blob: 63534a141b4eb6c0f36c5ac0d99d2733028ff96e [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>
Al Viroa74fb732012-10-10 21:28:25 -040072#include <linux/ptrace.h>
Tejun Heobb813f42013-01-18 14:05:56 -080073#include <linux/blkdev.h>
74#include <linux/elevator.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76#include <asm/io.h>
77#include <asm/bugs.h>
78#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070079#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080080#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#ifdef CONFIG_X86_LOCAL_APIC
83#include <asm/smp.h>
84#endif
85
Sam Ravnborgaae5f662007-02-26 16:45:41 +010086static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void fork_init(unsigned long);
90extern void mca_init(void);
91extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092extern void radix_tree_init(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080093#ifndef CONFIG_DEBUG_RODATA
94static inline void mark_rodata_ro(void) { }
95#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97#ifdef CONFIG_TC
98extern void tc_init(void);
99#endif
100
Tejun Heo2ce802f2011-01-20 12:06:35 +0100101/*
102 * Debug helper: via this flag we know that we are in 'early bootup code'
103 * where only the boot processor is running with IRQ disabled. This means
104 * two things - IRQ must not be enabled before the flag is cleared and some
105 * operations which are not allowed with IRQ disabled are allowed while the
106 * flag is set.
107 */
108bool early_boot_irqs_disabled __read_mostly;
109
Paul E. McKenneya6826042009-02-25 18:03:42 -0800110enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111EXPORT_SYMBOL(system_state);
112
113/*
114 * Boot command-line arguments
115 */
116#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
117#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
118
119extern void time_init(void);
120/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800121void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122extern void softirq_init(void);
123
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800124/* Untouched command line saved by arch-specific code. */
125char __initdata boot_command_line[COMMAND_LINE_SIZE];
126/* Untouched saved command line (eg. for /proc) */
127char *saved_command_line;
128/* Command line for parameter parsing */
129static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700132static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Jan Beulich8b3b2952007-07-15 23:41:07 -0700134/*
135 * If set, this is an indication to the drivers that reset the underlying
136 * device before going ahead with the initialization otherwise driver might
137 * rely on the BIOS and skip the reset operation.
138 *
139 * This is useful if kernel is booting in an unreliable environment.
140 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
141 * skipped and devices will be in unknown state.
142 */
143unsigned int reset_devices;
144EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Vivek Goyal7e962872006-09-27 01:50:44 -0700146static int __init set_reset_devices(char *str)
147{
148 reset_devices = 1;
149 return 1;
150}
151
152__setup("reset_devices", set_reset_devices);
153
David Howellsd7627462010-08-17 23:52:56 +0100154static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
155const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156static const char *panic_later, *panic_param;
157
Rusty Russell914dcaa2010-08-11 23:04:18 -0600158extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160static int __init obsolete_checksetup(char *line)
161{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600162 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200163 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 p = __setup_start;
166 do {
167 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200168 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200170 /* Already done in parse_early_param?
171 * (Needs exact match on param part).
172 * Keep iterating, as we can have early
173 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200175 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 } else if (!p->setup_func) {
177 printk(KERN_WARNING "Parameter %s is obsolete,"
178 " ignored\n", p->str);
179 return 1;
180 } else if (p->setup_func(line + n))
181 return 1;
182 }
183 p++;
184 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200185
186 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187}
188
189/*
190 * This should be approx 2 Bo*oMips to start (note initial shift), and will
191 * still work even if initially too large, it will just take slightly longer
192 */
193unsigned long loops_per_jiffy = (1<<12);
194
195EXPORT_SYMBOL(loops_per_jiffy);
196
197static int __init debug_kernel(char *str)
198{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800200 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201}
202
203static int __init quiet_kernel(char *str)
204{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800206 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207}
208
Yinghai Luf6f21c812008-02-08 04:21:58 -0800209early_param("debug", debug_kernel);
210early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212static int __init loglevel(char *str)
213{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200214 int newlevel;
215
216 /*
217 * Only update loglevel value when a correct setting was passed,
218 * to prevent blind crashes (when loglevel being set to 0) that
219 * are quite hard to debug
220 */
221 if (get_option(&str, &newlevel)) {
222 console_loglevel = newlevel;
223 return 0;
224 }
225
226 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
Yinghai Luf6f21c812008-02-08 04:21:58 -0800229early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
Chris Metcalfa99cd112012-04-06 12:53:50 -0400231/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700232static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (val) {
235 /* param=val or param="val"? */
236 if (val == param+strlen(param)+1)
237 val[-1] = '=';
238 else if (val == param+strlen(param)+2) {
239 val[-2] = '=';
240 memmove(val-1, val, strlen(val)+1);
241 val--;
242 } else
243 BUG();
244 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400245 return 0;
246}
247
248/*
249 * Unknown boot options get handed to init, unless they look like
250 * unused parameters (modprobe will find them in /proc/cmdline).
251 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700252static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400253{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700254 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 /* Handle obsolete-style parameters */
257 if (obsolete_checksetup(param))
258 return 0;
259
Rusty Russellf066a4f2009-12-01 14:56:44 +1030260 /* Unused module parameter. */
261 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264 if (panic_later)
265 return 0;
266
267 if (val) {
268 /* Environment option */
269 unsigned int i;
270 for (i = 0; envp_init[i]; i++) {
271 if (i == MAX_INIT_ENVS) {
272 panic_later = "Too many boot env vars at `%s'";
273 panic_param = param;
274 }
275 if (!strncmp(param, envp_init[i], val - param))
276 break;
277 }
278 envp_init[i] = param;
279 } else {
280 /* Command line option */
281 unsigned int i;
282 for (i = 0; argv_init[i]; i++) {
283 if (i == MAX_INIT_ARGS) {
284 panic_later = "Too many boot init vars at `%s'";
285 panic_param = param;
286 }
287 }
288 argv_init[i] = param;
289 }
290 return 0;
291}
292
293static int __init init_setup(char *str)
294{
295 unsigned int i;
296
297 execute_command = str;
298 /*
299 * In case LILO is going to boot us with default command line,
300 * it prepends "auto" before the whole cmdline which makes
301 * the shell think it should execute a script with such name.
302 * So we ignore all arguments entered _before_ init=... [MJ]
303 */
304 for (i = 1; i < MAX_INIT_ARGS; i++)
305 argv_init[i] = NULL;
306 return 1;
307}
308__setup("init=", init_setup);
309
Olof Johanssonffdfc402005-09-06 15:17:19 -0700310static int __init rdinit_setup(char *str)
311{
312 unsigned int i;
313
314 ramdisk_execute_command = str;
315 /* See "auto" comment in init_setup */
316 for (i = 1; i < MAX_INIT_ARGS; i++)
317 argv_init[i] = NULL;
318 return 1;
319}
320__setup("rdinit=", rdinit_setup);
321
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700323static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324#ifdef CONFIG_X86_LOCAL_APIC
325static void __init smp_init(void)
326{
327 APIC_init_uniprocessor();
328}
329#else
330#define smp_init() do { } while (0)
331#endif
332
Mike Travise0982e92008-03-26 14:23:48 -0700333static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335#endif
336
337/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800338 * We need to store the untouched command line for future reference.
339 * We also need to store the touched command line since the parameter
340 * parsing is performed in place, and we should allow a component to
341 * store reference of name/value for future reference.
342 */
343static void __init setup_command_line(char *command_line)
344{
345 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
346 static_command_line = alloc_bootmem(strlen (command_line)+1);
347 strcpy (saved_command_line, boot_command_line);
348 strcpy (static_command_line, command_line);
349}
350
351/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 * We need to finalize in a non-__init function or else race conditions
353 * between the root thread and the init thread may cause start_kernel to
354 * be reaped by free_initmem before the root thread has proceeded to
355 * cpu_idle.
356 *
357 * gcc-3.4 accidentally inlines this function, so use noinline.
358 */
359
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200360static __initdata DECLARE_COMPLETION(kthreadd_done);
361
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800362static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700364 int pid;
365
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700366 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200367 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200368 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200369 * the init task will end up wanting to create kthreads, which, if
370 * we schedule it before we create kthreadd, will OOPS.
371 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100372 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700374 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800375 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700376 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800377 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200378 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200379
380 /*
381 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200382 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200383 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200384 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100385 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800386 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200388}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
390/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600391static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600393 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200396 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700397 (strcmp(param, "console") == 0 &&
398 strcmp(p->str, "earlycon") == 0)
399 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 if (p->setup_func(val) != 0)
401 printk(KERN_WARNING
402 "Malformed early option '%s'\n", param);
403 }
404 }
405 /* We accept everything at this stage. */
406 return 0;
407}
408
Magnus Damm13977092009-03-30 14:37:25 -0700409void __init parse_early_options(char *cmdline)
410{
Pawel Moll026cee02012-03-26 12:50:51 +1030411 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700412}
413
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414/* Arch code calls this early on, or if not, just before other parsing. */
415void __init parse_early_param(void)
416{
417 static __initdata int done = 0;
418 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
419
420 if (done)
421 return;
422
423 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800424 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700425 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 done = 1;
427}
428
429/*
430 * Activate the first processor.
431 */
432
Stas Sergeev44fd2292006-03-23 02:59:44 -0800433static void __init boot_cpu_init(void)
434{
435 int cpu = smp_processor_id();
436 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030437 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100438 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030439 set_cpu_present(cpu, true);
440 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800441}
442
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000443void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700444{
445}
446
David Howellseded09c2012-11-02 13:20:42 +0000447# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000448void __init __weak thread_info_cache_init(void)
449{
450}
David Howellseded09c2012-11-02 13:20:42 +0000451#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000452
Pekka Enberg444f4782009-06-11 18:29:06 +0300453/*
454 * Set up kernel memory allocators
455 */
456static void __init mm_init(void)
457{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300458 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600459 * page_cgroup requires contiguous pages,
460 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300461 */
462 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300463 mem_init();
464 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200465 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000466 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300467 vmalloc_init();
468}
469
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470asmlinkage void __init start_kernel(void)
471{
472 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600473 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700474
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700475 /*
476 * Need to run as early as possible, to initialize the
477 * lockdep hash:
478 */
479 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800480 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700481 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100482
483 /*
484 * Set up the the initial canary ASAP:
485 */
486 boot_init_stack_canary();
487
Paul Menageddbcc7e2007-10-18 23:39:30 -0700488 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700489
490 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100491 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700492
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493/*
494 * Interrupts are still disabled. Do necessary setups, then
495 * enable them
496 */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800497 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800498 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200500 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700502 mm_init_owner(&init_mm, &init_task);
Linus Torvalds6345d242011-05-29 11:32:28 -0700503 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800504 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700505 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900506 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800507 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Jiang Liu9adb62a2012-07-31 16:43:28 -0700509 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300510 page_alloc_init();
511
512 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
513 parse_early_param();
514 parse_args("Booting kernel", static_command_line, __start___param,
515 __stop___param - __start___param,
Rusty Russellae82fdb2012-06-08 14:58:13 +0930516 -1, -1, &unknown_bootoption);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700517
518 jump_label_init();
519
Pekka Enberg83b519e2009-06-10 19:40:04 +0300520 /*
521 * These use large bootmem allocations and must precede
522 * kmem_cache_init()
523 */
Mike Travis162a7e72011-05-24 17:13:20 -0700524 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300525 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300526 vfs_caches_init_early();
527 sort_main_extable();
528 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300529 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 /*
532 * Set up the scheduler prior starting any interrupts (such as the
533 * timer interrupt). Full topology setup happens at smp_init()
534 * time - but meanwhile we still have a functioning scheduler.
535 */
536 sched_init();
537 /*
538 * Disable preemption - early bootup scheduling is extremely
539 * fragile until we cpu_idle() for the first time.
540 */
541 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800542 if (!irqs_disabled()) {
543 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
544 "enabled *very* early, fixing it\n");
545 local_irq_disable();
546 }
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100547 idr_init_cache();
Peter Zijlstra24a24bb2010-11-17 23:17:33 +0100548 perf_event_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800550 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800551 /* init some links before init_ISA_irqs() */
552 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 init_IRQ();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800555 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700557 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700558 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700559 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400560 call_function_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700561 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030562 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
563 "enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100564 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700565 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000566
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300567 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
569 /*
570 * HACK ALERT! This is early. We're enabling the console before
571 * we've done PCI setups etc, and console_init() must be aware of
572 * this. But we do want output early, in case something goes wrong.
573 */
574 console_init();
575 if (panic_later)
576 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700577
578 lockdep_info();
579
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700580 /*
581 * Need to run this when irqs are enabled, because it wants
582 * to self-test [hard/soft]-irqs on/off lock inversion bugs
583 * too:
584 */
585 locking_selftest();
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587#ifdef CONFIG_BLK_DEV_INITRD
588 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700589 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200591 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700592 page_to_pfn(virt_to_page((void *)initrd_start)),
593 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 initrd_start = 0;
595 }
596#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700597 page_cgroup_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700598 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100599 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700600 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 numa_policy_init();
602 if (late_time_init)
603 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200604 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 calibrate_delay();
606 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 anon_vma_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800608#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000609 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800610 efi_enter_virtual_mode();
611#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000612 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100613 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700614 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 proc_caches_init();
616 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 key_init();
618 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500619 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700620 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 signals_init();
622 /* rootfs populating might need page-writeback */
623 page_writeback_init();
624#ifdef CONFIG_PROC_FS
625 proc_root_init();
626#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700627 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700629 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700630 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
632 check_bugs();
633
634 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400635 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
Matt Fleming83e68182012-11-14 09:42:35 +0000637 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700638 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700639 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700640 }
Josh Triplett78510792012-09-28 17:55:44 -0700641
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400642 ftrace_init();
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 /* Do the rest non-__init'ed, we're now alive */
645 rest_init();
646}
647
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700648/* Call all constructor functions linked into the kernel. */
649static void __init do_ctors(void)
650{
651#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800652 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700653
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800654 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
655 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700656#endif
657}
658
Rusty Russell2329abf2012-01-13 09:32:18 +1030659bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500660core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200662static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200663
Kevin Winchestere4461272010-08-09 17:20:32 -0700664static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700665{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100666 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800667 unsigned long long duration;
668 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700669
Kevin Winchester22c5c032010-08-09 17:20:32 -0700670 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
671 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800672 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700673 rettime = ktime_get();
674 delta = ktime_sub(rettime, calltime);
675 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
676 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
677 ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700678
Kevin Winchester22c5c032010-08-09 17:20:32 -0700679 return ret;
680}
681
Kevin Winchestere4461272010-08-09 17:20:32 -0700682int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700683{
684 int count = preempt_count();
685 int ret;
686
687 if (initcall_debug)
688 ret = do_one_initcall_debug(fn);
689 else
690 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700691
692 msgbuf[0] = 0;
693
Américo Wang30dbb20e2010-05-26 18:57:53 +0800694 if (ret && ret != -ENODEV && initcall_debug)
695 sprintf(msgbuf, "error code %d ", ret);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700696
697 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700698 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700699 preempt_count() = count;
700 }
701 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700702 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700703 local_irq_enable();
704 }
705 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700706 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700707 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700708
Américo Wang30dbb20e2010-05-26 18:57:53 +0800709 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700710}
711
712
Pawel Moll026cee02012-03-26 12:50:51 +1030713extern initcall_t __initcall_start[];
714extern initcall_t __initcall0_start[];
715extern initcall_t __initcall1_start[];
716extern initcall_t __initcall2_start[];
717extern initcall_t __initcall3_start[];
718extern initcall_t __initcall4_start[];
719extern initcall_t __initcall5_start[];
720extern initcall_t __initcall6_start[];
721extern initcall_t __initcall7_start[];
722extern initcall_t __initcall_end[];
723
724static initcall_t *initcall_levels[] __initdata = {
725 __initcall0_start,
726 __initcall1_start,
727 __initcall2_start,
728 __initcall3_start,
729 __initcall4_start,
730 __initcall5_start,
731 __initcall6_start,
732 __initcall7_start,
733 __initcall_end,
734};
735
Jim Cromie96263d22012-06-14 16:00:59 -0600736/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030737static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600738 "early",
739 "core",
740 "postcore",
741 "arch",
742 "subsys",
743 "fs",
744 "device",
745 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030746};
747
Pawel Moll026cee02012-03-26 12:50:51 +1030748static void __init do_initcall_level(int level)
749{
750 extern const struct kernel_param __start___param[], __stop___param[];
751 initcall_t *fn;
752
753 strcpy(static_command_line, saved_command_line);
754 parse_args(initcall_level_names[level],
755 static_command_line, __start___param,
756 __stop___param - __start___param,
757 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700758 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030759
760 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
761 do_one_initcall(*fn);
762}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
764static void __init do_initcalls(void)
765{
Pawel Moll026cee02012-03-26 12:50:51 +1030766 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
Borislav Petkov19efb722012-06-01 18:56:00 +0200768 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030769 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770}
771
772/*
773 * Ok, the machine is now initialized. None of the devices
774 * have been touched yet, but the CPU subsystem is up and
775 * running, and memory and process management works.
776 *
777 * Now we can finally start doing some real work..
778 */
779static void __init do_basic_setup(void)
780{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800781 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700783 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800785 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700786 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700787 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800788 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789}
790
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700791static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700792{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800793 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700794
Pawel Moll026cee02012-03-26 12:50:51 +1030795 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800796 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700797}
798
Tejun Heobb813f42013-01-18 14:05:56 -0800799/*
800 * This function requests modules which should be loaded by default and is
801 * called twice right after initrd is mounted and right before init is
802 * exec'd. If such modules are on either initrd or rootfs, they will be
803 * loaded before control is passed to userland.
804 */
805void __init load_default_modules(void)
806{
807 load_default_elevator_module();
808}
809
Al Viroa74fb732012-10-10 21:28:25 -0400810static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811{
812 argv_init[0] = init_filename;
Al Viroae903ca2012-12-14 12:44:11 -0500813 return do_execve(init_filename,
814 (const char __user *const __user *)argv_init,
815 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816}
817
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530818static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400819
820static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100821{
Al Virod6b21232012-10-10 19:57:26 -0400822 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800823 /* need to finish all async __init code before freeing the memory */
824 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100825 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100826 mark_rodata_ro();
827 system_state = SYSTEM_RUNNING;
828 numa_default_policy();
829
Al Viro4a9d4b02012-06-24 09:56:45 +0400830 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700831
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100832 if (ramdisk_execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400833 if (!run_init_process(ramdisk_execute_command))
834 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100835 printk(KERN_WARNING "Failed to execute %s\n",
836 ramdisk_execute_command);
837 }
838
839 /*
840 * We try each of these until one succeeds.
841 *
842 * The Bourne shell can be used instead of init if we are
843 * trying to recover a really broken machine.
844 */
845 if (execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400846 if (!run_init_process(execute_command))
847 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100848 printk(KERN_WARNING "Failed to execute %s. Attempting "
849 "defaults...\n", execute_command);
850 }
Al Viroa74fb732012-10-10 21:28:25 -0400851 if (!run_init_process("/sbin/init") ||
852 !run_init_process("/etc/init") ||
853 !run_init_process("/bin/init") ||
854 !run_init_process("/bin/sh"))
855 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100856
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800857 panic("No init found. Try passing init= option to kernel. "
858 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100859}
860
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530861static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200863 /*
864 * Wait until kthreadd is all set-up.
865 */
866 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700867
868 /* Now the scheduler is fully set up and can do blocking allocations */
869 gfp_allowed_mask = __GFP_BITS_MASK;
870
Miao Xie58568d22009-06-16 15:31:49 -0700871 /*
872 * init can allocate pages on any node
873 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800874 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 /*
876 * init can run on any cpu.
877 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600878 set_cpus_allowed_ptr(current, cpu_all_mask);
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();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100885 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 smp_init();
888 sched_init_smp();
889
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 do_basic_setup();
891
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800892 /* Open the /dev/console on the rootfs, this should never fail */
893 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
894 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
895
896 (void) sys_dup(0);
897 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 /*
899 * check if there is an early userspace init. If yes, let it do all
900 * the work
901 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700902
903 if (!ramdisk_execute_command)
904 ramdisk_execute_command = "/init";
905
906 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
907 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700909 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 /*
912 * Ok, we have completed the initial bootup, and
913 * we're essentially up and running. Get rid of the
914 * initmem segments and start the user-mode stuff..
915 */
Tejun Heobb813f42013-01-18 14:05:56 -0800916
917 /* rootfs is available now, try loading default modules */
918 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919}