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 #ifdef CONFIG_RECLAIM_ACCT
102 #include <linux/reclaim_acct.h>
103 #endif
104
105 #include <asm/io.h>
106 #include <asm/bugs.h>
107 #include <asm/setup.h>
108 #include <asm/sections.h>
109 #include <asm/cacheflush.h>
110
111 #define CREATE_TRACE_POINTS
112 #include <trace/events/initcall.h>
113
114 #include <kunit/test.h>
115
116 static int kernel_init(void *);
117
118 extern void init_IRQ(void);
119 extern void radix_tree_init(void);
120
121 /*
122 * Debug helper: via this flag we know that we are in 'early bootup code'
123 * where only the boot processor is running with IRQ disabled. This means
124 * two things - IRQ must not be enabled before the flag is cleared and some
125 * operations which are not allowed with IRQ disabled are allowed while the
126 * flag is set.
127 */
128 bool early_boot_irqs_disabled __read_mostly;
129
130 enum system_states system_state __read_mostly;
131 EXPORT_SYMBOL(system_state);
132
133 /*
134 * Boot command-line arguments
135 */
136 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
137 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
138
139 extern void time_init(void);
140 /* Default late time init is NULL. archs can override this later. */
141 void (*__initdata late_time_init)(void);
142
143 /* Untouched command line saved by arch-specific code. */
144 char __initdata boot_command_line[COMMAND_LINE_SIZE];
145 /* Untouched saved command line (eg. for /proc) */
146 char *saved_command_line;
147 /* Command line for parameter parsing */
148 static char *static_command_line;
149 /* Untouched extra command line */
150 static char *extra_command_line;
151 /* Extra init arguments */
152 static char *extra_init_args;
153
154 #ifdef CONFIG_BOOT_CONFIG
155 /* Is bootconfig on command line? */
156 static bool bootconfig_found;
157 static bool initargs_found;
158 #else
159 # define bootconfig_found false
160 # define initargs_found false
161 #endif
162
163 static char *execute_command;
164 static char *ramdisk_execute_command = "/init";
165
166 /*
167 * Used to generate warnings if static_key manipulation functions are used
168 * before jump_label_init is called.
169 */
170 bool static_key_initialized __read_mostly;
171 EXPORT_SYMBOL_GPL(static_key_initialized);
172
173 /*
174 * If set, this is an indication to the drivers that reset the underlying
175 * device before going ahead with the initialization otherwise driver might
176 * rely on the BIOS and skip the reset operation.
177 *
178 * This is useful if kernel is booting in an unreliable environment.
179 * For ex. kdump situation where previous kernel has crashed, BIOS has been
180 * skipped and devices will be in unknown state.
181 */
182 unsigned int reset_devices;
183 EXPORT_SYMBOL(reset_devices);
184
set_reset_devices(char * str)185 static int __init set_reset_devices(char *str)
186 {
187 reset_devices = 1;
188 return 1;
189 }
190
191 __setup("reset_devices", set_reset_devices);
192
193 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
194 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
195 static const char *panic_later, *panic_param;
196
197 extern const struct obs_kernel_param __setup_start[], __setup_end[];
198
obsolete_checksetup(char * line)199 static bool __init obsolete_checksetup(char *line)
200 {
201 const struct obs_kernel_param *p;
202 bool had_early_param = false;
203
204 p = __setup_start;
205 do {
206 int n = strlen(p->str);
207 if (parameqn(line, p->str, n)) {
208 if (p->early) {
209 /* Already done in parse_early_param?
210 * (Needs exact match on param part).
211 * Keep iterating, as we can have early
212 * params and __setups of same names 8( */
213 if (line[n] == '\0' || line[n] == '=')
214 had_early_param = true;
215 } else if (!p->setup_func) {
216 pr_warn("Parameter %s is obsolete, ignored\n",
217 p->str);
218 return true;
219 } else if (p->setup_func(line + n))
220 return true;
221 }
222 p++;
223 } while (p < __setup_end);
224
225 return had_early_param;
226 }
227
228 /*
229 * This should be approx 2 Bo*oMips to start (note initial shift), and will
230 * still work even if initially too large, it will just take slightly longer
231 */
232 unsigned long loops_per_jiffy = (1<<12);
233 EXPORT_SYMBOL(loops_per_jiffy);
234
debug_kernel(char * str)235 static int __init debug_kernel(char *str)
236 {
237 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
238 return 0;
239 }
240
quiet_kernel(char * str)241 static int __init quiet_kernel(char *str)
242 {
243 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
244 return 0;
245 }
246
247 early_param("debug", debug_kernel);
248 early_param("quiet", quiet_kernel);
249
loglevel(char * str)250 static int __init loglevel(char *str)
251 {
252 int newlevel;
253
254 /*
255 * Only update loglevel value when a correct setting was passed,
256 * to prevent blind crashes (when loglevel being set to 0) that
257 * are quite hard to debug
258 */
259 if (get_option(&str, &newlevel)) {
260 console_loglevel = newlevel;
261 return 0;
262 }
263
264 return -EINVAL;
265 }
266
267 early_param("loglevel", loglevel);
268
269 #ifdef CONFIG_BLK_DEV_INITRD
get_boot_config_from_initrd(u32 * _size,u32 * _csum)270 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
271 {
272 u32 size, csum;
273 char *data;
274 u32 *hdr;
275 int i;
276
277 if (!initrd_end)
278 return NULL;
279
280 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
281 /*
282 * Since Grub may align the size of initrd to 4, we must
283 * check the preceding 3 bytes as well.
284 */
285 for (i = 0; i < 4; i++) {
286 if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
287 goto found;
288 data--;
289 }
290 return NULL;
291
292 found:
293 hdr = (u32 *)(data - 8);
294 size = le32_to_cpu(hdr[0]);
295 csum = le32_to_cpu(hdr[1]);
296
297 data = ((void *)hdr) - size;
298 if ((unsigned long)data < initrd_start) {
299 pr_err("bootconfig size %d is greater than initrd size %ld\n",
300 size, initrd_end - initrd_start);
301 return NULL;
302 }
303
304 /* Remove bootconfig from initramfs/initrd */
305 initrd_end = (unsigned long)data;
306 if (_size)
307 *_size = size;
308 if (_csum)
309 *_csum = csum;
310
311 return data;
312 }
313 #else
get_boot_config_from_initrd(u32 * _size,u32 * _csum)314 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
315 {
316 return NULL;
317 }
318 #endif
319
320 #ifdef CONFIG_BOOT_CONFIG
321
322 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
323
324 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
325
xbc_snprint_cmdline(char * buf,size_t size,struct xbc_node * root)326 static int __init xbc_snprint_cmdline(char *buf, size_t size,
327 struct xbc_node *root)
328 {
329 struct xbc_node *knode, *vnode;
330 char *end = buf + size;
331 const char *val;
332 int ret;
333
334 xbc_node_for_each_key_value(root, knode, val) {
335 ret = xbc_node_compose_key_after(root, knode,
336 xbc_namebuf, XBC_KEYLEN_MAX);
337 if (ret < 0)
338 return ret;
339
340 vnode = xbc_node_get_child(knode);
341 if (!vnode) {
342 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
343 if (ret < 0)
344 return ret;
345 buf += ret;
346 continue;
347 }
348 xbc_array_for_each_value(vnode, val) {
349 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
350 xbc_namebuf, val);
351 if (ret < 0)
352 return ret;
353 buf += ret;
354 }
355 }
356
357 return buf - (end - size);
358 }
359 #undef rest
360
361 /* Make an extra command line under given key word */
xbc_make_cmdline(const char * key)362 static char * __init xbc_make_cmdline(const char *key)
363 {
364 struct xbc_node *root;
365 char *new_cmdline;
366 int ret, len = 0;
367
368 root = xbc_find_node(key);
369 if (!root)
370 return NULL;
371
372 /* Count required buffer size */
373 len = xbc_snprint_cmdline(NULL, 0, root);
374 if (len <= 0)
375 return NULL;
376
377 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
378 if (!new_cmdline) {
379 pr_err("Failed to allocate memory for extra kernel cmdline.\n");
380 return NULL;
381 }
382
383 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
384 if (ret < 0 || ret > len) {
385 pr_err("Failed to print extra kernel cmdline.\n");
386 memblock_free(__pa(new_cmdline), len + 1);
387 return NULL;
388 }
389
390 return new_cmdline;
391 }
392
boot_config_checksum(unsigned char * p,u32 size)393 static u32 boot_config_checksum(unsigned char *p, u32 size)
394 {
395 u32 ret = 0;
396
397 while (size--)
398 ret += *p++;
399
400 return ret;
401 }
402
bootconfig_params(char * param,char * val,const char * unused,void * arg)403 static int __init bootconfig_params(char *param, char *val,
404 const char *unused, void *arg)
405 {
406 if (strcmp(param, "bootconfig") == 0) {
407 bootconfig_found = true;
408 }
409 return 0;
410 }
411
setup_boot_config(const char * cmdline)412 static void __init setup_boot_config(const char *cmdline)
413 {
414 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
415 const char *msg;
416 int pos;
417 u32 size, csum;
418 char *data, *copy, *err;
419 int ret;
420
421 /* Cut out the bootconfig data even if we have no bootconfig option */
422 data = get_boot_config_from_initrd(&size, &csum);
423
424 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
425 err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
426 bootconfig_params);
427
428 if (IS_ERR(err) || !bootconfig_found)
429 return;
430
431 /* parse_args() stops at '--' and returns an address */
432 if (err)
433 initargs_found = true;
434
435 if (!data) {
436 pr_err("'bootconfig' found on command line, but no bootconfig found\n");
437 return;
438 }
439
440 if (size >= XBC_DATA_MAX) {
441 pr_err("bootconfig size %d greater than max size %d\n",
442 size, XBC_DATA_MAX);
443 return;
444 }
445
446 if (boot_config_checksum((unsigned char *)data, size) != csum) {
447 pr_err("bootconfig checksum failed\n");
448 return;
449 }
450
451 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
452 if (!copy) {
453 pr_err("Failed to allocate memory for bootconfig\n");
454 return;
455 }
456
457 memcpy(copy, data, size);
458 copy[size] = '\0';
459
460 ret = xbc_init(copy, &msg, &pos);
461 if (ret < 0) {
462 if (pos < 0)
463 pr_err("Failed to init bootconfig: %s.\n", msg);
464 else
465 pr_err("Failed to parse bootconfig: %s at %d.\n",
466 msg, pos);
467 } else {
468 pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
469 /* keys starting with "kernel." are passed via cmdline */
470 extra_command_line = xbc_make_cmdline("kernel");
471 /* Also, "init." keys are init arguments */
472 extra_init_args = xbc_make_cmdline("init");
473 }
474 return;
475 }
476
477 #else
478
setup_boot_config(const char * cmdline)479 static void __init setup_boot_config(const char *cmdline)
480 {
481 /* Remove bootconfig data from initrd */
482 get_boot_config_from_initrd(NULL, NULL);
483 }
484
warn_bootconfig(char * str)485 static int __init warn_bootconfig(char *str)
486 {
487 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
488 return 0;
489 }
490 early_param("bootconfig", warn_bootconfig);
491
492 #endif
493
494 /* Change NUL term back to "=", to make "param" the whole string. */
repair_env_string(char * param,char * val)495 static void __init repair_env_string(char *param, char *val)
496 {
497 if (val) {
498 /* param=val or param="val"? */
499 if (val == param+strlen(param)+1)
500 val[-1] = '=';
501 else if (val == param+strlen(param)+2) {
502 val[-2] = '=';
503 memmove(val-1, val, strlen(val)+1);
504 } else
505 BUG();
506 }
507 }
508
509 /* Anything after -- gets handed straight to init. */
set_init_arg(char * param,char * val,const char * unused,void * arg)510 static int __init set_init_arg(char *param, char *val,
511 const char *unused, void *arg)
512 {
513 unsigned int i;
514
515 if (panic_later)
516 return 0;
517
518 repair_env_string(param, val);
519
520 for (i = 0; argv_init[i]; i++) {
521 if (i == MAX_INIT_ARGS) {
522 panic_later = "init";
523 panic_param = param;
524 return 0;
525 }
526 }
527 argv_init[i] = param;
528 return 0;
529 }
530
531 /*
532 * Unknown boot options get handed to init, unless they look like
533 * unused parameters (modprobe will find them in /proc/cmdline).
534 */
unknown_bootoption(char * param,char * val,const char * unused,void * arg)535 static int __init unknown_bootoption(char *param, char *val,
536 const char *unused, void *arg)
537 {
538 size_t len = strlen(param);
539
540 repair_env_string(param, val);
541
542 /* Handle obsolete-style parameters */
543 if (obsolete_checksetup(param))
544 return 0;
545
546 /* Unused module parameter. */
547 if (strnchr(param, len, '.'))
548 return 0;
549
550 if (panic_later)
551 return 0;
552
553 if (val) {
554 /* Environment option */
555 unsigned int i;
556 for (i = 0; envp_init[i]; i++) {
557 if (i == MAX_INIT_ENVS) {
558 panic_later = "env";
559 panic_param = param;
560 }
561 if (!strncmp(param, envp_init[i], len+1))
562 break;
563 }
564 envp_init[i] = param;
565 } else {
566 /* Command line option */
567 unsigned int i;
568 for (i = 0; argv_init[i]; i++) {
569 if (i == MAX_INIT_ARGS) {
570 panic_later = "init";
571 panic_param = param;
572 }
573 }
574 argv_init[i] = param;
575 }
576 return 0;
577 }
578
init_setup(char * str)579 static int __init init_setup(char *str)
580 {
581 unsigned int i;
582
583 execute_command = str;
584 /*
585 * In case LILO is going to boot us with default command line,
586 * it prepends "auto" before the whole cmdline which makes
587 * the shell think it should execute a script with such name.
588 * So we ignore all arguments entered _before_ init=... [MJ]
589 */
590 for (i = 1; i < MAX_INIT_ARGS; i++)
591 argv_init[i] = NULL;
592 return 1;
593 }
594 __setup("init=", init_setup);
595
rdinit_setup(char * str)596 static int __init rdinit_setup(char *str)
597 {
598 unsigned int i;
599
600 ramdisk_execute_command = str;
601 /* See "auto" comment in init_setup */
602 for (i = 1; i < MAX_INIT_ARGS; i++)
603 argv_init[i] = NULL;
604 return 1;
605 }
606 __setup("rdinit=", rdinit_setup);
607
608 #ifndef CONFIG_SMP
609 static const unsigned int setup_max_cpus = NR_CPUS;
setup_nr_cpu_ids(void)610 static inline void setup_nr_cpu_ids(void) { }
smp_prepare_cpus(unsigned int maxcpus)611 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
612 #endif
613
614 /*
615 * We need to store the untouched command line for future reference.
616 * We also need to store the touched command line since the parameter
617 * parsing is performed in place, and we should allow a component to
618 * store reference of name/value for future reference.
619 */
setup_command_line(char * command_line)620 static void __init setup_command_line(char *command_line)
621 {
622 size_t len, xlen = 0, ilen = 0;
623
624 if (extra_command_line)
625 xlen = strlen(extra_command_line);
626 if (extra_init_args)
627 ilen = strlen(extra_init_args) + 4; /* for " -- " */
628
629 len = xlen + strlen(boot_command_line) + 1;
630
631 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
632 if (!saved_command_line)
633 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
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
mem_encrypt_init(void)780 void __init __weak mem_encrypt_init(void) { }
781
poking_init(void)782 void __init __weak poking_init(void) { }
783
pgtable_cache_init(void)784 void __init __weak pgtable_cache_init(void) { }
785
786 bool initcall_debug;
787 core_param(initcall_debug, initcall_debug, bool, 0644);
788
789 #ifdef TRACEPOINTS_ENABLED
790 static void __init initcall_debug_enable(void);
791 #else
initcall_debug_enable(void)792 static inline void initcall_debug_enable(void)
793 {
794 }
795 #endif
796
797 /* Report memory auto-initialization states for this boot. */
report_meminit(void)798 static void __init report_meminit(void)
799 {
800 const char *stack;
801
802 if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
803 stack = "all(pattern)";
804 else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
805 stack = "all(zero)";
806 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
807 stack = "byref_all(zero)";
808 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
809 stack = "byref(zero)";
810 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
811 stack = "__user(zero)";
812 else
813 stack = "off";
814
815 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
816 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
817 want_init_on_free() ? "on" : "off");
818 if (want_init_on_free())
819 pr_info("mem auto-init: clearing system memory may take some time...\n");
820 }
821
822 /*
823 * Set up kernel memory allocators
824 */
mm_init(void)825 static void __init mm_init(void)
826 {
827 /*
828 * page_ext requires contiguous pages,
829 * bigger than MAX_ORDER unless SPARSEMEM.
830 */
831 page_ext_init_flatmem();
832 init_debug_pagealloc();
833 report_meminit();
834 mem_init();
835 /* page_owner must be initialized after buddy is ready */
836 page_ext_init_flatmem_late();
837 kmem_cache_init();
838 kmemleak_init();
839 pgtable_init();
840 debug_objects_mem_init();
841 vmalloc_init();
842 ioremap_huge_init();
843 /* Should be run before the first non-init thread is created */
844 init_espfix_bsp();
845 /* Should be run after espfix64 is set up. */
846 pti_init();
847 }
848
arch_call_rest_init(void)849 void __init __weak arch_call_rest_init(void)
850 {
851 rest_init();
852 }
853
start_kernel(void)854 asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
855 {
856 char *command_line;
857 char *after_dashes;
858
859 set_task_stack_end_magic(&init_task);
860 smp_setup_processor_id();
861 debug_objects_early_init();
862
863 cgroup_init_early();
864
865 local_irq_disable();
866 early_boot_irqs_disabled = true;
867
868 /*
869 * Interrupts are still disabled. Do necessary setups, then
870 * enable them.
871 */
872 boot_cpu_init();
873 page_address_init();
874 pr_notice("%s", linux_banner);
875 early_security_init();
876 setup_arch(&command_line);
877 setup_boot_config(command_line);
878 setup_command_line(command_line);
879 setup_nr_cpu_ids();
880 setup_per_cpu_areas();
881 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
882 boot_cpu_hotplug_init();
883
884 build_all_zonelists(NULL);
885 page_alloc_init();
886
887 pr_notice("Kernel command line: %s\n", saved_command_line);
888 /* parameters may set static keys */
889 jump_label_init();
890 parse_early_param();
891 after_dashes = parse_args("Booting kernel",
892 static_command_line, __start___param,
893 __stop___param - __start___param,
894 -1, -1, NULL, &unknown_bootoption);
895 if (!IS_ERR_OR_NULL(after_dashes))
896 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
897 NULL, set_init_arg);
898 if (extra_init_args)
899 parse_args("Setting extra init args", extra_init_args,
900 NULL, 0, -1, -1, NULL, set_init_arg);
901
902 /*
903 * These use large bootmem allocations and must precede
904 * kmem_cache_init()
905 */
906 setup_log_buf(0);
907 vfs_caches_init_early();
908 sort_main_extable();
909 trap_init();
910 mm_init();
911
912 ftrace_init();
913
914 /* trace_printk can be enabled here */
915 early_trace_init();
916
917 /*
918 * Set up the scheduler prior starting any interrupts (such as the
919 * timer interrupt). Full topology setup happens at smp_init()
920 * time - but meanwhile we still have a functioning scheduler.
921 */
922 sched_init();
923
924 if (WARN(!irqs_disabled(),
925 "Interrupts were enabled *very* early, fixing it\n"))
926 local_irq_disable();
927 radix_tree_init();
928
929 /*
930 * Set up housekeeping before setting up workqueues to allow the unbound
931 * workqueue to take non-housekeeping into account.
932 */
933 housekeeping_init();
934
935 /*
936 * Allow workqueue creation and work item queueing/cancelling
937 * early. Work item execution depends on kthreads and starts after
938 * workqueue_init().
939 */
940 workqueue_init_early();
941
942 rcu_init();
943
944 /* Trace events are available after this */
945 trace_init();
946
947 if (initcall_debug)
948 initcall_debug_enable();
949
950 context_tracking_init();
951 /* init some links before init_ISA_irqs() */
952 early_irq_init();
953 init_IRQ();
954 tick_init();
955 rcu_init_nohz();
956 init_timers();
957 hrtimers_init();
958 softirq_init();
959 timekeeping_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 rand_initialize()
965 * - rand_initialize() to get any arch-specific entropy like RDRAND
966 * - add_latent_entropy() to get any latent entropy
967 * - adding command line entropy
968 */
969 rand_initialize();
970 add_latent_entropy();
971 add_device_randomness(command_line, strlen(command_line));
972 boot_init_stack_canary();
973
974 time_init();
975 perf_event_init();
976 profile_init();
977 call_function_init();
978 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
979
980 early_boot_irqs_disabled = false;
981 local_irq_enable();
982
983 kmem_cache_init_late();
984
985 /*
986 * HACK ALERT! This is early. We're enabling the console before
987 * we've done PCI setups etc, and console_init() must be aware of
988 * this. But we do want output early, in case something goes wrong.
989 */
990 console_init();
991 if (panic_later)
992 panic("Too many boot %s vars at `%s'", panic_later,
993 panic_param);
994
995 lockdep_init();
996
997 /*
998 * Need to run this when irqs are enabled, because it wants
999 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1000 * too:
1001 */
1002 locking_selftest();
1003
1004 /*
1005 * This needs to be called before any devices perform DMA
1006 * operations that might use the SWIOTLB bounce buffers. It will
1007 * mark the bounce buffers as decrypted so that their usage will
1008 * not cause "plain-text" data to be decrypted when accessed.
1009 */
1010 mem_encrypt_init();
1011
1012 #ifdef CONFIG_BLK_DEV_INITRD
1013 if (initrd_start && !initrd_below_start_ok &&
1014 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1015 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1016 page_to_pfn(virt_to_page((void *)initrd_start)),
1017 min_low_pfn);
1018 initrd_start = 0;
1019 }
1020 #endif
1021 setup_per_cpu_pageset();
1022 numa_policy_init();
1023 acpi_early_init();
1024 if (late_time_init)
1025 late_time_init();
1026 sched_clock_init();
1027 calibrate_delay();
1028 pid_idr_init();
1029 anon_vma_init();
1030 #ifdef CONFIG_X86
1031 if (efi_enabled(EFI_RUNTIME_SERVICES))
1032 efi_enter_virtual_mode();
1033 #endif
1034 thread_stack_cache_init();
1035 cred_init();
1036 fork_init();
1037 proc_caches_init();
1038 uts_ns_init();
1039 buffer_init();
1040 key_init();
1041 security_init();
1042 dbg_late_init();
1043 vfs_caches_init();
1044 pagecache_init();
1045 signals_init();
1046 seq_file_init();
1047 proc_root_init();
1048 nsfs_init();
1049 cpuset_init();
1050 cgroup_init();
1051 taskstats_init_early();
1052 delayacct_init();
1053 #ifdef CONFIG_RECLAIM_ACCT
1054 reclaimacct_init();
1055 #endif
1056
1057 poking_init();
1058 check_bugs();
1059
1060 acpi_subsystem_init();
1061 arch_post_acpi_subsys_init();
1062 sfi_init_late();
1063 kcsan_init();
1064
1065 /* Do the rest non-__init'ed, we're now alive */
1066 arch_call_rest_init();
1067
1068 prevent_tail_call_optimization();
1069 }
1070
1071 /* Call all constructor functions linked into the kernel. */
do_ctors(void)1072 static void __init do_ctors(void)
1073 {
1074 #ifdef CONFIG_CONSTRUCTORS
1075 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1076
1077 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1078 (*fn)();
1079 #endif
1080 }
1081
1082 #ifdef CONFIG_KALLSYMS
1083 struct blacklist_entry {
1084 struct list_head next;
1085 char *buf;
1086 };
1087
1088 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1089
initcall_blacklist(char * str)1090 static int __init initcall_blacklist(char *str)
1091 {
1092 char *str_entry;
1093 struct blacklist_entry *entry;
1094
1095 /* str argument is a comma-separated list of functions */
1096 do {
1097 str_entry = strsep(&str, ",");
1098 if (str_entry) {
1099 pr_debug("blacklisting initcall %s\n", str_entry);
1100 entry = memblock_alloc(sizeof(*entry),
1101 SMP_CACHE_BYTES);
1102 if (!entry)
1103 panic("%s: Failed to allocate %zu bytes\n",
1104 __func__, sizeof(*entry));
1105 entry->buf = memblock_alloc(strlen(str_entry) + 1,
1106 SMP_CACHE_BYTES);
1107 if (!entry->buf)
1108 panic("%s: Failed to allocate %zu bytes\n",
1109 __func__, strlen(str_entry) + 1);
1110 strcpy(entry->buf, str_entry);
1111 list_add(&entry->next, &blacklisted_initcalls);
1112 }
1113 } while (str_entry);
1114
1115 return 0;
1116 }
1117
initcall_blacklisted(initcall_t fn)1118 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1119 {
1120 struct blacklist_entry *entry;
1121 char fn_name[KSYM_SYMBOL_LEN];
1122 unsigned long addr;
1123
1124 if (list_empty(&blacklisted_initcalls))
1125 return false;
1126
1127 addr = (unsigned long) dereference_function_descriptor(fn);
1128 sprint_symbol_no_offset(fn_name, addr);
1129
1130 /*
1131 * fn will be "function_name [module_name]" where [module_name] is not
1132 * displayed for built-in init functions. Strip off the [module_name].
1133 */
1134 strreplace(fn_name, ' ', '\0');
1135
1136 list_for_each_entry(entry, &blacklisted_initcalls, next) {
1137 if (!strcmp(fn_name, entry->buf)) {
1138 pr_debug("initcall %s blacklisted\n", fn_name);
1139 return true;
1140 }
1141 }
1142
1143 return false;
1144 }
1145 #else
initcall_blacklist(char * str)1146 static int __init initcall_blacklist(char *str)
1147 {
1148 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1149 return 0;
1150 }
1151
initcall_blacklisted(initcall_t fn)1152 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1153 {
1154 return false;
1155 }
1156 #endif
1157 __setup("initcall_blacklist=", initcall_blacklist);
1158
1159 static __init_or_module void
trace_initcall_start_cb(void * data,initcall_t fn)1160 trace_initcall_start_cb(void *data, initcall_t fn)
1161 {
1162 ktime_t *calltime = (ktime_t *)data;
1163
1164 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1165 *calltime = ktime_get();
1166 }
1167
1168 static __init_or_module void
trace_initcall_finish_cb(void * data,initcall_t fn,int ret)1169 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1170 {
1171 ktime_t *calltime = (ktime_t *)data;
1172 ktime_t delta, rettime;
1173 unsigned long long duration;
1174
1175 rettime = ktime_get();
1176 delta = ktime_sub(rettime, *calltime);
1177 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
1178 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1179 fn, ret, duration);
1180 }
1181
1182 static ktime_t initcall_calltime;
1183
1184 #ifdef TRACEPOINTS_ENABLED
initcall_debug_enable(void)1185 static void __init initcall_debug_enable(void)
1186 {
1187 int ret;
1188
1189 ret = register_trace_initcall_start(trace_initcall_start_cb,
1190 &initcall_calltime);
1191 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1192 &initcall_calltime);
1193 WARN(ret, "Failed to register initcall tracepoints\n");
1194 }
1195 # define do_trace_initcall_start trace_initcall_start
1196 # define do_trace_initcall_finish trace_initcall_finish
1197 #else
do_trace_initcall_start(initcall_t fn)1198 static inline void do_trace_initcall_start(initcall_t fn)
1199 {
1200 if (!initcall_debug)
1201 return;
1202 trace_initcall_start_cb(&initcall_calltime, fn);
1203 }
do_trace_initcall_finish(initcall_t fn,int ret)1204 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1205 {
1206 if (!initcall_debug)
1207 return;
1208 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1209 }
1210 #endif /* !TRACEPOINTS_ENABLED */
1211
do_one_initcall(initcall_t fn)1212 int __init_or_module do_one_initcall(initcall_t fn)
1213 {
1214 int count = preempt_count();
1215 char msgbuf[64];
1216 int ret;
1217
1218 if (initcall_blacklisted(fn))
1219 return -EPERM;
1220
1221 do_trace_initcall_start(fn);
1222 ret = fn();
1223 do_trace_initcall_finish(fn, ret);
1224
1225 msgbuf[0] = 0;
1226
1227 if (preempt_count() != count) {
1228 sprintf(msgbuf, "preemption imbalance ");
1229 preempt_count_set(count);
1230 }
1231 if (irqs_disabled()) {
1232 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1233 local_irq_enable();
1234 }
1235 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1236
1237 add_latent_entropy();
1238 return ret;
1239 }
1240
1241
1242 extern initcall_entry_t __initcall_start[];
1243 extern initcall_entry_t __initcall0_start[];
1244 extern initcall_entry_t __initcall1_start[];
1245 extern initcall_entry_t __initcall2_start[];
1246 extern initcall_entry_t __initcall3_start[];
1247 extern initcall_entry_t __initcall4_start[];
1248 extern initcall_entry_t __initcall5_start[];
1249 extern initcall_entry_t __initcall6_start[];
1250 extern initcall_entry_t __initcall7_start[];
1251 extern initcall_entry_t __initcall_end[];
1252
1253 static initcall_entry_t *initcall_levels[] __initdata = {
1254 __initcall0_start,
1255 __initcall1_start,
1256 __initcall2_start,
1257 __initcall3_start,
1258 __initcall4_start,
1259 __initcall5_start,
1260 __initcall6_start,
1261 __initcall7_start,
1262 __initcall_end,
1263 };
1264
1265 /* Keep these in sync with initcalls in include/linux/init.h */
1266 static const char *initcall_level_names[] __initdata = {
1267 "pure",
1268 "core",
1269 "postcore",
1270 "arch",
1271 "subsys",
1272 "fs",
1273 "device",
1274 "late",
1275 };
1276
ignore_unknown_bootoption(char * param,char * val,const char * unused,void * arg)1277 static int __init ignore_unknown_bootoption(char *param, char *val,
1278 const char *unused, void *arg)
1279 {
1280 return 0;
1281 }
1282
do_initcall_level(int level,char * command_line)1283 static void __init do_initcall_level(int level, char *command_line)
1284 {
1285 initcall_entry_t *fn;
1286
1287 parse_args(initcall_level_names[level],
1288 command_line, __start___param,
1289 __stop___param - __start___param,
1290 level, level,
1291 NULL, ignore_unknown_bootoption);
1292
1293 trace_initcall_level(initcall_level_names[level]);
1294 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1295 do_one_initcall(initcall_from_entry(fn));
1296 }
1297
do_initcalls(void)1298 static void __init do_initcalls(void)
1299 {
1300 int level;
1301 size_t len = strlen(saved_command_line) + 1;
1302 char *command_line;
1303
1304 command_line = kzalloc(len, GFP_KERNEL);
1305 if (!command_line)
1306 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1307
1308 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1309 /* Parser modifies command_line, restore it each time */
1310 strcpy(command_line, saved_command_line);
1311 do_initcall_level(level, command_line);
1312 }
1313
1314 kfree(command_line);
1315 }
1316
1317 /*
1318 * Ok, the machine is now initialized. None of the devices
1319 * have been touched yet, but the CPU subsystem is up and
1320 * running, and memory and process management works.
1321 *
1322 * Now we can finally start doing some real work..
1323 */
do_basic_setup(void)1324 static void __init do_basic_setup(void)
1325 {
1326 cpuset_init_smp();
1327 driver_init();
1328 init_irq_proc();
1329 do_ctors();
1330 usermodehelper_enable();
1331 do_initcalls();
1332 }
1333
do_pre_smp_initcalls(void)1334 static void __init do_pre_smp_initcalls(void)
1335 {
1336 initcall_entry_t *fn;
1337
1338 trace_initcall_level("early");
1339 for (fn = __initcall_start; fn < __initcall0_start; fn++)
1340 do_one_initcall(initcall_from_entry(fn));
1341 }
1342
run_init_process(const char * init_filename)1343 static int run_init_process(const char *init_filename)
1344 {
1345 const char *const *p;
1346
1347 argv_init[0] = init_filename;
1348 pr_info("Run %s as init process\n", init_filename);
1349 pr_debug(" with arguments:\n");
1350 for (p = argv_init; *p; p++)
1351 pr_debug(" %s\n", *p);
1352 pr_debug(" with environment:\n");
1353 for (p = envp_init; *p; p++)
1354 pr_debug(" %s\n", *p);
1355 return kernel_execve(init_filename, argv_init, envp_init);
1356 }
1357
try_to_run_init_process(const char * init_filename)1358 static int try_to_run_init_process(const char *init_filename)
1359 {
1360 int ret;
1361
1362 ret = run_init_process(init_filename);
1363
1364 if (ret && ret != -ENOENT) {
1365 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1366 init_filename, ret);
1367 }
1368
1369 return ret;
1370 }
1371
1372 static noinline void __init kernel_init_freeable(void);
1373
1374 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1375 bool rodata_enabled __ro_after_init = true;
set_debug_rodata(char * str)1376 static int __init set_debug_rodata(char *str)
1377 {
1378 return strtobool(str, &rodata_enabled);
1379 }
1380 __setup("rodata=", set_debug_rodata);
1381 #endif
1382
1383 #ifdef CONFIG_STRICT_KERNEL_RWX
mark_readonly(void)1384 static void mark_readonly(void)
1385 {
1386 if (rodata_enabled) {
1387 /*
1388 * load_module() results in W+X mappings, which are cleaned
1389 * up with call_rcu(). Let's make sure that queued work is
1390 * flushed so that we don't hit false positives looking for
1391 * insecure pages which are W+X.
1392 */
1393 rcu_barrier();
1394 mark_rodata_ro();
1395 rodata_test();
1396 } else
1397 pr_info("Kernel memory protection disabled.\n");
1398 }
1399 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
mark_readonly(void)1400 static inline void mark_readonly(void)
1401 {
1402 pr_warn("Kernel memory protection not selected by kernel config.\n");
1403 }
1404 #else
mark_readonly(void)1405 static inline void mark_readonly(void)
1406 {
1407 pr_warn("This architecture does not have kernel memory protection.\n");
1408 }
1409 #endif
1410
free_initmem(void)1411 void __weak free_initmem(void)
1412 {
1413 free_initmem_default(POISON_FREE_INITMEM);
1414 }
1415
kernel_init(void * unused)1416 static int __ref kernel_init(void *unused)
1417 {
1418 int ret;
1419
1420 kernel_init_freeable();
1421 /* need to finish all async __init code before freeing the memory */
1422 async_synchronize_full();
1423 kprobe_free_init_mem();
1424 ftrace_free_init_mem();
1425 kgdb_free_init_mem();
1426 free_initmem();
1427 mark_readonly();
1428
1429 /*
1430 * Kernel mappings are now finalized - update the userspace page-table
1431 * to finalize PTI.
1432 */
1433 pti_finalize();
1434
1435 system_state = SYSTEM_RUNNING;
1436 numa_default_policy();
1437
1438 rcu_end_inkernel_boot();
1439
1440 do_sysctl_args();
1441
1442 if (ramdisk_execute_command) {
1443 ret = run_init_process(ramdisk_execute_command);
1444 if (!ret)
1445 return 0;
1446 pr_err("Failed to execute %s (error %d)\n",
1447 ramdisk_execute_command, ret);
1448 }
1449
1450 /*
1451 * We try each of these until one succeeds.
1452 *
1453 * The Bourne shell can be used instead of init if we are
1454 * trying to recover a really broken machine.
1455 */
1456 if (execute_command) {
1457 ret = run_init_process(execute_command);
1458 if (!ret)
1459 return 0;
1460 panic("Requested init %s failed (error %d).",
1461 execute_command, ret);
1462 }
1463
1464 if (CONFIG_DEFAULT_INIT[0] != '\0') {
1465 ret = run_init_process(CONFIG_DEFAULT_INIT);
1466 if (ret)
1467 pr_err("Default init %s failed (error %d)\n",
1468 CONFIG_DEFAULT_INIT, ret);
1469 else
1470 return 0;
1471 }
1472
1473 if (!try_to_run_init_process("/sbin/init") ||
1474 !try_to_run_init_process("/etc/init") ||
1475 !try_to_run_init_process("/bin/init") ||
1476 !try_to_run_init_process("/bin/sh"))
1477 return 0;
1478
1479 panic("No working init found. Try passing init= option to kernel. "
1480 "See Linux Documentation/admin-guide/init.rst for guidance.");
1481 }
1482
1483 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
console_on_rootfs(void)1484 void __init console_on_rootfs(void)
1485 {
1486 struct file *file = filp_open("/dev/console", O_RDWR, 0);
1487
1488 if (IS_ERR(file)) {
1489 pr_err("Warning: unable to open an initial console.\n");
1490 return;
1491 }
1492 init_dup(file);
1493 init_dup(file);
1494 init_dup(file);
1495 fput(file);
1496 }
1497
kernel_init_freeable(void)1498 static noinline void __init kernel_init_freeable(void)
1499 {
1500 /*
1501 * Wait until kthreadd is all set-up.
1502 */
1503 wait_for_completion(&kthreadd_done);
1504
1505 /* Now the scheduler is fully set up and can do blocking allocations */
1506 gfp_allowed_mask = __GFP_BITS_MASK;
1507
1508 /*
1509 * init can allocate pages on any node
1510 */
1511 set_mems_allowed(node_states[N_MEMORY]);
1512
1513 cad_pid = get_pid(task_pid(current));
1514
1515 smp_prepare_cpus(setup_max_cpus);
1516
1517 workqueue_init();
1518
1519 init_mm_internals();
1520
1521 rcu_init_tasks_generic();
1522 do_pre_smp_initcalls();
1523 lockup_detector_init();
1524
1525 smp_init();
1526 sched_init_smp();
1527
1528 padata_init();
1529 page_alloc_init_late();
1530 /* Initialize page ext after all struct pages are initialized. */
1531 page_ext_init();
1532
1533 do_basic_setup();
1534
1535 kunit_run_all_tests();
1536
1537 console_on_rootfs();
1538
1539 /*
1540 * check if there is an early userspace init. If yes, let it do all
1541 * the work
1542 */
1543 if (init_eaccess(ramdisk_execute_command) != 0) {
1544 ramdisk_execute_command = NULL;
1545 prepare_namespace();
1546 }
1547
1548 /*
1549 * Ok, we have completed the initial bootup, and
1550 * we're essentially up and running. Get rid of the
1551 * initmem segments and start the user-mode stuff..
1552 *
1553 * rootfs is available now, try loading the public keys
1554 * and default modules
1555 */
1556
1557 integrity_load_keys();
1558 }
1559