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
 115static int kernel_init(void *);
 116
 117extern void init_IRQ(void);
 118extern 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 */
 127bool early_boot_irqs_disabled __read_mostly;
 128
 129enum system_states system_state __read_mostly;
 130EXPORT_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
 138extern void time_init(void);
 139/* Default late time init is NULL. archs can override this later. */
 140void (*__initdata late_time_init)(void);
 141
 142/* Untouched command line saved by arch-specific code. */
 143char __initdata boot_command_line[COMMAND_LINE_SIZE];
 144/* Untouched saved command line (eg. for /proc) */
 145char *saved_command_line;
 
 146/* Command line for parameter parsing */
 147static char *static_command_line;
 148/* Untouched extra command line */
 149static char *extra_command_line;
 150/* Extra init arguments */
 151static char *extra_init_args;
 152
 153#ifdef CONFIG_BOOT_CONFIG
 154/* Is bootconfig on command line? */
 155static bool bootconfig_found;
 156static bool initargs_found;
 157#else
 158# define bootconfig_found false
 159# define initargs_found false
 160#endif
 161
 162static char *execute_command;
 163static 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 */
 169bool static_key_initialized __read_mostly;
 170EXPORT_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 */
 181unsigned int reset_devices;
 182EXPORT_SYMBOL(reset_devices);
 183
 184static 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
 192static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 193const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 194static const char *panic_later, *panic_param;
 195
 196extern const struct obs_kernel_param __setup_start[], __setup_end[];
 197
 198static 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 */
 231unsigned long loops_per_jiffy = (1<<12);
 232EXPORT_SYMBOL(loops_per_jiffy);
 233
 234static int __init debug_kernel(char *str)
 235{
 236	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 237	return 0;
 238}
 239
 240static int __init quiet_kernel(char *str)
 241{
 242	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 243	return 0;
 244}
 245
 246early_param("debug", debug_kernel);
 247early_param("quiet", quiet_kernel);
 248
 249static 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
 266early_param("loglevel", loglevel);
 267
 268#ifdef CONFIG_BLK_DEV_INITRD
 269static 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
 291found:
 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
 313static 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
 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;
 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 */
 361static 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
 391static 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
 400static int __init warn_bootconfig(char *str)
 401{
 402	/* The 'bootconfig' has been handled by bootconfig_params(). */
 403	return 0;
 404}
 405
 406static void __init setup_boot_config(void)
 407{
 408	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 409	const char *msg;
 410	int pos;
 411	u32 size, csum;
 412	char *data, *copy, *err;
 413	int ret;
 414
 415	/* Cut out the bootconfig data even if we have no bootconfig option */
 416	data = get_boot_config_from_initrd(&size, &csum);
 
 
 
 417
 418	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 419	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
 420			 bootconfig_params);
 421
 422	if (IS_ERR(err) || !bootconfig_found)
 423		return;
 424
 425	/* parse_args() stops at '--' and returns an address */
 426	if (err)
 427		initargs_found = true;
 428
 429	if (!data) {
 430		pr_err("'bootconfig' found on command line, but no bootconfig found\n");
 
 
 
 
 431		return;
 432	}
 433
 434	if (size >= XBC_DATA_MAX) {
 435		pr_err("bootconfig size %d greater than max size %d\n",
 436			size, XBC_DATA_MAX);
 437		return;
 438	}
 439
 440	if (xbc_calc_checksum(data, size) != csum) {
 441		pr_err("bootconfig checksum failed\n");
 442		return;
 443	}
 444
 445	copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
 446	if (!copy) {
 447		pr_err("Failed to allocate memory for bootconfig\n");
 448		return;
 449	}
 450
 451	memcpy(copy, data, size);
 452	copy[size] = '\0';
 453
 454	ret = xbc_init(copy, &msg, &pos);
 455	if (ret < 0) {
 456		if (pos < 0)
 457			pr_err("Failed to init bootconfig: %s.\n", msg);
 458		else
 459			pr_err("Failed to parse bootconfig: %s at %d.\n",
 460				msg, pos);
 461	} else {
 462		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
 
 463		/* keys starting with "kernel." are passed via cmdline */
 464		extra_command_line = xbc_make_cmdline("kernel");
 465		/* Also, "init." keys are init arguments */
 466		extra_init_args = xbc_make_cmdline("init");
 467	}
 468	return;
 469}
 470
 471#else
 
 
 
 
 
 472
 473static void __init setup_boot_config(void)
 474{
 475	/* Remove bootconfig data from initrd */
 476	get_boot_config_from_initrd(NULL, NULL);
 477}
 478
 479static int __init warn_bootconfig(char *str)
 480{
 481	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 482	return 0;
 483}
 484#endif
 
 
 
 
 485early_param("bootconfig", warn_bootconfig);
 486
 487/* Change NUL term back to "=", to make "param" the whole string. */
 488static 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. */
 503static 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 */
 528static 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
 572static 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
 589static 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
 602static const unsigned int setup_max_cpus = NR_CPUS;
 603static inline void setup_nr_cpu_ids(void) { }
 604static 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 */
 613static void __init setup_command_line(char *command_line)
 614{
 615	size_t len, xlen = 0, ilen = 0;
 616
 617	if (extra_command_line)
 618		xlen = strlen(extra_command_line);
 619	if (extra_init_args)
 620		ilen = strlen(extra_init_args) + 4; /* for " -- " */
 621
 622	len = xlen + strlen(boot_command_line) + 1;
 623
 624	saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
 625	if (!saved_command_line)
 626		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
 627
 628	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 629	if (!static_command_line)
 630		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 631
 632	if (xlen) {
 633		/*
 634		 * We have to put extra_command_line before boot command
 635		 * lines because there could be dashes (separator of init
 636		 * command line) in the command lines.
 637		 */
 638		strcpy(saved_command_line, extra_command_line);
 639		strcpy(static_command_line, extra_command_line);
 640	}
 641	strcpy(saved_command_line + xlen, boot_command_line);
 642	strcpy(static_command_line + xlen, command_line);
 643
 644	if (ilen) {
 645		/*
 646		 * Append supplemental init boot args to saved_command_line
 647		 * so that user can check what command line options passed
 648		 * to init.
 
 
 649		 */
 650		len = strlen(saved_command_line);
 651		if (initargs_found) {
 652			saved_command_line[len++] = ' ';
 
 
 
 653		} else {
 
 654			strcpy(saved_command_line + len, " -- ");
 655			len += 4;
 
 656		}
 657
 658		strcpy(saved_command_line + len, extra_init_args);
 659	}
 
 
 660}
 661
 662/*
 663 * We need to finalize in a non-__init function or else race conditions
 664 * between the root thread and the init thread may cause start_kernel to
 665 * be reaped by free_initmem before the root thread has proceeded to
 666 * cpu_idle.
 667 *
 668 * gcc-3.4 accidentally inlines this function, so use noinline.
 669 */
 670
 671static __initdata DECLARE_COMPLETION(kthreadd_done);
 672
 673noinline void __ref rest_init(void)
 674{
 675	struct task_struct *tsk;
 676	int pid;
 677
 678	rcu_scheduler_starting();
 679	/*
 680	 * We need to spawn init first so that it obtains pid 1, however
 681	 * the init task will end up wanting to create kthreads, which, if
 682	 * we schedule it before we create kthreadd, will OOPS.
 683	 */
 684	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
 685	/*
 686	 * Pin init on the boot CPU. Task migration is not properly working
 687	 * until sched_init_smp() has been run. It will set the allowed
 688	 * CPUs for init to the non isolated CPUs.
 689	 */
 690	rcu_read_lock();
 691	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
 692	tsk->flags |= PF_NO_SETAFFINITY;
 693	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
 694	rcu_read_unlock();
 695
 696	numa_default_policy();
 697	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 698	rcu_read_lock();
 699	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 700	rcu_read_unlock();
 701
 702	/*
 703	 * Enable might_sleep() and smp_processor_id() checks.
 704	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
 705	 * kernel_thread() would trigger might_sleep() splats. With
 706	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
 707	 * already, but it's stuck on the kthreadd_done completion.
 708	 */
 709	system_state = SYSTEM_SCHEDULING;
 710
 711	complete(&kthreadd_done);
 712
 713	/*
 714	 * The boot idle thread must execute schedule()
 715	 * at least once to get things moving:
 716	 */
 717	schedule_preempt_disabled();
 718	/* Call into cpu_idle with preempt disabled */
 719	cpu_startup_entry(CPUHP_ONLINE);
 720}
 721
 722/* Check for early params. */
 723static int __init do_early_param(char *param, char *val,
 724				 const char *unused, void *arg)
 725{
 726	const struct obs_kernel_param *p;
 727
 728	for (p = __setup_start; p < __setup_end; p++) {
 729		if ((p->early && parameq(param, p->str)) ||
 730		    (strcmp(param, "console") == 0 &&
 731		     strcmp(p->str, "earlycon") == 0)
 732		) {
 733			if (p->setup_func(val) != 0)
 734				pr_warn("Malformed early option '%s'\n", param);
 735		}
 736	}
 737	/* We accept everything at this stage. */
 738	return 0;
 739}
 740
 741void __init parse_early_options(char *cmdline)
 742{
 743	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 744		   do_early_param);
 745}
 746
 747/* Arch code calls this early on, or if not, just before other parsing. */
 748void __init parse_early_param(void)
 749{
 750	static int done __initdata;
 751	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 752
 753	if (done)
 754		return;
 755
 756	/* All fall through to do_early_param. */
 757	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 758	parse_early_options(tmp_cmdline);
 759	done = 1;
 760}
 761
 762void __init __weak arch_post_acpi_subsys_init(void) { }
 763
 764void __init __weak smp_setup_processor_id(void)
 765{
 766}
 767
 768# if THREAD_SIZE >= PAGE_SIZE
 769void __init __weak thread_stack_cache_init(void)
 770{
 771}
 772#endif
 773
 774void __init __weak mem_encrypt_init(void) { }
 775
 776void __init __weak poking_init(void) { }
 777
 778void __init __weak pgtable_cache_init(void) { }
 779
 
 
 780bool initcall_debug;
 781core_param(initcall_debug, initcall_debug, bool, 0644);
 782
 783#ifdef TRACEPOINTS_ENABLED
 784static void __init initcall_debug_enable(void);
 785#else
 786static inline void initcall_debug_enable(void)
 787{
 788}
 789#endif
 790
 791/* Report memory auto-initialization states for this boot. */
 792static void __init report_meminit(void)
 793{
 794	const char *stack;
 795
 796	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
 797		stack = "all(pattern)";
 798	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
 799		stack = "all(zero)";
 800	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
 801		stack = "byref_all(zero)";
 802	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
 803		stack = "byref(zero)";
 804	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
 805		stack = "__user(zero)";
 806	else
 807		stack = "off";
 808
 809	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
 810		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
 811		want_init_on_free() ? "on" : "off");
 812	if (want_init_on_free())
 813		pr_info("mem auto-init: clearing system memory may take some time...\n");
 814}
 815
 816/*
 817 * Set up kernel memory allocators
 818 */
 819static void __init mm_init(void)
 820{
 821	/*
 822	 * page_ext requires contiguous pages,
 823	 * bigger than MAX_ORDER unless SPARSEMEM.
 824	 */
 825	page_ext_init_flatmem();
 826	init_mem_debugging_and_hardening();
 827	kfence_alloc_pool();
 828	report_meminit();
 829	stack_depot_init();
 830	mem_init();
 831	mem_init_print_info();
 832	/* page_owner must be initialized after buddy is ready */
 833	page_ext_init_flatmem_late();
 834	kmem_cache_init();
 835	kmemleak_init();
 836	pgtable_init();
 837	debug_objects_mem_init();
 838	vmalloc_init();
 839	/* Should be run before the first non-init thread is created */
 840	init_espfix_bsp();
 841	/* Should be run after espfix64 is set up. */
 842	pti_init();
 843}
 844
 845#ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
 846DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
 847			   randomize_kstack_offset);
 848DEFINE_PER_CPU(u32, kstack_offset);
 849
 850static int __init early_randomize_kstack_offset(char *buf)
 851{
 852	int ret;
 853	bool bool_result;
 854
 855	ret = kstrtobool(buf, &bool_result);
 856	if (ret)
 857		return ret;
 858
 859	if (bool_result)
 860		static_branch_enable(&randomize_kstack_offset);
 861	else
 862		static_branch_disable(&randomize_kstack_offset);
 863	return 0;
 864}
 865early_param("randomize_kstack_offset", early_randomize_kstack_offset);
 866#endif
 867
 868void __init __weak arch_call_rest_init(void)
 869{
 870	rest_init();
 871}
 872
 873static void __init print_unknown_bootoptions(void)
 874{
 875	char *unknown_options;
 876	char *end;
 877	const char *const *p;
 878	size_t len;
 879
 880	if (panic_later || (!argv_init[1] && !envp_init[2]))
 881		return;
 882
 883	/*
 884	 * Determine how many options we have to print out, plus a space
 885	 * before each
 886	 */
 887	len = 1; /* null terminator */
 888	for (p = &argv_init[1]; *p; p++) {
 889		len++;
 890		len += strlen(*p);
 891	}
 892	for (p = &envp_init[2]; *p; p++) {
 893		len++;
 894		len += strlen(*p);
 895	}
 896
 897	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
 898	if (!unknown_options) {
 899		pr_err("%s: Failed to allocate %zu bytes\n",
 900			__func__, len);
 901		return;
 902	}
 903	end = unknown_options;
 904
 905	for (p = &argv_init[1]; *p; p++)
 906		end += sprintf(end, " %s", *p);
 907	for (p = &envp_init[2]; *p; p++)
 908		end += sprintf(end, " %s", *p);
 909
 910	pr_notice("Unknown command line parameters:%s\n", unknown_options);
 911	memblock_free(__pa(unknown_options), len);
 
 
 912}
 913
 914asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 
 915{
 916	char *command_line;
 917	char *after_dashes;
 918
 919	set_task_stack_end_magic(&init_task);
 920	smp_setup_processor_id();
 921	debug_objects_early_init();
 922	init_vmlinux_build_id();
 923
 924	cgroup_init_early();
 925
 926	local_irq_disable();
 927	early_boot_irqs_disabled = true;
 928
 929	/*
 930	 * Interrupts are still disabled. Do necessary setups, then
 931	 * enable them.
 932	 */
 933	boot_cpu_init();
 934	page_address_init();
 935	pr_notice("%s", linux_banner);
 936	early_security_init();
 937	setup_arch(&command_line);
 938	setup_boot_config();
 939	setup_command_line(command_line);
 940	setup_nr_cpu_ids();
 941	setup_per_cpu_areas();
 942	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 943	boot_cpu_hotplug_init();
 944
 945	build_all_zonelists(NULL);
 946	page_alloc_init();
 947
 948	pr_notice("Kernel command line: %s\n", saved_command_line);
 949	/* parameters may set static keys */
 950	jump_label_init();
 951	parse_early_param();
 952	after_dashes = parse_args("Booting kernel",
 953				  static_command_line, __start___param,
 954				  __stop___param - __start___param,
 955				  -1, -1, NULL, &unknown_bootoption);
 956	print_unknown_bootoptions();
 957	if (!IS_ERR_OR_NULL(after_dashes))
 958		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 959			   NULL, set_init_arg);
 960	if (extra_init_args)
 961		parse_args("Setting extra init args", extra_init_args,
 962			   NULL, 0, -1, -1, NULL, set_init_arg);
 963
 
 
 
 964	/*
 965	 * These use large bootmem allocations and must precede
 966	 * kmem_cache_init()
 967	 */
 968	setup_log_buf(0);
 969	vfs_caches_init_early();
 970	sort_main_extable();
 971	trap_init();
 972	mm_init();
 973
 974	ftrace_init();
 975
 976	/* trace_printk can be enabled here */
 977	early_trace_init();
 978
 979	/*
 980	 * Set up the scheduler prior starting any interrupts (such as the
 981	 * timer interrupt). Full topology setup happens at smp_init()
 982	 * time - but meanwhile we still have a functioning scheduler.
 983	 */
 984	sched_init();
 985
 986	if (WARN(!irqs_disabled(),
 987		 "Interrupts were enabled *very* early, fixing it\n"))
 988		local_irq_disable();
 989	radix_tree_init();
 
 990
 991	/*
 992	 * Set up housekeeping before setting up workqueues to allow the unbound
 993	 * workqueue to take non-housekeeping into account.
 994	 */
 995	housekeeping_init();
 996
 997	/*
 998	 * Allow workqueue creation and work item queueing/cancelling
 999	 * early.  Work item execution depends on kthreads and starts after
1000	 * workqueue_init().
1001	 */
1002	workqueue_init_early();
1003
1004	rcu_init();
1005
1006	/* Trace events are available after this */
1007	trace_init();
1008
1009	if (initcall_debug)
1010		initcall_debug_enable();
1011
1012	context_tracking_init();
1013	/* init some links before init_ISA_irqs() */
1014	early_irq_init();
1015	init_IRQ();
1016	tick_init();
1017	rcu_init_nohz();
1018	init_timers();
1019	srcu_init();
1020	hrtimers_init();
1021	softirq_init();
1022	timekeeping_init();
1023	kfence_init();
1024
1025	/*
1026	 * For best initial stack canary entropy, prepare it after:
1027	 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
1028	 * - timekeeping_init() for ktime entropy used in rand_initialize()
1029	 * - rand_initialize() to get any arch-specific entropy like RDRAND
1030	 * - add_latent_entropy() to get any latent entropy
1031	 * - adding command line entropy
1032	 */
1033	rand_initialize();
1034	add_latent_entropy();
1035	add_device_randomness(command_line, strlen(command_line));
1036	boot_init_stack_canary();
1037
1038	time_init();
1039	perf_event_init();
1040	profile_init();
1041	call_function_init();
1042	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1043
1044	early_boot_irqs_disabled = false;
1045	local_irq_enable();
1046
1047	kmem_cache_init_late();
1048
1049	/*
1050	 * HACK ALERT! This is early. We're enabling the console before
1051	 * we've done PCI setups etc, and console_init() must be aware of
1052	 * this. But we do want output early, in case something goes wrong.
1053	 */
1054	console_init();
1055	if (panic_later)
1056		panic("Too many boot %s vars at `%s'", panic_later,
1057		      panic_param);
1058
1059	lockdep_init();
1060
1061	/*
1062	 * Need to run this when irqs are enabled, because it wants
1063	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1064	 * too:
1065	 */
1066	locking_selftest();
1067
1068	/*
1069	 * This needs to be called before any devices perform DMA
1070	 * operations that might use the SWIOTLB bounce buffers. It will
1071	 * mark the bounce buffers as decrypted so that their usage will
1072	 * not cause "plain-text" data to be decrypted when accessed.
1073	 */
1074	mem_encrypt_init();
1075
1076#ifdef CONFIG_BLK_DEV_INITRD
1077	if (initrd_start && !initrd_below_start_ok &&
1078	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1079		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1080		    page_to_pfn(virt_to_page((void *)initrd_start)),
1081		    min_low_pfn);
1082		initrd_start = 0;
1083	}
1084#endif
1085	setup_per_cpu_pageset();
1086	numa_policy_init();
1087	acpi_early_init();
1088	if (late_time_init)
1089		late_time_init();
1090	sched_clock_init();
1091	calibrate_delay();
 
 
 
1092	pid_idr_init();
1093	anon_vma_init();
1094#ifdef CONFIG_X86
1095	if (efi_enabled(EFI_RUNTIME_SERVICES))
1096		efi_enter_virtual_mode();
1097#endif
1098	thread_stack_cache_init();
1099	cred_init();
1100	fork_init();
1101	proc_caches_init();
1102	uts_ns_init();
1103	key_init();
1104	security_init();
1105	dbg_late_init();
 
1106	vfs_caches_init();
1107	pagecache_init();
1108	signals_init();
1109	seq_file_init();
1110	proc_root_init();
1111	nsfs_init();
1112	cpuset_init();
1113	cgroup_init();
1114	taskstats_init_early();
1115	delayacct_init();
1116
1117	poking_init();
1118	check_bugs();
1119
1120	acpi_subsystem_init();
1121	arch_post_acpi_subsys_init();
1122	kcsan_init();
1123
1124	/* Do the rest non-__init'ed, we're now alive */
1125	arch_call_rest_init();
1126
 
 
 
 
 
1127	prevent_tail_call_optimization();
 
1128}
1129
1130/* Call all constructor functions linked into the kernel. */
1131static void __init do_ctors(void)
1132{
1133/*
1134 * For UML, the constructors have already been called by the
1135 * normal setup code as it's just a normal ELF binary, so we
1136 * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1137 * even on UML for modules.
1138 */
1139#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1140	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1141
1142	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1143		(*fn)();
1144#endif
1145}
1146
1147#ifdef CONFIG_KALLSYMS
1148struct blacklist_entry {
1149	struct list_head next;
1150	char *buf;
1151};
1152
1153static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1154
1155static int __init initcall_blacklist(char *str)
1156{
1157	char *str_entry;
1158	struct blacklist_entry *entry;
1159
1160	/* str argument is a comma-separated list of functions */
1161	do {
1162		str_entry = strsep(&str, ",");
1163		if (str_entry) {
1164			pr_debug("blacklisting initcall %s\n", str_entry);
1165			entry = memblock_alloc(sizeof(*entry),
1166					       SMP_CACHE_BYTES);
1167			if (!entry)
1168				panic("%s: Failed to allocate %zu bytes\n",
1169				      __func__, sizeof(*entry));
1170			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1171						    SMP_CACHE_BYTES);
1172			if (!entry->buf)
1173				panic("%s: Failed to allocate %zu bytes\n",
1174				      __func__, strlen(str_entry) + 1);
1175			strcpy(entry->buf, str_entry);
1176			list_add(&entry->next, &blacklisted_initcalls);
1177		}
1178	} while (str_entry);
1179
1180	return 0;
1181}
1182
1183static bool __init_or_module initcall_blacklisted(initcall_t fn)
1184{
1185	struct blacklist_entry *entry;
1186	char fn_name[KSYM_SYMBOL_LEN];
1187	unsigned long addr;
1188
1189	if (list_empty(&blacklisted_initcalls))
1190		return false;
1191
1192	addr = (unsigned long) dereference_function_descriptor(fn);
1193	sprint_symbol_no_offset(fn_name, addr);
1194
1195	/*
1196	 * fn will be "function_name [module_name]" where [module_name] is not
1197	 * displayed for built-in init functions.  Strip off the [module_name].
1198	 */
1199	strreplace(fn_name, ' ', '\0');
1200
1201	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1202		if (!strcmp(fn_name, entry->buf)) {
1203			pr_debug("initcall %s blacklisted\n", fn_name);
1204			return true;
1205		}
1206	}
1207
1208	return false;
1209}
1210#else
1211static int __init initcall_blacklist(char *str)
1212{
1213	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1214	return 0;
1215}
1216
1217static bool __init_or_module initcall_blacklisted(initcall_t fn)
1218{
1219	return false;
1220}
1221#endif
1222__setup("initcall_blacklist=", initcall_blacklist);
1223
1224static __init_or_module void
1225trace_initcall_start_cb(void *data, initcall_t fn)
1226{
1227	ktime_t *calltime = (ktime_t *)data;
1228
1229	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
1230	*calltime = ktime_get();
1231}
1232
1233static __init_or_module void
1234trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1235{
1236	ktime_t *calltime = (ktime_t *)data;
1237	ktime_t delta, rettime;
1238	unsigned long long duration;
1239
1240	rettime = ktime_get();
1241	delta = ktime_sub(rettime, *calltime);
1242	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
1243	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1244		 fn, ret, duration);
1245}
1246
1247static ktime_t initcall_calltime;
1248
1249#ifdef TRACEPOINTS_ENABLED
1250static void __init initcall_debug_enable(void)
1251{
1252	int ret;
1253
1254	ret = register_trace_initcall_start(trace_initcall_start_cb,
1255					    &initcall_calltime);
1256	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1257					      &initcall_calltime);
1258	WARN(ret, "Failed to register initcall tracepoints\n");
1259}
1260# define do_trace_initcall_start	trace_initcall_start
1261# define do_trace_initcall_finish	trace_initcall_finish
1262#else
1263static inline void do_trace_initcall_start(initcall_t fn)
1264{
1265	if (!initcall_debug)
1266		return;
1267	trace_initcall_start_cb(&initcall_calltime, fn);
1268}
1269static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1270{
1271	if (!initcall_debug)
1272		return;
1273	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1274}
1275#endif /* !TRACEPOINTS_ENABLED */
1276
1277int __init_or_module do_one_initcall(initcall_t fn)
1278{
1279	int count = preempt_count();
1280	char msgbuf[64];
1281	int ret;
1282
1283	if (initcall_blacklisted(fn))
1284		return -EPERM;
1285
1286	do_trace_initcall_start(fn);
1287	ret = fn();
1288	do_trace_initcall_finish(fn, ret);
1289
1290	msgbuf[0] = 0;
1291
1292	if (preempt_count() != count) {
1293		sprintf(msgbuf, "preemption imbalance ");
1294		preempt_count_set(count);
1295	}
1296	if (irqs_disabled()) {
1297		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1298		local_irq_enable();
1299	}
1300	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1301
1302	add_latent_entropy();
1303	return ret;
1304}
1305
1306
1307extern initcall_entry_t __initcall_start[];
1308extern initcall_entry_t __initcall0_start[];
1309extern initcall_entry_t __initcall1_start[];
1310extern initcall_entry_t __initcall2_start[];
1311extern initcall_entry_t __initcall3_start[];
1312extern initcall_entry_t __initcall4_start[];
1313extern initcall_entry_t __initcall5_start[];
1314extern initcall_entry_t __initcall6_start[];
1315extern initcall_entry_t __initcall7_start[];
1316extern initcall_entry_t __initcall_end[];
1317
1318static initcall_entry_t *initcall_levels[] __initdata = {
1319	__initcall0_start,
1320	__initcall1_start,
1321	__initcall2_start,
1322	__initcall3_start,
1323	__initcall4_start,
1324	__initcall5_start,
1325	__initcall6_start,
1326	__initcall7_start,
1327	__initcall_end,
1328};
1329
1330/* Keep these in sync with initcalls in include/linux/init.h */
1331static const char *initcall_level_names[] __initdata = {
1332	"pure",
1333	"core",
1334	"postcore",
1335	"arch",
1336	"subsys",
1337	"fs",
1338	"device",
1339	"late",
1340};
1341
1342static int __init ignore_unknown_bootoption(char *param, char *val,
1343			       const char *unused, void *arg)
1344{
1345	return 0;
1346}
1347
1348static void __init do_initcall_level(int level, char *command_line)
1349{
1350	initcall_entry_t *fn;
1351
1352	parse_args(initcall_level_names[level],
1353		   command_line, __start___param,
1354		   __stop___param - __start___param,
1355		   level, level,
1356		   NULL, ignore_unknown_bootoption);
1357
1358	trace_initcall_level(initcall_level_names[level]);
1359	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1360		do_one_initcall(initcall_from_entry(fn));
1361}
1362
1363static void __init do_initcalls(void)
1364{
1365	int level;
1366	size_t len = strlen(saved_command_line) + 1;
1367	char *command_line;
1368
1369	command_line = kzalloc(len, GFP_KERNEL);
1370	if (!command_line)
1371		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1372
1373	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1374		/* Parser modifies command_line, restore it each time */
1375		strcpy(command_line, saved_command_line);
1376		do_initcall_level(level, command_line);
1377	}
1378
1379	kfree(command_line);
1380}
1381
1382/*
1383 * Ok, the machine is now initialized. None of the devices
1384 * have been touched yet, but the CPU subsystem is up and
1385 * running, and memory and process management works.
1386 *
1387 * Now we can finally start doing some real work..
1388 */
1389static void __init do_basic_setup(void)
1390{
1391	cpuset_init_smp();
1392	driver_init();
1393	init_irq_proc();
1394	do_ctors();
1395	do_initcalls();
1396}
1397
1398static void __init do_pre_smp_initcalls(void)
1399{
1400	initcall_entry_t *fn;
1401
1402	trace_initcall_level("early");
1403	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1404		do_one_initcall(initcall_from_entry(fn));
1405}
1406
1407static int run_init_process(const char *init_filename)
1408{
1409	const char *const *p;
1410
1411	argv_init[0] = init_filename;
1412	pr_info("Run %s as init process\n", init_filename);
1413	pr_debug("  with arguments:\n");
1414	for (p = argv_init; *p; p++)
1415		pr_debug("    %s\n", *p);
1416	pr_debug("  with environment:\n");
1417	for (p = envp_init; *p; p++)
1418		pr_debug("    %s\n", *p);
1419	return kernel_execve(init_filename, argv_init, envp_init);
1420}
1421
1422static int try_to_run_init_process(const char *init_filename)
1423{
1424	int ret;
1425
1426	ret = run_init_process(init_filename);
1427
1428	if (ret && ret != -ENOENT) {
1429		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1430		       init_filename, ret);
1431	}
1432
1433	return ret;
1434}
1435
1436static noinline void __init kernel_init_freeable(void);
1437
1438#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1439bool rodata_enabled __ro_after_init = true;
 
 
 
 
 
1440static int __init set_debug_rodata(char *str)
1441{
1442	return strtobool(str, &rodata_enabled);
 
 
 
 
 
 
 
 
 
1443}
1444__setup("rodata=", set_debug_rodata);
1445#endif
1446
1447#ifdef CONFIG_STRICT_KERNEL_RWX
1448static void mark_readonly(void)
1449{
1450	if (rodata_enabled) {
1451		/*
1452		 * load_module() results in W+X mappings, which are cleaned
1453		 * up with call_rcu().  Let's make sure that queued work is
1454		 * flushed so that we don't hit false positives looking for
1455		 * insecure pages which are W+X.
1456		 */
1457		rcu_barrier();
1458		mark_rodata_ro();
1459		rodata_test();
1460	} else
1461		pr_info("Kernel memory protection disabled.\n");
1462}
1463#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1464static inline void mark_readonly(void)
1465{
1466	pr_warn("Kernel memory protection not selected by kernel config.\n");
1467}
1468#else
1469static inline void mark_readonly(void)
1470{
1471	pr_warn("This architecture does not have kernel memory protection.\n");
1472}
1473#endif
1474
1475void __weak free_initmem(void)
1476{
1477	free_initmem_default(POISON_FREE_INITMEM);
1478}
1479
1480static int __ref kernel_init(void *unused)
1481{
1482	int ret;
1483
1484	/*
1485	 * Wait until kthreadd is all set-up.
1486	 */
1487	wait_for_completion(&kthreadd_done);
1488
1489	kernel_init_freeable();
1490	/* need to finish all async __init code before freeing the memory */
1491	async_synchronize_full();
 
 
1492	kprobe_free_init_mem();
1493	ftrace_free_init_mem();
1494	kgdb_free_init_mem();
 
1495	free_initmem();
1496	mark_readonly();
1497
1498	/*
1499	 * Kernel mappings are now finalized - update the userspace page-table
1500	 * to finalize PTI.
1501	 */
1502	pti_finalize();
1503
1504	system_state = SYSTEM_RUNNING;
1505	numa_default_policy();
1506
1507	rcu_end_inkernel_boot();
1508
1509	do_sysctl_args();
1510
1511	if (ramdisk_execute_command) {
1512		ret = run_init_process(ramdisk_execute_command);
1513		if (!ret)
1514			return 0;
1515		pr_err("Failed to execute %s (error %d)\n",
1516		       ramdisk_execute_command, ret);
1517	}
1518
1519	/*
1520	 * We try each of these until one succeeds.
1521	 *
1522	 * The Bourne shell can be used instead of init if we are
1523	 * trying to recover a really broken machine.
1524	 */
1525	if (execute_command) {
1526		ret = run_init_process(execute_command);
1527		if (!ret)
1528			return 0;
1529		panic("Requested init %s failed (error %d).",
1530		      execute_command, ret);
1531	}
1532
1533	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1534		ret = run_init_process(CONFIG_DEFAULT_INIT);
1535		if (ret)
1536			pr_err("Default init %s failed (error %d)\n",
1537			       CONFIG_DEFAULT_INIT, ret);
1538		else
1539			return 0;
1540	}
1541
1542	if (!try_to_run_init_process("/sbin/init") ||
1543	    !try_to_run_init_process("/etc/init") ||
1544	    !try_to_run_init_process("/bin/init") ||
1545	    !try_to_run_init_process("/bin/sh"))
1546		return 0;
1547
1548	panic("No working init found.  Try passing init= option to kernel. "
1549	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1550}
1551
1552/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1553void __init console_on_rootfs(void)
1554{
1555	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1556
1557	if (IS_ERR(file)) {
1558		pr_err("Warning: unable to open an initial console.\n");
1559		return;
1560	}
1561	init_dup(file);
1562	init_dup(file);
1563	init_dup(file);
1564	fput(file);
1565}
1566
1567static noinline void __init kernel_init_freeable(void)
1568{
1569	/* Now the scheduler is fully set up and can do blocking allocations */
1570	gfp_allowed_mask = __GFP_BITS_MASK;
1571
1572	/*
1573	 * init can allocate pages on any node
1574	 */
1575	set_mems_allowed(node_states[N_MEMORY]);
1576
1577	cad_pid = get_pid(task_pid(current));
1578
1579	smp_prepare_cpus(setup_max_cpus);
1580
1581	workqueue_init();
1582
1583	init_mm_internals();
1584
1585	rcu_init_tasks_generic();
1586	do_pre_smp_initcalls();
1587	lockup_detector_init();
1588
1589	smp_init();
1590	sched_init_smp();
1591
 
1592	padata_init();
1593	page_alloc_init_late();
1594	/* Initialize page ext after all struct pages are initialized. */
1595	page_ext_init();
1596
1597	do_basic_setup();
1598
1599	kunit_run_all_tests();
1600
1601	wait_for_initramfs();
1602	console_on_rootfs();
1603
1604	/*
1605	 * check if there is an early userspace init.  If yes, let it do all
1606	 * the work
1607	 */
1608	if (init_eaccess(ramdisk_execute_command) != 0) {
1609		ramdisk_execute_command = NULL;
1610		prepare_namespace();
1611	}
1612
1613	/*
1614	 * Ok, we have completed the initial bootup, and
1615	 * we're essentially up and running. Get rid of the
1616	 * initmem segments and start the user-mode stuff..
1617	 *
1618	 * rootfs is available now, try loading the public keys
1619	 * and default modules
1620	 */
1621
1622	integrity_load_keys();
1623}