xref: /linux/init/initramfs.c (revision 8434f9aa)
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 
21 #include "do_mounts.h"
22 
23 static __initdata bool csum_present;
24 static __initdata u32 io_csum;
25 
xwrite(struct file * file,const unsigned char * p,size_t count,loff_t * pos)26 static ssize_t __init xwrite(struct file *file, const unsigned char *p,
27 		size_t count, loff_t *pos)
28 {
29 	ssize_t out = 0;
30 
31 	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
32 	while (count) {
33 		ssize_t rv = kernel_write(file, p, count, pos);
34 
35 		if (rv < 0) {
36 			if (rv == -EINTR || rv == -EAGAIN)
37 				continue;
38 			return out ? out : rv;
39 		} else if (rv == 0)
40 			break;
41 
42 		if (csum_present) {
43 			ssize_t i;
44 
45 			for (i = 0; i < rv; i++)
46 				io_csum += p[i];
47 		}
48 
49 		p += rv;
50 		out += rv;
51 		count -= rv;
52 	}
53 
54 	return out;
55 }
56 
57 static __initdata char *message;
error(char * x)58 static void __init error(char *x)
59 {
60 	if (!message)
61 		message = x;
62 }
63 
64 #define panic_show_mem(fmt, ...) \
65 	({ show_mem(); panic(fmt, ##__VA_ARGS__); })
66 
67 /* link hash */
68 
69 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
70 
71 static __initdata struct hash {
72 	int ino, minor, major;
73 	umode_t mode;
74 	struct hash *next;
75 	char name[N_ALIGN(PATH_MAX)];
76 } *head[32];
77 
hash(int major,int minor,int ino)78 static inline int hash(int major, int minor, int ino)
79 {
80 	unsigned long tmp = ino + minor + (major << 3);
81 	tmp += tmp >> 5;
82 	return tmp & 31;
83 }
84 
find_link(int major,int minor,int ino,umode_t mode,char * name)85 static char __init *find_link(int major, int minor, int ino,
86 			      umode_t mode, char *name)
87 {
88 	struct hash **p, *q;
89 	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
90 		if ((*p)->ino != ino)
91 			continue;
92 		if ((*p)->minor != minor)
93 			continue;
94 		if ((*p)->major != major)
95 			continue;
96 		if (((*p)->mode ^ mode) & S_IFMT)
97 			continue;
98 		return (*p)->name;
99 	}
100 	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
101 	if (!q)
102 		panic_show_mem("can't allocate link hash entry");
103 	q->major = major;
104 	q->minor = minor;
105 	q->ino = ino;
106 	q->mode = mode;
107 	strcpy(q->name, name);
108 	q->next = NULL;
109 	*p = q;
110 	return NULL;
111 }
112 
free_hash(void)113 static void __init free_hash(void)
114 {
115 	struct hash **p, *q;
116 	for (p = head; p < head + 32; p++) {
117 		while (*p) {
118 			q = *p;
119 			*p = q->next;
120 			kfree(q);
121 		}
122 	}
123 }
124 
125 #ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
do_utime(char * filename,time64_t mtime)126 static void __init do_utime(char *filename, time64_t mtime)
127 {
128 	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
129 	init_utimes(filename, t);
130 }
131 
do_utime_path(const struct path * path,time64_t mtime)132 static void __init do_utime_path(const struct path *path, time64_t mtime)
133 {
134 	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
135 	vfs_utimes(path, t);
136 }
137 
138 static __initdata LIST_HEAD(dir_list);
139 struct dir_entry {
140 	struct list_head list;
141 	time64_t mtime;
142 	char name[];
143 };
144 
dir_add(const char * name,time64_t mtime)145 static void __init dir_add(const char *name, time64_t mtime)
146 {
147 	size_t nlen = strlen(name) + 1;
148 	struct dir_entry *de;
149 
150 	de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL);
151 	if (!de)
152 		panic_show_mem("can't allocate dir_entry buffer");
153 	INIT_LIST_HEAD(&de->list);
154 	strscpy(de->name, name, nlen);
155 	de->mtime = mtime;
156 	list_add(&de->list, &dir_list);
157 }
158 
dir_utime(void)159 static void __init dir_utime(void)
160 {
161 	struct dir_entry *de, *tmp;
162 	list_for_each_entry_safe(de, tmp, &dir_list, list) {
163 		list_del(&de->list);
164 		do_utime(de->name, de->mtime);
165 		kfree(de);
166 	}
167 }
168 #else
do_utime(char * filename,time64_t mtime)169 static void __init do_utime(char *filename, time64_t mtime) {}
do_utime_path(const struct path * path,time64_t mtime)170 static void __init do_utime_path(const struct path *path, time64_t mtime) {}
dir_add(const char * name,time64_t mtime)171 static void __init dir_add(const char *name, time64_t mtime) {}
dir_utime(void)172 static void __init dir_utime(void) {}
173 #endif
174 
175 static __initdata time64_t mtime;
176 
177 /* cpio header parsing */
178 
179 static __initdata unsigned long ino, major, minor, nlink;
180 static __initdata umode_t mode;
181 static __initdata unsigned long body_len, name_len;
182 static __initdata uid_t uid;
183 static __initdata gid_t gid;
184 static __initdata unsigned rdev;
185 static __initdata u32 hdr_csum;
186 
parse_header(char * s)187 static void __init parse_header(char *s)
188 {
189 	unsigned long parsed[13];
190 	char buf[9];
191 	int i;
192 
193 	buf[8] = '\0';
194 	for (i = 0, s += 6; i < 13; i++, s += 8) {
195 		memcpy(buf, s, 8);
196 		parsed[i] = simple_strtoul(buf, NULL, 16);
197 	}
198 	ino = parsed[0];
199 	mode = parsed[1];
200 	uid = parsed[2];
201 	gid = parsed[3];
202 	nlink = parsed[4];
203 	mtime = parsed[5]; /* breaks in y2106 */
204 	body_len = parsed[6];
205 	major = parsed[7];
206 	minor = parsed[8];
207 	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
208 	name_len = parsed[11];
209 	hdr_csum = parsed[12];
210 }
211 
212 /* FSM */
213 
214 static __initdata enum state {
215 	Start,
216 	Collect,
217 	GotHeader,
218 	SkipIt,
219 	GotName,
220 	CopyFile,
221 	GotSymlink,
222 	Reset
223 } state, next_state;
224 
225 static __initdata char *victim;
226 static unsigned long byte_count __initdata;
227 static __initdata loff_t this_header, next_header;
228 
eat(unsigned n)229 static inline void __init eat(unsigned n)
230 {
231 	victim += n;
232 	this_header += n;
233 	byte_count -= n;
234 }
235 
236 static __initdata char *collected;
237 static long remains __initdata;
238 static __initdata char *collect;
239 
read_into(char * buf,unsigned size,enum state next)240 static void __init read_into(char *buf, unsigned size, enum state next)
241 {
242 	if (byte_count >= size) {
243 		collected = victim;
244 		eat(size);
245 		state = next;
246 	} else {
247 		collect = collected = buf;
248 		remains = size;
249 		next_state = next;
250 		state = Collect;
251 	}
252 }
253 
254 static __initdata char *header_buf, *symlink_buf, *name_buf;
255 
do_start(void)256 static int __init do_start(void)
257 {
258 	read_into(header_buf, 110, GotHeader);
259 	return 0;
260 }
261 
do_collect(void)262 static int __init do_collect(void)
263 {
264 	unsigned long n = remains;
265 	if (byte_count < n)
266 		n = byte_count;
267 	memcpy(collect, victim, n);
268 	eat(n);
269 	collect += n;
270 	if ((remains -= n) != 0)
271 		return 1;
272 	state = next_state;
273 	return 0;
274 }
275 
do_header(void)276 static int __init do_header(void)
277 {
278 	if (!memcmp(collected, "070701", 6)) {
279 		csum_present = false;
280 	} else if (!memcmp(collected, "070702", 6)) {
281 		csum_present = true;
282 	} else {
283 		if (memcmp(collected, "070707", 6) == 0)
284 			error("incorrect cpio method used: use -H newc option");
285 		else
286 			error("no cpio magic");
287 		return 1;
288 	}
289 	parse_header(collected);
290 	next_header = this_header + N_ALIGN(name_len) + body_len;
291 	next_header = (next_header + 3) & ~3;
292 	state = SkipIt;
293 	if (name_len <= 0 || name_len > PATH_MAX)
294 		return 0;
295 	if (S_ISLNK(mode)) {
296 		if (body_len > PATH_MAX)
297 			return 0;
298 		collect = collected = symlink_buf;
299 		remains = N_ALIGN(name_len) + body_len;
300 		next_state = GotSymlink;
301 		state = Collect;
302 		return 0;
303 	}
304 	if (S_ISREG(mode) || !body_len)
305 		read_into(name_buf, N_ALIGN(name_len), GotName);
306 	return 0;
307 }
308 
do_skip(void)309 static int __init do_skip(void)
310 {
311 	if (this_header + byte_count < next_header) {
312 		eat(byte_count);
313 		return 1;
314 	} else {
315 		eat(next_header - this_header);
316 		state = next_state;
317 		return 0;
318 	}
319 }
320 
do_reset(void)321 static int __init do_reset(void)
322 {
323 	while (byte_count && *victim == '\0')
324 		eat(1);
325 	if (byte_count && (this_header & 3))
326 		error("broken padding");
327 	return 1;
328 }
329 
clean_path(char * path,umode_t fmode)330 static void __init clean_path(char *path, umode_t fmode)
331 {
332 	struct kstat st;
333 
334 	if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
335 	    (st.mode ^ fmode) & S_IFMT) {
336 		if (S_ISDIR(st.mode))
337 			init_rmdir(path);
338 		else
339 			init_unlink(path);
340 	}
341 }
342 
maybe_link(void)343 static int __init maybe_link(void)
344 {
345 	if (nlink >= 2) {
346 		char *old = find_link(major, minor, ino, mode, collected);
347 		if (old) {
348 			clean_path(collected, 0);
349 			return (init_link(old, collected) < 0) ? -1 : 1;
350 		}
351 	}
352 	return 0;
353 }
354 
355 static __initdata struct file *wfile;
356 static __initdata loff_t wfile_pos;
357 
do_name(void)358 static int __init do_name(void)
359 {
360 	state = SkipIt;
361 	next_state = Reset;
362 	if (strcmp(collected, "TRAILER!!!") == 0) {
363 		free_hash();
364 		return 0;
365 	}
366 	clean_path(collected, mode);
367 	if (S_ISREG(mode)) {
368 		int ml = maybe_link();
369 		if (ml >= 0) {
370 			int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
371 			if (ml != 1)
372 				openflags |= O_TRUNC;
373 			wfile = filp_open(collected, openflags, mode);
374 			if (IS_ERR(wfile))
375 				return 0;
376 			wfile_pos = 0;
377 			io_csum = 0;
378 
379 			vfs_fchown(wfile, uid, gid);
380 			vfs_fchmod(wfile, mode);
381 			if (body_len)
382 				vfs_truncate(&wfile->f_path, body_len);
383 			state = CopyFile;
384 		}
385 	} else if (S_ISDIR(mode)) {
386 		init_mkdir(collected, mode);
387 		init_chown(collected, uid, gid, 0);
388 		init_chmod(collected, mode);
389 		dir_add(collected, mtime);
390 	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
391 		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
392 		if (maybe_link() == 0) {
393 			init_mknod(collected, mode, rdev);
394 			init_chown(collected, uid, gid, 0);
395 			init_chmod(collected, mode);
396 			do_utime(collected, mtime);
397 		}
398 	}
399 	return 0;
400 }
401 
do_copy(void)402 static int __init do_copy(void)
403 {
404 	if (byte_count >= body_len) {
405 		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
406 			error("write error");
407 
408 		do_utime_path(&wfile->f_path, mtime);
409 		fput(wfile);
410 		if (csum_present && io_csum != hdr_csum)
411 			error("bad data checksum");
412 		eat(body_len);
413 		state = SkipIt;
414 		return 0;
415 	} else {
416 		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
417 			error("write error");
418 		body_len -= byte_count;
419 		eat(byte_count);
420 		return 1;
421 	}
422 }
423 
do_symlink(void)424 static int __init do_symlink(void)
425 {
426 	collected[N_ALIGN(name_len) + body_len] = '\0';
427 	clean_path(collected, 0);
428 	init_symlink(collected + N_ALIGN(name_len), collected);
429 	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
430 	do_utime(collected, mtime);
431 	state = SkipIt;
432 	next_state = Reset;
433 	return 0;
434 }
435 
436 static __initdata int (*actions[])(void) = {
437 	[Start]		= do_start,
438 	[Collect]	= do_collect,
439 	[GotHeader]	= do_header,
440 	[SkipIt]	= do_skip,
441 	[GotName]	= do_name,
442 	[CopyFile]	= do_copy,
443 	[GotSymlink]	= do_symlink,
444 	[Reset]		= do_reset,
445 };
446 
write_buffer(char * buf,unsigned long len)447 static long __init write_buffer(char *buf, unsigned long len)
448 {
449 	byte_count = len;
450 	victim = buf;
451 
452 	while (!actions[state]())
453 		;
454 	return len - byte_count;
455 }
456 
flush_buffer(void * bufv,unsigned long len)457 static long __init flush_buffer(void *bufv, unsigned long len)
458 {
459 	char *buf = bufv;
460 	long written;
461 	long origLen = len;
462 	if (message)
463 		return -1;
464 	while ((written = write_buffer(buf, len)) < len && !message) {
465 		char c = buf[written];
466 		if (c == '0') {
467 			buf += written;
468 			len -= written;
469 			state = Start;
470 		} else if (c == 0) {
471 			buf += written;
472 			len -= written;
473 			state = Reset;
474 		} else
475 			error("junk within compressed archive");
476 	}
477 	return origLen;
478 }
479 
480 static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
481 
482 #include <linux/decompress/generic.h>
483 
unpack_to_rootfs(char * buf,unsigned long len)484 static char * __init unpack_to_rootfs(char *buf, unsigned long len)
485 {
486 	long written;
487 	decompress_fn decompress;
488 	const char *compress_name;
489 	static __initdata char msg_buf[64];
490 
491 	header_buf = kmalloc(110, GFP_KERNEL);
492 	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
493 	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
494 
495 	if (!header_buf || !symlink_buf || !name_buf)
496 		panic_show_mem("can't allocate buffers");
497 
498 	state = Start;
499 	this_header = 0;
500 	message = NULL;
501 	while (!message && len) {
502 		loff_t saved_offset = this_header;
503 		if (*buf == '0' && !(this_header & 3)) {
504 			state = Start;
505 			written = write_buffer(buf, len);
506 			buf += written;
507 			len -= written;
508 			continue;
509 		}
510 		if (!*buf) {
511 			buf++;
512 			len--;
513 			this_header++;
514 			continue;
515 		}
516 		this_header = 0;
517 		decompress = decompress_method(buf, len, &compress_name);
518 		pr_debug("Detected %s compressed data\n", compress_name);
519 		if (decompress) {
520 			int res = decompress(buf, len, NULL, flush_buffer, NULL,
521 				   &my_inptr, error);
522 			if (res)
523 				error("decompressor failed");
524 		} else if (compress_name) {
525 			if (!message) {
526 				snprintf(msg_buf, sizeof msg_buf,
527 					 "compression method %s not configured",
528 					 compress_name);
529 				message = msg_buf;
530 			}
531 		} else
532 			error("invalid magic at start of compressed archive");
533 		if (state != Reset)
534 			error("junk at the end of compressed archive");
535 		this_header = saved_offset + my_inptr;
536 		buf += my_inptr;
537 		len -= my_inptr;
538 	}
539 	dir_utime();
540 	kfree(name_buf);
541 	kfree(symlink_buf);
542 	kfree(header_buf);
543 	return message;
544 }
545 
546 static int __initdata do_retain_initrd;
547 
retain_initrd_param(char * str)548 static int __init retain_initrd_param(char *str)
549 {
550 	if (*str)
551 		return 0;
552 	do_retain_initrd = 1;
553 	return 1;
554 }
555 __setup("retain_initrd", retain_initrd_param);
556 
557 #ifdef CONFIG_ARCH_HAS_KEEPINITRD
keepinitrd_setup(char * __unused)558 static int __init keepinitrd_setup(char *__unused)
559 {
560 	do_retain_initrd = 1;
561 	return 1;
562 }
563 __setup("keepinitrd", keepinitrd_setup);
564 #endif
565 
566 static bool __initdata initramfs_async = true;
initramfs_async_setup(char * str)567 static int __init initramfs_async_setup(char *str)
568 {
569 	return kstrtobool(str, &initramfs_async) == 0;
570 }
571 __setup("initramfs_async=", initramfs_async_setup);
572 
573 extern char __initramfs_start[];
574 extern unsigned long __initramfs_size;
575 #include <linux/initrd.h>
576 #include <linux/kexec.h>
577 
raw_read(struct file * file,struct kobject * kobj,struct bin_attribute * attr,char * buf,loff_t pos,size_t count)578 static ssize_t raw_read(struct file *file, struct kobject *kobj,
579 			struct bin_attribute *attr, char *buf,
580 			loff_t pos, size_t count)
581 {
582 	memcpy(buf, attr->private + pos, count);
583 	return count;
584 }
585 
586 static BIN_ATTR(initrd, 0440, raw_read, NULL, 0);
587 
reserve_initrd_mem(void)588 void __init reserve_initrd_mem(void)
589 {
590 	phys_addr_t start;
591 	unsigned long size;
592 
593 	/* Ignore the virtul address computed during device tree parsing */
594 	initrd_start = initrd_end = 0;
595 
596 	if (!phys_initrd_size)
597 		return;
598 	/*
599 	 * Round the memory region to page boundaries as per free_initrd_mem()
600 	 * This allows us to detect whether the pages overlapping the initrd
601 	 * are in use, but more importantly, reserves the entire set of pages
602 	 * as we don't want these pages allocated for other purposes.
603 	 */
604 	start = round_down(phys_initrd_start, PAGE_SIZE);
605 	size = phys_initrd_size + (phys_initrd_start - start);
606 	size = round_up(size, PAGE_SIZE);
607 
608 	if (!memblock_is_region_memory(start, size)) {
609 		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
610 		       (u64)start, size);
611 		goto disable;
612 	}
613 
614 	if (memblock_is_region_reserved(start, size)) {
615 		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
616 		       (u64)start, size);
617 		goto disable;
618 	}
619 
620 	memblock_reserve(start, size);
621 	/* Now convert initrd to virtual addresses */
622 	initrd_start = (unsigned long)__va(phys_initrd_start);
623 	initrd_end = initrd_start + phys_initrd_size;
624 	initrd_below_start_ok = 1;
625 
626 	return;
627 disable:
628 	pr_cont(" - disabling initrd\n");
629 	initrd_start = 0;
630 	initrd_end = 0;
631 }
632 
free_initrd_mem(unsigned long start,unsigned long end)633 void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
634 {
635 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
636 	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
637 	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
638 
639 	memblock_free((void *)aligned_start, aligned_end - aligned_start);
640 #endif
641 
642 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
643 			"initrd");
644 }
645 
646 #ifdef CONFIG_CRASH_RESERVE
kexec_free_initrd(void)647 static bool __init kexec_free_initrd(void)
648 {
649 	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
650 	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
651 
652 	/*
653 	 * If the initrd region is overlapped with crashkernel reserved region,
654 	 * free only memory that is not part of crashkernel region.
655 	 */
656 	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
657 		return false;
658 
659 	/*
660 	 * Initialize initrd memory region since the kexec boot does not do.
661 	 */
662 	memset((void *)initrd_start, 0, initrd_end - initrd_start);
663 	if (initrd_start < crashk_start)
664 		free_initrd_mem(initrd_start, crashk_start);
665 	if (initrd_end > crashk_end)
666 		free_initrd_mem(crashk_end, initrd_end);
667 	return true;
668 }
669 #else
kexec_free_initrd(void)670 static inline bool kexec_free_initrd(void)
671 {
672 	return false;
673 }
674 #endif /* CONFIG_KEXEC_CORE */
675 
676 #ifdef CONFIG_BLK_DEV_RAM
populate_initrd_image(char * err)677 static void __init populate_initrd_image(char *err)
678 {
679 	ssize_t written;
680 	struct file *file;
681 	loff_t pos = 0;
682 
683 	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
684 			err);
685 	file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
686 	if (IS_ERR(file))
687 		return;
688 
689 	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
690 			&pos);
691 	if (written != initrd_end - initrd_start)
692 		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
693 		       written, initrd_end - initrd_start);
694 	fput(file);
695 }
696 #endif /* CONFIG_BLK_DEV_RAM */
697 
do_populate_rootfs(void * unused,async_cookie_t cookie)698 static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
699 {
700 	/* Load the built in initramfs */
701 	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
702 	if (err)
703 		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
704 
705 	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
706 		goto done;
707 
708 	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
709 		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
710 	else
711 		printk(KERN_INFO "Unpacking initramfs...\n");
712 
713 	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
714 	if (err) {
715 #ifdef CONFIG_BLK_DEV_RAM
716 		populate_initrd_image(err);
717 #else
718 		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
719 #endif
720 	}
721 
722 done:
723 	/*
724 	 * If the initrd region is overlapped with crashkernel reserved region,
725 	 * free only memory that is not part of crashkernel region.
726 	 */
727 	if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
728 		free_initrd_mem(initrd_start, initrd_end);
729 	} else if (do_retain_initrd && initrd_start) {
730 		bin_attr_initrd.size = initrd_end - initrd_start;
731 		bin_attr_initrd.private = (void *)initrd_start;
732 		if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd))
733 			pr_err("Failed to create initrd sysfs file");
734 	}
735 	initrd_start = 0;
736 	initrd_end = 0;
737 
738 	init_flush_fput();
739 }
740 
741 static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
742 static async_cookie_t initramfs_cookie;
743 
wait_for_initramfs(void)744 void wait_for_initramfs(void)
745 {
746 	if (!initramfs_cookie) {
747 		/*
748 		 * Something before rootfs_initcall wants to access
749 		 * the filesystem/initramfs. Probably a bug. Make a
750 		 * note, avoid deadlocking the machine, and let the
751 		 * caller's access fail as it used to.
752 		 */
753 		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
754 		return;
755 	}
756 	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
757 }
758 EXPORT_SYMBOL_GPL(wait_for_initramfs);
759 
populate_rootfs(void)760 static int __init populate_rootfs(void)
761 {
762 	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
763 						 &initramfs_domain);
764 	usermodehelper_enable();
765 	if (!initramfs_async)
766 		wait_for_initramfs();
767 	return 0;
768 }
769 rootfs_initcall(populate_rootfs);
770