1/*
  2 *  linux/init/main.c
  3 *
  4 *  Copyright (C) 1991, 1992  Linus Torvalds
  5 *
  6 *  GK 2/5/95  -  Changed to support mounting root fs via NFS
  7 *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
  8 *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
  9 *  Simplified starting of init:  Michael A. Griffith <grif@acm.org> 
 10 */
 11
 12#define DEBUG		/* Enable initcall_debug */
 13
 14#include <linux/types.h>
 
 15#include <linux/module.h>
 16#include <linux/proc_fs.h>
 
 17#include <linux/kernel.h>
 18#include <linux/syscalls.h>
 19#include <linux/stackprotector.h>
 20#include <linux/string.h>
 21#include <linux/ctype.h>
 22#include <linux/delay.h>
 23#include <linux/ioport.h>
 24#include <linux/init.h>
 25#include <linux/initrd.h>
 26#include <linux/bootmem.h>
 27#include <linux/acpi.h>
 28#include <linux/tty.h>
 
 
 29#include <linux/percpu.h>
 30#include <linux/kmod.h>
 
 
 31#include <linux/vmalloc.h>
 32#include <linux/kernel_stat.h>
 33#include <linux/start_kernel.h>
 34#include <linux/security.h>
 35#include <linux/smp.h>
 36#include <linux/profile.h>
 
 37#include <linux/rcupdate.h>
 
 38#include <linux/moduleparam.h>
 39#include <linux/kallsyms.h>
 
 40#include <linux/writeback.h>
 41#include <linux/cpu.h>
 42#include <linux/cpuset.h>
 43#include <linux/cgroup.h>
 44#include <linux/efi.h>
 45#include <linux/tick.h>
 
 46#include <linux/interrupt.h>
 47#include <linux/taskstats_kern.h>
 48#include <linux/delayacct.h>
 49#include <linux/unistd.h>
 
 50#include <linux/rmap.h>
 51#include <linux/mempolicy.h>
 52#include <linux/key.h>
 53#include <linux/buffer_head.h>
 54#include <linux/page_cgroup.h>
 55#include <linux/debug_locks.h>
 56#include <linux/debugobjects.h>
 57#include <linux/lockdep.h>
 58#include <linux/kmemleak.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/kgdb.h>
 66#include <linux/ftrace.h>
 67#include <linux/async.h>
 68#include <linux/kmemcheck.h>
 69#include <linux/sfi.h>
 70#include <linux/shmem_fs.h>
 71#include <linux/slab.h>
 72#include <linux/perf_event.h>
 73#include <linux/file.h>
 74#include <linux/ptrace.h>
 
 75#include <linux/blkdev.h>
 76#include <linux/elevator.h>
 77#include <linux/sched_clock.h>
 
 78#include <linux/context_tracking.h>
 79#include <linux/random.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 80
 81#include <asm/io.h>
 82#include <asm/bugs.h>
 83#include <asm/setup.h>
 84#include <asm/sections.h>
 85#include <asm/cacheflush.h>
 86
 87#ifdef CONFIG_X86_LOCAL_APIC
 88#include <asm/smp.h>
 89#endif
 
 90
 91static int kernel_init(void *);
 92
 93extern void init_IRQ(void);
 94extern void fork_init(unsigned long);
 95extern void radix_tree_init(void);
 96#ifndef CONFIG_DEBUG_RODATA
 97static inline void mark_rodata_ro(void) { }
 98#endif
 99
100/*
101 * Debug helper: via this flag we know that we are in 'early bootup code'
102 * where only the boot processor is running with IRQ disabled.  This means
103 * two things - IRQ must not be enabled before the flag is cleared and some
104 * operations which are not allowed with IRQ disabled are allowed while the
105 * flag is set.
106 */
107bool early_boot_irqs_disabled __read_mostly;
108
109enum system_states system_state __read_mostly;
110EXPORT_SYMBOL(system_state);
111
112/*
113 * Boot command-line arguments
114 */
115#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
116#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
117
118extern void time_init(void);
119/* Default late time init is NULL. archs can override this later. */
120void (*__initdata late_time_init)(void);
121
122/* Untouched command line saved by arch-specific code. */
123char __initdata boot_command_line[COMMAND_LINE_SIZE];
124/* Untouched saved command line (eg. for /proc) */
125char *saved_command_line;
 
126/* Command line for parameter parsing */
127static char *static_command_line;
128/* Command line for per-initcall parameter parsing */
129static char *initcall_command_line;
 
 
 
 
 
 
 
 
 
 
 
130
131static char *execute_command;
132static char *ramdisk_execute_command;
133
134/*
135 * Used to generate warnings if static_key manipulation functions are used
136 * before jump_label_init is called.
137 */
138bool static_key_initialized __read_mostly = false;
139EXPORT_SYMBOL_GPL(static_key_initialized);
140
141/*
142 * If set, this is an indication to the drivers that reset the underlying
143 * device before going ahead with the initialization otherwise driver might
144 * rely on the BIOS and skip the reset operation.
145 *
146 * This is useful if kernel is booting in an unreliable environment.
147 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
148 * skipped and devices will be in unknown state.
149 */
150unsigned int reset_devices;
151EXPORT_SYMBOL(reset_devices);
152
153static int __init set_reset_devices(char *str)
154{
155	reset_devices = 1;
156	return 1;
157}
158
159__setup("reset_devices", set_reset_devices);
160
161static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
162const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
163static const char *panic_later, *panic_param;
164
165extern const struct obs_kernel_param __setup_start[], __setup_end[];
166
167static int __init obsolete_checksetup(char *line)
168{
169	const struct obs_kernel_param *p;
170	int had_early_param = 0;
171
172	p = __setup_start;
173	do {
174		int n = strlen(p->str);
175		if (parameqn(line, p->str, n)) {
176			if (p->early) {
177				/* Already done in parse_early_param?
178				 * (Needs exact match on param part).
179				 * Keep iterating, as we can have early
180				 * params and __setups of same names 8( */
181				if (line[n] == '\0' || line[n] == '=')
182					had_early_param = 1;
183			} else if (!p->setup_func) {
184				pr_warn("Parameter %s is obsolete, ignored\n",
185					p->str);
186				return 1;
187			} else if (p->setup_func(line + n))
188				return 1;
189		}
190		p++;
191	} while (p < __setup_end);
192
193	return had_early_param;
194}
195
196/*
197 * This should be approx 2 Bo*oMips to start (note initial shift), and will
198 * still work even if initially too large, it will just take slightly longer
199 */
200unsigned long loops_per_jiffy = (1<<12);
201
202EXPORT_SYMBOL(loops_per_jiffy);
203
204static int __init debug_kernel(char *str)
205{
206	console_loglevel = 10;
207	return 0;
208}
209
210static int __init quiet_kernel(char *str)
211{
212	console_loglevel = 4;
213	return 0;
214}
215
216early_param("debug", debug_kernel);
217early_param("quiet", quiet_kernel);
218
219static int __init loglevel(char *str)
220{
221	int newlevel;
222
223	/*
224	 * Only update loglevel value when a correct setting was passed,
225	 * to prevent blind crashes (when loglevel being set to 0) that
226	 * are quite hard to debug
227	 */
228	if (get_option(&str, &newlevel)) {
229		console_loglevel = newlevel;
230		return 0;
231	}
232
233	return -EINVAL;
234}
235
236early_param("loglevel", loglevel);
237
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
238/* Change NUL term back to "=", to make "param" the whole string. */
239static int __init repair_env_string(char *param, char *val, const char *unused)
240{
241	if (val) {
242		/* param=val or param="val"? */
243		if (val == param+strlen(param)+1)
244			val[-1] = '=';
245		else if (val == param+strlen(param)+2) {
246			val[-2] = '=';
247			memmove(val-1, val, strlen(val)+1);
248			val--;
249		} else
250			BUG();
251	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
252	return 0;
253}
254
255/*
256 * Unknown boot options get handed to init, unless they look like
257 * unused parameters (modprobe will find them in /proc/cmdline).
258 */
259static int __init unknown_bootoption(char *param, char *val, const char *unused)
 
260{
261	repair_env_string(param, val, unused);
 
 
262
263	/* Handle obsolete-style parameters */
264	if (obsolete_checksetup(param))
265		return 0;
266
267	/* Unused module parameter. */
268	if (strchr(param, '.') && (!val || strchr(param, '.') < val))
269		return 0;
270
271	if (panic_later)
272		return 0;
273
274	if (val) {
275		/* Environment option */
276		unsigned int i;
277		for (i = 0; envp_init[i]; i++) {
278			if (i == MAX_INIT_ENVS) {
279				panic_later = "env";
280				panic_param = param;
281			}
282			if (!strncmp(param, envp_init[i], val - param))
283				break;
284		}
285		envp_init[i] = param;
286	} else {
287		/* Command line option */
288		unsigned int i;
289		for (i = 0; argv_init[i]; i++) {
290			if (i == MAX_INIT_ARGS) {
291				panic_later = "init";
292				panic_param = param;
293			}
294		}
295		argv_init[i] = param;
296	}
297	return 0;
298}
299
300static int __init init_setup(char *str)
301{
302	unsigned int i;
303
304	execute_command = str;
305	/*
306	 * In case LILO is going to boot us with default command line,
307	 * it prepends "auto" before the whole cmdline which makes
308	 * the shell think it should execute a script with such name.
309	 * So we ignore all arguments entered _before_ init=... [MJ]
310	 */
311	for (i = 1; i < MAX_INIT_ARGS; i++)
312		argv_init[i] = NULL;
313	return 1;
314}
315__setup("init=", init_setup);
316
317static int __init rdinit_setup(char *str)
318{
319	unsigned int i;
320
321	ramdisk_execute_command = str;
322	/* See "auto" comment in init_setup */
323	for (i = 1; i < MAX_INIT_ARGS; i++)
324		argv_init[i] = NULL;
325	return 1;
326}
327__setup("rdinit=", rdinit_setup);
328
329#ifndef CONFIG_SMP
330static const unsigned int setup_max_cpus = NR_CPUS;
331#ifdef CONFIG_X86_LOCAL_APIC
332static void __init smp_init(void)
333{
334	APIC_init_uniprocessor();
335}
336#else
337#define smp_init()	do { } while (0)
338#endif
339
340static inline void setup_nr_cpu_ids(void) { }
341static inline void smp_prepare_cpus(unsigned int maxcpus) { }
342#endif
343
344/*
345 * We need to store the untouched command line for future reference.
346 * We also need to store the touched command line since the parameter
347 * parsing is performed in place, and we should allow a component to
348 * store reference of name/value for future reference.
349 */
350static void __init setup_command_line(char *command_line)
351{
352	saved_command_line =
353		memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
354	initcall_command_line =
355		memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
356	static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
357	strcpy (saved_command_line, boot_command_line);
358	strcpy (static_command_line, command_line);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
359}
360
361/*
362 * We need to finalize in a non-__init function or else race conditions
363 * between the root thread and the init thread may cause start_kernel to
364 * be reaped by free_initmem before the root thread has proceeded to
365 * cpu_idle.
366 *
367 * gcc-3.4 accidentally inlines this function, so use noinline.
368 */
369
370static __initdata DECLARE_COMPLETION(kthreadd_done);
371
372static noinline void __init_refok rest_init(void)
373{
 
374	int pid;
375
376	rcu_scheduler_starting();
377	/*
378	 * We need to spawn init first so that it obtains pid 1, however
379	 * the init task will end up wanting to create kthreads, which, if
380	 * we schedule it before we create kthreadd, will OOPS.
381	 */
382	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
 
 
 
 
 
 
 
 
 
 
 
383	numa_default_policy();
384	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
385	rcu_read_lock();
386	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
387	rcu_read_unlock();
 
 
 
 
 
 
 
 
 
 
388	complete(&kthreadd_done);
389
390	/*
391	 * The boot idle thread must execute schedule()
392	 * at least once to get things moving:
393	 */
394	init_idle_bootup_task(current);
395	schedule_preempt_disabled();
396	/* Call into cpu_idle with preempt disabled */
397	cpu_startup_entry(CPUHP_ONLINE);
398}
399
400/* Check for early params. */
401static int __init do_early_param(char *param, char *val, const char *unused)
 
402{
403	const struct obs_kernel_param *p;
404
405	for (p = __setup_start; p < __setup_end; p++) {
406		if ((p->early && parameq(param, p->str)) ||
407		    (strcmp(param, "console") == 0 &&
408		     strcmp(p->str, "earlycon") == 0)
409		) {
410			if (p->setup_func(val) != 0)
411				pr_warn("Malformed early option '%s'\n", param);
412		}
413	}
414	/* We accept everything at this stage. */
415	return 0;
416}
417
418void __init parse_early_options(char *cmdline)
419{
420	parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
 
421}
422
423/* Arch code calls this early on, or if not, just before other parsing. */
424void __init parse_early_param(void)
425{
426	static __initdata int done = 0;
427	static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
428
429	if (done)
430		return;
431
432	/* All fall through to do_early_param. */
433	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
434	parse_early_options(tmp_cmdline);
435	done = 1;
436}
437
438/*
439 *	Activate the first processor.
440 */
441
442static void __init boot_cpu_init(void)
443{
444	int cpu = smp_processor_id();
445	/* Mark the boot cpu "present", "online" etc for SMP and UP case */
446	set_cpu_online(cpu, true);
447	set_cpu_active(cpu, true);
448	set_cpu_present(cpu, true);
449	set_cpu_possible(cpu, true);
450}
451
452void __init __weak smp_setup_processor_id(void)
 
453{
454}
 
455
456# if THREAD_SIZE >= PAGE_SIZE
457void __init __weak thread_info_cache_init(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
458{
459}
460#endif
461
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
462/*
463 * Set up kernel memory allocators
464 */
465static void __init mm_init(void)
466{
467	/*
468	 * page_cgroup requires contiguous pages,
469	 * bigger than MAX_ORDER unless SPARSEMEM.
470	 */
471	page_cgroup_init_flatmem();
 
 
 
 
 
472	mem_init();
 
473	kmem_cache_init();
474	percpu_init_late();
 
 
 
 
 
475	pgtable_init();
 
476	vmalloc_init();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
477}
478
479asmlinkage __visible void __init start_kernel(void)
480{
481	char * command_line;
482	extern const struct kernel_param __start___param[], __stop___param[];
 
 
 
 
 
483
484	/*
485	 * Need to run as early as possible, to initialize the
486	 * lockdep hash:
487	 */
488	lockdep_init();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
489	smp_setup_processor_id();
490	debug_objects_early_init();
491
492	/*
493	 * Set up the the initial canary ASAP:
494	 */
495	boot_init_stack_canary();
496
497	cgroup_init_early();
498
499	local_irq_disable();
500	early_boot_irqs_disabled = true;
501
502/*
503 * Interrupts are still disabled. Do necessary setups, then
504 * enable them
505 */
506	boot_cpu_init();
507	page_address_init();
508	pr_notice("%s", linux_banner);
 
509	setup_arch(&command_line);
510	mm_init_owner(&init_mm, &init_task);
511	mm_init_cpumask(&init_mm);
512	setup_command_line(command_line);
513	setup_nr_cpu_ids();
514	setup_per_cpu_areas();
515	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 
516
517	build_all_zonelists(NULL, NULL);
518	page_alloc_init();
519
520	pr_notice("Kernel command line: %s\n", boot_command_line);
 
 
521	parse_early_param();
522	parse_args("Booting kernel", static_command_line, __start___param,
523		   __stop___param - __start___param,
524		   -1, -1, &unknown_bootoption);
 
 
 
 
 
 
 
 
525
526	jump_label_init();
 
527
528	/*
529	 * These use large bootmem allocations and must precede
530	 * kmem_cache_init()
531	 */
532	setup_log_buf(0);
533	pidhash_init();
534	vfs_caches_init_early();
535	sort_main_extable();
536	trap_init();
537	mm_init();
 
 
 
 
 
538
539	/*
540	 * Set up the scheduler prior starting any interrupts (such as the
541	 * timer interrupt). Full topology setup happens at smp_init()
542	 * time - but meanwhile we still have a functioning scheduler.
543	 */
544	sched_init();
 
 
 
 
 
 
 
545	/*
546	 * Disable preemption - early bootup scheduling is extremely
547	 * fragile until we cpu_idle() for the first time.
548	 */
549	preempt_disable();
550	if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))
551		local_irq_disable();
552	idr_init_cache();
 
 
 
 
 
553	rcu_init();
554	tick_nohz_init();
 
 
 
 
 
 
555	context_tracking_init();
556	radix_tree_init();
557	/* init some links before init_ISA_irqs() */
558	early_irq_init();
559	init_IRQ();
560	tick_init();
 
561	init_timers();
 
562	hrtimers_init();
563	softirq_init();
564	timekeeping_init();
565	time_init();
566	sched_clock_postinit();
 
 
 
 
 
 
 
567	perf_event_init();
568	profile_init();
569	call_function_init();
570	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 
571	early_boot_irqs_disabled = false;
572	local_irq_enable();
573
574	kmem_cache_init_late();
575
576	/*
577	 * HACK ALERT! This is early. We're enabling the console before
578	 * we've done PCI setups etc, and console_init() must be aware of
579	 * this. But we do want output early, in case something goes wrong.
580	 */
581	console_init();
582	if (panic_later)
583		panic("Too many boot %s vars at `%s'", panic_later,
584		      panic_param);
585
586	lockdep_info();
587
588	/*
589	 * Need to run this when irqs are enabled, because it wants
590	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
591	 * too:
592	 */
593	locking_selftest();
594
 
 
 
 
 
 
 
 
595#ifdef CONFIG_BLK_DEV_INITRD
596	if (initrd_start && !initrd_below_start_ok &&
597	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
598		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
599		    page_to_pfn(virt_to_page((void *)initrd_start)),
600		    min_low_pfn);
601		initrd_start = 0;
602	}
603#endif
604	page_cgroup_init();
605	debug_objects_mem_init();
606	kmemleak_init();
607	setup_per_cpu_pageset();
608	numa_policy_init();
 
609	if (late_time_init)
610		late_time_init();
611	sched_clock_init();
612	calibrate_delay();
613	pidmap_init();
614	anon_vma_init();
615	acpi_early_init();
616#ifdef CONFIG_X86
617	if (efi_enabled(EFI_RUNTIME_SERVICES))
618		efi_enter_virtual_mode();
619#endif
620	thread_info_cache_init();
621	cred_init();
622	fork_init(totalram_pages);
623	proc_caches_init();
624	buffer_init();
625	key_init();
626	security_init();
627	dbg_late_init();
628	vfs_caches_init(totalram_pages);
 
 
629	signals_init();
630	/* rootfs populating might need page-writeback */
631	page_writeback_init();
632#ifdef CONFIG_PROC_FS
633	proc_root_init();
634#endif
635	cgroup_init();
636	cpuset_init();
 
637	taskstats_init_early();
638	delayacct_init();
639
640	check_bugs();
641
642	sfi_init_late();
643
644	if (efi_enabled(EFI_RUNTIME_SERVICES)) {
645		efi_late_init();
646		efi_free_boot_services();
647	}
648
649	ftrace_init();
650
651	/* Do the rest non-__init'ed, we're now alive */
652	rest_init();
 
 
653}
654
655/* Call all constructor functions linked into the kernel. */
656static void __init do_ctors(void)
657{
658#ifdef CONFIG_CONSTRUCTORS
 
 
 
 
 
 
659	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
660
661	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
662		(*fn)();
663#endif
664}
665
666bool initcall_debug;
667core_param(initcall_debug, initcall_debug, bool, 0644);
 
 
 
668
669static int __init_or_module do_one_initcall_debug(initcall_t fn)
 
 
670{
671	ktime_t calltime, delta, rettime;
672	unsigned long long duration;
673	int ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
674
675	pr_debug("calling  %pF @ %i\n", fn, task_pid_nr(current));
676	calltime = ktime_get();
677	ret = fn();
678	rettime = ktime_get();
679	delta = ktime_sub(rettime, calltime);
680	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
681	pr_debug("initcall %pF returned %d after %lld usecs\n",
682		 fn, ret, duration);
683
684	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
685}
 
 
 
 
 
 
 
686
687int __init_or_module do_one_initcall(initcall_t fn)
688{
689	int count = preempt_count();
690	int ret;
691	char msgbuf[64];
 
692
693	if (initcall_debug)
694		ret = do_one_initcall_debug(fn);
695	else
696		ret = fn();
 
 
697
698	msgbuf[0] = 0;
699
700	if (preempt_count() != count) {
701		sprintf(msgbuf, "preemption imbalance ");
702		preempt_count_set(count);
703	}
704	if (irqs_disabled()) {
705		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
706		local_irq_enable();
707	}
708	WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
709
 
710	return ret;
711}
712
713
714extern initcall_t __initcall_start[];
715extern initcall_t __initcall0_start[];
716extern initcall_t __initcall1_start[];
717extern initcall_t __initcall2_start[];
718extern initcall_t __initcall3_start[];
719extern initcall_t __initcall4_start[];
720extern initcall_t __initcall5_start[];
721extern initcall_t __initcall6_start[];
722extern initcall_t __initcall7_start[];
723extern initcall_t __initcall_end[];
724
725static initcall_t *initcall_levels[] __initdata = {
726	__initcall0_start,
727	__initcall1_start,
728	__initcall2_start,
729	__initcall3_start,
730	__initcall4_start,
731	__initcall5_start,
732	__initcall6_start,
733	__initcall7_start,
734	__initcall_end,
735};
736
737/* Keep these in sync with initcalls in include/linux/init.h */
738static char *initcall_level_names[] __initdata = {
739	"early",
740	"core",
741	"postcore",
742	"arch",
743	"subsys",
744	"fs",
745	"device",
746	"late",
747};
748
749static void __init do_initcall_level(int level)
 
750{
751	extern const struct kernel_param __start___param[], __stop___param[];
752	initcall_t *fn;
 
 
 
 
753
754	strcpy(initcall_command_line, saved_command_line);
755	parse_args(initcall_level_names[level],
756		   initcall_command_line, __start___param,
757		   __stop___param - __start___param,
758		   level, level,
759		   &repair_env_string);
760
 
761	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
762		do_one_initcall(*fn);
763}
764
765static void __init do_initcalls(void)
766{
767	int level;
 
 
 
 
 
 
 
 
 
 
 
 
768
769	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
770		do_initcall_level(level);
771}
772
773/*
774 * Ok, the machine is now initialized. None of the devices
775 * have been touched yet, but the CPU subsystem is up and
776 * running, and memory and process management works.
777 *
778 * Now we can finally start doing some real work..
779 */
780static void __init do_basic_setup(void)
781{
782	cpuset_init_smp();
783	usermodehelper_init();
784	shmem_init();
785	driver_init();
786	init_irq_proc();
787	do_ctors();
788	usermodehelper_enable();
789	do_initcalls();
790	random_int_secret_init();
791}
792
793static void __init do_pre_smp_initcalls(void)
794{
795	initcall_t *fn;
796
 
797	for (fn = __initcall_start; fn < __initcall0_start; fn++)
798		do_one_initcall(*fn);
799}
800
801/*
802 * This function requests modules which should be loaded by default and is
803 * called twice right after initrd is mounted and right before init is
804 * exec'd.  If such modules are on either initrd or rootfs, they will be
805 * loaded before control is passed to userland.
806 */
807void __init load_default_modules(void)
808{
809	load_default_elevator_module();
810}
811
812static int run_init_process(const char *init_filename)
813{
 
 
814	argv_init[0] = init_filename;
815	return do_execve(getname_kernel(init_filename),
816		(const char __user *const __user *)argv_init,
817		(const char __user *const __user *)envp_init);
 
 
 
 
 
818}
819
820static int try_to_run_init_process(const char *init_filename)
821{
822	int ret;
823
824	ret = run_init_process(init_filename);
825
826	if (ret && ret != -ENOENT) {
827		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
828		       init_filename, ret);
829	}
830
831	return ret;
832}
833
834static noinline void __init kernel_init_freeable(void);
835
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
836static int __ref kernel_init(void *unused)
837{
838	int ret;
839
 
 
 
 
 
840	kernel_init_freeable();
841	/* need to finish all async __init code before freeing the memory */
842	async_synchronize_full();
 
 
 
 
 
 
843	free_initmem();
844	mark_rodata_ro();
 
 
 
 
 
 
 
845	system_state = SYSTEM_RUNNING;
846	numa_default_policy();
847
848	flush_delayed_fput();
 
 
849
850	if (ramdisk_execute_command) {
851		ret = run_init_process(ramdisk_execute_command);
852		if (!ret)
853			return 0;
854		pr_err("Failed to execute %s (error %d)\n",
855		       ramdisk_execute_command, ret);
856	}
857
858	/*
859	 * We try each of these until one succeeds.
860	 *
861	 * The Bourne shell can be used instead of init if we are
862	 * trying to recover a really broken machine.
863	 */
864	if (execute_command) {
865		ret = run_init_process(execute_command);
866		if (!ret)
867			return 0;
868		pr_err("Failed to execute %s (error %d).  Attempting defaults...\n",
869			execute_command, ret);
870	}
 
 
 
 
 
 
 
 
 
 
871	if (!try_to_run_init_process("/sbin/init") ||
872	    !try_to_run_init_process("/etc/init") ||
873	    !try_to_run_init_process("/bin/init") ||
874	    !try_to_run_init_process("/bin/sh"))
875		return 0;
876
877	panic("No working init found.  Try passing init= option to kernel. "
878	      "See Linux Documentation/init.txt for guidance.");
879}
880
881static noinline void __init kernel_init_freeable(void)
 
882{
883	/*
884	 * Wait until kthreadd is all set-up.
885	 */
886	wait_for_completion(&kthreadd_done);
887
 
 
 
 
 
 
 
 
 
 
 
 
888	/* Now the scheduler is fully set up and can do blocking allocations */
889	gfp_allowed_mask = __GFP_BITS_MASK;
890
891	/*
892	 * init can allocate pages on any node
893	 */
894	set_mems_allowed(node_states[N_MEMORY]);
895	/*
896	 * init can run on any cpu.
897	 */
898	set_cpus_allowed_ptr(current, cpu_all_mask);
899
900	cad_pid = task_pid(current);
901
902	smp_prepare_cpus(setup_max_cpus);
903
 
 
 
 
 
904	do_pre_smp_initcalls();
905	lockup_detector_init();
906
907	smp_init();
908	sched_init_smp();
909
 
 
 
 
 
 
910	do_basic_setup();
911
912	/* Open the /dev/console on the rootfs, this should never fail */
913	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
914		pr_err("Warning: unable to open an initial console.\n");
 
915
916	(void) sys_dup(0);
917	(void) sys_dup(0);
918	/*
919	 * check if there is an early userspace init.  If yes, let it do all
920	 * the work
921	 */
922
923	if (!ramdisk_execute_command)
924		ramdisk_execute_command = "/init";
925
926	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
927		ramdisk_execute_command = NULL;
928		prepare_namespace();
929	}
930
931	/*
932	 * Ok, we have completed the initial bootup, and
933	 * we're essentially up and running. Get rid of the
934	 * initmem segments and start the user-mode stuff..
 
 
 
935	 */
936
937	/* rootfs is available now, try loading default modules */
938	load_default_modules();
939}