blob: 7cc4b7889a88fad4ae8e6b1b5426024d253e5dfa [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>
Stephen Boyd38ff87f2013-06-01 23:39:40 -070077#include <linux/sched_clock.h>
Frederic Weisbecker65f382f2013-07-11 19:12:32 +020078#include <linux/context_tracking.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80#include <asm/io.h>
81#include <asm/bugs.h>
82#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070083#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080084#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
Linus Torvalds1da177e2005-04-16 15:20:36 -070086#ifdef CONFIG_X86_LOCAL_APIC
87#include <asm/smp.h>
88#endif
89
Sam Ravnborgaae5f662007-02-26 16:45:41 +010090static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093extern void fork_init(unsigned long);
94extern void mca_init(void);
95extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096extern void radix_tree_init(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080097#ifndef CONFIG_DEBUG_RODATA
98static inline void mark_rodata_ro(void) { }
99#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101#ifdef CONFIG_TC
102extern void tc_init(void);
103#endif
104
Tejun Heo2ce802f2011-01-20 12:06:35 +0100105/*
106 * Debug helper: via this flag we know that we are in 'early bootup code'
107 * where only the boot processor is running with IRQ disabled. This means
108 * two things - IRQ must not be enabled before the flag is cleared and some
109 * operations which are not allowed with IRQ disabled are allowed while the
110 * flag is set.
111 */
112bool early_boot_irqs_disabled __read_mostly;
113
Paul E. McKenneya6826042009-02-25 18:03:42 -0800114enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115EXPORT_SYMBOL(system_state);
116
117/*
118 * Boot command-line arguments
119 */
120#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
121#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
122
123extern void time_init(void);
124/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800125void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126extern void softirq_init(void);
127
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800128/* Untouched command line saved by arch-specific code. */
129char __initdata boot_command_line[COMMAND_LINE_SIZE];
130/* Untouched saved command line (eg. for /proc) */
131char *saved_command_line;
132/* Command line for parameter parsing */
133static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700136static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
Jan Beulich8b3b2952007-07-15 23:41:07 -0700138/*
139 * If set, this is an indication to the drivers that reset the underlying
140 * device before going ahead with the initialization otherwise driver might
141 * rely on the BIOS and skip the reset operation.
142 *
143 * This is useful if kernel is booting in an unreliable environment.
144 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
145 * skipped and devices will be in unknown state.
146 */
147unsigned int reset_devices;
148EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Vivek Goyal7e962872006-09-27 01:50:44 -0700150static int __init set_reset_devices(char *str)
151{
152 reset_devices = 1;
153 return 1;
154}
155
156__setup("reset_devices", set_reset_devices);
157
David Howellsd7627462010-08-17 23:52:56 +0100158static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
159const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160static const char *panic_later, *panic_param;
161
Rusty Russell914dcaa2010-08-11 23:04:18 -0600162extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164static int __init obsolete_checksetup(char *line)
165{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600166 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200167 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
169 p = __setup_start;
170 do {
171 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200172 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200174 /* Already done in parse_early_param?
175 * (Needs exact match on param part).
176 * Keep iterating, as we can have early
177 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200179 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700181 pr_warn("Parameter %s is obsolete, ignored\n",
182 p->str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 return 1;
184 } else if (p->setup_func(line + n))
185 return 1;
186 }
187 p++;
188 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200189
190 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
192
193/*
194 * This should be approx 2 Bo*oMips to start (note initial shift), and will
195 * still work even if initially too large, it will just take slightly longer
196 */
197unsigned long loops_per_jiffy = (1<<12);
198
199EXPORT_SYMBOL(loops_per_jiffy);
200
201static int __init debug_kernel(char *str)
202{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207static int __init quiet_kernel(char *str)
208{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800210 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
Yinghai Luf6f21c812008-02-08 04:21:58 -0800213early_param("debug", debug_kernel);
214early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216static int __init loglevel(char *str)
217{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200218 int newlevel;
219
220 /*
221 * Only update loglevel value when a correct setting was passed,
222 * to prevent blind crashes (when loglevel being set to 0) that
223 * are quite hard to debug
224 */
225 if (get_option(&str, &newlevel)) {
226 console_loglevel = newlevel;
227 return 0;
228 }
229
230 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231}
232
Yinghai Luf6f21c812008-02-08 04:21:58 -0800233early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Chris Metcalfa99cd112012-04-06 12:53:50 -0400235/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700236static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 if (val) {
239 /* param=val or param="val"? */
240 if (val == param+strlen(param)+1)
241 val[-1] = '=';
242 else if (val == param+strlen(param)+2) {
243 val[-2] = '=';
244 memmove(val-1, val, strlen(val)+1);
245 val--;
246 } else
247 BUG();
248 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400249 return 0;
250}
251
252/*
253 * Unknown boot options get handed to init, unless they look like
254 * unused parameters (modprobe will find them in /proc/cmdline).
255 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700256static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400257{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700258 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
260 /* Handle obsolete-style parameters */
261 if (obsolete_checksetup(param))
262 return 0;
263
Rusty Russellf066a4f2009-12-01 14:56:44 +1030264 /* Unused module parameter. */
265 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268 if (panic_later)
269 return 0;
270
271 if (val) {
272 /* Environment option */
273 unsigned int i;
274 for (i = 0; envp_init[i]; i++) {
275 if (i == MAX_INIT_ENVS) {
276 panic_later = "Too many boot env vars at `%s'";
277 panic_param = param;
278 }
279 if (!strncmp(param, envp_init[i], val - param))
280 break;
281 }
282 envp_init[i] = param;
283 } else {
284 /* Command line option */
285 unsigned int i;
286 for (i = 0; argv_init[i]; i++) {
287 if (i == MAX_INIT_ARGS) {
288 panic_later = "Too many boot init vars at `%s'";
289 panic_param = param;
290 }
291 }
292 argv_init[i] = param;
293 }
294 return 0;
295}
296
297static int __init init_setup(char *str)
298{
299 unsigned int i;
300
301 execute_command = str;
302 /*
303 * In case LILO is going to boot us with default command line,
304 * it prepends "auto" before the whole cmdline which makes
305 * the shell think it should execute a script with such name.
306 * So we ignore all arguments entered _before_ init=... [MJ]
307 */
308 for (i = 1; i < MAX_INIT_ARGS; i++)
309 argv_init[i] = NULL;
310 return 1;
311}
312__setup("init=", init_setup);
313
Olof Johanssonffdfc402005-09-06 15:17:19 -0700314static int __init rdinit_setup(char *str)
315{
316 unsigned int i;
317
318 ramdisk_execute_command = str;
319 /* See "auto" comment in init_setup */
320 for (i = 1; i < MAX_INIT_ARGS; i++)
321 argv_init[i] = NULL;
322 return 1;
323}
324__setup("rdinit=", rdinit_setup);
325
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700327static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328#ifdef CONFIG_X86_LOCAL_APIC
329static void __init smp_init(void)
330{
331 APIC_init_uniprocessor();
332}
333#else
334#define smp_init() do { } while (0)
335#endif
336
Mike Travise0982e92008-03-26 14:23:48 -0700337static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339#endif
340
341/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800342 * We need to store the untouched command line for future reference.
343 * We also need to store the touched command line since the parameter
344 * parsing is performed in place, and we should allow a component to
345 * store reference of name/value for future reference.
346 */
347static void __init setup_command_line(char *command_line)
348{
349 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
350 static_command_line = alloc_bootmem(strlen (command_line)+1);
351 strcpy (saved_command_line, boot_command_line);
352 strcpy (static_command_line, command_line);
353}
354
355/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 * We need to finalize in a non-__init function or else race conditions
357 * between the root thread and the init thread may cause start_kernel to
358 * be reaped by free_initmem before the root thread has proceeded to
359 * cpu_idle.
360 *
361 * gcc-3.4 accidentally inlines this function, so use noinline.
362 */
363
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200364static __initdata DECLARE_COMPLETION(kthreadd_done);
365
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800366static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700368 int pid;
369
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700370 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200371 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200372 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200373 * the init task will end up wanting to create kthreads, which, if
374 * we schedule it before we create kthreadd, will OOPS.
375 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100376 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700378 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800379 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700380 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800381 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200382 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200383
384 /*
385 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200386 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200387 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200388 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100389 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800390 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100391 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200392}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
394/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600395static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600397 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
399 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200400 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700401 (strcmp(param, "console") == 0 &&
402 strcmp(p->str, "earlycon") == 0)
403 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700405 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 }
407 }
408 /* We accept everything at this stage. */
409 return 0;
410}
411
Magnus Damm13977092009-03-30 14:37:25 -0700412void __init parse_early_options(char *cmdline)
413{
Pawel Moll026cee02012-03-26 12:50:51 +1030414 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700415}
416
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417/* Arch code calls this early on, or if not, just before other parsing. */
418void __init parse_early_param(void)
419{
420 static __initdata int done = 0;
421 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
422
423 if (done)
424 return;
425
426 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800427 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700428 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 done = 1;
430}
431
432/*
433 * Activate the first processor.
434 */
435
Stas Sergeev44fd2292006-03-23 02:59:44 -0800436static void __init boot_cpu_init(void)
437{
438 int cpu = smp_processor_id();
439 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030440 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100441 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030442 set_cpu_present(cpu, true);
443 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800444}
445
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000446void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700447{
448}
449
David Howellseded09c2012-11-02 13:20:42 +0000450# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000451void __init __weak thread_info_cache_init(void)
452{
453}
David Howellseded09c2012-11-02 13:20:42 +0000454#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000455
Pekka Enberg444f4782009-06-11 18:29:06 +0300456/*
457 * Set up kernel memory allocators
458 */
459static void __init mm_init(void)
460{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300461 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600462 * page_cgroup requires contiguous pages,
463 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300464 */
465 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300466 mem_init();
467 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200468 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000469 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300470 vmalloc_init();
471}
472
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473asmlinkage void __init start_kernel(void)
474{
475 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600476 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700477
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700478 /*
479 * Need to run as early as possible, to initialize the
480 * lockdep hash:
481 */
482 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800483 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700484 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100485
486 /*
487 * Set up the the initial canary ASAP:
488 */
489 boot_init_stack_canary();
490
Paul Menageddbcc7e2007-10-18 23:39:30 -0700491 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700492
493 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100494 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700495
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496/*
497 * Interrupts are still disabled. Do necessary setups, then
498 * enable them
499 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800500 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700502 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700504 mm_init_owner(&init_mm, &init_task);
Linus Torvalds6345d242011-05-29 11:32:28 -0700505 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800506 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700507 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900508 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800509 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
Jiang Liu9adb62a2012-07-31 16:43:28 -0700511 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300512 page_alloc_init();
513
Andrew Mortonea676e82013-04-29 16:18:20 -0700514 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300515 parse_early_param();
516 parse_args("Booting kernel", static_command_line, __start___param,
517 __stop___param - __start___param,
Rusty Russellae82fdb2012-06-08 14:58:13 +0930518 -1, -1, &unknown_bootoption);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700519
520 jump_label_init();
521
Pekka Enberg83b519e2009-06-10 19:40:04 +0300522 /*
523 * These use large bootmem allocations and must precede
524 * kmem_cache_init()
525 */
Mike Travis162a7e72011-05-24 17:13:20 -0700526 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300527 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300528 vfs_caches_init_early();
529 sort_main_extable();
530 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300531 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700532
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 /*
534 * Set up the scheduler prior starting any interrupts (such as the
535 * timer interrupt). Full topology setup happens at smp_init()
536 * time - but meanwhile we still have a functioning scheduler.
537 */
538 sched_init();
539 /*
540 * Disable preemption - early bootup scheduling is extremely
541 * fragile until we cpu_idle() for the first time.
542 */
543 preempt_disable();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700544 if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800545 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100546 idr_init_cache();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 rcu_init();
Frederic Weisbeckerd1e43fa2013-03-26 23:47:24 +0100548 tick_nohz_init();
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200549 context_tracking_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();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100554 tick_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800556 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700558 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700559 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700560 sched_clock_postinit();
Stephane Eranian9e630202013-04-03 14:21:33 +0200561 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700562 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400563 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700564 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100565 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700566 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000567
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300568 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
570 /*
571 * HACK ALERT! This is early. We're enabling the console before
572 * we've done PCI setups etc, and console_init() must be aware of
573 * this. But we do want output early, in case something goes wrong.
574 */
575 console_init();
576 if (panic_later)
577 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700578
579 lockdep_info();
580
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700581 /*
582 * Need to run this when irqs are enabled, because it wants
583 * to self-test [hard/soft]-irqs on/off lock inversion bugs
584 * too:
585 */
586 locking_selftest();
587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588#ifdef CONFIG_BLK_DEV_INITRD
589 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700590 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700591 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - 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
Kevin Winchestere4461272010-08-09 17:20:32 -0700662static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700663{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100664 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800665 unsigned long long duration;
666 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700667
Andrew Mortonea676e82013-04-29 16:18:20 -0700668 pr_debug("calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700669 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800670 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700671 rettime = ktime_get();
672 delta = ktime_sub(rettime, calltime);
673 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortonea676e82013-04-29 16:18:20 -0700674 pr_debug("initcall %pF returned %d after %lld usecs\n",
675 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700676
Kevin Winchester22c5c032010-08-09 17:20:32 -0700677 return ret;
678}
679
Kevin Winchestere4461272010-08-09 17:20:32 -0700680int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700681{
682 int count = preempt_count();
683 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700684 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700685
686 if (initcall_debug)
687 ret = do_one_initcall_debug(fn);
688 else
689 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700690
691 msgbuf[0] = 0;
692
Linus Torvaldse0df1542008-05-15 18:14:01 -0700693 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400694 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200695 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700696 }
697 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700698 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700699 local_irq_enable();
700 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700701 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700702
Américo Wang30dbb20e2010-05-26 18:57:53 +0800703 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700704}
705
706
Pawel Moll026cee02012-03-26 12:50:51 +1030707extern initcall_t __initcall_start[];
708extern initcall_t __initcall0_start[];
709extern initcall_t __initcall1_start[];
710extern initcall_t __initcall2_start[];
711extern initcall_t __initcall3_start[];
712extern initcall_t __initcall4_start[];
713extern initcall_t __initcall5_start[];
714extern initcall_t __initcall6_start[];
715extern initcall_t __initcall7_start[];
716extern initcall_t __initcall_end[];
717
718static initcall_t *initcall_levels[] __initdata = {
719 __initcall0_start,
720 __initcall1_start,
721 __initcall2_start,
722 __initcall3_start,
723 __initcall4_start,
724 __initcall5_start,
725 __initcall6_start,
726 __initcall7_start,
727 __initcall_end,
728};
729
Jim Cromie96263d22012-06-14 16:00:59 -0600730/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030731static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600732 "early",
733 "core",
734 "postcore",
735 "arch",
736 "subsys",
737 "fs",
738 "device",
739 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030740};
741
Pawel Moll026cee02012-03-26 12:50:51 +1030742static void __init do_initcall_level(int level)
743{
744 extern const struct kernel_param __start___param[], __stop___param[];
745 initcall_t *fn;
746
747 strcpy(static_command_line, saved_command_line);
748 parse_args(initcall_level_names[level],
749 static_command_line, __start___param,
750 __stop___param - __start___param,
751 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700752 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030753
754 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
755 do_one_initcall(*fn);
756}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757
758static void __init do_initcalls(void)
759{
Pawel Moll026cee02012-03-26 12:50:51 +1030760 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
Borislav Petkov19efb722012-06-01 18:56:00 +0200762 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030763 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764}
765
766/*
767 * Ok, the machine is now initialized. None of the devices
768 * have been touched yet, but the CPU subsystem is up and
769 * running, and memory and process management works.
770 *
771 * Now we can finally start doing some real work..
772 */
773static void __init do_basic_setup(void)
774{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800775 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700777 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800779 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700780 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700781 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800782 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783}
784
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700785static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700786{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800787 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700788
Pawel Moll026cee02012-03-26 12:50:51 +1030789 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800790 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700791}
792
Tejun Heobb813f42013-01-18 14:05:56 -0800793/*
794 * This function requests modules which should be loaded by default and is
795 * called twice right after initrd is mounted and right before init is
796 * exec'd. If such modules are on either initrd or rootfs, they will be
797 * loaded before control is passed to userland.
798 */
799void __init load_default_modules(void)
800{
801 load_default_elevator_module();
802}
803
Al Viroa74fb732012-10-10 21:28:25 -0400804static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805{
806 argv_init[0] = init_filename;
Al Viroae903ca2012-12-14 12:44:11 -0500807 return do_execve(init_filename,
808 (const char __user *const __user *)argv_init,
809 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810}
811
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530812static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400813
814static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100815{
Al Virod6b21232012-10-10 19:57:26 -0400816 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800817 /* need to finish all async __init code before freeing the memory */
818 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100819 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100820 mark_rodata_ro();
821 system_state = SYSTEM_RUNNING;
822 numa_default_policy();
823
Al Viro4a9d4b02012-06-24 09:56:45 +0400824 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700825
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100826 if (ramdisk_execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400827 if (!run_init_process(ramdisk_execute_command))
828 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700829 pr_err("Failed to execute %s\n", ramdisk_execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100830 }
831
832 /*
833 * We try each of these until one succeeds.
834 *
835 * The Bourne shell can be used instead of init if we are
836 * trying to recover a really broken machine.
837 */
838 if (execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400839 if (!run_init_process(execute_command))
840 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700841 pr_err("Failed to execute %s. Attempting defaults...\n",
842 execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100843 }
Al Viroa74fb732012-10-10 21:28:25 -0400844 if (!run_init_process("/sbin/init") ||
845 !run_init_process("/etc/init") ||
846 !run_init_process("/bin/init") ||
847 !run_init_process("/bin/sh"))
848 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100849
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800850 panic("No init found. Try passing init= option to kernel. "
851 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100852}
853
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530854static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200856 /*
857 * Wait until kthreadd is all set-up.
858 */
859 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700860
861 /* Now the scheduler is fully set up and can do blocking allocations */
862 gfp_allowed_mask = __GFP_BITS_MASK;
863
Miao Xie58568d22009-06-16 15:31:49 -0700864 /*
865 * init can allocate pages on any node
866 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800867 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 /*
869 * init can run on any cpu.
870 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600871 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700873 cad_pid = task_pid(current);
874
Andi Kleenca74a6f2008-01-30 13:33:17 +0100875 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876
877 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100878 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 smp_init();
881 sched_init_smp();
882
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 do_basic_setup();
884
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800885 /* Open the /dev/console on the rootfs, this should never fail */
886 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700887 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800888
889 (void) sys_dup(0);
890 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 /*
892 * check if there is an early userspace init. If yes, let it do all
893 * the work
894 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700895
896 if (!ramdisk_execute_command)
897 ramdisk_execute_command = "/init";
898
899 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
900 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700902 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904 /*
905 * Ok, we have completed the initial bootup, and
906 * we're essentially up and running. Get rid of the
907 * initmem segments and start the user-mode stuff..
908 */
Tejun Heobb813f42013-01-18 14:05:56 -0800909
910 /* rootfs is available now, try loading default modules */
911 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912}