1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/fs.h>
4#include <linux/slab.h>
5#include <linux/types.h>
6#include <linux/fcntl.h>
7#include <linux/delay.h>
8#include <linux/string.h>
9#include <linux/dirent.h>
10#include <linux/syscalls.h>
11#include <linux/utime.h>
12#include <linux/file.h>
13
14static ssize_t __init xwrite(int fd, const char *p, size_t count)
15{
16 ssize_t out = 0;
17
18 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
19 while (count) {
20 ssize_t rv = ksys_write(fd, p, count);
21
22 if (rv < 0) {
23 if (rv == -EINTR || rv == -EAGAIN)
24 continue;
25 return out ? out : rv;
26 } else if (rv == 0)
27 break;
28
29 p += rv;
30 out += rv;
31 count -= rv;
32 }
33
34 return out;
35}
36
37static __initdata char *message;
38static void __init error(char *x)
39{
40 if (!message)
41 message = x;
42}
43
44/* link hash */
45
46#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
47
48static __initdata struct hash {
49 int ino, minor, major;
50 umode_t mode;
51 struct hash *next;
52 char name[N_ALIGN(PATH_MAX)];
53} *head[32];
54
55static inline int hash(int major, int minor, int ino)
56{
57 unsigned long tmp = ino + minor + (major << 3);
58 tmp += tmp >> 5;
59 return tmp & 31;
60}
61
62static char __init *find_link(int major, int minor, int ino,
63 umode_t mode, char *name)
64{
65 struct hash **p, *q;
66 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
67 if ((*p)->ino != ino)
68 continue;
69 if ((*p)->minor != minor)
70 continue;
71 if ((*p)->major != major)
72 continue;
73 if (((*p)->mode ^ mode) & S_IFMT)
74 continue;
75 return (*p)->name;
76 }
77 q = kmalloc(sizeof(struct hash), GFP_KERNEL);
78 if (!q)
79 panic("can't allocate link hash entry");
80 q->major = major;
81 q->minor = minor;
82 q->ino = ino;
83 q->mode = mode;
84 strcpy(q->name, name);
85 q->next = NULL;
86 *p = q;
87 return NULL;
88}
89
90static void __init free_hash(void)
91{
92 struct hash **p, *q;
93 for (p = head; p < head + 32; p++) {
94 while (*p) {
95 q = *p;
96 *p = q->next;
97 kfree(q);
98 }
99 }
100}
101
102static long __init do_utime(char *filename, time64_t mtime)
103{
104 struct timespec64 t[2];
105
106 t[0].tv_sec = mtime;
107 t[0].tv_nsec = 0;
108 t[1].tv_sec = mtime;
109 t[1].tv_nsec = 0;
110
111 return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
112}
113
114static __initdata LIST_HEAD(dir_list);
115struct dir_entry {
116 struct list_head list;
117 char *name;
118 time64_t mtime;
119};
120
121static void __init dir_add(const char *name, time64_t mtime)
122{
123 struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
124 if (!de)
125 panic("can't allocate dir_entry buffer");
126 INIT_LIST_HEAD(&de->list);
127 de->name = kstrdup(name, GFP_KERNEL);
128 de->mtime = mtime;
129 list_add(&de->list, &dir_list);
130}
131
132static void __init dir_utime(void)
133{
134 struct dir_entry *de, *tmp;
135 list_for_each_entry_safe(de, tmp, &dir_list, list) {
136 list_del(&de->list);
137 do_utime(de->name, de->mtime);
138 kfree(de->name);
139 kfree(de);
140 }
141}
142
143static __initdata time64_t mtime;
144
145/* cpio header parsing */
146
147static __initdata unsigned long ino, major, minor, nlink;
148static __initdata umode_t mode;
149static __initdata unsigned long body_len, name_len;
150static __initdata uid_t uid;
151static __initdata gid_t gid;
152static __initdata unsigned rdev;
153
154static void __init parse_header(char *s)
155{
156 unsigned long parsed[12];
157 char buf[9];
158 int i;
159
160 buf[8] = '\0';
161 for (i = 0, s += 6; i < 12; i++, s += 8) {
162 memcpy(buf, s, 8);
163 parsed[i] = simple_strtoul(buf, NULL, 16);
164 }
165 ino = parsed[0];
166 mode = parsed[1];
167 uid = parsed[2];
168 gid = parsed[3];
169 nlink = parsed[4];
170 mtime = parsed[5]; /* breaks in y2106 */
171 body_len = parsed[6];
172 major = parsed[7];
173 minor = parsed[8];
174 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
175 name_len = parsed[11];
176}
177
178/* FSM */
179
180static __initdata enum state {
181 Start,
182 Collect,
183 GotHeader,
184 SkipIt,
185 GotName,
186 CopyFile,
187 GotSymlink,
188 Reset
189} state, next_state;
190
191static __initdata char *victim;
192static unsigned long byte_count __initdata;
193static __initdata loff_t this_header, next_header;
194
195static inline void __init eat(unsigned n)
196{
197 victim += n;
198 this_header += n;
199 byte_count -= n;
200}
201
202static __initdata char *vcollected;
203static __initdata char *collected;
204static long remains __initdata;
205static __initdata char *collect;
206
207static void __init read_into(char *buf, unsigned size, enum state next)
208{
209 if (byte_count >= size) {
210 collected = victim;
211 eat(size);
212 state = next;
213 } else {
214 collect = collected = buf;
215 remains = size;
216 next_state = next;
217 state = Collect;
218 }
219}
220
221static __initdata char *header_buf, *symlink_buf, *name_buf;
222
223static int __init do_start(void)
224{
225 read_into(header_buf, 110, GotHeader);
226 return 0;
227}
228
229static int __init do_collect(void)
230{
231 unsigned long n = remains;
232 if (byte_count < n)
233 n = byte_count;
234 memcpy(collect, victim, n);
235 eat(n);
236 collect += n;
237 if ((remains -= n) != 0)
238 return 1;
239 state = next_state;
240 return 0;
241}
242
243static int __init do_header(void)
244{
245 if (memcmp(collected, "070707", 6)==0) {
246 error("incorrect cpio method used: use -H newc option");
247 return 1;
248 }
249 if (memcmp(collected, "070701", 6)) {
250 error("no cpio magic");
251 return 1;
252 }
253 parse_header(collected);
254 next_header = this_header + N_ALIGN(name_len) + body_len;
255 next_header = (next_header + 3) & ~3;
256 state = SkipIt;
257 if (name_len <= 0 || name_len > PATH_MAX)
258 return 0;
259 if (S_ISLNK(mode)) {
260 if (body_len > PATH_MAX)
261 return 0;
262 collect = collected = symlink_buf;
263 remains = N_ALIGN(name_len) + body_len;
264 next_state = GotSymlink;
265 state = Collect;
266 return 0;
267 }
268 if (S_ISREG(mode) || !body_len)
269 read_into(name_buf, N_ALIGN(name_len), GotName);
270 return 0;
271}
272
273static int __init do_skip(void)
274{
275 if (this_header + byte_count < next_header) {
276 eat(byte_count);
277 return 1;
278 } else {
279 eat(next_header - this_header);
280 state = next_state;
281 return 0;
282 }
283}
284
285static int __init do_reset(void)
286{
287 while (byte_count && *victim == '\0')
288 eat(1);
289 if (byte_count && (this_header & 3))
290 error("broken padding");
291 return 1;
292}
293
294static void __init clean_path(char *path, umode_t fmode)
295{
296 struct kstat st;
297
298 if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
299 if (S_ISDIR(st.mode))
300 ksys_rmdir(path);
301 else
302 ksys_unlink(path);
303 }
304}
305
306static int __init maybe_link(void)
307{
308 if (nlink >= 2) {
309 char *old = find_link(major, minor, ino, mode, collected);
310 if (old) {
311 clean_path(collected, 0);
312 return (ksys_link(old, collected) < 0) ? -1 : 1;
313 }
314 }
315 return 0;
316}
317
318static __initdata int wfd;
319
320static int __init do_name(void)
321{
322 state = SkipIt;
323 next_state = Reset;
324 if (strcmp(collected, "TRAILER!!!") == 0) {
325 free_hash();
326 return 0;
327 }
328 clean_path(collected, mode);
329 if (S_ISREG(mode)) {
330 int ml = maybe_link();
331 if (ml >= 0) {
332 int openflags = O_WRONLY|O_CREAT;
333 if (ml != 1)
334 openflags |= O_TRUNC;
335 wfd = ksys_open(collected, openflags, mode);
336
337 if (wfd >= 0) {
338 ksys_fchown(wfd, uid, gid);
339 ksys_fchmod(wfd, mode);
340 if (body_len)
341 ksys_ftruncate(wfd, body_len);
342 vcollected = kstrdup(collected, GFP_KERNEL);
343 state = CopyFile;
344 }
345 }
346 } else if (S_ISDIR(mode)) {
347 ksys_mkdir(collected, mode);
348 ksys_chown(collected, uid, gid);
349 ksys_chmod(collected, mode);
350 dir_add(collected, mtime);
351 } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
352 S_ISFIFO(mode) || S_ISSOCK(mode)) {
353 if (maybe_link() == 0) {
354 ksys_mknod(collected, mode, rdev);
355 ksys_chown(collected, uid, gid);
356 ksys_chmod(collected, mode);
357 do_utime(collected, mtime);
358 }
359 }
360 return 0;
361}
362
363static int __init do_copy(void)
364{
365 if (byte_count >= body_len) {
366 if (xwrite(wfd, victim, body_len) != body_len)
367 error("write error");
368 ksys_close(wfd);
369 do_utime(vcollected, mtime);
370 kfree(vcollected);
371 eat(body_len);
372 state = SkipIt;
373 return 0;
374 } else {
375 if (xwrite(wfd, victim, byte_count) != byte_count)
376 error("write error");
377 body_len -= byte_count;
378 eat(byte_count);
379 return 1;
380 }
381}
382
383static int __init do_symlink(void)
384{
385 collected[N_ALIGN(name_len) + body_len] = '\0';
386 clean_path(collected, 0);
387 ksys_symlink(collected + N_ALIGN(name_len), collected);
388 ksys_lchown(collected, uid, gid);
389 do_utime(collected, mtime);
390 state = SkipIt;
391 next_state = Reset;
392 return 0;
393}
394
395static __initdata int (*actions[])(void) = {
396 [Start] = do_start,
397 [Collect] = do_collect,
398 [GotHeader] = do_header,
399 [SkipIt] = do_skip,
400 [GotName] = do_name,
401 [CopyFile] = do_copy,
402 [GotSymlink] = do_symlink,
403 [Reset] = do_reset,
404};
405
406static long __init write_buffer(char *buf, unsigned long len)
407{
408 byte_count = len;
409 victim = buf;
410
411 while (!actions[state]())
412 ;
413 return len - byte_count;
414}
415
416static long __init flush_buffer(void *bufv, unsigned long len)
417{
418 char *buf = (char *) bufv;
419 long written;
420 long origLen = len;
421 if (message)
422 return -1;
423 while ((written = write_buffer(buf, len)) < len && !message) {
424 char c = buf[written];
425 if (c == '0') {
426 buf += written;
427 len -= written;
428 state = Start;
429 } else if (c == 0) {
430 buf += written;
431 len -= written;
432 state = Reset;
433 } else
434 error("junk within compressed archive");
435 }
436 return origLen;
437}
438
439static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
440
441#include <linux/decompress/generic.h>
442
443static char * __init unpack_to_rootfs(char *buf, unsigned long len)
444{
445 long written;
446 decompress_fn decompress;
447 const char *compress_name;
448 static __initdata char msg_buf[64];
449
450 header_buf = kmalloc(110, GFP_KERNEL);
451 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
452 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
453
454 if (!header_buf || !symlink_buf || !name_buf)
455 panic("can't allocate buffers");
456
457 state = Start;
458 this_header = 0;
459 message = NULL;
460 while (!message && len) {
461 loff_t saved_offset = this_header;
462 if (*buf == '0' && !(this_header & 3)) {
463 state = Start;
464 written = write_buffer(buf, len);
465 buf += written;
466 len -= written;
467 continue;
468 }
469 if (!*buf) {
470 buf++;
471 len--;
472 this_header++;
473 continue;
474 }
475 this_header = 0;
476 decompress = decompress_method(buf, len, &compress_name);
477 pr_debug("Detected %s compressed data\n", compress_name);
478 if (decompress) {
479 int res = decompress(buf, len, NULL, flush_buffer, NULL,
480 &my_inptr, error);
481 if (res)
482 error("decompressor failed");
483 } else if (compress_name) {
484 if (!message) {
485 snprintf(msg_buf, sizeof msg_buf,
486 "compression method %s not configured",
487 compress_name);
488 message = msg_buf;
489 }
490 } else
491 error("invalid magic at start of compressed archive");
492 if (state != Reset)
493 error("junk at the end of compressed archive");
494 this_header = saved_offset + my_inptr;
495 buf += my_inptr;
496 len -= my_inptr;
497 }
498 dir_utime();
499 kfree(name_buf);
500 kfree(symlink_buf);
501 kfree(header_buf);
502 return message;
503}
504
505static int __initdata do_retain_initrd;
506
507static int __init retain_initrd_param(char *str)
508{
509 if (*str)
510 return 0;
511 do_retain_initrd = 1;
512 return 1;
513}
514__setup("retain_initrd", retain_initrd_param);
515
516extern char __initramfs_start[];
517extern unsigned long __initramfs_size;
518#include <linux/initrd.h>
519#include <linux/kexec.h>
520
521static void __init free_initrd(void)
522{
523#ifdef CONFIG_KEXEC_CORE
524 unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
525 unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
526#endif
527 if (do_retain_initrd)
528 goto skip;
529
530#ifdef CONFIG_KEXEC_CORE
531 /*
532 * If the initrd region is overlapped with crashkernel reserved region,
533 * free only memory that is not part of crashkernel region.
534 */
535 if (initrd_start < crashk_end && initrd_end > crashk_start) {
536 /*
537 * Initialize initrd memory region since the kexec boot does
538 * not do.
539 */
540 memset((void *)initrd_start, 0, initrd_end - initrd_start);
541 if (initrd_start < crashk_start)
542 free_initrd_mem(initrd_start, crashk_start);
543 if (initrd_end > crashk_end)
544 free_initrd_mem(crashk_end, initrd_end);
545 } else
546#endif
547 free_initrd_mem(initrd_start, initrd_end);
548skip:
549 initrd_start = 0;
550 initrd_end = 0;
551}
552
553#ifdef CONFIG_BLK_DEV_RAM
554#define BUF_SIZE 1024
555static void __init clean_rootfs(void)
556{
557 int fd;
558 void *buf;
559 struct linux_dirent64 *dirp;
560 int num;
561
562 fd = ksys_open("/", O_RDONLY, 0);
563 WARN_ON(fd < 0);
564 if (fd < 0)
565 return;
566 buf = kzalloc(BUF_SIZE, GFP_KERNEL);
567 WARN_ON(!buf);
568 if (!buf) {
569 ksys_close(fd);
570 return;
571 }
572
573 dirp = buf;
574 num = ksys_getdents64(fd, dirp, BUF_SIZE);
575 while (num > 0) {
576 while (num > 0) {
577 struct kstat st;
578 int ret;
579
580 ret = vfs_lstat(dirp->d_name, &st);
581 WARN_ON_ONCE(ret);
582 if (!ret) {
583 if (S_ISDIR(st.mode))
584 ksys_rmdir(dirp->d_name);
585 else
586 ksys_unlink(dirp->d_name);
587 }
588
589 num -= dirp->d_reclen;
590 dirp = (void *)dirp + dirp->d_reclen;
591 }
592 dirp = buf;
593 memset(buf, 0, BUF_SIZE);
594 num = ksys_getdents64(fd, dirp, BUF_SIZE);
595 }
596
597 ksys_close(fd);
598 kfree(buf);
599}
600#endif
601
602static int __init populate_rootfs(void)
603{
604 /* Load the built in initramfs */
605 char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
606 if (err)
607 panic("%s", err); /* Failed to decompress INTERNAL initramfs */
608 /* If available load the bootloader supplied initrd */
609 if (initrd_start && !IS_ENABLED(CONFIG_INITRAMFS_FORCE)) {
610#ifdef CONFIG_BLK_DEV_RAM
611 int fd;
612 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
613 err = unpack_to_rootfs((char *)initrd_start,
614 initrd_end - initrd_start);
615 if (!err) {
616 free_initrd();
617 goto done;
618 } else {
619 clean_rootfs();
620 unpack_to_rootfs(__initramfs_start, __initramfs_size);
621 }
622 printk(KERN_INFO "rootfs image is not initramfs (%s)"
623 "; looks like an initrd\n", err);
624 fd = ksys_open("/initrd.image",
625 O_WRONLY|O_CREAT, 0700);
626 if (fd >= 0) {
627 ssize_t written = xwrite(fd, (char *)initrd_start,
628 initrd_end - initrd_start);
629
630 if (written != initrd_end - initrd_start)
631 pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
632 written, initrd_end - initrd_start);
633
634 ksys_close(fd);
635 free_initrd();
636 }
637 done:
638 /* empty statement */;
639#else
640 printk(KERN_INFO "Unpacking initramfs...\n");
641 err = unpack_to_rootfs((char *)initrd_start,
642 initrd_end - initrd_start);
643 if (err)
644 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
645 free_initrd();
646#endif
647 }
648 flush_delayed_fput();
649 return 0;
650}
651rootfs_initcall(populate_rootfs);
652