projects/linux·blob v3.18 · refs

658 lines · 13.8 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 ssize_t __init xwrite(int fd, const char *p, size_t count)
23{
24 ssize_t out = 0;
25
26 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
27 while (count) {
28 ssize_t rv = sys_write(fd, p, count);
29
30 if (rv < 0) {
31 if (rv == -EINTR || rv == -EAGAIN)
32 continue;
33 return out ? out : rv;
34 } else if (rv == 0)
35 break;
36
37 p += rv;
38 out += rv;
39 count -= rv;
40 }
41
42 return out;
43}
44
45static __initdata char *message;
46static void __init error(char *x)
47{
48 if (!message)
49 message = x;
50}
51
52/* link hash */
53
54#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
55
56static __initdata struct hash {
57 int ino, minor, major;
58 umode_t mode;
59 struct hash *next;
60 char name[N_ALIGN(PATH_MAX)];
61} *head[32];
62
63static inline int hash(int major, int minor, int ino)
64{
65 unsigned long tmp = ino + minor + (major << 3);
66 tmp += tmp >> 5;
67 return tmp & 31;
68}
69
70static char __init *find_link(int major, int minor, int ino,
71 umode_t mode, char *name)
72{
73 struct hash **p, *q;
74 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
75 if ((*p)->ino != ino)
76 continue;
77 if ((*p)->minor != minor)
78 continue;
79 if ((*p)->major != major)
80 continue;
81 if (((*p)->mode ^ mode) & S_IFMT)
82 continue;
83 return (*p)->name;
84 }
85 q = kmalloc(sizeof(struct hash), GFP_KERNEL);
86 if (!q)
87 panic("can't allocate link hash entry");
88 q->major = major;
89 q->minor = minor;
90 q->ino = ino;
91 q->mode = mode;
92 strcpy(q->name, name);
93 q->next = NULL;
94 *p = q;
95 return NULL;
96}
97
98static void __init free_hash(void)
99{
100 struct hash **p, *q;
101 for (p = head; p < head + 32; p++) {
102 while (*p) {
103 q = *p;
104 *p = q->next;
105 kfree(q);
106 }
107 }
108}
109
110static long __init do_utime(char *filename, time_t mtime)
111{
112 struct timespec t[2];
113
114 t[0].tv_sec = mtime;
115 t[0].tv_nsec = 0;
116 t[1].tv_sec = mtime;
117 t[1].tv_nsec = 0;
118
119 return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
120}
121
122static __initdata LIST_HEAD(dir_list);
123struct dir_entry {
124 struct list_head list;
125 char *name;
126 time_t mtime;
127};
128
129static void __init dir_add(const char *name, time_t mtime)
130{
131 struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
132 if (!de)
133 panic("can't allocate dir_entry buffer");
134 INIT_LIST_HEAD(&de->list);
135 de->name = kstrdup(name, GFP_KERNEL);
136 de->mtime = mtime;
137 list_add(&de->list, &dir_list);
138}
139
140static void __init dir_utime(void)
141{
142 struct dir_entry *de, *tmp;
143 list_for_each_entry_safe(de, tmp, &dir_list, list) {
144 list_del(&de->list);
145 do_utime(de->name, de->mtime);
146 kfree(de->name);
147 kfree(de);
148 }
149}
150
151static __initdata time_t mtime;
152
153/* cpio header parsing */
154
155static __initdata unsigned long ino, major, minor, nlink;
156static __initdata umode_t mode;
157static __initdata unsigned long body_len, name_len;
158static __initdata uid_t uid;
159static __initdata gid_t gid;
160static __initdata unsigned rdev;
161
162static void __init parse_header(char *s)
163{
164 unsigned long parsed[12];
165 char buf[9];
166 int i;
167
168 buf[8] = '\0';
169 for (i = 0, s += 6; i < 12; i++, s += 8) {
170 memcpy(buf, s, 8);
171 parsed[i] = simple_strtoul(buf, NULL, 16);
172 }
173 ino = parsed[0];
174 mode = parsed[1];
175 uid = parsed[2];
176 gid = parsed[3];
177 nlink = parsed[4];
178 mtime = parsed[5];
179 body_len = parsed[6];
180 major = parsed[7];
181 minor = parsed[8];
182 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
183 name_len = parsed[11];
184}
185
186/* FSM */
187
188static __initdata enum state {
189 Start,
190 Collect,
191 GotHeader,
192 SkipIt,
193 GotName,
194 CopyFile,
195 GotSymlink,
196 Reset
197} state, next_state;
198
199static __initdata char *victim;
200static unsigned long byte_count __initdata;
201static __initdata loff_t this_header, next_header;
202
203static inline void __init eat(unsigned n)
204{
205 victim += n;
206 this_header += n;
207 byte_count -= n;
208}
209
210static __initdata char *vcollected;
211static __initdata char *collected;
212static long remains __initdata;
213static __initdata char *collect;
214
215static void __init read_into(char *buf, unsigned size, enum state next)
216{
217 if (byte_count >= size) {
218 collected = victim;
219 eat(size);
220 state = next;
221 } else {
222 collect = collected = buf;
223 remains = size;
224 next_state = next;
225 state = Collect;
226 }
227}
228
229static __initdata char *header_buf, *symlink_buf, *name_buf;
230
231static int __init do_start(void)
232{
233 read_into(header_buf, 110, GotHeader);
234 return 0;
235}
236
237static int __init do_collect(void)
238{
239 unsigned long n = remains;
240 if (byte_count < n)
241 n = byte_count;
242 memcpy(collect, victim, n);
243 eat(n);
244 collect += n;
245 if ((remains -= n) != 0)
246 return 1;
247 state = next_state;
248 return 0;
249}
250
251static int __init do_header(void)
252{
253 if (memcmp(collected, "070707", 6)==0) {
254 error("incorrect cpio method used: use -H newc option");
255 return 1;
256 }
257 if (memcmp(collected, "070701", 6)) {
258 error("no cpio magic");
259 return 1;
260 }
261 parse_header(collected);
262 next_header = this_header + N_ALIGN(name_len) + body_len;
263 next_header = (next_header + 3) & ~3;
264 state = SkipIt;
265 if (name_len <= 0 || name_len > PATH_MAX)
266 return 0;
267 if (S_ISLNK(mode)) {
268 if (body_len > PATH_MAX)
269 return 0;
270 collect = collected = symlink_buf;
271 remains = N_ALIGN(name_len) + body_len;
272 next_state = GotSymlink;
273 state = Collect;
274 return 0;
275 }
276 if (S_ISREG(mode) || !body_len)
277 read_into(name_buf, N_ALIGN(name_len), GotName);
278 return 0;
279}
280
281static int __init do_skip(void)
282{
283 if (this_header + byte_count < next_header) {
284 eat(byte_count);
285 return 1;
286 } else {
287 eat(next_header - this_header);
288 state = next_state;
289 return 0;
290 }
291}
292
293static int __init do_reset(void)
294{
295 while (byte_count && *victim == '\0')
296 eat(1);
297 if (byte_count && (this_header & 3))
298 error("broken padding");
299 return 1;
300}
301
302static int __init maybe_link(void)
303{
304 if (nlink >= 2) {
305 char *old = find_link(major, minor, ino, mode, collected);
306 if (old)
307 return (sys_link(old, collected) < 0) ? -1 : 1;
308 }
309 return 0;
310}
311
312static void __init clean_path(char *path, umode_t fmode)
313{
314 struct stat st;
315
316 if (!sys_newlstat(path, &st) && (st.st_mode ^ fmode) & S_IFMT) {
317 if (S_ISDIR(st.st_mode))
318 sys_rmdir(path);
319 else
320 sys_unlink(path);
321 }
322}
323
324static __initdata int wfd;
325
326static int __init do_name(void)
327{
328 state = SkipIt;
329 next_state = Reset;
330 if (strcmp(collected, "TRAILER!!!") == 0) {
331 free_hash();
332 return 0;
333 }
334 clean_path(collected, mode);
335 if (S_ISREG(mode)) {
336 int ml = maybe_link();
337 if (ml >= 0) {
338 int openflags = O_WRONLY|O_CREAT;
339 if (ml != 1)
340 openflags |= O_TRUNC;
341 wfd = sys_open(collected, openflags, mode);
342
343 if (wfd >= 0) {
344 sys_fchown(wfd, uid, gid);
345 sys_fchmod(wfd, mode);
346 if (body_len)
347 sys_ftruncate(wfd, body_len);
348 vcollected = kstrdup(collected, GFP_KERNEL);
349 state = CopyFile;
350 }
351 }
352 } else if (S_ISDIR(mode)) {
353 sys_mkdir(collected, mode);
354 sys_chown(collected, uid, gid);
355 sys_chmod(collected, mode);
356 dir_add(collected, mtime);
357 } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
358 S_ISFIFO(mode) || S_ISSOCK(mode)) {
359 if (maybe_link() == 0) {
360 sys_mknod(collected, mode, rdev);
361 sys_chown(collected, uid, gid);
362 sys_chmod(collected, mode);
363 do_utime(collected, mtime);
364 }
365 }
366 return 0;
367}
368
369static int __init do_copy(void)
370{
371 if (byte_count >= body_len) {
372 if (xwrite(wfd, victim, body_len) != body_len)
373 error("write error");
374 sys_close(wfd);
375 do_utime(vcollected, mtime);
376 kfree(vcollected);
377 eat(body_len);
378 state = SkipIt;
379 return 0;
380 } else {
381 if (xwrite(wfd, victim, byte_count) != byte_count)
382 error("write error");
383 body_len -= byte_count;
384 eat(byte_count);
385 return 1;
386 }
387}
388
389static int __init do_symlink(void)
390{
391 collected[N_ALIGN(name_len) + body_len] = '\0';
392 clean_path(collected, 0);
393 sys_symlink(collected + N_ALIGN(name_len), collected);
394 sys_lchown(collected, uid, gid);
395 do_utime(collected, mtime);
396 state = SkipIt;
397 next_state = Reset;
398 return 0;
399}
400
401static __initdata int (*actions[])(void) = {
402 [Start] = do_start,
403 [Collect] = do_collect,
404 [GotHeader] = do_header,
405 [SkipIt] = do_skip,
406 [GotName] = do_name,
407 [CopyFile] = do_copy,
408 [GotSymlink] = do_symlink,
409 [Reset] = do_reset,
410};
411
412static long __init write_buffer(char *buf, unsigned long len)
413{
414 byte_count = len;
415 victim = buf;
416
417 while (!actions[state]())
418 ;
419 return len - byte_count;
420}
421
422static long __init flush_buffer(void *bufv, unsigned long len)
423{
424 char *buf = (char *) bufv;
425 long written;
426 long origLen = len;
427 if (message)
428 return -1;
429 while ((written = write_buffer(buf, len)) < len && !message) {
430 char c = buf[written];
431 if (c == '0') {
432 buf += written;
433 len -= written;
434 state = Start;
435 } else if (c == 0) {
436 buf += written;
437 len -= written;
438 state = Reset;
439 } else
440 error("junk in compressed archive");
441 }
442 return origLen;
443}
444
445static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
446
447#include <linux/decompress/generic.h>
448
449static char * __init unpack_to_rootfs(char *buf, unsigned long len)
450{
451 long written;
452 decompress_fn decompress;
453 const char *compress_name;
454 static __initdata char msg_buf[64];
455
456 header_buf = kmalloc(110, GFP_KERNEL);
457 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
458 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
459
460 if (!header_buf || !symlink_buf || !name_buf)
461 panic("can't allocate buffers");
462
463 state = Start;
464 this_header = 0;
465 message = NULL;
466 while (!message && len) {
467 loff_t saved_offset = this_header;
468 if (*buf == '0' && !(this_header & 3)) {
469 state = Start;
470 written = write_buffer(buf, len);
471 buf += written;
472 len -= written;
473 continue;
474 }
475 if (!*buf) {
476 buf++;
477 len--;
478 this_header++;
479 continue;
480 }
481 this_header = 0;
482 decompress = decompress_method(buf, len, &compress_name);
483 pr_debug("Detected %s compressed data\n", compress_name);
484 if (decompress) {
485 int res = decompress(buf, len, NULL, flush_buffer, NULL,
486 &my_inptr, error);
487 if (res)
488 error("decompressor failed");
489 } else if (compress_name) {
490 if (!message) {
491 snprintf(msg_buf, sizeof msg_buf,
492 "compression method %s not configured",
493 compress_name);
494 message = msg_buf;
495 }
496 } else
497 error("junk in compressed archive");
498 if (state != Reset)
499 error("junk in compressed archive");
500 this_header = saved_offset + my_inptr;
501 buf += my_inptr;
502 len -= my_inptr;
503 }
504 dir_utime();
505 kfree(name_buf);
506 kfree(symlink_buf);
507 kfree(header_buf);
508 return message;
509}
510
511static int __initdata do_retain_initrd;
512
513static int __init retain_initrd_param(char *str)
514{
515 if (*str)
516 return 0;
517 do_retain_initrd = 1;
518 return 1;
519}
520__setup("retain_initrd", retain_initrd_param);
521
522extern char __initramfs_start[];
523extern unsigned long __initramfs_size;
524#include <linux/initrd.h>
525#include <linux/kexec.h>
526
527static void __init free_initrd(void)
528{
529#ifdef CONFIG_KEXEC
530 unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
531 unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
532#endif
533 if (do_retain_initrd)
534 goto skip;
535
536#ifdef CONFIG_KEXEC
537 /*
538 * If the initrd region is overlapped with crashkernel reserved region,
539 * free only memory that is not part of crashkernel region.
540 */
541 if (initrd_start < crashk_end && initrd_end > crashk_start) {
542 /*
543 * Initialize initrd memory region since the kexec boot does
544 * not do.
545 */
546 memset((void *)initrd_start, 0, initrd_end - initrd_start);
547 if (initrd_start < crashk_start)
548 free_initrd_mem(initrd_start, crashk_start);
549 if (initrd_end > crashk_end)
550 free_initrd_mem(crashk_end, initrd_end);
551 } else
552#endif
553 free_initrd_mem(initrd_start, initrd_end);
554skip:
555 initrd_start = 0;
556 initrd_end = 0;
557}
558
559#ifdef CONFIG_BLK_DEV_RAM
560#define BUF_SIZE 1024
561static void __init clean_rootfs(void)
562{
563 int fd;
564 void *buf;
565 struct linux_dirent64 *dirp;
566 int num;
567
568 fd = sys_open("/", O_RDONLY, 0);
569 WARN_ON(fd < 0);
570 if (fd < 0)
571 return;
572 buf = kzalloc(BUF_SIZE, GFP_KERNEL);
573 WARN_ON(!buf);
574 if (!buf) {
575 sys_close(fd);
576 return;
577 }
578
579 dirp = buf;
580 num = sys_getdents64(fd, dirp, BUF_SIZE);
581 while (num > 0) {
582 while (num > 0) {
583 struct stat st;
584 int ret;
585
586 ret = sys_newlstat(dirp->d_name, &st);
587 WARN_ON_ONCE(ret);
588 if (!ret) {
589 if (S_ISDIR(st.st_mode))
590 sys_rmdir(dirp->d_name);
591 else
592 sys_unlink(dirp->d_name);
593 }
594
595 num -= dirp->d_reclen;
596 dirp = (void *)dirp + dirp->d_reclen;
597 }
598 dirp = buf;
599 memset(buf, 0, BUF_SIZE);
600 num = sys_getdents64(fd, dirp, BUF_SIZE);
601 }
602
603 sys_close(fd);
604 kfree(buf);
605}
606#endif
607
608static int __init populate_rootfs(void)
609{
610 char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
611 if (err)
612 panic("%s", err); /* Failed to decompress INTERNAL initramfs */
613 if (initrd_start) {
614#ifdef CONFIG_BLK_DEV_RAM
615 int fd;
616 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
617 err = unpack_to_rootfs((char *)initrd_start,
618 initrd_end - initrd_start);
619 if (!err) {
620 free_initrd();
621 goto done;
622 } else {
623 clean_rootfs();
624 unpack_to_rootfs(__initramfs_start, __initramfs_size);
625 }
626 printk(KERN_INFO "rootfs image is not initramfs (%s)"
627 "; looks like an initrd\n", err);
628 fd = sys_open("/initrd.image",
629 O_WRONLY|O_CREAT, 0700);
630 if (fd >= 0) {
631 ssize_t written = xwrite(fd, (char *)initrd_start,
632 initrd_end - initrd_start);
633
634 if (written != initrd_end - initrd_start)
635 pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
636 written, initrd_end - initrd_start);
637
638 sys_close(fd);
639 free_initrd();
640 }
641 done:
642#else
643 printk(KERN_INFO "Unpacking initramfs...\n");
644 err = unpack_to_rootfs((char *)initrd_start,
645 initrd_end - initrd_start);
646 if (err)
647 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
648 free_initrd();
649#endif
650 /*
651 * Try loading default modules from initramfs. This gives
652 * us a chance to load before device_initcalls.
653 */
654 load_default_modules();
655 }
656 return 0;
657}
658rootfs_initcall(populate_rootfs);