linux/init/main.c
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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/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
  86static int kernel_init(void *);
  87
  88extern void init_IRQ(void);
  89extern void fork_init(unsigned long);
  90extern void mca_init(void);
  91extern void sbus_init(void);
  92extern void prio_tree_init(void);
  93extern void radix_tree_init(void);
  94extern void free_initmem(void);
  95#ifdef  CONFIG_ACPI
  96extern void acpi_early_init(void);
  97#else
  98static inline void acpi_early_init(void) { }
  99#endif
 100#ifndef CONFIG_DEBUG_RODATA
 101static inline void mark_rodata_ro(void) { }
 102#endif
 103
 104#ifdef CONFIG_TC
 105extern void tc_init(void);
 106#endif
 107
 108enum system_states system_state;
 109EXPORT_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
 117extern void time_init(void);
 118/* Default late time init is NULL. archs can override this later. */
 119void (*late_time_init)(void);
 120extern void softirq_init(void);
 121
 122/* Untouched command line saved by arch-specific code. */
 123char __initdata boot_command_line[COMMAND_LINE_SIZE];
 124/* Untouched saved command line (eg. for /proc) */
 125char *saved_command_line;
 126/* Command line for parameter parsing */
 127static char *static_command_line;
 128
 129static char *execute_command;
 130static char *ramdisk_execute_command;
 131
 132#ifdef CONFIG_SMP
 133/* Setup configured maximum number of CPUs to activate */
 134unsigned 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
 147static inline void disable_ioapic_setup(void) {};
 148#endif
 149
 150static int __init nosmp(char *str)
 151{
 152        setup_max_cpus = 0;
 153        disable_ioapic_setup();
 154        return 0;
 155}
 156
 157early_param("nosmp", nosmp);
 158
 159static 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
 168early_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 */
 182unsigned int reset_devices;
 183EXPORT_SYMBOL(reset_devices);
 184
 185static 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
 193static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 194char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 195static const char *panic_later, *panic_param;
 196
 197extern struct obs_kernel_param __setup_start[], __setup_end[];
 198
 199static 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 */
 232unsigned long loops_per_jiffy = (1<<12);
 233
 234EXPORT_SYMBOL(loops_per_jiffy);
 235
 236static int __init debug_kernel(char *str)
 237{
 238        console_loglevel = 10;
 239        return 0;
 240}
 241
 242static int __init quiet_kernel(char *str)
 243{
 244        console_loglevel = 4;
 245        return 0;
 246}
 247
 248early_param("debug", debug_kernel);
 249early_param("quiet", quiet_kernel);
 250
 251static int __init loglevel(char *str)
 252{
 253        get_option(&str, &console_loglevel);
 254        return 0;
 255}
 256
 257early_param("loglevel", loglevel);
 258
 259/*
 260 * Unknown boot options get handed to init, unless they look like
 261 * failed parameters
 262 */
 263static 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
 321int __read_mostly debug_pagealloc_enabled = 0;
 322#endif
 323
 324static 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
 341static 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
 356static void __init smp_init(void)
 357{
 358        APIC_init_uniprocessor();
 359}
 360#else
 361#define smp_init()      do { } while (0)
 362#endif
 363
 364static inline void setup_per_cpu_areas(void) { }
 365static inline void setup_nr_cpu_ids(void) { }
 366static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 367
 368#else
 369
 370#if NR_CPUS > BITS_PER_LONG
 371cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
 372EXPORT_SYMBOL(cpu_mask_all);
 373#endif
 374
 375/* Setup number of possible processor ids */
 376int nr_cpu_ids __read_mostly = NR_CPUS;
 377EXPORT_SYMBOL(nr_cpu_ids);
 378
 379/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
 380static 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
 391unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 392
 393EXPORT_SYMBOL(__per_cpu_offset);
 394
 395static 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. */
 414static 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 */
 446static 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
 463static 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. */
 488static 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. */
 507void __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
 525static 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
 534void __init __weak smp_setup_processor_id(void)
 535{
 536}
 537
 538void __init __weak thread_info_cache_init(void)
 539{
 540}
 541
 542asmlinkage 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
 700static int initcall_debug;
 701core_param(initcall_debug, initcall_debug, bool, 0644);
 702
 703int 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
 748extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
 749
 750static 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 */
 768static 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
 778static 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
 786static 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 */
 795static 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
 836static 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
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