blob: c0137b916aa12ba9fa3e027da4d613bc182e81d2 [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>
Paul Gortmaker8a293be2016-07-23 14:01:45 -040015#include <linux/extable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/module.h>
17#include <linux/proc_fs.h>
Ingo Molnar5c2c5c52017-02-05 14:24:31 +010018#include <linux/binfmts.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/kernel.h>
20#include <linux/syscalls.h>
Ingo Molnar9b5609f2008-02-14 09:41:09 +010021#include <linux/stackprotector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/string.h>
23#include <linux/ctype.h>
24#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/ioport.h>
26#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040029#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/tty.h>
Ingo Molnar38b8d202017-02-08 18:51:31 +010031#include <linux/nmi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/percpu.h>
33#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070034#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010036#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020038#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/profile.h>
40#include <linux/rcupdate.h>
41#include <linux/moduleparam.h>
42#include <linux/kallsyms.h>
43#include <linux/writeback.h>
44#include <linux/cpu.h>
45#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070046#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080048#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080049#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070050#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070051#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#include <linux/unistd.h>
53#include <linux/rmap.h>
54#include <linux/mempolicy.h>
55#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070056#include <linux/buffer_head.h>
Joonsoo Kimeefa864b2014-12-12 16:55:46 -080057#include <linux/page_ext.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070058#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070059#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070060#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010061#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080062#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080063#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070064#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010065#include <linux/sched.h>
Ingo Molnar1777e462017-02-05 14:47:12 +010066#include <linux/sched/init.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080067#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070068#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050069#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040070#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080071#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020072#include <linux/kmemcheck.h>
Feng Tang6ae69962009-08-14 15:13:46 -040073#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020074#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090075#include <linux/slab.h>
Peter Zijlstra24a24bb2010-11-17 23:17:33 +010076#include <linux/perf_event.h>
Al Viroa74fb732012-10-10 21:28:25 -040077#include <linux/ptrace.h>
Tejun Heobb813f42013-01-18 14:05:56 -080078#include <linux/blkdev.h>
79#include <linux/elevator.h>
Stephen Boyd38ff87f2013-06-01 23:39:40 -070080#include <linux/sched_clock.h>
Ingo Molnar29930022017-02-08 18:51:36 +010081#include <linux/sched/task.h>
Ingo Molnar68db0cf2017-02-08 18:51:37 +010082#include <linux/sched/task_stack.h>
Frederic Weisbecker65f382f2013-07-11 19:12:32 +020083#include <linux/context_tracking.h>
Theodore Ts'o47d06e52013-09-10 10:52:35 -040084#include <linux/random.h>
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -070085#include <linux/list.h>
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +020086#include <linux/integrity.h>
Al Viroe149ed22014-11-01 10:57:28 -040087#include <linux/proc_ns.h>
Toshi Kani0ddab1d2015-04-14 15:47:20 -070088#include <linux/io.h>
AKASHI Takahiro39290b32016-11-14 15:15:05 +090089#include <linux/cache.h>
Jinbum Park2959a5f2017-02-27 14:30:22 -080090#include <linux/rodata_test.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92#include <asm/io.h>
93#include <asm/bugs.h>
94#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070095#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080096#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Sam Ravnborgaae5f662007-02-26 16:45:41 +010098static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100extern void init_IRQ(void);
Heinrich Schuchardtff691f62015-04-16 12:47:44 -0700101extern void fork_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102extern void radix_tree_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Tejun Heo2ce802f2011-01-20 12:06:35 +0100104/*
105 * Debug helper: via this flag we know that we are in 'early bootup code'
106 * where only the boot processor is running with IRQ disabled. This means
107 * two things - IRQ must not be enabled before the flag is cleared and some
108 * operations which are not allowed with IRQ disabled are allowed while the
109 * flag is set.
110 */
111bool early_boot_irqs_disabled __read_mostly;
112
Paul E. McKenneya6826042009-02-25 18:03:42 -0800113enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114EXPORT_SYMBOL(system_state);
115
116/*
117 * Boot command-line arguments
118 */
119#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
120#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
121
122extern void time_init(void);
123/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800124void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800126/* Untouched command line saved by arch-specific code. */
127char __initdata boot_command_line[COMMAND_LINE_SIZE];
128/* Untouched saved command line (eg. for /proc) */
129char *saved_command_line;
130/* Command line for parameter parsing */
131static char *static_command_line;
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030132/* Command line for per-initcall parameter parsing */
133static char *initcall_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700136static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
Jan Beulich8b3b2952007-07-15 23:41:07 -0700138/*
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200139 * Used to generate warnings if static_key manipulation functions are used
140 * before jump_label_init is called.
141 */
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700142bool static_key_initialized __read_mostly;
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200143EXPORT_SYMBOL_GPL(static_key_initialized);
144
145/*
Jan Beulich8b3b2952007-07-15 23:41:07 -0700146 * If set, this is an indication to the drivers that reset the underlying
147 * device before going ahead with the initialization otherwise driver might
148 * rely on the BIOS and skip the reset operation.
149 *
150 * This is useful if kernel is booting in an unreliable environment.
Frans Klaverfc454fd2015-02-23 22:05:56 +0100151 * For ex. kdump situation where previous kernel has crashed, BIOS has been
Jan Beulich8b3b2952007-07-15 23:41:07 -0700152 * skipped and devices will be in unknown state.
153 */
154unsigned int reset_devices;
155EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
Vivek Goyal7e962872006-09-27 01:50:44 -0700157static int __init set_reset_devices(char *str)
158{
159 reset_devices = 1;
160 return 1;
161}
162
163__setup("reset_devices", set_reset_devices);
164
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700165static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
166const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167static const char *panic_later, *panic_param;
168
Rusty Russell914dcaa2010-08-11 23:04:18 -0600169extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Yaowei Bai31c025b2016-01-20 14:59:27 -0800171static bool __init obsolete_checksetup(char *line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600173 const struct obs_kernel_param *p;
Yaowei Bai31c025b2016-01-20 14:59:27 -0800174 bool had_early_param = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 p = __setup_start;
177 do {
178 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200179 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200181 /* Already done in parse_early_param?
182 * (Needs exact match on param part).
183 * Keep iterating, as we can have early
184 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 if (line[n] == '\0' || line[n] == '=')
Yaowei Bai31c025b2016-01-20 14:59:27 -0800186 had_early_param = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700188 pr_warn("Parameter %s is obsolete, ignored\n",
189 p->str);
Yaowei Bai31c025b2016-01-20 14:59:27 -0800190 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 } else if (p->setup_func(line + n))
Yaowei Bai31c025b2016-01-20 14:59:27 -0800192 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 }
194 p++;
195 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200196
197 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198}
199
200/*
201 * This should be approx 2 Bo*oMips to start (note initial shift), and will
202 * still work even if initially too large, it will just take slightly longer
203 */
204unsigned long loops_per_jiffy = (1<<12);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205EXPORT_SYMBOL(loops_per_jiffy);
206
207static int __init debug_kernel(char *str)
208{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700209 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800210 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
213static int __init quiet_kernel(char *str)
214{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700215 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800216 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
Yinghai Luf6f21c812008-02-08 04:21:58 -0800219early_param("debug", debug_kernel);
220early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222static int __init loglevel(char *str)
223{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200224 int newlevel;
225
226 /*
227 * Only update loglevel value when a correct setting was passed,
228 * to prevent blind crashes (when loglevel being set to 0) that
229 * are quite hard to debug
230 */
231 if (get_option(&str, &newlevel)) {
232 console_loglevel = newlevel;
233 return 0;
234 }
235
236 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237}
238
Yinghai Luf6f21c812008-02-08 04:21:58 -0800239early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
Chris Metcalfa99cd112012-04-06 12:53:50 -0400241/* Change NUL term back to "=", to make "param" the whole string. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700242static int __init repair_env_string(char *param, char *val,
243 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (val) {
246 /* param=val or param="val"? */
247 if (val == param+strlen(param)+1)
248 val[-1] = '=';
249 else if (val == param+strlen(param)+2) {
250 val[-2] = '=';
251 memmove(val-1, val, strlen(val)+1);
252 val--;
253 } else
254 BUG();
255 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400256 return 0;
257}
258
Rusty Russell51e158c2014-04-28 11:34:33 +0930259/* Anything after -- gets handed straight to init. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700260static int __init set_init_arg(char *param, char *val,
261 const char *unused, void *arg)
Rusty Russell51e158c2014-04-28 11:34:33 +0930262{
263 unsigned int i;
264
265 if (panic_later)
266 return 0;
267
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700268 repair_env_string(param, val, unused, NULL);
Rusty Russell51e158c2014-04-28 11:34:33 +0930269
270 for (i = 0; argv_init[i]; i++) {
271 if (i == MAX_INIT_ARGS) {
272 panic_later = "init";
273 panic_param = param;
274 return 0;
275 }
276 }
277 argv_init[i] = param;
278 return 0;
279}
280
Chris Metcalfa99cd112012-04-06 12:53:50 -0400281/*
282 * Unknown boot options get handed to init, unless they look like
283 * unused parameters (modprobe will find them in /proc/cmdline).
284 */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700285static int __init unknown_bootoption(char *param, char *val,
286 const char *unused, void *arg)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400287{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700288 repair_env_string(param, val, unused, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
290 /* Handle obsolete-style parameters */
291 if (obsolete_checksetup(param))
292 return 0;
293
Rusty Russellf066a4f2009-12-01 14:56:44 +1030294 /* Unused module parameter. */
295 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
298 if (panic_later)
299 return 0;
300
301 if (val) {
302 /* Environment option */
303 unsigned int i;
304 for (i = 0; envp_init[i]; i++) {
305 if (i == MAX_INIT_ENVS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800306 panic_later = "env";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 panic_param = param;
308 }
309 if (!strncmp(param, envp_init[i], val - param))
310 break;
311 }
312 envp_init[i] = param;
313 } else {
314 /* Command line option */
315 unsigned int i;
316 for (i = 0; argv_init[i]; i++) {
317 if (i == MAX_INIT_ARGS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800318 panic_later = "init";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 panic_param = param;
320 }
321 }
322 argv_init[i] = param;
323 }
324 return 0;
325}
326
327static int __init init_setup(char *str)
328{
329 unsigned int i;
330
331 execute_command = str;
332 /*
333 * In case LILO is going to boot us with default command line,
334 * it prepends "auto" before the whole cmdline which makes
335 * the shell think it should execute a script with such name.
336 * So we ignore all arguments entered _before_ init=... [MJ]
337 */
338 for (i = 1; i < MAX_INIT_ARGS; i++)
339 argv_init[i] = NULL;
340 return 1;
341}
342__setup("init=", init_setup);
343
Olof Johanssonffdfc402005-09-06 15:17:19 -0700344static int __init rdinit_setup(char *str)
345{
346 unsigned int i;
347
348 ramdisk_execute_command = str;
349 /* See "auto" comment in init_setup */
350 for (i = 1; i < MAX_INIT_ARGS; i++)
351 argv_init[i] = NULL;
352 return 1;
353}
354__setup("rdinit=", rdinit_setup);
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700357static const unsigned int setup_max_cpus = NR_CPUS;
Mike Travise0982e92008-03-26 14:23:48 -0700358static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360#endif
361
362/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800363 * We need to store the untouched command line for future reference.
364 * We also need to store the touched command line since the parameter
365 * parsing is performed in place, and we should allow a component to
366 * store reference of name/value for future reference.
367 */
368static void __init setup_command_line(char *command_line)
369{
Santosh Shilimkar098b0812014-01-21 15:50:21 -0800370 saved_command_line =
371 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
372 initcall_command_line =
373 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
374 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700375 strcpy(saved_command_line, boot_command_line);
376 strcpy(static_command_line, command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800377}
378
379/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 * We need to finalize in a non-__init function or else race conditions
381 * between the root thread and the init thread may cause start_kernel to
382 * be reaped by free_initmem before the root thread has proceeded to
383 * cpu_idle.
384 *
385 * gcc-3.4 accidentally inlines this function, so use noinline.
386 */
387
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200388static __initdata DECLARE_COMPLETION(kthreadd_done);
389
Fabian Frederickbd721ea2016-08-02 14:03:33 -0700390static noinline void __ref rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700392 int pid;
393
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700394 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200395 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200396 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200397 * the init task will end up wanting to create kthreads, which, if
398 * we schedule it before we create kthreadd, will OOPS.
399 */
Oleg Nesterov34a1b722014-06-04 16:12:19 -0700400 kernel_thread(kernel_init, NULL, CLONE_FS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700402 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800403 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700404 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800405 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200406 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200407
408 /*
409 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200410 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200411 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200412 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100413 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800414 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100415 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200416}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418/* Check for early params. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700419static int __init do_early_param(char *param, char *val,
420 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600422 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
424 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200425 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700426 (strcmp(param, "console") == 0 &&
427 strcmp(p->str, "earlycon") == 0)
428 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700430 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 }
432 }
433 /* We accept everything at this stage. */
434 return 0;
435}
436
Magnus Damm13977092009-03-30 14:37:25 -0700437void __init parse_early_options(char *cmdline)
438{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700439 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
440 do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700441}
442
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443/* Arch code calls this early on, or if not, just before other parsing. */
444void __init parse_early_param(void)
445{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700446 static int done __initdata;
447 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
449 if (done)
450 return;
451
452 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800453 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700454 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 done = 1;
456}
457
Thomas Gleixnere7ff3a42016-12-09 19:29:10 +0100458void __init __weak arch_post_acpi_subsys_init(void) { }
459
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000460void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700461{
462}
463
David Howellseded09c2012-11-02 13:20:42 +0000464# if THREAD_SIZE >= PAGE_SIZE
Linus Torvaldsb235bee2016-06-24 15:09:37 -0700465void __init __weak thread_stack_cache_init(void)
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000466{
467}
David Howellseded09c2012-11-02 13:20:42 +0000468#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000469
Pekka Enberg444f4782009-06-11 18:29:06 +0300470/*
471 * Set up kernel memory allocators
472 */
473static void __init mm_init(void)
474{
Joonsoo Kimeefa864b2014-12-12 16:55:46 -0800475 /*
476 * page_ext requires contiguous pages,
477 * bigger than MAX_ORDER unless SPARSEMEM.
478 */
479 page_ext_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300480 mem_init();
481 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200482 percpu_init_late();
Kirill A. Shutemovb35f1812014-01-21 15:49:07 -0800483 pgtable_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300484 vmalloc_init();
Toshi Kani0ddab1d2015-04-14 15:47:20 -0700485 ioremap_huge_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300486}
487
Andi Kleen722a9f92014-05-02 00:44:38 +0200488asmlinkage __visible void __init start_kernel(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700490 char *command_line;
491 char *after_dashes;
Andrew Morton033ab7f2006-06-30 01:55:50 -0700492
Aaron Tomlind4311ff2014-09-12 14:16:17 +0100493 set_task_stack_end_magic(&init_task);
Ming Lei73839c52011-11-17 13:34:31 +0800494 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700495 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100496
497 /*
498 * Set up the the initial canary ASAP:
499 */
500 boot_init_stack_canary();
501
Paul Menageddbcc7e2007-10-18 23:39:30 -0700502 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700503
504 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100505 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507/*
508 * Interrupts are still disabled. Do necessary setups, then
509 * enable them
510 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800511 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700513 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 setup_arch(&command_line);
Linus Torvalds6345d242011-05-29 11:32:28 -0700515 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800516 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700517 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900518 setup_per_cpu_areas();
Thomas Gleixnercff7d372016-02-26 18:43:28 +0000519 boot_cpu_state_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800520 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Jiang Liu9adb62a2012-07-31 16:43:28 -0700522 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300523 page_alloc_init();
524
Andrew Mortonea676e82013-04-29 16:18:20 -0700525 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300526 parse_early_param();
Rusty Russell51e158c2014-04-28 11:34:33 +0930527 after_dashes = parse_args("Booting kernel",
528 static_command_line, __start___param,
529 __stop___param - __start___param,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700530 -1, -1, NULL, &unknown_bootoption);
Daniel Thompson3438cf52014-11-11 16:29:46 +1030531 if (!IS_ERR_OR_NULL(after_dashes))
Rusty Russell51e158c2014-04-28 11:34:33 +0930532 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700533 NULL, set_init_arg);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700534
535 jump_label_init();
536
Pekka Enberg83b519e2009-06-10 19:40:04 +0300537 /*
538 * These use large bootmem allocations and must precede
539 * kmem_cache_init()
540 */
Mike Travis162a7e72011-05-24 17:13:20 -0700541 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300542 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300543 vfs_caches_init_early();
544 sort_main_extable();
545 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300546 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700547
Steven Rostedt (VMware)f6317182017-03-03 13:43:34 -0500548 ftrace_init();
549
Steven Rostedt (VMware)e725c732017-03-03 13:37:33 -0500550 /* trace_printk can be enabled here */
551 early_trace_init();
552
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 /*
554 * Set up the scheduler prior starting any interrupts (such as the
555 * timer interrupt). Full topology setup happens at smp_init()
556 * time - but meanwhile we still have a functioning scheduler.
557 */
558 sched_init();
559 /*
560 * Disable preemption - early bootup scheduling is extremely
561 * fragile until we cpu_idle() for the first time.
562 */
563 preempt_disable();
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700564 if (WARN(!irqs_disabled(),
565 "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800566 local_irq_disable();
Matthew Wilcox0a835c42016-12-20 10:27:56 -0500567 radix_tree_init();
Tejun Heo3347fa02016-09-16 15:49:32 -0400568
569 /*
570 * Allow workqueue creation and work item queueing/cancelling
571 * early. Work item execution depends on kthreads and starts after
572 * workqueue_init().
573 */
574 workqueue_init_early();
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 rcu_init();
Steven Rostedt (Red Hat)5f893b22014-12-12 20:05:10 -0500577
Steven Rostedt (VMware)e725c732017-03-03 13:37:33 -0500578 /* Trace events are available after this */
Steven Rostedt (Red Hat)5f893b22014-12-12 20:05:10 -0500579 trace_init();
580
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200581 context_tracking_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800582 /* init some links before init_ISA_irqs() */
583 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100585 tick_init();
Linus Torvaldsd6dd50e2014-10-13 15:44:12 +0200586 rcu_init_nohz();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800588 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700590 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700591 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700592 sched_clock_postinit();
Sergey Senozhatskyf92bac32016-12-27 23:16:05 +0900593 printk_safe_init();
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
Yang Shife53ca52016-05-27 14:27:30 -0700631 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();
638 calibrate_delay();
639 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 anon_vma_init();
Rafael J. Wysockic4e1acb2014-03-13 00:22:58 +0100641 acpi_early_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800642#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000643 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800644 efi_enter_virtual_mode();
645#endif
H. Peter Anvin197725d2014-05-04 10:00:49 -0700646#ifdef CONFIG_X86_ESPFIX64
H. Peter Anvin3891a042014-04-29 16:46:09 -0700647 /* Should be run before the first non-init thread is created */
648 init_espfix_bsp();
649#endif
Linus Torvaldsb235bee2016-06-24 15:09:37 -0700650 thread_stack_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100651 cred_init();
Heinrich Schuchardtff691f62015-04-16 12:47:44 -0700652 fork_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 proc_caches_init();
654 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 key_init();
656 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500657 dbg_late_init();
Mel Gorman4248b0d2015-08-06 15:46:20 -0700658 vfs_caches_init();
Nicholas Piggin62906022016-12-25 13:00:30 +1000659 pagecache_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 signals_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 proc_root_init();
Al Viroe149ed22014-11-01 10:57:28 -0400662 nsfs_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 cpuset_init();
Zefan Li695df212015-03-04 17:09:33 +0800664 cgroup_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700665 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700666 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
668 check_bugs();
669
Rafael J. Wysockib064a8f2015-06-10 01:33:36 +0200670 acpi_subsystem_init();
Thomas Gleixnere7ff3a42016-12-09 19:29:10 +0100671 arch_post_acpi_subsys_init();
Feng Tang6ae69962009-08-14 15:13:46 -0400672 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
Matt Fleming83e68182012-11-14 09:42:35 +0000674 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett78510792012-09-28 17:55:44 -0700675 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700676 }
Josh Triplett78510792012-09-28 17:55:44 -0700677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 /* Do the rest non-__init'ed, we're now alive */
679 rest_init();
680}
681
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700682/* Call all constructor functions linked into the kernel. */
683static void __init do_ctors(void)
684{
685#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800686 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700687
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800688 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
689 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700690#endif
691}
692
Rusty Russell2329abf2012-01-13 09:32:18 +1030693bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500694core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700696#ifdef CONFIG_KALLSYMS
697struct blacklist_entry {
698 struct list_head next;
699 char *buf;
700};
701
702static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
703
704static int __init initcall_blacklist(char *str)
705{
706 char *str_entry;
707 struct blacklist_entry *entry;
708
709 /* str argument is a comma-separated list of functions */
710 do {
711 str_entry = strsep(&str, ",");
712 if (str_entry) {
713 pr_debug("blacklisting initcall %s\n", str_entry);
714 entry = alloc_bootmem(sizeof(*entry));
715 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
716 strcpy(entry->buf, str_entry);
717 list_add(&entry->next, &blacklisted_initcalls);
718 }
719 } while (str_entry);
720
721 return 0;
722}
723
724static bool __init_or_module initcall_blacklisted(initcall_t fn)
725{
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700726 struct blacklist_entry *entry;
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700727 char fn_name[KSYM_SYMBOL_LEN];
Rasmus Villemoes0fd5ed82016-06-24 14:50:30 -0700728 unsigned long addr;
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700729
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700730 if (list_empty(&blacklisted_initcalls))
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700731 return false;
732
Rasmus Villemoes0fd5ed82016-06-24 14:50:30 -0700733 addr = (unsigned long) dereference_function_descriptor(fn);
734 sprint_symbol_no_offset(fn_name, addr);
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700735
Prarit Bhargava841c06d2016-08-02 14:07:15 -0700736 /*
737 * fn will be "function_name [module_name]" where [module_name] is not
738 * displayed for built-in init functions. Strip off the [module_name].
739 */
740 strreplace(fn_name, ' ', '\0');
741
Geliang Tange6fd1fb2016-03-15 14:52:46 -0700742 list_for_each_entry(entry, &blacklisted_initcalls, next) {
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700743 if (!strcmp(fn_name, entry->buf)) {
744 pr_debug("initcall %s blacklisted\n", fn_name);
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700745 return true;
746 }
747 }
748
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700749 return false;
750}
751#else
752static int __init initcall_blacklist(char *str)
753{
754 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
755 return 0;
756}
757
758static bool __init_or_module initcall_blacklisted(initcall_t fn)
759{
760 return false;
761}
762#endif
763__setup("initcall_blacklist=", initcall_blacklist);
764
Kevin Winchestere4461272010-08-09 17:20:32 -0700765static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700766{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100767 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800768 unsigned long long duration;
769 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700770
Andrew Mortond62cf812014-06-04 16:12:16 -0700771 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700772 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800773 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700774 rettime = ktime_get();
775 delta = ktime_sub(rettime, calltime);
776 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortond62cf812014-06-04 16:12:16 -0700777 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
Andrew Mortonea676e82013-04-29 16:18:20 -0700778 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700779
Kevin Winchester22c5c032010-08-09 17:20:32 -0700780 return ret;
781}
782
Kevin Winchestere4461272010-08-09 17:20:32 -0700783int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700784{
785 int count = preempt_count();
786 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700787 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700788
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700789 if (initcall_blacklisted(fn))
790 return -EPERM;
791
Kevin Winchester22c5c032010-08-09 17:20:32 -0700792 if (initcall_debug)
793 ret = do_one_initcall_debug(fn);
794 else
795 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700796
797 msgbuf[0] = 0;
798
Linus Torvaldse0df1542008-05-15 18:14:01 -0700799 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400800 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200801 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700802 }
803 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700804 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700805 local_irq_enable();
806 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700807 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700808
Emese Revfy38addce2016-06-20 20:41:19 +0200809 add_latent_entropy();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800810 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700811}
812
813
Pawel Moll026cee02012-03-26 12:50:51 +1030814extern initcall_t __initcall_start[];
815extern initcall_t __initcall0_start[];
816extern initcall_t __initcall1_start[];
817extern initcall_t __initcall2_start[];
818extern initcall_t __initcall3_start[];
819extern initcall_t __initcall4_start[];
820extern initcall_t __initcall5_start[];
821extern initcall_t __initcall6_start[];
822extern initcall_t __initcall7_start[];
823extern initcall_t __initcall_end[];
824
825static initcall_t *initcall_levels[] __initdata = {
826 __initcall0_start,
827 __initcall1_start,
828 __initcall2_start,
829 __initcall3_start,
830 __initcall4_start,
831 __initcall5_start,
832 __initcall6_start,
833 __initcall7_start,
834 __initcall_end,
835};
836
Jim Cromie96263d22012-06-14 16:00:59 -0600837/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030838static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600839 "early",
840 "core",
841 "postcore",
842 "arch",
843 "subsys",
844 "fs",
845 "device",
846 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030847};
848
Pawel Moll026cee02012-03-26 12:50:51 +1030849static void __init do_initcall_level(int level)
850{
Pawel Moll026cee02012-03-26 12:50:51 +1030851 initcall_t *fn;
852
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030853 strcpy(initcall_command_line, saved_command_line);
Pawel Moll026cee02012-03-26 12:50:51 +1030854 parse_args(initcall_level_names[level],
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030855 initcall_command_line, __start___param,
Pawel Moll026cee02012-03-26 12:50:51 +1030856 __stop___param - __start___param,
857 level, level,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700858 NULL, &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030859
860 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
861 do_one_initcall(*fn);
862}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
864static void __init do_initcalls(void)
865{
Pawel Moll026cee02012-03-26 12:50:51 +1030866 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
Borislav Petkov19efb722012-06-01 18:56:00 +0200868 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030869 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870}
871
872/*
873 * Ok, the machine is now initialized. None of the devices
874 * have been touched yet, but the CPU subsystem is up and
875 * running, and memory and process management works.
876 *
877 * Now we can finally start doing some real work..
878 */
879static void __init do_basic_setup(void)
880{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800881 cpuset_init_smp();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700882 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800884 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700885 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700886 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800887 do_initcalls();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888}
889
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700890static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700891{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800892 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700893
Pawel Moll026cee02012-03-26 12:50:51 +1030894 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800895 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700896}
897
Tejun Heobb813f42013-01-18 14:05:56 -0800898/*
899 * This function requests modules which should be loaded by default and is
900 * called twice right after initrd is mounted and right before init is
901 * exec'd. If such modules are on either initrd or rootfs, they will be
902 * loaded before control is passed to userland.
903 */
904void __init load_default_modules(void)
905{
906 load_default_elevator_module();
907}
908
Al Viroa74fb732012-10-10 21:28:25 -0400909static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910{
911 argv_init[0] = init_filename;
Linus Torvaldsc4ad8f92014-02-05 12:54:53 -0800912 return do_execve(getname_kernel(init_filename),
Al Viroae903ca2012-12-14 12:44:11 -0500913 (const char __user *const __user *)argv_init,
914 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915}
916
Michael Opdenackerba247622013-11-12 15:10:21 -0800917static int try_to_run_init_process(const char *init_filename)
918{
919 int ret;
920
921 ret = run_init_process(init_filename);
922
923 if (ret && ret != -ENOENT) {
924 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
925 init_filename, ret);
926 }
927
928 return ret;
929}
930
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530931static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400932
Laura Abbott0f5bf6d2017-02-06 16:31:58 -0800933#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
AKASHI Takahiro39290b32016-11-14 15:15:05 +0900934bool rodata_enabled __ro_after_init = true;
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800935static int __init set_debug_rodata(char *str)
936{
937 return strtobool(str, &rodata_enabled);
938}
939__setup("rodata=", set_debug_rodata);
AKASHI Takahiro39290b32016-11-14 15:15:05 +0900940#endif
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800941
Laura Abbott0f5bf6d2017-02-06 16:31:58 -0800942#ifdef CONFIG_STRICT_KERNEL_RWX
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800943static void mark_readonly(void)
944{
Jinbum Park2959a5f2017-02-27 14:30:22 -0800945 if (rodata_enabled) {
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800946 mark_rodata_ro();
Jinbum Park2959a5f2017-02-27 14:30:22 -0800947 rodata_test();
948 } else
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800949 pr_info("Kernel memory protection disabled.\n");
950}
951#else
952static inline void mark_readonly(void)
953{
954 pr_warn("This architecture does not have kernel memory protection.\n");
955}
956#endif
957
Al Virod6b21232012-10-10 19:57:26 -0400958static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100959{
Michael Opdenackerba247622013-11-12 15:10:21 -0800960 int ret;
961
Al Virod6b21232012-10-10 19:57:26 -0400962 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800963 /* need to finish all async __init code before freeing the memory */
964 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100965 free_initmem();
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800966 mark_readonly();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100967 system_state = SYSTEM_RUNNING;
968 numa_default_policy();
969
Paul E. McKenney967dcb82015-11-25 16:52:36 -0800970 rcu_end_inkernel_boot();
971
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100972 if (ramdisk_execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800973 ret = run_init_process(ramdisk_execute_command);
974 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400975 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800976 pr_err("Failed to execute %s (error %d)\n",
977 ramdisk_execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100978 }
979
980 /*
981 * We try each of these until one succeeds.
982 *
983 * The Bourne shell can be used instead of init if we are
984 * trying to recover a really broken machine.
985 */
986 if (execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800987 ret = run_init_process(execute_command);
988 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400989 return 0;
Andy Lutomirski6ef45362014-12-10 15:52:19 -0800990 panic("Requested init %s failed (error %d).",
991 execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100992 }
Michael Opdenackerba247622013-11-12 15:10:21 -0800993 if (!try_to_run_init_process("/sbin/init") ||
994 !try_to_run_init_process("/etc/init") ||
995 !try_to_run_init_process("/bin/init") ||
996 !try_to_run_init_process("/bin/sh"))
Al Viroa74fb732012-10-10 21:28:25 -0400997 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100998
Michael Opdenackerba247622013-11-12 15:10:21 -0800999 panic("No working init found. Try passing init= option to kernel. "
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001000 "See Linux Documentation/admin-guide/init.rst for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +01001001}
1002
Vineet Guptaf80b0c92012-12-21 12:25:44 +05301003static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +02001005 /*
1006 * Wait until kthreadd is all set-up.
1007 */
1008 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -07001009
1010 /* Now the scheduler is fully set up and can do blocking allocations */
1011 gfp_allowed_mask = __GFP_BITS_MASK;
1012
Miao Xie58568d22009-06-16 15:31:49 -07001013 /*
1014 * init can allocate pages on any node
1015 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -08001016 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 /*
1018 * init can run on any cpu.
1019 */
Rusty Russell1a2142a2009-03-30 22:05:10 -06001020 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Cedric Le Goater9ec52092006-10-02 02:19:00 -07001022 cad_pid = task_pid(current);
1023
Andi Kleenca74a6f2008-01-30 13:33:17 +01001024 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025
Tejun Heo3347fa02016-09-16 15:49:32 -04001026 workqueue_init();
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +01001029 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 smp_init();
1032 sched_init_smp();
1033
Mel Gorman0e1cc952015-06-30 14:57:27 -07001034 page_alloc_init_late();
1035
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 do_basic_setup();
1037
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001038 /* Open the /dev/console on the rootfs, this should never fail */
1039 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -07001040 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001041
1042 (void) sys_dup(0);
1043 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 /*
1045 * check if there is an early userspace init. If yes, let it do all
1046 * the work
1047 */
Olof Johanssonffdfc402005-09-06 15:17:19 -07001048
1049 if (!ramdisk_execute_command)
1050 ramdisk_execute_command = "/init";
1051
1052 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1053 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -07001055 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056
1057 /*
1058 * Ok, we have completed the initial bootup, and
1059 * we're essentially up and running. Get rid of the
1060 * initmem segments and start the user-mode stuff..
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001061 *
1062 * rootfs is available now, try loading the public keys
1063 * and default modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 */
Tejun Heobb813f42013-01-18 14:05:56 -08001065
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001066 integrity_load_keys();
Tejun Heobb813f42013-01-18 14:05:56 -08001067 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068}