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1/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
12#define DEBUG /* Enable initcall_debug */
13
14#include <linux/types.h>
15#include <linux/module.h>
16#include <linux/proc_fs.h>
17#include <linux/kernel.h>
18#include <linux/syscalls.h>
19#include <linux/stackprotector.h>
20#include <linux/string.h>
21#include <linux/ctype.h>
22#include <linux/delay.h>
23#include <linux/ioport.h>
24#include <linux/init.h>
25#include <linux/initrd.h>
26#include <linux/bootmem.h>
27#include <linux/acpi.h>
28#include <linux/tty.h>
29#include <linux/percpu.h>
30#include <linux/kmod.h>
31#include <linux/vmalloc.h>
32#include <linux/kernel_stat.h>
33#include <linux/start_kernel.h>
34#include <linux/security.h>
35#include <linux/smp.h>
36#include <linux/profile.h>
37#include <linux/rcupdate.h>
38#include <linux/moduleparam.h>
39#include <linux/kallsyms.h>
40#include <linux/writeback.h>
41#include <linux/cpu.h>
42#include <linux/cpuset.h>
43#include <linux/cgroup.h>
44#include <linux/efi.h>
45#include <linux/tick.h>
46#include <linux/interrupt.h>
47#include <linux/taskstats_kern.h>
48#include <linux/delayacct.h>
49#include <linux/unistd.h>
50#include <linux/rmap.h>
51#include <linux/mempolicy.h>
52#include <linux/key.h>
53#include <linux/buffer_head.h>
54#include <linux/page_ext.h>
55#include <linux/debug_locks.h>
56#include <linux/debugobjects.h>
57#include <linux/lockdep.h>
58#include <linux/kmemleak.h>
59#include <linux/pid_namespace.h>
60#include <linux/device.h>
61#include <linux/kthread.h>
62#include <linux/sched.h>
63#include <linux/signal.h>
64#include <linux/idr.h>
65#include <linux/kgdb.h>
66#include <linux/ftrace.h>
67#include <linux/async.h>
68#include <linux/kmemcheck.h>
69#include <linux/sfi.h>
70#include <linux/shmem_fs.h>
71#include <linux/slab.h>
72#include <linux/perf_event.h>
73#include <linux/file.h>
74#include <linux/ptrace.h>
75#include <linux/blkdev.h>
76#include <linux/elevator.h>
77#include <linux/sched_clock.h>
78#include <linux/context_tracking.h>
79#include <linux/random.h>
80#include <linux/list.h>
81#include <linux/integrity.h>
82#include <linux/proc_ns.h>
83#include <linux/io.h>
84
85#include <asm/io.h>
86#include <asm/bugs.h>
87#include <asm/setup.h>
88#include <asm/sections.h>
89#include <asm/cacheflush.h>
90
91static int kernel_init(void *);
92
93extern void init_IRQ(void);
94extern void fork_init(void);
95extern void radix_tree_init(void);
96
97/*
98 * Debug helper: via this flag we know that we are in 'early bootup code'
99 * where only the boot processor is running with IRQ disabled. This means
100 * two things - IRQ must not be enabled before the flag is cleared and some
101 * operations which are not allowed with IRQ disabled are allowed while the
102 * flag is set.
103 */
104bool early_boot_irqs_disabled __read_mostly;
105
106enum system_states system_state __read_mostly;
107EXPORT_SYMBOL(system_state);
108
109/*
110 * Boot command-line arguments
111 */
112#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
113#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
114
115extern void time_init(void);
116/* Default late time init is NULL. archs can override this later. */
117void (*__initdata late_time_init)(void);
118
119/* Untouched command line saved by arch-specific code. */
120char __initdata boot_command_line[COMMAND_LINE_SIZE];
121/* Untouched saved command line (eg. for /proc) */
122char *saved_command_line;
123/* Command line for parameter parsing */
124static char *static_command_line;
125/* Command line for per-initcall parameter parsing */
126static char *initcall_command_line;
127
128static char *execute_command;
129static char *ramdisk_execute_command;
130
131/*
132 * Used to generate warnings if static_key manipulation functions are used
133 * before jump_label_init is called.
134 */
135bool static_key_initialized __read_mostly;
136EXPORT_SYMBOL_GPL(static_key_initialized);
137
138/*
139 * If set, this is an indication to the drivers that reset the underlying
140 * device before going ahead with the initialization otherwise driver might
141 * rely on the BIOS and skip the reset operation.
142 *
143 * This is useful if kernel is booting in an unreliable environment.
144 * For ex. kdump situation where previous kernel has crashed, BIOS has been
145 * skipped and devices will be in unknown state.
146 */
147unsigned int reset_devices;
148EXPORT_SYMBOL(reset_devices);
149
150static int __init set_reset_devices(char *str)
151{
152 reset_devices = 1;
153 return 1;
154}
155
156__setup("reset_devices", set_reset_devices);
157
158static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
159const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
160static const char *panic_later, *panic_param;
161
162extern const struct obs_kernel_param __setup_start[], __setup_end[];
163
164static bool __init obsolete_checksetup(char *line)
165{
166 const struct obs_kernel_param *p;
167 bool had_early_param = false;
168
169 p = __setup_start;
170 do {
171 int n = strlen(p->str);
172 if (parameqn(line, p->str, n)) {
173 if (p->early) {
174 /* Already done in parse_early_param?
175 * (Needs exact match on param part).
176 * Keep iterating, as we can have early
177 * params and __setups of same names 8( */
178 if (line[n] == '\0' || line[n] == '=')
179 had_early_param = true;
180 } else if (!p->setup_func) {
181 pr_warn("Parameter %s is obsolete, ignored\n",
182 p->str);
183 return true;
184 } else if (p->setup_func(line + n))
185 return true;
186 }
187 p++;
188 } while (p < __setup_end);
189
190 return had_early_param;
191}
192
193/*
194 * This should be approx 2 Bo*oMips to start (note initial shift), and will
195 * still work even if initially too large, it will just take slightly longer
196 */
197unsigned long loops_per_jiffy = (1<<12);
198EXPORT_SYMBOL(loops_per_jiffy);
199
200static int __init debug_kernel(char *str)
201{
202 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
203 return 0;
204}
205
206static int __init quiet_kernel(char *str)
207{
208 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
209 return 0;
210}
211
212early_param("debug", debug_kernel);
213early_param("quiet", quiet_kernel);
214
215static int __init loglevel(char *str)
216{
217 int newlevel;
218
219 /*
220 * Only update loglevel value when a correct setting was passed,
221 * to prevent blind crashes (when loglevel being set to 0) that
222 * are quite hard to debug
223 */
224 if (get_option(&str, &newlevel)) {
225 console_loglevel = newlevel;
226 return 0;
227 }
228
229 return -EINVAL;
230}
231
232early_param("loglevel", loglevel);
233
234/* Change NUL term back to "=", to make "param" the whole string. */
235static int __init repair_env_string(char *param, char *val,
236 const char *unused, void *arg)
237{
238 if (val) {
239 /* param=val or param="val"? */
240 if (val == param+strlen(param)+1)
241 val[-1] = '=';
242 else if (val == param+strlen(param)+2) {
243 val[-2] = '=';
244 memmove(val-1, val, strlen(val)+1);
245 val--;
246 } else
247 BUG();
248 }
249 return 0;
250}
251
252/* Anything after -- gets handed straight to init. */
253static int __init set_init_arg(char *param, char *val,
254 const char *unused, void *arg)
255{
256 unsigned int i;
257
258 if (panic_later)
259 return 0;
260
261 repair_env_string(param, val, unused, NULL);
262
263 for (i = 0; argv_init[i]; i++) {
264 if (i == MAX_INIT_ARGS) {
265 panic_later = "init";
266 panic_param = param;
267 return 0;
268 }
269 }
270 argv_init[i] = param;
271 return 0;
272}
273
274/*
275 * Unknown boot options get handed to init, unless they look like
276 * unused parameters (modprobe will find them in /proc/cmdline).
277 */
278static int __init unknown_bootoption(char *param, char *val,
279 const char *unused, void *arg)
280{
281 repair_env_string(param, val, unused, NULL);
282
283 /* Handle obsolete-style parameters */
284 if (obsolete_checksetup(param))
285 return 0;
286
287 /* Unused module parameter. */
288 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
289 return 0;
290
291 if (panic_later)
292 return 0;
293
294 if (val) {
295 /* Environment option */
296 unsigned int i;
297 for (i = 0; envp_init[i]; i++) {
298 if (i == MAX_INIT_ENVS) {
299 panic_later = "env";
300 panic_param = param;
301 }
302 if (!strncmp(param, envp_init[i], val - param))
303 break;
304 }
305 envp_init[i] = param;
306 } else {
307 /* Command line option */
308 unsigned int i;
309 for (i = 0; argv_init[i]; i++) {
310 if (i == MAX_INIT_ARGS) {
311 panic_later = "init";
312 panic_param = param;
313 }
314 }
315 argv_init[i] = param;
316 }
317 return 0;
318}
319
320static int __init init_setup(char *str)
321{
322 unsigned int i;
323
324 execute_command = str;
325 /*
326 * In case LILO is going to boot us with default command line,
327 * it prepends "auto" before the whole cmdline which makes
328 * the shell think it should execute a script with such name.
329 * So we ignore all arguments entered _before_ init=... [MJ]
330 */
331 for (i = 1; i < MAX_INIT_ARGS; i++)
332 argv_init[i] = NULL;
333 return 1;
334}
335__setup("init=", init_setup);
336
337static int __init rdinit_setup(char *str)
338{
339 unsigned int i;
340
341 ramdisk_execute_command = str;
342 /* See "auto" comment in init_setup */
343 for (i = 1; i < MAX_INIT_ARGS; i++)
344 argv_init[i] = NULL;
345 return 1;
346}
347__setup("rdinit=", rdinit_setup);
348
349#ifndef CONFIG_SMP
350static const unsigned int setup_max_cpus = NR_CPUS;
351static inline void setup_nr_cpu_ids(void) { }
352static inline void smp_prepare_cpus(unsigned int maxcpus) { }
353#endif
354
355/*
356 * We need to store the untouched command line for future reference.
357 * We also need to store the touched command line since the parameter
358 * parsing is performed in place, and we should allow a component to
359 * store reference of name/value for future reference.
360 */
361static void __init setup_command_line(char *command_line)
362{
363 saved_command_line =
364 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
365 initcall_command_line =
366 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
367 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
368 strcpy(saved_command_line, boot_command_line);
369 strcpy(static_command_line, command_line);
370}
371
372/*
373 * We need to finalize in a non-__init function or else race conditions
374 * between the root thread and the init thread may cause start_kernel to
375 * be reaped by free_initmem before the root thread has proceeded to
376 * cpu_idle.
377 *
378 * gcc-3.4 accidentally inlines this function, so use noinline.
379 */
380
381static __initdata DECLARE_COMPLETION(kthreadd_done);
382
383static noinline void __init_refok rest_init(void)
384{
385 int pid;
386
387 rcu_scheduler_starting();
388 /*
389 * We need to spawn init first so that it obtains pid 1, however
390 * the init task will end up wanting to create kthreads, which, if
391 * we schedule it before we create kthreadd, will OOPS.
392 */
393 kernel_thread(kernel_init, NULL, CLONE_FS);
394 numa_default_policy();
395 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
396 rcu_read_lock();
397 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
398 rcu_read_unlock();
399 complete(&kthreadd_done);
400
401 /*
402 * The boot idle thread must execute schedule()
403 * at least once to get things moving:
404 */
405 init_idle_bootup_task(current);
406 schedule_preempt_disabled();
407 /* Call into cpu_idle with preempt disabled */
408 cpu_startup_entry(CPUHP_ONLINE);
409}
410
411/* Check for early params. */
412static int __init do_early_param(char *param, char *val,
413 const char *unused, void *arg)
414{
415 const struct obs_kernel_param *p;
416
417 for (p = __setup_start; p < __setup_end; p++) {
418 if ((p->early && parameq(param, p->str)) ||
419 (strcmp(param, "console") == 0 &&
420 strcmp(p->str, "earlycon") == 0)
421 ) {
422 if (p->setup_func(val) != 0)
423 pr_warn("Malformed early option '%s'\n", param);
424 }
425 }
426 /* We accept everything at this stage. */
427 return 0;
428}
429
430void __init parse_early_options(char *cmdline)
431{
432 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
433 do_early_param);
434}
435
436/* Arch code calls this early on, or if not, just before other parsing. */
437void __init parse_early_param(void)
438{
439 static int done __initdata;
440 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
441
442 if (done)
443 return;
444
445 /* All fall through to do_early_param. */
446 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
447 parse_early_options(tmp_cmdline);
448 done = 1;
449}
450
451void __init __weak smp_setup_processor_id(void)
452{
453}
454
455# if THREAD_SIZE >= PAGE_SIZE
456void __init __weak thread_info_cache_init(void)
457{
458}
459#endif
460
461/*
462 * Set up kernel memory allocators
463 */
464static void __init mm_init(void)
465{
466 /*
467 * page_ext requires contiguous pages,
468 * bigger than MAX_ORDER unless SPARSEMEM.
469 */
470 page_ext_init_flatmem();
471 mem_init();
472 kmem_cache_init();
473 percpu_init_late();
474 pgtable_init();
475 vmalloc_init();
476 ioremap_huge_init();
477}
478
479asmlinkage __visible void __init start_kernel(void)
480{
481 char *command_line;
482 char *after_dashes;
483
484 set_task_stack_end_magic(&init_task);
485 smp_setup_processor_id();
486 debug_objects_early_init();
487
488 /*
489 * Set up the the initial canary ASAP:
490 */
491 boot_init_stack_canary();
492
493 cgroup_init_early();
494
495 local_irq_disable();
496 early_boot_irqs_disabled = true;
497
498/*
499 * Interrupts are still disabled. Do necessary setups, then
500 * enable them
501 */
502 boot_cpu_init();
503 page_address_init();
504 pr_notice("%s", linux_banner);
505 setup_arch(&command_line);
506 mm_init_cpumask(&init_mm);
507 setup_command_line(command_line);
508 setup_nr_cpu_ids();
509 setup_per_cpu_areas();
510 boot_cpu_state_init();
511 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
512
513 build_all_zonelists(NULL, NULL);
514 page_alloc_init();
515
516 pr_notice("Kernel command line: %s\n", boot_command_line);
517 parse_early_param();
518 after_dashes = parse_args("Booting kernel",
519 static_command_line, __start___param,
520 __stop___param - __start___param,
521 -1, -1, NULL, &unknown_bootoption);
522 if (!IS_ERR_OR_NULL(after_dashes))
523 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
524 NULL, set_init_arg);
525
526 jump_label_init();
527
528 /*
529 * These use large bootmem allocations and must precede
530 * kmem_cache_init()
531 */
532 setup_log_buf(0);
533 pidhash_init();
534 vfs_caches_init_early();
535 sort_main_extable();
536 trap_init();
537 mm_init();
538
539 /*
540 * Set up the scheduler prior starting any interrupts (such as the
541 * timer interrupt). Full topology setup happens at smp_init()
542 * time - but meanwhile we still have a functioning scheduler.
543 */
544 sched_init();
545 /*
546 * Disable preemption - early bootup scheduling is extremely
547 * fragile until we cpu_idle() for the first time.
548 */
549 preempt_disable();
550 if (WARN(!irqs_disabled(),
551 "Interrupts were enabled *very* early, fixing it\n"))
552 local_irq_disable();
553 idr_init_cache();
554 rcu_init();
555
556 /* trace_printk() and trace points may be used after this */
557 trace_init();
558
559 context_tracking_init();
560 radix_tree_init();
561 /* init some links before init_ISA_irqs() */
562 early_irq_init();
563 init_IRQ();
564 tick_init();
565 rcu_init_nohz();
566 init_timers();
567 hrtimers_init();
568 softirq_init();
569 timekeeping_init();
570 time_init();
571 sched_clock_postinit();
572 perf_event_init();
573 profile_init();
574 call_function_init();
575 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
576 early_boot_irqs_disabled = false;
577 local_irq_enable();
578
579 kmem_cache_init_late();
580
581 /*
582 * HACK ALERT! This is early. We're enabling the console before
583 * we've done PCI setups etc, and console_init() must be aware of
584 * this. But we do want output early, in case something goes wrong.
585 */
586 console_init();
587 if (panic_later)
588 panic("Too many boot %s vars at `%s'", panic_later,
589 panic_param);
590
591 lockdep_info();
592
593 /*
594 * Need to run this when irqs are enabled, because it wants
595 * to self-test [hard/soft]-irqs on/off lock inversion bugs
596 * too:
597 */
598 locking_selftest();
599
600#ifdef CONFIG_BLK_DEV_INITRD
601 if (initrd_start && !initrd_below_start_ok &&
602 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
603 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
604 page_to_pfn(virt_to_page((void *)initrd_start)),
605 min_low_pfn);
606 initrd_start = 0;
607 }
608#endif
609 page_ext_init();
610 debug_objects_mem_init();
611 kmemleak_init();
612 setup_per_cpu_pageset();
613 numa_policy_init();
614 if (late_time_init)
615 late_time_init();
616 sched_clock_init();
617 calibrate_delay();
618 pidmap_init();
619 anon_vma_init();
620 acpi_early_init();
621#ifdef CONFIG_X86
622 if (efi_enabled(EFI_RUNTIME_SERVICES))
623 efi_enter_virtual_mode();
624#endif
625#ifdef CONFIG_X86_ESPFIX64
626 /* Should be run before the first non-init thread is created */
627 init_espfix_bsp();
628#endif
629 thread_info_cache_init();
630 cred_init();
631 fork_init();
632 proc_caches_init();
633 buffer_init();
634 key_init();
635 security_init();
636 dbg_late_init();
637 vfs_caches_init();
638 signals_init();
639 /* rootfs populating might need page-writeback */
640 page_writeback_init();
641 proc_root_init();
642 nsfs_init();
643 cpuset_init();
644 cgroup_init();
645 taskstats_init_early();
646 delayacct_init();
647
648 check_bugs();
649
650 acpi_subsystem_init();
651 sfi_init_late();
652
653 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
654 efi_late_init();
655 efi_free_boot_services();
656 }
657
658 ftrace_init();
659
660 /* Do the rest non-__init'ed, we're now alive */
661 rest_init();
662}
663
664/* Call all constructor functions linked into the kernel. */
665static void __init do_ctors(void)
666{
667#ifdef CONFIG_CONSTRUCTORS
668 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
669
670 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
671 (*fn)();
672#endif
673}
674
675bool initcall_debug;
676core_param(initcall_debug, initcall_debug, bool, 0644);
677
678#ifdef CONFIG_KALLSYMS
679struct blacklist_entry {
680 struct list_head next;
681 char *buf;
682};
683
684static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
685
686static int __init initcall_blacklist(char *str)
687{
688 char *str_entry;
689 struct blacklist_entry *entry;
690
691 /* str argument is a comma-separated list of functions */
692 do {
693 str_entry = strsep(&str, ",");
694 if (str_entry) {
695 pr_debug("blacklisting initcall %s\n", str_entry);
696 entry = alloc_bootmem(sizeof(*entry));
697 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
698 strcpy(entry->buf, str_entry);
699 list_add(&entry->next, &blacklisted_initcalls);
700 }
701 } while (str_entry);
702
703 return 0;
704}
705
706static bool __init_or_module initcall_blacklisted(initcall_t fn)
707{
708 struct blacklist_entry *entry;
709 char *fn_name;
710
711 fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
712 if (!fn_name)
713 return false;
714
715 list_for_each_entry(entry, &blacklisted_initcalls, next) {
716 if (!strcmp(fn_name, entry->buf)) {
717 pr_debug("initcall %s blacklisted\n", fn_name);
718 kfree(fn_name);
719 return true;
720 }
721 }
722
723 kfree(fn_name);
724 return false;
725}
726#else
727static int __init initcall_blacklist(char *str)
728{
729 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
730 return 0;
731}
732
733static bool __init_or_module initcall_blacklisted(initcall_t fn)
734{
735 return false;
736}
737#endif
738__setup("initcall_blacklist=", initcall_blacklist);
739
740static int __init_or_module do_one_initcall_debug(initcall_t fn)
741{
742 ktime_t calltime, delta, rettime;
743 unsigned long long duration;
744 int ret;
745
746 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
747 calltime = ktime_get();
748 ret = fn();
749 rettime = ktime_get();
750 delta = ktime_sub(rettime, calltime);
751 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
752 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
753 fn, ret, duration);
754
755 return ret;
756}
757
758int __init_or_module do_one_initcall(initcall_t fn)
759{
760 int count = preempt_count();
761 int ret;
762 char msgbuf[64];
763
764 if (initcall_blacklisted(fn))
765 return -EPERM;
766
767 if (initcall_debug)
768 ret = do_one_initcall_debug(fn);
769 else
770 ret = fn();
771
772 msgbuf[0] = 0;
773
774 if (preempt_count() != count) {
775 sprintf(msgbuf, "preemption imbalance ");
776 preempt_count_set(count);
777 }
778 if (irqs_disabled()) {
779 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
780 local_irq_enable();
781 }
782 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
783
784 return ret;
785}
786
787
788extern initcall_t __initcall_start[];
789extern initcall_t __initcall0_start[];
790extern initcall_t __initcall1_start[];
791extern initcall_t __initcall2_start[];
792extern initcall_t __initcall3_start[];
793extern initcall_t __initcall4_start[];
794extern initcall_t __initcall5_start[];
795extern initcall_t __initcall6_start[];
796extern initcall_t __initcall7_start[];
797extern initcall_t __initcall_end[];
798
799static initcall_t *initcall_levels[] __initdata = {
800 __initcall0_start,
801 __initcall1_start,
802 __initcall2_start,
803 __initcall3_start,
804 __initcall4_start,
805 __initcall5_start,
806 __initcall6_start,
807 __initcall7_start,
808 __initcall_end,
809};
810
811/* Keep these in sync with initcalls in include/linux/init.h */
812static char *initcall_level_names[] __initdata = {
813 "early",
814 "core",
815 "postcore",
816 "arch",
817 "subsys",
818 "fs",
819 "device",
820 "late",
821};
822
823static void __init do_initcall_level(int level)
824{
825 initcall_t *fn;
826
827 strcpy(initcall_command_line, saved_command_line);
828 parse_args(initcall_level_names[level],
829 initcall_command_line, __start___param,
830 __stop___param - __start___param,
831 level, level,
832 NULL, &repair_env_string);
833
834 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
835 do_one_initcall(*fn);
836}
837
838static void __init do_initcalls(void)
839{
840 int level;
841
842 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
843 do_initcall_level(level);
844}
845
846/*
847 * Ok, the machine is now initialized. None of the devices
848 * have been touched yet, but the CPU subsystem is up and
849 * running, and memory and process management works.
850 *
851 * Now we can finally start doing some real work..
852 */
853static void __init do_basic_setup(void)
854{
855 cpuset_init_smp();
856 shmem_init();
857 driver_init();
858 init_irq_proc();
859 do_ctors();
860 usermodehelper_enable();
861 do_initcalls();
862 random_int_secret_init();
863}
864
865static void __init do_pre_smp_initcalls(void)
866{
867 initcall_t *fn;
868
869 for (fn = __initcall_start; fn < __initcall0_start; fn++)
870 do_one_initcall(*fn);
871}
872
873/*
874 * This function requests modules which should be loaded by default and is
875 * called twice right after initrd is mounted and right before init is
876 * exec'd. If such modules are on either initrd or rootfs, they will be
877 * loaded before control is passed to userland.
878 */
879void __init load_default_modules(void)
880{
881 load_default_elevator_module();
882}
883
884static int run_init_process(const char *init_filename)
885{
886 argv_init[0] = init_filename;
887 return do_execve(getname_kernel(init_filename),
888 (const char __user *const __user *)argv_init,
889 (const char __user *const __user *)envp_init);
890}
891
892static int try_to_run_init_process(const char *init_filename)
893{
894 int ret;
895
896 ret = run_init_process(init_filename);
897
898 if (ret && ret != -ENOENT) {
899 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
900 init_filename, ret);
901 }
902
903 return ret;
904}
905
906static noinline void __init kernel_init_freeable(void);
907
908#ifdef CONFIG_DEBUG_RODATA
909static bool rodata_enabled = true;
910static int __init set_debug_rodata(char *str)
911{
912 return strtobool(str, &rodata_enabled);
913}
914__setup("rodata=", set_debug_rodata);
915
916static void mark_readonly(void)
917{
918 if (rodata_enabled)
919 mark_rodata_ro();
920 else
921 pr_info("Kernel memory protection disabled.\n");
922}
923#else
924static inline void mark_readonly(void)
925{
926 pr_warn("This architecture does not have kernel memory protection.\n");
927}
928#endif
929
930static int __ref kernel_init(void *unused)
931{
932 int ret;
933
934 kernel_init_freeable();
935 /* need to finish all async __init code before freeing the memory */
936 async_synchronize_full();
937 free_initmem();
938 mark_readonly();
939 system_state = SYSTEM_RUNNING;
940 numa_default_policy();
941
942 flush_delayed_fput();
943
944 rcu_end_inkernel_boot();
945
946 if (ramdisk_execute_command) {
947 ret = run_init_process(ramdisk_execute_command);
948 if (!ret)
949 return 0;
950 pr_err("Failed to execute %s (error %d)\n",
951 ramdisk_execute_command, ret);
952 }
953
954 /*
955 * We try each of these until one succeeds.
956 *
957 * The Bourne shell can be used instead of init if we are
958 * trying to recover a really broken machine.
959 */
960 if (execute_command) {
961 ret = run_init_process(execute_command);
962 if (!ret)
963 return 0;
964 panic("Requested init %s failed (error %d).",
965 execute_command, ret);
966 }
967 if (!try_to_run_init_process("/sbin/init") ||
968 !try_to_run_init_process("/etc/init") ||
969 !try_to_run_init_process("/bin/init") ||
970 !try_to_run_init_process("/bin/sh"))
971 return 0;
972
973 panic("No working init found. Try passing init= option to kernel. "
974 "See Linux Documentation/init.txt for guidance.");
975}
976
977static noinline void __init kernel_init_freeable(void)
978{
979 /*
980 * Wait until kthreadd is all set-up.
981 */
982 wait_for_completion(&kthreadd_done);
983
984 /* Now the scheduler is fully set up and can do blocking allocations */
985 gfp_allowed_mask = __GFP_BITS_MASK;
986
987 /*
988 * init can allocate pages on any node
989 */
990 set_mems_allowed(node_states[N_MEMORY]);
991 /*
992 * init can run on any cpu.
993 */
994 set_cpus_allowed_ptr(current, cpu_all_mask);
995
996 cad_pid = task_pid(current);
997
998 smp_prepare_cpus(setup_max_cpus);
999
1000 do_pre_smp_initcalls();
1001 lockup_detector_init();
1002
1003 smp_init();
1004 sched_init_smp();
1005
1006 page_alloc_init_late();
1007
1008 do_basic_setup();
1009
1010 /* Open the /dev/console on the rootfs, this should never fail */
1011 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1012 pr_err("Warning: unable to open an initial console.\n");
1013
1014 (void) sys_dup(0);
1015 (void) sys_dup(0);
1016 /*
1017 * check if there is an early userspace init. If yes, let it do all
1018 * the work
1019 */
1020
1021 if (!ramdisk_execute_command)
1022 ramdisk_execute_command = "/init";
1023
1024 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1025 ramdisk_execute_command = NULL;
1026 prepare_namespace();
1027 }
1028
1029 /*
1030 * Ok, we have completed the initial bootup, and
1031 * we're essentially up and running. Get rid of the
1032 * initmem segments and start the user-mode stuff..
1033 *
1034 * rootfs is available now, try loading the public keys
1035 * and default modules
1036 */
1037
1038 integrity_load_keys();
1039 load_default_modules();
1040}
1// 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/bootconfig.h>
32#include <linux/console.h>
33#include <linux/nmi.h>
34#include <linux/percpu.h>
35#include <linux/kmod.h>
36#include <linux/kprobes.h>
37#include <linux/kmsan.h>
38#include <linux/vmalloc.h>
39#include <linux/kernel_stat.h>
40#include <linux/start_kernel.h>
41#include <linux/security.h>
42#include <linux/smp.h>
43#include <linux/profile.h>
44#include <linux/kfence.h>
45#include <linux/rcupdate.h>
46#include <linux/srcu.h>
47#include <linux/moduleparam.h>
48#include <linux/kallsyms.h>
49#include <linux/buildid.h>
50#include <linux/writeback.h>
51#include <linux/cpu.h>
52#include <linux/cpuset.h>
53#include <linux/cgroup.h>
54#include <linux/efi.h>
55#include <linux/tick.h>
56#include <linux/sched/isolation.h>
57#include <linux/interrupt.h>
58#include <linux/taskstats_kern.h>
59#include <linux/delayacct.h>
60#include <linux/unistd.h>
61#include <linux/utsname.h>
62#include <linux/rmap.h>
63#include <linux/mempolicy.h>
64#include <linux/key.h>
65#include <linux/page_ext.h>
66#include <linux/debug_locks.h>
67#include <linux/debugobjects.h>
68#include <linux/lockdep.h>
69#include <linux/kmemleak.h>
70#include <linux/padata.h>
71#include <linux/pid_namespace.h>
72#include <linux/device/driver.h>
73#include <linux/kthread.h>
74#include <linux/sched.h>
75#include <linux/sched/init.h>
76#include <linux/signal.h>
77#include <linux/idr.h>
78#include <linux/kgdb.h>
79#include <linux/ftrace.h>
80#include <linux/async.h>
81#include <linux/shmem_fs.h>
82#include <linux/slab.h>
83#include <linux/perf_event.h>
84#include <linux/ptrace.h>
85#include <linux/pti.h>
86#include <linux/blkdev.h>
87#include <linux/sched/clock.h>
88#include <linux/sched/task.h>
89#include <linux/sched/task_stack.h>
90#include <linux/context_tracking.h>
91#include <linux/random.h>
92#include <linux/list.h>
93#include <linux/integrity.h>
94#include <linux/proc_ns.h>
95#include <linux/io.h>
96#include <linux/cache.h>
97#include <linux/rodata_test.h>
98#include <linux/jump_label.h>
99#include <linux/mem_encrypt.h>
100#include <linux/kcsan.h>
101#include <linux/init_syscalls.h>
102#include <linux/stackdepot.h>
103#include <linux/randomize_kstack.h>
104#include <net/net_namespace.h>
105
106#include <asm/io.h>
107#include <asm/bugs.h>
108#include <asm/setup.h>
109#include <asm/sections.h>
110#include <asm/cacheflush.h>
111
112#define CREATE_TRACE_POINTS
113#include <trace/events/initcall.h>
114
115#include <kunit/test.h>
116
117static int kernel_init(void *);
118
119extern void init_IRQ(void);
120extern void radix_tree_init(void);
121extern void maple_tree_init(void);
122
123/*
124 * Debug helper: via this flag we know that we are in 'early bootup code'
125 * where only the boot processor is running with IRQ disabled. This means
126 * two things - IRQ must not be enabled before the flag is cleared and some
127 * operations which are not allowed with IRQ disabled are allowed while the
128 * flag is set.
129 */
130bool early_boot_irqs_disabled __read_mostly;
131
132enum system_states system_state __read_mostly;
133EXPORT_SYMBOL(system_state);
134
135/*
136 * Boot command-line arguments
137 */
138#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
139#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
140
141extern void time_init(void);
142/* Default late time init is NULL. archs can override this later. */
143void (*__initdata late_time_init)(void);
144
145/* Untouched command line saved by arch-specific code. */
146char __initdata boot_command_line[COMMAND_LINE_SIZE];
147/* Untouched saved command line (eg. for /proc) */
148char *saved_command_line __ro_after_init;
149unsigned int saved_command_line_len __ro_after_init;
150/* Command line for parameter parsing */
151static char *static_command_line;
152/* Untouched extra command line */
153static char *extra_command_line;
154/* Extra init arguments */
155static char *extra_init_args;
156
157#ifdef CONFIG_BOOT_CONFIG
158/* Is bootconfig on command line? */
159static bool bootconfig_found;
160static size_t initargs_offs;
161#else
162# define bootconfig_found false
163# define initargs_offs 0
164#endif
165
166static char *execute_command;
167static char *ramdisk_execute_command = "/init";
168
169/*
170 * Used to generate warnings if static_key manipulation functions are used
171 * before jump_label_init is called.
172 */
173bool static_key_initialized __read_mostly;
174EXPORT_SYMBOL_GPL(static_key_initialized);
175
176/*
177 * If set, this is an indication to the drivers that reset the underlying
178 * device before going ahead with the initialization otherwise driver might
179 * rely on the BIOS and skip the reset operation.
180 *
181 * This is useful if kernel is booting in an unreliable environment.
182 * For ex. kdump situation where previous kernel has crashed, BIOS has been
183 * skipped and devices will be in unknown state.
184 */
185unsigned int reset_devices;
186EXPORT_SYMBOL(reset_devices);
187
188static int __init set_reset_devices(char *str)
189{
190 reset_devices = 1;
191 return 1;
192}
193
194__setup("reset_devices", set_reset_devices);
195
196static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
197const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
198static const char *panic_later, *panic_param;
199
200extern const struct obs_kernel_param __setup_start[], __setup_end[];
201
202static bool __init obsolete_checksetup(char *line)
203{
204 const struct obs_kernel_param *p;
205 bool had_early_param = false;
206
207 p = __setup_start;
208 do {
209 int n = strlen(p->str);
210 if (parameqn(line, p->str, n)) {
211 if (p->early) {
212 /* Already done in parse_early_param?
213 * (Needs exact match on param part).
214 * Keep iterating, as we can have early
215 * params and __setups of same names 8( */
216 if (line[n] == '\0' || line[n] == '=')
217 had_early_param = true;
218 } else if (!p->setup_func) {
219 pr_warn("Parameter %s is obsolete, ignored\n",
220 p->str);
221 return true;
222 } else if (p->setup_func(line + n))
223 return true;
224 }
225 p++;
226 } while (p < __setup_end);
227
228 return had_early_param;
229}
230
231/*
232 * This should be approx 2 Bo*oMips to start (note initial shift), and will
233 * still work even if initially too large, it will just take slightly longer
234 */
235unsigned long loops_per_jiffy = (1<<12);
236EXPORT_SYMBOL(loops_per_jiffy);
237
238static int __init debug_kernel(char *str)
239{
240 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
241 return 0;
242}
243
244static int __init quiet_kernel(char *str)
245{
246 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
247 return 0;
248}
249
250early_param("debug", debug_kernel);
251early_param("quiet", quiet_kernel);
252
253static int __init loglevel(char *str)
254{
255 int newlevel;
256
257 /*
258 * Only update loglevel value when a correct setting was passed,
259 * to prevent blind crashes (when loglevel being set to 0) that
260 * are quite hard to debug
261 */
262 if (get_option(&str, &newlevel)) {
263 console_loglevel = newlevel;
264 return 0;
265 }
266
267 return -EINVAL;
268}
269
270early_param("loglevel", loglevel);
271
272#ifdef CONFIG_BLK_DEV_INITRD
273static void * __init get_boot_config_from_initrd(size_t *_size)
274{
275 u32 size, csum;
276 char *data;
277 u32 *hdr;
278 int i;
279
280 if (!initrd_end)
281 return NULL;
282
283 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
284 /*
285 * Since Grub may align the size of initrd to 4, we must
286 * check the preceding 3 bytes as well.
287 */
288 for (i = 0; i < 4; i++) {
289 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
290 goto found;
291 data--;
292 }
293 return NULL;
294
295found:
296 hdr = (u32 *)(data - 8);
297 size = le32_to_cpu(hdr[0]);
298 csum = le32_to_cpu(hdr[1]);
299
300 data = ((void *)hdr) - size;
301 if ((unsigned long)data < initrd_start) {
302 pr_err("bootconfig size %d is greater than initrd size %ld\n",
303 size, initrd_end - initrd_start);
304 return NULL;
305 }
306
307 if (xbc_calc_checksum(data, size) != csum) {
308 pr_err("bootconfig checksum failed\n");
309 return NULL;
310 }
311
312 /* Remove bootconfig from initramfs/initrd */
313 initrd_end = (unsigned long)data;
314 if (_size)
315 *_size = size;
316
317 return data;
318}
319#else
320static void * __init get_boot_config_from_initrd(size_t *_size)
321{
322 return NULL;
323}
324#endif
325
326#ifdef CONFIG_BOOT_CONFIG
327
328static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
329
330#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
331
332static int __init xbc_snprint_cmdline(char *buf, size_t size,
333 struct xbc_node *root)
334{
335 struct xbc_node *knode, *vnode;
336 char *end = buf + size;
337 const char *val;
338 int ret;
339
340 xbc_node_for_each_key_value(root, knode, val) {
341 ret = xbc_node_compose_key_after(root, knode,
342 xbc_namebuf, XBC_KEYLEN_MAX);
343 if (ret < 0)
344 return ret;
345
346 vnode = xbc_node_get_child(knode);
347 if (!vnode) {
348 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
349 if (ret < 0)
350 return ret;
351 buf += ret;
352 continue;
353 }
354 xbc_array_for_each_value(vnode, val) {
355 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
356 xbc_namebuf, val);
357 if (ret < 0)
358 return ret;
359 buf += ret;
360 }
361 }
362
363 return buf - (end - size);
364}
365#undef rest
366
367/* Make an extra command line under given key word */
368static char * __init xbc_make_cmdline(const char *key)
369{
370 struct xbc_node *root;
371 char *new_cmdline;
372 int ret, len = 0;
373
374 root = xbc_find_node(key);
375 if (!root)
376 return NULL;
377
378 /* Count required buffer size */
379 len = xbc_snprint_cmdline(NULL, 0, root);
380 if (len <= 0)
381 return NULL;
382
383 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
384 if (!new_cmdline) {
385 pr_err("Failed to allocate memory for extra kernel cmdline.\n");
386 return NULL;
387 }
388
389 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
390 if (ret < 0 || ret > len) {
391 pr_err("Failed to print extra kernel cmdline.\n");
392 memblock_free(new_cmdline, len + 1);
393 return NULL;
394 }
395
396 return new_cmdline;
397}
398
399static int __init bootconfig_params(char *param, char *val,
400 const char *unused, void *arg)
401{
402 if (strcmp(param, "bootconfig") == 0) {
403 bootconfig_found = true;
404 }
405 return 0;
406}
407
408static int __init warn_bootconfig(char *str)
409{
410 /* The 'bootconfig' has been handled by bootconfig_params(). */
411 return 0;
412}
413
414static void __init setup_boot_config(void)
415{
416 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
417 const char *msg, *data;
418 int pos, ret;
419 size_t size;
420 char *err;
421
422 /* Cut out the bootconfig data even if we have no bootconfig option */
423 data = get_boot_config_from_initrd(&size);
424 /* If there is no bootconfig in initrd, try embedded one. */
425 if (!data)
426 data = xbc_get_embedded_bootconfig(&size);
427
428 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
429 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
430 bootconfig_params);
431
432 if (IS_ERR(err) || !bootconfig_found)
433 return;
434
435 /* parse_args() stops at the next param of '--' and returns an address */
436 if (err)
437 initargs_offs = err - tmp_cmdline;
438
439 if (!data) {
440 pr_err("'bootconfig' found on command line, but no bootconfig found\n");
441 return;
442 }
443
444 if (size >= XBC_DATA_MAX) {
445 pr_err("bootconfig size %ld greater than max size %d\n",
446 (long)size, XBC_DATA_MAX);
447 return;
448 }
449
450 ret = xbc_init(data, size, &msg, &pos);
451 if (ret < 0) {
452 if (pos < 0)
453 pr_err("Failed to init bootconfig: %s.\n", msg);
454 else
455 pr_err("Failed to parse bootconfig: %s at %d.\n",
456 msg, pos);
457 } else {
458 xbc_get_info(&ret, NULL);
459 pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
460 /* keys starting with "kernel." are passed via cmdline */
461 extra_command_line = xbc_make_cmdline("kernel");
462 /* Also, "init." keys are init arguments */
463 extra_init_args = xbc_make_cmdline("init");
464 }
465 return;
466}
467
468static void __init exit_boot_config(void)
469{
470 xbc_exit();
471}
472
473#else /* !CONFIG_BOOT_CONFIG */
474
475static void __init setup_boot_config(void)
476{
477 /* Remove bootconfig data from initrd */
478 get_boot_config_from_initrd(NULL);
479}
480
481static int __init warn_bootconfig(char *str)
482{
483 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
484 return 0;
485}
486
487#define exit_boot_config() do {} while (0)
488
489#endif /* CONFIG_BOOT_CONFIG */
490
491early_param("bootconfig", warn_bootconfig);
492
493/* Change NUL term back to "=", to make "param" the whole string. */
494static void __init repair_env_string(char *param, char *val)
495{
496 if (val) {
497 /* param=val or param="val"? */
498 if (val == param+strlen(param)+1)
499 val[-1] = '=';
500 else if (val == param+strlen(param)+2) {
501 val[-2] = '=';
502 memmove(val-1, val, strlen(val)+1);
503 } else
504 BUG();
505 }
506}
507
508/* Anything after -- gets handed straight to init. */
509static int __init set_init_arg(char *param, char *val,
510 const char *unused, void *arg)
511{
512 unsigned int i;
513
514 if (panic_later)
515 return 0;
516
517 repair_env_string(param, val);
518
519 for (i = 0; argv_init[i]; i++) {
520 if (i == MAX_INIT_ARGS) {
521 panic_later = "init";
522 panic_param = param;
523 return 0;
524 }
525 }
526 argv_init[i] = param;
527 return 0;
528}
529
530/*
531 * Unknown boot options get handed to init, unless they look like
532 * unused parameters (modprobe will find them in /proc/cmdline).
533 */
534static int __init unknown_bootoption(char *param, char *val,
535 const char *unused, void *arg)
536{
537 size_t len = strlen(param);
538
539 repair_env_string(param, val);
540
541 /* Handle obsolete-style parameters */
542 if (obsolete_checksetup(param))
543 return 0;
544
545 /* Unused module parameter. */
546 if (strnchr(param, len, '.'))
547 return 0;
548
549 if (panic_later)
550 return 0;
551
552 if (val) {
553 /* Environment option */
554 unsigned int i;
555 for (i = 0; envp_init[i]; i++) {
556 if (i == MAX_INIT_ENVS) {
557 panic_later = "env";
558 panic_param = param;
559 }
560 if (!strncmp(param, envp_init[i], len+1))
561 break;
562 }
563 envp_init[i] = param;
564 } else {
565 /* Command line option */
566 unsigned int i;
567 for (i = 0; argv_init[i]; i++) {
568 if (i == MAX_INIT_ARGS) {
569 panic_later = "init";
570 panic_param = param;
571 }
572 }
573 argv_init[i] = param;
574 }
575 return 0;
576}
577
578static int __init init_setup(char *str)
579{
580 unsigned int i;
581
582 execute_command = str;
583 /*
584 * In case LILO is going to boot us with default command line,
585 * it prepends "auto" before the whole cmdline which makes
586 * the shell think it should execute a script with such name.
587 * So we ignore all arguments entered _before_ init=... [MJ]
588 */
589 for (i = 1; i < MAX_INIT_ARGS; i++)
590 argv_init[i] = NULL;
591 return 1;
592}
593__setup("init=", init_setup);
594
595static int __init rdinit_setup(char *str)
596{
597 unsigned int i;
598
599 ramdisk_execute_command = str;
600 /* See "auto" comment in init_setup */
601 for (i = 1; i < MAX_INIT_ARGS; i++)
602 argv_init[i] = NULL;
603 return 1;
604}
605__setup("rdinit=", rdinit_setup);
606
607#ifndef CONFIG_SMP
608static const unsigned int setup_max_cpus = NR_CPUS;
609static inline void setup_nr_cpu_ids(void) { }
610static inline void smp_prepare_cpus(unsigned int maxcpus) { }
611#endif
612
613/*
614 * We need to store the untouched command line for future reference.
615 * We also need to store the touched command line since the parameter
616 * parsing is performed in place, and we should allow a component to
617 * store reference of name/value for future reference.
618 */
619static void __init setup_command_line(char *command_line)
620{
621 size_t len, xlen = 0, ilen = 0;
622
623 if (extra_command_line)
624 xlen = strlen(extra_command_line);
625 if (extra_init_args)
626 ilen = strlen(extra_init_args) + 4; /* for " -- " */
627
628 len = xlen + strlen(boot_command_line) + 1;
629
630 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
631 if (!saved_command_line)
632 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
633
634 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
635 if (!static_command_line)
636 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
637
638 if (xlen) {
639 /*
640 * We have to put extra_command_line before boot command
641 * lines because there could be dashes (separator of init
642 * command line) in the command lines.
643 */
644 strcpy(saved_command_line, extra_command_line);
645 strcpy(static_command_line, extra_command_line);
646 }
647 strcpy(saved_command_line + xlen, boot_command_line);
648 strcpy(static_command_line + xlen, command_line);
649
650 if (ilen) {
651 /*
652 * Append supplemental init boot args to saved_command_line
653 * so that user can check what command line options passed
654 * to init.
655 * The order should always be
656 * " -- "[bootconfig init-param][cmdline init-param]
657 */
658 if (initargs_offs) {
659 len = xlen + initargs_offs;
660 strcpy(saved_command_line + len, extra_init_args);
661 len += ilen - 4; /* strlen(extra_init_args) */
662 strcpy(saved_command_line + len,
663 boot_command_line + initargs_offs - 1);
664 } else {
665 len = strlen(saved_command_line);
666 strcpy(saved_command_line + len, " -- ");
667 len += 4;
668 strcpy(saved_command_line + len, extra_init_args);
669 }
670 }
671
672 saved_command_line_len = strlen(saved_command_line);
673}
674
675/*
676 * We need to finalize in a non-__init function or else race conditions
677 * between the root thread and the init thread may cause start_kernel to
678 * be reaped by free_initmem before the root thread has proceeded to
679 * cpu_idle.
680 *
681 * gcc-3.4 accidentally inlines this function, so use noinline.
682 */
683
684static __initdata DECLARE_COMPLETION(kthreadd_done);
685
686noinline void __ref rest_init(void)
687{
688 struct task_struct *tsk;
689 int pid;
690
691 rcu_scheduler_starting();
692 /*
693 * We need to spawn init first so that it obtains pid 1, however
694 * the init task will end up wanting to create kthreads, which, if
695 * we schedule it before we create kthreadd, will OOPS.
696 */
697 pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
698 /*
699 * Pin init on the boot CPU. Task migration is not properly working
700 * until sched_init_smp() has been run. It will set the allowed
701 * CPUs for init to the non isolated CPUs.
702 */
703 rcu_read_lock();
704 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
705 tsk->flags |= PF_NO_SETAFFINITY;
706 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
707 rcu_read_unlock();
708
709 numa_default_policy();
710 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
711 rcu_read_lock();
712 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
713 rcu_read_unlock();
714
715 /*
716 * Enable might_sleep() and smp_processor_id() checks.
717 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
718 * kernel_thread() would trigger might_sleep() splats. With
719 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
720 * already, but it's stuck on the kthreadd_done completion.
721 */
722 system_state = SYSTEM_SCHEDULING;
723
724 complete(&kthreadd_done);
725
726 /*
727 * The boot idle thread must execute schedule()
728 * at least once to get things moving:
729 */
730 schedule_preempt_disabled();
731 /* Call into cpu_idle with preempt disabled */
732 cpu_startup_entry(CPUHP_ONLINE);
733}
734
735/* Check for early params. */
736static int __init do_early_param(char *param, char *val,
737 const char *unused, void *arg)
738{
739 const struct obs_kernel_param *p;
740
741 for (p = __setup_start; p < __setup_end; p++) {
742 if ((p->early && parameq(param, p->str)) ||
743 (strcmp(param, "console") == 0 &&
744 strcmp(p->str, "earlycon") == 0)
745 ) {
746 if (p->setup_func(val) != 0)
747 pr_warn("Malformed early option '%s'\n", param);
748 }
749 }
750 /* We accept everything at this stage. */
751 return 0;
752}
753
754void __init parse_early_options(char *cmdline)
755{
756 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
757 do_early_param);
758}
759
760/* Arch code calls this early on, or if not, just before other parsing. */
761void __init parse_early_param(void)
762{
763 static int done __initdata;
764 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
765
766 if (done)
767 return;
768
769 /* All fall through to do_early_param. */
770 strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
771 parse_early_options(tmp_cmdline);
772 done = 1;
773}
774
775void __init __weak arch_post_acpi_subsys_init(void) { }
776
777void __init __weak smp_setup_processor_id(void)
778{
779}
780
781# if THREAD_SIZE >= PAGE_SIZE
782void __init __weak thread_stack_cache_init(void)
783{
784}
785#endif
786
787void __init __weak mem_encrypt_init(void) { }
788
789void __init __weak poking_init(void) { }
790
791void __init __weak pgtable_cache_init(void) { }
792
793void __init __weak trap_init(void) { }
794
795bool initcall_debug;
796core_param(initcall_debug, initcall_debug, bool, 0644);
797
798#ifdef TRACEPOINTS_ENABLED
799static void __init initcall_debug_enable(void);
800#else
801static inline void initcall_debug_enable(void)
802{
803}
804#endif
805
806/* Report memory auto-initialization states for this boot. */
807static void __init report_meminit(void)
808{
809 const char *stack;
810
811 if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
812 stack = "all(pattern)";
813 else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
814 stack = "all(zero)";
815 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
816 stack = "byref_all(zero)";
817 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
818 stack = "byref(zero)";
819 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
820 stack = "__user(zero)";
821 else
822 stack = "off";
823
824 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
825 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
826 want_init_on_free() ? "on" : "off");
827 if (want_init_on_free())
828 pr_info("mem auto-init: clearing system memory may take some time...\n");
829}
830
831/*
832 * Set up kernel memory allocators
833 */
834static void __init mm_init(void)
835{
836 /*
837 * page_ext requires contiguous pages,
838 * bigger than MAX_ORDER unless SPARSEMEM.
839 */
840 page_ext_init_flatmem();
841 init_mem_debugging_and_hardening();
842 kfence_alloc_pool();
843 report_meminit();
844 kmsan_init_shadow();
845 stack_depot_early_init();
846 mem_init();
847 mem_init_print_info();
848 kmem_cache_init();
849 /*
850 * page_owner must be initialized after buddy is ready, and also after
851 * slab is ready so that stack_depot_init() works properly
852 */
853 page_ext_init_flatmem_late();
854 kmemleak_init();
855 pgtable_init();
856 debug_objects_mem_init();
857 vmalloc_init();
858 /* Should be run after vmap initialization */
859 if (early_page_ext_enabled())
860 page_ext_init();
861 /* Should be run before the first non-init thread is created */
862 init_espfix_bsp();
863 /* Should be run after espfix64 is set up. */
864 pti_init();
865 kmsan_init_runtime();
866 mm_cache_init();
867}
868
869#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
870DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
871 randomize_kstack_offset);
872DEFINE_PER_CPU(u32, kstack_offset);
873
874static int __init early_randomize_kstack_offset(char *buf)
875{
876 int ret;
877 bool bool_result;
878
879 ret = kstrtobool(buf, &bool_result);
880 if (ret)
881 return ret;
882
883 if (bool_result)
884 static_branch_enable(&randomize_kstack_offset);
885 else
886 static_branch_disable(&randomize_kstack_offset);
887 return 0;
888}
889early_param("randomize_kstack_offset", early_randomize_kstack_offset);
890#endif
891
892void __init __weak arch_call_rest_init(void)
893{
894 rest_init();
895}
896
897static void __init print_unknown_bootoptions(void)
898{
899 char *unknown_options;
900 char *end;
901 const char *const *p;
902 size_t len;
903
904 if (panic_later || (!argv_init[1] && !envp_init[2]))
905 return;
906
907 /*
908 * Determine how many options we have to print out, plus a space
909 * before each
910 */
911 len = 1; /* null terminator */
912 for (p = &argv_init[1]; *p; p++) {
913 len++;
914 len += strlen(*p);
915 }
916 for (p = &envp_init[2]; *p; p++) {
917 len++;
918 len += strlen(*p);
919 }
920
921 unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
922 if (!unknown_options) {
923 pr_err("%s: Failed to allocate %zu bytes\n",
924 __func__, len);
925 return;
926 }
927 end = unknown_options;
928
929 for (p = &argv_init[1]; *p; p++)
930 end += sprintf(end, " %s", *p);
931 for (p = &envp_init[2]; *p; p++)
932 end += sprintf(end, " %s", *p);
933
934 /* Start at unknown_options[1] to skip the initial space */
935 pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
936 &unknown_options[1]);
937 memblock_free(unknown_options, len);
938}
939
940asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
941{
942 char *command_line;
943 char *after_dashes;
944
945 set_task_stack_end_magic(&init_task);
946 smp_setup_processor_id();
947 debug_objects_early_init();
948 init_vmlinux_build_id();
949
950 cgroup_init_early();
951
952 local_irq_disable();
953 early_boot_irqs_disabled = true;
954
955 /*
956 * Interrupts are still disabled. Do necessary setups, then
957 * enable them.
958 */
959 boot_cpu_init();
960 page_address_init();
961 pr_notice("%s", linux_banner);
962 early_security_init();
963 setup_arch(&command_line);
964 setup_boot_config();
965 setup_command_line(command_line);
966 setup_nr_cpu_ids();
967 setup_per_cpu_areas();
968 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
969 boot_cpu_hotplug_init();
970
971 build_all_zonelists(NULL);
972 page_alloc_init();
973
974 pr_notice("Kernel command line: %s\n", saved_command_line);
975 /* parameters may set static keys */
976 jump_label_init();
977 parse_early_param();
978 after_dashes = parse_args("Booting kernel",
979 static_command_line, __start___param,
980 __stop___param - __start___param,
981 -1, -1, NULL, &unknown_bootoption);
982 print_unknown_bootoptions();
983 if (!IS_ERR_OR_NULL(after_dashes))
984 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
985 NULL, set_init_arg);
986 if (extra_init_args)
987 parse_args("Setting extra init args", extra_init_args,
988 NULL, 0, -1, -1, NULL, set_init_arg);
989
990 /* Architectural and non-timekeeping rng init, before allocator init */
991 random_init_early(command_line);
992
993 /*
994 * These use large bootmem allocations and must precede
995 * kmem_cache_init()
996 */
997 setup_log_buf(0);
998 vfs_caches_init_early();
999 sort_main_extable();
1000 trap_init();
1001 mm_init();
1002 poking_init();
1003 ftrace_init();
1004
1005 /* trace_printk can be enabled here */
1006 early_trace_init();
1007
1008 /*
1009 * Set up the scheduler prior starting any interrupts (such as the
1010 * timer interrupt). Full topology setup happens at smp_init()
1011 * time - but meanwhile we still have a functioning scheduler.
1012 */
1013 sched_init();
1014
1015 if (WARN(!irqs_disabled(),
1016 "Interrupts were enabled *very* early, fixing it\n"))
1017 local_irq_disable();
1018 radix_tree_init();
1019 maple_tree_init();
1020
1021 /*
1022 * Set up housekeeping before setting up workqueues to allow the unbound
1023 * workqueue to take non-housekeeping into account.
1024 */
1025 housekeeping_init();
1026
1027 /*
1028 * Allow workqueue creation and work item queueing/cancelling
1029 * early. Work item execution depends on kthreads and starts after
1030 * workqueue_init().
1031 */
1032 workqueue_init_early();
1033
1034 rcu_init();
1035
1036 /* Trace events are available after this */
1037 trace_init();
1038
1039 if (initcall_debug)
1040 initcall_debug_enable();
1041
1042 context_tracking_init();
1043 /* init some links before init_ISA_irqs() */
1044 early_irq_init();
1045 init_IRQ();
1046 tick_init();
1047 rcu_init_nohz();
1048 init_timers();
1049 srcu_init();
1050 hrtimers_init();
1051 softirq_init();
1052 timekeeping_init();
1053 time_init();
1054
1055 /* This must be after timekeeping is initialized */
1056 random_init();
1057
1058 /* These make use of the fully initialized rng */
1059 kfence_init();
1060 boot_init_stack_canary();
1061
1062 perf_event_init();
1063 profile_init();
1064 call_function_init();
1065 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1066
1067 early_boot_irqs_disabled = false;
1068 local_irq_enable();
1069
1070 kmem_cache_init_late();
1071
1072 /*
1073 * HACK ALERT! This is early. We're enabling the console before
1074 * we've done PCI setups etc, and console_init() must be aware of
1075 * this. But we do want output early, in case something goes wrong.
1076 */
1077 console_init();
1078 if (panic_later)
1079 panic("Too many boot %s vars at `%s'", panic_later,
1080 panic_param);
1081
1082 lockdep_init();
1083
1084 /*
1085 * Need to run this when irqs are enabled, because it wants
1086 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1087 * too:
1088 */
1089 locking_selftest();
1090
1091 /*
1092 * This needs to be called before any devices perform DMA
1093 * operations that might use the SWIOTLB bounce buffers. It will
1094 * mark the bounce buffers as decrypted so that their usage will
1095 * not cause "plain-text" data to be decrypted when accessed.
1096 */
1097 mem_encrypt_init();
1098
1099#ifdef CONFIG_BLK_DEV_INITRD
1100 if (initrd_start && !initrd_below_start_ok &&
1101 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1102 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1103 page_to_pfn(virt_to_page((void *)initrd_start)),
1104 min_low_pfn);
1105 initrd_start = 0;
1106 }
1107#endif
1108 setup_per_cpu_pageset();
1109 numa_policy_init();
1110 acpi_early_init();
1111 if (late_time_init)
1112 late_time_init();
1113 sched_clock_init();
1114 calibrate_delay();
1115 pid_idr_init();
1116 anon_vma_init();
1117#ifdef CONFIG_X86
1118 if (efi_enabled(EFI_RUNTIME_SERVICES))
1119 efi_enter_virtual_mode();
1120#endif
1121 thread_stack_cache_init();
1122 cred_init();
1123 fork_init();
1124 proc_caches_init();
1125 uts_ns_init();
1126 key_init();
1127 security_init();
1128 dbg_late_init();
1129 net_ns_init();
1130 vfs_caches_init();
1131 pagecache_init();
1132 signals_init();
1133 seq_file_init();
1134 proc_root_init();
1135 nsfs_init();
1136 cpuset_init();
1137 cgroup_init();
1138 taskstats_init_early();
1139 delayacct_init();
1140
1141 check_bugs();
1142
1143 acpi_subsystem_init();
1144 arch_post_acpi_subsys_init();
1145 kcsan_init();
1146
1147 /* Do the rest non-__init'ed, we're now alive */
1148 arch_call_rest_init();
1149
1150 prevent_tail_call_optimization();
1151}
1152
1153/* Call all constructor functions linked into the kernel. */
1154static void __init do_ctors(void)
1155{
1156/*
1157 * For UML, the constructors have already been called by the
1158 * normal setup code as it's just a normal ELF binary, so we
1159 * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1160 * even on UML for modules.
1161 */
1162#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1163 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1164
1165 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1166 (*fn)();
1167#endif
1168}
1169
1170#ifdef CONFIG_KALLSYMS
1171struct blacklist_entry {
1172 struct list_head next;
1173 char *buf;
1174};
1175
1176static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1177
1178static int __init initcall_blacklist(char *str)
1179{
1180 char *str_entry;
1181 struct blacklist_entry *entry;
1182
1183 /* str argument is a comma-separated list of functions */
1184 do {
1185 str_entry = strsep(&str, ",");
1186 if (str_entry) {
1187 pr_debug("blacklisting initcall %s\n", str_entry);
1188 entry = memblock_alloc(sizeof(*entry),
1189 SMP_CACHE_BYTES);
1190 if (!entry)
1191 panic("%s: Failed to allocate %zu bytes\n",
1192 __func__, sizeof(*entry));
1193 entry->buf = memblock_alloc(strlen(str_entry) + 1,
1194 SMP_CACHE_BYTES);
1195 if (!entry->buf)
1196 panic("%s: Failed to allocate %zu bytes\n",
1197 __func__, strlen(str_entry) + 1);
1198 strcpy(entry->buf, str_entry);
1199 list_add(&entry->next, &blacklisted_initcalls);
1200 }
1201 } while (str_entry);
1202
1203 return 1;
1204}
1205
1206static bool __init_or_module initcall_blacklisted(initcall_t fn)
1207{
1208 struct blacklist_entry *entry;
1209 char fn_name[KSYM_SYMBOL_LEN];
1210 unsigned long addr;
1211
1212 if (list_empty(&blacklisted_initcalls))
1213 return false;
1214
1215 addr = (unsigned long) dereference_function_descriptor(fn);
1216 sprint_symbol_no_offset(fn_name, addr);
1217
1218 /*
1219 * fn will be "function_name [module_name]" where [module_name] is not
1220 * displayed for built-in init functions. Strip off the [module_name].
1221 */
1222 strreplace(fn_name, ' ', '\0');
1223
1224 list_for_each_entry(entry, &blacklisted_initcalls, next) {
1225 if (!strcmp(fn_name, entry->buf)) {
1226 pr_debug("initcall %s blacklisted\n", fn_name);
1227 return true;
1228 }
1229 }
1230
1231 return false;
1232}
1233#else
1234static int __init initcall_blacklist(char *str)
1235{
1236 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1237 return 0;
1238}
1239
1240static bool __init_or_module initcall_blacklisted(initcall_t fn)
1241{
1242 return false;
1243}
1244#endif
1245__setup("initcall_blacklist=", initcall_blacklist);
1246
1247static __init_or_module void
1248trace_initcall_start_cb(void *data, initcall_t fn)
1249{
1250 ktime_t *calltime = data;
1251
1252 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1253 *calltime = ktime_get();
1254}
1255
1256static __init_or_module void
1257trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1258{
1259 ktime_t rettime, *calltime = data;
1260
1261 rettime = ktime_get();
1262 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1263 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1264}
1265
1266static ktime_t initcall_calltime;
1267
1268#ifdef TRACEPOINTS_ENABLED
1269static void __init initcall_debug_enable(void)
1270{
1271 int ret;
1272
1273 ret = register_trace_initcall_start(trace_initcall_start_cb,
1274 &initcall_calltime);
1275 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1276 &initcall_calltime);
1277 WARN(ret, "Failed to register initcall tracepoints\n");
1278}
1279# define do_trace_initcall_start trace_initcall_start
1280# define do_trace_initcall_finish trace_initcall_finish
1281#else
1282static inline void do_trace_initcall_start(initcall_t fn)
1283{
1284 if (!initcall_debug)
1285 return;
1286 trace_initcall_start_cb(&initcall_calltime, fn);
1287}
1288static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1289{
1290 if (!initcall_debug)
1291 return;
1292 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1293}
1294#endif /* !TRACEPOINTS_ENABLED */
1295
1296int __init_or_module do_one_initcall(initcall_t fn)
1297{
1298 int count = preempt_count();
1299 char msgbuf[64];
1300 int ret;
1301
1302 if (initcall_blacklisted(fn))
1303 return -EPERM;
1304
1305 do_trace_initcall_start(fn);
1306 ret = fn();
1307 do_trace_initcall_finish(fn, ret);
1308
1309 msgbuf[0] = 0;
1310
1311 if (preempt_count() != count) {
1312 sprintf(msgbuf, "preemption imbalance ");
1313 preempt_count_set(count);
1314 }
1315 if (irqs_disabled()) {
1316 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1317 local_irq_enable();
1318 }
1319 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1320
1321 add_latent_entropy();
1322 return ret;
1323}
1324
1325
1326extern initcall_entry_t __initcall_start[];
1327extern initcall_entry_t __initcall0_start[];
1328extern initcall_entry_t __initcall1_start[];
1329extern initcall_entry_t __initcall2_start[];
1330extern initcall_entry_t __initcall3_start[];
1331extern initcall_entry_t __initcall4_start[];
1332extern initcall_entry_t __initcall5_start[];
1333extern initcall_entry_t __initcall6_start[];
1334extern initcall_entry_t __initcall7_start[];
1335extern initcall_entry_t __initcall_end[];
1336
1337static initcall_entry_t *initcall_levels[] __initdata = {
1338 __initcall0_start,
1339 __initcall1_start,
1340 __initcall2_start,
1341 __initcall3_start,
1342 __initcall4_start,
1343 __initcall5_start,
1344 __initcall6_start,
1345 __initcall7_start,
1346 __initcall_end,
1347};
1348
1349/* Keep these in sync with initcalls in include/linux/init.h */
1350static const char *initcall_level_names[] __initdata = {
1351 "pure",
1352 "core",
1353 "postcore",
1354 "arch",
1355 "subsys",
1356 "fs",
1357 "device",
1358 "late",
1359};
1360
1361static int __init ignore_unknown_bootoption(char *param, char *val,
1362 const char *unused, void *arg)
1363{
1364 return 0;
1365}
1366
1367static void __init do_initcall_level(int level, char *command_line)
1368{
1369 initcall_entry_t *fn;
1370
1371 parse_args(initcall_level_names[level],
1372 command_line, __start___param,
1373 __stop___param - __start___param,
1374 level, level,
1375 NULL, ignore_unknown_bootoption);
1376
1377 trace_initcall_level(initcall_level_names[level]);
1378 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1379 do_one_initcall(initcall_from_entry(fn));
1380}
1381
1382static void __init do_initcalls(void)
1383{
1384 int level;
1385 size_t len = saved_command_line_len + 1;
1386 char *command_line;
1387
1388 command_line = kzalloc(len, GFP_KERNEL);
1389 if (!command_line)
1390 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1391
1392 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1393 /* Parser modifies command_line, restore it each time */
1394 strcpy(command_line, saved_command_line);
1395 do_initcall_level(level, command_line);
1396 }
1397
1398 kfree(command_line);
1399}
1400
1401/*
1402 * Ok, the machine is now initialized. None of the devices
1403 * have been touched yet, but the CPU subsystem is up and
1404 * running, and memory and process management works.
1405 *
1406 * Now we can finally start doing some real work..
1407 */
1408static void __init do_basic_setup(void)
1409{
1410 cpuset_init_smp();
1411 driver_init();
1412 init_irq_proc();
1413 do_ctors();
1414 do_initcalls();
1415}
1416
1417static void __init do_pre_smp_initcalls(void)
1418{
1419 initcall_entry_t *fn;
1420
1421 trace_initcall_level("early");
1422 for (fn = __initcall_start; fn < __initcall0_start; fn++)
1423 do_one_initcall(initcall_from_entry(fn));
1424}
1425
1426static int run_init_process(const char *init_filename)
1427{
1428 const char *const *p;
1429
1430 argv_init[0] = init_filename;
1431 pr_info("Run %s as init process\n", init_filename);
1432 pr_debug(" with arguments:\n");
1433 for (p = argv_init; *p; p++)
1434 pr_debug(" %s\n", *p);
1435 pr_debug(" with environment:\n");
1436 for (p = envp_init; *p; p++)
1437 pr_debug(" %s\n", *p);
1438 return kernel_execve(init_filename, argv_init, envp_init);
1439}
1440
1441static int try_to_run_init_process(const char *init_filename)
1442{
1443 int ret;
1444
1445 ret = run_init_process(init_filename);
1446
1447 if (ret && ret != -ENOENT) {
1448 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1449 init_filename, ret);
1450 }
1451
1452 return ret;
1453}
1454
1455static noinline void __init kernel_init_freeable(void);
1456
1457#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1458bool rodata_enabled __ro_after_init = true;
1459
1460#ifndef arch_parse_debug_rodata
1461static inline bool arch_parse_debug_rodata(char *str) { return false; }
1462#endif
1463
1464static int __init set_debug_rodata(char *str)
1465{
1466 if (arch_parse_debug_rodata(str))
1467 return 0;
1468
1469 if (str && !strcmp(str, "on"))
1470 rodata_enabled = true;
1471 else if (str && !strcmp(str, "off"))
1472 rodata_enabled = false;
1473 else
1474 pr_warn("Invalid option string for rodata: '%s'\n", str);
1475 return 0;
1476}
1477early_param("rodata", set_debug_rodata);
1478#endif
1479
1480#ifdef CONFIG_STRICT_KERNEL_RWX
1481static void mark_readonly(void)
1482{
1483 if (rodata_enabled) {
1484 /*
1485 * load_module() results in W+X mappings, which are cleaned
1486 * up with call_rcu(). Let's make sure that queued work is
1487 * flushed so that we don't hit false positives looking for
1488 * insecure pages which are W+X.
1489 */
1490 rcu_barrier();
1491 mark_rodata_ro();
1492 rodata_test();
1493 } else
1494 pr_info("Kernel memory protection disabled.\n");
1495}
1496#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1497static inline void mark_readonly(void)
1498{
1499 pr_warn("Kernel memory protection not selected by kernel config.\n");
1500}
1501#else
1502static inline void mark_readonly(void)
1503{
1504 pr_warn("This architecture does not have kernel memory protection.\n");
1505}
1506#endif
1507
1508void __weak free_initmem(void)
1509{
1510 free_initmem_default(POISON_FREE_INITMEM);
1511}
1512
1513static int __ref kernel_init(void *unused)
1514{
1515 int ret;
1516
1517 /*
1518 * Wait until kthreadd is all set-up.
1519 */
1520 wait_for_completion(&kthreadd_done);
1521
1522 kernel_init_freeable();
1523 /* need to finish all async __init code before freeing the memory */
1524 async_synchronize_full();
1525
1526 system_state = SYSTEM_FREEING_INITMEM;
1527 kprobe_free_init_mem();
1528 ftrace_free_init_mem();
1529 kgdb_free_init_mem();
1530 exit_boot_config();
1531 free_initmem();
1532 mark_readonly();
1533
1534 /*
1535 * Kernel mappings are now finalized - update the userspace page-table
1536 * to finalize PTI.
1537 */
1538 pti_finalize();
1539
1540 system_state = SYSTEM_RUNNING;
1541 numa_default_policy();
1542
1543 rcu_end_inkernel_boot();
1544
1545 do_sysctl_args();
1546
1547 if (ramdisk_execute_command) {
1548 ret = run_init_process(ramdisk_execute_command);
1549 if (!ret)
1550 return 0;
1551 pr_err("Failed to execute %s (error %d)\n",
1552 ramdisk_execute_command, ret);
1553 }
1554
1555 /*
1556 * We try each of these until one succeeds.
1557 *
1558 * The Bourne shell can be used instead of init if we are
1559 * trying to recover a really broken machine.
1560 */
1561 if (execute_command) {
1562 ret = run_init_process(execute_command);
1563 if (!ret)
1564 return 0;
1565 panic("Requested init %s failed (error %d).",
1566 execute_command, ret);
1567 }
1568
1569 if (CONFIG_DEFAULT_INIT[0] != '\0') {
1570 ret = run_init_process(CONFIG_DEFAULT_INIT);
1571 if (ret)
1572 pr_err("Default init %s failed (error %d)\n",
1573 CONFIG_DEFAULT_INIT, ret);
1574 else
1575 return 0;
1576 }
1577
1578 if (!try_to_run_init_process("/sbin/init") ||
1579 !try_to_run_init_process("/etc/init") ||
1580 !try_to_run_init_process("/bin/init") ||
1581 !try_to_run_init_process("/bin/sh"))
1582 return 0;
1583
1584 panic("No working init found. Try passing init= option to kernel. "
1585 "See Linux Documentation/admin-guide/init.rst for guidance.");
1586}
1587
1588/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1589void __init console_on_rootfs(void)
1590{
1591 struct file *file = filp_open("/dev/console", O_RDWR, 0);
1592
1593 if (IS_ERR(file)) {
1594 pr_err("Warning: unable to open an initial console.\n");
1595 return;
1596 }
1597 init_dup(file);
1598 init_dup(file);
1599 init_dup(file);
1600 fput(file);
1601}
1602
1603static noinline void __init kernel_init_freeable(void)
1604{
1605 /* Now the scheduler is fully set up and can do blocking allocations */
1606 gfp_allowed_mask = __GFP_BITS_MASK;
1607
1608 /*
1609 * init can allocate pages on any node
1610 */
1611 set_mems_allowed(node_states[N_MEMORY]);
1612
1613 cad_pid = get_pid(task_pid(current));
1614
1615 smp_prepare_cpus(setup_max_cpus);
1616
1617 workqueue_init();
1618
1619 init_mm_internals();
1620
1621 rcu_init_tasks_generic();
1622 do_pre_smp_initcalls();
1623 lockup_detector_init();
1624
1625 smp_init();
1626 sched_init_smp();
1627
1628 padata_init();
1629 page_alloc_init_late();
1630 /* Initialize page ext after all struct pages are initialized. */
1631 if (!early_page_ext_enabled())
1632 page_ext_init();
1633
1634 do_basic_setup();
1635
1636 kunit_run_all_tests();
1637
1638 wait_for_initramfs();
1639 console_on_rootfs();
1640
1641 /*
1642 * check if there is an early userspace init. If yes, let it do all
1643 * the work
1644 */
1645 if (init_eaccess(ramdisk_execute_command) != 0) {
1646 ramdisk_execute_command = NULL;
1647 prepare_namespace();
1648 }
1649
1650 /*
1651 * Ok, we have completed the initial bootup, and
1652 * we're essentially up and running. Get rid of the
1653 * initmem segments and start the user-mode stuff..
1654 *
1655 * rootfs is available now, try loading the public keys
1656 * and default modules
1657 */
1658
1659 integrity_load_keys();
1660}