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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/init/main.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * GK 2/5/95 - Changed to support mounting root fs via NFS
8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
10 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
11 */
12
13#define DEBUG /* Enable initcall_debug */
14
15#include <linux/types.h>
16#include <linux/extable.h>
17#include <linux/module.h>
18#include <linux/proc_fs.h>
19#include <linux/binfmts.h>
20#include <linux/kernel.h>
21#include <linux/syscalls.h>
22#include <linux/stackprotector.h>
23#include <linux/string.h>
24#include <linux/ctype.h>
25#include <linux/delay.h>
26#include <linux/ioport.h>
27#include <linux/init.h>
28#include <linux/initrd.h>
29#include <linux/memblock.h>
30#include <linux/acpi.h>
31#include <linux/console.h>
32#include <linux/nmi.h>
33#include <linux/percpu.h>
34#include <linux/kmod.h>
35#include <linux/vmalloc.h>
36#include <linux/kernel_stat.h>
37#include <linux/start_kernel.h>
38#include <linux/security.h>
39#include <linux/smp.h>
40#include <linux/profile.h>
41#include <linux/rcupdate.h>
42#include <linux/moduleparam.h>
43#include <linux/kallsyms.h>
44#include <linux/writeback.h>
45#include <linux/cpu.h>
46#include <linux/cpuset.h>
47#include <linux/cgroup.h>
48#include <linux/efi.h>
49#include <linux/tick.h>
50#include <linux/sched/isolation.h>
51#include <linux/interrupt.h>
52#include <linux/taskstats_kern.h>
53#include <linux/delayacct.h>
54#include <linux/unistd.h>
55#include <linux/utsname.h>
56#include <linux/rmap.h>
57#include <linux/mempolicy.h>
58#include <linux/key.h>
59#include <linux/buffer_head.h>
60#include <linux/page_ext.h>
61#include <linux/debug_locks.h>
62#include <linux/debugobjects.h>
63#include <linux/lockdep.h>
64#include <linux/kmemleak.h>
65#include <linux/pid_namespace.h>
66#include <linux/device.h>
67#include <linux/kthread.h>
68#include <linux/sched.h>
69#include <linux/sched/init.h>
70#include <linux/signal.h>
71#include <linux/idr.h>
72#include <linux/kgdb.h>
73#include <linux/ftrace.h>
74#include <linux/async.h>
75#include <linux/sfi.h>
76#include <linux/shmem_fs.h>
77#include <linux/slab.h>
78#include <linux/perf_event.h>
79#include <linux/ptrace.h>
80#include <linux/pti.h>
81#include <linux/blkdev.h>
82#include <linux/elevator.h>
83#include <linux/sched/clock.h>
84#include <linux/sched/task.h>
85#include <linux/sched/task_stack.h>
86#include <linux/context_tracking.h>
87#include <linux/random.h>
88#include <linux/list.h>
89#include <linux/integrity.h>
90#include <linux/proc_ns.h>
91#include <linux/io.h>
92#include <linux/cache.h>
93#include <linux/rodata_test.h>
94#include <linux/jump_label.h>
95#include <linux/mem_encrypt.h>
96
97#include <asm/io.h>
98#include <asm/bugs.h>
99#include <asm/setup.h>
100#include <asm/sections.h>
101#include <asm/cacheflush.h>
102
103#define CREATE_TRACE_POINTS
104#include <trace/events/initcall.h>
105
106static int kernel_init(void *);
107
108extern void init_IRQ(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 size_t len = strlen(boot_command_line) + 1;
378
379 saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
380 if (!saved_command_line)
381 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
382
383 initcall_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
384 if (!initcall_command_line)
385 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
386
387 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
388 if (!static_command_line)
389 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
390
391 strcpy(saved_command_line, boot_command_line);
392 strcpy(static_command_line, command_line);
393}
394
395/*
396 * We need to finalize in a non-__init function or else race conditions
397 * between the root thread and the init thread may cause start_kernel to
398 * be reaped by free_initmem before the root thread has proceeded to
399 * cpu_idle.
400 *
401 * gcc-3.4 accidentally inlines this function, so use noinline.
402 */
403
404static __initdata DECLARE_COMPLETION(kthreadd_done);
405
406noinline void __ref rest_init(void)
407{
408 struct task_struct *tsk;
409 int pid;
410
411 rcu_scheduler_starting();
412 /*
413 * We need to spawn init first so that it obtains pid 1, however
414 * the init task will end up wanting to create kthreads, which, if
415 * we schedule it before we create kthreadd, will OOPS.
416 */
417 pid = kernel_thread(kernel_init, NULL, CLONE_FS);
418 /*
419 * Pin init on the boot CPU. Task migration is not properly working
420 * until sched_init_smp() has been run. It will set the allowed
421 * CPUs for init to the non isolated CPUs.
422 */
423 rcu_read_lock();
424 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
425 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
426 rcu_read_unlock();
427
428 numa_default_policy();
429 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
430 rcu_read_lock();
431 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
432 rcu_read_unlock();
433
434 /*
435 * Enable might_sleep() and smp_processor_id() checks.
436 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
437 * kernel_thread() would trigger might_sleep() splats. With
438 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
439 * already, but it's stuck on the kthreadd_done completion.
440 */
441 system_state = SYSTEM_SCHEDULING;
442
443 complete(&kthreadd_done);
444
445 /*
446 * The boot idle thread must execute schedule()
447 * at least once to get things moving:
448 */
449 schedule_preempt_disabled();
450 /* Call into cpu_idle with preempt disabled */
451 cpu_startup_entry(CPUHP_ONLINE);
452}
453
454/* Check for early params. */
455static int __init do_early_param(char *param, char *val,
456 const char *unused, void *arg)
457{
458 const struct obs_kernel_param *p;
459
460 for (p = __setup_start; p < __setup_end; p++) {
461 if ((p->early && parameq(param, p->str)) ||
462 (strcmp(param, "console") == 0 &&
463 strcmp(p->str, "earlycon") == 0)
464 ) {
465 if (p->setup_func(val) != 0)
466 pr_warn("Malformed early option '%s'\n", param);
467 }
468 }
469 /* We accept everything at this stage. */
470 return 0;
471}
472
473void __init parse_early_options(char *cmdline)
474{
475 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
476 do_early_param);
477}
478
479/* Arch code calls this early on, or if not, just before other parsing. */
480void __init parse_early_param(void)
481{
482 static int done __initdata;
483 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
484
485 if (done)
486 return;
487
488 /* All fall through to do_early_param. */
489 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
490 parse_early_options(tmp_cmdline);
491 done = 1;
492}
493
494void __init __weak arch_post_acpi_subsys_init(void) { }
495
496void __init __weak smp_setup_processor_id(void)
497{
498}
499
500# if THREAD_SIZE >= PAGE_SIZE
501void __init __weak thread_stack_cache_init(void)
502{
503}
504#endif
505
506void __init __weak mem_encrypt_init(void) { }
507
508void __init __weak poking_init(void) { }
509
510void __init __weak pgtable_cache_init(void) { }
511
512bool initcall_debug;
513core_param(initcall_debug, initcall_debug, bool, 0644);
514
515#ifdef TRACEPOINTS_ENABLED
516static void __init initcall_debug_enable(void);
517#else
518static inline void initcall_debug_enable(void)
519{
520}
521#endif
522
523/* Report memory auto-initialization states for this boot. */
524static void __init report_meminit(void)
525{
526 const char *stack;
527
528 if (IS_ENABLED(CONFIG_INIT_STACK_ALL))
529 stack = "all";
530 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
531 stack = "byref_all";
532 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
533 stack = "byref";
534 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
535 stack = "__user";
536 else
537 stack = "off";
538
539 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
540 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
541 want_init_on_free() ? "on" : "off");
542 if (want_init_on_free())
543 pr_info("mem auto-init: clearing system memory may take some time...\n");
544}
545
546/*
547 * Set up kernel memory allocators
548 */
549static void __init mm_init(void)
550{
551 /*
552 * page_ext requires contiguous pages,
553 * bigger than MAX_ORDER unless SPARSEMEM.
554 */
555 page_ext_init_flatmem();
556 report_meminit();
557 mem_init();
558 kmem_cache_init();
559 kmemleak_init();
560 pgtable_init();
561 debug_objects_mem_init();
562 vmalloc_init();
563 ioremap_huge_init();
564 /* Should be run before the first non-init thread is created */
565 init_espfix_bsp();
566 /* Should be run after espfix64 is set up. */
567 pti_init();
568}
569
570void __init __weak arch_call_rest_init(void)
571{
572 rest_init();
573}
574
575asmlinkage __visible void __init start_kernel(void)
576{
577 char *command_line;
578 char *after_dashes;
579
580 set_task_stack_end_magic(&init_task);
581 smp_setup_processor_id();
582 debug_objects_early_init();
583
584 cgroup_init_early();
585
586 local_irq_disable();
587 early_boot_irqs_disabled = true;
588
589 /*
590 * Interrupts are still disabled. Do necessary setups, then
591 * enable them.
592 */
593 boot_cpu_init();
594 page_address_init();
595 pr_notice("%s", linux_banner);
596 early_security_init();
597 setup_arch(&command_line);
598 setup_command_line(command_line);
599 setup_nr_cpu_ids();
600 setup_per_cpu_areas();
601 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
602 boot_cpu_hotplug_init();
603
604 build_all_zonelists(NULL);
605 page_alloc_init();
606
607 pr_notice("Kernel command line: %s\n", boot_command_line);
608 /* parameters may set static keys */
609 jump_label_init();
610 parse_early_param();
611 after_dashes = parse_args("Booting kernel",
612 static_command_line, __start___param,
613 __stop___param - __start___param,
614 -1, -1, NULL, &unknown_bootoption);
615 if (!IS_ERR_OR_NULL(after_dashes))
616 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
617 NULL, set_init_arg);
618
619 /*
620 * These use large bootmem allocations and must precede
621 * kmem_cache_init()
622 */
623 setup_log_buf(0);
624 vfs_caches_init_early();
625 sort_main_extable();
626 trap_init();
627 mm_init();
628
629 ftrace_init();
630
631 /* trace_printk can be enabled here */
632 early_trace_init();
633
634 /*
635 * Set up the scheduler prior starting any interrupts (such as the
636 * timer interrupt). Full topology setup happens at smp_init()
637 * time - but meanwhile we still have a functioning scheduler.
638 */
639 sched_init();
640 /*
641 * Disable preemption - early bootup scheduling is extremely
642 * fragile until we cpu_idle() for the first time.
643 */
644 preempt_disable();
645 if (WARN(!irqs_disabled(),
646 "Interrupts were enabled *very* early, fixing it\n"))
647 local_irq_disable();
648 radix_tree_init();
649
650 /*
651 * Set up housekeeping before setting up workqueues to allow the unbound
652 * workqueue to take non-housekeeping into account.
653 */
654 housekeeping_init();
655
656 /*
657 * Allow workqueue creation and work item queueing/cancelling
658 * early. Work item execution depends on kthreads and starts after
659 * workqueue_init().
660 */
661 workqueue_init_early();
662
663 rcu_init();
664
665 /* Trace events are available after this */
666 trace_init();
667
668 if (initcall_debug)
669 initcall_debug_enable();
670
671 context_tracking_init();
672 /* init some links before init_ISA_irqs() */
673 early_irq_init();
674 init_IRQ();
675 tick_init();
676 rcu_init_nohz();
677 init_timers();
678 hrtimers_init();
679 softirq_init();
680 timekeeping_init();
681
682 /*
683 * For best initial stack canary entropy, prepare it after:
684 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
685 * - timekeeping_init() for ktime entropy used in rand_initialize()
686 * - rand_initialize() to get any arch-specific entropy like RDRAND
687 * - add_latent_entropy() to get any latent entropy
688 * - adding command line entropy
689 */
690 rand_initialize();
691 add_latent_entropy();
692 add_device_randomness(command_line, strlen(command_line));
693 boot_init_stack_canary();
694
695 time_init();
696 printk_safe_init();
697 perf_event_init();
698 profile_init();
699 call_function_init();
700 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
701
702 early_boot_irqs_disabled = false;
703 local_irq_enable();
704
705 kmem_cache_init_late();
706
707 /*
708 * HACK ALERT! This is early. We're enabling the console before
709 * we've done PCI setups etc, and console_init() must be aware of
710 * this. But we do want output early, in case something goes wrong.
711 */
712 console_init();
713 if (panic_later)
714 panic("Too many boot %s vars at `%s'", panic_later,
715 panic_param);
716
717 lockdep_init();
718
719 /*
720 * Need to run this when irqs are enabled, because it wants
721 * to self-test [hard/soft]-irqs on/off lock inversion bugs
722 * too:
723 */
724 locking_selftest();
725
726 /*
727 * This needs to be called before any devices perform DMA
728 * operations that might use the SWIOTLB bounce buffers. It will
729 * mark the bounce buffers as decrypted so that their usage will
730 * not cause "plain-text" data to be decrypted when accessed.
731 */
732 mem_encrypt_init();
733
734#ifdef CONFIG_BLK_DEV_INITRD
735 if (initrd_start && !initrd_below_start_ok &&
736 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
737 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
738 page_to_pfn(virt_to_page((void *)initrd_start)),
739 min_low_pfn);
740 initrd_start = 0;
741 }
742#endif
743 setup_per_cpu_pageset();
744 numa_policy_init();
745 acpi_early_init();
746 if (late_time_init)
747 late_time_init();
748 sched_clock_init();
749 calibrate_delay();
750 pid_idr_init();
751 anon_vma_init();
752#ifdef CONFIG_X86
753 if (efi_enabled(EFI_RUNTIME_SERVICES))
754 efi_enter_virtual_mode();
755#endif
756 thread_stack_cache_init();
757 cred_init();
758 fork_init();
759 proc_caches_init();
760 uts_ns_init();
761 buffer_init();
762 key_init();
763 security_init();
764 dbg_late_init();
765 vfs_caches_init();
766 pagecache_init();
767 signals_init();
768 seq_file_init();
769 proc_root_init();
770 nsfs_init();
771 cpuset_init();
772 cgroup_init();
773 taskstats_init_early();
774 delayacct_init();
775
776 poking_init();
777 check_bugs();
778
779 acpi_subsystem_init();
780 arch_post_acpi_subsys_init();
781 sfi_init_late();
782
783 /* Do the rest non-__init'ed, we're now alive */
784 arch_call_rest_init();
785}
786
787/* Call all constructor functions linked into the kernel. */
788static void __init do_ctors(void)
789{
790#ifdef CONFIG_CONSTRUCTORS
791 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
792
793 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
794 (*fn)();
795#endif
796}
797
798#ifdef CONFIG_KALLSYMS
799struct blacklist_entry {
800 struct list_head next;
801 char *buf;
802};
803
804static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
805
806static int __init initcall_blacklist(char *str)
807{
808 char *str_entry;
809 struct blacklist_entry *entry;
810
811 /* str argument is a comma-separated list of functions */
812 do {
813 str_entry = strsep(&str, ",");
814 if (str_entry) {
815 pr_debug("blacklisting initcall %s\n", str_entry);
816 entry = memblock_alloc(sizeof(*entry),
817 SMP_CACHE_BYTES);
818 if (!entry)
819 panic("%s: Failed to allocate %zu bytes\n",
820 __func__, sizeof(*entry));
821 entry->buf = memblock_alloc(strlen(str_entry) + 1,
822 SMP_CACHE_BYTES);
823 if (!entry->buf)
824 panic("%s: Failed to allocate %zu bytes\n",
825 __func__, strlen(str_entry) + 1);
826 strcpy(entry->buf, str_entry);
827 list_add(&entry->next, &blacklisted_initcalls);
828 }
829 } while (str_entry);
830
831 return 0;
832}
833
834static bool __init_or_module initcall_blacklisted(initcall_t fn)
835{
836 struct blacklist_entry *entry;
837 char fn_name[KSYM_SYMBOL_LEN];
838 unsigned long addr;
839
840 if (list_empty(&blacklisted_initcalls))
841 return false;
842
843 addr = (unsigned long) dereference_function_descriptor(fn);
844 sprint_symbol_no_offset(fn_name, addr);
845
846 /*
847 * fn will be "function_name [module_name]" where [module_name] is not
848 * displayed for built-in init functions. Strip off the [module_name].
849 */
850 strreplace(fn_name, ' ', '\0');
851
852 list_for_each_entry(entry, &blacklisted_initcalls, next) {
853 if (!strcmp(fn_name, entry->buf)) {
854 pr_debug("initcall %s blacklisted\n", fn_name);
855 return true;
856 }
857 }
858
859 return false;
860}
861#else
862static int __init initcall_blacklist(char *str)
863{
864 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
865 return 0;
866}
867
868static bool __init_or_module initcall_blacklisted(initcall_t fn)
869{
870 return false;
871}
872#endif
873__setup("initcall_blacklist=", initcall_blacklist);
874
875static __init_or_module void
876trace_initcall_start_cb(void *data, initcall_t fn)
877{
878 ktime_t *calltime = (ktime_t *)data;
879
880 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
881 *calltime = ktime_get();
882}
883
884static __init_or_module void
885trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
886{
887 ktime_t *calltime = (ktime_t *)data;
888 ktime_t delta, rettime;
889 unsigned long long duration;
890
891 rettime = ktime_get();
892 delta = ktime_sub(rettime, *calltime);
893 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
894 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
895 fn, ret, duration);
896}
897
898static ktime_t initcall_calltime;
899
900#ifdef TRACEPOINTS_ENABLED
901static void __init initcall_debug_enable(void)
902{
903 int ret;
904
905 ret = register_trace_initcall_start(trace_initcall_start_cb,
906 &initcall_calltime);
907 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
908 &initcall_calltime);
909 WARN(ret, "Failed to register initcall tracepoints\n");
910}
911# define do_trace_initcall_start trace_initcall_start
912# define do_trace_initcall_finish trace_initcall_finish
913#else
914static inline void do_trace_initcall_start(initcall_t fn)
915{
916 if (!initcall_debug)
917 return;
918 trace_initcall_start_cb(&initcall_calltime, fn);
919}
920static inline void do_trace_initcall_finish(initcall_t fn, int ret)
921{
922 if (!initcall_debug)
923 return;
924 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
925}
926#endif /* !TRACEPOINTS_ENABLED */
927
928int __init_or_module do_one_initcall(initcall_t fn)
929{
930 int count = preempt_count();
931 char msgbuf[64];
932 int ret;
933
934 if (initcall_blacklisted(fn))
935 return -EPERM;
936
937 do_trace_initcall_start(fn);
938 ret = fn();
939 do_trace_initcall_finish(fn, ret);
940
941 msgbuf[0] = 0;
942
943 if (preempt_count() != count) {
944 sprintf(msgbuf, "preemption imbalance ");
945 preempt_count_set(count);
946 }
947 if (irqs_disabled()) {
948 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
949 local_irq_enable();
950 }
951 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
952
953 add_latent_entropy();
954 return ret;
955}
956
957
958extern initcall_entry_t __initcall_start[];
959extern initcall_entry_t __initcall0_start[];
960extern initcall_entry_t __initcall1_start[];
961extern initcall_entry_t __initcall2_start[];
962extern initcall_entry_t __initcall3_start[];
963extern initcall_entry_t __initcall4_start[];
964extern initcall_entry_t __initcall5_start[];
965extern initcall_entry_t __initcall6_start[];
966extern initcall_entry_t __initcall7_start[];
967extern initcall_entry_t __initcall_end[];
968
969static initcall_entry_t *initcall_levels[] __initdata = {
970 __initcall0_start,
971 __initcall1_start,
972 __initcall2_start,
973 __initcall3_start,
974 __initcall4_start,
975 __initcall5_start,
976 __initcall6_start,
977 __initcall7_start,
978 __initcall_end,
979};
980
981/* Keep these in sync with initcalls in include/linux/init.h */
982static const char *initcall_level_names[] __initdata = {
983 "pure",
984 "core",
985 "postcore",
986 "arch",
987 "subsys",
988 "fs",
989 "device",
990 "late",
991};
992
993static void __init do_initcall_level(int level)
994{
995 initcall_entry_t *fn;
996
997 strcpy(initcall_command_line, saved_command_line);
998 parse_args(initcall_level_names[level],
999 initcall_command_line, __start___param,
1000 __stop___param - __start___param,
1001 level, level,
1002 NULL, &repair_env_string);
1003
1004 trace_initcall_level(initcall_level_names[level]);
1005 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1006 do_one_initcall(initcall_from_entry(fn));
1007}
1008
1009static void __init do_initcalls(void)
1010{
1011 int level;
1012
1013 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
1014 do_initcall_level(level);
1015}
1016
1017/*
1018 * Ok, the machine is now initialized. None of the devices
1019 * have been touched yet, but the CPU subsystem is up and
1020 * running, and memory and process management works.
1021 *
1022 * Now we can finally start doing some real work..
1023 */
1024static void __init do_basic_setup(void)
1025{
1026 cpuset_init_smp();
1027 driver_init();
1028 init_irq_proc();
1029 do_ctors();
1030 usermodehelper_enable();
1031 do_initcalls();
1032}
1033
1034static void __init do_pre_smp_initcalls(void)
1035{
1036 initcall_entry_t *fn;
1037
1038 trace_initcall_level("early");
1039 for (fn = __initcall_start; fn < __initcall0_start; fn++)
1040 do_one_initcall(initcall_from_entry(fn));
1041}
1042
1043static int run_init_process(const char *init_filename)
1044{
1045 argv_init[0] = init_filename;
1046 pr_info("Run %s as init process\n", init_filename);
1047 return do_execve(getname_kernel(init_filename),
1048 (const char __user *const __user *)argv_init,
1049 (const char __user *const __user *)envp_init);
1050}
1051
1052static int try_to_run_init_process(const char *init_filename)
1053{
1054 int ret;
1055
1056 ret = run_init_process(init_filename);
1057
1058 if (ret && ret != -ENOENT) {
1059 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1060 init_filename, ret);
1061 }
1062
1063 return ret;
1064}
1065
1066static noinline void __init kernel_init_freeable(void);
1067
1068#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1069bool rodata_enabled __ro_after_init = true;
1070static int __init set_debug_rodata(char *str)
1071{
1072 return strtobool(str, &rodata_enabled);
1073}
1074__setup("rodata=", set_debug_rodata);
1075#endif
1076
1077#ifdef CONFIG_STRICT_KERNEL_RWX
1078static void mark_readonly(void)
1079{
1080 if (rodata_enabled) {
1081 /*
1082 * load_module() results in W+X mappings, which are cleaned
1083 * up with call_rcu(). Let's make sure that queued work is
1084 * flushed so that we don't hit false positives looking for
1085 * insecure pages which are W+X.
1086 */
1087 rcu_barrier();
1088 mark_rodata_ro();
1089 rodata_test();
1090 } else
1091 pr_info("Kernel memory protection disabled.\n");
1092}
1093#else
1094static inline void mark_readonly(void)
1095{
1096 pr_warn("This architecture does not have kernel memory protection.\n");
1097}
1098#endif
1099
1100void __weak free_initmem(void)
1101{
1102 free_initmem_default(POISON_FREE_INITMEM);
1103}
1104
1105static int __ref kernel_init(void *unused)
1106{
1107 int ret;
1108
1109 kernel_init_freeable();
1110 /* need to finish all async __init code before freeing the memory */
1111 async_synchronize_full();
1112 ftrace_free_init_mem();
1113 free_initmem();
1114 mark_readonly();
1115
1116 /*
1117 * Kernel mappings are now finalized - update the userspace page-table
1118 * to finalize PTI.
1119 */
1120 pti_finalize();
1121
1122 system_state = SYSTEM_RUNNING;
1123 numa_default_policy();
1124
1125 rcu_end_inkernel_boot();
1126
1127 if (ramdisk_execute_command) {
1128 ret = run_init_process(ramdisk_execute_command);
1129 if (!ret)
1130 return 0;
1131 pr_err("Failed to execute %s (error %d)\n",
1132 ramdisk_execute_command, ret);
1133 }
1134
1135 /*
1136 * We try each of these until one succeeds.
1137 *
1138 * The Bourne shell can be used instead of init if we are
1139 * trying to recover a really broken machine.
1140 */
1141 if (execute_command) {
1142 ret = run_init_process(execute_command);
1143 if (!ret)
1144 return 0;
1145 panic("Requested init %s failed (error %d).",
1146 execute_command, ret);
1147 }
1148 if (!try_to_run_init_process("/sbin/init") ||
1149 !try_to_run_init_process("/etc/init") ||
1150 !try_to_run_init_process("/bin/init") ||
1151 !try_to_run_init_process("/bin/sh"))
1152 return 0;
1153
1154 panic("No working init found. Try passing init= option to kernel. "
1155 "See Linux Documentation/admin-guide/init.rst for guidance.");
1156}
1157
1158static noinline void __init kernel_init_freeable(void)
1159{
1160 /*
1161 * Wait until kthreadd is all set-up.
1162 */
1163 wait_for_completion(&kthreadd_done);
1164
1165 /* Now the scheduler is fully set up and can do blocking allocations */
1166 gfp_allowed_mask = __GFP_BITS_MASK;
1167
1168 /*
1169 * init can allocate pages on any node
1170 */
1171 set_mems_allowed(node_states[N_MEMORY]);
1172
1173 cad_pid = task_pid(current);
1174
1175 smp_prepare_cpus(setup_max_cpus);
1176
1177 workqueue_init();
1178
1179 init_mm_internals();
1180
1181 do_pre_smp_initcalls();
1182 lockup_detector_init();
1183
1184 smp_init();
1185 sched_init_smp();
1186
1187 page_alloc_init_late();
1188 /* Initialize page ext after all struct pages are initialized. */
1189 page_ext_init();
1190
1191 do_basic_setup();
1192
1193 /* Open the /dev/console on the rootfs, this should never fail */
1194 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1195 pr_err("Warning: unable to open an initial console.\n");
1196
1197 (void) ksys_dup(0);
1198 (void) ksys_dup(0);
1199 /*
1200 * check if there is an early userspace init. If yes, let it do all
1201 * the work
1202 */
1203
1204 if (!ramdisk_execute_command)
1205 ramdisk_execute_command = "/init";
1206
1207 if (ksys_access((const char __user *)
1208 ramdisk_execute_command, 0) != 0) {
1209 ramdisk_execute_command = NULL;
1210 prepare_namespace();
1211 }
1212
1213 /*
1214 * Ok, we have completed the initial bootup, and
1215 * we're essentially up and running. Get rid of the
1216 * initmem segments and start the user-mode stuff..
1217 *
1218 * rootfs is available now, try loading the public keys
1219 * and default modules
1220 */
1221
1222 integrity_load_keys();
1223}
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}