1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * linux/init/main.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * GK 2/5/95 - Changed to support mounting
8 * Added initrd & change_root: Werner Almesbe
9 * Moan early if gcc is old, avoiding bogus k
10 * Simplified starting of init: Michael A. G
11 */
12
13 #define DEBUG /* Enable initcall_deb
14
15 #include <linux/types.h>
16 #include <linux/extable.h>
17 #include <linux/module.h>
18 #include <linux/proc_fs.h>
19 #include <linux/binfmts.h>
20 #include <linux/kernel.h>
21 #include <linux/syscalls.h>
22 #include <linux/stackprotector.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/delay.h>
26 #include <linux/ioport.h>
27 #include <linux/init.h>
28 #include <linux/initrd.h>
29 #include <linux/memblock.h>
30 #include <linux/acpi.h>
31 #include <linux/bootconfig.h>
32 #include <linux/console.h>
33 #include <linux/nmi.h>
34 #include <linux/percpu.h>
35 #include <linux/kmod.h>
36 #include <linux/kprobes.h>
37 #include <linux/kmsan.h>
38 #include <linux/vmalloc.h>
39 #include <linux/kernel_stat.h>
40 #include <linux/start_kernel.h>
41 #include <linux/security.h>
42 #include <linux/smp.h>
43 #include <linux/profile.h>
44 #include <linux/kfence.h>
45 #include <linux/rcupdate.h>
46 #include <linux/srcu.h>
47 #include <linux/moduleparam.h>
48 #include <linux/kallsyms.h>
49 #include <linux/buildid.h>
50 #include <linux/writeback.h>
51 #include <linux/cpu.h>
52 #include <linux/cpuset.h>
53 #include <linux/cgroup.h>
54 #include <linux/efi.h>
55 #include <linux/tick.h>
56 #include <linux/sched/isolation.h>
57 #include <linux/interrupt.h>
58 #include <linux/taskstats_kern.h>
59 #include <linux/delayacct.h>
60 #include <linux/unistd.h>
61 #include <linux/utsname.h>
62 #include <linux/rmap.h>
63 #include <linux/mempolicy.h>
64 #include <linux/key.h>
65 #include <linux/debug_locks.h>
66 #include <linux/debugobjects.h>
67 #include <linux/lockdep.h>
68 #include <linux/kmemleak.h>
69 #include <linux/padata.h>
70 #include <linux/pid_namespace.h>
71 #include <linux/device/driver.h>
72 #include <linux/kthread.h>
73 #include <linux/sched.h>
74 #include <linux/sched/init.h>
75 #include <linux/signal.h>
76 #include <linux/idr.h>
77 #include <linux/kgdb.h>
78 #include <linux/ftrace.h>
79 #include <linux/async.h>
80 #include <linux/shmem_fs.h>
81 #include <linux/slab.h>
82 #include <linux/perf_event.h>
83 #include <linux/ptrace.h>
84 #include <linux/pti.h>
85 #include <linux/blkdev.h>
86 #include <linux/sched/clock.h>
87 #include <linux/sched/task.h>
88 #include <linux/sched/task_stack.h>
89 #include <linux/context_tracking.h>
90 #include <linux/random.h>
91 #include <linux/moduleloader.h>
92 #include <linux/list.h>
93 #include <linux/integrity.h>
94 #include <linux/proc_ns.h>
95 #include <linux/io.h>
96 #include <linux/cache.h>
97 #include <linux/rodata_test.h>
98 #include <linux/jump_label.h>
99 #include <linux/kcsan.h>
100 #include <linux/init_syscalls.h>
101 #include <linux/stackdepot.h>
102 #include <linux/randomize_kstack.h>
103 #include <linux/pidfs.h>
104 #include <linux/ptdump.h>
105 #include <net/net_namespace.h>
106
107 #include <asm/io.h>
108 #include <asm/setup.h>
109 #include <asm/sections.h>
110 #include <asm/cacheflush.h>
111
112 #define CREATE_TRACE_POINTS
113 #include <trace/events/initcall.h>
114
115 #include <kunit/test.h>
116
117 static int kernel_init(void *);
118
119 /*
120 * Debug helper: via this flag we know that we
121 * where only the boot processor is running wi
122 * two things - IRQ must not be enabled before
123 * operations which are not allowed with IRQ d
124 * flag is set.
125 */
126 bool early_boot_irqs_disabled __read_mostly;
127
128 enum system_states system_state __read_mostly;
129 EXPORT_SYMBOL(system_state);
130
131 /*
132 * Boot command-line arguments
133 */
134 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMI
135 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMI
136
137 /* Default late time init is NULL. archs can o
138 void (*__initdata late_time_init)(void);
139
140 /* Untouched command line saved by arch-specif
141 char __initdata boot_command_line[COMMAND_LINE
142 /* Untouched saved command line (eg. for /proc
143 char *saved_command_line __ro_after_init;
144 unsigned int saved_command_line_len __ro_after
145 /* Command line for parameter parsing */
146 static char *static_command_line;
147 /* Untouched extra command line */
148 static char *extra_command_line;
149 /* Extra init arguments */
150 static char *extra_init_args;
151
152 #ifdef CONFIG_BOOT_CONFIG
153 /* Is bootconfig on command line? */
154 static bool bootconfig_found;
155 static size_t initargs_offs;
156 #else
157 # define bootconfig_found false
158 # define initargs_offs 0
159 #endif
160
161 static char *execute_command;
162 static char *ramdisk_execute_command = "/init"
163
164 /*
165 * Used to generate warnings if static_key man
166 * before jump_label_init is called.
167 */
168 bool static_key_initialized __read_mostly;
169 EXPORT_SYMBOL_GPL(static_key_initialized);
170
171 /*
172 * If set, this is an indication to the driver
173 * device before going ahead with the initiali
174 * rely on the BIOS and skip the reset operati
175 *
176 * This is useful if kernel is booting in an u
177 * For ex. kdump situation where previous kern
178 * skipped and devices will be in unknown stat
179 */
180 unsigned int reset_devices;
181 EXPORT_SYMBOL(reset_devices);
182
183 static int __init set_reset_devices(char *str)
184 {
185 reset_devices = 1;
186 return 1;
187 }
188
189 __setup("reset_devices", set_reset_devices);
190
191 static const char *argv_init[MAX_INIT_ARGS+2]
192 const char *envp_init[MAX_INIT_ENVS+2] = { "HO
193 static const char *panic_later, *panic_param;
194
195 static bool __init obsolete_checksetup(char *l
196 {
197 const struct obs_kernel_param *p;
198 bool had_early_param = false;
199
200 p = __setup_start;
201 do {
202 int n = strlen(p->str);
203 if (parameqn(line, p->str, n))
204 if (p->early) {
205 /* Already don
206 * (Needs exac
207 * Keep iterat
208 * params and
209 if (line[n] ==
210 had_ea
211 } else if (!p->setup_f
212 pr_warn("Param
213 p->str
214 return true;
215 } else if (p->setup_fu
216 return true;
217 }
218 p++;
219 } while (p < __setup_end);
220
221 return had_early_param;
222 }
223
224 /*
225 * This should be approx 2 Bo*oMips to start (
226 * still work even if initially too large, it
227 */
228 unsigned long loops_per_jiffy = (1<<12);
229 EXPORT_SYMBOL(loops_per_jiffy);
230
231 static int __init debug_kernel(char *str)
232 {
233 console_loglevel = CONSOLE_LOGLEVEL_DE
234 return 0;
235 }
236
237 static int __init quiet_kernel(char *str)
238 {
239 console_loglevel = CONSOLE_LOGLEVEL_QU
240 return 0;
241 }
242
243 early_param("debug", debug_kernel);
244 early_param("quiet", quiet_kernel);
245
246 static int __init loglevel(char *str)
247 {
248 int newlevel;
249
250 /*
251 * Only update loglevel value when a c
252 * to prevent blind crashes (when logl
253 * are quite hard to debug
254 */
255 if (get_option(&str, &newlevel)) {
256 console_loglevel = newlevel;
257 return 0;
258 }
259
260 return -EINVAL;
261 }
262
263 early_param("loglevel", loglevel);
264
265 #ifdef CONFIG_BLK_DEV_INITRD
266 static void * __init get_boot_config_from_init
267 {
268 u32 size, csum;
269 char *data;
270 u32 *hdr;
271 int i;
272
273 if (!initrd_end)
274 return NULL;
275
276 data = (char *)initrd_end - BOOTCONFIG
277 /*
278 * Since Grub may align the size of in
279 * check the preceding 3 bytes as well
280 */
281 for (i = 0; i < 4; i++) {
282 if (!memcmp(data, BOOTCONFIG_M
283 goto found;
284 data--;
285 }
286 return NULL;
287
288 found:
289 hdr = (u32 *)(data - 8);
290 size = le32_to_cpu(hdr[0]);
291 csum = le32_to_cpu(hdr[1]);
292
293 data = ((void *)hdr) - size;
294 if ((unsigned long)data < initrd_start
295 pr_err("bootconfig size %d is
296 size, initrd_end - ini
297 return NULL;
298 }
299
300 if (xbc_calc_checksum(data, size) != c
301 pr_err("bootconfig checksum fa
302 return NULL;
303 }
304
305 /* Remove bootconfig from initramfs/in
306 initrd_end = (unsigned long)data;
307 if (_size)
308 *_size = size;
309
310 return data;
311 }
312 #else
313 static void * __init get_boot_config_from_init
314 {
315 return NULL;
316 }
317 #endif
318
319 #ifdef CONFIG_BOOT_CONFIG
320
321 static char xbc_namebuf[XBC_KEYLEN_MAX] __init
322
323 #define rest(dst, end) ((end) > (dst) ? (end)
324
325 static int __init xbc_snprint_cmdline(char *bu
326 struct x
327 {
328 struct xbc_node *knode, *vnode;
329 char *end = buf + size;
330 const char *val, *q;
331 int ret;
332
333 xbc_node_for_each_key_value(root, knod
334 ret = xbc_node_compose_key_aft
335 xbc_na
336 if (ret < 0)
337 return ret;
338
339 vnode = xbc_node_get_child(kno
340 if (!vnode) {
341 ret = snprintf(buf, re
342 if (ret < 0)
343 return ret;
344 buf += ret;
345 continue;
346 }
347 xbc_array_for_each_value(vnode
348 /*
349 * For prettier and mo
350 * quote the value whe
351 * whitespace.
352 */
353 q = strpbrk(val, " \t\
354 ret = snprintf(buf, re
355 xbc_nam
356 if (ret < 0)
357 return ret;
358 buf += ret;
359 }
360 }
361
362 return buf - (end - size);
363 }
364 #undef rest
365
366 /* Make an extra command line under given key
367 static char * __init xbc_make_cmdline(const ch
368 {
369 struct xbc_node *root;
370 char *new_cmdline;
371 int ret, len = 0;
372
373 root = xbc_find_node(key);
374 if (!root)
375 return NULL;
376
377 /* Count required buffer size */
378 len = xbc_snprint_cmdline(NULL, 0, roo
379 if (len <= 0)
380 return NULL;
381
382 new_cmdline = memblock_alloc(len + 1,
383 if (!new_cmdline) {
384 pr_err("Failed to allocate mem
385 return NULL;
386 }
387
388 ret = xbc_snprint_cmdline(new_cmdline,
389 if (ret < 0 || ret > len) {
390 pr_err("Failed to print extra
391 memblock_free(new_cmdline, len
392 return NULL;
393 }
394
395 return new_cmdline;
396 }
397
398 static int __init bootconfig_params(char *para
399 const char
400 {
401 if (strcmp(param, "bootconfig") == 0)
402 bootconfig_found = true;
403 }
404 return 0;
405 }
406
407 static int __init warn_bootconfig(char *str)
408 {
409 /* The 'bootconfig' has been handled b
410 return 0;
411 }
412
413 static void __init setup_boot_config(void)
414 {
415 static char tmp_cmdline[COMMAND_LINE_S
416 const char *msg, *data;
417 int pos, ret;
418 size_t size;
419 char *err;
420
421 /* Cut out the bootconfig data even if
422 data = get_boot_config_from_initrd(&si
423 /* If there is no bootconfig in initrd
424 if (!data)
425 data = xbc_get_embedded_bootco
426
427 strscpy(tmp_cmdline, boot_command_line
428 err = parse_args("bootconfig", tmp_cmd
429 bootconfig_params);
430
431 if (IS_ERR(err) || !(bootconfig_found
432 return;
433
434 /* parse_args() stops at the next para
435 if (err)
436 initargs_offs = err - tmp_cmdl
437
438 if (!data) {
439 /* If user intended to use boo
440 if (bootconfig_found)
441 pr_err("'bootconfig' f
442 else
443 pr_info("No bootconfig
444 return;
445 }
446
447 if (size >= XBC_DATA_MAX) {
448 pr_err("bootconfig size %ld gr
449 (long)size, XBC_DATA_M
450 return;
451 }
452
453 ret = xbc_init(data, size, &msg, &pos)
454 if (ret < 0) {
455 if (pos < 0)
456 pr_err("Failed to init
457 else
458 pr_err("Failed to pars
459 msg, pos);
460 } else {
461 xbc_get_info(&ret, NULL);
462 pr_info("Load bootconfig: %ld
463 /* keys starting with "kernel.
464 extra_command_line = xbc_make_
465 /* Also, "init." keys are init
466 extra_init_args = xbc_make_cmd
467 }
468 return;
469 }
470
471 static void __init exit_boot_config(void)
472 {
473 xbc_exit();
474 }
475
476 #else /* !CONFIG_BOOT_CONFIG */
477
478 static void __init setup_boot_config(void)
479 {
480 /* Remove bootconfig data from initrd
481 get_boot_config_from_initrd(NULL);
482 }
483
484 static int __init warn_bootconfig(char *str)
485 {
486 pr_warn("WARNING: 'bootconfig' found o
487 return 0;
488 }
489
490 #define exit_boot_config() do {} while (0
491
492 #endif /* CONFIG_BOOT_CONFIG */
493
494 early_param("bootconfig", warn_bootconfig);
495
496 bool __init cmdline_has_extra_options(void)
497 {
498 return extra_command_line || extra_ini
499 }
500
501 /* Change NUL term back to "=", to make "param
502 static void __init repair_env_string(char *par
503 {
504 if (val) {
505 /* param=val or param="val"? *
506 if (val == param+strlen(param)
507 val[-1] = '=';
508 else if (val == param+strlen(p
509 val[-2] = '=';
510 memmove(val-1, val, st
511 } else
512 BUG();
513 }
514 }
515
516 /* Anything after -- gets handed straight to i
517 static int __init set_init_arg(char *param, ch
518 const char *unu
519 {
520 unsigned int i;
521
522 if (panic_later)
523 return 0;
524
525 repair_env_string(param, val);
526
527 for (i = 0; argv_init[i]; i++) {
528 if (i == MAX_INIT_ARGS) {
529 panic_later = "init";
530 panic_param = param;
531 return 0;
532 }
533 }
534 argv_init[i] = param;
535 return 0;
536 }
537
538 /*
539 * Unknown boot options get handed to init, un
540 * unused parameters (modprobe will find them
541 */
542 static int __init unknown_bootoption(char *par
543 const cha
544 {
545 size_t len = strlen(param);
546
547 /* Handle params aliased to sysctls */
548 if (sysctl_is_alias(param))
549 return 0;
550
551 repair_env_string(param, val);
552
553 /* Handle obsolete-style parameters */
554 if (obsolete_checksetup(param))
555 return 0;
556
557 /* Unused module parameter. */
558 if (strnchr(param, len, '.'))
559 return 0;
560
561 if (panic_later)
562 return 0;
563
564 if (val) {
565 /* Environment option */
566 unsigned int i;
567 for (i = 0; envp_init[i]; i++)
568 if (i == MAX_INIT_ENVS
569 panic_later =
570 panic_param =
571 }
572 if (!strncmp(param, en
573 break;
574 }
575 envp_init[i] = param;
576 } else {
577 /* Command line option */
578 unsigned int i;
579 for (i = 0; argv_init[i]; i++)
580 if (i == MAX_INIT_ARGS
581 panic_later =
582 panic_param =
583 }
584 }
585 argv_init[i] = param;
586 }
587 return 0;
588 }
589
590 static int __init init_setup(char *str)
591 {
592 unsigned int i;
593
594 execute_command = str;
595 /*
596 * In case LILO is going to boot us wi
597 * it prepends "auto" before the whole
598 * the shell think it should execute a
599 * So we ignore all arguments entered
600 */
601 for (i = 1; i < MAX_INIT_ARGS; i++)
602 argv_init[i] = NULL;
603 return 1;
604 }
605 __setup("init=", init_setup);
606
607 static int __init rdinit_setup(char *str)
608 {
609 unsigned int i;
610
611 ramdisk_execute_command = str;
612 /* See "auto" comment in init_setup */
613 for (i = 1; i < MAX_INIT_ARGS; i++)
614 argv_init[i] = NULL;
615 return 1;
616 }
617 __setup("rdinit=", rdinit_setup);
618
619 #ifndef CONFIG_SMP
620 static inline void setup_nr_cpu_ids(void) { }
621 static inline void smp_prepare_cpus(unsigned i
622 #endif
623
624 /*
625 * We need to store the untouched command line
626 * We also need to store the touched command l
627 * parsing is performed in place, and we shoul
628 * store reference of name/value for future re
629 */
630 static void __init setup_command_line(char *co
631 {
632 size_t len, xlen = 0, ilen = 0;
633
634 if (extra_command_line)
635 xlen = strlen(extra_command_li
636 if (extra_init_args) {
637 extra_init_args = strim(extra_
638 ilen = strlen(extra_init_args)
639 }
640
641 len = xlen + strlen(boot_command_line)
642
643 saved_command_line = memblock_alloc(le
644 if (!saved_command_line)
645 panic("%s: Failed to allocate
646
647 len = xlen + strlen(command_line) + 1;
648
649 static_command_line = memblock_alloc(l
650 if (!static_command_line)
651 panic("%s: Failed to allocate
652
653 if (xlen) {
654 /*
655 * We have to put extra_comman
656 * lines because there could b
657 * command line) in the comman
658 */
659 strcpy(saved_command_line, ext
660 strcpy(static_command_line, ex
661 }
662 strcpy(saved_command_line + xlen, boot
663 strcpy(static_command_line + xlen, com
664
665 if (ilen) {
666 /*
667 * Append supplemental init bo
668 * so that user can check what
669 * to init.
670 * The order should always be
671 * " -- "[bootconfig init-para
672 */
673 if (initargs_offs) {
674 len = xlen + initargs_
675 strcpy(saved_command_l
676 len += ilen - 4;
677 strcpy(saved_command_l
678 boot_command_l
679 } else {
680 len = strlen(saved_com
681 strcpy(saved_command_l
682 len += 4;
683 strcpy(saved_command_l
684 }
685 }
686
687 saved_command_line_len = strlen(saved_
688 }
689
690 /*
691 * We need to finalize in a non-__init functio
692 * between the root thread and the init thread
693 * be reaped by free_initmem before the root t
694 * cpu_idle.
695 *
696 * gcc-3.4 accidentally inlines this function,
697 */
698
699 static __initdata DECLARE_COMPLETION(kthreadd_
700
701 static noinline void __ref __noreturn rest_ini
702 {
703 struct task_struct *tsk;
704 int pid;
705
706 rcu_scheduler_starting();
707 /*
708 * We need to spawn init first so that
709 * the init task will end up wanting t
710 * we schedule it before we create kth
711 */
712 pid = user_mode_thread(kernel_init, NU
713 /*
714 * Pin init on the boot CPU. Task migr
715 * until sched_init_smp() has been run
716 * CPUs for init to the non isolated C
717 */
718 rcu_read_lock();
719 tsk = find_task_by_pid_ns(pid, &init_p
720 tsk->flags |= PF_NO_SETAFFINITY;
721 set_cpus_allowed_ptr(tsk, cpumask_of(s
722 rcu_read_unlock();
723
724 numa_default_policy();
725 pid = kernel_thread(kthreadd, NULL, NU
726 rcu_read_lock();
727 kthreadd_task = find_task_by_pid_ns(pi
728 rcu_read_unlock();
729
730 /*
731 * Enable might_sleep() and smp_proces
732 * They cannot be enabled earlier beca
733 * kernel_thread() would trigger might
734 * CONFIG_PREEMPT_VOLUNTARY=y the init
735 * already, but it's stuck on the kthr
736 */
737 system_state = SYSTEM_SCHEDULING;
738
739 complete(&kthreadd_done);
740
741 /*
742 * The boot idle thread must execute s
743 * at least once to get things moving:
744 */
745 schedule_preempt_disabled();
746 /* Call into cpu_idle with preempt dis
747 cpu_startup_entry(CPUHP_ONLINE);
748 }
749
750 /* Check for early params. */
751 static int __init do_early_param(char *param,
752 const char *u
753 {
754 const struct obs_kernel_param *p;
755
756 for (p = __setup_start; p < __setup_en
757 if ((p->early && parameq(param
758 (strcmp(param, "console")
759 strcmp(p->str, "earlycon"
760 ) {
761 if (p->setup_func(val)
762 pr_warn("Malfo
763 }
764 }
765 /* We accept everything at this stage.
766 return 0;
767 }
768
769 void __init parse_early_options(char *cmdline)
770 {
771 parse_args("early options", cmdline, N
772 do_early_param);
773 }
774
775 /* Arch code calls this early on, or if not, j
776 void __init parse_early_param(void)
777 {
778 static int done __initdata;
779 static char tmp_cmdline[COMMAND_LINE_S
780
781 if (done)
782 return;
783
784 /* All fall through to do_early_param.
785 strscpy(tmp_cmdline, boot_command_line
786 parse_early_options(tmp_cmdline);
787 done = 1;
788 }
789
790 void __init __weak arch_post_acpi_subsys_init(
791
792 void __init __weak smp_setup_processor_id(void
793 {
794 }
795
796 void __init __weak smp_prepare_boot_cpu(void)
797 {
798 }
799
800 # if THREAD_SIZE >= PAGE_SIZE
801 void __init __weak thread_stack_cache_init(voi
802 {
803 }
804 #endif
805
806 void __init __weak poking_init(void) { }
807
808 void __init __weak pgtable_cache_init(void) {
809
810 void __init __weak trap_init(void) { }
811
812 bool initcall_debug;
813 core_param(initcall_debug, initcall_debug, boo
814
815 #ifdef TRACEPOINTS_ENABLED
816 static void __init initcall_debug_enable(void)
817 #else
818 static inline void initcall_debug_enable(void)
819 {
820 }
821 #endif
822
823 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
824 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KS
825 randomize_kstack_of
826 DEFINE_PER_CPU(u32, kstack_offset);
827
828 static int __init early_randomize_kstack_offse
829 {
830 int ret;
831 bool bool_result;
832
833 ret = kstrtobool(buf, &bool_result);
834 if (ret)
835 return ret;
836
837 if (bool_result)
838 static_branch_enable(&randomiz
839 else
840 static_branch_disable(&randomi
841 return 0;
842 }
843 early_param("randomize_kstack_offset", early_r
844 #endif
845
846 static void __init print_unknown_bootoptions(v
847 {
848 char *unknown_options;
849 char *end;
850 const char *const *p;
851 size_t len;
852
853 if (panic_later || (!argv_init[1] && !
854 return;
855
856 /*
857 * Determine how many options we have
858 * before each
859 */
860 len = 1; /* null terminator */
861 for (p = &argv_init[1]; *p; p++) {
862 len++;
863 len += strlen(*p);
864 }
865 for (p = &envp_init[2]; *p; p++) {
866 len++;
867 len += strlen(*p);
868 }
869
870 unknown_options = memblock_alloc(len,
871 if (!unknown_options) {
872 pr_err("%s: Failed to allocate
873 __func__, len);
874 return;
875 }
876 end = unknown_options;
877
878 for (p = &argv_init[1]; *p; p++)
879 end += sprintf(end, " %s", *p)
880 for (p = &envp_init[2]; *p; p++)
881 end += sprintf(end, " %s", *p)
882
883 /* Start at unknown_options[1] to skip
884 pr_notice("Unknown kernel command line
885 &unknown_options[1]);
886 memblock_free(unknown_options, len);
887 }
888
889 static void __init early_numa_node_init(void)
890 {
891 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
892 #ifndef cpu_to_node
893 int cpu;
894
895 /* The early_cpu_to_node() should be r
896 for_each_possible_cpu(cpu)
897 set_cpu_numa_node(cpu, early_c
898 #endif
899 #endif
900 }
901
902 asmlinkage __visible __init __no_sanitize_addr
903 void start_kernel(void)
904 {
905 char *command_line;
906 char *after_dashes;
907
908 set_task_stack_end_magic(&init_task);
909 smp_setup_processor_id();
910 debug_objects_early_init();
911 init_vmlinux_build_id();
912
913 cgroup_init_early();
914
915 local_irq_disable();
916 early_boot_irqs_disabled = true;
917
918 /*
919 * Interrupts are still disabled. Do n
920 * enable them.
921 */
922 boot_cpu_init();
923 page_address_init();
924 pr_notice("%s", linux_banner);
925 setup_arch(&command_line);
926 /* Static keys and static calls are ne
927 jump_label_init();
928 static_call_init();
929 early_security_init();
930 setup_boot_config();
931 setup_command_line(command_line);
932 setup_nr_cpu_ids();
933 setup_per_cpu_areas();
934 smp_prepare_boot_cpu(); /* arch-specif
935 early_numa_node_init();
936 boot_cpu_hotplug_init();
937
938 pr_notice("Kernel command line: %s\n",
939 /* parameters may set static keys */
940 parse_early_param();
941 after_dashes = parse_args("Booting ker
942 static_comma
943 __stop___par
944 -1, -1, NULL
945 print_unknown_bootoptions();
946 if (!IS_ERR_OR_NULL(after_dashes))
947 parse_args("Setting init args"
948 NULL, set_init_arg)
949 if (extra_init_args)
950 parse_args("Setting extra init
951 NULL, 0, -1, -1, NU
952
953 /* Architectural and non-timekeeping r
954 random_init_early(command_line);
955
956 /*
957 * These use large bootmem allocations
958 * initalization of page allocator
959 */
960 setup_log_buf(0);
961 vfs_caches_init_early();
962 sort_main_extable();
963 trap_init();
964 mm_core_init();
965 poking_init();
966 ftrace_init();
967
968 /* trace_printk can be enabled here */
969 early_trace_init();
970
971 /*
972 * Set up the scheduler prior starting
973 * timer interrupt). Full topology set
974 * time - but meanwhile we still have
975 */
976 sched_init();
977
978 if (WARN(!irqs_disabled(),
979 "Interrupts were enabled *ver
980 local_irq_disable();
981 radix_tree_init();
982 maple_tree_init();
983
984 /*
985 * Set up housekeeping before setting
986 * workqueue to take non-housekeeping
987 */
988 housekeeping_init();
989
990 /*
991 * Allow workqueue creation and work i
992 * early. Work item execution depends
993 * workqueue_init().
994 */
995 workqueue_init_early();
996
997 rcu_init();
998
999 /* Trace events are available after th
1000 trace_init();
1001
1002 if (initcall_debug)
1003 initcall_debug_enable();
1004
1005 context_tracking_init();
1006 /* init some links before init_ISA_ir
1007 early_irq_init();
1008 init_IRQ();
1009 tick_init();
1010 rcu_init_nohz();
1011 init_timers();
1012 srcu_init();
1013 hrtimers_init();
1014 softirq_init();
1015 timekeeping_init();
1016 time_init();
1017
1018 /* This must be after timekeeping is
1019 random_init();
1020
1021 /* These make use of the fully initia
1022 kfence_init();
1023 boot_init_stack_canary();
1024
1025 perf_event_init();
1026 profile_init();
1027 call_function_init();
1028 WARN(!irqs_disabled(), "Interrupts we
1029
1030 early_boot_irqs_disabled = false;
1031 local_irq_enable();
1032
1033 kmem_cache_init_late();
1034
1035 /*
1036 * HACK ALERT! This is early. We're e
1037 * we've done PCI setups etc, and con
1038 * this. But we do want output early,
1039 */
1040 console_init();
1041 if (panic_later)
1042 panic("Too many boot %s vars
1043 panic_param);
1044
1045 lockdep_init();
1046
1047 /*
1048 * Need to run this when irqs are ena
1049 * to self-test [hard/soft]-irqs on/o
1050 * too:
1051 */
1052 locking_selftest();
1053
1054 #ifdef CONFIG_BLK_DEV_INITRD
1055 if (initrd_start && !initrd_below_sta
1056 page_to_pfn(virt_to_page((void *)
1057 pr_crit("initrd overwritten (
1058 page_to_pfn(virt_to_page(
1059 min_low_pfn);
1060 initrd_start = 0;
1061 }
1062 #endif
1063 setup_per_cpu_pageset();
1064 numa_policy_init();
1065 acpi_early_init();
1066 if (late_time_init)
1067 late_time_init();
1068 sched_clock_init();
1069 calibrate_delay();
1070
1071 arch_cpu_finalize_init();
1072
1073 pid_idr_init();
1074 anon_vma_init();
1075 #ifdef CONFIG_X86
1076 if (efi_enabled(EFI_RUNTIME_SERVICES)
1077 efi_enter_virtual_mode();
1078 #endif
1079 thread_stack_cache_init();
1080 cred_init();
1081 fork_init();
1082 proc_caches_init();
1083 uts_ns_init();
1084 key_init();
1085 security_init();
1086 dbg_late_init();
1087 net_ns_init();
1088 vfs_caches_init();
1089 pagecache_init();
1090 signals_init();
1091 seq_file_init();
1092 proc_root_init();
1093 nsfs_init();
1094 pidfs_init();
1095 cpuset_init();
1096 cgroup_init();
1097 taskstats_init_early();
1098 delayacct_init();
1099
1100 acpi_subsystem_init();
1101 arch_post_acpi_subsys_init();
1102 kcsan_init();
1103
1104 /* Do the rest non-__init'ed, we're n
1105 rest_init();
1106
1107 /*
1108 * Avoid stack canaries in callers of
1109 * and older.
1110 */
1111 #if !__has_attribute(__no_stack_protector__)
1112 prevent_tail_call_optimization();
1113 #endif
1114 }
1115
1116 /* Call all constructor functions linked into
1117 static void __init do_ctors(void)
1118 {
1119 /*
1120 * For UML, the constructors have already bee
1121 * normal setup code as it's just a normal EL
1122 * cannot do it again - but we do need CONFIG
1123 * even on UML for modules.
1124 */
1125 #if defined(CONFIG_CONSTRUCTORS) && !defined(
1126 ctor_fn_t *fn = (ctor_fn_t *) __ctors
1127
1128 for (; fn < (ctor_fn_t *) __ctors_end
1129 (*fn)();
1130 #endif
1131 }
1132
1133 #ifdef CONFIG_KALLSYMS
1134 struct blacklist_entry {
1135 struct list_head next;
1136 char *buf;
1137 };
1138
1139 static __initdata_or_module LIST_HEAD(blackli
1140
1141 static int __init initcall_blacklist(char *st
1142 {
1143 char *str_entry;
1144 struct blacklist_entry *entry;
1145
1146 /* str argument is a comma-separated
1147 do {
1148 str_entry = strsep(&str, ",")
1149 if (str_entry) {
1150 pr_debug("blacklistin
1151 entry = memblock_allo
1152
1153 if (!entry)
1154 panic("%s: Fa
1155 __func_
1156 entry->buf = memblock
1157
1158 if (!entry->buf)
1159 panic("%s: Fa
1160 __func_
1161 strcpy(entry->buf, st
1162 list_add(&entry->next
1163 }
1164 } while (str_entry);
1165
1166 return 1;
1167 }
1168
1169 static bool __init_or_module initcall_blackli
1170 {
1171 struct blacklist_entry *entry;
1172 char fn_name[KSYM_SYMBOL_LEN];
1173 unsigned long addr;
1174
1175 if (list_empty(&blacklisted_initcalls
1176 return false;
1177
1178 addr = (unsigned long) dereference_fu
1179 sprint_symbol_no_offset(fn_name, addr
1180
1181 /*
1182 * fn will be "function_name [module_
1183 * displayed for built-in init functi
1184 */
1185 strreplace(fn_name, ' ', '\0');
1186
1187 list_for_each_entry(entry, &blacklist
1188 if (!strcmp(fn_name, entry->b
1189 pr_debug("initcall %s
1190 return true;
1191 }
1192 }
1193
1194 return false;
1195 }
1196 #else
1197 static int __init initcall_blacklist(char *st
1198 {
1199 pr_warn("initcall_blacklist requires
1200 return 0;
1201 }
1202
1203 static bool __init_or_module initcall_blackli
1204 {
1205 return false;
1206 }
1207 #endif
1208 __setup("initcall_blacklist=", initcall_black
1209
1210 static __init_or_module void
1211 trace_initcall_start_cb(void *data, initcall_
1212 {
1213 ktime_t *calltime = data;
1214
1215 printk(KERN_DEBUG "calling %pS @ %i\
1216 *calltime = ktime_get();
1217 }
1218
1219 static __init_or_module void
1220 trace_initcall_finish_cb(void *data, initcall
1221 {
1222 ktime_t rettime, *calltime = data;
1223
1224 rettime = ktime_get();
1225 printk(KERN_DEBUG "initcall %pS retur
1226 fn, ret, (unsigned long long
1227 }
1228
1229 static ktime_t initcall_calltime;
1230
1231 #ifdef TRACEPOINTS_ENABLED
1232 static void __init initcall_debug_enable(void
1233 {
1234 int ret;
1235
1236 ret = register_trace_initcall_start(t
1237 &
1238 ret |= register_trace_initcall_finish
1239
1240 WARN(ret, "Failed to register initcal
1241 }
1242 # define do_trace_initcall_start trace
1243 # define do_trace_initcall_finish trace
1244 #else
1245 static inline void do_trace_initcall_start(in
1246 {
1247 if (!initcall_debug)
1248 return;
1249 trace_initcall_start_cb(&initcall_cal
1250 }
1251 static inline void do_trace_initcall_finish(i
1252 {
1253 if (!initcall_debug)
1254 return;
1255 trace_initcall_finish_cb(&initcall_ca
1256 }
1257 #endif /* !TRACEPOINTS_ENABLED */
1258
1259 int __init_or_module do_one_initcall(initcall
1260 {
1261 int count = preempt_count();
1262 char msgbuf[64];
1263 int ret;
1264
1265 if (initcall_blacklisted(fn))
1266 return -EPERM;
1267
1268 do_trace_initcall_start(fn);
1269 ret = fn();
1270 do_trace_initcall_finish(fn, ret);
1271
1272 msgbuf[0] = 0;
1273
1274 if (preempt_count() != count) {
1275 sprintf(msgbuf, "preemption i
1276 preempt_count_set(count);
1277 }
1278 if (irqs_disabled()) {
1279 strlcat(msgbuf, "disabled int
1280 local_irq_enable();
1281 }
1282 WARN(msgbuf[0], "initcall %pS returne
1283
1284 add_latent_entropy();
1285 return ret;
1286 }
1287
1288
1289 static initcall_entry_t *initcall_levels[] __
1290 __initcall0_start,
1291 __initcall1_start,
1292 __initcall2_start,
1293 __initcall3_start,
1294 __initcall4_start,
1295 __initcall5_start,
1296 __initcall6_start,
1297 __initcall7_start,
1298 __initcall_end,
1299 };
1300
1301 /* Keep these in sync with initcalls in inclu
1302 static const char *initcall_level_names[] __i
1303 "pure",
1304 "core",
1305 "postcore",
1306 "arch",
1307 "subsys",
1308 "fs",
1309 "device",
1310 "late",
1311 };
1312
1313 static int __init ignore_unknown_bootoption(c
1314 const char *un
1315 {
1316 return 0;
1317 }
1318
1319 static void __init do_initcall_level(int leve
1320 {
1321 initcall_entry_t *fn;
1322
1323 parse_args(initcall_level_names[level
1324 command_line, __start___pa
1325 __stop___param - __start__
1326 level, level,
1327 NULL, ignore_unknown_booto
1328
1329 trace_initcall_level(initcall_level_n
1330 for (fn = initcall_levels[level]; fn
1331 do_one_initcall(initcall_from
1332 }
1333
1334 static void __init do_initcalls(void)
1335 {
1336 int level;
1337 size_t len = saved_command_line_len +
1338 char *command_line;
1339
1340 command_line = kzalloc(len, GFP_KERNE
1341 if (!command_line)
1342 panic("%s: Failed to allocate
1343
1344 for (level = 0; level < ARRAY_SIZE(in
1345 /* Parser modifies command_li
1346 strcpy(command_line, saved_co
1347 do_initcall_level(level, comm
1348 }
1349
1350 kfree(command_line);
1351 }
1352
1353 /*
1354 * Ok, the machine is now initialized. None o
1355 * have been touched yet, but the CPU subsyst
1356 * running, and memory and process management
1357 *
1358 * Now we can finally start doing some real w
1359 */
1360 static void __init do_basic_setup(void)
1361 {
1362 cpuset_init_smp();
1363 driver_init();
1364 init_irq_proc();
1365 do_ctors();
1366 do_initcalls();
1367 }
1368
1369 static void __init do_pre_smp_initcalls(void)
1370 {
1371 initcall_entry_t *fn;
1372
1373 trace_initcall_level("early");
1374 for (fn = __initcall_start; fn < __in
1375 do_one_initcall(initcall_from
1376 }
1377
1378 static int run_init_process(const char *init_
1379 {
1380 const char *const *p;
1381
1382 argv_init[0] = init_filename;
1383 pr_info("Run %s as init process\n", i
1384 pr_debug(" with arguments:\n");
1385 for (p = argv_init; *p; p++)
1386 pr_debug(" %s\n", *p);
1387 pr_debug(" with environment:\n");
1388 for (p = envp_init; *p; p++)
1389 pr_debug(" %s\n", *p);
1390 return kernel_execve(init_filename, a
1391 }
1392
1393 static int try_to_run_init_process(const char
1394 {
1395 int ret;
1396
1397 ret = run_init_process(init_filename)
1398
1399 if (ret && ret != -ENOENT) {
1400 pr_err("Starting init: %s exi
1401 init_filename, ret);
1402 }
1403
1404 return ret;
1405 }
1406
1407 static noinline void __init kernel_init_freea
1408
1409 #if defined(CONFIG_STRICT_KERNEL_RWX) || defi
1410 bool rodata_enabled __ro_after_init = true;
1411
1412 #ifndef arch_parse_debug_rodata
1413 static inline bool arch_parse_debug_rodata(ch
1414 #endif
1415
1416 static int __init set_debug_rodata(char *str)
1417 {
1418 if (arch_parse_debug_rodata(str))
1419 return 0;
1420
1421 if (str && !strcmp(str, "on"))
1422 rodata_enabled = true;
1423 else if (str && !strcmp(str, "off"))
1424 rodata_enabled = false;
1425 else
1426 pr_warn("Invalid option strin
1427 return 0;
1428 }
1429 early_param("rodata", set_debug_rodata);
1430 #endif
1431
1432 static void mark_readonly(void)
1433 {
1434 if (IS_ENABLED(CONFIG_STRICT_KERNEL_R
1435 /*
1436 * load_module() results in W
1437 * up with init_free_wq. Let'
1438 * flushed so that we don't h
1439 * insecure pages which are W
1440 */
1441 flush_module_init_free_work()
1442 jump_label_init_ro();
1443 mark_rodata_ro();
1444 debug_checkwx();
1445 rodata_test();
1446 } else if (IS_ENABLED(CONFIG_STRICT_K
1447 pr_info("Kernel memory protec
1448 } else if (IS_ENABLED(CONFIG_ARCH_HAS
1449 pr_warn("Kernel memory protec
1450 } else {
1451 pr_warn("This architecture do
1452 }
1453 }
1454
1455 void __weak free_initmem(void)
1456 {
1457 free_initmem_default(POISON_FREE_INIT
1458 }
1459
1460 static int __ref kernel_init(void *unused)
1461 {
1462 int ret;
1463
1464 /*
1465 * Wait until kthreadd is all set-up.
1466 */
1467 wait_for_completion(&kthreadd_done);
1468
1469 kernel_init_freeable();
1470 /* need to finish all async __init co
1471 async_synchronize_full();
1472
1473 system_state = SYSTEM_FREEING_INITMEM
1474 kprobe_free_init_mem();
1475 ftrace_free_init_mem();
1476 kgdb_free_init_mem();
1477 exit_boot_config();
1478 free_initmem();
1479 mark_readonly();
1480
1481 /*
1482 * Kernel mappings are now finalized
1483 * to finalize PTI.
1484 */
1485 pti_finalize();
1486
1487 system_state = SYSTEM_RUNNING;
1488 numa_default_policy();
1489
1490 rcu_end_inkernel_boot();
1491
1492 do_sysctl_args();
1493
1494 if (ramdisk_execute_command) {
1495 ret = run_init_process(ramdis
1496 if (!ret)
1497 return 0;
1498 pr_err("Failed to execute %s
1499 ramdisk_execute_comman
1500 }
1501
1502 /*
1503 * We try each of these until one suc
1504 *
1505 * The Bourne shell can be used inste
1506 * trying to recover a really broken
1507 */
1508 if (execute_command) {
1509 ret = run_init_process(execut
1510 if (!ret)
1511 return 0;
1512 panic("Requested init %s fail
1513 execute_command, ret);
1514 }
1515
1516 if (CONFIG_DEFAULT_INIT[0] != '\0') {
1517 ret = run_init_process(CONFIG
1518 if (ret)
1519 pr_err("Default init
1520 CONFIG_DEFAULT
1521 else
1522 return 0;
1523 }
1524
1525 if (!try_to_run_init_process("/sbin/i
1526 !try_to_run_init_process("/etc/in
1527 !try_to_run_init_process("/bin/in
1528 !try_to_run_init_process("/bin/sh
1529 return 0;
1530
1531 panic("No working init found. Try pa
1532 "See Linux Documentation/admin-
1533 }
1534
1535 /* Open /dev/console, for stdin/stdout/stderr
1536 void __init console_on_rootfs(void)
1537 {
1538 struct file *file = filp_open("/dev/c
1539
1540 if (IS_ERR(file)) {
1541 pr_err("Warning: unable to op
1542 return;
1543 }
1544 init_dup(file);
1545 init_dup(file);
1546 init_dup(file);
1547 fput(file);
1548 }
1549
1550 static noinline void __init kernel_init_freea
1551 {
1552 /* Now the scheduler is fully set up
1553 gfp_allowed_mask = __GFP_BITS_MASK;
1554
1555 /*
1556 * init can allocate pages on any nod
1557 */
1558 set_mems_allowed(node_states[N_MEMORY
1559
1560 cad_pid = get_pid(task_pid(current));
1561
1562 smp_prepare_cpus(setup_max_cpus);
1563
1564 workqueue_init();
1565
1566 init_mm_internals();
1567
1568 rcu_init_tasks_generic();
1569 do_pre_smp_initcalls();
1570 lockup_detector_init();
1571
1572 smp_init();
1573 sched_init_smp();
1574
1575 workqueue_init_topology();
1576 async_init();
1577 padata_init();
1578 page_alloc_init_late();
1579
1580 do_basic_setup();
1581
1582 kunit_run_all_tests();
1583
1584 wait_for_initramfs();
1585 console_on_rootfs();
1586
1587 /*
1588 * check if there is an early userspa
1589 * the work
1590 */
1591 if (init_eaccess(ramdisk_execute_comm
1592 ramdisk_execute_command = NUL
1593 prepare_namespace();
1594 }
1595
1596 /*
1597 * Ok, we have completed the initial
1598 * we're essentially up and running.
1599 * initmem segments and start the use
1600 *
1601 * rootfs is available now, try loadi
1602 * and default modules
1603 */
1604
1605 integrity_load_keys();
1606 }
1607
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