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