1 /*
2 * Many of the syscalls used in this file expect some of the arguments
3 * to be __user pointers not __kernel pointers. To limit the sparse
4 * noise, turn off sparse checking for this file.
5 */
6 #ifdef __CHECKER__
7 #undef __CHECKER__
8 #warning "Sparse checking disabled for this file"
9 #endif
10
11 #include <linux/init.h>
12 #include <linux/fs.h>
13 #include <linux/slab.h>
14 #include <linux/types.h>
15 #include <linux/fcntl.h>
16 #include <linux/delay.h>
17 #include <linux/string.h>
18 #include <linux/dirent.h>
19 #include <linux/syscalls.h>
20 #include <linux/utime.h>
21 #include <linux/initramfs.h>
22
23 static __initdata char *message;
error(char * x)24 static void __init error(char *x)
25 {
26 if (!message)
27 message = x;
28 }
29
30 /* link hash */
31
32 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
33
34 static __initdata struct hash {
35 int ino, minor, major;
36 umode_t mode;
37 struct hash *next;
38 char name[N_ALIGN(PATH_MAX)];
39 } *head[32];
40
hash(int major,int minor,int ino)41 static inline int hash(int major, int minor, int ino)
42 {
43 unsigned long tmp = ino + minor + (major << 3);
44 tmp += tmp >> 5;
45 return tmp & 31;
46 }
47
find_link(int major,int minor,int ino,umode_t mode,char * name)48 static char __init *find_link(int major, int minor, int ino,
49 umode_t mode, char *name)
50 {
51 struct hash **p, *q;
52 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
53 if ((*p)->ino != ino)
54 continue;
55 if ((*p)->minor != minor)
56 continue;
57 if ((*p)->major != major)
58 continue;
59 if (((*p)->mode ^ mode) & S_IFMT)
60 continue;
61 return (*p)->name;
62 }
63 q = kmalloc(sizeof(struct hash), GFP_KERNEL);
64 if (!q)
65 panic("can't allocate link hash entry");
66 q->major = major;
67 q->minor = minor;
68 q->ino = ino;
69 q->mode = mode;
70 strcpy(q->name, name);
71 q->next = NULL;
72 *p = q;
73 return NULL;
74 }
75
free_hash(void)76 static void __init free_hash(void)
77 {
78 struct hash **p, *q;
79 for (p = head; p < head + 32; p++) {
80 while (*p) {
81 q = *p;
82 *p = q->next;
83 kfree(q);
84 }
85 }
86 }
87
do_utime(char * filename,time_t mtime)88 static long __init do_utime(char *filename, time_t mtime)
89 {
90 struct timespec t[2];
91
92 t[0].tv_sec = mtime;
93 t[0].tv_nsec = 0;
94 t[1].tv_sec = mtime;
95 t[1].tv_nsec = 0;
96
97 return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
98 }
99
100 static __initdata LIST_HEAD(dir_list);
101 struct dir_entry {
102 struct list_head list;
103 char *name;
104 time_t mtime;
105 };
106
dir_add(const char * name,time_t mtime)107 static void __init dir_add(const char *name, time_t mtime)
108 {
109 struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
110 if (!de)
111 panic("can't allocate dir_entry buffer");
112 INIT_LIST_HEAD(&de->list);
113 de->name = kstrdup(name, GFP_KERNEL);
114 de->mtime = mtime;
115 list_add(&de->list, &dir_list);
116 }
117
dir_utime(void)118 static void __init dir_utime(void)
119 {
120 struct dir_entry *de, *tmp;
121 list_for_each_entry_safe(de, tmp, &dir_list, list) {
122 list_del(&de->list);
123 do_utime(de->name, de->mtime);
124 kfree(de->name);
125 kfree(de);
126 }
127 }
128
129 static __initdata time_t mtime;
130
131 /* cpio header parsing */
132
133 static __initdata unsigned long ino, major, minor, nlink;
134 static __initdata umode_t mode;
135 static __initdata unsigned long body_len, name_len;
136 static __initdata uid_t uid;
137 static __initdata gid_t gid;
138 static __initdata unsigned rdev;
139
parse_header(char * s)140 static void __init parse_header(char *s)
141 {
142 unsigned long parsed[12];
143 char buf[9];
144 int i;
145
146 buf[8] = '\0';
147 for (i = 0, s += 6; i < 12; i++, s += 8) {
148 memcpy(buf, s, 8);
149 parsed[i] = simple_strtoul(buf, NULL, 16);
150 }
151 ino = parsed[0];
152 mode = parsed[1];
153 uid = parsed[2];
154 gid = parsed[3];
155 nlink = parsed[4];
156 mtime = parsed[5];
157 body_len = parsed[6];
158 major = parsed[7];
159 minor = parsed[8];
160 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
161 name_len = parsed[11];
162 }
163
164 /* FSM */
165
166 static __initdata enum state {
167 Start,
168 Collect,
169 GotHeader,
170 SkipIt,
171 GotName,
172 CopyFile,
173 GotSymlink,
174 Reset
175 } state, next_state;
176
177 static __initdata char *victim;
178 static __initdata unsigned count;
179 static __initdata loff_t this_header, next_header;
180
eat(unsigned n)181 static inline void __init eat(unsigned n)
182 {
183 victim += n;
184 this_header += n;
185 count -= n;
186 }
187
188 static __initdata char *vcollected;
189 static __initdata char *collected;
190 static __initdata int remains;
191 static __initdata char *collect;
192
read_into(char * buf,unsigned size,enum state next)193 static void __init read_into(char *buf, unsigned size, enum state next)
194 {
195 if (count >= size) {
196 collected = victim;
197 eat(size);
198 state = next;
199 } else {
200 collect = collected = buf;
201 remains = size;
202 next_state = next;
203 state = Collect;
204 }
205 }
206
207 static __initdata char *header_buf, *symlink_buf, *name_buf;
208
do_start(void)209 static int __init do_start(void)
210 {
211 read_into(header_buf, 110, GotHeader);
212 return 0;
213 }
214
do_collect(void)215 static int __init do_collect(void)
216 {
217 unsigned n = remains;
218 if (count < n)
219 n = count;
220 memcpy(collect, victim, n);
221 eat(n);
222 collect += n;
223 if ((remains -= n) != 0)
224 return 1;
225 state = next_state;
226 return 0;
227 }
228
do_header(void)229 static int __init do_header(void)
230 {
231 if (memcmp(collected, "070707", 6)==0) {
232 error("incorrect cpio method used: use -H newc option");
233 return 1;
234 }
235 if (memcmp(collected, "070701", 6)) {
236 error("no cpio magic");
237 return 1;
238 }
239 parse_header(collected);
240 next_header = this_header + N_ALIGN(name_len) + body_len;
241 next_header = (next_header + 3) & ~3;
242 state = SkipIt;
243 if (name_len <= 0 || name_len > PATH_MAX)
244 return 0;
245 if (S_ISLNK(mode)) {
246 if (body_len > PATH_MAX)
247 return 0;
248 collect = collected = symlink_buf;
249 remains = N_ALIGN(name_len) + body_len;
250 next_state = GotSymlink;
251 state = Collect;
252 return 0;
253 }
254 if (S_ISREG(mode) || !body_len)
255 read_into(name_buf, N_ALIGN(name_len), GotName);
256 return 0;
257 }
258
do_skip(void)259 static int __init do_skip(void)
260 {
261 if (this_header + count < next_header) {
262 eat(count);
263 return 1;
264 } else {
265 eat(next_header - this_header);
266 state = next_state;
267 return 0;
268 }
269 }
270
do_reset(void)271 static int __init do_reset(void)
272 {
273 while(count && *victim == '\0')
274 eat(1);
275 if (count && (this_header & 3))
276 error("broken padding");
277 return 1;
278 }
279
maybe_link(void)280 static int __init maybe_link(void)
281 {
282 if (nlink >= 2) {
283 char *old = find_link(major, minor, ino, mode, collected);
284 if (old)
285 return (sys_link(old, collected) < 0) ? -1 : 1;
286 }
287 return 0;
288 }
289
clean_path(char * path,umode_t mode)290 static void __init clean_path(char *path, umode_t mode)
291 {
292 struct stat st;
293
294 if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
295 if (S_ISDIR(st.st_mode))
296 sys_rmdir(path);
297 else
298 sys_unlink(path);
299 }
300 }
301
302 static __initdata int wfd;
303
do_name(void)304 static int __init do_name(void)
305 {
306 state = SkipIt;
307 next_state = Reset;
308 if (strcmp(collected, "TRAILER!!!") == 0) {
309 free_hash();
310 return 0;
311 }
312 clean_path(collected, mode);
313 if (S_ISREG(mode)) {
314 int ml = maybe_link();
315 if (ml >= 0) {
316 int openflags = O_WRONLY|O_CREAT;
317 if (ml != 1)
318 openflags |= O_TRUNC;
319 wfd = sys_open(collected, openflags, mode);
320
321 if (wfd >= 0) {
322 sys_fchown(wfd, uid, gid);
323 sys_fchmod(wfd, mode);
324 if (body_len)
325 sys_ftruncate(wfd, body_len);
326 vcollected = kstrdup(collected, GFP_KERNEL);
327 state = CopyFile;
328 }
329 }
330 } else if (S_ISDIR(mode)) {
331 sys_mkdir(collected, mode);
332 sys_chown(collected, uid, gid);
333 sys_chmod(collected, mode);
334 dir_add(collected, mtime);
335 } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
336 S_ISFIFO(mode) || S_ISSOCK(mode)) {
337 if (maybe_link() == 0) {
338 sys_mknod(collected, mode, rdev);
339 sys_chown(collected, uid, gid);
340 sys_chmod(collected, mode);
341 do_utime(collected, mtime);
342 }
343 }
344 return 0;
345 }
346
do_copy(void)347 static int __init do_copy(void)
348 {
349 if (count >= body_len) {
350 sys_write(wfd, victim, body_len);
351 sys_close(wfd);
352 do_utime(vcollected, mtime);
353 kfree(vcollected);
354 eat(body_len);
355 state = SkipIt;
356 return 0;
357 } else {
358 sys_write(wfd, victim, count);
359 body_len -= count;
360 eat(count);
361 return 1;
362 }
363 }
364
do_symlink(void)365 static int __init do_symlink(void)
366 {
367 collected[N_ALIGN(name_len) + body_len] = '\0';
368 clean_path(collected, 0);
369 sys_symlink(collected + N_ALIGN(name_len), collected);
370 sys_lchown(collected, uid, gid);
371 do_utime(collected, mtime);
372 state = SkipIt;
373 next_state = Reset;
374 return 0;
375 }
376
377 static __initdata int (*actions[])(void) = {
378 [Start] = do_start,
379 [Collect] = do_collect,
380 [GotHeader] = do_header,
381 [SkipIt] = do_skip,
382 [GotName] = do_name,
383 [CopyFile] = do_copy,
384 [GotSymlink] = do_symlink,
385 [Reset] = do_reset,
386 };
387
write_buffer(char * buf,unsigned len)388 static int __init write_buffer(char *buf, unsigned len)
389 {
390 count = len;
391 victim = buf;
392
393 while (!actions[state]())
394 ;
395 return len - count;
396 }
397
flush_buffer(void * bufv,unsigned len)398 static int __init flush_buffer(void *bufv, unsigned len)
399 {
400 char *buf = (char *) bufv;
401 int written;
402 int origLen = len;
403 if (message)
404 return -1;
405 while ((written = write_buffer(buf, len)) < len && !message) {
406 char c = buf[written];
407 if (c == '0') {
408 buf += written;
409 len -= written;
410 state = Start;
411 } else if (c == 0) {
412 buf += written;
413 len -= written;
414 state = Reset;
415 } else
416 error("junk in compressed archive");
417 }
418 return origLen;
419 }
420
421 static unsigned my_inptr; /* index of next byte to be processed in inbuf */
422
423 #include <linux/decompress/generic.h>
424
unpack_to_rootfs(char * buf,unsigned len)425 static char * __init unpack_to_rootfs(char *buf, unsigned len)
426 {
427 int written, res;
428 decompress_fn decompress;
429 const char *compress_name;
430 static __initdata char msg_buf[64];
431
432 header_buf = kmalloc(110, GFP_KERNEL);
433 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
434 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
435
436 if (!header_buf || !symlink_buf || !name_buf)
437 panic("can't allocate buffers");
438
439 state = Start;
440 this_header = 0;
441 message = NULL;
442 while (!message && len) {
443 loff_t saved_offset = this_header;
444 if (*buf == '0' && !(this_header & 3)) {
445 state = Start;
446 written = write_buffer(buf, len);
447 buf += written;
448 len -= written;
449 continue;
450 }
451 if (!*buf) {
452 buf++;
453 len--;
454 this_header++;
455 continue;
456 }
457 this_header = 0;
458 decompress = decompress_method(buf, len, &compress_name);
459 if (decompress) {
460 res = decompress(buf, len, NULL, flush_buffer, NULL,
461 &my_inptr, error);
462 if (res)
463 error("decompressor failed");
464 } else if (compress_name) {
465 if (!message) {
466 snprintf(msg_buf, sizeof msg_buf,
467 "compression method %s not configured",
468 compress_name);
469 message = msg_buf;
470 }
471 } else
472 error("junk in compressed archive");
473 if (state != Reset)
474 error("junk in compressed archive");
475 this_header = saved_offset + my_inptr;
476 buf += my_inptr;
477 len -= my_inptr;
478 }
479 dir_utime();
480 kfree(name_buf);
481 kfree(symlink_buf);
482 kfree(header_buf);
483 return message;
484 }
485
486 static int __initdata do_retain_initrd;
487
retain_initrd_param(char * str)488 static int __init retain_initrd_param(char *str)
489 {
490 if (*str)
491 return 0;
492 do_retain_initrd = 1;
493 return 1;
494 }
495 __setup("retain_initrd", retain_initrd_param);
496
497 extern char __initramfs_start[];
498 extern unsigned long __initramfs_size;
499 #include <linux/initrd.h>
500 #include <linux/kexec.h>
501
free_initrd(void)502 static void __init free_initrd(void)
503 {
504 #ifdef CONFIG_KEXEC
505 unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
506 unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
507 #endif
508 if (do_retain_initrd)
509 goto skip;
510
511 #ifdef CONFIG_KEXEC
512 /*
513 * If the initrd region is overlapped with crashkernel reserved region,
514 * free only memory that is not part of crashkernel region.
515 */
516 if (initrd_start < crashk_end && initrd_end > crashk_start) {
517 /*
518 * Initialize initrd memory region since the kexec boot does
519 * not do.
520 */
521 memset((void *)initrd_start, 0, initrd_end - initrd_start);
522 if (initrd_start < crashk_start)
523 free_initrd_mem(initrd_start, crashk_start);
524 if (initrd_end > crashk_end)
525 free_initrd_mem(crashk_end, initrd_end);
526 } else
527 #endif
528 free_initrd_mem(initrd_start, initrd_end);
529 skip:
530 initrd_start = 0;
531 initrd_end = 0;
532 }
533
534 #ifdef CONFIG_BLK_DEV_RAM
535 #define BUF_SIZE 1024
clean_rootfs(void)536 static void __init clean_rootfs(void)
537 {
538 int fd;
539 void *buf;
540 struct linux_dirent64 *dirp;
541 int num;
542
543 fd = sys_open("/", O_RDONLY, 0);
544 WARN_ON(fd < 0);
545 if (fd < 0)
546 return;
547 buf = kzalloc(BUF_SIZE, GFP_KERNEL);
548 WARN_ON(!buf);
549 if (!buf) {
550 sys_close(fd);
551 return;
552 }
553
554 dirp = buf;
555 num = sys_getdents64(fd, dirp, BUF_SIZE);
556 while (num > 0) {
557 while (num > 0) {
558 struct stat st;
559 int ret;
560
561 ret = sys_newlstat(dirp->d_name, &st);
562 WARN_ON_ONCE(ret);
563 if (!ret) {
564 if (S_ISDIR(st.st_mode))
565 sys_rmdir(dirp->d_name);
566 else
567 sys_unlink(dirp->d_name);
568 }
569
570 num -= dirp->d_reclen;
571 dirp = (void *)dirp + dirp->d_reclen;
572 }
573 dirp = buf;
574 memset(buf, 0, BUF_SIZE);
575 num = sys_getdents64(fd, dirp, BUF_SIZE);
576 }
577
578 sys_close(fd);
579 kfree(buf);
580 }
581 #endif
582
583 static int __initdata do_skip_initramfs;
584
skip_initramfs_param(char * str)585 static int __init skip_initramfs_param(char *str)
586 {
587 if (*str)
588 return 0;
589 do_skip_initramfs = 1;
590 return 1;
591 }
592 __setup("skip_initramfs", skip_initramfs_param);
593
populate_rootfs(void)594 static int __init populate_rootfs(void)
595 {
596 char *err;
597
598 if (do_skip_initramfs)
599 return default_rootfs();
600
601 err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
602 if (err)
603 panic(err); /* Failed to decompress INTERNAL initramfs */
604 if (initrd_start) {
605 #ifdef CONFIG_BLK_DEV_RAM
606 int fd;
607 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
608 err = unpack_to_rootfs((char *)initrd_start,
609 initrd_end - initrd_start);
610 if (!err) {
611 free_initrd();
612 goto done;
613 } else {
614 clean_rootfs();
615 unpack_to_rootfs(__initramfs_start, __initramfs_size);
616 }
617 printk(KERN_INFO "rootfs image is not initramfs (%s)"
618 "; looks like an initrd\n", err);
619 fd = sys_open("/initrd.image",
620 O_WRONLY|O_CREAT, 0700);
621 if (fd >= 0) {
622 sys_write(fd, (char *)initrd_start,
623 initrd_end - initrd_start);
624 sys_close(fd);
625 free_initrd();
626 }
627 done:
628 #else
629 printk(KERN_INFO "Unpacking initramfs...\n");
630 err = unpack_to_rootfs((char *)initrd_start,
631 initrd_end - initrd_start);
632 if (err)
633 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
634 free_initrd();
635 #endif
636 /*
637 * Try loading default modules from initramfs. This gives
638 * us a chance to load before device_initcalls.
639 */
640 load_default_modules();
641 }
642 return 0;
643 }
644 rootfs_initcall(populate_rootfs);
645