xref: /linux/init/initramfs.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/init.h>
3 #include <linux/async.h>
4 #include <linux/fs.h>
5 #include <linux/slab.h>
6 #include <linux/types.h>
7 #include <linux/fcntl.h>
8 #include <linux/delay.h>
9 #include <linux/string.h>
10 #include <linux/dirent.h>
11 #include <linux/syscalls.h>
12 #include <linux/utime.h>
13 #include <linux/file.h>
14 #include <linux/kstrtox.h>
15 #include <linux/memblock.h>
16 #include <linux/mm.h>
17 #include <linux/namei.h>
18 #include <linux/init_syscalls.h>
19 #include <linux/umh.h>
20 #include <linux/security.h>
21 
22 #include "do_mounts.h"
23 
24 static __initdata bool csum_present;
25 static __initdata u32 io_csum;
26 
xwrite(struct file * file,const unsigned char * p,size_t count,loff_t * pos)27 static ssize_t __init xwrite(struct file *file, const unsigned char *p,
28 		size_t count, loff_t *pos)
29 {
30 	ssize_t out = 0;
31 
32 	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
33 	while (count) {
34 		ssize_t rv = kernel_write(file, p, count, pos);
35 
36 		if (rv < 0) {
37 			if (rv == -EINTR || rv == -EAGAIN)
38 				continue;
39 			return out ? out : rv;
40 		} else if (rv == 0)
41 			break;
42 
43 		if (csum_present) {
44 			ssize_t i;
45 
46 			for (i = 0; i < rv; i++)
47 				io_csum += p[i];
48 		}
49 
50 		p += rv;
51 		out += rv;
52 		count -= rv;
53 	}
54 
55 	return out;
56 }
57 
58 static __initdata char *message;
error(char * x)59 static void __init error(char *x)
60 {
61 	if (!message)
62 		message = x;
63 }
64 
65 #define panic_show_mem(fmt, ...) \
66 	({ show_mem(); panic(fmt, ##__VA_ARGS__); })
67 
68 /* link hash */
69 
70 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
71 
72 static __initdata struct hash {
73 	int ino, minor, major;
74 	umode_t mode;
75 	struct hash *next;
76 	char name[N_ALIGN(PATH_MAX)];
77 } *head[32];
78 
hash(int major,int minor,int ino)79 static inline int hash(int major, int minor, int ino)
80 {
81 	unsigned long tmp = ino + minor + (major << 3);
82 	tmp += tmp >> 5;
83 	return tmp & 31;
84 }
85 
find_link(int major,int minor,int ino,umode_t mode,char * name)86 static char __init *find_link(int major, int minor, int ino,
87 			      umode_t mode, char *name)
88 {
89 	struct hash **p, *q;
90 	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
91 		if ((*p)->ino != ino)
92 			continue;
93 		if ((*p)->minor != minor)
94 			continue;
95 		if ((*p)->major != major)
96 			continue;
97 		if (((*p)->mode ^ mode) & S_IFMT)
98 			continue;
99 		return (*p)->name;
100 	}
101 	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
102 	if (!q)
103 		panic_show_mem("can't allocate link hash entry");
104 	q->major = major;
105 	q->minor = minor;
106 	q->ino = ino;
107 	q->mode = mode;
108 	strcpy(q->name, name);
109 	q->next = NULL;
110 	*p = q;
111 	return NULL;
112 }
113 
free_hash(void)114 static void __init free_hash(void)
115 {
116 	struct hash **p, *q;
117 	for (p = head; p < head + 32; p++) {
118 		while (*p) {
119 			q = *p;
120 			*p = q->next;
121 			kfree(q);
122 		}
123 	}
124 }
125 
126 #ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
do_utime(char * filename,time64_t mtime)127 static void __init do_utime(char *filename, time64_t mtime)
128 {
129 	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
130 	init_utimes(filename, t);
131 }
132 
do_utime_path(const struct path * path,time64_t mtime)133 static void __init do_utime_path(const struct path *path, time64_t mtime)
134 {
135 	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
136 	vfs_utimes(path, t);
137 }
138 
139 static __initdata LIST_HEAD(dir_list);
140 struct dir_entry {
141 	struct list_head list;
142 	time64_t mtime;
143 	char name[];
144 };
145 
dir_add(const char * name,time64_t mtime)146 static void __init dir_add(const char *name, time64_t mtime)
147 {
148 	size_t nlen = strlen(name) + 1;
149 	struct dir_entry *de;
150 
151 	de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL);
152 	if (!de)
153 		panic_show_mem("can't allocate dir_entry buffer");
154 	INIT_LIST_HEAD(&de->list);
155 	strscpy(de->name, name, nlen);
156 	de->mtime = mtime;
157 	list_add(&de->list, &dir_list);
158 }
159 
dir_utime(void)160 static void __init dir_utime(void)
161 {
162 	struct dir_entry *de, *tmp;
163 	list_for_each_entry_safe(de, tmp, &dir_list, list) {
164 		list_del(&de->list);
165 		do_utime(de->name, de->mtime);
166 		kfree(de);
167 	}
168 }
169 #else
do_utime(char * filename,time64_t mtime)170 static void __init do_utime(char *filename, time64_t mtime) {}
do_utime_path(const struct path * path,time64_t mtime)171 static void __init do_utime_path(const struct path *path, time64_t mtime) {}
dir_add(const char * name,time64_t mtime)172 static void __init dir_add(const char *name, time64_t mtime) {}
dir_utime(void)173 static void __init dir_utime(void) {}
174 #endif
175 
176 static __initdata time64_t mtime;
177 
178 /* cpio header parsing */
179 
180 static __initdata unsigned long ino, major, minor, nlink;
181 static __initdata umode_t mode;
182 static __initdata unsigned long body_len, name_len;
183 static __initdata uid_t uid;
184 static __initdata gid_t gid;
185 static __initdata unsigned rdev;
186 static __initdata u32 hdr_csum;
187 
parse_header(char * s)188 static void __init parse_header(char *s)
189 {
190 	unsigned long parsed[13];
191 	char buf[9];
192 	int i;
193 
194 	buf[8] = '\0';
195 	for (i = 0, s += 6; i < 13; i++, s += 8) {
196 		memcpy(buf, s, 8);
197 		parsed[i] = simple_strtoul(buf, NULL, 16);
198 	}
199 	ino = parsed[0];
200 	mode = parsed[1];
201 	uid = parsed[2];
202 	gid = parsed[3];
203 	nlink = parsed[4];
204 	mtime = parsed[5]; /* breaks in y2106 */
205 	body_len = parsed[6];
206 	major = parsed[7];
207 	minor = parsed[8];
208 	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
209 	name_len = parsed[11];
210 	hdr_csum = parsed[12];
211 }
212 
213 /* FSM */
214 
215 static __initdata enum state {
216 	Start,
217 	Collect,
218 	GotHeader,
219 	SkipIt,
220 	GotName,
221 	CopyFile,
222 	GotSymlink,
223 	Reset
224 } state, next_state;
225 
226 static __initdata char *victim;
227 static unsigned long byte_count __initdata;
228 static __initdata loff_t this_header, next_header;
229 
eat(unsigned n)230 static inline void __init eat(unsigned n)
231 {
232 	victim += n;
233 	this_header += n;
234 	byte_count -= n;
235 }
236 
237 static __initdata char *collected;
238 static long remains __initdata;
239 static __initdata char *collect;
240 
read_into(char * buf,unsigned size,enum state next)241 static void __init read_into(char *buf, unsigned size, enum state next)
242 {
243 	if (byte_count >= size) {
244 		collected = victim;
245 		eat(size);
246 		state = next;
247 	} else {
248 		collect = collected = buf;
249 		remains = size;
250 		next_state = next;
251 		state = Collect;
252 	}
253 }
254 
255 static __initdata char *header_buf, *symlink_buf, *name_buf;
256 
do_start(void)257 static int __init do_start(void)
258 {
259 	read_into(header_buf, 110, GotHeader);
260 	return 0;
261 }
262 
do_collect(void)263 static int __init do_collect(void)
264 {
265 	unsigned long n = remains;
266 	if (byte_count < n)
267 		n = byte_count;
268 	memcpy(collect, victim, n);
269 	eat(n);
270 	collect += n;
271 	if ((remains -= n) != 0)
272 		return 1;
273 	state = next_state;
274 	return 0;
275 }
276 
do_header(void)277 static int __init do_header(void)
278 {
279 	if (!memcmp(collected, "070701", 6)) {
280 		csum_present = false;
281 	} else if (!memcmp(collected, "070702", 6)) {
282 		csum_present = true;
283 	} else {
284 		if (memcmp(collected, "070707", 6) == 0)
285 			error("incorrect cpio method used: use -H newc option");
286 		else
287 			error("no cpio magic");
288 		return 1;
289 	}
290 	parse_header(collected);
291 	next_header = this_header + N_ALIGN(name_len) + body_len;
292 	next_header = (next_header + 3) & ~3;
293 	state = SkipIt;
294 	if (name_len <= 0 || name_len > PATH_MAX)
295 		return 0;
296 	if (S_ISLNK(mode)) {
297 		if (body_len > PATH_MAX)
298 			return 0;
299 		collect = collected = symlink_buf;
300 		remains = N_ALIGN(name_len) + body_len;
301 		next_state = GotSymlink;
302 		state = Collect;
303 		return 0;
304 	}
305 	if (S_ISREG(mode) || !body_len)
306 		read_into(name_buf, N_ALIGN(name_len), GotName);
307 	return 0;
308 }
309 
do_skip(void)310 static int __init do_skip(void)
311 {
312 	if (this_header + byte_count < next_header) {
313 		eat(byte_count);
314 		return 1;
315 	} else {
316 		eat(next_header - this_header);
317 		state = next_state;
318 		return 0;
319 	}
320 }
321 
do_reset(void)322 static int __init do_reset(void)
323 {
324 	while (byte_count && *victim == '\0')
325 		eat(1);
326 	if (byte_count && (this_header & 3))
327 		error("broken padding");
328 	return 1;
329 }
330 
clean_path(char * path,umode_t fmode)331 static void __init clean_path(char *path, umode_t fmode)
332 {
333 	struct kstat st;
334 
335 	if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
336 	    (st.mode ^ fmode) & S_IFMT) {
337 		if (S_ISDIR(st.mode))
338 			init_rmdir(path);
339 		else
340 			init_unlink(path);
341 	}
342 }
343 
maybe_link(void)344 static int __init maybe_link(void)
345 {
346 	if (nlink >= 2) {
347 		char *old = find_link(major, minor, ino, mode, collected);
348 		if (old) {
349 			clean_path(collected, 0);
350 			return (init_link(old, collected) < 0) ? -1 : 1;
351 		}
352 	}
353 	return 0;
354 }
355 
356 static __initdata struct file *wfile;
357 static __initdata loff_t wfile_pos;
358 
do_name(void)359 static int __init do_name(void)
360 {
361 	state = SkipIt;
362 	next_state = Reset;
363 
364 	/* name_len > 0 && name_len <= PATH_MAX checked in do_header */
365 	if (collected[name_len - 1] != '\0') {
366 		pr_err("initramfs name without nulterm: %.*s\n",
367 		       (int)name_len, collected);
368 		error("malformed archive");
369 		return 1;
370 	}
371 
372 	if (strcmp(collected, "TRAILER!!!") == 0) {
373 		free_hash();
374 		return 0;
375 	}
376 	clean_path(collected, mode);
377 	if (S_ISREG(mode)) {
378 		int ml = maybe_link();
379 		if (ml >= 0) {
380 			int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
381 			if (ml != 1)
382 				openflags |= O_TRUNC;
383 			wfile = filp_open(collected, openflags, mode);
384 			if (IS_ERR(wfile))
385 				return 0;
386 			wfile_pos = 0;
387 			io_csum = 0;
388 
389 			vfs_fchown(wfile, uid, gid);
390 			vfs_fchmod(wfile, mode);
391 			if (body_len)
392 				vfs_truncate(&wfile->f_path, body_len);
393 			state = CopyFile;
394 		}
395 	} else if (S_ISDIR(mode)) {
396 		init_mkdir(collected, mode);
397 		init_chown(collected, uid, gid, 0);
398 		init_chmod(collected, mode);
399 		dir_add(collected, mtime);
400 	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
401 		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
402 		if (maybe_link() == 0) {
403 			init_mknod(collected, mode, rdev);
404 			init_chown(collected, uid, gid, 0);
405 			init_chmod(collected, mode);
406 			do_utime(collected, mtime);
407 		}
408 	}
409 	return 0;
410 }
411 
do_copy(void)412 static int __init do_copy(void)
413 {
414 	if (byte_count >= body_len) {
415 		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
416 			error("write error");
417 
418 		do_utime_path(&wfile->f_path, mtime);
419 		fput(wfile);
420 		if (csum_present && io_csum != hdr_csum)
421 			error("bad data checksum");
422 		eat(body_len);
423 		state = SkipIt;
424 		return 0;
425 	} else {
426 		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
427 			error("write error");
428 		body_len -= byte_count;
429 		eat(byte_count);
430 		return 1;
431 	}
432 }
433 
do_symlink(void)434 static int __init do_symlink(void)
435 {
436 	if (collected[name_len - 1] != '\0') {
437 		pr_err("initramfs symlink without nulterm: %.*s\n",
438 		       (int)name_len, collected);
439 		error("malformed archive");
440 		return 1;
441 	}
442 	collected[N_ALIGN(name_len) + body_len] = '\0';
443 	clean_path(collected, 0);
444 	init_symlink(collected + N_ALIGN(name_len), collected);
445 	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
446 	do_utime(collected, mtime);
447 	state = SkipIt;
448 	next_state = Reset;
449 	return 0;
450 }
451 
452 static __initdata int (*actions[])(void) = {
453 	[Start]		= do_start,
454 	[Collect]	= do_collect,
455 	[GotHeader]	= do_header,
456 	[SkipIt]	= do_skip,
457 	[GotName]	= do_name,
458 	[CopyFile]	= do_copy,
459 	[GotSymlink]	= do_symlink,
460 	[Reset]		= do_reset,
461 };
462 
write_buffer(char * buf,unsigned long len)463 static long __init write_buffer(char *buf, unsigned long len)
464 {
465 	byte_count = len;
466 	victim = buf;
467 
468 	while (!actions[state]())
469 		;
470 	return len - byte_count;
471 }
472 
flush_buffer(void * bufv,unsigned long len)473 static long __init flush_buffer(void *bufv, unsigned long len)
474 {
475 	char *buf = bufv;
476 	long written;
477 	long origLen = len;
478 	if (message)
479 		return -1;
480 	while ((written = write_buffer(buf, len)) < len && !message) {
481 		char c = buf[written];
482 		if (c == '0') {
483 			buf += written;
484 			len -= written;
485 			state = Start;
486 		} else if (c == 0) {
487 			buf += written;
488 			len -= written;
489 			state = Reset;
490 		} else
491 			error("junk within compressed archive");
492 	}
493 	return origLen;
494 }
495 
496 static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
497 
498 #include <linux/decompress/generic.h>
499 
unpack_to_rootfs(char * buf,unsigned long len)500 static char * __init unpack_to_rootfs(char *buf, unsigned long len)
501 {
502 	long written;
503 	decompress_fn decompress;
504 	const char *compress_name;
505 	static __initdata char msg_buf[64];
506 
507 	header_buf = kmalloc(110, GFP_KERNEL);
508 	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
509 	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
510 
511 	if (!header_buf || !symlink_buf || !name_buf)
512 		panic_show_mem("can't allocate buffers");
513 
514 	state = Start;
515 	this_header = 0;
516 	message = NULL;
517 	while (!message && len) {
518 		loff_t saved_offset = this_header;
519 		if (*buf == '0' && !(this_header & 3)) {
520 			state = Start;
521 			written = write_buffer(buf, len);
522 			buf += written;
523 			len -= written;
524 			continue;
525 		}
526 		if (!*buf) {
527 			buf++;
528 			len--;
529 			this_header++;
530 			continue;
531 		}
532 		this_header = 0;
533 		decompress = decompress_method(buf, len, &compress_name);
534 		pr_debug("Detected %s compressed data\n", compress_name);
535 		if (decompress) {
536 			int res = decompress(buf, len, NULL, flush_buffer, NULL,
537 				   &my_inptr, error);
538 			if (res)
539 				error("decompressor failed");
540 		} else if (compress_name) {
541 			if (!message) {
542 				snprintf(msg_buf, sizeof msg_buf,
543 					 "compression method %s not configured",
544 					 compress_name);
545 				message = msg_buf;
546 			}
547 		} else
548 			error("invalid magic at start of compressed archive");
549 		if (state != Reset)
550 			error("junk at the end of compressed archive");
551 		this_header = saved_offset + my_inptr;
552 		buf += my_inptr;
553 		len -= my_inptr;
554 	}
555 	dir_utime();
556 	kfree(name_buf);
557 	kfree(symlink_buf);
558 	kfree(header_buf);
559 	return message;
560 }
561 
562 static int __initdata do_retain_initrd;
563 
retain_initrd_param(char * str)564 static int __init retain_initrd_param(char *str)
565 {
566 	if (*str)
567 		return 0;
568 	do_retain_initrd = 1;
569 	return 1;
570 }
571 __setup("retain_initrd", retain_initrd_param);
572 
573 #ifdef CONFIG_ARCH_HAS_KEEPINITRD
keepinitrd_setup(char * __unused)574 static int __init keepinitrd_setup(char *__unused)
575 {
576 	do_retain_initrd = 1;
577 	return 1;
578 }
579 __setup("keepinitrd", keepinitrd_setup);
580 #endif
581 
582 static bool __initdata initramfs_async = true;
initramfs_async_setup(char * str)583 static int __init initramfs_async_setup(char *str)
584 {
585 	return kstrtobool(str, &initramfs_async) == 0;
586 }
587 __setup("initramfs_async=", initramfs_async_setup);
588 
589 extern char __initramfs_start[];
590 extern unsigned long __initramfs_size;
591 #include <linux/initrd.h>
592 #include <linux/kexec.h>
593 
594 static BIN_ATTR(initrd, 0440, sysfs_bin_attr_simple_read, NULL, 0);
595 
reserve_initrd_mem(void)596 void __init reserve_initrd_mem(void)
597 {
598 	phys_addr_t start;
599 	unsigned long size;
600 
601 	/* Ignore the virtul address computed during device tree parsing */
602 	initrd_start = initrd_end = 0;
603 
604 	if (!phys_initrd_size)
605 		return;
606 	/*
607 	 * Round the memory region to page boundaries as per free_initrd_mem()
608 	 * This allows us to detect whether the pages overlapping the initrd
609 	 * are in use, but more importantly, reserves the entire set of pages
610 	 * as we don't want these pages allocated for other purposes.
611 	 */
612 	start = round_down(phys_initrd_start, PAGE_SIZE);
613 	size = phys_initrd_size + (phys_initrd_start - start);
614 	size = round_up(size, PAGE_SIZE);
615 
616 	if (!memblock_is_region_memory(start, size)) {
617 		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
618 		       (u64)start, size);
619 		goto disable;
620 	}
621 
622 	if (memblock_is_region_reserved(start, size)) {
623 		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
624 		       (u64)start, size);
625 		goto disable;
626 	}
627 
628 	memblock_reserve(start, size);
629 	/* Now convert initrd to virtual addresses */
630 	initrd_start = (unsigned long)__va(phys_initrd_start);
631 	initrd_end = initrd_start + phys_initrd_size;
632 	initrd_below_start_ok = 1;
633 
634 	return;
635 disable:
636 	pr_cont(" - disabling initrd\n");
637 	initrd_start = 0;
638 	initrd_end = 0;
639 }
640 
free_initrd_mem(unsigned long start,unsigned long end)641 void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
642 {
643 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
644 	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
645 	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
646 
647 	memblock_free((void *)aligned_start, aligned_end - aligned_start);
648 #endif
649 
650 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
651 			"initrd");
652 }
653 
654 #ifdef CONFIG_CRASH_RESERVE
kexec_free_initrd(void)655 static bool __init kexec_free_initrd(void)
656 {
657 	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
658 	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
659 
660 	/*
661 	 * If the initrd region is overlapped with crashkernel reserved region,
662 	 * free only memory that is not part of crashkernel region.
663 	 */
664 	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
665 		return false;
666 
667 	/*
668 	 * Initialize initrd memory region since the kexec boot does not do.
669 	 */
670 	memset((void *)initrd_start, 0, initrd_end - initrd_start);
671 	if (initrd_start < crashk_start)
672 		free_initrd_mem(initrd_start, crashk_start);
673 	if (initrd_end > crashk_end)
674 		free_initrd_mem(crashk_end, initrd_end);
675 	return true;
676 }
677 #else
kexec_free_initrd(void)678 static inline bool kexec_free_initrd(void)
679 {
680 	return false;
681 }
682 #endif /* CONFIG_KEXEC_CORE */
683 
684 #ifdef CONFIG_BLK_DEV_RAM
populate_initrd_image(char * err)685 static void __init populate_initrd_image(char *err)
686 {
687 	ssize_t written;
688 	struct file *file;
689 	loff_t pos = 0;
690 
691 	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
692 			err);
693 	file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
694 	if (IS_ERR(file))
695 		return;
696 
697 	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
698 			&pos);
699 	if (written != initrd_end - initrd_start)
700 		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
701 		       written, initrd_end - initrd_start);
702 	fput(file);
703 }
704 #endif /* CONFIG_BLK_DEV_RAM */
705 
do_populate_rootfs(void * unused,async_cookie_t cookie)706 static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
707 {
708 	/* Load the built in initramfs */
709 	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
710 	if (err)
711 		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
712 
713 	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
714 		goto done;
715 
716 	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
717 		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
718 	else
719 		printk(KERN_INFO "Unpacking initramfs...\n");
720 
721 	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
722 	if (err) {
723 #ifdef CONFIG_BLK_DEV_RAM
724 		populate_initrd_image(err);
725 #else
726 		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
727 #endif
728 	}
729 
730 done:
731 	security_initramfs_populated();
732 
733 	/*
734 	 * If the initrd region is overlapped with crashkernel reserved region,
735 	 * free only memory that is not part of crashkernel region.
736 	 */
737 	if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
738 		free_initrd_mem(initrd_start, initrd_end);
739 	} else if (do_retain_initrd && initrd_start) {
740 		bin_attr_initrd.size = initrd_end - initrd_start;
741 		bin_attr_initrd.private = (void *)initrd_start;
742 		if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd))
743 			pr_err("Failed to create initrd sysfs file");
744 	}
745 	initrd_start = 0;
746 	initrd_end = 0;
747 
748 	init_flush_fput();
749 }
750 
751 static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
752 static async_cookie_t initramfs_cookie;
753 
wait_for_initramfs(void)754 void wait_for_initramfs(void)
755 {
756 	if (!initramfs_cookie) {
757 		/*
758 		 * Something before rootfs_initcall wants to access
759 		 * the filesystem/initramfs. Probably a bug. Make a
760 		 * note, avoid deadlocking the machine, and let the
761 		 * caller's access fail as it used to.
762 		 */
763 		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
764 		return;
765 	}
766 	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
767 }
768 EXPORT_SYMBOL_GPL(wait_for_initramfs);
769 
populate_rootfs(void)770 static int __init populate_rootfs(void)
771 {
772 	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
773 						 &initramfs_domain);
774 	usermodehelper_enable();
775 	if (!initramfs_async)
776 		wait_for_initramfs();
777 	return 0;
778 }
779 rootfs_initcall(populate_rootfs);
780