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/debug_locks.h>
66 : #include <linux/debugobjects.h>
67 : #include <linux/lockdep.h>
68 : #include <linux/kmemleak.h>
69 : #include <linux/padata.h>
70 : #include <linux/pid_namespace.h>
71 : #include <linux/device/driver.h>
72 : #include <linux/kthread.h>
73 : #include <linux/sched.h>
74 : #include <linux/sched/init.h>
75 : #include <linux/signal.h>
76 : #include <linux/idr.h>
77 : #include <linux/kgdb.h>
78 : #include <linux/ftrace.h>
79 : #include <linux/async.h>
80 : #include <linux/shmem_fs.h>
81 : #include <linux/slab.h>
82 : #include <linux/perf_event.h>
83 : #include <linux/ptrace.h>
84 : #include <linux/pti.h>
85 : #include <linux/blkdev.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 : #include <linux/stackdepot.h>
102 : #include <linux/randomize_kstack.h>
103 : #include <net/net_namespace.h>
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 : extern void maple_tree_init(void);
121 :
122 : /*
123 : * Debug helper: via this flag we know that we are in 'early bootup code'
124 : * where only the boot processor is running with IRQ disabled. This means
125 : * two things - IRQ must not be enabled before the flag is cleared and some
126 : * operations which are not allowed with IRQ disabled are allowed while the
127 : * flag is set.
128 : */
129 : bool early_boot_irqs_disabled __read_mostly;
130 :
131 : enum system_states system_state __read_mostly;
132 : EXPORT_SYMBOL(system_state);
133 :
134 : /*
135 : * Boot command-line arguments
136 : */
137 : #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
138 : #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
139 :
140 : extern void time_init(void);
141 : /* Default late time init is NULL. archs can override this later. */
142 : void (*__initdata late_time_init)(void);
143 :
144 : /* Untouched command line saved by arch-specific code. */
145 : char __initdata boot_command_line[COMMAND_LINE_SIZE];
146 : /* Untouched saved command line (eg. for /proc) */
147 : char *saved_command_line __ro_after_init;
148 : unsigned int saved_command_line_len __ro_after_init;
149 : /* Command line for parameter parsing */
150 : static char *static_command_line;
151 : /* Untouched extra command line */
152 : static char *extra_command_line;
153 : /* Extra init arguments */
154 : static char *extra_init_args;
155 :
156 : #ifdef CONFIG_BOOT_CONFIG
157 : /* Is bootconfig on command line? */
158 : static bool bootconfig_found;
159 : static size_t initargs_offs;
160 : #else
161 : # define bootconfig_found false
162 : # define initargs_offs 0
163 : #endif
164 :
165 : static char *execute_command;
166 : static char *ramdisk_execute_command = "/init";
167 :
168 : /*
169 : * Used to generate warnings if static_key manipulation functions are used
170 : * before jump_label_init is called.
171 : */
172 : bool static_key_initialized __read_mostly;
173 : EXPORT_SYMBOL_GPL(static_key_initialized);
174 :
175 : /*
176 : * If set, this is an indication to the drivers that reset the underlying
177 : * device before going ahead with the initialization otherwise driver might
178 : * rely on the BIOS and skip the reset operation.
179 : *
180 : * This is useful if kernel is booting in an unreliable environment.
181 : * For ex. kdump situation where previous kernel has crashed, BIOS has been
182 : * skipped and devices will be in unknown state.
183 : */
184 : unsigned int reset_devices;
185 : EXPORT_SYMBOL(reset_devices);
186 :
187 0 : static int __init set_reset_devices(char *str)
188 : {
189 0 : reset_devices = 1;
190 0 : return 1;
191 : }
192 :
193 : __setup("reset_devices", set_reset_devices);
194 :
195 : static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
196 : const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
197 : static const char *panic_later, *panic_param;
198 :
199 : extern const struct obs_kernel_param __setup_start[], __setup_end[];
200 :
201 3 : static bool __init obsolete_checksetup(char *line)
202 : {
203 : const struct obs_kernel_param *p;
204 3 : bool had_early_param = false;
205 :
206 3 : p = __setup_start;
207 : do {
208 133 : int n = strlen(p->str);
209 133 : if (parameqn(line, p->str, n)) {
210 3 : if (p->early) {
211 : /* Already done in parse_early_param?
212 : * (Needs exact match on param part).
213 : * Keep iterating, as we can have early
214 : * params and __setups of same names 8( */
215 0 : if (line[n] == '\0' || line[n] == '=')
216 0 : had_early_param = true;
217 3 : } else if (!p->setup_func) {
218 0 : pr_warn("Parameter %s is obsolete, ignored\n",
219 : p->str);
220 0 : return true;
221 3 : } else if (p->setup_func(line + n))
222 : return true;
223 : }
224 131 : p++;
225 131 : } while (p < __setup_end);
226 :
227 : return had_early_param;
228 : }
229 :
230 : /*
231 : * This should be approx 2 Bo*oMips to start (note initial shift), and will
232 : * still work even if initially too large, it will just take slightly longer
233 : */
234 : unsigned long loops_per_jiffy = (1<<12);
235 : EXPORT_SYMBOL(loops_per_jiffy);
236 :
237 0 : static int __init debug_kernel(char *str)
238 : {
239 0 : console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
240 0 : return 0;
241 : }
242 :
243 0 : static int __init quiet_kernel(char *str)
244 : {
245 0 : console_loglevel = CONSOLE_LOGLEVEL_QUIET;
246 0 : return 0;
247 : }
248 :
249 : early_param("debug", debug_kernel);
250 : early_param("quiet", quiet_kernel);
251 :
252 0 : static int __init loglevel(char *str)
253 : {
254 : int newlevel;
255 :
256 : /*
257 : * Only update loglevel value when a correct setting was passed,
258 : * to prevent blind crashes (when loglevel being set to 0) that
259 : * are quite hard to debug
260 : */
261 0 : if (get_option(&str, &newlevel)) {
262 0 : console_loglevel = newlevel;
263 0 : return 0;
264 : }
265 :
266 : return -EINVAL;
267 : }
268 :
269 : early_param("loglevel", loglevel);
270 :
271 : #ifdef CONFIG_BLK_DEV_INITRD
272 : static void * __init get_boot_config_from_initrd(size_t *_size)
273 : {
274 : u32 size, csum;
275 : char *data;
276 : u32 *hdr;
277 : int i;
278 :
279 : if (!initrd_end)
280 : return NULL;
281 :
282 : data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
283 : /*
284 : * Since Grub may align the size of initrd to 4, we must
285 : * check the preceding 3 bytes as well.
286 : */
287 : for (i = 0; i < 4; i++) {
288 : if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
289 : goto found;
290 : data--;
291 : }
292 : return NULL;
293 :
294 : found:
295 : hdr = (u32 *)(data - 8);
296 : size = le32_to_cpu(hdr[0]);
297 : csum = le32_to_cpu(hdr[1]);
298 :
299 : data = ((void *)hdr) - size;
300 : if ((unsigned long)data < initrd_start) {
301 : pr_err("bootconfig size %d is greater than initrd size %ld\n",
302 : size, initrd_end - initrd_start);
303 : return NULL;
304 : }
305 :
306 : if (xbc_calc_checksum(data, size) != csum) {
307 : pr_err("bootconfig checksum failed\n");
308 : return NULL;
309 : }
310 :
311 : /* Remove bootconfig from initramfs/initrd */
312 : initrd_end = (unsigned long)data;
313 : if (_size)
314 : *_size = size;
315 :
316 : return data;
317 : }
318 : #else
319 : static void * __init get_boot_config_from_initrd(size_t *_size)
320 : {
321 : return NULL;
322 : }
323 : #endif
324 :
325 : #ifdef CONFIG_BOOT_CONFIG
326 :
327 : static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
328 :
329 : #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
330 :
331 : static int __init xbc_snprint_cmdline(char *buf, size_t size,
332 : struct xbc_node *root)
333 : {
334 : struct xbc_node *knode, *vnode;
335 : char *end = buf + size;
336 : const char *val;
337 : int ret;
338 :
339 : xbc_node_for_each_key_value(root, knode, val) {
340 : ret = xbc_node_compose_key_after(root, knode,
341 : xbc_namebuf, XBC_KEYLEN_MAX);
342 : if (ret < 0)
343 : return ret;
344 :
345 : vnode = xbc_node_get_child(knode);
346 : if (!vnode) {
347 : ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
348 : if (ret < 0)
349 : return ret;
350 : buf += ret;
351 : continue;
352 : }
353 : xbc_array_for_each_value(vnode, val) {
354 : ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
355 : xbc_namebuf, val);
356 : if (ret < 0)
357 : return ret;
358 : buf += ret;
359 : }
360 : }
361 :
362 : return buf - (end - size);
363 : }
364 : #undef rest
365 :
366 : /* Make an extra command line under given key word */
367 : static char * __init xbc_make_cmdline(const char *key)
368 : {
369 : struct xbc_node *root;
370 : char *new_cmdline;
371 : int ret, len = 0;
372 :
373 : root = xbc_find_node(key);
374 : if (!root)
375 : return NULL;
376 :
377 : /* Count required buffer size */
378 : len = xbc_snprint_cmdline(NULL, 0, root);
379 : if (len <= 0)
380 : return NULL;
381 :
382 : new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
383 : if (!new_cmdline) {
384 : pr_err("Failed to allocate memory for extra kernel cmdline.\n");
385 : return NULL;
386 : }
387 :
388 : ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
389 : if (ret < 0 || ret > len) {
390 : pr_err("Failed to print extra kernel cmdline.\n");
391 : memblock_free(new_cmdline, len + 1);
392 : return NULL;
393 : }
394 :
395 : return new_cmdline;
396 : }
397 :
398 : static int __init bootconfig_params(char *param, char *val,
399 : const char *unused, void *arg)
400 : {
401 : if (strcmp(param, "bootconfig") == 0) {
402 : bootconfig_found = true;
403 : }
404 : return 0;
405 : }
406 :
407 : static int __init warn_bootconfig(char *str)
408 : {
409 : /* The 'bootconfig' has been handled by bootconfig_params(). */
410 : return 0;
411 : }
412 :
413 : static void __init setup_boot_config(void)
414 : {
415 : static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
416 : const char *msg, *data;
417 : int pos, ret;
418 : size_t size;
419 : char *err;
420 :
421 : /* Cut out the bootconfig data even if we have no bootconfig option */
422 : data = get_boot_config_from_initrd(&size);
423 : /* If there is no bootconfig in initrd, try embedded one. */
424 : if (!data)
425 : data = xbc_get_embedded_bootconfig(&size);
426 :
427 : strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
428 : err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
429 : bootconfig_params);
430 :
431 : if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
432 : return;
433 :
434 : /* parse_args() stops at the next param of '--' and returns an address */
435 : if (err)
436 : initargs_offs = err - tmp_cmdline;
437 :
438 : if (!data) {
439 : /* If user intended to use bootconfig, show an error level message */
440 : if (bootconfig_found)
441 : pr_err("'bootconfig' found on command line, but no bootconfig found\n");
442 : else
443 : pr_info("No bootconfig data provided, so skipping bootconfig");
444 : return;
445 : }
446 :
447 : if (size >= XBC_DATA_MAX) {
448 : pr_err("bootconfig size %ld greater than max size %d\n",
449 : (long)size, XBC_DATA_MAX);
450 : return;
451 : }
452 :
453 : ret = xbc_init(data, size, &msg, &pos);
454 : if (ret < 0) {
455 : if (pos < 0)
456 : pr_err("Failed to init bootconfig: %s.\n", msg);
457 : else
458 : pr_err("Failed to parse bootconfig: %s at %d.\n",
459 : msg, pos);
460 : } else {
461 : xbc_get_info(&ret, NULL);
462 : pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
463 : /* keys starting with "kernel." are passed via cmdline */
464 : extra_command_line = xbc_make_cmdline("kernel");
465 : /* Also, "init." keys are init arguments */
466 : extra_init_args = xbc_make_cmdline("init");
467 : }
468 : return;
469 : }
470 :
471 : static void __init exit_boot_config(void)
472 : {
473 : xbc_exit();
474 : }
475 :
476 : #else /* !CONFIG_BOOT_CONFIG */
477 :
478 : static void __init setup_boot_config(void)
479 : {
480 : /* Remove bootconfig data from initrd */
481 1 : get_boot_config_from_initrd(NULL);
482 : }
483 :
484 0 : static int __init warn_bootconfig(char *str)
485 : {
486 0 : pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
487 0 : return 0;
488 : }
489 :
490 : #define exit_boot_config() do {} while (0)
491 :
492 : #endif /* CONFIG_BOOT_CONFIG */
493 :
494 : early_param("bootconfig", warn_bootconfig);
495 :
496 : /* Change NUL term back to "=", to make "param" the whole string. */
497 3 : static void __init repair_env_string(char *param, char *val)
498 : {
499 3 : if (val) {
500 : /* param=val or param="val"? */
501 3 : if (val == param+strlen(param)+1)
502 3 : val[-1] = '=';
503 0 : else if (val == param+strlen(param)+2) {
504 0 : val[-2] = '=';
505 0 : memmove(val-1, val, strlen(val)+1);
506 : } else
507 0 : BUG();
508 : }
509 3 : }
510 :
511 : /* Anything after -- gets handed straight to init. */
512 0 : static int __init set_init_arg(char *param, char *val,
513 : const char *unused, void *arg)
514 : {
515 : unsigned int i;
516 :
517 0 : if (panic_later)
518 : return 0;
519 :
520 0 : repair_env_string(param, val);
521 :
522 0 : for (i = 0; argv_init[i]; i++) {
523 0 : if (i == MAX_INIT_ARGS) {
524 0 : panic_later = "init";
525 0 : panic_param = param;
526 0 : return 0;
527 : }
528 : }
529 0 : argv_init[i] = param;
530 0 : return 0;
531 : }
532 :
533 : /*
534 : * Unknown boot options get handed to init, unless they look like
535 : * unused parameters (modprobe will find them in /proc/cmdline).
536 : */
537 3 : static int __init unknown_bootoption(char *param, char *val,
538 : const char *unused, void *arg)
539 : {
540 3 : size_t len = strlen(param);
541 :
542 3 : repair_env_string(param, val);
543 :
544 : /* Handle obsolete-style parameters */
545 3 : if (obsolete_checksetup(param))
546 : return 0;
547 :
548 : /* Unused module parameter. */
549 1 : if (strnchr(param, len, '.'))
550 : return 0;
551 :
552 1 : if (panic_later)
553 : return 0;
554 :
555 1 : if (val) {
556 : /* Environment option */
557 : unsigned int i;
558 2 : for (i = 0; envp_init[i]; i++) {
559 2 : if (i == MAX_INIT_ENVS) {
560 0 : panic_later = "env";
561 0 : panic_param = param;
562 : }
563 2 : if (!strncmp(param, envp_init[i], len+1))
564 : break;
565 : }
566 1 : envp_init[i] = param;
567 : } else {
568 : /* Command line option */
569 : unsigned int i;
570 0 : for (i = 0; argv_init[i]; i++) {
571 0 : if (i == MAX_INIT_ARGS) {
572 0 : panic_later = "init";
573 0 : panic_param = param;
574 : }
575 : }
576 0 : argv_init[i] = param;
577 : }
578 : return 0;
579 : }
580 :
581 0 : static int __init init_setup(char *str)
582 : {
583 : unsigned int i;
584 :
585 0 : execute_command = str;
586 : /*
587 : * In case LILO is going to boot us with default command line,
588 : * it prepends "auto" before the whole cmdline which makes
589 : * the shell think it should execute a script with such name.
590 : * So we ignore all arguments entered _before_ init=... [MJ]
591 : */
592 0 : for (i = 1; i < MAX_INIT_ARGS; i++)
593 0 : argv_init[i] = NULL;
594 0 : return 1;
595 : }
596 : __setup("init=", init_setup);
597 :
598 0 : static int __init rdinit_setup(char *str)
599 : {
600 : unsigned int i;
601 :
602 0 : ramdisk_execute_command = str;
603 : /* See "auto" comment in init_setup */
604 0 : for (i = 1; i < MAX_INIT_ARGS; i++)
605 0 : argv_init[i] = NULL;
606 0 : return 1;
607 : }
608 : __setup("rdinit=", rdinit_setup);
609 :
610 : #ifndef CONFIG_SMP
611 : static const unsigned int setup_max_cpus = NR_CPUS;
612 : static inline void setup_nr_cpu_ids(void) { }
613 : static inline void smp_prepare_cpus(unsigned int maxcpus) { }
614 : #endif
615 :
616 : /*
617 : * We need to store the untouched command line for future reference.
618 : * We also need to store the touched command line since the parameter
619 : * parsing is performed in place, and we should allow a component to
620 : * store reference of name/value for future reference.
621 : */
622 1 : static void __init setup_command_line(char *command_line)
623 : {
624 1 : size_t len, xlen = 0, ilen = 0;
625 :
626 1 : if (extra_command_line)
627 0 : xlen = strlen(extra_command_line);
628 1 : if (extra_init_args)
629 0 : ilen = strlen(extra_init_args) + 4; /* for " -- " */
630 :
631 1 : len = xlen + strlen(boot_command_line) + 1;
632 :
633 2 : saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
634 1 : if (!saved_command_line)
635 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
636 :
637 1 : static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
638 1 : if (!static_command_line)
639 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len);
640 :
641 1 : if (xlen) {
642 : /*
643 : * We have to put extra_command_line before boot command
644 : * lines because there could be dashes (separator of init
645 : * command line) in the command lines.
646 : */
647 0 : strcpy(saved_command_line, extra_command_line);
648 0 : strcpy(static_command_line, extra_command_line);
649 : }
650 1 : strcpy(saved_command_line + xlen, boot_command_line);
651 1 : strcpy(static_command_line + xlen, command_line);
652 :
653 1 : if (ilen) {
654 : /*
655 : * Append supplemental init boot args to saved_command_line
656 : * so that user can check what command line options passed
657 : * to init.
658 : * The order should always be
659 : * " -- "[bootconfig init-param][cmdline init-param]
660 : */
661 : if (initargs_offs) {
662 : len = xlen + initargs_offs;
663 : strcpy(saved_command_line + len, extra_init_args);
664 : len += ilen - 4; /* strlen(extra_init_args) */
665 : strcpy(saved_command_line + len,
666 : boot_command_line + initargs_offs - 1);
667 : } else {
668 0 : len = strlen(saved_command_line);
669 0 : strcpy(saved_command_line + len, " -- ");
670 0 : len += 4;
671 0 : strcpy(saved_command_line + len, extra_init_args);
672 : }
673 : }
674 :
675 1 : saved_command_line_len = strlen(saved_command_line);
676 1 : }
677 :
678 : /*
679 : * We need to finalize in a non-__init function or else race conditions
680 : * between the root thread and the init thread may cause start_kernel to
681 : * be reaped by free_initmem before the root thread has proceeded to
682 : * cpu_idle.
683 : *
684 : * gcc-3.4 accidentally inlines this function, so use noinline.
685 : */
686 :
687 : static __initdata DECLARE_COMPLETION(kthreadd_done);
688 :
689 1 : noinline void __ref __noreturn rest_init(void)
690 : {
691 : struct task_struct *tsk;
692 : int pid;
693 :
694 1 : rcu_scheduler_starting();
695 : /*
696 : * We need to spawn init first so that it obtains pid 1, however
697 : * the init task will end up wanting to create kthreads, which, if
698 : * we schedule it before we create kthreadd, will OOPS.
699 : */
700 1 : pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
701 : /*
702 : * Pin init on the boot CPU. Task migration is not properly working
703 : * until sched_init_smp() has been run. It will set the allowed
704 : * CPUs for init to the non isolated CPUs.
705 : */
706 : rcu_read_lock();
707 1 : tsk = find_task_by_pid_ns(pid, &init_pid_ns);
708 1 : tsk->flags |= PF_NO_SETAFFINITY;
709 2 : set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
710 : rcu_read_unlock();
711 :
712 : numa_default_policy();
713 1 : pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
714 : rcu_read_lock();
715 1 : kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
716 : rcu_read_unlock();
717 :
718 : /*
719 : * Enable might_sleep() and smp_processor_id() checks.
720 : * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
721 : * kernel_thread() would trigger might_sleep() splats. With
722 : * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
723 : * already, but it's stuck on the kthreadd_done completion.
724 : */
725 1 : system_state = SYSTEM_SCHEDULING;
726 :
727 1 : complete(&kthreadd_done);
728 :
729 : /*
730 : * The boot idle thread must execute schedule()
731 : * at least once to get things moving:
732 : */
733 1 : schedule_preempt_disabled();
734 : /* Call into cpu_idle with preempt disabled */
735 0 : cpu_startup_entry(CPUHP_ONLINE);
736 : }
737 :
738 : /* Check for early params. */
739 5 : static int __init do_early_param(char *param, char *val,
740 : const char *unused, void *arg)
741 : {
742 : const struct obs_kernel_param *p;
743 :
744 420 : for (p = __setup_start; p < __setup_end; p++) {
745 830 : if ((p->early && parameq(param, p->str)) ||
746 498 : (strcmp(param, "console") == 0 &&
747 83 : strcmp(p->str, "earlycon") == 0)
748 : ) {
749 0 : if (p->setup_func(val) != 0)
750 0 : pr_warn("Malformed early option '%s'\n", param);
751 : }
752 : }
753 : /* We accept everything at this stage. */
754 5 : return 0;
755 : }
756 :
757 1 : void __init parse_early_options(char *cmdline)
758 : {
759 1 : parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
760 : do_early_param);
761 1 : }
762 :
763 : /* Arch code calls this early on, or if not, just before other parsing. */
764 1 : void __init parse_early_param(void)
765 : {
766 : static int done __initdata;
767 : static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
768 :
769 1 : if (done)
770 : return;
771 :
772 : /* All fall through to do_early_param. */
773 1 : strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
774 1 : parse_early_options(tmp_cmdline);
775 1 : done = 1;
776 : }
777 :
778 1 : void __init __weak arch_post_acpi_subsys_init(void) { }
779 :
780 1 : void __init __weak smp_setup_processor_id(void)
781 : {
782 1 : }
783 :
784 : # if THREAD_SIZE >= PAGE_SIZE
785 1 : void __init __weak thread_stack_cache_init(void)
786 : {
787 1 : }
788 : #endif
789 :
790 1 : void __init __weak mem_encrypt_init(void) { }
791 :
792 1 : void __init __weak poking_init(void) { }
793 :
794 1 : void __init __weak pgtable_cache_init(void) { }
795 :
796 1 : void __init __weak trap_init(void) { }
797 :
798 : bool initcall_debug;
799 : core_param(initcall_debug, initcall_debug, bool, 0644);
800 :
801 : #ifdef TRACEPOINTS_ENABLED
802 : static void __init initcall_debug_enable(void);
803 : #else
804 : static inline void initcall_debug_enable(void)
805 : {
806 : }
807 : #endif
808 :
809 : #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
810 : DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
811 : randomize_kstack_offset);
812 : DEFINE_PER_CPU(u32, kstack_offset);
813 :
814 : static int __init early_randomize_kstack_offset(char *buf)
815 : {
816 : int ret;
817 : bool bool_result;
818 :
819 : ret = kstrtobool(buf, &bool_result);
820 : if (ret)
821 : return ret;
822 :
823 : if (bool_result)
824 : static_branch_enable(&randomize_kstack_offset);
825 : else
826 : static_branch_disable(&randomize_kstack_offset);
827 : return 0;
828 : }
829 : early_param("randomize_kstack_offset", early_randomize_kstack_offset);
830 : #endif
831 :
832 1 : void __init __weak __noreturn arch_call_rest_init(void)
833 : {
834 1 : rest_init();
835 : }
836 :
837 1 : static void __init print_unknown_bootoptions(void)
838 : {
839 : char *unknown_options;
840 : char *end;
841 : const char *const *p;
842 : size_t len;
843 :
844 1 : if (panic_later || (!argv_init[1] && !envp_init[2]))
845 : return;
846 :
847 : /*
848 : * Determine how many options we have to print out, plus a space
849 : * before each
850 : */
851 : len = 1; /* null terminator */
852 0 : for (p = &argv_init[1]; *p; p++) {
853 0 : len++;
854 0 : len += strlen(*p);
855 : }
856 1 : for (p = &envp_init[2]; *p; p++) {
857 1 : len++;
858 1 : len += strlen(*p);
859 : }
860 :
861 1 : unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
862 1 : if (!unknown_options) {
863 0 : pr_err("%s: Failed to allocate %zu bytes\n",
864 : __func__, len);
865 0 : return;
866 : }
867 : end = unknown_options;
868 :
869 0 : for (p = &argv_init[1]; *p; p++)
870 0 : end += sprintf(end, " %s", *p);
871 1 : for (p = &envp_init[2]; *p; p++)
872 1 : end += sprintf(end, " %s", *p);
873 :
874 : /* Start at unknown_options[1] to skip the initial space */
875 1 : pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
876 : &unknown_options[1]);
877 1 : memblock_free(unknown_options, len);
878 : }
879 :
880 1 : asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(void)
881 : {
882 : char *command_line;
883 : char *after_dashes;
884 :
885 1 : set_task_stack_end_magic(&init_task);
886 1 : smp_setup_processor_id();
887 : debug_objects_early_init();
888 : init_vmlinux_build_id();
889 :
890 : cgroup_init_early();
891 :
892 : local_irq_disable();
893 1 : early_boot_irqs_disabled = true;
894 :
895 : /*
896 : * Interrupts are still disabled. Do necessary setups, then
897 : * enable them.
898 : */
899 1 : boot_cpu_init();
900 : page_address_init();
901 1 : pr_notice("%s", linux_banner);
902 : early_security_init();
903 1 : setup_arch(&command_line);
904 : setup_boot_config();
905 1 : setup_command_line(command_line);
906 : setup_nr_cpu_ids();
907 1 : setup_per_cpu_areas();
908 : smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
909 1 : boot_cpu_hotplug_init();
910 :
911 1 : pr_notice("Kernel command line: %s\n", saved_command_line);
912 : /* parameters may set static keys */
913 : jump_label_init();
914 1 : parse_early_param();
915 1 : after_dashes = parse_args("Booting kernel",
916 : static_command_line, __start___param,
917 1 : __stop___param - __start___param,
918 : -1, -1, NULL, &unknown_bootoption);
919 1 : print_unknown_bootoptions();
920 1 : if (!IS_ERR_OR_NULL(after_dashes))
921 0 : parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
922 : NULL, set_init_arg);
923 1 : if (extra_init_args)
924 0 : parse_args("Setting extra init args", extra_init_args,
925 : NULL, 0, -1, -1, NULL, set_init_arg);
926 :
927 : /* Architectural and non-timekeeping rng init, before allocator init */
928 1 : random_init_early(command_line);
929 :
930 : /*
931 : * These use large bootmem allocations and must precede
932 : * initalization of page allocator
933 : */
934 1 : setup_log_buf(0);
935 1 : vfs_caches_init_early();
936 1 : sort_main_extable();
937 1 : trap_init();
938 1 : mm_core_init();
939 1 : poking_init();
940 : ftrace_init();
941 :
942 : /* trace_printk can be enabled here */
943 : early_trace_init();
944 :
945 : /*
946 : * Set up the scheduler prior starting any interrupts (such as the
947 : * timer interrupt). Full topology setup happens at smp_init()
948 : * time - but meanwhile we still have a functioning scheduler.
949 : */
950 1 : sched_init();
951 :
952 1 : if (WARN(!irqs_disabled(),
953 : "Interrupts were enabled *very* early, fixing it\n"))
954 : local_irq_disable();
955 1 : radix_tree_init();
956 1 : maple_tree_init();
957 :
958 : /*
959 : * Set up housekeeping before setting up workqueues to allow the unbound
960 : * workqueue to take non-housekeeping into account.
961 : */
962 : housekeeping_init();
963 :
964 : /*
965 : * Allow workqueue creation and work item queueing/cancelling
966 : * early. Work item execution depends on kthreads and starts after
967 : * workqueue_init().
968 : */
969 1 : workqueue_init_early();
970 :
971 1 : rcu_init();
972 :
973 : /* Trace events are available after this */
974 : trace_init();
975 :
976 : if (initcall_debug)
977 : initcall_debug_enable();
978 :
979 : context_tracking_init();
980 : /* init some links before init_ISA_irqs() */
981 1 : early_irq_init();
982 1 : init_IRQ();
983 1 : tick_init();
984 : rcu_init_nohz();
985 1 : init_timers();
986 1 : srcu_init();
987 1 : hrtimers_init();
988 1 : softirq_init();
989 1 : timekeeping_init();
990 1 : time_init();
991 :
992 : /* This must be after timekeeping is initialized */
993 1 : random_init();
994 :
995 : /* These make use of the fully initialized rng */
996 : kfence_init();
997 : boot_init_stack_canary();
998 :
999 : perf_event_init();
1000 : profile_init();
1001 : call_function_init();
1002 1 : WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1003 :
1004 1 : early_boot_irqs_disabled = false;
1005 : local_irq_enable();
1006 :
1007 1 : kmem_cache_init_late();
1008 :
1009 : /*
1010 : * HACK ALERT! This is early. We're enabling the console before
1011 : * we've done PCI setups etc, and console_init() must be aware of
1012 : * this. But we do want output early, in case something goes wrong.
1013 : */
1014 1 : console_init();
1015 1 : if (panic_later)
1016 0 : panic("Too many boot %s vars at `%s'", panic_later,
1017 : panic_param);
1018 :
1019 : lockdep_init();
1020 :
1021 : /*
1022 : * Need to run this when irqs are enabled, because it wants
1023 : * to self-test [hard/soft]-irqs on/off lock inversion bugs
1024 : * too:
1025 : */
1026 : locking_selftest();
1027 :
1028 : #ifdef CONFIG_BLK_DEV_INITRD
1029 : if (initrd_start && !initrd_below_start_ok &&
1030 : page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
1031 : pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1032 : page_to_pfn(virt_to_page((void *)initrd_start)),
1033 : min_low_pfn);
1034 : initrd_start = 0;
1035 : }
1036 : #endif
1037 1 : setup_per_cpu_pageset();
1038 : numa_policy_init();
1039 : acpi_early_init();
1040 1 : if (late_time_init)
1041 1 : late_time_init();
1042 1 : sched_clock_init();
1043 1 : calibrate_delay();
1044 :
1045 : /*
1046 : * This needs to be called before any devices perform DMA
1047 : * operations that might use the SWIOTLB bounce buffers. It will
1048 : * mark the bounce buffers as decrypted so that their usage will
1049 : * not cause "plain-text" data to be decrypted when accessed. It
1050 : * must be called after late_time_init() so that Hyper-V x86/x64
1051 : * hypercalls work when the SWIOTLB bounce buffers are decrypted.
1052 : */
1053 1 : mem_encrypt_init();
1054 :
1055 1 : pid_idr_init();
1056 1 : anon_vma_init();
1057 : #ifdef CONFIG_X86
1058 : if (efi_enabled(EFI_RUNTIME_SERVICES))
1059 : efi_enter_virtual_mode();
1060 : #endif
1061 1 : thread_stack_cache_init();
1062 1 : cred_init();
1063 1 : fork_init();
1064 1 : proc_caches_init();
1065 1 : uts_ns_init();
1066 : key_init();
1067 : security_init();
1068 : dbg_late_init();
1069 : net_ns_init();
1070 1 : vfs_caches_init();
1071 1 : pagecache_init();
1072 1 : signals_init();
1073 1 : seq_file_init();
1074 1 : proc_root_init();
1075 1 : nsfs_init();
1076 : cpuset_init();
1077 : cgroup_init();
1078 : taskstats_init_early();
1079 : delayacct_init();
1080 :
1081 1 : check_bugs();
1082 :
1083 : acpi_subsystem_init();
1084 1 : arch_post_acpi_subsys_init();
1085 : kcsan_init();
1086 :
1087 : /* Do the rest non-__init'ed, we're now alive */
1088 1 : arch_call_rest_init();
1089 :
1090 : prevent_tail_call_optimization();
1091 : }
1092 :
1093 : /* Call all constructor functions linked into the kernel. */
1094 : static void __init do_ctors(void)
1095 : {
1096 : /*
1097 : * For UML, the constructors have already been called by the
1098 : * normal setup code as it's just a normal ELF binary, so we
1099 : * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1100 : * even on UML for modules.
1101 : */
1102 : #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1103 : ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1104 :
1105 : for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1106 : (*fn)();
1107 : #endif
1108 : }
1109 :
1110 : #ifdef CONFIG_KALLSYMS
1111 : struct blacklist_entry {
1112 : struct list_head next;
1113 : char *buf;
1114 : };
1115 :
1116 : static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1117 :
1118 0 : static int __init initcall_blacklist(char *str)
1119 : {
1120 : char *str_entry;
1121 : struct blacklist_entry *entry;
1122 :
1123 : /* str argument is a comma-separated list of functions */
1124 : do {
1125 0 : str_entry = strsep(&str, ",");
1126 0 : if (str_entry) {
1127 0 : pr_debug("blacklisting initcall %s\n", str_entry);
1128 0 : entry = memblock_alloc(sizeof(*entry),
1129 : SMP_CACHE_BYTES);
1130 0 : if (!entry)
1131 0 : panic("%s: Failed to allocate %zu bytes\n",
1132 : __func__, sizeof(*entry));
1133 0 : entry->buf = memblock_alloc(strlen(str_entry) + 1,
1134 : SMP_CACHE_BYTES);
1135 0 : if (!entry->buf)
1136 0 : panic("%s: Failed to allocate %zu bytes\n",
1137 0 : __func__, strlen(str_entry) + 1);
1138 0 : strcpy(entry->buf, str_entry);
1139 0 : list_add(&entry->next, &blacklisted_initcalls);
1140 : }
1141 0 : } while (str_entry);
1142 :
1143 0 : return 1;
1144 : }
1145 :
1146 178 : static bool __init_or_module initcall_blacklisted(initcall_t fn)
1147 : {
1148 : struct blacklist_entry *entry;
1149 : char fn_name[KSYM_SYMBOL_LEN];
1150 : unsigned long addr;
1151 :
1152 178 : if (list_empty(&blacklisted_initcalls))
1153 : return false;
1154 :
1155 0 : addr = (unsigned long) dereference_function_descriptor(fn);
1156 0 : sprint_symbol_no_offset(fn_name, addr);
1157 :
1158 : /*
1159 : * fn will be "function_name [module_name]" where [module_name] is not
1160 : * displayed for built-in init functions. Strip off the [module_name].
1161 : */
1162 0 : strreplace(fn_name, ' ', '\0');
1163 :
1164 0 : list_for_each_entry(entry, &blacklisted_initcalls, next) {
1165 0 : if (!strcmp(fn_name, entry->buf)) {
1166 0 : pr_debug("initcall %s blacklisted\n", fn_name);
1167 0 : return true;
1168 : }
1169 : }
1170 :
1171 : return false;
1172 : }
1173 : #else
1174 : static int __init initcall_blacklist(char *str)
1175 : {
1176 : pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1177 : return 0;
1178 : }
1179 :
1180 : static bool __init_or_module initcall_blacklisted(initcall_t fn)
1181 : {
1182 : return false;
1183 : }
1184 : #endif
1185 : __setup("initcall_blacklist=", initcall_blacklist);
1186 :
1187 : static __init_or_module void
1188 0 : trace_initcall_start_cb(void *data, initcall_t fn)
1189 : {
1190 0 : ktime_t *calltime = data;
1191 :
1192 0 : printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1193 0 : *calltime = ktime_get();
1194 0 : }
1195 :
1196 : static __init_or_module void
1197 0 : trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1198 : {
1199 0 : ktime_t rettime, *calltime = data;
1200 :
1201 0 : rettime = ktime_get();
1202 0 : printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1203 : fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
1204 0 : }
1205 :
1206 : static ktime_t initcall_calltime;
1207 :
1208 : #ifdef TRACEPOINTS_ENABLED
1209 : static void __init initcall_debug_enable(void)
1210 : {
1211 : int ret;
1212 :
1213 : ret = register_trace_initcall_start(trace_initcall_start_cb,
1214 : &initcall_calltime);
1215 : ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1216 : &initcall_calltime);
1217 : WARN(ret, "Failed to register initcall tracepoints\n");
1218 : }
1219 : # define do_trace_initcall_start trace_initcall_start
1220 : # define do_trace_initcall_finish trace_initcall_finish
1221 : #else
1222 : static inline void do_trace_initcall_start(initcall_t fn)
1223 : {
1224 178 : if (!initcall_debug)
1225 : return;
1226 0 : trace_initcall_start_cb(&initcall_calltime, fn);
1227 : }
1228 : static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1229 : {
1230 178 : if (!initcall_debug)
1231 : return;
1232 0 : trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1233 : }
1234 : #endif /* !TRACEPOINTS_ENABLED */
1235 :
1236 178 : int __init_or_module do_one_initcall(initcall_t fn)
1237 : {
1238 178 : int count = preempt_count();
1239 : char msgbuf[64];
1240 : int ret;
1241 :
1242 178 : if (initcall_blacklisted(fn))
1243 : return -EPERM;
1244 :
1245 178 : do_trace_initcall_start(fn);
1246 178 : ret = fn();
1247 178 : do_trace_initcall_finish(fn, ret);
1248 :
1249 178 : msgbuf[0] = 0;
1250 :
1251 178 : if (preempt_count() != count) {
1252 0 : sprintf(msgbuf, "preemption imbalance ");
1253 : preempt_count_set(count);
1254 : }
1255 178 : if (irqs_disabled()) {
1256 0 : strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1257 : local_irq_enable();
1258 : }
1259 178 : WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1260 :
1261 : add_latent_entropy();
1262 178 : return ret;
1263 : }
1264 :
1265 :
1266 : extern initcall_entry_t __initcall_start[];
1267 : extern initcall_entry_t __initcall0_start[];
1268 : extern initcall_entry_t __initcall1_start[];
1269 : extern initcall_entry_t __initcall2_start[];
1270 : extern initcall_entry_t __initcall3_start[];
1271 : extern initcall_entry_t __initcall4_start[];
1272 : extern initcall_entry_t __initcall5_start[];
1273 : extern initcall_entry_t __initcall6_start[];
1274 : extern initcall_entry_t __initcall7_start[];
1275 : extern initcall_entry_t __initcall_end[];
1276 :
1277 : static initcall_entry_t *initcall_levels[] __initdata = {
1278 : __initcall0_start,
1279 : __initcall1_start,
1280 : __initcall2_start,
1281 : __initcall3_start,
1282 : __initcall4_start,
1283 : __initcall5_start,
1284 : __initcall6_start,
1285 : __initcall7_start,
1286 : __initcall_end,
1287 : };
1288 :
1289 : /* Keep these in sync with initcalls in include/linux/init.h */
1290 : static const char *initcall_level_names[] __initdata = {
1291 : "pure",
1292 : "core",
1293 : "postcore",
1294 : "arch",
1295 : "subsys",
1296 : "fs",
1297 : "device",
1298 : "late",
1299 : };
1300 :
1301 24 : static int __init ignore_unknown_bootoption(char *param, char *val,
1302 : const char *unused, void *arg)
1303 : {
1304 24 : return 0;
1305 : }
1306 :
1307 8 : static void __init do_initcall_level(int level, char *command_line)
1308 : {
1309 : initcall_entry_t *fn;
1310 :
1311 16 : parse_args(initcall_level_names[level],
1312 : command_line, __start___param,
1313 8 : __stop___param - __start___param,
1314 : level, level,
1315 : NULL, ignore_unknown_bootoption);
1316 :
1317 8 : trace_initcall_level(initcall_level_names[level]);
1318 180 : for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1319 172 : do_one_initcall(initcall_from_entry(fn));
1320 8 : }
1321 :
1322 1 : static void __init do_initcalls(void)
1323 : {
1324 : int level;
1325 1 : size_t len = saved_command_line_len + 1;
1326 : char *command_line;
1327 :
1328 1 : command_line = kzalloc(len, GFP_KERNEL);
1329 1 : if (!command_line)
1330 0 : panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1331 :
1332 8 : for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1333 : /* Parser modifies command_line, restore it each time */
1334 8 : strcpy(command_line, saved_command_line);
1335 8 : do_initcall_level(level, command_line);
1336 : }
1337 :
1338 1 : kfree(command_line);
1339 1 : }
1340 :
1341 : /*
1342 : * Ok, the machine is now initialized. None of the devices
1343 : * have been touched yet, but the CPU subsystem is up and
1344 : * running, and memory and process management works.
1345 : *
1346 : * Now we can finally start doing some real work..
1347 : */
1348 1 : static void __init do_basic_setup(void)
1349 : {
1350 : cpuset_init_smp();
1351 1 : driver_init();
1352 1 : init_irq_proc();
1353 : do_ctors();
1354 1 : do_initcalls();
1355 1 : }
1356 :
1357 1 : static void __init do_pre_smp_initcalls(void)
1358 : {
1359 : initcall_entry_t *fn;
1360 :
1361 1 : trace_initcall_level("early");
1362 7 : for (fn = __initcall_start; fn < __initcall0_start; fn++)
1363 6 : do_one_initcall(initcall_from_entry(fn));
1364 1 : }
1365 :
1366 0 : static int run_init_process(const char *init_filename)
1367 : {
1368 : const char *const *p;
1369 :
1370 0 : argv_init[0] = init_filename;
1371 0 : pr_info("Run %s as init process\n", init_filename);
1372 0 : pr_debug(" with arguments:\n");
1373 0 : for (p = argv_init; *p; p++)
1374 0 : pr_debug(" %s\n", *p);
1375 0 : pr_debug(" with environment:\n");
1376 0 : for (p = envp_init; *p; p++)
1377 0 : pr_debug(" %s\n", *p);
1378 0 : return kernel_execve(init_filename, argv_init, envp_init);
1379 : }
1380 :
1381 0 : static int try_to_run_init_process(const char *init_filename)
1382 : {
1383 : int ret;
1384 :
1385 0 : ret = run_init_process(init_filename);
1386 :
1387 0 : if (ret && ret != -ENOENT) {
1388 0 : pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1389 : init_filename, ret);
1390 : }
1391 :
1392 0 : return ret;
1393 : }
1394 :
1395 : static noinline void __init kernel_init_freeable(void);
1396 :
1397 : #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1398 : bool rodata_enabled __ro_after_init = true;
1399 :
1400 : #ifndef arch_parse_debug_rodata
1401 : static inline bool arch_parse_debug_rodata(char *str) { return false; }
1402 : #endif
1403 :
1404 : static int __init set_debug_rodata(char *str)
1405 : {
1406 : if (arch_parse_debug_rodata(str))
1407 : return 0;
1408 :
1409 : if (str && !strcmp(str, "on"))
1410 : rodata_enabled = true;
1411 : else if (str && !strcmp(str, "off"))
1412 : rodata_enabled = false;
1413 : else
1414 : pr_warn("Invalid option string for rodata: '%s'\n", str);
1415 : return 0;
1416 : }
1417 : early_param("rodata", set_debug_rodata);
1418 : #endif
1419 :
1420 : #ifdef CONFIG_STRICT_KERNEL_RWX
1421 : static void mark_readonly(void)
1422 : {
1423 : if (rodata_enabled) {
1424 : /*
1425 : * load_module() results in W+X mappings, which are cleaned
1426 : * up with call_rcu(). Let's make sure that queued work is
1427 : * flushed so that we don't hit false positives looking for
1428 : * insecure pages which are W+X.
1429 : */
1430 : rcu_barrier();
1431 : mark_rodata_ro();
1432 : rodata_test();
1433 : } else
1434 : pr_info("Kernel memory protection disabled.\n");
1435 : }
1436 : #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1437 : static inline void mark_readonly(void)
1438 : {
1439 : pr_warn("Kernel memory protection not selected by kernel config.\n");
1440 : }
1441 : #else
1442 : static inline void mark_readonly(void)
1443 : {
1444 0 : pr_warn("This architecture does not have kernel memory protection.\n");
1445 : }
1446 : #endif
1447 :
1448 0 : void __weak free_initmem(void)
1449 : {
1450 0 : free_initmem_default(POISON_FREE_INITMEM);
1451 0 : }
1452 :
1453 1 : static int __ref kernel_init(void *unused)
1454 : {
1455 : int ret;
1456 :
1457 : /*
1458 : * Wait until kthreadd is all set-up.
1459 : */
1460 1 : wait_for_completion(&kthreadd_done);
1461 :
1462 1 : kernel_init_freeable();
1463 : /* need to finish all async __init code before freeing the memory */
1464 0 : async_synchronize_full();
1465 :
1466 0 : system_state = SYSTEM_FREEING_INITMEM;
1467 : kprobe_free_init_mem();
1468 : ftrace_free_init_mem();
1469 : kgdb_free_init_mem();
1470 : exit_boot_config();
1471 0 : free_initmem();
1472 : mark_readonly();
1473 :
1474 : /*
1475 : * Kernel mappings are now finalized - update the userspace page-table
1476 : * to finalize PTI.
1477 : */
1478 : pti_finalize();
1479 :
1480 0 : system_state = SYSTEM_RUNNING;
1481 : numa_default_policy();
1482 :
1483 : rcu_end_inkernel_boot();
1484 :
1485 0 : do_sysctl_args();
1486 :
1487 0 : if (ramdisk_execute_command) {
1488 0 : ret = run_init_process(ramdisk_execute_command);
1489 0 : if (!ret)
1490 : return 0;
1491 0 : pr_err("Failed to execute %s (error %d)\n",
1492 : ramdisk_execute_command, ret);
1493 : }
1494 :
1495 : /*
1496 : * We try each of these until one succeeds.
1497 : *
1498 : * The Bourne shell can be used instead of init if we are
1499 : * trying to recover a really broken machine.
1500 : */
1501 0 : if (execute_command) {
1502 0 : ret = run_init_process(execute_command);
1503 0 : if (!ret)
1504 : return 0;
1505 0 : panic("Requested init %s failed (error %d).",
1506 : execute_command, ret);
1507 : }
1508 :
1509 : if (CONFIG_DEFAULT_INIT[0] != '\0') {
1510 : ret = run_init_process(CONFIG_DEFAULT_INIT);
1511 : if (ret)
1512 : pr_err("Default init %s failed (error %d)\n",
1513 : CONFIG_DEFAULT_INIT, ret);
1514 : else
1515 : return 0;
1516 : }
1517 :
1518 0 : if (!try_to_run_init_process("/sbin/init") ||
1519 0 : !try_to_run_init_process("/etc/init") ||
1520 0 : !try_to_run_init_process("/bin/init") ||
1521 0 : !try_to_run_init_process("/bin/sh"))
1522 : return 0;
1523 :
1524 0 : panic("No working init found. Try passing init= option to kernel. "
1525 : "See Linux Documentation/admin-guide/init.rst for guidance.");
1526 : }
1527 :
1528 : /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1529 0 : void __init console_on_rootfs(void)
1530 : {
1531 0 : struct file *file = filp_open("/dev/console", O_RDWR, 0);
1532 :
1533 0 : if (IS_ERR(file)) {
1534 0 : pr_err("Warning: unable to open an initial console.\n");
1535 0 : return;
1536 : }
1537 0 : init_dup(file);
1538 0 : init_dup(file);
1539 0 : init_dup(file);
1540 0 : fput(file);
1541 : }
1542 :
1543 1 : static noinline void __init kernel_init_freeable(void)
1544 : {
1545 : /* Now the scheduler is fully set up and can do blocking allocations */
1546 1 : gfp_allowed_mask = __GFP_BITS_MASK;
1547 :
1548 : /*
1549 : * init can allocate pages on any node
1550 : */
1551 1 : set_mems_allowed(node_states[N_MEMORY]);
1552 :
1553 2 : cad_pid = get_pid(task_pid(current));
1554 :
1555 1 : smp_prepare_cpus(setup_max_cpus);
1556 :
1557 1 : workqueue_init();
1558 :
1559 1 : init_mm_internals();
1560 :
1561 : rcu_init_tasks_generic();
1562 1 : do_pre_smp_initcalls();
1563 : lockup_detector_init();
1564 :
1565 : smp_init();
1566 1 : sched_init_smp();
1567 :
1568 : padata_init();
1569 1 : page_alloc_init_late();
1570 :
1571 1 : do_basic_setup();
1572 :
1573 1 : kunit_run_all_tests();
1574 :
1575 : wait_for_initramfs();
1576 0 : console_on_rootfs();
1577 :
1578 : /*
1579 : * check if there is an early userspace init. If yes, let it do all
1580 : * the work
1581 : */
1582 0 : if (init_eaccess(ramdisk_execute_command) != 0) {
1583 0 : ramdisk_execute_command = NULL;
1584 0 : prepare_namespace();
1585 : }
1586 :
1587 : /*
1588 : * Ok, we have completed the initial bootup, and
1589 : * we're essentially up and running. Get rid of the
1590 : * initmem segments and start the user-mode stuff..
1591 : *
1592 : * rootfs is available now, try loading the public keys
1593 : * and default modules
1594 : */
1595 :
1596 : integrity_load_keys();
1597 0 : }
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