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