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 #include <linux/types.h> 13 #include <linux/module.h> 14 #include <linux/proc_fs.h> 15 #include <linux/kernel.h> 16 #include <linux/syscalls.h> 17 #include <linux/stackprotector.h> 18 #include <linux/string.h> 19 #include <linux/ctype.h> 20 #include <linux/delay.h> 21 #include <linux/utsname.h> 22 #include <linux/ioport.h> 23 #include <linux/init.h> 24 #include <linux/smp_lock.h> 25 #include <linux/initrd.h> 26 #include <linux/bootmem.h> 27 #include <linux/acpi.h> 28 #include <linux/tty.h> 29 #include <linux/gfp.h> 30 #include <linux/percpu.h> 31 #include <linux/kmod.h> 32 #include <linux/vmalloc.h> 33 #include <linux/kernel_stat.h> 34 #include <linux/start_kernel.h> 35 #include <linux/security.h> 36 #include <linux/smp.h> 37 #include <linux/workqueue.h> 38 #include <linux/profile.h> 39 #include <linux/rcupdate.h> 40 #include <linux/moduleparam.h> 41 #include <linux/kallsyms.h> 42 #include <linux/writeback.h> 43 #include <linux/cpu.h> 44 #include <linux/cpuset.h> 45 #include <linux/cgroup.h> 46 #include <linux/efi.h> 47 #include <linux/tick.h> 48 #include <linux/interrupt.h> 49 #include <linux/taskstats_kern.h> 50 #include <linux/delayacct.h> 51 #include <linux/unistd.h> 52 #include <linux/rmap.h> 53 #include <linux/mempolicy.h> 54 #include <linux/key.h> 55 #include <linux/buffer_head.h> 56 #include <linux/page_cgroup.h> 57 #include <linux/debug_locks.h> 58 #include <linux/debugobjects.h> 59 #include <linux/lockdep.h> 60 #include <linux/kmemleak.h> 61 #include <linux/pid_namespace.h> 62 #include <linux/device.h> 63 #include <linux/kthread.h> 64 #include <linux/sched.h> 65 #include <linux/signal.h> 66 #include <linux/idr.h> 67 #include <linux/ftrace.h> 68 #include <linux/async.h> 69 #include <linux/kmemcheck.h> 70 #include <linux/kmemtrace.h> 71 #include <linux/shmem_fs.h> 72 #include <trace/boot.h> 73 74 #include <asm/io.h> 75 #include <asm/bugs.h> 76 #include <asm/setup.h> 77 #include <asm/sections.h> 78 #include <asm/cacheflush.h> 79 80 #ifdef CONFIG_X86_LOCAL_APIC 81 #include <asm/smp.h> 82 #endif 83 84 static int kernel_init(void *); 85 86 extern void init_IRQ(void); 87 extern void fork_init(unsigned long); 88 extern void mca_init(void); 89 extern void sbus_init(void); 90 extern void prio_tree_init(void); 91 extern void radix_tree_init(void); 92 extern void free_initmem(void); 93 #ifndef CONFIG_DEBUG_RODATA 94 static inline void mark_rodata_ro(void) { } 95 #endif 96 97 #ifdef CONFIG_TC 98 extern void tc_init(void); 99 #endif 100 101 enum system_states system_state __read_mostly; 102 EXPORT_SYMBOL(system_state); 103 104 /* 105 * Boot command-line arguments 106 */ 107 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 108 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 109 110 extern void time_init(void); 111 /* Default late time init is NULL. archs can override this later. */ 112 void (*__initdata late_time_init)(void); 113 extern void softirq_init(void); 114 115 /* Untouched command line saved by arch-specific code. */ 116 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 117 /* Untouched saved command line (eg. for /proc) */ 118 char *saved_command_line; 119 /* Command line for parameter parsing */ 120 static char *static_command_line; 121 122 static char *execute_command; 123 static char *ramdisk_execute_command; 124 125 #ifdef CONFIG_SMP 126 /* Setup configured maximum number of CPUs to activate */ 127 unsigned int __initdata setup_max_cpus = NR_CPUS; 128 129 /* 130 * Setup routine for controlling SMP activation 131 * 132 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP 133 * activation entirely (the MPS table probe still happens, though). 134 * 135 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer 136 * greater than 0, limits the maximum number of CPUs activated in 137 * SMP mode to <NUM>. 138 */ 139 140 void __weak arch_disable_smp_support(void) { } 141 142 static int __init nosmp(char *str) 143 { 144 setup_max_cpus = 0; 145 arch_disable_smp_support(); 146 147 return 0; 148 } 149 150 early_param("nosmp", nosmp); 151 152 static int __init maxcpus(char *str) 153 { 154 get_option(&str, &setup_max_cpus); 155 if (setup_max_cpus == 0) 156 arch_disable_smp_support(); 157 158 return 0; 159 } 160 161 early_param("maxcpus", maxcpus); 162 #else 163 const unsigned int setup_max_cpus = NR_CPUS; 164 #endif 165 166 /* 167 * If set, this is an indication to the drivers that reset the underlying 168 * device before going ahead with the initialization otherwise driver might 169 * rely on the BIOS and skip the reset operation. 170 * 171 * This is useful if kernel is booting in an unreliable environment. 172 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been 173 * skipped and devices will be in unknown state. 174 */ 175 unsigned int reset_devices; 176 EXPORT_SYMBOL(reset_devices); 177 178 static int __init set_reset_devices(char *str) 179 { 180 reset_devices = 1; 181 return 1; 182 } 183 184 __setup("reset_devices", set_reset_devices); 185 186 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 187 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 188 static const char *panic_later, *panic_param; 189 190 extern struct obs_kernel_param __setup_start[], __setup_end[]; 191 192 static int __init obsolete_checksetup(char *line) 193 { 194 struct obs_kernel_param *p; 195 int had_early_param = 0; 196 197 p = __setup_start; 198 do { 199 int n = strlen(p->str); 200 if (!strncmp(line, p->str, n)) { 201 if (p->early) { 202 /* Already done in parse_early_param? 203 * (Needs exact match on param part). 204 * Keep iterating, as we can have early 205 * params and __setups of same names 8( */ 206 if (line[n] == '\0' || line[n] == '=') 207 had_early_param = 1; 208 } else if (!p->setup_func) { 209 printk(KERN_WARNING "Parameter %s is obsolete," 210 " ignored\n", p->str); 211 return 1; 212 } else if (p->setup_func(line + n)) 213 return 1; 214 } 215 p++; 216 } while (p < __setup_end); 217 218 return had_early_param; 219 } 220 221 /* 222 * This should be approx 2 Bo*oMips to start (note initial shift), and will 223 * still work even if initially too large, it will just take slightly longer 224 */ 225 unsigned long loops_per_jiffy = (1<<12); 226 227 EXPORT_SYMBOL(loops_per_jiffy); 228 229 static int __init debug_kernel(char *str) 230 { 231 console_loglevel = 10; 232 return 0; 233 } 234 235 static int __init quiet_kernel(char *str) 236 { 237 console_loglevel = 4; 238 return 0; 239 } 240 241 early_param("debug", debug_kernel); 242 early_param("quiet", quiet_kernel); 243 244 static int __init loglevel(char *str) 245 { 246 get_option(&str, &console_loglevel); 247 return 0; 248 } 249 250 early_param("loglevel", loglevel); 251 252 /* 253 * Unknown boot options get handed to init, unless they look like 254 * failed parameters 255 */ 256 static int __init unknown_bootoption(char *param, char *val) 257 { 258 /* Change NUL term back to "=", to make "param" the whole string. */ 259 if (val) { 260 /* param=val or param="val"? */ 261 if (val == param+strlen(param)+1) 262 val[-1] = '='; 263 else if (val == param+strlen(param)+2) { 264 val[-2] = '='; 265 memmove(val-1, val, strlen(val)+1); 266 val--; 267 } else 268 BUG(); 269 } 270 271 /* Handle obsolete-style parameters */ 272 if (obsolete_checksetup(param)) 273 return 0; 274 275 /* 276 * Preemptive maintenance for "why didn't my misspelled command 277 * line work?" 278 */ 279 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) { 280 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param); 281 return 0; 282 } 283 284 if (panic_later) 285 return 0; 286 287 if (val) { 288 /* Environment option */ 289 unsigned int i; 290 for (i = 0; envp_init[i]; i++) { 291 if (i == MAX_INIT_ENVS) { 292 panic_later = "Too many boot env vars at `%s'"; 293 panic_param = param; 294 } 295 if (!strncmp(param, envp_init[i], val - param)) 296 break; 297 } 298 envp_init[i] = param; 299 } else { 300 /* Command line option */ 301 unsigned int i; 302 for (i = 0; argv_init[i]; i++) { 303 if (i == MAX_INIT_ARGS) { 304 panic_later = "Too many boot init vars at `%s'"; 305 panic_param = param; 306 } 307 } 308 argv_init[i] = param; 309 } 310 return 0; 311 } 312 313 #ifdef CONFIG_DEBUG_PAGEALLOC 314 int __read_mostly debug_pagealloc_enabled = 0; 315 #endif 316 317 static int __init init_setup(char *str) 318 { 319 unsigned int i; 320 321 execute_command = str; 322 /* 323 * In case LILO is going to boot us with default command line, 324 * it prepends "auto" before the whole cmdline which makes 325 * the shell think it should execute a script with such name. 326 * So we ignore all arguments entered _before_ init=... [MJ] 327 */ 328 for (i = 1; i < MAX_INIT_ARGS; i++) 329 argv_init[i] = NULL; 330 return 1; 331 } 332 __setup("init=", init_setup); 333 334 static int __init rdinit_setup(char *str) 335 { 336 unsigned int i; 337 338 ramdisk_execute_command = str; 339 /* See "auto" comment in init_setup */ 340 for (i = 1; i < MAX_INIT_ARGS; i++) 341 argv_init[i] = NULL; 342 return 1; 343 } 344 __setup("rdinit=", rdinit_setup); 345 346 #ifndef CONFIG_SMP 347 348 #ifdef CONFIG_X86_LOCAL_APIC 349 static void __init smp_init(void) 350 { 351 APIC_init_uniprocessor(); 352 } 353 #else 354 #define smp_init() do { } while (0) 355 #endif 356 357 static inline void setup_nr_cpu_ids(void) { } 358 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 359 360 #else 361 362 #if NR_CPUS > BITS_PER_LONG 363 cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL; 364 EXPORT_SYMBOL(cpu_mask_all); 365 #endif 366 367 /* Setup number of possible processor ids */ 368 int nr_cpu_ids __read_mostly = NR_CPUS; 369 EXPORT_SYMBOL(nr_cpu_ids); 370 371 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */ 372 static void __init setup_nr_cpu_ids(void) 373 { 374 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1; 375 } 376 377 /* Called by boot processor to activate the rest. */ 378 static void __init smp_init(void) 379 { 380 unsigned int cpu; 381 382 /* 383 * Set up the current CPU as possible to migrate to. 384 * The other ones will be done by cpu_up/cpu_down() 385 */ 386 set_cpu_active(smp_processor_id(), true); 387 388 /* FIXME: This should be done in userspace --RR */ 389 for_each_present_cpu(cpu) { 390 if (num_online_cpus() >= setup_max_cpus) 391 break; 392 if (!cpu_online(cpu)) 393 cpu_up(cpu); 394 } 395 396 /* Any cleanup work */ 397 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus()); 398 smp_cpus_done(setup_max_cpus); 399 } 400 401 #endif 402 403 /* 404 * We need to store the untouched command line for future reference. 405 * We also need to store the touched command line since the parameter 406 * parsing is performed in place, and we should allow a component to 407 * store reference of name/value for future reference. 408 */ 409 static void __init setup_command_line(char *command_line) 410 { 411 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1); 412 static_command_line = alloc_bootmem(strlen (command_line)+1); 413 strcpy (saved_command_line, boot_command_line); 414 strcpy (static_command_line, command_line); 415 } 416 417 /* 418 * We need to finalize in a non-__init function or else race conditions 419 * between the root thread and the init thread may cause start_kernel to 420 * be reaped by free_initmem before the root thread has proceeded to 421 * cpu_idle. 422 * 423 * gcc-3.4 accidentally inlines this function, so use noinline. 424 */ 425 426 static noinline void __init_refok rest_init(void) 427 __releases(kernel_lock) 428 { 429 int pid; 430 431 rcu_scheduler_starting(); 432 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); 433 numa_default_policy(); 434 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 435 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 436 unlock_kernel(); 437 438 /* 439 * The boot idle thread must execute schedule() 440 * at least once to get things moving: 441 */ 442 init_idle_bootup_task(current); 443 preempt_enable_no_resched(); 444 schedule(); 445 preempt_disable(); 446 447 /* Call into cpu_idle with preempt disabled */ 448 cpu_idle(); 449 } 450 451 /* Check for early params. */ 452 static int __init do_early_param(char *param, char *val) 453 { 454 struct obs_kernel_param *p; 455 456 for (p = __setup_start; p < __setup_end; p++) { 457 if ((p->early && strcmp(param, p->str) == 0) || 458 (strcmp(param, "console") == 0 && 459 strcmp(p->str, "earlycon") == 0) 460 ) { 461 if (p->setup_func(val) != 0) 462 printk(KERN_WARNING 463 "Malformed early option '%s'\n", param); 464 } 465 } 466 /* We accept everything at this stage. */ 467 return 0; 468 } 469 470 void __init parse_early_options(char *cmdline) 471 { 472 parse_args("early options", cmdline, NULL, 0, do_early_param); 473 } 474 475 /* Arch code calls this early on, or if not, just before other parsing. */ 476 void __init parse_early_param(void) 477 { 478 static __initdata int done = 0; 479 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; 480 481 if (done) 482 return; 483 484 /* All fall through to do_early_param. */ 485 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 486 parse_early_options(tmp_cmdline); 487 done = 1; 488 } 489 490 /* 491 * Activate the first processor. 492 */ 493 494 static void __init boot_cpu_init(void) 495 { 496 int cpu = smp_processor_id(); 497 /* Mark the boot cpu "present", "online" etc for SMP and UP case */ 498 set_cpu_online(cpu, true); 499 set_cpu_present(cpu, true); 500 set_cpu_possible(cpu, true); 501 } 502 503 void __init __weak smp_setup_processor_id(void) 504 { 505 } 506 507 void __init __weak thread_info_cache_init(void) 508 { 509 } 510 511 /* 512 * Set up kernel memory allocators 513 */ 514 static void __init mm_init(void) 515 { 516 /* 517 * page_cgroup requires countinous pages as memmap 518 * and it's bigger than MAX_ORDER unless SPARSEMEM. 519 */ 520 page_cgroup_init_flatmem(); 521 mem_init(); 522 kmem_cache_init(); 523 pgtable_cache_init(); 524 vmalloc_init(); 525 } 526 527 asmlinkage void __init start_kernel(void) 528 { 529 char * command_line; 530 extern struct kernel_param __start___param[], __stop___param[]; 531 532 smp_setup_processor_id(); 533 534 /* 535 * Need to run as early as possible, to initialize the 536 * lockdep hash: 537 */ 538 lockdep_init(); 539 debug_objects_early_init(); 540 541 /* 542 * Set up the the initial canary ASAP: 543 */ 544 boot_init_stack_canary(); 545 546 cgroup_init_early(); 547 548 local_irq_disable(); 549 early_boot_irqs_off(); 550 early_init_irq_lock_class(); 551 552 /* 553 * Interrupts are still disabled. Do necessary setups, then 554 * enable them 555 */ 556 lock_kernel(); 557 tick_init(); 558 boot_cpu_init(); 559 page_address_init(); 560 printk(KERN_NOTICE "%s", linux_banner); 561 setup_arch(&command_line); 562 mm_init_owner(&init_mm, &init_task); 563 setup_command_line(command_line); 564 setup_nr_cpu_ids(); 565 setup_per_cpu_areas(); 566 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 567 568 build_all_zonelists(); 569 page_alloc_init(); 570 571 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line); 572 parse_early_param(); 573 parse_args("Booting kernel", static_command_line, __start___param, 574 __stop___param - __start___param, 575 &unknown_bootoption); 576 /* 577 * These use large bootmem allocations and must precede 578 * kmem_cache_init() 579 */ 580 pidhash_init(); 581 vfs_caches_init_early(); 582 sort_main_extable(); 583 trap_init(); 584 mm_init(); 585 /* 586 * Set up the scheduler prior starting any interrupts (such as the 587 * timer interrupt). Full topology setup happens at smp_init() 588 * time - but meanwhile we still have a functioning scheduler. 589 */ 590 sched_init(); 591 /* 592 * Disable preemption - early bootup scheduling is extremely 593 * fragile until we cpu_idle() for the first time. 594 */ 595 preempt_disable(); 596 if (!irqs_disabled()) { 597 printk(KERN_WARNING "start_kernel(): bug: interrupts were " 598 "enabled *very* early, fixing it\n"); 599 local_irq_disable(); 600 } 601 rcu_init(); 602 /* init some links before init_ISA_irqs() */ 603 early_irq_init(); 604 init_IRQ(); 605 prio_tree_init(); 606 init_timers(); 607 hrtimers_init(); 608 softirq_init(); 609 timekeeping_init(); 610 time_init(); 611 profile_init(); 612 if (!irqs_disabled()) 613 printk(KERN_CRIT "start_kernel(): bug: interrupts were " 614 "enabled early\n"); 615 early_boot_irqs_on(); 616 local_irq_enable(); 617 618 /* Interrupts are enabled now so all GFP allocations are safe. */ 619 set_gfp_allowed_mask(__GFP_BITS_MASK); 620 621 kmem_cache_init_late(); 622 623 /* 624 * HACK ALERT! This is early. We're enabling the console before 625 * we've done PCI setups etc, and console_init() must be aware of 626 * this. But we do want output early, in case something goes wrong. 627 */ 628 console_init(); 629 if (panic_later) 630 panic(panic_later, panic_param); 631 632 lockdep_info(); 633 634 /* 635 * Need to run this when irqs are enabled, because it wants 636 * to self-test [hard/soft]-irqs on/off lock inversion bugs 637 * too: 638 */ 639 locking_selftest(); 640 641 #ifdef CONFIG_BLK_DEV_INITRD 642 if (initrd_start && !initrd_below_start_ok && 643 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 644 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " 645 "disabling it.\n", 646 page_to_pfn(virt_to_page((void *)initrd_start)), 647 min_low_pfn); 648 initrd_start = 0; 649 } 650 #endif 651 page_cgroup_init(); 652 enable_debug_pagealloc(); 653 kmemtrace_init(); 654 kmemleak_init(); 655 debug_objects_mem_init(); 656 idr_init_cache(); 657 setup_per_cpu_pageset(); 658 numa_policy_init(); 659 if (late_time_init) 660 late_time_init(); 661 sched_clock_init(); 662 calibrate_delay(); 663 pidmap_init(); 664 anon_vma_init(); 665 #ifdef CONFIG_X86 666 if (efi_enabled) 667 efi_enter_virtual_mode(); 668 #endif 669 thread_info_cache_init(); 670 cred_init(); 671 fork_init(num_physpages); 672 proc_caches_init(); 673 buffer_init(); 674 key_init(); 675 security_init(); 676 vfs_caches_init(num_physpages); 677 radix_tree_init(); 678 signals_init(); 679 /* rootfs populating might need page-writeback */ 680 page_writeback_init(); 681 #ifdef CONFIG_PROC_FS 682 proc_root_init(); 683 #endif 684 cgroup_init(); 685 cpuset_init(); 686 taskstats_init_early(); 687 delayacct_init(); 688 689 check_bugs(); 690 691 acpi_early_init(); /* before LAPIC and SMP init */ 692 693 ftrace_init(); 694 695 /* Do the rest non-__init'ed, we're now alive */ 696 rest_init(); 697 } 698 699 /* Call all constructor functions linked into the kernel. */ 700 static void __init do_ctors(void) 701 { 702 #ifdef CONFIG_CONSTRUCTORS 703 ctor_fn_t *call = (ctor_fn_t *) __ctors_start; 704 705 for (; call < (ctor_fn_t *) __ctors_end; call++) 706 (*call)(); 707 #endif 708 } 709 710 int initcall_debug; 711 core_param(initcall_debug, initcall_debug, bool, 0644); 712 713 static char msgbuf[64]; 714 static struct boot_trace_call call; 715 static struct boot_trace_ret ret; 716 717 int do_one_initcall(initcall_t fn) 718 { 719 int count = preempt_count(); 720 ktime_t calltime, delta, rettime; 721 722 if (initcall_debug) { 723 call.caller = task_pid_nr(current); 724 printk("calling %pF @ %i\n", fn, call.caller); 725 calltime = ktime_get(); 726 trace_boot_call(&call, fn); 727 enable_boot_trace(); 728 } 729 730 ret.result = fn(); 731 732 if (initcall_debug) { 733 disable_boot_trace(); 734 rettime = ktime_get(); 735 delta = ktime_sub(rettime, calltime); 736 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10; 737 trace_boot_ret(&ret, fn); 738 printk("initcall %pF returned %d after %Ld usecs\n", fn, 739 ret.result, ret.duration); 740 } 741 742 msgbuf[0] = 0; 743 744 if (ret.result && ret.result != -ENODEV && initcall_debug) 745 sprintf(msgbuf, "error code %d ", ret.result); 746 747 if (preempt_count() != count) { 748 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); 749 preempt_count() = count; 750 } 751 if (irqs_disabled()) { 752 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 753 local_irq_enable(); 754 } 755 if (msgbuf[0]) { 756 printk("initcall %pF returned with %s\n", fn, msgbuf); 757 } 758 759 return ret.result; 760 } 761 762 763 extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[]; 764 765 static void __init do_initcalls(void) 766 { 767 initcall_t *call; 768 769 for (call = __early_initcall_end; call < __initcall_end; call++) 770 do_one_initcall(*call); 771 772 /* Make sure there is no pending stuff from the initcall sequence */ 773 flush_scheduled_work(); 774 } 775 776 /* 777 * Ok, the machine is now initialized. None of the devices 778 * have been touched yet, but the CPU subsystem is up and 779 * running, and memory and process management works. 780 * 781 * Now we can finally start doing some real work.. 782 */ 783 static void __init do_basic_setup(void) 784 { 785 rcu_init_sched(); /* needed by module_init stage. */ 786 init_workqueues(); 787 cpuset_init_smp(); 788 usermodehelper_init(); 789 init_tmpfs(); 790 driver_init(); 791 init_irq_proc(); 792 do_ctors(); 793 do_initcalls(); 794 } 795 796 static void __init do_pre_smp_initcalls(void) 797 { 798 initcall_t *call; 799 800 for (call = __initcall_start; call < __early_initcall_end; call++) 801 do_one_initcall(*call); 802 } 803 804 static void run_init_process(char *init_filename) 805 { 806 argv_init[0] = init_filename; 807 kernel_execve(init_filename, argv_init, envp_init); 808 } 809 810 /* This is a non __init function. Force it to be noinline otherwise gcc 811 * makes it inline to init() and it becomes part of init.text section 812 */ 813 static noinline int init_post(void) 814 __releases(kernel_lock) 815 { 816 /* need to finish all async __init code before freeing the memory */ 817 async_synchronize_full(); 818 free_initmem(); 819 unlock_kernel(); 820 mark_rodata_ro(); 821 system_state = SYSTEM_RUNNING; 822 numa_default_policy(); 823 824 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 825 printk(KERN_WARNING "Warning: unable to open an initial console.\n"); 826 827 (void) sys_dup(0); 828 (void) sys_dup(0); 829 830 current->signal->flags |= SIGNAL_UNKILLABLE; 831 832 if (ramdisk_execute_command) { 833 run_init_process(ramdisk_execute_command); 834 printk(KERN_WARNING "Failed to execute %s\n", 835 ramdisk_execute_command); 836 } 837 838 /* 839 * We try each of these until one succeeds. 840 * 841 * The Bourne shell can be used instead of init if we are 842 * trying to recover a really broken machine. 843 */ 844 if (execute_command) { 845 run_init_process(execute_command); 846 printk(KERN_WARNING "Failed to execute %s. Attempting " 847 "defaults...\n", execute_command); 848 } 849 run_init_process("/sbin/init"); 850 run_init_process("/etc/init"); 851 run_init_process("/bin/init"); 852 run_init_process("/bin/sh"); 853 854 panic("No init found. Try passing init= option to kernel."); 855 } 856 857 static int __init kernel_init(void * unused) 858 { 859 lock_kernel(); 860 861 /* 862 * init can allocate pages on any node 863 */ 864 set_mems_allowed(node_possible_map); 865 /* 866 * init can run on any cpu. 867 */ 868 set_cpus_allowed_ptr(current, cpu_all_mask); 869 /* 870 * Tell the world that we're going to be the grim 871 * reaper of innocent orphaned children. 872 * 873 * We don't want people to have to make incorrect 874 * assumptions about where in the task array this 875 * can be found. 876 */ 877 init_pid_ns.child_reaper = current; 878 879 cad_pid = task_pid(current); 880 881 smp_prepare_cpus(setup_max_cpus); 882 883 do_pre_smp_initcalls(); 884 start_boot_trace(); 885 886 smp_init(); 887 sched_init_smp(); 888 889 do_basic_setup(); 890 891 /* 892 * check if there is an early userspace init. If yes, let it do all 893 * the work 894 */ 895 896 if (!ramdisk_execute_command) 897 ramdisk_execute_command = "/init"; 898 899 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { 900 ramdisk_execute_command = NULL; 901 prepare_namespace(); 902 } 903 904 /* 905 * Ok, we have completed the initial bootup, and 906 * we're essentially up and running. Get rid of the 907 * initmem segments and start the user-mode stuff.. 908 */ 909 910 init_post(); 911 return 0; 912 } 913