xref: /linux/init/main.c (revision a7a08b275a8bbade798c4bdaad07ade68fe7003c)
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/vmalloc.h>
38 #include <linux/kernel_stat.h>
39 #include <linux/start_kernel.h>
40 #include <linux/security.h>
41 #include <linux/smp.h>
42 #include <linux/profile.h>
43 #include <linux/kfence.h>
44 #include <linux/rcupdate.h>
45 #include <linux/srcu.h>
46 #include <linux/moduleparam.h>
47 #include <linux/kallsyms.h>
48 #include <linux/buildid.h>
49 #include <linux/writeback.h>
50 #include <linux/cpu.h>
51 #include <linux/cpuset.h>
52 #include <linux/cgroup.h>
53 #include <linux/efi.h>
54 #include <linux/tick.h>
55 #include <linux/sched/isolation.h>
56 #include <linux/interrupt.h>
57 #include <linux/taskstats_kern.h>
58 #include <linux/delayacct.h>
59 #include <linux/unistd.h>
60 #include <linux/utsname.h>
61 #include <linux/rmap.h>
62 #include <linux/mempolicy.h>
63 #include <linux/key.h>
64 #include <linux/page_ext.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/elevator.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/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/mem_encrypt.h>
100 #include <linux/kcsan.h>
101 #include <linux/init_syscalls.h>
102 #include <linux/stackdepot.h>
103 
104 #include <asm/io.h>
105 #include <asm/bugs.h>
106 #include <asm/setup.h>
107 #include <asm/sections.h>
108 #include <asm/cacheflush.h>
109 
110 #define CREATE_TRACE_POINTS
111 #include <trace/events/initcall.h>
112 
113 #include <kunit/test.h>
114 
115 static int kernel_init(void *);
116 
117 extern void init_IRQ(void);
118 extern void radix_tree_init(void);
119 
120 /*
121  * Debug helper: via this flag we know that we are in 'early bootup code'
122  * where only the boot processor is running with IRQ disabled.  This means
123  * two things - IRQ must not be enabled before the flag is cleared and some
124  * operations which are not allowed with IRQ disabled are allowed while the
125  * flag is set.
126  */
127 bool early_boot_irqs_disabled __read_mostly;
128 
129 enum system_states system_state __read_mostly;
130 EXPORT_SYMBOL(system_state);
131 
132 /*
133  * Boot command-line arguments
134  */
135 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
136 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
137 
138 extern void time_init(void);
139 /* Default late time init is NULL. archs can override this later. */
140 void (*__initdata late_time_init)(void);
141 
142 /* Untouched command line saved by arch-specific code. */
143 char __initdata boot_command_line[COMMAND_LINE_SIZE];
144 /* Untouched saved command line (eg. for /proc) */
145 char *saved_command_line;
146 /* Command line for parameter parsing */
147 static char *static_command_line;
148 /* Untouched extra command line */
149 static char *extra_command_line;
150 /* Extra init arguments */
151 static char *extra_init_args;
152 
153 #ifdef CONFIG_BOOT_CONFIG
154 /* Is bootconfig on command line? */
155 static bool bootconfig_found;
156 static bool initargs_found;
157 #else
158 # define bootconfig_found false
159 # define initargs_found false
160 #endif
161 
162 static char *execute_command;
163 static char *ramdisk_execute_command = "/init";
164 
165 /*
166  * Used to generate warnings if static_key manipulation functions are used
167  * before jump_label_init is called.
168  */
169 bool static_key_initialized __read_mostly;
170 EXPORT_SYMBOL_GPL(static_key_initialized);
171 
172 /*
173  * If set, this is an indication to the drivers that reset the underlying
174  * device before going ahead with the initialization otherwise driver might
175  * rely on the BIOS and skip the reset operation.
176  *
177  * This is useful if kernel is booting in an unreliable environment.
178  * For ex. kdump situation where previous kernel has crashed, BIOS has been
179  * skipped and devices will be in unknown state.
180  */
181 unsigned int reset_devices;
182 EXPORT_SYMBOL(reset_devices);
183 
184 static int __init set_reset_devices(char *str)
185 {
186 	reset_devices = 1;
187 	return 1;
188 }
189 
190 __setup("reset_devices", set_reset_devices);
191 
192 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
193 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
194 static const char *panic_later, *panic_param;
195 
196 extern const struct obs_kernel_param __setup_start[], __setup_end[];
197 
198 static bool __init obsolete_checksetup(char *line)
199 {
200 	const struct obs_kernel_param *p;
201 	bool had_early_param = false;
202 
203 	p = __setup_start;
204 	do {
205 		int n = strlen(p->str);
206 		if (parameqn(line, p->str, n)) {
207 			if (p->early) {
208 				/* Already done in parse_early_param?
209 				 * (Needs exact match on param part).
210 				 * Keep iterating, as we can have early
211 				 * params and __setups of same names 8( */
212 				if (line[n] == '\0' || line[n] == '=')
213 					had_early_param = true;
214 			} else if (!p->setup_func) {
215 				pr_warn("Parameter %s is obsolete, ignored\n",
216 					p->str);
217 				return true;
218 			} else if (p->setup_func(line + n))
219 				return true;
220 		}
221 		p++;
222 	} while (p < __setup_end);
223 
224 	return had_early_param;
225 }
226 
227 /*
228  * This should be approx 2 Bo*oMips to start (note initial shift), and will
229  * still work even if initially too large, it will just take slightly longer
230  */
231 unsigned long loops_per_jiffy = (1<<12);
232 EXPORT_SYMBOL(loops_per_jiffy);
233 
234 static int __init debug_kernel(char *str)
235 {
236 	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
237 	return 0;
238 }
239 
240 static int __init quiet_kernel(char *str)
241 {
242 	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
243 	return 0;
244 }
245 
246 early_param("debug", debug_kernel);
247 early_param("quiet", quiet_kernel);
248 
249 static int __init loglevel(char *str)
250 {
251 	int newlevel;
252 
253 	/*
254 	 * Only update loglevel value when a correct setting was passed,
255 	 * to prevent blind crashes (when loglevel being set to 0) that
256 	 * are quite hard to debug
257 	 */
258 	if (get_option(&str, &newlevel)) {
259 		console_loglevel = newlevel;
260 		return 0;
261 	}
262 
263 	return -EINVAL;
264 }
265 
266 early_param("loglevel", loglevel);
267 
268 #ifdef CONFIG_BLK_DEV_INITRD
269 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
270 {
271 	u32 size, csum;
272 	char *data;
273 	u32 *hdr;
274 	int i;
275 
276 	if (!initrd_end)
277 		return NULL;
278 
279 	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
280 	/*
281 	 * Since Grub may align the size of initrd to 4, we must
282 	 * check the preceding 3 bytes as well.
283 	 */
284 	for (i = 0; i < 4; i++) {
285 		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
286 			goto found;
287 		data--;
288 	}
289 	return NULL;
290 
291 found:
292 	hdr = (u32 *)(data - 8);
293 	size = le32_to_cpu(hdr[0]);
294 	csum = le32_to_cpu(hdr[1]);
295 
296 	data = ((void *)hdr) - size;
297 	if ((unsigned long)data < initrd_start) {
298 		pr_err("bootconfig size %d is greater than initrd size %ld\n",
299 			size, initrd_end - initrd_start);
300 		return NULL;
301 	}
302 
303 	/* Remove bootconfig from initramfs/initrd */
304 	initrd_end = (unsigned long)data;
305 	if (_size)
306 		*_size = size;
307 	if (_csum)
308 		*_csum = csum;
309 
310 	return data;
311 }
312 #else
313 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
314 {
315 	return NULL;
316 }
317 #endif
318 
319 #ifdef CONFIG_BOOT_CONFIG
320 
321 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
322 
323 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
324 
325 static int __init xbc_snprint_cmdline(char *buf, size_t size,
326 				      struct xbc_node *root)
327 {
328 	struct xbc_node *knode, *vnode;
329 	char *end = buf + size;
330 	const char *val;
331 	int ret;
332 
333 	xbc_node_for_each_key_value(root, knode, val) {
334 		ret = xbc_node_compose_key_after(root, knode,
335 					xbc_namebuf, XBC_KEYLEN_MAX);
336 		if (ret < 0)
337 			return ret;
338 
339 		vnode = xbc_node_get_child(knode);
340 		if (!vnode) {
341 			ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
342 			if (ret < 0)
343 				return ret;
344 			buf += ret;
345 			continue;
346 		}
347 		xbc_array_for_each_value(vnode, val) {
348 			ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
349 				       xbc_namebuf, val);
350 			if (ret < 0)
351 				return ret;
352 			buf += ret;
353 		}
354 	}
355 
356 	return buf - (end - size);
357 }
358 #undef rest
359 
360 /* Make an extra command line under given key word */
361 static char * __init xbc_make_cmdline(const char *key)
362 {
363 	struct xbc_node *root;
364 	char *new_cmdline;
365 	int ret, len = 0;
366 
367 	root = xbc_find_node(key);
368 	if (!root)
369 		return NULL;
370 
371 	/* Count required buffer size */
372 	len = xbc_snprint_cmdline(NULL, 0, root);
373 	if (len <= 0)
374 		return NULL;
375 
376 	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
377 	if (!new_cmdline) {
378 		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
379 		return NULL;
380 	}
381 
382 	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
383 	if (ret < 0 || ret > len) {
384 		pr_err("Failed to print extra kernel cmdline.\n");
385 		return NULL;
386 	}
387 
388 	return new_cmdline;
389 }
390 
391 static int __init bootconfig_params(char *param, char *val,
392 				    const char *unused, void *arg)
393 {
394 	if (strcmp(param, "bootconfig") == 0) {
395 		bootconfig_found = true;
396 	}
397 	return 0;
398 }
399 
400 static int __init warn_bootconfig(char *str)
401 {
402 	/* The 'bootconfig' has been handled by bootconfig_params(). */
403 	return 0;
404 }
405 
406 static void __init setup_boot_config(void)
407 {
408 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
409 	const char *msg;
410 	int pos;
411 	u32 size, csum;
412 	char *data, *copy, *err;
413 	int ret;
414 
415 	/* Cut out the bootconfig data even if we have no bootconfig option */
416 	data = get_boot_config_from_initrd(&size, &csum);
417 
418 	strlcpy(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)
423 		return;
424 
425 	/* parse_args() stops at '--' and returns an address */
426 	if (err)
427 		initargs_found = true;
428 
429 	if (!data) {
430 		pr_err("'bootconfig' found on command line, but no bootconfig found\n");
431 		return;
432 	}
433 
434 	if (size >= XBC_DATA_MAX) {
435 		pr_err("bootconfig size %d greater than max size %d\n",
436 			size, XBC_DATA_MAX);
437 		return;
438 	}
439 
440 	if (xbc_calc_checksum(data, size) != csum) {
441 		pr_err("bootconfig checksum failed\n");
442 		return;
443 	}
444 
445 	copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
446 	if (!copy) {
447 		pr_err("Failed to allocate memory for bootconfig\n");
448 		return;
449 	}
450 
451 	memcpy(copy, data, size);
452 	copy[size] = '\0';
453 
454 	ret = xbc_init(copy, &msg, &pos);
455 	if (ret < 0) {
456 		if (pos < 0)
457 			pr_err("Failed to init bootconfig: %s.\n", msg);
458 		else
459 			pr_err("Failed to parse bootconfig: %s at %d.\n",
460 				msg, pos);
461 	} else {
462 		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
463 		/* keys starting with "kernel." are passed via cmdline */
464 		extra_command_line = xbc_make_cmdline("kernel");
465 		/* Also, "init." keys are init arguments */
466 		extra_init_args = xbc_make_cmdline("init");
467 	}
468 	return;
469 }
470 
471 #else
472 
473 static void __init setup_boot_config(void)
474 {
475 	/* Remove bootconfig data from initrd */
476 	get_boot_config_from_initrd(NULL, NULL);
477 }
478 
479 static int __init warn_bootconfig(char *str)
480 {
481 	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
482 	return 0;
483 }
484 #endif
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 		 */
650 		len = strlen(saved_command_line);
651 		if (initargs_found) {
652 			saved_command_line[len++] = ' ';
653 		} else {
654 			strcpy(saved_command_line + len, " -- ");
655 			len += 4;
656 		}
657 
658 		strcpy(saved_command_line + len, extra_init_args);
659 	}
660 }
661 
662 /*
663  * We need to finalize in a non-__init function or else race conditions
664  * between the root thread and the init thread may cause start_kernel to
665  * be reaped by free_initmem before the root thread has proceeded to
666  * cpu_idle.
667  *
668  * gcc-3.4 accidentally inlines this function, so use noinline.
669  */
670 
671 static __initdata DECLARE_COMPLETION(kthreadd_done);
672 
673 noinline void __ref rest_init(void)
674 {
675 	struct task_struct *tsk;
676 	int pid;
677 
678 	rcu_scheduler_starting();
679 	/*
680 	 * We need to spawn init first so that it obtains pid 1, however
681 	 * the init task will end up wanting to create kthreads, which, if
682 	 * we schedule it before we create kthreadd, will OOPS.
683 	 */
684 	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
685 	/*
686 	 * Pin init on the boot CPU. Task migration is not properly working
687 	 * until sched_init_smp() has been run. It will set the allowed
688 	 * CPUs for init to the non isolated CPUs.
689 	 */
690 	rcu_read_lock();
691 	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
692 	tsk->flags |= PF_NO_SETAFFINITY;
693 	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
694 	rcu_read_unlock();
695 
696 	numa_default_policy();
697 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
698 	rcu_read_lock();
699 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
700 	rcu_read_unlock();
701 
702 	/*
703 	 * Enable might_sleep() and smp_processor_id() checks.
704 	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
705 	 * kernel_thread() would trigger might_sleep() splats. With
706 	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
707 	 * already, but it's stuck on the kthreadd_done completion.
708 	 */
709 	system_state = SYSTEM_SCHEDULING;
710 
711 	complete(&kthreadd_done);
712 
713 	/*
714 	 * The boot idle thread must execute schedule()
715 	 * at least once to get things moving:
716 	 */
717 	schedule_preempt_disabled();
718 	/* Call into cpu_idle with preempt disabled */
719 	cpu_startup_entry(CPUHP_ONLINE);
720 }
721 
722 /* Check for early params. */
723 static int __init do_early_param(char *param, char *val,
724 				 const char *unused, void *arg)
725 {
726 	const struct obs_kernel_param *p;
727 
728 	for (p = __setup_start; p < __setup_end; p++) {
729 		if ((p->early && parameq(param, p->str)) ||
730 		    (strcmp(param, "console") == 0 &&
731 		     strcmp(p->str, "earlycon") == 0)
732 		) {
733 			if (p->setup_func(val) != 0)
734 				pr_warn("Malformed early option '%s'\n", param);
735 		}
736 	}
737 	/* We accept everything at this stage. */
738 	return 0;
739 }
740 
741 void __init parse_early_options(char *cmdline)
742 {
743 	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
744 		   do_early_param);
745 }
746 
747 /* Arch code calls this early on, or if not, just before other parsing. */
748 void __init parse_early_param(void)
749 {
750 	static int done __initdata;
751 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
752 
753 	if (done)
754 		return;
755 
756 	/* All fall through to do_early_param. */
757 	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
758 	parse_early_options(tmp_cmdline);
759 	done = 1;
760 }
761 
762 void __init __weak arch_post_acpi_subsys_init(void) { }
763 
764 void __init __weak smp_setup_processor_id(void)
765 {
766 }
767 
768 # if THREAD_SIZE >= PAGE_SIZE
769 void __init __weak thread_stack_cache_init(void)
770 {
771 }
772 #endif
773 
774 void __init __weak mem_encrypt_init(void) { }
775 
776 void __init __weak poking_init(void) { }
777 
778 void __init __weak pgtable_cache_init(void) { }
779 
780 void __init __weak trap_init(void) { }
781 
782 bool initcall_debug;
783 core_param(initcall_debug, initcall_debug, bool, 0644);
784 
785 #ifdef TRACEPOINTS_ENABLED
786 static void __init initcall_debug_enable(void);
787 #else
788 static inline void initcall_debug_enable(void)
789 {
790 }
791 #endif
792 
793 /* Report memory auto-initialization states for this boot. */
794 static void __init report_meminit(void)
795 {
796 	const char *stack;
797 
798 	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
799 		stack = "all(pattern)";
800 	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
801 		stack = "all(zero)";
802 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
803 		stack = "byref_all(zero)";
804 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
805 		stack = "byref(zero)";
806 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
807 		stack = "__user(zero)";
808 	else
809 		stack = "off";
810 
811 	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
812 		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
813 		want_init_on_free() ? "on" : "off");
814 	if (want_init_on_free())
815 		pr_info("mem auto-init: clearing system memory may take some time...\n");
816 }
817 
818 /*
819  * Set up kernel memory allocators
820  */
821 static void __init mm_init(void)
822 {
823 	/*
824 	 * page_ext requires contiguous pages,
825 	 * bigger than MAX_ORDER unless SPARSEMEM.
826 	 */
827 	page_ext_init_flatmem();
828 	init_mem_debugging_and_hardening();
829 	kfence_alloc_pool();
830 	report_meminit();
831 	stack_depot_init();
832 	mem_init();
833 	mem_init_print_info();
834 	/* page_owner must be initialized after buddy is ready */
835 	page_ext_init_flatmem_late();
836 	kmem_cache_init();
837 	kmemleak_init();
838 	pgtable_init();
839 	debug_objects_mem_init();
840 	vmalloc_init();
841 	/* Should be run before the first non-init thread is created */
842 	init_espfix_bsp();
843 	/* Should be run after espfix64 is set up. */
844 	pti_init();
845 }
846 
847 #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
848 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
849 			   randomize_kstack_offset);
850 DEFINE_PER_CPU(u32, kstack_offset);
851 
852 static int __init early_randomize_kstack_offset(char *buf)
853 {
854 	int ret;
855 	bool bool_result;
856 
857 	ret = kstrtobool(buf, &bool_result);
858 	if (ret)
859 		return ret;
860 
861 	if (bool_result)
862 		static_branch_enable(&randomize_kstack_offset);
863 	else
864 		static_branch_disable(&randomize_kstack_offset);
865 	return 0;
866 }
867 early_param("randomize_kstack_offset", early_randomize_kstack_offset);
868 #endif
869 
870 void __init __weak arch_call_rest_init(void)
871 {
872 	rest_init();
873 }
874 
875 static void __init print_unknown_bootoptions(void)
876 {
877 	char *unknown_options;
878 	char *end;
879 	const char *const *p;
880 	size_t len;
881 
882 	if (panic_later || (!argv_init[1] && !envp_init[2]))
883 		return;
884 
885 	/*
886 	 * Determine how many options we have to print out, plus a space
887 	 * before each
888 	 */
889 	len = 1; /* null terminator */
890 	for (p = &argv_init[1]; *p; p++) {
891 		len++;
892 		len += strlen(*p);
893 	}
894 	for (p = &envp_init[2]; *p; p++) {
895 		len++;
896 		len += strlen(*p);
897 	}
898 
899 	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
900 	if (!unknown_options) {
901 		pr_err("%s: Failed to allocate %zu bytes\n",
902 			__func__, len);
903 		return;
904 	}
905 	end = unknown_options;
906 
907 	for (p = &argv_init[1]; *p; p++)
908 		end += sprintf(end, " %s", *p);
909 	for (p = &envp_init[2]; *p; p++)
910 		end += sprintf(end, " %s", *p);
911 
912 	pr_notice("Unknown command line parameters:%s\n", unknown_options);
913 	memblock_free(__pa(unknown_options), len);
914 }
915 
916 asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
917 {
918 	char *command_line;
919 	char *after_dashes;
920 
921 	set_task_stack_end_magic(&init_task);
922 	smp_setup_processor_id();
923 	debug_objects_early_init();
924 	init_vmlinux_build_id();
925 
926 	cgroup_init_early();
927 
928 	local_irq_disable();
929 	early_boot_irqs_disabled = true;
930 
931 	/*
932 	 * Interrupts are still disabled. Do necessary setups, then
933 	 * enable them.
934 	 */
935 	boot_cpu_init();
936 	page_address_init();
937 	pr_notice("%s", linux_banner);
938 	early_security_init();
939 	setup_arch(&command_line);
940 	setup_boot_config();
941 	setup_command_line(command_line);
942 	setup_nr_cpu_ids();
943 	setup_per_cpu_areas();
944 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
945 	boot_cpu_hotplug_init();
946 
947 	build_all_zonelists(NULL);
948 	page_alloc_init();
949 
950 	pr_notice("Kernel command line: %s\n", saved_command_line);
951 	/* parameters may set static keys */
952 	jump_label_init();
953 	parse_early_param();
954 	after_dashes = parse_args("Booting kernel",
955 				  static_command_line, __start___param,
956 				  __stop___param - __start___param,
957 				  -1, -1, NULL, &unknown_bootoption);
958 	print_unknown_bootoptions();
959 	if (!IS_ERR_OR_NULL(after_dashes))
960 		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
961 			   NULL, set_init_arg);
962 	if (extra_init_args)
963 		parse_args("Setting extra init args", extra_init_args,
964 			   NULL, 0, -1, -1, NULL, set_init_arg);
965 
966 	/*
967 	 * These use large bootmem allocations and must precede
968 	 * kmem_cache_init()
969 	 */
970 	setup_log_buf(0);
971 	vfs_caches_init_early();
972 	sort_main_extable();
973 	trap_init();
974 	mm_init();
975 
976 	ftrace_init();
977 
978 	/* trace_printk can be enabled here */
979 	early_trace_init();
980 
981 	/*
982 	 * Set up the scheduler prior starting any interrupts (such as the
983 	 * timer interrupt). Full topology setup happens at smp_init()
984 	 * time - but meanwhile we still have a functioning scheduler.
985 	 */
986 	sched_init();
987 
988 	if (WARN(!irqs_disabled(),
989 		 "Interrupts were enabled *very* early, fixing it\n"))
990 		local_irq_disable();
991 	radix_tree_init();
992 
993 	/*
994 	 * Set up housekeeping before setting up workqueues to allow the unbound
995 	 * workqueue to take non-housekeeping into account.
996 	 */
997 	housekeeping_init();
998 
999 	/*
1000 	 * Allow workqueue creation and work item queueing/cancelling
1001 	 * early.  Work item execution depends on kthreads and starts after
1002 	 * workqueue_init().
1003 	 */
1004 	workqueue_init_early();
1005 
1006 	rcu_init();
1007 
1008 	/* Trace events are available after this */
1009 	trace_init();
1010 
1011 	if (initcall_debug)
1012 		initcall_debug_enable();
1013 
1014 	context_tracking_init();
1015 	/* init some links before init_ISA_irqs() */
1016 	early_irq_init();
1017 	init_IRQ();
1018 	tick_init();
1019 	rcu_init_nohz();
1020 	init_timers();
1021 	srcu_init();
1022 	hrtimers_init();
1023 	softirq_init();
1024 	timekeeping_init();
1025 	kfence_init();
1026 
1027 	/*
1028 	 * For best initial stack canary entropy, prepare it after:
1029 	 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
1030 	 * - timekeeping_init() for ktime entropy used in rand_initialize()
1031 	 * - rand_initialize() to get any arch-specific entropy like RDRAND
1032 	 * - add_latent_entropy() to get any latent entropy
1033 	 * - adding command line entropy
1034 	 */
1035 	rand_initialize();
1036 	add_latent_entropy();
1037 	add_device_randomness(command_line, strlen(command_line));
1038 	boot_init_stack_canary();
1039 
1040 	time_init();
1041 	perf_event_init();
1042 	profile_init();
1043 	call_function_init();
1044 	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1045 
1046 	early_boot_irqs_disabled = false;
1047 	local_irq_enable();
1048 
1049 	kmem_cache_init_late();
1050 
1051 	/*
1052 	 * HACK ALERT! This is early. We're enabling the console before
1053 	 * we've done PCI setups etc, and console_init() must be aware of
1054 	 * this. But we do want output early, in case something goes wrong.
1055 	 */
1056 	console_init();
1057 	if (panic_later)
1058 		panic("Too many boot %s vars at `%s'", panic_later,
1059 		      panic_param);
1060 
1061 	lockdep_init();
1062 
1063 	/*
1064 	 * Need to run this when irqs are enabled, because it wants
1065 	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1066 	 * too:
1067 	 */
1068 	locking_selftest();
1069 
1070 	/*
1071 	 * This needs to be called before any devices perform DMA
1072 	 * operations that might use the SWIOTLB bounce buffers. It will
1073 	 * mark the bounce buffers as decrypted so that their usage will
1074 	 * not cause "plain-text" data to be decrypted when accessed.
1075 	 */
1076 	mem_encrypt_init();
1077 
1078 #ifdef CONFIG_BLK_DEV_INITRD
1079 	if (initrd_start && !initrd_below_start_ok &&
1080 	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1081 		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1082 		    page_to_pfn(virt_to_page((void *)initrd_start)),
1083 		    min_low_pfn);
1084 		initrd_start = 0;
1085 	}
1086 #endif
1087 	setup_per_cpu_pageset();
1088 	numa_policy_init();
1089 	acpi_early_init();
1090 	if (late_time_init)
1091 		late_time_init();
1092 	sched_clock_init();
1093 	calibrate_delay();
1094 	pid_idr_init();
1095 	anon_vma_init();
1096 #ifdef CONFIG_X86
1097 	if (efi_enabled(EFI_RUNTIME_SERVICES))
1098 		efi_enter_virtual_mode();
1099 #endif
1100 	thread_stack_cache_init();
1101 	cred_init();
1102 	fork_init();
1103 	proc_caches_init();
1104 	uts_ns_init();
1105 	key_init();
1106 	security_init();
1107 	dbg_late_init();
1108 	vfs_caches_init();
1109 	pagecache_init();
1110 	signals_init();
1111 	seq_file_init();
1112 	proc_root_init();
1113 	nsfs_init();
1114 	cpuset_init();
1115 	cgroup_init();
1116 	taskstats_init_early();
1117 	delayacct_init();
1118 
1119 	poking_init();
1120 	check_bugs();
1121 
1122 	acpi_subsystem_init();
1123 	arch_post_acpi_subsys_init();
1124 	kcsan_init();
1125 
1126 	/* Do the rest non-__init'ed, we're now alive */
1127 	arch_call_rest_init();
1128 
1129 	prevent_tail_call_optimization();
1130 }
1131 
1132 /* Call all constructor functions linked into the kernel. */
1133 static void __init do_ctors(void)
1134 {
1135 /*
1136  * For UML, the constructors have already been called by the
1137  * normal setup code as it's just a normal ELF binary, so we
1138  * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1139  * even on UML for modules.
1140  */
1141 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1142 	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1143 
1144 	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1145 		(*fn)();
1146 #endif
1147 }
1148 
1149 #ifdef CONFIG_KALLSYMS
1150 struct blacklist_entry {
1151 	struct list_head next;
1152 	char *buf;
1153 };
1154 
1155 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1156 
1157 static int __init initcall_blacklist(char *str)
1158 {
1159 	char *str_entry;
1160 	struct blacklist_entry *entry;
1161 
1162 	/* str argument is a comma-separated list of functions */
1163 	do {
1164 		str_entry = strsep(&str, ",");
1165 		if (str_entry) {
1166 			pr_debug("blacklisting initcall %s\n", str_entry);
1167 			entry = memblock_alloc(sizeof(*entry),
1168 					       SMP_CACHE_BYTES);
1169 			if (!entry)
1170 				panic("%s: Failed to allocate %zu bytes\n",
1171 				      __func__, sizeof(*entry));
1172 			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1173 						    SMP_CACHE_BYTES);
1174 			if (!entry->buf)
1175 				panic("%s: Failed to allocate %zu bytes\n",
1176 				      __func__, strlen(str_entry) + 1);
1177 			strcpy(entry->buf, str_entry);
1178 			list_add(&entry->next, &blacklisted_initcalls);
1179 		}
1180 	} while (str_entry);
1181 
1182 	return 0;
1183 }
1184 
1185 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1186 {
1187 	struct blacklist_entry *entry;
1188 	char fn_name[KSYM_SYMBOL_LEN];
1189 	unsigned long addr;
1190 
1191 	if (list_empty(&blacklisted_initcalls))
1192 		return false;
1193 
1194 	addr = (unsigned long) dereference_function_descriptor(fn);
1195 	sprint_symbol_no_offset(fn_name, addr);
1196 
1197 	/*
1198 	 * fn will be "function_name [module_name]" where [module_name] is not
1199 	 * displayed for built-in init functions.  Strip off the [module_name].
1200 	 */
1201 	strreplace(fn_name, ' ', '\0');
1202 
1203 	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1204 		if (!strcmp(fn_name, entry->buf)) {
1205 			pr_debug("initcall %s blacklisted\n", fn_name);
1206 			return true;
1207 		}
1208 	}
1209 
1210 	return false;
1211 }
1212 #else
1213 static int __init initcall_blacklist(char *str)
1214 {
1215 	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1216 	return 0;
1217 }
1218 
1219 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1220 {
1221 	return false;
1222 }
1223 #endif
1224 __setup("initcall_blacklist=", initcall_blacklist);
1225 
1226 static __init_or_module void
1227 trace_initcall_start_cb(void *data, initcall_t fn)
1228 {
1229 	ktime_t *calltime = (ktime_t *)data;
1230 
1231 	printk(KERN_DEBUG "calling  %pS @ %i irqs_disabled() %d\n", fn, task_pid_nr(current), irqs_disabled());
1232 	*calltime = ktime_get();
1233 }
1234 
1235 static __init_or_module void
1236 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1237 {
1238 	ktime_t *calltime = (ktime_t *)data;
1239 	ktime_t delta, rettime;
1240 	unsigned long long duration;
1241 
1242 	rettime = ktime_get();
1243 	delta = ktime_sub(rettime, *calltime);
1244 	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
1245 	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs, irqs_disabled() %d\n",
1246 		 fn, ret, duration, irqs_disabled());
1247 }
1248 
1249 static ktime_t initcall_calltime;
1250 
1251 #ifdef TRACEPOINTS_ENABLED
1252 static void __init initcall_debug_enable(void)
1253 {
1254 	int ret;
1255 
1256 	ret = register_trace_initcall_start(trace_initcall_start_cb,
1257 					    &initcall_calltime);
1258 	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1259 					      &initcall_calltime);
1260 	WARN(ret, "Failed to register initcall tracepoints\n");
1261 }
1262 # define do_trace_initcall_start	trace_initcall_start
1263 # define do_trace_initcall_finish	trace_initcall_finish
1264 #else
1265 static inline void do_trace_initcall_start(initcall_t fn)
1266 {
1267 	if (!initcall_debug)
1268 		return;
1269 	trace_initcall_start_cb(&initcall_calltime, fn);
1270 }
1271 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1272 {
1273 	if (!initcall_debug)
1274 		return;
1275 	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1276 }
1277 #endif /* !TRACEPOINTS_ENABLED */
1278 
1279 int __init_or_module do_one_initcall(initcall_t fn)
1280 {
1281 	int count = preempt_count();
1282 	char msgbuf[64];
1283 	int ret;
1284 
1285 	if (initcall_blacklisted(fn))
1286 		return -EPERM;
1287 
1288 	do_trace_initcall_start(fn);
1289 	ret = fn();
1290 	do_trace_initcall_finish(fn, ret);
1291 
1292 	msgbuf[0] = 0;
1293 
1294 	if (preempt_count() != count) {
1295 		sprintf(msgbuf, "preemption imbalance ");
1296 		preempt_count_set(count);
1297 	}
1298 	if (irqs_disabled()) {
1299 		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1300 		local_irq_enable();
1301 	}
1302 	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1303 
1304 	add_latent_entropy();
1305 	return ret;
1306 }
1307 
1308 
1309 extern initcall_entry_t __initcall_start[];
1310 extern initcall_entry_t __initcall0_start[];
1311 extern initcall_entry_t __initcall1_start[];
1312 extern initcall_entry_t __initcall2_start[];
1313 extern initcall_entry_t __initcall3_start[];
1314 extern initcall_entry_t __initcall4_start[];
1315 extern initcall_entry_t __initcall5_start[];
1316 extern initcall_entry_t __initcall6_start[];
1317 extern initcall_entry_t __initcall7_start[];
1318 extern initcall_entry_t __initcall_end[];
1319 
1320 static initcall_entry_t *initcall_levels[] __initdata = {
1321 	__initcall0_start,
1322 	__initcall1_start,
1323 	__initcall2_start,
1324 	__initcall3_start,
1325 	__initcall4_start,
1326 	__initcall5_start,
1327 	__initcall6_start,
1328 	__initcall7_start,
1329 	__initcall_end,
1330 };
1331 
1332 /* Keep these in sync with initcalls in include/linux/init.h */
1333 static const char *initcall_level_names[] __initdata = {
1334 	"pure",
1335 	"core",
1336 	"postcore",
1337 	"arch",
1338 	"subsys",
1339 	"fs",
1340 	"device",
1341 	"late",
1342 };
1343 
1344 static int __init ignore_unknown_bootoption(char *param, char *val,
1345 			       const char *unused, void *arg)
1346 {
1347 	return 0;
1348 }
1349 
1350 static void __init do_initcall_level(int level, char *command_line)
1351 {
1352 	initcall_entry_t *fn;
1353 
1354 	parse_args(initcall_level_names[level],
1355 		   command_line, __start___param,
1356 		   __stop___param - __start___param,
1357 		   level, level,
1358 		   NULL, ignore_unknown_bootoption);
1359 
1360 	trace_initcall_level(initcall_level_names[level]);
1361 	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1362 		do_one_initcall(initcall_from_entry(fn));
1363 }
1364 
1365 static void __init do_initcalls(void)
1366 {
1367 	int level;
1368 	size_t len = strlen(saved_command_line) + 1;
1369 	char *command_line;
1370 
1371 	command_line = kzalloc(len, GFP_KERNEL);
1372 	if (!command_line)
1373 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1374 
1375 	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1376 		/* Parser modifies command_line, restore it each time */
1377 		strcpy(command_line, saved_command_line);
1378 		do_initcall_level(level, command_line);
1379 	}
1380 
1381 	kfree(command_line);
1382 }
1383 
1384 /*
1385  * Ok, the machine is now initialized. None of the devices
1386  * have been touched yet, but the CPU subsystem is up and
1387  * running, and memory and process management works.
1388  *
1389  * Now we can finally start doing some real work..
1390  */
1391 static void __init do_basic_setup(void)
1392 {
1393 	cpuset_init_smp();
1394 	driver_init();
1395 	init_irq_proc();
1396 	do_ctors();
1397 	do_initcalls();
1398 }
1399 
1400 static void __init do_pre_smp_initcalls(void)
1401 {
1402 	initcall_entry_t *fn;
1403 
1404 	trace_initcall_level("early");
1405 	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1406 		do_one_initcall(initcall_from_entry(fn));
1407 }
1408 
1409 static int run_init_process(const char *init_filename)
1410 {
1411 	const char *const *p;
1412 
1413 	argv_init[0] = init_filename;
1414 	pr_info("Run %s as init process\n", init_filename);
1415 	pr_debug("  with arguments:\n");
1416 	for (p = argv_init; *p; p++)
1417 		pr_debug("    %s\n", *p);
1418 	pr_debug("  with environment:\n");
1419 	for (p = envp_init; *p; p++)
1420 		pr_debug("    %s\n", *p);
1421 	return kernel_execve(init_filename, argv_init, envp_init);
1422 }
1423 
1424 static int try_to_run_init_process(const char *init_filename)
1425 {
1426 	int ret;
1427 
1428 	ret = run_init_process(init_filename);
1429 
1430 	if (ret && ret != -ENOENT) {
1431 		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1432 		       init_filename, ret);
1433 	}
1434 
1435 	return ret;
1436 }
1437 
1438 static noinline void __init kernel_init_freeable(void);
1439 
1440 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1441 bool rodata_enabled __ro_after_init = true;
1442 static int __init set_debug_rodata(char *str)
1443 {
1444 	return strtobool(str, &rodata_enabled);
1445 }
1446 __setup("rodata=", set_debug_rodata);
1447 #endif
1448 
1449 #ifdef CONFIG_STRICT_KERNEL_RWX
1450 static void mark_readonly(void)
1451 {
1452 	if (rodata_enabled) {
1453 		/*
1454 		 * load_module() results in W+X mappings, which are cleaned
1455 		 * up with call_rcu().  Let's make sure that queued work is
1456 		 * flushed so that we don't hit false positives looking for
1457 		 * insecure pages which are W+X.
1458 		 */
1459 		rcu_barrier();
1460 		mark_rodata_ro();
1461 		rodata_test();
1462 	} else
1463 		pr_info("Kernel memory protection disabled.\n");
1464 }
1465 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1466 static inline void mark_readonly(void)
1467 {
1468 	pr_warn("Kernel memory protection not selected by kernel config.\n");
1469 }
1470 #else
1471 static inline void mark_readonly(void)
1472 {
1473 	pr_warn("This architecture does not have kernel memory protection.\n");
1474 }
1475 #endif
1476 
1477 void __weak free_initmem(void)
1478 {
1479 	free_initmem_default(POISON_FREE_INITMEM);
1480 }
1481 
1482 static int __ref kernel_init(void *unused)
1483 {
1484 	int ret;
1485 
1486 	/*
1487 	 * Wait until kthreadd is all set-up.
1488 	 */
1489 	wait_for_completion(&kthreadd_done);
1490 
1491 	kernel_init_freeable();
1492 	/* need to finish all async __init code before freeing the memory */
1493 	async_synchronize_full();
1494 	kprobe_free_init_mem();
1495 	ftrace_free_init_mem();
1496 	kgdb_free_init_mem();
1497 	free_initmem();
1498 	mark_readonly();
1499 
1500 	/*
1501 	 * Kernel mappings are now finalized - update the userspace page-table
1502 	 * to finalize PTI.
1503 	 */
1504 	pti_finalize();
1505 
1506 	system_state = SYSTEM_RUNNING;
1507 	numa_default_policy();
1508 
1509 	rcu_end_inkernel_boot();
1510 
1511 	do_sysctl_args();
1512 
1513 	if (ramdisk_execute_command) {
1514 		ret = run_init_process(ramdisk_execute_command);
1515 		if (!ret)
1516 			return 0;
1517 		pr_err("Failed to execute %s (error %d)\n",
1518 		       ramdisk_execute_command, ret);
1519 	}
1520 
1521 	/*
1522 	 * We try each of these until one succeeds.
1523 	 *
1524 	 * The Bourne shell can be used instead of init if we are
1525 	 * trying to recover a really broken machine.
1526 	 */
1527 	if (execute_command) {
1528 		ret = run_init_process(execute_command);
1529 		if (!ret)
1530 			return 0;
1531 		panic("Requested init %s failed (error %d).",
1532 		      execute_command, ret);
1533 	}
1534 
1535 	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1536 		ret = run_init_process(CONFIG_DEFAULT_INIT);
1537 		if (ret)
1538 			pr_err("Default init %s failed (error %d)\n",
1539 			       CONFIG_DEFAULT_INIT, ret);
1540 		else
1541 			return 0;
1542 	}
1543 
1544 	if (!try_to_run_init_process("/sbin/init") ||
1545 	    !try_to_run_init_process("/etc/init") ||
1546 	    !try_to_run_init_process("/bin/init") ||
1547 	    !try_to_run_init_process("/bin/sh"))
1548 		return 0;
1549 
1550 	panic("No working init found.  Try passing init= option to kernel. "
1551 	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1552 }
1553 
1554 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1555 void __init console_on_rootfs(void)
1556 {
1557 	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1558 
1559 	if (IS_ERR(file)) {
1560 		pr_err("Warning: unable to open an initial console.\n");
1561 		return;
1562 	}
1563 	init_dup(file);
1564 	init_dup(file);
1565 	init_dup(file);
1566 	fput(file);
1567 }
1568 
1569 static noinline void __init kernel_init_freeable(void)
1570 {
1571 	/* Now the scheduler is fully set up and can do blocking allocations */
1572 	gfp_allowed_mask = __GFP_BITS_MASK;
1573 
1574 	/*
1575 	 * init can allocate pages on any node
1576 	 */
1577 	set_mems_allowed(node_states[N_MEMORY]);
1578 
1579 	cad_pid = get_pid(task_pid(current));
1580 
1581 	smp_prepare_cpus(setup_max_cpus);
1582 
1583 	workqueue_init();
1584 
1585 	init_mm_internals();
1586 
1587 	rcu_init_tasks_generic();
1588 	do_pre_smp_initcalls();
1589 	lockup_detector_init();
1590 
1591 	smp_init();
1592 	sched_init_smp();
1593 
1594 	padata_init();
1595 	page_alloc_init_late();
1596 	/* Initialize page ext after all struct pages are initialized. */
1597 	page_ext_init();
1598 
1599 	do_basic_setup();
1600 
1601 	kunit_run_all_tests();
1602 
1603 	wait_for_initramfs();
1604 	console_on_rootfs();
1605 
1606 	/*
1607 	 * check if there is an early userspace init.  If yes, let it do all
1608 	 * the work
1609 	 */
1610 	if (init_eaccess(ramdisk_execute_command) != 0) {
1611 		ramdisk_execute_command = NULL;
1612 		prepare_namespace();
1613 	}
1614 
1615 	/*
1616 	 * Ok, we have completed the initial bootup, and
1617 	 * we're essentially up and running. Get rid of the
1618 	 * initmem segments and start the user-mode stuff..
1619 	 *
1620 	 * rootfs is available now, try loading the public keys
1621 	 * and default modules
1622 	 */
1623 
1624 	integrity_load_keys();
1625 }
1626