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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 <linux/unaligned.h>
108
#include <net/net_namespace.h>
109
110
#include <asm/io.h>
111
#include <asm/setup.h>
112
#include <asm/sections.h>
113
#include <asm/cacheflush.h>
114
115
#define CREATE_TRACE_POINTS
116
#include <trace/events/initcall.h>
117
118
#include <kunit/test.h>
119
120
static int kernel_init(void *);
121
122
/*
123
* Debug helper: via this flag we know that we are in 'early bootup code'
124
* where only the boot processor is running with IRQ disabled. This means
125
* two things - IRQ must not be enabled before the flag is cleared and some
126
* operations which are not allowed with IRQ disabled are allowed while the
127
* flag is set.
128
*/
129
bool early_boot_irqs_disabled __read_mostly;
130
131
enum system_states system_state __read_mostly;
132
EXPORT_SYMBOL(system_state);
133
134
/*
135
* Boot command-line arguments
136
*/
137
#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
138
#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
139
140
/* Default late time init is NULL. archs can override this later. */
141
void (*__initdata late_time_init)(void);
142
143
/* Untouched command line saved by arch-specific code. */
144
char __initdata boot_command_line[COMMAND_LINE_SIZE];
145
/* Untouched saved command line (eg. for /proc) */
146
char *saved_command_line __ro_after_init;
147
unsigned int saved_command_line_len __ro_after_init;
148
/* Command line for parameter parsing */
149
static char *static_command_line;
150
/* Untouched extra command line */
151
static char *extra_command_line;
152
/* Extra init arguments */
153
static char *extra_init_args;
154
155
#ifdef CONFIG_BOOT_CONFIG
156
/* Is bootconfig on command line? */
157
static bool bootconfig_found;
158
static size_t initargs_offs;
159
#else
160
# define bootconfig_found false
161
# define initargs_offs 0
162
#endif
163
164
static char *execute_command;
165
static char *ramdisk_execute_command = "/init";
166
static bool __initdata ramdisk_execute_command_set;
167
168
/*
169
* Used to generate warnings if static_key manipulation functions are used
170
* before jump_label_init is called.
171
*/
172
bool static_key_initialized __read_mostly;
173
EXPORT_SYMBOL_GPL(static_key_initialized);
174
175
/*
176
* If set, this is an indication to the drivers that reset the underlying
177
* device before going ahead with the initialization otherwise driver might
178
* rely on the BIOS and skip the reset operation.
179
*
180
* This is useful if kernel is booting in an unreliable environment.
181
* For ex. kdump situation where previous kernel has crashed, BIOS has been
182
* skipped and devices will be in unknown state.
183
*/
184
unsigned int reset_devices;
185
EXPORT_SYMBOL(reset_devices);
186
187
static int __init set_reset_devices(char *str)
188
{
189
reset_devices = 1;
190
return 1;
191
}
192
193
__setup("reset_devices", set_reset_devices);
194
195
static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
196
const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
197
static const char *panic_later, *panic_param;
198
199
static bool __init obsolete_checksetup(char *line)
200
{
201
const struct obs_kernel_param *p;
202
bool had_early_param = false;
203
204
p = __setup_start;
205
do {
206
int n = strlen(p->str);
207
if (parameqn(line, p->str, n)) {
208
if (p->early) {
209
/* Already done in parse_early_param?
210
* (Needs exact match on param part).
211
* Keep iterating, as we can have early
212
* params and __setups of same names 8( */
213
if (line[n] == '\0' || line[n] == '=')
214
had_early_param = true;
215
} else if (!p->setup_func) {
216
pr_warn("Parameter %s is obsolete, ignored\n",
217
p->str);
218
return true;
219
} else if (p->setup_func(line + n))
220
return true;
221
}
222
p++;
223
} while (p < __setup_end);
224
225
return had_early_param;
226
}
227
228
/*
229
* This should be approx 2 Bo*oMips to start (note initial shift), and will
230
* still work even if initially too large, it will just take slightly longer
231
*/
232
unsigned long loops_per_jiffy = (1<<12);
233
EXPORT_SYMBOL(loops_per_jiffy);
234
235
static int __init debug_kernel(char *str)
236
{
237
console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
238
return 0;
239
}
240
241
static int __init quiet_kernel(char *str)
242
{
243
console_loglevel = CONSOLE_LOGLEVEL_QUIET;
244
return 0;
245
}
246
247
early_param("debug", debug_kernel);
248
early_param("quiet", quiet_kernel);
249
250
static int __init loglevel(char *str)
251
{
252
int newlevel;
253
254
/*
255
* Only update loglevel value when a correct setting was passed,
256
* to prevent blind crashes (when loglevel being set to 0) that
257
* are quite hard to debug
258
*/
259
if (get_option(&str, &newlevel)) {
260
console_loglevel = newlevel;
261
return 0;
262
}
263
264
return -EINVAL;
265
}
266
267
early_param("loglevel", loglevel);
268
269
#ifdef CONFIG_BLK_DEV_INITRD
270
static void * __init get_boot_config_from_initrd(size_t *_size)
271
{
272
u32 size, csum;
273
char *data;
274
u8 *hdr;
275
int i;
276
277
if (!initrd_end)
278
return NULL;
279
280
data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
281
/*
282
* Since Grub may align the size of initrd to 4, we must
283
* check the preceding 3 bytes as well.
284
*/
285
for (i = 0; i < 4; i++) {
286
if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
287
goto found;
288
data--;
289
}
290
return NULL;
291
292
found:
293
hdr = (u8 *)(data - 8);
294
size = get_unaligned_le32(hdr);
295
csum = get_unaligned_le32(hdr + 4);
296
297
data = ((void *)hdr) - size;
298
if ((unsigned long)data < initrd_start) {
299
pr_err("bootconfig size %d is greater than initrd size %ld\n",
300
size, initrd_end - initrd_start);
301
return NULL;
302
}
303
304
if (xbc_calc_checksum(data, size) != csum) {
305
pr_err("bootconfig checksum failed\n");
306
return NULL;
307
}
308
309
/* Remove bootconfig from initramfs/initrd */
310
initrd_end = (unsigned long)data;
311
if (_size)
312
*_size = size;
313
314
return data;
315
}
316
#else
317
static void * __init get_boot_config_from_initrd(size_t *_size)
318
{
319
return NULL;
320
}
321
#endif
322
323
#ifdef CONFIG_BOOT_CONFIG
324
325
static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
326
327
#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
328
329
static int __init xbc_snprint_cmdline(char *buf, size_t size,
330
struct xbc_node *root)
331
{
332
struct xbc_node *knode, *vnode;
333
char *end = buf + size;
334
const char *val, *q;
335
int ret;
336
337
xbc_node_for_each_key_value(root, knode, val) {
338
ret = xbc_node_compose_key_after(root, knode,
339
xbc_namebuf, XBC_KEYLEN_MAX);
340
if (ret < 0)
341
return ret;
342
343
vnode = xbc_node_get_child(knode);
344
if (!vnode) {
345
ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
346
if (ret < 0)
347
return ret;
348
buf += ret;
349
continue;
350
}
351
xbc_array_for_each_value(vnode, val) {
352
/*
353
* For prettier and more readable /proc/cmdline, only
354
* quote the value when necessary, i.e. when it contains
355
* whitespace.
356
*/
357
q = strpbrk(val, " \t\r\n") ? "\"" : "";
358
ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ",
359
xbc_namebuf, q, val, q);
360
if (ret < 0)
361
return ret;
362
buf += ret;
363
}
364
}
365
366
return buf - (end - size);
367
}
368
#undef rest
369
370
/* Make an extra command line under given key word */
371
static char * __init xbc_make_cmdline(const char *key)
372
{
373
struct xbc_node *root;
374
char *new_cmdline;
375
int ret, len = 0;
376
377
root = xbc_find_node(key);
378
if (!root)
379
return NULL;
380
381
/* Count required buffer size */
382
len = xbc_snprint_cmdline(NULL, 0, root);
383
if (len <= 0)
384
return NULL;
385
386
new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
387
if (!new_cmdline) {
388
pr_err("Failed to allocate memory for extra kernel cmdline.\n");
389
return NULL;
390
}
391
392
ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
393
if (ret < 0 || ret > len) {
394
pr_err("Failed to print extra kernel cmdline.\n");
395
memblock_free(new_cmdline, len + 1);
396
return NULL;
397
}
398
399
return new_cmdline;
400
}
401
402
static int __init bootconfig_params(char *param, char *val,
403
const char *unused, void *arg)
404
{
405
if (strcmp(param, "bootconfig") == 0) {
406
bootconfig_found = true;
407
}
408
return 0;
409
}
410
411
static int __init warn_bootconfig(char *str)
412
{
413
/* The 'bootconfig' has been handled by bootconfig_params(). */
414
return 0;
415
}
416
417
static void __init setup_boot_config(void)
418
{
419
static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
420
const char *msg, *data;
421
int pos, ret;
422
size_t size;
423
char *err;
424
425
/* Cut out the bootconfig data even if we have no bootconfig option */
426
data = get_boot_config_from_initrd(&size);
427
/* If there is no bootconfig in initrd, try embedded one. */
428
if (!data)
429
data = xbc_get_embedded_bootconfig(&size);
430
431
strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
432
err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
433
bootconfig_params);
434
435
if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
436
return;
437
438
/* parse_args() stops at the next param of '--' and returns an address */
439
if (err)
440
initargs_offs = err - tmp_cmdline;
441
442
if (!data) {
443
/* If user intended to use bootconfig, show an error level message */
444
if (bootconfig_found)
445
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
446
else
447
pr_info("No bootconfig data provided, so skipping bootconfig");
448
return;
449
}
450
451
if (size >= XBC_DATA_MAX) {
452
pr_err("bootconfig size %ld greater than max size %d\n",
453
(long)size, XBC_DATA_MAX);
454
return;
455
}
456
457
ret = xbc_init(data, size, &msg, &pos);
458
if (ret < 0) {
459
if (pos < 0)
460
pr_err("Failed to init bootconfig: %s.\n", msg);
461
else
462
pr_err("Failed to parse bootconfig: %s at %d.\n",
463
msg, pos);
464
} else {
465
xbc_get_info(&ret, NULL);
466
pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
467
/* keys starting with "kernel." are passed via cmdline */
468
extra_command_line = xbc_make_cmdline("kernel");
469
/* Also, "init." keys are init arguments */
470
extra_init_args = xbc_make_cmdline("init");
471
}
472
return;
473
}
474
475
static void __init exit_boot_config(void)
476
{
477
xbc_exit();
478
}
479
480
#else /* !CONFIG_BOOT_CONFIG */
481
482
static void __init setup_boot_config(void)
483
{
484
/* Remove bootconfig data from initrd */
485
get_boot_config_from_initrd(NULL);
486
}
487
488
static int __init warn_bootconfig(char *str)
489
{
490
pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
491
return 0;
492
}
493
494
#define exit_boot_config() do {} while (0)
495
496
#endif /* CONFIG_BOOT_CONFIG */
497
498
early_param("bootconfig", warn_bootconfig);
499
500
bool __init cmdline_has_extra_options(void)
501
{
502
return extra_command_line || extra_init_args;
503
}
504
505
/* Change NUL term back to "=", to make "param" the whole string. */
506
static void __init repair_env_string(char *param, char *val)
507
{
508
if (val) {
509
/* param=val or param="val"? */
510
if (val == param+strlen(param)+1)
511
val[-1] = '=';
512
else if (val == param+strlen(param)+2) {
513
val[-2] = '=';
514
memmove(val-1, val, strlen(val)+1);
515
} else
516
BUG();
517
}
518
}
519
520
/* Anything after -- gets handed straight to init. */
521
static int __init set_init_arg(char *param, char *val,
522
const char *unused, void *arg)
523
{
524
unsigned int i;
525
526
if (panic_later)
527
return 0;
528
529
repair_env_string(param, val);
530
531
for (i = 0; argv_init[i]; i++) {
532
if (i == MAX_INIT_ARGS) {
533
panic_later = "init";
534
panic_param = param;
535
return 0;
536
}
537
}
538
argv_init[i] = param;
539
return 0;
540
}
541
542
/*
543
* Unknown boot options get handed to init, unless they look like
544
* unused parameters (modprobe will find them in /proc/cmdline).
545
*/
546
static int __init unknown_bootoption(char *param, char *val,
547
const char *unused, void *arg)
548
{
549
size_t len = strlen(param);
550
/*
551
* Well-known bootloader identifiers:
552
* 1. LILO/Grub pass "BOOT_IMAGE=...";
553
* 2. kexec/kdump (kexec-tools) pass "kexec".
554
*/
555
const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL };
556
557
/* Handle params aliased to sysctls */
558
if (sysctl_is_alias(param))
559
return 0;
560
561
repair_env_string(param, val);
562
563
/* Handle bootloader identifier */
564
for (int i = 0; bootloader[i]; i++) {
565
if (strstarts(param, bootloader[i]))
566
return 0;
567
}
568
569
/* Handle obsolete-style parameters */
570
if (obsolete_checksetup(param))
571
return 0;
572
573
/* Unused module parameter. */
574
if (strnchr(param, len, '.'))
575
return 0;
576
577
if (panic_later)
578
return 0;
579
580
if (val) {
581
/* Environment option */
582
unsigned int i;
583
for (i = 0; envp_init[i]; i++) {
584
if (i == MAX_INIT_ENVS) {
585
panic_later = "env";
586
panic_param = param;
587
}
588
if (!strncmp(param, envp_init[i], len+1))
589
break;
590
}
591
envp_init[i] = param;
592
} else {
593
/* Command line option */
594
unsigned int i;
595
for (i = 0; argv_init[i]; i++) {
596
if (i == MAX_INIT_ARGS) {
597
panic_later = "init";
598
panic_param = param;
599
}
600
}
601
argv_init[i] = param;
602
}
603
return 0;
604
}
605
606
static int __init init_setup(char *str)
607
{
608
unsigned int i;
609
610
execute_command = str;
611
/*
612
* In case LILO is going to boot us with default command line,
613
* it prepends "auto" before the whole cmdline which makes
614
* the shell think it should execute a script with such name.
615
* So we ignore all arguments entered _before_ init=... [MJ]
616
*/
617
for (i = 1; i < MAX_INIT_ARGS; i++)
618
argv_init[i] = NULL;
619
return 1;
620
}
621
__setup("init=", init_setup);
622
623
static int __init rdinit_setup(char *str)
624
{
625
unsigned int i;
626
627
ramdisk_execute_command = str;
628
ramdisk_execute_command_set = true;
629
/* See "auto" comment in init_setup */
630
for (i = 1; i < MAX_INIT_ARGS; i++)
631
argv_init[i] = NULL;
632
return 1;
633
}
634
__setup("rdinit=", rdinit_setup);
635
636
#ifndef CONFIG_SMP
637
static inline void setup_nr_cpu_ids(void) { }
638
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
639
#endif
640
641
/*
642
* We need to store the untouched command line for future reference.
643
* We also need to store the touched command line since the parameter
644
* parsing is performed in place, and we should allow a component to
645
* store reference of name/value for future reference.
646
*/
647
static void __init setup_command_line(char *command_line)
648
{
649
size_t len, xlen = 0, ilen = 0;
650
651
if (extra_command_line)
652
xlen = strlen(extra_command_line);
653
if (extra_init_args) {
654
extra_init_args = strim(extra_init_args); /* remove trailing space */
655
ilen = strlen(extra_init_args) + 4; /* for " -- " */
656
}
657
658
len = xlen + strlen(boot_command_line) + ilen + 1;
659
660
saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
661
662
len = xlen + strlen(command_line) + 1;
663
664
static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
665
666
if (xlen) {
667
/*
668
* We have to put extra_command_line before boot command
669
* lines because there could be dashes (separator of init
670
* command line) in the command lines.
671
*/
672
strcpy(saved_command_line, extra_command_line);
673
strcpy(static_command_line, extra_command_line);
674
}
675
strcpy(saved_command_line + xlen, boot_command_line);
676
strcpy(static_command_line + xlen, command_line);
677
678
if (ilen) {
679
/*
680
* Append supplemental init boot args to saved_command_line
681
* so that user can check what command line options passed
682
* to init.
683
* The order should always be
684
* " -- "[bootconfig init-param][cmdline init-param]
685
*/
686
if (initargs_offs) {
687
len = xlen + initargs_offs;
688
strcpy(saved_command_line + len, extra_init_args);
689
len += ilen - 4; /* strlen(extra_init_args) */
690
strcpy(saved_command_line + len,
691
boot_command_line + initargs_offs - 1);
692
} else {
693
len = strlen(saved_command_line);
694
strcpy(saved_command_line + len, " -- ");
695
len += 4;
696
strcpy(saved_command_line + len, extra_init_args);
697
}
698
}
699
700
saved_command_line_len = strlen(saved_command_line);
701
}
702
703
/*
704
* We need to finalize in a non-__init function or else race conditions
705
* between the root thread and the init thread may cause start_kernel to
706
* be reaped by free_initmem before the root thread has proceeded to
707
* cpu_idle.
708
*
709
* gcc-3.4 accidentally inlines this function, so use noinline.
710
*/
711
712
static __initdata DECLARE_COMPLETION(kthreadd_done);
713
714
static noinline void __ref __noreturn rest_init(void)
715
{
716
struct task_struct *tsk;
717
int pid;
718
719
rcu_scheduler_starting();
720
/*
721
* We need to spawn init first so that it obtains pid 1, however
722
* the init task will end up wanting to create kthreads, which, if
723
* we schedule it before we create kthreadd, will OOPS.
724
*/
725
pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
726
/*
727
* Pin init on the boot CPU. Task migration is not properly working
728
* until sched_init_smp() has been run. It will set the allowed
729
* CPUs for init to the non isolated CPUs.
730
*/
731
rcu_read_lock();
732
tsk = find_task_by_pid_ns(pid, &init_pid_ns);
733
tsk->flags |= PF_NO_SETAFFINITY;
734
set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
735
rcu_read_unlock();
736
737
numa_default_policy();
738
pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
739
rcu_read_lock();
740
kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
741
rcu_read_unlock();
742
743
/*
744
* Enable might_sleep() and smp_processor_id() checks.
745
* They cannot be enabled earlier because with CONFIG_PREEMPTION=y
746
* kernel_thread() would trigger might_sleep() splats. With
747
* CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
748
* already, but it's stuck on the kthreadd_done completion.
749
*/
750
system_state = SYSTEM_SCHEDULING;
751
752
complete(&kthreadd_done);
753
754
/*
755
* The boot idle thread must execute schedule()
756
* at least once to get things moving:
757
*/
758
schedule_preempt_disabled();
759
/* Call into cpu_idle with preempt disabled */
760
cpu_startup_entry(CPUHP_ONLINE);
761
}
762
763
/* Check for early params. */
764
static int __init do_early_param(char *param, char *val,
765
const char *unused, void *arg)
766
{
767
const struct obs_kernel_param *p;
768
769
for (p = __setup_start; p < __setup_end; p++) {
770
if (p->early && parameq(param, p->str)) {
771
if (p->setup_func(val) != 0)
772
pr_warn("Malformed early option '%s'\n", param);
773
}
774
}
775
/* We accept everything at this stage. */
776
return 0;
777
}
778
779
void __init parse_early_options(char *cmdline)
780
{
781
parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
782
do_early_param);
783
}
784
785
/* Arch code calls this early on, or if not, just before other parsing. */
786
void __init parse_early_param(void)
787
{
788
static int done __initdata;
789
static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
790
791
if (done)
792
return;
793
794
/* All fall through to do_early_param. */
795
strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
796
parse_early_options(tmp_cmdline);
797
done = 1;
798
}
799
800
void __init __weak arch_post_acpi_subsys_init(void) { }
801
802
void __init __weak smp_setup_processor_id(void)
803
{
804
}
805
806
void __init __weak smp_prepare_boot_cpu(void)
807
{
808
}
809
810
# if THREAD_SIZE >= PAGE_SIZE
811
void __init __weak thread_stack_cache_init(void)
812
{
813
}
814
#endif
815
816
void __init __weak poking_init(void) { }
817
818
void __init __weak pgtable_cache_init(void) { }
819
820
void __init __weak trap_init(void) { }
821
822
bool initcall_debug;
823
core_param(initcall_debug, initcall_debug, bool, 0644);
824
825
#ifdef TRACEPOINTS_ENABLED
826
static void __init initcall_debug_enable(void);
827
#else
828
static inline void initcall_debug_enable(void)
829
{
830
}
831
#endif
832
833
#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
834
DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
835
randomize_kstack_offset);
836
DEFINE_PER_CPU(u32, kstack_offset);
837
838
static int __init early_randomize_kstack_offset(char *buf)
839
{
840
int ret;
841
bool bool_result;
842
843
ret = kstrtobool(buf, &bool_result);
844
if (ret)
845
return ret;
846
847
if (bool_result)
848
static_branch_enable(&randomize_kstack_offset);
849
else
850
static_branch_disable(&randomize_kstack_offset);
851
return 0;
852
}
853
early_param("randomize_kstack_offset", early_randomize_kstack_offset);
854
#endif
855
856
static void __init print_unknown_bootoptions(void)
857
{
858
char *unknown_options;
859
char *end;
860
const char *const *p;
861
size_t len;
862
863
if (panic_later || (!argv_init[1] && !envp_init[2]))
864
return;
865
866
/*
867
* Determine how many options we have to print out, plus a space
868
* before each
869
*/
870
len = 1; /* null terminator */
871
for (p = &argv_init[1]; *p; p++) {
872
len++;
873
len += strlen(*p);
874
}
875
for (p = &envp_init[2]; *p; p++) {
876
len++;
877
len += strlen(*p);
878
}
879
880
unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
881
if (!unknown_options) {
882
pr_err("%s: Failed to allocate %zu bytes\n",
883
__func__, len);
884
return;
885
}
886
end = unknown_options;
887
888
for (p = &argv_init[1]; *p; p++)
889
end += sprintf(end, " %s", *p);
890
for (p = &envp_init[2]; *p; p++)
891
end += sprintf(end, " %s", *p);
892
893
/* Start at unknown_options[1] to skip the initial space */
894
pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
895
&unknown_options[1]);
896
memblock_free(unknown_options, len);
897
}
898
899
static void __init early_numa_node_init(void)
900
{
901
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
902
#ifndef cpu_to_node
903
int cpu;
904
905
/* The early_cpu_to_node() should be ready here. */
906
for_each_possible_cpu(cpu)
907
set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
908
#endif
909
#endif
910
}
911
912
#define KERNEL_CMDLINE_PREFIX "Kernel command line: "
913
#define KERNEL_CMDLINE_PREFIX_LEN (sizeof(KERNEL_CMDLINE_PREFIX) - 1)
914
#define KERNEL_CMDLINE_CONTINUATION " \\"
915
#define KERNEL_CMDLINE_CONTINUATION_LEN (sizeof(KERNEL_CMDLINE_CONTINUATION) - 1)
916
917
#define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN (KERNEL_CMDLINE_PREFIX_LEN + \
918
KERNEL_CMDLINE_CONTINUATION_LEN)
919
#define CMDLINE_LOG_WRAP_IDEAL_LEN (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \
920
MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \
921
CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \
922
MIN_CMDLINE_LOG_WRAP_IDEAL_LEN)
923
924
#define IDEAL_CMDLINE_LEN (CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN)
925
#define IDEAL_CMDLINE_SPLIT_LEN (IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN)
926
927
/**
928
* print_kernel_cmdline() - Print the kernel cmdline with wrapping.
929
* @cmdline: The cmdline to print.
930
*
931
* Print the kernel command line, trying to wrap based on the Kconfig knob
932
* CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN.
933
*
934
* Wrapping is based on spaces, ignoring quotes. All lines are prefixed
935
* with "Kernel command line: " and lines that are not the last line have
936
* a " \" suffix added to them. The prefix and suffix count towards the
937
* line length for wrapping purposes. The ideal length will be exceeded
938
* if no appropriate place to wrap is found.
939
*
940
* Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40:
941
* Kernel command line: loglevel=7 \
942
* Kernel command line: init=/sbin/init \
943
* Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \
944
* Kernel command line: rootwait ro \
945
* Kernel command line: my_quoted_arg="The \
946
* Kernel command line: quick brown fox \
947
* Kernel command line: jumps over the \
948
* Kernel command line: lazy dog."
949
*/
950
static void __init print_kernel_cmdline(const char *cmdline)
951
{
952
size_t len;
953
954
/* Config option of 0 or anything longer than the max disables wrapping */
955
if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 ||
956
IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) {
957
pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
958
return;
959
}
960
961
len = strlen(cmdline);
962
while (len > IDEAL_CMDLINE_LEN) {
963
const char *first_space;
964
const char *prev_cutoff;
965
const char *cutoff;
966
int to_print;
967
size_t used;
968
969
/* Find the last ' ' that wouldn't make the line too long */
970
prev_cutoff = NULL;
971
cutoff = cmdline;
972
while (true) {
973
cutoff = strchr(cutoff + 1, ' ');
974
if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN)
975
break;
976
prev_cutoff = cutoff;
977
}
978
if (prev_cutoff)
979
cutoff = prev_cutoff;
980
else if (!cutoff)
981
break;
982
983
/* Find the beginning and end of the string of spaces */
984
first_space = cutoff;
985
while (first_space > cmdline && first_space[-1] == ' ')
986
first_space--;
987
to_print = first_space - cmdline;
988
while (*cutoff == ' ')
989
cutoff++;
990
used = cutoff - cmdline;
991
992
/* If the whole string is used, break and do the final printout */
993
if (len == used)
994
break;
995
996
if (to_print)
997
pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX,
998
to_print, cmdline, KERNEL_CMDLINE_CONTINUATION);
999
1000
len -= used;
1001
cmdline += used;
1002
}
1003
if (len)
1004
pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
1005
}
1006
1007
asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
1008
void start_kernel(void)
1009
{
1010
char *command_line;
1011
char *after_dashes;
1012
1013
set_task_stack_end_magic(&init_task);
1014
smp_setup_processor_id();
1015
debug_objects_early_init();
1016
init_vmlinux_build_id();
1017
1018
cgroup_init_early();
1019
1020
local_irq_disable();
1021
early_boot_irqs_disabled = true;
1022
1023
/*
1024
* Interrupts are still disabled. Do necessary setups, then
1025
* enable them.
1026
*/
1027
boot_cpu_init();
1028
page_address_init();
1029
pr_notice("%s", linux_banner);
1030
setup_arch(&command_line);
1031
mm_core_init_early();
1032
/* Static keys and static calls are needed by LSMs */
1033
jump_label_init();
1034
static_call_init();
1035
early_security_init();
1036
setup_boot_config();
1037
setup_command_line(command_line);
1038
setup_nr_cpu_ids();
1039
setup_per_cpu_areas();
1040
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
1041
early_numa_node_init();
1042
boot_cpu_hotplug_init();
1043
1044
print_kernel_cmdline(saved_command_line);
1045
/* parameters may set static keys */
1046
parse_early_param();
1047
after_dashes = parse_args("Booting kernel",
1048
static_command_line, __start___param,
1049
__stop___param - __start___param,
1050
-1, -1, NULL, &unknown_bootoption);
1051
print_unknown_bootoptions();
1052
if (!IS_ERR_OR_NULL(after_dashes))
1053
parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
1054
NULL, set_init_arg);
1055
if (extra_init_args)
1056
parse_args("Setting extra init args", extra_init_args,
1057
NULL, 0, -1, -1, NULL, set_init_arg);
1058
1059
/* Architectural and non-timekeeping rng init, before allocator init */
1060
random_init_early(command_line);
1061
1062
/*
1063
* These use large bootmem allocations and must precede
1064
* initalization of page allocator
1065
*/
1066
setup_log_buf(0);
1067
vfs_caches_init_early();
1068
sort_main_extable();
1069
trap_init();
1070
mm_core_init();
1071
maple_tree_init();
1072
poking_init();
1073
ftrace_init();
1074
1075
/* trace_printk can be enabled here */
1076
early_trace_init();
1077
1078
/*
1079
* Set up the scheduler prior starting any interrupts (such as the
1080
* timer interrupt). Full topology setup happens at smp_init()
1081
* time - but meanwhile we still have a functioning scheduler.
1082
*/
1083
sched_init();
1084
1085
if (WARN(!irqs_disabled(),
1086
"Interrupts were enabled *very* early, fixing it\n"))
1087
local_irq_disable();
1088
radix_tree_init();
1089
1090
/*
1091
* Set up housekeeping before setting up workqueues to allow the unbound
1092
* workqueue to take non-housekeeping into account.
1093
*/
1094
housekeeping_init();
1095
1096
/*
1097
* Allow workqueue creation and work item queueing/cancelling
1098
* early. Work item execution depends on kthreads and starts after
1099
* workqueue_init().
1100
*/
1101
workqueue_init_early();
1102
1103
rcu_init();
1104
kvfree_rcu_init();
1105
1106
/* Trace events are available after this */
1107
trace_init();
1108
1109
if (initcall_debug)
1110
initcall_debug_enable();
1111
1112
context_tracking_init();
1113
/* init some links before init_ISA_irqs() */
1114
early_irq_init();
1115
init_IRQ();
1116
tick_init();
1117
rcu_init_nohz();
1118
timers_init();
1119
srcu_init();
1120
hrtimers_init();
1121
softirq_init();
1122
timekeeping_init();
1123
time_init();
1124
1125
/* This must be after timekeeping is initialized */
1126
random_init();
1127
1128
/* These make use of the fully initialized rng */
1129
kfence_init();
1130
boot_init_stack_canary();
1131
1132
perf_event_init();
1133
profile_init();
1134
call_function_init();
1135
WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1136
1137
early_boot_irqs_disabled = false;
1138
local_irq_enable();
1139
1140
kmem_cache_init_late();
1141
1142
/*
1143
* HACK ALERT! This is early. We're enabling the console before
1144
* we've done PCI setups etc, and console_init() must be aware of
1145
* this. But we do want output early, in case something goes wrong.
1146
*/
1147
console_init();
1148
if (panic_later)
1149
panic("Too many boot %s vars at `%s'", panic_later,
1150
panic_param);
1151
1152
lockdep_init();
1153
1154
/*
1155
* Need to run this when irqs are enabled, because it wants
1156
* to self-test [hard/soft]-irqs on/off lock inversion bugs
1157
* too:
1158
*/
1159
locking_selftest();
1160
1161
#ifdef CONFIG_BLK_DEV_INITRD
1162
if (initrd_start && !initrd_below_start_ok &&
1163
page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1164
pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1165
page_to_pfn(virt_to_page((void *)initrd_start)),
1166
min_low_pfn);
1167
initrd_start = 0;
1168
}
1169
#endif
1170
setup_per_cpu_pageset();
1171
numa_policy_init();
1172
acpi_early_init();
1173
if (late_time_init)
1174
late_time_init();
1175
sched_clock_init();
1176
calibrate_delay();
1177
1178
arch_cpu_finalize_init();
1179
1180
pid_idr_init();
1181
anon_vma_init();
1182
thread_stack_cache_init();
1183
cred_init();
1184
fork_init();
1185
proc_caches_init();
1186
uts_ns_init();
1187
time_ns_init();
1188
key_init();
1189
security_init();
1190
dbg_late_init();
1191
net_ns_init();
1192
vfs_caches_init();
1193
pagecache_init();
1194
signals_init();
1195
seq_file_init();
1196
proc_root_init();
1197
nsfs_init();
1198
pidfs_init();
1199
cpuset_init();
1200
mem_cgroup_init();
1201
cgroup_init();
1202
taskstats_init_early();
1203
delayacct_init();
1204
1205
acpi_subsystem_init();
1206
arch_post_acpi_subsys_init();
1207
kcsan_init();
1208
1209
/* Do the rest non-__init'ed, we're now alive */
1210
rest_init();
1211
1212
/*
1213
* Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
1214
* and older.
1215
*/
1216
#if !__has_attribute(__no_stack_protector__)
1217
prevent_tail_call_optimization();
1218
#endif
1219
}
1220
1221
/* Call all constructor functions linked into the kernel. */
1222
static void __init do_ctors(void)
1223
{
1224
/*
1225
* For UML, the constructors have already been called by the
1226
* normal setup code as it's just a normal ELF binary, so we
1227
* cannot do it again - but we do need CONFIG_CONSTRUCTORS
1228
* even on UML for modules.
1229
*/
1230
#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1231
ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1232
1233
for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1234
(*fn)();
1235
#endif
1236
}
1237
1238
#ifdef CONFIG_KALLSYMS
1239
struct blacklist_entry {
1240
struct list_head next;
1241
char *buf;
1242
};
1243
1244
static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1245
1246
static int __init initcall_blacklist(char *str)
1247
{
1248
char *str_entry;
1249
struct blacklist_entry *entry;
1250
1251
/* str argument is a comma-separated list of functions */
1252
do {
1253
str_entry = strsep(&str, ",");
1254
if (str_entry) {
1255
pr_debug("blacklisting initcall %s\n", str_entry);
1256
entry = memblock_alloc_or_panic(sizeof(*entry),
1257
SMP_CACHE_BYTES);
1258
entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1,
1259
SMP_CACHE_BYTES);
1260
strcpy(entry->buf, str_entry);
1261
list_add(&entry->next, &blacklisted_initcalls);
1262
}
1263
} while (str_entry);
1264
1265
return 1;
1266
}
1267
1268
static bool __init_or_module initcall_blacklisted(initcall_t fn)
1269
{
1270
struct blacklist_entry *entry;
1271
char fn_name[KSYM_SYMBOL_LEN];
1272
unsigned long addr;
1273
1274
if (list_empty(&blacklisted_initcalls))
1275
return false;
1276
1277
addr = (unsigned long) dereference_function_descriptor(fn);
1278
sprint_symbol_no_offset(fn_name, addr);
1279
1280
/*
1281
* fn will be "function_name [module_name]" where [module_name] is not
1282
* displayed for built-in init functions. Strip off the [module_name].
1283
*/
1284
strreplace(fn_name, ' ', '\0');
1285
1286
list_for_each_entry(entry, &blacklisted_initcalls, next) {
1287
if (!strcmp(fn_name, entry->buf)) {
1288
pr_debug("initcall %s blacklisted\n", fn_name);
1289
return true;
1290
}
1291
}
1292
1293
return false;
1294
}
1295
#else
1296
static int __init initcall_blacklist(char *str)
1297
{
1298
pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1299
return 0;
1300
}
1301
1302
static bool __init_or_module initcall_blacklisted(initcall_t fn)
1303
{
1304
return false;
1305
}
1306
#endif
1307
__setup("initcall_blacklist=", initcall_blacklist);
1308
1309
static __init_or_module void
1310
trace_initcall_start_cb(void *data, initcall_t fn)
1311
{
1312
ktime_t *calltime = data;
1313
1314
printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1315
*calltime = ktime_get();
1316
}
1317
1318
static __init_or_module void
1319
trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1320
{
1321
ktime_t rettime, *calltime = data;
1322
1323
rettime = ktime_get();
1324
printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1325
fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1326
}
1327
1328
static __init_or_module void
1329
trace_initcall_level_cb(void *data, const char *level)
1330
{
1331
printk(KERN_DEBUG "entering initcall level: %s\n", level);
1332
}
1333
1334
static ktime_t initcall_calltime;
1335
1336
#ifdef TRACEPOINTS_ENABLED
1337
static void __init initcall_debug_enable(void)
1338
{
1339
int ret;
1340
1341
ret = register_trace_initcall_start(trace_initcall_start_cb,
1342
&initcall_calltime);
1343
ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1344
&initcall_calltime);
1345
ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL);
1346
WARN(ret, "Failed to register initcall tracepoints\n");
1347
}
1348
# define do_trace_initcall_start trace_initcall_start
1349
# define do_trace_initcall_finish trace_initcall_finish
1350
# define do_trace_initcall_level trace_initcall_level
1351
#else
1352
static inline void do_trace_initcall_start(initcall_t fn)
1353
{
1354
if (!initcall_debug)
1355
return;
1356
trace_initcall_start_cb(&initcall_calltime, fn);
1357
}
1358
static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1359
{
1360
if (!initcall_debug)
1361
return;
1362
trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1363
}
1364
static inline void do_trace_initcall_level(const char *level)
1365
{
1366
if (!initcall_debug)
1367
return;
1368
trace_initcall_level_cb(NULL, level);
1369
}
1370
#endif /* !TRACEPOINTS_ENABLED */
1371
1372
int __init_or_module do_one_initcall(initcall_t fn)
1373
{
1374
int count = preempt_count();
1375
char msgbuf[64];
1376
int ret;
1377
1378
if (initcall_blacklisted(fn))
1379
return -EPERM;
1380
1381
do_trace_initcall_start(fn);
1382
ret = fn();
1383
do_trace_initcall_finish(fn, ret);
1384
1385
msgbuf[0] = 0;
1386
1387
if (preempt_count() != count) {
1388
sprintf(msgbuf, "preemption imbalance ");
1389
preempt_count_set(count);
1390
}
1391
if (irqs_disabled()) {
1392
strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1393
local_irq_enable();
1394
}
1395
WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1396
1397
add_latent_entropy();
1398
return ret;
1399
}
1400
1401
1402
static initcall_entry_t *initcall_levels[] __initdata = {
1403
__initcall0_start,
1404
__initcall1_start,
1405
__initcall2_start,
1406
__initcall3_start,
1407
__initcall4_start,
1408
__initcall5_start,
1409
__initcall6_start,
1410
__initcall7_start,
1411
__initcall_end,
1412
};
1413
1414
/* Keep these in sync with initcalls in include/linux/init.h */
1415
static const char *initcall_level_names[] __initdata = {
1416
"pure",
1417
"core",
1418
"postcore",
1419
"arch",
1420
"subsys",
1421
"fs",
1422
"device",
1423
"late",
1424
};
1425
1426
static int __init ignore_unknown_bootoption(char *param, char *val,
1427
const char *unused, void *arg)
1428
{
1429
return 0;
1430
}
1431
1432
static void __init do_initcall_level(int level, char *command_line)
1433
{
1434
initcall_entry_t *fn;
1435
1436
parse_args(initcall_level_names[level],
1437
command_line, __start___param,
1438
__stop___param - __start___param,
1439
level, level,
1440
NULL, ignore_unknown_bootoption);
1441
1442
do_trace_initcall_level(initcall_level_names[level]);
1443
for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1444
do_one_initcall(initcall_from_entry(fn));
1445
}
1446
1447
static void __init do_initcalls(void)
1448
{
1449
int level;
1450
size_t len = saved_command_line_len + 1;
1451
char *command_line;
1452
1453
command_line = kzalloc(len, GFP_KERNEL);
1454
if (!command_line)
1455
panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1456
1457
for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1458
/* Parser modifies command_line, restore it each time */
1459
strcpy(command_line, saved_command_line);
1460
do_initcall_level(level, command_line);
1461
}
1462
1463
kfree(command_line);
1464
}
1465
1466
/*
1467
* Ok, the machine is now initialized. None of the devices
1468
* have been touched yet, but the CPU subsystem is up and
1469
* running, and memory and process management works.
1470
*
1471
* Now we can finally start doing some real work..
1472
*/
1473
static void __init do_basic_setup(void)
1474
{
1475
cpuset_init_smp();
1476
driver_init();
1477
init_irq_proc();
1478
do_ctors();
1479
do_initcalls();
1480
}
1481
1482
static void __init do_pre_smp_initcalls(void)
1483
{
1484
initcall_entry_t *fn;
1485
1486
do_trace_initcall_level("early");
1487
for (fn = __initcall_start; fn < __initcall0_start; fn++)
1488
do_one_initcall(initcall_from_entry(fn));
1489
}
1490
1491
static int run_init_process(const char *init_filename)
1492
{
1493
const char *const *p;
1494
1495
argv_init[0] = init_filename;
1496
pr_info("Run %s as init process\n", init_filename);
1497
pr_debug(" with arguments:\n");
1498
for (p = argv_init; *p; p++)
1499
pr_debug(" %s\n", *p);
1500
pr_debug(" with environment:\n");
1501
for (p = envp_init; *p; p++)
1502
pr_debug(" %s\n", *p);
1503
return kernel_execve(init_filename, argv_init, envp_init);
1504
}
1505
1506
static int try_to_run_init_process(const char *init_filename)
1507
{
1508
int ret;
1509
1510
ret = run_init_process(init_filename);
1511
1512
if (ret && ret != -ENOENT) {
1513
pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1514
init_filename, ret);
1515
}
1516
1517
return ret;
1518
}
1519
1520
static noinline void __init kernel_init_freeable(void);
1521
1522
#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1523
bool rodata_enabled __ro_after_init = true;
1524
1525
#ifndef arch_parse_debug_rodata
1526
static inline bool arch_parse_debug_rodata(char *str) { return false; }
1527
#endif
1528
1529
static int __init set_debug_rodata(char *str)
1530
{
1531
if (arch_parse_debug_rodata(str))
1532
return 0;
1533
1534
if (str && !strcmp(str, "on"))
1535
rodata_enabled = true;
1536
else if (str && !strcmp(str, "off"))
1537
rodata_enabled = false;
1538
else
1539
pr_warn("Invalid option string for rodata: '%s'\n", str);
1540
return 0;
1541
}
1542
early_param("rodata", set_debug_rodata);
1543
#endif
1544
1545
static void mark_readonly(void)
1546
{
1547
if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) {
1548
/*
1549
* load_module() results in W+X mappings, which are cleaned
1550
* up with init_free_wq. Let's make sure that queued work is
1551
* flushed so that we don't hit false positives looking for
1552
* insecure pages which are W+X.
1553
*/
1554
flush_module_init_free_work();
1555
jump_label_init_ro();
1556
mark_rodata_ro();
1557
debug_checkwx();
1558
rodata_test();
1559
} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
1560
pr_info("Kernel memory protection disabled.\n");
1561
} else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) {
1562
pr_warn("Kernel memory protection not selected by kernel config.\n");
1563
} else {
1564
pr_warn("This architecture does not have kernel memory protection.\n");
1565
}
1566
}
1567
1568
void __weak free_initmem(void)
1569
{
1570
free_initmem_default(POISON_FREE_INITMEM);
1571
}
1572
1573
static int __ref kernel_init(void *unused)
1574
{
1575
int ret;
1576
1577
/*
1578
* Wait until kthreadd is all set-up.
1579
*/
1580
wait_for_completion(&kthreadd_done);
1581
1582
kernel_init_freeable();
1583
/* need to finish all async __init code before freeing the memory */
1584
async_synchronize_full();
1585
1586
system_state = SYSTEM_FREEING_INITMEM;
1587
kprobe_free_init_mem();
1588
ftrace_free_init_mem();
1589
kgdb_free_init_mem();
1590
exit_boot_config();
1591
free_initmem();
1592
mark_readonly();
1593
1594
/*
1595
* Kernel mappings are now finalized - update the userspace page-table
1596
* to finalize PTI.
1597
*/
1598
pti_finalize();
1599
1600
system_state = SYSTEM_RUNNING;
1601
numa_default_policy();
1602
1603
rcu_end_inkernel_boot();
1604
1605
do_sysctl_args();
1606
1607
if (ramdisk_execute_command) {
1608
ret = run_init_process(ramdisk_execute_command);
1609
if (!ret)
1610
return 0;
1611
pr_err("Failed to execute %s (error %d)\n",
1612
ramdisk_execute_command, ret);
1613
}
1614
1615
/*
1616
* We try each of these until one succeeds.
1617
*
1618
* The Bourne shell can be used instead of init if we are
1619
* trying to recover a really broken machine.
1620
*/
1621
if (execute_command) {
1622
ret = run_init_process(execute_command);
1623
if (!ret)
1624
return 0;
1625
panic("Requested init %s failed (error %d).",
1626
execute_command, ret);
1627
}
1628
1629
if (CONFIG_DEFAULT_INIT[0] != '\0') {
1630
ret = run_init_process(CONFIG_DEFAULT_INIT);
1631
if (ret)
1632
pr_err("Default init %s failed (error %d)\n",
1633
CONFIG_DEFAULT_INIT, ret);
1634
else
1635
return 0;
1636
}
1637
1638
if (!try_to_run_init_process("/sbin/init") ||
1639
!try_to_run_init_process("/etc/init") ||
1640
!try_to_run_init_process("/bin/init") ||
1641
!try_to_run_init_process("/bin/sh"))
1642
return 0;
1643
1644
panic("No working init found. Try passing init= option to kernel. "
1645
"See Linux Documentation/admin-guide/init.rst for guidance.");
1646
}
1647
1648
/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1649
void __init console_on_rootfs(void)
1650
{
1651
struct file *file = filp_open("/dev/console", O_RDWR, 0);
1652
1653
if (IS_ERR(file)) {
1654
pr_err("Warning: unable to open an initial console.\n");
1655
return;
1656
}
1657
init_dup(file);
1658
init_dup(file);
1659
init_dup(file);
1660
fput(file);
1661
}
1662
1663
static noinline void __init kernel_init_freeable(void)
1664
{
1665
/* Now the scheduler is fully set up and can do blocking allocations */
1666
gfp_allowed_mask = __GFP_BITS_MASK;
1667
1668
/*
1669
* init can allocate pages on any node
1670
*/
1671
set_mems_allowed(node_states[N_MEMORY]);
1672
1673
cad_pid = get_pid(task_pid(current));
1674
1675
smp_prepare_cpus(setup_max_cpus);
1676
1677
workqueue_init();
1678
1679
init_mm_internals();
1680
1681
do_pre_smp_initcalls();
1682
lockup_detector_init();
1683
1684
smp_init();
1685
sched_init_smp();
1686
1687
workqueue_init_topology();
1688
async_init();
1689
padata_init();
1690
page_alloc_init_late();
1691
1692
do_basic_setup();
1693
1694
kunit_run_all_tests();
1695
1696
wait_for_initramfs();
1697
console_on_rootfs();
1698
1699
/*
1700
* check if there is an early userspace init. If yes, let it do all
1701
* the work
1702
*/
1703
int ramdisk_command_access;
1704
ramdisk_command_access = init_eaccess(ramdisk_execute_command);
1705
if (ramdisk_command_access != 0) {
1706
if (ramdisk_execute_command_set)
1707
pr_warn("check access for rdinit=%s failed: %i, ignoring\n",
1708
ramdisk_execute_command, ramdisk_command_access);
1709
ramdisk_execute_command = NULL;
1710
prepare_namespace();
1711
}
1712
1713
/*
1714
* Ok, we have completed the initial bootup, and
1715
* we're essentially up and running. Get rid of the
1716
* initmem segments and start the user-mode stuff..
1717
*
1718
* rootfs is available now, try loading the public keys
1719
* and default modules
1720
*/
1721
1722
integrity_load_keys();
1723
}
1724
1725