blob: 00799c1d46288fb491e6eb07ccf17dc8406883cc [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040025#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/tty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/percpu.h>
28#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070029#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010031#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020033#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/profile.h>
35#include <linux/rcupdate.h>
36#include <linux/moduleparam.h>
37#include <linux/kallsyms.h>
38#include <linux/writeback.h>
39#include <linux/cpu.h>
40#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070041#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080043#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080044#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070045#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070046#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/unistd.h>
48#include <linux/rmap.h>
49#include <linux/mempolicy.h>
50#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070051#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070052#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070053#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070054#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070055#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010056#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080057#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080058#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070059#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010060#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080061#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070062#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050063#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040064#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080065#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020066#include <linux/kmemcheck.h>
Feng Tang6ae69962009-08-14 15:13:46 -040067#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020068#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090069#include <linux/slab.h>
Peter Zijlstra24a24bb2010-11-17 23:17:33 +010070#include <linux/perf_event.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72#include <asm/io.h>
73#include <asm/bugs.h>
74#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070075#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080076#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#ifdef CONFIG_X86_LOCAL_APIC
79#include <asm/smp.h>
80#endif
81
Sam Ravnborgaae5f662007-02-26 16:45:41 +010082static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085extern void fork_init(unsigned long);
86extern void mca_init(void);
87extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088extern void prio_tree_init(void);
89extern void radix_tree_init(void);
90extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080091#ifndef CONFIG_DEBUG_RODATA
92static inline void mark_rodata_ro(void) { }
93#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95#ifdef CONFIG_TC
96extern void tc_init(void);
97#endif
98
Paul E. McKenneya6826042009-02-25 18:03:42 -080099enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100EXPORT_SYMBOL(system_state);
101
102/*
103 * Boot command-line arguments
104 */
105#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
106#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
107
108extern void time_init(void);
109/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800110void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111extern void softirq_init(void);
112
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800113/* Untouched command line saved by arch-specific code. */
114char __initdata boot_command_line[COMMAND_LINE_SIZE];
115/* Untouched saved command line (eg. for /proc) */
116char *saved_command_line;
117/* Command line for parameter parsing */
118static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700121static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Jan Beulich8b3b2952007-07-15 23:41:07 -0700123#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124/* Setup configured maximum number of CPUs to activate */
Thomas Renninger75cbfb92010-05-26 17:03:33 +0200125unsigned int setup_max_cpus = NR_CPUS;
126EXPORT_SYMBOL(setup_max_cpus);
127
Vivek Goyal7e962872006-09-27 01:50:44 -0700128
129/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 * Setup routine for controlling SMP activation
131 *
132 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
133 * activation entirely (the MPS table probe still happens, though).
134 *
135 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
136 * greater than 0, limits the maximum number of CPUs activated in
137 * SMP mode to <NUM>.
138 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100139
140void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142static int __init nosmp(char *str)
143{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100144 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100145 arch_disable_smp_support();
146
Jan Beulich8b3b2952007-07-15 23:41:07 -0700147 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148}
149
Jan Beulich8b3b2952007-07-15 23:41:07 -0700150early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Yinghai Lu2b633e32010-02-10 01:20:37 -0800152/* this is hard limit */
153static int __init nrcpus(char *str)
154{
155 int nr_cpus;
156
157 get_option(&str, &nr_cpus);
158 if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
159 nr_cpu_ids = nr_cpus;
160
161 return 0;
162}
163
164early_param("nr_cpus", nrcpus);
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166static int __init maxcpus(char *str)
167{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100168 get_option(&str, &setup_max_cpus);
169 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100170 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400171
172 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
174
Hugh Dickins81340972007-08-27 16:02:12 +0100175early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700176#else
H Hartley Sweeten7463e632010-03-05 13:42:46 -0800177static const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700178#endif
179
180/*
181 * If set, this is an indication to the drivers that reset the underlying
182 * device before going ahead with the initialization otherwise driver might
183 * rely on the BIOS and skip the reset operation.
184 *
185 * This is useful if kernel is booting in an unreliable environment.
186 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
187 * skipped and devices will be in unknown state.
188 */
189unsigned int reset_devices;
190EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
Vivek Goyal7e962872006-09-27 01:50:44 -0700192static int __init set_reset_devices(char *str)
193{
194 reset_devices = 1;
195 return 1;
196}
197
198__setup("reset_devices", set_reset_devices);
199
David Howellsd7627462010-08-17 23:52:56 +0100200static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
201const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202static const char *panic_later, *panic_param;
203
Rusty Russell914dcaa2010-08-11 23:04:18 -0600204extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206static int __init obsolete_checksetup(char *line)
207{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600208 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200209 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 p = __setup_start;
212 do {
213 int n = strlen(p->str);
214 if (!strncmp(line, p->str, n)) {
215 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200216 /* Already done in parse_early_param?
217 * (Needs exact match on param part).
218 * Keep iterating, as we can have early
219 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200221 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 } else if (!p->setup_func) {
223 printk(KERN_WARNING "Parameter %s is obsolete,"
224 " ignored\n", p->str);
225 return 1;
226 } else if (p->setup_func(line + n))
227 return 1;
228 }
229 p++;
230 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200231
232 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
235/*
236 * This should be approx 2 Bo*oMips to start (note initial shift), and will
237 * still work even if initially too large, it will just take slightly longer
238 */
239unsigned long loops_per_jiffy = (1<<12);
240
241EXPORT_SYMBOL(loops_per_jiffy);
242
243static int __init debug_kernel(char *str)
244{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800246 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247}
248
249static int __init quiet_kernel(char *str)
250{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800252 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253}
254
Yinghai Luf6f21c812008-02-08 04:21:58 -0800255early_param("debug", debug_kernel);
256early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258static int __init loglevel(char *str)
259{
260 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800261 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262}
263
Yinghai Luf6f21c812008-02-08 04:21:58 -0800264early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266/*
267 * Unknown boot options get handed to init, unless they look like
Rusty Russellf066a4f2009-12-01 14:56:44 +1030268 * unused parameters (modprobe will find them in /proc/cmdline).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 */
270static int __init unknown_bootoption(char *param, char *val)
271{
272 /* Change NUL term back to "=", to make "param" the whole string. */
273 if (val) {
274 /* param=val or param="val"? */
275 if (val == param+strlen(param)+1)
276 val[-1] = '=';
277 else if (val == param+strlen(param)+2) {
278 val[-2] = '=';
279 memmove(val-1, val, strlen(val)+1);
280 val--;
281 } else
282 BUG();
283 }
284
285 /* Handle obsolete-style parameters */
286 if (obsolete_checksetup(param))
287 return 0;
288
Rusty Russellf066a4f2009-12-01 14:56:44 +1030289 /* Unused module parameter. */
290 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293 if (panic_later)
294 return 0;
295
296 if (val) {
297 /* Environment option */
298 unsigned int i;
299 for (i = 0; envp_init[i]; i++) {
300 if (i == MAX_INIT_ENVS) {
301 panic_later = "Too many boot env vars at `%s'";
302 panic_param = param;
303 }
304 if (!strncmp(param, envp_init[i], val - param))
305 break;
306 }
307 envp_init[i] = param;
308 } else {
309 /* Command line option */
310 unsigned int i;
311 for (i = 0; argv_init[i]; i++) {
312 if (i == MAX_INIT_ARGS) {
313 panic_later = "Too many boot init vars at `%s'";
314 panic_param = param;
315 }
316 }
317 argv_init[i] = param;
318 }
319 return 0;
320}
321
Ingo Molnar12d6f212008-01-30 13:33:58 +0100322#ifdef CONFIG_DEBUG_PAGEALLOC
323int __read_mostly debug_pagealloc_enabled = 0;
324#endif
325
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326static int __init init_setup(char *str)
327{
328 unsigned int i;
329
330 execute_command = str;
331 /*
332 * In case LILO is going to boot us with default command line,
333 * it prepends "auto" before the whole cmdline which makes
334 * the shell think it should execute a script with such name.
335 * So we ignore all arguments entered _before_ init=... [MJ]
336 */
337 for (i = 1; i < MAX_INIT_ARGS; i++)
338 argv_init[i] = NULL;
339 return 1;
340}
341__setup("init=", init_setup);
342
Olof Johanssonffdfc402005-09-06 15:17:19 -0700343static int __init rdinit_setup(char *str)
344{
345 unsigned int i;
346
347 ramdisk_execute_command = str;
348 /* See "auto" comment in init_setup */
349 for (i = 1; i < MAX_INIT_ARGS; i++)
350 argv_init[i] = NULL;
351 return 1;
352}
353__setup("rdinit=", rdinit_setup);
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355#ifndef CONFIG_SMP
356
357#ifdef CONFIG_X86_LOCAL_APIC
358static void __init smp_init(void)
359{
360 APIC_init_uniprocessor();
361}
362#else
363#define smp_init() do { } while (0)
364#endif
365
Mike Travise0982e92008-03-26 14:23:48 -0700366static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367static inline void smp_prepare_cpus(unsigned int maxcpus) { }
368
369#else
370
Mike Travise0982e92008-03-26 14:23:48 -0700371/* Setup number of possible processor ids */
372int nr_cpu_ids __read_mostly = NR_CPUS;
373EXPORT_SYMBOL(nr_cpu_ids);
374
375/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
376static void __init setup_nr_cpu_ids(void)
377{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030378 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700379}
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381/* Called by boot processor to activate the rest. */
382static void __init smp_init(void)
383{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800384 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
386 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800387 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100388 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800390 if (!cpu_online(cpu))
391 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 }
393
394 /* Any cleanup work */
395 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100396 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397}
398
399#endif
400
401/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800402 * We need to store the untouched command line for future reference.
403 * We also need to store the touched command line since the parameter
404 * parsing is performed in place, and we should allow a component to
405 * store reference of name/value for future reference.
406 */
407static void __init setup_command_line(char *command_line)
408{
409 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
410 static_command_line = alloc_bootmem(strlen (command_line)+1);
411 strcpy (saved_command_line, boot_command_line);
412 strcpy (static_command_line, command_line);
413}
414
415/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 * We need to finalize in a non-__init function or else race conditions
417 * between the root thread and the init thread may cause start_kernel to
418 * be reaped by free_initmem before the root thread has proceeded to
419 * cpu_idle.
420 *
421 * gcc-3.4 accidentally inlines this function, so use noinline.
422 */
423
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200424static __initdata DECLARE_COMPLETION(kthreadd_done);
425
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800426static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700428 int pid;
429
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700430 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200431 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200432 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200433 * the init task will end up wanting to create kthreads, which, if
434 * we schedule it before we create kthreadd, will OOPS.
435 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100436 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700438 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800439 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700440 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800441 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200442 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200443
444 /*
445 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200446 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200447 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200448 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800449 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200450 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800451 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200452
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800453 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200455}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457/* Check for early params. */
458static int __init do_early_param(char *param, char *val)
459{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600460 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700463 if ((p->early && strcmp(param, p->str) == 0) ||
464 (strcmp(param, "console") == 0 &&
465 strcmp(p->str, "earlycon") == 0)
466 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 if (p->setup_func(val) != 0)
468 printk(KERN_WARNING
469 "Malformed early option '%s'\n", param);
470 }
471 }
472 /* We accept everything at this stage. */
473 return 0;
474}
475
Magnus Damm13977092009-03-30 14:37:25 -0700476void __init parse_early_options(char *cmdline)
477{
478 parse_args("early options", cmdline, NULL, 0, do_early_param);
479}
480
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481/* Arch code calls this early on, or if not, just before other parsing. */
482void __init parse_early_param(void)
483{
484 static __initdata int done = 0;
485 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
486
487 if (done)
488 return;
489
490 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800491 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700492 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 done = 1;
494}
495
496/*
497 * Activate the first processor.
498 */
499
Stas Sergeev44fd2292006-03-23 02:59:44 -0800500static void __init boot_cpu_init(void)
501{
502 int cpu = smp_processor_id();
503 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030504 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100505 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030506 set_cpu_present(cpu, true);
507 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800508}
509
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000510void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700511{
512}
513
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000514void __init __weak thread_info_cache_init(void)
515{
516}
517
Pekka Enberg444f4782009-06-11 18:29:06 +0300518/*
519 * Set up kernel memory allocators
520 */
521static void __init mm_init(void)
522{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300523 /*
524 * page_cgroup requires countinous pages as memmap
525 * and it's bigger than MAX_ORDER unless SPARSEMEM.
526 */
527 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300528 mem_init();
529 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200530 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000531 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300532 vmalloc_init();
533}
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535asmlinkage void __init start_kernel(void)
536{
537 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600538 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700539
540 smp_setup_processor_id();
541
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700542 /*
543 * Need to run as early as possible, to initialize the
544 * lockdep hash:
545 */
546 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700547 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100548
549 /*
550 * Set up the the initial canary ASAP:
551 */
552 boot_init_stack_canary();
553
Paul Menageddbcc7e2007-10-18 23:39:30 -0700554 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700555
556 local_irq_disable();
557 early_boot_irqs_off();
558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559/*
560 * Interrupts are still disabled. Do necessary setups, then
561 * enable them
562 */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800563 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800564 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200566 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700568 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800569 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700570 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900571 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800572 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
Haicheng Li1f522502010-05-24 14:32:51 -0700574 build_all_zonelists(NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300575 page_alloc_init();
576
577 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
578 parse_early_param();
579 parse_args("Booting kernel", static_command_line, __start___param,
580 __stop___param - __start___param,
581 &unknown_bootoption);
582 /*
583 * These use large bootmem allocations and must precede
584 * kmem_cache_init()
585 */
586 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300587 vfs_caches_init_early();
588 sort_main_extable();
589 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300590 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 /*
592 * Set up the scheduler prior starting any interrupts (such as the
593 * timer interrupt). Full topology setup happens at smp_init()
594 * time - but meanwhile we still have a functioning scheduler.
595 */
596 sched_init();
597 /*
598 * Disable preemption - early bootup scheduling is extremely
599 * fragile until we cpu_idle() for the first time.
600 */
601 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800602 if (!irqs_disabled()) {
603 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
604 "enabled *very* early, fixing it\n");
605 local_irq_disable();
606 }
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100607 idr_init_cache();
Peter Zijlstra24a24bb2010-11-17 23:17:33 +0100608 perf_event_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800610 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800611 /* init some links before init_ISA_irqs() */
612 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100614 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800616 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700618 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700619 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700620 profile_init();
621 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030622 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
623 "enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700624 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700625 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000626
627 /* Interrupts are enabled now so all GFP allocations are safe. */
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800628 gfp_allowed_mask = __GFP_BITS_MASK;
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000629
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300630 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
632 /*
633 * HACK ALERT! This is early. We're enabling the console before
634 * we've done PCI setups etc, and console_init() must be aware of
635 * this. But we do want output early, in case something goes wrong.
636 */
637 console_init();
638 if (panic_later)
639 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700640
641 lockdep_info();
642
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700643 /*
644 * Need to run this when irqs are enabled, because it wants
645 * to self-test [hard/soft]-irqs on/off lock inversion bugs
646 * too:
647 */
648 locking_selftest();
649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650#ifdef CONFIG_BLK_DEV_INITRD
651 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700652 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200654 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700655 page_to_pfn(virt_to_page((void *)initrd_start)),
656 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 initrd_start = 0;
658 }
659#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700660 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100661 enable_debug_pagealloc();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100662 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700663 debug_objects_mem_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700664 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 numa_policy_init();
666 if (late_time_init)
667 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200668 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 calibrate_delay();
670 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 anon_vma_init();
672#ifdef CONFIG_X86
673 if (efi_enabled)
674 efi_enter_virtual_mode();
675#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000676 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100677 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700678 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 proc_caches_init();
680 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 key_init();
682 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500683 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700684 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 signals_init();
686 /* rootfs populating might need page-writeback */
687 page_writeback_init();
688#ifdef CONFIG_PROC_FS
689 proc_root_init();
690#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700691 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700693 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700694 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 check_bugs();
697
698 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400699 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400701 ftrace_init();
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 /* Do the rest non-__init'ed, we're now alive */
704 rest_init();
705}
706
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700707/* Call all constructor functions linked into the kernel. */
708static void __init do_ctors(void)
709{
710#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800711 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700712
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800713 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
714 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700715#endif
716}
717
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800718int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500719core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200721static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200722
Kevin Winchestere4461272010-08-09 17:20:32 -0700723static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700724{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100725 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800726 unsigned long long duration;
727 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700728
Kevin Winchester22c5c032010-08-09 17:20:32 -0700729 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
730 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800731 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700732 rettime = ktime_get();
733 delta = ktime_sub(rettime, calltime);
734 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
735 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
736 ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700737
Kevin Winchester22c5c032010-08-09 17:20:32 -0700738 return ret;
739}
740
Kevin Winchestere4461272010-08-09 17:20:32 -0700741int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700742{
743 int count = preempt_count();
744 int ret;
745
746 if (initcall_debug)
747 ret = do_one_initcall_debug(fn);
748 else
749 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700750
751 msgbuf[0] = 0;
752
Américo Wang30dbb20e2010-05-26 18:57:53 +0800753 if (ret && ret != -ENODEV && initcall_debug)
754 sprintf(msgbuf, "error code %d ", ret);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700755
756 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700757 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700758 preempt_count() = count;
759 }
760 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700761 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700762 local_irq_enable();
763 }
764 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700765 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700766 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700767
Américo Wang30dbb20e2010-05-26 18:57:53 +0800768 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700769}
770
771
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700772extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773
774static void __init do_initcalls(void)
775{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800776 initcall_t *fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800778 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
779 do_one_initcall(*fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780}
781
782/*
783 * Ok, the machine is now initialized. None of the devices
784 * have been touched yet, but the CPU subsystem is up and
785 * running, and memory and process management works.
786 *
787 * Now we can finally start doing some real work..
788 */
789static void __init do_basic_setup(void)
790{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800791 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200793 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800795 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700796 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 do_initcalls();
798}
799
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700800static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700801{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800802 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700803
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800804 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
805 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700806}
807
David Howellsd7627462010-08-17 23:52:56 +0100808static void run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809{
810 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700811 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812}
813
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100814/* This is a non __init function. Force it to be noinline otherwise gcc
815 * makes it inline to init() and it becomes part of init.text section
816 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800817static noinline int init_post(void)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100818{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800819 /* need to finish all async __init code before freeing the memory */
820 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100821 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100822 mark_rodata_ro();
823 system_state = SYSTEM_RUNNING;
824 numa_default_policy();
825
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100826
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700827 current->signal->flags |= SIGNAL_UNKILLABLE;
828
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100829 if (ramdisk_execute_command) {
830 run_init_process(ramdisk_execute_command);
831 printk(KERN_WARNING "Failed to execute %s\n",
832 ramdisk_execute_command);
833 }
834
835 /*
836 * We try each of these until one succeeds.
837 *
838 * The Bourne shell can be used instead of init if we are
839 * trying to recover a really broken machine.
840 */
841 if (execute_command) {
842 run_init_process(execute_command);
843 printk(KERN_WARNING "Failed to execute %s. Attempting "
844 "defaults...\n", execute_command);
845 }
846 run_init_process("/sbin/init");
847 run_init_process("/etc/init");
848 run_init_process("/bin/init");
849 run_init_process("/bin/sh");
850
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800851 panic("No init found. Try passing init= option to kernel. "
852 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100853}
854
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100855static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200857 /*
858 * Wait until kthreadd is all set-up.
859 */
860 wait_for_completion(&kthreadd_done);
Miao Xie58568d22009-06-16 15:31:49 -0700861 /*
862 * init can allocate pages on any node
863 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700864 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 /*
866 * init can run on any cpu.
867 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600868 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 /*
870 * Tell the world that we're going to be the grim
871 * reaper of innocent orphaned children.
872 *
873 * We don't want people to have to make incorrect
874 * assumptions about where in the task array this
875 * can be found.
876 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800877 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700879 cad_pid = task_pid(current);
880
Andi Kleenca74a6f2008-01-30 13:33:17 +0100881 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882
883 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100884 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 smp_init();
887 sched_init_smp();
888
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 do_basic_setup();
890
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800891 /* Open the /dev/console on the rootfs, this should never fail */
892 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
893 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
894
895 (void) sys_dup(0);
896 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 /*
898 * check if there is an early userspace init. If yes, let it do all
899 * the work
900 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700901
902 if (!ramdisk_execute_command)
903 ramdisk_execute_command = "/init";
904
905 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
906 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700908 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
910 /*
911 * Ok, we have completed the initial bootup, and
912 * we're essentially up and running. Get rid of the
913 * initmem segments and start the user-mode stuff..
914 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100915
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100916 init_post();
917 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918}