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/string.h> 18 #include <linux/ctype.h> 19 #include <linux/delay.h> 20 #include <linux/utsname.h> 21 #include <linux/ioport.h> 22 #include <linux/init.h> 23 #include <linux/smp_lock.h> 24 #include <linux/initrd.h> 25 #include <linux/bootmem.h> 26 #include <linux/tty.h> 27 #include <linux/gfp.h> 28 #include <linux/percpu.h> 29 #include <linux/kmod.h> 30 #include <linux/vmalloc.h> 31 #include <linux/kernel_stat.h> 32 #include <linux/start_kernel.h> 33 #include <linux/security.h> 34 #include <linux/smp.h> 35 #include <linux/workqueue.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/unwind.h> 54 #include <linux/buffer_head.h> 55 #include <linux/page_cgroup.h> 56 #include <linux/debug_locks.h> 57 #include <linux/debugobjects.h> 58 #include <linux/lockdep.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/ftrace.h> 66 67 #include <asm/io.h> 68 #include <asm/bugs.h> 69 #include <asm/setup.h> 70 #include <asm/sections.h> 71 #include <asm/cacheflush.h> 72 73 #ifdef CONFIG_X86_LOCAL_APIC 74 #include <asm/smp.h> 75 #endif 76 77 /* 78 * This is one of the first .c files built. Error out early if we have compiler 79 * trouble. 80 */ 81 82 #if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0 83 #warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended. 84 #endif 85 86 static int kernel_init(void *); 87 88 extern void init_IRQ(void); 89 extern void fork_init(unsigned long); 90 extern void mca_init(void); 91 extern void sbus_init(void); 92 extern void prio_tree_init(void); 93 extern void radix_tree_init(void); 94 extern void free_initmem(void); 95 #ifdef CONFIG_ACPI 96 extern void acpi_early_init(void); 97 #else 98 static inline void acpi_early_init(void) { } 99 #endif 100 #ifndef CONFIG_DEBUG_RODATA 101 static inline void mark_rodata_ro(void) { } 102 #endif 103 104 #ifdef CONFIG_TC 105 extern void tc_init(void); 106 #endif 107 108 enum system_states system_state; 109 EXPORT_SYMBOL(system_state); 110 111 /* 112 * Boot command-line arguments 113 */ 114 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 115 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 116 117 extern void time_init(void); 118 /* Default late time init is NULL. archs can override this later. */ 119 void (*late_time_init)(void); 120 extern void softirq_init(void); 121 122 /* Untouched command line saved by arch-specific code. */ 123 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 124 /* Untouched saved command line (eg. for /proc) */ 125 char *saved_command_line; 126 /* Command line for parameter parsing */ 127 static char *static_command_line; 128 129 static char *execute_command; 130 static char *ramdisk_execute_command; 131 132 #ifdef CONFIG_SMP 133 /* Setup configured maximum number of CPUs to activate */ 134 unsigned int __initdata setup_max_cpus = NR_CPUS; 135 136 /* 137 * Setup routine for controlling SMP activation 138 * 139 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP 140 * activation entirely (the MPS table probe still happens, though). 141 * 142 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer 143 * greater than 0, limits the maximum number of CPUs activated in 144 * SMP mode to <NUM>. 145 */ 146 #ifndef CONFIG_X86_IO_APIC 147 static inline void disable_ioapic_setup(void) {}; 148 #endif 149 150 static int __init nosmp(char *str) 151 { 152 setup_max_cpus = 0; 153 disable_ioapic_setup(); 154 return 0; 155 } 156 157 early_param("nosmp", nosmp); 158 159 static int __init maxcpus(char *str) 160 { 161 get_option(&str, &setup_max_cpus); 162 if (setup_max_cpus == 0) 163 disable_ioapic_setup(); 164 165 return 0; 166 } 167 168 early_param("maxcpus", maxcpus); 169 #else 170 #define setup_max_cpus NR_CPUS 171 #endif 172 173 /* 174 * If set, this is an indication to the drivers that reset the underlying 175 * device before going ahead with the initialization otherwise driver might 176 * rely on the BIOS and skip the reset operation. 177 * 178 * This is useful if kernel is booting in an unreliable environment. 179 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been 180 * skipped and devices will be in unknown state. 181 */ 182 unsigned int reset_devices; 183 EXPORT_SYMBOL(reset_devices); 184 185 static int __init set_reset_devices(char *str) 186 { 187 reset_devices = 1; 188 return 1; 189 } 190 191 __setup("reset_devices", set_reset_devices); 192 193 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 194 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 195 static const char *panic_later, *panic_param; 196 197 extern struct obs_kernel_param __setup_start[], __setup_end[]; 198 199 static int __init obsolete_checksetup(char *line) 200 { 201 struct obs_kernel_param *p; 202 int had_early_param = 0; 203 204 p = __setup_start; 205 do { 206 int n = strlen(p->str); 207 if (!strncmp(line, p->str, n)) { 208 if (p->early) { 209 /* Already done in parse_early_param? 210 * (Needs exact match on param part). 211 * Keep iterating, as we can have early 212 * params and __setups of same names 8( */ 213 if (line[n] == '\0' || line[n] == '=') 214 had_early_param = 1; 215 } else if (!p->setup_func) { 216 printk(KERN_WARNING "Parameter %s is obsolete," 217 " ignored\n", p->str); 218 return 1; 219 } else if (p->setup_func(line + n)) 220 return 1; 221 } 222 p++; 223 } while (p < __setup_end); 224 225 return had_early_param; 226 } 227 228 /* 229 * This should be approx 2 Bo*oMips to start (note initial shift), and will 230 * still work even if initially too large, it will just take slightly longer 231 */ 232 unsigned long loops_per_jiffy = (1<<12); 233 234 EXPORT_SYMBOL(loops_per_jiffy); 235 236 static int __init debug_kernel(char *str) 237 { 238 console_loglevel = 10; 239 return 0; 240 } 241 242 static int __init quiet_kernel(char *str) 243 { 244 console_loglevel = 4; 245 return 0; 246 } 247 248 early_param("debug", debug_kernel); 249 early_param("quiet", quiet_kernel); 250 251 static int __init loglevel(char *str) 252 { 253 get_option(&str, &console_loglevel); 254 return 0; 255 } 256 257 early_param("loglevel", loglevel); 258 259 /* 260 * Unknown boot options get handed to init, unless they look like 261 * failed parameters 262 */ 263 static int __init unknown_bootoption(char *param, char *val) 264 { 265 /* Change NUL term back to "=", to make "param" the whole string. */ 266 if (val) { 267 /* param=val or param="val"? */ 268 if (val == param+strlen(param)+1) 269 val[-1] = '='; 270 else if (val == param+strlen(param)+2) { 271 val[-2] = '='; 272 memmove(val-1, val, strlen(val)+1); 273 val--; 274 } else 275 BUG(); 276 } 277 278 /* Handle obsolete-style parameters */ 279 if (obsolete_checksetup(param)) 280 return 0; 281 282 /* 283 * Preemptive maintenance for "why didn't my misspelled command 284 * line work?" 285 */ 286 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) { 287 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param); 288 return 0; 289 } 290 291 if (panic_later) 292 return 0; 293 294 if (val) { 295 /* Environment option */ 296 unsigned int i; 297 for (i = 0; envp_init[i]; i++) { 298 if (i == MAX_INIT_ENVS) { 299 panic_later = "Too many boot env vars at `%s'"; 300 panic_param = param; 301 } 302 if (!strncmp(param, envp_init[i], val - param)) 303 break; 304 } 305 envp_init[i] = param; 306 } else { 307 /* Command line option */ 308 unsigned int i; 309 for (i = 0; argv_init[i]; i++) { 310 if (i == MAX_INIT_ARGS) { 311 panic_later = "Too many boot init vars at `%s'"; 312 panic_param = param; 313 } 314 } 315 argv_init[i] = param; 316 } 317 return 0; 318 } 319 320 #ifdef CONFIG_DEBUG_PAGEALLOC 321 int __read_mostly debug_pagealloc_enabled = 0; 322 #endif 323 324 static int __init init_setup(char *str) 325 { 326 unsigned int i; 327 328 execute_command = str; 329 /* 330 * In case LILO is going to boot us with default command line, 331 * it prepends "auto" before the whole cmdline which makes 332 * the shell think it should execute a script with such name. 333 * So we ignore all arguments entered _before_ init=... [MJ] 334 */ 335 for (i = 1; i < MAX_INIT_ARGS; i++) 336 argv_init[i] = NULL; 337 return 1; 338 } 339 __setup("init=", init_setup); 340 341 static int __init rdinit_setup(char *str) 342 { 343 unsigned int i; 344 345 ramdisk_execute_command = str; 346 /* See "auto" comment in init_setup */ 347 for (i = 1; i < MAX_INIT_ARGS; i++) 348 argv_init[i] = NULL; 349 return 1; 350 } 351 __setup("rdinit=", rdinit_setup); 352 353 #ifndef CONFIG_SMP 354 355 #ifdef CONFIG_X86_LOCAL_APIC 356 static void __init smp_init(void) 357 { 358 APIC_init_uniprocessor(); 359 } 360 #else 361 #define smp_init() do { } while (0) 362 #endif 363 364 static inline void setup_per_cpu_areas(void) { } 365 static inline void setup_nr_cpu_ids(void) { } 366 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 367 368 #else 369 370 #if NR_CPUS > BITS_PER_LONG 371 cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL; 372 EXPORT_SYMBOL(cpu_mask_all); 373 #endif 374 375 /* Setup number of possible processor ids */ 376 int nr_cpu_ids __read_mostly = NR_CPUS; 377 EXPORT_SYMBOL(nr_cpu_ids); 378 379 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */ 380 static void __init setup_nr_cpu_ids(void) 381 { 382 int cpu, highest_cpu = 0; 383 384 for_each_possible_cpu(cpu) 385 highest_cpu = cpu; 386 387 nr_cpu_ids = highest_cpu + 1; 388 } 389 390 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA 391 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 392 393 EXPORT_SYMBOL(__per_cpu_offset); 394 395 static void __init setup_per_cpu_areas(void) 396 { 397 unsigned long size, i; 398 char *ptr; 399 unsigned long nr_possible_cpus = num_possible_cpus(); 400 401 /* Copy section for each CPU (we discard the original) */ 402 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE); 403 ptr = alloc_bootmem_pages(size * nr_possible_cpus); 404 405 for_each_possible_cpu(i) { 406 __per_cpu_offset[i] = ptr - __per_cpu_start; 407 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); 408 ptr += size; 409 } 410 } 411 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ 412 413 /* Called by boot processor to activate the rest. */ 414 static void __init smp_init(void) 415 { 416 unsigned int cpu; 417 418 /* 419 * Set up the current CPU as possible to migrate to. 420 * The other ones will be done by cpu_up/cpu_down() 421 */ 422 cpu = smp_processor_id(); 423 cpu_set(cpu, cpu_active_map); 424 425 /* FIXME: This should be done in userspace --RR */ 426 for_each_present_cpu(cpu) { 427 if (num_online_cpus() >= setup_max_cpus) 428 break; 429 if (!cpu_online(cpu)) 430 cpu_up(cpu); 431 } 432 433 /* Any cleanup work */ 434 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus()); 435 smp_cpus_done(setup_max_cpus); 436 } 437 438 #endif 439 440 /* 441 * We need to store the untouched command line for future reference. 442 * We also need to store the touched command line since the parameter 443 * parsing is performed in place, and we should allow a component to 444 * store reference of name/value for future reference. 445 */ 446 static void __init setup_command_line(char *command_line) 447 { 448 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1); 449 static_command_line = alloc_bootmem(strlen (command_line)+1); 450 strcpy (saved_command_line, boot_command_line); 451 strcpy (static_command_line, command_line); 452 } 453 454 /* 455 * We need to finalize in a non-__init function or else race conditions 456 * between the root thread and the init thread may cause start_kernel to 457 * be reaped by free_initmem before the root thread has proceeded to 458 * cpu_idle. 459 * 460 * gcc-3.4 accidentally inlines this function, so use noinline. 461 */ 462 463 static void noinline __init_refok rest_init(void) 464 __releases(kernel_lock) 465 { 466 int pid; 467 468 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); 469 numa_default_policy(); 470 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 471 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 472 unlock_kernel(); 473 474 /* 475 * The boot idle thread must execute schedule() 476 * at least once to get things moving: 477 */ 478 init_idle_bootup_task(current); 479 preempt_enable_no_resched(); 480 schedule(); 481 preempt_disable(); 482 483 /* Call into cpu_idle with preempt disabled */ 484 cpu_idle(); 485 } 486 487 /* Check for early params. */ 488 static int __init do_early_param(char *param, char *val) 489 { 490 struct obs_kernel_param *p; 491 492 for (p = __setup_start; p < __setup_end; p++) { 493 if ((p->early && strcmp(param, p->str) == 0) || 494 (strcmp(param, "console") == 0 && 495 strcmp(p->str, "earlycon") == 0) 496 ) { 497 if (p->setup_func(val) != 0) 498 printk(KERN_WARNING 499 "Malformed early option '%s'\n", param); 500 } 501 } 502 /* We accept everything at this stage. */ 503 return 0; 504 } 505 506 /* Arch code calls this early on, or if not, just before other parsing. */ 507 void __init parse_early_param(void) 508 { 509 static __initdata int done = 0; 510 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; 511 512 if (done) 513 return; 514 515 /* All fall through to do_early_param. */ 516 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 517 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param); 518 done = 1; 519 } 520 521 /* 522 * Activate the first processor. 523 */ 524 525 static void __init boot_cpu_init(void) 526 { 527 int cpu = smp_processor_id(); 528 /* Mark the boot cpu "present", "online" etc for SMP and UP case */ 529 cpu_set(cpu, cpu_online_map); 530 cpu_set(cpu, cpu_present_map); 531 cpu_set(cpu, cpu_possible_map); 532 } 533 534 void __init __weak smp_setup_processor_id(void) 535 { 536 } 537 538 void __init __weak thread_info_cache_init(void) 539 { 540 } 541 542 asmlinkage void __init start_kernel(void) 543 { 544 char * command_line; 545 extern struct kernel_param __start___param[], __stop___param[]; 546 547 smp_setup_processor_id(); 548 549 /* 550 * Need to run as early as possible, to initialize the 551 * lockdep hash: 552 */ 553 unwind_init(); 554 lockdep_init(); 555 debug_objects_early_init(); 556 cgroup_init_early(); 557 558 local_irq_disable(); 559 early_boot_irqs_off(); 560 early_init_irq_lock_class(); 561 562 /* 563 * Interrupts are still disabled. Do necessary setups, then 564 * enable them 565 */ 566 lock_kernel(); 567 tick_init(); 568 boot_cpu_init(); 569 page_address_init(); 570 printk(KERN_NOTICE); 571 printk(linux_banner); 572 setup_arch(&command_line); 573 mm_init_owner(&init_mm, &init_task); 574 setup_command_line(command_line); 575 unwind_setup(); 576 setup_per_cpu_areas(); 577 setup_nr_cpu_ids(); 578 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 579 580 /* 581 * Set up the scheduler prior starting any interrupts (such as the 582 * timer interrupt). Full topology setup happens at smp_init() 583 * time - but meanwhile we still have a functioning scheduler. 584 */ 585 sched_init(); 586 /* 587 * Disable preemption - early bootup scheduling is extremely 588 * fragile until we cpu_idle() for the first time. 589 */ 590 preempt_disable(); 591 build_all_zonelists(); 592 page_alloc_init(); 593 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line); 594 parse_early_param(); 595 parse_args("Booting kernel", static_command_line, __start___param, 596 __stop___param - __start___param, 597 &unknown_bootoption); 598 if (!irqs_disabled()) { 599 printk(KERN_WARNING "start_kernel(): bug: interrupts were " 600 "enabled *very* early, fixing it\n"); 601 local_irq_disable(); 602 } 603 sort_main_extable(); 604 trap_init(); 605 rcu_init(); 606 init_IRQ(); 607 pidhash_init(); 608 init_timers(); 609 hrtimers_init(); 610 softirq_init(); 611 timekeeping_init(); 612 time_init(); 613 sched_clock_init(); 614 profile_init(); 615 if (!irqs_disabled()) 616 printk("start_kernel(): bug: interrupts were enabled early\n"); 617 early_boot_irqs_on(); 618 local_irq_enable(); 619 620 /* 621 * HACK ALERT! This is early. We're enabling the console before 622 * we've done PCI setups etc, and console_init() must be aware of 623 * this. But we do want output early, in case something goes wrong. 624 */ 625 console_init(); 626 if (panic_later) 627 panic(panic_later, panic_param); 628 629 lockdep_info(); 630 631 /* 632 * Need to run this when irqs are enabled, because it wants 633 * to self-test [hard/soft]-irqs on/off lock inversion bugs 634 * too: 635 */ 636 locking_selftest(); 637 638 #ifdef CONFIG_BLK_DEV_INITRD 639 if (initrd_start && !initrd_below_start_ok && 640 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 641 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " 642 "disabling it.\n", 643 page_to_pfn(virt_to_page((void *)initrd_start)), 644 min_low_pfn); 645 initrd_start = 0; 646 } 647 #endif 648 vmalloc_init(); 649 vfs_caches_init_early(); 650 cpuset_init_early(); 651 page_cgroup_init(); 652 mem_init(); 653 enable_debug_pagealloc(); 654 cpu_hotplug_init(); 655 kmem_cache_init(); 656 debug_objects_mem_init(); 657 idr_init_cache(); 658 setup_per_cpu_pageset(); 659 numa_policy_init(); 660 if (late_time_init) 661 late_time_init(); 662 calibrate_delay(); 663 pidmap_init(); 664 pgtable_cache_init(); 665 prio_tree_init(); 666 anon_vma_init(); 667 #ifdef CONFIG_X86 668 if (efi_enabled) 669 efi_enter_virtual_mode(); 670 #endif 671 thread_info_cache_init(); 672 fork_init(num_physpages); 673 proc_caches_init(); 674 buffer_init(); 675 key_init(); 676 security_init(); 677 vfs_caches_init(num_physpages); 678 radix_tree_init(); 679 signals_init(); 680 /* rootfs populating might need page-writeback */ 681 page_writeback_init(); 682 #ifdef CONFIG_PROC_FS 683 proc_root_init(); 684 #endif 685 cgroup_init(); 686 cpuset_init(); 687 taskstats_init_early(); 688 delayacct_init(); 689 690 check_bugs(); 691 692 acpi_early_init(); /* before LAPIC and SMP init */ 693 694 ftrace_init(); 695 696 /* Do the rest non-__init'ed, we're now alive */ 697 rest_init(); 698 } 699 700 static int initcall_debug; 701 core_param(initcall_debug, initcall_debug, bool, 0644); 702 703 int do_one_initcall(initcall_t fn) 704 { 705 int count = preempt_count(); 706 ktime_t delta; 707 char msgbuf[64]; 708 struct boot_trace it; 709 710 if (initcall_debug) { 711 it.caller = task_pid_nr(current); 712 printk("calling %pF @ %i\n", fn, it.caller); 713 it.calltime = ktime_get(); 714 } 715 716 it.result = fn(); 717 718 if (initcall_debug) { 719 it.rettime = ktime_get(); 720 delta = ktime_sub(it.rettime, it.calltime); 721 it.duration = (unsigned long long) delta.tv64 >> 10; 722 printk("initcall %pF returned %d after %Ld usecs\n", fn, 723 it.result, it.duration); 724 trace_boot(&it, fn); 725 } 726 727 msgbuf[0] = 0; 728 729 if (it.result && it.result != -ENODEV && initcall_debug) 730 sprintf(msgbuf, "error code %d ", it.result); 731 732 if (preempt_count() != count) { 733 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); 734 preempt_count() = count; 735 } 736 if (irqs_disabled()) { 737 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 738 local_irq_enable(); 739 } 740 if (msgbuf[0]) { 741 printk("initcall %pF returned with %s\n", fn, msgbuf); 742 } 743 744 return it.result; 745 } 746 747 748 extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[]; 749 750 static void __init do_initcalls(void) 751 { 752 initcall_t *call; 753 754 for (call = __early_initcall_end; call < __initcall_end; call++) 755 do_one_initcall(*call); 756 757 /* Make sure there is no pending stuff from the initcall sequence */ 758 flush_scheduled_work(); 759 } 760 761 /* 762 * Ok, the machine is now initialized. None of the devices 763 * have been touched yet, but the CPU subsystem is up and 764 * running, and memory and process management works. 765 * 766 * Now we can finally start doing some real work.. 767 */ 768 static void __init do_basic_setup(void) 769 { 770 rcu_init_sched(); /* needed by module_init stage. */ 771 init_workqueues(); 772 usermodehelper_init(); 773 driver_init(); 774 init_irq_proc(); 775 do_initcalls(); 776 } 777 778 static void __init do_pre_smp_initcalls(void) 779 { 780 initcall_t *call; 781 782 for (call = __initcall_start; call < __early_initcall_end; call++) 783 do_one_initcall(*call); 784 } 785 786 static void run_init_process(char *init_filename) 787 { 788 argv_init[0] = init_filename; 789 kernel_execve(init_filename, argv_init, envp_init); 790 } 791 792 /* This is a non __init function. Force it to be noinline otherwise gcc 793 * makes it inline to init() and it becomes part of init.text section 794 */ 795 static int noinline init_post(void) 796 { 797 free_initmem(); 798 unlock_kernel(); 799 mark_rodata_ro(); 800 system_state = SYSTEM_RUNNING; 801 numa_default_policy(); 802 803 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 804 printk(KERN_WARNING "Warning: unable to open an initial console.\n"); 805 806 (void) sys_dup(0); 807 (void) sys_dup(0); 808 809 current->signal->flags |= SIGNAL_UNKILLABLE; 810 811 if (ramdisk_execute_command) { 812 run_init_process(ramdisk_execute_command); 813 printk(KERN_WARNING "Failed to execute %s\n", 814 ramdisk_execute_command); 815 } 816 817 /* 818 * We try each of these until one succeeds. 819 * 820 * The Bourne shell can be used instead of init if we are 821 * trying to recover a really broken machine. 822 */ 823 if (execute_command) { 824 run_init_process(execute_command); 825 printk(KERN_WARNING "Failed to execute %s. Attempting " 826 "defaults...\n", execute_command); 827 } 828 run_init_process("/sbin/init"); 829 run_init_process("/etc/init"); 830 run_init_process("/bin/init"); 831 run_init_process("/bin/sh"); 832 833 panic("No init found. Try passing init= option to kernel."); 834 } 835 836 static int __init kernel_init(void * unused) 837 { 838 lock_kernel(); 839 /* 840 * init can run on any cpu. 841 */ 842 set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR); 843 /* 844 * Tell the world that we're going to be the grim 845 * reaper of innocent orphaned children. 846 * 847 * We don't want people to have to make incorrect 848 * assumptions about where in the task array this 849 * can be found. 850 */ 851 init_pid_ns.child_reaper = current; 852 853 cad_pid = task_pid(current); 854 855 smp_prepare_cpus(setup_max_cpus); 856 857 do_pre_smp_initcalls(); 858 start_boot_trace(); 859 860 smp_init(); 861 sched_init_smp(); 862 863 cpuset_init_smp(); 864 865 do_basic_setup(); 866 867 /* 868 * check if there is an early userspace init. If yes, let it do all 869 * the work 870 */ 871 872 if (!ramdisk_execute_command) 873 ramdisk_execute_command = "/init"; 874 875 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { 876 ramdisk_execute_command = NULL; 877 prepare_namespace(); 878 } 879 880 /* 881 * Ok, we have completed the initial bootup, and 882 * we're essentially up and running. Get rid of the 883 * initmem segments and start the user-mode stuff.. 884 */ 885 stop_boot_trace(); 886 init_post(); 887 return 0; 888 } 889