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 fork_init(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 saved_command_line = 378 memblock_alloc(strlen(boot_command_line) + 1, SMP_CACHE_BYTES); 379 initcall_command_line = 380 memblock_alloc(strlen(boot_command_line) + 1, SMP_CACHE_BYTES); 381 static_command_line = memblock_alloc(strlen(command_line) + 1, 382 SMP_CACHE_BYTES); 383 strcpy(saved_command_line, boot_command_line); 384 strcpy(static_command_line, command_line); 385 } 386 387 /* 388 * We need to finalize in a non-__init function or else race conditions 389 * between the root thread and the init thread may cause start_kernel to 390 * be reaped by free_initmem before the root thread has proceeded to 391 * cpu_idle. 392 * 393 * gcc-3.4 accidentally inlines this function, so use noinline. 394 */ 395 396 static __initdata DECLARE_COMPLETION(kthreadd_done); 397 398 noinline void __ref rest_init(void) 399 { 400 struct task_struct *tsk; 401 int pid; 402 403 rcu_scheduler_starting(); 404 /* 405 * We need to spawn init first so that it obtains pid 1, however 406 * the init task will end up wanting to create kthreads, which, if 407 * we schedule it before we create kthreadd, will OOPS. 408 */ 409 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 410 /* 411 * Pin init on the boot CPU. Task migration is not properly working 412 * until sched_init_smp() has been run. It will set the allowed 413 * CPUs for init to the non isolated CPUs. 414 */ 415 rcu_read_lock(); 416 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 417 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 418 rcu_read_unlock(); 419 420 numa_default_policy(); 421 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 422 rcu_read_lock(); 423 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 424 rcu_read_unlock(); 425 426 /* 427 * Enable might_sleep() and smp_processor_id() checks. 428 * They cannot be enabled earlier because with CONFIG_PREEMPT=y 429 * kernel_thread() would trigger might_sleep() splats. With 430 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 431 * already, but it's stuck on the kthreadd_done completion. 432 */ 433 system_state = SYSTEM_SCHEDULING; 434 435 complete(&kthreadd_done); 436 437 /* 438 * The boot idle thread must execute schedule() 439 * at least once to get things moving: 440 */ 441 schedule_preempt_disabled(); 442 /* Call into cpu_idle with preempt disabled */ 443 cpu_startup_entry(CPUHP_ONLINE); 444 } 445 446 /* Check for early params. */ 447 static int __init do_early_param(char *param, char *val, 448 const char *unused, void *arg) 449 { 450 const struct obs_kernel_param *p; 451 452 for (p = __setup_start; p < __setup_end; p++) { 453 if ((p->early && parameq(param, p->str)) || 454 (strcmp(param, "console") == 0 && 455 strcmp(p->str, "earlycon") == 0) 456 ) { 457 if (p->setup_func(val) != 0) 458 pr_warn("Malformed early option '%s'\n", param); 459 } 460 } 461 /* We accept everything at this stage. */ 462 return 0; 463 } 464 465 void __init parse_early_options(char *cmdline) 466 { 467 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 468 do_early_param); 469 } 470 471 /* Arch code calls this early on, or if not, just before other parsing. */ 472 void __init parse_early_param(void) 473 { 474 static int done __initdata; 475 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 476 477 if (done) 478 return; 479 480 /* All fall through to do_early_param. */ 481 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 482 parse_early_options(tmp_cmdline); 483 done = 1; 484 } 485 486 void __init __weak arch_post_acpi_subsys_init(void) { } 487 488 void __init __weak smp_setup_processor_id(void) 489 { 490 } 491 492 # if THREAD_SIZE >= PAGE_SIZE 493 void __init __weak thread_stack_cache_init(void) 494 { 495 } 496 #endif 497 498 void __init __weak mem_encrypt_init(void) { } 499 500 bool initcall_debug; 501 core_param(initcall_debug, initcall_debug, bool, 0644); 502 503 #ifdef TRACEPOINTS_ENABLED 504 static void __init initcall_debug_enable(void); 505 #else 506 static inline void initcall_debug_enable(void) 507 { 508 } 509 #endif 510 511 /* 512 * Set up kernel memory allocators 513 */ 514 static void __init mm_init(void) 515 { 516 /* 517 * page_ext requires contiguous pages, 518 * bigger than MAX_ORDER unless SPARSEMEM. 519 */ 520 page_ext_init_flatmem(); 521 mem_init(); 522 kmem_cache_init(); 523 pgtable_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 page_ext_init(); 699 kmemleak_init(); 700 debug_objects_mem_init(); 701 setup_per_cpu_pageset(); 702 numa_policy_init(); 703 acpi_early_init(); 704 if (late_time_init) 705 late_time_init(); 706 sched_clock_init(); 707 calibrate_delay(); 708 pid_idr_init(); 709 anon_vma_init(); 710 #ifdef CONFIG_X86 711 if (efi_enabled(EFI_RUNTIME_SERVICES)) 712 efi_enter_virtual_mode(); 713 #endif 714 thread_stack_cache_init(); 715 cred_init(); 716 fork_init(); 717 proc_caches_init(); 718 uts_ns_init(); 719 buffer_init(); 720 key_init(); 721 security_init(); 722 dbg_late_init(); 723 vfs_caches_init(); 724 pagecache_init(); 725 signals_init(); 726 seq_file_init(); 727 proc_root_init(); 728 nsfs_init(); 729 cpuset_init(); 730 cgroup_init(); 731 taskstats_init_early(); 732 delayacct_init(); 733 734 check_bugs(); 735 736 acpi_subsystem_init(); 737 arch_post_acpi_subsys_init(); 738 sfi_init_late(); 739 740 /* Do the rest non-__init'ed, we're now alive */ 741 arch_call_rest_init(); 742 } 743 744 /* Call all constructor functions linked into the kernel. */ 745 static void __init do_ctors(void) 746 { 747 #ifdef CONFIG_CONSTRUCTORS 748 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 749 750 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 751 (*fn)(); 752 #endif 753 } 754 755 #ifdef CONFIG_KALLSYMS 756 struct blacklist_entry { 757 struct list_head next; 758 char *buf; 759 }; 760 761 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 762 763 static int __init initcall_blacklist(char *str) 764 { 765 char *str_entry; 766 struct blacklist_entry *entry; 767 768 /* str argument is a comma-separated list of functions */ 769 do { 770 str_entry = strsep(&str, ","); 771 if (str_entry) { 772 pr_debug("blacklisting initcall %s\n", str_entry); 773 entry = memblock_alloc(sizeof(*entry), 774 SMP_CACHE_BYTES); 775 entry->buf = memblock_alloc(strlen(str_entry) + 1, 776 SMP_CACHE_BYTES); 777 strcpy(entry->buf, str_entry); 778 list_add(&entry->next, &blacklisted_initcalls); 779 } 780 } while (str_entry); 781 782 return 0; 783 } 784 785 static bool __init_or_module initcall_blacklisted(initcall_t fn) 786 { 787 struct blacklist_entry *entry; 788 char fn_name[KSYM_SYMBOL_LEN]; 789 unsigned long addr; 790 791 if (list_empty(&blacklisted_initcalls)) 792 return false; 793 794 addr = (unsigned long) dereference_function_descriptor(fn); 795 sprint_symbol_no_offset(fn_name, addr); 796 797 /* 798 * fn will be "function_name [module_name]" where [module_name] is not 799 * displayed for built-in init functions. Strip off the [module_name]. 800 */ 801 strreplace(fn_name, ' ', '\0'); 802 803 list_for_each_entry(entry, &blacklisted_initcalls, next) { 804 if (!strcmp(fn_name, entry->buf)) { 805 pr_debug("initcall %s blacklisted\n", fn_name); 806 return true; 807 } 808 } 809 810 return false; 811 } 812 #else 813 static int __init initcall_blacklist(char *str) 814 { 815 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 816 return 0; 817 } 818 819 static bool __init_or_module initcall_blacklisted(initcall_t fn) 820 { 821 return false; 822 } 823 #endif 824 __setup("initcall_blacklist=", initcall_blacklist); 825 826 static __init_or_module void 827 trace_initcall_start_cb(void *data, initcall_t fn) 828 { 829 ktime_t *calltime = (ktime_t *)data; 830 831 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); 832 *calltime = ktime_get(); 833 } 834 835 static __init_or_module void 836 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 837 { 838 ktime_t *calltime = (ktime_t *)data; 839 ktime_t delta, rettime; 840 unsigned long long duration; 841 842 rettime = ktime_get(); 843 delta = ktime_sub(rettime, *calltime); 844 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 845 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", 846 fn, ret, duration); 847 } 848 849 static ktime_t initcall_calltime; 850 851 #ifdef TRACEPOINTS_ENABLED 852 static void __init initcall_debug_enable(void) 853 { 854 int ret; 855 856 ret = register_trace_initcall_start(trace_initcall_start_cb, 857 &initcall_calltime); 858 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 859 &initcall_calltime); 860 WARN(ret, "Failed to register initcall tracepoints\n"); 861 } 862 # define do_trace_initcall_start trace_initcall_start 863 # define do_trace_initcall_finish trace_initcall_finish 864 #else 865 static inline void do_trace_initcall_start(initcall_t fn) 866 { 867 if (!initcall_debug) 868 return; 869 trace_initcall_start_cb(&initcall_calltime, fn); 870 } 871 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 872 { 873 if (!initcall_debug) 874 return; 875 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 876 } 877 #endif /* !TRACEPOINTS_ENABLED */ 878 879 int __init_or_module do_one_initcall(initcall_t fn) 880 { 881 int count = preempt_count(); 882 char msgbuf[64]; 883 int ret; 884 885 if (initcall_blacklisted(fn)) 886 return -EPERM; 887 888 do_trace_initcall_start(fn); 889 ret = fn(); 890 do_trace_initcall_finish(fn, ret); 891 892 msgbuf[0] = 0; 893 894 if (preempt_count() != count) { 895 sprintf(msgbuf, "preemption imbalance "); 896 preempt_count_set(count); 897 } 898 if (irqs_disabled()) { 899 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 900 local_irq_enable(); 901 } 902 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf); 903 904 add_latent_entropy(); 905 return ret; 906 } 907 908 909 extern initcall_entry_t __initcall_start[]; 910 extern initcall_entry_t __initcall0_start[]; 911 extern initcall_entry_t __initcall1_start[]; 912 extern initcall_entry_t __initcall2_start[]; 913 extern initcall_entry_t __initcall3_start[]; 914 extern initcall_entry_t __initcall4_start[]; 915 extern initcall_entry_t __initcall5_start[]; 916 extern initcall_entry_t __initcall6_start[]; 917 extern initcall_entry_t __initcall7_start[]; 918 extern initcall_entry_t __initcall_end[]; 919 920 static initcall_entry_t *initcall_levels[] __initdata = { 921 __initcall0_start, 922 __initcall1_start, 923 __initcall2_start, 924 __initcall3_start, 925 __initcall4_start, 926 __initcall5_start, 927 __initcall6_start, 928 __initcall7_start, 929 __initcall_end, 930 }; 931 932 /* Keep these in sync with initcalls in include/linux/init.h */ 933 static char *initcall_level_names[] __initdata = { 934 "pure", 935 "core", 936 "postcore", 937 "arch", 938 "subsys", 939 "fs", 940 "device", 941 "late", 942 }; 943 944 static void __init do_initcall_level(int level) 945 { 946 initcall_entry_t *fn; 947 948 strcpy(initcall_command_line, saved_command_line); 949 parse_args(initcall_level_names[level], 950 initcall_command_line, __start___param, 951 __stop___param - __start___param, 952 level, level, 953 NULL, &repair_env_string); 954 955 trace_initcall_level(initcall_level_names[level]); 956 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 957 do_one_initcall(initcall_from_entry(fn)); 958 } 959 960 static void __init do_initcalls(void) 961 { 962 int level; 963 964 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) 965 do_initcall_level(level); 966 } 967 968 /* 969 * Ok, the machine is now initialized. None of the devices 970 * have been touched yet, but the CPU subsystem is up and 971 * running, and memory and process management works. 972 * 973 * Now we can finally start doing some real work.. 974 */ 975 static void __init do_basic_setup(void) 976 { 977 cpuset_init_smp(); 978 shmem_init(); 979 driver_init(); 980 init_irq_proc(); 981 do_ctors(); 982 usermodehelper_enable(); 983 do_initcalls(); 984 } 985 986 static void __init do_pre_smp_initcalls(void) 987 { 988 initcall_entry_t *fn; 989 990 trace_initcall_level("early"); 991 for (fn = __initcall_start; fn < __initcall0_start; fn++) 992 do_one_initcall(initcall_from_entry(fn)); 993 } 994 995 /* 996 * This function requests modules which should be loaded by default and is 997 * called twice right after initrd is mounted and right before init is 998 * exec'd. If such modules are on either initrd or rootfs, they will be 999 * loaded before control is passed to userland. 1000 */ 1001 void __init load_default_modules(void) 1002 { 1003 load_default_elevator_module(); 1004 } 1005 1006 static int run_init_process(const char *init_filename) 1007 { 1008 argv_init[0] = init_filename; 1009 pr_info("Run %s as init process\n", init_filename); 1010 return do_execve(getname_kernel(init_filename), 1011 (const char __user *const __user *)argv_init, 1012 (const char __user *const __user *)envp_init); 1013 } 1014 1015 static int try_to_run_init_process(const char *init_filename) 1016 { 1017 int ret; 1018 1019 ret = run_init_process(init_filename); 1020 1021 if (ret && ret != -ENOENT) { 1022 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1023 init_filename, ret); 1024 } 1025 1026 return ret; 1027 } 1028 1029 static noinline void __init kernel_init_freeable(void); 1030 1031 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1032 bool rodata_enabled __ro_after_init = true; 1033 static int __init set_debug_rodata(char *str) 1034 { 1035 return strtobool(str, &rodata_enabled); 1036 } 1037 __setup("rodata=", set_debug_rodata); 1038 #endif 1039 1040 #ifdef CONFIG_STRICT_KERNEL_RWX 1041 static void mark_readonly(void) 1042 { 1043 if (rodata_enabled) { 1044 /* 1045 * load_module() results in W+X mappings, which are cleaned 1046 * up with call_rcu(). Let's make sure that queued work is 1047 * flushed so that we don't hit false positives looking for 1048 * insecure pages which are W+X. 1049 */ 1050 rcu_barrier(); 1051 mark_rodata_ro(); 1052 rodata_test(); 1053 } else 1054 pr_info("Kernel memory protection disabled.\n"); 1055 } 1056 #else 1057 static inline void mark_readonly(void) 1058 { 1059 pr_warn("This architecture does not have kernel memory protection.\n"); 1060 } 1061 #endif 1062 1063 static int __ref kernel_init(void *unused) 1064 { 1065 int ret; 1066 1067 kernel_init_freeable(); 1068 /* need to finish all async __init code before freeing the memory */ 1069 async_synchronize_full(); 1070 ftrace_free_init_mem(); 1071 free_initmem(); 1072 mark_readonly(); 1073 1074 /* 1075 * Kernel mappings are now finalized - update the userspace page-table 1076 * to finalize PTI. 1077 */ 1078 pti_finalize(); 1079 1080 system_state = SYSTEM_RUNNING; 1081 numa_default_policy(); 1082 1083 rcu_end_inkernel_boot(); 1084 1085 if (ramdisk_execute_command) { 1086 ret = run_init_process(ramdisk_execute_command); 1087 if (!ret) 1088 return 0; 1089 pr_err("Failed to execute %s (error %d)\n", 1090 ramdisk_execute_command, ret); 1091 } 1092 1093 /* 1094 * We try each of these until one succeeds. 1095 * 1096 * The Bourne shell can be used instead of init if we are 1097 * trying to recover a really broken machine. 1098 */ 1099 if (execute_command) { 1100 ret = run_init_process(execute_command); 1101 if (!ret) 1102 return 0; 1103 panic("Requested init %s failed (error %d).", 1104 execute_command, ret); 1105 } 1106 if (!try_to_run_init_process("/sbin/init") || 1107 !try_to_run_init_process("/etc/init") || 1108 !try_to_run_init_process("/bin/init") || 1109 !try_to_run_init_process("/bin/sh")) 1110 return 0; 1111 1112 panic("No working init found. Try passing init= option to kernel. " 1113 "See Linux Documentation/admin-guide/init.rst for guidance."); 1114 } 1115 1116 static noinline void __init kernel_init_freeable(void) 1117 { 1118 /* 1119 * Wait until kthreadd is all set-up. 1120 */ 1121 wait_for_completion(&kthreadd_done); 1122 1123 /* Now the scheduler is fully set up and can do blocking allocations */ 1124 gfp_allowed_mask = __GFP_BITS_MASK; 1125 1126 /* 1127 * init can allocate pages on any node 1128 */ 1129 set_mems_allowed(node_states[N_MEMORY]); 1130 1131 cad_pid = task_pid(current); 1132 1133 smp_prepare_cpus(setup_max_cpus); 1134 1135 workqueue_init(); 1136 1137 init_mm_internals(); 1138 1139 do_pre_smp_initcalls(); 1140 lockup_detector_init(); 1141 1142 smp_init(); 1143 sched_init_smp(); 1144 1145 page_alloc_init_late(); 1146 1147 do_basic_setup(); 1148 1149 /* Open the /dev/console on the rootfs, this should never fail */ 1150 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 1151 pr_err("Warning: unable to open an initial console.\n"); 1152 1153 (void) ksys_dup(0); 1154 (void) ksys_dup(0); 1155 /* 1156 * check if there is an early userspace init. If yes, let it do all 1157 * the work 1158 */ 1159 1160 if (!ramdisk_execute_command) 1161 ramdisk_execute_command = "/init"; 1162 1163 if (ksys_access((const char __user *) 1164 ramdisk_execute_command, 0) != 0) { 1165 ramdisk_execute_command = NULL; 1166 prepare_namespace(); 1167 } 1168 1169 /* 1170 * Ok, we have completed the initial bootup, and 1171 * we're essentially up and running. Get rid of the 1172 * initmem segments and start the user-mode stuff.. 1173 * 1174 * rootfs is available now, try loading the public keys 1175 * and default modules 1176 */ 1177 1178 integrity_load_keys(); 1179 load_default_modules(); 1180 } 1181