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