Root/init/main.c

1/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
12#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
15#include <linux/kernel.h>
16#include <linux/syscalls.h>
17#include <linux/stackprotector.h>
18#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
21#include <linux/utsname.h>
22#include <linux/ioport.h>
23#include <linux/init.h>
24#include <linux/smp_lock.h>
25#include <linux/initrd.h>
26#include <linux/bootmem.h>
27#include <linux/acpi.h>
28#include <linux/tty.h>
29#include <linux/gfp.h>
30#include <linux/percpu.h>
31#include <linux/kmod.h>
32#include <linux/vmalloc.h>
33#include <linux/kernel_stat.h>
34#include <linux/start_kernel.h>
35#include <linux/security.h>
36#include <linux/smp.h>
37#include <linux/workqueue.h>
38#include <linux/profile.h>
39#include <linux/rcupdate.h>
40#include <linux/moduleparam.h>
41#include <linux/kallsyms.h>
42#include <linux/writeback.h>
43#include <linux/cpu.h>
44#include <linux/cpuset.h>
45#include <linux/cgroup.h>
46#include <linux/efi.h>
47#include <linux/tick.h>
48#include <linux/interrupt.h>
49#include <linux/taskstats_kern.h>
50#include <linux/delayacct.h>
51#include <linux/unistd.h>
52#include <linux/rmap.h>
53#include <linux/mempolicy.h>
54#include <linux/key.h>
55#include <linux/buffer_head.h>
56#include <linux/page_cgroup.h>
57#include <linux/debug_locks.h>
58#include <linux/debugobjects.h>
59#include <linux/lockdep.h>
60#include <linux/kmemleak.h>
61#include <linux/pid_namespace.h>
62#include <linux/device.h>
63#include <linux/kthread.h>
64#include <linux/sched.h>
65#include <linux/signal.h>
66#include <linux/idr.h>
67#include <linux/ftrace.h>
68#include <linux/async.h>
69#include <linux/kmemcheck.h>
70#include <linux/kmemtrace.h>
71#include <trace/boot.h>
72
73#include <asm/io.h>
74#include <asm/bugs.h>
75#include <asm/setup.h>
76#include <asm/sections.h>
77#include <asm/cacheflush.h>
78
79#ifdef CONFIG_X86_LOCAL_APIC
80#include <asm/smp.h>
81#endif
82
83static int kernel_init(void *);
84
85extern void init_IRQ(void);
86extern void fork_init(unsigned long);
87extern void mca_init(void);
88extern void sbus_init(void);
89extern void prio_tree_init(void);
90extern void radix_tree_init(void);
91extern void free_initmem(void);
92#ifndef CONFIG_DEBUG_RODATA
93static inline void mark_rodata_ro(void) { }
94#endif
95
96#ifdef CONFIG_TC
97extern void tc_init(void);
98#endif
99
100enum system_states system_state __read_mostly;
101EXPORT_SYMBOL(system_state);
102
103/*
104 * Boot command-line arguments
105 */
106#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
107#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
108
109extern void time_init(void);
110/* Default late time init is NULL. archs can override this later. */
111void (*__initdata late_time_init)(void);
112extern void softirq_init(void);
113
114/* Untouched command line saved by arch-specific code. */
115char __initdata boot_command_line[COMMAND_LINE_SIZE];
116/* Untouched saved command line (eg. for /proc) */
117char *saved_command_line;
118/* Command line for parameter parsing */
119static char *static_command_line;
120
121static char *execute_command;
122static char *ramdisk_execute_command;
123
124#ifdef CONFIG_SMP
125/* Setup configured maximum number of CPUs to activate */
126unsigned int __initdata setup_max_cpus = NR_CPUS;
127
128/*
129 * Setup routine for controlling SMP activation
130 *
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
133 *
134 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
135 * greater than 0, limits the maximum number of CPUs activated in
136 * SMP mode to <NUM>.
137 */
138
139void __weak arch_disable_smp_support(void) { }
140
141static int __init nosmp(char *str)
142{
143    setup_max_cpus = 0;
144    arch_disable_smp_support();
145
146    return 0;
147}
148
149early_param("nosmp", nosmp);
150
151static int __init maxcpus(char *str)
152{
153    get_option(&str, &setup_max_cpus);
154    if (setup_max_cpus == 0)
155        arch_disable_smp_support();
156
157    return 0;
158}
159
160early_param("maxcpus", maxcpus);
161#else
162const unsigned int setup_max_cpus = NR_CPUS;
163#endif
164
165/*
166 * If set, this is an indication to the drivers that reset the underlying
167 * device before going ahead with the initialization otherwise driver might
168 * rely on the BIOS and skip the reset operation.
169 *
170 * This is useful if kernel is booting in an unreliable environment.
171 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
172 * skipped and devices will be in unknown state.
173 */
174unsigned int reset_devices;
175EXPORT_SYMBOL(reset_devices);
176
177static int __init set_reset_devices(char *str)
178{
179    reset_devices = 1;
180    return 1;
181}
182
183__setup("reset_devices", set_reset_devices);
184
185static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
186char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
187static const char *panic_later, *panic_param;
188
189extern struct obs_kernel_param __setup_start[], __setup_end[];
190
191static int __init obsolete_checksetup(char *line)
192{
193    struct obs_kernel_param *p;
194    int had_early_param = 0;
195
196    p = __setup_start;
197    do {
198        int n = strlen(p->str);
199        if (!strncmp(line, p->str, n)) {
200            if (p->early) {
201                /* Already done in parse_early_param?
202                 * (Needs exact match on param part).
203                 * Keep iterating, as we can have early
204                 * params and __setups of same names 8( */
205                if (line[n] == '\0' || line[n] == '=')
206                    had_early_param = 1;
207            } else if (!p->setup_func) {
208                printk(KERN_WARNING "Parameter %s is obsolete,"
209                       " ignored\n", p->str);
210                return 1;
211            } else if (p->setup_func(line + n))
212                return 1;
213        }
214        p++;
215    } while (p < __setup_end);
216
217    return had_early_param;
218}
219
220/*
221 * This should be approx 2 Bo*oMips to start (note initial shift), and will
222 * still work even if initially too large, it will just take slightly longer
223 */
224unsigned long loops_per_jiffy = (1<<12);
225
226EXPORT_SYMBOL(loops_per_jiffy);
227
228static int __init debug_kernel(char *str)
229{
230    console_loglevel = 10;
231    return 0;
232}
233
234static int __init quiet_kernel(char *str)
235{
236    console_loglevel = 4;
237    return 0;
238}
239
240early_param("debug", debug_kernel);
241early_param("quiet", quiet_kernel);
242
243static int __init loglevel(char *str)
244{
245    get_option(&str, &console_loglevel);
246    return 0;
247}
248
249early_param("loglevel", loglevel);
250
251/*
252 * Unknown boot options get handed to init, unless they look like
253 * failed parameters
254 */
255static int __init unknown_bootoption(char *param, char *val)
256{
257    /* Change NUL term back to "=", to make "param" the whole string. */
258    if (val) {
259        /* param=val or param="val"? */
260        if (val == param+strlen(param)+1)
261            val[-1] = '=';
262        else if (val == param+strlen(param)+2) {
263            val[-2] = '=';
264            memmove(val-1, val, strlen(val)+1);
265            val--;
266        } else
267            BUG();
268    }
269
270    /* Handle obsolete-style parameters */
271    if (obsolete_checksetup(param))
272        return 0;
273
274    /*
275     * Preemptive maintenance for "why didn't my misspelled command
276     * line work?"
277     */
278    if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
279        printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
280        return 0;
281    }
282
283    if (panic_later)
284        return 0;
285
286    if (val) {
287        /* Environment option */
288        unsigned int i;
289        for (i = 0; envp_init[i]; i++) {
290            if (i == MAX_INIT_ENVS) {
291                panic_later = "Too many boot env vars at `%s'";
292                panic_param = param;
293            }
294            if (!strncmp(param, envp_init[i], val - param))
295                break;
296        }
297        envp_init[i] = param;
298    } else {
299        /* Command line option */
300        unsigned int i;
301        for (i = 0; argv_init[i]; i++) {
302            if (i == MAX_INIT_ARGS) {
303                panic_later = "Too many boot init vars at `%s'";
304                panic_param = param;
305            }
306        }
307        argv_init[i] = param;
308    }
309    return 0;
310}
311
312#ifdef CONFIG_DEBUG_PAGEALLOC
313int __read_mostly debug_pagealloc_enabled = 0;
314#endif
315
316static int __init init_setup(char *str)
317{
318    unsigned int i;
319
320    execute_command = str;
321    /*
322     * In case LILO is going to boot us with default command line,
323     * it prepends "auto" before the whole cmdline which makes
324     * the shell think it should execute a script with such name.
325     * So we ignore all arguments entered _before_ init=... [MJ]
326     */
327    for (i = 1; i < MAX_INIT_ARGS; i++)
328        argv_init[i] = NULL;
329    return 1;
330}
331__setup("init=", init_setup);
332
333static int __init rdinit_setup(char *str)
334{
335    unsigned int i;
336
337    ramdisk_execute_command = str;
338    /* See "auto" comment in init_setup */
339    for (i = 1; i < MAX_INIT_ARGS; i++)
340        argv_init[i] = NULL;
341    return 1;
342}
343__setup("rdinit=", rdinit_setup);
344
345#ifndef CONFIG_SMP
346
347#ifdef CONFIG_X86_LOCAL_APIC
348static void __init smp_init(void)
349{
350    APIC_init_uniprocessor();
351}
352#else
353#define smp_init() do { } while (0)
354#endif
355
356static inline void setup_per_cpu_areas(void) { }
357static inline void setup_nr_cpu_ids(void) { }
358static inline void smp_prepare_cpus(unsigned int maxcpus) { }
359
360#else
361
362#if NR_CPUS > BITS_PER_LONG
363cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
364EXPORT_SYMBOL(cpu_mask_all);
365#endif
366
367/* Setup number of possible processor ids */
368int nr_cpu_ids __read_mostly = NR_CPUS;
369EXPORT_SYMBOL(nr_cpu_ids);
370
371/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
372static void __init setup_nr_cpu_ids(void)
373{
374    nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
375}
376
377#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
378unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
379
380EXPORT_SYMBOL(__per_cpu_offset);
381
382static void __init setup_per_cpu_areas(void)
383{
384    unsigned long size, i;
385    char *ptr;
386    unsigned long nr_possible_cpus = num_possible_cpus();
387
388    /* Copy section for each CPU (we discard the original) */
389    size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
390    ptr = alloc_bootmem_pages(size * nr_possible_cpus);
391
392    for_each_possible_cpu(i) {
393        __per_cpu_offset[i] = ptr - __per_cpu_start;
394        memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
395        ptr += size;
396    }
397}
398#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
399
400/* Called by boot processor to activate the rest. */
401static void __init smp_init(void)
402{
403    unsigned int cpu;
404
405    /*
406     * Set up the current CPU as possible to migrate to.
407     * The other ones will be done by cpu_up/cpu_down()
408     */
409    set_cpu_active(smp_processor_id(), true);
410
411    /* FIXME: This should be done in userspace --RR */
412    for_each_present_cpu(cpu) {
413        if (num_online_cpus() >= setup_max_cpus)
414            break;
415        if (!cpu_online(cpu))
416            cpu_up(cpu);
417    }
418
419    /* Any cleanup work */
420    printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
421    smp_cpus_done(setup_max_cpus);
422}
423
424#endif
425
426/*
427 * We need to store the untouched command line for future reference.
428 * We also need to store the touched command line since the parameter
429 * parsing is performed in place, and we should allow a component to
430 * store reference of name/value for future reference.
431 */
432static void __init setup_command_line(char *command_line)
433{
434    saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
435    static_command_line = alloc_bootmem(strlen (command_line)+1);
436    strcpy (saved_command_line, boot_command_line);
437    strcpy (static_command_line, command_line);
438}
439
440/*
441 * We need to finalize in a non-__init function or else race conditions
442 * between the root thread and the init thread may cause start_kernel to
443 * be reaped by free_initmem before the root thread has proceeded to
444 * cpu_idle.
445 *
446 * gcc-3.4 accidentally inlines this function, so use noinline.
447 */
448
449static noinline void __init_refok rest_init(void)
450    __releases(kernel_lock)
451{
452    int pid;
453
454    kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
455    numa_default_policy();
456    pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
457    kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
458    unlock_kernel();
459
460    /*
461     * The boot idle thread must execute schedule()
462     * at least once to get things moving:
463     */
464    init_idle_bootup_task(current);
465    rcu_scheduler_starting();
466    preempt_enable_no_resched();
467    schedule();
468    preempt_disable();
469
470    /* Call into cpu_idle with preempt disabled */
471    cpu_idle();
472}
473
474/* Check for early params. */
475static int __init do_early_param(char *param, char *val)
476{
477    struct obs_kernel_param *p;
478
479    for (p = __setup_start; p < __setup_end; p++) {
480        if ((p->early && strcmp(param, p->str) == 0) ||
481            (strcmp(param, "console") == 0 &&
482             strcmp(p->str, "earlycon") == 0)
483        ) {
484            if (p->setup_func(val) != 0)
485                printk(KERN_WARNING
486                       "Malformed early option '%s'\n", param);
487        }
488    }
489    /* We accept everything at this stage. */
490    return 0;
491}
492
493void __init parse_early_options(char *cmdline)
494{
495    parse_args("early options", cmdline, NULL, 0, do_early_param);
496}
497
498/* Arch code calls this early on, or if not, just before other parsing. */
499void __init parse_early_param(void)
500{
501    static __initdata int done = 0;
502    static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
503
504    if (done)
505        return;
506
507    /* All fall through to do_early_param. */
508    strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
509    parse_early_options(tmp_cmdline);
510    done = 1;
511}
512
513/*
514 * Activate the first processor.
515 */
516
517static void __init boot_cpu_init(void)
518{
519    int cpu = smp_processor_id();
520    /* Mark the boot cpu "present", "online" etc for SMP and UP case */
521    set_cpu_online(cpu, true);
522    set_cpu_present(cpu, true);
523    set_cpu_possible(cpu, true);
524}
525
526void __init __weak smp_setup_processor_id(void)
527{
528}
529
530void __init __weak thread_info_cache_init(void)
531{
532}
533
534/*
535 * Set up kernel memory allocators
536 */
537static void __init mm_init(void)
538{
539    /*
540     * page_cgroup requires countinous pages as memmap
541     * and it's bigger than MAX_ORDER unless SPARSEMEM.
542     */
543    page_cgroup_init_flatmem();
544    mem_init();
545    kmem_cache_init();
546    pgtable_cache_init();
547    vmalloc_init();
548}
549
550asmlinkage void __init start_kernel(void)
551{
552    char * command_line;
553    extern struct kernel_param __start___param[], __stop___param[];
554
555    smp_setup_processor_id();
556
557    /*
558     * Need to run as early as possible, to initialize the
559     * lockdep hash:
560     */
561    lockdep_init();
562    debug_objects_early_init();
563
564    /*
565     * Set up the the initial canary ASAP:
566     */
567    boot_init_stack_canary();
568
569    cgroup_init_early();
570
571    local_irq_disable();
572    early_boot_irqs_off();
573    early_init_irq_lock_class();
574
575/*
576 * Interrupts are still disabled. Do necessary setups, then
577 * enable them
578 */
579    lock_kernel();
580    tick_init();
581    boot_cpu_init();
582    page_address_init();
583    printk(KERN_NOTICE "%s", linux_banner);
584    setup_arch(&command_line);
585    mm_init_owner(&init_mm, &init_task);
586    setup_command_line(command_line);
587    setup_nr_cpu_ids();
588    setup_per_cpu_areas();
589    smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
590
591    build_all_zonelists();
592    page_alloc_init();
593
594    printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
595    parse_early_param();
596    parse_args("Booting kernel", static_command_line, __start___param,
597           __stop___param - __start___param,
598           &unknown_bootoption);
599    /*
600     * These use large bootmem allocations and must precede
601     * kmem_cache_init()
602     */
603    pidhash_init();
604    vfs_caches_init_early();
605    sort_main_extable();
606    trap_init();
607    mm_init();
608    /*
609     * Set up the scheduler prior starting any interrupts (such as the
610     * timer interrupt). Full topology setup happens at smp_init()
611     * time - but meanwhile we still have a functioning scheduler.
612     */
613    sched_init();
614    /*
615     * Disable preemption - early bootup scheduling is extremely
616     * fragile until we cpu_idle() for the first time.
617     */
618    preempt_disable();
619    if (!irqs_disabled()) {
620        printk(KERN_WARNING "start_kernel(): bug: interrupts were "
621                "enabled *very* early, fixing it\n");
622        local_irq_disable();
623    }
624    rcu_init();
625    /* init some links before init_ISA_irqs() */
626    early_irq_init();
627    init_IRQ();
628    prio_tree_init();
629    init_timers();
630    hrtimers_init();
631    softirq_init();
632    timekeeping_init();
633    time_init();
634    sched_clock_init();
635    profile_init();
636    if (!irqs_disabled())
637        printk(KERN_CRIT "start_kernel(): bug: interrupts were "
638                 "enabled early\n");
639    early_boot_irqs_on();
640    local_irq_enable();
641
642    /* Interrupts are enabled now so all GFP allocations are safe. */
643    set_gfp_allowed_mask(__GFP_BITS_MASK);
644
645    kmem_cache_init_late();
646
647    /*
648     * HACK ALERT! This is early. We're enabling the console before
649     * we've done PCI setups etc, and console_init() must be aware of
650     * this. But we do want output early, in case something goes wrong.
651     */
652    console_init();
653    if (panic_later)
654        panic(panic_later, panic_param);
655
656    lockdep_info();
657
658    /*
659     * Need to run this when irqs are enabled, because it wants
660     * to self-test [hard/soft]-irqs on/off lock inversion bugs
661     * too:
662     */
663    locking_selftest();
664
665#ifdef CONFIG_BLK_DEV_INITRD
666    if (initrd_start && !initrd_below_start_ok &&
667        page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
668        printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
669            "disabling it.\n",
670            page_to_pfn(virt_to_page((void *)initrd_start)),
671            min_low_pfn);
672        initrd_start = 0;
673    }
674#endif
675    page_cgroup_init();
676    enable_debug_pagealloc();
677    kmemtrace_init();
678    kmemleak_init();
679    debug_objects_mem_init();
680    idr_init_cache();
681    setup_per_cpu_pageset();
682    numa_policy_init();
683    if (late_time_init)
684        late_time_init();
685    calibrate_delay();
686    pidmap_init();
687    anon_vma_init();
688#ifdef CONFIG_X86
689    if (efi_enabled)
690        efi_enter_virtual_mode();
691#endif
692    thread_info_cache_init();
693    cred_init();
694    fork_init(num_physpages);
695    proc_caches_init();
696    buffer_init();
697    key_init();
698    security_init();
699    vfs_caches_init(num_physpages);
700    radix_tree_init();
701    signals_init();
702    /* rootfs populating might need page-writeback */
703    page_writeback_init();
704#ifdef CONFIG_PROC_FS
705    proc_root_init();
706#endif
707    cgroup_init();
708    cpuset_init();
709    taskstats_init_early();
710    delayacct_init();
711
712    check_bugs();
713
714    acpi_early_init(); /* before LAPIC and SMP init */
715
716    ftrace_init();
717
718    /* Do the rest non-__init'ed, we're now alive */
719    rest_init();
720}
721
722/* Call all constructor functions linked into the kernel. */
723static void __init do_ctors(void)
724{
725#ifdef CONFIG_CONSTRUCTORS
726    ctor_fn_t *call = (ctor_fn_t *) __ctors_start;
727
728    for (; call < (ctor_fn_t *) __ctors_end; call++)
729        (*call)();
730#endif
731}
732
733int initcall_debug;
734core_param(initcall_debug, initcall_debug, bool, 0644);
735
736static char msgbuf[64];
737static struct boot_trace_call call;
738static struct boot_trace_ret ret;
739
740int do_one_initcall(initcall_t fn)
741{
742    int count = preempt_count();
743    ktime_t calltime, delta, rettime;
744
745    if (initcall_debug) {
746        call.caller = task_pid_nr(current);
747        printk("calling %pF @ %i\n", fn, call.caller);
748        calltime = ktime_get();
749        trace_boot_call(&call, fn);
750        enable_boot_trace();
751    }
752
753    ret.result = fn();
754
755    if (initcall_debug) {
756        disable_boot_trace();
757        rettime = ktime_get();
758        delta = ktime_sub(rettime, calltime);
759        ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
760        trace_boot_ret(&ret, fn);
761        printk("initcall %pF returned %d after %Ld usecs\n", fn,
762            ret.result, ret.duration);
763    }
764
765    msgbuf[0] = 0;
766
767    if (ret.result && ret.result != -ENODEV && initcall_debug)
768        sprintf(msgbuf, "error code %d ", ret.result);
769
770    if (preempt_count() != count) {
771        strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
772        preempt_count() = count;
773    }
774    if (irqs_disabled()) {
775        strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
776        local_irq_enable();
777    }
778    if (msgbuf[0]) {
779        printk("initcall %pF returned with %s\n", fn, msgbuf);
780    }
781
782    return ret.result;
783}
784
785
786extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
787
788static void __init do_initcalls(void)
789{
790    initcall_t *call;
791
792    for (call = __early_initcall_end; call < __initcall_end; call++)
793        do_one_initcall(*call);
794
795    /* Make sure there is no pending stuff from the initcall sequence */
796    flush_scheduled_work();
797}
798
799/*
800 * Ok, the machine is now initialized. None of the devices
801 * have been touched yet, but the CPU subsystem is up and
802 * running, and memory and process management works.
803 *
804 * Now we can finally start doing some real work..
805 */
806static void __init do_basic_setup(void)
807{
808    rcu_init_sched(); /* needed by module_init stage. */
809    init_workqueues();
810    cpuset_init_smp();
811    usermodehelper_init();
812    driver_init();
813    init_irq_proc();
814    do_ctors();
815    do_initcalls();
816}
817
818static void __init do_pre_smp_initcalls(void)
819{
820    initcall_t *call;
821
822    for (call = __initcall_start; call < __early_initcall_end; call++)
823        do_one_initcall(*call);
824}
825
826static void run_init_process(char *init_filename)
827{
828    argv_init[0] = init_filename;
829    kernel_execve(init_filename, argv_init, envp_init);
830}
831
832/* This is a non __init function. Force it to be noinline otherwise gcc
833 * makes it inline to init() and it becomes part of init.text section
834 */
835static noinline int init_post(void)
836    __releases(kernel_lock)
837{
838    /* need to finish all async __init code before freeing the memory */
839    async_synchronize_full();
840    free_initmem();
841    unlock_kernel();
842    mark_rodata_ro();
843    system_state = SYSTEM_RUNNING;
844    numa_default_policy();
845
846    if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
847        printk(KERN_WARNING "Please be patient, while OpenWrt loads ...\n");
848
849    (void) sys_dup(0);
850    (void) sys_dup(0);
851
852    current->signal->flags |= SIGNAL_UNKILLABLE;
853
854    if (ramdisk_execute_command) {
855        run_init_process(ramdisk_execute_command);
856        printk(KERN_WARNING "Failed to execute %s\n",
857                ramdisk_execute_command);
858    }
859
860    /*
861     * We try each of these until one succeeds.
862     *
863     * The Bourne shell can be used instead of init if we are
864     * trying to recover a really broken machine.
865     */
866    if (execute_command) {
867        run_init_process(execute_command);
868        printk(KERN_WARNING "Failed to execute %s. Attempting "
869                    "defaults...\n", execute_command);
870    }
871    run_init_process("/etc/preinit");
872
873    panic("No init found. Try passing init= option to kernel.");
874}
875
876static int __init kernel_init(void * unused)
877{
878    lock_kernel();
879
880    /*
881     * init can allocate pages on any node
882     */
883    set_mems_allowed(node_possible_map);
884    /*
885     * init can run on any cpu.
886     */
887    set_cpus_allowed_ptr(current, cpu_all_mask);
888    /*
889     * Tell the world that we're going to be the grim
890     * reaper of innocent orphaned children.
891     *
892     * We don't want people to have to make incorrect
893     * assumptions about where in the task array this
894     * can be found.
895     */
896    init_pid_ns.child_reaper = current;
897
898    cad_pid = task_pid(current);
899
900    smp_prepare_cpus(setup_max_cpus);
901
902    do_pre_smp_initcalls();
903    start_boot_trace();
904
905    smp_init();
906    sched_init_smp();
907
908    do_basic_setup();
909
910    /*
911     * check if there is an early userspace init. If yes, let it do all
912     * the work
913     */
914
915    if (!ramdisk_execute_command)
916        ramdisk_execute_command = "/init";
917
918    if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
919        ramdisk_execute_command = NULL;
920        prepare_namespace();
921    }
922
923    /*
924     * Ok, we have completed the initial bootup, and
925     * we're essentially up and running. Get rid of the
926     * initmem segments and start the user-mode stuff..
927     */
928
929    init_post();
930    return 0;
931}
932

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