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/fs_struct.h> 107 #include <linux/ptdump.h> 108 #include <linux/time_namespace.h> 109 #include <linux/unaligned.h> 110 #include <linux/vdso_datastore.h> 111 #include <net/net_namespace.h> 112 113 #include <asm/io.h> 114 #include <asm/setup.h> 115 #include <asm/sections.h> 116 #include <asm/cacheflush.h> 117 118 #define CREATE_TRACE_POINTS 119 #include <trace/events/initcall.h> 120 121 #include <kunit/test.h> 122 123 static int kernel_init(void *); 124 125 /* 126 * Debug helper: via this flag we know that we are in 'early bootup code' 127 * where only the boot processor is running with IRQ disabled. This means 128 * two things - IRQ must not be enabled before the flag is cleared and some 129 * operations which are not allowed with IRQ disabled are allowed while the 130 * flag is set. 131 */ 132 bool early_boot_irqs_disabled __read_mostly; 133 134 enum system_states system_state __read_mostly; 135 EXPORT_SYMBOL(system_state); 136 137 /* 138 * Boot command-line arguments 139 */ 140 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 141 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 142 143 /* Default late time init is NULL. archs can override this later. */ 144 void (*__initdata late_time_init)(void); 145 146 /* Untouched command line saved by arch-specific code. */ 147 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 148 /* Untouched saved command line (eg. for /proc) */ 149 char *saved_command_line __ro_after_init; 150 unsigned int saved_command_line_len __ro_after_init; 151 /* Command line for parameter parsing */ 152 static char *static_command_line; 153 /* Untouched extra command line */ 154 static char *extra_command_line; 155 /* Extra init arguments */ 156 static char *extra_init_args; 157 158 #ifdef CONFIG_BOOT_CONFIG 159 /* Is bootconfig on command line? */ 160 static bool bootconfig_found; 161 static size_t initargs_offs; 162 #else 163 # define bootconfig_found false 164 # define initargs_offs 0 165 #endif 166 167 static char *execute_command; 168 static char *ramdisk_execute_command = "/init"; 169 static bool __initdata ramdisk_execute_command_set; 170 171 /* 172 * Used to generate warnings if static_key manipulation functions are used 173 * before jump_label_init is called. 174 */ 175 bool static_key_initialized __read_mostly; 176 EXPORT_SYMBOL_GPL(static_key_initialized); 177 178 /* 179 * If set, this is an indication to the drivers that reset the underlying 180 * device before going ahead with the initialization otherwise driver might 181 * rely on the BIOS and skip the reset operation. 182 * 183 * This is useful if kernel is booting in an unreliable environment. 184 * For ex. kdump situation where previous kernel has crashed, BIOS has been 185 * skipped and devices will be in unknown state. 186 */ 187 unsigned int reset_devices; 188 EXPORT_SYMBOL(reset_devices); 189 190 static int __init set_reset_devices(char *str) 191 { 192 reset_devices = 1; 193 return 1; 194 } 195 196 __setup("reset_devices", set_reset_devices); 197 198 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 199 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 200 static const char *panic_later, *panic_param; 201 202 static bool __init obsolete_checksetup(char *line) 203 { 204 const struct obs_kernel_param *p; 205 bool had_early_param = false; 206 207 p = __setup_start; 208 do { 209 int n = strlen(p->str); 210 if (parameqn(line, p->str, n)) { 211 if (p->early) { 212 /* Already done in parse_early_param? 213 * (Needs exact match on param part). 214 * Keep iterating, as we can have early 215 * params and __setups of same names 8( */ 216 if (line[n] == '\0' || line[n] == '=') 217 had_early_param = true; 218 } else if (!p->setup_func) { 219 pr_warn("Parameter %s is obsolete, ignored\n", 220 p->str); 221 return true; 222 } else if (p->setup_func(line + n)) 223 return true; 224 } 225 p++; 226 } while (p < __setup_end); 227 228 return had_early_param; 229 } 230 231 /* 232 * This should be approx 2 Bo*oMips to start (note initial shift), and will 233 * still work even if initially too large, it will just take slightly longer 234 */ 235 unsigned long loops_per_jiffy = (1<<12); 236 EXPORT_SYMBOL(loops_per_jiffy); 237 238 static int __init debug_kernel(char *str) 239 { 240 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 241 return 0; 242 } 243 244 static int __init quiet_kernel(char *str) 245 { 246 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 247 return 0; 248 } 249 250 early_param("debug", debug_kernel); 251 early_param("quiet", quiet_kernel); 252 253 static int __init loglevel(char *str) 254 { 255 int newlevel; 256 257 /* 258 * Only update loglevel value when a correct setting was passed, 259 * to prevent blind crashes (when loglevel being set to 0) that 260 * are quite hard to debug 261 */ 262 if (get_option(&str, &newlevel)) { 263 console_loglevel = newlevel; 264 return 0; 265 } 266 267 return -EINVAL; 268 } 269 270 early_param("loglevel", loglevel); 271 272 #ifdef CONFIG_BLK_DEV_INITRD 273 static void * __init get_boot_config_from_initrd(size_t *_size) 274 { 275 u32 size, csum; 276 char *data; 277 u8 *hdr; 278 int i; 279 280 if (!initrd_end || initrd_end < initrd_start || 281 initrd_end - initrd_start < BOOTCONFIG_MAGIC_LEN + 8) 282 return NULL; 283 284 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; 285 /* 286 * Since Grub may align the size of initrd to 4, we must 287 * check the preceding 3 bytes as well. 288 */ 289 for (i = 0; i < 4; i++) { 290 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) 291 goto found; 292 data--; 293 } 294 return NULL; 295 296 found: 297 hdr = (u8 *)(data - 8); 298 if ((unsigned long)hdr < initrd_start) 299 return NULL; 300 301 size = get_unaligned_le32(hdr); 302 csum = get_unaligned_le32(hdr + 4); 303 304 if (size > XBC_DATA_MAX) { 305 pr_err("bootconfig size %u is greater than max size %d\n", 306 size, XBC_DATA_MAX); 307 return NULL; 308 } 309 310 if (size > ((unsigned long)hdr - initrd_start)) { 311 pr_err("bootconfig size %u is greater than initrd size %lu\n", 312 size, initrd_end - initrd_start); 313 return NULL; 314 } 315 316 data = ((void *)hdr) - size; 317 318 if (xbc_calc_checksum(data, size) != csum) { 319 pr_err("bootconfig checksum failed\n"); 320 return NULL; 321 } 322 323 /* Remove bootconfig from initramfs/initrd */ 324 initrd_end = (unsigned long)data; 325 if (_size) 326 *_size = size; 327 328 return data; 329 } 330 #else 331 static void * __init get_boot_config_from_initrd(size_t *_size) 332 { 333 return NULL; 334 } 335 #endif 336 337 #ifdef CONFIG_BOOT_CONFIG 338 339 /* Make an extra command line under given key word */ 340 static char * __init xbc_make_cmdline(const char *key) 341 { 342 struct xbc_node *root; 343 char *new_cmdline; 344 int ret, len = 0; 345 346 root = xbc_find_node(key); 347 if (!root) 348 return NULL; 349 350 /* Count required buffer size */ 351 len = xbc_snprint_cmdline(NULL, 0, root); 352 if (len <= 0) 353 return NULL; 354 355 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 356 if (!new_cmdline) { 357 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 358 return NULL; 359 } 360 361 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 362 if (ret < 0 || ret > len) { 363 pr_err("Failed to print extra kernel cmdline.\n"); 364 memblock_free(new_cmdline, len + 1); 365 return NULL; 366 } 367 368 return new_cmdline; 369 } 370 371 static int __init warn_bootconfig(char *str) 372 { 373 /* The 'bootconfig' option is handled by setup_boot_config(). */ 374 return 0; 375 } 376 377 static void __init setup_boot_config(void) 378 { 379 const char *msg, *data; 380 int pos, ret, offs; 381 size_t size; 382 bool from_embedded = false; 383 384 /* Cut out the bootconfig data even if we have no bootconfig option */ 385 data = get_boot_config_from_initrd(&size); 386 /* If there is no bootconfig in initrd, try embedded one. */ 387 if (!data) { 388 data = xbc_get_embedded_bootconfig(&size); 389 from_embedded = true; 390 } 391 392 bootconfig_found = bootconfig_cmdline_requested(boot_command_line, &offs); 393 if (!(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE))) 394 return; 395 396 /* Offset of the init arguments after a "--", located by the helper. */ 397 initargs_offs = offs; 398 399 if (!data) { 400 /* If user intended to use bootconfig, show an error level message */ 401 if (bootconfig_found) 402 pr_err("'bootconfig' found on command line, but no bootconfig found\n"); 403 else 404 pr_info("No bootconfig data provided, so skipping bootconfig"); 405 return; 406 } 407 408 ret = xbc_init(data, size, &msg, &pos); 409 if (ret < 0) { 410 if (pos < 0) 411 pr_err("Failed to init bootconfig: %s.\n", msg); 412 else 413 pr_err("Failed to parse bootconfig: %s at %d.\n", 414 msg, pos); 415 } else { 416 xbc_get_info(&ret, NULL); 417 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); 418 /* 419 * keys starting with "kernel." are passed via cmdline. When 420 * this bootconfig came from the embedded source and 421 * setup_arch() already prepended the rendered "kernel" subtree 422 * to boot_command_line, rendering again here would duplicate 423 * the keys in saved_command_line and make accumulating handlers 424 * (console=, earlycon=, ...) re-register the same value. Skip 425 * only when the prepend really happened. 426 * 427 * On arches that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG, 428 * CONFIG_CMDLINE_FROM_BOOTCONFIG is unselectable and 429 * xbc_embedded_cmdline_applied() collapses to a stub returning 430 * false, so this path still runs and the embedded "kernel" 431 * keys reach the cmdline via the runtime parser exactly as 432 * before this series. 433 */ 434 if (!from_embedded || !xbc_embedded_cmdline_applied()) 435 extra_command_line = xbc_make_cmdline("kernel"); 436 /* Also, "init." keys are init arguments */ 437 extra_init_args = xbc_make_cmdline("init"); 438 } 439 return; 440 } 441 442 static void __init exit_boot_config(void) 443 { 444 xbc_exit(); 445 } 446 447 #else /* !CONFIG_BOOT_CONFIG */ 448 449 static void __init setup_boot_config(void) 450 { 451 /* Remove bootconfig data from initrd */ 452 get_boot_config_from_initrd(NULL); 453 } 454 455 static int __init warn_bootconfig(char *str) 456 { 457 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); 458 return 0; 459 } 460 461 #define exit_boot_config() do {} while (0) 462 463 #endif /* CONFIG_BOOT_CONFIG */ 464 465 early_param("bootconfig", warn_bootconfig); 466 467 bool __init cmdline_has_extra_options(void) 468 { 469 return extra_command_line || extra_init_args; 470 } 471 472 /* Change NUL term back to "=", to make "param" the whole string. */ 473 static void __init repair_env_string(char *param, char *val) 474 { 475 if (val) { 476 /* param=val or param="val"? */ 477 if (val == param+strlen(param)+1) 478 val[-1] = '='; 479 else if (val == param+strlen(param)+2) { 480 val[-2] = '='; 481 memmove(val-1, val, strlen(val)+1); 482 } else 483 BUG(); 484 } 485 } 486 487 /* Anything after -- gets handed straight to init. */ 488 static int __init set_init_arg(char *param, char *val, 489 const char *unused, void *arg) 490 { 491 unsigned int i; 492 493 if (panic_later) 494 return 0; 495 496 repair_env_string(param, val); 497 498 for (i = 0; argv_init[i]; i++) { 499 if (i == MAX_INIT_ARGS) { 500 panic_later = "init"; 501 panic_param = param; 502 return 0; 503 } 504 } 505 argv_init[i] = param; 506 return 0; 507 } 508 509 /* 510 * Unknown boot options get handed to init, unless they look like 511 * unused parameters (modprobe will find them in /proc/cmdline). 512 */ 513 static int __init unknown_bootoption(char *param, char *val, 514 const char *unused, void *arg) 515 { 516 size_t len = strlen(param); 517 /* 518 * Well-known bootloader identifiers: 519 * 1. LILO/Grub pass "BOOT_IMAGE=..."; 520 * 2. kexec/kdump (kexec-tools) pass "kexec". 521 */ 522 const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL }; 523 524 /* Handle params aliased to sysctls */ 525 if (sysctl_is_alias(param)) 526 return 0; 527 528 repair_env_string(param, val); 529 530 /* Handle bootloader identifier */ 531 for (int i = 0; bootloader[i]; i++) { 532 if (strstarts(param, bootloader[i])) 533 return 0; 534 } 535 536 /* Handle obsolete-style parameters */ 537 if (obsolete_checksetup(param)) 538 return 0; 539 540 /* Unused module parameter. */ 541 if (strnchr(param, len, '.')) 542 return 0; 543 544 if (panic_later) 545 return 0; 546 547 if (val) { 548 /* Environment option */ 549 unsigned int i; 550 for (i = 0; envp_init[i]; i++) { 551 if (i == MAX_INIT_ENVS) { 552 panic_later = "env"; 553 panic_param = param; 554 } 555 if (!strncmp(param, envp_init[i], len+1)) 556 break; 557 } 558 envp_init[i] = param; 559 } else { 560 /* Command line option */ 561 unsigned int i; 562 for (i = 0; argv_init[i]; i++) { 563 if (i == MAX_INIT_ARGS) { 564 panic_later = "init"; 565 panic_param = param; 566 } 567 } 568 argv_init[i] = param; 569 } 570 return 0; 571 } 572 573 static int __init init_setup(char *str) 574 { 575 unsigned int i; 576 577 execute_command = str; 578 /* 579 * In case LILO is going to boot us with default command line, 580 * it prepends "auto" before the whole cmdline which makes 581 * the shell think it should execute a script with such name. 582 * So we ignore all arguments entered _before_ init=... [MJ] 583 */ 584 for (i = 1; i < MAX_INIT_ARGS; i++) 585 argv_init[i] = NULL; 586 return 1; 587 } 588 __setup("init=", init_setup); 589 590 static int __init rdinit_setup(char *str) 591 { 592 unsigned int i; 593 594 ramdisk_execute_command = str; 595 ramdisk_execute_command_set = true; 596 /* See "auto" comment in init_setup */ 597 for (i = 1; i < MAX_INIT_ARGS; i++) 598 argv_init[i] = NULL; 599 return 1; 600 } 601 __setup("rdinit=", rdinit_setup); 602 603 #ifndef CONFIG_SMP 604 static inline void setup_nr_cpu_ids(void) { } 605 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 606 #endif 607 608 /* 609 * We need to store the untouched command line for future reference. 610 * We also need to store the touched command line since the parameter 611 * parsing is performed in place, and we should allow a component to 612 * store reference of name/value for future reference. 613 */ 614 static void __init setup_command_line(char *command_line) 615 { 616 size_t len, xlen = 0, ilen = 0; 617 618 if (extra_command_line) 619 xlen = strlen(extra_command_line); 620 if (extra_init_args) { 621 extra_init_args = strim(extra_init_args); /* remove trailing space */ 622 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 623 } 624 625 len = xlen + strlen(boot_command_line) + ilen + 1; 626 627 saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 628 629 len = xlen + strlen(command_line) + 1; 630 631 static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES); 632 633 if (xlen) { 634 /* 635 * We have to put extra_command_line before boot command 636 * lines because there could be dashes (separator of init 637 * command line) in the command lines. 638 */ 639 strcpy(saved_command_line, extra_command_line); 640 strcpy(static_command_line, extra_command_line); 641 } 642 strcpy(saved_command_line + xlen, boot_command_line); 643 strcpy(static_command_line + xlen, command_line); 644 645 if (ilen) { 646 /* 647 * Append supplemental init boot args to saved_command_line 648 * so that user can check what command line options passed 649 * to init. 650 * The order should always be 651 * " -- "[bootconfig init-param][cmdline init-param] 652 */ 653 if (initargs_offs) { 654 len = xlen + initargs_offs; 655 strcpy(saved_command_line + len, extra_init_args); 656 len += ilen - 4; /* strlen(extra_init_args) */ 657 strcpy(saved_command_line + len, 658 boot_command_line + initargs_offs - 1); 659 } else { 660 len = strlen(saved_command_line); 661 strcpy(saved_command_line + len, " -- "); 662 len += 4; 663 strcpy(saved_command_line + len, extra_init_args); 664 } 665 } 666 667 saved_command_line_len = strlen(saved_command_line); 668 } 669 670 /* 671 * We need to finalize in a non-__init function or else race conditions 672 * between the root thread and the init thread may cause start_kernel to 673 * be reaped by free_initmem before the root thread has proceeded to 674 * cpu_idle. 675 * 676 * gcc-3.4 accidentally inlines this function, so use noinline. 677 */ 678 679 static __initdata DECLARE_COMPLETION(kthreadd_done); 680 681 static noinline void __ref __noreturn rest_init(void) 682 { 683 struct kernel_clone_args init_args = { 684 .flags = (CLONE_VM | CLONE_UNTRACED), 685 .fn = kernel_init, 686 .fn_arg = NULL, 687 }; 688 struct task_struct *tsk; 689 int pid; 690 691 rcu_scheduler_starting(); 692 /* 693 * We need to spawn init first so that it obtains pid 1, however 694 * the init task will end up wanting to create kthreads, which, if 695 * we schedule it before we create kthreadd, will OOPS. 696 */ 697 pid = kernel_clone(&init_args); 698 /* 699 * Pin init on the boot CPU. Task migration is not properly working 700 * until sched_init_smp() has been run. It will set the allowed 701 * CPUs for init to the non isolated CPUs. 702 */ 703 rcu_read_lock(); 704 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 705 tsk->flags |= PF_NO_SETAFFINITY; 706 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 707 rcu_read_unlock(); 708 709 numa_default_policy(); 710 pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES); 711 rcu_read_lock(); 712 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 713 rcu_read_unlock(); 714 715 /* 716 * Enable might_sleep() and smp_processor_id() checks. 717 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 718 * kernel_thread() would trigger might_sleep() splats. With 719 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 720 * already, but it's stuck on the kthreadd_done completion. 721 */ 722 system_state = SYSTEM_SCHEDULING; 723 724 complete(&kthreadd_done); 725 726 /* 727 * The boot idle thread must execute schedule() 728 * at least once to get things moving: 729 */ 730 schedule_preempt_disabled(); 731 /* Call into cpu_idle with preempt disabled */ 732 cpu_startup_entry(CPUHP_ONLINE); 733 } 734 735 /* Check for early params. */ 736 static int __init do_early_param(char *param, char *val, 737 const char *unused, void *arg) 738 { 739 const struct obs_kernel_param *p; 740 741 for (p = __setup_start; p < __setup_end; p++) { 742 if (p->early && parameq(param, p->str)) { 743 if (p->setup_func(val) != 0) 744 pr_warn("Malformed early option '%s'\n", param); 745 } 746 } 747 /* We accept everything at this stage. */ 748 return 0; 749 } 750 751 void __init parse_early_options(char *cmdline) 752 { 753 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 754 do_early_param); 755 } 756 757 /* Arch code calls this early on, or if not, just before other parsing. */ 758 void __init parse_early_param(void) 759 { 760 static int done __initdata; 761 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 762 763 if (done) 764 return; 765 766 /* All fall through to do_early_param. */ 767 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 768 parse_early_options(tmp_cmdline); 769 done = 1; 770 } 771 772 void __init __weak arch_post_acpi_subsys_init(void) { } 773 774 void __init __weak smp_setup_processor_id(void) 775 { 776 } 777 778 void __init __weak smp_prepare_boot_cpu(void) 779 { 780 } 781 782 # if THREAD_SIZE >= PAGE_SIZE 783 void __init __weak thread_stack_cache_init(void) 784 { 785 } 786 #endif 787 788 void __init __weak poking_init(void) { } 789 790 void __init __weak pgtable_cache_init(void) { } 791 792 void __init __weak trap_init(void) { } 793 794 bool initcall_debug; 795 core_param(initcall_debug, initcall_debug, bool, 0644); 796 797 #ifdef TRACEPOINTS_ENABLED 798 static void __init initcall_debug_enable(void); 799 #else 800 static inline void initcall_debug_enable(void) 801 { 802 } 803 #endif 804 805 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET 806 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, 807 randomize_kstack_offset); 808 DEFINE_PER_CPU(struct rnd_state, kstack_rnd_state); 809 810 static int __init random_kstack_init(void) 811 { 812 prandom_seed_full_state(&kstack_rnd_state); 813 return 0; 814 } 815 late_initcall(random_kstack_init); 816 817 static int __init early_randomize_kstack_offset(char *buf) 818 { 819 int ret; 820 bool bool_result; 821 822 ret = kstrtobool(buf, &bool_result); 823 if (ret) 824 return ret; 825 826 if (bool_result) 827 static_branch_enable(&randomize_kstack_offset); 828 else 829 static_branch_disable(&randomize_kstack_offset); 830 return 0; 831 } 832 early_param("randomize_kstack_offset", early_randomize_kstack_offset); 833 #endif 834 835 static void __init print_unknown_bootoptions(void) 836 { 837 char *unknown_options; 838 char *end; 839 const char *const *p; 840 size_t len; 841 842 if (panic_later || (!argv_init[1] && !envp_init[2])) 843 return; 844 845 /* 846 * Determine how many options we have to print out, plus a space 847 * before each 848 */ 849 len = 1; /* null terminator */ 850 for (p = &argv_init[1]; *p; p++) { 851 len++; 852 len += strlen(*p); 853 } 854 for (p = &envp_init[2]; *p; p++) { 855 len++; 856 len += strlen(*p); 857 } 858 859 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES); 860 if (!unknown_options) { 861 pr_err("%s: Failed to allocate %zu bytes\n", 862 __func__, len); 863 return; 864 } 865 end = unknown_options; 866 867 for (p = &argv_init[1]; *p; p++) 868 end += sprintf(end, " %s", *p); 869 for (p = &envp_init[2]; *p; p++) 870 end += sprintf(end, " %s", *p); 871 872 /* Start at unknown_options[1] to skip the initial space */ 873 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n", 874 &unknown_options[1]); 875 memblock_free(unknown_options, len); 876 } 877 878 static void __init early_numa_node_init(void) 879 { 880 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 881 #ifndef cpu_to_node 882 int cpu; 883 884 /* The early_cpu_to_node() should be ready here. */ 885 for_each_possible_cpu(cpu) 886 set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); 887 #endif 888 #endif 889 } 890 891 #define KERNEL_CMDLINE_PREFIX "Kernel command line: " 892 #define KERNEL_CMDLINE_PREFIX_LEN (sizeof(KERNEL_CMDLINE_PREFIX) - 1) 893 #define KERNEL_CMDLINE_CONTINUATION " \\" 894 #define KERNEL_CMDLINE_CONTINUATION_LEN (sizeof(KERNEL_CMDLINE_CONTINUATION) - 1) 895 896 #define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN (KERNEL_CMDLINE_PREFIX_LEN + \ 897 KERNEL_CMDLINE_CONTINUATION_LEN) 898 #define CMDLINE_LOG_WRAP_IDEAL_LEN (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \ 899 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \ 900 CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \ 901 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN) 902 903 #define IDEAL_CMDLINE_LEN (CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN) 904 #define IDEAL_CMDLINE_SPLIT_LEN (IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN) 905 906 /** 907 * print_kernel_cmdline() - Print the kernel cmdline with wrapping. 908 * @cmdline: The cmdline to print. 909 * 910 * Print the kernel command line, trying to wrap based on the Kconfig knob 911 * CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN. 912 * 913 * Wrapping is based on spaces, ignoring quotes. All lines are prefixed 914 * with "Kernel command line: " and lines that are not the last line have 915 * a " \" suffix added to them. The prefix and suffix count towards the 916 * line length for wrapping purposes. The ideal length will be exceeded 917 * if no appropriate place to wrap is found. 918 * 919 * Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40: 920 * Kernel command line: loglevel=7 \ 921 * Kernel command line: init=/sbin/init \ 922 * Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \ 923 * Kernel command line: rootwait ro \ 924 * Kernel command line: my_quoted_arg="The \ 925 * Kernel command line: quick brown fox \ 926 * Kernel command line: jumps over the \ 927 * Kernel command line: lazy dog." 928 */ 929 static void __init print_kernel_cmdline(const char *cmdline) 930 { 931 size_t len; 932 933 /* Config option of 0 or anything longer than the max disables wrapping */ 934 if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 || 935 IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) { 936 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 937 return; 938 } 939 940 len = strlen(cmdline); 941 while (len > IDEAL_CMDLINE_LEN) { 942 const char *first_space; 943 const char *prev_cutoff; 944 const char *cutoff; 945 int to_print; 946 size_t used; 947 948 /* Find the last ' ' that wouldn't make the line too long */ 949 prev_cutoff = NULL; 950 cutoff = cmdline; 951 while (true) { 952 cutoff = strchr(cutoff + 1, ' '); 953 if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN) 954 break; 955 prev_cutoff = cutoff; 956 } 957 if (prev_cutoff) 958 cutoff = prev_cutoff; 959 else if (!cutoff) 960 break; 961 962 /* Find the beginning and end of the string of spaces */ 963 first_space = cutoff; 964 while (first_space > cmdline && first_space[-1] == ' ') 965 first_space--; 966 to_print = first_space - cmdline; 967 while (*cutoff == ' ') 968 cutoff++; 969 used = cutoff - cmdline; 970 971 /* If the whole string is used, break and do the final printout */ 972 if (len == used) 973 break; 974 975 if (to_print) 976 pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX, 977 to_print, cmdline, KERNEL_CMDLINE_CONTINUATION); 978 979 len -= used; 980 cmdline += used; 981 } 982 if (len) 983 pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline); 984 } 985 986 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector 987 void start_kernel(void) 988 { 989 char *command_line; 990 char *after_dashes; 991 992 set_task_stack_end_magic(&init_task); 993 smp_setup_processor_id(); 994 debug_objects_early_init(); 995 init_vmlinux_build_id(); 996 997 cgroup_init_early(); 998 999 local_irq_disable(); 1000 early_boot_irqs_disabled = true; 1001 1002 /* 1003 * Interrupts are still disabled. Do necessary setups, then 1004 * enable them. 1005 */ 1006 boot_cpu_init(); 1007 page_address_init(); 1008 pr_notice("%s", linux_banner); 1009 setup_arch(&command_line); 1010 mm_core_init_early(); 1011 /* Static keys and static calls are needed by LSMs */ 1012 jump_label_init(); 1013 static_call_init(); 1014 early_security_init(); 1015 setup_boot_config(); 1016 setup_command_line(command_line); 1017 setup_nr_cpu_ids(); 1018 setup_per_cpu_areas(); 1019 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 1020 early_numa_node_init(); 1021 boot_cpu_hotplug_init(); 1022 1023 print_kernel_cmdline(saved_command_line); 1024 /* parameters may set static keys */ 1025 parse_early_param(); 1026 after_dashes = parse_args("Booting kernel", 1027 static_command_line, __start___param, 1028 __stop___param - __start___param, 1029 -1, -1, NULL, &unknown_bootoption); 1030 print_unknown_bootoptions(); 1031 if (!IS_ERR_OR_NULL(after_dashes)) 1032 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 1033 NULL, set_init_arg); 1034 if (extra_init_args) 1035 parse_args("Setting extra init args", extra_init_args, 1036 NULL, 0, -1, -1, NULL, set_init_arg); 1037 1038 /* Architectural and non-timekeeping rng init, before allocator init */ 1039 random_init_early(command_line); 1040 1041 /* 1042 * These use large bootmem allocations and must precede 1043 * initalization of page allocator 1044 */ 1045 setup_log_buf(0); 1046 vfs_caches_init_early(); 1047 sort_main_extable(); 1048 trap_init(); 1049 mm_core_init(); 1050 maple_tree_init(); 1051 poking_init(); 1052 ftrace_init(); 1053 1054 /* trace_printk can be enabled here */ 1055 early_trace_init(); 1056 1057 /* 1058 * Set up the scheduler prior starting any interrupts (such as the 1059 * timer interrupt). Full topology setup happens at smp_init() 1060 * time - but meanwhile we still have a functioning scheduler. 1061 */ 1062 sched_init(); 1063 1064 if (WARN(!irqs_disabled(), 1065 "Interrupts were enabled *very* early, fixing it\n")) 1066 local_irq_disable(); 1067 radix_tree_init(); 1068 1069 /* 1070 * Set up housekeeping before setting up workqueues to allow the unbound 1071 * workqueue to take non-housekeeping into account. 1072 */ 1073 housekeeping_init(); 1074 1075 /* 1076 * Allow workqueue creation and work item queueing/cancelling 1077 * early. Work item execution depends on kthreads and starts after 1078 * workqueue_init(). 1079 */ 1080 workqueue_init_early(); 1081 1082 rcu_init(); 1083 kvfree_rcu_init(); 1084 1085 /* Trace events are available after this */ 1086 trace_init(); 1087 1088 if (initcall_debug) 1089 initcall_debug_enable(); 1090 1091 context_tracking_init(); 1092 /* init some links before init_ISA_irqs() */ 1093 early_irq_init(); 1094 init_IRQ(); 1095 tick_init(); 1096 rcu_init_nohz(); 1097 timers_init(); 1098 srcu_init(); 1099 hrtimers_init(); 1100 softirq_init(); 1101 vdso_setup_data_pages(); 1102 timekeeping_init(); 1103 time_init(); 1104 1105 /* This must be after timekeeping is initialized */ 1106 random_init(); 1107 1108 /* These make use of the fully initialized rng */ 1109 kfence_init(); 1110 boot_init_stack_canary(); 1111 1112 perf_event_init(); 1113 profile_init(); 1114 call_function_init(); 1115 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 1116 1117 early_boot_irqs_disabled = false; 1118 local_irq_enable(); 1119 1120 kmem_cache_init_late(); 1121 1122 /* 1123 * HACK ALERT! This is early. We're enabling the console before 1124 * we've done PCI setups etc, and console_init() must be aware of 1125 * this. But we do want output early, in case something goes wrong. 1126 */ 1127 console_init(); 1128 if (panic_later) 1129 panic("Too many boot %s vars at `%s'", panic_later, 1130 panic_param); 1131 1132 lockdep_init(); 1133 1134 /* 1135 * Need to run this when irqs are enabled, because it wants 1136 * to self-test [hard/soft]-irqs on/off lock inversion bugs 1137 * too: 1138 */ 1139 locking_selftest(); 1140 1141 #ifdef CONFIG_BLK_DEV_INITRD 1142 if (initrd_start && !initrd_below_start_ok && 1143 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 1144 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 1145 page_to_pfn(virt_to_page((void *)initrd_start)), 1146 min_low_pfn); 1147 initrd_start = 0; 1148 } 1149 #endif 1150 setup_per_cpu_pageset(); 1151 numa_policy_init(); 1152 acpi_early_init(); 1153 if (late_time_init) 1154 late_time_init(); 1155 sched_clock_init(); 1156 calibrate_delay(); 1157 1158 arch_cpu_finalize_init(); 1159 1160 pid_idr_init(); 1161 anon_vma_init(); 1162 thread_stack_cache_init(); 1163 cred_init(); 1164 fork_init(); 1165 proc_caches_init(); 1166 uts_ns_init(); 1167 time_ns_init(); 1168 key_init(); 1169 security_init(); 1170 dbg_late_init(); 1171 net_ns_init(); 1172 vfs_caches_init(); 1173 pagecache_init(); 1174 signals_init(); 1175 seq_file_init(); 1176 proc_root_init(); 1177 nsfs_init(); 1178 pidfs_init(); 1179 cpuset_init(); 1180 mem_cgroup_init(); 1181 cgroup_init(); 1182 taskstats_init_early(); 1183 delayacct_init(); 1184 1185 acpi_subsystem_init(); 1186 arch_post_acpi_subsys_init(); 1187 kcsan_init(); 1188 1189 /* Do the rest non-__init'ed, we're now alive */ 1190 rest_init(); 1191 1192 /* 1193 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10 1194 * and older. 1195 */ 1196 #if !__has_attribute(__no_stack_protector__) 1197 prevent_tail_call_optimization(); 1198 #endif 1199 } 1200 1201 /* Call all constructor functions linked into the kernel. */ 1202 static void __init do_ctors(void) 1203 { 1204 /* 1205 * For UML, the constructors have already been called by the 1206 * normal setup code as it's just a normal ELF binary, so we 1207 * cannot do it again - but we do need CONFIG_CONSTRUCTORS 1208 * even on UML for modules. 1209 */ 1210 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) 1211 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 1212 1213 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 1214 (*fn)(); 1215 #endif 1216 } 1217 1218 #ifdef CONFIG_KALLSYMS 1219 struct blacklist_entry { 1220 struct list_head next; 1221 char *buf; 1222 }; 1223 1224 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 1225 1226 static int __init initcall_blacklist(char *str) 1227 { 1228 char *str_entry; 1229 struct blacklist_entry *entry; 1230 1231 /* str argument is a comma-separated list of functions */ 1232 do { 1233 str_entry = strsep(&str, ","); 1234 if (str_entry) { 1235 pr_debug("blacklisting initcall %s\n", str_entry); 1236 entry = memblock_alloc_or_panic(sizeof(*entry), 1237 SMP_CACHE_BYTES); 1238 entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1, 1239 SMP_CACHE_BYTES); 1240 strcpy(entry->buf, str_entry); 1241 list_add(&entry->next, &blacklisted_initcalls); 1242 } 1243 } while (str_entry); 1244 1245 return 1; 1246 } 1247 1248 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1249 { 1250 struct blacklist_entry *entry; 1251 char fn_name[KSYM_SYMBOL_LEN]; 1252 unsigned long addr; 1253 1254 if (list_empty(&blacklisted_initcalls)) 1255 return false; 1256 1257 addr = (unsigned long) dereference_function_descriptor(fn); 1258 sprint_symbol_no_offset(fn_name, addr); 1259 1260 /* 1261 * fn will be "function_name [module_name]" where [module_name] is not 1262 * displayed for built-in init functions. Strip off the [module_name]. 1263 */ 1264 strreplace(fn_name, ' ', '\0'); 1265 1266 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1267 if (!strcmp(fn_name, entry->buf)) { 1268 pr_debug("initcall %s blacklisted\n", fn_name); 1269 return true; 1270 } 1271 } 1272 1273 return false; 1274 } 1275 #else 1276 static int __init initcall_blacklist(char *str) 1277 { 1278 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1279 return 0; 1280 } 1281 1282 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1283 { 1284 return false; 1285 } 1286 #endif 1287 __setup("initcall_blacklist=", initcall_blacklist); 1288 1289 static __init_or_module void 1290 trace_initcall_start_cb(void *data, initcall_t fn) 1291 { 1292 ktime_t *calltime = data; 1293 1294 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1295 *calltime = ktime_get(); 1296 } 1297 1298 static __init_or_module void 1299 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1300 { 1301 ktime_t rettime, *calltime = data; 1302 1303 rettime = ktime_get(); 1304 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1305 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime)); 1306 } 1307 1308 static __init_or_module void 1309 trace_initcall_level_cb(void *data, const char *level) 1310 { 1311 printk(KERN_DEBUG "entering initcall level: %s\n", level); 1312 } 1313 1314 static ktime_t initcall_calltime; 1315 1316 #ifdef TRACEPOINTS_ENABLED 1317 static void __init initcall_debug_enable(void) 1318 { 1319 int ret; 1320 1321 ret = register_trace_initcall_start(trace_initcall_start_cb, 1322 &initcall_calltime); 1323 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1324 &initcall_calltime); 1325 ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL); 1326 WARN(ret, "Failed to register initcall tracepoints\n"); 1327 } 1328 # define do_trace_initcall_start trace_initcall_start 1329 # define do_trace_initcall_finish trace_initcall_finish 1330 # define do_trace_initcall_level trace_initcall_level 1331 #else 1332 static inline void do_trace_initcall_start(initcall_t fn) 1333 { 1334 if (!initcall_debug) 1335 return; 1336 trace_initcall_start_cb(&initcall_calltime, fn); 1337 } 1338 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1339 { 1340 if (!initcall_debug) 1341 return; 1342 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1343 } 1344 static inline void do_trace_initcall_level(const char *level) 1345 { 1346 if (!initcall_debug) 1347 return; 1348 trace_initcall_level_cb(NULL, level); 1349 } 1350 #endif /* !TRACEPOINTS_ENABLED */ 1351 1352 int __init_or_module do_one_initcall(initcall_t fn) 1353 { 1354 int count = preempt_count(); 1355 char msgbuf[64]; 1356 int ret; 1357 1358 if (initcall_blacklisted(fn)) 1359 return -EPERM; 1360 1361 do_trace_initcall_start(fn); 1362 ret = fn(); 1363 do_trace_initcall_finish(fn, ret); 1364 1365 msgbuf[0] = 0; 1366 1367 if (preempt_count() != count) { 1368 sprintf(msgbuf, "preemption imbalance "); 1369 preempt_count_set(count); 1370 } 1371 if (irqs_disabled()) { 1372 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1373 local_irq_enable(); 1374 } 1375 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1376 1377 add_latent_entropy(); 1378 return ret; 1379 } 1380 1381 1382 static initcall_entry_t *initcall_levels[] __initdata = { 1383 __initcall0_start, 1384 __initcall1_start, 1385 __initcall2_start, 1386 __initcall3_start, 1387 __initcall4_start, 1388 __initcall5_start, 1389 __initcall6_start, 1390 __initcall7_start, 1391 __initcall_end, 1392 }; 1393 1394 /* Keep these in sync with initcalls in include/linux/init.h */ 1395 static const char *initcall_level_names[] __initdata = { 1396 "pure", 1397 "core", 1398 "postcore", 1399 "arch", 1400 "subsys", 1401 "fs", 1402 "device", 1403 "late", 1404 }; 1405 1406 static int __init ignore_unknown_bootoption(char *param, char *val, 1407 const char *unused, void *arg) 1408 { 1409 return 0; 1410 } 1411 1412 static void __init do_initcall_level(int level, char *command_line) 1413 { 1414 initcall_entry_t *fn; 1415 1416 parse_args(initcall_level_names[level], 1417 command_line, __start___param, 1418 __stop___param - __start___param, 1419 level, level, 1420 NULL, ignore_unknown_bootoption); 1421 1422 do_trace_initcall_level(initcall_level_names[level]); 1423 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1424 do_one_initcall(initcall_from_entry(fn)); 1425 } 1426 1427 static void __init do_initcalls(void) 1428 { 1429 int level; 1430 size_t len = saved_command_line_len + 1; 1431 char *command_line; 1432 1433 command_line = kzalloc(len, GFP_KERNEL); 1434 if (!command_line) 1435 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1436 1437 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1438 /* Parser modifies command_line, restore it each time */ 1439 strcpy(command_line, saved_command_line); 1440 do_initcall_level(level, command_line); 1441 } 1442 1443 kfree(command_line); 1444 } 1445 1446 /* 1447 * Ok, the machine is now initialized. None of the devices 1448 * have been touched yet, but the CPU subsystem is up and 1449 * running, and memory and process management works. 1450 * 1451 * Now we can finally start doing some real work.. 1452 */ 1453 static void __init do_basic_setup(void) 1454 { 1455 cpuset_init_smp(); 1456 ksysfs_init(); 1457 driver_init(); 1458 init_irq_proc(); 1459 do_ctors(); 1460 do_initcalls(); 1461 } 1462 1463 static void __init do_pre_smp_initcalls(void) 1464 { 1465 initcall_entry_t *fn; 1466 1467 do_trace_initcall_level("early"); 1468 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1469 do_one_initcall(initcall_from_entry(fn)); 1470 } 1471 1472 static int run_init_process(const char *init_filename) 1473 { 1474 const char *const *p; 1475 1476 argv_init[0] = init_filename; 1477 pr_info("Run %s as init process\n", init_filename); 1478 pr_debug(" with arguments:\n"); 1479 for (p = argv_init; *p; p++) 1480 pr_debug(" %s\n", *p); 1481 pr_debug(" with environment:\n"); 1482 for (p = envp_init; *p; p++) 1483 pr_debug(" %s\n", *p); 1484 return kernel_execve(init_filename, argv_init, envp_init); 1485 } 1486 1487 static int try_to_run_init_process(const char *init_filename) 1488 { 1489 int ret; 1490 1491 ret = run_init_process(init_filename); 1492 1493 if (ret && ret != -ENOENT) { 1494 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1495 init_filename, ret); 1496 } 1497 1498 return ret; 1499 } 1500 1501 static noinline void __init kernel_init_freeable(void); 1502 1503 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1504 bool rodata_enabled __ro_after_init = true; 1505 1506 #ifndef arch_parse_debug_rodata 1507 static inline bool arch_parse_debug_rodata(char *str) { return false; } 1508 #endif 1509 1510 static int __init set_debug_rodata(char *str) 1511 { 1512 if (arch_parse_debug_rodata(str)) 1513 return 0; 1514 1515 if (str && !strcmp(str, "on")) 1516 rodata_enabled = true; 1517 else if (str && !strcmp(str, "off")) 1518 rodata_enabled = false; 1519 else 1520 pr_warn("Invalid option string for rodata: '%s'\n", str); 1521 return 0; 1522 } 1523 early_param("rodata", set_debug_rodata); 1524 #endif 1525 1526 static void mark_readonly(void) 1527 { 1528 if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) { 1529 /* 1530 * load_module() results in W+X mappings, which are cleaned 1531 * up with init_free_wq. Let's make sure that queued work is 1532 * flushed so that we don't hit false positives looking for 1533 * insecure pages which are W+X. 1534 */ 1535 flush_module_init_free_work(); 1536 jump_label_init_ro(); 1537 mark_rodata_ro(); 1538 debug_checkwx(); 1539 rodata_test(); 1540 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { 1541 pr_info("Kernel memory protection disabled.\n"); 1542 } else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) { 1543 pr_warn("Kernel memory protection not selected by kernel config.\n"); 1544 } else { 1545 pr_warn("This architecture does not have kernel memory protection.\n"); 1546 } 1547 } 1548 1549 void __weak free_initmem(void) 1550 { 1551 free_initmem_default(POISON_FREE_INITMEM); 1552 } 1553 1554 static int __ref kernel_init(void *unused) 1555 { 1556 int ret; 1557 1558 init_userspace_fs(); 1559 1560 /* 1561 * Wait until kthreadd is all set-up. 1562 */ 1563 wait_for_completion(&kthreadd_done); 1564 1565 kernel_init_freeable(); 1566 /* need to finish all async __init code before freeing the memory */ 1567 async_synchronize_full(); 1568 1569 system_state = SYSTEM_FREEING_INITMEM; 1570 kprobe_free_init_mem(); 1571 ftrace_free_init_mem(); 1572 kgdb_free_init_mem(); 1573 exit_boot_config(); 1574 free_initmem(); 1575 mark_readonly(); 1576 1577 /* 1578 * Kernel mappings are now finalized - update the userspace page-table 1579 * to finalize PTI. 1580 */ 1581 pti_finalize(); 1582 1583 system_state = SYSTEM_RUNNING; 1584 numa_default_policy(); 1585 1586 rcu_end_inkernel_boot(); 1587 1588 do_sysctl_args(); 1589 1590 if (ramdisk_execute_command) { 1591 ret = run_init_process(ramdisk_execute_command); 1592 if (!ret) 1593 return 0; 1594 pr_err("Failed to execute %s (error %d)\n", 1595 ramdisk_execute_command, ret); 1596 } 1597 1598 /* 1599 * We try each of these until one succeeds. 1600 * 1601 * The Bourne shell can be used instead of init if we are 1602 * trying to recover a really broken machine. 1603 */ 1604 if (execute_command) { 1605 ret = run_init_process(execute_command); 1606 if (!ret) 1607 return 0; 1608 panic("Requested init %s failed (error %d).", 1609 execute_command, ret); 1610 } 1611 1612 if (CONFIG_DEFAULT_INIT[0] != '\0') { 1613 ret = run_init_process(CONFIG_DEFAULT_INIT); 1614 if (ret) 1615 pr_err("Default init %s failed (error %d)\n", 1616 CONFIG_DEFAULT_INIT, ret); 1617 else 1618 return 0; 1619 } 1620 1621 if (!try_to_run_init_process("/sbin/init") || 1622 !try_to_run_init_process("/etc/init") || 1623 !try_to_run_init_process("/bin/init") || 1624 !try_to_run_init_process("/bin/sh")) 1625 return 0; 1626 1627 panic("No working init found. Try passing init= option to kernel. " 1628 "See Linux Documentation/admin-guide/init.rst for guidance."); 1629 } 1630 1631 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ 1632 void __init console_on_rootfs(void) 1633 { 1634 struct file *file = filp_open("/dev/console", O_RDWR, 0); 1635 1636 if (IS_ERR(file)) { 1637 pr_err("Warning: unable to open an initial console.\n"); 1638 return; 1639 } 1640 init_dup(file); 1641 init_dup(file); 1642 init_dup(file); 1643 fput(file); 1644 } 1645 1646 static noinline void __init kernel_init_freeable(void) 1647 { 1648 /* Now the scheduler is fully set up and can do blocking allocations */ 1649 gfp_allowed_mask = __GFP_BITS_MASK; 1650 1651 /* 1652 * init can allocate pages on any node 1653 */ 1654 set_mems_allowed(node_states[N_MEMORY]); 1655 1656 rcu_assign_pointer(cad_pid, get_pid(task_pid(current))); 1657 1658 smp_prepare_cpus(setup_max_cpus); 1659 1660 workqueue_init(); 1661 1662 init_mm_internals(); 1663 1664 do_pre_smp_initcalls(); 1665 lockup_detector_init(); 1666 1667 smp_init(); 1668 sched_init_smp(); 1669 1670 workqueue_init_topology(); 1671 async_init(); 1672 padata_init(); 1673 page_alloc_init_late(); 1674 1675 do_basic_setup(); 1676 1677 kunit_run_all_tests(); 1678 1679 wait_for_initramfs(); 1680 console_on_rootfs(); 1681 1682 /* 1683 * check if there is an early userspace init. If yes, let it do all 1684 * the work 1685 */ 1686 int ramdisk_command_access; 1687 ramdisk_command_access = init_eaccess(ramdisk_execute_command); 1688 if (ramdisk_command_access != 0) { 1689 if (ramdisk_execute_command_set) 1690 pr_warn("check access for rdinit=%s failed: %i, ignoring\n", 1691 ramdisk_execute_command, ramdisk_command_access); 1692 ramdisk_execute_command = NULL; 1693 prepare_namespace(); 1694 } 1695 1696 /* 1697 * Ok, we have completed the initial bootup, and 1698 * we're essentially up and running. Get rid of the 1699 * initmem segments and start the user-mode stuff.. 1700 * 1701 * rootfs is available now, try loading the public keys 1702 * and default modules 1703 */ 1704 1705 integrity_load_keys(); 1706 } 1707