blob: d03d2ec2eacfd351241af097f6402cf9b509e8e5 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79#include <asm/io.h>
80#include <asm/bugs.h>
81#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070082#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080083#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#ifdef CONFIG_X86_LOCAL_APIC
86#include <asm/smp.h>
87#endif
88
Sam Ravnborgaae5f662007-02-26 16:45:41 +010089static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092extern void fork_init(unsigned long);
93extern void mca_init(void);
94extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095extern void radix_tree_init(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080096#ifndef CONFIG_DEBUG_RODATA
97static inline void mark_rodata_ro(void) { }
98#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100#ifdef CONFIG_TC
101extern void tc_init(void);
102#endif
103
Tejun Heo2ce802f2011-01-20 12:06:35 +0100104/*
105 * Debug helper: via this flag we know that we are in 'early bootup code'
106 * where only the boot processor is running with IRQ disabled. This means
107 * two things - IRQ must not be enabled before the flag is cleared and some
108 * operations which are not allowed with IRQ disabled are allowed while the
109 * flag is set.
110 */
111bool early_boot_irqs_disabled __read_mostly;
112
Paul E. McKenneya6826042009-02-25 18:03:42 -0800113enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114EXPORT_SYMBOL(system_state);
115
116/*
117 * Boot command-line arguments
118 */
119#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
120#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
121
122extern void time_init(void);
123/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800124void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125extern void softirq_init(void);
126
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800127/* Untouched command line saved by arch-specific code. */
128char __initdata boot_command_line[COMMAND_LINE_SIZE];
129/* Untouched saved command line (eg. for /proc) */
130char *saved_command_line;
131/* Command line for parameter parsing */
132static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700135static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
Jan Beulich8b3b2952007-07-15 23:41:07 -0700137/*
138 * If set, this is an indication to the drivers that reset the underlying
139 * device before going ahead with the initialization otherwise driver might
140 * rely on the BIOS and skip the reset operation.
141 *
142 * This is useful if kernel is booting in an unreliable environment.
143 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
144 * skipped and devices will be in unknown state.
145 */
146unsigned int reset_devices;
147EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Vivek Goyal7e962872006-09-27 01:50:44 -0700149static int __init set_reset_devices(char *str)
150{
151 reset_devices = 1;
152 return 1;
153}
154
155__setup("reset_devices", set_reset_devices);
156
David Howellsd7627462010-08-17 23:52:56 +0100157static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
158const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159static const char *panic_later, *panic_param;
160
Rusty Russell914dcaa2010-08-11 23:04:18 -0600161extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163static int __init obsolete_checksetup(char *line)
164{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600165 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200166 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 p = __setup_start;
169 do {
170 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200171 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200173 /* Already done in parse_early_param?
174 * (Needs exact match on param part).
175 * Keep iterating, as we can have early
176 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200178 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700180 pr_warn("Parameter %s is obsolete, ignored\n",
181 p->str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return 1;
183 } else if (p->setup_func(line + n))
184 return 1;
185 }
186 p++;
187 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200188
189 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
191
192/*
193 * This should be approx 2 Bo*oMips to start (note initial shift), and will
194 * still work even if initially too large, it will just take slightly longer
195 */
196unsigned long loops_per_jiffy = (1<<12);
197
198EXPORT_SYMBOL(loops_per_jiffy);
199
200static int __init debug_kernel(char *str)
201{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800203 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
206static int __init quiet_kernel(char *str)
207{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800209 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
Yinghai Luf6f21c812008-02-08 04:21:58 -0800212early_param("debug", debug_kernel);
213early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215static int __init loglevel(char *str)
216{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200217 int newlevel;
218
219 /*
220 * Only update loglevel value when a correct setting was passed,
221 * to prevent blind crashes (when loglevel being set to 0) that
222 * are quite hard to debug
223 */
224 if (get_option(&str, &newlevel)) {
225 console_loglevel = newlevel;
226 return 0;
227 }
228
229 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230}
231
Yinghai Luf6f21c812008-02-08 04:21:58 -0800232early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Chris Metcalfa99cd112012-04-06 12:53:50 -0400234/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700235static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 if (val) {
238 /* param=val or param="val"? */
239 if (val == param+strlen(param)+1)
240 val[-1] = '=';
241 else if (val == param+strlen(param)+2) {
242 val[-2] = '=';
243 memmove(val-1, val, strlen(val)+1);
244 val--;
245 } else
246 BUG();
247 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400248 return 0;
249}
250
251/*
252 * Unknown boot options get handed to init, unless they look like
253 * unused parameters (modprobe will find them in /proc/cmdline).
254 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700255static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400256{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700257 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
259 /* Handle obsolete-style parameters */
260 if (obsolete_checksetup(param))
261 return 0;
262
Rusty Russellf066a4f2009-12-01 14:56:44 +1030263 /* Unused module parameter. */
264 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267 if (panic_later)
268 return 0;
269
270 if (val) {
271 /* Environment option */
272 unsigned int i;
273 for (i = 0; envp_init[i]; i++) {
274 if (i == MAX_INIT_ENVS) {
275 panic_later = "Too many boot env vars at `%s'";
276 panic_param = param;
277 }
278 if (!strncmp(param, envp_init[i], val - param))
279 break;
280 }
281 envp_init[i] = param;
282 } else {
283 /* Command line option */
284 unsigned int i;
285 for (i = 0; argv_init[i]; i++) {
286 if (i == MAX_INIT_ARGS) {
287 panic_later = "Too many boot init vars at `%s'";
288 panic_param = param;
289 }
290 }
291 argv_init[i] = param;
292 }
293 return 0;
294}
295
296static int __init init_setup(char *str)
297{
298 unsigned int i;
299
300 execute_command = str;
301 /*
302 * In case LILO is going to boot us with default command line,
303 * it prepends "auto" before the whole cmdline which makes
304 * the shell think it should execute a script with such name.
305 * So we ignore all arguments entered _before_ init=... [MJ]
306 */
307 for (i = 1; i < MAX_INIT_ARGS; i++)
308 argv_init[i] = NULL;
309 return 1;
310}
311__setup("init=", init_setup);
312
Olof Johanssonffdfc402005-09-06 15:17:19 -0700313static int __init rdinit_setup(char *str)
314{
315 unsigned int i;
316
317 ramdisk_execute_command = str;
318 /* See "auto" comment in init_setup */
319 for (i = 1; i < MAX_INIT_ARGS; i++)
320 argv_init[i] = NULL;
321 return 1;
322}
323__setup("rdinit=", rdinit_setup);
324
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700326static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327#ifdef CONFIG_X86_LOCAL_APIC
328static void __init smp_init(void)
329{
330 APIC_init_uniprocessor();
331}
332#else
333#define smp_init() do { } while (0)
334#endif
335
Mike Travise0982e92008-03-26 14:23:48 -0700336static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338#endif
339
340/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800341 * We need to store the untouched command line for future reference.
342 * We also need to store the touched command line since the parameter
343 * parsing is performed in place, and we should allow a component to
344 * store reference of name/value for future reference.
345 */
346static void __init setup_command_line(char *command_line)
347{
348 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
349 static_command_line = alloc_bootmem(strlen (command_line)+1);
350 strcpy (saved_command_line, boot_command_line);
351 strcpy (static_command_line, command_line);
352}
353
354/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 * We need to finalize in a non-__init function or else race conditions
356 * between the root thread and the init thread may cause start_kernel to
357 * be reaped by free_initmem before the root thread has proceeded to
358 * cpu_idle.
359 *
360 * gcc-3.4 accidentally inlines this function, so use noinline.
361 */
362
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200363static __initdata DECLARE_COMPLETION(kthreadd_done);
364
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800365static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700367 int pid;
368
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700369 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200370 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200371 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200372 * the init task will end up wanting to create kthreads, which, if
373 * we schedule it before we create kthreadd, will OOPS.
374 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100375 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700377 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800378 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700379 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800380 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200381 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200382
383 /*
384 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200385 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200386 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200387 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100388 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800389 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100390 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200391}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
393/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600394static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600396 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
398 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200399 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700400 (strcmp(param, "console") == 0 &&
401 strcmp(p->str, "earlycon") == 0)
402 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700404 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 }
406 }
407 /* We accept everything at this stage. */
408 return 0;
409}
410
Magnus Damm13977092009-03-30 14:37:25 -0700411void __init parse_early_options(char *cmdline)
412{
Pawel Moll026cee02012-03-26 12:50:51 +1030413 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700414}
415
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416/* Arch code calls this early on, or if not, just before other parsing. */
417void __init parse_early_param(void)
418{
419 static __initdata int done = 0;
420 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
421
422 if (done)
423 return;
424
425 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800426 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700427 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 done = 1;
429}
430
431/*
432 * Activate the first processor.
433 */
434
Stas Sergeev44fd2292006-03-23 02:59:44 -0800435static void __init boot_cpu_init(void)
436{
437 int cpu = smp_processor_id();
438 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030439 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100440 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030441 set_cpu_present(cpu, true);
442 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800443}
444
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000445void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700446{
447}
448
David Howellseded09c2012-11-02 13:20:42 +0000449# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000450void __init __weak thread_info_cache_init(void)
451{
452}
David Howellseded09c2012-11-02 13:20:42 +0000453#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000454
Pekka Enberg444f4782009-06-11 18:29:06 +0300455/*
456 * Set up kernel memory allocators
457 */
458static void __init mm_init(void)
459{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300460 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600461 * page_cgroup requires contiguous pages,
462 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300463 */
464 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300465 mem_init();
466 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200467 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000468 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300469 vmalloc_init();
470}
471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472asmlinkage void __init start_kernel(void)
473{
474 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600475 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700476
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700477 /*
478 * Need to run as early as possible, to initialize the
479 * lockdep hash:
480 */
481 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800482 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700483 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100484
485 /*
486 * Set up the the initial canary ASAP:
487 */
488 boot_init_stack_canary();
489
Paul Menageddbcc7e2007-10-18 23:39:30 -0700490 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700491
492 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100493 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700494
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495/*
496 * Interrupts are still disabled. Do necessary setups, then
497 * enable them
498 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800499 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700501 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700503 mm_init_owner(&init_mm, &init_task);
Linus Torvalds6345d242011-05-29 11:32:28 -0700504 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800505 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700506 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900507 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800508 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509
Jiang Liu9adb62a2012-07-31 16:43:28 -0700510 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300511 page_alloc_init();
512
Andrew Mortonea676e82013-04-29 16:18:20 -0700513 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300514 parse_early_param();
515 parse_args("Booting kernel", static_command_line, __start___param,
516 __stop___param - __start___param,
Rusty Russellae82fdb2012-06-08 14:58:13 +0930517 -1, -1, &unknown_bootoption);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700518
519 jump_label_init();
520
Pekka Enberg83b519e2009-06-10 19:40:04 +0300521 /*
522 * These use large bootmem allocations and must precede
523 * kmem_cache_init()
524 */
Mike Travis162a7e72011-05-24 17:13:20 -0700525 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300526 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300527 vfs_caches_init_early();
528 sort_main_extable();
529 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300530 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 /*
533 * Set up the scheduler prior starting any interrupts (such as the
534 * timer interrupt). Full topology setup happens at smp_init()
535 * time - but meanwhile we still have a functioning scheduler.
536 */
537 sched_init();
538 /*
539 * Disable preemption - early bootup scheduling is extremely
540 * fragile until we cpu_idle() for the first time.
541 */
542 preempt_disable();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700543 if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800544 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100545 idr_init_cache();
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();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700558 sched_clock_postinit();
Stephane Eranian9e630202013-04-03 14:21:33 +0200559 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700560 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400561 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700562 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100563 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700564 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000565
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300566 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 /*
569 * HACK ALERT! This is early. We're enabling the console before
570 * we've done PCI setups etc, and console_init() must be aware of
571 * this. But we do want output early, in case something goes wrong.
572 */
573 console_init();
574 if (panic_later)
575 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700576
577 lockdep_info();
578
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700579 /*
580 * Need to run this when irqs are enabled, because it wants
581 * to self-test [hard/soft]-irqs on/off lock inversion bugs
582 * too:
583 */
584 locking_selftest();
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586#ifdef CONFIG_BLK_DEV_INITRD
587 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700588 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700589 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700590 page_to_pfn(virt_to_page((void *)initrd_start)),
591 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 initrd_start = 0;
593 }
594#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700595 page_cgroup_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700596 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100597 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700598 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 numa_policy_init();
600 if (late_time_init)
601 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200602 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 calibrate_delay();
604 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 anon_vma_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800606#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000607 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800608 efi_enter_virtual_mode();
609#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000610 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100611 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700612 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 proc_caches_init();
614 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 key_init();
616 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500617 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700618 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 signals_init();
620 /* rootfs populating might need page-writeback */
621 page_writeback_init();
622#ifdef CONFIG_PROC_FS
623 proc_root_init();
624#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700625 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700627 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700628 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 check_bugs();
631
632 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400633 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Matt Fleming83e68182012-11-14 09:42:35 +0000635 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700636 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700637 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700638 }
Josh Triplett78510792012-09-28 17:55:44 -0700639
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400640 ftrace_init();
641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 /* Do the rest non-__init'ed, we're now alive */
643 rest_init();
644}
645
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700646/* Call all constructor functions linked into the kernel. */
647static void __init do_ctors(void)
648{
649#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800650 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700651
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800652 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
653 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700654#endif
655}
656
Rusty Russell2329abf2012-01-13 09:32:18 +1030657bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500658core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
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;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700682 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700683
684 if (initcall_debug)
685 ret = do_one_initcall_debug(fn);
686 else
687 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700688
689 msgbuf[0] = 0;
690
Linus Torvaldse0df1542008-05-15 18:14:01 -0700691 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400692 sprintf(msgbuf, "preemption imbalance ");
Linus Torvaldse0df1542008-05-15 18:14:01 -0700693 preempt_count() = count;
694 }
695 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700696 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700697 local_irq_enable();
698 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700699 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700700
Américo Wang30dbb20e2010-05-26 18:57:53 +0800701 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700702}
703
704
Pawel Moll026cee02012-03-26 12:50:51 +1030705extern initcall_t __initcall_start[];
706extern initcall_t __initcall0_start[];
707extern initcall_t __initcall1_start[];
708extern initcall_t __initcall2_start[];
709extern initcall_t __initcall3_start[];
710extern initcall_t __initcall4_start[];
711extern initcall_t __initcall5_start[];
712extern initcall_t __initcall6_start[];
713extern initcall_t __initcall7_start[];
714extern initcall_t __initcall_end[];
715
716static initcall_t *initcall_levels[] __initdata = {
717 __initcall0_start,
718 __initcall1_start,
719 __initcall2_start,
720 __initcall3_start,
721 __initcall4_start,
722 __initcall5_start,
723 __initcall6_start,
724 __initcall7_start,
725 __initcall_end,
726};
727
Jim Cromie96263d22012-06-14 16:00:59 -0600728/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030729static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600730 "early",
731 "core",
732 "postcore",
733 "arch",
734 "subsys",
735 "fs",
736 "device",
737 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030738};
739
Pawel Moll026cee02012-03-26 12:50:51 +1030740static void __init do_initcall_level(int level)
741{
742 extern const struct kernel_param __start___param[], __stop___param[];
743 initcall_t *fn;
744
745 strcpy(static_command_line, saved_command_line);
746 parse_args(initcall_level_names[level],
747 static_command_line, __start___param,
748 __stop___param - __start___param,
749 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700750 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030751
752 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
753 do_one_initcall(*fn);
754}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756static void __init do_initcalls(void)
757{
Pawel Moll026cee02012-03-26 12:50:51 +1030758 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Borislav Petkov19efb722012-06-01 18:56:00 +0200760 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030761 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
764/*
765 * Ok, the machine is now initialized. None of the devices
766 * have been touched yet, but the CPU subsystem is up and
767 * running, and memory and process management works.
768 *
769 * Now we can finally start doing some real work..
770 */
771static void __init do_basic_setup(void)
772{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800773 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700775 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800777 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700778 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700779 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800780 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781}
782
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700783static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700784{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800785 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700786
Pawel Moll026cee02012-03-26 12:50:51 +1030787 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800788 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700789}
790
Tejun Heobb813f42013-01-18 14:05:56 -0800791/*
792 * This function requests modules which should be loaded by default and is
793 * called twice right after initrd is mounted and right before init is
794 * exec'd. If such modules are on either initrd or rootfs, they will be
795 * loaded before control is passed to userland.
796 */
797void __init load_default_modules(void)
798{
799 load_default_elevator_module();
800}
801
Al Viroa74fb732012-10-10 21:28:25 -0400802static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803{
804 argv_init[0] = init_filename;
Al Viroae903ca2012-12-14 12:44:11 -0500805 return do_execve(init_filename,
806 (const char __user *const __user *)argv_init,
807 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808}
809
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530810static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400811
812static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100813{
Al Virod6b21232012-10-10 19:57:26 -0400814 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800815 /* need to finish all async __init code before freeing the memory */
816 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100817 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100818 mark_rodata_ro();
819 system_state = SYSTEM_RUNNING;
820 numa_default_policy();
821
Al Viro4a9d4b02012-06-24 09:56:45 +0400822 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700823
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100824 if (ramdisk_execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400825 if (!run_init_process(ramdisk_execute_command))
826 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700827 pr_err("Failed to execute %s\n", ramdisk_execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100828 }
829
830 /*
831 * We try each of these until one succeeds.
832 *
833 * The Bourne shell can be used instead of init if we are
834 * trying to recover a really broken machine.
835 */
836 if (execute_command) {
Al Viroa74fb732012-10-10 21:28:25 -0400837 if (!run_init_process(execute_command))
838 return 0;
Andrew Mortonea676e82013-04-29 16:18:20 -0700839 pr_err("Failed to execute %s. Attempting defaults...\n",
840 execute_command);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100841 }
Al Viroa74fb732012-10-10 21:28:25 -0400842 if (!run_init_process("/sbin/init") ||
843 !run_init_process("/etc/init") ||
844 !run_init_process("/bin/init") ||
845 !run_init_process("/bin/sh"))
846 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100847
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800848 panic("No init found. Try passing init= option to kernel. "
849 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100850}
851
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530852static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200854 /*
855 * Wait until kthreadd is all set-up.
856 */
857 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700858
859 /* Now the scheduler is fully set up and can do blocking allocations */
860 gfp_allowed_mask = __GFP_BITS_MASK;
861
Miao Xie58568d22009-06-16 15:31:49 -0700862 /*
863 * init can allocate pages on any node
864 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800865 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 /*
867 * init can run on any cpu.
868 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600869 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700871 cad_pid = task_pid(current);
872
Andi Kleenca74a6f2008-01-30 13:33:17 +0100873 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874
875 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100876 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 smp_init();
879 sched_init_smp();
880
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 do_basic_setup();
882
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800883 /* Open the /dev/console on the rootfs, this should never fail */
884 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700885 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800886
887 (void) sys_dup(0);
888 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 /*
890 * check if there is an early userspace init. If yes, let it do all
891 * the work
892 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700893
894 if (!ramdisk_execute_command)
895 ramdisk_execute_command = "/init";
896
897 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
898 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700900 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901
902 /*
903 * Ok, we have completed the initial bootup, and
904 * we're essentially up and running. Get rid of the
905 * initmem segments and start the user-mode stuff..
906 */
Tejun Heobb813f42013-01-18 14:05:56 -0800907
908 /* rootfs is available now, try loading default modules */
909 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910}