #include <linux/kmsan.h> 39 #include <linux/ksysfs.h> 40 #include <linux/vmalloc.h> 41 #include <linux/kernel_stat.h> 42 #include <linux/start_kernel.h> 43 #include <linux/security.h> 44 #include <linux/smp.h> 45 #include <linux/profile.h> 46 #include <linux/kfence.h> 47 #include <linux/rcupdate.h> 48 #include <linux/srcu.h> 49 #include <linux/moduleparam.h> 50 #include <linux/kallsyms.h> 51 #include <linux/buildid.h> 52 #include <linux/writeback.h> 53 #include <linux/cpu.h> 54 #include <linux/cpuset.h> 55 #include <linux/memcontrol.h> 56 #include <linux/cgroup.h> 57 #include <linux/tick.h> 58 #include <linux/sched/isolation.h> 59 #include <linux/interrupt.h> 60 #include <linux/taskstats_kern.h> 61 #include <linux/delayacct.h> 62 #include <linux/unistd.h> 63 #include <linux/utsname.h> 64 #include <linux/rmap.h> 65 #include <linux/mempolicy.h> 66 #include <linux/key.h> 67 #include <linux/debug_locks.h> 68 #include <linux/debugobjects.h> 69 #include <linux/lockdep.h> 70 #include <linux/kmemleak.h> 71 #include <linux/padata.h> 72 #include <linux/pid_namespace.h> 73 #include <linux/device/driver.h> 74 #include <linux/kthread.h> 75 #include <linux/sched.h> 76 #include <linux/sched/init.h> 77 #include <linux/signal.h> 78 #include <linux/idr.h> 79 #include <linux/kgdb.h> 80 #include <linux/ftrace.h> 81 #include <linux/async.h> 82 #include <linux/shmem_fs.h> 83 #include <linux/slab.h> 84 #include <linux/perf_event.h> 85 #include <linux/ptrace.h> 86 #include <linux/pti.h> 87 #include <linux/blkdev.h> 88 #include <linux/sched/clock.h> 89 #include <linux/sched/task.h> 90 #include <linux/sched/task_stack.h> 91 #include <linux/context_tracking.h> 92 #include <linux/random.h> 93 #include <linux/moduleloader.h> 94 #include <linux/list.h> 95 #include <linux/integrity.h> 96 #include <linux/proc_ns.h> 97 #include <linux/io.h> 98 #include <linux/cache.h> 99 #include <linux/rodata_test.h> 100 #include <linux/jump_label.h> 101 #include <linux/kcsan.h> 102 #include <linux/init_syscalls.h> 103 #include <linux/stackdepot.h> 104 #include <linux/randomize_kstack.h> 105 #include <linux/pidfs.h> 106 #include <linux/ptdump.h> 107 #include <linux/time_namespace.h> 108 #include <linux/unaligned.h> 109 #include <net/net_namespace.h> 110 111 #include <asm/io.h> 112 #include <asm/setup.h> 113 #include <asm/sections.h> 114 #include <asm/cacheflush.h> 115 116 #define CREATE_TRACE_POINTS 117 #include <trace/events/initcall.h> 118 119 #include <kunit/test.h> 120 121 static int kernel_init(void *); 122 123 /* 124 * Debug helper: via this flag we know that we are in 'early bootup code' 125 * where only the boot processor is running with IRQ disabled. This means 126 * two things - IRQ must not be enabled before the flag is cleared and some 127 * operations which are not allowed with IRQ disabled are allowed while the 128 * flag is set. 129 */ 130 bool early_boot_irqs_disabled __read_mostly; 131 132 enum system_states system_state __read_mostly; 133 EXPORT_SYMBOL(system_state); 134 135 /* 136 * Boot command-line arguments 137 */ 138 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 139 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 140 141 /* 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 static bool __initdata ramdisk_execute_command_set; 168 169 /* 170 * Used to generate warnings if static_key manipulation functions are used 171 * before jump_label_init is called. 172 */ 173 bool static_key_initialized __read_mostly; 174 EXPORT_SYMBOL_GPL(static_key_initialized); 175 176 /* 177 * If set, this is an indication to the drivers that reset the underlying 178 * device before going ahead with the initialization otherwise driver might 179 * rely on the BIOS and skip the reset operation. 180 * 181 * This is useful if kernel is booting in an unreliable environment. 182 * For ex. kdump situation where previous kernel has crashed, BIOS has been 183 * skipped and devices will be in unknown state. 184 */ 185 unsigned int reset_devices; 186 EXPORT_SYMBOL(reset_devices); 187 188 static int __init set_reset_devices(char *str) 189 { 190 reset_devices = 1; 191 return 1; 192 } 193 194 __setup("reset_devices", set_reset_devices); 195 196 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 197 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 198 static const char *panic_later, *panic_param; 199 200 static bool __init obsolete_checksetup(char *line) 201 { 202 const struct obs_kernel_param *p; 203 bool had_early_param = false; 204 205 p = __setup_start; 206 do { 207 int n = strlen(p->str); 208 if (parameqn(line, p->str, n)) { 209 if (p->early) { 210 /* Already done in parse_early_param? 211 * (Needs exact match on param part). 212 * Keep iterating, as we can have early 213 * params and __setups of same names 8( */ 214 if (line[n] == '\0' || line[n] == '=') 215 had_early_param = true; 216 } else if (!p->setup_func) { 217 pr_warn("Parameter %s is obsolete, ignored\n", 218 p->str); 219 return true; 220 } else if (p->setup_func(line + n)) 221 return true; 222 } 223 p++; 224 } while (p < __setup_end); 225 226 return had_early_param; 227 } 228 229 /* 230 * This should be approx 2 Bo*oMips to start (note initial shift), and will 231 * still work even if initially too large, it will just take slightly longer 232 */ 233 unsigned long loops_per_jiffy = (1<<12); 234 EXPORT_SYMBOL(loops_per_jiffy); 235 236 static int __init debug_kernel(char *str) 237 { 238 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 239 return 0; 240 } 241 242 static int __init quiet_kernel(char *str) 243 { 244 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 245 return 0; 246 } 247 248 early_param("debug", debug_kernel); 249 early_param("quiet", quiet_kernel); 250 251 static int __init loglevel(char *str) 252 { 253 int newlevel; 254 255 /* 256 * Only update loglevel value when a correct setting was passed, 257 * to prevent blind crashes (when loglevel being set to 0) that 258 * are quite hard to debug 259 */ 260 if (get_option(&str, &newlevel)) { 261 console_loglevel = newlevel; 262 return 0; 263 } 264 265 return -EINVAL; 266 } 267 268 early_param("loglevel", loglevel); 269 270 #ifdef CONFIG_BLK_DEV_INITRD 271 static void * __init get_boot_config_from_initrd(size_t *_size) 272 { 273 u32 size, csum; 274 char *data; 275 u8 *hdr; 276 int i; 277 278 if (!initrd_end) 279 return NULL; 280 281 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 282 /* 283 * Since Grub may align the size of initrd to 4, we must 284 * check the preceding 3 bytes as well. 285 */ 286 for (i = 0; i < 4; i++) { 287 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 288 goto found; 289 data--; 290 } 291 return NULL; 292 293 found: 294 hdr = (u8 *)(data - 8); 295 size = get_unaligned_le32(hdr); 296 csum = get_unaligned_le32(hdr + 4); 297 298 data = ((void *)hdr) - size; 299 if ((unsigned long)data < initrd_start) { 300 pr_err("bootconfig size %d is greater than initrd size %ld\n", 301 size, initrd_end - initrd_start); 302 return NULL; 303 } 304 305 if (xbc_calc_checksum(data, size) != csum) { 306 pr_err("bootconfig checksum failed\n"); 307 return NULL; 308 } 309 310 /* Remove bootconfig from initramfs/initrd */ 311 initrd_end = (unsigned long)data; 312 if (_size) 313 *_size = size; 314 315 return data; 316 } 317 #else 318 static void * __init get_boot_config_from_initrd(size_t *_size) 319 { 320 return NULL; 321 } 322 #endif 323 324 #ifdef CONFIG_BOOT_CONFIG 325 326 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 327 328 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 329 330 static int __init xbc_snprint_cmdline(char *buf, size_t size, 331 struct xbc_node *root) 332 { 333 struct xbc_node *knode, *vnode; 334 char *end = buf + size; 335 const char *val, *q; 336 int ret; 337 338 xbc_node_for_each_key_value(root, knode, val) { 339 ret = xbc_node_compose_key_after(root, knode, 340 xbc_namebuf, XBC_KEYLEN_MAX); 341 if (ret < 0) 342 return ret; 343 344 vnode = xbc_node_get_child(knode); 345 if (!vnode) { 346 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 347 if (ret < 0) 348 return ret; 349 buf += ret; 350 continue; 351 } 352 xbc_array_for_each_value(vnode, val) { 353 /* 354 * For prettier and more readable /proc/cmdline, only 355 * quote the value when necessary, i.e. when it contains 356 * whitespace. 357 */ 358 q = strpbrk(val, " \t\r\n") ? "\"" : ""; 359 ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ", 360 xbc_namebuf, q, val, q); 361 if (ret < 0) 362 return ret; 363 buf += ret; 364 } 365 } 366 367 return buf - (end - size); 368 } 369 #undef rest 370 371 /* Make an extra command line under given key word */ 372 static char * __init xbc_make_cmdline(const char *key) 373 { 374 struct xbc_node *root; 375 char *new_cmdline; 376 int ret, len = 0; 377 378 root = xbc_find_node(key); 379 if (!root) 380 return NULL; 381 382 /* Count required buffer size */ 383 len = xbc_snprint_cmdline(NULL, 0, root); 384 if (len <= 0) 385 return NULL; 386 387 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 388 if (!new_cmdline) { 389 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 390 return NULL; 391 } 392 393 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 394 if (ret < 0 || ret > len) { 395 pr_err("Failed to print extra kernel cmdline.\n"); 396 memblock_free(new_cmdline, len + 1); 397 return NULL; 398 } 399 400 return new_cmdline; 401 } 402 403 static int __init bootconfig_params(char *param, char *val, 404 const char *unused, void *arg) 405 { 406 if (strcmp(param, "bootconfig") == 0) { 407 bootconfig_found = true; 408 } 409 return 0; 410 } 411 412 static int __init warn_bootconfig(char *str) 413 { 414 /* The 'bootconfig' has been handled by bootconfig_params(). */ 415 return 0; 416 } 417 418 static void __init setup_boot_config(void) 419 { 420 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 421 const char *msg, *data; 422 int pos, ret; 423 size_t size; 424 char *err; 425 426 /* Cut out the bootconfig data even if we have no bootconfig option */ 427 data = get_boot_config_from_initrd(&size); 428 /* If there is no bootconfig in initrd, try embedded one. */ 429 if (!data) 430 data = xbc_get_embedded_bootconfig(&size); 431 432 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 433 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 434 bootconfig_params); 435 436 if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE))) 437 return; 438 439 /* parse_args() stops at the next param of '--' and returns an address */ 440 if (err) 441 initargs_offs = err - tmp_cmdline; 442 443 if (!data) { 444 /* If user intended to use bootconfig, show an error level message */ 445 if (bootconfig_found) 446 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 447 else 448 pr_info("No bootconfig data provided, so skipping bootconfig"); 449 return; 450 } 451 452 if (size >= XBC_DATA_MAX) { 453 pr_err("bootconfig size %ld greater than max size %d\n", 454 (long)size, XBC_DATA_MAX); 455 return; 456 } 457 458 ret = xbc_init(data, size, &msg, &pos); 459 if (ret < 0) { 460 if (pos < 0) 461 pr_err("Failed to init bootconfig: %s.\n", msg); 462 else 463 pr_err("Failed to parse bootconfig: %s at %d.\n", 464 msg, pos); 465 } else { 466 xbc_get_info(&ret, NULL); 467 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); 468 /* keys starting with "kernel." are passed via cmdline */ 469 extra_command_line = xbc_make_cmdline("kernel"); 470 /* Also, "init." keys are init arguments */ 471 extra_init_args = xbc_make_cmdline("init"); 472 } 473 return; 474 } 475 476 static void __init exit_boot_config(void) 477 { 478 xbc_exit(); 479 } 480 481 #else /* !CONFIG_BOOT_CONFIG */ 482 483 static void __init setup_boot_config(void) 484 { 485 /* Remove bootconfig data from initrd */ 486 get_boot_config_from_initrd(NULL); 487 } 488 489 static int __init warn_bootconfig(char *str) 490 { 491 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 492 return 0; 493 } 494 495 #define exit_boot_config() do {} while (0) 496 497 #endif /* CONFIG_BOOT_CONFIG */ 498 499 early_param("bootconfig", warn_bootconfig); 500 501 bool __init cmdline_has_extra_options(void) 502 { 503 return extra_command_line || extra_init_args; 504 } 505 506 /* Change NUL term back to "=", to make "param" the whole string. */ 507 static void __init repair_env_string(char *param, char *val) 508 { 509 if (val) { 510 /* param=val or param="val"? */ 511 if (val == param+strlen(param)+1) 512 val[-1] = '='; 513 else if (val == param+strlen(param)+2) { 514 val[-2] = '='; 515 memmove(val-1, val, strlen(val)+1); 516 } else 517 BUG(); 518 } 519 } 520 521 /* Anything after -- gets handed straight to init. */ 522 static int __init set_init_arg(char *param, char *val, 523 const char *unused, void *arg) 524 { 525 unsigned int i; 526 527 if (panic_later) 528 return 0; 529 530 repair_env_string(param, val); 531 532 for (i = 0; argv_init[i]; i++) { 533 if (i == MAX_INIT_ARGS) { 534 panic_later = "init"; 535 panic_param = param; 536 return 0; 537 } 538 } 539 argv_init[i] = param; 540 return 0; 541 } 542 543 /* 544 * Unknown boot options get handed to init, unless they look like 545 * unused parameters (modprobe will find them in /proc/cmdline). 546 */ 547 static int __init unknown_bootoption(char *param, char *val, 548 const char *unused, void *arg) 549 { 550 size_t len = strlen(param); 551 /* 552 * Well-known bootloader identifiers: 553 * 1. LILO/Grub pass "BOOT_IMAGE=..."; 554 * 2. kexec/kdump (kexec-tools) pass "kexec". 555 */ 556 const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL }; 557 558 /* Handle params aliased to sysctls */ 559 if (sysctl_is_alias(param)) 560 return 0; 561 562 repair_env_string(param, val); 563 564 /* Handle bootloader identifier */ 565 for (int i = 0; bootloader[i]; i++) { 566 if (strstarts(param, bootloader[i])) 567 return 0; 568 } 569 570 /* Handle obsolete-style parameters */ 571 if (obsolete_checksetup(param)) 572 return 0; 573 574 /* Unused module parameter. */ 575 if (strnchr(param, len, '.')) 576 return 0; 577 578 if (panic_later) 579 return 0; 580 581 if (val) { 582 /* Environment option */ 583 unsigned int i; 584 for (i = 0; envp_init[i]; i++) { 585 if (i == MAX_INIT_ENVS) { 586 panic_later = "env"; 587 panic_param = param; 588 } 589 if (!strncmp(param, envp_init[i], len+1)) 590 break; 591 } 592 envp_init[i] = param; 593 } else { 594 /* Command line option */ 595 unsigned int i; 596 for (i = 0; argv_init[i]; i++) { 597 if (i == MAX_INIT_ARGS) { 598 panic_later = "init"; 599 panic_param = param; 600 } 601 } 602 argv_init[i] = param; 603 } 604 return 0; 605 } 606 607 static int __init init_setup(char *str) 608 { 609 unsigned int i; 610 611 execute_command = str; 612 /* 613 * In case LILO is going to boot us with default command line, 614 * it prepends "auto" before the whole cmdline which makes 615 * the shell think it should execute a script with such name. 616 * So we ignore all arguments entered _before_ init=... [MJ] 617 */ 618 for (i = 1; i < MAX_INIT_ARGS; i++) 619 argv_init[i] = NULL; 620 return 1; 621 } 622 __setup("init=", init_setup); 623 624 static int __init rdinit_setup(char *str) 625 { 626 unsigned int i; 627 628 ramdisk_execute_command = str; 629 ramdisk_execute_command_set = true; 630 /* See "auto" comment in init_setup */ 631 for (i = 1; i < MAX_INIT_ARGS; i++) 632 argv_init[i] = NULL; 633 return 1; 634 } 635 __setup("rdinit=", rdinit_setup); 636 637 #ifndef CONFIG_SMP 638 static inline void setup_nr_cpu_ids(void) { } 639 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 640 #endif 641 642 /* 643 * We need to store the untouched command line for future reference. 644 * We also need to store the touched command line since the parameter 645 * parsing is performed in place, and we should allow a component to 646 * store reference of name/value for future reference. 647 */ 648 static void __init setup_command_line(char *command_line) 649 { 650 size_t len, xlen = 0, ilen = 0; 651 652 if (extra_command_line) 653 xlen = strlen(extra_command_line); 654 if (extra_init_args) { 655 extra_init_args = strim(extra_init_args); /* remove trailing space */ 656 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 657 } 658 659 len = xlen + strlen(boot_command_line) + ilen + 1; 660 661 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 662 663 len = xlen + strlen(command_line) + 1; 664 665 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 666 667 if (xlen) { 668 /* 669 * We have to put extra_command_line before boot command 670 * lines because there could be dashes (separator of init 671 * command line) in the command lines. 672 */ 673 strcpy(saved_command_line, extra_command_line); 674 strcpy(static_command_line, extra_command_line); 675 } 676 strcpy(saved_command_line + xlen, boot_command_line); 677 strcpy(static_command_line + xlen, command_line); 678 679 if (ilen) { 680 /* 681 * Append supplemental init boot args to saved_command_line 682 * so that user can check what command line options passed 683 * to init. 684 * The order should always be 685 * " -- "[bootconfig init-param][cmdline init-param] 686 */ 687 if (initargs_offs) { 688 len = xlen + initargs_offs; 689 strcpy(saved_command_line + len, extra_init_args); 690 len += ilen - 4; /* strlen(extra_init_args) */ 691 strcpy(saved_command_line + len, 692 boot_command_line + initargs_offs - 1); 693 } else { 694 len = strlen(saved_command_line); 695 strcpy(saved_command_line + len, " -- "); 696 len += 4; 697 strcpy(saved_command_line + len, extra_init_args); 698 } 699 } 700 701 saved_command_line_len = strlen(saved_command_line); 702 } 703 704 /* 705 * We need to finalize in a non-__init function or else race conditions 706 * between the root thread and the init thread may cause start_kernel to 707 * be reaped by free_initmem before the root thread has proceeded to 708 * cpu_idle. 709 * 710 * gcc-3.4 accidentally inlines this function, so use noinline. 711 */ 712 713 static __initdata DECLARE_COMPLETION(kthreadd_done); 714 715 static noinline void __ref __noreturn rest_init(void) 716 { 717 struct task_struct *tsk; 718 int pid; 719 720 rcu_scheduler_starting(); 721 /* 722 * We need to spawn init first so that it obtains pid 1, however 723 * the init task will end up wanting to create kthreads, which, if 724 * we schedule it before we create kthreadd, will OOPS. 725 */ 726 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 727 /* 728 * Pin init on the boot CPU. Task migration is not properly working 729 * until sched_init_smp() has been run. It will set the allowed 730 * CPUs for init to the non isolated CPUs. 731 */ 732 rcu_read_lock(); 733 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 734 tsk->flags |= PF_NO_SETAFFINITY; 735 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 736 rcu_read_unlock(); 737 738 numa_default_policy(); 739 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 740 rcu_read_lock(); 741 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 742 rcu_read_unlock(); 743 744 /* 745 * Enable might_sleep() and smp_processor_id() checks. 746 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 747 * kernel_thread() would trigger might_sleep() splats. With 748 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 749 * already, but it's stuck on the kthreadd_done completion. 750 */ 751 system_state = SYSTEM_SCHEDULING; 752 753 complete(&kthreadd_done); 754 755 /* 756 * The boot idle thread must execute schedule() 757 * at least once to get things moving: 758 */ 759 schedule_preempt_disabled(); 760 /* Call into cpu_idle with preempt disabled */ 761 cpu_startup_entry(CPUHP_ONLINE); 762 } 763 764 /* Check for early params. */ 765 static int __init do_early_param(char *param, char *val, 766 const char *unused, void *arg) 767 { 768 const struct obs_kernel_param *p; 769 770 for (p = __setup_start; p < __setup_end; p++) { 771 if (p->early && parameq(param, p->str)) { 772 if (p->setup_func(val) != 0) 773 pr_warn("Malformed early option '%s'\n", param); 774 } 775 } 776 /* We accept everything at this stage. */ 777 return 0; 778 } 779 780 void __init parse_early_options(char *cmdline) 781 { 782 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 783 do_early_param); 784 } 785 786 /* Arch code calls this early on, or if not, just before other parsing. */ 787 void __init parse_early_param(void) 788 { 789 static int done __initdata; 790 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 791 792 if (done) 793 return; 794 795 /* All fall through to do_early_param. */ 796 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 797 parse_early_options(tmp_cmdline); 798 done = 1; 799 } 800 801 void __init __weak arch_post_acpi_subsys_init(void) { } 802 803 void __init __weak smp_setup_processor_id(void) 804 { 805 } 806 807 void __init __weak smp_prepare_boot_cpu(void) 808 { 809 } 810 811 # if THREAD_SIZE >= PAGE_SIZE 812 void __init __weak thread_stack_cache_init(void) 813 { 814 } 815 #endif 816 817 void __init __weak poking_init(void) { } 818 819 void __init __weak pgtable_cache_init(void) { } 820 821 void __init __weak trap_init(void) { } 822 823 bool initcall_debug; 824 core_param(initcall_debug, initcall_debug, bool, 0644); 825 826 #ifdef TRACEPOINTS_ENABLED 827 static void __init initcall_debug_enable(void); 828 #else 829 static inline void initcall_debug_enable(void) 830 { 831 } 832 #endif 833 834 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 835 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 836 randomize_kstack_offset); 837 DEFINE_PER_CPU(struct rnd_state, kstack_rnd_state); 838 839 static int __init random_kstack_init(void) 840 { 841 prandom_seed_full_state(&kstack_rnd_state); 842 return 0; 843 } 844 late_initcall(random_kstack_init); 845 846 static int __init early_randomize_kstack_offset(char *buf) 847 { 848 int ret; 849 bool bool_result; 850 851 ret = kstrtobool(buf, &bool_result); 852 if (ret) 853 return ret; 854 855 if (bool_result) 856 static_branch_enable(&randomize_kstack_offset); 857 else 858 static_branch_disable(&randomize_kstack_offset); 859 return 0; 860 } 861 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 862 #endif 863 864 static void __init print_unknown_bootoptions(void) 865 { 866 char *unknown_options; 867 char *end; 868 const char *const *p; 869 size_t len; 870 871 if (panic_later || (!argv_init[1] && !envp_init[2])) 872 return; 873 874 /* 875 * Determine how many options we have to print out, plus a space 876 * before each 877 */ 878 len = 1; /* null terminator */ 879 for (p = &argv_init[1]; *p; p++) { 880 len++; 881 len += strlen(*p); 882 } 883 for (p = &envp_init[2]; *p; p++) { 884 len++; 885 len += strlen(*p); 886 } 887 888 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 889 if (!unknown_options) { 890 pr_err("%s: Failed to allocate %zu bytes\n", 891 __func__, len); 892 return; 893 } 894 end = unknown_options; 895 896 for (p = &argv_init[1]; *p; p++) 897 end += sprintf(end, " %s", *p); 898 for (p = &envp_init[2]; *p; p++) 899 end += sprintf(end, " %s", *p); 900 901 /* Start at unknown_options[1] to skip the initial space */ 902 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 903 &unknown_options[1]); 904 memblock_free(unknown_options, len); 905 } 906 907 static void __init early_numa_node_init(void) 908 { 909 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 910 #ifndef cpu_to_node 911 int cpu; 912 913 /* The early_cpu_to_node() should be ready here. */ 914 for_each_possible_cpu(cpu) 915 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 916 #endif 917 #endif 918 } 919 920 #define KERNEL_CMDLINE_PREFIX "Kernel command line: " 921 #define KERNEL_CMDLINE_PREFIX_LEN (sizeof(KERNEL_CMDLINE_PREFIX) - 1) 922 #define KERNEL_CMDLINE_CONTINUATION " \\" 923 #define KERNEL_CMDLINE_CONTINUATION_LEN (sizeof(KERNEL_CMDLINE_CONTINUATION) - 1) 924 925 #define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN (KERNEL_CMDLINE_PREFIX_LEN + \ 926 KERNEL_CMDLINE_CONTINUATION_LEN) 927 #define CMDLINE_LOG_WRAP_IDEAL_LEN (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \ 928 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \ 929 CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \ 930 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN) 931 932 #define IDEAL_CMDLINE_LEN (CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN) 933 #define IDEAL_CMDLINE_SPLIT_LEN (IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN) 934 935 /** 936 * print_kernel_cmdline() - Print the kernel cmdline with wrapping. 937 * @cmdline: The cmdline to print. 938 * 939 * Print the kernel command line, trying to wrap based on the Kconfig knob 940 * CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN. 941 * 942 * Wrapping is based on spaces, ignoring quotes. All lines are prefixed 943 * with "Kernel command line: " and lines that are not the last line have 944 * a " \" suffix added to them. The prefix and suffix count towards the 945 * line length for wrapping purposes. The ideal length will be exceeded 946 * if no appropriate place to wrap is found. 947 * 948 * Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40: 949 * Kernel command line: loglevel=7 \ 950 * Kernel command line: init=/sbin/init \ 951 * Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \ 952 * Kernel command line: rootwait ro \ 953 * Kernel command line: my_quoted_arg="The \ 954 * Kernel command line: quick brown fox \ 955 * Kernel command line: jumps over the \ 956 * Kernel command line: lazy dog." 957 */ 958 static void __init print_kernel_cmdline(const char *cmdline) 959 { 960 size_t len; 961 962 /* Config option of 0 or anything longer than the max disables wrapping */ 963 if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 || 964 IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) { 965 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 966 return; 967 } 968 969 len = strlen(cmdline); 970 while (len > IDEAL_CMDLINE_LEN) { 971 const char *first_space; 972 const char *prev_cutoff; 973 const char *cutoff; 974 int to_print; 975 size_t used; 976 977 /* Find the last ' ' that wouldn't make the line too long */ 978 prev_cutoff = NULL; 979 cutoff = cmdline; 980 while (true) { 981 cutoff = strchr(cutoff + 1, ' '); 982 if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN) 983 break; 984 prev_cutoff = cutoff; 985 } 986 if (prev_cutoff) 987 cutoff = prev_cutoff; 988 else if (!cutoff) 989 break; 990 991 /* Find the beginning and end of the string of spaces */ 992 first_space = cutoff; 993 while (first_space > cmdline && first_space[-1] == ' ') 994 first_space--; 995 to_print = first_space - cmdline; 996 while (*cutoff == ' ') 997 cutoff++; 998 used = cutoff - cmdline; 999 1000 /* If the whole string is used, break and do the final printout */ 1001 if (len == used) 1002 break; 1003 1004 if (to_print) 1005 pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX, 1006 to_print, cmdline, KERNEL_CMDLINE_CONTINUATION); 1007 1008 len -= used; 1009 cmdline += used; 1010 } 1011 if (len) 1012 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 1013 } 1014 1015 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 1016 void start_kernel(void) 1017 { 1018 char *command_line; 1019 char *after_dashes; 1020 1021 set_task_stack_end_magic(&init_task); 1022 smp_setup_processor_id(); 1023 debug_objects_early_init(); 1024 init_vmlinux_build_id(); 1025 1026 cgroup_init_early(); 1027 1028 local_irq_disable(); 1029 early_boot_irqs_disabled = true; 1030 1031 /* 1032 * Interrupts are still disabled. Do necessary setups, then 1033 * enable them. 1034 */ 1035 boot_cpu_init(); 1036 page_address_init(); 1037 pr_notice("%s", linux_banner); 1038 setup_arch(&command_line); 1039 mm_core_init_early(); 1040 /* Static keys and static calls are needed by LSMs */ 1041 jump_label_init(); 1042 static_call_init(); 1043 early_security_init(); 1044 setup_boot_config(); 1045 setup_command_line(command_line); 1046 setup_nr_cpu_ids(); 1047 setup_per_cpu_areas(); 1048 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 1049 early_numa_node_init(); 1050 boot_cpu_hotplug_init(); 1051 1052 print_kernel_cmdline(saved_command_line); 1053 /* parameters may set static keys */ 1054 parse_early_param(); 1055 after_dashes = parse_args("Booting kernel", 1056 static_command_line, __start___param, 1057 __stop___param - __start___param, 1058 -1, -1, NULL, &unknown_bootoption); 1059 print_unknown_bootoptions(); 1060 if (!IS_ERR_OR_NULL(after_dashes)) 1061 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 1062 NULL, set_init_arg); 1063 if (extra_init_args) 1064 parse_args("Setting extra init args", extra_init_args, 1065 NULL, 0, -1, -1, NULL, set_init_arg); 1066 1067 /* Architectural and non-timekeeping rng init, before allocator init */ 1068 random_init_early(command_line); 1069 1070 /* 1071 * These use large bootmem allocations and must precede 1072 * initalization of page allocator 1073 */ 1074 setup_log_buf(0); 1075 vfs_caches_init_early(); 1076 sort_main_extable(); 1077 trap_init(); 1078 mm_core_init(); 1079 maple_tree_init(); 1080 poking_init(); 1081 ftrace_init(); 1082 1083 /* trace_printk can be enabled here */ 1084 early_trace_init(); 1085 1086 /* 1087 * Set up the scheduler prior starting any interrupts (such as the 1088 * timer interrupt). Full topology setup happens at smp_init() 1089 * time - but meanwhile we still have a functioning scheduler. 1090 */ 1091 sched_init(); 1092 1093 if (WARN(!irqs_disabled(), 1094 "Interrupts were enabled *very* early, fixing it\n")) 1095 local_irq_disable(); 1096 radix_tree_init(); 1097 1098 /* 1099 * Set up housekeeping before setting up workqueues to allow the unbound 1100 * workqueue to take non-housekeeping into account. 1101 */ 1102 housekeeping_init(); 1103 1104 /* 1105 * Allow workqueue creation and work item queueing/cancelling 1106 * early. Work item execution depends on kthreads and starts after 1107 * workqueue_init(). 1108 */ 1109 workqueue_init_early(); 1110 1111 rcu_init(); 1112 kvfree_rcu_init(); 1113 1114 /* Trace events are available after this */ 1115 trace_init(); 1116 1117 if (initcall_debug) 1118 initcall_debug_enable(); 1119 1120 context_tracking_init(); 1121 /* init some links before init_ISA_irqs() */ 1122 early_irq_init(); 1123 init_IRQ(); 1124 tick_init(); 1125 rcu_init_nohz(); 1126 timers_init(); 1127 srcu_init(); 1128 hrtimers_init(); 1129 softirq_init(); 1130 timekeeping_init(); 1131 time_init(); 1132 1133 /* This must be after timekeeping is initialized */ 1134 random_init(); 1135 1136 /* These make use of the fully initialized rng */ 1137 kfence_init(); 1138 boot_init_stack_canary(); 1139 1140 perf_event_init(); 1141 profile_init(); 1142 call_function_init(); 1143 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1144 1145 early_boot_irqs_disabled = false; 1146 local_irq_enable(); 1147 1148 kmem_cache_init_late(); 1149 1150 /* 1151 * HACK ALERT! This is early. We're enabling the console before 1152 * we've done PCI setups etc, and console_init() must be aware of 1153 * this. But we do want output early, in case something goes wrong. 1154 */ 1155 console_init(); 1156 if (panic_later) 1157 panic("Too many boot %s vars at `%s'", panic_later, 1158 panic_param); 1159 1160 lockdep_init(); 1161 1162 /* 1163 * Need to run this when irqs are enabled, because it wants 1164 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1165 * too: 1166 */ 1167 locking_selftest(); 1168 1169 #ifdef CONFIG_BLK_DEV_INITRD 1170 if (initrd_start && !initrd_below_start_ok && 1171 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1172 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1173 page_to_pfn(virt_to_page((void *)initrd_start)), 1174 min_low_pfn); 1175 initrd_start = 0; 1176 } 1177 #endif 1178 setup_per_cpu_pageset(); 1179 numa_policy_init(); 1180 acpi_early_init(); 1181 if (late_time_init) 1182 late_time_init(); 1183 sched_clock_init(); 1184 calibrate_delay(); 1185 1186 arch_cpu_finalize_init(); 1187 1188 pid_idr_init(); 1189 anon_vma_init(); 1190 thread_stack_cache_init(); 1191 cred_init(); 1192 fork_init(); 1193 proc_caches_init(); 1194 uts_ns_init(); 1195 time_ns_init(); 1196 key_init(); 1197 security_init(); 1198 dbg_late_init(); 1199 net_ns_init(); 1200 vfs_caches_init(); 1201 pagecache_init(); 1202 signals_init(); 1203 seq_file_init(); 1204 proc_root_init(); 1205 nsfs_init(); 1206 pidfs_init(); 1207 cpuset_init(); 1208 mem_cgroup_init(); 1209 cgroup_init(); 1210 taskstats_init_early(); 1211 delayacct_init(); 1212 1213 acpi_subsystem_init(); 1214 arch_post_acpi_subsys_init(); 1215 kcsan_init(); 1216 1217 /* Do the rest non-__init'ed, we're now alive */ 1218 rest_init(); 1219 1220 /* 1221 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1222 * and older. 1223 */ 1224 #if !__has_attribute(__no_stack_protector__) 1225 prevent_tail_call_optimization(); 1226 #endif 1227 } 1228 1229 /* Call all constructor functions linked into the kernel. */ 1230 static void __init do_ctors(void) 1231 { 1232 /* 1233 * For UML, the constructors have already been called by the 1234 * normal setup code as it's just a normal ELF binary, so we 1235 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1236 * even on UML for modules. 1237 */ 1238 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1239 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1240 1241 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1242 (*fn)(); 1243 #endif 1244 } 1245 1246 #ifdef CONFIG_KALLSYMS 1247 struct blacklist_entry { 1248 struct list_head next; 1249 char *buf; 1250 }; 1251 1252 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1253 1254 static int __init initcall_blacklist(char *str) 1255 { 1256 char *str_entry; 1257 struct blacklist_entry *entry; 1258 1259 /* str argument is a comma-separated list of functions */ 1260 do { 1261 str_entry = strsep(&str, ","); 1262 if (str_entry) { 1263 pr_debug("blacklisting initcall %s\n", str_entry); 1264 entry = memblock_alloc_or_panic(sizeof(*entry), 1265 SMP_CACHE_BYTES); 1266 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1267 SMP_CACHE_BYTES); 1268 strcpy(entry->buf, str_entry); 1269 list_add(&entry->next, &blacklisted_initcalls); 1270 } 1271 } while (str_entry); 1272 1273 return 1; 1274 } 1275 1276 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1277 { 1278 struct blacklist_entry *entry; 1279 char fn_name[KSYM_SYMBOL_LEN]; 1280 unsigned long addr; 1281 1282 if (list_empty(&blacklisted_initcalls)) 1283 return false; 1284 1285 addr = (unsigned long) dereference_function_descriptor(fn); 1286 sprint_symbol_no_offset(fn_name, addr); 1287 1288 /* 1289 * fn will be "function_name [module_name]" where [module_name] is not 1290 * displayed for built-in init functions. Strip off the [module_name]. 1291 */ 1292 strreplace(fn_name, ' ', '\0'); 1293 1294 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1295 if (!strcmp(fn_name, entry->buf)) { 1296 pr_debug("initcall %s blacklisted\n", fn_name); 1297 return true; 1298 } 1299 } 1300 1301 return false; 1302 } 1303 #else 1304 static int __init initcall_blacklist(char *str) 1305 { 1306 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1307 return 0; 1308 } 1309 1310 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1311 { 1312 return false; 1313 } 1314 #endif 1315 __setup("initcall_blacklist=", initcall_blacklist); 1316 1317 static __init_or_module void 1318 trace_initcall_start_cb(void *data, initcall_t fn) 1319 { 1320 ktime_t *calltime = data; 1321 1322 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1323 *calltime = ktime_get(); 1324 } 1325 1326 static __init_or_module void 1327 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1328 { 1329 ktime_t rettime, *calltime = data; 1330 1331 rettime = ktime_get(); 1332 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1333 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1334 } 1335 1336 static __init_or_module void 1337 trace_initcall_level_cb(void *data, const char *level) 1338 { 1339 printk(KERN_DEBUG "entering initcall level: %s\n", level); 1340 } 1341 1342 static ktime_t initcall_calltime; 1343 1344 #ifdef TRACEPOINTS_ENABLED 1345 static void __init initcall_debug_enable(void) 1346 { 1347 int ret; 1348 1349 ret = register_trace_initcall_start(trace_initcall_start_cb, 1350 &initcall_calltime); 1351 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1352 &initcall_calltime); 1353 ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL); 1354 WARN(ret, "Failed to register initcall tracepoints\n"); 1355 } 1356 # define do_trace_initcall_start trace_initcall_start 1357 # define do_trace_initcall_finish trace_initcall_finish 1358 # define do_trace_initcall_level trace_initcall_level 1359 #else 1360 static inline void do_trace_initcall_start(initcall_t fn) 1361 { 1362 if (!initcall_debug) 1363 return; 1364 trace_initcall_start_cb(&initcall_calltime, fn); 1365 } 1366 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1367 { 1368 if (!initcall_debug) 1369 return; 1370 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1371 } 1372 static inline void do_trace_initcall_level(const char *level) 1373 { 1374 if (!initcall_debug) 1375 return; 1376 trace_initcall_level_cb(NULL, level); 1377 } 1378 #endif /* !TRACEPOINTS_ENABLED */ 1379 1380 int __init_or_module do_one_initcall(initcall_t fn) 1381 { 1382 int count = preempt_count(); 1383 char msgbuf[64]; 1384 int ret; 1385 1386 if (initcall_blacklisted(fn)) 1387 return -EPERM; 1388 1389 do_trace_initcall_start(fn); 1390 ret = fn(); 1391 do_trace_initcall_finish(fn, ret); 1392 1393 msgbuf[0] = 0; 1394 1395 if (preempt_count() != count) { 1396 sprintf(msgbuf, "preemption imbalance "); 1397 preempt_count_set(count); 1398 } 1399 if (irqs_disabled()) { 1400 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1401 local_irq_enable(); 1402 } 1403 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1404 1405 add_latent_entropy(); 1406 return ret; 1407 } 1408 1409 1410 static initcall_entry_t *initcall_levels[] __initdata = { 1411 __initcall0_start, 1412 __initcall1_start, 1413 __initcall2_start, 1414 __initcall3_start, 1415 __initcall4_start, 1416 __initcall5_start, 1417 __initcall6_start, 1418 __initcall7_start, 1419 __initcall_end, 1420 }; 1421 1422 /* Keep these in sync with initcalls in include/linux/init.h */ 1423 static const char *initcall_level_names[] __initdata = { 1424 "pure", 1425 "core", 1426 "postcore", 1427 "arch", 1428 "subsys", 1429 "fs", 1430 "device", 1431 "late", 1432 }; 1433 1434 static int __init ignore_unknown_bootoption(char *param, char *val, 1435 const char *unused, void *arg) 1436 { 1437 return 0; 1438 } 1439 1440 static void __init do_initcall_level(int level, char *command_line) 1441 { 1442 initcall_entry_t *fn; 1443 1444 parse_args(initcall_level_names[level], 1445 command_line, __start___param, 1446 __stop___param - __start___param, 1447 level, level, 1448 NULL, ignore_unknown_bootoption); 1449 1450 do_trace_initcall_level(initcall_level_names[level]); 1451 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1452 do_one_initcall(initcall_from_entry(fn)); 1453 } 1454 1455 static void __init do_initcalls(void) 1456 { 1457 int level; 1458 size_t len = saved_command_line_len + 1; 1459 char *command_line; 1460 1461 command_line = kzalloc(len, GFP_KERNEL); 1462 if (!command_line) 1463 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1464 1465 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1466 /* Parser modifies command_line, restore it each time */ 1467 strcpy(command_line, saved_command_line); 1468 do_initcall_level(level, command_line); 1469 } 1470 1471 kfree(command_line); 1472 } 1473 1474 /* 1475 * Ok, the machine is now initialized. None of the devices 1476 * have been touched yet, but the CPU subsystem is up and 1477 * running, and memory and process management works. 1478 * 1479 * Now we can finally start doing some real work.. 1480 */ 1481 static void __init do_basic_setup(void) 1482 { 1483 cpuset_init_smp(); 1484 ksysfs_init(); 1485 driver_init(); 1486 init_irq_proc(); 1487 do_ctors(); 1488 do_initcalls(); 1489 } 1490 1491 static void __init do_pre_smp_initcalls(void) 1492 { 1493 initcall_entry_t *fn; 1494 1495 do_trace_initcall_level("early"); 1496 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1497 do_one_initcall(initcall_from_entry(fn)); 1498 } 1499 1500 static int run_init_process(const char *init_filename) 1501 { 1502 const char *const *p; 1503 1504 argv_init[0] = init_filename; 1505 pr_info("Run %s as init process\n", init_filename); 1506 pr_debug(" with arguments:\n"); 1507 for (p = argv_init; *p; p++) 1508 pr_debug(" %s\n", *p); 1509 pr_debug(" with environment:\n"); 1510 for (p = envp_init; *p; p++) 1511 pr_debug(" %s\n", *p); 1512 return kernel_execve(init_filename, argv_init, envp_init); 1513 } 1514 1515 static int try_to_run_init_process(const char *init_filename) 1516 { 1517 int ret; 1518 1519 ret = run_init_process(init_filename); 1520 1521 if (ret && ret != -ENOENT) { 1522 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1523 init_filename, ret); 1524 } 1525 1526 return ret; 1527 } 1528 1529 static noinline void __init kernel_init_freeable(void); 1530 1531 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1532 bool rodata_enabled __ro_after_init = true; 1533 1534 #ifndef arch_parse_debug_rodata 1535 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1536 #endif 1537 1538 static int __init set_debug_rodata(char *str) 1539 { 1540 if (arch_parse_debug_rodata(str)) 1541 return 0; 1542 1543 if (str && !strcmp(str, "on")) 1544 rodata_enabled = true; 1545 else if (str && !strcmp(str, "off")) 1546 rodata_enabled = false; 1547 else 1548 pr_warn("Invalid option string for rodata: '%s'\n", str); 1549 return 0; 1550 } 1551 early_param("rodata", set_debug_rodata); 1552 #endif 1553 1554 static void mark_readonly(void) 1555 { 1556 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1557 /* 1558 * load_module() results in W+X mappings, which are cleaned 1559 * up with init_free_wq. Let's make sure that queued work is 1560 * flushed so that we don't hit false positives looking for 1561 * insecure pages which are W+X. 1562 */ 1563 flush_module_init_free_work(); 1564 jump_label_init_ro(); 1565 mark_rodata_ro(); 1566 debug_checkwx(); 1567 rodata_test(); 1568 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1569 pr_info("Kernel memory protection disabled.\n"); 1570 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1571 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1572 } else { 1573 pr_warn("This architecture does not have kernel memory protection.\n"); 1574 } 1575 } 1576 1577 void __weak free_initmem(void) 1578 { 1579 free_initmem_default(POISON_FREE_INITMEM); 1580 } 1581 1582 static int __ref kernel_init(void *unused) 1583 { 1584 int ret; 1585 1586 /* 1587 * Wait until kthreadd is all set-up. 1588 */ 1589 wait_for_completion(&kthreadd_done); 1590 1591 kernel_init_freeable(); 1592 /* need to finish all async __init code before freeing the memory */ 1593 async_synchronize_full(); 1594 1595 system_state = SYSTEM_FREEING_INITMEM; 1596 kprobe_free_init_mem(); 1597 ftrace_free_init_mem(); 1598 kgdb_free_init_mem(); 1599 exit_boot_config(); 1600 free_initmem(); 1601 mark_readonly(); 1602 1603 /* 1604 * Kernel mappings are now finalized - update the userspace page-table 1605 * to finalize PTI. 1606 */ 1607 pti_finalize(); 1608 1609 system_state = SYSTEM_RUNNING; 1610 numa_default_policy(); 1611 1612 rcu_end_inkernel_boot(); 1613 1614 do_sysctl_args(); 1615 1616 if (ramdisk_execute_command) { 1617 ret = run_init_process(ramdisk_execute_command); 1618 if (!ret) 1619 return 0; 1620 pr_err("Failed to execute %s (error %d)\n", 1621 ramdisk_execute_command, ret); 1622 } 1623 1624 /* 1625 * We try each of these until one succeeds. 1626 * 1627 * The Bourne shell can be used instead of init if we are 1628 * trying to recover a really broken machine. 1629 */ 1630 if (execute_command) { 1631 ret = run_init_process(execute_command); 1632 if (!ret) 1633 return 0; 1634 panic("Requested init %s failed (error %d).", 1635 execute_command, ret); 1636 } 1637 1638 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1639 ret = run_init_process(CONFIG_DEFAULT_INIT); 1640 if (ret) 1641 pr_err("Default init %s failed (error %d)\n", 1642 CONFIG_DEFAULT_INIT, ret); 1643 else 1644 return 0; 1645 } 1646 1647 if (!try_to_run_init_process("/sbin/init") || 1648 !try_to_run_init_process("/etc/init") || 1649 !try_to_run_init_process("/bin/init") || 1650 !try_to_run_init_process("/bin/sh")) 1651 return 0; 1652 1653 panic("No working init found. Try passing init= option to kernel. " 1654 "See Linux Documentation/admin-guide/init.rst for guidance."); 1655 } 1656 1657 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1658 void __init console_on_rootfs(void) 1659 { 1660 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1661 1662 if (IS_ERR(file)) { 1663 pr_err("Warning: unable to open an initial console.\n"); 1664 return; 1665 } 1666 init_dup(file); 1667 init_dup(file); 1668 init_dup(file); 1669 fput(file); 1670 } 1671 1672 static noinline void __init kernel_init_freeable(void) 1673 { 1674 /* Now the scheduler is fully set up and can do blocking allocations */ 1675 gfp_allowed_mask = __GFP_BITS_MASK; 1676 1677 /* 1678 * init can allocate pages on any node 1679 */ 1680 set_mems_allowed(node_states[N_MEMORY]); 1681 1682 cad_pid = get_pid(task_pid(current)); 1683 1684 smp_prepare_cpus(setup_max_cpus); 1685 1686 workqueue_init(); 1687 1688 init_mm_internals(); 1689 1690 do_pre_smp_initcalls(); 1691 lockup_detector_init(); 1692 1693 smp_init(); 1694 sched_init_smp(); 1695 1696 workqueue_init_topology(); 1697 async_init(); 1698 padata_init(); 1699 page_alloc_init_late(); 1700 1701 do_basic_setup(); 1702 1703 kunit_run_all_tests(); 1704 1705 wait_for_initramfs(); 1706 console_on_rootfs(); 1707 1708 /* 1709 * check if there is an early userspace init. If yes, let it do all 1710 * the work 1711 */ 1712 int ramdisk_command_access; 1713 ramdisk_command_access = init_eaccess(ramdisk_execute_command); 1714 if (ramdisk_command_access != 0) { 1715 if (ramdisk_execute_command_set) 1716 pr_warn("check access for rdinit=%s failed: %i, ignoring\n", 1717 ramdisk_execute_command, ramdisk_command_access); 1718 ramdisk_execute_command = NULL; 1719 prepare_namespace(); 1720 } 1721 1722 /* 1723 * Ok, we have completed the initial bootup, and 1724 * we're essentially up and running. Get rid of the 1725 * initmem segments and start the user-mode stuff.. 1726 * 1727 * rootfs is available now, try loading the public keys 1728 * and default modules 1729 */ 1730 1731 integrity_load_keys(); 1732 } 1733