xref: /openbmc/linux/init/main.c (revision bdac5c2b243f68ec15f8203c3348ae79fee8e8d8)
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 size_t initargs_offs;
157 #else
158 # define bootconfig_found false
159 # define initargs_offs 0
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, *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 the next param of '--' and returns an address */
426 	if (err)
427 		initargs_offs = err - tmp_cmdline;
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 	ret = xbc_init(data, size, &msg, &pos);
446 	if (ret < 0) {
447 		if (pos < 0)
448 			pr_err("Failed to init bootconfig: %s.\n", msg);
449 		else
450 			pr_err("Failed to parse bootconfig: %s at %d.\n",
451 				msg, pos);
452 	} else {
453 		pr_info("Load bootconfig: %d bytes %d nodes\n", 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_destroy_all();
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, 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 
667 /*
668  * We need to finalize in a non-__init function or else race conditions
669  * between the root thread and the init thread may cause start_kernel to
670  * be reaped by free_initmem before the root thread has proceeded to
671  * cpu_idle.
672  *
673  * gcc-3.4 accidentally inlines this function, so use noinline.
674  */
675 
676 static __initdata DECLARE_COMPLETION(kthreadd_done);
677 
678 noinline void __ref rest_init(void)
679 {
680 	struct task_struct *tsk;
681 	int pid;
682 
683 	rcu_scheduler_starting();
684 	/*
685 	 * We need to spawn init first so that it obtains pid 1, however
686 	 * the init task will end up wanting to create kthreads, which, if
687 	 * we schedule it before we create kthreadd, will OOPS.
688 	 */
689 	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
690 	/*
691 	 * Pin init on the boot CPU. Task migration is not properly working
692 	 * until sched_init_smp() has been run. It will set the allowed
693 	 * CPUs for init to the non isolated CPUs.
694 	 */
695 	rcu_read_lock();
696 	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
697 	tsk->flags |= PF_NO_SETAFFINITY;
698 	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
699 	rcu_read_unlock();
700 
701 	numa_default_policy();
702 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
703 	rcu_read_lock();
704 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
705 	rcu_read_unlock();
706 
707 	/*
708 	 * Enable might_sleep() and smp_processor_id() checks.
709 	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
710 	 * kernel_thread() would trigger might_sleep() splats. With
711 	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
712 	 * already, but it's stuck on the kthreadd_done completion.
713 	 */
714 	system_state = SYSTEM_SCHEDULING;
715 
716 	complete(&kthreadd_done);
717 
718 	/*
719 	 * The boot idle thread must execute schedule()
720 	 * at least once to get things moving:
721 	 */
722 	schedule_preempt_disabled();
723 	/* Call into cpu_idle with preempt disabled */
724 	cpu_startup_entry(CPUHP_ONLINE);
725 }
726 
727 /* Check for early params. */
728 static int __init do_early_param(char *param, char *val,
729 				 const char *unused, void *arg)
730 {
731 	const struct obs_kernel_param *p;
732 
733 	for (p = __setup_start; p < __setup_end; p++) {
734 		if ((p->early && parameq(param, p->str)) ||
735 		    (strcmp(param, "console") == 0 &&
736 		     strcmp(p->str, "earlycon") == 0)
737 		) {
738 			if (p->setup_func(val) != 0)
739 				pr_warn("Malformed early option '%s'\n", param);
740 		}
741 	}
742 	/* We accept everything at this stage. */
743 	return 0;
744 }
745 
746 void __init parse_early_options(char *cmdline)
747 {
748 	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
749 		   do_early_param);
750 }
751 
752 /* Arch code calls this early on, or if not, just before other parsing. */
753 void __init parse_early_param(void)
754 {
755 	static int done __initdata;
756 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
757 
758 	if (done)
759 		return;
760 
761 	/* All fall through to do_early_param. */
762 	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
763 	parse_early_options(tmp_cmdline);
764 	done = 1;
765 }
766 
767 void __init __weak arch_post_acpi_subsys_init(void) { }
768 
769 void __init __weak smp_setup_processor_id(void)
770 {
771 }
772 
773 # if THREAD_SIZE >= PAGE_SIZE
774 void __init __weak thread_stack_cache_init(void)
775 {
776 }
777 #endif
778 
779 void __init __weak mem_encrypt_init(void) { }
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 /* Report memory auto-initialization states for this boot. */
799 static void __init report_meminit(void)
800 {
801 	const char *stack;
802 
803 	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
804 		stack = "all(pattern)";
805 	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
806 		stack = "all(zero)";
807 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
808 		stack = "byref_all(zero)";
809 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
810 		stack = "byref(zero)";
811 	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
812 		stack = "__user(zero)";
813 	else
814 		stack = "off";
815 
816 	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
817 		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
818 		want_init_on_free() ? "on" : "off");
819 	if (want_init_on_free())
820 		pr_info("mem auto-init: clearing system memory may take some time...\n");
821 }
822 
823 /*
824  * Set up kernel memory allocators
825  */
826 static void __init mm_init(void)
827 {
828 	/*
829 	 * page_ext requires contiguous pages,
830 	 * bigger than MAX_ORDER unless SPARSEMEM.
831 	 */
832 	page_ext_init_flatmem();
833 	init_mem_debugging_and_hardening();
834 	kfence_alloc_pool();
835 	report_meminit();
836 	stack_depot_init();
837 	mem_init();
838 	mem_init_print_info();
839 	/* page_owner must be initialized after buddy is ready */
840 	page_ext_init_flatmem_late();
841 	kmem_cache_init();
842 	kmemleak_init();
843 	pgtable_init();
844 	debug_objects_mem_init();
845 	vmalloc_init();
846 	/* Should be run before the first non-init thread is created */
847 	init_espfix_bsp();
848 	/* Should be run after espfix64 is set up. */
849 	pti_init();
850 }
851 
852 #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
853 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
854 			   randomize_kstack_offset);
855 DEFINE_PER_CPU(u32, kstack_offset);
856 
857 static int __init early_randomize_kstack_offset(char *buf)
858 {
859 	int ret;
860 	bool bool_result;
861 
862 	ret = kstrtobool(buf, &bool_result);
863 	if (ret)
864 		return ret;
865 
866 	if (bool_result)
867 		static_branch_enable(&randomize_kstack_offset);
868 	else
869 		static_branch_disable(&randomize_kstack_offset);
870 	return 0;
871 }
872 early_param("randomize_kstack_offset", early_randomize_kstack_offset);
873 #endif
874 
875 void __init __weak arch_call_rest_init(void)
876 {
877 	rest_init();
878 }
879 
880 static void __init print_unknown_bootoptions(void)
881 {
882 	char *unknown_options;
883 	char *end;
884 	const char *const *p;
885 	size_t len;
886 
887 	if (panic_later || (!argv_init[1] && !envp_init[2]))
888 		return;
889 
890 	/*
891 	 * Determine how many options we have to print out, plus a space
892 	 * before each
893 	 */
894 	len = 1; /* null terminator */
895 	for (p = &argv_init[1]; *p; p++) {
896 		len++;
897 		len += strlen(*p);
898 	}
899 	for (p = &envp_init[2]; *p; p++) {
900 		len++;
901 		len += strlen(*p);
902 	}
903 
904 	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
905 	if (!unknown_options) {
906 		pr_err("%s: Failed to allocate %zu bytes\n",
907 			__func__, len);
908 		return;
909 	}
910 	end = unknown_options;
911 
912 	for (p = &argv_init[1]; *p; p++)
913 		end += sprintf(end, " %s", *p);
914 	for (p = &envp_init[2]; *p; p++)
915 		end += sprintf(end, " %s", *p);
916 
917 	pr_notice("Unknown command line parameters:%s\n", unknown_options);
918 	memblock_free_ptr(unknown_options, len);
919 }
920 
921 asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
922 {
923 	char *command_line;
924 	char *after_dashes;
925 
926 	set_task_stack_end_magic(&init_task);
927 	smp_setup_processor_id();
928 	debug_objects_early_init();
929 	init_vmlinux_build_id();
930 
931 	cgroup_init_early();
932 
933 	local_irq_disable();
934 	early_boot_irqs_disabled = true;
935 
936 	/*
937 	 * Interrupts are still disabled. Do necessary setups, then
938 	 * enable them.
939 	 */
940 	boot_cpu_init();
941 	page_address_init();
942 	pr_notice("%s", linux_banner);
943 	early_security_init();
944 	setup_arch(&command_line);
945 	setup_boot_config();
946 	setup_command_line(command_line);
947 	setup_nr_cpu_ids();
948 	setup_per_cpu_areas();
949 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
950 	boot_cpu_hotplug_init();
951 
952 	build_all_zonelists(NULL);
953 	page_alloc_init();
954 
955 	pr_notice("Kernel command line: %s\n", saved_command_line);
956 	/* parameters may set static keys */
957 	jump_label_init();
958 	parse_early_param();
959 	after_dashes = parse_args("Booting kernel",
960 				  static_command_line, __start___param,
961 				  __stop___param - __start___param,
962 				  -1, -1, NULL, &unknown_bootoption);
963 	print_unknown_bootoptions();
964 	if (!IS_ERR_OR_NULL(after_dashes))
965 		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
966 			   NULL, set_init_arg);
967 	if (extra_init_args)
968 		parse_args("Setting extra init args", extra_init_args,
969 			   NULL, 0, -1, -1, NULL, set_init_arg);
970 
971 	/*
972 	 * These use large bootmem allocations and must precede
973 	 * kmem_cache_init()
974 	 */
975 	setup_log_buf(0);
976 	vfs_caches_init_early();
977 	sort_main_extable();
978 	trap_init();
979 	mm_init();
980 
981 	ftrace_init();
982 
983 	/* trace_printk can be enabled here */
984 	early_trace_init();
985 
986 	/*
987 	 * Set up the scheduler prior starting any interrupts (such as the
988 	 * timer interrupt). Full topology setup happens at smp_init()
989 	 * time - but meanwhile we still have a functioning scheduler.
990 	 */
991 	sched_init();
992 
993 	if (WARN(!irqs_disabled(),
994 		 "Interrupts were enabled *very* early, fixing it\n"))
995 		local_irq_disable();
996 	radix_tree_init();
997 
998 	/*
999 	 * Set up housekeeping before setting up workqueues to allow the unbound
1000 	 * workqueue to take non-housekeeping into account.
1001 	 */
1002 	housekeeping_init();
1003 
1004 	/*
1005 	 * Allow workqueue creation and work item queueing/cancelling
1006 	 * early.  Work item execution depends on kthreads and starts after
1007 	 * workqueue_init().
1008 	 */
1009 	workqueue_init_early();
1010 
1011 	rcu_init();
1012 
1013 	/* Trace events are available after this */
1014 	trace_init();
1015 
1016 	if (initcall_debug)
1017 		initcall_debug_enable();
1018 
1019 	context_tracking_init();
1020 	/* init some links before init_ISA_irqs() */
1021 	early_irq_init();
1022 	init_IRQ();
1023 	tick_init();
1024 	rcu_init_nohz();
1025 	init_timers();
1026 	srcu_init();
1027 	hrtimers_init();
1028 	softirq_init();
1029 	timekeeping_init();
1030 	kfence_init();
1031 
1032 	/*
1033 	 * For best initial stack canary entropy, prepare it after:
1034 	 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
1035 	 * - timekeeping_init() for ktime entropy used in rand_initialize()
1036 	 * - rand_initialize() to get any arch-specific entropy like RDRAND
1037 	 * - add_latent_entropy() to get any latent entropy
1038 	 * - adding command line entropy
1039 	 */
1040 	rand_initialize();
1041 	add_latent_entropy();
1042 	add_device_randomness(command_line, strlen(command_line));
1043 	boot_init_stack_canary();
1044 
1045 	time_init();
1046 	perf_event_init();
1047 	profile_init();
1048 	call_function_init();
1049 	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1050 
1051 	early_boot_irqs_disabled = false;
1052 	local_irq_enable();
1053 
1054 	kmem_cache_init_late();
1055 
1056 	/*
1057 	 * HACK ALERT! This is early. We're enabling the console before
1058 	 * we've done PCI setups etc, and console_init() must be aware of
1059 	 * this. But we do want output early, in case something goes wrong.
1060 	 */
1061 	console_init();
1062 	if (panic_later)
1063 		panic("Too many boot %s vars at `%s'", panic_later,
1064 		      panic_param);
1065 
1066 	lockdep_init();
1067 
1068 	/*
1069 	 * Need to run this when irqs are enabled, because it wants
1070 	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1071 	 * too:
1072 	 */
1073 	locking_selftest();
1074 
1075 	/*
1076 	 * This needs to be called before any devices perform DMA
1077 	 * operations that might use the SWIOTLB bounce buffers. It will
1078 	 * mark the bounce buffers as decrypted so that their usage will
1079 	 * not cause "plain-text" data to be decrypted when accessed.
1080 	 */
1081 	mem_encrypt_init();
1082 
1083 #ifdef CONFIG_BLK_DEV_INITRD
1084 	if (initrd_start && !initrd_below_start_ok &&
1085 	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1086 		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1087 		    page_to_pfn(virt_to_page((void *)initrd_start)),
1088 		    min_low_pfn);
1089 		initrd_start = 0;
1090 	}
1091 #endif
1092 	setup_per_cpu_pageset();
1093 	numa_policy_init();
1094 	acpi_early_init();
1095 	if (late_time_init)
1096 		late_time_init();
1097 	sched_clock_init();
1098 	calibrate_delay();
1099 	pid_idr_init();
1100 	anon_vma_init();
1101 #ifdef CONFIG_X86
1102 	if (efi_enabled(EFI_RUNTIME_SERVICES))
1103 		efi_enter_virtual_mode();
1104 #endif
1105 	thread_stack_cache_init();
1106 	cred_init();
1107 	fork_init();
1108 	proc_caches_init();
1109 	uts_ns_init();
1110 	key_init();
1111 	security_init();
1112 	dbg_late_init();
1113 	vfs_caches_init();
1114 	pagecache_init();
1115 	signals_init();
1116 	seq_file_init();
1117 	proc_root_init();
1118 	nsfs_init();
1119 	cpuset_init();
1120 	cgroup_init();
1121 	taskstats_init_early();
1122 	delayacct_init();
1123 
1124 	poking_init();
1125 	check_bugs();
1126 
1127 	acpi_subsystem_init();
1128 	arch_post_acpi_subsys_init();
1129 	kcsan_init();
1130 
1131 	/* Do the rest non-__init'ed, we're now alive */
1132 	arch_call_rest_init();
1133 
1134 	prevent_tail_call_optimization();
1135 }
1136 
1137 /* Call all constructor functions linked into the kernel. */
1138 static void __init do_ctors(void)
1139 {
1140 /*
1141  * For UML, the constructors have already been called by the
1142  * normal setup code as it's just a normal ELF binary, so we
1143  * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1144  * even on UML for modules.
1145  */
1146 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1147 	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1148 
1149 	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1150 		(*fn)();
1151 #endif
1152 }
1153 
1154 #ifdef CONFIG_KALLSYMS
1155 struct blacklist_entry {
1156 	struct list_head next;
1157 	char *buf;
1158 };
1159 
1160 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1161 
1162 static int __init initcall_blacklist(char *str)
1163 {
1164 	char *str_entry;
1165 	struct blacklist_entry *entry;
1166 
1167 	/* str argument is a comma-separated list of functions */
1168 	do {
1169 		str_entry = strsep(&str, ",");
1170 		if (str_entry) {
1171 			pr_debug("blacklisting initcall %s\n", str_entry);
1172 			entry = memblock_alloc(sizeof(*entry),
1173 					       SMP_CACHE_BYTES);
1174 			if (!entry)
1175 				panic("%s: Failed to allocate %zu bytes\n",
1176 				      __func__, sizeof(*entry));
1177 			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1178 						    SMP_CACHE_BYTES);
1179 			if (!entry->buf)
1180 				panic("%s: Failed to allocate %zu bytes\n",
1181 				      __func__, strlen(str_entry) + 1);
1182 			strcpy(entry->buf, str_entry);
1183 			list_add(&entry->next, &blacklisted_initcalls);
1184 		}
1185 	} while (str_entry);
1186 
1187 	return 0;
1188 }
1189 
1190 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1191 {
1192 	struct blacklist_entry *entry;
1193 	char fn_name[KSYM_SYMBOL_LEN];
1194 	unsigned long addr;
1195 
1196 	if (list_empty(&blacklisted_initcalls))
1197 		return false;
1198 
1199 	addr = (unsigned long) dereference_function_descriptor(fn);
1200 	sprint_symbol_no_offset(fn_name, addr);
1201 
1202 	/*
1203 	 * fn will be "function_name [module_name]" where [module_name] is not
1204 	 * displayed for built-in init functions.  Strip off the [module_name].
1205 	 */
1206 	strreplace(fn_name, ' ', '\0');
1207 
1208 	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1209 		if (!strcmp(fn_name, entry->buf)) {
1210 			pr_debug("initcall %s blacklisted\n", fn_name);
1211 			return true;
1212 		}
1213 	}
1214 
1215 	return false;
1216 }
1217 #else
1218 static int __init initcall_blacklist(char *str)
1219 {
1220 	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1221 	return 0;
1222 }
1223 
1224 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1225 {
1226 	return false;
1227 }
1228 #endif
1229 __setup("initcall_blacklist=", initcall_blacklist);
1230 
1231 static __init_or_module void
1232 trace_initcall_start_cb(void *data, initcall_t fn)
1233 {
1234 	ktime_t *calltime = (ktime_t *)data;
1235 
1236 	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
1237 	*calltime = ktime_get();
1238 }
1239 
1240 static __init_or_module void
1241 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1242 {
1243 	ktime_t *calltime = (ktime_t *)data;
1244 	ktime_t delta, rettime;
1245 	unsigned long long duration;
1246 
1247 	rettime = ktime_get();
1248 	delta = ktime_sub(rettime, *calltime);
1249 	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
1250 	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1251 		 fn, ret, duration);
1252 }
1253 
1254 static ktime_t initcall_calltime;
1255 
1256 #ifdef TRACEPOINTS_ENABLED
1257 static void __init initcall_debug_enable(void)
1258 {
1259 	int ret;
1260 
1261 	ret = register_trace_initcall_start(trace_initcall_start_cb,
1262 					    &initcall_calltime);
1263 	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1264 					      &initcall_calltime);
1265 	WARN(ret, "Failed to register initcall tracepoints\n");
1266 }
1267 # define do_trace_initcall_start	trace_initcall_start
1268 # define do_trace_initcall_finish	trace_initcall_finish
1269 #else
1270 static inline void do_trace_initcall_start(initcall_t fn)
1271 {
1272 	if (!initcall_debug)
1273 		return;
1274 	trace_initcall_start_cb(&initcall_calltime, fn);
1275 }
1276 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1277 {
1278 	if (!initcall_debug)
1279 		return;
1280 	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1281 }
1282 #endif /* !TRACEPOINTS_ENABLED */
1283 
1284 int __init_or_module do_one_initcall(initcall_t fn)
1285 {
1286 	int count = preempt_count();
1287 	char msgbuf[64];
1288 	int ret;
1289 
1290 	if (initcall_blacklisted(fn))
1291 		return -EPERM;
1292 
1293 	do_trace_initcall_start(fn);
1294 	ret = fn();
1295 	do_trace_initcall_finish(fn, ret);
1296 
1297 	msgbuf[0] = 0;
1298 
1299 	if (preempt_count() != count) {
1300 		sprintf(msgbuf, "preemption imbalance ");
1301 		preempt_count_set(count);
1302 	}
1303 	if (irqs_disabled()) {
1304 		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1305 		local_irq_enable();
1306 	}
1307 	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1308 
1309 	add_latent_entropy();
1310 	return ret;
1311 }
1312 
1313 
1314 extern initcall_entry_t __initcall_start[];
1315 extern initcall_entry_t __initcall0_start[];
1316 extern initcall_entry_t __initcall1_start[];
1317 extern initcall_entry_t __initcall2_start[];
1318 extern initcall_entry_t __initcall3_start[];
1319 extern initcall_entry_t __initcall4_start[];
1320 extern initcall_entry_t __initcall5_start[];
1321 extern initcall_entry_t __initcall6_start[];
1322 extern initcall_entry_t __initcall7_start[];
1323 extern initcall_entry_t __initcall_end[];
1324 
1325 static initcall_entry_t *initcall_levels[] __initdata = {
1326 	__initcall0_start,
1327 	__initcall1_start,
1328 	__initcall2_start,
1329 	__initcall3_start,
1330 	__initcall4_start,
1331 	__initcall5_start,
1332 	__initcall6_start,
1333 	__initcall7_start,
1334 	__initcall_end,
1335 };
1336 
1337 /* Keep these in sync with initcalls in include/linux/init.h */
1338 static const char *initcall_level_names[] __initdata = {
1339 	"pure",
1340 	"core",
1341 	"postcore",
1342 	"arch",
1343 	"subsys",
1344 	"fs",
1345 	"device",
1346 	"late",
1347 };
1348 
1349 static int __init ignore_unknown_bootoption(char *param, char *val,
1350 			       const char *unused, void *arg)
1351 {
1352 	return 0;
1353 }
1354 
1355 static void __init do_initcall_level(int level, char *command_line)
1356 {
1357 	initcall_entry_t *fn;
1358 
1359 	parse_args(initcall_level_names[level],
1360 		   command_line, __start___param,
1361 		   __stop___param - __start___param,
1362 		   level, level,
1363 		   NULL, ignore_unknown_bootoption);
1364 
1365 	trace_initcall_level(initcall_level_names[level]);
1366 	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1367 		do_one_initcall(initcall_from_entry(fn));
1368 }
1369 
1370 static void __init do_initcalls(void)
1371 {
1372 	int level;
1373 	size_t len = strlen(saved_command_line) + 1;
1374 	char *command_line;
1375 
1376 	command_line = kzalloc(len, GFP_KERNEL);
1377 	if (!command_line)
1378 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1379 
1380 	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1381 		/* Parser modifies command_line, restore it each time */
1382 		strcpy(command_line, saved_command_line);
1383 		do_initcall_level(level, command_line);
1384 	}
1385 
1386 	kfree(command_line);
1387 }
1388 
1389 /*
1390  * Ok, the machine is now initialized. None of the devices
1391  * have been touched yet, but the CPU subsystem is up and
1392  * running, and memory and process management works.
1393  *
1394  * Now we can finally start doing some real work..
1395  */
1396 static void __init do_basic_setup(void)
1397 {
1398 	cpuset_init_smp();
1399 	driver_init();
1400 	init_irq_proc();
1401 	do_ctors();
1402 	do_initcalls();
1403 }
1404 
1405 static void __init do_pre_smp_initcalls(void)
1406 {
1407 	initcall_entry_t *fn;
1408 
1409 	trace_initcall_level("early");
1410 	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1411 		do_one_initcall(initcall_from_entry(fn));
1412 }
1413 
1414 static int run_init_process(const char *init_filename)
1415 {
1416 	const char *const *p;
1417 
1418 	argv_init[0] = init_filename;
1419 	pr_info("Run %s as init process\n", init_filename);
1420 	pr_debug("  with arguments:\n");
1421 	for (p = argv_init; *p; p++)
1422 		pr_debug("    %s\n", *p);
1423 	pr_debug("  with environment:\n");
1424 	for (p = envp_init; *p; p++)
1425 		pr_debug("    %s\n", *p);
1426 	return kernel_execve(init_filename, argv_init, envp_init);
1427 }
1428 
1429 static int try_to_run_init_process(const char *init_filename)
1430 {
1431 	int ret;
1432 
1433 	ret = run_init_process(init_filename);
1434 
1435 	if (ret && ret != -ENOENT) {
1436 		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1437 		       init_filename, ret);
1438 	}
1439 
1440 	return ret;
1441 }
1442 
1443 static noinline void __init kernel_init_freeable(void);
1444 
1445 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1446 bool rodata_enabled __ro_after_init = true;
1447 static int __init set_debug_rodata(char *str)
1448 {
1449 	return strtobool(str, &rodata_enabled);
1450 }
1451 __setup("rodata=", set_debug_rodata);
1452 #endif
1453 
1454 #ifdef CONFIG_STRICT_KERNEL_RWX
1455 static void mark_readonly(void)
1456 {
1457 	if (rodata_enabled) {
1458 		/*
1459 		 * load_module() results in W+X mappings, which are cleaned
1460 		 * up with call_rcu().  Let's make sure that queued work is
1461 		 * flushed so that we don't hit false positives looking for
1462 		 * insecure pages which are W+X.
1463 		 */
1464 		rcu_barrier();
1465 		mark_rodata_ro();
1466 		rodata_test();
1467 	} else
1468 		pr_info("Kernel memory protection disabled.\n");
1469 }
1470 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1471 static inline void mark_readonly(void)
1472 {
1473 	pr_warn("Kernel memory protection not selected by kernel config.\n");
1474 }
1475 #else
1476 static inline void mark_readonly(void)
1477 {
1478 	pr_warn("This architecture does not have kernel memory protection.\n");
1479 }
1480 #endif
1481 
1482 void __weak free_initmem(void)
1483 {
1484 	free_initmem_default(POISON_FREE_INITMEM);
1485 }
1486 
1487 static int __ref kernel_init(void *unused)
1488 {
1489 	int ret;
1490 
1491 	/*
1492 	 * Wait until kthreadd is all set-up.
1493 	 */
1494 	wait_for_completion(&kthreadd_done);
1495 
1496 	kernel_init_freeable();
1497 	/* need to finish all async __init code before freeing the memory */
1498 	async_synchronize_full();
1499 	kprobe_free_init_mem();
1500 	ftrace_free_init_mem();
1501 	kgdb_free_init_mem();
1502 	exit_boot_config();
1503 	free_initmem();
1504 	mark_readonly();
1505 
1506 	/*
1507 	 * Kernel mappings are now finalized - update the userspace page-table
1508 	 * to finalize PTI.
1509 	 */
1510 	pti_finalize();
1511 
1512 	system_state = SYSTEM_RUNNING;
1513 	numa_default_policy();
1514 
1515 	rcu_end_inkernel_boot();
1516 
1517 	do_sysctl_args();
1518 
1519 	if (ramdisk_execute_command) {
1520 		ret = run_init_process(ramdisk_execute_command);
1521 		if (!ret)
1522 			return 0;
1523 		pr_err("Failed to execute %s (error %d)\n",
1524 		       ramdisk_execute_command, ret);
1525 	}
1526 
1527 	/*
1528 	 * We try each of these until one succeeds.
1529 	 *
1530 	 * The Bourne shell can be used instead of init if we are
1531 	 * trying to recover a really broken machine.
1532 	 */
1533 	if (execute_command) {
1534 		ret = run_init_process(execute_command);
1535 		if (!ret)
1536 			return 0;
1537 		panic("Requested init %s failed (error %d).",
1538 		      execute_command, ret);
1539 	}
1540 
1541 	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1542 		ret = run_init_process(CONFIG_DEFAULT_INIT);
1543 		if (ret)
1544 			pr_err("Default init %s failed (error %d)\n",
1545 			       CONFIG_DEFAULT_INIT, ret);
1546 		else
1547 			return 0;
1548 	}
1549 
1550 	if (!try_to_run_init_process("/sbin/init") ||
1551 	    !try_to_run_init_process("/etc/init") ||
1552 	    !try_to_run_init_process("/bin/init") ||
1553 	    !try_to_run_init_process("/bin/sh"))
1554 		return 0;
1555 
1556 	panic("No working init found.  Try passing init= option to kernel. "
1557 	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1558 }
1559 
1560 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1561 void __init console_on_rootfs(void)
1562 {
1563 	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1564 
1565 	if (IS_ERR(file)) {
1566 		pr_err("Warning: unable to open an initial console.\n");
1567 		return;
1568 	}
1569 	init_dup(file);
1570 	init_dup(file);
1571 	init_dup(file);
1572 	fput(file);
1573 }
1574 
1575 static noinline void __init kernel_init_freeable(void)
1576 {
1577 	/* Now the scheduler is fully set up and can do blocking allocations */
1578 	gfp_allowed_mask = __GFP_BITS_MASK;
1579 
1580 	/*
1581 	 * init can allocate pages on any node
1582 	 */
1583 	set_mems_allowed(node_states[N_MEMORY]);
1584 
1585 	cad_pid = get_pid(task_pid(current));
1586 
1587 	smp_prepare_cpus(setup_max_cpus);
1588 
1589 	workqueue_init();
1590 
1591 	init_mm_internals();
1592 
1593 	rcu_init_tasks_generic();
1594 	do_pre_smp_initcalls();
1595 	lockup_detector_init();
1596 
1597 	smp_init();
1598 	sched_init_smp();
1599 
1600 	padata_init();
1601 	page_alloc_init_late();
1602 	/* Initialize page ext after all struct pages are initialized. */
1603 	page_ext_init();
1604 
1605 	do_basic_setup();
1606 
1607 	kunit_run_all_tests();
1608 
1609 	wait_for_initramfs();
1610 	console_on_rootfs();
1611 
1612 	/*
1613 	 * check if there is an early userspace init.  If yes, let it do all
1614 	 * the work
1615 	 */
1616 	if (init_eaccess(ramdisk_execute_command) != 0) {
1617 		ramdisk_execute_command = NULL;
1618 		prepare_namespace();
1619 	}
1620 
1621 	/*
1622 	 * Ok, we have completed the initial bootup, and
1623 	 * we're essentially up and running. Get rid of the
1624 	 * initmem segments and start the user-mode stuff..
1625 	 *
1626 	 * rootfs is available now, try loading the public keys
1627 	 * and default modules
1628 	 */
1629 
1630 	integrity_load_keys();
1631 }
1632