main.c 21.2 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
/*
 *  linux/init/main.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  GK 2/5/95  -  Changed to support mounting root fs via NFS
 *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
 *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
 *  Simplified starting of init:  Michael A. Griffith <grif@acm.org> 
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/syscalls.h>
I
Ingo Molnar 已提交
17
#include <linux/stackprotector.h>
L
Linus Torvalds 已提交
18 19 20 21 22 23 24 25 26 27 28 29 30
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/utsname.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/tty.h>
#include <linux/gfp.h>
#include <linux/percpu.h>
#include <linux/kmod.h>
N
Nick Piggin 已提交
31
#include <linux/vmalloc.h>
L
Linus Torvalds 已提交
32
#include <linux/kernel_stat.h>
33
#include <linux/start_kernel.h>
L
Linus Torvalds 已提交
34
#include <linux/security.h>
35
#include <linux/smp.h>
L
Linus Torvalds 已提交
36 37 38 39 40 41 42 43
#include <linux/workqueue.h>
#include <linux/profile.h>
#include <linux/rcupdate.h>
#include <linux/moduleparam.h>
#include <linux/kallsyms.h>
#include <linux/writeback.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
44
#include <linux/cgroup.h>
L
Linus Torvalds 已提交
45
#include <linux/efi.h>
46
#include <linux/tick.h>
47
#include <linux/interrupt.h>
48
#include <linux/taskstats_kern.h>
49
#include <linux/delayacct.h>
L
Linus Torvalds 已提交
50 51 52 53
#include <linux/unistd.h>
#include <linux/rmap.h>
#include <linux/mempolicy.h>
#include <linux/key.h>
A
Adrian Bunk 已提交
54
#include <linux/buffer_head.h>
55
#include <linux/page_cgroup.h>
56
#include <linux/debug_locks.h>
57
#include <linux/debugobjects.h>
I
Ingo Molnar 已提交
58
#include <linux/lockdep.h>
59
#include <linux/pid_namespace.h>
60
#include <linux/device.h>
61
#include <linux/kthread.h>
62
#include <linux/sched.h>
63
#include <linux/signal.h>
64
#include <linux/idr.h>
65
#include <linux/ftrace.h>
66
#include <linux/async.h>
67
#include <trace/boot.h>
L
Linus Torvalds 已提交
68 69 70 71

#include <asm/io.h>
#include <asm/bugs.h>
#include <asm/setup.h>
72
#include <asm/sections.h>
73
#include <asm/cacheflush.h>
L
Linus Torvalds 已提交
74 75 76 77 78

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/smp.h>
#endif

79
static int kernel_init(void *);
L
Linus Torvalds 已提交
80 81 82 83 84 85 86 87 88 89 90 91 92

extern void init_IRQ(void);
extern void fork_init(unsigned long);
extern void mca_init(void);
extern void sbus_init(void);
extern void prio_tree_init(void);
extern void radix_tree_init(void);
extern void free_initmem(void);
#ifdef	CONFIG_ACPI
extern void acpi_early_init(void);
#else
static inline void acpi_early_init(void) { }
#endif
93 94 95
#ifndef CONFIG_DEBUG_RODATA
static inline void mark_rodata_ro(void) { }
#endif
L
Linus Torvalds 已提交
96 97 98 99 100

#ifdef CONFIG_TC
extern void tc_init(void);
#endif

101
enum system_states system_state __read_mostly;
L
Linus Torvalds 已提交
102 103 104 105 106 107 108 109 110 111
EXPORT_SYMBOL(system_state);

/*
 * Boot command-line arguments
 */
#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT

extern void time_init(void);
/* Default late time init is NULL. archs can override this later. */
112
void (*__initdata late_time_init)(void);
L
Linus Torvalds 已提交
113 114
extern void softirq_init(void);

115 116 117 118 119 120
/* Untouched command line saved by arch-specific code. */
char __initdata boot_command_line[COMMAND_LINE_SIZE];
/* Untouched saved command line (eg. for /proc) */
char *saved_command_line;
/* Command line for parameter parsing */
static char *static_command_line;
L
Linus Torvalds 已提交
121 122

static char *execute_command;
123
static char *ramdisk_execute_command;
L
Linus Torvalds 已提交
124

J
Jan Beulich 已提交
125
#ifdef CONFIG_SMP
L
Linus Torvalds 已提交
126
/* Setup configured maximum number of CPUs to activate */
127
unsigned int __initdata setup_max_cpus = NR_CPUS;
128

L
Linus Torvalds 已提交
129 130 131 132 133 134 135 136 137 138
/*
 * Setup routine for controlling SMP activation
 *
 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
 * activation entirely (the MPS table probe still happens, though).
 *
 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
 * greater than 0, limits the maximum number of CPUs activated in
 * SMP mode to <NUM>.
 */
139 140

void __weak arch_disable_smp_support(void) { }
141

L
Linus Torvalds 已提交
142 143
static int __init nosmp(char *str)
{
144
	setup_max_cpus = 0;
145 146
	arch_disable_smp_support();

J
Jan Beulich 已提交
147
	return 0;
L
Linus Torvalds 已提交
148 149
}

J
Jan Beulich 已提交
150
early_param("nosmp", nosmp);
L
Linus Torvalds 已提交
151 152 153

static int __init maxcpus(char *str)
{
154 155
	get_option(&str, &setup_max_cpus);
	if (setup_max_cpus == 0)
156
		arch_disable_smp_support();
157 158

	return 0;
L
Linus Torvalds 已提交
159 160
}

H
Hugh Dickins 已提交
161
early_param("maxcpus", maxcpus);
J
Jan Beulich 已提交
162
#else
163
const unsigned int setup_max_cpus = NR_CPUS;
J
Jan Beulich 已提交
164 165 166 167 168 169 170 171 172 173 174 175 176
#endif

/*
 * If set, this is an indication to the drivers that reset the underlying
 * device before going ahead with the initialization otherwise driver might
 * rely on the BIOS and skip the reset operation.
 *
 * This is useful if kernel is booting in an unreliable environment.
 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
 * skipped and devices will be in unknown state.
 */
unsigned int reset_devices;
EXPORT_SYMBOL(reset_devices);
L
Linus Torvalds 已提交
177

178 179 180 181 182 183 184 185
static int __init set_reset_devices(char *str)
{
	reset_devices = 1;
	return 1;
}

__setup("reset_devices", set_reset_devices);

L
Linus Torvalds 已提交
186 187 188 189 190 191 192 193 194
static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
static const char *panic_later, *panic_param;

extern struct obs_kernel_param __setup_start[], __setup_end[];

static int __init obsolete_checksetup(char *line)
{
	struct obs_kernel_param *p;
195
	int had_early_param = 0;
L
Linus Torvalds 已提交
196 197 198 199 200 201

	p = __setup_start;
	do {
		int n = strlen(p->str);
		if (!strncmp(line, p->str, n)) {
			if (p->early) {
202 203 204 205
				/* Already done in parse_early_param?
				 * (Needs exact match on param part).
				 * Keep iterating, as we can have early
				 * params and __setups of same names 8( */
L
Linus Torvalds 已提交
206
				if (line[n] == '\0' || line[n] == '=')
207
					had_early_param = 1;
L
Linus Torvalds 已提交
208 209 210 211 212 213 214 215 216
			} else if (!p->setup_func) {
				printk(KERN_WARNING "Parameter %s is obsolete,"
				       " ignored\n", p->str);
				return 1;
			} else if (p->setup_func(line + n))
				return 1;
		}
		p++;
	} while (p < __setup_end);
217 218

	return had_early_param;
L
Linus Torvalds 已提交
219 220 221 222 223 224 225 226 227 228 229 230 231
}

/*
 * This should be approx 2 Bo*oMips to start (note initial shift), and will
 * still work even if initially too large, it will just take slightly longer
 */
unsigned long loops_per_jiffy = (1<<12);

EXPORT_SYMBOL(loops_per_jiffy);

static int __init debug_kernel(char *str)
{
	console_loglevel = 10;
232
	return 0;
L
Linus Torvalds 已提交
233 234 235 236 237
}

static int __init quiet_kernel(char *str)
{
	console_loglevel = 4;
238
	return 0;
L
Linus Torvalds 已提交
239 240
}

241 242
early_param("debug", debug_kernel);
early_param("quiet", quiet_kernel);
L
Linus Torvalds 已提交
243 244 245 246

static int __init loglevel(char *str)
{
	get_option(&str, &console_loglevel);
247
	return 0;
L
Linus Torvalds 已提交
248 249
}

250
early_param("loglevel", loglevel);
L
Linus Torvalds 已提交
251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275

/*
 * Unknown boot options get handed to init, unless they look like
 * failed parameters
 */
static int __init unknown_bootoption(char *param, char *val)
{
	/* Change NUL term back to "=", to make "param" the whole string. */
	if (val) {
		/* param=val or param="val"? */
		if (val == param+strlen(param)+1)
			val[-1] = '=';
		else if (val == param+strlen(param)+2) {
			val[-2] = '=';
			memmove(val-1, val, strlen(val)+1);
			val--;
		} else
			BUG();
	}

	/* Handle obsolete-style parameters */
	if (obsolete_checksetup(param))
		return 0;

	/*
S
Simon Arlott 已提交
276
	 * Preemptive maintenance for "why didn't my misspelled command
L
Linus Torvalds 已提交
277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
	 * line work?"
	 */
	if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
		printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
		return 0;
	}

	if (panic_later)
		return 0;

	if (val) {
		/* Environment option */
		unsigned int i;
		for (i = 0; envp_init[i]; i++) {
			if (i == MAX_INIT_ENVS) {
				panic_later = "Too many boot env vars at `%s'";
				panic_param = param;
			}
			if (!strncmp(param, envp_init[i], val - param))
				break;
		}
		envp_init[i] = param;
	} else {
		/* Command line option */
		unsigned int i;
		for (i = 0; argv_init[i]; i++) {
			if (i == MAX_INIT_ARGS) {
				panic_later = "Too many boot init vars at `%s'";
				panic_param = param;
			}
		}
		argv_init[i] = param;
	}
	return 0;
}

313 314 315 316
#ifdef CONFIG_DEBUG_PAGEALLOC
int __read_mostly debug_pagealloc_enabled = 0;
#endif

L
Linus Torvalds 已提交
317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
static int __init init_setup(char *str)
{
	unsigned int i;

	execute_command = str;
	/*
	 * In case LILO is going to boot us with default command line,
	 * it prepends "auto" before the whole cmdline which makes
	 * the shell think it should execute a script with such name.
	 * So we ignore all arguments entered _before_ init=... [MJ]
	 */
	for (i = 1; i < MAX_INIT_ARGS; i++)
		argv_init[i] = NULL;
	return 1;
}
__setup("init=", init_setup);

334 335 336 337 338 339 340 341 342 343 344 345
static int __init rdinit_setup(char *str)
{
	unsigned int i;

	ramdisk_execute_command = str;
	/* See "auto" comment in init_setup */
	for (i = 1; i < MAX_INIT_ARGS; i++)
		argv_init[i] = NULL;
	return 1;
}
__setup("rdinit=", rdinit_setup);

L
Linus Torvalds 已提交
346 347 348 349 350 351 352 353 354 355 356 357
#ifndef CONFIG_SMP

#ifdef CONFIG_X86_LOCAL_APIC
static void __init smp_init(void)
{
	APIC_init_uniprocessor();
}
#else
#define smp_init()	do { } while (0)
#endif

static inline void setup_per_cpu_areas(void) { }
358
static inline void setup_nr_cpu_ids(void) { }
L
Linus Torvalds 已提交
359 360 361 362
static inline void smp_prepare_cpus(unsigned int maxcpus) { }

#else

363 364 365 366 367
#if NR_CPUS > BITS_PER_LONG
cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_mask_all);
#endif

368 369 370 371 372 373 374
/* Setup number of possible processor ids */
int nr_cpu_ids __read_mostly = NR_CPUS;
EXPORT_SYMBOL(nr_cpu_ids);

/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
static void __init setup_nr_cpu_ids(void)
{
R
Rusty Russell 已提交
375
	nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
376 377
}

378
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
E
Eric Dumazet 已提交
379
unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
L
Linus Torvalds 已提交
380 381 382 383 384 385 386

EXPORT_SYMBOL(__per_cpu_offset);

static void __init setup_per_cpu_areas(void)
{
	unsigned long size, i;
	char *ptr;
387
	unsigned long nr_possible_cpus = num_possible_cpus();
L
Linus Torvalds 已提交
388 389

	/* Copy section for each CPU (we discard the original) */
390 391
	size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
	ptr = alloc_bootmem_pages(size * nr_possible_cpus);
L
Linus Torvalds 已提交
392

393
	for_each_possible_cpu(i) {
L
Linus Torvalds 已提交
394 395
		__per_cpu_offset[i] = ptr - __per_cpu_start;
		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
396
		ptr += size;
L
Linus Torvalds 已提交
397 398
	}
}
399
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
L
Linus Torvalds 已提交
400 401 402 403

/* Called by boot processor to activate the rest. */
static void __init smp_init(void)
{
404
	unsigned int cpu;
L
Linus Torvalds 已提交
405

406 407 408 409 410 411 412
	/*
	 * Set up the current CPU as possible to migrate to.
	 * The other ones will be done by cpu_up/cpu_down()
	 */
	cpu = smp_processor_id();
	cpu_set(cpu, cpu_active_map);

L
Linus Torvalds 已提交
413
	/* FIXME: This should be done in userspace --RR */
414
	for_each_present_cpu(cpu) {
415
		if (num_online_cpus() >= setup_max_cpus)
L
Linus Torvalds 已提交
416
			break;
417 418
		if (!cpu_online(cpu))
			cpu_up(cpu);
L
Linus Torvalds 已提交
419 420 421 422
	}

	/* Any cleanup work */
	printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
423
	smp_cpus_done(setup_max_cpus);
L
Linus Torvalds 已提交
424 425 426 427
}

#endif

428 429 430 431 432 433 434 435 436 437 438 439 440 441
/*
 * We need to store the untouched command line for future reference.
 * We also need to store the touched command line since the parameter
 * parsing is performed in place, and we should allow a component to
 * store reference of name/value for future reference.
 */
static void __init setup_command_line(char *command_line)
{
	saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
	static_command_line = alloc_bootmem(strlen (command_line)+1);
	strcpy (saved_command_line, boot_command_line);
	strcpy (static_command_line, command_line);
}

L
Linus Torvalds 已提交
442 443 444 445 446 447 448 449 450
/*
 * We need to finalize in a non-__init function or else race conditions
 * between the root thread and the init thread may cause start_kernel to
 * be reaped by free_initmem before the root thread has proceeded to
 * cpu_idle.
 *
 * gcc-3.4 accidentally inlines this function, so use noinline.
 */

451
static noinline void __init_refok rest_init(void)
L
Linus Torvalds 已提交
452 453
	__releases(kernel_lock)
{
454 455
	int pid;

456
	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
L
Linus Torvalds 已提交
457
	numa_default_policy();
458
	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
P
Pavel Emelyanov 已提交
459
	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
L
Linus Torvalds 已提交
460
	unlock_kernel();
461 462 463

	/*
	 * The boot idle thread must execute schedule()
I
Ingo Molnar 已提交
464
	 * at least once to get things moving:
465
	 */
I
Ingo Molnar 已提交
466
	init_idle_bootup_task(current);
467
	rcu_scheduler_starting();
468
	preempt_enable_no_resched();
469
	schedule();
470
	preempt_disable();
471

472
	/* Call into cpu_idle with preempt disabled */
L
Linus Torvalds 已提交
473
	cpu_idle();
I
Ingo Molnar 已提交
474
}
L
Linus Torvalds 已提交
475 476 477 478 479 480 481

/* Check for early params. */
static int __init do_early_param(char *param, char *val)
{
	struct obs_kernel_param *p;

	for (p = __setup_start; p < __setup_end; p++) {
482 483 484 485
		if ((p->early && strcmp(param, p->str) == 0) ||
		    (strcmp(param, "console") == 0 &&
		     strcmp(p->str, "earlycon") == 0)
		) {
L
Linus Torvalds 已提交
486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504
			if (p->setup_func(val) != 0)
				printk(KERN_WARNING
				       "Malformed early option '%s'\n", param);
		}
	}
	/* We accept everything at this stage. */
	return 0;
}

/* Arch code calls this early on, or if not, just before other parsing. */
void __init parse_early_param(void)
{
	static __initdata int done = 0;
	static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];

	if (done)
		return;

	/* All fall through to do_early_param. */
505
	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
L
Linus Torvalds 已提交
506 507 508 509 510 511 512 513
	parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
	done = 1;
}

/*
 *	Activate the first processor.
 */

514 515 516 517
static void __init boot_cpu_init(void)
{
	int cpu = smp_processor_id();
	/* Mark the boot cpu "present", "online" etc for SMP and UP case */
518 519 520
	set_cpu_online(cpu, true);
	set_cpu_present(cpu, true);
	set_cpu_possible(cpu, true);
521 522
}

523
void __init __weak smp_setup_processor_id(void)
524 525 526
{
}

527 528 529 530
void __init __weak thread_info_cache_init(void)
{
}

L
Linus Torvalds 已提交
531 532 533 534
asmlinkage void __init start_kernel(void)
{
	char * command_line;
	extern struct kernel_param __start___param[], __stop___param[];
535 536 537

	smp_setup_processor_id();

I
Ingo Molnar 已提交
538 539 540 541 542
	/*
	 * Need to run as early as possible, to initialize the
	 * lockdep hash:
	 */
	lockdep_init();
543
	debug_objects_early_init();
544 545 546 547 548 549

	/*
	 * Set up the the initial canary ASAP:
	 */
	boot_init_stack_canary();

550
	cgroup_init_early();
I
Ingo Molnar 已提交
551 552 553

	local_irq_disable();
	early_boot_irqs_off();
I
Ingo Molnar 已提交
554
	early_init_irq_lock_class();
I
Ingo Molnar 已提交
555

L
Linus Torvalds 已提交
556 557 558 559 560
/*
 * Interrupts are still disabled. Do necessary setups, then
 * enable them
 */
	lock_kernel();
561
	tick_init();
562
	boot_cpu_init();
L
Linus Torvalds 已提交
563 564
	page_address_init();
	printk(KERN_NOTICE);
565
	printk(linux_banner);
L
Linus Torvalds 已提交
566
	setup_arch(&command_line);
567
	mm_init_owner(&init_mm, &init_task);
568
	setup_command_line(command_line);
L
Linus Torvalds 已提交
569
	setup_per_cpu_areas();
570
	setup_nr_cpu_ids();
571
	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
L
Linus Torvalds 已提交
572 573 574 575 576 577 578 579 580 581 582 583 584 585

	/*
	 * Set up the scheduler prior starting any interrupts (such as the
	 * timer interrupt). Full topology setup happens at smp_init()
	 * time - but meanwhile we still have a functioning scheduler.
	 */
	sched_init();
	/*
	 * Disable preemption - early bootup scheduling is extremely
	 * fragile until we cpu_idle() for the first time.
	 */
	preempt_disable();
	build_all_zonelists();
	page_alloc_init();
586
	printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
L
Linus Torvalds 已提交
587
	parse_early_param();
588
	parse_args("Booting kernel", static_command_line, __start___param,
L
Linus Torvalds 已提交
589 590
		   __stop___param - __start___param,
		   &unknown_bootoption);
591 592 593 594 595
	if (!irqs_disabled()) {
		printk(KERN_WARNING "start_kernel(): bug: interrupts were "
				"enabled *very* early, fixing it\n");
		local_irq_disable();
	}
L
Linus Torvalds 已提交
596 597 598
	sort_main_extable();
	trap_init();
	rcu_init();
599 600
	/* init some links before init_ISA_irqs() */
	early_irq_init();
L
Linus Torvalds 已提交
601 602 603
	init_IRQ();
	pidhash_init();
	init_timers();
604
	hrtimers_init();
L
Linus Torvalds 已提交
605
	softirq_init();
606
	timekeeping_init();
J
john stultz 已提交
607
	time_init();
608
	sched_clock_init();
609 610
	profile_init();
	if (!irqs_disabled())
611 612
		printk(KERN_CRIT "start_kernel(): bug: interrupts were "
				 "enabled early\n");
I
Ingo Molnar 已提交
613
	early_boot_irqs_on();
614
	local_irq_enable();
L
Linus Torvalds 已提交
615 616 617 618 619 620 621 622 623

	/*
	 * HACK ALERT! This is early. We're enabling the console before
	 * we've done PCI setups etc, and console_init() must be aware of
	 * this. But we do want output early, in case something goes wrong.
	 */
	console_init();
	if (panic_later)
		panic(panic_later, panic_param);
I
Ingo Molnar 已提交
624 625 626

	lockdep_info();

627 628 629 630 631 632 633
	/*
	 * Need to run this when irqs are enabled, because it wants
	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
	 * too:
	 */
	locking_selftest();

L
Linus Torvalds 已提交
634 635
#ifdef CONFIG_BLK_DEV_INITRD
	if (initrd_start && !initrd_below_start_ok &&
636
	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
L
Linus Torvalds 已提交
637
		printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
638
		    "disabling it.\n",
639 640
		    page_to_pfn(virt_to_page((void *)initrd_start)),
		    min_low_pfn);
L
Linus Torvalds 已提交
641 642 643
		initrd_start = 0;
	}
#endif
N
Nick Piggin 已提交
644
	vmalloc_init();
L
Linus Torvalds 已提交
645
	vfs_caches_init_early();
646
	cpuset_init_early();
647
	page_cgroup_init();
L
Linus Torvalds 已提交
648
	mem_init();
649
	enable_debug_pagealloc();
650
	cpu_hotplug_init();
L
Linus Torvalds 已提交
651
	kmem_cache_init();
652
	debug_objects_mem_init();
653
	idr_init_cache();
654
	setup_per_cpu_pageset();
L
Linus Torvalds 已提交
655 656 657 658 659 660 661 662 663 664 665 666
	numa_policy_init();
	if (late_time_init)
		late_time_init();
	calibrate_delay();
	pidmap_init();
	pgtable_cache_init();
	prio_tree_init();
	anon_vma_init();
#ifdef CONFIG_X86
	if (efi_enabled)
		efi_enter_virtual_mode();
#endif
667
	thread_info_cache_init();
D
David Howells 已提交
668
	cred_init();
L
Linus Torvalds 已提交
669 670 671 672 673 674 675 676 677 678 679 680 681
	fork_init(num_physpages);
	proc_caches_init();
	buffer_init();
	key_init();
	security_init();
	vfs_caches_init(num_physpages);
	radix_tree_init();
	signals_init();
	/* rootfs populating might need page-writeback */
	page_writeback_init();
#ifdef CONFIG_PROC_FS
	proc_root_init();
#endif
682
	cgroup_init();
L
Linus Torvalds 已提交
683
	cpuset_init();
684
	taskstats_init_early();
685
	delayacct_init();
L
Linus Torvalds 已提交
686 687 688 689 690

	check_bugs();

	acpi_early_init(); /* before LAPIC and SMP init */

691 692
	ftrace_init();

L
Linus Torvalds 已提交
693 694 695 696
	/* Do the rest non-__init'ed, we're now alive */
	rest_init();
}

697
int initcall_debug;
R
Rusty Russell 已提交
698
core_param(initcall_debug, initcall_debug, bool, 0644);
L
Linus Torvalds 已提交
699

700
int do_one_initcall(initcall_t fn)
L
Linus Torvalds 已提交
701 702
{
	int count = preempt_count();
703
	ktime_t calltime, delta, rettime;
704
	char msgbuf[64];
705 706
	struct boot_trace_call call;
	struct boot_trace_ret ret;
L
Linus Torvalds 已提交
707

708
	if (initcall_debug) {
709 710 711 712
		call.caller = task_pid_nr(current);
		printk("calling  %pF @ %i\n", fn, call.caller);
		calltime = ktime_get();
		trace_boot_call(&call, fn);
713
		enable_boot_trace();
714
	}
L
Linus Torvalds 已提交
715

716
	ret.result = fn();
L
Linus Torvalds 已提交
717

718
	if (initcall_debug) {
719
		disable_boot_trace();
720 721
		rettime = ktime_get();
		delta = ktime_sub(rettime, calltime);
722
		ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
723
		trace_boot_ret(&ret, fn);
724
		printk("initcall %pF returned %d after %Ld usecs\n", fn,
725
			ret.result, ret.duration);
726
	}
727

728
	msgbuf[0] = 0;
729

730 731
	if (ret.result && ret.result != -ENODEV && initcall_debug)
		sprintf(msgbuf, "error code %d ", ret.result);
732

733
	if (preempt_count() != count) {
734
		strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
735
		preempt_count() = count;
L
Linus Torvalds 已提交
736
	}
737
	if (irqs_disabled()) {
738
		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
739 740 741
		local_irq_enable();
	}
	if (msgbuf[0]) {
742
		printk("initcall %pF returned with %s\n", fn, msgbuf);
743
	}
744

745
	return ret.result;
746 747 748
}


749
extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
750 751 752 753 754

static void __init do_initcalls(void)
{
	initcall_t *call;

755
	for (call = __early_initcall_end; call < __initcall_end; call++)
756
		do_one_initcall(*call);
L
Linus Torvalds 已提交
757 758 759 760 761 762 763 764 765 766 767 768 769 770

	/* Make sure there is no pending stuff from the initcall sequence */
	flush_scheduled_work();
}

/*
 * Ok, the machine is now initialized. None of the devices
 * have been touched yet, but the CPU subsystem is up and
 * running, and memory and process management works.
 *
 * Now we can finally start doing some real work..
 */
static void __init do_basic_setup(void)
{
P
Paul E. McKenney 已提交
771
	rcu_init_sched(); /* needed by module_init stage. */
772
	init_workqueues();
L
Linus Torvalds 已提交
773 774
	usermodehelper_init();
	driver_init();
775
	init_irq_proc();
L
Linus Torvalds 已提交
776 777 778
	do_initcalls();
}

779
static void __init do_pre_smp_initcalls(void)
780 781 782 783 784 785 786
{
	initcall_t *call;

	for (call = __initcall_start; call < __early_initcall_end; call++)
		do_one_initcall(*call);
}

L
Linus Torvalds 已提交
787 788 789
static void run_init_process(char *init_filename)
{
	argv_init[0] = init_filename;
A
Arnd Bergmann 已提交
790
	kernel_execve(init_filename, argv_init, envp_init);
L
Linus Torvalds 已提交
791 792
}

793 794 795
/* This is a non __init function. Force it to be noinline otherwise gcc
 * makes it inline to init() and it becomes part of init.text section
 */
796
static noinline int init_post(void)
797
{
798 799
	/* need to finish all async __init code before freeing the memory */
	async_synchronize_full();
800 801 802 803 804 805 806 807 808 809 810 811
	free_initmem();
	unlock_kernel();
	mark_rodata_ro();
	system_state = SYSTEM_RUNNING;
	numa_default_policy();

	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
		printk(KERN_WARNING "Warning: unable to open an initial console.\n");

	(void) sys_dup(0);
	(void) sys_dup(0);

812 813
	current->signal->flags |= SIGNAL_UNKILLABLE;

814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
	if (ramdisk_execute_command) {
		run_init_process(ramdisk_execute_command);
		printk(KERN_WARNING "Failed to execute %s\n",
				ramdisk_execute_command);
	}

	/*
	 * We try each of these until one succeeds.
	 *
	 * The Bourne shell can be used instead of init if we are
	 * trying to recover a really broken machine.
	 */
	if (execute_command) {
		run_init_process(execute_command);
		printk(KERN_WARNING "Failed to execute %s.  Attempting "
					"defaults...\n", execute_command);
	}
	run_init_process("/sbin/init");
	run_init_process("/etc/init");
	run_init_process("/bin/init");
	run_init_process("/bin/sh");

	panic("No init found.  Try passing init= option to kernel.");
}

839
static int __init kernel_init(void * unused)
L
Linus Torvalds 已提交
840 841 842 843 844
{
	lock_kernel();
	/*
	 * init can run on any cpu.
	 */
845
	set_cpus_allowed_ptr(current, cpu_all_mask);
L
Linus Torvalds 已提交
846 847 848 849 850 851 852 853
	/*
	 * Tell the world that we're going to be the grim
	 * reaper of innocent orphaned children.
	 *
	 * We don't want people to have to make incorrect
	 * assumptions about where in the task array this
	 * can be found.
	 */
854
	init_pid_ns.child_reaper = current;
L
Linus Torvalds 已提交
855

856 857
	cad_pid = task_pid(current);

858
	smp_prepare_cpus(setup_max_cpus);
L
Linus Torvalds 已提交
859 860

	do_pre_smp_initcalls();
861
	start_boot_trace();
L
Linus Torvalds 已提交
862 863 864 865 866 867 868 869 870 871 872 873

	smp_init();
	sched_init_smp();

	cpuset_init_smp();

	do_basic_setup();

	/*
	 * check if there is an early userspace init.  If yes, let it do all
	 * the work
	 */
874 875 876 877 878 879

	if (!ramdisk_execute_command)
		ramdisk_execute_command = "/init";

	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
		ramdisk_execute_command = NULL;
L
Linus Torvalds 已提交
880
		prepare_namespace();
881
	}
L
Linus Torvalds 已提交
882 883 884 885 886 887

	/*
	 * Ok, we have completed the initial bootup, and
	 * we're essentially up and running. Get rid of the
	 * initmem segments and start the user-mode stuff..
	 */
888

889 890
	init_post();
	return 0;
L
Linus Torvalds 已提交
891
}