1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/init/main.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * GK 2/5/95 - Changed to support mounting root fs via NFS 8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 10 * Simplified starting of init: Michael A. Griffith <grif@acm.org> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/extable.h> 17 #include <linux/module.h> 18 #include <linux/proc_fs.h> 19 #include <linux/binfmts.h> 20 #include <linux/kernel.h> 21 #include <linux/syscalls.h> 22 #include <linux/stackprotector.h> 23 #include <linux/string.h> 24 #include <linux/ctype.h> 25 #include <linux/delay.h> 26 #include <linux/ioport.h> 27 #include <linux/init.h> 28 #include <linux/initrd.h> 29 #include <linux/memblock.h> 30 #include <linux/acpi.h> 31 #include <linux/console.h> 32 #include <linux/nmi.h> 33 #include <linux/percpu.h> 34 #include <linux/kmod.h> 35 #include <linux/vmalloc.h> 36 #include <linux/kernel_stat.h> 37 #include <linux/start_kernel.h> 38 #include <linux/security.h> 39 #include <linux/smp.h> 40 #include <linux/profile.h> 41 #include <linux/rcupdate.h> 42 #include <linux/moduleparam.h> 43 #include <linux/kallsyms.h> 44 #include <linux/writeback.h> 45 #include <linux/cpu.h> 46 #include <linux/cpuset.h> 47 #include <linux/cgroup.h> 48 #include <linux/efi.h> 49 #include <linux/tick.h> 50 #include <linux/sched/isolation.h> 51 #include <linux/interrupt.h> 52 #include <linux/taskstats_kern.h> 53 #include <linux/delayacct.h> 54 #include <linux/unistd.h> 55 #include <linux/utsname.h> 56 #include <linux/rmap.h> 57 #include <linux/mempolicy.h> 58 #include <linux/key.h> 59 #include <linux/buffer_head.h> 60 #include <linux/page_ext.h> 61 #include <linux/debug_locks.h> 62 #include <linux/debugobjects.h> 63 #include <linux/lockdep.h> 64 #include <linux/kmemleak.h> 65 #include <linux/pid_namespace.h> 66 #include <linux/device.h> 67 #include <linux/kthread.h> 68 #include <linux/sched.h> 69 #include <linux/sched/init.h> 70 #include <linux/signal.h> 71 #include <linux/idr.h> 72 #include <linux/kgdb.h> 73 #include <linux/ftrace.h> 74 #include <linux/async.h> 75 #include <linux/sfi.h> 76 #include <linux/shmem_fs.h> 77 #include <linux/slab.h> 78 #include <linux/perf_event.h> 79 #include <linux/ptrace.h> 80 #include <linux/pti.h> 81 #include <linux/blkdev.h> 82 #include <linux/elevator.h> 83 #include <linux/sched/clock.h> 84 #include <linux/sched/task.h> 85 #include <linux/sched/task_stack.h> 86 #include <linux/context_tracking.h> 87 #include <linux/random.h> 88 #include <linux/list.h> 89 #include <linux/integrity.h> 90 #include <linux/proc_ns.h> 91 #include <linux/io.h> 92 #include <linux/cache.h> 93 #include <linux/rodata_test.h> 94 #include <linux/jump_label.h> 95 #include <linux/mem_encrypt.h> 96 97 #include <asm/io.h> 98 #include <asm/bugs.h> 99 #include <asm/setup.h> 100 #include <asm/sections.h> 101 #include <asm/cacheflush.h> 102 103 #define CREATE_TRACE_POINTS 104 #include <trace/events/initcall.h> 105 106 static int kernel_init(void *); 107 108 extern void init_IRQ(void); 109 extern void radix_tree_init(void); 110 111 /* 112 * Debug helper: via this flag we know that we are in 'early bootup code' 113 * where only the boot processor is running with IRQ disabled. This means 114 * two things - IRQ must not be enabled before the flag is cleared and some 115 * operations which are not allowed with IRQ disabled are allowed while the 116 * flag is set. 117 */ 118 bool early_boot_irqs_disabled __read_mostly; 119 120 enum system_states system_state __read_mostly; 121 EXPORT_SYMBOL(system_state); 122 123 /* 124 * Boot command-line arguments 125 */ 126 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 127 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 128 129 extern void time_init(void); 130 /* Default late time init is NULL. archs can override this later. */ 131 void (*__initdata late_time_init)(void); 132 133 /* Untouched command line saved by arch-specific code. */ 134 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 135 /* Untouched saved command line (eg. for /proc) */ 136 char *saved_command_line; 137 /* Command line for parameter parsing */ 138 static char *static_command_line; 139 /* Command line for per-initcall parameter parsing */ 140 static char *initcall_command_line; 141 142 static char *execute_command; 143 static char *ramdisk_execute_command; 144 145 /* 146 * Used to generate warnings if static_key manipulation functions are used 147 * before jump_label_init is called. 148 */ 149 bool static_key_initialized __read_mostly; 150 EXPORT_SYMBOL_GPL(static_key_initialized); 151 152 /* 153 * If set, this is an indication to the drivers that reset the underlying 154 * device before going ahead with the initialization otherwise driver might 155 * rely on the BIOS and skip the reset operation. 156 * 157 * This is useful if kernel is booting in an unreliable environment. 158 * For ex. kdump situation where previous kernel has crashed, BIOS has been 159 * skipped and devices will be in unknown state. 160 */ 161 unsigned int reset_devices; 162 EXPORT_SYMBOL(reset_devices); 163 164 static int __init set_reset_devices(char *str) 165 { 166 reset_devices = 1; 167 return 1; 168 } 169 170 __setup("reset_devices", set_reset_devices); 171 172 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 173 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 174 static const char *panic_later, *panic_param; 175 176 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 177 178 static bool __init obsolete_checksetup(char *line) 179 { 180 const struct obs_kernel_param *p; 181 bool had_early_param = false; 182 183 p = __setup_start; 184 do { 185 int n = strlen(p->str); 186 if (parameqn(line, p->str, n)) { 187 if (p->early) { 188 /* Already done in parse_early_param? 189 * (Needs exact match on param part). 190 * Keep iterating, as we can have early 191 * params and __setups of same names 8( */ 192 if (line[n] == '\0' || line[n] == '=') 193 had_early_param = true; 194 } else if (!p->setup_func) { 195 pr_warn("Parameter %s is obsolete, ignored\n", 196 p->str); 197 return true; 198 } else if (p->setup_func(line + n)) 199 return true; 200 } 201 p++; 202 } while (p < __setup_end); 203 204 return had_early_param; 205 } 206 207 /* 208 * This should be approx 2 Bo*oMips to start (note initial shift), and will 209 * still work even if initially too large, it will just take slightly longer 210 */ 211 unsigned long loops_per_jiffy = (1<<12); 212 EXPORT_SYMBOL(loops_per_jiffy); 213 214 static int __init debug_kernel(char *str) 215 { 216 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 217 return 0; 218 } 219 220 static int __init quiet_kernel(char *str) 221 { 222 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 223 return 0; 224 } 225 226 early_param("debug", debug_kernel); 227 early_param("quiet", quiet_kernel); 228 229 static int __init loglevel(char *str) 230 { 231 int newlevel; 232 233 /* 234 * Only update loglevel value when a correct setting was passed, 235 * to prevent blind crashes (when loglevel being set to 0) that 236 * are quite hard to debug 237 */ 238 if (get_option(&str, &newlevel)) { 239 console_loglevel = newlevel; 240 return 0; 241 } 242 243 return -EINVAL; 244 } 245 246 early_param("loglevel", loglevel); 247 248 /* Change NUL term back to "=", to make "param" the whole string. */ 249 static int __init repair_env_string(char *param, char *val, 250 const char *unused, void *arg) 251 { 252 if (val) { 253 /* param=val or param="val"? */ 254 if (val == param+strlen(param)+1) 255 val[-1] = '='; 256 else if (val == param+strlen(param)+2) { 257 val[-2] = '='; 258 memmove(val-1, val, strlen(val)+1); 259 val--; 260 } else 261 BUG(); 262 } 263 return 0; 264 } 265 266 /* Anything after -- gets handed straight to init. */ 267 static int __init set_init_arg(char *param, char *val, 268 const char *unused, void *arg) 269 { 270 unsigned int i; 271 272 if (panic_later) 273 return 0; 274 275 repair_env_string(param, val, unused, NULL); 276 277 for (i = 0; argv_init[i]; i++) { 278 if (i == MAX_INIT_ARGS) { 279 panic_later = "init"; 280 panic_param = param; 281 return 0; 282 } 283 } 284 argv_init[i] = param; 285 return 0; 286 } 287 288 /* 289 * Unknown boot options get handed to init, unless they look like 290 * unused parameters (modprobe will find them in /proc/cmdline). 291 */ 292 static int __init unknown_bootoption(char *param, char *val, 293 const char *unused, void *arg) 294 { 295 repair_env_string(param, val, unused, NULL); 296 297 /* Handle obsolete-style parameters */ 298 if (obsolete_checksetup(param)) 299 return 0; 300 301 /* Unused module parameter. */ 302 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 303 return 0; 304 305 if (panic_later) 306 return 0; 307 308 if (val) { 309 /* Environment option */ 310 unsigned int i; 311 for (i = 0; envp_init[i]; i++) { 312 if (i == MAX_INIT_ENVS) { 313 panic_later = "env"; 314 panic_param = param; 315 } 316 if (!strncmp(param, envp_init[i], val - param)) 317 break; 318 } 319 envp_init[i] = param; 320 } else { 321 /* Command line option */ 322 unsigned int i; 323 for (i = 0; argv_init[i]; i++) { 324 if (i == MAX_INIT_ARGS) { 325 panic_later = "init"; 326 panic_param = param; 327 } 328 } 329 argv_init[i] = param; 330 } 331 return 0; 332 } 333 334 static int __init init_setup(char *str) 335 { 336 unsigned int i; 337 338 execute_command = str; 339 /* 340 * In case LILO is going to boot us with default command line, 341 * it prepends "auto" before the whole cmdline which makes 342 * the shell think it should execute a script with such name. 343 * So we ignore all arguments entered _before_ init=... [MJ] 344 */ 345 for (i = 1; i < MAX_INIT_ARGS; i++) 346 argv_init[i] = NULL; 347 return 1; 348 } 349 __setup("init=", init_setup); 350 351 static int __init rdinit_setup(char *str) 352 { 353 unsigned int i; 354 355 ramdisk_execute_command = str; 356 /* See "auto" comment in init_setup */ 357 for (i = 1; i < MAX_INIT_ARGS; i++) 358 argv_init[i] = NULL; 359 return 1; 360 } 361 __setup("rdinit=", rdinit_setup); 362 363 #ifndef CONFIG_SMP 364 static const unsigned int setup_max_cpus = NR_CPUS; 365 static inline void setup_nr_cpu_ids(void) { } 366 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 367 #endif 368 369 /* 370 * We need to store the untouched command line for future reference. 371 * We also need to store the touched command line since the parameter 372 * parsing is performed in place, and we should allow a component to 373 * store reference of name/value for future reference. 374 */ 375 static void __init setup_command_line(char *command_line) 376 { 377 size_t len = strlen(boot_command_line) + 1; 378 379 saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 380 if (!saved_command_line) 381 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 382 383 initcall_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 384 if (!initcall_command_line) 385 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 386 387 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 388 if (!static_command_line) 389 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 390 391 strcpy(saved_command_line, boot_command_line); 392 strcpy(static_command_line, command_line); 393 } 394 395 /* 396 * We need to finalize in a non-__init function or else race conditions 397 * between the root thread and the init thread may cause start_kernel to 398 * be reaped by free_initmem before the root thread has proceeded to 399 * cpu_idle. 400 * 401 * gcc-3.4 accidentally inlines this function, so use noinline. 402 */ 403 404 static __initdata DECLARE_COMPLETION(kthreadd_done); 405 406 noinline void __ref rest_init(void) 407 { 408 struct task_struct *tsk; 409 int pid; 410 411 rcu_scheduler_starting(); 412 /* 413 * We need to spawn init first so that it obtains pid 1, however 414 * the init task will end up wanting to create kthreads, which, if 415 * we schedule it before we create kthreadd, will OOPS. 416 */ 417 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 418 /* 419 * Pin init on the boot CPU. Task migration is not properly working 420 * until sched_init_smp() has been run. It will set the allowed 421 * CPUs for init to the non isolated CPUs. 422 */ 423 rcu_read_lock(); 424 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 425 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 426 rcu_read_unlock(); 427 428 numa_default_policy(); 429 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 430 rcu_read_lock(); 431 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 432 rcu_read_unlock(); 433 434 /* 435 * Enable might_sleep() and smp_processor_id() checks. 436 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 437 * kernel_thread() would trigger might_sleep() splats. With 438 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 439 * already, but it's stuck on the kthreadd_done completion. 440 */ 441 system_state = SYSTEM_SCHEDULING; 442 443 complete(&kthreadd_done); 444 445 /* 446 * The boot idle thread must execute schedule() 447 * at least once to get things moving: 448 */ 449 schedule_preempt_disabled(); 450 /* Call into cpu_idle with preempt disabled */ 451 cpu_startup_entry(CPUHP_ONLINE); 452 } 453 454 /* Check for early params. */ 455 static int __init do_early_param(char *param, char *val, 456 const char *unused, void *arg) 457 { 458 const struct obs_kernel_param *p; 459 460 for (p = __setup_start; p < __setup_end; p++) { 461 if ((p->early && parameq(param, p->str)) || 462 (strcmp(param, "console") == 0 && 463 strcmp(p->str, "earlycon") == 0) 464 ) { 465 if (p->setup_func(val) != 0) 466 pr_warn("Malformed early option '%s'\n", param); 467 } 468 } 469 /* We accept everything at this stage. */ 470 return 0; 471 } 472 473 void __init parse_early_options(char *cmdline) 474 { 475 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 476 do_early_param); 477 } 478 479 /* Arch code calls this early on, or if not, just before other parsing. */ 480 void __init parse_early_param(void) 481 { 482 static int done __initdata; 483 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 484 485 if (done) 486 return; 487 488 /* All fall through to do_early_param. */ 489 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 490 parse_early_options(tmp_cmdline); 491 done = 1; 492 } 493 494 void __init __weak arch_post_acpi_subsys_init(void) { } 495 496 void __init __weak smp_setup_processor_id(void) 497 { 498 } 499 500 # if THREAD_SIZE >= PAGE_SIZE 501 void __init __weak thread_stack_cache_init(void) 502 { 503 } 504 #endif 505 506 void __init __weak mem_encrypt_init(void) { } 507 508 void __init __weak poking_init(void) { } 509 510 void __init __weak pgtable_cache_init(void) { } 511 512 bool initcall_debug; 513 core_param(initcall_debug, initcall_debug, bool, 0644); 514 515 #ifdef TRACEPOINTS_ENABLED 516 static void __init initcall_debug_enable(void); 517 #else 518 static inline void initcall_debug_enable(void) 519 { 520 } 521 #endif 522 523 /* Report memory auto-initialization states for this boot. */ 524 static void __init report_meminit(void) 525 { 526 const char *stack; 527 528 if (IS_ENABLED(CONFIG_INIT_STACK_ALL)) 529 stack = "all"; 530 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) 531 stack = "byref_all"; 532 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) 533 stack = "byref"; 534 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) 535 stack = "__user"; 536 else 537 stack = "off"; 538 539 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", 540 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", 541 want_init_on_free() ? "on" : "off"); 542 if (want_init_on_free()) 543 pr_info("mem auto-init: clearing system memory may take some time...\n"); 544 } 545 546 /* 547 * Set up kernel memory allocators 548 */ 549 static void __init mm_init(void) 550 { 551 /* 552 * page_ext requires contiguous pages, 553 * bigger than MAX_ORDER unless SPARSEMEM. 554 */ 555 page_ext_init_flatmem(); 556 report_meminit(); 557 mem_init(); 558 kmem_cache_init(); 559 kmemleak_init(); 560 pgtable_init(); 561 debug_objects_mem_init(); 562 vmalloc_init(); 563 ioremap_huge_init(); 564 /* Should be run before the first non-init thread is created */ 565 init_espfix_bsp(); 566 /* Should be run after espfix64 is set up. */ 567 pti_init(); 568 } 569 570 void __init __weak arch_call_rest_init(void) 571 { 572 rest_init(); 573 } 574 575 asmlinkage __visible void __init start_kernel(void) 576 { 577 char *command_line; 578 char *after_dashes; 579 580 set_task_stack_end_magic(&init_task); 581 smp_setup_processor_id(); 582 debug_objects_early_init(); 583 584 cgroup_init_early(); 585 586 local_irq_disable(); 587 early_boot_irqs_disabled = true; 588 589 /* 590 * Interrupts are still disabled. Do necessary setups, then 591 * enable them. 592 */ 593 boot_cpu_init(); 594 page_address_init(); 595 pr_notice("%s", linux_banner); 596 early_security_init(); 597 setup_arch(&command_line); 598 setup_command_line(command_line); 599 setup_nr_cpu_ids(); 600 setup_per_cpu_areas(); 601 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 602 boot_cpu_hotplug_init(); 603 604 build_all_zonelists(NULL); 605 page_alloc_init(); 606 607 pr_notice("Kernel command line: %s\n", boot_command_line); 608 /* parameters may set static keys */ 609 jump_label_init(); 610 parse_early_param(); 611 after_dashes = parse_args("Booting kernel", 612 static_command_line, __start___param, 613 __stop___param - __start___param, 614 -1, -1, NULL, &unknown_bootoption); 615 if (!IS_ERR_OR_NULL(after_dashes)) 616 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 617 NULL, set_init_arg); 618 619 /* 620 * These use large bootmem allocations and must precede 621 * kmem_cache_init() 622 */ 623 setup_log_buf(0); 624 vfs_caches_init_early(); 625 sort_main_extable(); 626 trap_init(); 627 mm_init(); 628 629 ftrace_init(); 630 631 /* trace_printk can be enabled here */ 632 early_trace_init(); 633 634 /* 635 * Set up the scheduler prior starting any interrupts (such as the 636 * timer interrupt). Full topology setup happens at smp_init() 637 * time - but meanwhile we still have a functioning scheduler. 638 */ 639 sched_init(); 640 /* 641 * Disable preemption - early bootup scheduling is extremely 642 * fragile until we cpu_idle() for the first time. 643 */ 644 preempt_disable(); 645 if (WARN(!irqs_disabled(), 646 "Interrupts were enabled *very* early, fixing it\n")) 647 local_irq_disable(); 648 radix_tree_init(); 649 650 /* 651 * Set up housekeeping before setting up workqueues to allow the unbound 652 * workqueue to take non-housekeeping into account. 653 */ 654 housekeeping_init(); 655 656 /* 657 * Allow workqueue creation and work item queueing/cancelling 658 * early. Work item execution depends on kthreads and starts after 659 * workqueue_init(). 660 */ 661 workqueue_init_early(); 662 663 rcu_init(); 664 665 /* Trace events are available after this */ 666 trace_init(); 667 668 if (initcall_debug) 669 initcall_debug_enable(); 670 671 context_tracking_init(); 672 /* init some links before init_ISA_irqs() */ 673 early_irq_init(); 674 init_IRQ(); 675 tick_init(); 676 rcu_init_nohz(); 677 init_timers(); 678 hrtimers_init(); 679 softirq_init(); 680 timekeeping_init(); 681 682 /* 683 * For best initial stack canary entropy, prepare it after: 684 * - setup_arch() for any UEFI RNG entropy and boot cmdline access 685 * - timekeeping_init() for ktime entropy used in rand_initialize() 686 * - rand_initialize() to get any arch-specific entropy like RDRAND 687 * - add_latent_entropy() to get any latent entropy 688 * - adding command line entropy 689 */ 690 rand_initialize(); 691 add_latent_entropy(); 692 add_device_randomness(command_line, strlen(command_line)); 693 boot_init_stack_canary(); 694 695 time_init(); 696 printk_safe_init(); 697 perf_event_init(); 698 profile_init(); 699 call_function_init(); 700 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 701 702 early_boot_irqs_disabled = false; 703 local_irq_enable(); 704 705 kmem_cache_init_late(); 706 707 /* 708 * HACK ALERT! This is early. We're enabling the console before 709 * we've done PCI setups etc, and console_init() must be aware of 710 * this. But we do want output early, in case something goes wrong. 711 */ 712 console_init(); 713 if (panic_later) 714 panic("Too many boot %s vars at `%s'", panic_later, 715 panic_param); 716 717 lockdep_init(); 718 719 /* 720 * Need to run this when irqs are enabled, because it wants 721 * to self-test [hard/soft]-irqs on/off lock inversion bugs 722 * too: 723 */ 724 locking_selftest(); 725 726 /* 727 * This needs to be called before any devices perform DMA 728 * operations that might use the SWIOTLB bounce buffers. It will 729 * mark the bounce buffers as decrypted so that their usage will 730 * not cause "plain-text" data to be decrypted when accessed. 731 */ 732 mem_encrypt_init(); 733 734 #ifdef CONFIG_BLK_DEV_INITRD 735 if (initrd_start && !initrd_below_start_ok && 736 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 737 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 738 page_to_pfn(virt_to_page((void *)initrd_start)), 739 min_low_pfn); 740 initrd_start = 0; 741 } 742 #endif 743 setup_per_cpu_pageset(); 744 numa_policy_init(); 745 acpi_early_init(); 746 if (late_time_init) 747 late_time_init(); 748 sched_clock_init(); 749 calibrate_delay(); 750 pid_idr_init(); 751 anon_vma_init(); 752 #ifdef CONFIG_X86 753 if (efi_enabled(EFI_RUNTIME_SERVICES)) 754 efi_enter_virtual_mode(); 755 #endif 756 thread_stack_cache_init(); 757 cred_init(); 758 fork_init(); 759 proc_caches_init(); 760 uts_ns_init(); 761 buffer_init(); 762 key_init(); 763 security_init(); 764 dbg_late_init(); 765 vfs_caches_init(); 766 pagecache_init(); 767 signals_init(); 768 seq_file_init(); 769 proc_root_init(); 770 nsfs_init(); 771 cpuset_init(); 772 cgroup_init(); 773 taskstats_init_early(); 774 delayacct_init(); 775 776 poking_init(); 777 check_bugs(); 778 779 acpi_subsystem_init(); 780 arch_post_acpi_subsys_init(); 781 sfi_init_late(); 782 783 /* Do the rest non-__init'ed, we're now alive */ 784 arch_call_rest_init(); 785 } 786 787 /* Call all constructor functions linked into the kernel. */ 788 static void __init do_ctors(void) 789 { 790 #ifdef CONFIG_CONSTRUCTORS 791 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 792 793 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 794 (*fn)(); 795 #endif 796 } 797 798 #ifdef CONFIG_KALLSYMS 799 struct blacklist_entry { 800 struct list_head next; 801 char *buf; 802 }; 803 804 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 805 806 static int __init initcall_blacklist(char *str) 807 { 808 char *str_entry; 809 struct blacklist_entry *entry; 810 811 /* str argument is a comma-separated list of functions */ 812 do { 813 str_entry = strsep(&str, ","); 814 if (str_entry) { 815 pr_debug("blacklisting initcall %s\n", str_entry); 816 entry = memblock_alloc(sizeof(*entry), 817 SMP_CACHE_BYTES); 818 if (!entry) 819 panic("%s: Failed to allocate %zu bytes\n", 820 __func__, sizeof(*entry)); 821 entry->buf = memblock_alloc(strlen(str_entry) + 1, 822 SMP_CACHE_BYTES); 823 if (!entry->buf) 824 panic("%s: Failed to allocate %zu bytes\n", 825 __func__, strlen(str_entry) + 1); 826 strcpy(entry->buf, str_entry); 827 list_add(&entry->next, &blacklisted_initcalls); 828 } 829 } while (str_entry); 830 831 return 0; 832 } 833 834 static bool __init_or_module initcall_blacklisted(initcall_t fn) 835 { 836 struct blacklist_entry *entry; 837 char fn_name[KSYM_SYMBOL_LEN]; 838 unsigned long addr; 839 840 if (list_empty(&blacklisted_initcalls)) 841 return false; 842 843 addr = (unsigned long) dereference_function_descriptor(fn); 844 sprint_symbol_no_offset(fn_name, addr); 845 846 /* 847 * fn will be "function_name [module_name]" where [module_name] is not 848 * displayed for built-in init functions. Strip off the [module_name]. 849 */ 850 strreplace(fn_name, ' ', '\0'); 851 852 list_for_each_entry(entry, &blacklisted_initcalls, next) { 853 if (!strcmp(fn_name, entry->buf)) { 854 pr_debug("initcall %s blacklisted\n", fn_name); 855 return true; 856 } 857 } 858 859 return false; 860 } 861 #else 862 static int __init initcall_blacklist(char *str) 863 { 864 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 865 return 0; 866 } 867 868 static bool __init_or_module initcall_blacklisted(initcall_t fn) 869 { 870 return false; 871 } 872 #endif 873 __setup("initcall_blacklist=", initcall_blacklist); 874 875 static __init_or_module void 876 trace_initcall_start_cb(void *data, initcall_t fn) 877 { 878 ktime_t *calltime = (ktime_t *)data; 879 880 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 881 *calltime = ktime_get(); 882 } 883 884 static __init_or_module void 885 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 886 { 887 ktime_t *calltime = (ktime_t *)data; 888 ktime_t delta, rettime; 889 unsigned long long duration; 890 891 rettime = ktime_get(); 892 delta = ktime_sub(rettime, *calltime); 893 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 894 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 895 fn, ret, duration); 896 } 897 898 static ktime_t initcall_calltime; 899 900 #ifdef TRACEPOINTS_ENABLED 901 static void __init initcall_debug_enable(void) 902 { 903 int ret; 904 905 ret = register_trace_initcall_start(trace_initcall_start_cb, 906 &initcall_calltime); 907 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 908 &initcall_calltime); 909 WARN(ret, "Failed to register initcall tracepoints\n"); 910 } 911 # define do_trace_initcall_start trace_initcall_start 912 # define do_trace_initcall_finish trace_initcall_finish 913 #else 914 static inline void do_trace_initcall_start(initcall_t fn) 915 { 916 if (!initcall_debug) 917 return; 918 trace_initcall_start_cb(&initcall_calltime, fn); 919 } 920 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 921 { 922 if (!initcall_debug) 923 return; 924 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 925 } 926 #endif /* !TRACEPOINTS_ENABLED */ 927 928 int __init_or_module do_one_initcall(initcall_t fn) 929 { 930 int count = preempt_count(); 931 char msgbuf[64]; 932 int ret; 933 934 if (initcall_blacklisted(fn)) 935 return -EPERM; 936 937 do_trace_initcall_start(fn); 938 ret = fn(); 939 do_trace_initcall_finish(fn, ret); 940 941 msgbuf[0] = 0; 942 943 if (preempt_count() != count) { 944 sprintf(msgbuf, "preemption imbalance "); 945 preempt_count_set(count); 946 } 947 if (irqs_disabled()) { 948 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 949 local_irq_enable(); 950 } 951 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 952 953 add_latent_entropy(); 954 return ret; 955 } 956 957 958 extern initcall_entry_t __initcall_start[]; 959 extern initcall_entry_t __initcall0_start[]; 960 extern initcall_entry_t __initcall1_start[]; 961 extern initcall_entry_t __initcall2_start[]; 962 extern initcall_entry_t __initcall3_start[]; 963 extern initcall_entry_t __initcall4_start[]; 964 extern initcall_entry_t __initcall5_start[]; 965 extern initcall_entry_t __initcall6_start[]; 966 extern initcall_entry_t __initcall7_start[]; 967 extern initcall_entry_t __initcall_end[]; 968 969 static initcall_entry_t *initcall_levels[] __initdata = { 970 __initcall0_start, 971 __initcall1_start, 972 __initcall2_start, 973 __initcall3_start, 974 __initcall4_start, 975 __initcall5_start, 976 __initcall6_start, 977 __initcall7_start, 978 __initcall_end, 979 }; 980 981 /* Keep these in sync with initcalls in include/linux/init.h */ 982 static const char *initcall_level_names[] __initdata = { 983 "pure", 984 "core", 985 "postcore", 986 "arch", 987 "subsys", 988 "fs", 989 "device", 990 "late", 991 }; 992 993 static void __init do_initcall_level(int level) 994 { 995 initcall_entry_t *fn; 996 997 strcpy(initcall_command_line, saved_command_line); 998 parse_args(initcall_level_names[level], 999 initcall_command_line, __start___param, 1000 __stop___param - __start___param, 1001 level, level, 1002 NULL, &repair_env_string); 1003 1004 trace_initcall_level(initcall_level_names[level]); 1005 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1006 do_one_initcall(initcall_from_entry(fn)); 1007 } 1008 1009 static void __init do_initcalls(void) 1010 { 1011 int level; 1012 1013 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) 1014 do_initcall_level(level); 1015 } 1016 1017 /* 1018 * Ok, the machine is now initialized. None of the devices 1019 * have been touched yet, but the CPU subsystem is up and 1020 * running, and memory and process management works. 1021 * 1022 * Now we can finally start doing some real work.. 1023 */ 1024 static void __init do_basic_setup(void) 1025 { 1026 cpuset_init_smp(); 1027 driver_init(); 1028 init_irq_proc(); 1029 do_ctors(); 1030 usermodehelper_enable(); 1031 do_initcalls(); 1032 } 1033 1034 static void __init do_pre_smp_initcalls(void) 1035 { 1036 initcall_entry_t *fn; 1037 1038 trace_initcall_level("early"); 1039 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1040 do_one_initcall(initcall_from_entry(fn)); 1041 } 1042 1043 static int run_init_process(const char *init_filename) 1044 { 1045 argv_init[0] = init_filename; 1046 pr_info("Run %s as init process\n", init_filename); 1047 return do_execve(getname_kernel(init_filename), 1048 (const char __user *const __user *)argv_init, 1049 (const char __user *const __user *)envp_init); 1050 } 1051 1052 static int try_to_run_init_process(const char *init_filename) 1053 { 1054 int ret; 1055 1056 ret = run_init_process(init_filename); 1057 1058 if (ret && ret != -ENOENT) { 1059 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1060 init_filename, ret); 1061 } 1062 1063 return ret; 1064 } 1065 1066 static noinline void __init kernel_init_freeable(void); 1067 1068 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1069 bool rodata_enabled __ro_after_init = true; 1070 static int __init set_debug_rodata(char *str) 1071 { 1072 return strtobool(str, &rodata_enabled); 1073 } 1074 __setup("rodata=", set_debug_rodata); 1075 #endif 1076 1077 #ifdef CONFIG_STRICT_KERNEL_RWX 1078 static void mark_readonly(void) 1079 { 1080 if (rodata_enabled) { 1081 /* 1082 * load_module() results in W+X mappings, which are cleaned 1083 * up with call_rcu(). Let's make sure that queued work is 1084 * flushed so that we don't hit false positives looking for 1085 * insecure pages which are W+X. 1086 */ 1087 rcu_barrier(); 1088 mark_rodata_ro(); 1089 rodata_test(); 1090 } else 1091 pr_info("Kernel memory protection disabled.\n"); 1092 } 1093 #else 1094 static inline void mark_readonly(void) 1095 { 1096 pr_warn("This architecture does not have kernel memory protection.\n"); 1097 } 1098 #endif 1099 1100 void __weak free_initmem(void) 1101 { 1102 free_initmem_default(POISON_FREE_INITMEM); 1103 } 1104 1105 static int __ref kernel_init(void *unused) 1106 { 1107 int ret; 1108 1109 kernel_init_freeable(); 1110 /* need to finish all async __init code before freeing the memory */ 1111 async_synchronize_full(); 1112 ftrace_free_init_mem(); 1113 free_initmem(); 1114 mark_readonly(); 1115 1116 /* 1117 * Kernel mappings are now finalized - update the userspace page-table 1118 * to finalize PTI. 1119 */ 1120 pti_finalize(); 1121 1122 system_state = SYSTEM_RUNNING; 1123 numa_default_policy(); 1124 1125 rcu_end_inkernel_boot(); 1126 1127 if (ramdisk_execute_command) { 1128 ret = run_init_process(ramdisk_execute_command); 1129 if (!ret) 1130 return 0; 1131 pr_err("Failed to execute %s (error %d)\n", 1132 ramdisk_execute_command, ret); 1133 } 1134 1135 /* 1136 * We try each of these until one succeeds. 1137 * 1138 * The Bourne shell can be used instead of init if we are 1139 * trying to recover a really broken machine. 1140 */ 1141 if (execute_command) { 1142 ret = run_init_process(execute_command); 1143 if (!ret) 1144 return 0; 1145 panic("Requested init %s failed (error %d).", 1146 execute_command, ret); 1147 } 1148 if (!try_to_run_init_process("/sbin/init") || 1149 !try_to_run_init_process("/etc/init") || 1150 !try_to_run_init_process("/bin/init") || 1151 !try_to_run_init_process("/bin/sh")) 1152 return 0; 1153 1154 panic("No working init found. Try passing init= option to kernel. " 1155 "See Linux Documentation/admin-guide/init.rst for guidance."); 1156 } 1157 1158 void console_on_rootfs(void) 1159 { 1160 /* Open the /dev/console as stdin, this should never fail */ 1161 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 1162 pr_err("Warning: unable to open an initial console.\n"); 1163 1164 /* create stdout/stderr */ 1165 (void) ksys_dup(0); 1166 (void) ksys_dup(0); 1167 } 1168 1169 static noinline void __init kernel_init_freeable(void) 1170 { 1171 /* 1172 * Wait until kthreadd is all set-up. 1173 */ 1174 wait_for_completion(&kthreadd_done); 1175 1176 /* Now the scheduler is fully set up and can do blocking allocations */ 1177 gfp_allowed_mask = __GFP_BITS_MASK; 1178 1179 /* 1180 * init can allocate pages on any node 1181 */ 1182 set_mems_allowed(node_states[N_MEMORY]); 1183 1184 cad_pid = task_pid(current); 1185 1186 smp_prepare_cpus(setup_max_cpus); 1187 1188 workqueue_init(); 1189 1190 init_mm_internals(); 1191 1192 do_pre_smp_initcalls(); 1193 lockup_detector_init(); 1194 1195 smp_init(); 1196 sched_init_smp(); 1197 1198 page_alloc_init_late(); 1199 /* Initialize page ext after all struct pages are initialized. */ 1200 page_ext_init(); 1201 1202 do_basic_setup(); 1203 1204 console_on_rootfs(); 1205 1206 /* 1207 * check if there is an early userspace init. If yes, let it do all 1208 * the work 1209 */ 1210 1211 if (!ramdisk_execute_command) 1212 ramdisk_execute_command = "/init"; 1213 1214 if (ksys_access((const char __user *) 1215 ramdisk_execute_command, 0) != 0) { 1216 ramdisk_execute_command = NULL; 1217 prepare_namespace(); 1218 } 1219 1220 /* 1221 * Ok, we have completed the initial bootup, and 1222 * we're essentially up and running. Get rid of the 1223 * initmem segments and start the user-mode stuff.. 1224 * 1225 * rootfs is available now, try loading the public keys 1226 * and default modules 1227 */ 1228 1229 integrity_load_keys(); 1230 } 1231