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