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v3.1
 
 
 
 
 
 
 
 
 
 
 
  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);
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Many of the syscalls used in this file expect some of the arguments
  4 * to be __user pointers not __kernel pointers.  To limit the sparse
  5 * noise, turn off sparse checking for this file.
  6 */
  7#ifdef __CHECKER__
  8#undef __CHECKER__
  9#warning "Sparse checking disabled for this file"
 10#endif
 11
 12#include <linux/init.h>
 13#include <linux/fs.h>
 14#include <linux/slab.h>
 15#include <linux/types.h>
 16#include <linux/fcntl.h>
 17#include <linux/delay.h>
 18#include <linux/string.h>
 19#include <linux/dirent.h>
 20#include <linux/syscalls.h>
 21#include <linux/utime.h>
 22#include <linux/file.h>
 23
 24static ssize_t __init xwrite(int fd, const char *p, size_t count)
 25{
 26	ssize_t out = 0;
 27
 28	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
 29	while (count) {
 30		ssize_t rv = ksys_write(fd, p, count);
 31
 32		if (rv < 0) {
 33			if (rv == -EINTR || rv == -EAGAIN)
 34				continue;
 35			return out ? out : rv;
 36		} else if (rv == 0)
 37			break;
 38
 39		p += rv;
 40		out += rv;
 41		count -= rv;
 42	}
 43
 44	return out;
 45}
 46
 47static __initdata char *message;
 48static void __init error(char *x)
 49{
 50	if (!message)
 51		message = x;
 52}
 53
 54/* link hash */
 55
 56#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
 57
 58static __initdata struct hash {
 59	int ino, minor, major;
 60	umode_t mode;
 61	struct hash *next;
 62	char name[N_ALIGN(PATH_MAX)];
 63} *head[32];
 64
 65static inline int hash(int major, int minor, int ino)
 66{
 67	unsigned long tmp = ino + minor + (major << 3);
 68	tmp += tmp >> 5;
 69	return tmp & 31;
 70}
 71
 72static char __init *find_link(int major, int minor, int ino,
 73			      umode_t mode, char *name)
 74{
 75	struct hash **p, *q;
 76	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
 77		if ((*p)->ino != ino)
 78			continue;
 79		if ((*p)->minor != minor)
 80			continue;
 81		if ((*p)->major != major)
 82			continue;
 83		if (((*p)->mode ^ mode) & S_IFMT)
 84			continue;
 85		return (*p)->name;
 86	}
 87	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
 88	if (!q)
 89		panic("can't allocate link hash entry");
 90	q->major = major;
 91	q->minor = minor;
 92	q->ino = ino;
 93	q->mode = mode;
 94	strcpy(q->name, name);
 95	q->next = NULL;
 96	*p = q;
 97	return NULL;
 98}
 99
100static void __init free_hash(void)
101{
102	struct hash **p, *q;
103	for (p = head; p < head + 32; p++) {
104		while (*p) {
105			q = *p;
106			*p = q->next;
107			kfree(q);
108		}
109	}
110}
111
112static long __init do_utime(char *filename, time64_t mtime)
113{
114	struct timespec64 t[2];
115
116	t[0].tv_sec = mtime;
117	t[0].tv_nsec = 0;
118	t[1].tv_sec = mtime;
119	t[1].tv_nsec = 0;
120
121	return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
122}
123
124static __initdata LIST_HEAD(dir_list);
125struct dir_entry {
126	struct list_head list;
127	char *name;
128	time64_t mtime;
129};
130
131static void __init dir_add(const char *name, time64_t mtime)
132{
133	struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
134	if (!de)
135		panic("can't allocate dir_entry buffer");
136	INIT_LIST_HEAD(&de->list);
137	de->name = kstrdup(name, GFP_KERNEL);
138	de->mtime = mtime;
139	list_add(&de->list, &dir_list);
140}
141
142static void __init dir_utime(void)
143{
144	struct dir_entry *de, *tmp;
145	list_for_each_entry_safe(de, tmp, &dir_list, list) {
146		list_del(&de->list);
147		do_utime(de->name, de->mtime);
148		kfree(de->name);
149		kfree(de);
150	}
151}
152
153static __initdata time64_t mtime;
154
155/* cpio header parsing */
156
157static __initdata unsigned long ino, major, minor, nlink;
158static __initdata umode_t mode;
159static __initdata unsigned long body_len, name_len;
160static __initdata uid_t uid;
161static __initdata gid_t gid;
162static __initdata unsigned rdev;
163
164static void __init parse_header(char *s)
165{
166	unsigned long parsed[12];
167	char buf[9];
168	int i;
169
170	buf[8] = '\0';
171	for (i = 0, s += 6; i < 12; i++, s += 8) {
172		memcpy(buf, s, 8);
173		parsed[i] = simple_strtoul(buf, NULL, 16);
174	}
175	ino = parsed[0];
176	mode = parsed[1];
177	uid = parsed[2];
178	gid = parsed[3];
179	nlink = parsed[4];
180	mtime = parsed[5]; /* breaks in y2106 */
181	body_len = parsed[6];
182	major = parsed[7];
183	minor = parsed[8];
184	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
185	name_len = parsed[11];
186}
187
188/* FSM */
189
190static __initdata enum state {
191	Start,
192	Collect,
193	GotHeader,
194	SkipIt,
195	GotName,
196	CopyFile,
197	GotSymlink,
198	Reset
199} state, next_state;
200
201static __initdata char *victim;
202static unsigned long byte_count __initdata;
203static __initdata loff_t this_header, next_header;
204
205static inline void __init eat(unsigned n)
206{
207	victim += n;
208	this_header += n;
209	byte_count -= n;
210}
211
212static __initdata char *vcollected;
213static __initdata char *collected;
214static long remains __initdata;
215static __initdata char *collect;
216
217static void __init read_into(char *buf, unsigned size, enum state next)
218{
219	if (byte_count >= size) {
220		collected = victim;
221		eat(size);
222		state = next;
223	} else {
224		collect = collected = buf;
225		remains = size;
226		next_state = next;
227		state = Collect;
228	}
229}
230
231static __initdata char *header_buf, *symlink_buf, *name_buf;
232
233static int __init do_start(void)
234{
235	read_into(header_buf, 110, GotHeader);
236	return 0;
237}
238
239static int __init do_collect(void)
240{
241	unsigned long n = remains;
242	if (byte_count < n)
243		n = byte_count;
244	memcpy(collect, victim, n);
245	eat(n);
246	collect += n;
247	if ((remains -= n) != 0)
248		return 1;
249	state = next_state;
250	return 0;
251}
252
253static int __init do_header(void)
254{
255	if (memcmp(collected, "070707", 6)==0) {
256		error("incorrect cpio method used: use -H newc option");
257		return 1;
258	}
259	if (memcmp(collected, "070701", 6)) {
260		error("no cpio magic");
261		return 1;
262	}
263	parse_header(collected);
264	next_header = this_header + N_ALIGN(name_len) + body_len;
265	next_header = (next_header + 3) & ~3;
266	state = SkipIt;
267	if (name_len <= 0 || name_len > PATH_MAX)
268		return 0;
269	if (S_ISLNK(mode)) {
270		if (body_len > PATH_MAX)
271			return 0;
272		collect = collected = symlink_buf;
273		remains = N_ALIGN(name_len) + body_len;
274		next_state = GotSymlink;
275		state = Collect;
276		return 0;
277	}
278	if (S_ISREG(mode) || !body_len)
279		read_into(name_buf, N_ALIGN(name_len), GotName);
280	return 0;
281}
282
283static int __init do_skip(void)
284{
285	if (this_header + byte_count < next_header) {
286		eat(byte_count);
287		return 1;
288	} else {
289		eat(next_header - this_header);
290		state = next_state;
291		return 0;
292	}
293}
294
295static int __init do_reset(void)
296{
297	while (byte_count && *victim == '\0')
298		eat(1);
299	if (byte_count && (this_header & 3))
300		error("broken padding");
301	return 1;
302}
303
304static int __init maybe_link(void)
305{
306	if (nlink >= 2) {
307		char *old = find_link(major, minor, ino, mode, collected);
308		if (old)
309			return (ksys_link(old, collected) < 0) ? -1 : 1;
310	}
311	return 0;
312}
313
314static void __init clean_path(char *path, umode_t fmode)
315{
316	struct kstat st;
317
318	if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
319		if (S_ISDIR(st.mode))
320			ksys_rmdir(path);
321		else
322			ksys_unlink(path);
323	}
324}
325
326static __initdata int wfd;
327
328static int __init do_name(void)
329{
330	state = SkipIt;
331	next_state = Reset;
332	if (strcmp(collected, "TRAILER!!!") == 0) {
333		free_hash();
334		return 0;
335	}
336	clean_path(collected, mode);
337	if (S_ISREG(mode)) {
338		int ml = maybe_link();
339		if (ml >= 0) {
340			int openflags = O_WRONLY|O_CREAT;
341			if (ml != 1)
342				openflags |= O_TRUNC;
343			wfd = ksys_open(collected, openflags, mode);
344
345			if (wfd >= 0) {
346				ksys_fchown(wfd, uid, gid);
347				ksys_fchmod(wfd, mode);
348				if (body_len)
349					ksys_ftruncate(wfd, body_len);
350				vcollected = kstrdup(collected, GFP_KERNEL);
351				state = CopyFile;
352			}
353		}
354	} else if (S_ISDIR(mode)) {
355		ksys_mkdir(collected, mode);
356		ksys_chown(collected, uid, gid);
357		ksys_chmod(collected, mode);
358		dir_add(collected, mtime);
359	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
360		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
361		if (maybe_link() == 0) {
362			ksys_mknod(collected, mode, rdev);
363			ksys_chown(collected, uid, gid);
364			ksys_chmod(collected, mode);
365			do_utime(collected, mtime);
366		}
367	}
368	return 0;
369}
370
371static int __init do_copy(void)
372{
373	if (byte_count >= body_len) {
374		if (xwrite(wfd, victim, body_len) != body_len)
375			error("write error");
376		ksys_close(wfd);
377		do_utime(vcollected, mtime);
378		kfree(vcollected);
379		eat(body_len);
380		state = SkipIt;
381		return 0;
382	} else {
383		if (xwrite(wfd, victim, byte_count) != byte_count)
384			error("write error");
385		body_len -= byte_count;
386		eat(byte_count);
387		return 1;
388	}
389}
390
391static int __init do_symlink(void)
392{
393	collected[N_ALIGN(name_len) + body_len] = '\0';
394	clean_path(collected, 0);
395	ksys_symlink(collected + N_ALIGN(name_len), collected);
396	ksys_lchown(collected, uid, gid);
397	do_utime(collected, mtime);
398	state = SkipIt;
399	next_state = Reset;
400	return 0;
401}
402
403static __initdata int (*actions[])(void) = {
404	[Start]		= do_start,
405	[Collect]	= do_collect,
406	[GotHeader]	= do_header,
407	[SkipIt]	= do_skip,
408	[GotName]	= do_name,
409	[CopyFile]	= do_copy,
410	[GotSymlink]	= do_symlink,
411	[Reset]		= do_reset,
412};
413
414static long __init write_buffer(char *buf, unsigned long len)
415{
416	byte_count = len;
417	victim = buf;
418
419	while (!actions[state]())
420		;
421	return len - byte_count;
422}
423
424static long __init flush_buffer(void *bufv, unsigned long len)
425{
426	char *buf = (char *) bufv;
427	long written;
428	long origLen = len;
429	if (message)
430		return -1;
431	while ((written = write_buffer(buf, len)) < len && !message) {
432		char c = buf[written];
433		if (c == '0') {
434			buf += written;
435			len -= written;
436			state = Start;
437		} else if (c == 0) {
438			buf += written;
439			len -= written;
440			state = Reset;
441		} else
442			error("junk in compressed archive");
443	}
444	return origLen;
445}
446
447static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
448
449#include <linux/decompress/generic.h>
450
451static char * __init unpack_to_rootfs(char *buf, unsigned long len)
452{
453	long written;
454	decompress_fn decompress;
455	const char *compress_name;
456	static __initdata char msg_buf[64];
457
458	header_buf = kmalloc(110, GFP_KERNEL);
459	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
460	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
461
462	if (!header_buf || !symlink_buf || !name_buf)
463		panic("can't allocate buffers");
464
465	state = Start;
466	this_header = 0;
467	message = NULL;
468	while (!message && len) {
469		loff_t saved_offset = this_header;
470		if (*buf == '0' && !(this_header & 3)) {
471			state = Start;
472			written = write_buffer(buf, len);
473			buf += written;
474			len -= written;
475			continue;
476		}
477		if (!*buf) {
478			buf++;
479			len--;
480			this_header++;
481			continue;
482		}
483		this_header = 0;
484		decompress = decompress_method(buf, len, &compress_name);
485		pr_debug("Detected %s compressed data\n", compress_name);
486		if (decompress) {
487			int res = decompress(buf, len, NULL, flush_buffer, NULL,
488				   &my_inptr, error);
489			if (res)
490				error("decompressor failed");
491		} else if (compress_name) {
492			if (!message) {
493				snprintf(msg_buf, sizeof msg_buf,
494					 "compression method %s not configured",
495					 compress_name);
496				message = msg_buf;
497			}
498		} else
499			error("junk in compressed archive");
500		if (state != Reset)
501			error("junk in compressed archive");
502		this_header = saved_offset + my_inptr;
503		buf += my_inptr;
504		len -= my_inptr;
505	}
506	dir_utime();
507	kfree(name_buf);
508	kfree(symlink_buf);
509	kfree(header_buf);
510	return message;
511}
512
513static int __initdata do_retain_initrd;
514
515static int __init retain_initrd_param(char *str)
516{
517	if (*str)
518		return 0;
519	do_retain_initrd = 1;
520	return 1;
521}
522__setup("retain_initrd", retain_initrd_param);
523
524extern char __initramfs_start[];
525extern unsigned long __initramfs_size;
526#include <linux/initrd.h>
527#include <linux/kexec.h>
528
529static void __init free_initrd(void)
530{
531#ifdef CONFIG_KEXEC_CORE
532	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
533	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
534#endif
535	if (do_retain_initrd)
536		goto skip;
537
538#ifdef CONFIG_KEXEC_CORE
539	/*
540	 * If the initrd region is overlapped with crashkernel reserved region,
541	 * free only memory that is not part of crashkernel region.
542	 */
543	if (initrd_start < crashk_end && initrd_end > crashk_start) {
544		/*
545		 * Initialize initrd memory region since the kexec boot does
546		 * not do.
547		 */
548		memset((void *)initrd_start, 0, initrd_end - initrd_start);
549		if (initrd_start < crashk_start)
550			free_initrd_mem(initrd_start, crashk_start);
551		if (initrd_end > crashk_end)
552			free_initrd_mem(crashk_end, initrd_end);
553	} else
554#endif
555		free_initrd_mem(initrd_start, initrd_end);
556skip:
557	initrd_start = 0;
558	initrd_end = 0;
559}
560
561#ifdef CONFIG_BLK_DEV_RAM
562#define BUF_SIZE 1024
563static void __init clean_rootfs(void)
564{
565	int fd;
566	void *buf;
567	struct linux_dirent64 *dirp;
568	int num;
569
570	fd = ksys_open("/", O_RDONLY, 0);
571	WARN_ON(fd < 0);
572	if (fd < 0)
573		return;
574	buf = kzalloc(BUF_SIZE, GFP_KERNEL);
575	WARN_ON(!buf);
576	if (!buf) {
577		ksys_close(fd);
578		return;
579	}
580
581	dirp = buf;
582	num = ksys_getdents64(fd, dirp, BUF_SIZE);
583	while (num > 0) {
584		while (num > 0) {
585			struct kstat st;
586			int ret;
587
588			ret = vfs_lstat(dirp->d_name, &st);
589			WARN_ON_ONCE(ret);
590			if (!ret) {
591				if (S_ISDIR(st.mode))
592					ksys_rmdir(dirp->d_name);
593				else
594					ksys_unlink(dirp->d_name);
595			}
596
597			num -= dirp->d_reclen;
598			dirp = (void *)dirp + dirp->d_reclen;
599		}
600		dirp = buf;
601		memset(buf, 0, BUF_SIZE);
602		num = ksys_getdents64(fd, dirp, BUF_SIZE);
603	}
604
605	ksys_close(fd);
606	kfree(buf);
607}
608#endif
609
610static int __init populate_rootfs(void)
611{
612	/* Load the built in initramfs */
613	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
614	if (err)
615		panic("%s", err); /* Failed to decompress INTERNAL initramfs */
616	/* If available load the bootloader supplied initrd */
617	if (initrd_start && !IS_ENABLED(CONFIG_INITRAMFS_FORCE)) {
618#ifdef CONFIG_BLK_DEV_RAM
619		int fd;
620		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
621		err = unpack_to_rootfs((char *)initrd_start,
622			initrd_end - initrd_start);
623		if (!err) {
624			free_initrd();
625			goto done;
626		} else {
627			clean_rootfs();
628			unpack_to_rootfs(__initramfs_start, __initramfs_size);
629		}
630		printk(KERN_INFO "rootfs image is not initramfs (%s)"
631				"; looks like an initrd\n", err);
632		fd = ksys_open("/initrd.image",
633			      O_WRONLY|O_CREAT, 0700);
634		if (fd >= 0) {
635			ssize_t written = xwrite(fd, (char *)initrd_start,
636						initrd_end - initrd_start);
637
638			if (written != initrd_end - initrd_start)
639				pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
640				       written, initrd_end - initrd_start);
641
642			ksys_close(fd);
643			free_initrd();
644		}
645	done:
646		/* empty statement */;
647#else
648		printk(KERN_INFO "Unpacking initramfs...\n");
649		err = unpack_to_rootfs((char *)initrd_start,
650			initrd_end - initrd_start);
651		if (err)
652			printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
653		free_initrd();
654#endif
655	}
656	flush_delayed_fput();
657	/*
658	 * Try loading default modules from initramfs.  This gives
659	 * us a chance to load before device_initcalls.
660	 */
661	load_default_modules();
662
663	return 0;
664}
665rootfs_initcall(populate_rootfs);