blob: a42fdf4aeba91ada21882d86d552ed722c00eb5a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/syscalls.h>
Ingo Molnar9b5609f2008-02-14 09:41:09 +010017#include <linux/stackprotector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/smp_lock.h>
24#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040026#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/tty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/percpu.h>
29#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070030#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010032#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020034#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#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>
Paul Menageddbcc7e2007-10-18 23:39:30 -070043#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080045#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080046#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070047#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070048#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/unistd.h>
50#include <linux/rmap.h>
51#include <linux/mempolicy.h>
52#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070053#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070054#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070055#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070056#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070057#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010058#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080059#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080060#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070061#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010062#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080063#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070064#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050065#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040066#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080067#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020068#include <linux/kmemcheck.h>
Zhaolei02af61b2009-04-10 14:26:18 +080069#include <linux/kmemtrace.h>
Feng Tang6ae69962009-08-14 15:13:46 -040070#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020071#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090072#include <linux/slab.h>
Frederic Weisbecker3f5ec132008-11-11 23:21:31 +010073#include <trace/boot.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75#include <asm/io.h>
76#include <asm/bugs.h>
77#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070078#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080079#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#ifdef CONFIG_X86_LOCAL_APIC
82#include <asm/smp.h>
83#endif
84
Sam Ravnborgaae5f662007-02-26 16:45:41 +010085static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088extern void fork_init(unsigned long);
89extern void mca_init(void);
90extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091extern void prio_tree_init(void);
92extern void radix_tree_init(void);
93extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080094#ifndef CONFIG_DEBUG_RODATA
95static inline void mark_rodata_ro(void) { }
96#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98#ifdef CONFIG_TC
99extern void tc_init(void);
100#endif
101
Paul E. McKenneya6826042009-02-25 18:03:42 -0800102enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103EXPORT_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. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800113void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114extern void softirq_init(void);
115
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800116/* 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
123static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700124static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Jan Beulich8b3b2952007-07-15 23:41:07 -0700126#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127/* Setup configured maximum number of CPUs to activate */
Thomas Renninger75cbfb92010-05-26 17:03:33 +0200128unsigned int setup_max_cpus = NR_CPUS;
129EXPORT_SYMBOL(setup_max_cpus);
130
Vivek Goyal7e962872006-09-27 01:50:44 -0700131
132/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * Setup routine for controlling SMP activation
134 *
135 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
136 * activation entirely (the MPS table probe still happens, though).
137 *
138 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
139 * greater than 0, limits the maximum number of CPUs activated in
140 * SMP mode to <NUM>.
141 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100142
143void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145static int __init nosmp(char *str)
146{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100147 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100148 arch_disable_smp_support();
149
Jan Beulich8b3b2952007-07-15 23:41:07 -0700150 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151}
152
Jan Beulich8b3b2952007-07-15 23:41:07 -0700153early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
Yinghai Lu2b633e32010-02-10 01:20:37 -0800155/* this is hard limit */
156static int __init nrcpus(char *str)
157{
158 int nr_cpus;
159
160 get_option(&str, &nr_cpus);
161 if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
162 nr_cpu_ids = nr_cpus;
163
164 return 0;
165}
166
167early_param("nr_cpus", nrcpus);
168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169static int __init maxcpus(char *str)
170{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100171 get_option(&str, &setup_max_cpus);
172 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100173 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400174
175 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176}
177
Hugh Dickins81340972007-08-27 16:02:12 +0100178early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700179#else
H Hartley Sweeten7463e632010-03-05 13:42:46 -0800180static const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700181#endif
182
183/*
184 * If set, this is an indication to the drivers that reset the underlying
185 * device before going ahead with the initialization otherwise driver might
186 * rely on the BIOS and skip the reset operation.
187 *
188 * This is useful if kernel is booting in an unreliable environment.
189 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
190 * skipped and devices will be in unknown state.
191 */
192unsigned int reset_devices;
193EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Vivek Goyal7e962872006-09-27 01:50:44 -0700195static int __init set_reset_devices(char *str)
196{
197 reset_devices = 1;
198 return 1;
199}
200
201__setup("reset_devices", set_reset_devices);
202
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
204char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
205static const char *panic_later, *panic_param;
206
207extern struct obs_kernel_param __setup_start[], __setup_end[];
208
209static int __init obsolete_checksetup(char *line)
210{
211 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200212 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 p = __setup_start;
215 do {
216 int n = strlen(p->str);
217 if (!strncmp(line, p->str, n)) {
218 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200219 /* Already done in parse_early_param?
220 * (Needs exact match on param part).
221 * Keep iterating, as we can have early
222 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200224 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 } else if (!p->setup_func) {
226 printk(KERN_WARNING "Parameter %s is obsolete,"
227 " ignored\n", p->str);
228 return 1;
229 } else if (p->setup_func(line + n))
230 return 1;
231 }
232 p++;
233 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200234
235 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
238/*
239 * This should be approx 2 Bo*oMips to start (note initial shift), and will
240 * still work even if initially too large, it will just take slightly longer
241 */
242unsigned long loops_per_jiffy = (1<<12);
243
244EXPORT_SYMBOL(loops_per_jiffy);
245
246static int __init debug_kernel(char *str)
247{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800249 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
251
252static int __init quiet_kernel(char *str)
253{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800255 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
Yinghai Luf6f21c812008-02-08 04:21:58 -0800258early_param("debug", debug_kernel);
259early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
261static int __init loglevel(char *str)
262{
263 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800264 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Yinghai Luf6f21c812008-02-08 04:21:58 -0800267early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269/*
270 * Unknown boot options get handed to init, unless they look like
Rusty Russellf066a4f2009-12-01 14:56:44 +1030271 * unused parameters (modprobe will find them in /proc/cmdline).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 */
273static int __init unknown_bootoption(char *param, char *val)
274{
275 /* Change NUL term back to "=", to make "param" the whole string. */
276 if (val) {
277 /* param=val or param="val"? */
278 if (val == param+strlen(param)+1)
279 val[-1] = '=';
280 else if (val == param+strlen(param)+2) {
281 val[-2] = '=';
282 memmove(val-1, val, strlen(val)+1);
283 val--;
284 } else
285 BUG();
286 }
287
288 /* Handle obsolete-style parameters */
289 if (obsolete_checksetup(param))
290 return 0;
291
Rusty Russellf066a4f2009-12-01 14:56:44 +1030292 /* Unused module parameter. */
293 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
296 if (panic_later)
297 return 0;
298
299 if (val) {
300 /* Environment option */
301 unsigned int i;
302 for (i = 0; envp_init[i]; i++) {
303 if (i == MAX_INIT_ENVS) {
304 panic_later = "Too many boot env vars at `%s'";
305 panic_param = param;
306 }
307 if (!strncmp(param, envp_init[i], val - param))
308 break;
309 }
310 envp_init[i] = param;
311 } else {
312 /* Command line option */
313 unsigned int i;
314 for (i = 0; argv_init[i]; i++) {
315 if (i == MAX_INIT_ARGS) {
316 panic_later = "Too many boot init vars at `%s'";
317 panic_param = param;
318 }
319 }
320 argv_init[i] = param;
321 }
322 return 0;
323}
324
Ingo Molnar12d6f212008-01-30 13:33:58 +0100325#ifdef CONFIG_DEBUG_PAGEALLOC
326int __read_mostly debug_pagealloc_enabled = 0;
327#endif
328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329static int __init init_setup(char *str)
330{
331 unsigned int i;
332
333 execute_command = str;
334 /*
335 * In case LILO is going to boot us with default command line,
336 * it prepends "auto" before the whole cmdline which makes
337 * the shell think it should execute a script with such name.
338 * So we ignore all arguments entered _before_ init=... [MJ]
339 */
340 for (i = 1; i < MAX_INIT_ARGS; i++)
341 argv_init[i] = NULL;
342 return 1;
343}
344__setup("init=", init_setup);
345
Olof Johanssonffdfc402005-09-06 15:17:19 -0700346static int __init rdinit_setup(char *str)
347{
348 unsigned int i;
349
350 ramdisk_execute_command = str;
351 /* See "auto" comment in init_setup */
352 for (i = 1; i < MAX_INIT_ARGS; i++)
353 argv_init[i] = NULL;
354 return 1;
355}
356__setup("rdinit=", rdinit_setup);
357
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358#ifndef CONFIG_SMP
359
360#ifdef CONFIG_X86_LOCAL_APIC
361static void __init smp_init(void)
362{
363 APIC_init_uniprocessor();
364}
365#else
366#define smp_init() do { } while (0)
367#endif
368
Mike Travise0982e92008-03-26 14:23:48 -0700369static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370static inline void smp_prepare_cpus(unsigned int maxcpus) { }
371
372#else
373
Mike Travise0982e92008-03-26 14:23:48 -0700374/* Setup number of possible processor ids */
375int nr_cpu_ids __read_mostly = NR_CPUS;
376EXPORT_SYMBOL(nr_cpu_ids);
377
378/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
379static void __init setup_nr_cpu_ids(void)
380{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030381 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700382}
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384/* Called by boot processor to activate the rest. */
385static void __init smp_init(void)
386{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800387 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800390 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100391 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800393 if (!cpu_online(cpu))
394 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 }
396
397 /* Any cleanup work */
398 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100399 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
402#endif
403
404/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800405 * We need to store the untouched command line for future reference.
406 * We also need to store the touched command line since the parameter
407 * parsing is performed in place, and we should allow a component to
408 * store reference of name/value for future reference.
409 */
410static void __init setup_command_line(char *command_line)
411{
412 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
413 static_command_line = alloc_bootmem(strlen (command_line)+1);
414 strcpy (saved_command_line, boot_command_line);
415 strcpy (static_command_line, command_line);
416}
417
418/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 * We need to finalize in a non-__init function or else race conditions
420 * between the root thread and the init thread may cause start_kernel to
421 * be reaped by free_initmem before the root thread has proceeded to
422 * cpu_idle.
423 *
424 * gcc-3.4 accidentally inlines this function, so use noinline.
425 */
426
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200427static __initdata DECLARE_COMPLETION(kthreadd_done);
428
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800429static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 __releases(kernel_lock)
431{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700432 int pid;
433
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700434 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200435 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200436 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200437 * the init task will end up wanting to create kthreads, which, if
438 * we schedule it before we create kthreadd, will OOPS.
439 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100440 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700442 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800443 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700444 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800445 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200446 complete(&kthreadd_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200448
449 /*
450 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200451 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200452 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200453 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800454 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200455 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800456 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200457
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800458 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200460}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462/* Check for early params. */
463static int __init do_early_param(char *param, char *val)
464{
465 struct obs_kernel_param *p;
466
467 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700468 if ((p->early && strcmp(param, p->str) == 0) ||
469 (strcmp(param, "console") == 0 &&
470 strcmp(p->str, "earlycon") == 0)
471 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 if (p->setup_func(val) != 0)
473 printk(KERN_WARNING
474 "Malformed early option '%s'\n", param);
475 }
476 }
477 /* We accept everything at this stage. */
478 return 0;
479}
480
Magnus Damm13977092009-03-30 14:37:25 -0700481void __init parse_early_options(char *cmdline)
482{
483 parse_args("early options", cmdline, NULL, 0, do_early_param);
484}
485
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486/* Arch code calls this early on, or if not, just before other parsing. */
487void __init parse_early_param(void)
488{
489 static __initdata int done = 0;
490 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
491
492 if (done)
493 return;
494
495 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800496 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700497 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 done = 1;
499}
500
501/*
502 * Activate the first processor.
503 */
504
Stas Sergeev44fd2292006-03-23 02:59:44 -0800505static void __init boot_cpu_init(void)
506{
507 int cpu = smp_processor_id();
508 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030509 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100510 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030511 set_cpu_present(cpu, true);
512 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800513}
514
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000515void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700516{
517}
518
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000519void __init __weak thread_info_cache_init(void)
520{
521}
522
Pekka Enberg444f4782009-06-11 18:29:06 +0300523/*
524 * Set up kernel memory allocators
525 */
526static void __init mm_init(void)
527{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300528 /*
529 * page_cgroup requires countinous pages as memmap
530 * and it's bigger than MAX_ORDER unless SPARSEMEM.
531 */
532 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300533 mem_init();
534 kmem_cache_init();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000535 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300536 vmalloc_init();
537}
538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539asmlinkage void __init start_kernel(void)
540{
541 char * command_line;
542 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700543
544 smp_setup_processor_id();
545
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700546 /*
547 * Need to run as early as possible, to initialize the
548 * lockdep hash:
549 */
550 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700551 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100552
553 /*
554 * Set up the the initial canary ASAP:
555 */
556 boot_init_stack_canary();
557
Paul Menageddbcc7e2007-10-18 23:39:30 -0700558 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700559
560 local_irq_disable();
561 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700562 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700563
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564/*
565 * Interrupts are still disabled. Do necessary setups, then
566 * enable them
567 */
568 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800569 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800570 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200572 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700574 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800575 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700576 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900577 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800578 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
Haicheng Li1f522502010-05-24 14:32:51 -0700580 build_all_zonelists(NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300581 page_alloc_init();
582
583 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
584 parse_early_param();
585 parse_args("Booting kernel", static_command_line, __start___param,
586 __stop___param - __start___param,
587 &unknown_bootoption);
588 /*
589 * These use large bootmem allocations and must precede
590 * kmem_cache_init()
591 */
592 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300593 vfs_caches_init_early();
594 sort_main_extable();
595 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300596 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 /*
598 * Set up the scheduler prior starting any interrupts (such as the
599 * timer interrupt). Full topology setup happens at smp_init()
600 * time - but meanwhile we still have a functioning scheduler.
601 */
602 sched_init();
603 /*
604 * Disable preemption - early bootup scheduling is extremely
605 * fragile until we cpu_idle() for the first time.
606 */
607 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800608 if (!irqs_disabled()) {
609 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
610 "enabled *very* early, fixing it\n");
611 local_irq_disable();
612 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800614 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800615 /* init some links before init_ISA_irqs() */
616 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100618 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800620 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700622 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700623 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700624 profile_init();
625 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030626 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
627 "enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700628 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700629 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000630
631 /* Interrupts are enabled now so all GFP allocations are safe. */
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800632 gfp_allowed_mask = __GFP_BITS_MASK;
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000633
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300634 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
636 /*
637 * HACK ALERT! This is early. We're enabling the console before
638 * we've done PCI setups etc, and console_init() must be aware of
639 * this. But we do want output early, in case something goes wrong.
640 */
641 console_init();
642 if (panic_later)
643 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700644
645 lockdep_info();
646
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700647 /*
648 * Need to run this when irqs are enabled, because it wants
649 * to self-test [hard/soft]-irqs on/off lock inversion bugs
650 * too:
651 */
652 locking_selftest();
653
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654#ifdef CONFIG_BLK_DEV_INITRD
655 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700656 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200658 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700659 page_to_pfn(virt_to_page((void *)initrd_start)),
660 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 initrd_start = 0;
662 }
663#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700664 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100665 enable_debug_pagealloc();
Eduard - Gabriel Munteanub9ce08c2008-08-10 20:14:03 +0300666 kmemtrace_init();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100667 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700668 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700669 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700670 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 numa_policy_init();
672 if (late_time_init)
673 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200674 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 calibrate_delay();
676 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 anon_vma_init();
678#ifdef CONFIG_X86
679 if (efi_enabled)
680 efi_enter_virtual_mode();
681#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000682 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100683 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700684 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 proc_caches_init();
686 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 key_init();
688 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500689 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700690 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 signals_init();
692 /* rootfs populating might need page-writeback */
693 page_writeback_init();
694#ifdef CONFIG_PROC_FS
695 proc_root_init();
696#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700697 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700699 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700700 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
702 check_bugs();
703
704 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400705 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400707 ftrace_init();
708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 /* Do the rest non-__init'ed, we're now alive */
710 rest_init();
711}
712
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700713/* Call all constructor functions linked into the kernel. */
714static void __init do_ctors(void)
715{
716#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800717 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700718
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800719 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
720 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700721#endif
722}
723
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800724int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500725core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200727static char msgbuf[64];
728static struct boot_trace_call call;
729static struct boot_trace_ret ret;
730
Arjan van de Ven59f94152008-07-30 12:49:02 -0700731int do_one_initcall(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700732{
733 int count = preempt_count();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100734 ktime_t calltime, delta, rettime;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700735
736 if (initcall_debug) {
Frederic Weisbecker74239072008-11-11 23:24:42 +0100737 call.caller = task_pid_nr(current);
738 printk("calling %pF @ %i\n", fn, call.caller);
739 calltime = ktime_get();
740 trace_boot_call(&call, fn);
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100741 enable_boot_trace();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700742 }
743
Frederic Weisbecker74239072008-11-11 23:24:42 +0100744 ret.result = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700745
746 if (initcall_debug) {
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100747 disable_boot_trace();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100748 rettime = ktime_get();
749 delta = ktime_sub(rettime, calltime);
Will Newton1d926f22008-11-21 14:08:59 -0800750 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Frederic Weisbecker74239072008-11-11 23:24:42 +0100751 trace_boot_ret(&ret, fn);
Tim Birdca538f62008-10-09 15:23:05 -0700752 printk("initcall %pF returned %d after %Ld usecs\n", fn,
Frederic Weisbecker74239072008-11-11 23:24:42 +0100753 ret.result, ret.duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700754 }
755
756 msgbuf[0] = 0;
757
Frederic Weisbecker74239072008-11-11 23:24:42 +0100758 if (ret.result && ret.result != -ENODEV && initcall_debug)
759 sprintf(msgbuf, "error code %d ", ret.result);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700760
761 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700762 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700763 preempt_count() = count;
764 }
765 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700766 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700767 local_irq_enable();
768 }
769 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700770 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700771 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700772
Frederic Weisbecker74239072008-11-11 23:24:42 +0100773 return ret.result;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700774}
775
776
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700777extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
779static void __init do_initcalls(void)
780{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800781 initcall_t *fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800783 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
784 do_one_initcall(*fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785
786 /* Make sure there is no pending stuff from the initcall sequence */
787 flush_scheduled_work();
788}
789
790/*
791 * Ok, the machine is now initialized. None of the devices
792 * have been touched yet, but the CPU subsystem is up and
793 * running, and memory and process management works.
794 *
795 * Now we can finally start doing some real work..
796 */
797static void __init do_basic_setup(void)
798{
Linus Torvalds4403b402008-10-25 19:53:38 -0700799 init_workqueues();
Lai Jiangshan759ee092009-03-25 17:06:30 +0800800 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200802 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800804 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700805 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 do_initcalls();
807}
808
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700809static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700810{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800811 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700812
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800813 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
814 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700815}
816
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817static void run_init_process(char *init_filename)
818{
819 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700820 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821}
822
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100823/* This is a non __init function. Force it to be noinline otherwise gcc
824 * makes it inline to init() and it becomes part of init.text section
825 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800826static noinline int init_post(void)
Hannes Ederacdd0522009-03-31 15:23:50 -0700827 __releases(kernel_lock)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100828{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800829 /* need to finish all async __init code before freeing the memory */
830 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100831 free_initmem();
832 unlock_kernel();
833 mark_rodata_ro();
834 system_state = SYSTEM_RUNNING;
835 numa_default_policy();
836
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100837
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700838 current->signal->flags |= SIGNAL_UNKILLABLE;
839
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100840 if (ramdisk_execute_command) {
841 run_init_process(ramdisk_execute_command);
842 printk(KERN_WARNING "Failed to execute %s\n",
843 ramdisk_execute_command);
844 }
845
846 /*
847 * We try each of these until one succeeds.
848 *
849 * The Bourne shell can be used instead of init if we are
850 * trying to recover a really broken machine.
851 */
852 if (execute_command) {
853 run_init_process(execute_command);
854 printk(KERN_WARNING "Failed to execute %s. Attempting "
855 "defaults...\n", execute_command);
856 }
857 run_init_process("/sbin/init");
858 run_init_process("/etc/init");
859 run_init_process("/bin/init");
860 run_init_process("/bin/sh");
861
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800862 panic("No init found. Try passing init= option to kernel. "
863 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100864}
865
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100866static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200868 /*
869 * Wait until kthreadd is all set-up.
870 */
871 wait_for_completion(&kthreadd_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 lock_kernel();
Miao Xie58568d22009-06-16 15:31:49 -0700873
874 /*
875 * init can allocate pages on any node
876 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700877 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 /*
879 * init can run on any cpu.
880 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600881 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 /*
883 * Tell the world that we're going to be the grim
884 * reaper of innocent orphaned children.
885 *
886 * We don't want people to have to make incorrect
887 * assumptions about where in the task array this
888 * can be found.
889 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800890 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700892 cad_pid = task_pid(current);
893
Andi Kleenca74a6f2008-01-30 13:33:17 +0100894 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
896 do_pre_smp_initcalls();
Frédéric Weisbecker3bf77af2008-09-23 11:38:18 +0100897 start_boot_trace();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 smp_init();
900 sched_init_smp();
901
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 do_basic_setup();
903
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800904 /* Open the /dev/console on the rootfs, this should never fail */
905 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
906 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
907
908 (void) sys_dup(0);
909 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 /*
911 * check if there is an early userspace init. If yes, let it do all
912 * the work
913 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700914
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700921 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922
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 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100928
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100929 init_post();
930 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931}