1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/init/main.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 *
   7 *  GK 2/5/95  -  Changed to support mounting root fs via NFS
   8 *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
   9 *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
  10 *  Simplified starting of init:  Michael A. Griffith <grif@acm.org>
  11 */
  12
  13#define DEBUG		/* Enable initcall_debug */
  14
  15#include <linux/types.h>
  16#include <linux/extable.h>
  17#include <linux/module.h>
  18#include <linux/proc_fs.h>
  19#include <linux/binfmts.h>
  20#include <linux/kernel.h>
  21#include <linux/syscalls.h>
  22#include <linux/stackprotector.h>
  23#include <linux/string.h>
  24#include <linux/ctype.h>
  25#include <linux/delay.h>
  26#include <linux/ioport.h>
  27#include <linux/init.h>
  28#include <linux/initrd.h>
  29#include <linux/memblock.h>
  30#include <linux/acpi.h>
  31#include <linux/bootconfig.h>
  32#include <linux/console.h>
  33#include <linux/nmi.h>
  34#include <linux/percpu.h>
  35#include <linux/kmod.h>
  36#include <linux/kprobes.h>
  37#include <linux/kmsan.h>
  38#include <linux/vmalloc.h>
  39#include <linux/kernel_stat.h>
  40#include <linux/start_kernel.h>
  41#include <linux/security.h>
  42#include <linux/smp.h>
  43#include <linux/profile.h>
  44#include <linux/kfence.h>
  45#include <linux/rcupdate.h>
  46#include <linux/srcu.h>
  47#include <linux/moduleparam.h>
  48#include <linux/kallsyms.h>
  49#include <linux/buildid.h>
  50#include <linux/writeback.h>
  51#include <linux/cpu.h>
  52#include <linux/cpuset.h>
  53#include <linux/cgroup.h>
  54#include <linux/efi.h>
  55#include <linux/tick.h>
  56#include <linux/sched/isolation.h>
  57#include <linux/interrupt.h>
  58#include <linux/taskstats_kern.h>
  59#include <linux/delayacct.h>
  60#include <linux/unistd.h>
  61#include <linux/utsname.h>
  62#include <linux/rmap.h>
  63#include <linux/mempolicy.h>
  64#include <linux/key.h>
  65#include <linux/debug_locks.h>
  66#include <linux/debugobjects.h>
  67#include <linux/lockdep.h>
  68#include <linux/kmemleak.h>
  69#include <linux/padata.h>
  70#include <linux/pid_namespace.h>
  71#include <linux/device/driver.h>
  72#include <linux/kthread.h>
  73#include <linux/sched.h>
  74#include <linux/sched/init.h>
  75#include <linux/signal.h>
  76#include <linux/idr.h>
  77#include <linux/kgdb.h>
  78#include <linux/ftrace.h>
  79#include <linux/async.h>
  80#include <linux/shmem_fs.h>
  81#include <linux/slab.h>
  82#include <linux/perf_event.h>
  83#include <linux/ptrace.h>
  84#include <linux/pti.h>
  85#include <linux/blkdev.h>
  86#include <linux/sched/clock.h>
  87#include <linux/sched/task.h>
  88#include <linux/sched/task_stack.h>
  89#include <linux/context_tracking.h>
  90#include <linux/random.h>
  91#include <linux/moduleloader.h>
  92#include <linux/list.h>
  93#include <linux/integrity.h>
  94#include <linux/proc_ns.h>
  95#include <linux/io.h>
  96#include <linux/cache.h>
  97#include <linux/rodata_test.h>
  98#include <linux/jump_label.h>
  99#include <linux/kcsan.h>
 100#include <linux/init_syscalls.h>
 101#include <linux/stackdepot.h>
 102#include <linux/randomize_kstack.h>
 103#include <linux/pidfs.h>
 104#include <linux/ptdump.h>
 105#include <net/net_namespace.h>
 106
 107#include <asm/io.h>
 108#include <asm/setup.h>
 109#include <asm/sections.h>
 110#include <asm/cacheflush.h>
 111
 112#define CREATE_TRACE_POINTS
 113#include <trace/events/initcall.h>
 114
 115#include <kunit/test.h>
 116
 117static int kernel_init(void *);
 118
 119/*
 120 * Debug helper: via this flag we know that we are in 'early bootup code'
 121 * where only the boot processor is running with IRQ disabled.  This means
 122 * two things - IRQ must not be enabled before the flag is cleared and some
 123 * operations which are not allowed with IRQ disabled are allowed while the
 124 * flag is set.
 125 */
 126bool early_boot_irqs_disabled __read_mostly;
 127
 128enum system_states system_state __read_mostly;
 129EXPORT_SYMBOL(system_state);
 130
 131/*
 132 * Boot command-line arguments
 133 */
 134#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 135#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 136
 137/* Default late time init is NULL. archs can override this later. */
 138void (*__initdata late_time_init)(void);
 139
 140/* Untouched command line saved by arch-specific code. */
 141char __initdata boot_command_line[COMMAND_LINE_SIZE];
 142/* Untouched saved command line (eg. for /proc) */
 143char *saved_command_line __ro_after_init;
 144unsigned int saved_command_line_len __ro_after_init;
 145/* Command line for parameter parsing */
 146static char *static_command_line;
 147/* Untouched extra command line */
 148static char *extra_command_line;
 149/* Extra init arguments */
 150static char *extra_init_args;
 151
 152#ifdef CONFIG_BOOT_CONFIG
 153/* Is bootconfig on command line? */
 154static bool bootconfig_found;
 155static size_t initargs_offs;
 156#else
 157# define bootconfig_found false
 158# define initargs_offs 0
 159#endif
 160
 161static char *execute_command;
 162static char *ramdisk_execute_command = "/init";
 163
 164/*
 165 * Used to generate warnings if static_key manipulation functions are used
 166 * before jump_label_init is called.
 167 */
 168bool static_key_initialized __read_mostly;
 169EXPORT_SYMBOL_GPL(static_key_initialized);
 170
 171/*
 172 * If set, this is an indication to the drivers that reset the underlying
 173 * device before going ahead with the initialization otherwise driver might
 174 * rely on the BIOS and skip the reset operation.
 175 *
 176 * This is useful if kernel is booting in an unreliable environment.
 177 * For ex. kdump situation where previous kernel has crashed, BIOS has been
 178 * skipped and devices will be in unknown state.
 179 */
 180unsigned int reset_devices;
 181EXPORT_SYMBOL(reset_devices);
 182
 183static int __init set_reset_devices(char *str)
 184{
 185	reset_devices = 1;
 186	return 1;
 187}
 188
 189__setup("reset_devices", set_reset_devices);
 190
 191static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 192const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 193static const char *panic_later, *panic_param;
 194
 195static bool __init obsolete_checksetup(char *line)
 196{
 197	const struct obs_kernel_param *p;
 198	bool had_early_param = false;
 199
 200	p = __setup_start;
 201	do {
 202		int n = strlen(p->str);
 203		if (parameqn(line, p->str, n)) {
 204			if (p->early) {
 205				/* Already done in parse_early_param?
 206				 * (Needs exact match on param part).
 207				 * Keep iterating, as we can have early
 208				 * params and __setups of same names 8( */
 209				if (line[n] == '\0' || line[n] == '=')
 210					had_early_param = true;
 211			} else if (!p->setup_func) {
 212				pr_warn("Parameter %s is obsolete, ignored\n",
 213					p->str);
 214				return true;
 215			} else if (p->setup_func(line + n))
 216				return true;
 217		}
 218		p++;
 219	} while (p < __setup_end);
 220
 221	return had_early_param;
 222}
 223
 224/*
 225 * This should be approx 2 Bo*oMips to start (note initial shift), and will
 226 * still work even if initially too large, it will just take slightly longer
 227 */
 228unsigned long loops_per_jiffy = (1<<12);
 229EXPORT_SYMBOL(loops_per_jiffy);
 230
 231static int __init debug_kernel(char *str)
 232{
 233	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 234	return 0;
 235}
 236
 237static int __init quiet_kernel(char *str)
 238{
 239	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 240	return 0;
 241}
 242
 243early_param("debug", debug_kernel);
 244early_param("quiet", quiet_kernel);
 245
 246static int __init loglevel(char *str)
 247{
 248	int newlevel;
 249
 250	/*
 251	 * Only update loglevel value when a correct setting was passed,
 252	 * to prevent blind crashes (when loglevel being set to 0) that
 253	 * are quite hard to debug
 254	 */
 255	if (get_option(&str, &newlevel)) {
 256		console_loglevel = newlevel;
 257		return 0;
 258	}
 259
 260	return -EINVAL;
 261}
 262
 263early_param("loglevel", loglevel);
 264
 265#ifdef CONFIG_BLK_DEV_INITRD
 266static void * __init get_boot_config_from_initrd(size_t *_size)
 267{
 268	u32 size, csum;
 269	char *data;
 270	u32 *hdr;
 271	int i;
 272
 273	if (!initrd_end)
 274		return NULL;
 275
 276	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
 277	/*
 278	 * Since Grub may align the size of initrd to 4, we must
 279	 * check the preceding 3 bytes as well.
 280	 */
 281	for (i = 0; i < 4; i++) {
 282		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
 283			goto found;
 284		data--;
 285	}
 286	return NULL;
 287
 288found:
 289	hdr = (u32 *)(data - 8);
 290	size = le32_to_cpu(hdr[0]);
 291	csum = le32_to_cpu(hdr[1]);
 292
 293	data = ((void *)hdr) - size;
 294	if ((unsigned long)data < initrd_start) {
 295		pr_err("bootconfig size %d is greater than initrd size %ld\n",
 296			size, initrd_end - initrd_start);
 297		return NULL;
 298	}
 299
 300	if (xbc_calc_checksum(data, size) != csum) {
 301		pr_err("bootconfig checksum failed\n");
 302		return NULL;
 303	}
 304
 305	/* Remove bootconfig from initramfs/initrd */
 306	initrd_end = (unsigned long)data;
 307	if (_size)
 308		*_size = size;
 309
 310	return data;
 311}
 312#else
 313static void * __init get_boot_config_from_initrd(size_t *_size)
 314{
 315	return NULL;
 316}
 317#endif
 318
 319#ifdef CONFIG_BOOT_CONFIG
 320
 321static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
 322
 323#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
 324
 325static 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, *q;
 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			/*
 349			 * For prettier and more readable /proc/cmdline, only
 350			 * quote the value when necessary, i.e. when it contains
 351			 * whitespace.
 352			 */
 353			q = strpbrk(val, " \t\r\n") ? "\"" : "";
 354			ret = snprintf(buf, rest(buf, end), "%s=%s%s%s ",
 355				       xbc_namebuf, q, val, q);
 356			if (ret < 0)
 357				return ret;
 358			buf += ret;
 359		}
 360	}
 361
 362	return buf - (end - size);
 363}
 364#undef rest
 365
 366/* Make an extra command line under given key word */
 367static char * __init xbc_make_cmdline(const char *key)
 368{
 369	struct xbc_node *root;
 370	char *new_cmdline;
 371	int ret, len = 0;
 372
 373	root = xbc_find_node(key);
 374	if (!root)
 375		return NULL;
 376
 377	/* Count required buffer size */
 378	len = xbc_snprint_cmdline(NULL, 0, root);
 379	if (len <= 0)
 380		return NULL;
 381
 382	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
 383	if (!new_cmdline) {
 384		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
 385		return NULL;
 386	}
 387
 388	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
 389	if (ret < 0 || ret > len) {
 390		pr_err("Failed to print extra kernel cmdline.\n");
 391		memblock_free(new_cmdline, len + 1);
 392		return NULL;
 393	}
 394
 395	return new_cmdline;
 396}
 397
 398static int __init bootconfig_params(char *param, char *val,
 399				    const char *unused, void *arg)
 400{
 401	if (strcmp(param, "bootconfig") == 0) {
 402		bootconfig_found = true;
 403	}
 404	return 0;
 405}
 406
 407static int __init warn_bootconfig(char *str)
 408{
 409	/* The 'bootconfig' has been handled by bootconfig_params(). */
 410	return 0;
 411}
 412
 413static void __init setup_boot_config(void)
 414{
 415	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 416	const char *msg, *data;
 417	int pos, ret;
 418	size_t size;
 419	char *err;
 420
 421	/* Cut out the bootconfig data even if we have no bootconfig option */
 422	data = get_boot_config_from_initrd(&size);
 423	/* If there is no bootconfig in initrd, try embedded one. */
 424	if (!data)
 425		data = xbc_get_embedded_bootconfig(&size);
 426
 427	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 428	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
 429			 bootconfig_params);
 430
 431	if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
 432		return;
 433
 434	/* parse_args() stops at the next param of '--' and returns an address */
 435	if (err)
 436		initargs_offs = err - tmp_cmdline;
 437
 438	if (!data) {
 439		/* If user intended to use bootconfig, show an error level message */
 440		if (bootconfig_found)
 441			pr_err("'bootconfig' found on command line, but no bootconfig found\n");
 442		else
 443			pr_info("No bootconfig data provided, so skipping bootconfig");
 444		return;
 445	}
 446
 447	if (size >= XBC_DATA_MAX) {
 448		pr_err("bootconfig size %ld greater than max size %d\n",
 449			(long)size, XBC_DATA_MAX);
 450		return;
 451	}
 452
 453	ret = xbc_init(data, size, &msg, &pos);
 454	if (ret < 0) {
 455		if (pos < 0)
 456			pr_err("Failed to init bootconfig: %s.\n", msg);
 457		else
 458			pr_err("Failed to parse bootconfig: %s at %d.\n",
 459				msg, pos);
 460	} else {
 461		xbc_get_info(&ret, NULL);
 462		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)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
 471static void __init exit_boot_config(void)
 472{
 473	xbc_exit();
 474}
 475
 476#else	/* !CONFIG_BOOT_CONFIG */
 477
 478static void __init setup_boot_config(void)
 479{
 480	/* Remove bootconfig data from initrd */
 481	get_boot_config_from_initrd(NULL);
 482}
 483
 484static int __init warn_bootconfig(char *str)
 485{
 486	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 487	return 0;
 488}
 489
 490#define exit_boot_config()	do {} while (0)
 491
 492#endif	/* CONFIG_BOOT_CONFIG */
 493
 494early_param("bootconfig", warn_bootconfig);
 495
 496bool __init cmdline_has_extra_options(void)
 497{
 498	return extra_command_line || extra_init_args;
 499}
 500
 501/* Change NUL term back to "=", to make "param" the whole string. */
 502static void __init repair_env_string(char *param, char *val)
 503{
 504	if (val) {
 505		/* param=val or param="val"? */
 506		if (val == param+strlen(param)+1)
 507			val[-1] = '=';
 508		else if (val == param+strlen(param)+2) {
 509			val[-2] = '=';
 510			memmove(val-1, val, strlen(val)+1);
 511		} else
 512			BUG();
 513	}
 514}
 515
 516/* Anything after -- gets handed straight to init. */
 517static int __init set_init_arg(char *param, char *val,
 518			       const char *unused, void *arg)
 519{
 520	unsigned int i;
 521
 522	if (panic_later)
 523		return 0;
 524
 525	repair_env_string(param, val);
 526
 527	for (i = 0; argv_init[i]; i++) {
 528		if (i == MAX_INIT_ARGS) {
 529			panic_later = "init";
 530			panic_param = param;
 531			return 0;
 532		}
 533	}
 534	argv_init[i] = param;
 535	return 0;
 536}
 537
 538/*
 539 * Unknown boot options get handed to init, unless they look like
 540 * unused parameters (modprobe will find them in /proc/cmdline).
 541 */
 542static int __init unknown_bootoption(char *param, char *val,
 543				     const char *unused, void *arg)
 544{
 545	size_t len = strlen(param);
 546
 547	/* Handle params aliased to sysctls */
 548	if (sysctl_is_alias(param))
 549		return 0;
 550
 551	repair_env_string(param, val);
 552
 553	/* Handle obsolete-style parameters */
 554	if (obsolete_checksetup(param))
 555		return 0;
 556
 557	/* Unused module parameter. */
 558	if (strnchr(param, len, '.'))
 559		return 0;
 560
 561	if (panic_later)
 562		return 0;
 563
 564	if (val) {
 565		/* Environment option */
 566		unsigned int i;
 567		for (i = 0; envp_init[i]; i++) {
 568			if (i == MAX_INIT_ENVS) {
 569				panic_later = "env";
 570				panic_param = param;
 571			}
 572			if (!strncmp(param, envp_init[i], len+1))
 573				break;
 574		}
 575		envp_init[i] = param;
 576	} else {
 577		/* Command line option */
 578		unsigned int i;
 579		for (i = 0; argv_init[i]; i++) {
 580			if (i == MAX_INIT_ARGS) {
 581				panic_later = "init";
 582				panic_param = param;
 583			}
 584		}
 585		argv_init[i] = param;
 586	}
 587	return 0;
 588}
 589
 590static int __init init_setup(char *str)
 591{
 592	unsigned int i;
 593
 594	execute_command = str;
 595	/*
 596	 * In case LILO is going to boot us with default command line,
 597	 * it prepends "auto" before the whole cmdline which makes
 598	 * the shell think it should execute a script with such name.
 599	 * So we ignore all arguments entered _before_ init=... [MJ]
 600	 */
 601	for (i = 1; i < MAX_INIT_ARGS; i++)
 602		argv_init[i] = NULL;
 603	return 1;
 604}
 605__setup("init=", init_setup);
 606
 607static int __init rdinit_setup(char *str)
 608{
 609	unsigned int i;
 610
 611	ramdisk_execute_command = str;
 612	/* See "auto" comment in init_setup */
 613	for (i = 1; i < MAX_INIT_ARGS; i++)
 614		argv_init[i] = NULL;
 615	return 1;
 616}
 617__setup("rdinit=", rdinit_setup);
 618
 619#ifndef CONFIG_SMP
 620static inline void setup_nr_cpu_ids(void) { }
 621static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 622#endif
 623
 624/*
 625 * We need to store the untouched command line for future reference.
 626 * We also need to store the touched command line since the parameter
 627 * parsing is performed in place, and we should allow a component to
 628 * store reference of name/value for future reference.
 629 */
 630static void __init setup_command_line(char *command_line)
 631{
 632	size_t len, xlen = 0, ilen = 0;
 633
 634	if (extra_command_line)
 635		xlen = strlen(extra_command_line);
 636	if (extra_init_args) {
 637		extra_init_args = strim(extra_init_args); /* remove trailing space */
 638		ilen = strlen(extra_init_args) + 4; /* for " -- " */
 639	}
 640
 641	len = xlen + strlen(boot_command_line) + ilen + 1;
 642
 643	saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 644	if (!saved_command_line)
 645		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 646
 647	len = xlen + strlen(command_line) + 1;
 648
 649	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 650	if (!static_command_line)
 651		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 652
 653	if (xlen) {
 654		/*
 655		 * We have to put extra_command_line before boot command
 656		 * lines because there could be dashes (separator of init
 657		 * command line) in the command lines.
 658		 */
 659		strcpy(saved_command_line, extra_command_line);
 660		strcpy(static_command_line, extra_command_line);
 661	}
 662	strcpy(saved_command_line + xlen, boot_command_line);
 663	strcpy(static_command_line + xlen, command_line);
 664
 665	if (ilen) {
 666		/*
 667		 * Append supplemental init boot args to saved_command_line
 668		 * so that user can check what command line options passed
 669		 * to init.
 670		 * The order should always be
 671		 * " -- "[bootconfig init-param][cmdline init-param]
 672		 */
 673		if (initargs_offs) {
 674			len = xlen + initargs_offs;
 675			strcpy(saved_command_line + len, extra_init_args);
 676			len += ilen - 4;	/* strlen(extra_init_args) */
 677			strcpy(saved_command_line + len,
 678				boot_command_line + initargs_offs - 1);
 679		} else {
 680			len = strlen(saved_command_line);
 681			strcpy(saved_command_line + len, " -- ");
 682			len += 4;
 683			strcpy(saved_command_line + len, extra_init_args);
 684		}
 685	}
 686
 687	saved_command_line_len = strlen(saved_command_line);
 688}
 689
 690/*
 691 * We need to finalize in a non-__init function or else race conditions
 692 * between the root thread and the init thread may cause start_kernel to
 693 * be reaped by free_initmem before the root thread has proceeded to
 694 * cpu_idle.
 695 *
 696 * gcc-3.4 accidentally inlines this function, so use noinline.
 697 */
 698
 699static __initdata DECLARE_COMPLETION(kthreadd_done);
 700
 701static noinline void __ref __noreturn rest_init(void)
 702{
 703	struct task_struct *tsk;
 704	int pid;
 705
 706	rcu_scheduler_starting();
 707	/*
 708	 * We need to spawn init first so that it obtains pid 1, however
 709	 * the init task will end up wanting to create kthreads, which, if
 710	 * we schedule it before we create kthreadd, will OOPS.
 711	 */
 712	pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
 713	/*
 714	 * Pin init on the boot CPU. Task migration is not properly working
 715	 * until sched_init_smp() has been run. It will set the allowed
 716	 * CPUs for init to the non isolated CPUs.
 717	 */
 718	rcu_read_lock();
 719	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
 720	tsk->flags |= PF_NO_SETAFFINITY;
 721	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
 722	rcu_read_unlock();
 723
 724	numa_default_policy();
 725	pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
 726	rcu_read_lock();
 727	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 728	rcu_read_unlock();
 729
 730	/*
 731	 * Enable might_sleep() and smp_processor_id() checks.
 732	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
 733	 * kernel_thread() would trigger might_sleep() splats. With
 734	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
 735	 * already, but it's stuck on the kthreadd_done completion.
 736	 */
 737	system_state = SYSTEM_SCHEDULING;
 738
 739	complete(&kthreadd_done);
 740
 741	/*
 742	 * The boot idle thread must execute schedule()
 743	 * at least once to get things moving:
 744	 */
 745	schedule_preempt_disabled();
 746	/* Call into cpu_idle with preempt disabled */
 747	cpu_startup_entry(CPUHP_ONLINE);
 748}
 749
 750/* Check for early params. */
 751static int __init do_early_param(char *param, char *val,
 752				 const char *unused, void *arg)
 753{
 754	const struct obs_kernel_param *p;
 755
 756	for (p = __setup_start; p < __setup_end; p++) {
 757		if (p->early && parameq(param, p->str)) {
 
 
 
 758			if (p->setup_func(val) != 0)
 759				pr_warn("Malformed early option '%s'\n", param);
 760		}
 761	}
 762	/* We accept everything at this stage. */
 763	return 0;
 764}
 765
 766void __init parse_early_options(char *cmdline)
 767{
 768	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 769		   do_early_param);
 770}
 771
 772/* Arch code calls this early on, or if not, just before other parsing. */
 773void __init parse_early_param(void)
 774{
 775	static int done __initdata;
 776	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 777
 778	if (done)
 779		return;
 780
 781	/* All fall through to do_early_param. */
 782	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 783	parse_early_options(tmp_cmdline);
 784	done = 1;
 785}
 786
 787void __init __weak arch_post_acpi_subsys_init(void) { }
 788
 789void __init __weak smp_setup_processor_id(void)
 790{
 791}
 792
 793void __init __weak smp_prepare_boot_cpu(void)
 794{
 795}
 796
 797# if THREAD_SIZE >= PAGE_SIZE
 798void __init __weak thread_stack_cache_init(void)
 799{
 800}
 801#endif
 802
 803void __init __weak poking_init(void) { }
 804
 805void __init __weak pgtable_cache_init(void) { }
 806
 807void __init __weak trap_init(void) { }
 808
 809bool initcall_debug;
 810core_param(initcall_debug, initcall_debug, bool, 0644);
 811
 812#ifdef TRACEPOINTS_ENABLED
 813static void __init initcall_debug_enable(void);
 814#else
 815static inline void initcall_debug_enable(void)
 816{
 817}
 818#endif
 819
 820#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
 821DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
 822			   randomize_kstack_offset);
 823DEFINE_PER_CPU(u32, kstack_offset);
 824
 825static int __init early_randomize_kstack_offset(char *buf)
 826{
 827	int ret;
 828	bool bool_result;
 829
 830	ret = kstrtobool(buf, &bool_result);
 831	if (ret)
 832		return ret;
 833
 834	if (bool_result)
 835		static_branch_enable(&randomize_kstack_offset);
 836	else
 837		static_branch_disable(&randomize_kstack_offset);
 838	return 0;
 839}
 840early_param("randomize_kstack_offset", early_randomize_kstack_offset);
 841#endif
 842
 843static void __init print_unknown_bootoptions(void)
 844{
 845	char *unknown_options;
 846	char *end;
 847	const char *const *p;
 848	size_t len;
 849
 850	if (panic_later || (!argv_init[1] && !envp_init[2]))
 851		return;
 852
 853	/*
 854	 * Determine how many options we have to print out, plus a space
 855	 * before each
 856	 */
 857	len = 1; /* null terminator */
 858	for (p = &argv_init[1]; *p; p++) {
 859		len++;
 860		len += strlen(*p);
 861	}
 862	for (p = &envp_init[2]; *p; p++) {
 863		len++;
 864		len += strlen(*p);
 865	}
 866
 867	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
 868	if (!unknown_options) {
 869		pr_err("%s: Failed to allocate %zu bytes\n",
 870			__func__, len);
 871		return;
 872	}
 873	end = unknown_options;
 874
 875	for (p = &argv_init[1]; *p; p++)
 876		end += sprintf(end, " %s", *p);
 877	for (p = &envp_init[2]; *p; p++)
 878		end += sprintf(end, " %s", *p);
 879
 880	/* Start at unknown_options[1] to skip the initial space */
 881	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
 882		&unknown_options[1]);
 883	memblock_free(unknown_options, len);
 884}
 885
 886static void __init early_numa_node_init(void)
 887{
 888#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
 889#ifndef cpu_to_node
 890	int cpu;
 891
 892	/* The early_cpu_to_node() should be ready here. */
 893	for_each_possible_cpu(cpu)
 894		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
 895#endif
 896#endif
 897}
 898
 899asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
 900void start_kernel(void)
 901{
 902	char *command_line;
 903	char *after_dashes;
 904
 905	set_task_stack_end_magic(&init_task);
 906	smp_setup_processor_id();
 907	debug_objects_early_init();
 908	init_vmlinux_build_id();
 909
 910	cgroup_init_early();
 911
 912	local_irq_disable();
 913	early_boot_irqs_disabled = true;
 914
 915	/*
 916	 * Interrupts are still disabled. Do necessary setups, then
 917	 * enable them.
 918	 */
 919	boot_cpu_init();
 920	page_address_init();
 921	pr_notice("%s", linux_banner);
 922	setup_arch(&command_line);
 923	/* Static keys and static calls are needed by LSMs */
 924	jump_label_init();
 925	static_call_init();
 926	early_security_init();
 
 927	setup_boot_config();
 928	setup_command_line(command_line);
 929	setup_nr_cpu_ids();
 930	setup_per_cpu_areas();
 931	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 932	early_numa_node_init();
 933	boot_cpu_hotplug_init();
 934
 935	pr_notice("Kernel command line: %s\n", saved_command_line);
 936	/* parameters may set static keys */
 
 937	parse_early_param();
 938	after_dashes = parse_args("Booting kernel",
 939				  static_command_line, __start___param,
 940				  __stop___param - __start___param,
 941				  -1, -1, NULL, &unknown_bootoption);
 942	print_unknown_bootoptions();
 943	if (!IS_ERR_OR_NULL(after_dashes))
 944		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 945			   NULL, set_init_arg);
 946	if (extra_init_args)
 947		parse_args("Setting extra init args", extra_init_args,
 948			   NULL, 0, -1, -1, NULL, set_init_arg);
 949
 950	/* Architectural and non-timekeeping rng init, before allocator init */
 951	random_init_early(command_line);
 952
 953	/*
 954	 * These use large bootmem allocations and must precede
 955	 * initalization of page allocator
 956	 */
 957	setup_log_buf(0);
 958	vfs_caches_init_early();
 959	sort_main_extable();
 960	trap_init();
 961	mm_core_init();
 962	poking_init();
 963	ftrace_init();
 964
 965	/* trace_printk can be enabled here */
 966	early_trace_init();
 967
 968	/*
 969	 * Set up the scheduler prior starting any interrupts (such as the
 970	 * timer interrupt). Full topology setup happens at smp_init()
 971	 * time - but meanwhile we still have a functioning scheduler.
 972	 */
 973	sched_init();
 974
 975	if (WARN(!irqs_disabled(),
 976		 "Interrupts were enabled *very* early, fixing it\n"))
 977		local_irq_disable();
 978	radix_tree_init();
 979	maple_tree_init();
 980
 981	/*
 982	 * Set up housekeeping before setting up workqueues to allow the unbound
 983	 * workqueue to take non-housekeeping into account.
 984	 */
 985	housekeeping_init();
 986
 987	/*
 988	 * Allow workqueue creation and work item queueing/cancelling
 989	 * early.  Work item execution depends on kthreads and starts after
 990	 * workqueue_init().
 991	 */
 992	workqueue_init_early();
 993
 994	rcu_init();
 995
 996	/* Trace events are available after this */
 997	trace_init();
 998
 999	if (initcall_debug)
1000		initcall_debug_enable();
1001
1002	context_tracking_init();
1003	/* init some links before init_ISA_irqs() */
1004	early_irq_init();
1005	init_IRQ();
1006	tick_init();
1007	rcu_init_nohz();
1008	init_timers();
1009	srcu_init();
1010	hrtimers_init();
1011	softirq_init();
1012	timekeeping_init();
1013	time_init();
1014
1015	/* This must be after timekeeping is initialized */
1016	random_init();
1017
1018	/* These make use of the fully initialized rng */
1019	kfence_init();
1020	boot_init_stack_canary();
1021
1022	perf_event_init();
1023	profile_init();
1024	call_function_init();
1025	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1026
1027	early_boot_irqs_disabled = false;
1028	local_irq_enable();
1029
1030	kmem_cache_init_late();
1031
1032	/*
1033	 * HACK ALERT! This is early. We're enabling the console before
1034	 * we've done PCI setups etc, and console_init() must be aware of
1035	 * this. But we do want output early, in case something goes wrong.
1036	 */
1037	console_init();
1038	if (panic_later)
1039		panic("Too many boot %s vars at `%s'", panic_later,
1040		      panic_param);
1041
1042	lockdep_init();
1043
1044	/*
1045	 * Need to run this when irqs are enabled, because it wants
1046	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1047	 * too:
1048	 */
1049	locking_selftest();
1050
1051#ifdef CONFIG_BLK_DEV_INITRD
1052	if (initrd_start && !initrd_below_start_ok &&
1053	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1054		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1055		    page_to_pfn(virt_to_page((void *)initrd_start)),
1056		    min_low_pfn);
1057		initrd_start = 0;
1058	}
1059#endif
1060	setup_per_cpu_pageset();
1061	numa_policy_init();
1062	acpi_early_init();
1063	if (late_time_init)
1064		late_time_init();
1065	sched_clock_init();
1066	calibrate_delay();
1067
1068	arch_cpu_finalize_init();
1069
1070	pid_idr_init();
1071	anon_vma_init();
1072#ifdef CONFIG_X86
1073	if (efi_enabled(EFI_RUNTIME_SERVICES))
1074		efi_enter_virtual_mode();
1075#endif
1076	thread_stack_cache_init();
1077	cred_init();
1078	fork_init();
1079	proc_caches_init();
1080	uts_ns_init();
1081	key_init();
1082	security_init();
1083	dbg_late_init();
1084	net_ns_init();
1085	vfs_caches_init();
1086	pagecache_init();
1087	signals_init();
1088	seq_file_init();
1089	proc_root_init();
1090	nsfs_init();
1091	pidfs_init();
1092	cpuset_init();
1093	cgroup_init();
1094	taskstats_init_early();
1095	delayacct_init();
1096
1097	acpi_subsystem_init();
1098	arch_post_acpi_subsys_init();
1099	kcsan_init();
1100
1101	/* Do the rest non-__init'ed, we're now alive */
1102	rest_init();
1103
1104	/*
1105	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
1106	 * and older.
1107	 */
1108#if !__has_attribute(__no_stack_protector__)
1109	prevent_tail_call_optimization();
1110#endif
1111}
1112
1113/* Call all constructor functions linked into the kernel. */
1114static void __init do_ctors(void)
1115{
1116/*
1117 * For UML, the constructors have already been called by the
1118 * normal setup code as it's just a normal ELF binary, so we
1119 * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1120 * even on UML for modules.
1121 */
1122#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1123	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1124
1125	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1126		(*fn)();
1127#endif
1128}
1129
1130#ifdef CONFIG_KALLSYMS
1131struct blacklist_entry {
1132	struct list_head next;
1133	char *buf;
1134};
1135
1136static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1137
1138static int __init initcall_blacklist(char *str)
1139{
1140	char *str_entry;
1141	struct blacklist_entry *entry;
1142
1143	/* str argument is a comma-separated list of functions */
1144	do {
1145		str_entry = strsep(&str, ",");
1146		if (str_entry) {
1147			pr_debug("blacklisting initcall %s\n", str_entry);
1148			entry = memblock_alloc(sizeof(*entry),
1149					       SMP_CACHE_BYTES);
1150			if (!entry)
1151				panic("%s: Failed to allocate %zu bytes\n",
1152				      __func__, sizeof(*entry));
1153			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1154						    SMP_CACHE_BYTES);
1155			if (!entry->buf)
1156				panic("%s: Failed to allocate %zu bytes\n",
1157				      __func__, strlen(str_entry) + 1);
1158			strcpy(entry->buf, str_entry);
1159			list_add(&entry->next, &blacklisted_initcalls);
1160		}
1161	} while (str_entry);
1162
1163	return 1;
1164}
1165
1166static bool __init_or_module initcall_blacklisted(initcall_t fn)
1167{
1168	struct blacklist_entry *entry;
1169	char fn_name[KSYM_SYMBOL_LEN];
1170	unsigned long addr;
1171
1172	if (list_empty(&blacklisted_initcalls))
1173		return false;
1174
1175	addr = (unsigned long) dereference_function_descriptor(fn);
1176	sprint_symbol_no_offset(fn_name, addr);
1177
1178	/*
1179	 * fn will be "function_name [module_name]" where [module_name] is not
1180	 * displayed for built-in init functions.  Strip off the [module_name].
1181	 */
1182	strreplace(fn_name, ' ', '\0');
1183
1184	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1185		if (!strcmp(fn_name, entry->buf)) {
1186			pr_debug("initcall %s blacklisted\n", fn_name);
1187			return true;
1188		}
1189	}
1190
1191	return false;
1192}
1193#else
1194static int __init initcall_blacklist(char *str)
1195{
1196	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1197	return 0;
1198}
1199
1200static bool __init_or_module initcall_blacklisted(initcall_t fn)
1201{
1202	return false;
1203}
1204#endif
1205__setup("initcall_blacklist=", initcall_blacklist);
1206
1207static __init_or_module void
1208trace_initcall_start_cb(void *data, initcall_t fn)
1209{
1210	ktime_t *calltime = data;
1211
1212	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
1213	*calltime = ktime_get();
1214}
1215
1216static __init_or_module void
1217trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1218{
1219	ktime_t rettime, *calltime = data;
1220
1221	rettime = ktime_get();
1222	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1223		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1224}
1225
1226static ktime_t initcall_calltime;
1227
1228#ifdef TRACEPOINTS_ENABLED
1229static void __init initcall_debug_enable(void)
1230{
1231	int ret;
1232
1233	ret = register_trace_initcall_start(trace_initcall_start_cb,
1234					    &initcall_calltime);
1235	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1236					      &initcall_calltime);
1237	WARN(ret, "Failed to register initcall tracepoints\n");
1238}
1239# define do_trace_initcall_start	trace_initcall_start
1240# define do_trace_initcall_finish	trace_initcall_finish
1241#else
1242static inline void do_trace_initcall_start(initcall_t fn)
1243{
1244	if (!initcall_debug)
1245		return;
1246	trace_initcall_start_cb(&initcall_calltime, fn);
1247}
1248static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1249{
1250	if (!initcall_debug)
1251		return;
1252	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1253}
1254#endif /* !TRACEPOINTS_ENABLED */
1255
1256int __init_or_module do_one_initcall(initcall_t fn)
1257{
1258	int count = preempt_count();
1259	char msgbuf[64];
1260	int ret;
1261
1262	if (initcall_blacklisted(fn))
1263		return -EPERM;
1264
1265	do_trace_initcall_start(fn);
1266	ret = fn();
1267	do_trace_initcall_finish(fn, ret);
1268
1269	msgbuf[0] = 0;
1270
1271	if (preempt_count() != count) {
1272		sprintf(msgbuf, "preemption imbalance ");
1273		preempt_count_set(count);
1274	}
1275	if (irqs_disabled()) {
1276		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1277		local_irq_enable();
1278	}
1279	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1280
1281	add_latent_entropy();
1282	return ret;
1283}
1284
1285
1286static initcall_entry_t *initcall_levels[] __initdata = {
1287	__initcall0_start,
1288	__initcall1_start,
1289	__initcall2_start,
1290	__initcall3_start,
1291	__initcall4_start,
1292	__initcall5_start,
1293	__initcall6_start,
1294	__initcall7_start,
1295	__initcall_end,
1296};
1297
1298/* Keep these in sync with initcalls in include/linux/init.h */
1299static const char *initcall_level_names[] __initdata = {
1300	"pure",
1301	"core",
1302	"postcore",
1303	"arch",
1304	"subsys",
1305	"fs",
1306	"device",
1307	"late",
1308};
1309
1310static int __init ignore_unknown_bootoption(char *param, char *val,
1311			       const char *unused, void *arg)
1312{
1313	return 0;
1314}
1315
1316static void __init do_initcall_level(int level, char *command_line)
1317{
1318	initcall_entry_t *fn;
1319
1320	parse_args(initcall_level_names[level],
1321		   command_line, __start___param,
1322		   __stop___param - __start___param,
1323		   level, level,
1324		   NULL, ignore_unknown_bootoption);
1325
1326	trace_initcall_level(initcall_level_names[level]);
1327	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1328		do_one_initcall(initcall_from_entry(fn));
1329}
1330
1331static void __init do_initcalls(void)
1332{
1333	int level;
1334	size_t len = saved_command_line_len + 1;
1335	char *command_line;
1336
1337	command_line = kzalloc(len, GFP_KERNEL);
1338	if (!command_line)
1339		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1340
1341	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1342		/* Parser modifies command_line, restore it each time */
1343		strcpy(command_line, saved_command_line);
1344		do_initcall_level(level, command_line);
1345	}
1346
1347	kfree(command_line);
1348}
1349
1350/*
1351 * Ok, the machine is now initialized. None of the devices
1352 * have been touched yet, but the CPU subsystem is up and
1353 * running, and memory and process management works.
1354 *
1355 * Now we can finally start doing some real work..
1356 */
1357static void __init do_basic_setup(void)
1358{
1359	cpuset_init_smp();
1360	driver_init();
1361	init_irq_proc();
1362	do_ctors();
1363	do_initcalls();
1364}
1365
1366static void __init do_pre_smp_initcalls(void)
1367{
1368	initcall_entry_t *fn;
1369
1370	trace_initcall_level("early");
1371	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1372		do_one_initcall(initcall_from_entry(fn));
1373}
1374
1375static int run_init_process(const char *init_filename)
1376{
1377	const char *const *p;
1378
1379	argv_init[0] = init_filename;
1380	pr_info("Run %s as init process\n", init_filename);
1381	pr_debug("  with arguments:\n");
1382	for (p = argv_init; *p; p++)
1383		pr_debug("    %s\n", *p);
1384	pr_debug("  with environment:\n");
1385	for (p = envp_init; *p; p++)
1386		pr_debug("    %s\n", *p);
1387	return kernel_execve(init_filename, argv_init, envp_init);
1388}
1389
1390static int try_to_run_init_process(const char *init_filename)
1391{
1392	int ret;
1393
1394	ret = run_init_process(init_filename);
1395
1396	if (ret && ret != -ENOENT) {
1397		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1398		       init_filename, ret);
1399	}
1400
1401	return ret;
1402}
1403
1404static noinline void __init kernel_init_freeable(void);
1405
1406#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1407bool rodata_enabled __ro_after_init = true;
1408
1409#ifndef arch_parse_debug_rodata
1410static inline bool arch_parse_debug_rodata(char *str) { return false; }
1411#endif
1412
1413static int __init set_debug_rodata(char *str)
1414{
1415	if (arch_parse_debug_rodata(str))
1416		return 0;
1417
1418	if (str && !strcmp(str, "on"))
1419		rodata_enabled = true;
1420	else if (str && !strcmp(str, "off"))
1421		rodata_enabled = false;
1422	else
1423		pr_warn("Invalid option string for rodata: '%s'\n", str);
1424	return 0;
1425}
1426early_param("rodata", set_debug_rodata);
1427#endif
1428
1429static void mark_readonly(void)
1430{
1431	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) {
1432		/*
1433		 * load_module() results in W+X mappings, which are cleaned
1434		 * up with init_free_wq. Let's make sure that queued work is
1435		 * flushed so that we don't hit false positives looking for
1436		 * insecure pages which are W+X.
1437		 */
1438		flush_module_init_free_work();
1439		jump_label_init_ro();
1440		mark_rodata_ro();
1441		debug_checkwx();
1442		rodata_test();
1443	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
1444		pr_info("Kernel memory protection disabled.\n");
1445	} else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) {
1446		pr_warn("Kernel memory protection not selected by kernel config.\n");
1447	} else {
1448		pr_warn("This architecture does not have kernel memory protection.\n");
1449	}
1450}
1451
1452void __weak free_initmem(void)
1453{
1454	free_initmem_default(POISON_FREE_INITMEM);
1455}
1456
1457static int __ref kernel_init(void *unused)
1458{
1459	int ret;
1460
1461	/*
1462	 * Wait until kthreadd is all set-up.
1463	 */
1464	wait_for_completion(&kthreadd_done);
1465
1466	kernel_init_freeable();
1467	/* need to finish all async __init code before freeing the memory */
1468	async_synchronize_full();
1469
1470	system_state = SYSTEM_FREEING_INITMEM;
1471	kprobe_free_init_mem();
1472	ftrace_free_init_mem();
1473	kgdb_free_init_mem();
1474	exit_boot_config();
1475	free_initmem();
1476	mark_readonly();
1477
1478	/*
1479	 * Kernel mappings are now finalized - update the userspace page-table
1480	 * to finalize PTI.
1481	 */
1482	pti_finalize();
1483
1484	system_state = SYSTEM_RUNNING;
1485	numa_default_policy();
1486
1487	rcu_end_inkernel_boot();
1488
1489	do_sysctl_args();
1490
1491	if (ramdisk_execute_command) {
1492		ret = run_init_process(ramdisk_execute_command);
1493		if (!ret)
1494			return 0;
1495		pr_err("Failed to execute %s (error %d)\n",
1496		       ramdisk_execute_command, ret);
1497	}
1498
1499	/*
1500	 * We try each of these until one succeeds.
1501	 *
1502	 * The Bourne shell can be used instead of init if we are
1503	 * trying to recover a really broken machine.
1504	 */
1505	if (execute_command) {
1506		ret = run_init_process(execute_command);
1507		if (!ret)
1508			return 0;
1509		panic("Requested init %s failed (error %d).",
1510		      execute_command, ret);
1511	}
1512
1513	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1514		ret = run_init_process(CONFIG_DEFAULT_INIT);
1515		if (ret)
1516			pr_err("Default init %s failed (error %d)\n",
1517			       CONFIG_DEFAULT_INIT, ret);
1518		else
1519			return 0;
1520	}
1521
1522	if (!try_to_run_init_process("/sbin/init") ||
1523	    !try_to_run_init_process("/etc/init") ||
1524	    !try_to_run_init_process("/bin/init") ||
1525	    !try_to_run_init_process("/bin/sh"))
1526		return 0;
1527
1528	panic("No working init found.  Try passing init= option to kernel. "
1529	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1530}
1531
1532/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1533void __init console_on_rootfs(void)
1534{
1535	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1536
1537	if (IS_ERR(file)) {
1538		pr_err("Warning: unable to open an initial console.\n");
1539		return;
1540	}
1541	init_dup(file);
1542	init_dup(file);
1543	init_dup(file);
1544	fput(file);
1545}
1546
1547static noinline void __init kernel_init_freeable(void)
1548{
1549	/* Now the scheduler is fully set up and can do blocking allocations */
1550	gfp_allowed_mask = __GFP_BITS_MASK;
1551
1552	/*
1553	 * init can allocate pages on any node
1554	 */
1555	set_mems_allowed(node_states[N_MEMORY]);
1556
1557	cad_pid = get_pid(task_pid(current));
1558
1559	smp_prepare_cpus(setup_max_cpus);
1560
1561	workqueue_init();
1562
1563	init_mm_internals();
1564
1565	rcu_init_tasks_generic();
1566	do_pre_smp_initcalls();
1567	lockup_detector_init();
1568
1569	smp_init();
1570	sched_init_smp();
1571
1572	workqueue_init_topology();
1573	async_init();
1574	padata_init();
1575	page_alloc_init_late();
1576
1577	do_basic_setup();
1578
1579	kunit_run_all_tests();
1580
1581	wait_for_initramfs();
1582	console_on_rootfs();
1583
1584	/*
1585	 * check if there is an early userspace init.  If yes, let it do all
1586	 * the work
1587	 */
1588	if (init_eaccess(ramdisk_execute_command) != 0) {
1589		ramdisk_execute_command = NULL;
1590		prepare_namespace();
1591	}
1592
1593	/*
1594	 * Ok, we have completed the initial bootup, and
1595	 * we're essentially up and running. Get rid of the
1596	 * initmem segments and start the user-mode stuff..
1597	 *
1598	 * rootfs is available now, try loading the public keys
1599	 * and default modules
1600	 */
1601
1602	integrity_load_keys();
1603}