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/module.h> 16 #include <linux/proc_fs.h> 17 #include <linux/kernel.h> 18 #include <linux/syscalls.h> 19 #include <linux/stackprotector.h> 20 #include <linux/string.h> 21 #include <linux/ctype.h> 22 #include <linux/delay.h> 23 #include <linux/ioport.h> 24 #include <linux/init.h> 25 #include <linux/initrd.h> 26 #include <linux/bootmem.h> 27 #include <linux/acpi.h> 28 #include <linux/tty.h> 29 #include <linux/percpu.h> 30 #include <linux/kmod.h> 31 #include <linux/vmalloc.h> 32 #include <linux/kernel_stat.h> 33 #include <linux/start_kernel.h> 34 #include <linux/security.h> 35 #include <linux/smp.h> 36 #include <linux/profile.h> 37 #include <linux/rcupdate.h> 38 #include <linux/moduleparam.h> 39 #include <linux/kallsyms.h> 40 #include <linux/writeback.h> 41 #include <linux/cpu.h> 42 #include <linux/cpuset.h> 43 #include <linux/cgroup.h> 44 #include <linux/efi.h> 45 #include <linux/tick.h> 46 #include <linux/interrupt.h> 47 #include <linux/taskstats_kern.h> 48 #include <linux/delayacct.h> 49 #include <linux/unistd.h> 50 #include <linux/rmap.h> 51 #include <linux/mempolicy.h> 52 #include <linux/key.h> 53 #include <linux/buffer_head.h> 54 #include <linux/page_cgroup.h> 55 #include <linux/debug_locks.h> 56 #include <linux/debugobjects.h> 57 #include <linux/lockdep.h> 58 #include <linux/kmemleak.h> 59 #include <linux/pid_namespace.h> 60 #include <linux/device.h> 61 #include <linux/kthread.h> 62 #include <linux/sched.h> 63 #include <linux/signal.h> 64 #include <linux/idr.h> 65 #include <linux/kgdb.h> 66 #include <linux/ftrace.h> 67 #include <linux/async.h> 68 #include <linux/kmemcheck.h> 69 #include <linux/sfi.h> 70 #include <linux/shmem_fs.h> 71 #include <linux/slab.h> 72 #include <linux/perf_event.h> 73 #include <linux/file.h> 74 #include <linux/ptrace.h> 75 #include <linux/blkdev.h> 76 #include <linux/elevator.h> 77 #include <linux/sched_clock.h> 78 #include <linux/context_tracking.h> 79 #include <linux/random.h> 80 #include <linux/list.h> 81 82 #include <asm/io.h> 83 #include <asm/bugs.h> 84 #include <asm/setup.h> 85 #include <asm/sections.h> 86 #include <asm/cacheflush.h> 87 88 #ifdef CONFIG_X86_LOCAL_APIC 89 #include <asm/smp.h> 90 #endif 91 92 static int kernel_init(void *); 93 94 extern void init_IRQ(void); 95 extern void fork_init(unsigned long); 96 extern void radix_tree_init(void); 97 #ifndef CONFIG_DEBUG_RODATA 98 static inline void mark_rodata_ro(void) { } 99 #endif 100 101 /* 102 * Debug helper: via this flag we know that we are in 'early bootup code' 103 * where only the boot processor is running with IRQ disabled. This means 104 * two things - IRQ must not be enabled before the flag is cleared and some 105 * operations which are not allowed with IRQ disabled are allowed while the 106 * flag is set. 107 */ 108 bool early_boot_irqs_disabled __read_mostly; 109 110 enum system_states system_state __read_mostly; 111 EXPORT_SYMBOL(system_state); 112 113 /* 114 * Boot command-line arguments 115 */ 116 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 117 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 118 119 extern void time_init(void); 120 /* Default late time init is NULL. archs can override this later. */ 121 void (*__initdata late_time_init)(void); 122 123 /* Untouched command line saved by arch-specific code. */ 124 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 125 /* Untouched saved command line (eg. for /proc) */ 126 char *saved_command_line; 127 /* Command line for parameter parsing */ 128 static char *static_command_line; 129 /* Command line for per-initcall parameter parsing */ 130 static char *initcall_command_line; 131 132 static char *execute_command; 133 static char *ramdisk_execute_command; 134 135 /* 136 * Used to generate warnings if static_key manipulation functions are used 137 * before jump_label_init is called. 138 */ 139 bool static_key_initialized __read_mostly; 140 EXPORT_SYMBOL_GPL(static_key_initialized); 141 142 /* 143 * If set, this is an indication to the drivers that reset the underlying 144 * device before going ahead with the initialization otherwise driver might 145 * rely on the BIOS and skip the reset operation. 146 * 147 * This is useful if kernel is booting in an unreliable environment. 148 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been 149 * skipped and devices will be in unknown state. 150 */ 151 unsigned int reset_devices; 152 EXPORT_SYMBOL(reset_devices); 153 154 static int __init set_reset_devices(char *str) 155 { 156 reset_devices = 1; 157 return 1; 158 } 159 160 __setup("reset_devices", set_reset_devices); 161 162 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 163 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 164 static const char *panic_later, *panic_param; 165 166 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 167 168 static int __init obsolete_checksetup(char *line) 169 { 170 const struct obs_kernel_param *p; 171 int had_early_param = 0; 172 173 p = __setup_start; 174 do { 175 int n = strlen(p->str); 176 if (parameqn(line, p->str, n)) { 177 if (p->early) { 178 /* Already done in parse_early_param? 179 * (Needs exact match on param part). 180 * Keep iterating, as we can have early 181 * params and __setups of same names 8( */ 182 if (line[n] == '\0' || line[n] == '=') 183 had_early_param = 1; 184 } else if (!p->setup_func) { 185 pr_warn("Parameter %s is obsolete, ignored\n", 186 p->str); 187 return 1; 188 } else if (p->setup_func(line + n)) 189 return 1; 190 } 191 p++; 192 } while (p < __setup_end); 193 194 return had_early_param; 195 } 196 197 /* 198 * This should be approx 2 Bo*oMips to start (note initial shift), and will 199 * still work even if initially too large, it will just take slightly longer 200 */ 201 unsigned long loops_per_jiffy = (1<<12); 202 EXPORT_SYMBOL(loops_per_jiffy); 203 204 static int __init debug_kernel(char *str) 205 { 206 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 207 return 0; 208 } 209 210 static int __init quiet_kernel(char *str) 211 { 212 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 213 return 0; 214 } 215 216 early_param("debug", debug_kernel); 217 early_param("quiet", quiet_kernel); 218 219 static int __init loglevel(char *str) 220 { 221 int newlevel; 222 223 /* 224 * Only update loglevel value when a correct setting was passed, 225 * to prevent blind crashes (when loglevel being set to 0) that 226 * are quite hard to debug 227 */ 228 if (get_option(&str, &newlevel)) { 229 console_loglevel = newlevel; 230 return 0; 231 } 232 233 return -EINVAL; 234 } 235 236 early_param("loglevel", loglevel); 237 238 /* Change NUL term back to "=", to make "param" the whole string. */ 239 static int __init repair_env_string(char *param, char *val, const char *unused) 240 { 241 if (val) { 242 /* param=val or param="val"? */ 243 if (val == param+strlen(param)+1) 244 val[-1] = '='; 245 else if (val == param+strlen(param)+2) { 246 val[-2] = '='; 247 memmove(val-1, val, strlen(val)+1); 248 val--; 249 } else 250 BUG(); 251 } 252 return 0; 253 } 254 255 /* Anything after -- gets handed straight to init. */ 256 static int __init set_init_arg(char *param, char *val, const char *unused) 257 { 258 unsigned int i; 259 260 if (panic_later) 261 return 0; 262 263 repair_env_string(param, val, unused); 264 265 for (i = 0; argv_init[i]; i++) { 266 if (i == MAX_INIT_ARGS) { 267 panic_later = "init"; 268 panic_param = param; 269 return 0; 270 } 271 } 272 argv_init[i] = param; 273 return 0; 274 } 275 276 /* 277 * Unknown boot options get handed to init, unless they look like 278 * unused parameters (modprobe will find them in /proc/cmdline). 279 */ 280 static int __init unknown_bootoption(char *param, char *val, const char *unused) 281 { 282 repair_env_string(param, val, unused); 283 284 /* Handle obsolete-style parameters */ 285 if (obsolete_checksetup(param)) 286 return 0; 287 288 /* Unused module parameter. */ 289 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 290 return 0; 291 292 if (panic_later) 293 return 0; 294 295 if (val) { 296 /* Environment option */ 297 unsigned int i; 298 for (i = 0; envp_init[i]; i++) { 299 if (i == MAX_INIT_ENVS) { 300 panic_later = "env"; 301 panic_param = param; 302 } 303 if (!strncmp(param, envp_init[i], val - param)) 304 break; 305 } 306 envp_init[i] = param; 307 } else { 308 /* Command line option */ 309 unsigned int i; 310 for (i = 0; argv_init[i]; i++) { 311 if (i == MAX_INIT_ARGS) { 312 panic_later = "init"; 313 panic_param = param; 314 } 315 } 316 argv_init[i] = param; 317 } 318 return 0; 319 } 320 321 static int __init init_setup(char *str) 322 { 323 unsigned int i; 324 325 execute_command = str; 326 /* 327 * In case LILO is going to boot us with default command line, 328 * it prepends "auto" before the whole cmdline which makes 329 * the shell think it should execute a script with such name. 330 * So we ignore all arguments entered _before_ init=... [MJ] 331 */ 332 for (i = 1; i < MAX_INIT_ARGS; i++) 333 argv_init[i] = NULL; 334 return 1; 335 } 336 __setup("init=", init_setup); 337 338 static int __init rdinit_setup(char *str) 339 { 340 unsigned int i; 341 342 ramdisk_execute_command = str; 343 /* See "auto" comment in init_setup */ 344 for (i = 1; i < MAX_INIT_ARGS; i++) 345 argv_init[i] = NULL; 346 return 1; 347 } 348 __setup("rdinit=", rdinit_setup); 349 350 #ifndef CONFIG_SMP 351 static const unsigned int setup_max_cpus = NR_CPUS; 352 #ifdef CONFIG_X86_LOCAL_APIC 353 static void __init smp_init(void) 354 { 355 APIC_init_uniprocessor(); 356 } 357 #else 358 #define smp_init() do { } while (0) 359 #endif 360 361 static inline void setup_nr_cpu_ids(void) { } 362 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 363 #endif 364 365 /* 366 * We need to store the untouched command line for future reference. 367 * We also need to store the touched command line since the parameter 368 * parsing is performed in place, and we should allow a component to 369 * store reference of name/value for future reference. 370 */ 371 static void __init setup_command_line(char *command_line) 372 { 373 saved_command_line = 374 memblock_virt_alloc(strlen(boot_command_line) + 1, 0); 375 initcall_command_line = 376 memblock_virt_alloc(strlen(boot_command_line) + 1, 0); 377 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0); 378 strcpy(saved_command_line, boot_command_line); 379 strcpy(static_command_line, command_line); 380 } 381 382 /* 383 * We need to finalize in a non-__init function or else race conditions 384 * between the root thread and the init thread may cause start_kernel to 385 * be reaped by free_initmem before the root thread has proceeded to 386 * cpu_idle. 387 * 388 * gcc-3.4 accidentally inlines this function, so use noinline. 389 */ 390 391 static __initdata DECLARE_COMPLETION(kthreadd_done); 392 393 static noinline void __init_refok rest_init(void) 394 { 395 int pid; 396 397 rcu_scheduler_starting(); 398 /* 399 * We need to spawn init first so that it obtains pid 1, however 400 * the init task will end up wanting to create kthreads, which, if 401 * we schedule it before we create kthreadd, will OOPS. 402 */ 403 kernel_thread(kernel_init, NULL, CLONE_FS); 404 numa_default_policy(); 405 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 406 rcu_read_lock(); 407 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 408 rcu_read_unlock(); 409 complete(&kthreadd_done); 410 411 /* 412 * The boot idle thread must execute schedule() 413 * at least once to get things moving: 414 */ 415 init_idle_bootup_task(current); 416 schedule_preempt_disabled(); 417 /* Call into cpu_idle with preempt disabled */ 418 cpu_startup_entry(CPUHP_ONLINE); 419 } 420 421 /* Check for early params. */ 422 static int __init do_early_param(char *param, char *val, const char *unused) 423 { 424 const struct obs_kernel_param *p; 425 426 for (p = __setup_start; p < __setup_end; p++) { 427 if ((p->early && parameq(param, p->str)) || 428 (strcmp(param, "console") == 0 && 429 strcmp(p->str, "earlycon") == 0) 430 ) { 431 if (p->setup_func(val) != 0) 432 pr_warn("Malformed early option '%s'\n", param); 433 } 434 } 435 /* We accept everything at this stage. */ 436 return 0; 437 } 438 439 void __init parse_early_options(char *cmdline) 440 { 441 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param); 442 } 443 444 /* Arch code calls this early on, or if not, just before other parsing. */ 445 void __init parse_early_param(void) 446 { 447 static int done __initdata; 448 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 449 450 if (done) 451 return; 452 453 /* All fall through to do_early_param. */ 454 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 455 parse_early_options(tmp_cmdline); 456 done = 1; 457 } 458 459 /* 460 * Activate the first processor. 461 */ 462 463 static void __init boot_cpu_init(void) 464 { 465 int cpu = smp_processor_id(); 466 /* Mark the boot cpu "present", "online" etc for SMP and UP case */ 467 set_cpu_online(cpu, true); 468 set_cpu_active(cpu, true); 469 set_cpu_present(cpu, true); 470 set_cpu_possible(cpu, true); 471 } 472 473 void __init __weak smp_setup_processor_id(void) 474 { 475 } 476 477 # if THREAD_SIZE >= PAGE_SIZE 478 void __init __weak thread_info_cache_init(void) 479 { 480 } 481 #endif 482 483 /* 484 * Set up kernel memory allocators 485 */ 486 static void __init mm_init(void) 487 { 488 /* 489 * page_cgroup requires contiguous pages, 490 * bigger than MAX_ORDER unless SPARSEMEM. 491 */ 492 page_cgroup_init_flatmem(); 493 mem_init(); 494 kmem_cache_init(); 495 percpu_init_late(); 496 pgtable_init(); 497 vmalloc_init(); 498 } 499 500 asmlinkage __visible void __init start_kernel(void) 501 { 502 char *command_line; 503 char *after_dashes; 504 505 /* 506 * Need to run as early as possible, to initialize the 507 * lockdep hash: 508 */ 509 lockdep_init(); 510 set_task_stack_end_magic(&init_task); 511 smp_setup_processor_id(); 512 debug_objects_early_init(); 513 514 /* 515 * Set up the the initial canary ASAP: 516 */ 517 boot_init_stack_canary(); 518 519 cgroup_init_early(); 520 521 local_irq_disable(); 522 early_boot_irqs_disabled = true; 523 524 /* 525 * Interrupts are still disabled. Do necessary setups, then 526 * enable them 527 */ 528 boot_cpu_init(); 529 page_address_init(); 530 pr_notice("%s", linux_banner); 531 setup_arch(&command_line); 532 mm_init_cpumask(&init_mm); 533 setup_command_line(command_line); 534 setup_nr_cpu_ids(); 535 setup_per_cpu_areas(); 536 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 537 538 build_all_zonelists(NULL, NULL); 539 page_alloc_init(); 540 541 pr_notice("Kernel command line: %s\n", boot_command_line); 542 parse_early_param(); 543 after_dashes = parse_args("Booting kernel", 544 static_command_line, __start___param, 545 __stop___param - __start___param, 546 -1, -1, &unknown_bootoption); 547 if (after_dashes) 548 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 549 set_init_arg); 550 551 jump_label_init(); 552 553 /* 554 * These use large bootmem allocations and must precede 555 * kmem_cache_init() 556 */ 557 setup_log_buf(0); 558 pidhash_init(); 559 vfs_caches_init_early(); 560 sort_main_extable(); 561 trap_init(); 562 mm_init(); 563 564 /* 565 * Set up the scheduler prior starting any interrupts (such as the 566 * timer interrupt). Full topology setup happens at smp_init() 567 * time - but meanwhile we still have a functioning scheduler. 568 */ 569 sched_init(); 570 /* 571 * Disable preemption - early bootup scheduling is extremely 572 * fragile until we cpu_idle() for the first time. 573 */ 574 preempt_disable(); 575 if (WARN(!irqs_disabled(), 576 "Interrupts were enabled *very* early, fixing it\n")) 577 local_irq_disable(); 578 idr_init_cache(); 579 rcu_init(); 580 context_tracking_init(); 581 radix_tree_init(); 582 /* init some links before init_ISA_irqs() */ 583 early_irq_init(); 584 init_IRQ(); 585 tick_init(); 586 rcu_init_nohz(); 587 init_timers(); 588 hrtimers_init(); 589 softirq_init(); 590 timekeeping_init(); 591 time_init(); 592 sched_clock_postinit(); 593 perf_event_init(); 594 profile_init(); 595 call_function_init(); 596 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 597 early_boot_irqs_disabled = false; 598 local_irq_enable(); 599 600 kmem_cache_init_late(); 601 602 /* 603 * HACK ALERT! This is early. We're enabling the console before 604 * we've done PCI setups etc, and console_init() must be aware of 605 * this. But we do want output early, in case something goes wrong. 606 */ 607 console_init(); 608 if (panic_later) 609 panic("Too many boot %s vars at `%s'", panic_later, 610 panic_param); 611 612 lockdep_info(); 613 614 /* 615 * Need to run this when irqs are enabled, because it wants 616 * to self-test [hard/soft]-irqs on/off lock inversion bugs 617 * too: 618 */ 619 locking_selftest(); 620 621 #ifdef CONFIG_BLK_DEV_INITRD 622 if (initrd_start && !initrd_below_start_ok && 623 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 624 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 625 page_to_pfn(virt_to_page((void *)initrd_start)), 626 min_low_pfn); 627 initrd_start = 0; 628 } 629 #endif 630 page_cgroup_init(); 631 debug_objects_mem_init(); 632 kmemleak_init(); 633 setup_per_cpu_pageset(); 634 numa_policy_init(); 635 if (late_time_init) 636 late_time_init(); 637 sched_clock_init(); 638 calibrate_delay(); 639 pidmap_init(); 640 anon_vma_init(); 641 acpi_early_init(); 642 #ifdef CONFIG_X86 643 if (efi_enabled(EFI_RUNTIME_SERVICES)) 644 efi_enter_virtual_mode(); 645 #endif 646 #ifdef CONFIG_X86_ESPFIX64 647 /* Should be run before the first non-init thread is created */ 648 init_espfix_bsp(); 649 #endif 650 thread_info_cache_init(); 651 cred_init(); 652 fork_init(totalram_pages); 653 proc_caches_init(); 654 buffer_init(); 655 key_init(); 656 security_init(); 657 dbg_late_init(); 658 vfs_caches_init(totalram_pages); 659 signals_init(); 660 /* rootfs populating might need page-writeback */ 661 page_writeback_init(); 662 proc_root_init(); 663 cgroup_init(); 664 cpuset_init(); 665 taskstats_init_early(); 666 delayacct_init(); 667 668 check_bugs(); 669 670 sfi_init_late(); 671 672 if (efi_enabled(EFI_RUNTIME_SERVICES)) { 673 efi_late_init(); 674 efi_free_boot_services(); 675 } 676 677 ftrace_init(); 678 679 /* Do the rest non-__init'ed, we're now alive */ 680 rest_init(); 681 } 682 683 /* Call all constructor functions linked into the kernel. */ 684 static void __init do_ctors(void) 685 { 686 #ifdef CONFIG_CONSTRUCTORS 687 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 688 689 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 690 (*fn)(); 691 #endif 692 } 693 694 bool initcall_debug; 695 core_param(initcall_debug, initcall_debug, bool, 0644); 696 697 #ifdef CONFIG_KALLSYMS 698 struct blacklist_entry { 699 struct list_head next; 700 char *buf; 701 }; 702 703 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 704 705 static int __init initcall_blacklist(char *str) 706 { 707 char *str_entry; 708 struct blacklist_entry *entry; 709 710 /* str argument is a comma-separated list of functions */ 711 do { 712 str_entry = strsep(&str, ","); 713 if (str_entry) { 714 pr_debug("blacklisting initcall %s\n", str_entry); 715 entry = alloc_bootmem(sizeof(*entry)); 716 entry->buf = alloc_bootmem(strlen(str_entry) + 1); 717 strcpy(entry->buf, str_entry); 718 list_add(&entry->next, &blacklisted_initcalls); 719 } 720 } while (str_entry); 721 722 return 0; 723 } 724 725 static bool __init_or_module initcall_blacklisted(initcall_t fn) 726 { 727 struct list_head *tmp; 728 struct blacklist_entry *entry; 729 char *fn_name; 730 731 fn_name = kasprintf(GFP_KERNEL, "%pf", fn); 732 if (!fn_name) 733 return false; 734 735 list_for_each(tmp, &blacklisted_initcalls) { 736 entry = list_entry(tmp, struct blacklist_entry, next); 737 if (!strcmp(fn_name, entry->buf)) { 738 pr_debug("initcall %s blacklisted\n", fn_name); 739 kfree(fn_name); 740 return true; 741 } 742 } 743 744 kfree(fn_name); 745 return false; 746 } 747 #else 748 static int __init initcall_blacklist(char *str) 749 { 750 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 751 return 0; 752 } 753 754 static bool __init_or_module initcall_blacklisted(initcall_t fn) 755 { 756 return false; 757 } 758 #endif 759 __setup("initcall_blacklist=", initcall_blacklist); 760 761 static int __init_or_module do_one_initcall_debug(initcall_t fn) 762 { 763 ktime_t calltime, delta, rettime; 764 unsigned long long duration; 765 int ret; 766 767 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); 768 calltime = ktime_get(); 769 ret = fn(); 770 rettime = ktime_get(); 771 delta = ktime_sub(rettime, calltime); 772 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 773 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", 774 fn, ret, duration); 775 776 return ret; 777 } 778 779 int __init_or_module do_one_initcall(initcall_t fn) 780 { 781 int count = preempt_count(); 782 int ret; 783 char msgbuf[64]; 784 785 if (initcall_blacklisted(fn)) 786 return -EPERM; 787 788 if (initcall_debug) 789 ret = do_one_initcall_debug(fn); 790 else 791 ret = fn(); 792 793 msgbuf[0] = 0; 794 795 if (preempt_count() != count) { 796 sprintf(msgbuf, "preemption imbalance "); 797 preempt_count_set(count); 798 } 799 if (irqs_disabled()) { 800 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 801 local_irq_enable(); 802 } 803 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf); 804 805 return ret; 806 } 807 808 809 extern initcall_t __initcall_start[]; 810 extern initcall_t __initcall0_start[]; 811 extern initcall_t __initcall1_start[]; 812 extern initcall_t __initcall2_start[]; 813 extern initcall_t __initcall3_start[]; 814 extern initcall_t __initcall4_start[]; 815 extern initcall_t __initcall5_start[]; 816 extern initcall_t __initcall6_start[]; 817 extern initcall_t __initcall7_start[]; 818 extern initcall_t __initcall_end[]; 819 820 static initcall_t *initcall_levels[] __initdata = { 821 __initcall0_start, 822 __initcall1_start, 823 __initcall2_start, 824 __initcall3_start, 825 __initcall4_start, 826 __initcall5_start, 827 __initcall6_start, 828 __initcall7_start, 829 __initcall_end, 830 }; 831 832 /* Keep these in sync with initcalls in include/linux/init.h */ 833 static char *initcall_level_names[] __initdata = { 834 "early", 835 "core", 836 "postcore", 837 "arch", 838 "subsys", 839 "fs", 840 "device", 841 "late", 842 }; 843 844 static void __init do_initcall_level(int level) 845 { 846 initcall_t *fn; 847 848 strcpy(initcall_command_line, saved_command_line); 849 parse_args(initcall_level_names[level], 850 initcall_command_line, __start___param, 851 __stop___param - __start___param, 852 level, level, 853 &repair_env_string); 854 855 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 856 do_one_initcall(*fn); 857 } 858 859 static void __init do_initcalls(void) 860 { 861 int level; 862 863 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) 864 do_initcall_level(level); 865 } 866 867 /* 868 * Ok, the machine is now initialized. None of the devices 869 * have been touched yet, but the CPU subsystem is up and 870 * running, and memory and process management works. 871 * 872 * Now we can finally start doing some real work.. 873 */ 874 static void __init do_basic_setup(void) 875 { 876 cpuset_init_smp(); 877 usermodehelper_init(); 878 shmem_init(); 879 driver_init(); 880 init_irq_proc(); 881 do_ctors(); 882 usermodehelper_enable(); 883 do_initcalls(); 884 random_int_secret_init(); 885 } 886 887 static void __init do_pre_smp_initcalls(void) 888 { 889 initcall_t *fn; 890 891 for (fn = __initcall_start; fn < __initcall0_start; fn++) 892 do_one_initcall(*fn); 893 } 894 895 /* 896 * This function requests modules which should be loaded by default and is 897 * called twice right after initrd is mounted and right before init is 898 * exec'd. If such modules are on either initrd or rootfs, they will be 899 * loaded before control is passed to userland. 900 */ 901 void __init load_default_modules(void) 902 { 903 load_default_elevator_module(); 904 } 905 906 static int run_init_process(const char *init_filename) 907 { 908 argv_init[0] = init_filename; 909 return do_execve(getname_kernel(init_filename), 910 (const char __user *const __user *)argv_init, 911 (const char __user *const __user *)envp_init); 912 } 913 914 static int try_to_run_init_process(const char *init_filename) 915 { 916 int ret; 917 918 ret = run_init_process(init_filename); 919 920 if (ret && ret != -ENOENT) { 921 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 922 init_filename, ret); 923 } 924 925 return ret; 926 } 927 928 static noinline void __init kernel_init_freeable(void); 929 930 static int __ref kernel_init(void *unused) 931 { 932 int ret; 933 934 kernel_init_freeable(); 935 /* need to finish all async __init code before freeing the memory */ 936 async_synchronize_full(); 937 free_initmem(); 938 mark_rodata_ro(); 939 system_state = SYSTEM_RUNNING; 940 numa_default_policy(); 941 942 flush_delayed_fput(); 943 944 if (ramdisk_execute_command) { 945 ret = run_init_process(ramdisk_execute_command); 946 if (!ret) 947 return 0; 948 pr_err("Failed to execute %s (error %d)\n", 949 ramdisk_execute_command, ret); 950 } 951 952 /* 953 * We try each of these until one succeeds. 954 * 955 * The Bourne shell can be used instead of init if we are 956 * trying to recover a really broken machine. 957 */ 958 if (execute_command) { 959 ret = run_init_process(execute_command); 960 if (!ret) 961 return 0; 962 pr_err("Failed to execute %s (error %d). Attempting defaults...\n", 963 execute_command, ret); 964 } 965 if (!try_to_run_init_process("/sbin/init") || 966 !try_to_run_init_process("/etc/init") || 967 !try_to_run_init_process("/bin/init") || 968 !try_to_run_init_process("/bin/sh")) 969 return 0; 970 971 panic("No working init found. Try passing init= option to kernel. " 972 "See Linux Documentation/init.txt for guidance."); 973 } 974 975 static noinline void __init kernel_init_freeable(void) 976 { 977 /* 978 * Wait until kthreadd is all set-up. 979 */ 980 wait_for_completion(&kthreadd_done); 981 982 /* Now the scheduler is fully set up and can do blocking allocations */ 983 gfp_allowed_mask = __GFP_BITS_MASK; 984 985 /* 986 * init can allocate pages on any node 987 */ 988 set_mems_allowed(node_states[N_MEMORY]); 989 /* 990 * init can run on any cpu. 991 */ 992 set_cpus_allowed_ptr(current, cpu_all_mask); 993 994 cad_pid = task_pid(current); 995 996 smp_prepare_cpus(setup_max_cpus); 997 998 do_pre_smp_initcalls(); 999 lockup_detector_init(); 1000 1001 smp_init(); 1002 sched_init_smp(); 1003 1004 do_basic_setup(); 1005 1006 /* Open the /dev/console on the rootfs, this should never fail */ 1007 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 1008 pr_err("Warning: unable to open an initial console.\n"); 1009 1010 (void) sys_dup(0); 1011 (void) sys_dup(0); 1012 /* 1013 * check if there is an early userspace init. If yes, let it do all 1014 * the work 1015 */ 1016 1017 if (!ramdisk_execute_command) 1018 ramdisk_execute_command = "/init"; 1019 1020 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { 1021 ramdisk_execute_command = NULL; 1022 prepare_namespace(); 1023 } 1024 1025 /* 1026 * Ok, we have completed the initial bootup, and 1027 * we're essentially up and running. Get rid of the 1028 * initmem segments and start the user-mode stuff.. 1029 */ 1030 1031 /* rootfs is available now, try loading default modules */ 1032 load_default_modules(); 1033 } 1034