1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/async.h>
4#include <linux/fs.h>
5#include <linux/slab.h>
6#include <linux/types.h>
7#include <linux/fcntl.h>
8#include <linux/delay.h>
9#include <linux/string.h>
10#include <linux/dirent.h>
11#include <linux/syscalls.h>
12#include <linux/utime.h>
13#include <linux/file.h>
14#include <linux/kstrtox.h>
15#include <linux/memblock.h>
16#include <linux/mm.h>
17#include <linux/namei.h>
18#include <linux/init_syscalls.h>
19#include <linux/umh.h>
20
21#include "do_mounts.h"
22
23static __initdata bool csum_present;
24static __initdata u32 io_csum;
25
26static ssize_t __init xwrite(struct file *file, const unsigned char *p,
27		size_t count, loff_t *pos)
28{
29	ssize_t out = 0;
30
31	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
32	while (count) {
33		ssize_t rv = kernel_write(file, p, count, pos);
34
35		if (rv < 0) {
36			if (rv == -EINTR || rv == -EAGAIN)
37				continue;
38			return out ? out : rv;
39		} else if (rv == 0)
40			break;
41
42		if (csum_present) {
43			ssize_t i;
44
45			for (i = 0; i < rv; i++)
46				io_csum += p[i];
47		}
48
49		p += rv;
50		out += rv;
51		count -= rv;
52	}
53
54	return out;
55}
56
57static __initdata char *message;
58static void __init error(char *x)
59{
60	if (!message)
61		message = x;
62}
63
64#define panic_show_mem(fmt, ...) \
65	({ show_mem(); panic(fmt, ##__VA_ARGS__); })
66
67/* link hash */
68
69#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
70
71static __initdata struct hash {
72	int ino, minor, major;
73	umode_t mode;
74	struct hash *next;
75	char name[N_ALIGN(PATH_MAX)];
76} *head[32];
77
78static inline int hash(int major, int minor, int ino)
79{
80	unsigned long tmp = ino + minor + (major << 3);
81	tmp += tmp >> 5;
82	return tmp & 31;
83}
84
85static char __init *find_link(int major, int minor, int ino,
86			      umode_t mode, char *name)
87{
88	struct hash **p, *q;
89	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
90		if ((*p)->ino != ino)
91			continue;
92		if ((*p)->minor != minor)
93			continue;
94		if ((*p)->major != major)
95			continue;
96		if (((*p)->mode ^ mode) & S_IFMT)
97			continue;
98		return (*p)->name;
99	}
100	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
101	if (!q)
102		panic_show_mem("can't allocate link hash entry");
103	q->major = major;
104	q->minor = minor;
105	q->ino = ino;
106	q->mode = mode;
107	strcpy(q->name, name);
108	q->next = NULL;
109	*p = q;
110	return NULL;
111}
112
113static void __init free_hash(void)
114{
115	struct hash **p, *q;
116	for (p = head; p < head + 32; p++) {
117		while (*p) {
118			q = *p;
119			*p = q->next;
120			kfree(q);
121		}
122	}
123}
124
125#ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
126static void __init do_utime(char *filename, time64_t mtime)
127{
128	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
129	init_utimes(filename, t);
130}
131
132static void __init do_utime_path(const struct path *path, time64_t mtime)
133{
134	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
135	vfs_utimes(path, t);
136}
137
138static __initdata LIST_HEAD(dir_list);
139struct dir_entry {
140	struct list_head list;
141	time64_t mtime;
142	char name[];
143};
144
145static void __init dir_add(const char *name, time64_t mtime)
146{
147	size_t nlen = strlen(name) + 1;
148	struct dir_entry *de;
149
150	de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL);
151	if (!de)
152		panic_show_mem("can't allocate dir_entry buffer");
153	INIT_LIST_HEAD(&de->list);
154	strscpy(de->name, name, nlen);
155	de->mtime = mtime;
156	list_add(&de->list, &dir_list);
157}
158
159static void __init dir_utime(void)
160{
161	struct dir_entry *de, *tmp;
162	list_for_each_entry_safe(de, tmp, &dir_list, list) {
163		list_del(&de->list);
164		do_utime(de->name, de->mtime);
165		kfree(de);
166	}
167}
168#else
169static void __init do_utime(char *filename, time64_t mtime) {}
170static void __init do_utime_path(const struct path *path, time64_t mtime) {}
171static void __init dir_add(const char *name, time64_t mtime) {}
172static void __init dir_utime(void) {}
173#endif
174
175static __initdata time64_t mtime;
176
177/* cpio header parsing */
178
179static __initdata unsigned long ino, major, minor, nlink;
180static __initdata umode_t mode;
181static __initdata unsigned long body_len, name_len;
182static __initdata uid_t uid;
183static __initdata gid_t gid;
184static __initdata unsigned rdev;
185static __initdata u32 hdr_csum;
186
187static void __init parse_header(char *s)
188{
189	unsigned long parsed[13];
190	char buf[9];
191	int i;
192
193	buf[8] = '\0';
194	for (i = 0, s += 6; i < 13; i++, s += 8) {
195		memcpy(buf, s, 8);
196		parsed[i] = simple_strtoul(buf, NULL, 16);
197	}
198	ino = parsed[0];
199	mode = parsed[1];
200	uid = parsed[2];
201	gid = parsed[3];
202	nlink = parsed[4];
203	mtime = parsed[5]; /* breaks in y2106 */
204	body_len = parsed[6];
205	major = parsed[7];
206	minor = parsed[8];
207	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
208	name_len = parsed[11];
209	hdr_csum = parsed[12];
210}
211
212/* FSM */
213
214static __initdata enum state {
215	Start,
216	Collect,
217	GotHeader,
218	SkipIt,
219	GotName,
220	CopyFile,
221	GotSymlink,
222	Reset
223} state, next_state;
224
225static __initdata char *victim;
226static unsigned long byte_count __initdata;
227static __initdata loff_t this_header, next_header;
228
229static inline void __init eat(unsigned n)
230{
231	victim += n;
232	this_header += n;
233	byte_count -= n;
234}
235
236static __initdata char *collected;
237static long remains __initdata;
238static __initdata char *collect;
239
240static void __init read_into(char *buf, unsigned size, enum state next)
241{
242	if (byte_count >= size) {
243		collected = victim;
244		eat(size);
245		state = next;
246	} else {
247		collect = collected = buf;
248		remains = size;
249		next_state = next;
250		state = Collect;
251	}
252}
253
254static __initdata char *header_buf, *symlink_buf, *name_buf;
255
256static int __init do_start(void)
257{
258	read_into(header_buf, 110, GotHeader);
259	return 0;
260}
261
262static int __init do_collect(void)
263{
264	unsigned long n = remains;
265	if (byte_count < n)
266		n = byte_count;
267	memcpy(collect, victim, n);
268	eat(n);
269	collect += n;
270	if ((remains -= n) != 0)
271		return 1;
272	state = next_state;
273	return 0;
274}
275
276static int __init do_header(void)
277{
278	if (!memcmp(collected, "070701", 6)) {
279		csum_present = false;
280	} else if (!memcmp(collected, "070702", 6)) {
281		csum_present = true;
282	} else {
283		if (memcmp(collected, "070707", 6) == 0)
284			error("incorrect cpio method used: use -H newc option");
285		else
286			error("no cpio magic");
287		return 1;
288	}
289	parse_header(collected);
290	next_header = this_header + N_ALIGN(name_len) + body_len;
291	next_header = (next_header + 3) & ~3;
292	state = SkipIt;
293	if (name_len <= 0 || name_len > PATH_MAX)
294		return 0;
295	if (S_ISLNK(mode)) {
296		if (body_len > PATH_MAX)
297			return 0;
298		collect = collected = symlink_buf;
299		remains = N_ALIGN(name_len) + body_len;
300		next_state = GotSymlink;
301		state = Collect;
302		return 0;
303	}
304	if (S_ISREG(mode) || !body_len)
305		read_into(name_buf, N_ALIGN(name_len), GotName);
306	return 0;
307}
308
309static int __init do_skip(void)
310{
311	if (this_header + byte_count < next_header) {
312		eat(byte_count);
313		return 1;
314	} else {
315		eat(next_header - this_header);
316		state = next_state;
317		return 0;
318	}
319}
320
321static int __init do_reset(void)
322{
323	while (byte_count && *victim == '\0')
324		eat(1);
325	if (byte_count && (this_header & 3))
326		error("broken padding");
327	return 1;
328}
329
330static void __init clean_path(char *path, umode_t fmode)
331{
332	struct kstat st;
333
334	if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
335	    (st.mode ^ fmode) & S_IFMT) {
336		if (S_ISDIR(st.mode))
337			init_rmdir(path);
338		else
339			init_unlink(path);
340	}
341}
342
343static int __init maybe_link(void)
344{
345	if (nlink >= 2) {
346		char *old = find_link(major, minor, ino, mode, collected);
347		if (old) {
348			clean_path(collected, 0);
349			return (init_link(old, collected) < 0) ? -1 : 1;
350		}
351	}
352	return 0;
353}
354
355static __initdata struct file *wfile;
356static __initdata loff_t wfile_pos;
357
358static int __init do_name(void)
359{
360	state = SkipIt;
361	next_state = Reset;
362	if (strcmp(collected, "TRAILER!!!") == 0) {
363		free_hash();
364		return 0;
365	}
366	clean_path(collected, mode);
367	if (S_ISREG(mode)) {
368		int ml = maybe_link();
369		if (ml >= 0) {
370			int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
371			if (ml != 1)
372				openflags |= O_TRUNC;
373			wfile = filp_open(collected, openflags, mode);
374			if (IS_ERR(wfile))
375				return 0;
376			wfile_pos = 0;
377			io_csum = 0;
378
379			vfs_fchown(wfile, uid, gid);
380			vfs_fchmod(wfile, mode);
381			if (body_len)
382				vfs_truncate(&wfile->f_path, body_len);
383			state = CopyFile;
384		}
385	} else if (S_ISDIR(mode)) {
386		init_mkdir(collected, mode);
387		init_chown(collected, uid, gid, 0);
388		init_chmod(collected, mode);
389		dir_add(collected, mtime);
390	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
391		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
392		if (maybe_link() == 0) {
393			init_mknod(collected, mode, rdev);
394			init_chown(collected, uid, gid, 0);
395			init_chmod(collected, mode);
396			do_utime(collected, mtime);
397		}
398	}
399	return 0;
400}
401
402static int __init do_copy(void)
403{
404	if (byte_count >= body_len) {
405		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
406			error("write error");
407
408		do_utime_path(&wfile->f_path, mtime);
409		fput(wfile);
410		if (csum_present && io_csum != hdr_csum)
411			error("bad data checksum");
412		eat(body_len);
413		state = SkipIt;
414		return 0;
415	} else {
416		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
417			error("write error");
418		body_len -= byte_count;
419		eat(byte_count);
420		return 1;
421	}
422}
423
424static int __init do_symlink(void)
425{
426	collected[N_ALIGN(name_len) + body_len] = '\0';
427	clean_path(collected, 0);
428	init_symlink(collected + N_ALIGN(name_len), collected);
429	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
430	do_utime(collected, mtime);
431	state = SkipIt;
432	next_state = Reset;
433	return 0;
434}
435
436static __initdata int (*actions[])(void) = {
437	[Start]		= do_start,
438	[Collect]	= do_collect,
439	[GotHeader]	= do_header,
440	[SkipIt]	= do_skip,
441	[GotName]	= do_name,
442	[CopyFile]	= do_copy,
443	[GotSymlink]	= do_symlink,
444	[Reset]		= do_reset,
445};
446
447static long __init write_buffer(char *buf, unsigned long len)
448{
449	byte_count = len;
450	victim = buf;
451
452	while (!actions[state]())
453		;
454	return len - byte_count;
455}
456
457static long __init flush_buffer(void *bufv, unsigned long len)
458{
459	char *buf = bufv;
460	long written;
461	long origLen = len;
462	if (message)
463		return -1;
464	while ((written = write_buffer(buf, len)) < len && !message) {
465		char c = buf[written];
466		if (c == '0') {
467			buf += written;
468			len -= written;
469			state = Start;
470		} else if (c == 0) {
471			buf += written;
472			len -= written;
473			state = Reset;
474		} else
475			error("junk within compressed archive");
476	}
477	return origLen;
478}
479
480static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
481
482#include <linux/decompress/generic.h>
483
484static char * __init unpack_to_rootfs(char *buf, unsigned long len)
485{
486	long written;
487	decompress_fn decompress;
488	const char *compress_name;
489	static __initdata char msg_buf[64];
490
491	header_buf = kmalloc(110, GFP_KERNEL);
492	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
493	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
494
495	if (!header_buf || !symlink_buf || !name_buf)
496		panic_show_mem("can't allocate buffers");
497
498	state = Start;
499	this_header = 0;
500	message = NULL;
501	while (!message && len) {
502		loff_t saved_offset = this_header;
503		if (*buf == '0' && !(this_header & 3)) {
504			state = Start;
505			written = write_buffer(buf, len);
506			buf += written;
507			len -= written;
508			continue;
509		}
510		if (!*buf) {
511			buf++;
512			len--;
513			this_header++;
514			continue;
515		}
516		this_header = 0;
517		decompress = decompress_method(buf, len, &compress_name);
518		pr_debug("Detected %s compressed data\n", compress_name);
519		if (decompress) {
520			int res = decompress(buf, len, NULL, flush_buffer, NULL,
521				   &my_inptr, error);
522			if (res)
523				error("decompressor failed");
524		} else if (compress_name) {
525			if (!message) {
526				snprintf(msg_buf, sizeof msg_buf,
527					 "compression method %s not configured",
528					 compress_name);
529				message = msg_buf;
530			}
531		} else
532			error("invalid magic at start of compressed archive");
533		if (state != Reset)
534			error("junk at the end of compressed archive");
535		this_header = saved_offset + my_inptr;
536		buf += my_inptr;
537		len -= my_inptr;
538	}
539	dir_utime();
540	kfree(name_buf);
541	kfree(symlink_buf);
542	kfree(header_buf);
543	return message;
544}
545
546static int __initdata do_retain_initrd;
547
548static int __init retain_initrd_param(char *str)
549{
550	if (*str)
551		return 0;
552	do_retain_initrd = 1;
553	return 1;
554}
555__setup("retain_initrd", retain_initrd_param);
556
557#ifdef CONFIG_ARCH_HAS_KEEPINITRD
558static int __init keepinitrd_setup(char *__unused)
559{
560	do_retain_initrd = 1;
561	return 1;
562}
563__setup("keepinitrd", keepinitrd_setup);
564#endif
565
566static bool __initdata initramfs_async = true;
567static int __init initramfs_async_setup(char *str)
568{
569	return kstrtobool(str, &initramfs_async) == 0;
570}
571__setup("initramfs_async=", initramfs_async_setup);
572
573extern char __initramfs_start[];
574extern unsigned long __initramfs_size;
575#include <linux/initrd.h>
576#include <linux/kexec.h>
577
578static ssize_t raw_read(struct file *file, struct kobject *kobj,
579			struct bin_attribute *attr, char *buf,
580			loff_t pos, size_t count)
581{
582	memcpy(buf, attr->private + pos, count);
583	return count;
584}
585
586static BIN_ATTR(initrd, 0440, raw_read, NULL, 0);
587
588void __init reserve_initrd_mem(void)
589{
590	phys_addr_t start;
591	unsigned long size;
592
593	/* Ignore the virtul address computed during device tree parsing */
594	initrd_start = initrd_end = 0;
595
596	if (!phys_initrd_size)
597		return;
598	/*
599	 * Round the memory region to page boundaries as per free_initrd_mem()
600	 * This allows us to detect whether the pages overlapping the initrd
601	 * are in use, but more importantly, reserves the entire set of pages
602	 * as we don't want these pages allocated for other purposes.
603	 */
604	start = round_down(phys_initrd_start, PAGE_SIZE);
605	size = phys_initrd_size + (phys_initrd_start - start);
606	size = round_up(size, PAGE_SIZE);
607
608	if (!memblock_is_region_memory(start, size)) {
609		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
610		       (u64)start, size);
611		goto disable;
612	}
613
614	if (memblock_is_region_reserved(start, size)) {
615		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
616		       (u64)start, size);
617		goto disable;
618	}
619
620	memblock_reserve(start, size);
621	/* Now convert initrd to virtual addresses */
622	initrd_start = (unsigned long)__va(phys_initrd_start);
623	initrd_end = initrd_start + phys_initrd_size;
624	initrd_below_start_ok = 1;
625
626	return;
627disable:
628	pr_cont(" - disabling initrd\n");
629	initrd_start = 0;
630	initrd_end = 0;
631}
632
633void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
634{
635#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
636	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
637	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
638
639	memblock_free((void *)aligned_start, aligned_end - aligned_start);
640#endif
641
642	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
643			"initrd");
644}
645
646#ifdef CONFIG_CRASH_RESERVE
647static bool __init kexec_free_initrd(void)
648{
649	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
650	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
651
652	/*
653	 * If the initrd region is overlapped with crashkernel reserved region,
654	 * free only memory that is not part of crashkernel region.
655	 */
656	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
657		return false;
658
659	/*
660	 * Initialize initrd memory region since the kexec boot does not do.
661	 */
662	memset((void *)initrd_start, 0, initrd_end - initrd_start);
663	if (initrd_start < crashk_start)
664		free_initrd_mem(initrd_start, crashk_start);
665	if (initrd_end > crashk_end)
666		free_initrd_mem(crashk_end, initrd_end);
667	return true;
668}
669#else
670static inline bool kexec_free_initrd(void)
671{
672	return false;
673}
674#endif /* CONFIG_KEXEC_CORE */
675
676#ifdef CONFIG_BLK_DEV_RAM
677static void __init populate_initrd_image(char *err)
678{
679	ssize_t written;
680	struct file *file;
681	loff_t pos = 0;
682
683	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
684			err);
685	file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
686	if (IS_ERR(file))
687		return;
688
689	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
690			&pos);
691	if (written != initrd_end - initrd_start)
692		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
693		       written, initrd_end - initrd_start);
694	fput(file);
695}
696#endif /* CONFIG_BLK_DEV_RAM */
697
698static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
699{
700	/* Load the built in initramfs */
701	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
702	if (err)
703		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
704
705	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
706		goto done;
707
708	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
709		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
710	else
711		printk(KERN_INFO "Unpacking initramfs...\n");
712
713	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
714	if (err) {
715#ifdef CONFIG_BLK_DEV_RAM
716		populate_initrd_image(err);
717#else
718		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
719#endif
720	}
721
722done:
723	/*
724	 * If the initrd region is overlapped with crashkernel reserved region,
725	 * free only memory that is not part of crashkernel region.
726	 */
727	if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
728		free_initrd_mem(initrd_start, initrd_end);
729	} else if (do_retain_initrd && initrd_start) {
730		bin_attr_initrd.size = initrd_end - initrd_start;
731		bin_attr_initrd.private = (void *)initrd_start;
732		if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd))
733			pr_err("Failed to create initrd sysfs file");
734	}
735	initrd_start = 0;
736	initrd_end = 0;
737
738	init_flush_fput();
739}
740
741static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
742static async_cookie_t initramfs_cookie;
743
744void wait_for_initramfs(void)
745{
746	if (!initramfs_cookie) {
747		/*
748		 * Something before rootfs_initcall wants to access
749		 * the filesystem/initramfs. Probably a bug. Make a
750		 * note, avoid deadlocking the machine, and let the
751		 * caller's access fail as it used to.
752		 */
753		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
754		return;
755	}
756	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
757}
758EXPORT_SYMBOL_GPL(wait_for_initramfs);
759
760static int __init populate_rootfs(void)
761{
762	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
763						 &initramfs_domain);
764	usermodehelper_enable();
765	if (!initramfs_async)
766		wait_for_initramfs();
767	return 0;
768}
769rootfs_initcall(populate_rootfs);
770