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  	if (strcmp(collected, "TRAILER!!!") == 0) {
364  		free_hash();
365  		return 0;
366  	}
367  	clean_path(collected, mode);
368  	if (S_ISREG(mode)) {
369  		int ml = maybe_link();
370  		if (ml >= 0) {
371  			int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
372  			if (ml != 1)
373  				openflags |= O_TRUNC;
374  			wfile = filp_open(collected, openflags, mode);
375  			if (IS_ERR(wfile))
376  				return 0;
377  			wfile_pos = 0;
378  			io_csum = 0;
379  
380  			vfs_fchown(wfile, uid, gid);
381  			vfs_fchmod(wfile, mode);
382  			if (body_len)
383  				vfs_truncate(&wfile->f_path, body_len);
384  			state = CopyFile;
385  		}
386  	} else if (S_ISDIR(mode)) {
387  		init_mkdir(collected, mode);
388  		init_chown(collected, uid, gid, 0);
389  		init_chmod(collected, mode);
390  		dir_add(collected, mtime);
391  	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
392  		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
393  		if (maybe_link() == 0) {
394  			init_mknod(collected, mode, rdev);
395  			init_chown(collected, uid, gid, 0);
396  			init_chmod(collected, mode);
397  			do_utime(collected, mtime);
398  		}
399  	}
400  	return 0;
401  }
402  
do_copy(void)403  static int __init do_copy(void)
404  {
405  	if (byte_count >= body_len) {
406  		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
407  			error("write error");
408  
409  		do_utime_path(&wfile->f_path, mtime);
410  		fput(wfile);
411  		if (csum_present && io_csum != hdr_csum)
412  			error("bad data checksum");
413  		eat(body_len);
414  		state = SkipIt;
415  		return 0;
416  	} else {
417  		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
418  			error("write error");
419  		body_len -= byte_count;
420  		eat(byte_count);
421  		return 1;
422  	}
423  }
424  
do_symlink(void)425  static int __init do_symlink(void)
426  {
427  	collected[N_ALIGN(name_len) + body_len] = '\0';
428  	clean_path(collected, 0);
429  	init_symlink(collected + N_ALIGN(name_len), collected);
430  	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
431  	do_utime(collected, mtime);
432  	state = SkipIt;
433  	next_state = Reset;
434  	return 0;
435  }
436  
437  static __initdata int (*actions[])(void) = {
438  	[Start]		= do_start,
439  	[Collect]	= do_collect,
440  	[GotHeader]	= do_header,
441  	[SkipIt]	= do_skip,
442  	[GotName]	= do_name,
443  	[CopyFile]	= do_copy,
444  	[GotSymlink]	= do_symlink,
445  	[Reset]		= do_reset,
446  };
447  
write_buffer(char * buf,unsigned long len)448  static long __init write_buffer(char *buf, unsigned long len)
449  {
450  	byte_count = len;
451  	victim = buf;
452  
453  	while (!actions[state]())
454  		;
455  	return len - byte_count;
456  }
457  
flush_buffer(void * bufv,unsigned long len)458  static long __init flush_buffer(void *bufv, unsigned long len)
459  {
460  	char *buf = bufv;
461  	long written;
462  	long origLen = len;
463  	if (message)
464  		return -1;
465  	while ((written = write_buffer(buf, len)) < len && !message) {
466  		char c = buf[written];
467  		if (c == '0') {
468  			buf += written;
469  			len -= written;
470  			state = Start;
471  		} else if (c == 0) {
472  			buf += written;
473  			len -= written;
474  			state = Reset;
475  		} else
476  			error("junk within compressed archive");
477  	}
478  	return origLen;
479  }
480  
481  static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
482  
483  #include <linux/decompress/generic.h>
484  
unpack_to_rootfs(char * buf,unsigned long len)485  static char * __init unpack_to_rootfs(char *buf, unsigned long len)
486  {
487  	long written;
488  	decompress_fn decompress;
489  	const char *compress_name;
490  	static __initdata char msg_buf[64];
491  
492  	header_buf = kmalloc(110, GFP_KERNEL);
493  	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
494  	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
495  
496  	if (!header_buf || !symlink_buf || !name_buf)
497  		panic_show_mem("can't allocate buffers");
498  
499  	state = Start;
500  	this_header = 0;
501  	message = NULL;
502  	while (!message && len) {
503  		loff_t saved_offset = this_header;
504  		if (*buf == '0' && !(this_header & 3)) {
505  			state = Start;
506  			written = write_buffer(buf, len);
507  			buf += written;
508  			len -= written;
509  			continue;
510  		}
511  		if (!*buf) {
512  			buf++;
513  			len--;
514  			this_header++;
515  			continue;
516  		}
517  		this_header = 0;
518  		decompress = decompress_method(buf, len, &compress_name);
519  		pr_debug("Detected %s compressed data\n", compress_name);
520  		if (decompress) {
521  			int res = decompress(buf, len, NULL, flush_buffer, NULL,
522  				   &my_inptr, error);
523  			if (res)
524  				error("decompressor failed");
525  		} else if (compress_name) {
526  			if (!message) {
527  				snprintf(msg_buf, sizeof msg_buf,
528  					 "compression method %s not configured",
529  					 compress_name);
530  				message = msg_buf;
531  			}
532  		} else
533  			error("invalid magic at start of compressed archive");
534  		if (state != Reset)
535  			error("junk at the end of compressed archive");
536  		this_header = saved_offset + my_inptr;
537  		buf += my_inptr;
538  		len -= my_inptr;
539  	}
540  	dir_utime();
541  	kfree(name_buf);
542  	kfree(symlink_buf);
543  	kfree(header_buf);
544  	return message;
545  }
546  
547  static int __initdata do_retain_initrd;
548  
retain_initrd_param(char * str)549  static int __init retain_initrd_param(char *str)
550  {
551  	if (*str)
552  		return 0;
553  	do_retain_initrd = 1;
554  	return 1;
555  }
556  __setup("retain_initrd", retain_initrd_param);
557  
558  #ifdef CONFIG_ARCH_HAS_KEEPINITRD
keepinitrd_setup(char * __unused)559  static int __init keepinitrd_setup(char *__unused)
560  {
561  	do_retain_initrd = 1;
562  	return 1;
563  }
564  __setup("keepinitrd", keepinitrd_setup);
565  #endif
566  
567  static bool __initdata initramfs_async = true;
initramfs_async_setup(char * str)568  static int __init initramfs_async_setup(char *str)
569  {
570  	return kstrtobool(str, &initramfs_async) == 0;
571  }
572  __setup("initramfs_async=", initramfs_async_setup);
573  
574  extern char __initramfs_start[];
575  extern unsigned long __initramfs_size;
576  #include <linux/initrd.h>
577  #include <linux/kexec.h>
578  
579  static BIN_ATTR(initrd, 0440, sysfs_bin_attr_simple_read, NULL, 0);
580  
reserve_initrd_mem(void)581  void __init reserve_initrd_mem(void)
582  {
583  	phys_addr_t start;
584  	unsigned long size;
585  
586  	/* Ignore the virtul address computed during device tree parsing */
587  	initrd_start = initrd_end = 0;
588  
589  	if (!phys_initrd_size)
590  		return;
591  	/*
592  	 * Round the memory region to page boundaries as per free_initrd_mem()
593  	 * This allows us to detect whether the pages overlapping the initrd
594  	 * are in use, but more importantly, reserves the entire set of pages
595  	 * as we don't want these pages allocated for other purposes.
596  	 */
597  	start = round_down(phys_initrd_start, PAGE_SIZE);
598  	size = phys_initrd_size + (phys_initrd_start - start);
599  	size = round_up(size, PAGE_SIZE);
600  
601  	if (!memblock_is_region_memory(start, size)) {
602  		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
603  		       (u64)start, size);
604  		goto disable;
605  	}
606  
607  	if (memblock_is_region_reserved(start, size)) {
608  		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
609  		       (u64)start, size);
610  		goto disable;
611  	}
612  
613  	memblock_reserve(start, size);
614  	/* Now convert initrd to virtual addresses */
615  	initrd_start = (unsigned long)__va(phys_initrd_start);
616  	initrd_end = initrd_start + phys_initrd_size;
617  	initrd_below_start_ok = 1;
618  
619  	return;
620  disable:
621  	pr_cont(" - disabling initrd\n");
622  	initrd_start = 0;
623  	initrd_end = 0;
624  }
625  
free_initrd_mem(unsigned long start,unsigned long end)626  void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
627  {
628  #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
629  	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
630  	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
631  
632  	memblock_free((void *)aligned_start, aligned_end - aligned_start);
633  #endif
634  
635  	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
636  			"initrd");
637  }
638  
639  #ifdef CONFIG_CRASH_RESERVE
kexec_free_initrd(void)640  static bool __init kexec_free_initrd(void)
641  {
642  	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
643  	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
644  
645  	/*
646  	 * If the initrd region is overlapped with crashkernel reserved region,
647  	 * free only memory that is not part of crashkernel region.
648  	 */
649  	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
650  		return false;
651  
652  	/*
653  	 * Initialize initrd memory region since the kexec boot does not do.
654  	 */
655  	memset((void *)initrd_start, 0, initrd_end - initrd_start);
656  	if (initrd_start < crashk_start)
657  		free_initrd_mem(initrd_start, crashk_start);
658  	if (initrd_end > crashk_end)
659  		free_initrd_mem(crashk_end, initrd_end);
660  	return true;
661  }
662  #else
kexec_free_initrd(void)663  static inline bool kexec_free_initrd(void)
664  {
665  	return false;
666  }
667  #endif /* CONFIG_KEXEC_CORE */
668  
669  #ifdef CONFIG_BLK_DEV_RAM
populate_initrd_image(char * err)670  static void __init populate_initrd_image(char *err)
671  {
672  	ssize_t written;
673  	struct file *file;
674  	loff_t pos = 0;
675  
676  	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
677  			err);
678  	file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
679  	if (IS_ERR(file))
680  		return;
681  
682  	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
683  			&pos);
684  	if (written != initrd_end - initrd_start)
685  		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
686  		       written, initrd_end - initrd_start);
687  	fput(file);
688  }
689  #endif /* CONFIG_BLK_DEV_RAM */
690  
do_populate_rootfs(void * unused,async_cookie_t cookie)691  static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
692  {
693  	/* Load the built in initramfs */
694  	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
695  	if (err)
696  		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
697  
698  	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
699  		goto done;
700  
701  	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
702  		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
703  	else
704  		printk(KERN_INFO "Unpacking initramfs...\n");
705  
706  	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
707  	if (err) {
708  #ifdef CONFIG_BLK_DEV_RAM
709  		populate_initrd_image(err);
710  #else
711  		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
712  #endif
713  	}
714  
715  done:
716  	security_initramfs_populated();
717  
718  	/*
719  	 * If the initrd region is overlapped with crashkernel reserved region,
720  	 * free only memory that is not part of crashkernel region.
721  	 */
722  	if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
723  		free_initrd_mem(initrd_start, initrd_end);
724  	} else if (do_retain_initrd && initrd_start) {
725  		bin_attr_initrd.size = initrd_end - initrd_start;
726  		bin_attr_initrd.private = (void *)initrd_start;
727  		if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd))
728  			pr_err("Failed to create initrd sysfs file");
729  	}
730  	initrd_start = 0;
731  	initrd_end = 0;
732  
733  	init_flush_fput();
734  }
735  
736  static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
737  static async_cookie_t initramfs_cookie;
738  
wait_for_initramfs(void)739  void wait_for_initramfs(void)
740  {
741  	if (!initramfs_cookie) {
742  		/*
743  		 * Something before rootfs_initcall wants to access
744  		 * the filesystem/initramfs. Probably a bug. Make a
745  		 * note, avoid deadlocking the machine, and let the
746  		 * caller's access fail as it used to.
747  		 */
748  		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
749  		return;
750  	}
751  	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
752  }
753  EXPORT_SYMBOL_GPL(wait_for_initramfs);
754  
populate_rootfs(void)755  static int __init populate_rootfs(void)
756  {
757  	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
758  						 &initramfs_domain);
759  	usermodehelper_enable();
760  	if (!initramfs_async)
761  		wait_for_initramfs();
762  	return 0;
763  }
764  rootfs_initcall(populate_rootfs);
765