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457c8996 1// SPDX-License-Identifier: GPL-2.0-only
1da177e4
LT
2/*
3 * linux/init/main.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * GK 2/5/95 - Changed to support mounting root fs via NFS
8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
dd4d9fec 10 * Simplified starting of init: Michael A. Griffith <[email protected]>
1da177e4
LT
11 */
12
ea676e84
AM
13#define DEBUG /* Enable initcall_debug */
14
1da177e4 15#include <linux/types.h>
8a293be0 16#include <linux/extable.h>
1da177e4
LT
17#include <linux/module.h>
18#include <linux/proc_fs.h>
5c2c5c55 19#include <linux/binfmts.h>
1da177e4
LT
20#include <linux/kernel.h>
21#include <linux/syscalls.h>
9b5609fd 22#include <linux/stackprotector.h>
1da177e4
LT
23#include <linux/string.h>
24#include <linux/ctype.h>
25#include <linux/delay.h>
1da177e4
LT
26#include <linux/ioport.h>
27#include <linux/init.h>
1da177e4 28#include <linux/initrd.h>
57c8a661 29#include <linux/memblock.h>
4a7a16dc 30#include <linux/acpi.h>
7684b858 31#include <linux/bootconfig.h>
0c688614 32#include <linux/console.h>
38b8d208 33#include <linux/nmi.h>
1da177e4
LT
34#include <linux/percpu.h>
35#include <linux/kmod.h>
db64fe02 36#include <linux/vmalloc.h>
1da177e4 37#include <linux/kernel_stat.h>
d7cd5611 38#include <linux/start_kernel.h>
1da177e4 39#include <linux/security.h>
3d442233 40#include <linux/smp.h>
1da177e4
LT
41#include <linux/profile.h>
42#include <linux/rcupdate.h>
43#include <linux/moduleparam.h>
44#include <linux/kallsyms.h>
45#include <linux/writeback.h>
46#include <linux/cpu.h>
47#include <linux/cpuset.h>
ddbcc7e8 48#include <linux/cgroup.h>
1da177e4 49#include <linux/efi.h>
906568c9 50#include <linux/tick.h>
78634061 51#include <linux/sched/isolation.h>
6168a702 52#include <linux/interrupt.h>
c757249a 53#include <linux/taskstats_kern.h>
ca74e92b 54#include <linux/delayacct.h>
1da177e4 55#include <linux/unistd.h>
3ea056c5 56#include <linux/utsname.h>
1da177e4
LT
57#include <linux/rmap.h>
58#include <linux/mempolicy.h>
59#include <linux/key.h>
b6cd0b77 60#include <linux/buffer_head.h>
eefa864b 61#include <linux/page_ext.h>
9a11b49a 62#include <linux/debug_locks.h>
3ac7fe5a 63#include <linux/debugobjects.h>
fbb9ce95 64#include <linux/lockdep.h>
3c7b4e6b 65#include <linux/kmemleak.h>
84d73786 66#include <linux/pid_namespace.h>
4c002c97 67#include <linux/device/driver.h>
73c27992 68#include <linux/kthread.h>
e6fe6649 69#include <linux/sched.h>
1777e463 70#include <linux/sched/init.h>
a1c9eea9 71#include <linux/signal.h>
199f0ca5 72#include <linux/idr.h>
0b4b3827 73#include <linux/kgdb.h>
68bf21aa 74#include <linux/ftrace.h>
22a9d645 75#include <linux/async.h>
6ae6996a 76#include <linux/sfi.h>
2b2af54a 77#include <linux/shmem_fs.h>
5a0e3ad6 78#include <linux/slab.h>
24a24bb6 79#include <linux/perf_event.h>
a74fb73c 80#include <linux/ptrace.h>
aa8c6248 81#include <linux/pti.h>
bb813f4c
TH
82#include <linux/blkdev.h>
83#include <linux/elevator.h>
5d2a4e91 84#include <linux/sched/clock.h>
29930025 85#include <linux/sched/task.h>
68db0cf1 86#include <linux/sched/task_stack.h>
65f382fd 87#include <linux/context_tracking.h>
47d06e53 88#include <linux/random.h>
7b0b73d7 89#include <linux/list.h>
c9cd2ce2 90#include <linux/integrity.h>
e149ed2b 91#include <linux/proc_ns.h>
0ddab1d2 92#include <linux/io.h>
39290b38 93#include <linux/cache.h>
2959a5f7 94#include <linux/rodata_test.h>
33352244 95#include <linux/jump_label.h>
ae67d58d 96#include <linux/mem_encrypt.h>
1da177e4
LT
97
98#include <asm/io.h>
99#include <asm/bugs.h>
100#include <asm/setup.h>
a940199f 101#include <asm/sections.h>
37b73c82 102#include <asm/cacheflush.h>
1da177e4 103
4ee7c60d
SRV
104#define CREATE_TRACE_POINTS
105#include <trace/events/initcall.h>
106
aae5f662 107static int kernel_init(void *);
1da177e4
LT
108
109extern void init_IRQ(void);
1da177e4 110extern void radix_tree_init(void);
1da177e4 111
2ce802f6
TH
112/*
113 * Debug helper: via this flag we know that we are in 'early bootup code'
114 * where only the boot processor is running with IRQ disabled. This means
115 * two things - IRQ must not be enabled before the flag is cleared and some
116 * operations which are not allowed with IRQ disabled are allowed while the
117 * flag is set.
118 */
119bool early_boot_irqs_disabled __read_mostly;
120
a6826048 121enum system_states system_state __read_mostly;
1da177e4
LT
122EXPORT_SYMBOL(system_state);
123
124/*
125 * Boot command-line arguments
126 */
127#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
128#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
129
130extern void time_init(void);
131/* Default late time init is NULL. archs can override this later. */
d2e3192b 132void (*__initdata late_time_init)(void);
1da177e4 133
30d7e0d4
ABL
134/* Untouched command line saved by arch-specific code. */
135char __initdata boot_command_line[COMMAND_LINE_SIZE];
136/* Untouched saved command line (eg. for /proc) */
137char *saved_command_line;
138/* Command line for parameter parsing */
139static char *static_command_line;
51887d03
MH
140/* Untouched extra command line */
141static char *extra_command_line;
13199162
MH
142/* Extra init arguments */
143static char *extra_init_args;
1da177e4 144
f61872bb
SRV
145#ifdef CONFIG_BOOT_CONFIG
146/* Is bootconfig on command line? */
147static bool bootconfig_found;
148static bool initargs_found;
149#else
150# define bootconfig_found false
151# define initargs_found false
152#endif
153
1da177e4 154static char *execute_command;
ffdfc409 155static char *ramdisk_execute_command;
1da177e4 156
c4b2c0c5
HFS
157/*
158 * Used to generate warnings if static_key manipulation functions are used
159 * before jump_label_init is called.
160 */
dd4d9fec 161bool static_key_initialized __read_mostly;
c4b2c0c5
HFS
162EXPORT_SYMBOL_GPL(static_key_initialized);
163
8b3b2955
JB
164/*
165 * If set, this is an indication to the drivers that reset the underlying
166 * device before going ahead with the initialization otherwise driver might
167 * rely on the BIOS and skip the reset operation.
168 *
169 * This is useful if kernel is booting in an unreliable environment.
fc454fdc 170 * For ex. kdump situation where previous kernel has crashed, BIOS has been
8b3b2955
JB
171 * skipped and devices will be in unknown state.
172 */
173unsigned int reset_devices;
174EXPORT_SYMBOL(reset_devices);
1da177e4 175
7e96287d
VG
176static int __init set_reset_devices(char *str)
177{
178 reset_devices = 1;
179 return 1;
180}
181
182__setup("reset_devices", set_reset_devices);
183
dd4d9fec
FF
184static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
185const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
1da177e4
LT
186static const char *panic_later, *panic_param;
187
914dcaa8 188extern const struct obs_kernel_param __setup_start[], __setup_end[];
1da177e4 189
31c025b5 190static bool __init obsolete_checksetup(char *line)
1da177e4 191{
914dcaa8 192 const struct obs_kernel_param *p;
31c025b5 193 bool had_early_param = false;
1da177e4
LT
194
195 p = __setup_start;
196 do {
197 int n = strlen(p->str);
b1e4d20c 198 if (parameqn(line, p->str, n)) {
1da177e4 199 if (p->early) {
33df0d19
RR
200 /* Already done in parse_early_param?
201 * (Needs exact match on param part).
202 * Keep iterating, as we can have early
203 * params and __setups of same names 8( */
1da177e4 204 if (line[n] == '\0' || line[n] == '=')
31c025b5 205 had_early_param = true;
1da177e4 206 } else if (!p->setup_func) {
ea676e84
AM
207 pr_warn("Parameter %s is obsolete, ignored\n",
208 p->str);
31c025b5 209 return true;
1da177e4 210 } else if (p->setup_func(line + n))
31c025b5 211 return true;
1da177e4
LT
212 }
213 p++;
214 } while (p < __setup_end);
33df0d19
RR
215
216 return had_early_param;
1da177e4
LT
217}
218
219/*
220 * This should be approx 2 Bo*oMips to start (note initial shift), and will
221 * still work even if initially too large, it will just take slightly longer
222 */
223unsigned long loops_per_jiffy = (1<<12);
1da177e4
LT
224EXPORT_SYMBOL(loops_per_jiffy);
225
226static int __init debug_kernel(char *str)
227{
a8fe19eb 228 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
f6f21c81 229 return 0;
1da177e4
LT
230}
231
232static int __init quiet_kernel(char *str)
233{
a8fe19eb 234 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
f6f21c81 235 return 0;
1da177e4
LT
236}
237
f6f21c81
YL
238early_param("debug", debug_kernel);
239early_param("quiet", quiet_kernel);
1da177e4
LT
240
241static int __init loglevel(char *str)
242{
808bf29b
AS
243 int newlevel;
244
245 /*
246 * Only update loglevel value when a correct setting was passed,
247 * to prevent blind crashes (when loglevel being set to 0) that
248 * are quite hard to debug
249 */
250 if (get_option(&str, &newlevel)) {
251 console_loglevel = newlevel;
252 return 0;
253 }
254
255 return -EINVAL;
1da177e4
LT
256}
257
f6f21c81 258early_param("loglevel", loglevel);
1da177e4 259
7684b858 260#ifdef CONFIG_BOOT_CONFIG
51887d03
MH
261
262char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
263
264#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
265
266static int __init xbc_snprint_cmdline(char *buf, size_t size,
267 struct xbc_node *root)
268{
269 struct xbc_node *knode, *vnode;
270 char *end = buf + size;
51887d03
MH
271 const char *val;
272 int ret;
273
274 xbc_node_for_each_key_value(root, knode, val) {
275 ret = xbc_node_compose_key_after(root, knode,
276 xbc_namebuf, XBC_KEYLEN_MAX);
277 if (ret < 0)
278 return ret;
279
280 vnode = xbc_node_get_child(knode);
88b91371
MH
281 if (!vnode) {
282 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
283 if (ret < 0)
284 return ret;
285 buf += ret;
51887d03 286 continue;
88b91371 287 }
51887d03 288 xbc_array_for_each_value(vnode, val) {
88b91371
MH
289 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
290 xbc_namebuf, val);
51887d03
MH
291 if (ret < 0)
292 return ret;
293 buf += ret;
51887d03 294 }
51887d03
MH
295 }
296
297 return buf - (end - size);
298}
299#undef rest
300
301/* Make an extra command line under given key word */
302static char * __init xbc_make_cmdline(const char *key)
303{
304 struct xbc_node *root;
305 char *new_cmdline;
306 int ret, len = 0;
307
308 root = xbc_find_node(key);
309 if (!root)
310 return NULL;
311
312 /* Count required buffer size */
313 len = xbc_snprint_cmdline(NULL, 0, root);
314 if (len <= 0)
315 return NULL;
316
317 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
318 if (!new_cmdline) {
319 pr_err("Failed to allocate memory for extra kernel cmdline.\n");
320 return NULL;
321 }
322
323 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
324 if (ret < 0 || ret > len) {
325 pr_err("Failed to print extra kernel cmdline.\n");
326 return NULL;
327 }
328
329 return new_cmdline;
330}
331
08d9e686 332static u32 boot_config_checksum(unsigned char *p, u32 size)
7684b858
MH
333{
334 u32 ret = 0;
335
336 while (size--)
337 ret += *p++;
338
339 return ret;
340}
341
f61872bb
SRV
342static int __init bootconfig_params(char *param, char *val,
343 const char *unused, void *arg)
344{
345 if (strcmp(param, "bootconfig") == 0) {
346 bootconfig_found = true;
347 } else if (strcmp(param, "--") == 0) {
348 initargs_found = true;
349 }
350 return 0;
351}
352
7495e092 353static void __init setup_boot_config(const char *cmdline)
7684b858 354{
f61872bb 355 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
7684b858
MH
356 u32 size, csum;
357 char *data, *copy;
358 u32 *hdr;
a0057403 359 int ret;
7684b858 360
f61872bb
SRV
361 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
362 parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
363 bootconfig_params);
364
365 if (!bootconfig_found)
7684b858
MH
366 return;
367
7495e092
SRV
368 if (!initrd_end)
369 goto not_found;
370
85c46b78
MH
371 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
372 if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
373 goto not_found;
374
375 hdr = (u32 *)(data - 8);
7684b858
MH
376 size = hdr[0];
377 csum = hdr[1];
378
7495e092
SRV
379 if (size >= XBC_DATA_MAX) {
380 pr_err("bootconfig size %d greater than max size %d\n",
381 size, XBC_DATA_MAX);
7684b858 382 return;
7495e092 383 }
7684b858
MH
384
385 data = ((void *)hdr) - size;
386 if ((unsigned long)data < initrd_start)
7495e092 387 goto not_found;
7684b858 388
7495e092
SRV
389 if (boot_config_checksum((unsigned char *)data, size) != csum) {
390 pr_err("bootconfig checksum failed\n");
7684b858 391 return;
7495e092 392 }
7684b858
MH
393
394 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
395 if (!copy) {
e241d14a 396 pr_err("Failed to allocate memory for bootconfig\n");
7684b858
MH
397 return;
398 }
399
400 memcpy(copy, data, size);
401 copy[size] = '\0';
402
a0057403
MH
403 ret = xbc_init(copy);
404 if (ret < 0)
e241d14a 405 pr_err("Failed to parse bootconfig\n");
51887d03 406 else {
a0057403 407 pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
51887d03
MH
408 /* keys starting with "kernel." are passed via cmdline */
409 extra_command_line = xbc_make_cmdline("kernel");
13199162
MH
410 /* Also, "init." keys are init arguments */
411 extra_init_args = xbc_make_cmdline("init");
51887d03 412 }
7495e092
SRV
413 return;
414not_found:
415 pr_err("'bootconfig' found on command line, but no bootconfig found\n");
7684b858
MH
416}
417#else
7495e092 418#define setup_boot_config(cmdline) do { } while (0)
d8a953dd
MH
419
420static int __init warn_bootconfig(char *str)
421{
422 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOTCONFIG is not set.\n");
423 return 0;
424}
425early_param("bootconfig", warn_bootconfig);
426
7684b858
MH
427#endif
428
a99cd112 429/* Change NUL term back to "=", to make "param" the whole string. */
7e2762e1 430static void __init repair_env_string(char *param, char *val)
1da177e4 431{
1da177e4
LT
432 if (val) {
433 /* param=val or param="val"? */
434 if (val == param+strlen(param)+1)
435 val[-1] = '=';
436 else if (val == param+strlen(param)+2) {
437 val[-2] = '=';
438 memmove(val-1, val, strlen(val)+1);
1da177e4
LT
439 } else
440 BUG();
441 }
a99cd112
CM
442}
443
51e158c1 444/* Anything after -- gets handed straight to init. */
ecc86170
LR
445static int __init set_init_arg(char *param, char *val,
446 const char *unused, void *arg)
51e158c1
RR
447{
448 unsigned int i;
449
450 if (panic_later)
451 return 0;
452
7e2762e1 453 repair_env_string(param, val);
51e158c1
RR
454
455 for (i = 0; argv_init[i]; i++) {
456 if (i == MAX_INIT_ARGS) {
457 panic_later = "init";
458 panic_param = param;
459 return 0;
460 }
461 }
462 argv_init[i] = param;
463 return 0;
464}
465
a99cd112
CM
466/*
467 * Unknown boot options get handed to init, unless they look like
468 * unused parameters (modprobe will find them in /proc/cmdline).
469 */
ecc86170
LR
470static int __init unknown_bootoption(char *param, char *val,
471 const char *unused, void *arg)
a99cd112 472{
283900e8
AS
473 size_t len = strlen(param);
474
7e2762e1 475 repair_env_string(param, val);
1da177e4
LT
476
477 /* Handle obsolete-style parameters */
478 if (obsolete_checksetup(param))
479 return 0;
480
f066a4f6 481 /* Unused module parameter. */
283900e8 482 if (strnchr(param, len, '.'))
1da177e4 483 return 0;
1da177e4
LT
484
485 if (panic_later)
486 return 0;
487
488 if (val) {
489 /* Environment option */
490 unsigned int i;
491 for (i = 0; envp_init[i]; i++) {
492 if (i == MAX_INIT_ENVS) {
499a4584 493 panic_later = "env";
1da177e4
LT
494 panic_param = param;
495 }
283900e8 496 if (!strncmp(param, envp_init[i], len+1))
1da177e4
LT
497 break;
498 }
499 envp_init[i] = param;
500 } else {
501 /* Command line option */
502 unsigned int i;
503 for (i = 0; argv_init[i]; i++) {
504 if (i == MAX_INIT_ARGS) {
499a4584 505 panic_later = "init";
1da177e4
LT
506 panic_param = param;
507 }
508 }
509 argv_init[i] = param;
510 }
511 return 0;
512}
513
514static int __init init_setup(char *str)
515{
516 unsigned int i;
517
518 execute_command = str;
519 /*
520 * In case LILO is going to boot us with default command line,
521 * it prepends "auto" before the whole cmdline which makes
522 * the shell think it should execute a script with such name.
523 * So we ignore all arguments entered _before_ init=... [MJ]
524 */
525 for (i = 1; i < MAX_INIT_ARGS; i++)
526 argv_init[i] = NULL;
527 return 1;
528}
529__setup("init=", init_setup);
530
ffdfc409
OJ
531static int __init rdinit_setup(char *str)
532{
533 unsigned int i;
534
535 ramdisk_execute_command = str;
536 /* See "auto" comment in init_setup */
537 for (i = 1; i < MAX_INIT_ARGS; i++)
538 argv_init[i] = NULL;
539 return 1;
540}
541__setup("rdinit=", rdinit_setup);
542
1da177e4 543#ifndef CONFIG_SMP
34db18a0 544static const unsigned int setup_max_cpus = NR_CPUS;
e0982e90 545static inline void setup_nr_cpu_ids(void) { }
1da177e4 546static inline void smp_prepare_cpus(unsigned int maxcpus) { }
1da177e4
LT
547#endif
548
30d7e0d4
ABL
549/*
550 * We need to store the untouched command line for future reference.
551 * We also need to store the touched command line since the parameter
552 * parsing is performed in place, and we should allow a component to
553 * store reference of name/value for future reference.
554 */
555static void __init setup_command_line(char *command_line)
556{
13199162 557 size_t len, xlen = 0, ilen = 0;
f5c7310a 558
51887d03
MH
559 if (extra_command_line)
560 xlen = strlen(extra_command_line);
13199162
MH
561 if (extra_init_args)
562 ilen = strlen(extra_init_args) + 4; /* for " -- " */
f5c7310a 563
51887d03 564 len = xlen + strlen(boot_command_line) + 1;
f5c7310a 565
13199162 566 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
f5c7310a 567 if (!saved_command_line)
13199162 568 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
f5c7310a
MR
569
570 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
571 if (!static_command_line)
572 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
573
51887d03
MH
574 if (xlen) {
575 /*
576 * We have to put extra_command_line before boot command
577 * lines because there could be dashes (separator of init
578 * command line) in the command lines.
579 */
580 strcpy(saved_command_line, extra_command_line);
581 strcpy(static_command_line, extra_command_line);
582 }
583 strcpy(saved_command_line + xlen, boot_command_line);
584 strcpy(static_command_line + xlen, command_line);
13199162
MH
585
586 if (ilen) {
587 /*
588 * Append supplemental init boot args to saved_command_line
589 * so that user can check what command line options passed
590 * to init.
591 */
592 len = strlen(saved_command_line);
f61872bb
SRV
593 if (initargs_found) {
594 saved_command_line[len++] = ' ';
595 } else {
13199162
MH
596 strcpy(saved_command_line + len, " -- ");
597 len += 4;
f61872bb 598 }
13199162
MH
599
600 strcpy(saved_command_line + len, extra_init_args);
601 }
30d7e0d4
ABL
602}
603
1da177e4
LT
604/*
605 * We need to finalize in a non-__init function or else race conditions
606 * between the root thread and the init thread may cause start_kernel to
607 * be reaped by free_initmem before the root thread has proceeded to
608 * cpu_idle.
609 *
610 * gcc-3.4 accidentally inlines this function, so use noinline.
611 */
612
b433c3d4
PZ
613static __initdata DECLARE_COMPLETION(kthreadd_done);
614
53c99bd6 615noinline void __ref rest_init(void)
1da177e4 616{
8fb12156 617 struct task_struct *tsk;
73c27992
EB
618 int pid;
619
7db905e6 620 rcu_scheduler_starting();
b433c3d4 621 /*
97158569 622 * We need to spawn init first so that it obtains pid 1, however
b433c3d4
PZ
623 * the init task will end up wanting to create kthreads, which, if
624 * we schedule it before we create kthreadd, will OOPS.
625 */
8fb12156
TG
626 pid = kernel_thread(kernel_init, NULL, CLONE_FS);
627 /*
628 * Pin init on the boot CPU. Task migration is not properly working
629 * until sched_init_smp() has been run. It will set the allowed
630 * CPUs for init to the non isolated CPUs.
631 */
632 rcu_read_lock();
633 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
634 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
635 rcu_read_unlock();
636
1da177e4 637 numa_default_policy();
73c27992 638 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
d11c563d 639 rcu_read_lock();
5cd20455 640 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
d11c563d 641 rcu_read_unlock();
1c3c5eab
TG
642
643 /*
644 * Enable might_sleep() and smp_processor_id() checks.
c1a280b6 645 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
1c3c5eab
TG
646 * kernel_thread() would trigger might_sleep() splats. With
647 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
648 * already, but it's stuck on the kthreadd_done completion.
649 */
650 system_state = SYSTEM_SCHEDULING;
651
b433c3d4 652 complete(&kthreadd_done);
f340c0d1
IM
653
654 /*
655 * The boot idle thread must execute schedule()
1df21055 656 * at least once to get things moving:
f340c0d1 657 */
bd2f5536 658 schedule_preempt_disabled();
5bfb5d69 659 /* Call into cpu_idle with preempt disabled */
a1a04ec3 660 cpu_startup_entry(CPUHP_ONLINE);
1df21055 661}
1da177e4
LT
662
663/* Check for early params. */
ecc86170
LR
664static int __init do_early_param(char *param, char *val,
665 const char *unused, void *arg)
1da177e4 666{
914dcaa8 667 const struct obs_kernel_param *p;
1da177e4
LT
668
669 for (p = __setup_start; p < __setup_end; p++) {
b1e4d20c 670 if ((p->early && parameq(param, p->str)) ||
18a8bd94
YL
671 (strcmp(param, "console") == 0 &&
672 strcmp(p->str, "earlycon") == 0)
673 ) {
1da177e4 674 if (p->setup_func(val) != 0)
ea676e84 675 pr_warn("Malformed early option '%s'\n", param);
1da177e4
LT
676 }
677 }
678 /* We accept everything at this stage. */
679 return 0;
680}
681
13977091
MD
682void __init parse_early_options(char *cmdline)
683{
ecc86170
LR
684 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
685 do_early_param);
13977091
MD
686}
687
1da177e4
LT
688/* Arch code calls this early on, or if not, just before other parsing. */
689void __init parse_early_param(void)
690{
dd4d9fec
FF
691 static int done __initdata;
692 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
1da177e4
LT
693
694 if (done)
695 return;
696
697 /* All fall through to do_early_param. */
30d7e0d4 698 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
13977091 699 parse_early_options(tmp_cmdline);
1da177e4
LT
700 done = 1;
701}
702
e7ff3a47
TG
703void __init __weak arch_post_acpi_subsys_init(void) { }
704
839ad62e 705void __init __weak smp_setup_processor_id(void)
033ab7f8
AM
706{
707}
708
eded09cc 709# if THREAD_SIZE >= PAGE_SIZE
b235beea 710void __init __weak thread_stack_cache_init(void)
8c9843e5
BH
711{
712}
eded09cc 713#endif
8c9843e5 714
c7753208
TL
715void __init __weak mem_encrypt_init(void) { }
716
4fc19708
NA
717void __init __weak poking_init(void) { }
718
782de70c 719void __init __weak pgtable_cache_init(void) { }
caa84136 720
4e37958d
SRV
721bool initcall_debug;
722core_param(initcall_debug, initcall_debug, bool, 0644);
b0dc52f1
SRV
723
724#ifdef TRACEPOINTS_ENABLED
4e37958d 725static void __init initcall_debug_enable(void);
b0dc52f1
SRV
726#else
727static inline void initcall_debug_enable(void)
728{
729}
730#endif
4e37958d 731
23a5c8cb
AP
732/* Report memory auto-initialization states for this boot. */
733static void __init report_meminit(void)
734{
735 const char *stack;
736
737 if (IS_ENABLED(CONFIG_INIT_STACK_ALL))
738 stack = "all";
739 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
740 stack = "byref_all";
741 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
742 stack = "byref";
743 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
744 stack = "__user";
745 else
746 stack = "off";
747
748 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
749 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
750 want_init_on_free() ? "on" : "off");
751 if (want_init_on_free())
752 pr_info("mem auto-init: clearing system memory may take some time...\n");
753}
754
444f478f
PE
755/*
756 * Set up kernel memory allocators
757 */
758static void __init mm_init(void)
759{
eefa864b
JK
760 /*
761 * page_ext requires contiguous pages,
762 * bigger than MAX_ORDER unless SPARSEMEM.
763 */
764 page_ext_init_flatmem();
8e57f8ac 765 init_debug_pagealloc();
23a5c8cb 766 report_meminit();
444f478f
PE
767 mem_init();
768 kmem_cache_init();
c5665868 769 kmemleak_init();
b35f1819 770 pgtable_init();
a9ee3a63 771 debug_objects_mem_init();
444f478f 772 vmalloc_init();
0ddab1d2 773 ioremap_huge_init();
613e396b
TG
774 /* Should be run before the first non-init thread is created */
775 init_espfix_bsp();
aa8c6248
TG
776 /* Should be run after espfix64 is set up. */
777 pti_init();
444f478f
PE
778}
779
53c99bd6
MS
780void __init __weak arch_call_rest_init(void)
781{
782 rest_init();
783}
784
722a9f92 785asmlinkage __visible void __init start_kernel(void)
1da177e4 786{
dd4d9fec
FF
787 char *command_line;
788 char *after_dashes;
033ab7f8 789
d4311ff1 790 set_task_stack_end_magic(&init_task);
73839c5b 791 smp_setup_processor_id();
3ac7fe5a 792 debug_objects_early_init();
42059429 793
ddbcc7e8 794 cgroup_init_early();
fbb9ce95
IM
795
796 local_irq_disable();
2ce802f6 797 early_boot_irqs_disabled = true;
fbb9ce95 798
1b3b3b49
VK
799 /*
800 * Interrupts are still disabled. Do necessary setups, then
801 * enable them.
802 */
44fd2299 803 boot_cpu_init();
1da177e4 804 page_address_init();
ea676e84 805 pr_notice("%s", linux_banner);
e6b1db98 806 early_security_init();
1da177e4 807 setup_arch(&command_line);
7495e092 808 setup_boot_config(command_line);
30d7e0d4 809 setup_command_line(command_line);
e0982e90 810 setup_nr_cpu_ids();
d6647bdf 811 setup_per_cpu_areas();
44fd2299 812 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
b5b1404d 813 boot_cpu_hotplug_init();
1da177e4 814
72675e13 815 build_all_zonelists(NULL);
83b519e8
PE
816 page_alloc_init();
817
51887d03 818 pr_notice("Kernel command line: %s\n", saved_command_line);
6041186a
DW
819 /* parameters may set static keys */
820 jump_label_init();
83b519e8 821 parse_early_param();
51e158c1
RR
822 after_dashes = parse_args("Booting kernel",
823 static_command_line, __start___param,
824 __stop___param - __start___param,
ecc86170 825 -1, -1, NULL, &unknown_bootoption);
3438cf54 826 if (!IS_ERR_OR_NULL(after_dashes))
51e158c1 827 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
ecc86170 828 NULL, set_init_arg);
13199162
MH
829 if (extra_init_args)
830 parse_args("Setting extra init args", extra_init_args,
831 NULL, 0, -1, -1, NULL, set_init_arg);
97ce2c88 832
83b519e8
PE
833 /*
834 * These use large bootmem allocations and must precede
835 * kmem_cache_init()
836 */
162a7e75 837 setup_log_buf(0);
83b519e8
PE
838 vfs_caches_init_early();
839 sort_main_extable();
840 trap_init();
444f478f 841 mm_init();
de03c72c 842
f631718d
SRV
843 ftrace_init();
844
e725c731
SRV
845 /* trace_printk can be enabled here */
846 early_trace_init();
847
1da177e4
LT
848 /*
849 * Set up the scheduler prior starting any interrupts (such as the
850 * timer interrupt). Full topology setup happens at smp_init()
851 * time - but meanwhile we still have a functioning scheduler.
852 */
853 sched_init();
854 /*
855 * Disable preemption - early bootup scheduling is extremely
856 * fragile until we cpu_idle() for the first time.
857 */
858 preempt_disable();
dd4d9fec
FF
859 if (WARN(!irqs_disabled(),
860 "Interrupts were enabled *very* early, fixing it\n"))
c4a68306 861 local_irq_disable();
0a835c4f 862 radix_tree_init();
3347fa09 863
7d229c66
TS
864 /*
865 * Set up housekeeping before setting up workqueues to allow the unbound
866 * workqueue to take non-housekeeping into account.
867 */
868 housekeeping_init();
869
3347fa09
TH
870 /*
871 * Allow workqueue creation and work item queueing/cancelling
872 * early. Work item execution depends on kthreads and starts after
873 * workqueue_init().
874 */
875 workqueue_init_early();
876
1da177e4 877 rcu_init();
5f893b26 878
e725c731 879 /* Trace events are available after this */
5f893b26
SRRH
880 trace_init();
881
4e37958d
SRV
882 if (initcall_debug)
883 initcall_debug_enable();
884
65f382fd 885 context_tracking_init();
0b8f1efa
YL
886 /* init some links before init_ISA_irqs() */
887 early_irq_init();
1da177e4 888 init_IRQ();
ad2b1353 889 tick_init();
d6dd50e0 890 rcu_init_nohz();
1da177e4 891 init_timers();
c0a31329 892 hrtimers_init();
1da177e4 893 softirq_init();
ad596171 894 timekeeping_init();
d5553523
KC
895
896 /*
897 * For best initial stack canary entropy, prepare it after:
898 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
899 * - timekeeping_init() for ktime entropy used in rand_initialize()
900 * - rand_initialize() to get any arch-specific entropy like RDRAND
901 * - add_latent_entropy() to get any latent entropy
902 * - adding command line entropy
903 */
904 rand_initialize();
905 add_latent_entropy();
906 add_device_randomness(command_line, strlen(command_line));
907 boot_init_stack_canary();
908
88fecaa2 909 time_init();
f92bac3b 910 printk_safe_init();
9e630205 911 perf_event_init();
93e02814 912 profile_init();
d8ad7d11 913 call_function_init();
f91eb62f 914 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
c3bc8fd6 915
2ce802f6 916 early_boot_irqs_disabled = false;
93e02814 917 local_irq_enable();
dcce284a 918
7e85ee0c 919 kmem_cache_init_late();
1da177e4
LT
920
921 /*
922 * HACK ALERT! This is early. We're enabling the console before
923 * we've done PCI setups etc, and console_init() must be aware of
924 * this. But we do want output early, in case something goes wrong.
925 */
926 console_init();
927 if (panic_later)
499a4584
TH
928 panic("Too many boot %s vars at `%s'", panic_later,
929 panic_param);
fbb9ce95 930
c3bc8fd6 931 lockdep_init();
fbb9ce95 932
9a11b49a
IM
933 /*
934 * Need to run this when irqs are enabled, because it wants
935 * to self-test [hard/soft]-irqs on/off lock inversion bugs
936 * too:
937 */
938 locking_selftest();
939
c7753208
TL
940 /*
941 * This needs to be called before any devices perform DMA
942 * operations that might use the SWIOTLB bounce buffers. It will
943 * mark the bounce buffers as decrypted so that their usage will
944 * not cause "plain-text" data to be decrypted when accessed.
945 */
946 mem_encrypt_init();
947
1da177e4
LT
948#ifdef CONFIG_BLK_DEV_INITRD
949 if (initrd_start && !initrd_below_start_ok &&
bd673c7c 950 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
ea676e84 951 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
bd673c7c
GU
952 page_to_pfn(virt_to_page((void *)initrd_start)),
953 min_low_pfn);
1da177e4
LT
954 initrd_start = 0;
955 }
956#endif
e7c8d5c9 957 setup_per_cpu_pageset();
1da177e4 958 numa_policy_init();
9c71206d 959 acpi_early_init();
1da177e4
LT
960 if (late_time_init)
961 late_time_init();
857baa87 962 sched_clock_init();
1da177e4 963 calibrate_delay();
95846ecf 964 pid_idr_init();
1da177e4 965 anon_vma_init();
11520e5e 966#ifdef CONFIG_X86
83e68189 967 if (efi_enabled(EFI_RUNTIME_SERVICES))
11520e5e
LT
968 efi_enter_virtual_mode();
969#endif
b235beea 970 thread_stack_cache_init();
d84f4f99 971 cred_init();
ff691f6e 972 fork_init();
1da177e4 973 proc_caches_init();
3ea056c5 974 uts_ns_init();
1da177e4 975 buffer_init();
1da177e4
LT
976 key_init();
977 security_init();
0b4b3827 978 dbg_late_init();
4248b0da 979 vfs_caches_init();
62906027 980 pagecache_init();
1da177e4 981 signals_init();
09652320 982 seq_file_init();
1da177e4 983 proc_root_init();
e149ed2b 984 nsfs_init();
1da177e4 985 cpuset_init();
695df213 986 cgroup_init();
c757249a 987 taskstats_init_early();
ca74e92b 988 delayacct_init();
1da177e4 989
4fc19708 990 poking_init();
1da177e4
LT
991 check_bugs();
992
b064a8fa 993 acpi_subsystem_init();
e7ff3a47 994 arch_post_acpi_subsys_init();
6ae6996a 995 sfi_init_late();
1da177e4
LT
996
997 /* Do the rest non-__init'ed, we're now alive */
53c99bd6 998 arch_call_rest_init();
1da177e4
LT
999}
1000
b99b87f7
PO
1001/* Call all constructor functions linked into the kernel. */
1002static void __init do_ctors(void)
1003{
1004#ifdef CONFIG_CONSTRUCTORS
196a15b4 1005 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
b99b87f7 1006
196a15b4
HS
1007 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1008 (*fn)();
b99b87f7
PO
1009#endif
1010}
1011
7b0b73d7
PB
1012#ifdef CONFIG_KALLSYMS
1013struct blacklist_entry {
1014 struct list_head next;
1015 char *buf;
1016};
1017
1018static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1019
1020static int __init initcall_blacklist(char *str)
1021{
1022 char *str_entry;
1023 struct blacklist_entry *entry;
1024
1025 /* str argument is a comma-separated list of functions */
1026 do {
1027 str_entry = strsep(&str, ",");
1028 if (str_entry) {
1029 pr_debug("blacklisting initcall %s\n", str_entry);
7e1c4e27
MR
1030 entry = memblock_alloc(sizeof(*entry),
1031 SMP_CACHE_BYTES);
f5c7310a
MR
1032 if (!entry)
1033 panic("%s: Failed to allocate %zu bytes\n",
1034 __func__, sizeof(*entry));
7e1c4e27
MR
1035 entry->buf = memblock_alloc(strlen(str_entry) + 1,
1036 SMP_CACHE_BYTES);
f5c7310a
MR
1037 if (!entry->buf)
1038 panic("%s: Failed to allocate %zu bytes\n",
1039 __func__, strlen(str_entry) + 1);
7b0b73d7
PB
1040 strcpy(entry->buf, str_entry);
1041 list_add(&entry->next, &blacklisted_initcalls);
1042 }
1043 } while (str_entry);
1044
1045 return 0;
1046}
1047
1048static bool __init_or_module initcall_blacklisted(initcall_t fn)
1049{
7b0b73d7 1050 struct blacklist_entry *entry;
c8cdd2be 1051 char fn_name[KSYM_SYMBOL_LEN];
0fd5ed8d 1052 unsigned long addr;
7b0b73d7 1053
c8cdd2be 1054 if (list_empty(&blacklisted_initcalls))
7b0b73d7
PB
1055 return false;
1056
0fd5ed8d
RV
1057 addr = (unsigned long) dereference_function_descriptor(fn);
1058 sprint_symbol_no_offset(fn_name, addr);
c8cdd2be 1059
841c06d7
PB
1060 /*
1061 * fn will be "function_name [module_name]" where [module_name] is not
1062 * displayed for built-in init functions. Strip off the [module_name].
1063 */
1064 strreplace(fn_name, ' ', '\0');
1065
e6fd1fb3 1066 list_for_each_entry(entry, &blacklisted_initcalls, next) {
7b0b73d7
PB
1067 if (!strcmp(fn_name, entry->buf)) {
1068 pr_debug("initcall %s blacklisted\n", fn_name);
7b0b73d7
PB
1069 return true;
1070 }
1071 }
1072
7b0b73d7
PB
1073 return false;
1074}
1075#else
1076static int __init initcall_blacklist(char *str)
1077{
1078 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1079 return 0;
1080}
1081
1082static bool __init_or_module initcall_blacklisted(initcall_t fn)
1083{
1084 return false;
1085}
1086#endif
1087__setup("initcall_blacklist=", initcall_blacklist);
1088
4e37958d
SRV
1089static __init_or_module void
1090trace_initcall_start_cb(void *data, initcall_t fn)
1da177e4 1091{
4e37958d 1092 ktime_t *calltime = (ktime_t *)data;
1da177e4 1093
d75f773c 1094 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
4e37958d
SRV
1095 *calltime = ktime_get();
1096}
1097
1098static __init_or_module void
1099trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1100{
1101 ktime_t *calltime = (ktime_t *)data;
1102 ktime_t delta, rettime;
1103 unsigned long long duration;
1104
22c5c03b 1105 rettime = ktime_get();
4e37958d 1106 delta = ktime_sub(rettime, *calltime);
22c5c03b 1107 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
d75f773c 1108 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
ea676e84 1109 fn, ret, duration);
4e37958d 1110}
1da177e4 1111
4e37958d
SRV
1112static ktime_t initcall_calltime;
1113
b0dc52f1 1114#ifdef TRACEPOINTS_ENABLED
4e37958d
SRV
1115static void __init initcall_debug_enable(void)
1116{
1117 int ret;
1118
1119 ret = register_trace_initcall_start(trace_initcall_start_cb,
1120 &initcall_calltime);
1121 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1122 &initcall_calltime);
1123 WARN(ret, "Failed to register initcall tracepoints\n");
22c5c03b 1124}
b0dc52f1
SRV
1125# define do_trace_initcall_start trace_initcall_start
1126# define do_trace_initcall_finish trace_initcall_finish
1127#else
1128static inline void do_trace_initcall_start(initcall_t fn)
1129{
1130 if (!initcall_debug)
1131 return;
1132 trace_initcall_start_cb(&initcall_calltime, fn);
1133}
1134static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1135{
1136 if (!initcall_debug)
1137 return;
1138 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1139}
1140#endif /* !TRACEPOINTS_ENABLED */
22c5c03b 1141
e4461271 1142int __init_or_module do_one_initcall(initcall_t fn)
22c5c03b
KW
1143{
1144 int count = preempt_count();
ff1c8fac 1145 char msgbuf[64];
4e37958d 1146 int ret;
22c5c03b 1147
7b0b73d7
PB
1148 if (initcall_blacklisted(fn))
1149 return -EPERM;
1150
b0dc52f1 1151 do_trace_initcall_start(fn);
4e37958d 1152 ret = fn();
b0dc52f1 1153 do_trace_initcall_finish(fn, ret);
8f0c45cd 1154
e0df154f 1155 msgbuf[0] = 0;
e662e1cf 1156
e0df154f 1157 if (preempt_count() != count) {
bf5d770b 1158 sprintf(msgbuf, "preemption imbalance ");
4a2b4b22 1159 preempt_count_set(count);
1da177e4 1160 }
e0df154f 1161 if (irqs_disabled()) {
a76bfd0d 1162 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
e0df154f
LT
1163 local_irq_enable();
1164 }
d75f773c 1165 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
59f9415f 1166
38addce8 1167 add_latent_entropy();
30dbb20e 1168 return ret;
e0df154f
LT
1169}
1170
1171
1b1eeca7
AB
1172extern initcall_entry_t __initcall_start[];
1173extern initcall_entry_t __initcall0_start[];
1174extern initcall_entry_t __initcall1_start[];
1175extern initcall_entry_t __initcall2_start[];
1176extern initcall_entry_t __initcall3_start[];
1177extern initcall_entry_t __initcall4_start[];
1178extern initcall_entry_t __initcall5_start[];
1179extern initcall_entry_t __initcall6_start[];
1180extern initcall_entry_t __initcall7_start[];
1181extern initcall_entry_t __initcall_end[];
1182
1183static initcall_entry_t *initcall_levels[] __initdata = {
026cee00
PM
1184 __initcall0_start,
1185 __initcall1_start,
1186 __initcall2_start,
1187 __initcall3_start,
1188 __initcall4_start,
1189 __initcall5_start,
1190 __initcall6_start,
1191 __initcall7_start,
1192 __initcall_end,
1193};
1194
96263d28 1195/* Keep these in sync with initcalls in include/linux/init.h */
7c8f7193 1196static const char *initcall_level_names[] __initdata = {
a6fb6012 1197 "pure",
9fb48c74
JC
1198 "core",
1199 "postcore",
1200 "arch",
1201 "subsys",
1202 "fs",
1203 "device",
1204 "late",
026cee00
PM
1205};
1206
7e2762e1
AS
1207static int __init ignore_unknown_bootoption(char *param, char *val,
1208 const char *unused, void *arg)
1209{
1210 return 0;
1211}
1212
0068c92a 1213static void __init do_initcall_level(int level, char *command_line)
e0df154f 1214{
1b1eeca7 1215 initcall_entry_t *fn;
e0df154f 1216
026cee00 1217 parse_args(initcall_level_names[level],
0068c92a 1218 command_line, __start___param,
026cee00
PM
1219 __stop___param - __start___param,
1220 level, level,
7e2762e1 1221 NULL, ignore_unknown_bootoption);
026cee00 1222
4ee7c60d 1223 trace_initcall_level(initcall_level_names[level]);
026cee00 1224 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1b1eeca7 1225 do_one_initcall(initcall_from_entry(fn));
1da177e4
LT
1226}
1227
026cee00
PM
1228static void __init do_initcalls(void)
1229{
1230 int level;
0068c92a
MH
1231 size_t len = strlen(saved_command_line) + 1;
1232 char *command_line;
1233
1234 command_line = kzalloc(len, GFP_KERNEL);
1235 if (!command_line)
1236 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1237
1238 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1239 /* Parser modifies command_line, restore it each time */
1240 strcpy(command_line, saved_command_line);
1241 do_initcall_level(level, command_line);
1242 }
026cee00 1243
0068c92a 1244 kfree(command_line);
026cee00
PM
1245}
1246
1da177e4
LT
1247/*
1248 * Ok, the machine is now initialized. None of the devices
1249 * have been touched yet, but the CPU subsystem is up and
1250 * running, and memory and process management works.
1251 *
1252 * Now we can finally start doing some real work..
1253 */
1254static void __init do_basic_setup(void)
1255{
759ee091 1256 cpuset_init_smp();
1da177e4 1257 driver_init();
b04c3afb 1258 init_irq_proc();
b99b87f7 1259 do_ctors();
d5767c53 1260 usermodehelper_enable();
b0f84374 1261 do_initcalls();
1da177e4
LT
1262}
1263
7babe8db 1264static void __init do_pre_smp_initcalls(void)
c2147a50 1265{
1b1eeca7 1266 initcall_entry_t *fn;
c2147a50 1267
4ee7c60d 1268 trace_initcall_level("early");
026cee00 1269 for (fn = __initcall_start; fn < __initcall0_start; fn++)
1b1eeca7 1270 do_one_initcall(initcall_from_entry(fn));
c2147a50
EGM
1271}
1272
a74fb73c 1273static int run_init_process(const char *init_filename)
1da177e4 1274{
b88c50ac
AS
1275 const char *const *p;
1276
1da177e4 1277 argv_init[0] = init_filename;
3f5c15d8 1278 pr_info("Run %s as init process\n", init_filename);
b88c50ac
AS
1279 pr_debug(" with arguments:\n");
1280 for (p = argv_init; *p; p++)
1281 pr_debug(" %s\n", *p);
1282 pr_debug(" with environment:\n");
1283 for (p = envp_init; *p; p++)
1284 pr_debug(" %s\n", *p);
c4ad8f98 1285 return do_execve(getname_kernel(init_filename),
ae903caa
AV
1286 (const char __user *const __user *)argv_init,
1287 (const char __user *const __user *)envp_init);
1da177e4
LT
1288}
1289
ba24762b
MO
1290static int try_to_run_init_process(const char *init_filename)
1291{
1292 int ret;
1293
1294 ret = run_init_process(init_filename);
1295
1296 if (ret && ret != -ENOENT) {
1297 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1298 init_filename, ret);
1299 }
1300
1301 return ret;
1302}
1303
f80b0c90 1304static noinline void __init kernel_init_freeable(void);
d6b21238 1305
0f5bf6d0 1306#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
39290b38 1307bool rodata_enabled __ro_after_init = true;
d2aa1aca
KC
1308static int __init set_debug_rodata(char *str)
1309{
1310 return strtobool(str, &rodata_enabled);
1311}
1312__setup("rodata=", set_debug_rodata);
39290b38 1313#endif
d2aa1aca 1314
0f5bf6d0 1315#ifdef CONFIG_STRICT_KERNEL_RWX
d2aa1aca
KC
1316static void mark_readonly(void)
1317{
2959a5f7 1318 if (rodata_enabled) {
ae646f0b 1319 /*
ba180314
PM
1320 * load_module() results in W+X mappings, which are cleaned
1321 * up with call_rcu(). Let's make sure that queued work is
ae646f0b
JH
1322 * flushed so that we don't hit false positives looking for
1323 * insecure pages which are W+X.
1324 */
ba180314 1325 rcu_barrier();
d2aa1aca 1326 mark_rodata_ro();
2959a5f7
JP
1327 rodata_test();
1328 } else
d2aa1aca
KC
1329 pr_info("Kernel memory protection disabled.\n");
1330}
f596ded1
CL
1331#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1332static inline void mark_readonly(void)
1333{
1334 pr_warn("Kernel memory protection not selected by kernel config.\n");
1335}
d2aa1aca
KC
1336#else
1337static inline void mark_readonly(void)
1338{
1339 pr_warn("This architecture does not have kernel memory protection.\n");
1340}
1341#endif
1342
997aef68
MR
1343void __weak free_initmem(void)
1344{
f4039999 1345 free_initmem_default(POISON_FREE_INITMEM);
997aef68
MR
1346}
1347
d6b21238 1348static int __ref kernel_init(void *unused)
ee5bfa64 1349{
ba24762b
MO
1350 int ret;
1351
d6b21238 1352 kernel_init_freeable();
22a9d645
AV
1353 /* need to finish all async __init code before freeing the memory */
1354 async_synchronize_full();
b80f0f6c 1355 ftrace_free_init_mem();
ee5bfa64 1356 free_initmem();
d2aa1aca 1357 mark_readonly();
b976690f
JR
1358
1359 /*
1360 * Kernel mappings are now finalized - update the userspace page-table
1361 * to finalize PTI.
1362 */
1363 pti_finalize();
1364
ee5bfa64
VG
1365 system_state = SYSTEM_RUNNING;
1366 numa_default_policy();
1367
967dcb8f
PM
1368 rcu_end_inkernel_boot();
1369
ee5bfa64 1370 if (ramdisk_execute_command) {
ba24762b
MO
1371 ret = run_init_process(ramdisk_execute_command);
1372 if (!ret)
a74fb73c 1373 return 0;
ba24762b
MO
1374 pr_err("Failed to execute %s (error %d)\n",
1375 ramdisk_execute_command, ret);
ee5bfa64
VG
1376 }
1377
1378 /*
1379 * We try each of these until one succeeds.
1380 *
1381 * The Bourne shell can be used instead of init if we are
1382 * trying to recover a really broken machine.
1383 */
1384 if (execute_command) {
ba24762b
MO
1385 ret = run_init_process(execute_command);
1386 if (!ret)
a74fb73c 1387 return 0;
6ef4536e
AL
1388 panic("Requested init %s failed (error %d).",
1389 execute_command, ret);
ee5bfa64 1390 }
ba24762b
MO
1391 if (!try_to_run_init_process("/sbin/init") ||
1392 !try_to_run_init_process("/etc/init") ||
1393 !try_to_run_init_process("/bin/init") ||
1394 !try_to_run_init_process("/bin/sh"))
a74fb73c 1395 return 0;
ee5bfa64 1396
ba24762b 1397 panic("No working init found. Try passing init= option to kernel. "
8c27ceff 1398 "See Linux Documentation/admin-guide/init.rst for guidance.");
ee5bfa64
VG
1399}
1400
b49a733d
DB
1401void console_on_rootfs(void)
1402{
74f1a299
DB
1403 /* Open the /dev/console as stdin, this should never fail */
1404 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1405 pr_err("Warning: unable to open an initial console.\n");
b49a733d 1406
74f1a299
DB
1407 /* create stdout/stderr */
1408 (void) ksys_dup(0);
1409 (void) ksys_dup(0);
b49a733d
DB
1410}
1411
f80b0c90 1412static noinline void __init kernel_init_freeable(void)
1da177e4 1413{
b433c3d4
PZ
1414 /*
1415 * Wait until kthreadd is all set-up.
1416 */
1417 wait_for_completion(&kthreadd_done);
31a67102
LT
1418
1419 /* Now the scheduler is fully set up and can do blocking allocations */
1420 gfp_allowed_mask = __GFP_BITS_MASK;
1421
58568d2a
MX
1422 /*
1423 * init can allocate pages on any node
1424 */
3c466d46 1425 set_mems_allowed(node_states[N_MEMORY]);
1da177e4 1426
9ec52099
CLG
1427 cad_pid = task_pid(current);
1428
ca74a6f8 1429 smp_prepare_cpus(setup_max_cpus);
1da177e4 1430
3347fa09
TH
1431 workqueue_init();
1432
597b7305
MH
1433 init_mm_internals();
1434
1da177e4 1435 do_pre_smp_initcalls();
004417a6 1436 lockup_detector_init();
1da177e4 1437
1da177e4
LT
1438 smp_init();
1439 sched_init_smp();
1440
0e1cc95b 1441 page_alloc_init_late();
2f1ee091
QC
1442 /* Initialize page ext after all struct pages are initialized. */
1443 page_ext_init();
0e1cc95b 1444
1da177e4
LT
1445 do_basic_setup();
1446
b49a733d 1447 console_on_rootfs();
2bd3a997 1448
1da177e4
LT
1449 /*
1450 * check if there is an early userspace init. If yes, let it do all
1451 * the work
1452 */
ffdfc409
OJ
1453
1454 if (!ramdisk_execute_command)
1455 ramdisk_execute_command = "/init";
1456
cbfe20f5
DB
1457 if (ksys_access((const char __user *)
1458 ramdisk_execute_command, 0) != 0) {
ffdfc409 1459 ramdisk_execute_command = NULL;
1da177e4 1460 prepare_namespace();
ffdfc409 1461 }
1da177e4
LT
1462
1463 /*
1464 * Ok, we have completed the initial bootup, and
1465 * we're essentially up and running. Get rid of the
1466 * initmem segments and start the user-mode stuff..
c9cd2ce2
DK
1467 *
1468 * rootfs is available now, try loading the public keys
1469 * and default modules
1da177e4 1470 */
bb813f4c 1471
c9cd2ce2 1472 integrity_load_keys();
1da177e4 1473}
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