blob: 8646401f7a0e4b77579aa13f8de6ac191787be73 [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 Molnar9b5609fd2008-02-14 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 Molnarfbb9ce92006-07-03 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71#include <asm/io.h>
72#include <asm/bugs.h>
73#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070074#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080075#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#ifdef CONFIG_X86_LOCAL_APIC
78#include <asm/smp.h>
79#endif
80
Sam Ravnborgaae5f662007-02-26 16:45:41 +010081static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084extern void fork_init(unsigned long);
85extern void mca_init(void);
86extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087extern void prio_tree_init(void);
88extern void radix_tree_init(void);
89extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080090#ifndef CONFIG_DEBUG_RODATA
91static inline void mark_rodata_ro(void) { }
92#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94#ifdef CONFIG_TC
95extern void tc_init(void);
96#endif
97
Paul E. McKenneya6826042009-02-25 18:03:42 -080098enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099EXPORT_SYMBOL(system_state);
100
101/*
102 * Boot command-line arguments
103 */
104#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
105#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
106
107extern void time_init(void);
108/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800109void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110extern void softirq_init(void);
111
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800112/* Untouched command line saved by arch-specific code. */
113char __initdata boot_command_line[COMMAND_LINE_SIZE];
114/* Untouched saved command line (eg. for /proc) */
115char *saved_command_line;
116/* Command line for parameter parsing */
117static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700120static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Jan Beulich8b3b2952007-07-15 23:41:07 -0700122#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123/* Setup configured maximum number of CPUs to activate */
Thomas Renninger75cbfb92010-05-26 17:03:33 +0200124unsigned int setup_max_cpus = NR_CPUS;
125EXPORT_SYMBOL(setup_max_cpus);
126
Vivek Goyal7e962872006-09-27 01:50:44 -0700127
128/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 * Setup routine for controlling SMP activation
130 *
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
133 *
134 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
135 * greater than 0, limits the maximum number of CPUs activated in
136 * SMP mode to <NUM>.
137 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100138
139void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141static int __init nosmp(char *str)
142{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100143 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100144 arch_disable_smp_support();
145
Jan Beulich8b3b2952007-07-15 23:41:07 -0700146 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147}
148
Jan Beulich8b3b2952007-07-15 23:41:07 -0700149early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
Yinghai Lu2b633e32010-02-10 01:20:37 -0800151/* this is hard limit */
152static int __init nrcpus(char *str)
153{
154 int nr_cpus;
155
156 get_option(&str, &nr_cpus);
157 if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
158 nr_cpu_ids = nr_cpus;
159
160 return 0;
161}
162
163early_param("nr_cpus", nrcpus);
164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165static int __init maxcpus(char *str)
166{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100167 get_option(&str, &setup_max_cpus);
168 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100169 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400170
171 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}
173
Hugh Dickins81340972007-08-27 16:02:12 +0100174early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700175#else
H Hartley Sweeten7463e632010-03-05 13:42:46 -0800176static const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700177#endif
178
179/*
180 * If set, this is an indication to the drivers that reset the underlying
181 * device before going ahead with the initialization otherwise driver might
182 * rely on the BIOS and skip the reset operation.
183 *
184 * This is useful if kernel is booting in an unreliable environment.
185 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
186 * skipped and devices will be in unknown state.
187 */
188unsigned int reset_devices;
189EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Vivek Goyal7e962872006-09-27 01:50:44 -0700191static int __init set_reset_devices(char *str)
192{
193 reset_devices = 1;
194 return 1;
195}
196
197__setup("reset_devices", set_reset_devices);
198
David Howellsd7627462010-08-17 23:52:56 +0100199static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
200const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201static const char *panic_later, *panic_param;
202
Rusty Russell914dcaa2010-08-11 23:04:18 -0600203extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205static int __init obsolete_checksetup(char *line)
206{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600207 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200208 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 p = __setup_start;
211 do {
212 int n = strlen(p->str);
213 if (!strncmp(line, p->str, n)) {
214 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200215 /* Already done in parse_early_param?
216 * (Needs exact match on param part).
217 * Keep iterating, as we can have early
218 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200220 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 } else if (!p->setup_func) {
222 printk(KERN_WARNING "Parameter %s is obsolete,"
223 " ignored\n", p->str);
224 return 1;
225 } else if (p->setup_func(line + n))
226 return 1;
227 }
228 p++;
229 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200230
231 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
233
234/*
235 * This should be approx 2 Bo*oMips to start (note initial shift), and will
236 * still work even if initially too large, it will just take slightly longer
237 */
238unsigned long loops_per_jiffy = (1<<12);
239
240EXPORT_SYMBOL(loops_per_jiffy);
241
242static int __init debug_kernel(char *str)
243{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800245 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
248static int __init quiet_kernel(char *str)
249{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800251 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
253
Yinghai Luf6f21c812008-02-08 04:21:58 -0800254early_param("debug", debug_kernel);
255early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257static int __init loglevel(char *str)
258{
259 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800260 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
Yinghai Luf6f21c812008-02-08 04:21:58 -0800263early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265/*
266 * Unknown boot options get handed to init, unless they look like
Rusty Russellf066a4f2009-12-01 14:56:44 +1030267 * unused parameters (modprobe will find them in /proc/cmdline).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 */
269static int __init unknown_bootoption(char *param, char *val)
270{
271 /* Change NUL term back to "=", to make "param" the whole string. */
272 if (val) {
273 /* param=val or param="val"? */
274 if (val == param+strlen(param)+1)
275 val[-1] = '=';
276 else if (val == param+strlen(param)+2) {
277 val[-2] = '=';
278 memmove(val-1, val, strlen(val)+1);
279 val--;
280 } else
281 BUG();
282 }
283
284 /* Handle obsolete-style parameters */
285 if (obsolete_checksetup(param))
286 return 0;
287
Rusty Russellf066a4f2009-12-01 14:56:44 +1030288 /* Unused module parameter. */
289 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 if (panic_later)
293 return 0;
294
295 if (val) {
296 /* Environment option */
297 unsigned int i;
298 for (i = 0; envp_init[i]; i++) {
299 if (i == MAX_INIT_ENVS) {
300 panic_later = "Too many boot env vars at `%s'";
301 panic_param = param;
302 }
303 if (!strncmp(param, envp_init[i], val - param))
304 break;
305 }
306 envp_init[i] = param;
307 } else {
308 /* Command line option */
309 unsigned int i;
310 for (i = 0; argv_init[i]; i++) {
311 if (i == MAX_INIT_ARGS) {
312 panic_later = "Too many boot init vars at `%s'";
313 panic_param = param;
314 }
315 }
316 argv_init[i] = param;
317 }
318 return 0;
319}
320
Ingo Molnar12d6f212008-01-30 13:33:58 +0100321#ifdef CONFIG_DEBUG_PAGEALLOC
322int __read_mostly debug_pagealloc_enabled = 0;
323#endif
324
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325static int __init init_setup(char *str)
326{
327 unsigned int i;
328
329 execute_command = str;
330 /*
331 * In case LILO is going to boot us with default command line,
332 * it prepends "auto" before the whole cmdline which makes
333 * the shell think it should execute a script with such name.
334 * So we ignore all arguments entered _before_ init=... [MJ]
335 */
336 for (i = 1; i < MAX_INIT_ARGS; i++)
337 argv_init[i] = NULL;
338 return 1;
339}
340__setup("init=", init_setup);
341
Olof Johanssonffdfc402005-09-06 15:17:19 -0700342static int __init rdinit_setup(char *str)
343{
344 unsigned int i;
345
346 ramdisk_execute_command = str;
347 /* See "auto" comment in init_setup */
348 for (i = 1; i < MAX_INIT_ARGS; i++)
349 argv_init[i] = NULL;
350 return 1;
351}
352__setup("rdinit=", rdinit_setup);
353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354#ifndef CONFIG_SMP
355
356#ifdef CONFIG_X86_LOCAL_APIC
357static void __init smp_init(void)
358{
359 APIC_init_uniprocessor();
360}
361#else
362#define smp_init() do { } while (0)
363#endif
364
Mike Travise0982e92008-03-26 14:23:48 -0700365static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366static inline void smp_prepare_cpus(unsigned int maxcpus) { }
367
368#else
369
Mike Travise0982e92008-03-26 14:23:48 -0700370/* Setup number of possible processor ids */
371int nr_cpu_ids __read_mostly = NR_CPUS;
372EXPORT_SYMBOL(nr_cpu_ids);
373
374/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
375static void __init setup_nr_cpu_ids(void)
376{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030377 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700378}
379
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380/* Called by boot processor to activate the rest. */
381static void __init smp_init(void)
382{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800383 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
385 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800386 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100387 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800389 if (!cpu_online(cpu))
390 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 }
392
393 /* Any cleanup work */
394 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100395 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396}
397
398#endif
399
400/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800401 * We need to store the untouched command line for future reference.
402 * We also need to store the touched command line since the parameter
403 * parsing is performed in place, and we should allow a component to
404 * store reference of name/value for future reference.
405 */
406static void __init setup_command_line(char *command_line)
407{
408 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
409 static_command_line = alloc_bootmem(strlen (command_line)+1);
410 strcpy (saved_command_line, boot_command_line);
411 strcpy (static_command_line, command_line);
412}
413
414/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 * We need to finalize in a non-__init function or else race conditions
416 * between the root thread and the init thread may cause start_kernel to
417 * be reaped by free_initmem before the root thread has proceeded to
418 * cpu_idle.
419 *
420 * gcc-3.4 accidentally inlines this function, so use noinline.
421 */
422
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200423static __initdata DECLARE_COMPLETION(kthreadd_done);
424
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800425static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700427 int pid;
428
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700429 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200430 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200431 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200432 * the init task will end up wanting to create kthreads, which, if
433 * we schedule it before we create kthreadd, will OOPS.
434 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100435 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700437 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800438 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700439 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800440 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200441 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200442
443 /*
444 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200445 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200446 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200447 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800448 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200449 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800450 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200451
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800452 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200454}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
456/* Check for early params. */
457static int __init do_early_param(char *param, char *val)
458{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600459 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
461 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700462 if ((p->early && strcmp(param, p->str) == 0) ||
463 (strcmp(param, "console") == 0 &&
464 strcmp(p->str, "earlycon") == 0)
465 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 if (p->setup_func(val) != 0)
467 printk(KERN_WARNING
468 "Malformed early option '%s'\n", param);
469 }
470 }
471 /* We accept everything at this stage. */
472 return 0;
473}
474
Magnus Damm13977092009-03-30 14:37:25 -0700475void __init parse_early_options(char *cmdline)
476{
477 parse_args("early options", cmdline, NULL, 0, do_early_param);
478}
479
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480/* Arch code calls this early on, or if not, just before other parsing. */
481void __init parse_early_param(void)
482{
483 static __initdata int done = 0;
484 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
485
486 if (done)
487 return;
488
489 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800490 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700491 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 done = 1;
493}
494
495/*
496 * Activate the first processor.
497 */
498
Stas Sergeev44fd2292006-03-23 02:59:44 -0800499static void __init boot_cpu_init(void)
500{
501 int cpu = smp_processor_id();
502 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030503 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100504 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030505 set_cpu_present(cpu, true);
506 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800507}
508
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000509void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700510{
511}
512
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000513void __init __weak thread_info_cache_init(void)
514{
515}
516
Pekka Enberg444f4782009-06-11 18:29:06 +0300517/*
518 * Set up kernel memory allocators
519 */
520static void __init mm_init(void)
521{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300522 /*
523 * page_cgroup requires countinous pages as memmap
524 * and it's bigger than MAX_ORDER unless SPARSEMEM.
525 */
526 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300527 mem_init();
528 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200529 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000530 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300531 vmalloc_init();
532}
533
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534asmlinkage void __init start_kernel(void)
535{
536 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600537 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700538
539 smp_setup_processor_id();
540
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700541 /*
542 * Need to run as early as possible, to initialize the
543 * lockdep hash:
544 */
545 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700546 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100547
548 /*
549 * Set up the the initial canary ASAP:
550 */
551 boot_init_stack_canary();
552
Paul Menageddbcc7e2007-10-18 23:39:30 -0700553 cgroup_init_early();
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700554
555 local_irq_disable();
556 early_boot_irqs_off();
557
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558/*
559 * Interrupts are still disabled. Do necessary setups, then
560 * enable them
561 */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800562 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800563 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200565 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700567 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800568 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700569 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900570 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800571 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572
Haicheng Li1f522502010-05-24 14:32:51 -0700573 build_all_zonelists(NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300574 page_alloc_init();
575
576 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
577 parse_early_param();
578 parse_args("Booting kernel", static_command_line, __start___param,
579 __stop___param - __start___param,
580 &unknown_bootoption);
581 /*
582 * These use large bootmem allocations and must precede
583 * kmem_cache_init()
584 */
585 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300586 vfs_caches_init_early();
587 sort_main_extable();
588 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300589 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 /*
591 * Set up the scheduler prior starting any interrupts (such as the
592 * timer interrupt). Full topology setup happens at smp_init()
593 * time - but meanwhile we still have a functioning scheduler.
594 */
595 sched_init();
596 /*
597 * Disable preemption - early bootup scheduling is extremely
598 * fragile until we cpu_idle() for the first time.
599 */
600 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800601 if (!irqs_disabled()) {
602 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
603 "enabled *very* early, fixing it\n");
604 local_irq_disable();
605 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800607 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800608 /* init some links before init_ISA_irqs() */
609 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100611 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800613 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700615 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700616 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700617 profile_init();
618 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030619 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
620 "enabled early\n");
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700621 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700622 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000623
624 /* Interrupts are enabled now so all GFP allocations are safe. */
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800625 gfp_allowed_mask = __GFP_BITS_MASK;
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000626
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300627 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629 /*
630 * HACK ALERT! This is early. We're enabling the console before
631 * we've done PCI setups etc, and console_init() must be aware of
632 * this. But we do want output early, in case something goes wrong.
633 */
634 console_init();
635 if (panic_later)
636 panic(panic_later, panic_param);
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700637
638 lockdep_info();
639
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700640 /*
641 * Need to run this when irqs are enabled, because it wants
642 * to self-test [hard/soft]-irqs on/off lock inversion bugs
643 * too:
644 */
645 locking_selftest();
646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647#ifdef CONFIG_BLK_DEV_INITRD
648 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700649 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200651 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700652 page_to_pfn(virt_to_page((void *)initrd_start)),
653 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 initrd_start = 0;
655 }
656#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700657 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100658 enable_debug_pagealloc();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100659 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700660 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700661 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700662 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 numa_policy_init();
664 if (late_time_init)
665 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200666 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 calibrate_delay();
668 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 anon_vma_init();
670#ifdef CONFIG_X86
671 if (efi_enabled)
672 efi_enter_virtual_mode();
673#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000674 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100675 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700676 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 proc_caches_init();
678 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 key_init();
680 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500681 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700682 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 signals_init();
684 /* rootfs populating might need page-writeback */
685 page_writeback_init();
686#ifdef CONFIG_PROC_FS
687 proc_root_init();
688#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700689 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700691 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700692 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 check_bugs();
695
696 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400697 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400699 ftrace_init();
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 /* Do the rest non-__init'ed, we're now alive */
702 rest_init();
703}
704
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700705/* Call all constructor functions linked into the kernel. */
706static void __init do_ctors(void)
707{
708#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800709 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700710
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800711 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
712 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700713#endif
714}
715
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800716int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500717core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200719static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200720
Kevin Winchestere4461272010-08-09 17:20:32 -0700721static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700722{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100723 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800724 unsigned long long duration;
725 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700726
Kevin Winchester22c5c032010-08-09 17:20:32 -0700727 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
728 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800729 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700730 rettime = ktime_get();
731 delta = ktime_sub(rettime, calltime);
732 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
733 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
734 ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700735
Kevin Winchester22c5c032010-08-09 17:20:32 -0700736 return ret;
737}
738
Kevin Winchestere4461272010-08-09 17:20:32 -0700739int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700740{
741 int count = preempt_count();
742 int ret;
743
744 if (initcall_debug)
745 ret = do_one_initcall_debug(fn);
746 else
747 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700748
749 msgbuf[0] = 0;
750
Américo Wang30dbb20e2010-05-26 18:57:53 +0800751 if (ret && ret != -ENODEV && initcall_debug)
752 sprintf(msgbuf, "error code %d ", ret);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700753
754 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700755 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700756 preempt_count() = count;
757 }
758 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700759 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700760 local_irq_enable();
761 }
762 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700763 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700764 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700765
Américo Wang30dbb20e2010-05-26 18:57:53 +0800766 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700767}
768
769
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700770extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771
772static void __init do_initcalls(void)
773{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800774 initcall_t *fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800776 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
777 do_one_initcall(*fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
779 /* Make sure there is no pending stuff from the initcall sequence */
780 flush_scheduled_work();
781}
782
783/*
784 * Ok, the machine is now initialized. None of the devices
785 * have been touched yet, but the CPU subsystem is up and
786 * running, and memory and process management works.
787 *
788 * Now we can finally start doing some real work..
789 */
790static void __init do_basic_setup(void)
791{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800792 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200794 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800796 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700797 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 do_initcalls();
799}
800
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700801static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700802{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800803 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700804
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800805 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
806 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700807}
808
David Howellsd7627462010-08-17 23:52:56 +0100809static void run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810{
811 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700812 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813}
814
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100815/* This is a non __init function. Force it to be noinline otherwise gcc
816 * makes it inline to init() and it becomes part of init.text section
817 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800818static noinline int init_post(void)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100819{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800820 /* need to finish all async __init code before freeing the memory */
821 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100822 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100823 mark_rodata_ro();
824 system_state = SYSTEM_RUNNING;
825 numa_default_policy();
826
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100827
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700828 current->signal->flags |= SIGNAL_UNKILLABLE;
829
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100830 if (ramdisk_execute_command) {
831 run_init_process(ramdisk_execute_command);
832 printk(KERN_WARNING "Failed to execute %s\n",
833 ramdisk_execute_command);
834 }
835
836 /*
837 * We try each of these until one succeeds.
838 *
839 * The Bourne shell can be used instead of init if we are
840 * trying to recover a really broken machine.
841 */
842 if (execute_command) {
843 run_init_process(execute_command);
844 printk(KERN_WARNING "Failed to execute %s. Attempting "
845 "defaults...\n", execute_command);
846 }
847 run_init_process("/sbin/init");
848 run_init_process("/etc/init");
849 run_init_process("/bin/init");
850 run_init_process("/bin/sh");
851
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800852 panic("No init found. Try passing init= option to kernel. "
853 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100854}
855
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100856static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200858 /*
859 * Wait until kthreadd is all set-up.
860 */
861 wait_for_completion(&kthreadd_done);
Miao Xie58568d22009-06-16 15:31:49 -0700862 /*
863 * init can allocate pages on any node
864 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700865 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 /*
867 * init can run on any cpu.
868 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600869 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 /*
871 * Tell the world that we're going to be the grim
872 * reaper of innocent orphaned children.
873 *
874 * We don't want people to have to make incorrect
875 * assumptions about where in the task array this
876 * can be found.
877 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800878 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700880 cad_pid = task_pid(current);
881
Andi Kleenca74a6f2008-01-30 13:33:17 +0100882 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 do_pre_smp_initcalls();
885
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}