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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>
AKASHI Takahiro39290b32016-11-14 15:15:05 +090084#include <linux/cache.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86#include <asm/io.h>
87#include <asm/bugs.h>
88#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070089#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080090#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Sam Ravnborgaae5f662007-02-26 16:45:41 +010092static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94extern void init_IRQ(void);
Heinrich Schuchardtff691f62015-04-16 12:47:44 -070095extern void fork_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096extern void radix_tree_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Tejun Heo2ce802f2011-01-20 12:06:35 +010098/*
99 * Debug helper: via this flag we know that we are in 'early bootup code'
100 * where only the boot processor is running with IRQ disabled. This means
101 * two things - IRQ must not be enabled before the flag is cleared and some
102 * operations which are not allowed with IRQ disabled are allowed while the
103 * flag is set.
104 */
105bool early_boot_irqs_disabled __read_mostly;
106
Paul E. McKenneya6826042009-02-25 18:03:42 -0800107enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108EXPORT_SYMBOL(system_state);
109
110/*
111 * Boot command-line arguments
112 */
113#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
114#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
115
116extern void time_init(void);
117/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800118void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800120/* Untouched command line saved by arch-specific code. */
121char __initdata boot_command_line[COMMAND_LINE_SIZE];
122/* Untouched saved command line (eg. for /proc) */
123char *saved_command_line;
124/* Command line for parameter parsing */
125static char *static_command_line;
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030126/* Command line for per-initcall parameter parsing */
127static char *initcall_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700130static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Jan Beulich8b3b2952007-07-15 23:41:07 -0700132/*
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200133 * Used to generate warnings if static_key manipulation functions are used
134 * before jump_label_init is called.
135 */
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700136bool static_key_initialized __read_mostly;
Hannes Frederic Sowac4b2c0c2013-10-19 21:48:53 +0200137EXPORT_SYMBOL_GPL(static_key_initialized);
138
139/*
Jan Beulich8b3b2952007-07-15 23:41:07 -0700140 * If set, this is an indication to the drivers that reset the underlying
141 * device before going ahead with the initialization otherwise driver might
142 * rely on the BIOS and skip the reset operation.
143 *
144 * This is useful if kernel is booting in an unreliable environment.
Frans Klaverfc454fd2015-02-23 22:05:56 +0100145 * For ex. kdump situation where previous kernel has crashed, BIOS has been
Jan Beulich8b3b2952007-07-15 23:41:07 -0700146 * skipped and devices will be in unknown state.
147 */
148unsigned int reset_devices;
149EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
Vivek Goyal7e962872006-09-27 01:50:44 -0700151static int __init set_reset_devices(char *str)
152{
153 reset_devices = 1;
154 return 1;
155}
156
157__setup("reset_devices", set_reset_devices);
158
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700159static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
160const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161static const char *panic_later, *panic_param;
162
Rusty Russell914dcaa2010-08-11 23:04:18 -0600163extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Yaowei Bai31c025b2016-01-20 14:59:27 -0800165static bool __init obsolete_checksetup(char *line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600167 const struct obs_kernel_param *p;
Yaowei Bai31c025b2016-01-20 14:59:27 -0800168 bool had_early_param = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 p = __setup_start;
171 do {
172 int n = strlen(p->str);
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200173 if (parameqn(line, p->str, n)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200175 /* Already done in parse_early_param?
176 * (Needs exact match on param part).
177 * Keep iterating, as we can have early
178 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 if (line[n] == '\0' || line[n] == '=')
Yaowei Bai31c025b2016-01-20 14:59:27 -0800180 had_early_param = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 } else if (!p->setup_func) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700182 pr_warn("Parameter %s is obsolete, ignored\n",
183 p->str);
Yaowei Bai31c025b2016-01-20 14:59:27 -0800184 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 } else if (p->setup_func(line + n))
Yaowei Bai31c025b2016-01-20 14:59:27 -0800186 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 }
188 p++;
189 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200190
191 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192}
193
194/*
195 * This should be approx 2 Bo*oMips to start (note initial shift), and will
196 * still work even if initially too large, it will just take slightly longer
197 */
198unsigned long loops_per_jiffy = (1<<12);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199EXPORT_SYMBOL(loops_per_jiffy);
200
201static int __init debug_kernel(char *str)
202{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700203 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207static int __init quiet_kernel(char *str)
208{
Borislav Petkova8fe19e2014-06-04 16:11:46 -0700209 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800210 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
Yinghai Luf6f21c812008-02-08 04:21:58 -0800213early_param("debug", debug_kernel);
214early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216static int __init loglevel(char *str)
217{
Alexander Sverdlin808bf292011-09-21 09:51:40 +0200218 int newlevel;
219
220 /*
221 * Only update loglevel value when a correct setting was passed,
222 * to prevent blind crashes (when loglevel being set to 0) that
223 * are quite hard to debug
224 */
225 if (get_option(&str, &newlevel)) {
226 console_loglevel = newlevel;
227 return 0;
228 }
229
230 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231}
232
Yinghai Luf6f21c812008-02-08 04:21:58 -0800233early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Chris Metcalfa99cd112012-04-06 12:53:50 -0400235/* Change NUL term back to "=", to make "param" the whole string. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700236static int __init repair_env_string(char *param, char *val,
237 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 if (val) {
240 /* param=val or param="val"? */
241 if (val == param+strlen(param)+1)
242 val[-1] = '=';
243 else if (val == param+strlen(param)+2) {
244 val[-2] = '=';
245 memmove(val-1, val, strlen(val)+1);
246 val--;
247 } else
248 BUG();
249 }
Chris Metcalfa99cd112012-04-06 12:53:50 -0400250 return 0;
251}
252
Rusty Russell51e158c2014-04-28 11:34:33 +0930253/* Anything after -- gets handed straight to init. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700254static int __init set_init_arg(char *param, char *val,
255 const char *unused, void *arg)
Rusty Russell51e158c2014-04-28 11:34:33 +0930256{
257 unsigned int i;
258
259 if (panic_later)
260 return 0;
261
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700262 repair_env_string(param, val, unused, NULL);
Rusty Russell51e158c2014-04-28 11:34:33 +0930263
264 for (i = 0; argv_init[i]; i++) {
265 if (i == MAX_INIT_ARGS) {
266 panic_later = "init";
267 panic_param = param;
268 return 0;
269 }
270 }
271 argv_init[i] = param;
272 return 0;
273}
274
Chris Metcalfa99cd112012-04-06 12:53:50 -0400275/*
276 * Unknown boot options get handed to init, unless they look like
277 * unused parameters (modprobe will find them in /proc/cmdline).
278 */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700279static int __init unknown_bootoption(char *param, char *val,
280 const char *unused, void *arg)
Chris Metcalfa99cd112012-04-06 12:53:50 -0400281{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700282 repair_env_string(param, val, unused, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 /* Handle obsolete-style parameters */
285 if (obsolete_checksetup(param))
286 return 0;
287
Rusty Russellf066a4f2009-12-01 14:56:44 +1030288 /* Unused module parameter. */
289 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 if (panic_later)
293 return 0;
294
295 if (val) {
296 /* Environment option */
297 unsigned int i;
298 for (i = 0; envp_init[i]; i++) {
299 if (i == MAX_INIT_ENVS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800300 panic_later = "env";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 panic_param = param;
302 }
303 if (!strncmp(param, envp_init[i], val - param))
304 break;
305 }
306 envp_init[i] = param;
307 } else {
308 /* Command line option */
309 unsigned int i;
310 for (i = 0; argv_init[i]; i++) {
311 if (i == MAX_INIT_ARGS) {
Tetsuo Handa499a4582014-01-23 15:54:56 -0800312 panic_later = "init";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 panic_param = param;
314 }
315 }
316 argv_init[i] = param;
317 }
318 return 0;
319}
320
321static int __init init_setup(char *str)
322{
323 unsigned int i;
324
325 execute_command = str;
326 /*
327 * In case LILO is going to boot us with default command line,
328 * it prepends "auto" before the whole cmdline which makes
329 * the shell think it should execute a script with such name.
330 * So we ignore all arguments entered _before_ init=... [MJ]
331 */
332 for (i = 1; i < MAX_INIT_ARGS; i++)
333 argv_init[i] = NULL;
334 return 1;
335}
336__setup("init=", init_setup);
337
Olof Johanssonffdfc402005-09-06 15:17:19 -0700338static int __init rdinit_setup(char *str)
339{
340 unsigned int i;
341
342 ramdisk_execute_command = str;
343 /* See "auto" comment in init_setup */
344 for (i = 1; i < MAX_INIT_ARGS; i++)
345 argv_init[i] = NULL;
346 return 1;
347}
348__setup("rdinit=", rdinit_setup);
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350#ifndef CONFIG_SMP
Amerigo Wang34db18a02011-03-22 16:34:06 -0700351static const unsigned int setup_max_cpus = NR_CPUS;
Mike Travise0982e92008-03-26 14:23:48 -0700352static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353static inline void smp_prepare_cpus(unsigned int maxcpus) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354#endif
355
356/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800357 * We need to store the untouched command line for future reference.
358 * We also need to store the touched command line since the parameter
359 * parsing is performed in place, and we should allow a component to
360 * store reference of name/value for future reference.
361 */
362static void __init setup_command_line(char *command_line)
363{
Santosh Shilimkar098b0812014-01-21 15:50:21 -0800364 saved_command_line =
365 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
366 initcall_command_line =
367 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
368 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700369 strcpy(saved_command_line, boot_command_line);
370 strcpy(static_command_line, command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800371}
372
373/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 * We need to finalize in a non-__init function or else race conditions
375 * between the root thread and the init thread may cause start_kernel to
376 * be reaped by free_initmem before the root thread has proceeded to
377 * cpu_idle.
378 *
379 * gcc-3.4 accidentally inlines this function, so use noinline.
380 */
381
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200382static __initdata DECLARE_COMPLETION(kthreadd_done);
383
Fabian Frederickbd721ea2016-08-02 14:03:33 -0700384static noinline void __ref rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700386 int pid;
387
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700388 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200389 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200390 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200391 * the init task will end up wanting to create kthreads, which, if
392 * we schedule it before we create kthreadd, will OOPS.
393 */
Oleg Nesterov34a1b722014-06-04 16:12:19 -0700394 kernel_thread(kernel_init, NULL, CLONE_FS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700396 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800397 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700398 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800399 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200400 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200401
402 /*
403 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200404 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200405 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200406 init_idle_bootup_task(current);
Thomas Gleixnerbd2f5532011-03-21 12:33:18 +0100407 schedule_preempt_disabled();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800408 /* Call into cpu_idle with preempt disabled */
Thomas Gleixnera1a04ec2013-03-21 22:49:34 +0100409 cpu_startup_entry(CPUHP_ONLINE);
Ingo Molnar1df21052007-07-09 18:51:58 +0200410}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
412/* Check for early params. */
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700413static int __init do_early_param(char *param, char *val,
414 const char *unused, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600416 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 for (p = __setup_start; p < __setup_end; p++) {
Michal Schmidtb1e4d202011-10-10 00:03:37 +0200419 if ((p->early && parameq(param, p->str)) ||
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700420 (strcmp(param, "console") == 0 &&
421 strcmp(p->str, "earlycon") == 0)
422 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 if (p->setup_func(val) != 0)
Andrew Mortonea676e82013-04-29 16:18:20 -0700424 pr_warn("Malformed early option '%s'\n", param);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 }
426 }
427 /* We accept everything at this stage. */
428 return 0;
429}
430
Magnus Damm13977092009-03-30 14:37:25 -0700431void __init parse_early_options(char *cmdline)
432{
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700433 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
434 do_early_param);
Magnus Damm13977092009-03-30 14:37:25 -0700435}
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437/* Arch code calls this early on, or if not, just before other parsing. */
438void __init parse_early_param(void)
439{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700440 static int done __initdata;
441 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
443 if (done)
444 return;
445
446 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800447 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700448 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 done = 1;
450}
451
Thomas Gleixnere7ff3a42016-12-09 19:29:10 +0100452void __init __weak arch_post_acpi_subsys_init(void) { }
453
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000454void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700455{
456}
457
David Howellseded09c2012-11-02 13:20:42 +0000458# if THREAD_SIZE >= PAGE_SIZE
Linus Torvaldsb235bee2016-06-24 15:09:37 -0700459void __init __weak thread_stack_cache_init(void)
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000460{
461}
David Howellseded09c2012-11-02 13:20:42 +0000462#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000463
Pekka Enberg444f4782009-06-11 18:29:06 +0300464/*
465 * Set up kernel memory allocators
466 */
467static void __init mm_init(void)
468{
Joonsoo Kimeefa864b2014-12-12 16:55:46 -0800469 /*
470 * page_ext requires contiguous pages,
471 * bigger than MAX_ORDER unless SPARSEMEM.
472 */
473 page_ext_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300474 mem_init();
475 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200476 percpu_init_late();
Kirill A. Shutemovb35f1812014-01-21 15:49:07 -0800477 pgtable_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300478 vmalloc_init();
Toshi Kani0ddab1d2015-04-14 15:47:20 -0700479 ioremap_huge_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300480}
481
Andi Kleen722a9f92014-05-02 00:44:38 +0200482asmlinkage __visible void __init start_kernel(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700484 char *command_line;
485 char *after_dashes;
Andrew Morton033ab7f2006-06-30 01:55:50 -0700486
Aaron Tomlind4311ff2014-09-12 14:16:17 +0100487 set_task_stack_end_magic(&init_task);
Ming Lei73839c52011-11-17 13:34:31 +0800488 smp_setup_processor_id();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700489 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100490
491 /*
492 * Set up the the initial canary ASAP:
493 */
494 boot_init_stack_canary();
495
Paul Menageddbcc7e2007-10-18 23:39:30 -0700496 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700497
498 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100499 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501/*
502 * Interrupts are still disabled. Do necessary setups, then
503 * enable them
504 */
Stas Sergeev44fd2292006-03-23 02:59:44 -0800505 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 page_address_init();
Andrew Mortonea676e82013-04-29 16:18:20 -0700507 pr_notice("%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 setup_arch(&command_line);
Linus Torvalds6345d242011-05-29 11:32:28 -0700509 mm_init_cpumask(&init_mm);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800510 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700511 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900512 setup_per_cpu_areas();
Thomas Gleixnercff7d372016-02-26 18:43:28 +0000513 boot_cpu_state_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800514 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515
Jiang Liu9adb62a2012-07-31 16:43:28 -0700516 build_all_zonelists(NULL, NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300517 page_alloc_init();
518
Andrew Mortonea676e82013-04-29 16:18:20 -0700519 pr_notice("Kernel command line: %s\n", boot_command_line);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300520 parse_early_param();
Rusty Russell51e158c2014-04-28 11:34:33 +0930521 after_dashes = parse_args("Booting kernel",
522 static_command_line, __start___param,
523 __stop___param - __start___param,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700524 -1, -1, NULL, &unknown_bootoption);
Daniel Thompson3438cf52014-11-11 16:29:46 +1030525 if (!IS_ERR_OR_NULL(after_dashes))
Rusty Russell51e158c2014-04-28 11:34:33 +0930526 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700527 NULL, set_init_arg);
Jeremy Fitzhardinge97ce2c82011-10-12 16:17:54 -0700528
529 jump_label_init();
530
Pekka Enberg83b519e2009-06-10 19:40:04 +0300531 /*
532 * These use large bootmem allocations and must precede
533 * kmem_cache_init()
534 */
Mike Travis162a7e72011-05-24 17:13:20 -0700535 setup_log_buf(0);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300536 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300537 vfs_caches_init_early();
538 sort_main_extable();
539 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300540 mm_init();
KOSAKI Motohirode03c722011-05-24 17:12:15 -0700541
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 /*
543 * Set up the scheduler prior starting any interrupts (such as the
544 * timer interrupt). Full topology setup happens at smp_init()
545 * time - but meanwhile we still have a functioning scheduler.
546 */
547 sched_init();
548 /*
549 * Disable preemption - early bootup scheduling is extremely
550 * fragile until we cpu_idle() for the first time.
551 */
552 preempt_disable();
Fabian Frederickdd4d9fe2014-08-08 14:23:44 -0700553 if (WARN(!irqs_disabled(),
554 "Interrupts were enabled *very* early, fixing it\n"))
Ard van Breemenc4a68302007-01-05 16:36:19 -0800555 local_irq_disable();
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100556 idr_init_cache();
Tejun Heo3347fa02016-09-16 15:49:32 -0400557
558 /*
559 * Allow workqueue creation and work item queueing/cancelling
560 * early. Work item execution depends on kthreads and starts after
561 * workqueue_init().
562 */
563 workqueue_init_early();
564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 rcu_init();
Steven Rostedt (Red Hat)5f893b22014-12-12 20:05:10 -0500566
567 /* trace_printk() and trace points may be used after this */
568 trace_init();
569
Frederic Weisbecker65f382f2013-07-11 19:12:32 +0200570 context_tracking_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800571 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800572 /* init some links before init_ISA_irqs() */
573 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 init_IRQ();
Thomas Gleixnerad2b1352013-03-05 15:14:05 +0100575 tick_init();
Linus Torvaldsd6dd50e2014-10-13 15:44:12 +0200576 rcu_init_nohz();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800578 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700580 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700581 time_init();
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700582 sched_clock_postinit();
Petr Mladek42a0bb32016-05-20 17:00:33 -0700583 printk_nmi_init();
Stephane Eranian9e630202013-04-03 14:21:33 +0200584 perf_event_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700585 profile_init();
Takao Indohd8ad7d12011-03-29 12:35:04 -0400586 call_function_init();
Steven Rostedtf91eb622013-04-29 16:18:18 -0700587 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100588 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700589 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000590
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300591 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
593 /*
594 * HACK ALERT! This is early. We're enabling the console before
595 * we've done PCI setups etc, and console_init() must be aware of
596 * this. But we do want output early, in case something goes wrong.
597 */
598 console_init();
599 if (panic_later)
Tetsuo Handa499a4582014-01-23 15:54:56 -0800600 panic("Too many boot %s vars at `%s'", panic_later,
601 panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700602
603 lockdep_info();
604
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700605 /*
606 * Need to run this when irqs are enabled, because it wants
607 * to self-test [hard/soft]-irqs on/off lock inversion bugs
608 * too:
609 */
610 locking_selftest();
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612#ifdef CONFIG_BLK_DEV_INITRD
613 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700614 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Andrew Mortonea676e82013-04-29 16:18:20 -0700615 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700616 page_to_pfn(virt_to_page((void *)initrd_start)),
617 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 initrd_start = 0;
619 }
620#endif
Yang Shife53ca52016-05-27 14:27:30 -0700621 page_ext_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700622 debug_objects_mem_init();
Catalin Marinas9b090f22011-05-19 16:25:30 +0100623 kmemleak_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700624 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 numa_policy_init();
626 if (late_time_init)
627 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200628 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 calibrate_delay();
630 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 anon_vma_init();
Rafael J. Wysockic4e1acb2014-03-13 00:22:58 +0100632 acpi_early_init();
Linus Torvalds11520e52012-12-15 15:15:24 -0800633#ifdef CONFIG_X86
Matt Fleming83e68182012-11-14 09:42:35 +0000634 if (efi_enabled(EFI_RUNTIME_SERVICES))
Linus Torvalds11520e52012-12-15 15:15:24 -0800635 efi_enter_virtual_mode();
636#endif
H. Peter Anvin197725d2014-05-04 10:00:49 -0700637#ifdef CONFIG_X86_ESPFIX64
H. Peter Anvin3891a042014-04-29 16:46:09 -0700638 /* Should be run before the first non-init thread is created */
639 init_espfix_bsp();
640#endif
Linus Torvaldsb235bee2016-06-24 15:09:37 -0700641 thread_stack_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100642 cred_init();
Heinrich Schuchardtff691f62015-04-16 12:47:44 -0700643 fork_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 proc_caches_init();
645 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 key_init();
647 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500648 dbg_late_init();
Mel Gorman4248b0d2015-08-06 15:46:20 -0700649 vfs_caches_init();
Nicholas Piggin62906022016-12-25 13:00:30 +1000650 pagecache_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 signals_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 proc_root_init();
Al Viroe149ed22014-11-01 10:57:28 -0400653 nsfs_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 cpuset_init();
Zefan Li695df212015-03-04 17:09:33 +0800655 cgroup_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700656 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700657 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
659 check_bugs();
660
Rafael J. Wysockib064a8f2015-06-10 01:33:36 +0200661 acpi_subsystem_init();
Thomas Gleixnere7ff3a42016-12-09 19:29:10 +0100662 arch_post_acpi_subsys_init();
Feng Tang6ae69962009-08-14 15:13:46 -0400663 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
Matt Fleming83e68182012-11-14 09:42:35 +0000665 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
Josh Triplett2223af32012-09-28 17:57:05 -0700666 efi_late_init();
Josh Triplett78510792012-09-28 17:55:44 -0700667 efi_free_boot_services();
Josh Triplett2223af32012-09-28 17:57:05 -0700668 }
Josh Triplett78510792012-09-28 17:55:44 -0700669
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400670 ftrace_init();
671
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 /* Do the rest non-__init'ed, we're now alive */
673 rest_init();
674}
675
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700676/* Call all constructor functions linked into the kernel. */
677static void __init do_ctors(void)
678{
679#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800680 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700681
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800682 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
683 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700684#endif
685}
686
Rusty Russell2329abf2012-01-13 09:32:18 +1030687bool initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500688core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700690#ifdef CONFIG_KALLSYMS
691struct blacklist_entry {
692 struct list_head next;
693 char *buf;
694};
695
696static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
697
698static int __init initcall_blacklist(char *str)
699{
700 char *str_entry;
701 struct blacklist_entry *entry;
702
703 /* str argument is a comma-separated list of functions */
704 do {
705 str_entry = strsep(&str, ",");
706 if (str_entry) {
707 pr_debug("blacklisting initcall %s\n", str_entry);
708 entry = alloc_bootmem(sizeof(*entry));
709 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
710 strcpy(entry->buf, str_entry);
711 list_add(&entry->next, &blacklisted_initcalls);
712 }
713 } while (str_entry);
714
715 return 0;
716}
717
718static bool __init_or_module initcall_blacklisted(initcall_t fn)
719{
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700720 struct blacklist_entry *entry;
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700721 char fn_name[KSYM_SYMBOL_LEN];
Rasmus Villemoes0fd5ed82016-06-24 14:50:30 -0700722 unsigned long addr;
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700723
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700724 if (list_empty(&blacklisted_initcalls))
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700725 return false;
726
Rasmus Villemoes0fd5ed82016-06-24 14:50:30 -0700727 addr = (unsigned long) dereference_function_descriptor(fn);
728 sprint_symbol_no_offset(fn_name, addr);
Rasmus Villemoesc8cdd2b2016-05-20 17:04:27 -0700729
Prarit Bhargava841c06d2016-08-02 14:07:15 -0700730 /*
731 * fn will be "function_name [module_name]" where [module_name] is not
732 * displayed for built-in init functions. Strip off the [module_name].
733 */
734 strreplace(fn_name, ' ', '\0');
735
Geliang Tange6fd1fb2016-03-15 14:52:46 -0700736 list_for_each_entry(entry, &blacklisted_initcalls, next) {
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700737 if (!strcmp(fn_name, entry->buf)) {
738 pr_debug("initcall %s blacklisted\n", fn_name);
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700739 return true;
740 }
741 }
742
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700743 return false;
744}
745#else
746static int __init initcall_blacklist(char *str)
747{
748 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
749 return 0;
750}
751
752static bool __init_or_module initcall_blacklisted(initcall_t fn)
753{
754 return false;
755}
756#endif
757__setup("initcall_blacklist=", initcall_blacklist);
758
Kevin Winchestere4461272010-08-09 17:20:32 -0700759static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700760{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100761 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800762 unsigned long long duration;
763 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700764
Andrew Mortond62cf812014-06-04 16:12:16 -0700765 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
Kevin Winchester22c5c032010-08-09 17:20:32 -0700766 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800767 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700768 rettime = ktime_get();
769 delta = ktime_sub(rettime, calltime);
770 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Andrew Mortond62cf812014-06-04 16:12:16 -0700771 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
Andrew Mortonea676e82013-04-29 16:18:20 -0700772 fn, ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700773
Kevin Winchester22c5c032010-08-09 17:20:32 -0700774 return ret;
775}
776
Kevin Winchestere4461272010-08-09 17:20:32 -0700777int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700778{
779 int count = preempt_count();
780 int ret;
Steven Rostedtff1c8fa2013-07-03 15:05:37 -0700781 char msgbuf[64];
Kevin Winchester22c5c032010-08-09 17:20:32 -0700782
Prarit Bhargava7b0b73d2014-06-04 16:12:17 -0700783 if (initcall_blacklisted(fn))
784 return -EPERM;
785
Kevin Winchester22c5c032010-08-09 17:20:32 -0700786 if (initcall_debug)
787 ret = do_one_initcall_debug(fn);
788 else
789 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700790
791 msgbuf[0] = 0;
792
Linus Torvaldse0df1542008-05-15 18:14:01 -0700793 if (preempt_count() != count) {
Steven Rostedtbf5d7702013-05-01 13:35:51 -0400794 sprintf(msgbuf, "preemption imbalance ");
Peter Zijlstra4a2b4b22013-08-14 14:55:24 +0200795 preempt_count_set(count);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700796 }
797 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700798 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700799 local_irq_enable();
800 }
Steven Rostedtf91eb622013-04-29 16:18:18 -0700801 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
Arjan van de Ven59f94152008-07-30 12:49:02 -0700802
Emese Revfy38addce2016-06-20 20:41:19 +0200803 add_latent_entropy();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800804 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700805}
806
807
Pawel Moll026cee02012-03-26 12:50:51 +1030808extern initcall_t __initcall_start[];
809extern initcall_t __initcall0_start[];
810extern initcall_t __initcall1_start[];
811extern initcall_t __initcall2_start[];
812extern initcall_t __initcall3_start[];
813extern initcall_t __initcall4_start[];
814extern initcall_t __initcall5_start[];
815extern initcall_t __initcall6_start[];
816extern initcall_t __initcall7_start[];
817extern initcall_t __initcall_end[];
818
819static initcall_t *initcall_levels[] __initdata = {
820 __initcall0_start,
821 __initcall1_start,
822 __initcall2_start,
823 __initcall3_start,
824 __initcall4_start,
825 __initcall5_start,
826 __initcall6_start,
827 __initcall7_start,
828 __initcall_end,
829};
830
Jim Cromie96263d22012-06-14 16:00:59 -0600831/* Keep these in sync with initcalls in include/linux/init.h */
Pawel Moll026cee02012-03-26 12:50:51 +1030832static char *initcall_level_names[] __initdata = {
Jim Cromie9fb48c72012-04-27 14:30:34 -0600833 "early",
834 "core",
835 "postcore",
836 "arch",
837 "subsys",
838 "fs",
839 "device",
840 "late",
Pawel Moll026cee02012-03-26 12:50:51 +1030841};
842
Pawel Moll026cee02012-03-26 12:50:51 +1030843static void __init do_initcall_level(int level)
844{
Pawel Moll026cee02012-03-26 12:50:51 +1030845 initcall_t *fn;
846
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030847 strcpy(initcall_command_line, saved_command_line);
Pawel Moll026cee02012-03-26 12:50:51 +1030848 parse_args(initcall_level_names[level],
Krzysztof Mazur08746a62013-10-31 13:45:39 +1030849 initcall_command_line, __start___param,
Pawel Moll026cee02012-03-26 12:50:51 +1030850 __stop___param - __start___param,
851 level, level,
Luis R. Rodriguezecc86172015-03-30 16:20:03 -0700852 NULL, &repair_env_string);
Pawel Moll026cee02012-03-26 12:50:51 +1030853
854 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
855 do_one_initcall(*fn);
856}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857
858static void __init do_initcalls(void)
859{
Pawel Moll026cee02012-03-26 12:50:51 +1030860 int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
Borislav Petkov19efb722012-06-01 18:56:00 +0200862 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
Pawel Moll026cee02012-03-26 12:50:51 +1030863 do_initcall_level(level);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864}
865
866/*
867 * Ok, the machine is now initialized. None of the devices
868 * have been touched yet, but the CPU subsystem is up and
869 * running, and memory and process management works.
870 *
871 * Now we can finally start doing some real work..
872 */
873static void __init do_basic_setup(void)
874{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800875 cpuset_init_smp();
Hugh Dickins41ffe5d2011-08-03 16:21:21 -0700876 shmem_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800878 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700879 do_ctors();
Linus Torvaldsd5767c52011-09-28 10:23:44 -0700880 usermodehelper_enable();
wangyanqingb0f84372011-09-29 15:09:40 +0800881 do_initcalls();
Theodore Ts'o47d06e52013-09-10 10:52:35 -0400882 random_int_secret_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883}
884
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700885static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700886{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800887 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700888
Pawel Moll026cee02012-03-26 12:50:51 +1030889 for (fn = __initcall_start; fn < __initcall0_start; fn++)
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800890 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700891}
892
Tejun Heobb813f42013-01-18 14:05:56 -0800893/*
894 * This function requests modules which should be loaded by default and is
895 * called twice right after initrd is mounted and right before init is
896 * exec'd. If such modules are on either initrd or rootfs, they will be
897 * loaded before control is passed to userland.
898 */
899void __init load_default_modules(void)
900{
901 load_default_elevator_module();
902}
903
Al Viroa74fb732012-10-10 21:28:25 -0400904static int run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905{
906 argv_init[0] = init_filename;
Linus Torvaldsc4ad8f92014-02-05 12:54:53 -0800907 return do_execve(getname_kernel(init_filename),
Al Viroae903ca2012-12-14 12:44:11 -0500908 (const char __user *const __user *)argv_init,
909 (const char __user *const __user *)envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910}
911
Michael Opdenackerba247622013-11-12 15:10:21 -0800912static int try_to_run_init_process(const char *init_filename)
913{
914 int ret;
915
916 ret = run_init_process(init_filename);
917
918 if (ret && ret != -ENOENT) {
919 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
920 init_filename, ret);
921 }
922
923 return ret;
924}
925
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530926static noinline void __init kernel_init_freeable(void);
Al Virod6b21232012-10-10 19:57:26 -0400927
Arnd Bergmann4d217a52016-11-28 15:59:13 +0100928#if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
AKASHI Takahiro39290b32016-11-14 15:15:05 +0900929bool rodata_enabled __ro_after_init = true;
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800930static int __init set_debug_rodata(char *str)
931{
932 return strtobool(str, &rodata_enabled);
933}
934__setup("rodata=", set_debug_rodata);
AKASHI Takahiro39290b32016-11-14 15:15:05 +0900935#endif
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800936
AKASHI Takahiro39290b32016-11-14 15:15:05 +0900937#ifdef CONFIG_DEBUG_RODATA
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800938static void mark_readonly(void)
939{
940 if (rodata_enabled)
941 mark_rodata_ro();
942 else
943 pr_info("Kernel memory protection disabled.\n");
944}
945#else
946static inline void mark_readonly(void)
947{
948 pr_warn("This architecture does not have kernel memory protection.\n");
949}
950#endif
951
Al Virod6b21232012-10-10 19:57:26 -0400952static int __ref kernel_init(void *unused)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100953{
Michael Opdenackerba247622013-11-12 15:10:21 -0800954 int ret;
955
Al Virod6b21232012-10-10 19:57:26 -0400956 kernel_init_freeable();
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800957 /* need to finish all async __init code before freeing the memory */
958 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100959 free_initmem();
Kees Cookd2aa1ac2016-02-17 14:41:13 -0800960 mark_readonly();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100961 system_state = SYSTEM_RUNNING;
962 numa_default_policy();
963
Al Viro4a9d4b02012-06-24 09:56:45 +0400964 flush_delayed_fput();
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700965
Paul E. McKenney967dcb82015-11-25 16:52:36 -0800966 rcu_end_inkernel_boot();
967
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100968 if (ramdisk_execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800969 ret = run_init_process(ramdisk_execute_command);
970 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400971 return 0;
Michael Opdenackerba247622013-11-12 15:10:21 -0800972 pr_err("Failed to execute %s (error %d)\n",
973 ramdisk_execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100974 }
975
976 /*
977 * We try each of these until one succeeds.
978 *
979 * The Bourne shell can be used instead of init if we are
980 * trying to recover a really broken machine.
981 */
982 if (execute_command) {
Michael Opdenackerba247622013-11-12 15:10:21 -0800983 ret = run_init_process(execute_command);
984 if (!ret)
Al Viroa74fb732012-10-10 21:28:25 -0400985 return 0;
Andy Lutomirski6ef45362014-12-10 15:52:19 -0800986 panic("Requested init %s failed (error %d).",
987 execute_command, ret);
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100988 }
Michael Opdenackerba247622013-11-12 15:10:21 -0800989 if (!try_to_run_init_process("/sbin/init") ||
990 !try_to_run_init_process("/etc/init") ||
991 !try_to_run_init_process("/bin/init") ||
992 !try_to_run_init_process("/bin/sh"))
Al Viroa74fb732012-10-10 21:28:25 -0400993 return 0;
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100994
Michael Opdenackerba247622013-11-12 15:10:21 -0800995 panic("No working init found. Try passing init= option to kernel. "
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -0200996 "See Linux Documentation/admin-guide/init.rst for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100997}
998
Vineet Guptaf80b0c92012-12-21 12:25:44 +0530999static noinline void __init kernel_init_freeable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +02001001 /*
1002 * Wait until kthreadd is all set-up.
1003 */
1004 wait_for_completion(&kthreadd_done);
Linus Torvalds31a67102012-05-21 12:52:42 -07001005
1006 /* Now the scheduler is fully set up and can do blocking allocations */
1007 gfp_allowed_mask = __GFP_BITS_MASK;
1008
Miao Xie58568d22009-06-16 15:31:49 -07001009 /*
1010 * init can allocate pages on any node
1011 */
Lai Jiangshan3c466d42012-12-12 13:51:40 -08001012 set_mems_allowed(node_states[N_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 /*
1014 * init can run on any cpu.
1015 */
Rusty Russell1a2142a2009-03-30 22:05:10 -06001016 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
Cedric Le Goater9ec52092006-10-02 02:19:00 -07001018 cad_pid = task_pid(current);
1019
Andi Kleenca74a6f2008-01-30 13:33:17 +01001020 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Tejun Heo3347fa02016-09-16 15:49:32 -04001022 workqueue_init();
1023
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +01001025 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 smp_init();
1028 sched_init_smp();
1029
Mel Gorman0e1cc952015-06-30 14:57:27 -07001030 page_alloc_init_late();
1031
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 do_basic_setup();
1033
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001034 /* Open the /dev/console on the rootfs, this should never fail */
1035 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
Andrew Mortonea676e82013-04-29 16:18:20 -07001036 pr_err("Warning: unable to open an initial console.\n");
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -08001037
1038 (void) sys_dup(0);
1039 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 /*
1041 * check if there is an early userspace init. If yes, let it do all
1042 * the work
1043 */
Olof Johanssonffdfc402005-09-06 15:17:19 -07001044
1045 if (!ramdisk_execute_command)
1046 ramdisk_execute_command = "/init";
1047
1048 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1049 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -07001051 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052
1053 /*
1054 * Ok, we have completed the initial bootup, and
1055 * we're essentially up and running. Get rid of the
1056 * initmem segments and start the user-mode stuff..
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001057 *
1058 * rootfs is available now, try loading the public keys
1059 * and default modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 */
Tejun Heobb813f42013-01-18 14:05:56 -08001061
Dmitry Kasatkinc9cd2ce2014-11-05 17:01:15 +02001062 integrity_load_keys();
Tejun Heobb813f42013-01-18 14:05:56 -08001063 load_default_modules();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064}