xref: /linux/init/main.c (revision f949cb759051b24aa6cacda73964327608c08a89)
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 <grif@acm.org>
11  */
12 
13 #define DEBUG		/* Enable initcall_debug */
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/list.h>
92 #include <linux/integrity.h>
93 #include <linux/proc_ns.h>
94 #include <linux/io.h>
95 #include <linux/cache.h>
96 #include <linux/rodata_test.h>
97 #include <linux/jump_label.h>
98 #include <linux/kcsan.h>
99 #include <linux/init_syscalls.h>
100 #include <linux/stackdepot.h>
101 #include <linux/randomize_kstack.h>
102 #include <net/net_namespace.h>
103 
104 #include <asm/io.h>
105 #include <asm/setup.h>
106 #include <asm/sections.h>
107 #include <asm/cacheflush.h>
108 
109 #define CREATE_TRACE_POINTS
110 #include <trace/events/initcall.h>
111 
112 #include <kunit/test.h>
113 
114 static int kernel_init(void *);
115 
116 /*
117  * Debug helper: via this flag we know that we are in 'early bootup code'
118  * where only the boot processor is running with IRQ disabled.  This means
119  * two things - IRQ must not be enabled before the flag is cleared and some
120  * operations which are not allowed with IRQ disabled are allowed while the
121  * flag is set.
122  */
123 bool early_boot_irqs_disabled __read_mostly;
124 
125 enum system_states system_state __read_mostly;
126 EXPORT_SYMBOL(system_state);
127 
128 /*
129  * Boot command-line arguments
130  */
131 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
132 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
133 
134 /* Default late time init is NULL. archs can override this later. */
135 void (*__initdata late_time_init)(void);
136 
137 /* Untouched command line saved by arch-specific code. */
138 char __initdata boot_command_line[COMMAND_LINE_SIZE];
139 /* Untouched saved command line (eg. for /proc) */
140 char *saved_command_line __ro_after_init;
141 unsigned int saved_command_line_len __ro_after_init;
142 /* Command line for parameter parsing */
143 static char *static_command_line;
144 /* Untouched extra command line */
145 static char *extra_command_line;
146 /* Extra init arguments */
147 static char *extra_init_args;
148 
149 #ifdef CONFIG_BOOT_CONFIG
150 /* Is bootconfig on command line? */
151 static bool bootconfig_found;
152 static size_t initargs_offs;
153 #else
154 # define bootconfig_found false
155 # define initargs_offs 0
156 #endif
157 
158 static char *execute_command;
159 static char *ramdisk_execute_command = "/init";
160 
161 /*
162  * Used to generate warnings if static_key manipulation functions are used
163  * before jump_label_init is called.
164  */
165 bool static_key_initialized __read_mostly;
166 EXPORT_SYMBOL_GPL(static_key_initialized);
167 
168 /*
169  * If set, this is an indication to the drivers that reset the underlying
170  * device before going ahead with the initialization otherwise driver might
171  * rely on the BIOS and skip the reset operation.
172  *
173  * This is useful if kernel is booting in an unreliable environment.
174  * For ex. kdump situation where previous kernel has crashed, BIOS has been
175  * skipped and devices will be in unknown state.
176  */
177 unsigned int reset_devices;
178 EXPORT_SYMBOL(reset_devices);
179 
180 static int __init set_reset_devices(char *str)
181 {
182 	reset_devices = 1;
183 	return 1;
184 }
185 
186 __setup("reset_devices", set_reset_devices);
187 
188 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
189 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
190 static const char *panic_later, *panic_param;
191 
192 static bool __init obsolete_checksetup(char *line)
193 {
194 	const struct obs_kernel_param *p;
195 	bool had_early_param = false;
196 
197 	p = __setup_start;
198 	do {
199 		int n = strlen(p->str);
200 		if (parameqn(line, p->str, n)) {
201 			if (p->early) {
202 				/* Already done in parse_early_param?
203 				 * (Needs exact match on param part).
204 				 * Keep iterating, as we can have early
205 				 * params and __setups of same names 8( */
206 				if (line[n] == '\0' || line[n] == '=')
207 					had_early_param = true;
208 			} else if (!p->setup_func) {
209 				pr_warn("Parameter %s is obsolete, ignored\n",
210 					p->str);
211 				return true;
212 			} else if (p->setup_func(line + n))
213 				return true;
214 		}
215 		p++;
216 	} while (p < __setup_end);
217 
218 	return had_early_param;
219 }
220 
221 /*
222  * This should be approx 2 Bo*oMips to start (note initial shift), and will
223  * still work even if initially too large, it will just take slightly longer
224  */
225 unsigned long loops_per_jiffy = (1<<12);
226 EXPORT_SYMBOL(loops_per_jiffy);
227 
228 static int __init debug_kernel(char *str)
229 {
230 	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
231 	return 0;
232 }
233 
234 static int __init quiet_kernel(char *str)
235 {
236 	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
237 	return 0;
238 }
239 
240 early_param("debug", debug_kernel);
241 early_param("quiet", quiet_kernel);
242 
243 static int __init loglevel(char *str)
244 {
245 	int newlevel;
246 
247 	/*
248 	 * Only update loglevel value when a correct setting was passed,
249 	 * to prevent blind crashes (when loglevel being set to 0) that
250 	 * are quite hard to debug
251 	 */
252 	if (get_option(&str, &newlevel)) {
253 		console_loglevel = newlevel;
254 		return 0;
255 	}
256 
257 	return -EINVAL;
258 }
259 
260 early_param("loglevel", loglevel);
261 
262 #ifdef CONFIG_BLK_DEV_INITRD
263 static void * __init get_boot_config_from_initrd(size_t *_size)
264 {
265 	u32 size, csum;
266 	char *data;
267 	u32 *hdr;
268 	int i;
269 
270 	if (!initrd_end)
271 		return NULL;
272 
273 	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
274 	/*
275 	 * Since Grub may align the size of initrd to 4, we must
276 	 * check the preceding 3 bytes as well.
277 	 */
278 	for (i = 0; i < 4; i++) {
279 		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
280 			goto found;
281 		data--;
282 	}
283 	return NULL;
284 
285 found:
286 	hdr = (u32 *)(data - 8);
287 	size = le32_to_cpu(hdr[0]);
288 	csum = le32_to_cpu(hdr[1]);
289 
290 	data = ((void *)hdr) - size;
291 	if ((unsigned long)data < initrd_start) {
292 		pr_err("bootconfig size %d is greater than initrd size %ld\n",
293 			size, initrd_end - initrd_start);
294 		return NULL;
295 	}
296 
297 	if (xbc_calc_checksum(data, size) != csum) {
298 		pr_err("bootconfig checksum failed\n");
299 		return NULL;
300 	}
301 
302 	/* Remove bootconfig from initramfs/initrd */
303 	initrd_end = (unsigned long)data;
304 	if (_size)
305 		*_size = size;
306 
307 	return data;
308 }
309 #else
310 static void * __init get_boot_config_from_initrd(size_t *_size)
311 {
312 	return NULL;
313 }
314 #endif
315 
316 #ifdef CONFIG_BOOT_CONFIG
317 
318 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
319 
320 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
321 
322 static int __init xbc_snprint_cmdline(char *buf, size_t size,
323 				      struct xbc_node *root)
324 {
325 	struct xbc_node *knode, *vnode;
326 	char *end = buf + size;
327 	const char *val;
328 	int ret;
329 
330 	xbc_node_for_each_key_value(root, knode, val) {
331 		ret = xbc_node_compose_key_after(root, knode,
332 					xbc_namebuf, XBC_KEYLEN_MAX);
333 		if (ret < 0)
334 			return ret;
335 
336 		vnode = xbc_node_get_child(knode);
337 		if (!vnode) {
338 			ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
339 			if (ret < 0)
340 				return ret;
341 			buf += ret;
342 			continue;
343 		}
344 		xbc_array_for_each_value(vnode, val) {
345 			ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
346 				       xbc_namebuf, val);
347 			if (ret < 0)
348 				return ret;
349 			buf += ret;
350 		}
351 	}
352 
353 	return buf - (end - size);
354 }
355 #undef rest
356 
357 /* Make an extra command line under given key word */
358 static char * __init xbc_make_cmdline(const char *key)
359 {
360 	struct xbc_node *root;
361 	char *new_cmdline;
362 	int ret, len = 0;
363 
364 	root = xbc_find_node(key);
365 	if (!root)
366 		return NULL;
367 
368 	/* Count required buffer size */
369 	len = xbc_snprint_cmdline(NULL, 0, root);
370 	if (len <= 0)
371 		return NULL;
372 
373 	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
374 	if (!new_cmdline) {
375 		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
376 		return NULL;
377 	}
378 
379 	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
380 	if (ret < 0 || ret > len) {
381 		pr_err("Failed to print extra kernel cmdline.\n");
382 		memblock_free(new_cmdline, len + 1);
383 		return NULL;
384 	}
385 
386 	return new_cmdline;
387 }
388 
389 static int __init bootconfig_params(char *param, char *val,
390 				    const char *unused, void *arg)
391 {
392 	if (strcmp(param, "bootconfig") == 0) {
393 		bootconfig_found = true;
394 	}
395 	return 0;
396 }
397 
398 static int __init warn_bootconfig(char *str)
399 {
400 	/* The 'bootconfig' has been handled by bootconfig_params(). */
401 	return 0;
402 }
403 
404 static void __init setup_boot_config(void)
405 {
406 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
407 	const char *msg, *data;
408 	int pos, ret;
409 	size_t size;
410 	char *err;
411 
412 	/* Cut out the bootconfig data even if we have no bootconfig option */
413 	data = get_boot_config_from_initrd(&size);
414 	/* If there is no bootconfig in initrd, try embedded one. */
415 	if (!data)
416 		data = xbc_get_embedded_bootconfig(&size);
417 
418 	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
419 	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
420 			 bootconfig_params);
421 
422 	if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
423 		return;
424 
425 	/* parse_args() stops at the next param of '--' and returns an address */
426 	if (err)
427 		initargs_offs = err - tmp_cmdline;
428 
429 	if (!data) {
430 		/* If user intended to use bootconfig, show an error level message */
431 		if (bootconfig_found)
432 			pr_err("'bootconfig' found on command line, but no bootconfig found\n");
433 		else
434 			pr_info("No bootconfig data provided, so skipping bootconfig");
435 		return;
436 	}
437 
438 	if (size >= XBC_DATA_MAX) {
439 		pr_err("bootconfig size %ld greater than max size %d\n",
440 			(long)size, XBC_DATA_MAX);
441 		return;
442 	}
443 
444 	ret = xbc_init(data, size, &msg, &pos);
445 	if (ret < 0) {
446 		if (pos < 0)
447 			pr_err("Failed to init bootconfig: %s.\n", msg);
448 		else
449 			pr_err("Failed to parse bootconfig: %s at %d.\n",
450 				msg, pos);
451 	} else {
452 		xbc_get_info(&ret, NULL);
453 		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
454 		/* keys starting with "kernel." are passed via cmdline */
455 		extra_command_line = xbc_make_cmdline("kernel");
456 		/* Also, "init." keys are init arguments */
457 		extra_init_args = xbc_make_cmdline("init");
458 	}
459 	return;
460 }
461 
462 static void __init exit_boot_config(void)
463 {
464 	xbc_exit();
465 }
466 
467 #else	/* !CONFIG_BOOT_CONFIG */
468 
469 static void __init setup_boot_config(void)
470 {
471 	/* Remove bootconfig data from initrd */
472 	get_boot_config_from_initrd(NULL);
473 }
474 
475 static int __init warn_bootconfig(char *str)
476 {
477 	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
478 	return 0;
479 }
480 
481 #define exit_boot_config()	do {} while (0)
482 
483 #endif	/* CONFIG_BOOT_CONFIG */
484 
485 early_param("bootconfig", warn_bootconfig);
486 
487 /* Change NUL term back to "=", to make "param" the whole string. */
488 static void __init repair_env_string(char *param, char *val)
489 {
490 	if (val) {
491 		/* param=val or param="val"? */
492 		if (val == param+strlen(param)+1)
493 			val[-1] = '=';
494 		else if (val == param+strlen(param)+2) {
495 			val[-2] = '=';
496 			memmove(val-1, val, strlen(val)+1);
497 		} else
498 			BUG();
499 	}
500 }
501 
502 /* Anything after -- gets handed straight to init. */
503 static int __init set_init_arg(char *param, char *val,
504 			       const char *unused, void *arg)
505 {
506 	unsigned int i;
507 
508 	if (panic_later)
509 		return 0;
510 
511 	repair_env_string(param, val);
512 
513 	for (i = 0; argv_init[i]; i++) {
514 		if (i == MAX_INIT_ARGS) {
515 			panic_later = "init";
516 			panic_param = param;
517 			return 0;
518 		}
519 	}
520 	argv_init[i] = param;
521 	return 0;
522 }
523 
524 /*
525  * Unknown boot options get handed to init, unless they look like
526  * unused parameters (modprobe will find them in /proc/cmdline).
527  */
528 static int __init unknown_bootoption(char *param, char *val,
529 				     const char *unused, void *arg)
530 {
531 	size_t len = strlen(param);
532 
533 	repair_env_string(param, val);
534 
535 	/* Handle obsolete-style parameters */
536 	if (obsolete_checksetup(param))
537 		return 0;
538 
539 	/* Unused module parameter. */
540 	if (strnchr(param, len, '.'))
541 		return 0;
542 
543 	if (panic_later)
544 		return 0;
545 
546 	if (val) {
547 		/* Environment option */
548 		unsigned int i;
549 		for (i = 0; envp_init[i]; i++) {
550 			if (i == MAX_INIT_ENVS) {
551 				panic_later = "env";
552 				panic_param = param;
553 			}
554 			if (!strncmp(param, envp_init[i], len+1))
555 				break;
556 		}
557 		envp_init[i] = param;
558 	} else {
559 		/* Command line option */
560 		unsigned int i;
561 		for (i = 0; argv_init[i]; i++) {
562 			if (i == MAX_INIT_ARGS) {
563 				panic_later = "init";
564 				panic_param = param;
565 			}
566 		}
567 		argv_init[i] = param;
568 	}
569 	return 0;
570 }
571 
572 static int __init init_setup(char *str)
573 {
574 	unsigned int i;
575 
576 	execute_command = str;
577 	/*
578 	 * In case LILO is going to boot us with default command line,
579 	 * it prepends "auto" before the whole cmdline which makes
580 	 * the shell think it should execute a script with such name.
581 	 * So we ignore all arguments entered _before_ init=... [MJ]
582 	 */
583 	for (i = 1; i < MAX_INIT_ARGS; i++)
584 		argv_init[i] = NULL;
585 	return 1;
586 }
587 __setup("init=", init_setup);
588 
589 static int __init rdinit_setup(char *str)
590 {
591 	unsigned int i;
592 
593 	ramdisk_execute_command = str;
594 	/* See "auto" comment in init_setup */
595 	for (i = 1; i < MAX_INIT_ARGS; i++)
596 		argv_init[i] = NULL;
597 	return 1;
598 }
599 __setup("rdinit=", rdinit_setup);
600 
601 #ifndef CONFIG_SMP
602 static const unsigned int setup_max_cpus = NR_CPUS;
603 static inline void setup_nr_cpu_ids(void) { }
604 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
605 #endif
606 
607 /*
608  * We need to store the untouched command line for future reference.
609  * We also need to store the touched command line since the parameter
610  * parsing is performed in place, and we should allow a component to
611  * store reference of name/value for future reference.
612  */
613 static void __init setup_command_line(char *command_line)
614 {
615 	size_t len, xlen = 0, ilen = 0;
616 
617 	if (extra_command_line)
618 		xlen = strlen(extra_command_line);
619 	if (extra_init_args)
620 		ilen = strlen(extra_init_args) + 4; /* for " -- " */
621 
622 	len = xlen + strlen(boot_command_line) + 1;
623 
624 	saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
625 	if (!saved_command_line)
626 		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
627 
628 	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
629 	if (!static_command_line)
630 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
631 
632 	if (xlen) {
633 		/*
634 		 * We have to put extra_command_line before boot command
635 		 * lines because there could be dashes (separator of init
636 		 * command line) in the command lines.
637 		 */
638 		strcpy(saved_command_line, extra_command_line);
639 		strcpy(static_command_line, extra_command_line);
640 	}
641 	strcpy(saved_command_line + xlen, boot_command_line);
642 	strcpy(static_command_line + xlen, command_line);
643 
644 	if (ilen) {
645 		/*
646 		 * Append supplemental init boot args to saved_command_line
647 		 * so that user can check what command line options passed
648 		 * to init.
649 		 * The order should always be
650 		 * " -- "[bootconfig init-param][cmdline init-param]
651 		 */
652 		if (initargs_offs) {
653 			len = xlen + initargs_offs;
654 			strcpy(saved_command_line + len, extra_init_args);
655 			len += ilen - 4;	/* strlen(extra_init_args) */
656 			strcpy(saved_command_line + len,
657 				boot_command_line + initargs_offs - 1);
658 		} else {
659 			len = strlen(saved_command_line);
660 			strcpy(saved_command_line + len, " -- ");
661 			len += 4;
662 			strcpy(saved_command_line + len, extra_init_args);
663 		}
664 	}
665 
666 	saved_command_line_len = strlen(saved_command_line);
667 }
668 
669 /*
670  * We need to finalize in a non-__init function or else race conditions
671  * between the root thread and the init thread may cause start_kernel to
672  * be reaped by free_initmem before the root thread has proceeded to
673  * cpu_idle.
674  *
675  * gcc-3.4 accidentally inlines this function, so use noinline.
676  */
677 
678 static __initdata DECLARE_COMPLETION(kthreadd_done);
679 
680 noinline void __ref __noreturn rest_init(void)
681 {
682 	struct task_struct *tsk;
683 	int pid;
684 
685 	rcu_scheduler_starting();
686 	/*
687 	 * We need to spawn init first so that it obtains pid 1, however
688 	 * the init task will end up wanting to create kthreads, which, if
689 	 * we schedule it before we create kthreadd, will OOPS.
690 	 */
691 	pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
692 	/*
693 	 * Pin init on the boot CPU. Task migration is not properly working
694 	 * until sched_init_smp() has been run. It will set the allowed
695 	 * CPUs for init to the non isolated CPUs.
696 	 */
697 	rcu_read_lock();
698 	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
699 	tsk->flags |= PF_NO_SETAFFINITY;
700 	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
701 	rcu_read_unlock();
702 
703 	numa_default_policy();
704 	pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
705 	rcu_read_lock();
706 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
707 	rcu_read_unlock();
708 
709 	/*
710 	 * Enable might_sleep() and smp_processor_id() checks.
711 	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
712 	 * kernel_thread() would trigger might_sleep() splats. With
713 	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
714 	 * already, but it's stuck on the kthreadd_done completion.
715 	 */
716 	system_state = SYSTEM_SCHEDULING;
717 
718 	complete(&kthreadd_done);
719 
720 	/*
721 	 * The boot idle thread must execute schedule()
722 	 * at least once to get things moving:
723 	 */
724 	schedule_preempt_disabled();
725 	/* Call into cpu_idle with preempt disabled */
726 	cpu_startup_entry(CPUHP_ONLINE);
727 }
728 
729 /* Check for early params. */
730 static int __init do_early_param(char *param, char *val,
731 				 const char *unused, void *arg)
732 {
733 	const struct obs_kernel_param *p;
734 
735 	for (p = __setup_start; p < __setup_end; p++) {
736 		if ((p->early && parameq(param, p->str)) ||
737 		    (strcmp(param, "console") == 0 &&
738 		     strcmp(p->str, "earlycon") == 0)
739 		) {
740 			if (p->setup_func(val) != 0)
741 				pr_warn("Malformed early option '%s'\n", param);
742 		}
743 	}
744 	/* We accept everything at this stage. */
745 	return 0;
746 }
747 
748 void __init parse_early_options(char *cmdline)
749 {
750 	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
751 		   do_early_param);
752 }
753 
754 /* Arch code calls this early on, or if not, just before other parsing. */
755 void __init parse_early_param(void)
756 {
757 	static int done __initdata;
758 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
759 
760 	if (done)
761 		return;
762 
763 	/* All fall through to do_early_param. */
764 	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
765 	parse_early_options(tmp_cmdline);
766 	done = 1;
767 }
768 
769 void __init __weak arch_post_acpi_subsys_init(void) { }
770 
771 void __init __weak smp_setup_processor_id(void)
772 {
773 }
774 
775 # if THREAD_SIZE >= PAGE_SIZE
776 void __init __weak thread_stack_cache_init(void)
777 {
778 }
779 #endif
780 
781 void __init __weak poking_init(void) { }
782 
783 void __init __weak pgtable_cache_init(void) { }
784 
785 void __init __weak trap_init(void) { }
786 
787 bool initcall_debug;
788 core_param(initcall_debug, initcall_debug, bool, 0644);
789 
790 #ifdef TRACEPOINTS_ENABLED
791 static void __init initcall_debug_enable(void);
792 #else
793 static inline void initcall_debug_enable(void)
794 {
795 }
796 #endif
797 
798 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
799 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
800 			   randomize_kstack_offset);
801 DEFINE_PER_CPU(u32, kstack_offset);
802 
803 static int __init early_randomize_kstack_offset(char *buf)
804 {
805 	int ret;
806 	bool bool_result;
807 
808 	ret = kstrtobool(buf, &bool_result);
809 	if (ret)
810 		return ret;
811 
812 	if (bool_result)
813 		static_branch_enable(&randomize_kstack_offset);
814 	else
815 		static_branch_disable(&randomize_kstack_offset);
816 	return 0;
817 }
818 early_param("randomize_kstack_offset", early_randomize_kstack_offset);
819 #endif
820 
821 void __init __weak __noreturn arch_call_rest_init(void)
822 {
823 	rest_init();
824 }
825 
826 static void __init print_unknown_bootoptions(void)
827 {
828 	char *unknown_options;
829 	char *end;
830 	const char *const *p;
831 	size_t len;
832 
833 	if (panic_later || (!argv_init[1] && !envp_init[2]))
834 		return;
835 
836 	/*
837 	 * Determine how many options we have to print out, plus a space
838 	 * before each
839 	 */
840 	len = 1; /* null terminator */
841 	for (p = &argv_init[1]; *p; p++) {
842 		len++;
843 		len += strlen(*p);
844 	}
845 	for (p = &envp_init[2]; *p; p++) {
846 		len++;
847 		len += strlen(*p);
848 	}
849 
850 	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
851 	if (!unknown_options) {
852 		pr_err("%s: Failed to allocate %zu bytes\n",
853 			__func__, len);
854 		return;
855 	}
856 	end = unknown_options;
857 
858 	for (p = &argv_init[1]; *p; p++)
859 		end += sprintf(end, " %s", *p);
860 	for (p = &envp_init[2]; *p; p++)
861 		end += sprintf(end, " %s", *p);
862 
863 	/* Start at unknown_options[1] to skip the initial space */
864 	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
865 		&unknown_options[1]);
866 	memblock_free(unknown_options, len);
867 }
868 
869 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
870 void start_kernel(void)
871 {
872 	char *command_line;
873 	char *after_dashes;
874 
875 	set_task_stack_end_magic(&init_task);
876 	smp_setup_processor_id();
877 	debug_objects_early_init();
878 	init_vmlinux_build_id();
879 
880 	cgroup_init_early();
881 
882 	local_irq_disable();
883 	early_boot_irqs_disabled = true;
884 
885 	/*
886 	 * Interrupts are still disabled. Do necessary setups, then
887 	 * enable them.
888 	 */
889 	boot_cpu_init();
890 	page_address_init();
891 	pr_notice("%s", linux_banner);
892 	early_security_init();
893 	setup_arch(&command_line);
894 	setup_boot_config();
895 	setup_command_line(command_line);
896 	setup_nr_cpu_ids();
897 	setup_per_cpu_areas();
898 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
899 	boot_cpu_hotplug_init();
900 
901 	pr_notice("Kernel command line: %s\n", saved_command_line);
902 	/* parameters may set static keys */
903 	jump_label_init();
904 	parse_early_param();
905 	after_dashes = parse_args("Booting kernel",
906 				  static_command_line, __start___param,
907 				  __stop___param - __start___param,
908 				  -1, -1, NULL, &unknown_bootoption);
909 	print_unknown_bootoptions();
910 	if (!IS_ERR_OR_NULL(after_dashes))
911 		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
912 			   NULL, set_init_arg);
913 	if (extra_init_args)
914 		parse_args("Setting extra init args", extra_init_args,
915 			   NULL, 0, -1, -1, NULL, set_init_arg);
916 
917 	/* Architectural and non-timekeeping rng init, before allocator init */
918 	random_init_early(command_line);
919 
920 	/*
921 	 * These use large bootmem allocations and must precede
922 	 * initalization of page allocator
923 	 */
924 	setup_log_buf(0);
925 	vfs_caches_init_early();
926 	sort_main_extable();
927 	trap_init();
928 	mm_core_init();
929 	poking_init();
930 	ftrace_init();
931 
932 	/* trace_printk can be enabled here */
933 	early_trace_init();
934 
935 	/*
936 	 * Set up the scheduler prior starting any interrupts (such as the
937 	 * timer interrupt). Full topology setup happens at smp_init()
938 	 * time - but meanwhile we still have a functioning scheduler.
939 	 */
940 	sched_init();
941 
942 	if (WARN(!irqs_disabled(),
943 		 "Interrupts were enabled *very* early, fixing it\n"))
944 		local_irq_disable();
945 	radix_tree_init();
946 	maple_tree_init();
947 
948 	/*
949 	 * Set up housekeeping before setting up workqueues to allow the unbound
950 	 * workqueue to take non-housekeeping into account.
951 	 */
952 	housekeeping_init();
953 
954 	/*
955 	 * Allow workqueue creation and work item queueing/cancelling
956 	 * early.  Work item execution depends on kthreads and starts after
957 	 * workqueue_init().
958 	 */
959 	workqueue_init_early();
960 
961 	rcu_init();
962 
963 	/* Trace events are available after this */
964 	trace_init();
965 
966 	if (initcall_debug)
967 		initcall_debug_enable();
968 
969 	context_tracking_init();
970 	/* init some links before init_ISA_irqs() */
971 	early_irq_init();
972 	init_IRQ();
973 	tick_init();
974 	rcu_init_nohz();
975 	init_timers();
976 	srcu_init();
977 	hrtimers_init();
978 	softirq_init();
979 	timekeeping_init();
980 	time_init();
981 
982 	/* This must be after timekeeping is initialized */
983 	random_init();
984 
985 	/* These make use of the fully initialized rng */
986 	kfence_init();
987 	boot_init_stack_canary();
988 
989 	perf_event_init();
990 	profile_init();
991 	call_function_init();
992 	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
993 
994 	early_boot_irqs_disabled = false;
995 	local_irq_enable();
996 
997 	kmem_cache_init_late();
998 
999 	/*
1000 	 * HACK ALERT! This is early. We're enabling the console before
1001 	 * we've done PCI setups etc, and console_init() must be aware of
1002 	 * this. But we do want output early, in case something goes wrong.
1003 	 */
1004 	console_init();
1005 	if (panic_later)
1006 		panic("Too many boot %s vars at `%s'", panic_later,
1007 		      panic_param);
1008 
1009 	lockdep_init();
1010 
1011 	/*
1012 	 * Need to run this when irqs are enabled, because it wants
1013 	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1014 	 * too:
1015 	 */
1016 	locking_selftest();
1017 
1018 #ifdef CONFIG_BLK_DEV_INITRD
1019 	if (initrd_start && !initrd_below_start_ok &&
1020 	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1021 		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1022 		    page_to_pfn(virt_to_page((void *)initrd_start)),
1023 		    min_low_pfn);
1024 		initrd_start = 0;
1025 	}
1026 #endif
1027 	setup_per_cpu_pageset();
1028 	numa_policy_init();
1029 	acpi_early_init();
1030 	if (late_time_init)
1031 		late_time_init();
1032 	sched_clock_init();
1033 	calibrate_delay();
1034 
1035 	arch_cpu_finalize_init();
1036 
1037 	pid_idr_init();
1038 	anon_vma_init();
1039 #ifdef CONFIG_X86
1040 	if (efi_enabled(EFI_RUNTIME_SERVICES))
1041 		efi_enter_virtual_mode();
1042 #endif
1043 	thread_stack_cache_init();
1044 	cred_init();
1045 	fork_init();
1046 	proc_caches_init();
1047 	uts_ns_init();
1048 	key_init();
1049 	security_init();
1050 	dbg_late_init();
1051 	net_ns_init();
1052 	vfs_caches_init();
1053 	pagecache_init();
1054 	signals_init();
1055 	seq_file_init();
1056 	proc_root_init();
1057 	nsfs_init();
1058 	cpuset_init();
1059 	cgroup_init();
1060 	taskstats_init_early();
1061 	delayacct_init();
1062 
1063 	acpi_subsystem_init();
1064 	arch_post_acpi_subsys_init();
1065 	kcsan_init();
1066 
1067 	/* Do the rest non-__init'ed, we're now alive */
1068 	arch_call_rest_init();
1069 
1070 	/*
1071 	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
1072 	 * and older.
1073 	 */
1074 #if !__has_attribute(__no_stack_protector__)
1075 	prevent_tail_call_optimization();
1076 #endif
1077 }
1078 
1079 /* Call all constructor functions linked into the kernel. */
1080 static void __init do_ctors(void)
1081 {
1082 /*
1083  * For UML, the constructors have already been called by the
1084  * normal setup code as it's just a normal ELF binary, so we
1085  * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1086  * even on UML for modules.
1087  */
1088 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1089 	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1090 
1091 	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1092 		(*fn)();
1093 #endif
1094 }
1095 
1096 #ifdef CONFIG_KALLSYMS
1097 struct blacklist_entry {
1098 	struct list_head next;
1099 	char *buf;
1100 };
1101 
1102 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1103 
1104 static int __init initcall_blacklist(char *str)
1105 {
1106 	char *str_entry;
1107 	struct blacklist_entry *entry;
1108 
1109 	/* str argument is a comma-separated list of functions */
1110 	do {
1111 		str_entry = strsep(&str, ",");
1112 		if (str_entry) {
1113 			pr_debug("blacklisting initcall %s\n", str_entry);
1114 			entry = memblock_alloc(sizeof(*entry),
1115 					       SMP_CACHE_BYTES);
1116 			if (!entry)
1117 				panic("%s: Failed to allocate %zu bytes\n",
1118 				      __func__, sizeof(*entry));
1119 			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1120 						    SMP_CACHE_BYTES);
1121 			if (!entry->buf)
1122 				panic("%s: Failed to allocate %zu bytes\n",
1123 				      __func__, strlen(str_entry) + 1);
1124 			strcpy(entry->buf, str_entry);
1125 			list_add(&entry->next, &blacklisted_initcalls);
1126 		}
1127 	} while (str_entry);
1128 
1129 	return 1;
1130 }
1131 
1132 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1133 {
1134 	struct blacklist_entry *entry;
1135 	char fn_name[KSYM_SYMBOL_LEN];
1136 	unsigned long addr;
1137 
1138 	if (list_empty(&blacklisted_initcalls))
1139 		return false;
1140 
1141 	addr = (unsigned long) dereference_function_descriptor(fn);
1142 	sprint_symbol_no_offset(fn_name, addr);
1143 
1144 	/*
1145 	 * fn will be "function_name [module_name]" where [module_name] is not
1146 	 * displayed for built-in init functions.  Strip off the [module_name].
1147 	 */
1148 	strreplace(fn_name, ' ', '\0');
1149 
1150 	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1151 		if (!strcmp(fn_name, entry->buf)) {
1152 			pr_debug("initcall %s blacklisted\n", fn_name);
1153 			return true;
1154 		}
1155 	}
1156 
1157 	return false;
1158 }
1159 #else
1160 static int __init initcall_blacklist(char *str)
1161 {
1162 	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1163 	return 0;
1164 }
1165 
1166 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1167 {
1168 	return false;
1169 }
1170 #endif
1171 __setup("initcall_blacklist=", initcall_blacklist);
1172 
1173 static __init_or_module void
1174 trace_initcall_start_cb(void *data, initcall_t fn)
1175 {
1176 	ktime_t *calltime = data;
1177 
1178 	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
1179 	*calltime = ktime_get();
1180 }
1181 
1182 static __init_or_module void
1183 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1184 {
1185 	ktime_t rettime, *calltime = data;
1186 
1187 	rettime = ktime_get();
1188 	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1189 		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1190 }
1191 
1192 static ktime_t initcall_calltime;
1193 
1194 #ifdef TRACEPOINTS_ENABLED
1195 static void __init initcall_debug_enable(void)
1196 {
1197 	int ret;
1198 
1199 	ret = register_trace_initcall_start(trace_initcall_start_cb,
1200 					    &initcall_calltime);
1201 	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1202 					      &initcall_calltime);
1203 	WARN(ret, "Failed to register initcall tracepoints\n");
1204 }
1205 # define do_trace_initcall_start	trace_initcall_start
1206 # define do_trace_initcall_finish	trace_initcall_finish
1207 #else
1208 static inline void do_trace_initcall_start(initcall_t fn)
1209 {
1210 	if (!initcall_debug)
1211 		return;
1212 	trace_initcall_start_cb(&initcall_calltime, fn);
1213 }
1214 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1215 {
1216 	if (!initcall_debug)
1217 		return;
1218 	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1219 }
1220 #endif /* !TRACEPOINTS_ENABLED */
1221 
1222 int __init_or_module do_one_initcall(initcall_t fn)
1223 {
1224 	int count = preempt_count();
1225 	char msgbuf[64];
1226 	int ret;
1227 
1228 	if (initcall_blacklisted(fn))
1229 		return -EPERM;
1230 
1231 	do_trace_initcall_start(fn);
1232 	ret = fn();
1233 	do_trace_initcall_finish(fn, ret);
1234 
1235 	msgbuf[0] = 0;
1236 
1237 	if (preempt_count() != count) {
1238 		sprintf(msgbuf, "preemption imbalance ");
1239 		preempt_count_set(count);
1240 	}
1241 	if (irqs_disabled()) {
1242 		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1243 		local_irq_enable();
1244 	}
1245 	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1246 
1247 	add_latent_entropy();
1248 	return ret;
1249 }
1250 
1251 
1252 static initcall_entry_t *initcall_levels[] __initdata = {
1253 	__initcall0_start,
1254 	__initcall1_start,
1255 	__initcall2_start,
1256 	__initcall3_start,
1257 	__initcall4_start,
1258 	__initcall5_start,
1259 	__initcall6_start,
1260 	__initcall7_start,
1261 	__initcall_end,
1262 };
1263 
1264 /* Keep these in sync with initcalls in include/linux/init.h */
1265 static const char *initcall_level_names[] __initdata = {
1266 	"pure",
1267 	"core",
1268 	"postcore",
1269 	"arch",
1270 	"subsys",
1271 	"fs",
1272 	"device",
1273 	"late",
1274 };
1275 
1276 static int __init ignore_unknown_bootoption(char *param, char *val,
1277 			       const char *unused, void *arg)
1278 {
1279 	return 0;
1280 }
1281 
1282 static void __init do_initcall_level(int level, char *command_line)
1283 {
1284 	initcall_entry_t *fn;
1285 
1286 	parse_args(initcall_level_names[level],
1287 		   command_line, __start___param,
1288 		   __stop___param - __start___param,
1289 		   level, level,
1290 		   NULL, ignore_unknown_bootoption);
1291 
1292 	trace_initcall_level(initcall_level_names[level]);
1293 	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1294 		do_one_initcall(initcall_from_entry(fn));
1295 }
1296 
1297 static void __init do_initcalls(void)
1298 {
1299 	int level;
1300 	size_t len = saved_command_line_len + 1;
1301 	char *command_line;
1302 
1303 	command_line = kzalloc(len, GFP_KERNEL);
1304 	if (!command_line)
1305 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1306 
1307 	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1308 		/* Parser modifies command_line, restore it each time */
1309 		strcpy(command_line, saved_command_line);
1310 		do_initcall_level(level, command_line);
1311 	}
1312 
1313 	kfree(command_line);
1314 }
1315 
1316 /*
1317  * Ok, the machine is now initialized. None of the devices
1318  * have been touched yet, but the CPU subsystem is up and
1319  * running, and memory and process management works.
1320  *
1321  * Now we can finally start doing some real work..
1322  */
1323 static void __init do_basic_setup(void)
1324 {
1325 	cpuset_init_smp();
1326 	driver_init();
1327 	init_irq_proc();
1328 	do_ctors();
1329 	do_initcalls();
1330 }
1331 
1332 static void __init do_pre_smp_initcalls(void)
1333 {
1334 	initcall_entry_t *fn;
1335 
1336 	trace_initcall_level("early");
1337 	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1338 		do_one_initcall(initcall_from_entry(fn));
1339 }
1340 
1341 static int run_init_process(const char *init_filename)
1342 {
1343 	const char *const *p;
1344 
1345 	argv_init[0] = init_filename;
1346 	pr_info("Run %s as init process\n", init_filename);
1347 	pr_debug("  with arguments:\n");
1348 	for (p = argv_init; *p; p++)
1349 		pr_debug("    %s\n", *p);
1350 	pr_debug("  with environment:\n");
1351 	for (p = envp_init; *p; p++)
1352 		pr_debug("    %s\n", *p);
1353 	return kernel_execve(init_filename, argv_init, envp_init);
1354 }
1355 
1356 static int try_to_run_init_process(const char *init_filename)
1357 {
1358 	int ret;
1359 
1360 	ret = run_init_process(init_filename);
1361 
1362 	if (ret && ret != -ENOENT) {
1363 		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1364 		       init_filename, ret);
1365 	}
1366 
1367 	return ret;
1368 }
1369 
1370 static noinline void __init kernel_init_freeable(void);
1371 
1372 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1373 bool rodata_enabled __ro_after_init = true;
1374 
1375 #ifndef arch_parse_debug_rodata
1376 static inline bool arch_parse_debug_rodata(char *str) { return false; }
1377 #endif
1378 
1379 static int __init set_debug_rodata(char *str)
1380 {
1381 	if (arch_parse_debug_rodata(str))
1382 		return 0;
1383 
1384 	if (str && !strcmp(str, "on"))
1385 		rodata_enabled = true;
1386 	else if (str && !strcmp(str, "off"))
1387 		rodata_enabled = false;
1388 	else
1389 		pr_warn("Invalid option string for rodata: '%s'\n", str);
1390 	return 0;
1391 }
1392 early_param("rodata", set_debug_rodata);
1393 #endif
1394 
1395 #ifdef CONFIG_STRICT_KERNEL_RWX
1396 static void mark_readonly(void)
1397 {
1398 	if (rodata_enabled) {
1399 		/*
1400 		 * load_module() results in W+X mappings, which are cleaned
1401 		 * up with call_rcu().  Let's make sure that queued work is
1402 		 * flushed so that we don't hit false positives looking for
1403 		 * insecure pages which are W+X.
1404 		 */
1405 		rcu_barrier();
1406 		mark_rodata_ro();
1407 		rodata_test();
1408 	} else
1409 		pr_info("Kernel memory protection disabled.\n");
1410 }
1411 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1412 static inline void mark_readonly(void)
1413 {
1414 	pr_warn("Kernel memory protection not selected by kernel config.\n");
1415 }
1416 #else
1417 static inline void mark_readonly(void)
1418 {
1419 	pr_warn("This architecture does not have kernel memory protection.\n");
1420 }
1421 #endif
1422 
1423 void __weak free_initmem(void)
1424 {
1425 	free_initmem_default(POISON_FREE_INITMEM);
1426 }
1427 
1428 static int __ref kernel_init(void *unused)
1429 {
1430 	int ret;
1431 
1432 	/*
1433 	 * Wait until kthreadd is all set-up.
1434 	 */
1435 	wait_for_completion(&kthreadd_done);
1436 
1437 	kernel_init_freeable();
1438 	/* need to finish all async __init code before freeing the memory */
1439 	async_synchronize_full();
1440 
1441 	system_state = SYSTEM_FREEING_INITMEM;
1442 	kprobe_free_init_mem();
1443 	ftrace_free_init_mem();
1444 	kgdb_free_init_mem();
1445 	exit_boot_config();
1446 	free_initmem();
1447 	mark_readonly();
1448 
1449 	/*
1450 	 * Kernel mappings are now finalized - update the userspace page-table
1451 	 * to finalize PTI.
1452 	 */
1453 	pti_finalize();
1454 
1455 	system_state = SYSTEM_RUNNING;
1456 	numa_default_policy();
1457 
1458 	rcu_end_inkernel_boot();
1459 
1460 	do_sysctl_args();
1461 
1462 	if (ramdisk_execute_command) {
1463 		ret = run_init_process(ramdisk_execute_command);
1464 		if (!ret)
1465 			return 0;
1466 		pr_err("Failed to execute %s (error %d)\n",
1467 		       ramdisk_execute_command, ret);
1468 	}
1469 
1470 	/*
1471 	 * We try each of these until one succeeds.
1472 	 *
1473 	 * The Bourne shell can be used instead of init if we are
1474 	 * trying to recover a really broken machine.
1475 	 */
1476 	if (execute_command) {
1477 		ret = run_init_process(execute_command);
1478 		if (!ret)
1479 			return 0;
1480 		panic("Requested init %s failed (error %d).",
1481 		      execute_command, ret);
1482 	}
1483 
1484 	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1485 		ret = run_init_process(CONFIG_DEFAULT_INIT);
1486 		if (ret)
1487 			pr_err("Default init %s failed (error %d)\n",
1488 			       CONFIG_DEFAULT_INIT, ret);
1489 		else
1490 			return 0;
1491 	}
1492 
1493 	if (!try_to_run_init_process("/sbin/init") ||
1494 	    !try_to_run_init_process("/etc/init") ||
1495 	    !try_to_run_init_process("/bin/init") ||
1496 	    !try_to_run_init_process("/bin/sh"))
1497 		return 0;
1498 
1499 	panic("No working init found.  Try passing init= option to kernel. "
1500 	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1501 }
1502 
1503 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1504 void __init console_on_rootfs(void)
1505 {
1506 	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1507 
1508 	if (IS_ERR(file)) {
1509 		pr_err("Warning: unable to open an initial console.\n");
1510 		return;
1511 	}
1512 	init_dup(file);
1513 	init_dup(file);
1514 	init_dup(file);
1515 	fput(file);
1516 }
1517 
1518 static noinline void __init kernel_init_freeable(void)
1519 {
1520 	/* Now the scheduler is fully set up and can do blocking allocations */
1521 	gfp_allowed_mask = __GFP_BITS_MASK;
1522 
1523 	/*
1524 	 * init can allocate pages on any node
1525 	 */
1526 	set_mems_allowed(node_states[N_MEMORY]);
1527 
1528 	cad_pid = get_pid(task_pid(current));
1529 
1530 	smp_prepare_cpus(setup_max_cpus);
1531 
1532 	workqueue_init();
1533 
1534 	init_mm_internals();
1535 
1536 	rcu_init_tasks_generic();
1537 	do_pre_smp_initcalls();
1538 	lockup_detector_init();
1539 
1540 	smp_init();
1541 	sched_init_smp();
1542 
1543 	workqueue_init_topology();
1544 	padata_init();
1545 	page_alloc_init_late();
1546 
1547 	do_basic_setup();
1548 
1549 	kunit_run_all_tests();
1550 
1551 	wait_for_initramfs();
1552 	console_on_rootfs();
1553 
1554 	/*
1555 	 * check if there is an early userspace init.  If yes, let it do all
1556 	 * the work
1557 	 */
1558 	if (init_eaccess(ramdisk_execute_command) != 0) {
1559 		ramdisk_execute_command = NULL;
1560 		prepare_namespace();
1561 	}
1562 
1563 	/*
1564 	 * Ok, we have completed the initial bootup, and
1565 	 * we're essentially up and running. Get rid of the
1566 	 * initmem segments and start the user-mode stuff..
1567 	 *
1568 	 * rootfs is available now, try loading the public keys
1569 	 * and default modules
1570 	 */
1571 
1572 	integrity_load_keys();
1573 }
1574