projects/linux·blob v2.6.23 · refs

585 lines · 11.9 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/syscalls.h>
9
10static __initdata char *message;
11static void __init error(char *x)
12{
13 if (!message)
14 message = x;
15}
16
17static void __init *malloc(size_t size)
18{
19 return kmalloc(size, GFP_KERNEL);
20}
21
22static void __init free(void *where)
23{
24 kfree(where);
25}
26
27/* link hash */
28
29#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
30
31static __initdata struct hash {
32 int ino, minor, major;
33 mode_t mode;
34 struct hash *next;
35 char name[N_ALIGN(PATH_MAX)];
36} *head[32];
37
38static inline int hash(int major, int minor, int ino)
39{
40 unsigned long tmp = ino + minor + (major << 3);
41 tmp += tmp >> 5;
42 return tmp & 31;
43}
44
45static char __init *find_link(int major, int minor, int ino,
46 mode_t mode, char *name)
47{
48 struct hash **p, *q;
49 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
50 if ((*p)->ino != ino)
51 continue;
52 if ((*p)->minor != minor)
53 continue;
54 if ((*p)->major != major)
55 continue;
56 if (((*p)->mode ^ mode) & S_IFMT)
57 continue;
58 return (*p)->name;
59 }
60 q = (struct hash *)malloc(sizeof(struct hash));
61 if (!q)
62 panic("can't allocate link hash entry");
63 q->major = major;
64 q->minor = minor;
65 q->ino = ino;
66 q->mode = mode;
67 strcpy(q->name, name);
68 q->next = NULL;
69 *p = q;
70 return NULL;
71}
72
73static void __init free_hash(void)
74{
75 struct hash **p, *q;
76 for (p = head; p < head + 32; p++) {
77 while (*p) {
78 q = *p;
79 *p = q->next;
80 free(q);
81 }
82 }
83}
84
85/* cpio header parsing */
86
87static __initdata unsigned long ino, major, minor, nlink;
88static __initdata mode_t mode;
89static __initdata unsigned long body_len, name_len;
90static __initdata uid_t uid;
91static __initdata gid_t gid;
92static __initdata unsigned rdev;
93
94static void __init parse_header(char *s)
95{
96 unsigned long parsed[12];
97 char buf[9];
98 int i;
99
100 buf[8] = '\0';
101 for (i = 0, s += 6; i < 12; i++, s += 8) {
102 memcpy(buf, s, 8);
103 parsed[i] = simple_strtoul(buf, NULL, 16);
104 }
105 ino = parsed[0];
106 mode = parsed[1];
107 uid = parsed[2];
108 gid = parsed[3];
109 nlink = parsed[4];
110 body_len = parsed[6];
111 major = parsed[7];
112 minor = parsed[8];
113 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
114 name_len = parsed[11];
115}
116
117/* FSM */
118
119static __initdata enum state {
120 Start,
121 Collect,
122 GotHeader,
123 SkipIt,
124 GotName,
125 CopyFile,
126 GotSymlink,
127 Reset
128} state, next_state;
129
130static __initdata char *victim;
131static __initdata unsigned count;
132static __initdata loff_t this_header, next_header;
133
134static __initdata int dry_run;
135
136static inline void __init eat(unsigned n)
137{
138 victim += n;
139 this_header += n;
140 count -= n;
141}
142
143static __initdata char *collected;
144static __initdata int remains;
145static __initdata char *collect;
146
147static void __init read_into(char *buf, unsigned size, enum state next)
148{
149 if (count >= size) {
150 collected = victim;
151 eat(size);
152 state = next;
153 } else {
154 collect = collected = buf;
155 remains = size;
156 next_state = next;
157 state = Collect;
158 }
159}
160
161static __initdata char *header_buf, *symlink_buf, *name_buf;
162
163static int __init do_start(void)
164{
165 read_into(header_buf, 110, GotHeader);
166 return 0;
167}
168
169static int __init do_collect(void)
170{
171 unsigned n = remains;
172 if (count < n)
173 n = count;
174 memcpy(collect, victim, n);
175 eat(n);
176 collect += n;
177 if ((remains -= n) != 0)
178 return 1;
179 state = next_state;
180 return 0;
181}
182
183static int __init do_header(void)
184{
185 if (memcmp(collected, "070707", 6)==0) {
186 error("incorrect cpio method used: use -H newc option");
187 return 1;
188 }
189 if (memcmp(collected, "070701", 6)) {
190 error("no cpio magic");
191 return 1;
192 }
193 parse_header(collected);
194 next_header = this_header + N_ALIGN(name_len) + body_len;
195 next_header = (next_header + 3) & ~3;
196 if (dry_run) {
197 read_into(name_buf, N_ALIGN(name_len), GotName);
198 return 0;
199 }
200 state = SkipIt;
201 if (name_len <= 0 || name_len > PATH_MAX)
202 return 0;
203 if (S_ISLNK(mode)) {
204 if (body_len > PATH_MAX)
205 return 0;
206 collect = collected = symlink_buf;
207 remains = N_ALIGN(name_len) + body_len;
208 next_state = GotSymlink;
209 state = Collect;
210 return 0;
211 }
212 if (S_ISREG(mode) || !body_len)
213 read_into(name_buf, N_ALIGN(name_len), GotName);
214 return 0;
215}
216
217static int __init do_skip(void)
218{
219 if (this_header + count < next_header) {
220 eat(count);
221 return 1;
222 } else {
223 eat(next_header - this_header);
224 state = next_state;
225 return 0;
226 }
227}
228
229static int __init do_reset(void)
230{
231 while(count && *victim == '\0')
232 eat(1);
233 if (count && (this_header & 3))
234 error("broken padding");
235 return 1;
236}
237
238static int __init maybe_link(void)
239{
240 if (nlink >= 2) {
241 char *old = find_link(major, minor, ino, mode, collected);
242 if (old)
243 return (sys_link(old, collected) < 0) ? -1 : 1;
244 }
245 return 0;
246}
247
248static void __init clean_path(char *path, mode_t mode)
249{
250 struct stat st;
251
252 if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
253 if (S_ISDIR(st.st_mode))
254 sys_rmdir(path);
255 else
256 sys_unlink(path);
257 }
258}
259
260static __initdata int wfd;
261
262static int __init do_name(void)
263{
264 state = SkipIt;
265 next_state = Reset;
266 if (strcmp(collected, "TRAILER!!!") == 0) {
267 free_hash();
268 return 0;
269 }
270 if (dry_run)
271 return 0;
272 clean_path(collected, mode);
273 if (S_ISREG(mode)) {
274 int ml = maybe_link();
275 if (ml >= 0) {
276 int openflags = O_WRONLY|O_CREAT;
277 if (ml != 1)
278 openflags |= O_TRUNC;
279 wfd = sys_open(collected, openflags, mode);
280
281 if (wfd >= 0) {
282 sys_fchown(wfd, uid, gid);
283 sys_fchmod(wfd, mode);
284 state = CopyFile;
285 }
286 }
287 } else if (S_ISDIR(mode)) {
288 sys_mkdir(collected, mode);
289 sys_chown(collected, uid, gid);
290 sys_chmod(collected, mode);
291 } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
292 S_ISFIFO(mode) || S_ISSOCK(mode)) {
293 if (maybe_link() == 0) {
294 sys_mknod(collected, mode, rdev);
295 sys_chown(collected, uid, gid);
296 sys_chmod(collected, mode);
297 }
298 }
299 return 0;
300}
301
302static int __init do_copy(void)
303{
304 if (count >= body_len) {
305 sys_write(wfd, victim, body_len);
306 sys_close(wfd);
307 eat(body_len);
308 state = SkipIt;
309 return 0;
310 } else {
311 sys_write(wfd, victim, count);
312 body_len -= count;
313 eat(count);
314 return 1;
315 }
316}
317
318static int __init do_symlink(void)
319{
320 collected[N_ALIGN(name_len) + body_len] = '\0';
321 clean_path(collected, 0);
322 sys_symlink(collected + N_ALIGN(name_len), collected);
323 sys_lchown(collected, uid, gid);
324 state = SkipIt;
325 next_state = Reset;
326 return 0;
327}
328
329static __initdata int (*actions[])(void) = {
330 [Start] = do_start,
331 [Collect] = do_collect,
332 [GotHeader] = do_header,
333 [SkipIt] = do_skip,
334 [GotName] = do_name,
335 [CopyFile] = do_copy,
336 [GotSymlink] = do_symlink,
337 [Reset] = do_reset,
338};
339
340static int __init write_buffer(char *buf, unsigned len)
341{
342 count = len;
343 victim = buf;
344
345 while (!actions[state]())
346 ;
347 return len - count;
348}
349
350static void __init flush_buffer(char *buf, unsigned len)
351{
352 int written;
353 if (message)
354 return;
355 while ((written = write_buffer(buf, len)) < len && !message) {
356 char c = buf[written];
357 if (c == '0') {
358 buf += written;
359 len -= written;
360 state = Start;
361 } else if (c == 0) {
362 buf += written;
363 len -= written;
364 state = Reset;
365 } else
366 error("junk in compressed archive");
367 }
368}
369
370/*
371 * gzip declarations
372 */
373
374#define OF(args) args
375
376#ifndef memzero
377#define memzero(s, n) memset ((s), 0, (n))
378#endif
379
380typedef unsigned char uch;
381typedef unsigned short ush;
382typedef unsigned long ulg;
383
384#define WSIZE 0x8000 /* window size--must be a power of two, and */
385 /* at least 32K for zip's deflate method */
386
387static uch *inbuf;
388static uch *window;
389
390static unsigned insize; /* valid bytes in inbuf */
391static unsigned inptr; /* index of next byte to be processed in inbuf */
392static unsigned outcnt; /* bytes in output buffer */
393static long bytes_out;
394
395#define get_byte() (inptr < insize ? inbuf[inptr++] : -1)
396
397/* Diagnostic functions (stubbed out) */
398#define Assert(cond,msg)
399#define Trace(x)
400#define Tracev(x)
401#define Tracevv(x)
402#define Tracec(c,x)
403#define Tracecv(c,x)
404
405#define STATIC static
406#define INIT __init
407
408static void __init flush_window(void);
409static void __init error(char *m);
410static void __init gzip_mark(void **);
411static void __init gzip_release(void **);
412
413#include "../lib/inflate.c"
414
415static void __init gzip_mark(void **ptr)
416{
417}
418
419static void __init gzip_release(void **ptr)
420{
421}
422
423/* ===========================================================================
424 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
425 * (Used for the decompressed data only.)
426 */
427static void __init flush_window(void)
428{
429 ulg c = crc; /* temporary variable */
430 unsigned n;
431 uch *in, ch;
432
433 flush_buffer(window, outcnt);
434 in = window;
435 for (n = 0; n < outcnt; n++) {
436 ch = *in++;
437 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
438 }
439 crc = c;
440 bytes_out += (ulg)outcnt;
441 outcnt = 0;
442}
443
444static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
445{
446 int written;
447 dry_run = check_only;
448 header_buf = malloc(110);
449 symlink_buf = malloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1);
450 name_buf = malloc(N_ALIGN(PATH_MAX));
451 window = malloc(WSIZE);
452 if (!window || !header_buf || !symlink_buf || !name_buf)
453 panic("can't allocate buffers");
454 state = Start;
455 this_header = 0;
456 message = NULL;
457 while (!message && len) {
458 loff_t saved_offset = this_header;
459 if (*buf == '0' && !(this_header & 3)) {
460 state = Start;
461 written = write_buffer(buf, len);
462 buf += written;
463 len -= written;
464 continue;
465 }
466 if (!*buf) {
467 buf++;
468 len--;
469 this_header++;
470 continue;
471 }
472 this_header = 0;
473 insize = len;
474 inbuf = buf;
475 inptr = 0;
476 outcnt = 0; /* bytes in output buffer */
477 bytes_out = 0;
478 crc = (ulg)0xffffffffL; /* shift register contents */
479 makecrc();
480 gunzip();
481 if (state != Reset)
482 error("junk in gzipped archive");
483 this_header = saved_offset + inptr;
484 buf += inptr;
485 len -= inptr;
486 }
487 free(window);
488 free(name_buf);
489 free(symlink_buf);
490 free(header_buf);
491 return message;
492}
493
494static int __initdata do_retain_initrd;
495
496static int __init retain_initrd_param(char *str)
497{
498 if (*str)
499 return 0;
500 do_retain_initrd = 1;
501 return 1;
502}
503__setup("retain_initrd", retain_initrd_param);
504
505extern char __initramfs_start[], __initramfs_end[];
506#ifdef CONFIG_BLK_DEV_INITRD
507#include <linux/initrd.h>
508#include <linux/kexec.h>
509
510static void __init free_initrd(void)
511{
512#ifdef CONFIG_KEXEC
513 unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
514 unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
515#endif
516 if (do_retain_initrd)
517 goto skip;
518
519#ifdef CONFIG_KEXEC
520 /*
521 * If the initrd region is overlapped with crashkernel reserved region,
522 * free only memory that is not part of crashkernel region.
523 */
524 if (initrd_start < crashk_end && initrd_end > crashk_start) {
525 /*
526 * Initialize initrd memory region since the kexec boot does
527 * not do.
528 */
529 memset((void *)initrd_start, 0, initrd_end - initrd_start);
530 if (initrd_start < crashk_start)
531 free_initrd_mem(initrd_start, crashk_start);
532 if (initrd_end > crashk_end)
533 free_initrd_mem(crashk_end, initrd_end);
534 } else
535#endif
536 free_initrd_mem(initrd_start, initrd_end);
537skip:
538 initrd_start = 0;
539 initrd_end = 0;
540}
541
542#endif
543
544static int __init populate_rootfs(void)
545{
546 char *err = unpack_to_rootfs(__initramfs_start,
547 __initramfs_end - __initramfs_start, 0);
548 if (err)
549 panic(err);
550#ifdef CONFIG_BLK_DEV_INITRD
551 if (initrd_start) {
552#ifdef CONFIG_BLK_DEV_RAM
553 int fd;
554 printk(KERN_INFO "checking if image is initramfs...");
555 err = unpack_to_rootfs((char *)initrd_start,
556 initrd_end - initrd_start, 1);
557 if (!err) {
558 printk(" it is\n");
559 unpack_to_rootfs((char *)initrd_start,
560 initrd_end - initrd_start, 0);
561 free_initrd();
562 return 0;
563 }
564 printk("it isn't (%s); looks like an initrd\n", err);
565 fd = sys_open("/initrd.image", O_WRONLY|O_CREAT, 0700);
566 if (fd >= 0) {
567 sys_write(fd, (char *)initrd_start,
568 initrd_end - initrd_start);
569 sys_close(fd);
570 free_initrd();
571 }
572#else
573 printk(KERN_INFO "Unpacking initramfs...");
574 err = unpack_to_rootfs((char *)initrd_start,
575 initrd_end - initrd_start, 0);
576 if (err)
577 panic(err);
578 printk(" done\n");
579 free_initrd();
580#endif
581 }
582#endif
583 return 0;
584}
585rootfs_initcall(populate_rootfs);