blob: b28673087ac006e79f4563b1a06d39eb1b163d37 [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>
Al Viro4a9d4b02012-06-24 09:56:45 +040071#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73#include <asm/io.h>
74#include <asm/bugs.h>
75#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070076#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080077#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#ifdef CONFIG_X86_LOCAL_APIC
80#include <asm/smp.h>
81#endif
82
Sam Ravnborgaae5f662007-02-26 16:45:41 +010083static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086extern void fork_init(unsigned long);
87extern void mca_init(void);
88extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void prio_tree_init(void);
90extern void radix_tree_init(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
Tejun Heo2ce802f2011-01-20 12:06:35 +010099/*
100 * Debug helper: via this flag we know that we are in 'early bootup code'
101 * where only the boot processor is running with IRQ disabled. This means
102 * two things - IRQ must not be enabled before the flag is cleared and some
103 * operations which are not allowed with IRQ disabled are allowed while the
104 * flag is set.
105 */
106bool early_boot_irqs_disabled __read_mostly;
107
Paul E. McKenneya6826042009-02-25 18:03:42 -0800108enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109EXPORT_SYMBOL(system_state);
110
111/*
112 * Boot command-line arguments
113 */
114#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
115#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
116
117extern void time_init(void);
118/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800119void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120extern void softirq_init(void);
121
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800122/* Untouched command line saved by arch-specific code. */
123char __initdata boot_command_line[COMMAND_LINE_SIZE];
124/* Untouched saved command line (eg. for /proc) */
125char *saved_command_line;
126/* Command line for parameter parsing */
127static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700130static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Jan Beulich8b3b2952007-07-15 23:41:07 -0700132/*
133 * If set, this is an indication to the drivers that reset the underlying
134 * device before going ahead with the initialization otherwise driver might
135 * rely on the BIOS and skip the reset operation.
136 *
137 * This is useful if kernel is booting in an unreliable environment.
138 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
139 * skipped and devices will be in unknown state.
140 */
141unsigned int reset_devices;
142EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Vivek Goyal7e962872006-09-27 01:50:44 -0700144static int __init set_reset_devices(char *str)
145{
146 reset_devices = 1;
147 return 1;
148}
149
150__setup("reset_devices", set_reset_devices);
151
David Howellsd7627462010-08-17 23:52:56 +0100152static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
153const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154static const char *panic_later, *panic_param;
155
Rusty Russell914dcaa2010-08-11 23:04:18 -0600156extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158static int __init obsolete_checksetup(char *line)
159{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600160 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200161 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 p = __setup_start;
164 do {
165 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200166 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200168 /* Already done in parse_early_param?
169 * (Needs exact match on param part).
170 * Keep iterating, as we can have early
171 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200173 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 } else if (!p->setup_func) {
175 printk(KERN_WARNING "Parameter %s is obsolete,"
176 " ignored\n", p->str);
177 return 1;
178 } else if (p->setup_func(line + n))
179 return 1;
180 }
181 p++;
182 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200183
184 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185}
186
187/*
188 * This should be approx 2 Bo*oMips to start (note initial shift), and will
189 * still work even if initially too large, it will just take slightly longer
190 */
191unsigned long loops_per_jiffy = (1<<12);
192
193EXPORT_SYMBOL(loops_per_jiffy);
194
195static int __init debug_kernel(char *str)
196{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800198 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199}
200
201static int __init quiet_kernel(char *str)
202{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
Yinghai Luf6f21c812008-02-08 04:21:58 -0800207early_param("debug", debug_kernel);
208early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210static int __init loglevel(char *str)
211{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200212 int newlevel;
213
214 /*
215 * Only update loglevel value when a correct setting was passed,
216 * to prevent blind crashes (when loglevel being set to 0) that
217 * are quite hard to debug
218 */
219 if (get_option(&str, &newlevel)) {
220 console_loglevel = newlevel;
221 return 0;
222 }
223
224 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
Yinghai Luf6f21c812008-02-08 04:21:58 -0800227early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Chris Metcalfa99cd112012-04-06 12:53:50 -0400229/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700230static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 if (val) {
233 /* param=val or param="val"? */
234 if (val == param+strlen(param)+1)
235 val[-1] = '=';
236 else if (val == param+strlen(param)+2) {
237 val[-2] = '=';
238 memmove(val-1, val, strlen(val)+1);
239 val--;
240 } else
241 BUG();
242 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400243 return 0;
244}
245
246/*
247 * Unknown boot options get handed to init, unless they look like
248 * unused parameters (modprobe will find them in /proc/cmdline).
249 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700250static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400251{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700252 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
254 /* Handle obsolete-style parameters */
255 if (obsolete_checksetup(param))
256 return 0;
257
Rusty Russellf066a4f2009-12-01 14:56:44 +1030258 /* Unused module parameter. */
259 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
262 if (panic_later)
263 return 0;
264
265 if (val) {
266 /* Environment option */
267 unsigned int i;
268 for (i = 0; envp_init[i]; i++) {
269 if (i == MAX_INIT_ENVS) {
270 panic_later = "Too many boot env vars at `%s'";
271 panic_param = param;
272 }
273 if (!strncmp(param, envp_init[i], val - param))
274 break;
275 }
276 envp_init[i] = param;
277 } else {
278 /* Command line option */
279 unsigned int i;
280 for (i = 0; argv_init[i]; i++) {
281 if (i == MAX_INIT_ARGS) {
282 panic_later = "Too many boot init vars at `%s'";
283 panic_param = param;
284 }
285 }
286 argv_init[i] = param;
287 }
288 return 0;
289}
290
291static int __init init_setup(char *str)
292{
293 unsigned int i;
294
295 execute_command = str;
296 /*
297 * In case LILO is going to boot us with default command line,
298 * it prepends "auto" before the whole cmdline which makes
299 * the shell think it should execute a script with such name.
300 * So we ignore all arguments entered _before_ init=... [MJ]
301 */
302 for (i = 1; i < MAX_INIT_ARGS; i++)
303 argv_init[i] = NULL;
304 return 1;
305}
306__setup("init=", init_setup);
307
Olof Johanssonffdfc402005-09-06 15:17:19 -0700308static int __init rdinit_setup(char *str)
309{
310 unsigned int i;
311
312 ramdisk_execute_command = str;
313 /* See "auto" comment in init_setup */
314 for (i = 1; i < MAX_INIT_ARGS; i++)
315 argv_init[i] = NULL;
316 return 1;
317}
318__setup("rdinit=", rdinit_setup);
319
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700321static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322#ifdef CONFIG_X86_LOCAL_APIC
323static void __init smp_init(void)
324{
325 APIC_init_uniprocessor();
326}
327#else
328#define smp_init() do { } while (0)
329#endif
330
Mike Travise0982e92008-03-26 14:23:48 -0700331static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333#endif
334
335/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800336 * We need to store the untouched command line for future reference.
337 * We also need to store the touched command line since the parameter
338 * parsing is performed in place, and we should allow a component to
339 * store reference of name/value for future reference.
340 */
341static void __init setup_command_line(char *command_line)
342{
343 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
344 static_command_line = alloc_bootmem(strlen (command_line)+1);
345 strcpy (saved_command_line, boot_command_line);
346 strcpy (static_command_line, command_line);
347}
348
349/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * We need to finalize in a non-__init function or else race conditions
351 * between the root thread and the init thread may cause start_kernel to
352 * be reaped by free_initmem before the root thread has proceeded to
353 * cpu_idle.
354 *
355 * gcc-3.4 accidentally inlines this function, so use noinline.
356 */
357
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200358static __initdata DECLARE_COMPLETION(kthreadd_done);
359
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800360static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700362 int pid;
363
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700364 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200365 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200366 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200367 * the init task will end up wanting to create kthreads, which, if
368 * we schedule it before we create kthreadd, will OOPS.
369 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100370 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700372 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800373 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700374 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800375 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200376 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200377
378 /*
379 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200380 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200381 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200382 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100383 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800384 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200386}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
388/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600389static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600391 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
393 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200394 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700395 (strcmp(param, "console") == 0 &&
396 strcmp(p->str, "earlycon") == 0)
397 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 if (p->setup_func(val) != 0)
399 printk(KERN_WARNING
400 "Malformed early option '%s'\n", param);
401 }
402 }
403 /* We accept everything at this stage. */
404 return 0;
405}
406
Magnus Damm13977092009-03-30 14:37:25 -0700407void __init parse_early_options(char *cmdline)
408{
Pawel Moll026cee02012-03-26 12:50:51 +1030409 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700410}
411
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412/* Arch code calls this early on, or if not, just before other parsing. */
413void __init parse_early_param(void)
414{
415 static __initdata int done = 0;
416 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
417
418 if (done)
419 return;
420
421 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800422 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700423 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 done = 1;
425}
426
427/*
428 * Activate the first processor.
429 */
430
Stas Sergeev44fd2292006-03-23 02:59:44 -0800431static void __init boot_cpu_init(void)
432{
433 int cpu = smp_processor_id();
434 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030435 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100436 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030437 set_cpu_present(cpu, true);
438 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800439}
440
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000441void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700442{
443}
444
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000445void __init __weak thread_info_cache_init(void)
446{
447}
448
Pekka Enberg444f4782009-06-11 18:29:06 +0300449/*
450 * Set up kernel memory allocators
451 */
452static void __init mm_init(void)
453{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300454 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600455 * page_cgroup requires contiguous pages,
456 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300457 */
458 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300459 mem_init();
460 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200461 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000462 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300463 vmalloc_init();
464}
465
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466asmlinkage void __init start_kernel(void)
467{
468 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600469 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700470
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700471 /*
472 * Need to run as early as possible, to initialize the
473 * lockdep hash:
474 */
475 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800476 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700477 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100478
479 /*
480 * Set up the the initial canary ASAP:
481 */
482 boot_init_stack_canary();
483
Paul Menageddbcc7e2007-10-18 23:39:30 -0700484 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700485
486 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100487 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700488
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489/*
490 * Interrupts are still disabled. Do necessary setups, then
491 * enable them
492 */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800493 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800494 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200496 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700498 mm_init_owner(&init_mm, &init_task);
Linus Torvalds6345d242011-05-29 11:32:28 -0700499 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800500 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700501 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900502 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800503 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
Jiang Liu9adb62a2012-07-31 16:43:28 -0700505 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300506 page_alloc_init();
507
508 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
509 parse_early_param();
510 parse_args("Booting kernel", static_command_line, __start___param,
511 __stop___param - __start___param,
Rusty Russellae82fdb2012-06-08 14:58:13 +0930512 -1, -1, &unknown_bootoption);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700513
514 jump_label_init();
515
Pekka Enberg83b519e2009-06-10 19:40:04 +0300516 /*
517 * These use large bootmem allocations and must precede
518 * kmem_cache_init()
519 */
Mike Travis162a7e72011-05-24 17:13:20 -0700520 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300521 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300522 vfs_caches_init_early();
523 sort_main_extable();
524 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300525 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700526
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 /*
528 * Set up the scheduler prior starting any interrupts (such as the
529 * timer interrupt). Full topology setup happens at smp_init()
530 * time - but meanwhile we still have a functioning scheduler.
531 */
532 sched_init();
533 /*
534 * Disable preemption - early bootup scheduling is extremely
535 * fragile until we cpu_idle() for the first time.
536 */
537 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800538 if (!irqs_disabled()) {
539 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
540 "enabled *very* early, fixing it\n");
541 local_irq_disable();
542 }
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100543 idr_init_cache();
Peter Zijlstra24a24bb2010-11-17 23:17:33 +0100544 perf_event_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800546 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800547 /* init some links before init_ISA_irqs() */
548 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100550 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800552 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700554 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700555 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700556 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400557 call_function_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700558 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030559 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
560 "enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100561 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700562 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000563
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300564 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566 /*
567 * HACK ALERT! This is early. We're enabling the console before
568 * we've done PCI setups etc, and console_init() must be aware of
569 * this. But we do want output early, in case something goes wrong.
570 */
571 console_init();
572 if (panic_later)
573 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700574
575 lockdep_info();
576
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700577 /*
578 * Need to run this when irqs are enabled, because it wants
579 * to self-test [hard/soft]-irqs on/off lock inversion bugs
580 * too:
581 */
582 locking_selftest();
583
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584#ifdef CONFIG_BLK_DEV_INITRD
585 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700586 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200588 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700589 page_to_pfn(virt_to_page((void *)initrd_start)),
590 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 initrd_start = 0;
592 }
593#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700594 page_cgroup_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700595 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100596 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700597 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 numa_policy_init();
599 if (late_time_init)
600 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200601 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 calibrate_delay();
603 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 anon_vma_init();
H. Peter Anvinf026cfa2012-08-14 09:53:38 -0700605#ifdef CONFIG_X86
606 if (efi_enabled)
607 efi_enter_virtual_mode();
608#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000609 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100610 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700611 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 proc_caches_init();
613 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 key_init();
615 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500616 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700617 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 signals_init();
619 /* rootfs populating might need page-writeback */
620 page_writeback_init();
621#ifdef CONFIG_PROC_FS
622 proc_root_init();
623#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700624 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700626 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700627 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629 check_bugs();
630
631 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400632 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400634 ftrace_init();
635
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 /* Do the rest non-__init'ed, we're now alive */
637 rest_init();
638}
639
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700640/* Call all constructor functions linked into the kernel. */
641static void __init do_ctors(void)
642{
643#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800644 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700645
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800646 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
647 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700648#endif
649}
650
Rusty Russell2329abf2012-01-13 09:32:18 +1030651bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500652core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200654static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200655
Kevin Winchestere4461272010-08-09 17:20:32 -0700656static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700657{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100658 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800659 unsigned long long duration;
660 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700661
Kevin Winchester22c5c032010-08-09 17:20:32 -0700662 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
663 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800664 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700665 rettime = ktime_get();
666 delta = ktime_sub(rettime, calltime);
667 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
668 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
669 ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700670
Kevin Winchester22c5c032010-08-09 17:20:32 -0700671 return ret;
672}
673
Kevin Winchestere4461272010-08-09 17:20:32 -0700674int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700675{
676 int count = preempt_count();
677 int ret;
678
679 if (initcall_debug)
680 ret = do_one_initcall_debug(fn);
681 else
682 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700683
684 msgbuf[0] = 0;
685
Américo Wang30dbb20e2010-05-26 18:57:53 +0800686 if (ret && ret != -ENODEV && initcall_debug)
687 sprintf(msgbuf, "error code %d ", ret);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700688
689 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700690 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700691 preempt_count() = count;
692 }
693 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700694 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700695 local_irq_enable();
696 }
697 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700698 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700699 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700700
Américo Wang30dbb20e2010-05-26 18:57:53 +0800701 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700702}
703
704
Pawel Moll026cee02012-03-26 12:50:51 +1030705extern initcall_t __initcall_start[];
706extern initcall_t __initcall0_start[];
707extern initcall_t __initcall1_start[];
708extern initcall_t __initcall2_start[];
709extern initcall_t __initcall3_start[];
710extern initcall_t __initcall4_start[];
711extern initcall_t __initcall5_start[];
712extern initcall_t __initcall6_start[];
713extern initcall_t __initcall7_start[];
714extern initcall_t __initcall_end[];
715
716static initcall_t *initcall_levels[] __initdata = {
717 __initcall0_start,
718 __initcall1_start,
719 __initcall2_start,
720 __initcall3_start,
721 __initcall4_start,
722 __initcall5_start,
723 __initcall6_start,
724 __initcall7_start,
725 __initcall_end,
726};
727
Jim Cromie96263d22012-06-14 16:00:59 -0600728/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030729static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600730 "early",
731 "core",
732 "postcore",
733 "arch",
734 "subsys",
735 "fs",
736 "device",
737 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030738};
739
Pawel Moll026cee02012-03-26 12:50:51 +1030740static void __init do_initcall_level(int level)
741{
742 extern const struct kernel_param __start___param[], __stop___param[];
743 initcall_t *fn;
744
745 strcpy(static_command_line, saved_command_line);
746 parse_args(initcall_level_names[level],
747 static_command_line, __start___param,
748 __stop___param - __start___param,
749 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700750 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030751
752 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
753 do_one_initcall(*fn);
754}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756static void __init do_initcalls(void)
757{
Pawel Moll026cee02012-03-26 12:50:51 +1030758 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Borislav Petkov19efb722012-06-01 18:56:00 +0200760 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030761 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
764/*
765 * Ok, the machine is now initialized. None of the devices
766 * have been touched yet, but the CPU subsystem is up and
767 * running, and memory and process management works.
768 *
769 * Now we can finally start doing some real work..
770 */
771static void __init do_basic_setup(void)
772{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800773 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700775 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800777 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700778 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700779 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800780 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781}
782
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700783static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700784{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800785 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700786
Pawel Moll026cee02012-03-26 12:50:51 +1030787 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800788 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700789}
790
David Howellsd7627462010-08-17 23:52:56 +0100791static void run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792{
793 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700794 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795}
796
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100797/* This is a non __init function. Force it to be noinline otherwise gcc
798 * makes it inline to init() and it becomes part of init.text section
799 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800800static noinline int init_post(void)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100801{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800802 /* need to finish all async __init code before freeing the memory */
803 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100804 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100805 mark_rodata_ro();
806 system_state = SYSTEM_RUNNING;
807 numa_default_policy();
808
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700809 current->signal->flags |= SIGNAL_UNKILLABLE;
Al Viro4a9d4b02012-06-24 09:56:45 +0400810 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700811
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100812 if (ramdisk_execute_command) {
813 run_init_process(ramdisk_execute_command);
814 printk(KERN_WARNING "Failed to execute %s\n",
815 ramdisk_execute_command);
816 }
817
818 /*
819 * We try each of these until one succeeds.
820 *
821 * The Bourne shell can be used instead of init if we are
822 * trying to recover a really broken machine.
823 */
824 if (execute_command) {
825 run_init_process(execute_command);
826 printk(KERN_WARNING "Failed to execute %s. Attempting "
827 "defaults...\n", execute_command);
828 }
829 run_init_process("/sbin/init");
830 run_init_process("/etc/init");
831 run_init_process("/bin/init");
832 run_init_process("/bin/sh");
833
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800834 panic("No init found. Try passing init= option to kernel. "
835 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100836}
837
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100838static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200840 /*
841 * Wait until kthreadd is all set-up.
842 */
843 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700844
845 /* Now the scheduler is fully set up and can do blocking allocations */
846 gfp_allowed_mask = __GFP_BITS_MASK;
847
Miao Xie58568d22009-06-16 15:31:49 -0700848 /*
849 * init can allocate pages on any node
850 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700851 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 /*
853 * init can run on any cpu.
854 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600855 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700857 cad_pid = task_pid(current);
858
Andi Kleenca74a6f2008-01-30 13:33:17 +0100859 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
861 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100862 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 smp_init();
865 sched_init_smp();
866
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 do_basic_setup();
868
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800869 /* Open the /dev/console on the rootfs, this should never fail */
870 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
871 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
872
873 (void) sys_dup(0);
874 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 /*
876 * check if there is an early userspace init. If yes, let it do all
877 * the work
878 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700879
880 if (!ramdisk_execute_command)
881 ramdisk_execute_command = "/init";
882
883 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
884 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700886 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
888 /*
889 * Ok, we have completed the initial bootup, and
890 * we're essentially up and running. Get rid of the
891 * initmem segments and start the user-mode stuff..
892 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100893
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100894 init_post();
895 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896}