path: root/init/main.c

/*
 *  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>
#include <linux/stackprotector.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/acpi.h>
#include <linux/tty.h>
#include <linux/percpu.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/kernel_stat.h>
#include <linux/start_kernel.h>
#include <linux/security.h>
#include <linux/smp.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>
#include <linux/cgroup.h>
#include <linux/efi.h>
#include <linux/tick.h>
#include <linux/interrupt.h>
#include <linux/taskstats_kern.h>
#include <linux/delayacct.h>
#include <linux/unistd.h>
#include <linux/rmap.h>
#include <linux/mempolicy.h>
#include <linux/key.h>
#include <linux/buffer_head.h>
#include <linux/page_cgroup.h>
#include <linux/debug_locks.h>
#include <linux/debugobjects.h>
#include <linux/lockdep.h>
#include <linux/kmemleak.h>
#include <linux/pid_namespace.h>
#include <linux/device.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/idr.h>
#include <linux/kgdb.h>
#include <linux/ftrace.h>
#include <linux/async.h>
#include <linux/kmemcheck.h>
#include <linux/sfi.h>
#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/perf_event.h>

#include <asm/io.h>
#include <asm/bugs.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/asm_code_footprint.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/smp.h>
#endif

static int kernel_init(void *);

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);
#ifndef CONFIG_DEBUG_RODATA
static inline void mark_rodata_ro(void) { }
#endif

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

bool early_boot_irqs_disabled __read_mostly;

enum system_states system_state __read_mostly;
EXPORT_SYMBOL(system_state);

#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT

extern void time_init(void);
void (*__initdata late_time_init)(void);
extern void softirq_init(void);

char __initdata boot_command_line[COMMAND_LINE_SIZE];
char *saved_command_line;
char *hashed_command_line;
static char *static_command_line;

static char *execute_command;
static char *ramdisk_execute_command;

unsigned int reset_devices;
EXPORT_SYMBOL(reset_devices);

static int __init set_reset_devices(char *str)
{
	reset_devices = 1;
	return 1;
}

__setup("reset_devices", set_reset_devices);

static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
static const char *panic_later, *panic_param;

extern const struct obs_kernel_param __setup_start[], __setup_end[];

static int __init obsolete_checksetup(char *line)
{
	const struct obs_kernel_param *p;
	int had_early_param = 0;

	p = __setup_start;
	do {
		int n = strlen(p->str);
		if (parameqn(line, p->str, n)) {
			if (p->early) {
				if (line[n] == '\0' || line[n] == '=')
					had_early_param = 1;
			} 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);

	return had_early_param;
}

unsigned long loops_per_jiffy = (1<<12);

EXPORT_SYMBOL(loops_per_jiffy);

static int __init debug_kernel(char *str)
{
	console_loglevel = 10;
	return 0;
}

static int __init quiet_kernel(char *str)
{
	console_loglevel = 4;
	return 0;
}

early_param("debug", debug_kernel);
early_param("quiet", quiet_kernel);

static int __init loglevel(char *str)
{
	int newlevel;

	if (get_option(&str, &newlevel)) {
		console_loglevel = newlevel;
		return 0;
	}

	return -EINVAL;
}

early_param("loglevel", loglevel);

static int __init repair_env_string(char *param, char *val)
{
	if (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();
	}
	return 0;
}

static int __init unknown_bootoption(char *param, char *val)
{
	repair_env_string(param, val);

	
	if (obsolete_checksetup(param))
		return 0;

	
	if (strchr(param, '.') && (!val || strchr(param, '.') < val))
		return 0;

	if (panic_later)
		return 0;

	if (val) {
		
		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 {
		
		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;
}

static int __init init_setup(char *str)
{
	unsigned int i;

	execute_command = str;
	for (i = 1; i < MAX_INIT_ARGS; i++)
		argv_init[i] = NULL;
	return 1;
}
__setup("init=", init_setup);

static int __init rdinit_setup(char *str)
{
	unsigned int i;

	ramdisk_execute_command = str;
	
	for (i = 1; i < MAX_INIT_ARGS; i++)
		argv_init[i] = NULL;
	return 1;
}
__setup("rdinit=", rdinit_setup);

#ifndef CONFIG_SMP
static const unsigned int setup_max_cpus = NR_CPUS;
#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_nr_cpu_ids(void) { }
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
#endif

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);
}

#define RAW_SN_LEN	4

static void __init hash_sn(void)
{
	char *p;
	unsigned int td_sf = 0;
	size_t cmdline_len, sf_len;

	cmdline_len = strlen(saved_command_line);
	sf_len = strlen("td.sf=");

	hashed_command_line = alloc_bootmem(cmdline_len + 1);
	strncpy(hashed_command_line, saved_command_line, cmdline_len);
	hashed_command_line[cmdline_len] = '\0';

	p = saved_command_line;
	for (p = saved_command_line; p < saved_command_line + cmdline_len - sf_len; p++) {
		if (!strncmp(p, "td.sf=", sf_len)) {
			p += sf_len;
			if (*p != '0')
				td_sf = 1;
			break;
		}
	}
	if (td_sf) {
		unsigned int i;
		size_t sn_len = 0;

		for (p = hashed_command_line; p < hashed_command_line + cmdline_len - strlen("androidboot.serialno="); p++) {
			if (!strncmp(p, "androidboot.serialno=", strlen("androidboot.serialno="))) {
				p += strlen("androidboot.serialno=");
				while (*p != ' '  && *p != '\0') {
					sn_len++;
					p++;
				}
				p -= sn_len;
				for (i = sn_len - 1; i >= RAW_SN_LEN; i--)
					*p++ = '*';
				break;
			}
		}
	}
}


static __initdata DECLARE_COMPLETION(kthreadd_done);

static noinline void __init_refok rest_init(void)
{
	int pid;
	const struct sched_param param = { .sched_priority = 1 };

	asm_code_footprint();

	rcu_scheduler_starting();
	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
	numa_default_policy();
	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
	rcu_read_lock();
	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
	rcu_read_unlock();
	sched_setscheduler_nocheck(kthreadd_task, SCHED_FIFO, &param);
	complete(&kthreadd_done);

	init_idle_bootup_task(current);
	schedule_preempt_disabled();
	
	cpu_idle();
}

static int __init do_early_param(char *param, char *val)
{
	const struct obs_kernel_param *p;

	for (p = __setup_start; p < __setup_end; p++) {
		if ((p->early && parameq(param, p->str)) ||
		    (strcmp(param, "console") == 0 &&
		     strcmp(p->str, "earlycon") == 0)
		) {
			if (p->setup_func(val) != 0)
				printk(KERN_WARNING
				       "Malformed early option '%s'\n", param);
		}
	}
	
	return 0;
}

void __init parse_early_options(char *cmdline)
{
	parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
}

void __init parse_early_param(void)
{
	static __initdata int done = 0;
	static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];

	if (done)
		return;

	
	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
	parse_early_options(tmp_cmdline);
	done = 1;
}


static void __init boot_cpu_init(void)
{
	int cpu = smp_processor_id();
	
	set_cpu_online(cpu, true);
	set_cpu_active(cpu, true);
	set_cpu_present(cpu, true);
	set_cpu_possible(cpu, true);
}

void __init __weak smp_setup_processor_id(void)
{
}

void __init __weak thread_info_cache_init(void)
{
}

static void __init mm_init(void)
{
	page_cgroup_init_flatmem();
	mem_init();
	kmem_cache_init();
	percpu_init_late();
	pgtable_cache_init();
	vmalloc_init();
}

asmlinkage void __init start_kernel(void)
{
	char * command_line;
	extern const struct kernel_param __start___param[], __stop___param[];

	asm_code_footprint();

	lockdep_init();
	smp_setup_processor_id();
	debug_objects_early_init();

	cgroup_init_early();

	local_irq_disable();
	early_boot_irqs_disabled = true;

	tick_init();
	boot_cpu_init();
	page_address_init();
	printk(KERN_NOTICE "%s", linux_banner);
	setup_arch(&command_line);
	boot_init_stack_canary();
	mm_init_owner(&init_mm, &init_task);
	mm_init_cpumask(&init_mm);
	setup_command_line(command_line);
	hash_sn();
	setup_nr_cpu_ids();
	setup_per_cpu_areas();
	smp_prepare_boot_cpu();	

	build_all_zonelists(NULL);
	page_alloc_init();

	printk(KERN_NOTICE "Kernel command line: %s\n", hashed_command_line);
	parse_early_param();
	parse_args("Booting kernel", static_command_line, __start___param,
		   __stop___param - __start___param,
		   -1, -1, &unknown_bootoption);

	jump_label_init();

	setup_log_buf(0);
	pidhash_init();
	vfs_caches_init_early();
	sort_main_extable();
	trap_init();
	mm_init();

	sched_init();
	preempt_disable();
	if (!irqs_disabled()) {
		printk(KERN_WARNING "start_kernel(): bug: interrupts were "
				"enabled *very* early, fixing it\n");
		local_irq_disable();
	}
	idr_init_cache();
	perf_event_init();
	rcu_init();
	radix_tree_init();
	
	early_irq_init();
	init_IRQ();
	prio_tree_init();
	init_timers();
	hrtimers_init();
	softirq_init();
	timekeeping_init();
	time_init();
	profile_init();
	call_function_init();
	if (!irqs_disabled())
		printk(KERN_CRIT "start_kernel(): bug: interrupts were "
				 "enabled early\n");
	early_boot_irqs_disabled = false;
	local_irq_enable();

	kmem_cache_init_late();

	console_init();
	if (panic_later)
		panic(panic_later, panic_param);

	lockdep_info();

	locking_selftest();

#ifdef CONFIG_BLK_DEV_INITRD
	if (initrd_start && !initrd_below_start_ok &&
	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
		printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
		    "disabling it.\n",
		    page_to_pfn(virt_to_page((void *)initrd_start)),
		    min_low_pfn);
		initrd_start = 0;
	}
#endif
	page_cgroup_init();
	debug_objects_mem_init();
	kmemleak_init();
	setup_per_cpu_pageset();
	numa_policy_init();
	if (late_time_init)
		late_time_init();
	sched_clock_init();
	calibrate_delay();
	pidmap_init();
	anon_vma_init();
#ifdef CONFIG_X86
	if (efi_enabled)
		efi_enter_virtual_mode();
#endif
#ifdef CONFIG_X86_ESPFIX64
	/* Should be run before the first non-init thread is created */
	init_espfix_bsp();
#endif
	thread_info_cache_init();
	cred_init();
	fork_init(totalram_pages);
	proc_caches_init();
	buffer_init();
	key_init();
	security_init();
	dbg_late_init();
	vfs_caches_init(totalram_pages);
	signals_init();
	
	page_writeback_init();
#ifdef CONFIG_PROC_FS
	proc_root_init();
#endif
	cgroup_init();
	cpuset_init();
	taskstats_init_early();
	delayacct_init();

	check_bugs();

	acpi_early_init(); 
	sfi_init_late();

	ftrace_init();

	
	rest_init();
}

static void __init do_ctors(void)
{
#ifdef CONFIG_CONSTRUCTORS
	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;

	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
		(*fn)();
#endif
}

bool initcall_debug;
core_param(initcall_debug, initcall_debug, bool, 0644);

static char msgbuf[64];

static int __init_or_module do_one_initcall_debug(initcall_t fn)
{
	ktime_t calltime, delta, rettime;
	unsigned long long duration;
	int ret;

	printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
	calltime = ktime_get();
	ret = fn();
	rettime = ktime_get();
	delta = ktime_sub(rettime, calltime);
	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
	printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
		ret, duration);

	return ret;
}

int __init_or_module do_one_initcall(initcall_t fn)
{
	int count = preempt_count();
	int ret;

	if (initcall_debug)
		ret = do_one_initcall_debug(fn);
	else
		ret = fn();

	msgbuf[0] = 0;

	if (ret && ret != -ENODEV && initcall_debug)
		sprintf(msgbuf, "error code %d ", ret);

	if (preempt_count() != count) {
		strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
		preempt_count() = count;
	}
	if (irqs_disabled()) {
		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
		local_irq_enable();
	}
	if (msgbuf[0]) {
		printk("initcall %pF returned with %s\n", fn, msgbuf);
	}

	return ret;
}


extern initcall_t __initcall_start[];
extern initcall_t __initcall0_start[];
extern initcall_t __initcall1_start[];
extern initcall_t __initcall2_start[];
extern initcall_t __initcall3_start[];
extern initcall_t __initcall4_start[];
extern initcall_t __initcall5_start[];
extern initcall_t __initcall6_start[];
extern initcall_t __initcall7_start[];
extern initcall_t __initcall_end[];

static initcall_t *initcall_levels[] __initdata = {
	__initcall0_start,
	__initcall1_start,
	__initcall2_start,
	__initcall3_start,
	__initcall4_start,
	__initcall5_start,
	__initcall6_start,
	__initcall7_start,
	__initcall_end,
};

static char *initcall_level_names[] __initdata = {
	"early parameters",
	"core parameters",
	"postcore parameters",
	"arch parameters",
	"subsys parameters",
	"fs parameters",
	"device parameters",
	"late parameters",
};

static void __init do_initcall_level(int level)
{
	extern const struct kernel_param __start___param[], __stop___param[];
	initcall_t *fn;

	strcpy(static_command_line, saved_command_line);
	parse_args(initcall_level_names[level],
		   static_command_line, __start___param,
		   __stop___param - __start___param,
		   level, level,
		   repair_env_string);

	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
		do_one_initcall(*fn);
}

static void __init do_initcalls(void)
{
	int level;

	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
		do_initcall_level(level);
}

static void __init do_basic_setup(void)
{
	cpuset_init_smp();
	usermodehelper_init();
	shmem_init();
	driver_init();
	init_irq_proc();
	do_ctors();
	usermodehelper_enable();
	do_initcalls();
}

static void __init do_pre_smp_initcalls(void)
{
	initcall_t *fn;

	for (fn = __initcall_start; fn < __initcall0_start; fn++)
		do_one_initcall(*fn);
}

static void run_init_process(const char *init_filename)
{
	argv_init[0] = init_filename;
	kernel_execve(init_filename, argv_init, envp_init);
}

static noinline int init_post(void)
{
	
	async_synchronize_full();
	free_initmem();
	mark_rodata_ro();
	system_state = SYSTEM_RUNNING;
	numa_default_policy();


	current->signal->flags |= SIGNAL_UNKILLABLE;

	if (ramdisk_execute_command) {
		run_init_process(ramdisk_execute_command);
		printk(KERN_WARNING "Failed to execute %s\n",
				ramdisk_execute_command);
	}

	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. "
	      "See Linux Documentation/init.txt for guidance.");
}

static int __init kernel_init(void * unused)
{
	wait_for_completion(&kthreadd_done);

	
	gfp_allowed_mask = __GFP_BITS_MASK;

	set_mems_allowed(node_states[N_HIGH_MEMORY]);
	set_cpus_allowed_ptr(current, cpu_all_mask);

	cad_pid = task_pid(current);

	smp_prepare_cpus(setup_max_cpus);

	do_pre_smp_initcalls();
	lockup_detector_init();

	smp_init();
	sched_init_smp();

	do_basic_setup();

	
	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);

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

	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
		ramdisk_execute_command = NULL;
		prepare_namespace();
	}


	init_post();
	return 0;
}