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