projects/linux·blob v3.2 · refs

611 lines · 12.6 KiB

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