1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/init/main.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * GK 2/5/95 - Changed to support mounting root fs via NFS 8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 10 * Simplified starting of init: Michael A. Griffith <grif@acm.org> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/export.h> 17 #include <linux/extable.h> 18 #include <linux/module.h> 19 #include <linux/proc_fs.h> 20 #include <linux/binfmts.h> 21 #include <linux/kernel.h> 22 #include <linux/syscalls.h> 23 #include <linux/stackprotector.h> 24 #include <linux/string.h> 25 #include <linux/ctype.h> 26 #include <linux/delay.h> 27 #include <linux/ioport.h> 28 #include <linux/init.h> 29 #include <linux/initrd.h> 30 #include <linux/memblock.h> 31 #include <linux/acpi.h> 32 #include <linux/bootconfig.h> 33 #include <linux/console.h> 34 #include <linux/nmi.h> 35 #include <linux/percpu.h> 36 #include <linux/kmod.h> 37 #include <linux/kprobes.h> 38 #include <linux/kmsan.h> 39 #include <linux/vmalloc.h> 40 #include <linux/kernel_stat.h> 41 #include <linux/start_kernel.h> 42 #include <linux/security.h> 43 #include <linux/smp.h> 44 #include <linux/profile.h> 45 #include <linux/kfence.h> 46 #include <linux/rcupdate.h> 47 #include <linux/srcu.h> 48 #include <linux/moduleparam.h> 49 #include <linux/kallsyms.h> 50 #include <linux/buildid.h> 51 #include <linux/writeback.h> 52 #include <linux/cpu.h> 53 #include <linux/cpuset.h> 54 #include <linux/memcontrol.h> 55 #include <linux/cgroup.h> 56 #include <linux/tick.h> 57 #include <linux/sched/isolation.h> 58 #include <linux/interrupt.h> 59 #include <linux/taskstats_kern.h> 60 #include <linux/delayacct.h> 61 #include <linux/unistd.h> 62 #include <linux/utsname.h> 63 #include <linux/rmap.h> 64 #include <linux/mempolicy.h> 65 #include <linux/key.h> 66 #include <linux/debug_locks.h> 67 #include <linux/debugobjects.h> 68 #include <linux/lockdep.h> 69 #include <linux/kmemleak.h> 70 #include <linux/padata.h> 71 #include <linux/pid_namespace.h> 72 #include <linux/device/driver.h> 73 #include <linux/kthread.h> 74 #include <linux/sched.h> 75 #include <linux/sched/init.h> 76 #include <linux/signal.h> 77 #include <linux/idr.h> 78 #include <linux/kgdb.h> 79 #include <linux/ftrace.h> 80 #include <linux/async.h> 81 #include <linux/shmem_fs.h> 82 #include <linux/slab.h> 83 #include <linux/perf_event.h> 84 #include <linux/ptrace.h> 85 #include <linux/pti.h> 86 #include <linux/blkdev.h> 87 #include <linux/sched/clock.h> 88 #include <linux/sched/task.h> 89 #include <linux/sched/task_stack.h> 90 #include <linux/context_tracking.h> 91 #include <linux/random.h> 92 #include <linux/moduleloader.h> 93 #include <linux/list.h> 94 #include <linux/integrity.h> 95 #include <linux/proc_ns.h> 96 #include <linux/io.h> 97 #include <linux/cache.h> 98 #include <linux/rodata_test.h> 99 #include <linux/jump_label.h> 100 #include <linux/kcsan.h> 101 #include <linux/init_syscalls.h> 102 #include <linux/stackdepot.h> 103 #include <linux/randomize_kstack.h> 104 #include <linux/pidfs.h> 105 #include <linux/ptdump.h> 106 #include <linux/time_namespace.h> 107 #include <net/net_namespace.h> 108 109 #include <asm/io.h> 110 #include <asm/setup.h> 111 #include <asm/sections.h> 112 #include <asm/cacheflush.h> 113 114 #define CREATE_TRACE_POINTS 115 #include <trace/events/initcall.h> 116 117 #include <kunit/test.h> 118 119 static int kernel_init(void *); 120 121 /* 122 * Debug helper: via this flag we know that we are in 'early bootup code' 123 * where only the boot processor is running with IRQ disabled. This means 124 * two things - IRQ must not be enabled before the flag is cleared and some 125 * operations which are not allowed with IRQ disabled are allowed while the 126 * flag is set. 127 */ 128 bool early_boot_irqs_disabled __read_mostly; 129 130 enum system_states system_state __read_mostly; 131 EXPORT_SYMBOL(system_state); 132 133 /* 134 * Boot command-line arguments 135 */ 136 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 137 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 138 139 /* 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 __ro_after_init; 146 unsigned int saved_command_line_len __ro_after_init; 147 /* Command line for parameter parsing */ 148 static char *static_command_line; 149 /* Untouched extra command line */ 150 static char *extra_command_line; 151 /* Extra init arguments */ 152 static char *extra_init_args; 153 154 #ifdef CONFIG_BOOT_CONFIG 155 /* Is bootconfig on command line? */ 156 static bool bootconfig_found; 157 static size_t initargs_offs; 158 #else 159 # define bootconfig_found false 160 # define initargs_offs 0 161 #endif 162 163 static char *execute_command; 164 static char *ramdisk_execute_command = "/init"; 165 166 /* 167 * Used to generate warnings if static_key manipulation functions are used 168 * before jump_label_init is called. 169 */ 170 bool static_key_initialized __read_mostly; 171 EXPORT_SYMBOL_GPL(static_key_initialized); 172 173 /* 174 * If set, this is an indication to the drivers that reset the underlying 175 * device before going ahead with the initialization otherwise driver might 176 * rely on the BIOS and skip the reset operation. 177 * 178 * This is useful if kernel is booting in an unreliable environment. 179 * For ex. kdump situation where previous kernel has crashed, BIOS has been 180 * skipped and devices will be in unknown state. 181 */ 182 unsigned int reset_devices; 183 EXPORT_SYMBOL(reset_devices); 184 185 static int __init set_reset_devices(char *str) 186 { 187 reset_devices = 1; 188 return 1; 189 } 190 191 __setup("reset_devices", set_reset_devices); 192 193 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 194 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 195 static const char *panic_later, *panic_param; 196 197 static bool __init obsolete_checksetup(char *line) 198 { 199 const struct obs_kernel_param *p; 200 bool had_early_param = false; 201 202 p = __setup_start; 203 do { 204 int n = strlen(p->str); 205 if (parameqn(line, p->str, n)) { 206 if (p->early) { 207 /* Already done in parse_early_param? 208 * (Needs exact match on param part). 209 * Keep iterating, as we can have early 210 * params and __setups of same names 8( */ 211 if (line[n] == '\0' || line[n] == '=') 212 had_early_param = true; 213 } else if (!p->setup_func) { 214 pr_warn("Parameter %s is obsolete, ignored\n", 215 p->str); 216 return true; 217 } else if (p->setup_func(line + n)) 218 return true; 219 } 220 p++; 221 } while (p < __setup_end); 222 223 return had_early_param; 224 } 225 226 /* 227 * This should be approx 2 Bo*oMips to start (note initial shift), and will 228 * still work even if initially too large, it will just take slightly longer 229 */ 230 unsigned long loops_per_jiffy = (1<<12); 231 EXPORT_SYMBOL(loops_per_jiffy); 232 233 static int __init debug_kernel(char *str) 234 { 235 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 236 return 0; 237 } 238 239 static int __init quiet_kernel(char *str) 240 { 241 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 242 return 0; 243 } 244 245 early_param("debug", debug_kernel); 246 early_param("quiet", quiet_kernel); 247 248 static int __init loglevel(char *str) 249 { 250 int newlevel; 251 252 /* 253 * Only update loglevel value when a correct setting was passed, 254 * to prevent blind crashes (when loglevel being set to 0) that 255 * are quite hard to debug 256 */ 257 if (get_option(&str, &newlevel)) { 258 console_loglevel = newlevel; 259 return 0; 260 } 261 262 return -EINVAL; 263 } 264 265 early_param("loglevel", loglevel); 266 267 #ifdef CONFIG_BLK_DEV_INITRD 268 static void * __init get_boot_config_from_initrd(size_t *_size) 269 { 270 u32 size, csum; 271 char *data; 272 u32 *hdr; 273 int i; 274 275 if (!initrd_end) 276 return NULL; 277 278 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 279 /* 280 * Since Grub may align the size of initrd to 4, we must 281 * check the preceding 3 bytes as well. 282 */ 283 for (i = 0; i < 4; i++) { 284 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 285 goto found; 286 data--; 287 } 288 return NULL; 289 290 found: 291 hdr = (u32 *)(data - 8); 292 size = le32_to_cpu(hdr[0]); 293 csum = le32_to_cpu(hdr[1]); 294 295 data = ((void *)hdr) - size; 296 if ((unsigned long)data < initrd_start) { 297 pr_err("bootconfig size %d is greater than initrd size %ld\n", 298 size, initrd_end - initrd_start); 299 return NULL; 300 } 301 302 if (xbc_calc_checksum(data, size) != csum) { 303 pr_err("bootconfig checksum failed\n"); 304 return NULL; 305 } 306 307 /* Remove bootconfig from initramfs/initrd */ 308 initrd_end = (unsigned long)data; 309 if (_size) 310 *_size = size; 311 312 return data; 313 } 314 #else 315 static void * __init get_boot_config_from_initrd(size_t *_size) 316 { 317 return NULL; 318 } 319 #endif 320 321 #ifdef CONFIG_BOOT_CONFIG 322 323 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 324 325 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 326 327 static int __init xbc_snprint_cmdline(char *buf, size_t size, 328 struct xbc_node *root) 329 { 330 struct xbc_node *knode, *vnode; 331 char *end = buf + size; 332 const char *val, *q; 333 int ret; 334 335 xbc_node_for_each_key_value(root, knode, val) { 336 ret = xbc_node_compose_key_after(root, knode, 337 xbc_namebuf, XBC_KEYLEN_MAX); 338 if (ret < 0) 339 return ret; 340 341 vnode = xbc_node_get_child(knode); 342 if (!vnode) { 343 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); 344 if (ret < 0) 345 return ret; 346 buf += ret; 347 continue; 348 } 349 xbc_array_for_each_value(vnode, val) { 350 /* 351 * For prettier and more readable /proc/cmdline, only 352 * quote the value when necessary, i.e. when it contains 353 * whitespace. 354 */ 355 q = strpbrk(val, " \t\r\n") ? "\"" : ""; 356 ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ", 357 xbc_namebuf, q, val, q); 358 if (ret < 0) 359 return ret; 360 buf += ret; 361 } 362 } 363 364 return buf - (end - size); 365 } 366 #undef rest 367 368 /* Make an extra command line under given key word */ 369 static char * __init xbc_make_cmdline(const char *key) 370 { 371 struct xbc_node *root; 372 char *new_cmdline; 373 int ret, len = 0; 374 375 root = xbc_find_node(key); 376 if (!root) 377 return NULL; 378 379 /* Count required buffer size */ 380 len = xbc_snprint_cmdline(NULL, 0, root); 381 if (len <= 0) 382 return NULL; 383 384 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 385 if (!new_cmdline) { 386 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 387 return NULL; 388 } 389 390 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 391 if (ret < 0 || ret > len) { 392 pr_err("Failed to print extra kernel cmdline.\n"); 393 memblock_free(new_cmdline, len + 1); 394 return NULL; 395 } 396 397 return new_cmdline; 398 } 399 400 static int __init bootconfig_params(char *param, char *val, 401 const char *unused, void *arg) 402 { 403 if (strcmp(param, "bootconfig") == 0) { 404 bootconfig_found = true; 405 } 406 return 0; 407 } 408 409 static int __init warn_bootconfig(char *str) 410 { 411 /* The 'bootconfig' has been handled by bootconfig_params(). */ 412 return 0; 413 } 414 415 static void __init setup_boot_config(void) 416 { 417 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 418 const char *msg, *data; 419 int pos, ret; 420 size_t size; 421 char *err; 422 423 /* Cut out the bootconfig data even if we have no bootconfig option */ 424 data = get_boot_config_from_initrd(&size); 425 /* If there is no bootconfig in initrd, try embedded one. */ 426 if (!data) 427 data = xbc_get_embedded_bootconfig(&size); 428 429 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 430 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, 431 bootconfig_params); 432 433 if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE))) 434 return; 435 436 /* parse_args() stops at the next param of '--' and returns an address */ 437 if (err) 438 initargs_offs = err - tmp_cmdline; 439 440 if (!data) { 441 /* If user intended to use bootconfig, show an error level message */ 442 if (bootconfig_found) 443 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 444 else 445 pr_info("No bootconfig data provided, so skipping bootconfig"); 446 return; 447 } 448 449 if (size >= XBC_DATA_MAX) { 450 pr_err("bootconfig size %ld greater than max size %d\n", 451 (long)size, XBC_DATA_MAX); 452 return; 453 } 454 455 ret = xbc_init(data, size, &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 xbc_get_info(&ret, NULL); 464 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); 465 /* keys starting with "kernel." are passed via cmdline */ 466 extra_command_line = xbc_make_cmdline("kernel"); 467 /* Also, "init." keys are init arguments */ 468 extra_init_args = xbc_make_cmdline("init"); 469 } 470 return; 471 } 472 473 static void __init exit_boot_config(void) 474 { 475 xbc_exit(); 476 } 477 478 #else /* !CONFIG_BOOT_CONFIG */ 479 480 static void __init setup_boot_config(void) 481 { 482 /* Remove bootconfig data from initrd */ 483 get_boot_config_from_initrd(NULL); 484 } 485 486 static int __init warn_bootconfig(char *str) 487 { 488 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 489 return 0; 490 } 491 492 #define exit_boot_config() do {} while (0) 493 494 #endif /* CONFIG_BOOT_CONFIG */ 495 496 early_param("bootconfig", warn_bootconfig); 497 498 bool __init cmdline_has_extra_options(void) 499 { 500 return extra_command_line || extra_init_args; 501 } 502 503 /* Change NUL term back to "=", to make "param" the whole string. */ 504 static void __init repair_env_string(char *param, char *val) 505 { 506 if (val) { 507 /* param=val or param="val"? */ 508 if (val == param+strlen(param)+1) 509 val[-1] = '='; 510 else if (val == param+strlen(param)+2) { 511 val[-2] = '='; 512 memmove(val-1, val, strlen(val)+1); 513 } else 514 BUG(); 515 } 516 } 517 518 /* Anything after -- gets handed straight to init. */ 519 static int __init set_init_arg(char *param, char *val, 520 const char *unused, void *arg) 521 { 522 unsigned int i; 523 524 if (panic_later) 525 return 0; 526 527 repair_env_string(param, val); 528 529 for (i = 0; argv_init[i]; i++) { 530 if (i == MAX_INIT_ARGS) { 531 panic_later = "init"; 532 panic_param = param; 533 return 0; 534 } 535 } 536 argv_init[i] = param; 537 return 0; 538 } 539 540 /* 541 * Unknown boot options get handed to init, unless they look like 542 * unused parameters (modprobe will find them in /proc/cmdline). 543 */ 544 static int __init unknown_bootoption(char *param, char *val, 545 const char *unused, void *arg) 546 { 547 size_t len = strlen(param); 548 /* 549 * Well-known bootloader identifiers: 550 * 1. LILO/Grub pass "BOOT_IMAGE=..."; 551 * 2. kexec/kdump (kexec-tools) pass "kexec". 552 */ 553 const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL }; 554 555 /* Handle params aliased to sysctls */ 556 if (sysctl_is_alias(param)) 557 return 0; 558 559 repair_env_string(param, val); 560 561 /* Handle bootloader identifier */ 562 for (int i = 0; bootloader[i]; i++) { 563 if (strstarts(param, bootloader[i])) 564 return 0; 565 } 566 567 /* Handle obsolete-style parameters */ 568 if (obsolete_checksetup(param)) 569 return 0; 570 571 /* Unused module parameter. */ 572 if (strnchr(param, len, '.')) 573 return 0; 574 575 if (panic_later) 576 return 0; 577 578 if (val) { 579 /* Environment option */ 580 unsigned int i; 581 for (i = 0; envp_init[i]; i++) { 582 if (i == MAX_INIT_ENVS) { 583 panic_later = "env"; 584 panic_param = param; 585 } 586 if (!strncmp(param, envp_init[i], len+1)) 587 break; 588 } 589 envp_init[i] = param; 590 } else { 591 /* Command line option */ 592 unsigned int i; 593 for (i = 0; argv_init[i]; i++) { 594 if (i == MAX_INIT_ARGS) { 595 panic_later = "init"; 596 panic_param = param; 597 } 598 } 599 argv_init[i] = param; 600 } 601 return 0; 602 } 603 604 static int __init init_setup(char *str) 605 { 606 unsigned int i; 607 608 execute_command = str; 609 /* 610 * In case LILO is going to boot us with default command line, 611 * it prepends "auto" before the whole cmdline which makes 612 * the shell think it should execute a script with such name. 613 * So we ignore all arguments entered _before_ init=... [MJ] 614 */ 615 for (i = 1; i < MAX_INIT_ARGS; i++) 616 argv_init[i] = NULL; 617 return 1; 618 } 619 __setup("init=", init_setup); 620 621 static int __init rdinit_setup(char *str) 622 { 623 unsigned int i; 624 625 ramdisk_execute_command = str; 626 /* See "auto" comment in init_setup */ 627 for (i = 1; i < MAX_INIT_ARGS; i++) 628 argv_init[i] = NULL; 629 return 1; 630 } 631 __setup("rdinit=", rdinit_setup); 632 633 #ifndef CONFIG_SMP 634 static inline void setup_nr_cpu_ids(void) { } 635 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 636 #endif 637 638 /* 639 * We need to store the untouched command line for future reference. 640 * We also need to store the touched command line since the parameter 641 * parsing is performed in place, and we should allow a component to 642 * store reference of name/value for future reference. 643 */ 644 static void __init setup_command_line(char *command_line) 645 { 646 size_t len, xlen = 0, ilen = 0; 647 648 if (extra_command_line) 649 xlen = strlen(extra_command_line); 650 if (extra_init_args) { 651 extra_init_args = strim(extra_init_args); /* remove trailing space */ 652 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 653 } 654 655 len = xlen + strlen(boot_command_line) + ilen + 1; 656 657 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 658 659 len = xlen + strlen(command_line) + 1; 660 661 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 662 663 if (xlen) { 664 /* 665 * We have to put extra_command_line before boot command 666 * lines because there could be dashes (separator of init 667 * command line) in the command lines. 668 */ 669 strcpy(saved_command_line, extra_command_line); 670 strcpy(static_command_line, extra_command_line); 671 } 672 strcpy(saved_command_line + xlen, boot_command_line); 673 strcpy(static_command_line + xlen, command_line); 674 675 if (ilen) { 676 /* 677 * Append supplemental init boot args to saved_command_line 678 * so that user can check what command line options passed 679 * to init. 680 * The order should always be 681 * " -- "[bootconfig init-param][cmdline init-param] 682 */ 683 if (initargs_offs) { 684 len = xlen + initargs_offs; 685 strcpy(saved_command_line + len, extra_init_args); 686 len += ilen - 4; /* strlen(extra_init_args) */ 687 strcpy(saved_command_line + len, 688 boot_command_line + initargs_offs - 1); 689 } else { 690 len = strlen(saved_command_line); 691 strcpy(saved_command_line + len, " -- "); 692 len += 4; 693 strcpy(saved_command_line + len, extra_init_args); 694 } 695 } 696 697 saved_command_line_len = strlen(saved_command_line); 698 } 699 700 /* 701 * We need to finalize in a non-__init function or else race conditions 702 * between the root thread and the init thread may cause start_kernel to 703 * be reaped by free_initmem before the root thread has proceeded to 704 * cpu_idle. 705 * 706 * gcc-3.4 accidentally inlines this function, so use noinline. 707 */ 708 709 static __initdata DECLARE_COMPLETION(kthreadd_done); 710 711 static noinline void __ref __noreturn rest_init(void) 712 { 713 struct task_struct *tsk; 714 int pid; 715 716 rcu_scheduler_starting(); 717 /* 718 * We need to spawn init first so that it obtains pid 1, however 719 * the init task will end up wanting to create kthreads, which, if 720 * we schedule it before we create kthreadd, will OOPS. 721 */ 722 pid = user_mode_thread(kernel_init, NULL, CLONE_FS); 723 /* 724 * Pin init on the boot CPU. Task migration is not properly working 725 * until sched_init_smp() has been run. It will set the allowed 726 * CPUs for init to the non isolated CPUs. 727 */ 728 rcu_read_lock(); 729 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 730 tsk->flags |= PF_NO_SETAFFINITY; 731 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 732 rcu_read_unlock(); 733 734 numa_default_policy(); 735 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 736 rcu_read_lock(); 737 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 738 rcu_read_unlock(); 739 740 /* 741 * Enable might_sleep() and smp_processor_id() checks. 742 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 743 * kernel_thread() would trigger might_sleep() splats. With 744 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 745 * already, but it's stuck on the kthreadd_done completion. 746 */ 747 system_state = SYSTEM_SCHEDULING; 748 749 complete(&kthreadd_done); 750 751 /* 752 * The boot idle thread must execute schedule() 753 * at least once to get things moving: 754 */ 755 schedule_preempt_disabled(); 756 /* Call into cpu_idle with preempt disabled */ 757 cpu_startup_entry(CPUHP_ONLINE); 758 } 759 760 /* Check for early params. */ 761 static int __init do_early_param(char *param, char *val, 762 const char *unused, void *arg) 763 { 764 const struct obs_kernel_param *p; 765 766 for (p = __setup_start; p < __setup_end; p++) { 767 if (p->early && parameq(param, p->str)) { 768 if (p->setup_func(val) != 0) 769 pr_warn("Malformed early option '%s'\n", param); 770 } 771 } 772 /* We accept everything at this stage. */ 773 return 0; 774 } 775 776 void __init parse_early_options(char *cmdline) 777 { 778 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 779 do_early_param); 780 } 781 782 /* Arch code calls this early on, or if not, just before other parsing. */ 783 void __init parse_early_param(void) 784 { 785 static int done __initdata; 786 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 787 788 if (done) 789 return; 790 791 /* All fall through to do_early_param. */ 792 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 793 parse_early_options(tmp_cmdline); 794 done = 1; 795 } 796 797 void __init __weak arch_post_acpi_subsys_init(void) { } 798 799 void __init __weak smp_setup_processor_id(void) 800 { 801 } 802 803 void __init __weak smp_prepare_boot_cpu(void) 804 { 805 } 806 807 # if THREAD_SIZE >= PAGE_SIZE 808 void __init __weak thread_stack_cache_init(void) 809 { 810 } 811 #endif 812 813 void __init __weak poking_init(void) { } 814 815 void __init __weak pgtable_cache_init(void) { } 816 817 void __init __weak trap_init(void) { } 818 819 bool initcall_debug; 820 core_param(initcall_debug, initcall_debug, bool, 0644); 821 822 #ifdef TRACEPOINTS_ENABLED 823 static void __init initcall_debug_enable(void); 824 #else 825 static inline void initcall_debug_enable(void) 826 { 827 } 828 #endif 829 830 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 831 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 832 randomize_kstack_offset); 833 DEFINE_PER_CPU(u32, kstack_offset); 834 835 static int __init early_randomize_kstack_offset(char *buf) 836 { 837 int ret; 838 bool bool_result; 839 840 ret = kstrtobool(buf, &bool_result); 841 if (ret) 842 return ret; 843 844 if (bool_result) 845 static_branch_enable(&randomize_kstack_offset); 846 else 847 static_branch_disable(&randomize_kstack_offset); 848 return 0; 849 } 850 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 851 #endif 852 853 static void __init print_unknown_bootoptions(void) 854 { 855 char *unknown_options; 856 char *end; 857 const char *const *p; 858 size_t len; 859 860 if (panic_later || (!argv_init[1] && !envp_init[2])) 861 return; 862 863 /* 864 * Determine how many options we have to print out, plus a space 865 * before each 866 */ 867 len = 1; /* null terminator */ 868 for (p = &argv_init[1]; *p; p++) { 869 len++; 870 len += strlen(*p); 871 } 872 for (p = &envp_init[2]; *p; p++) { 873 len++; 874 len += strlen(*p); 875 } 876 877 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 878 if (!unknown_options) { 879 pr_err("%s: Failed to allocate %zu bytes\n", 880 __func__, len); 881 return; 882 } 883 end = unknown_options; 884 885 for (p = &argv_init[1]; *p; p++) 886 end += sprintf(end, " %s", *p); 887 for (p = &envp_init[2]; *p; p++) 888 end += sprintf(end, " %s", *p); 889 890 /* Start at unknown_options[1] to skip the initial space */ 891 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 892 &unknown_options[1]); 893 memblock_free(unknown_options, len); 894 } 895 896 static void __init early_numa_node_init(void) 897 { 898 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 899 #ifndef cpu_to_node 900 int cpu; 901 902 /* The early_cpu_to_node() should be ready here. */ 903 for_each_possible_cpu(cpu) 904 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 905 #endif 906 #endif 907 } 908 909 #define KERNEL_CMDLINE_PREFIX "Kernel command line: " 910 #define KERNEL_CMDLINE_PREFIX_LEN (sizeof(KERNEL_CMDLINE_PREFIX) - 1) 911 #define KERNEL_CMDLINE_CONTINUATION " \\" 912 #define KERNEL_CMDLINE_CONTINUATION_LEN (sizeof(KERNEL_CMDLINE_CONTINUATION) - 1) 913 914 #define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN (KERNEL_CMDLINE_PREFIX_LEN + \ 915 KERNEL_CMDLINE_CONTINUATION_LEN) 916 #define CMDLINE_LOG_WRAP_IDEAL_LEN (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \ 917 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \ 918 CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \ 919 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN) 920 921 #define IDEAL_CMDLINE_LEN (CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN) 922 #define IDEAL_CMDLINE_SPLIT_LEN (IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN) 923 924 /** 925 * print_kernel_cmdline() - Print the kernel cmdline with wrapping. 926 * @cmdline: The cmdline to print. 927 * 928 * Print the kernel command line, trying to wrap based on the Kconfig knob 929 * CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN. 930 * 931 * Wrapping is based on spaces, ignoring quotes. All lines are prefixed 932 * with "Kernel command line: " and lines that are not the last line have 933 * a " \" suffix added to them. The prefix and suffix count towards the 934 * line length for wrapping purposes. The ideal length will be exceeded 935 * if no appropriate place to wrap is found. 936 * 937 * Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40: 938 * Kernel command line: loglevel=7 \ 939 * Kernel command line: init=/sbin/init \ 940 * Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \ 941 * Kernel command line: rootwait ro \ 942 * Kernel command line: my_quoted_arg="The \ 943 * Kernel command line: quick brown fox \ 944 * Kernel command line: jumps over the \ 945 * Kernel command line: lazy dog." 946 */ 947 static void __init print_kernel_cmdline(const char *cmdline) 948 { 949 size_t len; 950 951 /* Config option of 0 or anything longer than the max disables wrapping */ 952 if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 || 953 IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) { 954 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 955 return; 956 } 957 958 len = strlen(cmdline); 959 while (len > IDEAL_CMDLINE_LEN) { 960 const char *first_space; 961 const char *prev_cutoff; 962 const char *cutoff; 963 int to_print; 964 size_t used; 965 966 /* Find the last ' ' that wouldn't make the line too long */ 967 prev_cutoff = NULL; 968 cutoff = cmdline; 969 while (true) { 970 cutoff = strchr(cutoff + 1, ' '); 971 if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN) 972 break; 973 prev_cutoff = cutoff; 974 } 975 if (prev_cutoff) 976 cutoff = prev_cutoff; 977 else if (!cutoff) 978 break; 979 980 /* Find the beginning and end of the string of spaces */ 981 first_space = cutoff; 982 while (first_space > cmdline && first_space[-1] == ' ') 983 first_space--; 984 to_print = first_space - cmdline; 985 while (*cutoff == ' ') 986 cutoff++; 987 used = cutoff - cmdline; 988 989 /* If the whole string is used, break and do the final printout */ 990 if (len == used) 991 break; 992 993 if (to_print) 994 pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX, 995 to_print, cmdline, KERNEL_CMDLINE_CONTINUATION); 996 997 len -= used; 998 cmdline += used; 999 } 1000 if (len) 1001 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 1002 } 1003 1004 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 1005 void start_kernel(void) 1006 { 1007 char *command_line; 1008 char *after_dashes; 1009 1010 set_task_stack_end_magic(&init_task); 1011 smp_setup_processor_id(); 1012 debug_objects_early_init(); 1013 init_vmlinux_build_id(); 1014 1015 cgroup_init_early(); 1016 1017 local_irq_disable(); 1018 early_boot_irqs_disabled = true; 1019 1020 /* 1021 * Interrupts are still disabled. Do necessary setups, then 1022 * enable them. 1023 */ 1024 boot_cpu_init(); 1025 page_address_init(); 1026 pr_notice("%s", linux_banner); 1027 setup_arch(&command_line); 1028 /* Static keys and static calls are needed by LSMs */ 1029 jump_label_init(); 1030 static_call_init(); 1031 early_security_init(); 1032 setup_boot_config(); 1033 setup_command_line(command_line); 1034 setup_nr_cpu_ids(); 1035 setup_per_cpu_areas(); 1036 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 1037 early_numa_node_init(); 1038 boot_cpu_hotplug_init(); 1039 1040 print_kernel_cmdline(saved_command_line); 1041 /* parameters may set static keys */ 1042 parse_early_param(); 1043 after_dashes = parse_args("Booting kernel", 1044 static_command_line, __start___param, 1045 __stop___param - __start___param, 1046 -1, -1, NULL, &unknown_bootoption); 1047 print_unknown_bootoptions(); 1048 if (!IS_ERR_OR_NULL(after_dashes)) 1049 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 1050 NULL, set_init_arg); 1051 if (extra_init_args) 1052 parse_args("Setting extra init args", extra_init_args, 1053 NULL, 0, -1, -1, NULL, set_init_arg); 1054 1055 /* Architectural and non-timekeeping rng init, before allocator init */ 1056 random_init_early(command_line); 1057 1058 /* 1059 * These use large bootmem allocations and must precede 1060 * initalization of page allocator 1061 */ 1062 setup_log_buf(0); 1063 vfs_caches_init_early(); 1064 sort_main_extable(); 1065 trap_init(); 1066 mm_core_init(); 1067 maple_tree_init(); 1068 poking_init(); 1069 ftrace_init(); 1070 1071 /* trace_printk can be enabled here */ 1072 early_trace_init(); 1073 1074 /* 1075 * Set up the scheduler prior starting any interrupts (such as the 1076 * timer interrupt). Full topology setup happens at smp_init() 1077 * time - but meanwhile we still have a functioning scheduler. 1078 */ 1079 sched_init(); 1080 1081 if (WARN(!irqs_disabled(), 1082 "Interrupts were enabled *very* early, fixing it\n")) 1083 local_irq_disable(); 1084 radix_tree_init(); 1085 1086 /* 1087 * Set up housekeeping before setting up workqueues to allow the unbound 1088 * workqueue to take non-housekeeping into account. 1089 */ 1090 housekeeping_init(); 1091 1092 /* 1093 * Allow workqueue creation and work item queueing/cancelling 1094 * early. Work item execution depends on kthreads and starts after 1095 * workqueue_init(). 1096 */ 1097 workqueue_init_early(); 1098 1099 rcu_init(); 1100 kvfree_rcu_init(); 1101 1102 /* Trace events are available after this */ 1103 trace_init(); 1104 1105 if (initcall_debug) 1106 initcall_debug_enable(); 1107 1108 context_tracking_init(); 1109 /* init some links before init_ISA_irqs() */ 1110 early_irq_init(); 1111 init_IRQ(); 1112 tick_init(); 1113 rcu_init_nohz(); 1114 timers_init(); 1115 srcu_init(); 1116 hrtimers_init(); 1117 softirq_init(); 1118 timekeeping_init(); 1119 time_init(); 1120 1121 /* This must be after timekeeping is initialized */ 1122 random_init(); 1123 1124 /* These make use of the fully initialized rng */ 1125 kfence_init(); 1126 boot_init_stack_canary(); 1127 1128 perf_event_init(); 1129 profile_init(); 1130 call_function_init(); 1131 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1132 1133 early_boot_irqs_disabled = false; 1134 local_irq_enable(); 1135 1136 kmem_cache_init_late(); 1137 1138 /* 1139 * HACK ALERT! This is early. We're enabling the console before 1140 * we've done PCI setups etc, and console_init() must be aware of 1141 * this. But we do want output early, in case something goes wrong. 1142 */ 1143 console_init(); 1144 if (panic_later) 1145 panic("Too many boot %s vars at `%s'", panic_later, 1146 panic_param); 1147 1148 lockdep_init(); 1149 1150 /* 1151 * Need to run this when irqs are enabled, because it wants 1152 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1153 * too: 1154 */ 1155 locking_selftest(); 1156 1157 #ifdef CONFIG_BLK_DEV_INITRD 1158 if (initrd_start && !initrd_below_start_ok && 1159 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1160 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1161 page_to_pfn(virt_to_page((void *)initrd_start)), 1162 min_low_pfn); 1163 initrd_start = 0; 1164 } 1165 #endif 1166 setup_per_cpu_pageset(); 1167 numa_policy_init(); 1168 acpi_early_init(); 1169 if (late_time_init) 1170 late_time_init(); 1171 sched_clock_init(); 1172 calibrate_delay(); 1173 1174 arch_cpu_finalize_init(); 1175 1176 pid_idr_init(); 1177 anon_vma_init(); 1178 thread_stack_cache_init(); 1179 cred_init(); 1180 fork_init(); 1181 proc_caches_init(); 1182 uts_ns_init(); 1183 time_ns_init(); 1184 key_init(); 1185 security_init(); 1186 dbg_late_init(); 1187 net_ns_init(); 1188 vfs_caches_init(); 1189 pagecache_init(); 1190 signals_init(); 1191 seq_file_init(); 1192 proc_root_init(); 1193 nsfs_init(); 1194 pidfs_init(); 1195 cpuset_init(); 1196 mem_cgroup_init(); 1197 cgroup_init(); 1198 taskstats_init_early(); 1199 delayacct_init(); 1200 1201 acpi_subsystem_init(); 1202 arch_post_acpi_subsys_init(); 1203 kcsan_init(); 1204 1205 /* Do the rest non-__init'ed, we're now alive */ 1206 rest_init(); 1207 1208 /* 1209 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1210 * and older. 1211 */ 1212 #if !__has_attribute(__no_stack_protector__) 1213 prevent_tail_call_optimization(); 1214 #endif 1215 } 1216 1217 /* Call all constructor functions linked into the kernel. */ 1218 static void __init do_ctors(void) 1219 { 1220 /* 1221 * For UML, the constructors have already been called by the 1222 * normal setup code as it's just a normal ELF binary, so we 1223 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1224 * even on UML for modules. 1225 */ 1226 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1227 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1228 1229 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1230 (*fn)(); 1231 #endif 1232 } 1233 1234 #ifdef CONFIG_KALLSYMS 1235 struct blacklist_entry { 1236 struct list_head next; 1237 char *buf; 1238 }; 1239 1240 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1241 1242 static int __init initcall_blacklist(char *str) 1243 { 1244 char *str_entry; 1245 struct blacklist_entry *entry; 1246 1247 /* str argument is a comma-separated list of functions */ 1248 do { 1249 str_entry = strsep(&str, ","); 1250 if (str_entry) { 1251 pr_debug("blacklisting initcall %s\n", str_entry); 1252 entry = memblock_alloc_or_panic(sizeof(*entry), 1253 SMP_CACHE_BYTES); 1254 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1255 SMP_CACHE_BYTES); 1256 strcpy(entry->buf, str_entry); 1257 list_add(&entry->next, &blacklisted_initcalls); 1258 } 1259 } while (str_entry); 1260 1261 return 1; 1262 } 1263 1264 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1265 { 1266 struct blacklist_entry *entry; 1267 char fn_name[KSYM_SYMBOL_LEN]; 1268 unsigned long addr; 1269 1270 if (list_empty(&blacklisted_initcalls)) 1271 return false; 1272 1273 addr = (unsigned long) dereference_function_descriptor(fn); 1274 sprint_symbol_no_offset(fn_name, addr); 1275 1276 /* 1277 * fn will be "function_name [module_name]" where [module_name] is not 1278 * displayed for built-in init functions. Strip off the [module_name]. 1279 */ 1280 strreplace(fn_name, ' ', '\0'); 1281 1282 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1283 if (!strcmp(fn_name, entry->buf)) { 1284 pr_debug("initcall %s blacklisted\n", fn_name); 1285 return true; 1286 } 1287 } 1288 1289 return false; 1290 } 1291 #else 1292 static int __init initcall_blacklist(char *str) 1293 { 1294 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1295 return 0; 1296 } 1297 1298 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1299 { 1300 return false; 1301 } 1302 #endif 1303 __setup("initcall_blacklist=", initcall_blacklist); 1304 1305 static __init_or_module void 1306 trace_initcall_start_cb(void *data, initcall_t fn) 1307 { 1308 ktime_t *calltime = data; 1309 1310 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1311 *calltime = ktime_get(); 1312 } 1313 1314 static __init_or_module void 1315 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1316 { 1317 ktime_t rettime, *calltime = data; 1318 1319 rettime = ktime_get(); 1320 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1321 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1322 } 1323 1324 static __init_or_module void 1325 trace_initcall_level_cb(void *data, const char *level) 1326 { 1327 printk(KERN_DEBUG "entering initcall level: %s\n", level); 1328 } 1329 1330 static ktime_t initcall_calltime; 1331 1332 #ifdef TRACEPOINTS_ENABLED 1333 static void __init initcall_debug_enable(void) 1334 { 1335 int ret; 1336 1337 ret = register_trace_initcall_start(trace_initcall_start_cb, 1338 &initcall_calltime); 1339 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1340 &initcall_calltime); 1341 ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL); 1342 WARN(ret, "Failed to register initcall tracepoints\n"); 1343 } 1344 # define do_trace_initcall_start trace_initcall_start 1345 # define do_trace_initcall_finish trace_initcall_finish 1346 # define do_trace_initcall_level trace_initcall_level 1347 #else 1348 static inline void do_trace_initcall_start(initcall_t fn) 1349 { 1350 if (!initcall_debug) 1351 return; 1352 trace_initcall_start_cb(&initcall_calltime, fn); 1353 } 1354 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1355 { 1356 if (!initcall_debug) 1357 return; 1358 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1359 } 1360 static inline void do_trace_initcall_level(const char *level) 1361 { 1362 if (!initcall_debug) 1363 return; 1364 trace_initcall_level_cb(NULL, level); 1365 } 1366 #endif /* !TRACEPOINTS_ENABLED */ 1367 1368 int __init_or_module do_one_initcall(initcall_t fn) 1369 { 1370 int count = preempt_count(); 1371 char msgbuf[64]; 1372 int ret; 1373 1374 if (initcall_blacklisted(fn)) 1375 return -EPERM; 1376 1377 do_trace_initcall_start(fn); 1378 ret = fn(); 1379 do_trace_initcall_finish(fn, ret); 1380 1381 msgbuf[0] = 0; 1382 1383 if (preempt_count() != count) { 1384 sprintf(msgbuf, "preemption imbalance "); 1385 preempt_count_set(count); 1386 } 1387 if (irqs_disabled()) { 1388 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1389 local_irq_enable(); 1390 } 1391 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1392 1393 add_latent_entropy(); 1394 return ret; 1395 } 1396 1397 1398 static initcall_entry_t *initcall_levels[] __initdata = { 1399 __initcall0_start, 1400 __initcall1_start, 1401 __initcall2_start, 1402 __initcall3_start, 1403 __initcall4_start, 1404 __initcall5_start, 1405 __initcall6_start, 1406 __initcall7_start, 1407 __initcall_end, 1408 }; 1409 1410 /* Keep these in sync with initcalls in include/linux/init.h */ 1411 static const char *initcall_level_names[] __initdata = { 1412 "pure", 1413 "core", 1414 "postcore", 1415 "arch", 1416 "subsys", 1417 "fs", 1418 "device", 1419 "late", 1420 }; 1421 1422 static int __init ignore_unknown_bootoption(char *param, char *val, 1423 const char *unused, void *arg) 1424 { 1425 return 0; 1426 } 1427 1428 static void __init do_initcall_level(int level, char *command_line) 1429 { 1430 initcall_entry_t *fn; 1431 1432 parse_args(initcall_level_names[level], 1433 command_line, __start___param, 1434 __stop___param - __start___param, 1435 level, level, 1436 NULL, ignore_unknown_bootoption); 1437 1438 do_trace_initcall_level(initcall_level_names[level]); 1439 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1440 do_one_initcall(initcall_from_entry(fn)); 1441 } 1442 1443 static void __init do_initcalls(void) 1444 { 1445 int level; 1446 size_t len = saved_command_line_len + 1; 1447 char *command_line; 1448 1449 command_line = kzalloc(len, GFP_KERNEL); 1450 if (!command_line) 1451 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1452 1453 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1454 /* Parser modifies command_line, restore it each time */ 1455 strcpy(command_line, saved_command_line); 1456 do_initcall_level(level, command_line); 1457 } 1458 1459 kfree(command_line); 1460 } 1461 1462 /* 1463 * Ok, the machine is now initialized. None of the devices 1464 * have been touched yet, but the CPU subsystem is up and 1465 * running, and memory and process management works. 1466 * 1467 * Now we can finally start doing some real work.. 1468 */ 1469 static void __init do_basic_setup(void) 1470 { 1471 cpuset_init_smp(); 1472 driver_init(); 1473 init_irq_proc(); 1474 do_ctors(); 1475 do_initcalls(); 1476 } 1477 1478 static void __init do_pre_smp_initcalls(void) 1479 { 1480 initcall_entry_t *fn; 1481 1482 do_trace_initcall_level("early"); 1483 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1484 do_one_initcall(initcall_from_entry(fn)); 1485 } 1486 1487 static int run_init_process(const char *init_filename) 1488 { 1489 const char *const *p; 1490 1491 argv_init[0] = init_filename; 1492 pr_info("Run %s as init process\n", init_filename); 1493 pr_debug(" with arguments:\n"); 1494 for (p = argv_init; *p; p++) 1495 pr_debug(" %s\n", *p); 1496 pr_debug(" with environment:\n"); 1497 for (p = envp_init; *p; p++) 1498 pr_debug(" %s\n", *p); 1499 return kernel_execve(init_filename, argv_init, envp_init); 1500 } 1501 1502 static int try_to_run_init_process(const char *init_filename) 1503 { 1504 int ret; 1505 1506 ret = run_init_process(init_filename); 1507 1508 if (ret && ret != -ENOENT) { 1509 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1510 init_filename, ret); 1511 } 1512 1513 return ret; 1514 } 1515 1516 static noinline void __init kernel_init_freeable(void); 1517 1518 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1519 bool rodata_enabled __ro_after_init = true; 1520 1521 #ifndef arch_parse_debug_rodata 1522 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1523 #endif 1524 1525 static int __init set_debug_rodata(char *str) 1526 { 1527 if (arch_parse_debug_rodata(str)) 1528 return 0; 1529 1530 if (str && !strcmp(str, "on")) 1531 rodata_enabled = true; 1532 else if (str && !strcmp(str, "off")) 1533 rodata_enabled = false; 1534 else 1535 pr_warn("Invalid option string for rodata: '%s'\n", str); 1536 return 0; 1537 } 1538 early_param("rodata", set_debug_rodata); 1539 #endif 1540 1541 static void mark_readonly(void) 1542 { 1543 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1544 /* 1545 * load_module() results in W+X mappings, which are cleaned 1546 * up with init_free_wq. Let's make sure that queued work is 1547 * flushed so that we don't hit false positives looking for 1548 * insecure pages which are W+X. 1549 */ 1550 flush_module_init_free_work(); 1551 jump_label_init_ro(); 1552 mark_rodata_ro(); 1553 debug_checkwx(); 1554 rodata_test(); 1555 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1556 pr_info("Kernel memory protection disabled.\n"); 1557 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1558 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1559 } else { 1560 pr_warn("This architecture does not have kernel memory protection.\n"); 1561 } 1562 } 1563 1564 void __weak free_initmem(void) 1565 { 1566 free_initmem_default(POISON_FREE_INITMEM); 1567 } 1568 1569 static int __ref kernel_init(void *unused) 1570 { 1571 int ret; 1572 1573 /* 1574 * Wait until kthreadd is all set-up. 1575 */ 1576 wait_for_completion(&kthreadd_done); 1577 1578 kernel_init_freeable(); 1579 /* need to finish all async __init code before freeing the memory */ 1580 async_synchronize_full(); 1581 1582 system_state = SYSTEM_FREEING_INITMEM; 1583 kprobe_free_init_mem(); 1584 ftrace_free_init_mem(); 1585 kgdb_free_init_mem(); 1586 exit_boot_config(); 1587 free_initmem(); 1588 mark_readonly(); 1589 1590 /* 1591 * Kernel mappings are now finalized - update the userspace page-table 1592 * to finalize PTI. 1593 */ 1594 pti_finalize(); 1595 1596 system_state = SYSTEM_RUNNING; 1597 numa_default_policy(); 1598 1599 rcu_end_inkernel_boot(); 1600 1601 do_sysctl_args(); 1602 1603 if (ramdisk_execute_command) { 1604 ret = run_init_process(ramdisk_execute_command); 1605 if (!ret) 1606 return 0; 1607 pr_err("Failed to execute %s (error %d)\n", 1608 ramdisk_execute_command, ret); 1609 } 1610 1611 /* 1612 * We try each of these until one succeeds. 1613 * 1614 * The Bourne shell can be used instead of init if we are 1615 * trying to recover a really broken machine. 1616 */ 1617 if (execute_command) { 1618 ret = run_init_process(execute_command); 1619 if (!ret) 1620 return 0; 1621 panic("Requested init %s failed (error %d).", 1622 execute_command, ret); 1623 } 1624 1625 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1626 ret = run_init_process(CONFIG_DEFAULT_INIT); 1627 if (ret) 1628 pr_err("Default init %s failed (error %d)\n", 1629 CONFIG_DEFAULT_INIT, ret); 1630 else 1631 return 0; 1632 } 1633 1634 if (!try_to_run_init_process("/sbin/init") || 1635 !try_to_run_init_process("/etc/init") || 1636 !try_to_run_init_process("/bin/init") || 1637 !try_to_run_init_process("/bin/sh")) 1638 return 0; 1639 1640 panic("No working init found. Try passing init= option to kernel. " 1641 "See Linux Documentation/admin-guide/init.rst for guidance."); 1642 } 1643 1644 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1645 void __init console_on_rootfs(void) 1646 { 1647 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1648 1649 if (IS_ERR(file)) { 1650 pr_err("Warning: unable to open an initial console.\n"); 1651 return; 1652 } 1653 init_dup(file); 1654 init_dup(file); 1655 init_dup(file); 1656 fput(file); 1657 } 1658 1659 static noinline void __init kernel_init_freeable(void) 1660 { 1661 /* Now the scheduler is fully set up and can do blocking allocations */ 1662 gfp_allowed_mask = __GFP_BITS_MASK; 1663 1664 /* 1665 * init can allocate pages on any node 1666 */ 1667 set_mems_allowed(node_states[N_MEMORY]); 1668 1669 cad_pid = get_pid(task_pid(current)); 1670 1671 smp_prepare_cpus(setup_max_cpus); 1672 1673 workqueue_init(); 1674 1675 init_mm_internals(); 1676 1677 do_pre_smp_initcalls(); 1678 lockup_detector_init(); 1679 1680 smp_init(); 1681 sched_init_smp(); 1682 1683 workqueue_init_topology(); 1684 async_init(); 1685 padata_init(); 1686 page_alloc_init_late(); 1687 1688 do_basic_setup(); 1689 1690 kunit_run_all_tests(); 1691 1692 wait_for_initramfs(); 1693 console_on_rootfs(); 1694 1695 /* 1696 * check if there is an early userspace init. If yes, let it do all 1697 * the work 1698 */ 1699 int ramdisk_command_access; 1700 ramdisk_command_access = init_eaccess(ramdisk_execute_command); 1701 if (ramdisk_command_access != 0) { 1702 pr_warn("check access for rdinit=%s failed: %i, ignoring\n", 1703 ramdisk_execute_command, ramdisk_command_access); 1704 ramdisk_execute_command = NULL; 1705 prepare_namespace(); 1706 } 1707 1708 /* 1709 * Ok, we have completed the initial bootup, and 1710 * we're essentially up and running. Get rid of the 1711 * initmem segments and start the user-mode stuff.. 1712 * 1713 * rootfs is available now, try loading the public keys 1714 * and default modules 1715 */ 1716 1717 integrity_load_keys(); 1718 } 1719