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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_ext.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#include <linux/list.h>
81#include <linux/integrity.h>
82#include <linux/proc_ns.h>
83#include <linux/io.h>
84
85#include <asm/io.h>
86#include <asm/bugs.h>
87#include <asm/setup.h>
88#include <asm/sections.h>
89#include <asm/cacheflush.h>
90
91static int kernel_init(void *);
92
93extern void init_IRQ(void);
94extern void fork_init(void);
95extern void radix_tree_init(void);
96
97/*
98 * Debug helper: via this flag we know that we are in 'early bootup code'
99 * where only the boot processor is running with IRQ disabled. This means
100 * two things - IRQ must not be enabled before the flag is cleared and some
101 * operations which are not allowed with IRQ disabled are allowed while the
102 * flag is set.
103 */
104bool early_boot_irqs_disabled __read_mostly;
105
106enum system_states system_state __read_mostly;
107EXPORT_SYMBOL(system_state);
108
109/*
110 * Boot command-line arguments
111 */
112#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
113#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
114
115extern void time_init(void);
116/* Default late time init is NULL. archs can override this later. */
117void (*__initdata late_time_init)(void);
118
119/* Untouched command line saved by arch-specific code. */
120char __initdata boot_command_line[COMMAND_LINE_SIZE];
121/* Untouched saved command line (eg. for /proc) */
122char *saved_command_line;
123/* Command line for parameter parsing */
124static char *static_command_line;
125/* Command line for per-initcall parameter parsing */
126static char *initcall_command_line;
127
128static char *execute_command;
129static char *ramdisk_execute_command;
130
131/*
132 * Used to generate warnings if static_key manipulation functions are used
133 * before jump_label_init is called.
134 */
135bool static_key_initialized __read_mostly;
136EXPORT_SYMBOL_GPL(static_key_initialized);
137
138/*
139 * If set, this is an indication to the drivers that reset the underlying
140 * device before going ahead with the initialization otherwise driver might
141 * rely on the BIOS and skip the reset operation.
142 *
143 * This is useful if kernel is booting in an unreliable environment.
144 * For ex. kdump situation where previous kernel has crashed, BIOS has been
145 * skipped and devices will be in unknown state.
146 */
147unsigned int reset_devices;
148EXPORT_SYMBOL(reset_devices);
149
150static int __init set_reset_devices(char *str)
151{
152 reset_devices = 1;
153 return 1;
154}
155
156__setup("reset_devices", set_reset_devices);
157
158static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
159const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
160static const char *panic_later, *panic_param;
161
162extern const struct obs_kernel_param __setup_start[], __setup_end[];
163
164static bool __init obsolete_checksetup(char *line)
165{
166 const struct obs_kernel_param *p;
167 bool had_early_param = false;
168
169 p = __setup_start;
170 do {
171 int n = strlen(p->str);
172 if (parameqn(line, p->str, n)) {
173 if (p->early) {
174 /* Already done in parse_early_param?
175 * (Needs exact match on param part).
176 * Keep iterating, as we can have early
177 * params and __setups of same names 8( */
178 if (line[n] == '\0' || line[n] == '=')
179 had_early_param = true;
180 } else if (!p->setup_func) {
181 pr_warn("Parameter %s is obsolete, ignored\n",
182 p->str);
183 return true;
184 } else if (p->setup_func(line + n))
185 return true;
186 }
187 p++;
188 } while (p < __setup_end);
189
190 return had_early_param;
191}
192
193/*
194 * This should be approx 2 Bo*oMips to start (note initial shift), and will
195 * still work even if initially too large, it will just take slightly longer
196 */
197unsigned long loops_per_jiffy = (1<<12);
198EXPORT_SYMBOL(loops_per_jiffy);
199
200static int __init debug_kernel(char *str)
201{
202 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
203 return 0;
204}
205
206static int __init quiet_kernel(char *str)
207{
208 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
209 return 0;
210}
211
212early_param("debug", debug_kernel);
213early_param("quiet", quiet_kernel);
214
215static int __init loglevel(char *str)
216{
217 int newlevel;
218
219 /*
220 * Only update loglevel value when a correct setting was passed,
221 * to prevent blind crashes (when loglevel being set to 0) that
222 * are quite hard to debug
223 */
224 if (get_option(&str, &newlevel)) {
225 console_loglevel = newlevel;
226 return 0;
227 }
228
229 return -EINVAL;
230}
231
232early_param("loglevel", loglevel);
233
234/* Change NUL term back to "=", to make "param" the whole string. */
235static int __init repair_env_string(char *param, char *val,
236 const char *unused, void *arg)
237{
238 if (val) {
239 /* param=val or param="val"? */
240 if (val == param+strlen(param)+1)
241 val[-1] = '=';
242 else if (val == param+strlen(param)+2) {
243 val[-2] = '=';
244 memmove(val-1, val, strlen(val)+1);
245 val--;
246 } else
247 BUG();
248 }
249 return 0;
250}
251
252/* Anything after -- gets handed straight to init. */
253static int __init set_init_arg(char *param, char *val,
254 const char *unused, void *arg)
255{
256 unsigned int i;
257
258 if (panic_later)
259 return 0;
260
261 repair_env_string(param, val, unused, NULL);
262
263 for (i = 0; argv_init[i]; i++) {
264 if (i == MAX_INIT_ARGS) {
265 panic_later = "init";
266 panic_param = param;
267 return 0;
268 }
269 }
270 argv_init[i] = param;
271 return 0;
272}
273
274/*
275 * Unknown boot options get handed to init, unless they look like
276 * unused parameters (modprobe will find them in /proc/cmdline).
277 */
278static int __init unknown_bootoption(char *param, char *val,
279 const char *unused, void *arg)
280{
281 repair_env_string(param, val, unused, NULL);
282
283 /* Handle obsolete-style parameters */
284 if (obsolete_checksetup(param))
285 return 0;
286
287 /* Unused module parameter. */
288 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
289 return 0;
290
291 if (panic_later)
292 return 0;
293
294 if (val) {
295 /* Environment option */
296 unsigned int i;
297 for (i = 0; envp_init[i]; i++) {
298 if (i == MAX_INIT_ENVS) {
299 panic_later = "env";
300 panic_param = param;
301 }
302 if (!strncmp(param, envp_init[i], val - param))
303 break;
304 }
305 envp_init[i] = param;
306 } else {
307 /* Command line option */
308 unsigned int i;
309 for (i = 0; argv_init[i]; i++) {
310 if (i == MAX_INIT_ARGS) {
311 panic_later = "init";
312 panic_param = param;
313 }
314 }
315 argv_init[i] = param;
316 }
317 return 0;
318}
319
320static int __init init_setup(char *str)
321{
322 unsigned int i;
323
324 execute_command = str;
325 /*
326 * In case LILO is going to boot us with default command line,
327 * it prepends "auto" before the whole cmdline which makes
328 * the shell think it should execute a script with such name.
329 * So we ignore all arguments entered _before_ init=... [MJ]
330 */
331 for (i = 1; i < MAX_INIT_ARGS; i++)
332 argv_init[i] = NULL;
333 return 1;
334}
335__setup("init=", init_setup);
336
337static int __init rdinit_setup(char *str)
338{
339 unsigned int i;
340
341 ramdisk_execute_command = str;
342 /* See "auto" comment in init_setup */
343 for (i = 1; i < MAX_INIT_ARGS; i++)
344 argv_init[i] = NULL;
345 return 1;
346}
347__setup("rdinit=", rdinit_setup);
348
349#ifndef CONFIG_SMP
350static const unsigned int setup_max_cpus = NR_CPUS;
351static inline void setup_nr_cpu_ids(void) { }
352static inline void smp_prepare_cpus(unsigned int maxcpus) { }
353#endif
354
355/*
356 * We need to store the untouched command line for future reference.
357 * We also need to store the touched command line since the parameter
358 * parsing is performed in place, and we should allow a component to
359 * store reference of name/value for future reference.
360 */
361static void __init setup_command_line(char *command_line)
362{
363 saved_command_line =
364 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
365 initcall_command_line =
366 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
367 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
368 strcpy(saved_command_line, boot_command_line);
369 strcpy(static_command_line, command_line);
370}
371
372/*
373 * We need to finalize in a non-__init function or else race conditions
374 * between the root thread and the init thread may cause start_kernel to
375 * be reaped by free_initmem before the root thread has proceeded to
376 * cpu_idle.
377 *
378 * gcc-3.4 accidentally inlines this function, so use noinline.
379 */
380
381static __initdata DECLARE_COMPLETION(kthreadd_done);
382
383static noinline void __init_refok rest_init(void)
384{
385 int pid;
386
387 rcu_scheduler_starting();
388 /*
389 * We need to spawn init first so that it obtains pid 1, however
390 * the init task will end up wanting to create kthreads, which, if
391 * we schedule it before we create kthreadd, will OOPS.
392 */
393 kernel_thread(kernel_init, NULL, CLONE_FS);
394 numa_default_policy();
395 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
396 rcu_read_lock();
397 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
398 rcu_read_unlock();
399 complete(&kthreadd_done);
400
401 /*
402 * The boot idle thread must execute schedule()
403 * at least once to get things moving:
404 */
405 init_idle_bootup_task(current);
406 schedule_preempt_disabled();
407 /* Call into cpu_idle with preempt disabled */
408 cpu_startup_entry(CPUHP_ONLINE);
409}
410
411/* Check for early params. */
412static int __init do_early_param(char *param, char *val,
413 const char *unused, void *arg)
414{
415 const struct obs_kernel_param *p;
416
417 for (p = __setup_start; p < __setup_end; p++) {
418 if ((p->early && parameq(param, p->str)) ||
419 (strcmp(param, "console") == 0 &&
420 strcmp(p->str, "earlycon") == 0)
421 ) {
422 if (p->setup_func(val) != 0)
423 pr_warn("Malformed early option '%s'\n", param);
424 }
425 }
426 /* We accept everything at this stage. */
427 return 0;
428}
429
430void __init parse_early_options(char *cmdline)
431{
432 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
433 do_early_param);
434}
435
436/* Arch code calls this early on, or if not, just before other parsing. */
437void __init parse_early_param(void)
438{
439 static int done __initdata;
440 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
441
442 if (done)
443 return;
444
445 /* All fall through to do_early_param. */
446 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
447 parse_early_options(tmp_cmdline);
448 done = 1;
449}
450
451void __init __weak smp_setup_processor_id(void)
452{
453}
454
455# if THREAD_SIZE >= PAGE_SIZE
456void __init __weak thread_info_cache_init(void)
457{
458}
459#endif
460
461/*
462 * Set up kernel memory allocators
463 */
464static void __init mm_init(void)
465{
466 /*
467 * page_ext requires contiguous pages,
468 * bigger than MAX_ORDER unless SPARSEMEM.
469 */
470 page_ext_init_flatmem();
471 mem_init();
472 kmem_cache_init();
473 percpu_init_late();
474 pgtable_init();
475 vmalloc_init();
476 ioremap_huge_init();
477}
478
479asmlinkage __visible void __init start_kernel(void)
480{
481 char *command_line;
482 char *after_dashes;
483
484 set_task_stack_end_magic(&init_task);
485 smp_setup_processor_id();
486 debug_objects_early_init();
487
488 /*
489 * Set up the the initial canary ASAP:
490 */
491 boot_init_stack_canary();
492
493 cgroup_init_early();
494
495 local_irq_disable();
496 early_boot_irqs_disabled = true;
497
498/*
499 * Interrupts are still disabled. Do necessary setups, then
500 * enable them
501 */
502 boot_cpu_init();
503 page_address_init();
504 pr_notice("%s", linux_banner);
505 setup_arch(&command_line);
506 mm_init_cpumask(&init_mm);
507 setup_command_line(command_line);
508 setup_nr_cpu_ids();
509 setup_per_cpu_areas();
510 boot_cpu_state_init();
511 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
512
513 build_all_zonelists(NULL, NULL);
514 page_alloc_init();
515
516 pr_notice("Kernel command line: %s\n", boot_command_line);
517 parse_early_param();
518 after_dashes = parse_args("Booting kernel",
519 static_command_line, __start___param,
520 __stop___param - __start___param,
521 -1, -1, NULL, &unknown_bootoption);
522 if (!IS_ERR_OR_NULL(after_dashes))
523 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
524 NULL, set_init_arg);
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(),
551 "Interrupts were enabled *very* early, fixing it\n"))
552 local_irq_disable();
553 idr_init_cache();
554 rcu_init();
555
556 /* trace_printk() and trace points may be used after this */
557 trace_init();
558
559 context_tracking_init();
560 radix_tree_init();
561 /* init some links before init_ISA_irqs() */
562 early_irq_init();
563 init_IRQ();
564 tick_init();
565 rcu_init_nohz();
566 init_timers();
567 hrtimers_init();
568 softirq_init();
569 timekeeping_init();
570 time_init();
571 sched_clock_postinit();
572 perf_event_init();
573 profile_init();
574 call_function_init();
575 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
576 early_boot_irqs_disabled = false;
577 local_irq_enable();
578
579 kmem_cache_init_late();
580
581 /*
582 * HACK ALERT! This is early. We're enabling the console before
583 * we've done PCI setups etc, and console_init() must be aware of
584 * this. But we do want output early, in case something goes wrong.
585 */
586 console_init();
587 if (panic_later)
588 panic("Too many boot %s vars at `%s'", panic_later,
589 panic_param);
590
591 lockdep_info();
592
593 /*
594 * Need to run this when irqs are enabled, because it wants
595 * to self-test [hard/soft]-irqs on/off lock inversion bugs
596 * too:
597 */
598 locking_selftest();
599
600#ifdef CONFIG_BLK_DEV_INITRD
601 if (initrd_start && !initrd_below_start_ok &&
602 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
603 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
604 page_to_pfn(virt_to_page((void *)initrd_start)),
605 min_low_pfn);
606 initrd_start = 0;
607 }
608#endif
609 page_ext_init();
610 debug_objects_mem_init();
611 kmemleak_init();
612 setup_per_cpu_pageset();
613 numa_policy_init();
614 if (late_time_init)
615 late_time_init();
616 sched_clock_init();
617 calibrate_delay();
618 pidmap_init();
619 anon_vma_init();
620 acpi_early_init();
621#ifdef CONFIG_X86
622 if (efi_enabled(EFI_RUNTIME_SERVICES))
623 efi_enter_virtual_mode();
624#endif
625#ifdef CONFIG_X86_ESPFIX64
626 /* Should be run before the first non-init thread is created */
627 init_espfix_bsp();
628#endif
629 thread_info_cache_init();
630 cred_init();
631 fork_init();
632 proc_caches_init();
633 buffer_init();
634 key_init();
635 security_init();
636 dbg_late_init();
637 vfs_caches_init();
638 signals_init();
639 /* rootfs populating might need page-writeback */
640 page_writeback_init();
641 proc_root_init();
642 nsfs_init();
643 cpuset_init();
644 cgroup_init();
645 taskstats_init_early();
646 delayacct_init();
647
648 check_bugs();
649
650 acpi_subsystem_init();
651 sfi_init_late();
652
653 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
654 efi_late_init();
655 efi_free_boot_services();
656 }
657
658 ftrace_init();
659
660 /* Do the rest non-__init'ed, we're now alive */
661 rest_init();
662}
663
664/* Call all constructor functions linked into the kernel. */
665static void __init do_ctors(void)
666{
667#ifdef CONFIG_CONSTRUCTORS
668 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
669
670 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
671 (*fn)();
672#endif
673}
674
675bool initcall_debug;
676core_param(initcall_debug, initcall_debug, bool, 0644);
677
678#ifdef CONFIG_KALLSYMS
679struct blacklist_entry {
680 struct list_head next;
681 char *buf;
682};
683
684static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
685
686static int __init initcall_blacklist(char *str)
687{
688 char *str_entry;
689 struct blacklist_entry *entry;
690
691 /* str argument is a comma-separated list of functions */
692 do {
693 str_entry = strsep(&str, ",");
694 if (str_entry) {
695 pr_debug("blacklisting initcall %s\n", str_entry);
696 entry = alloc_bootmem(sizeof(*entry));
697 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
698 strcpy(entry->buf, str_entry);
699 list_add(&entry->next, &blacklisted_initcalls);
700 }
701 } while (str_entry);
702
703 return 0;
704}
705
706static bool __init_or_module initcall_blacklisted(initcall_t fn)
707{
708 struct blacklist_entry *entry;
709 char *fn_name;
710
711 fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
712 if (!fn_name)
713 return false;
714
715 list_for_each_entry(entry, &blacklisted_initcalls, next) {
716 if (!strcmp(fn_name, entry->buf)) {
717 pr_debug("initcall %s blacklisted\n", fn_name);
718 kfree(fn_name);
719 return true;
720 }
721 }
722
723 kfree(fn_name);
724 return false;
725}
726#else
727static int __init initcall_blacklist(char *str)
728{
729 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
730 return 0;
731}
732
733static bool __init_or_module initcall_blacklisted(initcall_t fn)
734{
735 return false;
736}
737#endif
738__setup("initcall_blacklist=", initcall_blacklist);
739
740static int __init_or_module do_one_initcall_debug(initcall_t fn)
741{
742 ktime_t calltime, delta, rettime;
743 unsigned long long duration;
744 int ret;
745
746 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
747 calltime = ktime_get();
748 ret = fn();
749 rettime = ktime_get();
750 delta = ktime_sub(rettime, calltime);
751 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
752 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
753 fn, ret, duration);
754
755 return ret;
756}
757
758int __init_or_module do_one_initcall(initcall_t fn)
759{
760 int count = preempt_count();
761 int ret;
762 char msgbuf[64];
763
764 if (initcall_blacklisted(fn))
765 return -EPERM;
766
767 if (initcall_debug)
768 ret = do_one_initcall_debug(fn);
769 else
770 ret = fn();
771
772 msgbuf[0] = 0;
773
774 if (preempt_count() != count) {
775 sprintf(msgbuf, "preemption imbalance ");
776 preempt_count_set(count);
777 }
778 if (irqs_disabled()) {
779 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
780 local_irq_enable();
781 }
782 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
783
784 return ret;
785}
786
787
788extern initcall_t __initcall_start[];
789extern initcall_t __initcall0_start[];
790extern initcall_t __initcall1_start[];
791extern initcall_t __initcall2_start[];
792extern initcall_t __initcall3_start[];
793extern initcall_t __initcall4_start[];
794extern initcall_t __initcall5_start[];
795extern initcall_t __initcall6_start[];
796extern initcall_t __initcall7_start[];
797extern initcall_t __initcall_end[];
798
799static initcall_t *initcall_levels[] __initdata = {
800 __initcall0_start,
801 __initcall1_start,
802 __initcall2_start,
803 __initcall3_start,
804 __initcall4_start,
805 __initcall5_start,
806 __initcall6_start,
807 __initcall7_start,
808 __initcall_end,
809};
810
811/* Keep these in sync with initcalls in include/linux/init.h */
812static char *initcall_level_names[] __initdata = {
813 "early",
814 "core",
815 "postcore",
816 "arch",
817 "subsys",
818 "fs",
819 "device",
820 "late",
821};
822
823static void __init do_initcall_level(int level)
824{
825 initcall_t *fn;
826
827 strcpy(initcall_command_line, saved_command_line);
828 parse_args(initcall_level_names[level],
829 initcall_command_line, __start___param,
830 __stop___param - __start___param,
831 level, level,
832 NULL, &repair_env_string);
833
834 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
835 do_one_initcall(*fn);
836}
837
838static void __init do_initcalls(void)
839{
840 int level;
841
842 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
843 do_initcall_level(level);
844}
845
846/*
847 * Ok, the machine is now initialized. None of the devices
848 * have been touched yet, but the CPU subsystem is up and
849 * running, and memory and process management works.
850 *
851 * Now we can finally start doing some real work..
852 */
853static void __init do_basic_setup(void)
854{
855 cpuset_init_smp();
856 shmem_init();
857 driver_init();
858 init_irq_proc();
859 do_ctors();
860 usermodehelper_enable();
861 do_initcalls();
862 random_int_secret_init();
863}
864
865static void __init do_pre_smp_initcalls(void)
866{
867 initcall_t *fn;
868
869 for (fn = __initcall_start; fn < __initcall0_start; fn++)
870 do_one_initcall(*fn);
871}
872
873/*
874 * This function requests modules which should be loaded by default and is
875 * called twice right after initrd is mounted and right before init is
876 * exec'd. If such modules are on either initrd or rootfs, they will be
877 * loaded before control is passed to userland.
878 */
879void __init load_default_modules(void)
880{
881 load_default_elevator_module();
882}
883
884static int run_init_process(const char *init_filename)
885{
886 argv_init[0] = init_filename;
887 return do_execve(getname_kernel(init_filename),
888 (const char __user *const __user *)argv_init,
889 (const char __user *const __user *)envp_init);
890}
891
892static int try_to_run_init_process(const char *init_filename)
893{
894 int ret;
895
896 ret = run_init_process(init_filename);
897
898 if (ret && ret != -ENOENT) {
899 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
900 init_filename, ret);
901 }
902
903 return ret;
904}
905
906static noinline void __init kernel_init_freeable(void);
907
908#ifdef CONFIG_DEBUG_RODATA
909static bool rodata_enabled = true;
910static int __init set_debug_rodata(char *str)
911{
912 return strtobool(str, &rodata_enabled);
913}
914__setup("rodata=", set_debug_rodata);
915
916static void mark_readonly(void)
917{
918 if (rodata_enabled)
919 mark_rodata_ro();
920 else
921 pr_info("Kernel memory protection disabled.\n");
922}
923#else
924static inline void mark_readonly(void)
925{
926 pr_warn("This architecture does not have kernel memory protection.\n");
927}
928#endif
929
930static int __ref kernel_init(void *unused)
931{
932 int ret;
933
934 kernel_init_freeable();
935 /* need to finish all async __init code before freeing the memory */
936 async_synchronize_full();
937 free_initmem();
938 mark_readonly();
939 system_state = SYSTEM_RUNNING;
940 numa_default_policy();
941
942 flush_delayed_fput();
943
944 rcu_end_inkernel_boot();
945
946 if (ramdisk_execute_command) {
947 ret = run_init_process(ramdisk_execute_command);
948 if (!ret)
949 return 0;
950 pr_err("Failed to execute %s (error %d)\n",
951 ramdisk_execute_command, ret);
952 }
953
954 /*
955 * We try each of these until one succeeds.
956 *
957 * The Bourne shell can be used instead of init if we are
958 * trying to recover a really broken machine.
959 */
960 if (execute_command) {
961 ret = run_init_process(execute_command);
962 if (!ret)
963 return 0;
964 panic("Requested init %s failed (error %d).",
965 execute_command, ret);
966 }
967 if (!try_to_run_init_process("/sbin/init") ||
968 !try_to_run_init_process("/etc/init") ||
969 !try_to_run_init_process("/bin/init") ||
970 !try_to_run_init_process("/bin/sh"))
971 return 0;
972
973 panic("No working init found. Try passing init= option to kernel. "
974 "See Linux Documentation/init.txt for guidance.");
975}
976
977static noinline void __init kernel_init_freeable(void)
978{
979 /*
980 * Wait until kthreadd is all set-up.
981 */
982 wait_for_completion(&kthreadd_done);
983
984 /* Now the scheduler is fully set up and can do blocking allocations */
985 gfp_allowed_mask = __GFP_BITS_MASK;
986
987 /*
988 * init can allocate pages on any node
989 */
990 set_mems_allowed(node_states[N_MEMORY]);
991 /*
992 * init can run on any cpu.
993 */
994 set_cpus_allowed_ptr(current, cpu_all_mask);
995
996 cad_pid = task_pid(current);
997
998 smp_prepare_cpus(setup_max_cpus);
999
1000 do_pre_smp_initcalls();
1001 lockup_detector_init();
1002
1003 smp_init();
1004 sched_init_smp();
1005
1006 page_alloc_init_late();
1007
1008 do_basic_setup();
1009
1010 /* Open the /dev/console on the rootfs, this should never fail */
1011 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1012 pr_err("Warning: unable to open an initial console.\n");
1013
1014 (void) sys_dup(0);
1015 (void) sys_dup(0);
1016 /*
1017 * check if there is an early userspace init. If yes, let it do all
1018 * the work
1019 */
1020
1021 if (!ramdisk_execute_command)
1022 ramdisk_execute_command = "/init";
1023
1024 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1025 ramdisk_execute_command = NULL;
1026 prepare_namespace();
1027 }
1028
1029 /*
1030 * Ok, we have completed the initial bootup, and
1031 * we're essentially up and running. Get rid of the
1032 * initmem segments and start the user-mode stuff..
1033 *
1034 * rootfs is available now, try loading the public keys
1035 * and default modules
1036 */
1037
1038 integrity_load_keys();
1039 load_default_modules();
1040}
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_ext.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#include <linux/list.h>
81#include <linux/integrity.h>
82#include <linux/proc_ns.h>
83#include <linux/io.h>
84#include <linux/cache.h>
85
86#include <asm/io.h>
87#include <asm/bugs.h>
88#include <asm/setup.h>
89#include <asm/sections.h>
90#include <asm/cacheflush.h>
91
92static int kernel_init(void *);
93
94extern void init_IRQ(void);
95extern void fork_init(void);
96extern void radix_tree_init(void);
97
98/*
99 * Debug helper: via this flag we know that we are in 'early bootup code'
100 * where only the boot processor is running with IRQ disabled. This means
101 * two things - IRQ must not be enabled before the flag is cleared and some
102 * operations which are not allowed with IRQ disabled are allowed while the
103 * flag is set.
104 */
105bool early_boot_irqs_disabled __read_mostly;
106
107enum system_states system_state __read_mostly;
108EXPORT_SYMBOL(system_state);
109
110/*
111 * Boot command-line arguments
112 */
113#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
114#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
115
116extern void time_init(void);
117/* Default late time init is NULL. archs can override this later. */
118void (*__initdata late_time_init)(void);
119
120/* Untouched command line saved by arch-specific code. */
121char __initdata boot_command_line[COMMAND_LINE_SIZE];
122/* Untouched saved command line (eg. for /proc) */
123char *saved_command_line;
124/* Command line for parameter parsing */
125static char *static_command_line;
126/* Command line for per-initcall parameter parsing */
127static char *initcall_command_line;
128
129static char *execute_command;
130static char *ramdisk_execute_command;
131
132/*
133 * Used to generate warnings if static_key manipulation functions are used
134 * before jump_label_init is called.
135 */
136bool static_key_initialized __read_mostly;
137EXPORT_SYMBOL_GPL(static_key_initialized);
138
139/*
140 * If set, this is an indication to the drivers that reset the underlying
141 * device before going ahead with the initialization otherwise driver might
142 * rely on the BIOS and skip the reset operation.
143 *
144 * This is useful if kernel is booting in an unreliable environment.
145 * For ex. kdump situation where previous kernel has crashed, BIOS has been
146 * skipped and devices will be in unknown state.
147 */
148unsigned int reset_devices;
149EXPORT_SYMBOL(reset_devices);
150
151static int __init set_reset_devices(char *str)
152{
153 reset_devices = 1;
154 return 1;
155}
156
157__setup("reset_devices", set_reset_devices);
158
159static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
160const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
161static const char *panic_later, *panic_param;
162
163extern const struct obs_kernel_param __setup_start[], __setup_end[];
164
165static bool __init obsolete_checksetup(char *line)
166{
167 const struct obs_kernel_param *p;
168 bool had_early_param = false;
169
170 p = __setup_start;
171 do {
172 int n = strlen(p->str);
173 if (parameqn(line, p->str, n)) {
174 if (p->early) {
175 /* Already done in parse_early_param?
176 * (Needs exact match on param part).
177 * Keep iterating, as we can have early
178 * params and __setups of same names 8( */
179 if (line[n] == '\0' || line[n] == '=')
180 had_early_param = true;
181 } else if (!p->setup_func) {
182 pr_warn("Parameter %s is obsolete, ignored\n",
183 p->str);
184 return true;
185 } else if (p->setup_func(line + n))
186 return true;
187 }
188 p++;
189 } while (p < __setup_end);
190
191 return had_early_param;
192}
193
194/*
195 * This should be approx 2 Bo*oMips to start (note initial shift), and will
196 * still work even if initially too large, it will just take slightly longer
197 */
198unsigned long loops_per_jiffy = (1<<12);
199EXPORT_SYMBOL(loops_per_jiffy);
200
201static int __init debug_kernel(char *str)
202{
203 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
204 return 0;
205}
206
207static int __init quiet_kernel(char *str)
208{
209 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
210 return 0;
211}
212
213early_param("debug", debug_kernel);
214early_param("quiet", quiet_kernel);
215
216static int __init loglevel(char *str)
217{
218 int newlevel;
219
220 /*
221 * Only update loglevel value when a correct setting was passed,
222 * to prevent blind crashes (when loglevel being set to 0) that
223 * are quite hard to debug
224 */
225 if (get_option(&str, &newlevel)) {
226 console_loglevel = newlevel;
227 return 0;
228 }
229
230 return -EINVAL;
231}
232
233early_param("loglevel", loglevel);
234
235/* Change NUL term back to "=", to make "param" the whole string. */
236static int __init repair_env_string(char *param, char *val,
237 const char *unused, void *arg)
238{
239 if (val) {
240 /* param=val or param="val"? */
241 if (val == param+strlen(param)+1)
242 val[-1] = '=';
243 else if (val == param+strlen(param)+2) {
244 val[-2] = '=';
245 memmove(val-1, val, strlen(val)+1);
246 val--;
247 } else
248 BUG();
249 }
250 return 0;
251}
252
253/* Anything after -- gets handed straight to init. */
254static int __init set_init_arg(char *param, char *val,
255 const char *unused, void *arg)
256{
257 unsigned int i;
258
259 if (panic_later)
260 return 0;
261
262 repair_env_string(param, val, unused, NULL);
263
264 for (i = 0; argv_init[i]; i++) {
265 if (i == MAX_INIT_ARGS) {
266 panic_later = "init";
267 panic_param = param;
268 return 0;
269 }
270 }
271 argv_init[i] = param;
272 return 0;
273}
274
275/*
276 * Unknown boot options get handed to init, unless they look like
277 * unused parameters (modprobe will find them in /proc/cmdline).
278 */
279static int __init unknown_bootoption(char *param, char *val,
280 const char *unused, void *arg)
281{
282 repair_env_string(param, val, unused, NULL);
283
284 /* Handle obsolete-style parameters */
285 if (obsolete_checksetup(param))
286 return 0;
287
288 /* Unused module parameter. */
289 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
290 return 0;
291
292 if (panic_later)
293 return 0;
294
295 if (val) {
296 /* Environment option */
297 unsigned int i;
298 for (i = 0; envp_init[i]; i++) {
299 if (i == MAX_INIT_ENVS) {
300 panic_later = "env";
301 panic_param = param;
302 }
303 if (!strncmp(param, envp_init[i], val - param))
304 break;
305 }
306 envp_init[i] = param;
307 } else {
308 /* Command line option */
309 unsigned int i;
310 for (i = 0; argv_init[i]; i++) {
311 if (i == MAX_INIT_ARGS) {
312 panic_later = "init";
313 panic_param = param;
314 }
315 }
316 argv_init[i] = param;
317 }
318 return 0;
319}
320
321static int __init init_setup(char *str)
322{
323 unsigned int i;
324
325 execute_command = str;
326 /*
327 * In case LILO is going to boot us with default command line,
328 * it prepends "auto" before the whole cmdline which makes
329 * the shell think it should execute a script with such name.
330 * So we ignore all arguments entered _before_ init=... [MJ]
331 */
332 for (i = 1; i < MAX_INIT_ARGS; i++)
333 argv_init[i] = NULL;
334 return 1;
335}
336__setup("init=", init_setup);
337
338static int __init rdinit_setup(char *str)
339{
340 unsigned int i;
341
342 ramdisk_execute_command = str;
343 /* See "auto" comment in init_setup */
344 for (i = 1; i < MAX_INIT_ARGS; i++)
345 argv_init[i] = NULL;
346 return 1;
347}
348__setup("rdinit=", rdinit_setup);
349
350#ifndef CONFIG_SMP
351static const unsigned int setup_max_cpus = NR_CPUS;
352static inline void setup_nr_cpu_ids(void) { }
353static inline void smp_prepare_cpus(unsigned int maxcpus) { }
354#endif
355
356/*
357 * We need to store the untouched command line for future reference.
358 * We also need to store the touched command line since the parameter
359 * parsing is performed in place, and we should allow a component to
360 * store reference of name/value for future reference.
361 */
362static void __init setup_command_line(char *command_line)
363{
364 saved_command_line =
365 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
366 initcall_command_line =
367 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
368 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
369 strcpy(saved_command_line, boot_command_line);
370 strcpy(static_command_line, command_line);
371}
372
373/*
374 * We need to finalize in a non-__init function or else race conditions
375 * between the root thread and the init thread may cause start_kernel to
376 * be reaped by free_initmem before the root thread has proceeded to
377 * cpu_idle.
378 *
379 * gcc-3.4 accidentally inlines this function, so use noinline.
380 */
381
382static __initdata DECLARE_COMPLETION(kthreadd_done);
383
384static noinline void __ref rest_init(void)
385{
386 int pid;
387
388 rcu_scheduler_starting();
389 /*
390 * We need to spawn init first so that it obtains pid 1, however
391 * the init task will end up wanting to create kthreads, which, if
392 * we schedule it before we create kthreadd, will OOPS.
393 */
394 kernel_thread(kernel_init, NULL, CLONE_FS);
395 numa_default_policy();
396 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
397 rcu_read_lock();
398 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
399 rcu_read_unlock();
400 complete(&kthreadd_done);
401
402 /*
403 * The boot idle thread must execute schedule()
404 * at least once to get things moving:
405 */
406 init_idle_bootup_task(current);
407 schedule_preempt_disabled();
408 /* Call into cpu_idle with preempt disabled */
409 cpu_startup_entry(CPUHP_ONLINE);
410}
411
412/* Check for early params. */
413static int __init do_early_param(char *param, char *val,
414 const char *unused, void *arg)
415{
416 const struct obs_kernel_param *p;
417
418 for (p = __setup_start; p < __setup_end; p++) {
419 if ((p->early && parameq(param, p->str)) ||
420 (strcmp(param, "console") == 0 &&
421 strcmp(p->str, "earlycon") == 0)
422 ) {
423 if (p->setup_func(val) != 0)
424 pr_warn("Malformed early option '%s'\n", param);
425 }
426 }
427 /* We accept everything at this stage. */
428 return 0;
429}
430
431void __init parse_early_options(char *cmdline)
432{
433 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
434 do_early_param);
435}
436
437/* Arch code calls this early on, or if not, just before other parsing. */
438void __init parse_early_param(void)
439{
440 static int done __initdata;
441 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
442
443 if (done)
444 return;
445
446 /* All fall through to do_early_param. */
447 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
448 parse_early_options(tmp_cmdline);
449 done = 1;
450}
451
452void __init __weak arch_post_acpi_subsys_init(void) { }
453
454void __init __weak smp_setup_processor_id(void)
455{
456}
457
458# if THREAD_SIZE >= PAGE_SIZE
459void __init __weak thread_stack_cache_init(void)
460{
461}
462#endif
463
464/*
465 * Set up kernel memory allocators
466 */
467static void __init mm_init(void)
468{
469 /*
470 * page_ext requires contiguous pages,
471 * bigger than MAX_ORDER unless SPARSEMEM.
472 */
473 page_ext_init_flatmem();
474 mem_init();
475 kmem_cache_init();
476 percpu_init_late();
477 pgtable_init();
478 vmalloc_init();
479 ioremap_huge_init();
480}
481
482asmlinkage __visible void __init start_kernel(void)
483{
484 char *command_line;
485 char *after_dashes;
486
487 set_task_stack_end_magic(&init_task);
488 smp_setup_processor_id();
489 debug_objects_early_init();
490
491 /*
492 * Set up the the initial canary ASAP:
493 */
494 boot_init_stack_canary();
495
496 cgroup_init_early();
497
498 local_irq_disable();
499 early_boot_irqs_disabled = true;
500
501/*
502 * Interrupts are still disabled. Do necessary setups, then
503 * enable them
504 */
505 boot_cpu_init();
506 page_address_init();
507 pr_notice("%s", linux_banner);
508 setup_arch(&command_line);
509 mm_init_cpumask(&init_mm);
510 setup_command_line(command_line);
511 setup_nr_cpu_ids();
512 setup_per_cpu_areas();
513 boot_cpu_state_init();
514 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
515
516 build_all_zonelists(NULL, NULL);
517 page_alloc_init();
518
519 pr_notice("Kernel command line: %s\n", boot_command_line);
520 parse_early_param();
521 after_dashes = parse_args("Booting kernel",
522 static_command_line, __start___param,
523 __stop___param - __start___param,
524 -1, -1, NULL, &unknown_bootoption);
525 if (!IS_ERR_OR_NULL(after_dashes))
526 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
527 NULL, set_init_arg);
528
529 jump_label_init();
530
531 /*
532 * These use large bootmem allocations and must precede
533 * kmem_cache_init()
534 */
535 setup_log_buf(0);
536 pidhash_init();
537 vfs_caches_init_early();
538 sort_main_extable();
539 trap_init();
540 mm_init();
541
542 /*
543 * Set up the scheduler prior starting any interrupts (such as the
544 * timer interrupt). Full topology setup happens at smp_init()
545 * time - but meanwhile we still have a functioning scheduler.
546 */
547 sched_init();
548 /*
549 * Disable preemption - early bootup scheduling is extremely
550 * fragile until we cpu_idle() for the first time.
551 */
552 preempt_disable();
553 if (WARN(!irqs_disabled(),
554 "Interrupts were enabled *very* early, fixing it\n"))
555 local_irq_disable();
556 idr_init_cache();
557
558 /*
559 * Allow workqueue creation and work item queueing/cancelling
560 * early. Work item execution depends on kthreads and starts after
561 * workqueue_init().
562 */
563 workqueue_init_early();
564
565 rcu_init();
566
567 /* trace_printk() and trace points may be used after this */
568 trace_init();
569
570 context_tracking_init();
571 radix_tree_init();
572 /* init some links before init_ISA_irqs() */
573 early_irq_init();
574 init_IRQ();
575 tick_init();
576 rcu_init_nohz();
577 init_timers();
578 hrtimers_init();
579 softirq_init();
580 timekeeping_init();
581 time_init();
582 sched_clock_postinit();
583 printk_nmi_init();
584 perf_event_init();
585 profile_init();
586 call_function_init();
587 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
588 early_boot_irqs_disabled = false;
589 local_irq_enable();
590
591 kmem_cache_init_late();
592
593 /*
594 * HACK ALERT! This is early. We're enabling the console before
595 * we've done PCI setups etc, and console_init() must be aware of
596 * this. But we do want output early, in case something goes wrong.
597 */
598 console_init();
599 if (panic_later)
600 panic("Too many boot %s vars at `%s'", panic_later,
601 panic_param);
602
603 lockdep_info();
604
605 /*
606 * Need to run this when irqs are enabled, because it wants
607 * to self-test [hard/soft]-irqs on/off lock inversion bugs
608 * too:
609 */
610 locking_selftest();
611
612#ifdef CONFIG_BLK_DEV_INITRD
613 if (initrd_start && !initrd_below_start_ok &&
614 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
615 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
616 page_to_pfn(virt_to_page((void *)initrd_start)),
617 min_low_pfn);
618 initrd_start = 0;
619 }
620#endif
621 page_ext_init();
622 debug_objects_mem_init();
623 kmemleak_init();
624 setup_per_cpu_pageset();
625 numa_policy_init();
626 if (late_time_init)
627 late_time_init();
628 sched_clock_init();
629 calibrate_delay();
630 pidmap_init();
631 anon_vma_init();
632 acpi_early_init();
633#ifdef CONFIG_X86
634 if (efi_enabled(EFI_RUNTIME_SERVICES))
635 efi_enter_virtual_mode();
636#endif
637#ifdef CONFIG_X86_ESPFIX64
638 /* Should be run before the first non-init thread is created */
639 init_espfix_bsp();
640#endif
641 thread_stack_cache_init();
642 cred_init();
643 fork_init();
644 proc_caches_init();
645 buffer_init();
646 key_init();
647 security_init();
648 dbg_late_init();
649 vfs_caches_init();
650 pagecache_init();
651 signals_init();
652 proc_root_init();
653 nsfs_init();
654 cpuset_init();
655 cgroup_init();
656 taskstats_init_early();
657 delayacct_init();
658
659 check_bugs();
660
661 acpi_subsystem_init();
662 arch_post_acpi_subsys_init();
663 sfi_init_late();
664
665 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
666 efi_late_init();
667 efi_free_boot_services();
668 }
669
670 ftrace_init();
671
672 /* Do the rest non-__init'ed, we're now alive */
673 rest_init();
674}
675
676/* Call all constructor functions linked into the kernel. */
677static void __init do_ctors(void)
678{
679#ifdef CONFIG_CONSTRUCTORS
680 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
681
682 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
683 (*fn)();
684#endif
685}
686
687bool initcall_debug;
688core_param(initcall_debug, initcall_debug, bool, 0644);
689
690#ifdef CONFIG_KALLSYMS
691struct blacklist_entry {
692 struct list_head next;
693 char *buf;
694};
695
696static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
697
698static int __init initcall_blacklist(char *str)
699{
700 char *str_entry;
701 struct blacklist_entry *entry;
702
703 /* str argument is a comma-separated list of functions */
704 do {
705 str_entry = strsep(&str, ",");
706 if (str_entry) {
707 pr_debug("blacklisting initcall %s\n", str_entry);
708 entry = alloc_bootmem(sizeof(*entry));
709 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
710 strcpy(entry->buf, str_entry);
711 list_add(&entry->next, &blacklisted_initcalls);
712 }
713 } while (str_entry);
714
715 return 0;
716}
717
718static bool __init_or_module initcall_blacklisted(initcall_t fn)
719{
720 struct blacklist_entry *entry;
721 char fn_name[KSYM_SYMBOL_LEN];
722 unsigned long addr;
723
724 if (list_empty(&blacklisted_initcalls))
725 return false;
726
727 addr = (unsigned long) dereference_function_descriptor(fn);
728 sprint_symbol_no_offset(fn_name, addr);
729
730 /*
731 * fn will be "function_name [module_name]" where [module_name] is not
732 * displayed for built-in init functions. Strip off the [module_name].
733 */
734 strreplace(fn_name, ' ', '\0');
735
736 list_for_each_entry(entry, &blacklisted_initcalls, next) {
737 if (!strcmp(fn_name, entry->buf)) {
738 pr_debug("initcall %s blacklisted\n", fn_name);
739 return true;
740 }
741 }
742
743 return false;
744}
745#else
746static int __init initcall_blacklist(char *str)
747{
748 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
749 return 0;
750}
751
752static bool __init_or_module initcall_blacklisted(initcall_t fn)
753{
754 return false;
755}
756#endif
757__setup("initcall_blacklist=", initcall_blacklist);
758
759static int __init_or_module do_one_initcall_debug(initcall_t fn)
760{
761 ktime_t calltime, delta, rettime;
762 unsigned long long duration;
763 int ret;
764
765 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
766 calltime = ktime_get();
767 ret = fn();
768 rettime = ktime_get();
769 delta = ktime_sub(rettime, calltime);
770 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
771 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
772 fn, ret, duration);
773
774 return ret;
775}
776
777int __init_or_module do_one_initcall(initcall_t fn)
778{
779 int count = preempt_count();
780 int ret;
781 char msgbuf[64];
782
783 if (initcall_blacklisted(fn))
784 return -EPERM;
785
786 if (initcall_debug)
787 ret = do_one_initcall_debug(fn);
788 else
789 ret = fn();
790
791 msgbuf[0] = 0;
792
793 if (preempt_count() != count) {
794 sprintf(msgbuf, "preemption imbalance ");
795 preempt_count_set(count);
796 }
797 if (irqs_disabled()) {
798 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
799 local_irq_enable();
800 }
801 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
802
803 add_latent_entropy();
804 return ret;
805}
806
807
808extern initcall_t __initcall_start[];
809extern initcall_t __initcall0_start[];
810extern initcall_t __initcall1_start[];
811extern initcall_t __initcall2_start[];
812extern initcall_t __initcall3_start[];
813extern initcall_t __initcall4_start[];
814extern initcall_t __initcall5_start[];
815extern initcall_t __initcall6_start[];
816extern initcall_t __initcall7_start[];
817extern initcall_t __initcall_end[];
818
819static initcall_t *initcall_levels[] __initdata = {
820 __initcall0_start,
821 __initcall1_start,
822 __initcall2_start,
823 __initcall3_start,
824 __initcall4_start,
825 __initcall5_start,
826 __initcall6_start,
827 __initcall7_start,
828 __initcall_end,
829};
830
831/* Keep these in sync with initcalls in include/linux/init.h */
832static char *initcall_level_names[] __initdata = {
833 "early",
834 "core",
835 "postcore",
836 "arch",
837 "subsys",
838 "fs",
839 "device",
840 "late",
841};
842
843static void __init do_initcall_level(int level)
844{
845 initcall_t *fn;
846
847 strcpy(initcall_command_line, saved_command_line);
848 parse_args(initcall_level_names[level],
849 initcall_command_line, __start___param,
850 __stop___param - __start___param,
851 level, level,
852 NULL, &repair_env_string);
853
854 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
855 do_one_initcall(*fn);
856}
857
858static void __init do_initcalls(void)
859{
860 int level;
861
862 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
863 do_initcall_level(level);
864}
865
866/*
867 * Ok, the machine is now initialized. None of the devices
868 * have been touched yet, but the CPU subsystem is up and
869 * running, and memory and process management works.
870 *
871 * Now we can finally start doing some real work..
872 */
873static void __init do_basic_setup(void)
874{
875 cpuset_init_smp();
876 shmem_init();
877 driver_init();
878 init_irq_proc();
879 do_ctors();
880 usermodehelper_enable();
881 do_initcalls();
882}
883
884static void __init do_pre_smp_initcalls(void)
885{
886 initcall_t *fn;
887
888 for (fn = __initcall_start; fn < __initcall0_start; fn++)
889 do_one_initcall(*fn);
890}
891
892/*
893 * This function requests modules which should be loaded by default and is
894 * called twice right after initrd is mounted and right before init is
895 * exec'd. If such modules are on either initrd or rootfs, they will be
896 * loaded before control is passed to userland.
897 */
898void __init load_default_modules(void)
899{
900 load_default_elevator_module();
901}
902
903static int run_init_process(const char *init_filename)
904{
905 argv_init[0] = init_filename;
906 return do_execve(getname_kernel(init_filename),
907 (const char __user *const __user *)argv_init,
908 (const char __user *const __user *)envp_init);
909}
910
911static int try_to_run_init_process(const char *init_filename)
912{
913 int ret;
914
915 ret = run_init_process(init_filename);
916
917 if (ret && ret != -ENOENT) {
918 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
919 init_filename, ret);
920 }
921
922 return ret;
923}
924
925static noinline void __init kernel_init_freeable(void);
926
927#if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
928bool rodata_enabled __ro_after_init = true;
929static int __init set_debug_rodata(char *str)
930{
931 return strtobool(str, &rodata_enabled);
932}
933__setup("rodata=", set_debug_rodata);
934#endif
935
936#ifdef CONFIG_DEBUG_RODATA
937static void mark_readonly(void)
938{
939 if (rodata_enabled)
940 mark_rodata_ro();
941 else
942 pr_info("Kernel memory protection disabled.\n");
943}
944#else
945static inline void mark_readonly(void)
946{
947 pr_warn("This architecture does not have kernel memory protection.\n");
948}
949#endif
950
951static int __ref kernel_init(void *unused)
952{
953 int ret;
954
955 kernel_init_freeable();
956 /* need to finish all async __init code before freeing the memory */
957 async_synchronize_full();
958 free_initmem();
959 mark_readonly();
960 system_state = SYSTEM_RUNNING;
961 numa_default_policy();
962
963 flush_delayed_fput();
964
965 rcu_end_inkernel_boot();
966
967 if (ramdisk_execute_command) {
968 ret = run_init_process(ramdisk_execute_command);
969 if (!ret)
970 return 0;
971 pr_err("Failed to execute %s (error %d)\n",
972 ramdisk_execute_command, ret);
973 }
974
975 /*
976 * We try each of these until one succeeds.
977 *
978 * The Bourne shell can be used instead of init if we are
979 * trying to recover a really broken machine.
980 */
981 if (execute_command) {
982 ret = run_init_process(execute_command);
983 if (!ret)
984 return 0;
985 panic("Requested init %s failed (error %d).",
986 execute_command, ret);
987 }
988 if (!try_to_run_init_process("/sbin/init") ||
989 !try_to_run_init_process("/etc/init") ||
990 !try_to_run_init_process("/bin/init") ||
991 !try_to_run_init_process("/bin/sh"))
992 return 0;
993
994 panic("No working init found. Try passing init= option to kernel. "
995 "See Linux Documentation/admin-guide/init.rst for guidance.");
996}
997
998static noinline void __init kernel_init_freeable(void)
999{
1000 /*
1001 * Wait until kthreadd is all set-up.
1002 */
1003 wait_for_completion(&kthreadd_done);
1004
1005 /* Now the scheduler is fully set up and can do blocking allocations */
1006 gfp_allowed_mask = __GFP_BITS_MASK;
1007
1008 /*
1009 * init can allocate pages on any node
1010 */
1011 set_mems_allowed(node_states[N_MEMORY]);
1012 /*
1013 * init can run on any cpu.
1014 */
1015 set_cpus_allowed_ptr(current, cpu_all_mask);
1016
1017 cad_pid = task_pid(current);
1018
1019 smp_prepare_cpus(setup_max_cpus);
1020
1021 workqueue_init();
1022
1023 do_pre_smp_initcalls();
1024 lockup_detector_init();
1025
1026 smp_init();
1027 sched_init_smp();
1028
1029 page_alloc_init_late();
1030
1031 do_basic_setup();
1032
1033 /* Open the /dev/console on the rootfs, this should never fail */
1034 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1035 pr_err("Warning: unable to open an initial console.\n");
1036
1037 (void) sys_dup(0);
1038 (void) sys_dup(0);
1039 /*
1040 * check if there is an early userspace init. If yes, let it do all
1041 * the work
1042 */
1043
1044 if (!ramdisk_execute_command)
1045 ramdisk_execute_command = "/init";
1046
1047 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1048 ramdisk_execute_command = NULL;
1049 prepare_namespace();
1050 }
1051
1052 /*
1053 * Ok, we have completed the initial bootup, and
1054 * we're essentially up and running. Get rid of the
1055 * initmem segments and start the user-mode stuff..
1056 *
1057 * rootfs is available now, try loading the public keys
1058 * and default modules
1059 */
1060
1061 integrity_load_keys();
1062 load_default_modules();
1063}