blob: 58c132d7de4b06e5e9bb6681a214d954bc2bb64b [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>
Theodore Ts'o47d06e52013-09-10 10:52:35 -040079#include <linux/random.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81#include <asm/io.h>
82#include <asm/bugs.h>
83#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070084#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080085#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#ifdef CONFIG_X86_LOCAL_APIC
88#include <asm/smp.h>
89#endif
90
Sam Ravnborgaae5f662007-02-26 16:45:41 +010091static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094extern void fork_init(unsigned long);
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
Tejun Heo2ce802f2011-01-20 12:06:35 +0100100/*
101 * Debug helper: via this flag we know that we are in 'early bootup code'
102 * where only the boot processor is running with IRQ disabled. This means
103 * two things - IRQ must not be enabled before the flag is cleared and some
104 * operations which are not allowed with IRQ disabled are allowed while the
105 * flag is set.
106 */
107bool early_boot_irqs_disabled __read_mostly;
108
Paul E. McKenneya6826042009-02-25 18:03:42 -0800109enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110EXPORT_SYMBOL(system_state);
111
112/*
113 * Boot command-line arguments
114 */
115#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
116#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
117
118extern void time_init(void);
119/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800120void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800122/* Untouched command line saved by arch-specific code. */
123char __initdata boot_command_line[COMMAND_LINE_SIZE];
124/* Untouched saved command line (eg. for /proc) */
125char *saved_command_line;
126/* Command line for parameter parsing */
127static char *static_command_line;
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030128/* Command line for per-initcall parameter parsing */
129static char *initcall_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700132static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Jan Beulich8b3b2952007-07-15 23:41:07 -0700134/*
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200135 * Used to generate warnings if static_key manipulation functions are used
136 * before jump_label_init is called.
137 */
138bool static_key_initialized __read_mostly = false;
139EXPORT_SYMBOL_GPL(static_key_initialized);
140
141/*
Jan Beulich8b3b2952007-07-15 23:41:07 -0700142 * If set, this is an indication to the drivers that reset the underlying
143 * device before going ahead with the initialization otherwise driver might
144 * rely on the BIOS and skip the reset operation.
145 *
146 * This is useful if kernel is booting in an unreliable environment.
147 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
148 * skipped and devices will be in unknown state.
149 */
150unsigned int reset_devices;
151EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Vivek Goyal7e962872006-09-27 01:50:44 -0700153static int __init set_reset_devices(char *str)
154{
155 reset_devices = 1;
156 return 1;
157}
158
159__setup("reset_devices", set_reset_devices);
160
David Howellsd7627462010-08-17 23:52:56 +0100161static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
162const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163static const char *panic_later, *panic_param;
164
Rusty Russell914dcaa2010-08-11 23:04:18 -0600165extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167static int __init obsolete_checksetup(char *line)
168{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600169 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200170 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172 p = __setup_start;
173 do {
174 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200175 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200177 /* Already done in parse_early_param?
178 * (Needs exact match on param part).
179 * Keep iterating, as we can have early
180 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200182 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700184 pr_warn("Parameter %s is obsolete, ignored\n",
185 p->str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 return 1;
187 } else if (p->setup_func(line + n))
188 return 1;
189 }
190 p++;
191 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200192
193 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194}
195
196/*
197 * This should be approx 2 Bo*oMips to start (note initial shift), and will
198 * still work even if initially too large, it will just take slightly longer
199 */
200unsigned long loops_per_jiffy = (1<<12);
201
202EXPORT_SYMBOL(loops_per_jiffy);
203
204static int __init debug_kernel(char *str)
205{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800207 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208}
209
210static int __init quiet_kernel(char *str)
211{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800213 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214}
215
Yinghai Luf6f21c812008-02-08 04:21:58 -0800216early_param("debug", debug_kernel);
217early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
219static int __init loglevel(char *str)
220{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200221 int newlevel;
222
223 /*
224 * Only update loglevel value when a correct setting was passed,
225 * to prevent blind crashes (when loglevel being set to 0) that
226 * are quite hard to debug
227 */
228 if (get_option(&str, &newlevel)) {
229 console_loglevel = newlevel;
230 return 0;
231 }
232
233 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
Yinghai Luf6f21c812008-02-08 04:21:58 -0800236early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
Chris Metcalfa99cd112012-04-06 12:53:50 -0400238/* Change NUL term back to "=", to make "param" the whole string. */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700239static int __init repair_env_string(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 if (val) {
242 /* param=val or param="val"? */
243 if (val == param+strlen(param)+1)
244 val[-1] = '=';
245 else if (val == param+strlen(param)+2) {
246 val[-2] = '=';
247 memmove(val-1, val, strlen(val)+1);
248 val--;
249 } else
250 BUG();
251 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400252 return 0;
253}
254
255/*
256 * Unknown boot options get handed to init, unless they look like
257 * unused parameters (modprobe will find them in /proc/cmdline).
258 */
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700259static int __init unknown_bootoption(char *param, char *val, const char *unused)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400260{
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700261 repair_env_string(param, val, unused);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 /* Handle obsolete-style parameters */
264 if (obsolete_checksetup(param))
265 return 0;
266
Rusty Russellf066a4f2009-12-01 14:56:44 +1030267 /* Unused module parameter. */
268 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271 if (panic_later)
272 return 0;
273
274 if (val) {
275 /* Environment option */
276 unsigned int i;
277 for (i = 0; envp_init[i]; i++) {
278 if (i == MAX_INIT_ENVS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800279 panic_later = "env";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 panic_param = param;
281 }
282 if (!strncmp(param, envp_init[i], val - param))
283 break;
284 }
285 envp_init[i] = param;
286 } else {
287 /* Command line option */
288 unsigned int i;
289 for (i = 0; argv_init[i]; i++) {
290 if (i == MAX_INIT_ARGS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800291 panic_later = "init";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 panic_param = param;
293 }
294 }
295 argv_init[i] = param;
296 }
297 return 0;
298}
299
300static int __init init_setup(char *str)
301{
302 unsigned int i;
303
304 execute_command = str;
305 /*
306 * In case LILO is going to boot us with default command line,
307 * it prepends "auto" before the whole cmdline which makes
308 * the shell think it should execute a script with such name.
309 * So we ignore all arguments entered _before_ init=... [MJ]
310 */
311 for (i = 1; i < MAX_INIT_ARGS; i++)
312 argv_init[i] = NULL;
313 return 1;
314}
315__setup("init=", init_setup);
316
Olof Johanssonffdfc402005-09-06 15:17:19 -0700317static int __init rdinit_setup(char *str)
318{
319 unsigned int i;
320
321 ramdisk_execute_command = str;
322 /* See "auto" comment in init_setup */
323 for (i = 1; i < MAX_INIT_ARGS; i++)
324 argv_init[i] = NULL;
325 return 1;
326}
327__setup("rdinit=", rdinit_setup);
328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700330static const unsigned int setup_max_cpus = NR_CPUS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331#ifdef CONFIG_X86_LOCAL_APIC
332static void __init smp_init(void)
333{
334 APIC_init_uniprocessor();
335}
336#else
337#define smp_init() do { } while (0)
338#endif
339
Mike Travise0982e92008-03-26 14:23:48 -0700340static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342#endif
343
344/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800345 * We need to store the untouched command line for future reference.
346 * We also need to store the touched command line since the parameter
347 * parsing is performed in place, and we should allow a component to
348 * store reference of name/value for future reference.
349 */
350static void __init setup_command_line(char *command_line)
351{
Santosh Shilimkar098b0812014-01-21 15:50:21 -0800352 saved_command_line =
353 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
354 initcall_command_line =
355 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
356 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800357 strcpy (saved_command_line, boot_command_line);
358 strcpy (static_command_line, command_line);
359}
360
361/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 * We need to finalize in a non-__init function or else race conditions
363 * between the root thread and the init thread may cause start_kernel to
364 * be reaped by free_initmem before the root thread has proceeded to
365 * cpu_idle.
366 *
367 * gcc-3.4 accidentally inlines this function, so use noinline.
368 */
369
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200370static __initdata DECLARE_COMPLETION(kthreadd_done);
371
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800372static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700374 int pid;
375
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700376 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200377 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200378 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200379 * the init task will end up wanting to create kthreads, which, if
380 * we schedule it before we create kthreadd, will OOPS.
381 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100382 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700384 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800385 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700386 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800387 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200388 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200389
390 /*
391 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200392 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200393 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200394 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100395 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800396 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100397 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200398}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400/* Check for early params. */
Jim Cromie9fb48c72012-04-27 14:30:34 -0600401static int __init do_early_param(char *param, char *val, const char *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600403 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
405 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200406 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700407 (strcmp(param, "console") == 0 &&
408 strcmp(p->str, "earlycon") == 0)
409 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700411 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 }
413 }
414 /* We accept everything at this stage. */
415 return 0;
416}
417
Magnus Damm13977092009-03-30 14:37:25 -0700418void __init parse_early_options(char *cmdline)
419{
Pawel Moll026cee02012-03-26 12:50:51 +1030420 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700421}
422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423/* Arch code calls this early on, or if not, just before other parsing. */
424void __init parse_early_param(void)
425{
426 static __initdata int done = 0;
427 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
428
429 if (done)
430 return;
431
432 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800433 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700434 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 done = 1;
436}
437
438/*
439 * Activate the first processor.
440 */
441
Stas Sergeev44fd2292006-03-23 02:59:44 -0800442static void __init boot_cpu_init(void)
443{
444 int cpu = smp_processor_id();
445 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030446 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100447 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030448 set_cpu_present(cpu, true);
449 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800450}
451
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000452void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700453{
454}
455
David Howellseded09c2012-11-02 13:20:42 +0000456# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000457void __init __weak thread_info_cache_init(void)
458{
459}
David Howellseded09c2012-11-02 13:20:42 +0000460#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000461
Pekka Enberg444f4782009-06-11 18:29:06 +0300462/*
463 * Set up kernel memory allocators
464 */
465static void __init mm_init(void)
466{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300467 /*
Jim Cromie7fa87ce2012-03-14 19:12:22 -0600468 * page_cgroup requires contiguous pages,
469 * bigger than MAX_ORDER unless SPARSEMEM.
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300470 */
471 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300472 mem_init();
473 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200474 percpu_init_late();
Kirill A. Shutemovb35f1812014-01-21 15:49:07 -0800475 pgtable_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300476 vmalloc_init();
477}
478
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479asmlinkage void __init start_kernel(void)
480{
481 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600482 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700483
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700484 /*
485 * Need to run as early as possible, to initialize the
486 * lockdep hash:
487 */
488 lockdep_init();
Ming Lei73839c52011-11-17 13:34:31 +0800489 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700490 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100491
492 /*
493 * Set up the the initial canary ASAP:
494 */
495 boot_init_stack_canary();
496
Paul Menageddbcc7e2007-10-18 23:39:30 -0700497 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700498
499 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100500 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700501
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502/*
503 * Interrupts are still disabled. Do necessary setups, then
504 * enable them
505 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800506 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700508 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700510 mm_init_owner(&init_mm, &init_task);
Linus Torvalds6345d242011-05-29 11:32:28 -0700511 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800512 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700513 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900514 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800515 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
Jiang Liu9adb62a2012-07-31 16:43:28 -0700517 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300518 page_alloc_init();
519
Andrew Mortonea676e82013-04-29 16:18:20 -0700520 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300521 parse_early_param();
522 parse_args("Booting kernel", static_command_line, __start___param,
523 __stop___param - __start___param,
Rusty Russellae82fdb2012-06-08 14:58:13 +0930524 -1, -1, &unknown_bootoption);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700525
526 jump_label_init();
527
Pekka Enberg83b519e2009-06-10 19:40:04 +0300528 /*
529 * These use large bootmem allocations and must precede
530 * kmem_cache_init()
531 */
Mike Travis162a7e72011-05-24 17:13:20 -0700532 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300533 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300534 vfs_caches_init_early();
535 sort_main_extable();
536 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300537 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 /*
540 * Set up the scheduler prior starting any interrupts (such as the
541 * timer interrupt). Full topology setup happens at smp_init()
542 * time - but meanwhile we still have a functioning scheduler.
543 */
544 sched_init();
545 /*
546 * Disable preemption - early bootup scheduling is extremely
547 * fragile until we cpu_idle() for the first time.
548 */
549 preempt_disable();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700550 if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800551 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100552 idr_init_cache();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 rcu_init();
Frederic Weisbeckerd1e43fa2013-03-26 23:47:24 +0100554 tick_nohz_init();
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200555 context_tracking_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800556 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800557 /* init some links before init_ISA_irqs() */
558 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100560 tick_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800562 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700564 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700565 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700566 sched_clock_postinit();
Stephane Eranian9e630202013-04-03 14:21:33 +0200567 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700568 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400569 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700570 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100571 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700572 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000573
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300574 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
576 /*
577 * HACK ALERT! This is early. We're enabling the console before
578 * we've done PCI setups etc, and console_init() must be aware of
579 * this. But we do want output early, in case something goes wrong.
580 */
581 console_init();
582 if (panic_later)
Tetsuo Handa499a4582014-01-23 15:54:56 -0800583 panic("Too many boot %s vars at `%s'", panic_later,
584 panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700585
586 lockdep_info();
587
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700588 /*
589 * Need to run this when irqs are enabled, because it wants
590 * to self-test [hard/soft]-irqs on/off lock inversion bugs
591 * too:
592 */
593 locking_selftest();
594
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595#ifdef CONFIG_BLK_DEV_INITRD
596 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700597 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700598 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700599 page_to_pfn(virt_to_page((void *)initrd_start)),
600 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 initrd_start = 0;
602 }
603#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700604 page_cgroup_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700605 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100606 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700607 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 numa_policy_init();
609 if (late_time_init)
610 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200611 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 calibrate_delay();
613 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 anon_vma_init();
Rafael J. Wysockic4e1acb2014-03-13 00:22:58 +0100615 acpi_early_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800616#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000617 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800618 efi_enter_virtual_mode();
619#endif
H. Peter Anvin197725d2014-05-04 10:00:49 -0700620#ifdef CONFIG_X86_ESPFIX64
H. Peter Anvin3891a042014-04-29 16:46:09 -0700621 /* Should be run before the first non-init thread is created */
622 init_espfix_bsp();
623#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000624 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100625 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700626 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 proc_caches_init();
628 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 key_init();
630 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500631 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700632 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 signals_init();
634 /* rootfs populating might need page-writeback */
635 page_writeback_init();
636#ifdef CONFIG_PROC_FS
637 proc_root_init();
638#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700639 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700641 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700642 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
644 check_bugs();
645
Feng Tang6ae69962009-08-14 15:13:46 -0400646 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Matt Fleming83e68182012-11-14 09:42:35 +0000648 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700649 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700650 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700651 }
Josh Triplett78510792012-09-28 17:55:44 -0700652
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400653 ftrace_init();
654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 /* Do the rest non-__init'ed, we're now alive */
656 rest_init();
657}
658
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700659/* Call all constructor functions linked into the kernel. */
660static void __init do_ctors(void)
661{
662#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800663 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700664
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800665 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
666 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700667#endif
668}
669
Rusty Russell2329abf2012-01-13 09:32:18 +1030670bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500671core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
Kevin Winchestere4461272010-08-09 17:20:32 -0700673static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700674{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100675 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800676 unsigned long long duration;
677 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700678
Andrew Mortonea676e82013-04-29 16:18:20 -0700679 pr_debug("calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700680 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800681 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700682 rettime = ktime_get();
683 delta = ktime_sub(rettime, calltime);
684 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortonea676e82013-04-29 16:18:20 -0700685 pr_debug("initcall %pF returned %d after %lld usecs\n",
686 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700687
Kevin Winchester22c5c032010-08-09 17:20:32 -0700688 return ret;
689}
690
Kevin Winchestere4461272010-08-09 17:20:32 -0700691int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700692{
693 int count = preempt_count();
694 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700695 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700696
697 if (initcall_debug)
698 ret = do_one_initcall_debug(fn);
699 else
700 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700701
702 msgbuf[0] = 0;
703
Linus Torvaldse0df1542008-05-15 18:14:01 -0700704 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400705 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200706 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700707 }
708 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700709 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700710 local_irq_enable();
711 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700712 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700713
Américo Wang30dbb20e2010-05-26 18:57:53 +0800714 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700715}
716
717
Pawel Moll026cee02012-03-26 12:50:51 +1030718extern initcall_t __initcall_start[];
719extern initcall_t __initcall0_start[];
720extern initcall_t __initcall1_start[];
721extern initcall_t __initcall2_start[];
722extern initcall_t __initcall3_start[];
723extern initcall_t __initcall4_start[];
724extern initcall_t __initcall5_start[];
725extern initcall_t __initcall6_start[];
726extern initcall_t __initcall7_start[];
727extern initcall_t __initcall_end[];
728
729static initcall_t *initcall_levels[] __initdata = {
730 __initcall0_start,
731 __initcall1_start,
732 __initcall2_start,
733 __initcall3_start,
734 __initcall4_start,
735 __initcall5_start,
736 __initcall6_start,
737 __initcall7_start,
738 __initcall_end,
739};
740
Jim Cromie96263d22012-06-14 16:00:59 -0600741/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030742static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600743 "early",
744 "core",
745 "postcore",
746 "arch",
747 "subsys",
748 "fs",
749 "device",
750 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030751};
752
Pawel Moll026cee02012-03-26 12:50:51 +1030753static void __init do_initcall_level(int level)
754{
755 extern const struct kernel_param __start___param[], __stop___param[];
756 initcall_t *fn;
757
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030758 strcpy(initcall_command_line, saved_command_line);
Pawel Moll026cee02012-03-26 12:50:51 +1030759 parse_args(initcall_level_names[level],
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030760 initcall_command_line, __start___param,
Pawel Moll026cee02012-03-26 12:50:51 +1030761 __stop___param - __start___param,
762 level, level,
Greg Kroah-Hartmaneb157422012-05-02 14:33:37 -0700763 &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030764
765 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
766 do_one_initcall(*fn);
767}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
769static void __init do_initcalls(void)
770{
Pawel Moll026cee02012-03-26 12:50:51 +1030771 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
Borislav Petkov19efb722012-06-01 18:56:00 +0200773 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030774 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775}
776
777/*
778 * Ok, the machine is now initialized. None of the devices
779 * have been touched yet, but the CPU subsystem is up and
780 * running, and memory and process management works.
781 *
782 * Now we can finally start doing some real work..
783 */
784static void __init do_basic_setup(void)
785{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800786 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 usermodehelper_init();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700788 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800790 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700791 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700792 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800793 do_initcalls();
Theodore Ts'o47d06e52013-09-10 10:52:35 -0400794 random_int_secret_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795}
796
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700797static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700798{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800799 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700800
Pawel Moll026cee02012-03-26 12:50:51 +1030801 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800802 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700803}
804
Tejun Heobb813f42013-01-18 14:05:56 -0800805/*
806 * This function requests modules which should be loaded by default and is
807 * called twice right after initrd is mounted and right before init is
808 * exec'd. If such modules are on either initrd or rootfs, they will be
809 * loaded before control is passed to userland.
810 */
811void __init load_default_modules(void)
812{
813 load_default_elevator_module();
814}
815
Al Viroa74fb732012-10-10 21:28:25 -0400816static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817{
818 argv_init[0] = init_filename;
Linus Torvaldsc4ad8f92014-02-05 12:54:53 -0800819 return do_execve(getname_kernel(init_filename),
Al Viroae903ca2012-12-14 12:44:11 -0500820 (const char __user *const __user *)argv_init,
821 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822}
823
Michael Opdenackerba247622013-11-12 15:10:21 -0800824static int try_to_run_init_process(const char *init_filename)
825{
826 int ret;
827
828 ret = run_init_process(init_filename);
829
830 if (ret && ret != -ENOENT) {
831 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
832 init_filename, ret);
833 }
834
835 return ret;
836}
837
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530838static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400839
840static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100841{
Michael Opdenackerba247622013-11-12 15:10:21 -0800842 int ret;
843
Al Virod6b21232012-10-10 19:57:26 -0400844 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800845 /* need to finish all async __init code before freeing the memory */
846 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100847 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100848 mark_rodata_ro();
849 system_state = SYSTEM_RUNNING;
850 numa_default_policy();
851
Al Viro4a9d4b02012-06-24 09:56:45 +0400852 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700853
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100854 if (ramdisk_execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800855 ret = run_init_process(ramdisk_execute_command);
856 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400857 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800858 pr_err("Failed to execute %s (error %d)\n",
859 ramdisk_execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100860 }
861
862 /*
863 * We try each of these until one succeeds.
864 *
865 * The Bourne shell can be used instead of init if we are
866 * trying to recover a really broken machine.
867 */
868 if (execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800869 ret = run_init_process(execute_command);
870 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400871 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800872 pr_err("Failed to execute %s (error %d). Attempting defaults...\n",
873 execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100874 }
Michael Opdenackerba247622013-11-12 15:10:21 -0800875 if (!try_to_run_init_process("/sbin/init") ||
876 !try_to_run_init_process("/etc/init") ||
877 !try_to_run_init_process("/bin/init") ||
878 !try_to_run_init_process("/bin/sh"))
Al Viroa74fb732012-10-10 21:28:25 -0400879 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100880
Michael Opdenackerba247622013-11-12 15:10:21 -0800881 panic("No working init found. Try passing init= option to kernel. "
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800882 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100883}
884
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530885static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200887 /*
888 * Wait until kthreadd is all set-up.
889 */
890 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700891
892 /* Now the scheduler is fully set up and can do blocking allocations */
893 gfp_allowed_mask = __GFP_BITS_MASK;
894
Miao Xie58568d22009-06-16 15:31:49 -0700895 /*
896 * init can allocate pages on any node
897 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800898 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 /*
900 * init can run on any cpu.
901 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600902 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700904 cad_pid = task_pid(current);
905
Andi Kleenca74a6f2008-01-30 13:33:17 +0100906 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907
908 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100909 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 smp_init();
912 sched_init_smp();
913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 do_basic_setup();
915
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800916 /* Open the /dev/console on the rootfs, this should never fail */
917 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700918 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800919
920 (void) sys_dup(0);
921 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 /*
923 * check if there is an early userspace init. If yes, let it do all
924 * the work
925 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700926
927 if (!ramdisk_execute_command)
928 ramdisk_execute_command = "/init";
929
930 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
931 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700933 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
935 /*
936 * Ok, we have completed the initial bootup, and
937 * we're essentially up and running. Get rid of the
938 * initmem segments and start the user-mode stuff..
939 */
Tejun Heobb813f42013-01-18 14:05:56 -0800940
941 /* rootfs is available now, try loading default modules */
942 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943}