projects/linux·blob v3.13 · refs

627 lines · 13.0 KiB

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