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/page_ext.h>
  66#include <linux/debug_locks.h>
  67#include <linux/debugobjects.h>
  68#include <linux/lockdep.h>
  69#include <linux/kmemleak.h>
  70#include <linux/padata.h>
  71#include <linux/pid_namespace.h>
  72#include <linux/device/driver.h>
  73#include <linux/kthread.h>
  74#include <linux/sched.h>
  75#include <linux/sched/init.h>
  76#include <linux/signal.h>
  77#include <linux/idr.h>
  78#include <linux/kgdb.h>
  79#include <linux/ftrace.h>
  80#include <linux/async.h>
 
  81#include <linux/shmem_fs.h>
  82#include <linux/slab.h>
  83#include <linux/perf_event.h>
  84#include <linux/ptrace.h>
  85#include <linux/pti.h>
  86#include <linux/blkdev.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#include <linux/randomize_kstack.h>
 104#include <net/net_namespace.h>
 105
 106#include <asm/io.h>
 107#include <asm/bugs.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
 119extern void init_IRQ(void);
 120extern void radix_tree_init(void);
 121extern void maple_tree_init(void);
 122
 123/*
 124 * Debug helper: via this flag we know that we are in 'early bootup code'
 125 * where only the boot processor is running with IRQ disabled.  This means
 126 * two things - IRQ must not be enabled before the flag is cleared and some
 127 * operations which are not allowed with IRQ disabled are allowed while the
 128 * flag is set.
 129 */
 130bool early_boot_irqs_disabled __read_mostly;
 131
 132enum system_states system_state __read_mostly;
 133EXPORT_SYMBOL(system_state);
 134
 135/*
 136 * Boot command-line arguments
 137 */
 138#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 139#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 140
 141extern void time_init(void);
 142/* Default late time init is NULL. archs can override this later. */
 143void (*__initdata late_time_init)(void);
 144
 145/* Untouched command line saved by arch-specific code. */
 146char __initdata boot_command_line[COMMAND_LINE_SIZE];
 147/* Untouched saved command line (eg. for /proc) */
 148char *saved_command_line __ro_after_init;
 149unsigned int saved_command_line_len __ro_after_init;
 150/* Command line for parameter parsing */
 151static char *static_command_line;
 152/* Untouched extra command line */
 153static char *extra_command_line;
 154/* Extra init arguments */
 155static char *extra_init_args;
 156
 157#ifdef CONFIG_BOOT_CONFIG
 158/* Is bootconfig on command line? */
 159static bool bootconfig_found;
 160static size_t initargs_offs;
 161#else
 162# define bootconfig_found false
 163# define initargs_offs 0
 164#endif
 165
 166static char *execute_command;
 167static char *ramdisk_execute_command = "/init";
 168
 169/*
 170 * Used to generate warnings if static_key manipulation functions are used
 171 * before jump_label_init is called.
 172 */
 173bool static_key_initialized __read_mostly;
 174EXPORT_SYMBOL_GPL(static_key_initialized);
 175
 176/*
 177 * If set, this is an indication to the drivers that reset the underlying
 178 * device before going ahead with the initialization otherwise driver might
 179 * rely on the BIOS and skip the reset operation.
 180 *
 181 * This is useful if kernel is booting in an unreliable environment.
 182 * For ex. kdump situation where previous kernel has crashed, BIOS has been
 183 * skipped and devices will be in unknown state.
 184 */
 185unsigned int reset_devices;
 186EXPORT_SYMBOL(reset_devices);
 187
 188static int __init set_reset_devices(char *str)
 189{
 190	reset_devices = 1;
 191	return 1;
 192}
 193
 194__setup("reset_devices", set_reset_devices);
 195
 196static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 197const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 198static const char *panic_later, *panic_param;
 199
 200extern const struct obs_kernel_param __setup_start[], __setup_end[];
 201
 202static bool __init obsolete_checksetup(char *line)
 203{
 204	const struct obs_kernel_param *p;
 205	bool had_early_param = false;
 206
 207	p = __setup_start;
 208	do {
 209		int n = strlen(p->str);
 210		if (parameqn(line, p->str, n)) {
 211			if (p->early) {
 212				/* Already done in parse_early_param?
 213				 * (Needs exact match on param part).
 214				 * Keep iterating, as we can have early
 215				 * params and __setups of same names 8( */
 216				if (line[n] == '\0' || line[n] == '=')
 217					had_early_param = true;
 218			} else if (!p->setup_func) {
 219				pr_warn("Parameter %s is obsolete, ignored\n",
 220					p->str);
 221				return true;
 222			} else if (p->setup_func(line + n))
 223				return true;
 224		}
 225		p++;
 226	} while (p < __setup_end);
 227
 228	return had_early_param;
 229}
 230
 231/*
 232 * This should be approx 2 Bo*oMips to start (note initial shift), and will
 233 * still work even if initially too large, it will just take slightly longer
 234 */
 235unsigned long loops_per_jiffy = (1<<12);
 236EXPORT_SYMBOL(loops_per_jiffy);
 237
 238static int __init debug_kernel(char *str)
 239{
 240	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 241	return 0;
 242}
 243
 244static int __init quiet_kernel(char *str)
 245{
 246	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 247	return 0;
 248}
 249
 250early_param("debug", debug_kernel);
 251early_param("quiet", quiet_kernel);
 252
 253static int __init loglevel(char *str)
 254{
 255	int newlevel;
 256
 257	/*
 258	 * Only update loglevel value when a correct setting was passed,
 259	 * to prevent blind crashes (when loglevel being set to 0) that
 260	 * are quite hard to debug
 261	 */
 262	if (get_option(&str, &newlevel)) {
 263		console_loglevel = newlevel;
 264		return 0;
 265	}
 266
 267	return -EINVAL;
 268}
 269
 270early_param("loglevel", loglevel);
 271
 272#ifdef CONFIG_BLK_DEV_INITRD
 273static void * __init get_boot_config_from_initrd(size_t *_size)
 274{
 275	u32 size, csum;
 276	char *data;
 277	u32 *hdr;
 278	int i;
 279
 280	if (!initrd_end)
 281		return NULL;
 282
 283	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
 284	/*
 285	 * Since Grub may align the size of initrd to 4, we must
 286	 * check the preceding 3 bytes as well.
 287	 */
 288	for (i = 0; i < 4; i++) {
 289		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
 290			goto found;
 291		data--;
 292	}
 293	return NULL;
 294
 295found:
 296	hdr = (u32 *)(data - 8);
 297	size = le32_to_cpu(hdr[0]);
 298	csum = le32_to_cpu(hdr[1]);
 299
 300	data = ((void *)hdr) - size;
 301	if ((unsigned long)data < initrd_start) {
 302		pr_err("bootconfig size %d is greater than initrd size %ld\n",
 303			size, initrd_end - initrd_start);
 304		return NULL;
 305	}
 306
 307	if (xbc_calc_checksum(data, size) != csum) {
 308		pr_err("bootconfig checksum failed\n");
 309		return NULL;
 310	}
 311
 312	/* Remove bootconfig from initramfs/initrd */
 313	initrd_end = (unsigned long)data;
 314	if (_size)
 315		*_size = size;
 
 
 316
 317	return data;
 318}
 319#else
 320static void * __init get_boot_config_from_initrd(size_t *_size)
 321{
 322	return NULL;
 323}
 324#endif
 325
 326#ifdef CONFIG_BOOT_CONFIG
 327
 328static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
 329
 330#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
 331
 332static int __init xbc_snprint_cmdline(char *buf, size_t size,
 333				      struct xbc_node *root)
 334{
 335	struct xbc_node *knode, *vnode;
 336	char *end = buf + size;
 337	const char *val;
 338	int ret;
 339
 340	xbc_node_for_each_key_value(root, knode, val) {
 341		ret = xbc_node_compose_key_after(root, knode,
 342					xbc_namebuf, XBC_KEYLEN_MAX);
 343		if (ret < 0)
 344			return ret;
 345
 346		vnode = xbc_node_get_child(knode);
 347		if (!vnode) {
 348			ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
 349			if (ret < 0)
 350				return ret;
 351			buf += ret;
 352			continue;
 353		}
 354		xbc_array_for_each_value(vnode, val) {
 355			ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
 356				       xbc_namebuf, val);
 357			if (ret < 0)
 358				return ret;
 359			buf += ret;
 360		}
 361	}
 362
 363	return buf - (end - size);
 364}
 365#undef rest
 366
 367/* Make an extra command line under given key word */
 368static char * __init xbc_make_cmdline(const char *key)
 369{
 370	struct xbc_node *root;
 371	char *new_cmdline;
 372	int ret, len = 0;
 373
 374	root = xbc_find_node(key);
 375	if (!root)
 376		return NULL;
 377
 378	/* Count required buffer size */
 379	len = xbc_snprint_cmdline(NULL, 0, root);
 380	if (len <= 0)
 381		return NULL;
 382
 383	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
 384	if (!new_cmdline) {
 385		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
 386		return NULL;
 387	}
 388
 389	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
 390	if (ret < 0 || ret > len) {
 391		pr_err("Failed to print extra kernel cmdline.\n");
 392		memblock_free(new_cmdline, len + 1);
 393		return NULL;
 394	}
 395
 396	return new_cmdline;
 397}
 398
 
 
 
 
 
 
 
 
 
 
 399static int __init bootconfig_params(char *param, char *val,
 400				    const char *unused, void *arg)
 401{
 402	if (strcmp(param, "bootconfig") == 0) {
 403		bootconfig_found = true;
 404	}
 405	return 0;
 406}
 407
 408static int __init warn_bootconfig(char *str)
 409{
 410	/* The 'bootconfig' has been handled by bootconfig_params(). */
 411	return 0;
 412}
 413
 414static void __init setup_boot_config(void)
 415{
 416	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 417	const char *msg, *data;
 418	int pos, ret;
 419	size_t size;
 420	char *err;
 
 421
 422	/* Cut out the bootconfig data even if we have no bootconfig option */
 423	data = get_boot_config_from_initrd(&size);
 424	/* If there is no bootconfig in initrd, try embedded one. */
 425	if (!data)
 426		data = xbc_get_embedded_bootconfig(&size);
 427
 428	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 429	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
 430			 bootconfig_params);
 431
 432	if (IS_ERR(err) || !bootconfig_found)
 433		return;
 434
 435	/* parse_args() stops at the next param of '--' and returns an address */
 436	if (err)
 437		initargs_offs = err - tmp_cmdline;
 438
 439	if (!data) {
 440		pr_err("'bootconfig' found on command line, but no bootconfig found\n");
 441		return;
 442	}
 443
 444	if (size >= XBC_DATA_MAX) {
 445		pr_err("bootconfig size %ld greater than max size %d\n",
 446			(long)size, XBC_DATA_MAX);
 
 
 
 
 
 
 
 
 
 
 
 447		return;
 448	}
 449
 450	ret = xbc_init(data, size, &msg, &pos);
 
 
 
 451	if (ret < 0) {
 452		if (pos < 0)
 453			pr_err("Failed to init bootconfig: %s.\n", msg);
 454		else
 455			pr_err("Failed to parse bootconfig: %s at %d.\n",
 456				msg, pos);
 457	} else {
 458		xbc_get_info(&ret, NULL);
 459		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
 460		/* keys starting with "kernel." are passed via cmdline */
 461		extra_command_line = xbc_make_cmdline("kernel");
 462		/* Also, "init." keys are init arguments */
 463		extra_init_args = xbc_make_cmdline("init");
 464	}
 465	return;
 466}
 467
 468static void __init exit_boot_config(void)
 469{
 470	xbc_exit();
 471}
 472
 473#else	/* !CONFIG_BOOT_CONFIG */
 474
 475static void __init setup_boot_config(void)
 476{
 477	/* Remove bootconfig data from initrd */
 478	get_boot_config_from_initrd(NULL);
 479}
 480
 481static int __init warn_bootconfig(char *str)
 482{
 483	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 484	return 0;
 485}
 486
 487#define exit_boot_config()	do {} while (0)
 488
 489#endif	/* CONFIG_BOOT_CONFIG */
 490
 491early_param("bootconfig", warn_bootconfig);
 492
 
 
 493/* Change NUL term back to "=", to make "param" the whole string. */
 494static void __init repair_env_string(char *param, char *val)
 495{
 496	if (val) {
 497		/* param=val or param="val"? */
 498		if (val == param+strlen(param)+1)
 499			val[-1] = '=';
 500		else if (val == param+strlen(param)+2) {
 501			val[-2] = '=';
 502			memmove(val-1, val, strlen(val)+1);
 503		} else
 504			BUG();
 505	}
 506}
 507
 508/* Anything after -- gets handed straight to init. */
 509static int __init set_init_arg(char *param, char *val,
 510			       const char *unused, void *arg)
 511{
 512	unsigned int i;
 513
 514	if (panic_later)
 515		return 0;
 516
 517	repair_env_string(param, val);
 518
 519	for (i = 0; argv_init[i]; i++) {
 520		if (i == MAX_INIT_ARGS) {
 521			panic_later = "init";
 522			panic_param = param;
 523			return 0;
 524		}
 525	}
 526	argv_init[i] = param;
 527	return 0;
 528}
 529
 530/*
 531 * Unknown boot options get handed to init, unless they look like
 532 * unused parameters (modprobe will find them in /proc/cmdline).
 533 */
 534static int __init unknown_bootoption(char *param, char *val,
 535				     const char *unused, void *arg)
 536{
 537	size_t len = strlen(param);
 538
 539	repair_env_string(param, val);
 540
 541	/* Handle obsolete-style parameters */
 542	if (obsolete_checksetup(param))
 543		return 0;
 544
 545	/* Unused module parameter. */
 546	if (strnchr(param, len, '.'))
 547		return 0;
 548
 549	if (panic_later)
 550		return 0;
 551
 552	if (val) {
 553		/* Environment option */
 554		unsigned int i;
 555		for (i = 0; envp_init[i]; i++) {
 556			if (i == MAX_INIT_ENVS) {
 557				panic_later = "env";
 558				panic_param = param;
 559			}
 560			if (!strncmp(param, envp_init[i], len+1))
 561				break;
 562		}
 563		envp_init[i] = param;
 564	} else {
 565		/* Command line option */
 566		unsigned int i;
 567		for (i = 0; argv_init[i]; i++) {
 568			if (i == MAX_INIT_ARGS) {
 569				panic_later = "init";
 570				panic_param = param;
 571			}
 572		}
 573		argv_init[i] = param;
 574	}
 575	return 0;
 576}
 577
 578static int __init init_setup(char *str)
 579{
 580	unsigned int i;
 581
 582	execute_command = str;
 583	/*
 584	 * In case LILO is going to boot us with default command line,
 585	 * it prepends "auto" before the whole cmdline which makes
 586	 * the shell think it should execute a script with such name.
 587	 * So we ignore all arguments entered _before_ init=... [MJ]
 588	 */
 589	for (i = 1; i < MAX_INIT_ARGS; i++)
 590		argv_init[i] = NULL;
 591	return 1;
 592}
 593__setup("init=", init_setup);
 594
 595static int __init rdinit_setup(char *str)
 596{
 597	unsigned int i;
 598
 599	ramdisk_execute_command = str;
 600	/* See "auto" comment in init_setup */
 601	for (i = 1; i < MAX_INIT_ARGS; i++)
 602		argv_init[i] = NULL;
 603	return 1;
 604}
 605__setup("rdinit=", rdinit_setup);
 606
 607#ifndef CONFIG_SMP
 608static const unsigned int setup_max_cpus = NR_CPUS;
 609static inline void setup_nr_cpu_ids(void) { }
 610static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 611#endif
 612
 613/*
 614 * We need to store the untouched command line for future reference.
 615 * We also need to store the touched command line since the parameter
 616 * parsing is performed in place, and we should allow a component to
 617 * store reference of name/value for future reference.
 618 */
 619static void __init setup_command_line(char *command_line)
 620{
 621	size_t len, xlen = 0, ilen = 0;
 622
 623	if (extra_command_line)
 624		xlen = strlen(extra_command_line);
 625	if (extra_init_args)
 626		ilen = strlen(extra_init_args) + 4; /* for " -- " */
 627
 628	len = xlen + strlen(boot_command_line) + 1;
 629
 630	saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
 631	if (!saved_command_line)
 632		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
 633
 634	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 635	if (!static_command_line)
 636		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 637
 638	if (xlen) {
 639		/*
 640		 * We have to put extra_command_line before boot command
 641		 * lines because there could be dashes (separator of init
 642		 * command line) in the command lines.
 643		 */
 644		strcpy(saved_command_line, extra_command_line);
 645		strcpy(static_command_line, extra_command_line);
 646	}
 647	strcpy(saved_command_line + xlen, boot_command_line);
 648	strcpy(static_command_line + xlen, command_line);
 649
 650	if (ilen) {
 651		/*
 652		 * Append supplemental init boot args to saved_command_line
 653		 * so that user can check what command line options passed
 654		 * to init.
 655		 * The order should always be
 656		 * " -- "[bootconfig init-param][cmdline init-param]
 657		 */
 658		if (initargs_offs) {
 659			len = xlen + initargs_offs;
 660			strcpy(saved_command_line + len, extra_init_args);
 661			len += ilen - 4;	/* strlen(extra_init_args) */
 662			strcpy(saved_command_line + len,
 663				boot_command_line + initargs_offs - 1);
 664		} else {
 665			len = strlen(saved_command_line);
 666			strcpy(saved_command_line + len, " -- ");
 667			len += 4;
 668			strcpy(saved_command_line + len, extra_init_args);
 669		}
 670	}
 671
 672	saved_command_line_len = strlen(saved_command_line);
 
 673}
 674
 675/*
 676 * We need to finalize in a non-__init function or else race conditions
 677 * between the root thread and the init thread may cause start_kernel to
 678 * be reaped by free_initmem before the root thread has proceeded to
 679 * cpu_idle.
 680 *
 681 * gcc-3.4 accidentally inlines this function, so use noinline.
 682 */
 683
 684static __initdata DECLARE_COMPLETION(kthreadd_done);
 685
 686noinline void __ref rest_init(void)
 687{
 688	struct task_struct *tsk;
 689	int pid;
 690
 691	rcu_scheduler_starting();
 692	/*
 693	 * We need to spawn init first so that it obtains pid 1, however
 694	 * the init task will end up wanting to create kthreads, which, if
 695	 * we schedule it before we create kthreadd, will OOPS.
 696	 */
 697	pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
 698	/*
 699	 * Pin init on the boot CPU. Task migration is not properly working
 700	 * until sched_init_smp() has been run. It will set the allowed
 701	 * CPUs for init to the non isolated CPUs.
 702	 */
 703	rcu_read_lock();
 704	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
 705	tsk->flags |= PF_NO_SETAFFINITY;
 706	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
 707	rcu_read_unlock();
 708
 709	numa_default_policy();
 710	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 711	rcu_read_lock();
 712	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 713	rcu_read_unlock();
 714
 715	/*
 716	 * Enable might_sleep() and smp_processor_id() checks.
 717	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
 718	 * kernel_thread() would trigger might_sleep() splats. With
 719	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
 720	 * already, but it's stuck on the kthreadd_done completion.
 721	 */
 722	system_state = SYSTEM_SCHEDULING;
 723
 724	complete(&kthreadd_done);
 725
 726	/*
 727	 * The boot idle thread must execute schedule()
 728	 * at least once to get things moving:
 729	 */
 730	schedule_preempt_disabled();
 731	/* Call into cpu_idle with preempt disabled */
 732	cpu_startup_entry(CPUHP_ONLINE);
 733}
 734
 735/* Check for early params. */
 736static int __init do_early_param(char *param, char *val,
 737				 const char *unused, void *arg)
 738{
 739	const struct obs_kernel_param *p;
 740
 741	for (p = __setup_start; p < __setup_end; p++) {
 742		if ((p->early && parameq(param, p->str)) ||
 743		    (strcmp(param, "console") == 0 &&
 744		     strcmp(p->str, "earlycon") == 0)
 745		) {
 746			if (p->setup_func(val) != 0)
 747				pr_warn("Malformed early option '%s'\n", param);
 748		}
 749	}
 750	/* We accept everything at this stage. */
 751	return 0;
 752}
 753
 754void __init parse_early_options(char *cmdline)
 755{
 756	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 757		   do_early_param);
 758}
 759
 760/* Arch code calls this early on, or if not, just before other parsing. */
 761void __init parse_early_param(void)
 762{
 763	static int done __initdata;
 764	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 765
 766	if (done)
 767		return;
 768
 769	/* All fall through to do_early_param. */
 770	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 771	parse_early_options(tmp_cmdline);
 772	done = 1;
 773}
 774
 775void __init __weak arch_post_acpi_subsys_init(void) { }
 776
 777void __init __weak smp_setup_processor_id(void)
 778{
 779}
 780
 781# if THREAD_SIZE >= PAGE_SIZE
 782void __init __weak thread_stack_cache_init(void)
 783{
 784}
 785#endif
 786
 787void __init __weak mem_encrypt_init(void) { }
 788
 789void __init __weak poking_init(void) { }
 790
 791void __init __weak pgtable_cache_init(void) { }
 792
 793void __init __weak trap_init(void) { }
 794
 795bool initcall_debug;
 796core_param(initcall_debug, initcall_debug, bool, 0644);
 797
 798#ifdef TRACEPOINTS_ENABLED
 799static void __init initcall_debug_enable(void);
 800#else
 801static inline void initcall_debug_enable(void)
 802{
 803}
 804#endif
 805
 806/* Report memory auto-initialization states for this boot. */
 807static void __init report_meminit(void)
 808{
 809	const char *stack;
 810
 811	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
 812		stack = "all(pattern)";
 813	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
 814		stack = "all(zero)";
 815	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
 816		stack = "byref_all(zero)";
 817	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
 818		stack = "byref(zero)";
 819	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
 820		stack = "__user(zero)";
 821	else
 822		stack = "off";
 823
 824	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
 825		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
 826		want_init_on_free() ? "on" : "off");
 827	if (want_init_on_free())
 828		pr_info("mem auto-init: clearing system memory may take some time...\n");
 829}
 830
 831/*
 832 * Set up kernel memory allocators
 833 */
 834static void __init mm_init(void)
 835{
 836	/*
 837	 * page_ext requires contiguous pages,
 838	 * bigger than MAX_ORDER unless SPARSEMEM.
 839	 */
 840	page_ext_init_flatmem();
 841	init_mem_debugging_and_hardening();
 842	kfence_alloc_pool();
 843	report_meminit();
 844	kmsan_init_shadow();
 845	stack_depot_early_init();
 846	mem_init();
 847	mem_init_print_info();
 848	kmem_cache_init();
 849	/*
 850	 * page_owner must be initialized after buddy is ready, and also after
 851	 * slab is ready so that stack_depot_init() works properly
 852	 */
 853	page_ext_init_flatmem_late();
 854	kmemleak_init();
 855	pgtable_init();
 856	debug_objects_mem_init();
 857	vmalloc_init();
 858	/* Should be run after vmap initialization */
 859	if (early_page_ext_enabled())
 860		page_ext_init();
 861	/* Should be run before the first non-init thread is created */
 862	init_espfix_bsp();
 863	/* Should be run after espfix64 is set up. */
 864	pti_init();
 865	kmsan_init_runtime();
 866	mm_cache_init();
 867}
 868
 869#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
 870DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
 871			   randomize_kstack_offset);
 872DEFINE_PER_CPU(u32, kstack_offset);
 873
 874static int __init early_randomize_kstack_offset(char *buf)
 875{
 876	int ret;
 877	bool bool_result;
 878
 879	ret = kstrtobool(buf, &bool_result);
 880	if (ret)
 881		return ret;
 882
 883	if (bool_result)
 884		static_branch_enable(&randomize_kstack_offset);
 885	else
 886		static_branch_disable(&randomize_kstack_offset);
 887	return 0;
 888}
 889early_param("randomize_kstack_offset", early_randomize_kstack_offset);
 890#endif
 891
 892void __init __weak arch_call_rest_init(void)
 893{
 894	rest_init();
 895}
 896
 897static void __init print_unknown_bootoptions(void)
 898{
 899	char *unknown_options;
 900	char *end;
 901	const char *const *p;
 902	size_t len;
 903
 904	if (panic_later || (!argv_init[1] && !envp_init[2]))
 905		return;
 906
 907	/*
 908	 * Determine how many options we have to print out, plus a space
 909	 * before each
 910	 */
 911	len = 1; /* null terminator */
 912	for (p = &argv_init[1]; *p; p++) {
 913		len++;
 914		len += strlen(*p);
 915	}
 916	for (p = &envp_init[2]; *p; p++) {
 917		len++;
 918		len += strlen(*p);
 919	}
 920
 921	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
 922	if (!unknown_options) {
 923		pr_err("%s: Failed to allocate %zu bytes\n",
 924			__func__, len);
 925		return;
 926	}
 927	end = unknown_options;
 928
 929	for (p = &argv_init[1]; *p; p++)
 930		end += sprintf(end, " %s", *p);
 931	for (p = &envp_init[2]; *p; p++)
 932		end += sprintf(end, " %s", *p);
 933
 934	/* Start at unknown_options[1] to skip the initial space */
 935	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
 936		&unknown_options[1]);
 937	memblock_free(unknown_options, len);
 938}
 939
 940asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 941{
 942	char *command_line;
 943	char *after_dashes;
 944
 945	set_task_stack_end_magic(&init_task);
 946	smp_setup_processor_id();
 947	debug_objects_early_init();
 948	init_vmlinux_build_id();
 949
 950	cgroup_init_early();
 951
 952	local_irq_disable();
 953	early_boot_irqs_disabled = true;
 954
 955	/*
 956	 * Interrupts are still disabled. Do necessary setups, then
 957	 * enable them.
 958	 */
 959	boot_cpu_init();
 960	page_address_init();
 961	pr_notice("%s", linux_banner);
 962	early_security_init();
 963	setup_arch(&command_line);
 964	setup_boot_config();
 965	setup_command_line(command_line);
 966	setup_nr_cpu_ids();
 967	setup_per_cpu_areas();
 968	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 969	boot_cpu_hotplug_init();
 970
 971	build_all_zonelists(NULL);
 972	page_alloc_init();
 973
 974	pr_notice("Kernel command line: %s\n", saved_command_line);
 975	/* parameters may set static keys */
 976	jump_label_init();
 977	parse_early_param();
 978	after_dashes = parse_args("Booting kernel",
 979				  static_command_line, __start___param,
 980				  __stop___param - __start___param,
 981				  -1, -1, NULL, &unknown_bootoption);
 982	print_unknown_bootoptions();
 983	if (!IS_ERR_OR_NULL(after_dashes))
 984		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 985			   NULL, set_init_arg);
 986	if (extra_init_args)
 987		parse_args("Setting extra init args", extra_init_args,
 988			   NULL, 0, -1, -1, NULL, set_init_arg);
 989
 990	/* Architectural and non-timekeeping rng init, before allocator init */
 991	random_init_early(command_line);
 992
 993	/*
 994	 * These use large bootmem allocations and must precede
 995	 * kmem_cache_init()
 996	 */
 997	setup_log_buf(0);
 998	vfs_caches_init_early();
 999	sort_main_extable();
1000	trap_init();
1001	mm_init();
1002	poking_init();
1003	ftrace_init();
1004
1005	/* trace_printk can be enabled here */
1006	early_trace_init();
1007
1008	/*
1009	 * Set up the scheduler prior starting any interrupts (such as the
1010	 * timer interrupt). Full topology setup happens at smp_init()
1011	 * time - but meanwhile we still have a functioning scheduler.
1012	 */
1013	sched_init();
1014
 
 
 
 
1015	if (WARN(!irqs_disabled(),
1016		 "Interrupts were enabled *very* early, fixing it\n"))
1017		local_irq_disable();
1018	radix_tree_init();
1019	maple_tree_init();
1020
1021	/*
1022	 * Set up housekeeping before setting up workqueues to allow the unbound
1023	 * workqueue to take non-housekeeping into account.
1024	 */
1025	housekeeping_init();
1026
1027	/*
1028	 * Allow workqueue creation and work item queueing/cancelling
1029	 * early.  Work item execution depends on kthreads and starts after
1030	 * workqueue_init().
1031	 */
1032	workqueue_init_early();
1033
1034	rcu_init();
1035
1036	/* Trace events are available after this */
1037	trace_init();
1038
1039	if (initcall_debug)
1040		initcall_debug_enable();
1041
1042	context_tracking_init();
1043	/* init some links before init_ISA_irqs() */
1044	early_irq_init();
1045	init_IRQ();
1046	tick_init();
1047	rcu_init_nohz();
1048	init_timers();
1049	srcu_init();
1050	hrtimers_init();
1051	softirq_init();
1052	timekeeping_init();
1053	time_init();
1054
1055	/* This must be after timekeeping is initialized */
1056	random_init();
1057
1058	/* These make use of the fully initialized rng */
1059	kfence_init();
 
 
 
 
 
 
 
 
 
1060	boot_init_stack_canary();
1061
 
1062	perf_event_init();
1063	profile_init();
1064	call_function_init();
1065	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1066
1067	early_boot_irqs_disabled = false;
1068	local_irq_enable();
1069
1070	kmem_cache_init_late();
1071
1072	/*
1073	 * HACK ALERT! This is early. We're enabling the console before
1074	 * we've done PCI setups etc, and console_init() must be aware of
1075	 * this. But we do want output early, in case something goes wrong.
1076	 */
1077	console_init();
1078	if (panic_later)
1079		panic("Too many boot %s vars at `%s'", panic_later,
1080		      panic_param);
1081
1082	lockdep_init();
1083
1084	/*
1085	 * Need to run this when irqs are enabled, because it wants
1086	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1087	 * too:
1088	 */
1089	locking_selftest();
1090
1091	/*
1092	 * This needs to be called before any devices perform DMA
1093	 * operations that might use the SWIOTLB bounce buffers. It will
1094	 * mark the bounce buffers as decrypted so that their usage will
1095	 * not cause "plain-text" data to be decrypted when accessed.
1096	 */
1097	mem_encrypt_init();
1098
1099#ifdef CONFIG_BLK_DEV_INITRD
1100	if (initrd_start && !initrd_below_start_ok &&
1101	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1102		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1103		    page_to_pfn(virt_to_page((void *)initrd_start)),
1104		    min_low_pfn);
1105		initrd_start = 0;
1106	}
1107#endif
1108	setup_per_cpu_pageset();
1109	numa_policy_init();
1110	acpi_early_init();
1111	if (late_time_init)
1112		late_time_init();
1113	sched_clock_init();
1114	calibrate_delay();
1115	pid_idr_init();
1116	anon_vma_init();
1117#ifdef CONFIG_X86
1118	if (efi_enabled(EFI_RUNTIME_SERVICES))
1119		efi_enter_virtual_mode();
1120#endif
1121	thread_stack_cache_init();
1122	cred_init();
1123	fork_init();
1124	proc_caches_init();
1125	uts_ns_init();
 
1126	key_init();
1127	security_init();
1128	dbg_late_init();
1129	net_ns_init();
1130	vfs_caches_init();
1131	pagecache_init();
1132	signals_init();
1133	seq_file_init();
1134	proc_root_init();
1135	nsfs_init();
1136	cpuset_init();
1137	cgroup_init();
1138	taskstats_init_early();
1139	delayacct_init();
1140
 
1141	check_bugs();
1142
1143	acpi_subsystem_init();
1144	arch_post_acpi_subsys_init();
 
1145	kcsan_init();
1146
1147	/* Do the rest non-__init'ed, we're now alive */
1148	arch_call_rest_init();
1149
1150	prevent_tail_call_optimization();
1151}
1152
1153/* Call all constructor functions linked into the kernel. */
1154static void __init do_ctors(void)
1155{
1156/*
1157 * For UML, the constructors have already been called by the
1158 * normal setup code as it's just a normal ELF binary, so we
1159 * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1160 * even on UML for modules.
1161 */
1162#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1163	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1164
1165	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1166		(*fn)();
1167#endif
1168}
1169
1170#ifdef CONFIG_KALLSYMS
1171struct blacklist_entry {
1172	struct list_head next;
1173	char *buf;
1174};
1175
1176static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1177
1178static int __init initcall_blacklist(char *str)
1179{
1180	char *str_entry;
1181	struct blacklist_entry *entry;
1182
1183	/* str argument is a comma-separated list of functions */
1184	do {
1185		str_entry = strsep(&str, ",");
1186		if (str_entry) {
1187			pr_debug("blacklisting initcall %s\n", str_entry);
1188			entry = memblock_alloc(sizeof(*entry),
1189					       SMP_CACHE_BYTES);
1190			if (!entry)
1191				panic("%s: Failed to allocate %zu bytes\n",
1192				      __func__, sizeof(*entry));
1193			entry->buf = memblock_alloc(strlen(str_entry) + 1,
1194						    SMP_CACHE_BYTES);
1195			if (!entry->buf)
1196				panic("%s: Failed to allocate %zu bytes\n",
1197				      __func__, strlen(str_entry) + 1);
1198			strcpy(entry->buf, str_entry);
1199			list_add(&entry->next, &blacklisted_initcalls);
1200		}
1201	} while (str_entry);
1202
1203	return 1;
1204}
1205
1206static bool __init_or_module initcall_blacklisted(initcall_t fn)
1207{
1208	struct blacklist_entry *entry;
1209	char fn_name[KSYM_SYMBOL_LEN];
1210	unsigned long addr;
1211
1212	if (list_empty(&blacklisted_initcalls))
1213		return false;
1214
1215	addr = (unsigned long) dereference_function_descriptor(fn);
1216	sprint_symbol_no_offset(fn_name, addr);
1217
1218	/*
1219	 * fn will be "function_name [module_name]" where [module_name] is not
1220	 * displayed for built-in init functions.  Strip off the [module_name].
1221	 */
1222	strreplace(fn_name, ' ', '\0');
1223
1224	list_for_each_entry(entry, &blacklisted_initcalls, next) {
1225		if (!strcmp(fn_name, entry->buf)) {
1226			pr_debug("initcall %s blacklisted\n", fn_name);
1227			return true;
1228		}
1229	}
1230
1231	return false;
1232}
1233#else
1234static int __init initcall_blacklist(char *str)
1235{
1236	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1237	return 0;
1238}
1239
1240static bool __init_or_module initcall_blacklisted(initcall_t fn)
1241{
1242	return false;
1243}
1244#endif
1245__setup("initcall_blacklist=", initcall_blacklist);
1246
1247static __init_or_module void
1248trace_initcall_start_cb(void *data, initcall_t fn)
1249{
1250	ktime_t *calltime = data;
1251
1252	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
1253	*calltime = ktime_get();
1254}
1255
1256static __init_or_module void
1257trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1258{
1259	ktime_t rettime, *calltime = data;
 
 
1260
1261	rettime = ktime_get();
 
 
1262	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1263		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1264}
1265
1266static ktime_t initcall_calltime;
1267
1268#ifdef TRACEPOINTS_ENABLED
1269static void __init initcall_debug_enable(void)
1270{
1271	int ret;
1272
1273	ret = register_trace_initcall_start(trace_initcall_start_cb,
1274					    &initcall_calltime);
1275	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1276					      &initcall_calltime);
1277	WARN(ret, "Failed to register initcall tracepoints\n");
1278}
1279# define do_trace_initcall_start	trace_initcall_start
1280# define do_trace_initcall_finish	trace_initcall_finish
1281#else
1282static inline void do_trace_initcall_start(initcall_t fn)
1283{
1284	if (!initcall_debug)
1285		return;
1286	trace_initcall_start_cb(&initcall_calltime, fn);
1287}
1288static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1289{
1290	if (!initcall_debug)
1291		return;
1292	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1293}
1294#endif /* !TRACEPOINTS_ENABLED */
1295
1296int __init_or_module do_one_initcall(initcall_t fn)
1297{
1298	int count = preempt_count();
1299	char msgbuf[64];
1300	int ret;
1301
1302	if (initcall_blacklisted(fn))
1303		return -EPERM;
1304
1305	do_trace_initcall_start(fn);
1306	ret = fn();
1307	do_trace_initcall_finish(fn, ret);
1308
1309	msgbuf[0] = 0;
1310
1311	if (preempt_count() != count) {
1312		sprintf(msgbuf, "preemption imbalance ");
1313		preempt_count_set(count);
1314	}
1315	if (irqs_disabled()) {
1316		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1317		local_irq_enable();
1318	}
1319	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1320
1321	add_latent_entropy();
1322	return ret;
1323}
1324
1325
1326extern initcall_entry_t __initcall_start[];
1327extern initcall_entry_t __initcall0_start[];
1328extern initcall_entry_t __initcall1_start[];
1329extern initcall_entry_t __initcall2_start[];
1330extern initcall_entry_t __initcall3_start[];
1331extern initcall_entry_t __initcall4_start[];
1332extern initcall_entry_t __initcall5_start[];
1333extern initcall_entry_t __initcall6_start[];
1334extern initcall_entry_t __initcall7_start[];
1335extern initcall_entry_t __initcall_end[];
1336
1337static initcall_entry_t *initcall_levels[] __initdata = {
1338	__initcall0_start,
1339	__initcall1_start,
1340	__initcall2_start,
1341	__initcall3_start,
1342	__initcall4_start,
1343	__initcall5_start,
1344	__initcall6_start,
1345	__initcall7_start,
1346	__initcall_end,
1347};
1348
1349/* Keep these in sync with initcalls in include/linux/init.h */
1350static const char *initcall_level_names[] __initdata = {
1351	"pure",
1352	"core",
1353	"postcore",
1354	"arch",
1355	"subsys",
1356	"fs",
1357	"device",
1358	"late",
1359};
1360
1361static int __init ignore_unknown_bootoption(char *param, char *val,
1362			       const char *unused, void *arg)
1363{
1364	return 0;
1365}
1366
1367static void __init do_initcall_level(int level, char *command_line)
1368{
1369	initcall_entry_t *fn;
1370
1371	parse_args(initcall_level_names[level],
1372		   command_line, __start___param,
1373		   __stop___param - __start___param,
1374		   level, level,
1375		   NULL, ignore_unknown_bootoption);
1376
1377	trace_initcall_level(initcall_level_names[level]);
1378	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1379		do_one_initcall(initcall_from_entry(fn));
1380}
1381
1382static void __init do_initcalls(void)
1383{
1384	int level;
1385	size_t len = saved_command_line_len + 1;
1386	char *command_line;
1387
1388	command_line = kzalloc(len, GFP_KERNEL);
1389	if (!command_line)
1390		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1391
1392	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1393		/* Parser modifies command_line, restore it each time */
1394		strcpy(command_line, saved_command_line);
1395		do_initcall_level(level, command_line);
1396	}
1397
1398	kfree(command_line);
1399}
1400
1401/*
1402 * Ok, the machine is now initialized. None of the devices
1403 * have been touched yet, but the CPU subsystem is up and
1404 * running, and memory and process management works.
1405 *
1406 * Now we can finally start doing some real work..
1407 */
1408static void __init do_basic_setup(void)
1409{
1410	cpuset_init_smp();
1411	driver_init();
1412	init_irq_proc();
1413	do_ctors();
 
1414	do_initcalls();
1415}
1416
1417static void __init do_pre_smp_initcalls(void)
1418{
1419	initcall_entry_t *fn;
1420
1421	trace_initcall_level("early");
1422	for (fn = __initcall_start; fn < __initcall0_start; fn++)
1423		do_one_initcall(initcall_from_entry(fn));
1424}
1425
1426static int run_init_process(const char *init_filename)
1427{
1428	const char *const *p;
1429
1430	argv_init[0] = init_filename;
1431	pr_info("Run %s as init process\n", init_filename);
1432	pr_debug("  with arguments:\n");
1433	for (p = argv_init; *p; p++)
1434		pr_debug("    %s\n", *p);
1435	pr_debug("  with environment:\n");
1436	for (p = envp_init; *p; p++)
1437		pr_debug("    %s\n", *p);
1438	return kernel_execve(init_filename, argv_init, envp_init);
1439}
1440
1441static int try_to_run_init_process(const char *init_filename)
1442{
1443	int ret;
1444
1445	ret = run_init_process(init_filename);
1446
1447	if (ret && ret != -ENOENT) {
1448		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1449		       init_filename, ret);
1450	}
1451
1452	return ret;
1453}
1454
1455static noinline void __init kernel_init_freeable(void);
1456
1457#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1458bool rodata_enabled __ro_after_init = true;
1459
1460#ifndef arch_parse_debug_rodata
1461static inline bool arch_parse_debug_rodata(char *str) { return false; }
1462#endif
1463
1464static int __init set_debug_rodata(char *str)
1465{
1466	if (arch_parse_debug_rodata(str))
1467		return 0;
1468
1469	if (str && !strcmp(str, "on"))
1470		rodata_enabled = true;
1471	else if (str && !strcmp(str, "off"))
1472		rodata_enabled = false;
1473	else
1474		pr_warn("Invalid option string for rodata: '%s'\n", str);
1475	return 0;
1476}
1477early_param("rodata", set_debug_rodata);
1478#endif
1479
1480#ifdef CONFIG_STRICT_KERNEL_RWX
1481static void mark_readonly(void)
1482{
1483	if (rodata_enabled) {
1484		/*
1485		 * load_module() results in W+X mappings, which are cleaned
1486		 * up with call_rcu().  Let's make sure that queued work is
1487		 * flushed so that we don't hit false positives looking for
1488		 * insecure pages which are W+X.
1489		 */
1490		rcu_barrier();
1491		mark_rodata_ro();
1492		rodata_test();
1493	} else
1494		pr_info("Kernel memory protection disabled.\n");
1495}
1496#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1497static inline void mark_readonly(void)
1498{
1499	pr_warn("Kernel memory protection not selected by kernel config.\n");
1500}
1501#else
1502static inline void mark_readonly(void)
1503{
1504	pr_warn("This architecture does not have kernel memory protection.\n");
1505}
1506#endif
1507
1508void __weak free_initmem(void)
1509{
1510	free_initmem_default(POISON_FREE_INITMEM);
1511}
1512
1513static int __ref kernel_init(void *unused)
1514{
1515	int ret;
1516
1517	/*
1518	 * Wait until kthreadd is all set-up.
1519	 */
1520	wait_for_completion(&kthreadd_done);
1521
1522	kernel_init_freeable();
1523	/* need to finish all async __init code before freeing the memory */
1524	async_synchronize_full();
1525
1526	system_state = SYSTEM_FREEING_INITMEM;
1527	kprobe_free_init_mem();
1528	ftrace_free_init_mem();
1529	kgdb_free_init_mem();
1530	exit_boot_config();
1531	free_initmem();
1532	mark_readonly();
1533
1534	/*
1535	 * Kernel mappings are now finalized - update the userspace page-table
1536	 * to finalize PTI.
1537	 */
1538	pti_finalize();
1539
1540	system_state = SYSTEM_RUNNING;
1541	numa_default_policy();
1542
1543	rcu_end_inkernel_boot();
1544
1545	do_sysctl_args();
1546
1547	if (ramdisk_execute_command) {
1548		ret = run_init_process(ramdisk_execute_command);
1549		if (!ret)
1550			return 0;
1551		pr_err("Failed to execute %s (error %d)\n",
1552		       ramdisk_execute_command, ret);
1553	}
1554
1555	/*
1556	 * We try each of these until one succeeds.
1557	 *
1558	 * The Bourne shell can be used instead of init if we are
1559	 * trying to recover a really broken machine.
1560	 */
1561	if (execute_command) {
1562		ret = run_init_process(execute_command);
1563		if (!ret)
1564			return 0;
1565		panic("Requested init %s failed (error %d).",
1566		      execute_command, ret);
1567	}
1568
1569	if (CONFIG_DEFAULT_INIT[0] != '\0') {
1570		ret = run_init_process(CONFIG_DEFAULT_INIT);
1571		if (ret)
1572			pr_err("Default init %s failed (error %d)\n",
1573			       CONFIG_DEFAULT_INIT, ret);
1574		else
1575			return 0;
1576	}
1577
1578	if (!try_to_run_init_process("/sbin/init") ||
1579	    !try_to_run_init_process("/etc/init") ||
1580	    !try_to_run_init_process("/bin/init") ||
1581	    !try_to_run_init_process("/bin/sh"))
1582		return 0;
1583
1584	panic("No working init found.  Try passing init= option to kernel. "
1585	      "See Linux Documentation/admin-guide/init.rst for guidance.");
1586}
1587
1588/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1589void __init console_on_rootfs(void)
1590{
1591	struct file *file = filp_open("/dev/console", O_RDWR, 0);
1592
1593	if (IS_ERR(file)) {
1594		pr_err("Warning: unable to open an initial console.\n");
1595		return;
1596	}
1597	init_dup(file);
1598	init_dup(file);
1599	init_dup(file);
1600	fput(file);
1601}
1602
1603static noinline void __init kernel_init_freeable(void)
1604{
 
 
 
 
 
1605	/* Now the scheduler is fully set up and can do blocking allocations */
1606	gfp_allowed_mask = __GFP_BITS_MASK;
1607
1608	/*
1609	 * init can allocate pages on any node
1610	 */
1611	set_mems_allowed(node_states[N_MEMORY]);
1612
1613	cad_pid = get_pid(task_pid(current));
1614
1615	smp_prepare_cpus(setup_max_cpus);
1616
1617	workqueue_init();
1618
1619	init_mm_internals();
1620
1621	rcu_init_tasks_generic();
1622	do_pre_smp_initcalls();
1623	lockup_detector_init();
1624
1625	smp_init();
1626	sched_init_smp();
1627
1628	padata_init();
1629	page_alloc_init_late();
1630	/* Initialize page ext after all struct pages are initialized. */
1631	if (!early_page_ext_enabled())
1632		page_ext_init();
1633
1634	do_basic_setup();
1635
1636	kunit_run_all_tests();
1637
1638	wait_for_initramfs();
1639	console_on_rootfs();
1640
1641	/*
1642	 * check if there is an early userspace init.  If yes, let it do all
1643	 * the work
1644	 */
1645	if (init_eaccess(ramdisk_execute_command) != 0) {
1646		ramdisk_execute_command = NULL;
1647		prepare_namespace();
1648	}
1649
1650	/*
1651	 * Ok, we have completed the initial bootup, and
1652	 * we're essentially up and running. Get rid of the
1653	 * initmem segments and start the user-mode stuff..
1654	 *
1655	 * rootfs is available now, try loading the public keys
1656	 * and default modules
1657	 */
1658
1659	integrity_load_keys();
1660}