new retransmit part 3
[cor_2_6_31.git] / init / main.c
blob2c5ade79eb81718702dd1fdf44e8b129e69f88a9
1 /*
2 * linux/init/main.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
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>
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>
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>
79 #ifdef CONFIG_X86_LOCAL_APIC
80 #include <asm/smp.h>
81 #endif
83 static int kernel_init(void *);
85 extern void init_IRQ(void);
86 extern void fork_init(unsigned long);
87 extern void mca_init(void);
88 extern void sbus_init(void);
89 extern void prio_tree_init(void);
90 extern void radix_tree_init(void);
91 extern void free_initmem(void);
92 #ifndef CONFIG_DEBUG_RODATA
93 static inline void mark_rodata_ro(void) { }
94 #endif
96 #ifdef CONFIG_TC
97 extern void tc_init(void);
98 #endif
100 enum system_states system_state __read_mostly;
101 EXPORT_SYMBOL(system_state);
104 * Boot command-line arguments
106 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
107 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
109 extern void time_init(void);
110 /* Default late time init is NULL. archs can override this later. */
111 void (*__initdata late_time_init)(void);
112 extern void softirq_init(void);
114 /* Untouched command line saved by arch-specific code. */
115 char __initdata boot_command_line[COMMAND_LINE_SIZE];
116 /* Untouched saved command line (eg. for /proc) */
117 char *saved_command_line;
118 /* Command line for parameter parsing */
119 static char *static_command_line;
121 static char *execute_command;
122 static char *ramdisk_execute_command;
124 #ifdef CONFIG_SMP
125 /* Setup configured maximum number of CPUs to activate */
126 unsigned int __initdata setup_max_cpus = NR_CPUS;
129 * Setup routine for controlling SMP activation
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
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>.
139 void __weak arch_disable_smp_support(void) { }
141 static int __init nosmp(char *str)
143 setup_max_cpus = 0;
144 arch_disable_smp_support();
146 return 0;
149 early_param("nosmp", nosmp);
151 static int __init maxcpus(char *str)
153 get_option(&str, &setup_max_cpus);
154 if (setup_max_cpus == 0)
155 arch_disable_smp_support();
157 return 0;
160 early_param("maxcpus", maxcpus);
161 #else
162 const unsigned int setup_max_cpus = NR_CPUS;
163 #endif
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.
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.
174 unsigned int reset_devices;
175 EXPORT_SYMBOL(reset_devices);
177 static int __init set_reset_devices(char *str)
179 reset_devices = 1;
180 return 1;
183 __setup("reset_devices", set_reset_devices);
185 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
186 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
187 static const char *panic_later, *panic_param;
189 extern struct obs_kernel_param __setup_start[], __setup_end[];
191 static int __init obsolete_checksetup(char *line)
193 struct obs_kernel_param *p;
194 int had_early_param = 0;
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;
214 p++;
215 } while (p < __setup_end);
217 return had_early_param;
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
224 unsigned long loops_per_jiffy = (1<<12);
226 EXPORT_SYMBOL(loops_per_jiffy);
228 static int __init debug_kernel(char *str)
230 console_loglevel = 10;
231 return 0;
234 static int __init quiet_kernel(char *str)
236 console_loglevel = 4;
237 return 0;
240 early_param("debug", debug_kernel);
241 early_param("quiet", quiet_kernel);
243 static int __init loglevel(char *str)
245 get_option(&str, &console_loglevel);
246 return 0;
249 early_param("loglevel", loglevel);
252 * Unknown boot options get handed to init, unless they look like
253 * failed parameters
255 static int __init unknown_bootoption(char *param, char *val)
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();
270 /* Handle obsolete-style parameters */
271 if (obsolete_checksetup(param))
272 return 0;
275 * Preemptive maintenance for "why didn't my misspelled command
276 * line work?"
278 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
279 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
280 return 0;
283 if (panic_later)
284 return 0;
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;
294 if (!strncmp(param, envp_init[i], val - param))
295 break;
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;
307 argv_init[i] = param;
309 return 0;
312 #ifdef CONFIG_DEBUG_PAGEALLOC
313 int __read_mostly debug_pagealloc_enabled = 0;
314 #endif
316 static int __init init_setup(char *str)
318 unsigned int i;
320 execute_command = str;
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]
327 for (i = 1; i < MAX_INIT_ARGS; i++)
328 argv_init[i] = NULL;
329 return 1;
331 __setup("init=", init_setup);
333 static int __init rdinit_setup(char *str)
335 unsigned int i;
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;
343 __setup("rdinit=", rdinit_setup);
345 #ifndef CONFIG_SMP
347 #ifdef CONFIG_X86_LOCAL_APIC
348 static void __init smp_init(void)
350 APIC_init_uniprocessor();
352 #else
353 #define smp_init() do { } while (0)
354 #endif
356 static inline void setup_per_cpu_areas(void) { }
357 static inline void setup_nr_cpu_ids(void) { }
358 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
360 #else
362 #if NR_CPUS > BITS_PER_LONG
363 cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
364 EXPORT_SYMBOL(cpu_mask_all);
365 #endif
367 /* Setup number of possible processor ids */
368 int nr_cpu_ids __read_mostly = NR_CPUS;
369 EXPORT_SYMBOL(nr_cpu_ids);
371 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
372 static void __init setup_nr_cpu_ids(void)
374 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
377 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
378 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
380 EXPORT_SYMBOL(__per_cpu_offset);
382 static void __init setup_per_cpu_areas(void)
384 unsigned long size, i;
385 char *ptr;
386 unsigned long nr_possible_cpus = num_possible_cpus();
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);
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;
398 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
400 /* Called by boot processor to activate the rest. */
401 static void __init smp_init(void)
403 unsigned int cpu;
406 * Set up the current CPU as possible to migrate to.
407 * The other ones will be done by cpu_up/cpu_down()
409 set_cpu_active(smp_processor_id(), true);
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);
419 /* Any cleanup work */
420 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
421 smp_cpus_done(setup_max_cpus);
424 #endif
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.
432 static void __init setup_command_line(char *command_line)
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);
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.
446 * gcc-3.4 accidentally inlines this function, so use noinline.
449 static noinline void __init_refok rest_init(void)
450 __releases(kernel_lock)
452 int pid;
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();
461 * The boot idle thread must execute schedule()
462 * at least once to get things moving:
464 init_idle_bootup_task(current);
465 rcu_scheduler_starting();
466 preempt_enable_no_resched();
467 schedule();
468 preempt_disable();
470 /* Call into cpu_idle with preempt disabled */
471 cpu_idle();
474 /* Check for early params. */
475 static int __init do_early_param(char *param, char *val)
477 struct obs_kernel_param *p;
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)
484 if (p->setup_func(val) != 0)
485 printk(KERN_WARNING
486 "Malformed early option '%s'\n", param);
489 /* We accept everything at this stage. */
490 return 0;
493 void __init parse_early_options(char *cmdline)
495 parse_args("early options", cmdline, NULL, 0, do_early_param);
498 /* Arch code calls this early on, or if not, just before other parsing. */
499 void __init parse_early_param(void)
501 static __initdata int done = 0;
502 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
504 if (done)
505 return;
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;
514 * Activate the first processor.
517 static void __init boot_cpu_init(void)
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);
526 void __init __weak smp_setup_processor_id(void)
530 void __init __weak thread_info_cache_init(void)
535 * Set up kernel memory allocators
537 static void __init mm_init(void)
540 * page_cgroup requires countinous pages as memmap
541 * and it's bigger than MAX_ORDER unless SPARSEMEM.
543 page_cgroup_init_flatmem();
544 mem_init();
545 kmem_cache_init();
546 pgtable_cache_init();
547 vmalloc_init();
550 asmlinkage void __init start_kernel(void)
552 char * command_line;
553 extern struct kernel_param __start___param[], __stop___param[];
555 smp_setup_processor_id();
558 * Need to run as early as possible, to initialize the
559 * lockdep hash:
561 lockdep_init();
562 debug_objects_early_init();
565 * Set up the the initial canary ASAP:
567 boot_init_stack_canary();
569 cgroup_init_early();
571 local_irq_disable();
572 early_boot_irqs_off();
573 early_init_irq_lock_class();
576 * Interrupts are still disabled. Do necessary setups, then
577 * enable them
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_per_cpu_areas();
588 setup_nr_cpu_ids();
589 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
591 build_all_zonelists();
592 page_alloc_init();
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);
600 * These use large bootmem allocations and must precede
601 * kmem_cache_init()
603 pidhash_init();
604 vfs_caches_init_early();
605 sort_main_extable();
606 trap_init();
607 mm_init();
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.
613 sched_init();
615 * Disable preemption - early bootup scheduling is extremely
616 * fragile until we cpu_idle() for the first time.
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();
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();
642 /* Interrupts are enabled now so all GFP allocations are safe. */
643 set_gfp_allowed_mask(__GFP_BITS_MASK);
645 kmem_cache_init_late();
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.
652 console_init();
653 if (panic_later)
654 panic(panic_later, panic_param);
656 lockdep_info();
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:
663 locking_selftest();
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;
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();
712 check_bugs();
714 acpi_early_init(); /* before LAPIC and SMP init */
716 ftrace_init();
718 /* Do the rest non-__init'ed, we're now alive */
719 rest_init();
722 /* Call all constructor functions linked into the kernel. */
723 static void __init do_ctors(void)
725 #ifdef CONFIG_CONSTRUCTORS
726 ctor_fn_t *call = (ctor_fn_t *) __ctors_start;
728 for (; call < (ctor_fn_t *) __ctors_end; call++)
729 (*call)();
730 #endif
733 int initcall_debug;
734 core_param(initcall_debug, initcall_debug, bool, 0644);
736 int do_one_initcall(initcall_t fn)
738 int count = preempt_count();
739 ktime_t calltime, delta, rettime;
740 char msgbuf[64];
741 struct boot_trace_call call;
742 struct boot_trace_ret ret;
744 if (initcall_debug) {
745 call.caller = task_pid_nr(current);
746 printk("calling %pF @ %i\n", fn, call.caller);
747 calltime = ktime_get();
748 trace_boot_call(&call, fn);
749 enable_boot_trace();
752 ret.result = fn();
754 if (initcall_debug) {
755 disable_boot_trace();
756 rettime = ktime_get();
757 delta = ktime_sub(rettime, calltime);
758 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
759 trace_boot_ret(&ret, fn);
760 printk("initcall %pF returned %d after %Ld usecs\n", fn,
761 ret.result, ret.duration);
764 msgbuf[0] = 0;
766 if (ret.result && ret.result != -ENODEV && initcall_debug)
767 sprintf(msgbuf, "error code %d ", ret.result);
769 if (preempt_count() != count) {
770 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
771 preempt_count() = count;
773 if (irqs_disabled()) {
774 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
775 local_irq_enable();
777 if (msgbuf[0]) {
778 printk("initcall %pF returned with %s\n", fn, msgbuf);
781 return ret.result;
785 extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
787 static void __init do_initcalls(void)
789 initcall_t *call;
791 for (call = __early_initcall_end; call < __initcall_end; call++)
792 do_one_initcall(*call);
794 /* Make sure there is no pending stuff from the initcall sequence */
795 flush_scheduled_work();
799 * Ok, the machine is now initialized. None of the devices
800 * have been touched yet, but the CPU subsystem is up and
801 * running, and memory and process management works.
803 * Now we can finally start doing some real work..
805 static void __init do_basic_setup(void)
807 rcu_init_sched(); /* needed by module_init stage. */
808 init_workqueues();
809 cpuset_init_smp();
810 usermodehelper_init();
811 driver_init();
812 init_irq_proc();
813 do_ctors();
814 do_initcalls();
817 static void __init do_pre_smp_initcalls(void)
819 initcall_t *call;
821 for (call = __initcall_start; call < __early_initcall_end; call++)
822 do_one_initcall(*call);
825 static void run_init_process(char *init_filename)
827 argv_init[0] = init_filename;
828 kernel_execve(init_filename, argv_init, envp_init);
831 /* This is a non __init function. Force it to be noinline otherwise gcc
832 * makes it inline to init() and it becomes part of init.text section
834 static noinline int init_post(void)
835 __releases(kernel_lock)
837 /* need to finish all async __init code before freeing the memory */
838 async_synchronize_full();
839 free_initmem();
840 unlock_kernel();
841 mark_rodata_ro();
842 system_state = SYSTEM_RUNNING;
843 numa_default_policy();
845 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
846 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
848 (void) sys_dup(0);
849 (void) sys_dup(0);
851 current->signal->flags |= SIGNAL_UNKILLABLE;
853 if (ramdisk_execute_command) {
854 run_init_process(ramdisk_execute_command);
855 printk(KERN_WARNING "Failed to execute %s\n",
856 ramdisk_execute_command);
860 * We try each of these until one succeeds.
862 * The Bourne shell can be used instead of init if we are
863 * trying to recover a really broken machine.
865 if (execute_command) {
866 run_init_process(execute_command);
867 printk(KERN_WARNING "Failed to execute %s. Attempting "
868 "defaults...\n", execute_command);
870 run_init_process("/sbin/init");
871 run_init_process("/etc/init");
872 run_init_process("/bin/init");
873 run_init_process("/bin/sh");
875 panic("No init found. Try passing init= option to kernel.");
878 static int __init kernel_init(void * unused)
880 lock_kernel();
883 * init can allocate pages on any node
885 set_mems_allowed(node_possible_map);
887 * init can run on any cpu.
889 set_cpus_allowed_ptr(current, cpu_all_mask);
891 * Tell the world that we're going to be the grim
892 * reaper of innocent orphaned children.
894 * We don't want people to have to make incorrect
895 * assumptions about where in the task array this
896 * can be found.
898 init_pid_ns.child_reaper = current;
900 cad_pid = task_pid(current);
902 smp_prepare_cpus(setup_max_cpus);
904 do_pre_smp_initcalls();
905 start_boot_trace();
907 smp_init();
908 sched_init_smp();
910 do_basic_setup();
913 * check if there is an early userspace init. If yes, let it do all
914 * the work
917 if (!ramdisk_execute_command)
918 ramdisk_execute_command = "/init";
920 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
921 ramdisk_execute_command = NULL;
922 prepare_namespace();
926 * Ok, we have completed the initial bootup, and
927 * we're essentially up and running. Get rid of the
928 * initmem segments and start the user-mode stuff..
931 init_post();
932 return 0;