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torvalds
GitHub Repository: torvalds/linux
Path: blob/master/init/main.c
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1
// SPDX-License-Identifier: GPL-2.0-only
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
10
* Simplified starting of init: Michael A. Griffith <[email protected]>
11
*/
12
13
#define DEBUG /* Enable initcall_debug */
14
15
#include <linux/types.h>
16
#include <linux/export.h>
17
#include <linux/extable.h>
18
#include <linux/module.h>
19
#include <linux/proc_fs.h>
20
#include <linux/binfmts.h>
21
#include <linux/kernel.h>
22
#include <linux/syscalls.h>
23
#include <linux/stackprotector.h>
24
#include <linux/string.h>
25
#include <linux/ctype.h>
26
#include <linux/delay.h>
27
#include <linux/ioport.h>
28
#include <linux/init.h>
29
#include <linux/initrd.h>
30
#include <linux/memblock.h>
31
#include <linux/acpi.h>
32
#include <linux/bootconfig.h>
33
#include <linux/console.h>
34
#include <linux/nmi.h>
35
#include <linux/percpu.h>
36
#include <linux/kmod.h>
37
#include <linux/kprobes.h>
38
#include <linux/kmsan.h>
39
#include <linux/vmalloc.h>
40
#include <linux/kernel_stat.h>
41
#include <linux/start_kernel.h>
42
#include <linux/security.h>
43
#include <linux/smp.h>
44
#include <linux/profile.h>
45
#include <linux/kfence.h>
46
#include <linux/rcupdate.h>
47
#include <linux/srcu.h>
48
#include <linux/moduleparam.h>
49
#include <linux/kallsyms.h>
50
#include <linux/buildid.h>
51
#include <linux/writeback.h>
52
#include <linux/cpu.h>
53
#include <linux/cpuset.h>
54
#include <linux/memcontrol.h>
55
#include <linux/cgroup.h>
56
#include <linux/tick.h>
57
#include <linux/sched/isolation.h>
58
#include <linux/interrupt.h>
59
#include <linux/taskstats_kern.h>
60
#include <linux/delayacct.h>
61
#include <linux/unistd.h>
62
#include <linux/utsname.h>
63
#include <linux/rmap.h>
64
#include <linux/mempolicy.h>
65
#include <linux/key.h>
66
#include <linux/debug_locks.h>
67
#include <linux/debugobjects.h>
68
#include <linux/lockdep.h>
69
#include <linux/kmemleak.h>
70
#include <linux/padata.h>
71
#include <linux/pid_namespace.h>
72
#include <linux/device/driver.h>
73
#include <linux/kthread.h>
74
#include <linux/sched.h>
75
#include <linux/sched/init.h>
76
#include <linux/signal.h>
77
#include <linux/idr.h>
78
#include <linux/kgdb.h>
79
#include <linux/ftrace.h>
80
#include <linux/async.h>
81
#include <linux/shmem_fs.h>
82
#include <linux/slab.h>
83
#include <linux/perf_event.h>
84
#include <linux/ptrace.h>
85
#include <linux/pti.h>
86
#include <linux/blkdev.h>
87
#include <linux/sched/clock.h>
88
#include <linux/sched/task.h>
89
#include <linux/sched/task_stack.h>
90
#include <linux/context_tracking.h>
91
#include <linux/random.h>
92
#include <linux/moduleloader.h>
93
#include <linux/list.h>
94
#include <linux/integrity.h>
95
#include <linux/proc_ns.h>
96
#include <linux/io.h>
97
#include <linux/cache.h>
98
#include <linux/rodata_test.h>
99
#include <linux/jump_label.h>
100
#include <linux/kcsan.h>
101
#include <linux/init_syscalls.h>
102
#include <linux/stackdepot.h>
103
#include <linux/randomize_kstack.h>
104
#include <linux/pidfs.h>
105
#include <linux/ptdump.h>
106
#include <linux/time_namespace.h>
107
#include <net/net_namespace.h>
108
109
#include <asm/io.h>
110
#include <asm/setup.h>
111
#include <asm/sections.h>
112
#include <asm/cacheflush.h>
113
114
#define CREATE_TRACE_POINTS
115
#include <trace/events/initcall.h>
116
117
#include <kunit/test.h>
118
119
static int kernel_init(void *);
120
121
/*
122
* Debug helper: via this flag we know that we are in 'early bootup code'
123
* where only the boot processor is running with IRQ disabled. This means
124
* two things - IRQ must not be enabled before the flag is cleared and some
125
* operations which are not allowed with IRQ disabled are allowed while the
126
* flag is set.
127
*/
128
bool early_boot_irqs_disabled __read_mostly;
129
130
enum system_states system_state __read_mostly;
131
EXPORT_SYMBOL(system_state);
132
133
/*
134
* Boot command-line arguments
135
*/
136
#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
137
#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
138
139
/* Default late time init is NULL. archs can override this later. */
140
void (*__initdata late_time_init)(void);
141
142
/* Untouched command line saved by arch-specific code. */
143
char __initdata boot_command_line[COMMAND_LINE_SIZE];
144
/* Untouched saved command line (eg. for /proc) */
145
char *saved_command_line __ro_after_init;
146
unsigned int saved_command_line_len __ro_after_init;
147
/* Command line for parameter parsing */
148
static char *static_command_line;
149
/* Untouched extra command line */
150
static char *extra_command_line;
151
/* Extra init arguments */
152
static char *extra_init_args;
153
154
#ifdef CONFIG_BOOT_CONFIG
155
/* Is bootconfig on command line? */
156
static bool bootconfig_found;
157
static size_t initargs_offs;
158
#else
159
# define bootconfig_found false
160
# define initargs_offs 0
161
#endif
162
163
static char *execute_command;
164
static char *ramdisk_execute_command = "/init";
165
166
/*
167
* Used to generate warnings if static_key manipulation functions are used
168
* before jump_label_init is called.
169
*/
170
bool static_key_initialized __read_mostly;
171
EXPORT_SYMBOL_GPL(static_key_initialized);
172
173
/*
174
* If set, this is an indication to the drivers that reset the underlying
175
* device before going ahead with the initialization otherwise driver might
176
* rely on the BIOS and skip the reset operation.
177
*
178
* This is useful if kernel is booting in an unreliable environment.
179
* For ex. kdump situation where previous kernel has crashed, BIOS has been
180
* skipped and devices will be in unknown state.
181
*/
182
unsigned int reset_devices;
183
EXPORT_SYMBOL(reset_devices);
184
185
static int __init set_reset_devices(char *str)
186
{
187
reset_devices = 1;
188
return 1;
189
}
190
191
__setup("reset_devices", set_reset_devices);
192
193
static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
194
const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
195
static const char *panic_later, *panic_param;
196
197
static bool __init obsolete_checksetup(char *line)
198
{
199
const struct obs_kernel_param *p;
200
bool had_early_param = false;
201
202
p = __setup_start;
203
do {
204
int n = strlen(p->str);
205
if (parameqn(line, p->str, n)) {
206
if (p->early) {
207
/* Already done in parse_early_param?
208
* (Needs exact match on param part).
209
* Keep iterating, as we can have early
210
* params and __setups of same names 8( */
211
if (line[n] == '\0' || line[n] == '=')
212
had_early_param = true;
213
} else if (!p->setup_func) {
214
pr_warn("Parameter %s is obsolete, ignored\n",
215
p->str);
216
return true;
217
} else if (p->setup_func(line + n))
218
return true;
219
}
220
p++;
221
} while (p < __setup_end);
222
223
return had_early_param;
224
}
225
226
/*
227
* This should be approx 2 Bo*oMips to start (note initial shift), and will
228
* still work even if initially too large, it will just take slightly longer
229
*/
230
unsigned long loops_per_jiffy = (1<<12);
231
EXPORT_SYMBOL(loops_per_jiffy);
232
233
static int __init debug_kernel(char *str)
234
{
235
console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
236
return 0;
237
}
238
239
static int __init quiet_kernel(char *str)
240
{
241
console_loglevel = CONSOLE_LOGLEVEL_QUIET;
242
return 0;
243
}
244
245
early_param("debug", debug_kernel);
246
early_param("quiet", quiet_kernel);
247
248
static int __init loglevel(char *str)
249
{
250
int newlevel;
251
252
/*
253
* Only update loglevel value when a correct setting was passed,
254
* to prevent blind crashes (when loglevel being set to 0) that
255
* are quite hard to debug
256
*/
257
if (get_option(&str, &newlevel)) {
258
console_loglevel = newlevel;
259
return 0;
260
}
261
262
return -EINVAL;
263
}
264
265
early_param("loglevel", loglevel);
266
267
#ifdef CONFIG_BLK_DEV_INITRD
268
static void * __init get_boot_config_from_initrd(size_t *_size)
269
{
270
u32 size, csum;
271
char *data;
272
u32 *hdr;
273
int i;
274
275
if (!initrd_end)
276
return NULL;
277
278
data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
279
/*
280
* Since Grub may align the size of initrd to 4, we must
281
* check the preceding 3 bytes as well.
282
*/
283
for (i = 0; i < 4; i++) {
284
if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
285
goto found;
286
data--;
287
}
288
return NULL;
289
290
found:
291
hdr = (u32 *)(data - 8);
292
size = le32_to_cpu(hdr[0]);
293
csum = le32_to_cpu(hdr[1]);
294
295
data = ((void *)hdr) - size;
296
if ((unsigned long)data < initrd_start) {
297
pr_err("bootconfig size %d is greater than initrd size %ld\n",
298
size, initrd_end - initrd_start);
299
return NULL;
300
}
301
302
if (xbc_calc_checksum(data, size) != csum) {
303
pr_err("bootconfig checksum failed\n");
304
return NULL;
305
}
306
307
/* Remove bootconfig from initramfs/initrd */
308
initrd_end = (unsigned long)data;
309
if (_size)
310
*_size = size;
311
312
return data;
313
}
314
#else
315
static void * __init get_boot_config_from_initrd(size_t *_size)
316
{
317
return NULL;
318
}
319
#endif
320
321
#ifdef CONFIG_BOOT_CONFIG
322
323
static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
324
325
#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
326
327
static int __init xbc_snprint_cmdline(char *buf, size_t size,
328
struct xbc_node *root)
329
{
330
struct xbc_node *knode, *vnode;
331
char *end = buf + size;
332
const char *val, *q;
333
int ret;
334
335
xbc_node_for_each_key_value(root, knode, val) {
336
ret = xbc_node_compose_key_after(root, knode,
337
xbc_namebuf, XBC_KEYLEN_MAX);
338
if (ret < 0)
339
return ret;
340
341
vnode = xbc_node_get_child(knode);
342
if (!vnode) {
343
ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
344
if (ret < 0)
345
return ret;
346
buf += ret;
347
continue;
348
}
349
xbc_array_for_each_value(vnode, val) {
350
/*
351
* For prettier and more readable /proc/cmdline, only
352
* quote the value when necessary, i.e. when it contains
353
* whitespace.
354
*/
355
q = strpbrk(val, " \t\r\n") ? "\"" : "";
356
ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ",
357
xbc_namebuf, q, val, q);
358
if (ret < 0)
359
return ret;
360
buf += ret;
361
}
362
}
363
364
return buf - (end - size);
365
}
366
#undef rest
367
368
/* Make an extra command line under given key word */
369
static char * __init xbc_make_cmdline(const char *key)
370
{
371
struct xbc_node *root;
372
char *new_cmdline;
373
int ret, len = 0;
374
375
root = xbc_find_node(key);
376
if (!root)
377
return NULL;
378
379
/* Count required buffer size */
380
len = xbc_snprint_cmdline(NULL, 0, root);
381
if (len <= 0)
382
return NULL;
383
384
new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
385
if (!new_cmdline) {
386
pr_err("Failed to allocate memory for extra kernel cmdline.\n");
387
return NULL;
388
}
389
390
ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
391
if (ret < 0 || ret > len) {
392
pr_err("Failed to print extra kernel cmdline.\n");
393
memblock_free(new_cmdline, len + 1);
394
return NULL;
395
}
396
397
return new_cmdline;
398
}
399
400
static int __init bootconfig_params(char *param, char *val,
401
const char *unused, void *arg)
402
{
403
if (strcmp(param, "bootconfig") == 0) {
404
bootconfig_found = true;
405
}
406
return 0;
407
}
408
409
static int __init warn_bootconfig(char *str)
410
{
411
/* The 'bootconfig' has been handled by bootconfig_params(). */
412
return 0;
413
}
414
415
static void __init setup_boot_config(void)
416
{
417
static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
418
const char *msg, *data;
419
int pos, ret;
420
size_t size;
421
char *err;
422
423
/* Cut out the bootconfig data even if we have no bootconfig option */
424
data = get_boot_config_from_initrd(&size);
425
/* If there is no bootconfig in initrd, try embedded one. */
426
if (!data)
427
data = xbc_get_embedded_bootconfig(&size);
428
429
strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
430
err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
431
bootconfig_params);
432
433
if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
434
return;
435
436
/* parse_args() stops at the next param of '--' and returns an address */
437
if (err)
438
initargs_offs = err - tmp_cmdline;
439
440
if (!data) {
441
/* If user intended to use bootconfig, show an error level message */
442
if (bootconfig_found)
443
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
444
else
445
pr_info("No bootconfig data provided, so skipping bootconfig");
446
return;
447
}
448
449
if (size >= XBC_DATA_MAX) {
450
pr_err("bootconfig size %ld greater than max size %d\n",
451
(long)size, XBC_DATA_MAX);
452
return;
453
}
454
455
ret = xbc_init(data, size, &msg, &pos);
456
if (ret < 0) {
457
if (pos < 0)
458
pr_err("Failed to init bootconfig: %s.\n", msg);
459
else
460
pr_err("Failed to parse bootconfig: %s at %d.\n",
461
msg, pos);
462
} else {
463
xbc_get_info(&ret, NULL);
464
pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
465
/* keys starting with "kernel." are passed via cmdline */
466
extra_command_line = xbc_make_cmdline("kernel");
467
/* Also, "init." keys are init arguments */
468
extra_init_args = xbc_make_cmdline("init");
469
}
470
return;
471
}
472
473
static void __init exit_boot_config(void)
474
{
475
xbc_exit();
476
}
477
478
#else /* !CONFIG_BOOT_CONFIG */
479
480
static void __init setup_boot_config(void)
481
{
482
/* Remove bootconfig data from initrd */
483
get_boot_config_from_initrd(NULL);
484
}
485
486
static int __init warn_bootconfig(char *str)
487
{
488
pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
489
return 0;
490
}
491
492
#define exit_boot_config() do {} while (0)
493
494
#endif /* CONFIG_BOOT_CONFIG */
495
496
early_param("bootconfig", warn_bootconfig);
497
498
bool __init cmdline_has_extra_options(void)
499
{
500
return extra_command_line || extra_init_args;
501
}
502
503
/* Change NUL term back to "=", to make "param" the whole string. */
504
static void __init repair_env_string(char *param, char *val)
505
{
506
if (val) {
507
/* param=val or param="val"? */
508
if (val == param+strlen(param)+1)
509
val[-1] = '=';
510
else if (val == param+strlen(param)+2) {
511
val[-2] = '=';
512
memmove(val-1, val, strlen(val)+1);
513
} else
514
BUG();
515
}
516
}
517
518
/* Anything after -- gets handed straight to init. */
519
static int __init set_init_arg(char *param, char *val,
520
const char *unused, void *arg)
521
{
522
unsigned int i;
523
524
if (panic_later)
525
return 0;
526
527
repair_env_string(param, val);
528
529
for (i = 0; argv_init[i]; i++) {
530
if (i == MAX_INIT_ARGS) {
531
panic_later = "init";
532
panic_param = param;
533
return 0;
534
}
535
}
536
argv_init[i] = param;
537
return 0;
538
}
539
540
/*
541
* Unknown boot options get handed to init, unless they look like
542
* unused parameters (modprobe will find them in /proc/cmdline).
543
*/
544
static int __init unknown_bootoption(char *param, char *val,
545
const char *unused, void *arg)
546
{
547
size_t len = strlen(param);
548
/*
549
* Well-known bootloader identifiers:
550
* 1. LILO/Grub pass "BOOT_IMAGE=...";
551
* 2. kexec/kdump (kexec-tools) pass "kexec".
552
*/
553
const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL };
554
555
/* Handle params aliased to sysctls */
556
if (sysctl_is_alias(param))
557
return 0;
558
559
repair_env_string(param, val);
560
561
/* Handle bootloader identifier */
562
for (int i = 0; bootloader[i]; i++) {
563
if (strstarts(param, bootloader[i]))
564
return 0;
565
}
566
567
/* Handle obsolete-style parameters */
568
if (obsolete_checksetup(param))
569
return 0;
570
571
/* Unused module parameter. */
572
if (strnchr(param, len, '.'))
573
return 0;
574
575
if (panic_later)
576
return 0;
577
578
if (val) {
579
/* Environment option */
580
unsigned int i;
581
for (i = 0; envp_init[i]; i++) {
582
if (i == MAX_INIT_ENVS) {
583
panic_later = "env";
584
panic_param = param;
585
}
586
if (!strncmp(param, envp_init[i], len+1))
587
break;
588
}
589
envp_init[i] = param;
590
} else {
591
/* Command line option */
592
unsigned int i;
593
for (i = 0; argv_init[i]; i++) {
594
if (i == MAX_INIT_ARGS) {
595
panic_later = "init";
596
panic_param = param;
597
}
598
}
599
argv_init[i] = param;
600
}
601
return 0;
602
}
603
604
static int __init init_setup(char *str)
605
{
606
unsigned int i;
607
608
execute_command = str;
609
/*
610
* In case LILO is going to boot us with default command line,
611
* it prepends "auto" before the whole cmdline which makes
612
* the shell think it should execute a script with such name.
613
* So we ignore all arguments entered _before_ init=... [MJ]
614
*/
615
for (i = 1; i < MAX_INIT_ARGS; i++)
616
argv_init[i] = NULL;
617
return 1;
618
}
619
__setup("init=", init_setup);
620
621
static int __init rdinit_setup(char *str)
622
{
623
unsigned int i;
624
625
ramdisk_execute_command = str;
626
/* See "auto" comment in init_setup */
627
for (i = 1; i < MAX_INIT_ARGS; i++)
628
argv_init[i] = NULL;
629
return 1;
630
}
631
__setup("rdinit=", rdinit_setup);
632
633
#ifndef CONFIG_SMP
634
static inline void setup_nr_cpu_ids(void) { }
635
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
636
#endif
637
638
/*
639
* We need to store the untouched command line for future reference.
640
* We also need to store the touched command line since the parameter
641
* parsing is performed in place, and we should allow a component to
642
* store reference of name/value for future reference.
643
*/
644
static void __init setup_command_line(char *command_line)
645
{
646
size_t len, xlen = 0, ilen = 0;
647
648
if (extra_command_line)
649
xlen = strlen(extra_command_line);
650
if (extra_init_args) {
651
extra_init_args = strim(extra_init_args); /* remove trailing space */
652
ilen = strlen(extra_init_args) + 4; /* for " -- " */
653
}
654
655
len = xlen + strlen(boot_command_line) + ilen + 1;
656
657
saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
658
659
len = xlen + strlen(command_line) + 1;
660
661
static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
662
663
if (xlen) {
664
/*
665
* We have to put extra_command_line before boot command
666
* lines because there could be dashes (separator of init
667
* command line) in the command lines.
668
*/
669
strcpy(saved_command_line, extra_command_line);
670
strcpy(static_command_line, extra_command_line);
671
}
672
strcpy(saved_command_line + xlen, boot_command_line);
673
strcpy(static_command_line + xlen, command_line);
674
675
if (ilen) {
676
/*
677
* Append supplemental init boot args to saved_command_line
678
* so that user can check what command line options passed
679
* to init.
680
* The order should always be
681
* " -- "[bootconfig init-param][cmdline init-param]
682
*/
683
if (initargs_offs) {
684
len = xlen + initargs_offs;
685
strcpy(saved_command_line + len, extra_init_args);
686
len += ilen - 4; /* strlen(extra_init_args) */
687
strcpy(saved_command_line + len,
688
boot_command_line + initargs_offs - 1);
689
} else {
690
len = strlen(saved_command_line);
691
strcpy(saved_command_line + len, " -- ");
692
len += 4;
693
strcpy(saved_command_line + len, extra_init_args);
694
}
695
}
696
697
saved_command_line_len = strlen(saved_command_line);
698
}
699
700
/*
701
* We need to finalize in a non-__init function or else race conditions
702
* between the root thread and the init thread may cause start_kernel to
703
* be reaped by free_initmem before the root thread has proceeded to
704
* cpu_idle.
705
*
706
* gcc-3.4 accidentally inlines this function, so use noinline.
707
*/
708
709
static __initdata DECLARE_COMPLETION(kthreadd_done);
710
711
static noinline void __ref __noreturn rest_init(void)
712
{
713
struct task_struct *tsk;
714
int pid;
715
716
rcu_scheduler_starting();
717
/*
718
* We need to spawn init first so that it obtains pid 1, however
719
* the init task will end up wanting to create kthreads, which, if
720
* we schedule it before we create kthreadd, will OOPS.
721
*/
722
pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
723
/*
724
* Pin init on the boot CPU. Task migration is not properly working
725
* until sched_init_smp() has been run. It will set the allowed
726
* CPUs for init to the non isolated CPUs.
727
*/
728
rcu_read_lock();
729
tsk = find_task_by_pid_ns(pid, &init_pid_ns);
730
tsk->flags |= PF_NO_SETAFFINITY;
731
set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
732
rcu_read_unlock();
733
734
numa_default_policy();
735
pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
736
rcu_read_lock();
737
kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
738
rcu_read_unlock();
739
740
/*
741
* Enable might_sleep() and smp_processor_id() checks.
742
* They cannot be enabled earlier because with CONFIG_PREEMPTION=y
743
* kernel_thread() would trigger might_sleep() splats. With
744
* CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
745
* already, but it's stuck on the kthreadd_done completion.
746
*/
747
system_state = SYSTEM_SCHEDULING;
748
749
complete(&kthreadd_done);
750
751
/*
752
* The boot idle thread must execute schedule()
753
* at least once to get things moving:
754
*/
755
schedule_preempt_disabled();
756
/* Call into cpu_idle with preempt disabled */
757
cpu_startup_entry(CPUHP_ONLINE);
758
}
759
760
/* Check for early params. */
761
static int __init do_early_param(char *param, char *val,
762
const char *unused, void *arg)
763
{
764
const struct obs_kernel_param *p;
765
766
for (p = __setup_start; p < __setup_end; p++) {
767
if (p->early && parameq(param, p->str)) {
768
if (p->setup_func(val) != 0)
769
pr_warn("Malformed early option '%s'\n", param);
770
}
771
}
772
/* We accept everything at this stage. */
773
return 0;
774
}
775
776
void __init parse_early_options(char *cmdline)
777
{
778
parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
779
do_early_param);
780
}
781
782
/* Arch code calls this early on, or if not, just before other parsing. */
783
void __init parse_early_param(void)
784
{
785
static int done __initdata;
786
static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
787
788
if (done)
789
return;
790
791
/* All fall through to do_early_param. */
792
strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
793
parse_early_options(tmp_cmdline);
794
done = 1;
795
}
796
797
void __init __weak arch_post_acpi_subsys_init(void) { }
798
799
void __init __weak smp_setup_processor_id(void)
800
{
801
}
802
803
void __init __weak smp_prepare_boot_cpu(void)
804
{
805
}
806
807
# if THREAD_SIZE >= PAGE_SIZE
808
void __init __weak thread_stack_cache_init(void)
809
{
810
}
811
#endif
812
813
void __init __weak poking_init(void) { }
814
815
void __init __weak pgtable_cache_init(void) { }
816
817
void __init __weak trap_init(void) { }
818
819
bool initcall_debug;
820
core_param(initcall_debug, initcall_debug, bool, 0644);
821
822
#ifdef TRACEPOINTS_ENABLED
823
static void __init initcall_debug_enable(void);
824
#else
825
static inline void initcall_debug_enable(void)
826
{
827
}
828
#endif
829
830
#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
831
DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
832
randomize_kstack_offset);
833
DEFINE_PER_CPU(u32, kstack_offset);
834
835
static int __init early_randomize_kstack_offset(char *buf)
836
{
837
int ret;
838
bool bool_result;
839
840
ret = kstrtobool(buf, &bool_result);
841
if (ret)
842
return ret;
843
844
if (bool_result)
845
static_branch_enable(&randomize_kstack_offset);
846
else
847
static_branch_disable(&randomize_kstack_offset);
848
return 0;
849
}
850
early_param("randomize_kstack_offset", early_randomize_kstack_offset);
851
#endif
852
853
static void __init print_unknown_bootoptions(void)
854
{
855
char *unknown_options;
856
char *end;
857
const char *const *p;
858
size_t len;
859
860
if (panic_later || (!argv_init[1] && !envp_init[2]))
861
return;
862
863
/*
864
* Determine how many options we have to print out, plus a space
865
* before each
866
*/
867
len = 1; /* null terminator */
868
for (p = &argv_init[1]; *p; p++) {
869
len++;
870
len += strlen(*p);
871
}
872
for (p = &envp_init[2]; *p; p++) {
873
len++;
874
len += strlen(*p);
875
}
876
877
unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
878
if (!unknown_options) {
879
pr_err("%s: Failed to allocate %zu bytes\n",
880
__func__, len);
881
return;
882
}
883
end = unknown_options;
884
885
for (p = &argv_init[1]; *p; p++)
886
end += sprintf(end, " %s", *p);
887
for (p = &envp_init[2]; *p; p++)
888
end += sprintf(end, " %s", *p);
889
890
/* Start at unknown_options[1] to skip the initial space */
891
pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
892
&unknown_options[1]);
893
memblock_free(unknown_options, len);
894
}
895
896
static void __init early_numa_node_init(void)
897
{
898
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
899
#ifndef cpu_to_node
900
int cpu;
901
902
/* The early_cpu_to_node() should be ready here. */
903
for_each_possible_cpu(cpu)
904
set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
905
#endif
906
#endif
907
}
908
909
#define KERNEL_CMDLINE_PREFIX "Kernel command line: "
910
#define KERNEL_CMDLINE_PREFIX_LEN (sizeof(KERNEL_CMDLINE_PREFIX) - 1)
911
#define KERNEL_CMDLINE_CONTINUATION " \\"
912
#define KERNEL_CMDLINE_CONTINUATION_LEN (sizeof(KERNEL_CMDLINE_CONTINUATION) - 1)
913
914
#define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN (KERNEL_CMDLINE_PREFIX_LEN + \
915
KERNEL_CMDLINE_CONTINUATION_LEN)
916
#define CMDLINE_LOG_WRAP_IDEAL_LEN (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \
917
MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \
918
CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \
919
MIN_CMDLINE_LOG_WRAP_IDEAL_LEN)
920
921
#define IDEAL_CMDLINE_LEN (CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN)
922
#define IDEAL_CMDLINE_SPLIT_LEN (IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN)
923
924
/**
925
* print_kernel_cmdline() - Print the kernel cmdline with wrapping.
926
* @cmdline: The cmdline to print.
927
*
928
* Print the kernel command line, trying to wrap based on the Kconfig knob
929
* CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN.
930
*
931
* Wrapping is based on spaces, ignoring quotes. All lines are prefixed
932
* with "Kernel command line: " and lines that are not the last line have
933
* a " \" suffix added to them. The prefix and suffix count towards the
934
* line length for wrapping purposes. The ideal length will be exceeded
935
* if no appropriate place to wrap is found.
936
*
937
* Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40:
938
* Kernel command line: loglevel=7 \
939
* Kernel command line: init=/sbin/init \
940
* Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \
941
* Kernel command line: rootwait ro \
942
* Kernel command line: my_quoted_arg="The \
943
* Kernel command line: quick brown fox \
944
* Kernel command line: jumps over the \
945
* Kernel command line: lazy dog."
946
*/
947
static void __init print_kernel_cmdline(const char *cmdline)
948
{
949
size_t len;
950
951
/* Config option of 0 or anything longer than the max disables wrapping */
952
if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 ||
953
IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) {
954
pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
955
return;
956
}
957
958
len = strlen(cmdline);
959
while (len > IDEAL_CMDLINE_LEN) {
960
const char *first_space;
961
const char *prev_cutoff;
962
const char *cutoff;
963
int to_print;
964
size_t used;
965
966
/* Find the last ' ' that wouldn't make the line too long */
967
prev_cutoff = NULL;
968
cutoff = cmdline;
969
while (true) {
970
cutoff = strchr(cutoff + 1, ' ');
971
if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN)
972
break;
973
prev_cutoff = cutoff;
974
}
975
if (prev_cutoff)
976
cutoff = prev_cutoff;
977
else if (!cutoff)
978
break;
979
980
/* Find the beginning and end of the string of spaces */
981
first_space = cutoff;
982
while (first_space > cmdline && first_space[-1] == ' ')
983
first_space--;
984
to_print = first_space - cmdline;
985
while (*cutoff == ' ')
986
cutoff++;
987
used = cutoff - cmdline;
988
989
/* If the whole string is used, break and do the final printout */
990
if (len == used)
991
break;
992
993
if (to_print)
994
pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX,
995
to_print, cmdline, KERNEL_CMDLINE_CONTINUATION);
996
997
len -= used;
998
cmdline += used;
999
}
1000
if (len)
1001
pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
1002
}
1003
1004
asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
1005
void start_kernel(void)
1006
{
1007
char *command_line;
1008
char *after_dashes;
1009
1010
set_task_stack_end_magic(&init_task);
1011
smp_setup_processor_id();
1012
debug_objects_early_init();
1013
init_vmlinux_build_id();
1014
1015
cgroup_init_early();
1016
1017
local_irq_disable();
1018
early_boot_irqs_disabled = true;
1019
1020
/*
1021
* Interrupts are still disabled. Do necessary setups, then
1022
* enable them.
1023
*/
1024
boot_cpu_init();
1025
page_address_init();
1026
pr_notice("%s", linux_banner);
1027
setup_arch(&command_line);
1028
/* Static keys and static calls are needed by LSMs */
1029
jump_label_init();
1030
static_call_init();
1031
early_security_init();
1032
setup_boot_config();
1033
setup_command_line(command_line);
1034
setup_nr_cpu_ids();
1035
setup_per_cpu_areas();
1036
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
1037
early_numa_node_init();
1038
boot_cpu_hotplug_init();
1039
1040
print_kernel_cmdline(saved_command_line);
1041
/* parameters may set static keys */
1042
parse_early_param();
1043
after_dashes = parse_args("Booting kernel",
1044
static_command_line, __start___param,
1045
__stop___param - __start___param,
1046
-1, -1, NULL, &unknown_bootoption);
1047
print_unknown_bootoptions();
1048
if (!IS_ERR_OR_NULL(after_dashes))
1049
parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
1050
NULL, set_init_arg);
1051
if (extra_init_args)
1052
parse_args("Setting extra init args", extra_init_args,
1053
NULL, 0, -1, -1, NULL, set_init_arg);
1054
1055
/* Architectural and non-timekeeping rng init, before allocator init */
1056
random_init_early(command_line);
1057
1058
/*
1059
* These use large bootmem allocations and must precede
1060
* initalization of page allocator
1061
*/
1062
setup_log_buf(0);
1063
vfs_caches_init_early();
1064
sort_main_extable();
1065
trap_init();
1066
mm_core_init();
1067
maple_tree_init();
1068
poking_init();
1069
ftrace_init();
1070
1071
/* trace_printk can be enabled here */
1072
early_trace_init();
1073
1074
/*
1075
* Set up the scheduler prior starting any interrupts (such as the
1076
* timer interrupt). Full topology setup happens at smp_init()
1077
* time - but meanwhile we still have a functioning scheduler.
1078
*/
1079
sched_init();
1080
1081
if (WARN(!irqs_disabled(),
1082
"Interrupts were enabled *very* early, fixing it\n"))
1083
local_irq_disable();
1084
radix_tree_init();
1085
1086
/*
1087
* Set up housekeeping before setting up workqueues to allow the unbound
1088
* workqueue to take non-housekeeping into account.
1089
*/
1090
housekeeping_init();
1091
1092
/*
1093
* Allow workqueue creation and work item queueing/cancelling
1094
* early. Work item execution depends on kthreads and starts after
1095
* workqueue_init().
1096
*/
1097
workqueue_init_early();
1098
1099
rcu_init();
1100
kvfree_rcu_init();
1101
1102
/* Trace events are available after this */
1103
trace_init();
1104
1105
if (initcall_debug)
1106
initcall_debug_enable();
1107
1108
context_tracking_init();
1109
/* init some links before init_ISA_irqs() */
1110
early_irq_init();
1111
init_IRQ();
1112
tick_init();
1113
rcu_init_nohz();
1114
timers_init();
1115
srcu_init();
1116
hrtimers_init();
1117
softirq_init();
1118
timekeeping_init();
1119
time_init();
1120
1121
/* This must be after timekeeping is initialized */
1122
random_init();
1123
1124
/* These make use of the fully initialized rng */
1125
kfence_init();
1126
boot_init_stack_canary();
1127
1128
perf_event_init();
1129
profile_init();
1130
call_function_init();
1131
WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1132
1133
early_boot_irqs_disabled = false;
1134
local_irq_enable();
1135
1136
kmem_cache_init_late();
1137
1138
/*
1139
* HACK ALERT! This is early. We're enabling the console before
1140
* we've done PCI setups etc, and console_init() must be aware of
1141
* this. But we do want output early, in case something goes wrong.
1142
*/
1143
console_init();
1144
if (panic_later)
1145
panic("Too many boot %s vars at `%s'", panic_later,
1146
panic_param);
1147
1148
lockdep_init();
1149
1150
/*
1151
* Need to run this when irqs are enabled, because it wants
1152
* to self-test [hard/soft]-irqs on/off lock inversion bugs
1153
* too:
1154
*/
1155
locking_selftest();
1156
1157
#ifdef CONFIG_BLK_DEV_INITRD
1158
if (initrd_start && !initrd_below_start_ok &&
1159
page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1160
pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1161
page_to_pfn(virt_to_page((void *)initrd_start)),
1162
min_low_pfn);
1163
initrd_start = 0;
1164
}
1165
#endif
1166
setup_per_cpu_pageset();
1167
numa_policy_init();
1168
acpi_early_init();
1169
if (late_time_init)
1170
late_time_init();
1171
sched_clock_init();
1172
calibrate_delay();
1173
1174
arch_cpu_finalize_init();
1175
1176
pid_idr_init();
1177
anon_vma_init();
1178
thread_stack_cache_init();
1179
cred_init();
1180
fork_init();
1181
proc_caches_init();
1182
uts_ns_init();
1183
time_ns_init();
1184
key_init();
1185
security_init();
1186
dbg_late_init();
1187
net_ns_init();
1188
vfs_caches_init();
1189
pagecache_init();
1190
signals_init();
1191
seq_file_init();
1192
proc_root_init();
1193
nsfs_init();
1194
pidfs_init();
1195
cpuset_init();
1196
mem_cgroup_init();
1197
cgroup_init();
1198
taskstats_init_early();
1199
delayacct_init();
1200
1201
acpi_subsystem_init();
1202
arch_post_acpi_subsys_init();
1203
kcsan_init();
1204
1205
/* Do the rest non-__init'ed, we're now alive */
1206
rest_init();
1207
1208
/*
1209
* Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
1210
* and older.
1211
*/
1212
#if !__has_attribute(__no_stack_protector__)
1213
prevent_tail_call_optimization();
1214
#endif
1215
}
1216
1217
/* Call all constructor functions linked into the kernel. */
1218
static void __init do_ctors(void)
1219
{
1220
/*
1221
* For UML, the constructors have already been called by the
1222
* normal setup code as it's just a normal ELF binary, so we
1223
* cannot do it again - but we do need CONFIG_CONSTRUCTORS
1224
* even on UML for modules.
1225
*/
1226
#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1227
ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1228
1229
for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1230
(*fn)();
1231
#endif
1232
}
1233
1234
#ifdef CONFIG_KALLSYMS
1235
struct blacklist_entry {
1236
struct list_head next;
1237
char *buf;
1238
};
1239
1240
static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1241
1242
static int __init initcall_blacklist(char *str)
1243
{
1244
char *str_entry;
1245
struct blacklist_entry *entry;
1246
1247
/* str argument is a comma-separated list of functions */
1248
do {
1249
str_entry = strsep(&str, ",");
1250
if (str_entry) {
1251
pr_debug("blacklisting initcall %s\n", str_entry);
1252
entry = memblock_alloc_or_panic(sizeof(*entry),
1253
SMP_CACHE_BYTES);
1254
entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1,
1255
SMP_CACHE_BYTES);
1256
strcpy(entry->buf, str_entry);
1257
list_add(&entry->next, &blacklisted_initcalls);
1258
}
1259
} while (str_entry);
1260
1261
return 1;
1262
}
1263
1264
static bool __init_or_module initcall_blacklisted(initcall_t fn)
1265
{
1266
struct blacklist_entry *entry;
1267
char fn_name[KSYM_SYMBOL_LEN];
1268
unsigned long addr;
1269
1270
if (list_empty(&blacklisted_initcalls))
1271
return false;
1272
1273
addr = (unsigned long) dereference_function_descriptor(fn);
1274
sprint_symbol_no_offset(fn_name, addr);
1275
1276
/*
1277
* fn will be "function_name [module_name]" where [module_name] is not
1278
* displayed for built-in init functions. Strip off the [module_name].
1279
*/
1280
strreplace(fn_name, ' ', '\0');
1281
1282
list_for_each_entry(entry, &blacklisted_initcalls, next) {
1283
if (!strcmp(fn_name, entry->buf)) {
1284
pr_debug("initcall %s blacklisted\n", fn_name);
1285
return true;
1286
}
1287
}
1288
1289
return false;
1290
}
1291
#else
1292
static int __init initcall_blacklist(char *str)
1293
{
1294
pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1295
return 0;
1296
}
1297
1298
static bool __init_or_module initcall_blacklisted(initcall_t fn)
1299
{
1300
return false;
1301
}
1302
#endif
1303
__setup("initcall_blacklist=", initcall_blacklist);
1304
1305
static __init_or_module void
1306
trace_initcall_start_cb(void *data, initcall_t fn)
1307
{
1308
ktime_t *calltime = data;
1309
1310
printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1311
*calltime = ktime_get();
1312
}
1313
1314
static __init_or_module void
1315
trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1316
{
1317
ktime_t rettime, *calltime = data;
1318
1319
rettime = ktime_get();
1320
printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1321
fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1322
}
1323
1324
static __init_or_module void
1325
trace_initcall_level_cb(void *data, const char *level)
1326
{
1327
printk(KERN_DEBUG "entering initcall level: %s\n", level);
1328
}
1329
1330
static ktime_t initcall_calltime;
1331
1332
#ifdef TRACEPOINTS_ENABLED
1333
static void __init initcall_debug_enable(void)
1334
{
1335
int ret;
1336
1337
ret = register_trace_initcall_start(trace_initcall_start_cb,
1338
&initcall_calltime);
1339
ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1340
&initcall_calltime);
1341
ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL);
1342
WARN(ret, "Failed to register initcall tracepoints\n");
1343
}
1344
# define do_trace_initcall_start trace_initcall_start
1345
# define do_trace_initcall_finish trace_initcall_finish
1346
# define do_trace_initcall_level trace_initcall_level
1347
#else
1348
static inline void do_trace_initcall_start(initcall_t fn)
1349
{
1350
if (!initcall_debug)
1351
return;
1352
trace_initcall_start_cb(&initcall_calltime, fn);
1353
}
1354
static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1355
{
1356
if (!initcall_debug)
1357
return;
1358
trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1359
}
1360
static inline void do_trace_initcall_level(const char *level)
1361
{
1362
if (!initcall_debug)
1363
return;
1364
trace_initcall_level_cb(NULL, level);
1365
}
1366
#endif /* !TRACEPOINTS_ENABLED */
1367
1368
int __init_or_module do_one_initcall(initcall_t fn)
1369
{
1370
int count = preempt_count();
1371
char msgbuf[64];
1372
int ret;
1373
1374
if (initcall_blacklisted(fn))
1375
return -EPERM;
1376
1377
do_trace_initcall_start(fn);
1378
ret = fn();
1379
do_trace_initcall_finish(fn, ret);
1380
1381
msgbuf[0] = 0;
1382
1383
if (preempt_count() != count) {
1384
sprintf(msgbuf, "preemption imbalance ");
1385
preempt_count_set(count);
1386
}
1387
if (irqs_disabled()) {
1388
strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1389
local_irq_enable();
1390
}
1391
WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1392
1393
add_latent_entropy();
1394
return ret;
1395
}
1396
1397
1398
static initcall_entry_t *initcall_levels[] __initdata = {
1399
__initcall0_start,
1400
__initcall1_start,
1401
__initcall2_start,
1402
__initcall3_start,
1403
__initcall4_start,
1404
__initcall5_start,
1405
__initcall6_start,
1406
__initcall7_start,
1407
__initcall_end,
1408
};
1409
1410
/* Keep these in sync with initcalls in include/linux/init.h */
1411
static const char *initcall_level_names[] __initdata = {
1412
"pure",
1413
"core",
1414
"postcore",
1415
"arch",
1416
"subsys",
1417
"fs",
1418
"device",
1419
"late",
1420
};
1421
1422
static int __init ignore_unknown_bootoption(char *param, char *val,
1423
const char *unused, void *arg)
1424
{
1425
return 0;
1426
}
1427
1428
static void __init do_initcall_level(int level, char *command_line)
1429
{
1430
initcall_entry_t *fn;
1431
1432
parse_args(initcall_level_names[level],
1433
command_line, __start___param,
1434
__stop___param - __start___param,
1435
level, level,
1436
NULL, ignore_unknown_bootoption);
1437
1438
do_trace_initcall_level(initcall_level_names[level]);
1439
for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1440
do_one_initcall(initcall_from_entry(fn));
1441
}
1442
1443
static void __init do_initcalls(void)
1444
{
1445
int level;
1446
size_t len = saved_command_line_len + 1;
1447
char *command_line;
1448
1449
command_line = kzalloc(len, GFP_KERNEL);
1450
if (!command_line)
1451
panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1452
1453
for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1454
/* Parser modifies command_line, restore it each time */
1455
strcpy(command_line, saved_command_line);
1456
do_initcall_level(level, command_line);
1457
}
1458
1459
kfree(command_line);
1460
}
1461
1462
/*
1463
* Ok, the machine is now initialized. None of the devices
1464
* have been touched yet, but the CPU subsystem is up and
1465
* running, and memory and process management works.
1466
*
1467
* Now we can finally start doing some real work..
1468
*/
1469
static void __init do_basic_setup(void)
1470
{
1471
cpuset_init_smp();
1472
driver_init();
1473
init_irq_proc();
1474
do_ctors();
1475
do_initcalls();
1476
}
1477
1478
static void __init do_pre_smp_initcalls(void)
1479
{
1480
initcall_entry_t *fn;
1481
1482
do_trace_initcall_level("early");
1483
for (fn = __initcall_start; fn < __initcall0_start; fn++)
1484
do_one_initcall(initcall_from_entry(fn));
1485
}
1486
1487
static int run_init_process(const char *init_filename)
1488
{
1489
const char *const *p;
1490
1491
argv_init[0] = init_filename;
1492
pr_info("Run %s as init process\n", init_filename);
1493
pr_debug(" with arguments:\n");
1494
for (p = argv_init; *p; p++)
1495
pr_debug(" %s\n", *p);
1496
pr_debug(" with environment:\n");
1497
for (p = envp_init; *p; p++)
1498
pr_debug(" %s\n", *p);
1499
return kernel_execve(init_filename, argv_init, envp_init);
1500
}
1501
1502
static int try_to_run_init_process(const char *init_filename)
1503
{
1504
int ret;
1505
1506
ret = run_init_process(init_filename);
1507
1508
if (ret && ret != -ENOENT) {
1509
pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1510
init_filename, ret);
1511
}
1512
1513
return ret;
1514
}
1515
1516
static noinline void __init kernel_init_freeable(void);
1517
1518
#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1519
bool rodata_enabled __ro_after_init = true;
1520
1521
#ifndef arch_parse_debug_rodata
1522
static inline bool arch_parse_debug_rodata(char *str) { return false; }
1523
#endif
1524
1525
static int __init set_debug_rodata(char *str)
1526
{
1527
if (arch_parse_debug_rodata(str))
1528
return 0;
1529
1530
if (str && !strcmp(str, "on"))
1531
rodata_enabled = true;
1532
else if (str && !strcmp(str, "off"))
1533
rodata_enabled = false;
1534
else
1535
pr_warn("Invalid option string for rodata: '%s'\n", str);
1536
return 0;
1537
}
1538
early_param("rodata", set_debug_rodata);
1539
#endif
1540
1541
static void mark_readonly(void)
1542
{
1543
if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) {
1544
/*
1545
* load_module() results in W+X mappings, which are cleaned
1546
* up with init_free_wq. Let's make sure that queued work is
1547
* flushed so that we don't hit false positives looking for
1548
* insecure pages which are W+X.
1549
*/
1550
flush_module_init_free_work();
1551
jump_label_init_ro();
1552
mark_rodata_ro();
1553
debug_checkwx();
1554
rodata_test();
1555
} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
1556
pr_info("Kernel memory protection disabled.\n");
1557
} else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) {
1558
pr_warn("Kernel memory protection not selected by kernel config.\n");
1559
} else {
1560
pr_warn("This architecture does not have kernel memory protection.\n");
1561
}
1562
}
1563
1564
void __weak free_initmem(void)
1565
{
1566
free_initmem_default(POISON_FREE_INITMEM);
1567
}
1568
1569
static int __ref kernel_init(void *unused)
1570
{
1571
int ret;
1572
1573
/*
1574
* Wait until kthreadd is all set-up.
1575
*/
1576
wait_for_completion(&kthreadd_done);
1577
1578
kernel_init_freeable();
1579
/* need to finish all async __init code before freeing the memory */
1580
async_synchronize_full();
1581
1582
system_state = SYSTEM_FREEING_INITMEM;
1583
kprobe_free_init_mem();
1584
ftrace_free_init_mem();
1585
kgdb_free_init_mem();
1586
exit_boot_config();
1587
free_initmem();
1588
mark_readonly();
1589
1590
/*
1591
* Kernel mappings are now finalized - update the userspace page-table
1592
* to finalize PTI.
1593
*/
1594
pti_finalize();
1595
1596
system_state = SYSTEM_RUNNING;
1597
numa_default_policy();
1598
1599
rcu_end_inkernel_boot();
1600
1601
do_sysctl_args();
1602
1603
if (ramdisk_execute_command) {
1604
ret = run_init_process(ramdisk_execute_command);
1605
if (!ret)
1606
return 0;
1607
pr_err("Failed to execute %s (error %d)\n",
1608
ramdisk_execute_command, ret);
1609
}
1610
1611
/*
1612
* We try each of these until one succeeds.
1613
*
1614
* The Bourne shell can be used instead of init if we are
1615
* trying to recover a really broken machine.
1616
*/
1617
if (execute_command) {
1618
ret = run_init_process(execute_command);
1619
if (!ret)
1620
return 0;
1621
panic("Requested init %s failed (error %d).",
1622
execute_command, ret);
1623
}
1624
1625
if (CONFIG_DEFAULT_INIT[0] != '\0') {
1626
ret = run_init_process(CONFIG_DEFAULT_INIT);
1627
if (ret)
1628
pr_err("Default init %s failed (error %d)\n",
1629
CONFIG_DEFAULT_INIT, ret);
1630
else
1631
return 0;
1632
}
1633
1634
if (!try_to_run_init_process("/sbin/init") ||
1635
!try_to_run_init_process("/etc/init") ||
1636
!try_to_run_init_process("/bin/init") ||
1637
!try_to_run_init_process("/bin/sh"))
1638
return 0;
1639
1640
panic("No working init found. Try passing init= option to kernel. "
1641
"See Linux Documentation/admin-guide/init.rst for guidance.");
1642
}
1643
1644
/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1645
void __init console_on_rootfs(void)
1646
{
1647
struct file *file = filp_open("/dev/console", O_RDWR, 0);
1648
1649
if (IS_ERR(file)) {
1650
pr_err("Warning: unable to open an initial console.\n");
1651
return;
1652
}
1653
init_dup(file);
1654
init_dup(file);
1655
init_dup(file);
1656
fput(file);
1657
}
1658
1659
static noinline void __init kernel_init_freeable(void)
1660
{
1661
/* Now the scheduler is fully set up and can do blocking allocations */
1662
gfp_allowed_mask = __GFP_BITS_MASK;
1663
1664
/*
1665
* init can allocate pages on any node
1666
*/
1667
set_mems_allowed(node_states[N_MEMORY]);
1668
1669
cad_pid = get_pid(task_pid(current));
1670
1671
smp_prepare_cpus(setup_max_cpus);
1672
1673
workqueue_init();
1674
1675
init_mm_internals();
1676
1677
do_pre_smp_initcalls();
1678
lockup_detector_init();
1679
1680
smp_init();
1681
sched_init_smp();
1682
1683
workqueue_init_topology();
1684
async_init();
1685
padata_init();
1686
page_alloc_init_late();
1687
1688
do_basic_setup();
1689
1690
kunit_run_all_tests();
1691
1692
wait_for_initramfs();
1693
console_on_rootfs();
1694
1695
/*
1696
* check if there is an early userspace init. If yes, let it do all
1697
* the work
1698
*/
1699
int ramdisk_command_access;
1700
ramdisk_command_access = init_eaccess(ramdisk_execute_command);
1701
if (ramdisk_command_access != 0) {
1702
pr_warn("check access for rdinit=%s failed: %i, ignoring\n",
1703
ramdisk_execute_command, ramdisk_command_access);
1704
ramdisk_execute_command = NULL;
1705
prepare_namespace();
1706
}
1707
1708
/*
1709
* Ok, we have completed the initial bootup, and
1710
* we're essentially up and running. Get rid of the
1711
* initmem segments and start the user-mode stuff..
1712
*
1713
* rootfs is available now, try loading the public keys
1714
* and default modules
1715
*/
1716
1717
integrity_load_keys();
1718
}
1719
1720