blob: 9484f4ba88d05aa589bb737d96836a1a01db55ce [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
Andrew Mortonea676e82013-04-29 16:18:20 -070012#define DEBUG /* Enable initcall_debug */
13
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/types.h>
15#include <linux/module.h>
16#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/kernel.h>
18#include <linux/syscalls.h>
Ingo Molnar9b5609f2008-02-14 09:41:09 +010019#include <linux/stackprotector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/string.h>
21#include <linux/ctype.h>
22#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/ioport.h>
24#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040027#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/tty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/percpu.h>
30#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070031#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010033#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020035#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/profile.h>
37#include <linux/rcupdate.h>
38#include <linux/moduleparam.h>
39#include <linux/kallsyms.h>
40#include <linux/writeback.h>
41#include <linux/cpu.h>
42#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070043#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080045#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080046#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070047#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070048#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/unistd.h>
50#include <linux/rmap.h>
51#include <linux/mempolicy.h>
52#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070053#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070054#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070055#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070056#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070057#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010058#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080059#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080060#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070061#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010062#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080063#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070064#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050065#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040066#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080067#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020068#include <linux/kmemcheck.h>
Feng Tang6ae69962009-08-14 15:13:46 -040069#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020070#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090071#include <linux/slab.h>
Peter Zijlstra24a24bb2010-11-17 23:17:33 +010072#include <linux/perf_event.h>
Al Viro4a9d4b02012-06-24 09:56:45 +040073#include <linux/file.h>
Al Viroa74fb732012-10-10 21:28:25 -040074#include <linux/ptrace.h>
Tejun Heobb813f42013-01-18 14:05:56 -080075#include <linux/blkdev.h>
76#include <linux/elevator.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78#include <asm/io.h>
79#include <asm/bugs.h>
80#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070081#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080082#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#ifdef CONFIG_X86_LOCAL_APIC
85#include <asm/smp.h>
86#endif
87
Sam Ravnborgaae5f662007-02-26 16:45:41 +010088static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
90extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091extern void fork_init(unsigned long);
92extern void mca_init(void);
93extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094extern void radix_tree_init(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080095#ifndef CONFIG_DEBUG_RODATA
96static inline void mark_rodata_ro(void) { }
97#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99#ifdef CONFIG_TC
100extern void tc_init(void);
101#endif
102
Tejun Heo2ce802f2011-01-20 12:06:35 +0100103/*
104 * Debug helper: via this flag we know that we are in 'early bootup code'
105 * where only the boot processor is running with IRQ disabled. This means
106 * two things - IRQ must not be enabled before the flag is cleared and some
107 * operations which are not allowed with IRQ disabled are allowed while the
108 * flag is set.
109 */
110bool early_boot_irqs_disabled __read_mostly;
111
Paul E. McKenneya6826042009-02-25 18:03:42 -0800112enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113EXPORT_SYMBOL(system_state);
114
115/*
116 * Boot command-line arguments
117 */
118#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
119#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
120
121extern void time_init(void);
122/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800123void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124extern void softirq_init(void);
125
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800126/* Untouched command line saved by arch-specific code. */
127char __initdata boot_command_line[COMMAND_LINE_SIZE];
128/* Untouched saved command line (eg. for /proc) */
129char *saved_command_line;
130/* Command line for parameter parsing */
131static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700134static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
Jan Beulich8b3b2952007-07-15 23:41:07 -0700136/*
137 * If set, this is an indication to the drivers that reset the underlying
138 * device before going ahead with the initialization otherwise driver might
139 * rely on the BIOS and skip the reset operation.
140 *
141 * This is useful if kernel is booting in an unreliable environment.
142 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
143 * skipped and devices will be in unknown state.
144 */
145unsigned int reset_devices;
146EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Vivek Goyal7e962872006-09-27 01:50:44 -0700148static int __init set_reset_devices(char *str)
149{
150 reset_devices = 1;
151 return 1;
152}
153
154__setup("reset_devices", set_reset_devices);
155
David Howellsd7627462010-08-17 23:52:56 +0100156static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
157const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158static const char *panic_later, *panic_param;
159
Rusty Russell914dcaa2010-08-11 23:04:18 -0600160extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162static int __init obsolete_checksetup(char *line)
163{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600164 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200165 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 p = __setup_start;
168 do {
169 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200170 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200172 /* Already done in parse_early_param?
173 * (Needs exact match on param part).
174 * Keep iterating, as we can have early
175 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200177 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700179 pr_warn("Parameter %s is obsolete, ignored\n",
180 p->str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 return 1;
182 } else if (p->setup_func(line + n))
183 return 1;
184 }
185 p++;
186 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200187
188 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
191/*
192 * This should be approx 2 Bo*oMips to start (note initial shift), and will
193 * still work even if initially too large, it will just take slightly longer
194 */
195unsigned long loops_per_jiffy = (1<<12);
196
197EXPORT_SYMBOL(loops_per_jiffy);
198
199static int __init debug_kernel(char *str)
200{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800202 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
205static int __init quiet_kernel(char *str)
206{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800208 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209}
210
Yinghai Luf6f21c812008-02-08 04:21:58 -0800211early_param("debug", debug_kernel);
212early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214static int __init loglevel(char *str)
215{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200216 int newlevel;
217
218 /*
219 * Only update loglevel value when a correct setting was passed,
220 * to prevent blind crashes (when loglevel being set to 0) that
221 * are quite hard to debug
222 */
223 if (get_option(&str, &newlevel)) {
224 console_loglevel = newlevel;
225 return 0;
226 }
227
228 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230
Yinghai Luf6f21c812008-02-08 04:21:58 -0800231early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
Chris Metcalfa99cd112012-04-06 12:53:50 -0400233/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700234static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 if (val) {
237 /* param=val or param="val"? */
238 if (val == param+strlen(param)+1)
239 val[-1] = '=';
240 else if (val == param+strlen(param)+2) {
241 val[-2] = '=';
242 memmove(val-1, val, strlen(val)+1);
243 val--;
244 } else
245 BUG();
246 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400247 return 0;
248}
249
250/*
251 * Unknown boot options get handed to init, unless they look like
252 * unused parameters (modprobe will find them in /proc/cmdline).
253 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700254static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400255{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700256 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 /* Handle obsolete-style parameters */
259 if (obsolete_checksetup(param))
260 return 0;
261
Rusty Russellf066a4f2009-12-01 14:56:44 +1030262 /* Unused module parameter. */
263 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266 if (panic_later)
267 return 0;
268
269 if (val) {
270 /* Environment option */
271 unsigned int i;
272 for (i = 0; envp_init[i]; i++) {
273 if (i == MAX_INIT_ENVS) {
274 panic_later = "Too many boot env vars at `%s'";
275 panic_param = param;
276 }
277 if (!strncmp(param, envp_init[i], val - param))
278 break;
279 }
280 envp_init[i] = param;
281 } else {
282 /* Command line option */
283 unsigned int i;
284 for (i = 0; argv_init[i]; i++) {
285 if (i == MAX_INIT_ARGS) {
286 panic_later = "Too many boot init vars at `%s'";
287 panic_param = param;
288 }
289 }
290 argv_init[i] = param;
291 }
292 return 0;
293}
294
295static int __init init_setup(char *str)
296{
297 unsigned int i;
298
299 execute_command = str;
300 /*
301 * In case LILO is going to boot us with default command line,
302 * it prepends "auto" before the whole cmdline which makes
303 * the shell think it should execute a script with such name.
304 * So we ignore all arguments entered _before_ init=... [MJ]
305 */
306 for (i = 1; i < MAX_INIT_ARGS; i++)
307 argv_init[i] = NULL;
308 return 1;
309}
310__setup("init=", init_setup);
311
Olof Johanssonffdfc402005-09-06 15:17:19 -0700312static int __init rdinit_setup(char *str)
313{
314 unsigned int i;
315
316 ramdisk_execute_command = str;
317 /* See "auto" comment in init_setup */
318 for (i = 1; i < MAX_INIT_ARGS; i++)
319 argv_init[i] = NULL;
320 return 1;
321}
322__setup("rdinit=", rdinit_setup);
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700325static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326#ifdef CONFIG_X86_LOCAL_APIC
327static void __init smp_init(void)
328{
329 APIC_init_uniprocessor();
330}
331#else
332#define smp_init() do { } while (0)
333#endif
334
Mike Travise0982e92008-03-26 14:23:48 -0700335static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337#endif
338
339/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800340 * We need to store the untouched command line for future reference.
341 * We also need to store the touched command line since the parameter
342 * parsing is performed in place, and we should allow a component to
343 * store reference of name/value for future reference.
344 */
345static void __init setup_command_line(char *command_line)
346{
347 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
348 static_command_line = alloc_bootmem(strlen (command_line)+1);
349 strcpy (saved_command_line, boot_command_line);
350 strcpy (static_command_line, command_line);
351}
352
353/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 * We need to finalize in a non-__init function or else race conditions
355 * between the root thread and the init thread may cause start_kernel to
356 * be reaped by free_initmem before the root thread has proceeded to
357 * cpu_idle.
358 *
359 * gcc-3.4 accidentally inlines this function, so use noinline.
360 */
361
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200362static __initdata DECLARE_COMPLETION(kthreadd_done);
363
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800364static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700366 int pid;
367
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700368 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200369 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200370 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200371 * the init task will end up wanting to create kthreads, which, if
372 * we schedule it before we create kthreadd, will OOPS.
373 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100374 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700376 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800377 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700378 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800379 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200380 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200381
382 /*
383 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200384 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200385 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200386 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100387 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800388 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100389 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200390}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600393static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600395 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
397 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200398 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700399 (strcmp(param, "console") == 0 &&
400 strcmp(p->str, "earlycon") == 0)
401 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700403 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 }
405 }
406 /* We accept everything at this stage. */
407 return 0;
408}
409
Magnus Damm13977092009-03-30 14:37:25 -0700410void __init parse_early_options(char *cmdline)
411{
Pawel Moll026cee02012-03-26 12:50:51 +1030412 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700413}
414
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415/* Arch code calls this early on, or if not, just before other parsing. */
416void __init parse_early_param(void)
417{
418 static __initdata int done = 0;
419 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
420
421 if (done)
422 return;
423
424 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800425 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700426 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 done = 1;
428}
429
430/*
431 * Activate the first processor.
432 */
433
Stas Sergeev44fd2292006-03-23 02:59:44 -0800434static void __init boot_cpu_init(void)
435{
436 int cpu = smp_processor_id();
437 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030438 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100439 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030440 set_cpu_present(cpu, true);
441 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800442}
443
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000444void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700445{
446}
447
David Howellseded09c2012-11-02 13:20:42 +0000448# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000449void __init __weak thread_info_cache_init(void)
450{
451}
David Howellseded09c2012-11-02 13:20:42 +0000452#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000453
Pekka Enberg444f4782009-06-11 18:29:06 +0300454/*
455 * Set up kernel memory allocators
456 */
457static void __init mm_init(void)
458{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300459 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600460 * page_cgroup requires contiguous pages,
461 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300462 */
463 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300464 mem_init();
465 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200466 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000467 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300468 vmalloc_init();
469}
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471asmlinkage void __init start_kernel(void)
472{
473 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600474 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700475
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700476 /*
477 * Need to run as early as possible, to initialize the
478 * lockdep hash:
479 */
480 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800481 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700482 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100483
484 /*
485 * Set up the the initial canary ASAP:
486 */
487 boot_init_stack_canary();
488
Paul Menageddbcc7e2007-10-18 23:39:30 -0700489 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700490
491 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100492 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494/*
495 * Interrupts are still disabled. Do necessary setups, then
496 * enable them
497 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800498 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700500 pr_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
Andrew Mortonea676e82013-04-29 16:18:20 -0700512 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300513 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();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700542 if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800543 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100544 idr_init_cache();
Peter Zijlstra24a24bb2010-11-17 23:17:33 +0100545 perf_event_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 rcu_init();
Frederic Weisbeckerd1e43fa2013-03-26 23:47:24 +0100547 tick_nohz_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800548 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800549 /* init some links before init_ISA_irqs() */
550 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100552 tick_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800554 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700556 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700557 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700558 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400559 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700560 WARN(!irqs_disabled(), "Interrupts were 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) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700587 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700588 page_to_pfn(virt_to_page((void *)initrd_start)),
589 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 initrd_start = 0;
591 }
592#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700593 page_cgroup_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700594 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100595 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700596 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 numa_policy_init();
598 if (late_time_init)
599 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200600 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 calibrate_delay();
602 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 anon_vma_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800604#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000605 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800606 efi_enter_virtual_mode();
607#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000608 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100609 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700610 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 proc_caches_init();
612 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 key_init();
614 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500615 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700616 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 signals_init();
618 /* rootfs populating might need page-writeback */
619 page_writeback_init();
620#ifdef CONFIG_PROC_FS
621 proc_root_init();
622#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700623 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700625 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700626 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
628 check_bugs();
629
630 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400631 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
Matt Fleming83e68182012-11-14 09:42:35 +0000633 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700634 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700635 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700636 }
Josh Triplett78510792012-09-28 17:55:44 -0700637
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400638 ftrace_init();
639
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 /* Do the rest non-__init'ed, we're now alive */
641 rest_init();
642}
643
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700644/* Call all constructor functions linked into the kernel. */
645static void __init do_ctors(void)
646{
647#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800648 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700649
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800650 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
651 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700652#endif
653}
654
Rusty Russell2329abf2012-01-13 09:32:18 +1030655bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500656core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200658static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200659
Kevin Winchestere4461272010-08-09 17:20:32 -0700660static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700661{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100662 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800663 unsigned long long duration;
664 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700665
Andrew Mortonea676e82013-04-29 16:18:20 -0700666 pr_debug("calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700667 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800668 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700669 rettime = ktime_get();
670 delta = ktime_sub(rettime, calltime);
671 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortonea676e82013-04-29 16:18:20 -0700672 pr_debug("initcall %pF returned %d after %lld usecs\n",
673 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700674
Kevin Winchester22c5c032010-08-09 17:20:32 -0700675 return ret;
676}
677
Kevin Winchestere4461272010-08-09 17:20:32 -0700678int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700679{
680 int count = preempt_count();
681 int ret;
682
683 if (initcall_debug)
684 ret = do_one_initcall_debug(fn);
685 else
686 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700687
688 msgbuf[0] = 0;
689
Linus Torvaldse0df1542008-05-15 18:14:01 -0700690 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400691 sprintf(msgbuf, "preemption imbalance ");
Linus Torvaldse0df1542008-05-15 18:14:01 -0700692 preempt_count() = count;
693 }
694 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700695 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700696 local_irq_enable();
697 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700698 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700699
Américo Wang30dbb20e2010-05-26 18:57:53 +0800700 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700701}
702
703
Pawel Moll026cee02012-03-26 12:50:51 +1030704extern initcall_t __initcall_start[];
705extern initcall_t __initcall0_start[];
706extern initcall_t __initcall1_start[];
707extern initcall_t __initcall2_start[];
708extern initcall_t __initcall3_start[];
709extern initcall_t __initcall4_start[];
710extern initcall_t __initcall5_start[];
711extern initcall_t __initcall6_start[];
712extern initcall_t __initcall7_start[];
713extern initcall_t __initcall_end[];
714
715static initcall_t *initcall_levels[] __initdata = {
716 __initcall0_start,
717 __initcall1_start,
718 __initcall2_start,
719 __initcall3_start,
720 __initcall4_start,
721 __initcall5_start,
722 __initcall6_start,
723 __initcall7_start,
724 __initcall_end,
725};
726
Jim Cromie96263d22012-06-14 16:00:59 -0600727/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030728static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600729 "early",
730 "core",
731 "postcore",
732 "arch",
733 "subsys",
734 "fs",
735 "device",
736 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030737};
738
Pawel Moll026cee02012-03-26 12:50:51 +1030739static void __init do_initcall_level(int level)
740{
741 extern const struct kernel_param __start___param[], __stop___param[];
742 initcall_t *fn;
743
744 strcpy(static_command_line, saved_command_line);
745 parse_args(initcall_level_names[level],
746 static_command_line, __start___param,
747 __stop___param - __start___param,
748 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700749 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030750
751 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
752 do_one_initcall(*fn);
753}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
755static void __init do_initcalls(void)
756{
Pawel Moll026cee02012-03-26 12:50:51 +1030757 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
Borislav Petkov19efb722012-06-01 18:56:00 +0200759 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030760 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761}
762
763/*
764 * Ok, the machine is now initialized. None of the devices
765 * have been touched yet, but the CPU subsystem is up and
766 * running, and memory and process management works.
767 *
768 * Now we can finally start doing some real work..
769 */
770static void __init do_basic_setup(void)
771{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800772 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700774 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800776 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700777 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700778 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800779 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780}
781
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700782static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700783{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800784 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700785
Pawel Moll026cee02012-03-26 12:50:51 +1030786 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800787 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700788}
789
Tejun Heobb813f42013-01-18 14:05:56 -0800790/*
791 * This function requests modules which should be loaded by default and is
792 * called twice right after initrd is mounted and right before init is
793 * exec'd. If such modules are on either initrd or rootfs, they will be
794 * loaded before control is passed to userland.
795 */
796void __init load_default_modules(void)
797{
798 load_default_elevator_module();
799}
800
Al Viroa74fb732012-10-10 21:28:25 -0400801static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
803 argv_init[0] = init_filename;
Al Viroae903ca2012-12-14 12:44:11 -0500804 return do_execve(init_filename,
805 (const char __user *const __user *)argv_init,
806 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807}
808
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530809static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400810
811static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100812{
Al Virod6b21232012-10-10 19:57:26 -0400813 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800814 /* need to finish all async __init code before freeing the memory */
815 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100816 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100817 mark_rodata_ro();
818 system_state = SYSTEM_RUNNING;
819 numa_default_policy();
820
Al Viro4a9d4b02012-06-24 09:56:45 +0400821 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700822
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100823 if (ramdisk_execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400824 if (!run_init_process(ramdisk_execute_command))
825 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700826 pr_err("Failed to execute %s\n", ramdisk_execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100827 }
828
829 /*
830 * We try each of these until one succeeds.
831 *
832 * The Bourne shell can be used instead of init if we are
833 * trying to recover a really broken machine.
834 */
835 if (execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400836 if (!run_init_process(execute_command))
837 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700838 pr_err("Failed to execute %s. Attempting defaults...\n",
839 execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100840 }
Al Viroa74fb732012-10-10 21:28:25 -0400841 if (!run_init_process("/sbin/init") ||
842 !run_init_process("/etc/init") ||
843 !run_init_process("/bin/init") ||
844 !run_init_process("/bin/sh"))
845 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100846
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800847 panic("No init found. Try passing init= option to kernel. "
848 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100849}
850
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530851static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200853 /*
854 * Wait until kthreadd is all set-up.
855 */
856 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700857
858 /* Now the scheduler is fully set up and can do blocking allocations */
859 gfp_allowed_mask = __GFP_BITS_MASK;
860
Miao Xie58568d22009-06-16 15:31:49 -0700861 /*
862 * init can allocate pages on any node
863 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800864 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 /*
866 * init can run on any cpu.
867 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600868 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700870 cad_pid = task_pid(current);
871
Andi Kleenca74a6f2008-01-30 13:33:17 +0100872 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
874 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100875 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 smp_init();
878 sched_init_smp();
879
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 do_basic_setup();
881
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800882 /* Open the /dev/console on the rootfs, this should never fail */
883 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700884 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800885
886 (void) sys_dup(0);
887 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 /*
889 * check if there is an early userspace init. If yes, let it do all
890 * the work
891 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700892
893 if (!ramdisk_execute_command)
894 ramdisk_execute_command = "/init";
895
896 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
897 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700899 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901 /*
902 * Ok, we have completed the initial bootup, and
903 * we're essentially up and running. Get rid of the
904 * initmem segments and start the user-mode stuff..
905 */
Tejun Heobb813f42013-01-18 14:05:56 -0800906
907 /* rootfs is available now, try loading default modules */
908 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909}