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