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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#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
15#include <linux/kernel.h>
16#include <linux/syscalls.h>
17#include <linux/stackprotector.h>
18#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/initrd.h>
24#include <linux/bootmem.h>
25#include <linux/acpi.h>
26#include <linux/tty.h>
27#include <linux/percpu.h>
28#include <linux/kmod.h>
29#include <linux/vmalloc.h>
30#include <linux/kernel_stat.h>
31#include <linux/start_kernel.h>
32#include <linux/security.h>
33#include <linux/smp.h>
34#include <linux/profile.h>
35#include <linux/rcupdate.h>
36#include <linux/moduleparam.h>
37#include <linux/kallsyms.h>
38#include <linux/writeback.h>
39#include <linux/cpu.h>
40#include <linux/cpuset.h>
41#include <linux/cgroup.h>
42#include <linux/efi.h>
43#include <linux/tick.h>
44#include <linux/interrupt.h>
45#include <linux/taskstats_kern.h>
46#include <linux/delayacct.h>
47#include <linux/unistd.h>
48#include <linux/rmap.h>
49#include <linux/mempolicy.h>
50#include <linux/key.h>
51#include <linux/buffer_head.h>
52#include <linux/page_cgroup.h>
53#include <linux/debug_locks.h>
54#include <linux/debugobjects.h>
55#include <linux/lockdep.h>
56#include <linux/kmemleak.h>
57#include <linux/pid_namespace.h>
58#include <linux/device.h>
59#include <linux/kthread.h>
60#include <linux/sched.h>
61#include <linux/signal.h>
62#include <linux/idr.h>
63#include <linux/kgdb.h>
64#include <linux/ftrace.h>
65#include <linux/async.h>
66#include <linux/kmemcheck.h>
67#include <linux/sfi.h>
68#include <linux/shmem_fs.h>
69#include <linux/slab.h>
70#include <linux/perf_event.h>
71
72#include <asm/io.h>
73#include <asm/bugs.h>
74#include <asm/setup.h>
75#include <asm/sections.h>
76#include <asm/cacheflush.h>
77
78#ifdef CONFIG_X86_LOCAL_APIC
79#include <asm/smp.h>
80#endif
81
82static int kernel_init(void *);
83
84extern void init_IRQ(void);
85extern void fork_init(unsigned long);
86extern void mca_init(void);
87extern void sbus_init(void);
88extern void prio_tree_init(void);
89extern void radix_tree_init(void);
90extern void free_initmem(void);
91#ifndef CONFIG_DEBUG_RODATA
92static inline void mark_rodata_ro(void) { }
93#endif
94
95#ifdef CONFIG_TC
96extern void tc_init(void);
97#endif
98
99/*
100 * Debug helper: via this flag we know that we are in 'early bootup code'
101 * where only the boot processor is running with IRQ disabled. This means
102 * two things - IRQ must not be enabled before the flag is cleared and some
103 * operations which are not allowed with IRQ disabled are allowed while the
104 * flag is set.
105 */
106bool early_boot_irqs_disabled __read_mostly;
107
108enum system_states system_state __read_mostly;
109EXPORT_SYMBOL(system_state);
110
111/*
112 * Boot command-line arguments
113 */
114#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
115#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
116
117extern void time_init(void);
118/* Default late time init is NULL. archs can override this later. */
119void (*__initdata late_time_init)(void);
120extern void softirq_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
129static char *execute_command;
130static char *ramdisk_execute_command;
131
132/*
133 * If set, this is an indication to the drivers that reset the underlying
134 * device before going ahead with the initialization otherwise driver might
135 * rely on the BIOS and skip the reset operation.
136 *
137 * This is useful if kernel is booting in an unreliable environment.
138 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
139 * skipped and devices will be in unknown state.
140 */
141unsigned int reset_devices;
142EXPORT_SYMBOL(reset_devices);
143
144static int __init set_reset_devices(char *str)
145{
146 reset_devices = 1;
147 return 1;
148}
149
150__setup("reset_devices", set_reset_devices);
151
152static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
153const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
154static const char *panic_later, *panic_param;
155
156extern const struct obs_kernel_param __setup_start[], __setup_end[];
157
158static int __init obsolete_checksetup(char *line)
159{
160 const struct obs_kernel_param *p;
161 int had_early_param = 0;
162
163 p = __setup_start;
164 do {
165 int n = strlen(p->str);
166 if (!strncmp(line, p->str, n)) {
167 if (p->early) {
168 /* Already done in parse_early_param?
169 * (Needs exact match on param part).
170 * Keep iterating, as we can have early
171 * params and __setups of same names 8( */
172 if (line[n] == '\0' || line[n] == '=')
173 had_early_param = 1;
174 } else if (!p->setup_func) {
175 printk(KERN_WARNING "Parameter %s is obsolete,"
176 " ignored\n", p->str);
177 return 1;
178 } else if (p->setup_func(line + n))
179 return 1;
180 }
181 p++;
182 } while (p < __setup_end);
183
184 return had_early_param;
185}
186
187/*
188 * This should be approx 2 Bo*oMips to start (note initial shift), and will
189 * still work even if initially too large, it will just take slightly longer
190 */
191unsigned long loops_per_jiffy = (1<<12);
192
193EXPORT_SYMBOL(loops_per_jiffy);
194
195static int __init debug_kernel(char *str)
196{
197 console_loglevel = 10;
198 return 0;
199}
200
201static int __init quiet_kernel(char *str)
202{
203 console_loglevel = 4;
204 return 0;
205}
206
207early_param("debug", debug_kernel);
208early_param("quiet", quiet_kernel);
209
210static int __init loglevel(char *str)
211{
212 int newlevel;
213
214 /*
215 * Only update loglevel value when a correct setting was passed,
216 * to prevent blind crashes (when loglevel being set to 0) that
217 * are quite hard to debug
218 */
219 if (get_option(&str, &newlevel)) {
220 console_loglevel = newlevel;
221 return 0;
222 }
223
224 return -EINVAL;
225}
226
227early_param("loglevel", loglevel);
228
229/*
230 * Unknown boot options get handed to init, unless they look like
231 * unused parameters (modprobe will find them in /proc/cmdline).
232 */
233static int __init unknown_bootoption(char *param, char *val)
234{
235 /* Change NUL term back to "=", to make "param" the whole string. */
236 if (val) {
237 /* param=val or param="val"? */
238 if (val == param+strlen(param)+1)
239 val[-1] = '=';
240 else if (val == param+strlen(param)+2) {
241 val[-2] = '=';
242 memmove(val-1, val, strlen(val)+1);
243 val--;
244 } else
245 BUG();
246 }
247
248 /* Handle obsolete-style parameters */
249 if (obsolete_checksetup(param))
250 return 0;
251
252 /* Unused module parameter. */
253 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
254 return 0;
255
256 if (panic_later)
257 return 0;
258
259 if (val) {
260 /* Environment option */
261 unsigned int i;
262 for (i = 0; envp_init[i]; i++) {
263 if (i == MAX_INIT_ENVS) {
264 panic_later = "Too many boot env vars at `%s'";
265 panic_param = param;
266 }
267 if (!strncmp(param, envp_init[i], val - param))
268 break;
269 }
270 envp_init[i] = param;
271 } else {
272 /* Command line option */
273 unsigned int i;
274 for (i = 0; argv_init[i]; i++) {
275 if (i == MAX_INIT_ARGS) {
276 panic_later = "Too many boot init vars at `%s'";
277 panic_param = param;
278 }
279 }
280 argv_init[i] = param;
281 }
282 return 0;
283}
284
285#ifdef CONFIG_DEBUG_PAGEALLOC
286int __read_mostly debug_pagealloc_enabled = 0;
287#endif
288
289static int __init init_setup(char *str)
290{
291 unsigned int i;
292
293 execute_command = str;
294 /*
295 * In case LILO is going to boot us with default command line,
296 * it prepends "auto" before the whole cmdline which makes
297 * the shell think it should execute a script with such name.
298 * So we ignore all arguments entered _before_ init=... [MJ]
299 */
300 for (i = 1; i < MAX_INIT_ARGS; i++)
301 argv_init[i] = NULL;
302 return 1;
303}
304__setup("init=", init_setup);
305
306static int __init rdinit_setup(char *str)
307{
308 unsigned int i;
309
310 ramdisk_execute_command = str;
311 /* See "auto" comment in init_setup */
312 for (i = 1; i < MAX_INIT_ARGS; i++)
313 argv_init[i] = NULL;
314 return 1;
315}
316__setup("rdinit=", rdinit_setup);
317
318#ifndef CONFIG_SMP
319static const unsigned int setup_max_cpus = NR_CPUS;
320#ifdef CONFIG_X86_LOCAL_APIC
321static void __init smp_init(void)
322{
323 APIC_init_uniprocessor();
324}
325#else
326#define smp_init() do { } while (0)
327#endif
328
329static inline void setup_nr_cpu_ids(void) { }
330static inline void smp_prepare_cpus(unsigned int maxcpus) { }
331#endif
332
333/*
334 * We need to store the untouched command line for future reference.
335 * We also need to store the touched command line since the parameter
336 * parsing is performed in place, and we should allow a component to
337 * store reference of name/value for future reference.
338 */
339static void __init setup_command_line(char *command_line)
340{
341 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
342 static_command_line = alloc_bootmem(strlen (command_line)+1);
343 strcpy (saved_command_line, boot_command_line);
344 strcpy (static_command_line, command_line);
345}
346
347/*
348 * We need to finalize in a non-__init function or else race conditions
349 * between the root thread and the init thread may cause start_kernel to
350 * be reaped by free_initmem before the root thread has proceeded to
351 * cpu_idle.
352 *
353 * gcc-3.4 accidentally inlines this function, so use noinline.
354 */
355
356static __initdata DECLARE_COMPLETION(kthreadd_done);
357
358static noinline void __init_refok rest_init(void)
359{
360 int pid;
361
362 rcu_scheduler_starting();
363 /*
364 * We need to spawn init first so that it obtains pid 1, however
365 * the init task will end up wanting to create kthreads, which, if
366 * we schedule it before we create kthreadd, will OOPS.
367 */
368 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
369 numa_default_policy();
370 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
371 rcu_read_lock();
372 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
373 rcu_read_unlock();
374 complete(&kthreadd_done);
375
376 /*
377 * The boot idle thread must execute schedule()
378 * at least once to get things moving:
379 */
380 init_idle_bootup_task(current);
381 preempt_enable_no_resched();
382 schedule();
383
384 /* Call into cpu_idle with preempt disabled */
385 preempt_disable();
386 cpu_idle();
387}
388
389/* Check for early params. */
390static int __init do_early_param(char *param, char *val)
391{
392 const struct obs_kernel_param *p;
393
394 for (p = __setup_start; p < __setup_end; p++) {
395 if ((p->early && strcmp(param, p->str) == 0) ||
396 (strcmp(param, "console") == 0 &&
397 strcmp(p->str, "earlycon") == 0)
398 ) {
399 if (p->setup_func(val) != 0)
400 printk(KERN_WARNING
401 "Malformed early option '%s'\n", param);
402 }
403 }
404 /* We accept everything at this stage. */
405 return 0;
406}
407
408void __init parse_early_options(char *cmdline)
409{
410 parse_args("early options", cmdline, NULL, 0, do_early_param);
411}
412
413/* Arch code calls this early on, or if not, just before other parsing. */
414void __init parse_early_param(void)
415{
416 static __initdata int done = 0;
417 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
418
419 if (done)
420 return;
421
422 /* All fall through to do_early_param. */
423 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
424 parse_early_options(tmp_cmdline);
425 done = 1;
426}
427
428/*
429 * Activate the first processor.
430 */
431
432static void __init boot_cpu_init(void)
433{
434 int cpu = smp_processor_id();
435 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
436 set_cpu_online(cpu, true);
437 set_cpu_active(cpu, true);
438 set_cpu_present(cpu, true);
439 set_cpu_possible(cpu, true);
440}
441
442void __init __weak smp_setup_processor_id(void)
443{
444}
445
446void __init __weak thread_info_cache_init(void)
447{
448}
449
450/*
451 * Set up kernel memory allocators
452 */
453static void __init mm_init(void)
454{
455 /*
456 * page_cgroup requires countinous pages as memmap
457 * and it's bigger than MAX_ORDER unless SPARSEMEM.
458 */
459 page_cgroup_init_flatmem();
460 mem_init();
461 kmem_cache_init();
462 percpu_init_late();
463 pgtable_cache_init();
464 vmalloc_init();
465}
466
467asmlinkage void __init start_kernel(void)
468{
469 char * command_line;
470 extern const struct kernel_param __start___param[], __stop___param[];
471
472 smp_setup_processor_id();
473
474 /*
475 * Need to run as early as possible, to initialize the
476 * lockdep hash:
477 */
478 lockdep_init();
479 debug_objects_early_init();
480
481 /*
482 * Set up the the initial canary ASAP:
483 */
484 boot_init_stack_canary();
485
486 cgroup_init_early();
487
488 local_irq_disable();
489 early_boot_irqs_disabled = true;
490
491/*
492 * Interrupts are still disabled. Do necessary setups, then
493 * enable them
494 */
495 tick_init();
496 boot_cpu_init();
497 page_address_init();
498 printk(KERN_NOTICE "%s", linux_banner);
499 setup_arch(&command_line);
500 mm_init_owner(&init_mm, &init_task);
501 mm_init_cpumask(&init_mm);
502 setup_command_line(command_line);
503 setup_nr_cpu_ids();
504 setup_per_cpu_areas();
505 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
506
507 build_all_zonelists(NULL);
508 page_alloc_init();
509
510 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
511 parse_early_param();
512 parse_args("Booting kernel", static_command_line, __start___param,
513 __stop___param - __start___param,
514 &unknown_bootoption);
515 /*
516 * These use large bootmem allocations and must precede
517 * kmem_cache_init()
518 */
519 setup_log_buf(0);
520 pidhash_init();
521 vfs_caches_init_early();
522 sort_main_extable();
523 trap_init();
524 mm_init();
525
526 /*
527 * Set up the scheduler prior starting any interrupts (such as the
528 * timer interrupt). Full topology setup happens at smp_init()
529 * time - but meanwhile we still have a functioning scheduler.
530 */
531 sched_init();
532 /*
533 * Disable preemption - early bootup scheduling is extremely
534 * fragile until we cpu_idle() for the first time.
535 */
536 preempt_disable();
537 if (!irqs_disabled()) {
538 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
539 "enabled *very* early, fixing it\n");
540 local_irq_disable();
541 }
542 idr_init_cache();
543 perf_event_init();
544 rcu_init();
545 radix_tree_init();
546 /* init some links before init_ISA_irqs() */
547 early_irq_init();
548 init_IRQ();
549 prio_tree_init();
550 init_timers();
551 hrtimers_init();
552 softirq_init();
553 timekeeping_init();
554 time_init();
555 profile_init();
556 call_function_init();
557 if (!irqs_disabled())
558 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
559 "enabled early\n");
560 early_boot_irqs_disabled = false;
561 local_irq_enable();
562
563 /* Interrupts are enabled now so all GFP allocations are safe. */
564 gfp_allowed_mask = __GFP_BITS_MASK;
565
566 kmem_cache_init_late();
567
568 /*
569 * HACK ALERT! This is early. We're enabling the console before
570 * we've done PCI setups etc, and console_init() must be aware of
571 * this. But we do want output early, in case something goes wrong.
572 */
573 console_init();
574 if (panic_later)
575 panic(panic_later, panic_param);
576
577 lockdep_info();
578
579 /*
580 * Need to run this when irqs are enabled, because it wants
581 * to self-test [hard/soft]-irqs on/off lock inversion bugs
582 * too:
583 */
584 locking_selftest();
585
586#ifdef CONFIG_BLK_DEV_INITRD
587 if (initrd_start && !initrd_below_start_ok &&
588 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
589 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
590 "disabling it.\n",
591 page_to_pfn(virt_to_page((void *)initrd_start)),
592 min_low_pfn);
593 initrd_start = 0;
594 }
595#endif
596 page_cgroup_init();
597 enable_debug_pagealloc();
598 debug_objects_mem_init();
599 kmemleak_init();
600 setup_per_cpu_pageset();
601 numa_policy_init();
602 if (late_time_init)
603 late_time_init();
604 sched_clock_init();
605 calibrate_delay();
606 pidmap_init();
607 anon_vma_init();
608#ifdef CONFIG_X86
609 if (efi_enabled)
610 efi_enter_virtual_mode();
611#endif
612 thread_info_cache_init();
613 cred_init();
614 fork_init(totalram_pages);
615 proc_caches_init();
616 buffer_init();
617 key_init();
618 security_init();
619 dbg_late_init();
620 vfs_caches_init(totalram_pages);
621 signals_init();
622 /* rootfs populating might need page-writeback */
623 page_writeback_init();
624#ifdef CONFIG_PROC_FS
625 proc_root_init();
626#endif
627 cgroup_init();
628 cpuset_init();
629 taskstats_init_early();
630 delayacct_init();
631
632 check_bugs();
633
634 acpi_early_init(); /* before LAPIC and SMP init */
635 sfi_init_late();
636
637 ftrace_init();
638
639 /* Do the rest non-__init'ed, we're now alive */
640 rest_init();
641}
642
643/* Call all constructor functions linked into the kernel. */
644static void __init do_ctors(void)
645{
646#ifdef CONFIG_CONSTRUCTORS
647 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
648
649 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
650 (*fn)();
651#endif
652}
653
654int initcall_debug;
655core_param(initcall_debug, initcall_debug, bool, 0644);
656
657static char msgbuf[64];
658
659static int __init_or_module do_one_initcall_debug(initcall_t fn)
660{
661 ktime_t calltime, delta, rettime;
662 unsigned long long duration;
663 int ret;
664
665 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
666 calltime = ktime_get();
667 ret = fn();
668 rettime = ktime_get();
669 delta = ktime_sub(rettime, calltime);
670 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
671 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
672 ret, duration);
673
674 return ret;
675}
676
677int __init_or_module do_one_initcall(initcall_t fn)
678{
679 int count = preempt_count();
680 int ret;
681
682 if (initcall_debug)
683 ret = do_one_initcall_debug(fn);
684 else
685 ret = fn();
686
687 msgbuf[0] = 0;
688
689 if (ret && ret != -ENODEV && initcall_debug)
690 sprintf(msgbuf, "error code %d ", ret);
691
692 if (preempt_count() != count) {
693 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
694 preempt_count() = count;
695 }
696 if (irqs_disabled()) {
697 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
698 local_irq_enable();
699 }
700 if (msgbuf[0]) {
701 printk("initcall %pF returned with %s\n", fn, msgbuf);
702 }
703
704 return ret;
705}
706
707
708extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
709
710static void __init do_initcalls(void)
711{
712 initcall_t *fn;
713
714 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
715 do_one_initcall(*fn);
716}
717
718/*
719 * Ok, the machine is now initialized. None of the devices
720 * have been touched yet, but the CPU subsystem is up and
721 * running, and memory and process management works.
722 *
723 * Now we can finally start doing some real work..
724 */
725static void __init do_basic_setup(void)
726{
727 cpuset_init_smp();
728 usermodehelper_init();
729 shmem_init();
730 driver_init();
731 init_irq_proc();
732 do_ctors();
733 usermodehelper_enable();
734 do_initcalls();
735}
736
737static void __init do_pre_smp_initcalls(void)
738{
739 initcall_t *fn;
740
741 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
742 do_one_initcall(*fn);
743}
744
745static void run_init_process(const char *init_filename)
746{
747 argv_init[0] = init_filename;
748 kernel_execve(init_filename, argv_init, envp_init);
749}
750
751/* This is a non __init function. Force it to be noinline otherwise gcc
752 * makes it inline to init() and it becomes part of init.text section
753 */
754static noinline int init_post(void)
755{
756 /* need to finish all async __init code before freeing the memory */
757 async_synchronize_full();
758 free_initmem();
759 mark_rodata_ro();
760 system_state = SYSTEM_RUNNING;
761 numa_default_policy();
762
763
764 current->signal->flags |= SIGNAL_UNKILLABLE;
765
766 if (ramdisk_execute_command) {
767 run_init_process(ramdisk_execute_command);
768 printk(KERN_WARNING "Failed to execute %s\n",
769 ramdisk_execute_command);
770 }
771
772 /*
773 * We try each of these until one succeeds.
774 *
775 * The Bourne shell can be used instead of init if we are
776 * trying to recover a really broken machine.
777 */
778 if (execute_command) {
779 run_init_process(execute_command);
780 printk(KERN_WARNING "Failed to execute %s. Attempting "
781 "defaults...\n", execute_command);
782 }
783 run_init_process("/sbin/init");
784 run_init_process("/etc/init");
785 run_init_process("/bin/init");
786 run_init_process("/bin/sh");
787
788 panic("No init found. Try passing init= option to kernel. "
789 "See Linux Documentation/init.txt for guidance.");
790}
791
792static int __init kernel_init(void * unused)
793{
794 /*
795 * Wait until kthreadd is all set-up.
796 */
797 wait_for_completion(&kthreadd_done);
798 /*
799 * init can allocate pages on any node
800 */
801 set_mems_allowed(node_states[N_HIGH_MEMORY]);
802 /*
803 * init can run on any cpu.
804 */
805 set_cpus_allowed_ptr(current, cpu_all_mask);
806
807 cad_pid = task_pid(current);
808
809 smp_prepare_cpus(setup_max_cpus);
810
811 do_pre_smp_initcalls();
812 lockup_detector_init();
813
814 smp_init();
815 sched_init_smp();
816
817 do_basic_setup();
818
819 /* Open the /dev/console on the rootfs, this should never fail */
820 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
821 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
822
823 (void) sys_dup(0);
824 (void) sys_dup(0);
825 /*
826 * check if there is an early userspace init. If yes, let it do all
827 * the work
828 */
829
830 if (!ramdisk_execute_command)
831 ramdisk_execute_command = "/init";
832
833 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
834 ramdisk_execute_command = NULL;
835 prepare_namespace();
836 }
837
838 /*
839 * Ok, we have completed the initial bootup, and
840 * we're essentially up and running. Get rid of the
841 * initmem segments and start the user-mode stuff..
842 */
843
844 init_post();
845 return 0;
846}
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/extable.h>
16#include <linux/module.h>
17#include <linux/proc_fs.h>
18#include <linux/binfmts.h>
19#include <linux/kernel.h>
20#include <linux/syscalls.h>
21#include <linux/stackprotector.h>
22#include <linux/string.h>
23#include <linux/ctype.h>
24#include <linux/delay.h>
25#include <linux/ioport.h>
26#include <linux/init.h>
27#include <linux/initrd.h>
28#include <linux/bootmem.h>
29#include <linux/acpi.h>
30#include <linux/console.h>
31#include <linux/nmi.h>
32#include <linux/percpu.h>
33#include <linux/kmod.h>
34#include <linux/vmalloc.h>
35#include <linux/kernel_stat.h>
36#include <linux/start_kernel.h>
37#include <linux/security.h>
38#include <linux/smp.h>
39#include <linux/profile.h>
40#include <linux/rcupdate.h>
41#include <linux/moduleparam.h>
42#include <linux/kallsyms.h>
43#include <linux/writeback.h>
44#include <linux/cpu.h>
45#include <linux/cpuset.h>
46#include <linux/cgroup.h>
47#include <linux/efi.h>
48#include <linux/tick.h>
49#include <linux/sched/isolation.h>
50#include <linux/interrupt.h>
51#include <linux/taskstats_kern.h>
52#include <linux/delayacct.h>
53#include <linux/unistd.h>
54#include <linux/utsname.h>
55#include <linux/rmap.h>
56#include <linux/mempolicy.h>
57#include <linux/key.h>
58#include <linux/buffer_head.h>
59#include <linux/page_ext.h>
60#include <linux/debug_locks.h>
61#include <linux/debugobjects.h>
62#include <linux/lockdep.h>
63#include <linux/kmemleak.h>
64#include <linux/pid_namespace.h>
65#include <linux/device.h>
66#include <linux/kthread.h>
67#include <linux/sched.h>
68#include <linux/sched/init.h>
69#include <linux/signal.h>
70#include <linux/idr.h>
71#include <linux/kgdb.h>
72#include <linux/ftrace.h>
73#include <linux/async.h>
74#include <linux/sfi.h>
75#include <linux/shmem_fs.h>
76#include <linux/slab.h>
77#include <linux/perf_event.h>
78#include <linux/ptrace.h>
79#include <linux/pti.h>
80#include <linux/blkdev.h>
81#include <linux/elevator.h>
82#include <linux/sched_clock.h>
83#include <linux/sched/task.h>
84#include <linux/sched/task_stack.h>
85#include <linux/context_tracking.h>
86#include <linux/random.h>
87#include <linux/list.h>
88#include <linux/integrity.h>
89#include <linux/proc_ns.h>
90#include <linux/io.h>
91#include <linux/cache.h>
92#include <linux/rodata_test.h>
93#include <linux/jump_label.h>
94#include <linux/mem_encrypt.h>
95
96#include <asm/io.h>
97#include <asm/bugs.h>
98#include <asm/setup.h>
99#include <asm/sections.h>
100#include <asm/cacheflush.h>
101
102#define CREATE_TRACE_POINTS
103#include <trace/events/initcall.h>
104
105static int kernel_init(void *);
106
107extern void init_IRQ(void);
108extern void fork_init(void);
109extern void radix_tree_init(void);
110
111/*
112 * Debug helper: via this flag we know that we are in 'early bootup code'
113 * where only the boot processor is running with IRQ disabled. This means
114 * two things - IRQ must not be enabled before the flag is cleared and some
115 * operations which are not allowed with IRQ disabled are allowed while the
116 * flag is set.
117 */
118bool early_boot_irqs_disabled __read_mostly;
119
120enum system_states system_state __read_mostly;
121EXPORT_SYMBOL(system_state);
122
123/*
124 * Boot command-line arguments
125 */
126#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
127#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
128
129extern void time_init(void);
130/* Default late time init is NULL. archs can override this later. */
131void (*__initdata late_time_init)(void);
132
133/* Untouched command line saved by arch-specific code. */
134char __initdata boot_command_line[COMMAND_LINE_SIZE];
135/* Untouched saved command line (eg. for /proc) */
136char *saved_command_line;
137/* Command line for parameter parsing */
138static char *static_command_line;
139/* Command line for per-initcall parameter parsing */
140static char *initcall_command_line;
141
142static char *execute_command;
143static char *ramdisk_execute_command;
144
145/*
146 * Used to generate warnings if static_key manipulation functions are used
147 * before jump_label_init is called.
148 */
149bool static_key_initialized __read_mostly;
150EXPORT_SYMBOL_GPL(static_key_initialized);
151
152/*
153 * If set, this is an indication to the drivers that reset the underlying
154 * device before going ahead with the initialization otherwise driver might
155 * rely on the BIOS and skip the reset operation.
156 *
157 * This is useful if kernel is booting in an unreliable environment.
158 * For ex. kdump situation where previous kernel has crashed, BIOS has been
159 * skipped and devices will be in unknown state.
160 */
161unsigned int reset_devices;
162EXPORT_SYMBOL(reset_devices);
163
164static int __init set_reset_devices(char *str)
165{
166 reset_devices = 1;
167 return 1;
168}
169
170__setup("reset_devices", set_reset_devices);
171
172static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
173const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
174static const char *panic_later, *panic_param;
175
176extern const struct obs_kernel_param __setup_start[], __setup_end[];
177
178static bool __init obsolete_checksetup(char *line)
179{
180 const struct obs_kernel_param *p;
181 bool had_early_param = false;
182
183 p = __setup_start;
184 do {
185 int n = strlen(p->str);
186 if (parameqn(line, p->str, n)) {
187 if (p->early) {
188 /* Already done in parse_early_param?
189 * (Needs exact match on param part).
190 * Keep iterating, as we can have early
191 * params and __setups of same names 8( */
192 if (line[n] == '\0' || line[n] == '=')
193 had_early_param = true;
194 } else if (!p->setup_func) {
195 pr_warn("Parameter %s is obsolete, ignored\n",
196 p->str);
197 return true;
198 } else if (p->setup_func(line + n))
199 return true;
200 }
201 p++;
202 } while (p < __setup_end);
203
204 return had_early_param;
205}
206
207/*
208 * This should be approx 2 Bo*oMips to start (note initial shift), and will
209 * still work even if initially too large, it will just take slightly longer
210 */
211unsigned long loops_per_jiffy = (1<<12);
212EXPORT_SYMBOL(loops_per_jiffy);
213
214static int __init debug_kernel(char *str)
215{
216 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
217 return 0;
218}
219
220static int __init quiet_kernel(char *str)
221{
222 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
223 return 0;
224}
225
226early_param("debug", debug_kernel);
227early_param("quiet", quiet_kernel);
228
229static int __init loglevel(char *str)
230{
231 int newlevel;
232
233 /*
234 * Only update loglevel value when a correct setting was passed,
235 * to prevent blind crashes (when loglevel being set to 0) that
236 * are quite hard to debug
237 */
238 if (get_option(&str, &newlevel)) {
239 console_loglevel = newlevel;
240 return 0;
241 }
242
243 return -EINVAL;
244}
245
246early_param("loglevel", loglevel);
247
248/* Change NUL term back to "=", to make "param" the whole string. */
249static int __init repair_env_string(char *param, char *val,
250 const char *unused, void *arg)
251{
252 if (val) {
253 /* param=val or param="val"? */
254 if (val == param+strlen(param)+1)
255 val[-1] = '=';
256 else if (val == param+strlen(param)+2) {
257 val[-2] = '=';
258 memmove(val-1, val, strlen(val)+1);
259 val--;
260 } else
261 BUG();
262 }
263 return 0;
264}
265
266/* Anything after -- gets handed straight to init. */
267static int __init set_init_arg(char *param, char *val,
268 const char *unused, void *arg)
269{
270 unsigned int i;
271
272 if (panic_later)
273 return 0;
274
275 repair_env_string(param, val, unused, NULL);
276
277 for (i = 0; argv_init[i]; i++) {
278 if (i == MAX_INIT_ARGS) {
279 panic_later = "init";
280 panic_param = param;
281 return 0;
282 }
283 }
284 argv_init[i] = param;
285 return 0;
286}
287
288/*
289 * Unknown boot options get handed to init, unless they look like
290 * unused parameters (modprobe will find them in /proc/cmdline).
291 */
292static int __init unknown_bootoption(char *param, char *val,
293 const char *unused, void *arg)
294{
295 repair_env_string(param, val, unused, NULL);
296
297 /* Handle obsolete-style parameters */
298 if (obsolete_checksetup(param))
299 return 0;
300
301 /* Unused module parameter. */
302 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
303 return 0;
304
305 if (panic_later)
306 return 0;
307
308 if (val) {
309 /* Environment option */
310 unsigned int i;
311 for (i = 0; envp_init[i]; i++) {
312 if (i == MAX_INIT_ENVS) {
313 panic_later = "env";
314 panic_param = param;
315 }
316 if (!strncmp(param, envp_init[i], val - param))
317 break;
318 }
319 envp_init[i] = param;
320 } else {
321 /* Command line option */
322 unsigned int i;
323 for (i = 0; argv_init[i]; i++) {
324 if (i == MAX_INIT_ARGS) {
325 panic_later = "init";
326 panic_param = param;
327 }
328 }
329 argv_init[i] = param;
330 }
331 return 0;
332}
333
334static int __init init_setup(char *str)
335{
336 unsigned int i;
337
338 execute_command = str;
339 /*
340 * In case LILO is going to boot us with default command line,
341 * it prepends "auto" before the whole cmdline which makes
342 * the shell think it should execute a script with such name.
343 * So we ignore all arguments entered _before_ init=... [MJ]
344 */
345 for (i = 1; i < MAX_INIT_ARGS; i++)
346 argv_init[i] = NULL;
347 return 1;
348}
349__setup("init=", init_setup);
350
351static int __init rdinit_setup(char *str)
352{
353 unsigned int i;
354
355 ramdisk_execute_command = str;
356 /* See "auto" comment in init_setup */
357 for (i = 1; i < MAX_INIT_ARGS; i++)
358 argv_init[i] = NULL;
359 return 1;
360}
361__setup("rdinit=", rdinit_setup);
362
363#ifndef CONFIG_SMP
364static const unsigned int setup_max_cpus = NR_CPUS;
365static inline void setup_nr_cpu_ids(void) { }
366static inline void smp_prepare_cpus(unsigned int maxcpus) { }
367#endif
368
369/*
370 * We need to store the untouched command line for future reference.
371 * We also need to store the touched command line since the parameter
372 * parsing is performed in place, and we should allow a component to
373 * store reference of name/value for future reference.
374 */
375static void __init setup_command_line(char *command_line)
376{
377 saved_command_line =
378 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
379 initcall_command_line =
380 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
381 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
382 strcpy(saved_command_line, boot_command_line);
383 strcpy(static_command_line, command_line);
384}
385
386/*
387 * We need to finalize in a non-__init function or else race conditions
388 * between the root thread and the init thread may cause start_kernel to
389 * be reaped by free_initmem before the root thread has proceeded to
390 * cpu_idle.
391 *
392 * gcc-3.4 accidentally inlines this function, so use noinline.
393 */
394
395static __initdata DECLARE_COMPLETION(kthreadd_done);
396
397static noinline void __ref rest_init(void)
398{
399 struct task_struct *tsk;
400 int pid;
401
402 rcu_scheduler_starting();
403 /*
404 * We need to spawn init first so that it obtains pid 1, however
405 * the init task will end up wanting to create kthreads, which, if
406 * we schedule it before we create kthreadd, will OOPS.
407 */
408 pid = kernel_thread(kernel_init, NULL, CLONE_FS);
409 /*
410 * Pin init on the boot CPU. Task migration is not properly working
411 * until sched_init_smp() has been run. It will set the allowed
412 * CPUs for init to the non isolated CPUs.
413 */
414 rcu_read_lock();
415 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
416 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
417 rcu_read_unlock();
418
419 numa_default_policy();
420 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
421 rcu_read_lock();
422 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
423 rcu_read_unlock();
424
425 /*
426 * Enable might_sleep() and smp_processor_id() checks.
427 * They cannot be enabled earlier because with CONFIG_PREEMPT=y
428 * kernel_thread() would trigger might_sleep() splats. With
429 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
430 * already, but it's stuck on the kthreadd_done completion.
431 */
432 system_state = SYSTEM_SCHEDULING;
433
434 complete(&kthreadd_done);
435
436 /*
437 * The boot idle thread must execute schedule()
438 * at least once to get things moving:
439 */
440 schedule_preempt_disabled();
441 /* Call into cpu_idle with preempt disabled */
442 cpu_startup_entry(CPUHP_ONLINE);
443}
444
445/* Check for early params. */
446static int __init do_early_param(char *param, char *val,
447 const char *unused, void *arg)
448{
449 const struct obs_kernel_param *p;
450
451 for (p = __setup_start; p < __setup_end; p++) {
452 if ((p->early && parameq(param, p->str)) ||
453 (strcmp(param, "console") == 0 &&
454 strcmp(p->str, "earlycon") == 0)
455 ) {
456 if (p->setup_func(val) != 0)
457 pr_warn("Malformed early option '%s'\n", param);
458 }
459 }
460 /* We accept everything at this stage. */
461 return 0;
462}
463
464void __init parse_early_options(char *cmdline)
465{
466 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
467 do_early_param);
468}
469
470/* Arch code calls this early on, or if not, just before other parsing. */
471void __init parse_early_param(void)
472{
473 static int done __initdata;
474 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
475
476 if (done)
477 return;
478
479 /* All fall through to do_early_param. */
480 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
481 parse_early_options(tmp_cmdline);
482 done = 1;
483}
484
485void __init __weak arch_post_acpi_subsys_init(void) { }
486
487void __init __weak smp_setup_processor_id(void)
488{
489}
490
491# if THREAD_SIZE >= PAGE_SIZE
492void __init __weak thread_stack_cache_init(void)
493{
494}
495#endif
496
497void __init __weak mem_encrypt_init(void) { }
498
499bool initcall_debug;
500core_param(initcall_debug, initcall_debug, bool, 0644);
501
502#ifdef TRACEPOINTS_ENABLED
503static void __init initcall_debug_enable(void);
504#else
505static inline void initcall_debug_enable(void)
506{
507}
508#endif
509
510/*
511 * Set up kernel memory allocators
512 */
513static void __init mm_init(void)
514{
515 /*
516 * page_ext requires contiguous pages,
517 * bigger than MAX_ORDER unless SPARSEMEM.
518 */
519 page_ext_init_flatmem();
520 mem_init();
521 kmem_cache_init();
522 pgtable_init();
523 vmalloc_init();
524 ioremap_huge_init();
525 /* Should be run before the first non-init thread is created */
526 init_espfix_bsp();
527 /* Should be run after espfix64 is set up. */
528 pti_init();
529}
530
531asmlinkage __visible void __init start_kernel(void)
532{
533 char *command_line;
534 char *after_dashes;
535
536 set_task_stack_end_magic(&init_task);
537 smp_setup_processor_id();
538 debug_objects_early_init();
539
540 cgroup_init_early();
541
542 local_irq_disable();
543 early_boot_irqs_disabled = true;
544
545 /*
546 * Interrupts are still disabled. Do necessary setups, then
547 * enable them.
548 */
549 boot_cpu_init();
550 page_address_init();
551 pr_notice("%s", linux_banner);
552 setup_arch(&command_line);
553 /*
554 * Set up the the initial canary and entropy after arch
555 * and after adding latent and command line entropy.
556 */
557 add_latent_entropy();
558 add_device_randomness(command_line, strlen(command_line));
559 boot_init_stack_canary();
560 mm_init_cpumask(&init_mm);
561 setup_command_line(command_line);
562 setup_nr_cpu_ids();
563 setup_per_cpu_areas();
564 boot_cpu_state_init();
565 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
566
567 build_all_zonelists(NULL);
568 page_alloc_init();
569
570 pr_notice("Kernel command line: %s\n", boot_command_line);
571 parse_early_param();
572 after_dashes = parse_args("Booting kernel",
573 static_command_line, __start___param,
574 __stop___param - __start___param,
575 -1, -1, NULL, &unknown_bootoption);
576 if (!IS_ERR_OR_NULL(after_dashes))
577 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
578 NULL, set_init_arg);
579
580 jump_label_init();
581
582 /*
583 * These use large bootmem allocations and must precede
584 * kmem_cache_init()
585 */
586 setup_log_buf(0);
587 vfs_caches_init_early();
588 sort_main_extable();
589 trap_init();
590 mm_init();
591
592 ftrace_init();
593
594 /* trace_printk can be enabled here */
595 early_trace_init();
596
597 /*
598 * Set up the scheduler prior starting any interrupts (such as the
599 * timer interrupt). Full topology setup happens at smp_init()
600 * time - but meanwhile we still have a functioning scheduler.
601 */
602 sched_init();
603 /*
604 * Disable preemption - early bootup scheduling is extremely
605 * fragile until we cpu_idle() for the first time.
606 */
607 preempt_disable();
608 if (WARN(!irqs_disabled(),
609 "Interrupts were enabled *very* early, fixing it\n"))
610 local_irq_disable();
611 radix_tree_init();
612
613 /*
614 * Set up housekeeping before setting up workqueues to allow the unbound
615 * workqueue to take non-housekeeping into account.
616 */
617 housekeeping_init();
618
619 /*
620 * Allow workqueue creation and work item queueing/cancelling
621 * early. Work item execution depends on kthreads and starts after
622 * workqueue_init().
623 */
624 workqueue_init_early();
625
626 rcu_init();
627
628 /* Trace events are available after this */
629 trace_init();
630
631 if (initcall_debug)
632 initcall_debug_enable();
633
634 context_tracking_init();
635 /* init some links before init_ISA_irqs() */
636 early_irq_init();
637 init_IRQ();
638 tick_init();
639 rcu_init_nohz();
640 init_timers();
641 hrtimers_init();
642 softirq_init();
643 timekeeping_init();
644 time_init();
645 sched_clock_postinit();
646 printk_safe_init();
647 perf_event_init();
648 profile_init();
649 call_function_init();
650 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
651 early_boot_irqs_disabled = false;
652 local_irq_enable();
653
654 kmem_cache_init_late();
655
656 /*
657 * HACK ALERT! This is early. We're enabling the console before
658 * we've done PCI setups etc, and console_init() must be aware of
659 * this. But we do want output early, in case something goes wrong.
660 */
661 console_init();
662 if (panic_later)
663 panic("Too many boot %s vars at `%s'", panic_later,
664 panic_param);
665
666 lockdep_info();
667
668 /*
669 * Need to run this when irqs are enabled, because it wants
670 * to self-test [hard/soft]-irqs on/off lock inversion bugs
671 * too:
672 */
673 locking_selftest();
674
675 /*
676 * This needs to be called before any devices perform DMA
677 * operations that might use the SWIOTLB bounce buffers. It will
678 * mark the bounce buffers as decrypted so that their usage will
679 * not cause "plain-text" data to be decrypted when accessed.
680 */
681 mem_encrypt_init();
682
683#ifdef CONFIG_BLK_DEV_INITRD
684 if (initrd_start && !initrd_below_start_ok &&
685 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
686 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
687 page_to_pfn(virt_to_page((void *)initrd_start)),
688 min_low_pfn);
689 initrd_start = 0;
690 }
691#endif
692 page_ext_init();
693 kmemleak_init();
694 debug_objects_mem_init();
695 setup_per_cpu_pageset();
696 numa_policy_init();
697 acpi_early_init();
698 if (late_time_init)
699 late_time_init();
700 calibrate_delay();
701 pid_idr_init();
702 anon_vma_init();
703#ifdef CONFIG_X86
704 if (efi_enabled(EFI_RUNTIME_SERVICES))
705 efi_enter_virtual_mode();
706#endif
707 thread_stack_cache_init();
708 cred_init();
709 fork_init();
710 proc_caches_init();
711 uts_ns_init();
712 buffer_init();
713 key_init();
714 security_init();
715 dbg_late_init();
716 vfs_caches_init();
717 pagecache_init();
718 signals_init();
719 seq_file_init();
720 proc_root_init();
721 nsfs_init();
722 cpuset_init();
723 cgroup_init();
724 taskstats_init_early();
725 delayacct_init();
726
727 check_bugs();
728
729 acpi_subsystem_init();
730 arch_post_acpi_subsys_init();
731 sfi_init_late();
732
733 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
734 efi_free_boot_services();
735 }
736
737 /* Do the rest non-__init'ed, we're now alive */
738 rest_init();
739}
740
741/* Call all constructor functions linked into the kernel. */
742static void __init do_ctors(void)
743{
744#ifdef CONFIG_CONSTRUCTORS
745 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
746
747 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
748 (*fn)();
749#endif
750}
751
752#ifdef CONFIG_KALLSYMS
753struct blacklist_entry {
754 struct list_head next;
755 char *buf;
756};
757
758static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
759
760static int __init initcall_blacklist(char *str)
761{
762 char *str_entry;
763 struct blacklist_entry *entry;
764
765 /* str argument is a comma-separated list of functions */
766 do {
767 str_entry = strsep(&str, ",");
768 if (str_entry) {
769 pr_debug("blacklisting initcall %s\n", str_entry);
770 entry = alloc_bootmem(sizeof(*entry));
771 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
772 strcpy(entry->buf, str_entry);
773 list_add(&entry->next, &blacklisted_initcalls);
774 }
775 } while (str_entry);
776
777 return 0;
778}
779
780static bool __init_or_module initcall_blacklisted(initcall_t fn)
781{
782 struct blacklist_entry *entry;
783 char fn_name[KSYM_SYMBOL_LEN];
784 unsigned long addr;
785
786 if (list_empty(&blacklisted_initcalls))
787 return false;
788
789 addr = (unsigned long) dereference_function_descriptor(fn);
790 sprint_symbol_no_offset(fn_name, addr);
791
792 /*
793 * fn will be "function_name [module_name]" where [module_name] is not
794 * displayed for built-in init functions. Strip off the [module_name].
795 */
796 strreplace(fn_name, ' ', '\0');
797
798 list_for_each_entry(entry, &blacklisted_initcalls, next) {
799 if (!strcmp(fn_name, entry->buf)) {
800 pr_debug("initcall %s blacklisted\n", fn_name);
801 return true;
802 }
803 }
804
805 return false;
806}
807#else
808static int __init initcall_blacklist(char *str)
809{
810 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
811 return 0;
812}
813
814static bool __init_or_module initcall_blacklisted(initcall_t fn)
815{
816 return false;
817}
818#endif
819__setup("initcall_blacklist=", initcall_blacklist);
820
821static __init_or_module void
822trace_initcall_start_cb(void *data, initcall_t fn)
823{
824 ktime_t *calltime = (ktime_t *)data;
825
826 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
827 *calltime = ktime_get();
828}
829
830static __init_or_module void
831trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
832{
833 ktime_t *calltime = (ktime_t *)data;
834 ktime_t delta, rettime;
835 unsigned long long duration;
836
837 rettime = ktime_get();
838 delta = ktime_sub(rettime, *calltime);
839 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
840 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
841 fn, ret, duration);
842}
843
844static ktime_t initcall_calltime;
845
846#ifdef TRACEPOINTS_ENABLED
847static void __init initcall_debug_enable(void)
848{
849 int ret;
850
851 ret = register_trace_initcall_start(trace_initcall_start_cb,
852 &initcall_calltime);
853 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
854 &initcall_calltime);
855 WARN(ret, "Failed to register initcall tracepoints\n");
856}
857# define do_trace_initcall_start trace_initcall_start
858# define do_trace_initcall_finish trace_initcall_finish
859#else
860static inline void do_trace_initcall_start(initcall_t fn)
861{
862 if (!initcall_debug)
863 return;
864 trace_initcall_start_cb(&initcall_calltime, fn);
865}
866static inline void do_trace_initcall_finish(initcall_t fn, int ret)
867{
868 if (!initcall_debug)
869 return;
870 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
871}
872#endif /* !TRACEPOINTS_ENABLED */
873
874int __init_or_module do_one_initcall(initcall_t fn)
875{
876 int count = preempt_count();
877 char msgbuf[64];
878 int ret;
879
880 if (initcall_blacklisted(fn))
881 return -EPERM;
882
883 do_trace_initcall_start(fn);
884 ret = fn();
885 do_trace_initcall_finish(fn, ret);
886
887 msgbuf[0] = 0;
888
889 if (preempt_count() != count) {
890 sprintf(msgbuf, "preemption imbalance ");
891 preempt_count_set(count);
892 }
893 if (irqs_disabled()) {
894 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
895 local_irq_enable();
896 }
897 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
898
899 add_latent_entropy();
900 return ret;
901}
902
903
904extern initcall_t __initcall_start[];
905extern initcall_t __initcall0_start[];
906extern initcall_t __initcall1_start[];
907extern initcall_t __initcall2_start[];
908extern initcall_t __initcall3_start[];
909extern initcall_t __initcall4_start[];
910extern initcall_t __initcall5_start[];
911extern initcall_t __initcall6_start[];
912extern initcall_t __initcall7_start[];
913extern initcall_t __initcall_end[];
914
915static initcall_t *initcall_levels[] __initdata = {
916 __initcall0_start,
917 __initcall1_start,
918 __initcall2_start,
919 __initcall3_start,
920 __initcall4_start,
921 __initcall5_start,
922 __initcall6_start,
923 __initcall7_start,
924 __initcall_end,
925};
926
927/* Keep these in sync with initcalls in include/linux/init.h */
928static char *initcall_level_names[] __initdata = {
929 "pure",
930 "core",
931 "postcore",
932 "arch",
933 "subsys",
934 "fs",
935 "device",
936 "late",
937};
938
939static void __init do_initcall_level(int level)
940{
941 initcall_t *fn;
942
943 strcpy(initcall_command_line, saved_command_line);
944 parse_args(initcall_level_names[level],
945 initcall_command_line, __start___param,
946 __stop___param - __start___param,
947 level, level,
948 NULL, &repair_env_string);
949
950 trace_initcall_level(initcall_level_names[level]);
951 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
952 do_one_initcall(*fn);
953}
954
955static void __init do_initcalls(void)
956{
957 int level;
958
959 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
960 do_initcall_level(level);
961}
962
963/*
964 * Ok, the machine is now initialized. None of the devices
965 * have been touched yet, but the CPU subsystem is up and
966 * running, and memory and process management works.
967 *
968 * Now we can finally start doing some real work..
969 */
970static void __init do_basic_setup(void)
971{
972 cpuset_init_smp();
973 shmem_init();
974 driver_init();
975 init_irq_proc();
976 do_ctors();
977 usermodehelper_enable();
978 do_initcalls();
979}
980
981static void __init do_pre_smp_initcalls(void)
982{
983 initcall_t *fn;
984
985 trace_initcall_level("early");
986 for (fn = __initcall_start; fn < __initcall0_start; fn++)
987 do_one_initcall(*fn);
988}
989
990/*
991 * This function requests modules which should be loaded by default and is
992 * called twice right after initrd is mounted and right before init is
993 * exec'd. If such modules are on either initrd or rootfs, they will be
994 * loaded before control is passed to userland.
995 */
996void __init load_default_modules(void)
997{
998 load_default_elevator_module();
999}
1000
1001static int run_init_process(const char *init_filename)
1002{
1003 argv_init[0] = init_filename;
1004 return do_execve(getname_kernel(init_filename),
1005 (const char __user *const __user *)argv_init,
1006 (const char __user *const __user *)envp_init);
1007}
1008
1009static int try_to_run_init_process(const char *init_filename)
1010{
1011 int ret;
1012
1013 ret = run_init_process(init_filename);
1014
1015 if (ret && ret != -ENOENT) {
1016 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1017 init_filename, ret);
1018 }
1019
1020 return ret;
1021}
1022
1023static noinline void __init kernel_init_freeable(void);
1024
1025#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1026bool rodata_enabled __ro_after_init = true;
1027static int __init set_debug_rodata(char *str)
1028{
1029 return strtobool(str, &rodata_enabled);
1030}
1031__setup("rodata=", set_debug_rodata);
1032#endif
1033
1034#ifdef CONFIG_STRICT_KERNEL_RWX
1035static void mark_readonly(void)
1036{
1037 if (rodata_enabled) {
1038 /*
1039 * load_module() results in W+X mappings, which are cleaned up
1040 * with call_rcu_sched(). Let's make sure that queued work is
1041 * flushed so that we don't hit false positives looking for
1042 * insecure pages which are W+X.
1043 */
1044 rcu_barrier_sched();
1045 mark_rodata_ro();
1046 rodata_test();
1047 } else
1048 pr_info("Kernel memory protection disabled.\n");
1049}
1050#else
1051static inline void mark_readonly(void)
1052{
1053 pr_warn("This architecture does not have kernel memory protection.\n");
1054}
1055#endif
1056
1057static int __ref kernel_init(void *unused)
1058{
1059 int ret;
1060
1061 kernel_init_freeable();
1062 /* need to finish all async __init code before freeing the memory */
1063 async_synchronize_full();
1064 ftrace_free_init_mem();
1065 jump_label_invalidate_initmem();
1066 free_initmem();
1067 mark_readonly();
1068 system_state = SYSTEM_RUNNING;
1069 numa_default_policy();
1070
1071 rcu_end_inkernel_boot();
1072
1073 if (ramdisk_execute_command) {
1074 ret = run_init_process(ramdisk_execute_command);
1075 if (!ret)
1076 return 0;
1077 pr_err("Failed to execute %s (error %d)\n",
1078 ramdisk_execute_command, ret);
1079 }
1080
1081 /*
1082 * We try each of these until one succeeds.
1083 *
1084 * The Bourne shell can be used instead of init if we are
1085 * trying to recover a really broken machine.
1086 */
1087 if (execute_command) {
1088 ret = run_init_process(execute_command);
1089 if (!ret)
1090 return 0;
1091 panic("Requested init %s failed (error %d).",
1092 execute_command, ret);
1093 }
1094 if (!try_to_run_init_process("/sbin/init") ||
1095 !try_to_run_init_process("/etc/init") ||
1096 !try_to_run_init_process("/bin/init") ||
1097 !try_to_run_init_process("/bin/sh"))
1098 return 0;
1099
1100 panic("No working init found. Try passing init= option to kernel. "
1101 "See Linux Documentation/admin-guide/init.rst for guidance.");
1102}
1103
1104static noinline void __init kernel_init_freeable(void)
1105{
1106 /*
1107 * Wait until kthreadd is all set-up.
1108 */
1109 wait_for_completion(&kthreadd_done);
1110
1111 /* Now the scheduler is fully set up and can do blocking allocations */
1112 gfp_allowed_mask = __GFP_BITS_MASK;
1113
1114 /*
1115 * init can allocate pages on any node
1116 */
1117 set_mems_allowed(node_states[N_MEMORY]);
1118
1119 cad_pid = task_pid(current);
1120
1121 smp_prepare_cpus(setup_max_cpus);
1122
1123 workqueue_init();
1124
1125 init_mm_internals();
1126
1127 do_pre_smp_initcalls();
1128 lockup_detector_init();
1129
1130 smp_init();
1131 sched_init_smp();
1132
1133 page_alloc_init_late();
1134
1135 do_basic_setup();
1136
1137 /* Open the /dev/console on the rootfs, this should never fail */
1138 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1139 pr_err("Warning: unable to open an initial console.\n");
1140
1141 (void) ksys_dup(0);
1142 (void) ksys_dup(0);
1143 /*
1144 * check if there is an early userspace init. If yes, let it do all
1145 * the work
1146 */
1147
1148 if (!ramdisk_execute_command)
1149 ramdisk_execute_command = "/init";
1150
1151 if (ksys_access((const char __user *)
1152 ramdisk_execute_command, 0) != 0) {
1153 ramdisk_execute_command = NULL;
1154 prepare_namespace();
1155 }
1156
1157 /*
1158 * Ok, we have completed the initial bootup, and
1159 * we're essentially up and running. Get rid of the
1160 * initmem segments and start the user-mode stuff..
1161 *
1162 * rootfs is available now, try loading the public keys
1163 * and default modules
1164 */
1165
1166 integrity_load_keys();
1167 load_default_modules();
1168}