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