Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * linux/init/main.c
4 : *
5 : * Copyright (C) 1991, 1992 Linus Torvalds
6 : *
7 : * GK 2/5/95 - Changed to support mounting root fs via NFS
8 : * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
9 : * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
10 : * Simplified starting of init: Michael A. Griffith <grif@acm.org>
11 : */
12 :
13 : #define DEBUG /* Enable initcall_debug */
14 :
15 : #include <linux/types.h>
16 : #include <linux/extable.h>
17 : #include <linux/module.h>
18 : #include <linux/proc_fs.h>
19 : #include <linux/binfmts.h>
20 : #include <linux/kernel.h>
21 : #include <linux/syscalls.h>
22 : #include <linux/stackprotector.h>
23 : #include <linux/string.h>
24 : #include <linux/ctype.h>
25 : #include <linux/delay.h>
26 : #include <linux/ioport.h>
27 : #include <linux/init.h>
28 : #include <linux/initrd.h>
29 : #include <linux/memblock.h>
30 : #include <linux/acpi.h>
31 : #include <linux/bootconfig.h>
32 : #include <linux/console.h>
33 : #include <linux/nmi.h>
34 : #include <linux/percpu.h>
35 : #include <linux/kmod.h>
36 : #include <linux/kprobes.h>
37 : #include <linux/kmsan.h>
38 : #include <linux/vmalloc.h>
39 : #include <linux/kernel_stat.h>
40 : #include <linux/start_kernel.h>
41 : #include <linux/security.h>
42 : #include <linux/smp.h>
43 : #include <linux/profile.h>
44 : #include <linux/kfence.h>
45 : #include <linux/rcupdate.h>
46 : #include <linux/srcu.h>
47 : #include <linux/moduleparam.h>
48 : #include <linux/kallsyms.h>
49 : #include <linux/buildid.h>
50 : #include <linux/writeback.h>
51 : #include <linux/cpu.h>
52 : #include <linux/cpuset.h>
53 : #include <linux/cgroup.h>
54 : #include <linux/efi.h>
55 : #include <linux/tick.h>
56 : #include <linux/sched/isolation.h>
57 : #include <linux/interrupt.h>
58 : #include <linux/taskstats_kern.h>
59 : #include <linux/delayacct.h>
60 : #include <linux/unistd.h>
61 : #include <linux/utsname.h>
62 : #include <linux/rmap.h>
63 : #include <linux/mempolicy.h>
64 : #include <linux/key.h>
65 : #include <linux/page_ext.h>
66 : #include <linux/debug_locks.h>
67 : #include <linux/debugobjects.h>
68 : #include <linux/lockdep.h>
69 : #include <linux/kmemleak.h>
70 : #include <linux/padata.h>
71 : #include <linux/pid_namespace.h>
72 : #include <linux/device/driver.h>
73 : #include <linux/kthread.h>
74 : #include <linux/sched.h>
75 : #include <linux/sched/init.h>
76 : #include <linux/signal.h>
77 : #include <linux/idr.h>
78 : #include <linux/kgdb.h>
79 : #include <linux/ftrace.h>
80 : #include <linux/async.h>
81 : #include <linux/shmem_fs.h>
82 : #include <linux/slab.h>
83 : #include <linux/perf_event.h>
84 : #include <linux/ptrace.h>
85 : #include <linux/pti.h>
86 : #include <linux/blkdev.h>
87 : #include <linux/sched/clock.h>
88 : #include <linux/sched/task.h>
89 : #include <linux/sched/task_stack.h>
90 : #include <linux/context_tracking.h>
91 : #include <linux/random.h>
92 : #include <linux/list.h>
93 : #include <linux/integrity.h>
94 : #include <linux/proc_ns.h>
95 : #include <linux/io.h>
96 : #include <linux/cache.h>
97 : #include <linux/rodata_test.h>
98 : #include <linux/jump_label.h>
99 : #include <linux/mem_encrypt.h>
100 : #include <linux/kcsan.h>
101 : #include <linux/init_syscalls.h>
102 : #include <linux/stackdepot.h>
103 : #include <linux/randomize_kstack.h>
104 : #include <net/net_namespace.h>
105 :
106 : #include <asm/io.h>
107 : #include <asm/bugs.h>
108 : #include <asm/setup.h>
109 : #include <asm/sections.h>
110 : #include <asm/cacheflush.h>
111 :
112 : #define CREATE_TRACE_POINTS
113 : #include <trace/events/initcall.h>
114 :
115 : #include <kunit/test.h>
116 :
117 : static int kernel_init(void *);
118 :
119 : extern void init_IRQ(void);
120 : extern void radix_tree_init(void);
121 : extern void maple_tree_init(void);
122 :
123 : /*
124 : * Debug helper: via this flag we know that we are in 'early bootup code'
125 : * where only the boot processor is running with IRQ disabled. This means
126 : * two things - IRQ must not be enabled before the flag is cleared and some
127 : * operations which are not allowed with IRQ disabled are allowed while the
128 : * flag is set.
129 : */
130 : bool early_boot_irqs_disabled __read_mostly;
131 :
132 : enum system_states system_state __read_mostly;
133 : EXPORT_SYMBOL(system_state);
134 :
135 : /*
136 : * Boot command-line arguments
137 : */
138 : #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
139 : #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
140 :
141 : extern void time_init(void);
142 : /* Default late time init is NULL. archs can override this later. */
143 : void (*__initdata late_time_init)(void);
144 :
145 : /* Untouched command line saved by arch-specific code. */
146 : char __initdata boot_command_line[COMMAND_LINE_SIZE];
147 : /* Untouched saved command line (eg. for /proc) */
148 : char *saved_command_line __ro_after_init;
149 : unsigned int saved_command_line_len __ro_after_init;
150 : /* Command line for parameter parsing */
151 : static char *static_command_line;
152 : /* Untouched extra command line */
153 : static char *extra_command_line;
154 : /* Extra init arguments */
155 : static char *extra_init_args;
156 :
157 : #ifdef CONFIG_BOOT_CONFIG
158 : /* Is bootconfig on command line? */
159 : static bool bootconfig_found = IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE);
160 : static size_t initargs_offs;
161 : #else
162 : # define bootconfig_found false
163 : # define initargs_offs 0
164 : #endif
165 :
166 : static char *execute_command;
167 : static char *ramdisk_execute_command = "/init";
168 :
169 : /*
170 : * Used to generate warnings if static_key manipulation functions are used
171 : * before jump_label_init is called.
172 : */
173 : bool static_key_initialized __read_mostly;
174 : EXPORT_SYMBOL_GPL(static_key_initialized);
175 :
176 : /*
177 : * If set, this is an indication to the drivers that reset the underlying
178 : * device before going ahead with the initialization otherwise driver might
179 : * rely on the BIOS and skip the reset operation.
180 : *
181 : * This is useful if kernel is booting in an unreliable environment.
182 : * For ex. kdump situation where previous kernel has crashed, BIOS has been
183 : * skipped and devices will be in unknown state.
184 : */
185 : unsigned int reset_devices;
186 : EXPORT_SYMBOL(reset_devices);
187 :
188 0 : static int __init set_reset_devices(char *str)
189 : {
190 0 : reset_devices = 1;
191 0 : return 1;
192 : }
193 :
194 : __setup("reset_devices", set_reset_devices);
195 :
196 : static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
197 : const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
198 : static const char *panic_later, *panic_param;
199 :
200 : extern const struct obs_kernel_param __setup_start[], __setup_end[];
201 :
202 3 : static bool __init obsolete_checksetup(char *line)
203 : {
204 : const struct obs_kernel_param *p;
205 3 : bool had_early_param = false;
206 :
207 3 : p = __setup_start;
208 : do {
209 134 : int n = strlen(p->str);
210 134 : if (parameqn(line, p->str, n)) {
211 3 : if (p->early) {
212 : /* Already done in parse_early_param?
213 : * (Needs exact match on param part).
214 : * Keep iterating, as we can have early
215 : * params and __setups of same names 8( */
216 0 : if (line[n] == '\0' || line[n] == '=')
217 0 : had_early_param = true;
218 3 : } else if (!p->setup_func) {
219 0 : pr_warn("Parameter %s is obsolete, ignored\n",
220 : p->str);
221 0 : return true;
222 3 : } else if (p->setup_func(line + n))
223 : return true;
224 : }
225 132 : p++;
226 132 : } while (p < __setup_end);
227 :
228 : return had_early_param;
229 : }
230 :
231 : /*
232 : * This should be approx 2 Bo*oMips to start (note initial shift), and will
233 : * still work even if initially too large, it will just take slightly longer
234 : */
235 : unsigned long loops_per_jiffy = (1<<12);
236 : EXPORT_SYMBOL(loops_per_jiffy);
237 :
238 0 : static int __init debug_kernel(char *str)
239 : {
240 0 : console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
241 0 : return 0;
242 : }
243 :
244 0 : static int __init quiet_kernel(char *str)
245 : {
246 0 : console_loglevel = CONSOLE_LOGLEVEL_QUIET;
247 0 : return 0;
248 : }
249 :
250 : early_param("debug", debug_kernel);
251 : early_param("quiet", quiet_kernel);
252 :
253 0 : static int __init loglevel(char *str)
254 : {
255 : int newlevel;
256 :
257 : /*
258 : * Only update loglevel value when a correct setting was passed,
259 : * to prevent blind crashes (when loglevel being set to 0) that
260 : * are quite hard to debug
261 : */
262 0 : if (get_option(&str, &newlevel)) {
263 0 : console_loglevel = newlevel;
264 0 : return 0;
265 : }
266 :
267 : return -EINVAL;
268 : }
269 :
270 : early_param("loglevel", loglevel);
271 :
272 : #ifdef CONFIG_BLK_DEV_INITRD
273 : static void * __init get_boot_config_from_initrd(size_t *_size)
274 : {
275 : u32 size, csum;
276 : char *data;
277 : u32 *hdr;
278 : int i;
279 :
280 : if (!initrd_end)
281 : return NULL;
282 :
283 : data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
284 : /*
285 : * Since Grub may align the size of initrd to 4, we must
286 : * check the preceding 3 bytes as well.
287 : */
288 : for (i = 0; i < 4; i++) {
289 : if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
290 : goto found;
291 : data--;
292 : }
293 : return NULL;
294 :
295 : found:
296 : hdr = (u32 *)(data - 8);
297 : size = le32_to_cpu(hdr[0]);
298 : csum = le32_to_cpu(hdr[1]);
299 :
300 : data = ((void *)hdr) - size;
301 : if ((unsigned long)data < initrd_start) {
302 : pr_err("bootconfig size %d is greater than initrd size %ld\n",
303 : size, initrd_end - initrd_start);
304 : return NULL;
305 : }
306 :
307 : if (xbc_calc_checksum(data, size) != csum) {
308 : pr_err("bootconfig checksum failed\n");
309 : return NULL;
310 : }
311 :
312 : /* Remove bootconfig from initramfs/initrd */
313 : initrd_end = (unsigned long)data;
314 : if (_size)
315 : *_size = size;
316 :
317 : return data;
318 : }
319 : #else
320 : static void * __init get_boot_config_from_initrd(size_t *_size)
321 : {
322 : return NULL;
323 : }
324 : #endif
325 :
326 : #ifdef CONFIG_BOOT_CONFIG
327 :
328 : static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
329 :
330 : #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
331 :
332 : static int __init xbc_snprint_cmdline(char *buf, size_t size,
333 : struct xbc_node *root)
334 : {
335 : struct xbc_node *knode, *vnode;
336 : char *end = buf + size;
337 : const char *val;
338 : int ret;
339 :
340 : xbc_node_for_each_key_value(root, knode, val) {
341 : ret = xbc_node_compose_key_after(root, knode,
342 : xbc_namebuf, XBC_KEYLEN_MAX);
343 : if (ret < 0)
344 : return ret;
345 :
346 : vnode = xbc_node_get_child(knode);
347 : if (!vnode) {
348 : ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
349 : if (ret < 0)
350 : return ret;
351 : buf += ret;
352 : continue;
353 : }
354 : xbc_array_for_each_value(vnode, val) {
355 : ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
356 : xbc_namebuf, val);
357 : if (ret < 0)
358 : return ret;
359 : buf += ret;
360 : }
361 : }
362 :
363 : return buf - (end - size);
364 : }
365 : #undef rest
366 :
367 : /* Make an extra command line under given key word */
368 : static char * __init xbc_make_cmdline(const char *key)
369 : {
370 : struct xbc_node *root;
371 : char *new_cmdline;
372 : int ret, len = 0;
373 :
374 : root = xbc_find_node(key);
375 : if (!root)
376 : return NULL;
377 :
378 : /* Count required buffer size */
379 : len = xbc_snprint_cmdline(NULL, 0, root);
380 : if (len <= 0)
381 : return NULL;
382 :
383 : new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
384 : if (!new_cmdline) {
385 : pr_err("Failed to allocate memory for extra kernel cmdline.\n");
386 : return NULL;
387 : }
388 :
389 : ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
390 : if (ret < 0 || ret > len) {
391 : pr_err("Failed to print extra kernel cmdline.\n");
392 : memblock_free(new_cmdline, len + 1);
393 : return NULL;
394 : }
395 :
396 : return new_cmdline;
397 : }
398 :
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 :
408 : static int __init warn_bootconfig(char *str)
409 : {
410 : /* The 'bootconfig' has been handled by bootconfig_params(). */
411 : return 0;
412 : }
413 :
414 : static void __init setup_boot_config(void)
415 : {
416 : static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
417 : const char *msg, *data;
418 : int pos, ret;
419 : size_t size;
420 : char *err;
421 :
422 : /* Cut out the bootconfig data even if we have no bootconfig option */
423 : data = get_boot_config_from_initrd(&size);
424 : /* If there is no bootconfig in initrd, try embedded one. */
425 : if (!data)
426 : data = xbc_get_embedded_bootconfig(&size);
427 :
428 : strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
429 : err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
430 : bootconfig_params);
431 :
432 : if (IS_ERR(err) || !bootconfig_found)
433 : return;
434 :
435 : /* parse_args() stops at the next param of '--' and returns an address */
436 : if (err)
437 : initargs_offs = err - tmp_cmdline;
438 :
439 : if (!data) {
440 : pr_err("'bootconfig' found on command line, but no bootconfig found\n");
441 : return;
442 : }
443 :
444 : if (size >= XBC_DATA_MAX) {
445 : pr_err("bootconfig size %ld greater than max size %d\n",
446 : (long)size, XBC_DATA_MAX);
447 : return;
448 : }
449 :
450 : ret = xbc_init(data, size, &msg, &pos);
451 : if (ret < 0) {
452 : if (pos < 0)
453 : pr_err("Failed to init bootconfig: %s.\n", msg);
454 : else
455 : pr_err("Failed to parse bootconfig: %s at %d.\n",
456 : msg, pos);
457 : } else {
458 : xbc_get_info(&ret, NULL);
459 : pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
460 : /* keys starting with "kernel." are passed via cmdline */
461 : extra_command_line = xbc_make_cmdline("kernel");
462 : /* Also, "init." keys are init arguments */
463 : extra_init_args = xbc_make_cmdline("init");
464 : }
465 : return;
466 : }
467 :
468 : static void __init exit_boot_config(void)
469 : {
470 : xbc_exit();
471 : }
472 :
473 : #else /* !CONFIG_BOOT_CONFIG */
474 :
475 : static void __init setup_boot_config(void)
476 : {
477 : /* Remove bootconfig data from initrd */
478 1 : get_boot_config_from_initrd(NULL);
479 : }
480 :
481 0 : static int __init warn_bootconfig(char *str)
482 : {
483 0 : pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
484 0 : return 0;
485 : }
486 :
487 : #define exit_boot_config() do {} while (0)
488 :
489 : #endif /* CONFIG_BOOT_CONFIG */
490 :
491 : early_param("bootconfig", warn_bootconfig);
492 :
493 : /* Change NUL term back to "=", to make "param" the whole string. */
494 3 : static void __init repair_env_string(char *param, char *val)
495 : {
496 3 : if (val) {
497 : /* param=val or param="val"? */
498 3 : if (val == param+strlen(param)+1)
499 3 : val[-1] = '=';
500 0 : else if (val == param+strlen(param)+2) {
501 0 : val[-2] = '=';
502 0 : memmove(val-1, val, strlen(val)+1);
503 : } else
504 0 : BUG();
505 : }
506 3 : }
507 :
508 : /* Anything after -- gets handed straight to init. */
509 0 : static int __init set_init_arg(char *param, char *val,
510 : const char *unused, void *arg)
511 : {
512 : unsigned int i;
513 :
514 0 : if (panic_later)
515 : return 0;
516 :
517 0 : repair_env_string(param, val);
518 :
519 0 : for (i = 0; argv_init[i]; i++) {
520 0 : if (i == MAX_INIT_ARGS) {
521 0 : panic_later = "init";
522 0 : panic_param = param;
523 0 : return 0;
524 : }
525 : }
526 0 : argv_init[i] = param;
527 0 : return 0;
528 : }
529 :
530 : /*
531 : * Unknown boot options get handed to init, unless they look like
532 : * unused parameters (modprobe will find them in /proc/cmdline).
533 : */
534 3 : static int __init unknown_bootoption(char *param, char *val,
535 : const char *unused, void *arg)
536 : {
537 3 : size_t len = strlen(param);
538 :
539 3 : repair_env_string(param, val);
540 :
541 : /* Handle obsolete-style parameters */
542 3 : if (obsolete_checksetup(param))
543 : return 0;
544 :
545 : /* Unused module parameter. */
546 1 : if (strnchr(param, len, '.'))
547 : return 0;
548 :
549 1 : if (panic_later)
550 : return 0;
551 :
552 1 : if (val) {
553 : /* Environment option */
554 : unsigned int i;
555 2 : for (i = 0; envp_init[i]; i++) {
556 2 : if (i == MAX_INIT_ENVS) {
557 0 : panic_later = "env";
558 0 : panic_param = param;
559 : }
560 2 : if (!strncmp(param, envp_init[i], len+1))
561 : break;
562 : }
563 1 : envp_init[i] = param;
564 : } else {
565 : /* Command line option */
566 : unsigned int i;
567 0 : for (i = 0; argv_init[i]; i++) {
568 0 : if (i == MAX_INIT_ARGS) {
569 0 : panic_later = "init";
570 0 : panic_param = param;
571 : }
572 : }
573 0 : argv_init[i] = param;
574 : }
575 : return 0;
576 : }
577 :
578 0 : static int __init init_setup(char *str)
579 : {
580 : unsigned int i;
581 :
582 0 : execute_command = str;
583 : /*
584 : * In case LILO is going to boot us with default command line,
585 : * it prepends "auto" before the whole cmdline which makes
586 : * the shell think it should execute a script with such name.
587 : * So we ignore all arguments entered _before_ init=... [MJ]
588 : */
589 0 : for (i = 1; i < MAX_INIT_ARGS; i++)
590 0 : argv_init[i] = NULL;
591 0 : return 1;
592 : }
593 : __setup("init=", init_setup);
594 :
595 0 : static int __init rdinit_setup(char *str)
596 : {
597 : unsigned int i;
598 :
599 0 : ramdisk_execute_command = str;
600 : /* See "auto" comment in init_setup */
601 0 : for (i = 1; i < MAX_INIT_ARGS; i++)
602 0 : argv_init[i] = NULL;
603 0 : return 1;
604 : }
605 : __setup("rdinit=", rdinit_setup);
606 :
607 : #ifndef CONFIG_SMP
608 : static const unsigned int setup_max_cpus = NR_CPUS;
609 : static inline void setup_nr_cpu_ids(void) { }
610 : static inline void smp_prepare_cpus(unsigned int maxcpus) { }
611 : #endif
612 :
613 : /*
614 : * We need to store the untouched command line for future reference.
615 : * We also need to store the touched command line since the parameter
616 : * parsing is performed in place, and we should allow a component to
617 : * store reference of name/value for future reference.
618 : */
619 1 : static void __init setup_command_line(char *command_line)
620 : {
621 1 : size_t len, xlen = 0, ilen = 0;
622 :
623 1 : if (extra_command_line)
624 0 : xlen = strlen(extra_command_line);
625 1 : if (extra_init_args)
626 0 : ilen = strlen(extra_init_args) + 4; /* for " -- " */
627 :
628 1 : len = xlen + strlen(boot_command_line) + 1;
629 :
630 2 : saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
631 1 : if (!saved_command_line)
632 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
633 :
634 1 : static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
635 1 : if (!static_command_line)
636 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len);
637 :
638 1 : if (xlen) {
639 : /*
640 : * We have to put extra_command_line before boot command
641 : * lines because there could be dashes (separator of init
642 : * command line) in the command lines.
643 : */
644 0 : strcpy(saved_command_line, extra_command_line);
645 0 : strcpy(static_command_line, extra_command_line);
646 : }
647 1 : strcpy(saved_command_line + xlen, boot_command_line);
648 1 : strcpy(static_command_line + xlen, command_line);
649 :
650 1 : if (ilen) {
651 : /*
652 : * Append supplemental init boot args to saved_command_line
653 : * so that user can check what command line options passed
654 : * to init.
655 : * The order should always be
656 : * " -- "[bootconfig init-param][cmdline init-param]
657 : */
658 : if (initargs_offs) {
659 : len = xlen + initargs_offs;
660 : strcpy(saved_command_line + len, extra_init_args);
661 : len += ilen - 4; /* strlen(extra_init_args) */
662 : strcpy(saved_command_line + len,
663 : boot_command_line + initargs_offs - 1);
664 : } else {
665 0 : len = strlen(saved_command_line);
666 0 : strcpy(saved_command_line + len, " -- ");
667 0 : len += 4;
668 0 : strcpy(saved_command_line + len, extra_init_args);
669 : }
670 : }
671 :
672 1 : saved_command_line_len = strlen(saved_command_line);
673 1 : }
674 :
675 : /*
676 : * We need to finalize in a non-__init function or else race conditions
677 : * between the root thread and the init thread may cause start_kernel to
678 : * be reaped by free_initmem before the root thread has proceeded to
679 : * cpu_idle.
680 : *
681 : * gcc-3.4 accidentally inlines this function, so use noinline.
682 : */
683 :
684 : static __initdata DECLARE_COMPLETION(kthreadd_done);
685 :
686 1 : noinline void __ref rest_init(void)
687 : {
688 : struct task_struct *tsk;
689 : int pid;
690 :
691 1 : rcu_scheduler_starting();
692 : /*
693 : * We need to spawn init first so that it obtains pid 1, however
694 : * the init task will end up wanting to create kthreads, which, if
695 : * we schedule it before we create kthreadd, will OOPS.
696 : */
697 1 : pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
698 : /*
699 : * Pin init on the boot CPU. Task migration is not properly working
700 : * until sched_init_smp() has been run. It will set the allowed
701 : * CPUs for init to the non isolated CPUs.
702 : */
703 : rcu_read_lock();
704 1 : tsk = find_task_by_pid_ns(pid, &init_pid_ns);
705 1 : tsk->flags |= PF_NO_SETAFFINITY;
706 2 : set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
707 : rcu_read_unlock();
708 :
709 : numa_default_policy();
710 1 : pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
711 : rcu_read_lock();
712 1 : kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
713 : rcu_read_unlock();
714 :
715 : /*
716 : * Enable might_sleep() and smp_processor_id() checks.
717 : * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
718 : * kernel_thread() would trigger might_sleep() splats. With
719 : * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
720 : * already, but it's stuck on the kthreadd_done completion.
721 : */
722 1 : system_state = SYSTEM_SCHEDULING;
723 :
724 1 : complete(&kthreadd_done);
725 :
726 : /*
727 : * The boot idle thread must execute schedule()
728 : * at least once to get things moving:
729 : */
730 1 : schedule_preempt_disabled();
731 : /* Call into cpu_idle with preempt disabled */
732 0 : cpu_startup_entry(CPUHP_ONLINE);
733 : }
734 :
735 : /* Check for early params. */
736 5 : static int __init do_early_param(char *param, char *val,
737 : const char *unused, void *arg)
738 : {
739 : const struct obs_kernel_param *p;
740 :
741 420 : for (p = __setup_start; p < __setup_end; p++) {
742 830 : if ((p->early && parameq(param, p->str)) ||
743 498 : (strcmp(param, "console") == 0 &&
744 83 : strcmp(p->str, "earlycon") == 0)
745 : ) {
746 0 : if (p->setup_func(val) != 0)
747 0 : pr_warn("Malformed early option '%s'\n", param);
748 : }
749 : }
750 : /* We accept everything at this stage. */
751 5 : return 0;
752 : }
753 :
754 1 : void __init parse_early_options(char *cmdline)
755 : {
756 1 : parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
757 : do_early_param);
758 1 : }
759 :
760 : /* Arch code calls this early on, or if not, just before other parsing. */
761 1 : void __init parse_early_param(void)
762 : {
763 : static int done __initdata;
764 : static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
765 :
766 1 : if (done)
767 : return;
768 :
769 : /* All fall through to do_early_param. */
770 1 : strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
771 1 : parse_early_options(tmp_cmdline);
772 1 : done = 1;
773 : }
774 :
775 1 : void __init __weak arch_post_acpi_subsys_init(void) { }
776 :
777 1 : void __init __weak smp_setup_processor_id(void)
778 : {
779 1 : }
780 :
781 : # if THREAD_SIZE >= PAGE_SIZE
782 1 : void __init __weak thread_stack_cache_init(void)
783 : {
784 1 : }
785 : #endif
786 :
787 1 : void __init __weak mem_encrypt_init(void) { }
788 :
789 1 : void __init __weak poking_init(void) { }
790 :
791 1 : void __init __weak pgtable_cache_init(void) { }
792 :
793 1 : void __init __weak trap_init(void) { }
794 :
795 : bool initcall_debug;
796 : core_param(initcall_debug, initcall_debug, bool, 0644);
797 :
798 : #ifdef TRACEPOINTS_ENABLED
799 : static void __init initcall_debug_enable(void);
800 : #else
801 : static inline void initcall_debug_enable(void)
802 : {
803 : }
804 : #endif
805 :
806 : /* Report memory auto-initialization states for this boot. */
807 1 : static void __init report_meminit(void)
808 : {
809 : const char *stack;
810 :
811 : if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
812 : stack = "all(pattern)";
813 : else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
814 : stack = "all(zero)";
815 : else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
816 : stack = "byref_all(zero)";
817 : else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
818 : stack = "byref(zero)";
819 : else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
820 : stack = "__user(zero)";
821 : else
822 1 : stack = "off";
823 :
824 2 : pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
825 : stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
826 : want_init_on_free() ? "on" : "off");
827 1 : if (want_init_on_free())
828 0 : pr_info("mem auto-init: clearing system memory may take some time...\n");
829 1 : }
830 :
831 : /*
832 : * Set up kernel memory allocators
833 : */
834 1 : static void __init mm_init(void)
835 : {
836 : /*
837 : * page_ext requires contiguous pages,
838 : * bigger than MAX_ORDER unless SPARSEMEM.
839 : */
840 : page_ext_init_flatmem();
841 1 : init_mem_debugging_and_hardening();
842 : kfence_alloc_pool();
843 1 : report_meminit();
844 : kmsan_init_shadow();
845 1 : stack_depot_early_init();
846 1 : mem_init();
847 1 : mem_init_print_info();
848 1 : kmem_cache_init();
849 : /*
850 : * page_owner must be initialized after buddy is ready, and also after
851 : * slab is ready so that stack_depot_init() works properly
852 : */
853 : page_ext_init_flatmem_late();
854 : kmemleak_init();
855 : pgtable_init();
856 : debug_objects_mem_init();
857 1 : vmalloc_init();
858 : /* If no deferred init page_ext now, as vmap is fully initialized */
859 : if (!deferred_struct_pages)
860 : page_ext_init();
861 : /* Should be run before the first non-init thread is created */
862 : init_espfix_bsp();
863 : /* Should be run after espfix64 is set up. */
864 : pti_init();
865 : kmsan_init_runtime();
866 1 : mm_cache_init();
867 1 : }
868 :
869 : #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
870 : DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
871 : randomize_kstack_offset);
872 : DEFINE_PER_CPU(u32, kstack_offset);
873 :
874 : static int __init early_randomize_kstack_offset(char *buf)
875 : {
876 : int ret;
877 : bool bool_result;
878 :
879 : ret = kstrtobool(buf, &bool_result);
880 : if (ret)
881 : return ret;
882 :
883 : if (bool_result)
884 : static_branch_enable(&randomize_kstack_offset);
885 : else
886 : static_branch_disable(&randomize_kstack_offset);
887 : return 0;
888 : }
889 : early_param("randomize_kstack_offset", early_randomize_kstack_offset);
890 : #endif
891 :
892 1 : void __init __weak arch_call_rest_init(void)
893 : {
894 1 : rest_init();
895 : }
896 :
897 1 : static void __init print_unknown_bootoptions(void)
898 : {
899 : char *unknown_options;
900 : char *end;
901 : const char *const *p;
902 : size_t len;
903 :
904 1 : if (panic_later || (!argv_init[1] && !envp_init[2]))
905 : return;
906 :
907 : /*
908 : * Determine how many options we have to print out, plus a space
909 : * before each
910 : */
911 : len = 1; /* null terminator */
912 0 : for (p = &argv_init[1]; *p; p++) {
913 0 : len++;
914 0 : len += strlen(*p);
915 : }
916 1 : for (p = &envp_init[2]; *p; p++) {
917 1 : len++;
918 1 : len += strlen(*p);
919 : }
920 :
921 1 : unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
922 1 : if (!unknown_options) {
923 0 : pr_err("%s: Failed to allocate %zu bytes\n",
924 : __func__, len);
925 0 : return;
926 : }
927 : end = unknown_options;
928 :
929 0 : for (p = &argv_init[1]; *p; p++)
930 0 : end += sprintf(end, " %s", *p);
931 1 : for (p = &envp_init[2]; *p; p++)
932 1 : end += sprintf(end, " %s", *p);
933 :
934 : /* Start at unknown_options[1] to skip the initial space */
935 1 : pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
936 : &unknown_options[1]);
937 1 : memblock_free(unknown_options, len);
938 : }
939 :
940 1 : asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
941 : {
942 : char *command_line;
943 : char *after_dashes;
944 :
945 1 : set_task_stack_end_magic(&init_task);
946 1 : smp_setup_processor_id();
947 : debug_objects_early_init();
948 : init_vmlinux_build_id();
949 :
950 : cgroup_init_early();
951 :
952 : local_irq_disable();
953 1 : early_boot_irqs_disabled = true;
954 :
955 : /*
956 : * Interrupts are still disabled. Do necessary setups, then
957 : * enable them.
958 : */
959 1 : boot_cpu_init();
960 : page_address_init();
961 1 : pr_notice("%s", linux_banner);
962 : early_security_init();
963 1 : setup_arch(&command_line);
964 : setup_boot_config();
965 1 : setup_command_line(command_line);
966 : setup_nr_cpu_ids();
967 1 : setup_per_cpu_areas();
968 : smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
969 1 : boot_cpu_hotplug_init();
970 :
971 1 : build_all_zonelists(NULL);
972 1 : page_alloc_init();
973 :
974 1 : pr_notice("Kernel command line: %s\n", saved_command_line);
975 : /* parameters may set static keys */
976 : jump_label_init();
977 1 : parse_early_param();
978 1 : after_dashes = parse_args("Booting kernel",
979 : static_command_line, __start___param,
980 1 : __stop___param - __start___param,
981 : -1, -1, NULL, &unknown_bootoption);
982 1 : print_unknown_bootoptions();
983 1 : if (!IS_ERR_OR_NULL(after_dashes))
984 0 : parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
985 : NULL, set_init_arg);
986 1 : if (extra_init_args)
987 0 : parse_args("Setting extra init args", extra_init_args,
988 : NULL, 0, -1, -1, NULL, set_init_arg);
989 :
990 : /* Architectural and non-timekeeping rng init, before allocator init */
991 1 : random_init_early(command_line);
992 :
993 : /*
994 : * These use large bootmem allocations and must precede
995 : * kmem_cache_init()
996 : */
997 1 : setup_log_buf(0);
998 1 : vfs_caches_init_early();
999 1 : sort_main_extable();
1000 1 : trap_init();
1001 1 : mm_init();
1002 1 : poking_init();
1003 : ftrace_init();
1004 :
1005 : /* trace_printk can be enabled here */
1006 : early_trace_init();
1007 :
1008 : /*
1009 : * Set up the scheduler prior starting any interrupts (such as the
1010 : * timer interrupt). Full topology setup happens at smp_init()
1011 : * time - but meanwhile we still have a functioning scheduler.
1012 : */
1013 1 : sched_init();
1014 :
1015 1 : if (WARN(!irqs_disabled(),
1016 : "Interrupts were enabled *very* early, fixing it\n"))
1017 : local_irq_disable();
1018 1 : radix_tree_init();
1019 1 : maple_tree_init();
1020 :
1021 : /*
1022 : * Set up housekeeping before setting up workqueues to allow the unbound
1023 : * workqueue to take non-housekeeping into account.
1024 : */
1025 : housekeeping_init();
1026 :
1027 : /*
1028 : * Allow workqueue creation and work item queueing/cancelling
1029 : * early. Work item execution depends on kthreads and starts after
1030 : * workqueue_init().
1031 : */
1032 1 : workqueue_init_early();
1033 :
1034 1 : rcu_init();
1035 :
1036 : /* Trace events are available after this */
1037 : trace_init();
1038 :
1039 : if (initcall_debug)
1040 : initcall_debug_enable();
1041 :
1042 : context_tracking_init();
1043 : /* init some links before init_ISA_irqs() */
1044 1 : early_irq_init();
1045 1 : init_IRQ();
1046 1 : tick_init();
1047 : rcu_init_nohz();
1048 1 : init_timers();
1049 1 : srcu_init();
1050 1 : hrtimers_init();
1051 1 : softirq_init();
1052 1 : timekeeping_init();
1053 1 : time_init();
1054 :
1055 : /* This must be after timekeeping is initialized */
1056 1 : random_init();
1057 :
1058 : /* These make use of the fully initialized rng */
1059 : kfence_init();
1060 : boot_init_stack_canary();
1061 :
1062 : perf_event_init();
1063 : profile_init();
1064 : call_function_init();
1065 1 : WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1066 :
1067 1 : early_boot_irqs_disabled = false;
1068 : local_irq_enable();
1069 :
1070 1 : kmem_cache_init_late();
1071 :
1072 : /*
1073 : * HACK ALERT! This is early. We're enabling the console before
1074 : * we've done PCI setups etc, and console_init() must be aware of
1075 : * this. But we do want output early, in case something goes wrong.
1076 : */
1077 1 : console_init();
1078 1 : if (panic_later)
1079 0 : panic("Too many boot %s vars at `%s'", panic_later,
1080 : panic_param);
1081 :
1082 : lockdep_init();
1083 :
1084 : /*
1085 : * Need to run this when irqs are enabled, because it wants
1086 : * to self-test [hard/soft]-irqs on/off lock inversion bugs
1087 : * too:
1088 : */
1089 : locking_selftest();
1090 :
1091 : /*
1092 : * This needs to be called before any devices perform DMA
1093 : * operations that might use the SWIOTLB bounce buffers. It will
1094 : * mark the bounce buffers as decrypted so that their usage will
1095 : * not cause "plain-text" data to be decrypted when accessed.
1096 : */
1097 1 : mem_encrypt_init();
1098 :
1099 : #ifdef CONFIG_BLK_DEV_INITRD
1100 : if (initrd_start && !initrd_below_start_ok &&
1101 : page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1102 : pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1103 : page_to_pfn(virt_to_page((void *)initrd_start)),
1104 : min_low_pfn);
1105 : initrd_start = 0;
1106 : }
1107 : #endif
1108 1 : setup_per_cpu_pageset();
1109 : numa_policy_init();
1110 : acpi_early_init();
1111 1 : if (late_time_init)
1112 1 : late_time_init();
1113 1 : sched_clock_init();
1114 1 : calibrate_delay();
1115 1 : pid_idr_init();
1116 1 : anon_vma_init();
1117 : #ifdef CONFIG_X86
1118 : if (efi_enabled(EFI_RUNTIME_SERVICES))
1119 : efi_enter_virtual_mode();
1120 : #endif
1121 1 : thread_stack_cache_init();
1122 1 : cred_init();
1123 1 : fork_init();
1124 1 : proc_caches_init();
1125 1 : uts_ns_init();
1126 : key_init();
1127 : security_init();
1128 : dbg_late_init();
1129 : net_ns_init();
1130 1 : vfs_caches_init();
1131 1 : pagecache_init();
1132 1 : signals_init();
1133 1 : seq_file_init();
1134 1 : proc_root_init();
1135 1 : nsfs_init();
1136 : cpuset_init();
1137 : cgroup_init();
1138 : taskstats_init_early();
1139 : delayacct_init();
1140 :
1141 1 : check_bugs();
1142 :
1143 : acpi_subsystem_init();
1144 1 : arch_post_acpi_subsys_init();
1145 : kcsan_init();
1146 :
1147 : /* Do the rest non-__init'ed, we're now alive */
1148 1 : arch_call_rest_init();
1149 :
1150 0 : prevent_tail_call_optimization();
1151 0 : }
1152 :
1153 : /* Call all constructor functions linked into the kernel. */
1154 : static void __init do_ctors(void)
1155 : {
1156 : /*
1157 : * For UML, the constructors have already been called by the
1158 : * normal setup code as it's just a normal ELF binary, so we
1159 : * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1160 : * even on UML for modules.
1161 : */
1162 : #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1163 : ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1164 :
1165 : for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1166 : (*fn)();
1167 : #endif
1168 : }
1169 :
1170 : #ifdef CONFIG_KALLSYMS
1171 : struct blacklist_entry {
1172 : struct list_head next;
1173 : char *buf;
1174 : };
1175 :
1176 : static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1177 :
1178 0 : static int __init initcall_blacklist(char *str)
1179 : {
1180 : char *str_entry;
1181 : struct blacklist_entry *entry;
1182 :
1183 : /* str argument is a comma-separated list of functions */
1184 : do {
1185 0 : str_entry = strsep(&str, ",");
1186 0 : if (str_entry) {
1187 0 : pr_debug("blacklisting initcall %s\n", str_entry);
1188 0 : entry = memblock_alloc(sizeof(*entry),
1189 : SMP_CACHE_BYTES);
1190 0 : if (!entry)
1191 0 : panic("%s: Failed to allocate %zu bytes\n",
1192 : __func__, sizeof(*entry));
1193 0 : entry->buf = memblock_alloc(strlen(str_entry) + 1,
1194 : SMP_CACHE_BYTES);
1195 0 : if (!entry->buf)
1196 0 : panic("%s: Failed to allocate %zu bytes\n",
1197 0 : __func__, strlen(str_entry) + 1);
1198 0 : strcpy(entry->buf, str_entry);
1199 0 : list_add(&entry->next, &blacklisted_initcalls);
1200 : }
1201 0 : } while (str_entry);
1202 :
1203 0 : return 1;
1204 : }
1205 :
1206 178 : static bool __init_or_module initcall_blacklisted(initcall_t fn)
1207 : {
1208 : struct blacklist_entry *entry;
1209 : char fn_name[KSYM_SYMBOL_LEN];
1210 : unsigned long addr;
1211 :
1212 178 : if (list_empty(&blacklisted_initcalls))
1213 : return false;
1214 :
1215 0 : addr = (unsigned long) dereference_function_descriptor(fn);
1216 0 : sprint_symbol_no_offset(fn_name, addr);
1217 :
1218 : /*
1219 : * fn will be "function_name [module_name]" where [module_name] is not
1220 : * displayed for built-in init functions. Strip off the [module_name].
1221 : */
1222 0 : strreplace(fn_name, ' ', '\0');
1223 :
1224 0 : list_for_each_entry(entry, &blacklisted_initcalls, next) {
1225 0 : if (!strcmp(fn_name, entry->buf)) {
1226 0 : pr_debug("initcall %s blacklisted\n", fn_name);
1227 0 : return true;
1228 : }
1229 : }
1230 :
1231 : return false;
1232 : }
1233 : #else
1234 : static int __init initcall_blacklist(char *str)
1235 : {
1236 : pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1237 : return 0;
1238 : }
1239 :
1240 : static bool __init_or_module initcall_blacklisted(initcall_t fn)
1241 : {
1242 : return false;
1243 : }
1244 : #endif
1245 : __setup("initcall_blacklist=", initcall_blacklist);
1246 :
1247 : static __init_or_module void
1248 0 : trace_initcall_start_cb(void *data, initcall_t fn)
1249 : {
1250 0 : ktime_t *calltime = data;
1251 :
1252 0 : printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1253 0 : *calltime = ktime_get();
1254 0 : }
1255 :
1256 : static __init_or_module void
1257 0 : trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1258 : {
1259 0 : ktime_t rettime, *calltime = data;
1260 :
1261 0 : rettime = ktime_get();
1262 0 : printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1263 : fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1264 0 : }
1265 :
1266 : static ktime_t initcall_calltime;
1267 :
1268 : #ifdef TRACEPOINTS_ENABLED
1269 : static void __init initcall_debug_enable(void)
1270 : {
1271 : int ret;
1272 :
1273 : ret = register_trace_initcall_start(trace_initcall_start_cb,
1274 : &initcall_calltime);
1275 : ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1276 : &initcall_calltime);
1277 : WARN(ret, "Failed to register initcall tracepoints\n");
1278 : }
1279 : # define do_trace_initcall_start trace_initcall_start
1280 : # define do_trace_initcall_finish trace_initcall_finish
1281 : #else
1282 : static inline void do_trace_initcall_start(initcall_t fn)
1283 : {
1284 178 : if (!initcall_debug)
1285 : return;
1286 0 : trace_initcall_start_cb(&initcall_calltime, fn);
1287 : }
1288 : static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1289 : {
1290 178 : if (!initcall_debug)
1291 : return;
1292 0 : trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1293 : }
1294 : #endif /* !TRACEPOINTS_ENABLED */
1295 :
1296 178 : int __init_or_module do_one_initcall(initcall_t fn)
1297 : {
1298 178 : int count = preempt_count();
1299 : char msgbuf[64];
1300 : int ret;
1301 :
1302 178 : if (initcall_blacklisted(fn))
1303 : return -EPERM;
1304 :
1305 178 : do_trace_initcall_start(fn);
1306 178 : ret = fn();
1307 178 : do_trace_initcall_finish(fn, ret);
1308 :
1309 178 : msgbuf[0] = 0;
1310 :
1311 178 : if (preempt_count() != count) {
1312 0 : sprintf(msgbuf, "preemption imbalance ");
1313 : preempt_count_set(count);
1314 : }
1315 178 : if (irqs_disabled()) {
1316 0 : strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1317 : local_irq_enable();
1318 : }
1319 178 : WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1320 :
1321 : add_latent_entropy();
1322 178 : return ret;
1323 : }
1324 :
1325 :
1326 : extern initcall_entry_t __initcall_start[];
1327 : extern initcall_entry_t __initcall0_start[];
1328 : extern initcall_entry_t __initcall1_start[];
1329 : extern initcall_entry_t __initcall2_start[];
1330 : extern initcall_entry_t __initcall3_start[];
1331 : extern initcall_entry_t __initcall4_start[];
1332 : extern initcall_entry_t __initcall5_start[];
1333 : extern initcall_entry_t __initcall6_start[];
1334 : extern initcall_entry_t __initcall7_start[];
1335 : extern initcall_entry_t __initcall_end[];
1336 :
1337 : static initcall_entry_t *initcall_levels[] __initdata = {
1338 : __initcall0_start,
1339 : __initcall1_start,
1340 : __initcall2_start,
1341 : __initcall3_start,
1342 : __initcall4_start,
1343 : __initcall5_start,
1344 : __initcall6_start,
1345 : __initcall7_start,
1346 : __initcall_end,
1347 : };
1348 :
1349 : /* Keep these in sync with initcalls in include/linux/init.h */
1350 : static const char *initcall_level_names[] __initdata = {
1351 : "pure",
1352 : "core",
1353 : "postcore",
1354 : "arch",
1355 : "subsys",
1356 : "fs",
1357 : "device",
1358 : "late",
1359 : };
1360 :
1361 24 : static int __init ignore_unknown_bootoption(char *param, char *val,
1362 : const char *unused, void *arg)
1363 : {
1364 24 : return 0;
1365 : }
1366 :
1367 8 : static void __init do_initcall_level(int level, char *command_line)
1368 : {
1369 : initcall_entry_t *fn;
1370 :
1371 16 : parse_args(initcall_level_names[level],
1372 : command_line, __start___param,
1373 8 : __stop___param - __start___param,
1374 : level, level,
1375 : NULL, ignore_unknown_bootoption);
1376 :
1377 8 : trace_initcall_level(initcall_level_names[level]);
1378 181 : for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1379 173 : do_one_initcall(initcall_from_entry(fn));
1380 8 : }
1381 :
1382 1 : static void __init do_initcalls(void)
1383 : {
1384 : int level;
1385 1 : size_t len = saved_command_line_len + 1;
1386 : char *command_line;
1387 :
1388 1 : command_line = kzalloc(len, GFP_KERNEL);
1389 1 : if (!command_line)
1390 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1391 :
1392 8 : for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1393 : /* Parser modifies command_line, restore it each time */
1394 8 : strcpy(command_line, saved_command_line);
1395 8 : do_initcall_level(level, command_line);
1396 : }
1397 :
1398 1 : kfree(command_line);
1399 1 : }
1400 :
1401 : /*
1402 : * Ok, the machine is now initialized. None of the devices
1403 : * have been touched yet, but the CPU subsystem is up and
1404 : * running, and memory and process management works.
1405 : *
1406 : * Now we can finally start doing some real work..
1407 : */
1408 1 : static void __init do_basic_setup(void)
1409 : {
1410 : cpuset_init_smp();
1411 1 : driver_init();
1412 1 : init_irq_proc();
1413 : do_ctors();
1414 1 : do_initcalls();
1415 1 : }
1416 :
1417 1 : static void __init do_pre_smp_initcalls(void)
1418 : {
1419 : initcall_entry_t *fn;
1420 :
1421 1 : trace_initcall_level("early");
1422 6 : for (fn = __initcall_start; fn < __initcall0_start; fn++)
1423 5 : do_one_initcall(initcall_from_entry(fn));
1424 1 : }
1425 :
1426 0 : static int run_init_process(const char *init_filename)
1427 : {
1428 : const char *const *p;
1429 :
1430 0 : argv_init[0] = init_filename;
1431 0 : pr_info("Run %s as init process\n", init_filename);
1432 0 : pr_debug(" with arguments:\n");
1433 0 : for (p = argv_init; *p; p++)
1434 0 : pr_debug(" %s\n", *p);
1435 0 : pr_debug(" with environment:\n");
1436 0 : for (p = envp_init; *p; p++)
1437 0 : pr_debug(" %s\n", *p);
1438 0 : return kernel_execve(init_filename, argv_init, envp_init);
1439 : }
1440 :
1441 0 : static int try_to_run_init_process(const char *init_filename)
1442 : {
1443 : int ret;
1444 :
1445 0 : ret = run_init_process(init_filename);
1446 :
1447 0 : if (ret && ret != -ENOENT) {
1448 0 : pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1449 : init_filename, ret);
1450 : }
1451 :
1452 0 : return ret;
1453 : }
1454 :
1455 : static noinline void __init kernel_init_freeable(void);
1456 :
1457 : #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1458 : bool rodata_enabled __ro_after_init = true;
1459 :
1460 : #ifndef arch_parse_debug_rodata
1461 : static inline bool arch_parse_debug_rodata(char *str) { return false; }
1462 : #endif
1463 :
1464 : static int __init set_debug_rodata(char *str)
1465 : {
1466 : if (arch_parse_debug_rodata(str))
1467 : return 0;
1468 :
1469 : if (str && !strcmp(str, "on"))
1470 : rodata_enabled = true;
1471 : else if (str && !strcmp(str, "off"))
1472 : rodata_enabled = false;
1473 : else
1474 : pr_warn("Invalid option string for rodata: '%s'\n", str);
1475 : return 0;
1476 : }
1477 : early_param("rodata", set_debug_rodata);
1478 : #endif
1479 :
1480 : #ifdef CONFIG_STRICT_KERNEL_RWX
1481 : static void mark_readonly(void)
1482 : {
1483 : if (rodata_enabled) {
1484 : /*
1485 : * load_module() results in W+X mappings, which are cleaned
1486 : * up with call_rcu(). Let's make sure that queued work is
1487 : * flushed so that we don't hit false positives looking for
1488 : * insecure pages which are W+X.
1489 : */
1490 : rcu_barrier();
1491 : mark_rodata_ro();
1492 : rodata_test();
1493 : } else
1494 : pr_info("Kernel memory protection disabled.\n");
1495 : }
1496 : #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1497 : static inline void mark_readonly(void)
1498 : {
1499 : pr_warn("Kernel memory protection not selected by kernel config.\n");
1500 : }
1501 : #else
1502 : static inline void mark_readonly(void)
1503 : {
1504 0 : pr_warn("This architecture does not have kernel memory protection.\n");
1505 : }
1506 : #endif
1507 :
1508 0 : void __weak free_initmem(void)
1509 : {
1510 0 : free_initmem_default(POISON_FREE_INITMEM);
1511 0 : }
1512 :
1513 1 : static int __ref kernel_init(void *unused)
1514 : {
1515 : int ret;
1516 :
1517 : /*
1518 : * Wait until kthreadd is all set-up.
1519 : */
1520 1 : wait_for_completion(&kthreadd_done);
1521 :
1522 1 : kernel_init_freeable();
1523 : /* need to finish all async __init code before freeing the memory */
1524 0 : async_synchronize_full();
1525 :
1526 0 : system_state = SYSTEM_FREEING_INITMEM;
1527 : kprobe_free_init_mem();
1528 : ftrace_free_init_mem();
1529 : kgdb_free_init_mem();
1530 : exit_boot_config();
1531 0 : free_initmem();
1532 : mark_readonly();
1533 :
1534 : /*
1535 : * Kernel mappings are now finalized - update the userspace page-table
1536 : * to finalize PTI.
1537 : */
1538 : pti_finalize();
1539 :
1540 0 : system_state = SYSTEM_RUNNING;
1541 : numa_default_policy();
1542 :
1543 : rcu_end_inkernel_boot();
1544 :
1545 0 : do_sysctl_args();
1546 :
1547 0 : if (ramdisk_execute_command) {
1548 0 : ret = run_init_process(ramdisk_execute_command);
1549 0 : if (!ret)
1550 : return 0;
1551 0 : pr_err("Failed to execute %s (error %d)\n",
1552 : ramdisk_execute_command, ret);
1553 : }
1554 :
1555 : /*
1556 : * We try each of these until one succeeds.
1557 : *
1558 : * The Bourne shell can be used instead of init if we are
1559 : * trying to recover a really broken machine.
1560 : */
1561 0 : if (execute_command) {
1562 0 : ret = run_init_process(execute_command);
1563 0 : if (!ret)
1564 : return 0;
1565 0 : panic("Requested init %s failed (error %d).",
1566 : execute_command, ret);
1567 : }
1568 :
1569 : if (CONFIG_DEFAULT_INIT[0] != '\0') {
1570 : ret = run_init_process(CONFIG_DEFAULT_INIT);
1571 : if (ret)
1572 : pr_err("Default init %s failed (error %d)\n",
1573 : CONFIG_DEFAULT_INIT, ret);
1574 : else
1575 : return 0;
1576 : }
1577 :
1578 0 : if (!try_to_run_init_process("/sbin/init") ||
1579 0 : !try_to_run_init_process("/etc/init") ||
1580 0 : !try_to_run_init_process("/bin/init") ||
1581 0 : !try_to_run_init_process("/bin/sh"))
1582 : return 0;
1583 :
1584 0 : panic("No working init found. Try passing init= option to kernel. "
1585 : "See Linux Documentation/admin-guide/init.rst for guidance.");
1586 : }
1587 :
1588 : /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1589 0 : void __init console_on_rootfs(void)
1590 : {
1591 0 : struct file *file = filp_open("/dev/console", O_RDWR, 0);
1592 :
1593 0 : if (IS_ERR(file)) {
1594 0 : pr_err("Warning: unable to open an initial console.\n");
1595 0 : return;
1596 : }
1597 0 : init_dup(file);
1598 0 : init_dup(file);
1599 0 : init_dup(file);
1600 0 : fput(file);
1601 : }
1602 :
1603 1 : static noinline void __init kernel_init_freeable(void)
1604 : {
1605 : /* Now the scheduler is fully set up and can do blocking allocations */
1606 1 : gfp_allowed_mask = __GFP_BITS_MASK;
1607 :
1608 : /*
1609 : * init can allocate pages on any node
1610 : */
1611 1 : set_mems_allowed(node_states[N_MEMORY]);
1612 :
1613 2 : cad_pid = get_pid(task_pid(current));
1614 :
1615 1 : smp_prepare_cpus(setup_max_cpus);
1616 :
1617 1 : workqueue_init();
1618 :
1619 1 : init_mm_internals();
1620 :
1621 : rcu_init_tasks_generic();
1622 1 : do_pre_smp_initcalls();
1623 : lockup_detector_init();
1624 :
1625 : smp_init();
1626 1 : sched_init_smp();
1627 :
1628 : padata_init();
1629 1 : page_alloc_init_late();
1630 : /* Initialize page ext after all struct pages are initialized. */
1631 : if (deferred_struct_pages)
1632 : page_ext_init();
1633 :
1634 1 : do_basic_setup();
1635 :
1636 1 : kunit_run_all_tests();
1637 :
1638 : wait_for_initramfs();
1639 0 : console_on_rootfs();
1640 :
1641 : /*
1642 : * check if there is an early userspace init. If yes, let it do all
1643 : * the work
1644 : */
1645 0 : if (init_eaccess(ramdisk_execute_command) != 0) {
1646 0 : ramdisk_execute_command = NULL;
1647 0 : prepare_namespace();
1648 : }
1649 :
1650 : /*
1651 : * Ok, we have completed the initial bootup, and
1652 : * we're essentially up and running. Get rid of the
1653 : * initmem segments and start the user-mode stuff..
1654 : *
1655 : * rootfs is available now, try loading the public keys
1656 : * and default modules
1657 : */
1658 :
1659 : integrity_load_keys();
1660 0 : }
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