blob: 58c9e374704bb20cfff41fa92afcf7cafe498c32 [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
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -07009 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
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>
Joonsoo Kimeefa864b2014-12-12 16:55:46 -080054#include <linux/page_ext.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>
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -070080#include <linux/list.h>
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +020081#include <linux/integrity.h>
Al Viroe149ed22014-11-01 10:57:28 -040082#include <linux/proc_ns.h>
Toshi Kani0ddab1d2015-04-14 15:47:20 -070083#include <linux/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85#include <asm/io.h>
86#include <asm/bugs.h>
87#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070088#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080089#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
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);
Heinrich Schuchardtff691f62015-04-16 12:47:44 -070094extern void fork_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
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 */
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700138bool static_key_initialized __read_mostly;
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200139EXPORT_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.
Frans Klaverfc454fd2015-02-23 22:05:56 +0100147 * For ex. kdump situation where previous kernel has crashed, BIOS has been
Jan Beulich8b3b2952007-07-15 23:41:07 -0700148 * 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
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700161static 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
Yaowei Bai31c025b2016-01-20 14:59:27 -0800167static bool __init obsolete_checksetup(char *line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600169 const struct obs_kernel_param *p;
Yaowei Bai31c025b2016-01-20 14:59:27 -0800170 bool had_early_param = false;
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] == '=')
Yaowei Bai31c025b2016-01-20 14:59:27 -0800182 had_early_param = true;
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);
Yaowei Bai31c025b2016-01-20 14:59:27 -0800186 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 } else if (p->setup_func(line + n))
Yaowei Bai31c025b2016-01-20 14:59:27 -0800188 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 }
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201EXPORT_SYMBOL(loops_per_jiffy);
202
203static int __init debug_kernel(char *str)
204{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700205 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800206 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207}
208
209static int __init quiet_kernel(char *str)
210{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700211 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800212 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213}
214
Yinghai Luf6f21c812008-02-08 04:21:58 -0800215early_param("debug", debug_kernel);
216early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
218static int __init loglevel(char *str)
219{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200220 int newlevel;
221
222 /*
223 * Only update loglevel value when a correct setting was passed,
224 * to prevent blind crashes (when loglevel being set to 0) that
225 * are quite hard to debug
226 */
227 if (get_option(&str, &newlevel)) {
228 console_loglevel = newlevel;
229 return 0;
230 }
231
232 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
Yinghai Luf6f21c812008-02-08 04:21:58 -0800235early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Chris Metcalfa99cd112012-04-06 12:53:50 -0400237/* Change NUL term back to "=", to make "param" the whole string. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700238static int __init repair_env_string(char *param, char *val,
239 const char *unused, void *arg)
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
Rusty Russell51e158c2014-04-28 11:34:33 +0930255/* Anything after -- gets handed straight to init. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700256static int __init set_init_arg(char *param, char *val,
257 const char *unused, void *arg)
Rusty Russell51e158c2014-04-28 11:34:33 +0930258{
259 unsigned int i;
260
261 if (panic_later)
262 return 0;
263
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700264 repair_env_string(param, val, unused, NULL);
Rusty Russell51e158c2014-04-28 11:34:33 +0930265
266 for (i = 0; argv_init[i]; i++) {
267 if (i == MAX_INIT_ARGS) {
268 panic_later = "init";
269 panic_param = param;
270 return 0;
271 }
272 }
273 argv_init[i] = param;
274 return 0;
275}
276
Chris Metcalfa99cd112012-04-06 12:53:50 -0400277/*
278 * Unknown boot options get handed to init, unless they look like
279 * unused parameters (modprobe will find them in /proc/cmdline).
280 */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700281static int __init unknown_bootoption(char *param, char *val,
282 const char *unused, void *arg)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400283{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700284 repair_env_string(param, val, unused, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
286 /* Handle obsolete-style parameters */
287 if (obsolete_checksetup(param))
288 return 0;
289
Rusty Russellf066a4f2009-12-01 14:56:44 +1030290 /* Unused module parameter. */
291 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294 if (panic_later)
295 return 0;
296
297 if (val) {
298 /* Environment option */
299 unsigned int i;
300 for (i = 0; envp_init[i]; i++) {
301 if (i == MAX_INIT_ENVS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800302 panic_later = "env";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 panic_param = param;
304 }
305 if (!strncmp(param, envp_init[i], val - param))
306 break;
307 }
308 envp_init[i] = param;
309 } else {
310 /* Command line option */
311 unsigned int i;
312 for (i = 0; argv_init[i]; i++) {
313 if (i == MAX_INIT_ARGS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800314 panic_later = "init";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 panic_param = param;
316 }
317 }
318 argv_init[i] = param;
319 }
320 return 0;
321}
322
323static int __init init_setup(char *str)
324{
325 unsigned int i;
326
327 execute_command = str;
328 /*
329 * In case LILO is going to boot us with default command line,
330 * it prepends "auto" before the whole cmdline which makes
331 * the shell think it should execute a script with such name.
332 * So we ignore all arguments entered _before_ init=... [MJ]
333 */
334 for (i = 1; i < MAX_INIT_ARGS; i++)
335 argv_init[i] = NULL;
336 return 1;
337}
338__setup("init=", init_setup);
339
Olof Johanssonffdfc402005-09-06 15:17:19 -0700340static int __init rdinit_setup(char *str)
341{
342 unsigned int i;
343
344 ramdisk_execute_command = str;
345 /* See "auto" comment in init_setup */
346 for (i = 1; i < MAX_INIT_ARGS; i++)
347 argv_init[i] = NULL;
348 return 1;
349}
350__setup("rdinit=", rdinit_setup);
351
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700353static const unsigned int setup_max_cpus = NR_CPUS;
Mike Travise0982e92008-03-26 14:23:48 -0700354static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356#endif
357
358/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800359 * We need to store the untouched command line for future reference.
360 * We also need to store the touched command line since the parameter
361 * parsing is performed in place, and we should allow a component to
362 * store reference of name/value for future reference.
363 */
364static void __init setup_command_line(char *command_line)
365{
Santosh Shilimkar098b0812014-01-21 15:50:21 -0800366 saved_command_line =
367 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
368 initcall_command_line =
369 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
370 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700371 strcpy(saved_command_line, boot_command_line);
372 strcpy(static_command_line, command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800373}
374
375/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 * We need to finalize in a non-__init function or else race conditions
377 * between the root thread and the init thread may cause start_kernel to
378 * be reaped by free_initmem before the root thread has proceeded to
379 * cpu_idle.
380 *
381 * gcc-3.4 accidentally inlines this function, so use noinline.
382 */
383
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200384static __initdata DECLARE_COMPLETION(kthreadd_done);
385
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800386static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700388 int pid;
389
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700390 rcu_scheduler_starting();
Paul E. McKenney00df35f2015-04-12 08:06:55 -0700391 smpboot_thread_init();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200392 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200393 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200394 * the init task will end up wanting to create kthreads, which, if
395 * we schedule it before we create kthreadd, will OOPS.
396 */
Oleg Nesterov34a1b722014-06-04 16:12:19 -0700397 kernel_thread(kernel_init, NULL, CLONE_FS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700399 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800400 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700401 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800402 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200403 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200404
405 /*
406 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200407 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200408 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200409 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100410 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800411 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100412 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200413}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
415/* Check for early params. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700416static int __init do_early_param(char *param, char *val,
417 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600419 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
421 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200422 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700423 (strcmp(param, "console") == 0 &&
424 strcmp(p->str, "earlycon") == 0)
425 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700427 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 }
429 }
430 /* We accept everything at this stage. */
431 return 0;
432}
433
Magnus Damm13977092009-03-30 14:37:25 -0700434void __init parse_early_options(char *cmdline)
435{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700436 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
437 do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700438}
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440/* Arch code calls this early on, or if not, just before other parsing. */
441void __init parse_early_param(void)
442{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700443 static int done __initdata;
444 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446 if (done)
447 return;
448
449 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800450 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700451 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 done = 1;
453}
454
455/*
456 * Activate the first processor.
457 */
458
Stas Sergeev44fd2292006-03-23 02:59:44 -0800459static void __init boot_cpu_init(void)
460{
461 int cpu = smp_processor_id();
462 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030463 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100464 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030465 set_cpu_present(cpu, true);
466 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800467}
468
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000469void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700470{
471}
472
David Howellseded09c2012-11-02 13:20:42 +0000473# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000474void __init __weak thread_info_cache_init(void)
475{
476}
David Howellseded09c2012-11-02 13:20:42 +0000477#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000478
Pekka Enberg444f4782009-06-11 18:29:06 +0300479/*
480 * Set up kernel memory allocators
481 */
482static void __init mm_init(void)
483{
Joonsoo Kimeefa864b2014-12-12 16:55:46 -0800484 /*
485 * page_ext requires contiguous pages,
486 * bigger than MAX_ORDER unless SPARSEMEM.
487 */
488 page_ext_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300489 mem_init();
490 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200491 percpu_init_late();
Kirill A. Shutemovb35f1812014-01-21 15:49:07 -0800492 pgtable_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300493 vmalloc_init();
Toshi Kani0ddab1d2015-04-14 15:47:20 -0700494 ioremap_huge_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300495}
496
Andi Kleen722a9f92014-05-02 00:44:38 +0200497asmlinkage __visible void __init start_kernel(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700499 char *command_line;
500 char *after_dashes;
Andrew Morton033ab7f2006-06-30 01:55:50 -0700501
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700502 /*
503 * Need to run as early as possible, to initialize the
504 * lockdep hash:
505 */
506 lockdep_init();
Aaron Tomlind4311ff2014-09-12 14:16:17 +0100507 set_task_stack_end_magic(&init_task);
Ming Lei73839c52011-11-17 13:34:31 +0800508 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700509 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100510
511 /*
512 * Set up the the initial canary ASAP:
513 */
514 boot_init_stack_canary();
515
Paul Menageddbcc7e2007-10-18 23:39:30 -0700516 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700517
518 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100519 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521/*
522 * Interrupts are still disabled. Do necessary setups, then
523 * enable them
524 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800525 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700527 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 setup_arch(&command_line);
Linus Torvalds6345d242011-05-29 11:32:28 -0700529 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800530 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700531 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900532 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800533 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534
Jiang Liu9adb62a2012-07-31 16:43:28 -0700535 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300536 page_alloc_init();
537
Andrew Mortonea676e82013-04-29 16:18:20 -0700538 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300539 parse_early_param();
Rusty Russell51e158c2014-04-28 11:34:33 +0930540 after_dashes = parse_args("Booting kernel",
541 static_command_line, __start___param,
542 __stop___param - __start___param,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700543 -1, -1, NULL, &unknown_bootoption);
Daniel Thompson3438cf52014-11-11 16:29:46 +1030544 if (!IS_ERR_OR_NULL(after_dashes))
Rusty Russell51e158c2014-04-28 11:34:33 +0930545 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700546 NULL, set_init_arg);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700547
548 jump_label_init();
549
Pekka Enberg83b519e2009-06-10 19:40:04 +0300550 /*
551 * These use large bootmem allocations and must precede
552 * kmem_cache_init()
553 */
Mike Travis162a7e72011-05-24 17:13:20 -0700554 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300555 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300556 vfs_caches_init_early();
557 sort_main_extable();
558 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300559 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 /*
562 * Set up the scheduler prior starting any interrupts (such as the
563 * timer interrupt). Full topology setup happens at smp_init()
564 * time - but meanwhile we still have a functioning scheduler.
565 */
566 sched_init();
567 /*
568 * Disable preemption - early bootup scheduling is extremely
569 * fragile until we cpu_idle() for the first time.
570 */
571 preempt_disable();
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700572 if (WARN(!irqs_disabled(),
573 "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800574 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100575 idr_init_cache();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 rcu_init();
Steven Rostedt (Red Hat)5f893b22014-12-12 20:05:10 -0500577
578 /* trace_printk() and trace points may be used after this */
579 trace_init();
580
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200581 context_tracking_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800582 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800583 /* init some links before init_ISA_irqs() */
584 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100586 tick_init();
Linus Torvaldsd6dd50e2014-10-13 15:44:12 +0200587 rcu_init_nohz();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800589 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700591 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700592 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700593 sched_clock_postinit();
Stephane Eranian9e630202013-04-03 14:21:33 +0200594 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700595 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400596 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700597 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100598 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700599 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000600
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300601 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
603 /*
604 * HACK ALERT! This is early. We're enabling the console before
605 * we've done PCI setups etc, and console_init() must be aware of
606 * this. But we do want output early, in case something goes wrong.
607 */
608 console_init();
609 if (panic_later)
Tetsuo Handa499a4582014-01-23 15:54:56 -0800610 panic("Too many boot %s vars at `%s'", panic_later,
611 panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700612
613 lockdep_info();
614
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700615 /*
616 * Need to run this when irqs are enabled, because it wants
617 * to self-test [hard/soft]-irqs on/off lock inversion bugs
618 * too:
619 */
620 locking_selftest();
621
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622#ifdef CONFIG_BLK_DEV_INITRD
623 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700624 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700625 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700626 page_to_pfn(virt_to_page((void *)initrd_start)),
627 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 initrd_start = 0;
629 }
630#endif
Joonsoo Kimeefa864b2014-12-12 16:55:46 -0800631 page_ext_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700632 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100633 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700634 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 numa_policy_init();
636 if (late_time_init)
637 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200638 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 calibrate_delay();
640 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 anon_vma_init();
Rafael J. Wysockic4e1acb2014-03-13 00:22:58 +0100642 acpi_early_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800643#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000644 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800645 efi_enter_virtual_mode();
646#endif
H. Peter Anvin197725d2014-05-04 10:00:49 -0700647#ifdef CONFIG_X86_ESPFIX64
H. Peter Anvin3891a042014-04-29 16:46:09 -0700648 /* Should be run before the first non-init thread is created */
649 init_espfix_bsp();
650#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000651 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100652 cred_init();
Heinrich Schuchardtff691f62015-04-16 12:47:44 -0700653 fork_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 proc_caches_init();
655 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 key_init();
657 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500658 dbg_late_init();
Mel Gorman4248b0d2015-08-06 15:46:20 -0700659 vfs_caches_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 signals_init();
661 /* rootfs populating might need page-writeback */
662 page_writeback_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 proc_root_init();
Al Viroe149ed22014-11-01 10:57:28 -0400664 nsfs_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 cpuset_init();
Zefan Li695df212015-03-04 17:09:33 +0800666 cgroup_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700667 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700668 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
670 check_bugs();
671
Rafael J. Wysockib064a8f2015-06-10 01:33:36 +0200672 acpi_subsystem_init();
Feng Tang6ae69962009-08-14 15:13:46 -0400673 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
Matt Fleming83e68182012-11-14 09:42:35 +0000675 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700676 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700677 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700678 }
Josh Triplett78510792012-09-28 17:55:44 -0700679
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400680 ftrace_init();
681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 /* Do the rest non-__init'ed, we're now alive */
683 rest_init();
684}
685
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700686/* Call all constructor functions linked into the kernel. */
687static void __init do_ctors(void)
688{
689#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800690 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700691
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800692 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
693 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700694#endif
695}
696
Rusty Russell2329abf2012-01-13 09:32:18 +1030697bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500698core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700700#ifdef CONFIG_KALLSYMS
701struct blacklist_entry {
702 struct list_head next;
703 char *buf;
704};
705
706static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
707
708static int __init initcall_blacklist(char *str)
709{
710 char *str_entry;
711 struct blacklist_entry *entry;
712
713 /* str argument is a comma-separated list of functions */
714 do {
715 str_entry = strsep(&str, ",");
716 if (str_entry) {
717 pr_debug("blacklisting initcall %s\n", str_entry);
718 entry = alloc_bootmem(sizeof(*entry));
719 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
720 strcpy(entry->buf, str_entry);
721 list_add(&entry->next, &blacklisted_initcalls);
722 }
723 } while (str_entry);
724
725 return 0;
726}
727
728static bool __init_or_module initcall_blacklisted(initcall_t fn)
729{
730 struct list_head *tmp;
731 struct blacklist_entry *entry;
732 char *fn_name;
733
734 fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
735 if (!fn_name)
736 return false;
737
738 list_for_each(tmp, &blacklisted_initcalls) {
739 entry = list_entry(tmp, struct blacklist_entry, next);
740 if (!strcmp(fn_name, entry->buf)) {
741 pr_debug("initcall %s blacklisted\n", fn_name);
742 kfree(fn_name);
743 return true;
744 }
745 }
746
747 kfree(fn_name);
748 return false;
749}
750#else
751static int __init initcall_blacklist(char *str)
752{
753 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
754 return 0;
755}
756
757static bool __init_or_module initcall_blacklisted(initcall_t fn)
758{
759 return false;
760}
761#endif
762__setup("initcall_blacklist=", initcall_blacklist);
763
Kevin Winchestere4461272010-08-09 17:20:32 -0700764static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700765{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100766 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800767 unsigned long long duration;
768 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700769
Andrew Mortond62cf812014-06-04 16:12:16 -0700770 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700771 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800772 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700773 rettime = ktime_get();
774 delta = ktime_sub(rettime, calltime);
775 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortond62cf812014-06-04 16:12:16 -0700776 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
Andrew Mortonea676e82013-04-29 16:18:20 -0700777 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700778
Kevin Winchester22c5c032010-08-09 17:20:32 -0700779 return ret;
780}
781
Kevin Winchestere4461272010-08-09 17:20:32 -0700782int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700783{
784 int count = preempt_count();
785 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700786 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700787
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700788 if (initcall_blacklisted(fn))
789 return -EPERM;
790
Kevin Winchester22c5c032010-08-09 17:20:32 -0700791 if (initcall_debug)
792 ret = do_one_initcall_debug(fn);
793 else
794 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700795
796 msgbuf[0] = 0;
797
Linus Torvaldse0df1542008-05-15 18:14:01 -0700798 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400799 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200800 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700801 }
802 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700803 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700804 local_irq_enable();
805 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700806 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700807
Américo Wang30dbb20e2010-05-26 18:57:53 +0800808 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700809}
810
811
Pawel Moll026cee02012-03-26 12:50:51 +1030812extern initcall_t __initcall_start[];
813extern initcall_t __initcall0_start[];
814extern initcall_t __initcall1_start[];
815extern initcall_t __initcall2_start[];
816extern initcall_t __initcall3_start[];
817extern initcall_t __initcall4_start[];
818extern initcall_t __initcall5_start[];
819extern initcall_t __initcall6_start[];
820extern initcall_t __initcall7_start[];
821extern initcall_t __initcall_end[];
822
823static initcall_t *initcall_levels[] __initdata = {
824 __initcall0_start,
825 __initcall1_start,
826 __initcall2_start,
827 __initcall3_start,
828 __initcall4_start,
829 __initcall5_start,
830 __initcall6_start,
831 __initcall7_start,
832 __initcall_end,
833};
834
Jim Cromie96263d22012-06-14 16:00:59 -0600835/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030836static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600837 "early",
838 "core",
839 "postcore",
840 "arch",
841 "subsys",
842 "fs",
843 "device",
844 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030845};
846
Pawel Moll026cee02012-03-26 12:50:51 +1030847static void __init do_initcall_level(int level)
848{
Pawel Moll026cee02012-03-26 12:50:51 +1030849 initcall_t *fn;
850
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030851 strcpy(initcall_command_line, saved_command_line);
Pawel Moll026cee02012-03-26 12:50:51 +1030852 parse_args(initcall_level_names[level],
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030853 initcall_command_line, __start___param,
Pawel Moll026cee02012-03-26 12:50:51 +1030854 __stop___param - __start___param,
855 level, level,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700856 NULL, &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030857
858 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
859 do_one_initcall(*fn);
860}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862static void __init do_initcalls(void)
863{
Pawel Moll026cee02012-03-26 12:50:51 +1030864 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
Borislav Petkov19efb722012-06-01 18:56:00 +0200866 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030867 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868}
869
870/*
871 * Ok, the machine is now initialized. None of the devices
872 * have been touched yet, but the CPU subsystem is up and
873 * running, and memory and process management works.
874 *
875 * Now we can finally start doing some real work..
876 */
877static void __init do_basic_setup(void)
878{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800879 cpuset_init_smp();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700880 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800882 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700883 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700884 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800885 do_initcalls();
Theodore Ts'o47d06e52013-09-10 10:52:35 -0400886 random_int_secret_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887}
888
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700889static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700890{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800891 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700892
Pawel Moll026cee02012-03-26 12:50:51 +1030893 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800894 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700895}
896
Tejun Heobb813f42013-01-18 14:05:56 -0800897/*
898 * This function requests modules which should be loaded by default and is
899 * called twice right after initrd is mounted and right before init is
900 * exec'd. If such modules are on either initrd or rootfs, they will be
901 * loaded before control is passed to userland.
902 */
903void __init load_default_modules(void)
904{
905 load_default_elevator_module();
906}
907
Al Viroa74fb732012-10-10 21:28:25 -0400908static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909{
910 argv_init[0] = init_filename;
Linus Torvaldsc4ad8f92014-02-05 12:54:53 -0800911 return do_execve(getname_kernel(init_filename),
Al Viroae903ca2012-12-14 12:44:11 -0500912 (const char __user *const __user *)argv_init,
913 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914}
915
Michael Opdenackerba247622013-11-12 15:10:21 -0800916static int try_to_run_init_process(const char *init_filename)
917{
918 int ret;
919
920 ret = run_init_process(init_filename);
921
922 if (ret && ret != -ENOENT) {
923 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
924 init_filename, ret);
925 }
926
927 return ret;
928}
929
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530930static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400931
932static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100933{
Michael Opdenackerba247622013-11-12 15:10:21 -0800934 int ret;
935
Al Virod6b21232012-10-10 19:57:26 -0400936 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800937 /* need to finish all async __init code before freeing the memory */
938 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100939 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100940 mark_rodata_ro();
941 system_state = SYSTEM_RUNNING;
942 numa_default_policy();
943
Al Viro4a9d4b02012-06-24 09:56:45 +0400944 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700945
Paul E. McKenney967dcb82015-11-25 16:52:36 -0800946 rcu_end_inkernel_boot();
947
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100948 if (ramdisk_execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800949 ret = run_init_process(ramdisk_execute_command);
950 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400951 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800952 pr_err("Failed to execute %s (error %d)\n",
953 ramdisk_execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100954 }
955
956 /*
957 * We try each of these until one succeeds.
958 *
959 * The Bourne shell can be used instead of init if we are
960 * trying to recover a really broken machine.
961 */
962 if (execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800963 ret = run_init_process(execute_command);
964 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400965 return 0;
Andy Lutomirski6ef45362014-12-10 15:52:19 -0800966 panic("Requested init %s failed (error %d).",
967 execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100968 }
Michael Opdenackerba247622013-11-12 15:10:21 -0800969 if (!try_to_run_init_process("/sbin/init") ||
970 !try_to_run_init_process("/etc/init") ||
971 !try_to_run_init_process("/bin/init") ||
972 !try_to_run_init_process("/bin/sh"))
Al Viroa74fb732012-10-10 21:28:25 -0400973 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100974
Michael Opdenackerba247622013-11-12 15:10:21 -0800975 panic("No working init found. Try passing init= option to kernel. "
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800976 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100977}
978
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530979static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200981 /*
982 * Wait until kthreadd is all set-up.
983 */
984 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700985
986 /* Now the scheduler is fully set up and can do blocking allocations */
987 gfp_allowed_mask = __GFP_BITS_MASK;
988
Miao Xie58568d22009-06-16 15:31:49 -0700989 /*
990 * init can allocate pages on any node
991 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800992 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 /*
994 * init can run on any cpu.
995 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600996 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700998 cad_pid = task_pid(current);
999
Andi Kleenca74a6f2008-01-30 13:33:17 +01001000 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001
1002 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +01001003 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 smp_init();
1006 sched_init_smp();
1007
Mel Gorman0e1cc952015-06-30 14:57:27 -07001008 page_alloc_init_late();
1009
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 do_basic_setup();
1011
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001012 /* Open the /dev/console on the rootfs, this should never fail */
1013 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -07001014 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001015
1016 (void) sys_dup(0);
1017 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 /*
1019 * check if there is an early userspace init. If yes, let it do all
1020 * the work
1021 */
Olof Johanssonffdfc402005-09-06 15:17:19 -07001022
1023 if (!ramdisk_execute_command)
1024 ramdisk_execute_command = "/init";
1025
1026 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1027 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -07001029 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030
1031 /*
1032 * Ok, we have completed the initial bootup, and
1033 * we're essentially up and running. Get rid of the
1034 * initmem segments and start the user-mode stuff..
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001035 *
1036 * rootfs is available now, try loading the public keys
1037 * and default modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 */
Tejun Heobb813f42013-01-18 14:05:56 -08001039
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001040 integrity_load_keys();
Tejun Heobb813f42013-01-18 14:05:56 -08001041 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042}