blob: 4c17fda5c2ff51c33eb4bf5fbd06a810087c3287 [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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Tejun Heo2ce802f2011-01-20 12:06:35 +010097/*
98 * Debug helper: via this flag we know that we are in 'early bootup code'
99 * where only the boot processor is running with IRQ disabled. This means
100 * two things - IRQ must not be enabled before the flag is cleared and some
101 * operations which are not allowed with IRQ disabled are allowed while the
102 * flag is set.
103 */
104bool early_boot_irqs_disabled __read_mostly;
105
Paul E. McKenneya6826042009-02-25 18:03:42 -0800106enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107EXPORT_SYMBOL(system_state);
108
109/*
110 * Boot command-line arguments
111 */
112#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
113#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
114
115extern void time_init(void);
116/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800117void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800119/* Untouched command line saved by arch-specific code. */
120char __initdata boot_command_line[COMMAND_LINE_SIZE];
121/* Untouched saved command line (eg. for /proc) */
122char *saved_command_line;
123/* Command line for parameter parsing */
124static char *static_command_line;
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030125/* Command line for per-initcall parameter parsing */
126static char *initcall_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
128static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700129static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Jan Beulich8b3b2952007-07-15 23:41:07 -0700131/*
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200132 * Used to generate warnings if static_key manipulation functions are used
133 * before jump_label_init is called.
134 */
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700135bool static_key_initialized __read_mostly;
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200136EXPORT_SYMBOL_GPL(static_key_initialized);
137
138/*
Jan Beulich8b3b2952007-07-15 23:41:07 -0700139 * If set, this is an indication to the drivers that reset the underlying
140 * device before going ahead with the initialization otherwise driver might
141 * rely on the BIOS and skip the reset operation.
142 *
143 * This is useful if kernel is booting in an unreliable environment.
Frans Klaverfc454fd2015-02-23 22:05:56 +0100144 * For ex. kdump situation where previous kernel has crashed, BIOS has been
Jan Beulich8b3b2952007-07-15 23:41:07 -0700145 * skipped and devices will be in unknown state.
146 */
147unsigned int reset_devices;
148EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Vivek Goyal7e962872006-09-27 01:50:44 -0700150static int __init set_reset_devices(char *str)
151{
152 reset_devices = 1;
153 return 1;
154}
155
156__setup("reset_devices", set_reset_devices);
157
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700158static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
159const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160static const char *panic_later, *panic_param;
161
Rusty Russell914dcaa2010-08-11 23:04:18 -0600162extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Yaowei Bai31c025b2016-01-20 14:59:27 -0800164static bool __init obsolete_checksetup(char *line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600166 const struct obs_kernel_param *p;
Yaowei Bai31c025b2016-01-20 14:59:27 -0800167 bool had_early_param = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
169 p = __setup_start;
170 do {
171 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200172 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200174 /* Already done in parse_early_param?
175 * (Needs exact match on param part).
176 * Keep iterating, as we can have early
177 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 if (line[n] == '\0' || line[n] == '=')
Yaowei Bai31c025b2016-01-20 14:59:27 -0800179 had_early_param = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700181 pr_warn("Parameter %s is obsolete, ignored\n",
182 p->str);
Yaowei Bai31c025b2016-01-20 14:59:27 -0800183 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 } else if (p->setup_func(line + n))
Yaowei Bai31c025b2016-01-20 14:59:27 -0800185 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 }
187 p++;
188 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200189
190 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
192
193/*
194 * This should be approx 2 Bo*oMips to start (note initial shift), and will
195 * still work even if initially too large, it will just take slightly longer
196 */
197unsigned long loops_per_jiffy = (1<<12);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198EXPORT_SYMBOL(loops_per_jiffy);
199
200static int __init debug_kernel(char *str)
201{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700202 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800203 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
206static int __init quiet_kernel(char *str)
207{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700208 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800209 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
Yinghai Luf6f21c812008-02-08 04:21:58 -0800212early_param("debug", debug_kernel);
213early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215static int __init loglevel(char *str)
216{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200217 int newlevel;
218
219 /*
220 * Only update loglevel value when a correct setting was passed,
221 * to prevent blind crashes (when loglevel being set to 0) that
222 * are quite hard to debug
223 */
224 if (get_option(&str, &newlevel)) {
225 console_loglevel = newlevel;
226 return 0;
227 }
228
229 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230}
231
Yinghai Luf6f21c812008-02-08 04:21:58 -0800232early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Chris Metcalfa99cd112012-04-06 12:53:50 -0400234/* Change NUL term back to "=", to make "param" the whole string. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700235static int __init repair_env_string(char *param, char *val,
236 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 if (val) {
239 /* param=val or param="val"? */
240 if (val == param+strlen(param)+1)
241 val[-1] = '=';
242 else if (val == param+strlen(param)+2) {
243 val[-2] = '=';
244 memmove(val-1, val, strlen(val)+1);
245 val--;
246 } else
247 BUG();
248 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400249 return 0;
250}
251
Rusty Russell51e158c2014-04-28 11:34:33 +0930252/* Anything after -- gets handed straight to init. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700253static int __init set_init_arg(char *param, char *val,
254 const char *unused, void *arg)
Rusty Russell51e158c2014-04-28 11:34:33 +0930255{
256 unsigned int i;
257
258 if (panic_later)
259 return 0;
260
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700261 repair_env_string(param, val, unused, NULL);
Rusty Russell51e158c2014-04-28 11:34:33 +0930262
263 for (i = 0; argv_init[i]; i++) {
264 if (i == MAX_INIT_ARGS) {
265 panic_later = "init";
266 panic_param = param;
267 return 0;
268 }
269 }
270 argv_init[i] = param;
271 return 0;
272}
273
Chris Metcalfa99cd112012-04-06 12:53:50 -0400274/*
275 * Unknown boot options get handed to init, unless they look like
276 * unused parameters (modprobe will find them in /proc/cmdline).
277 */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700278static int __init unknown_bootoption(char *param, char *val,
279 const char *unused, void *arg)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400280{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700281 repair_env_string(param, val, unused, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 /* Handle obsolete-style parameters */
284 if (obsolete_checksetup(param))
285 return 0;
286
Rusty Russellf066a4f2009-12-01 14:56:44 +1030287 /* Unused module parameter. */
288 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291 if (panic_later)
292 return 0;
293
294 if (val) {
295 /* Environment option */
296 unsigned int i;
297 for (i = 0; envp_init[i]; i++) {
298 if (i == MAX_INIT_ENVS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800299 panic_later = "env";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 panic_param = param;
301 }
302 if (!strncmp(param, envp_init[i], val - param))
303 break;
304 }
305 envp_init[i] = param;
306 } else {
307 /* Command line option */
308 unsigned int i;
309 for (i = 0; argv_init[i]; i++) {
310 if (i == MAX_INIT_ARGS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800311 panic_later = "init";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 panic_param = param;
313 }
314 }
315 argv_init[i] = param;
316 }
317 return 0;
318}
319
320static int __init init_setup(char *str)
321{
322 unsigned int i;
323
324 execute_command = str;
325 /*
326 * In case LILO is going to boot us with default command line,
327 * it prepends "auto" before the whole cmdline which makes
328 * the shell think it should execute a script with such name.
329 * So we ignore all arguments entered _before_ init=... [MJ]
330 */
331 for (i = 1; i < MAX_INIT_ARGS; i++)
332 argv_init[i] = NULL;
333 return 1;
334}
335__setup("init=", init_setup);
336
Olof Johanssonffdfc402005-09-06 15:17:19 -0700337static int __init rdinit_setup(char *str)
338{
339 unsigned int i;
340
341 ramdisk_execute_command = str;
342 /* See "auto" comment in init_setup */
343 for (i = 1; i < MAX_INIT_ARGS; i++)
344 argv_init[i] = NULL;
345 return 1;
346}
347__setup("rdinit=", rdinit_setup);
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700350static const unsigned int setup_max_cpus = NR_CPUS;
Mike Travise0982e92008-03-26 14:23:48 -0700351static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353#endif
354
355/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800356 * We need to store the untouched command line for future reference.
357 * We also need to store the touched command line since the parameter
358 * parsing is performed in place, and we should allow a component to
359 * store reference of name/value for future reference.
360 */
361static void __init setup_command_line(char *command_line)
362{
Santosh Shilimkar098b0812014-01-21 15:50:21 -0800363 saved_command_line =
364 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
365 initcall_command_line =
366 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
367 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700368 strcpy(saved_command_line, boot_command_line);
369 strcpy(static_command_line, command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800370}
371
372/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 * We need to finalize in a non-__init function or else race conditions
374 * between the root thread and the init thread may cause start_kernel to
375 * be reaped by free_initmem before the root thread has proceeded to
376 * cpu_idle.
377 *
378 * gcc-3.4 accidentally inlines this function, so use noinline.
379 */
380
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200381static __initdata DECLARE_COMPLETION(kthreadd_done);
382
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800383static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700385 int pid;
386
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700387 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200388 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200389 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200390 * the init task will end up wanting to create kthreads, which, if
391 * we schedule it before we create kthreadd, will OOPS.
392 */
Oleg Nesterov34a1b722014-06-04 16:12:19 -0700393 kernel_thread(kernel_init, NULL, CLONE_FS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700395 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800396 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700397 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800398 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200399 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200400
401 /*
402 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200403 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200404 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200405 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100406 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800407 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100408 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200409}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410
411/* Check for early params. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700412static int __init do_early_param(char *param, char *val,
413 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600415 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200418 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700419 (strcmp(param, "console") == 0 &&
420 strcmp(p->str, "earlycon") == 0)
421 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700423 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 }
425 }
426 /* We accept everything at this stage. */
427 return 0;
428}
429
Magnus Damm13977092009-03-30 14:37:25 -0700430void __init parse_early_options(char *cmdline)
431{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700432 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
433 do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700434}
435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436/* Arch code calls this early on, or if not, just before other parsing. */
437void __init parse_early_param(void)
438{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700439 static int done __initdata;
440 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
442 if (done)
443 return;
444
445 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800446 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700447 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 done = 1;
449}
450
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000451void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700452{
453}
454
David Howellseded09c2012-11-02 13:20:42 +0000455# if THREAD_SIZE >= PAGE_SIZE
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000456void __init __weak thread_info_cache_init(void)
457{
458}
David Howellseded09c2012-11-02 13:20:42 +0000459#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000460
Pekka Enberg444f4782009-06-11 18:29:06 +0300461/*
462 * Set up kernel memory allocators
463 */
464static void __init mm_init(void)
465{
Joonsoo Kimeefa864b2014-12-12 16:55:46 -0800466 /*
467 * page_ext requires contiguous pages,
468 * bigger than MAX_ORDER unless SPARSEMEM.
469 */
470 page_ext_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300471 mem_init();
472 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200473 percpu_init_late();
Kirill A. Shutemovb35f1812014-01-21 15:49:07 -0800474 pgtable_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300475 vmalloc_init();
Toshi Kani0ddab1d2015-04-14 15:47:20 -0700476 ioremap_huge_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300477}
478
Andi Kleen722a9f92014-05-02 00:44:38 +0200479asmlinkage __visible void __init start_kernel(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700481 char *command_line;
482 char *after_dashes;
Andrew Morton033ab7f2006-06-30 01:55:50 -0700483
Aaron Tomlind4311ff2014-09-12 14:16:17 +0100484 set_task_stack_end_magic(&init_task);
Ming Lei73839c52011-11-17 13:34:31 +0800485 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700486 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100487
488 /*
489 * Set up the the initial canary ASAP:
490 */
491 boot_init_stack_canary();
492
Paul Menageddbcc7e2007-10-18 23:39:30 -0700493 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700494
495 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100496 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700497
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498/*
499 * Interrupts are still disabled. Do necessary setups, then
500 * enable them
501 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800502 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700504 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 setup_arch(&command_line);
Linus Torvalds6345d242011-05-29 11:32:28 -0700506 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800507 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700508 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900509 setup_per_cpu_areas();
Thomas Gleixnercff7d372016-02-26 18:43:28 +0000510 boot_cpu_state_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800511 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
Jiang Liu9adb62a2012-07-31 16:43:28 -0700513 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300514 page_alloc_init();
515
Andrew Mortonea676e82013-04-29 16:18:20 -0700516 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300517 parse_early_param();
Rusty Russell51e158c2014-04-28 11:34:33 +0930518 after_dashes = parse_args("Booting kernel",
519 static_command_line, __start___param,
520 __stop___param - __start___param,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700521 -1, -1, NULL, &unknown_bootoption);
Daniel Thompson3438cf52014-11-11 16:29:46 +1030522 if (!IS_ERR_OR_NULL(after_dashes))
Rusty Russell51e158c2014-04-28 11:34:33 +0930523 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700524 NULL, set_init_arg);
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();
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700550 if (WARN(!irqs_disabled(),
551 "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800552 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100553 idr_init_cache();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 rcu_init();
Steven Rostedt (Red Hat)5f893b22014-12-12 20:05:10 -0500555
556 /* trace_printk() and trace points may be used after this */
557 trace_init();
558
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200559 context_tracking_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800560 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800561 /* init some links before init_ISA_irqs() */
562 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100564 tick_init();
Linus Torvaldsd6dd50e2014-10-13 15:44:12 +0200565 rcu_init_nohz();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800567 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700569 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700570 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700571 sched_clock_postinit();
Petr Mladek42a0bb32016-05-20 17:00:33 -0700572 printk_nmi_init();
Stephane Eranian9e630202013-04-03 14:21:33 +0200573 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700574 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400575 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700576 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100577 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700578 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000579
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300580 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581
582 /*
583 * HACK ALERT! This is early. We're enabling the console before
584 * we've done PCI setups etc, and console_init() must be aware of
585 * this. But we do want output early, in case something goes wrong.
586 */
587 console_init();
588 if (panic_later)
Tetsuo Handa499a4582014-01-23 15:54:56 -0800589 panic("Too many boot %s vars at `%s'", panic_later,
590 panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700591
592 lockdep_info();
593
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700594 /*
595 * Need to run this when irqs are enabled, because it wants
596 * to self-test [hard/soft]-irqs on/off lock inversion bugs
597 * too:
598 */
599 locking_selftest();
600
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601#ifdef CONFIG_BLK_DEV_INITRD
602 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700603 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700604 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700605 page_to_pfn(virt_to_page((void *)initrd_start)),
606 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 initrd_start = 0;
608 }
609#endif
Yang Shife53ca52016-05-27 14:27:30 -0700610 page_ext_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700611 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100612 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700613 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 numa_policy_init();
615 if (late_time_init)
616 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200617 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 calibrate_delay();
619 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 anon_vma_init();
Rafael J. Wysockic4e1acb2014-03-13 00:22:58 +0100621 acpi_early_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800622#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000623 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800624 efi_enter_virtual_mode();
625#endif
H. Peter Anvin197725d2014-05-04 10:00:49 -0700626#ifdef CONFIG_X86_ESPFIX64
H. Peter Anvin3891a042014-04-29 16:46:09 -0700627 /* Should be run before the first non-init thread is created */
628 init_espfix_bsp();
629#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000630 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100631 cred_init();
Heinrich Schuchardtff691f62015-04-16 12:47:44 -0700632 fork_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 proc_caches_init();
634 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 key_init();
636 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500637 dbg_late_init();
Mel Gorman4248b0d2015-08-06 15:46:20 -0700638 vfs_caches_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 signals_init();
640 /* rootfs populating might need page-writeback */
641 page_writeback_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 proc_root_init();
Al Viroe149ed22014-11-01 10:57:28 -0400643 nsfs_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 cpuset_init();
Zefan Li695df212015-03-04 17:09:33 +0800645 cgroup_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700646 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700647 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649 check_bugs();
650
Rafael J. Wysockib064a8f2015-06-10 01:33:36 +0200651 acpi_subsystem_init();
Feng Tang6ae69962009-08-14 15:13:46 -0400652 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
Matt Fleming83e68182012-11-14 09:42:35 +0000654 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700655 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700656 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700657 }
Josh Triplett78510792012-09-28 17:55:44 -0700658
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400659 ftrace_init();
660
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 /* Do the rest non-__init'ed, we're now alive */
662 rest_init();
663}
664
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700665/* Call all constructor functions linked into the kernel. */
666static void __init do_ctors(void)
667{
668#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800669 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700670
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800671 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
672 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700673#endif
674}
675
Rusty Russell2329abf2012-01-13 09:32:18 +1030676bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500677core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700679#ifdef CONFIG_KALLSYMS
680struct blacklist_entry {
681 struct list_head next;
682 char *buf;
683};
684
685static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
686
687static int __init initcall_blacklist(char *str)
688{
689 char *str_entry;
690 struct blacklist_entry *entry;
691
692 /* str argument is a comma-separated list of functions */
693 do {
694 str_entry = strsep(&str, ",");
695 if (str_entry) {
696 pr_debug("blacklisting initcall %s\n", str_entry);
697 entry = alloc_bootmem(sizeof(*entry));
698 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
699 strcpy(entry->buf, str_entry);
700 list_add(&entry->next, &blacklisted_initcalls);
701 }
702 } while (str_entry);
703
704 return 0;
705}
706
707static bool __init_or_module initcall_blacklisted(initcall_t fn)
708{
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700709 struct blacklist_entry *entry;
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700710 char fn_name[KSYM_SYMBOL_LEN];
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700711
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700712 if (list_empty(&blacklisted_initcalls))
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700713 return false;
714
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700715 sprint_symbol_no_offset(fn_name, (unsigned long)fn);
716
Geliang Tange6fd1fb2016-03-15 14:52:46 -0700717 list_for_each_entry(entry, &blacklisted_initcalls, next) {
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700718 if (!strcmp(fn_name, entry->buf)) {
719 pr_debug("initcall %s blacklisted\n", fn_name);
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700720 return true;
721 }
722 }
723
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700724 return false;
725}
726#else
727static int __init initcall_blacklist(char *str)
728{
729 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
730 return 0;
731}
732
733static bool __init_or_module initcall_blacklisted(initcall_t fn)
734{
735 return false;
736}
737#endif
738__setup("initcall_blacklist=", initcall_blacklist);
739
Kevin Winchestere4461272010-08-09 17:20:32 -0700740static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700741{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100742 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800743 unsigned long long duration;
744 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700745
Andrew Mortond62cf812014-06-04 16:12:16 -0700746 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700747 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800748 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700749 rettime = ktime_get();
750 delta = ktime_sub(rettime, calltime);
751 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortond62cf812014-06-04 16:12:16 -0700752 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
Andrew Mortonea676e82013-04-29 16:18:20 -0700753 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700754
Kevin Winchester22c5c032010-08-09 17:20:32 -0700755 return ret;
756}
757
Kevin Winchestere4461272010-08-09 17:20:32 -0700758int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700759{
760 int count = preempt_count();
761 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700762 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700763
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700764 if (initcall_blacklisted(fn))
765 return -EPERM;
766
Kevin Winchester22c5c032010-08-09 17:20:32 -0700767 if (initcall_debug)
768 ret = do_one_initcall_debug(fn);
769 else
770 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700771
772 msgbuf[0] = 0;
773
Linus Torvaldse0df1542008-05-15 18:14:01 -0700774 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400775 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200776 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700777 }
778 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700779 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700780 local_irq_enable();
781 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700782 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700783
Américo Wang30dbb20e2010-05-26 18:57:53 +0800784 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700785}
786
787
Pawel Moll026cee02012-03-26 12:50:51 +1030788extern initcall_t __initcall_start[];
789extern initcall_t __initcall0_start[];
790extern initcall_t __initcall1_start[];
791extern initcall_t __initcall2_start[];
792extern initcall_t __initcall3_start[];
793extern initcall_t __initcall4_start[];
794extern initcall_t __initcall5_start[];
795extern initcall_t __initcall6_start[];
796extern initcall_t __initcall7_start[];
797extern initcall_t __initcall_end[];
798
799static initcall_t *initcall_levels[] __initdata = {
800 __initcall0_start,
801 __initcall1_start,
802 __initcall2_start,
803 __initcall3_start,
804 __initcall4_start,
805 __initcall5_start,
806 __initcall6_start,
807 __initcall7_start,
808 __initcall_end,
809};
810
Jim Cromie96263d22012-06-14 16:00:59 -0600811/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030812static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600813 "early",
814 "core",
815 "postcore",
816 "arch",
817 "subsys",
818 "fs",
819 "device",
820 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030821};
822
Pawel Moll026cee02012-03-26 12:50:51 +1030823static void __init do_initcall_level(int level)
824{
Pawel Moll026cee02012-03-26 12:50:51 +1030825 initcall_t *fn;
826
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030827 strcpy(initcall_command_line, saved_command_line);
Pawel Moll026cee02012-03-26 12:50:51 +1030828 parse_args(initcall_level_names[level],
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030829 initcall_command_line, __start___param,
Pawel Moll026cee02012-03-26 12:50:51 +1030830 __stop___param - __start___param,
831 level, level,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700832 NULL, &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030833
834 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
835 do_one_initcall(*fn);
836}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
838static void __init do_initcalls(void)
839{
Pawel Moll026cee02012-03-26 12:50:51 +1030840 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
Borislav Petkov19efb722012-06-01 18:56:00 +0200842 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030843 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844}
845
846/*
847 * Ok, the machine is now initialized. None of the devices
848 * have been touched yet, but the CPU subsystem is up and
849 * running, and memory and process management works.
850 *
851 * Now we can finally start doing some real work..
852 */
853static void __init do_basic_setup(void)
854{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800855 cpuset_init_smp();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700856 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800858 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700859 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700860 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800861 do_initcalls();
Theodore Ts'o47d06e52013-09-10 10:52:35 -0400862 random_int_secret_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863}
864
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700865static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700866{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800867 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700868
Pawel Moll026cee02012-03-26 12:50:51 +1030869 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800870 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700871}
872
Tejun Heobb813f42013-01-18 14:05:56 -0800873/*
874 * This function requests modules which should be loaded by default and is
875 * called twice right after initrd is mounted and right before init is
876 * exec'd. If such modules are on either initrd or rootfs, they will be
877 * loaded before control is passed to userland.
878 */
879void __init load_default_modules(void)
880{
881 load_default_elevator_module();
882}
883
Al Viroa74fb732012-10-10 21:28:25 -0400884static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885{
886 argv_init[0] = init_filename;
Linus Torvaldsc4ad8f92014-02-05 12:54:53 -0800887 return do_execve(getname_kernel(init_filename),
Al Viroae903ca2012-12-14 12:44:11 -0500888 (const char __user *const __user *)argv_init,
889 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890}
891
Michael Opdenackerba247622013-11-12 15:10:21 -0800892static int try_to_run_init_process(const char *init_filename)
893{
894 int ret;
895
896 ret = run_init_process(init_filename);
897
898 if (ret && ret != -ENOENT) {
899 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
900 init_filename, ret);
901 }
902
903 return ret;
904}
905
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530906static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400907
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800908#ifdef CONFIG_DEBUG_RODATA
909static bool rodata_enabled = true;
910static int __init set_debug_rodata(char *str)
911{
912 return strtobool(str, &rodata_enabled);
913}
914__setup("rodata=", set_debug_rodata);
915
916static void mark_readonly(void)
917{
918 if (rodata_enabled)
919 mark_rodata_ro();
920 else
921 pr_info("Kernel memory protection disabled.\n");
922}
923#else
924static inline void mark_readonly(void)
925{
926 pr_warn("This architecture does not have kernel memory protection.\n");
927}
928#endif
929
Al Virod6b21232012-10-10 19:57:26 -0400930static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100931{
Michael Opdenackerba247622013-11-12 15:10:21 -0800932 int ret;
933
Al Virod6b21232012-10-10 19:57:26 -0400934 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800935 /* need to finish all async __init code before freeing the memory */
936 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100937 free_initmem();
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800938 mark_readonly();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100939 system_state = SYSTEM_RUNNING;
940 numa_default_policy();
941
Al Viro4a9d4b02012-06-24 09:56:45 +0400942 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700943
Paul E. McKenney967dcb82015-11-25 16:52:36 -0800944 rcu_end_inkernel_boot();
945
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100946 if (ramdisk_execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800947 ret = run_init_process(ramdisk_execute_command);
948 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400949 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800950 pr_err("Failed to execute %s (error %d)\n",
951 ramdisk_execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100952 }
953
954 /*
955 * We try each of these until one succeeds.
956 *
957 * The Bourne shell can be used instead of init if we are
958 * trying to recover a really broken machine.
959 */
960 if (execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800961 ret = run_init_process(execute_command);
962 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400963 return 0;
Andy Lutomirski6ef45362014-12-10 15:52:19 -0800964 panic("Requested init %s failed (error %d).",
965 execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100966 }
Michael Opdenackerba247622013-11-12 15:10:21 -0800967 if (!try_to_run_init_process("/sbin/init") ||
968 !try_to_run_init_process("/etc/init") ||
969 !try_to_run_init_process("/bin/init") ||
970 !try_to_run_init_process("/bin/sh"))
Al Viroa74fb732012-10-10 21:28:25 -0400971 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100972
Michael Opdenackerba247622013-11-12 15:10:21 -0800973 panic("No working init found. Try passing init= option to kernel. "
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800974 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100975}
976
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530977static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200979 /*
980 * Wait until kthreadd is all set-up.
981 */
982 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -0700983
984 /* Now the scheduler is fully set up and can do blocking allocations */
985 gfp_allowed_mask = __GFP_BITS_MASK;
986
Miao Xie58568d22009-06-16 15:31:49 -0700987 /*
988 * init can allocate pages on any node
989 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -0800990 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 /*
992 * init can run on any cpu.
993 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600994 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700996 cad_pid = task_pid(current);
997
Andi Kleenca74a6f2008-01-30 13:33:17 +0100998 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
1000 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +01001001 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 smp_init();
1004 sched_init_smp();
1005
Mel Gorman0e1cc952015-06-30 14:57:27 -07001006 page_alloc_init_late();
1007
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 do_basic_setup();
1009
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001010 /* Open the /dev/console on the rootfs, this should never fail */
1011 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -07001012 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001013
1014 (void) sys_dup(0);
1015 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 /*
1017 * check if there is an early userspace init. If yes, let it do all
1018 * the work
1019 */
Olof Johanssonffdfc402005-09-06 15:17:19 -07001020
1021 if (!ramdisk_execute_command)
1022 ramdisk_execute_command = "/init";
1023
1024 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1025 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -07001027 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
1029 /*
1030 * Ok, we have completed the initial bootup, and
1031 * we're essentially up and running. Get rid of the
1032 * initmem segments and start the user-mode stuff..
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001033 *
1034 * rootfs is available now, try loading the public keys
1035 * and default modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 */
Tejun Heobb813f42013-01-18 14:05:56 -08001037
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001038 integrity_load_keys();
Tejun Heobb813f42013-01-18 14:05:56 -08001039 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040}