1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/async.h>
4#include <linux/export.h>
5#include <linux/fs.h>
6#include <linux/slab.h>
7#include <linux/types.h>
8#include <linux/fcntl.h>
9#include <linux/delay.h>
10#include <linux/string.h>
11#include <linux/dirent.h>
12#include <linux/syscalls.h>
13#include <linux/utime.h>
14#include <linux/file.h>
15#include <linux/kstrtox.h>
16#include <linux/memblock.h>
17#include <linux/mm.h>
18#include <linux/namei.h>
19#include <linux/init_syscalls.h>
20#include <linux/umh.h>
21#include <linux/security.h>
22#include <linux/overflow.h>
23
24#include "do_mounts.h"
25#include "initramfs_internal.h"
26
27static __initdata bool csum_present;
28static __initdata u32 io_csum;
29
30static ssize_t __init xwrite(struct file *file, const unsigned char *p,
31 size_t count, loff_t *pos)
32{
33 ssize_t out = 0;
34
35 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
36 while (count) {
37 ssize_t rv = kernel_write(file, p, count, pos);
38
39 if (rv < 0) {
40 if (rv == -EINTR || rv == -EAGAIN)
41 continue;
42 return out ? out : rv;
43 } else if (rv == 0)
44 break;
45
46 if (csum_present) {
47 ssize_t i;
48
49 for (i = 0; i < rv; i++)
50 io_csum += p[i];
51 }
52
53 p += rv;
54 out += rv;
55 count -= rv;
56 }
57
58 return out;
59}
60
61static __initdata char *message;
62static void __init error(char *x)
63{
64 if (!message)
65 message = x;
66}
67
68#define panic_show_mem(fmt, ...) \
69 ({ show_mem(); panic(fmt, ##__VA_ARGS__); })
70
71/* link hash */
72
73#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
74
75static __initdata struct hash {
76 int ino, minor, major;
77 umode_t mode;
78 struct hash *next;
79 char name[N_ALIGN(PATH_MAX)];
80} *head[32];
81static __initdata bool hardlink_seen;
82
83static inline int hash(int major, int minor, int ino)
84{
85 unsigned long tmp = ino + minor + (major << 3);
86 tmp += tmp >> 5;
87 return tmp & 31;
88}
89
90static char __init *find_link(int major, int minor, int ino,
91 umode_t mode, char *name)
92{
93 struct hash **p, *q;
94 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
95 if ((*p)->ino != ino)
96 continue;
97 if ((*p)->minor != minor)
98 continue;
99 if ((*p)->major != major)
100 continue;
101 if (((*p)->mode ^ mode) & S_IFMT)
102 continue;
103 return (*p)->name;
104 }
105 q = kmalloc(sizeof(struct hash), GFP_KERNEL);
106 if (!q)
107 panic_show_mem("can't allocate link hash entry");
108 q->major = major;
109 q->minor = minor;
110 q->ino = ino;
111 q->mode = mode;
112 strscpy(q->name, name);
113 q->next = NULL;
114 *p = q;
115 hardlink_seen = true;
116 return NULL;
117}
118
119static void __init free_hash(void)
120{
121 struct hash **p, *q;
122 for (p = head; hardlink_seen && p < head + 32; p++) {
123 while (*p) {
124 q = *p;
125 *p = q->next;
126 kfree(objp: q);
127 }
128 }
129 hardlink_seen = false;
130}
131
132#ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
133static void __init do_utime(char *filename, time64_t mtime)
134{
135 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
136 init_utimes(filename, ts: t);
137}
138
139static void __init do_utime_path(const struct path *path, time64_t mtime)
140{
141 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
142 vfs_utimes(path, times: t);
143}
144
145static __initdata LIST_HEAD(dir_list);
146struct dir_entry {
147 struct list_head list;
148 time64_t mtime;
149 char name[];
150};
151
152static void __init dir_add(const char *name, size_t nlen, time64_t mtime)
153{
154 struct dir_entry *de;
155
156 de = kmalloc(struct_size(de, name, nlen), GFP_KERNEL);
157 if (!de)
158 panic_show_mem("can't allocate dir_entry buffer");
159 INIT_LIST_HEAD(list: &de->list);
160 strscpy(de->name, name, nlen);
161 de->mtime = mtime;
162 list_add(new: &de->list, head: &dir_list);
163}
164
165static void __init dir_utime(void)
166{
167 struct dir_entry *de, *tmp;
168 list_for_each_entry_safe(de, tmp, &dir_list, list) {
169 list_del(entry: &de->list);
170 do_utime(filename: de->name, mtime: de->mtime);
171 kfree(objp: de);
172 }
173}
174#else
175static void __init do_utime(char *filename, time64_t mtime) {}
176static void __init do_utime_path(const struct path *path, time64_t mtime) {}
177static void __init dir_add(const char *name, size_t nlen, time64_t mtime) {}
178static void __init dir_utime(void) {}
179#endif
180
181static __initdata time64_t mtime;
182
183/* cpio header parsing */
184
185static __initdata unsigned long ino, major, minor, nlink;
186static __initdata umode_t mode;
187static __initdata unsigned long body_len, name_len;
188static __initdata uid_t uid;
189static __initdata gid_t gid;
190static __initdata unsigned rdev;
191static __initdata u32 hdr_csum;
192
193static void __init parse_header(char *s)
194{
195 unsigned long parsed[13];
196 int i;
197
198 for (i = 0, s += 6; i < 13; i++, s += 8)
199 parsed[i] = simple_strntoul(s, NULL, 16, 8);
200
201 ino = parsed[0];
202 mode = parsed[1];
203 uid = parsed[2];
204 gid = parsed[3];
205 nlink = parsed[4];
206 mtime = parsed[5]; /* breaks in y2106 */
207 body_len = parsed[6];
208 major = parsed[7];
209 minor = parsed[8];
210 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
211 name_len = parsed[11];
212 hdr_csum = parsed[12];
213}
214
215/* FSM */
216
217static __initdata enum state {
218 Start,
219 Collect,
220 GotHeader,
221 SkipIt,
222 GotName,
223 CopyFile,
224 GotSymlink,
225 Reset
226} state, next_state;
227
228static __initdata char *victim;
229static unsigned long byte_count __initdata;
230static __initdata loff_t this_header, next_header;
231
232static inline void __init eat(unsigned n)
233{
234 victim += n;
235 this_header += n;
236 byte_count -= n;
237}
238
239static __initdata char *collected;
240static long remains __initdata;
241static __initdata char *collect;
242
243static void __init read_into(char *buf, unsigned size, enum state next)
244{
245 if (byte_count >= size) {
246 collected = victim;
247 eat(n: size);
248 state = next;
249 } else {
250 collect = collected = buf;
251 remains = size;
252 next_state = next;
253 state = Collect;
254 }
255}
256
257static __initdata char *header_buf, *symlink_buf, *name_buf;
258
259static int __init do_start(void)
260{
261 read_into(buf: header_buf, CPIO_HDRLEN, next: GotHeader);
262 return 0;
263}
264
265static int __init do_collect(void)
266{
267 unsigned long n = remains;
268 if (byte_count < n)
269 n = byte_count;
270 memcpy(to: collect, from: victim, len: n);
271 eat(n);
272 collect += n;
273 if ((remains -= n) != 0)
274 return 1;
275 state = next_state;
276 return 0;
277}
278
279static int __init do_header(void)
280{
281 if (!memcmp(collected, "070701", 6)) {
282 csum_present = false;
283 } else if (!memcmp(collected, "070702", 6)) {
284 csum_present = true;
285 } else {
286 if (memcmp(collected, "070707", 6) == 0)
287 error(x: "incorrect cpio method used: use -H newc option");
288 else
289 error(x: "no cpio magic");
290 return 1;
291 }
292 parse_header(s: collected);
293 next_header = this_header + N_ALIGN(name_len) + body_len;
294 next_header = (next_header + 3) & ~3;
295 state = SkipIt;
296 if (name_len <= 0 || name_len > PATH_MAX)
297 return 0;
298 if (S_ISLNK(mode)) {
299 if (body_len > PATH_MAX)
300 return 0;
301 collect = collected = symlink_buf;
302 remains = N_ALIGN(name_len) + body_len;
303 next_state = GotSymlink;
304 state = Collect;
305 return 0;
306 }
307 if (S_ISREG(mode) || !body_len)
308 read_into(buf: name_buf, N_ALIGN(name_len), next: GotName);
309 return 0;
310}
311
312static int __init do_skip(void)
313{
314 if (this_header + byte_count < next_header) {
315 eat(n: byte_count);
316 return 1;
317 } else {
318 eat(n: next_header - this_header);
319 state = next_state;
320 return 0;
321 }
322}
323
324static int __init do_reset(void)
325{
326 while (byte_count && *victim == '\0')
327 eat(n: 1);
328 if (byte_count && (this_header & 3))
329 error(x: "broken padding");
330 return 1;
331}
332
333static void __init clean_path(char *path, umode_t fmode)
334{
335 struct kstat st;
336
337 if (!init_stat(filename: path, stat: &st, AT_SYMLINK_NOFOLLOW) &&
338 (st.mode ^ fmode) & S_IFMT) {
339 if (S_ISDIR(st.mode))
340 init_rmdir(pathname: path);
341 else
342 init_unlink(pathname: path);
343 }
344}
345
346static int __init maybe_link(void)
347{
348 if (nlink >= 2) {
349 char *old = find_link(major, minor, ino, mode, name: collected);
350 if (old) {
351 clean_path(path: collected, fmode: 0);
352 return (init_link(oldname: old, newname: collected) < 0) ? -1 : 1;
353 }
354 }
355 return 0;
356}
357
358static __initdata struct file *wfile;
359static __initdata loff_t wfile_pos;
360
361static int __init do_name(void)
362{
363 state = SkipIt;
364 next_state = Reset;
365
366 /* name_len > 0 && name_len <= PATH_MAX checked in do_header */
367 if (collected[name_len - 1] != '\0') {
368 pr_err("initramfs name without nulterm: %.*s\n",
369 (int)name_len, collected);
370 error(x: "malformed archive");
371 return 1;
372 }
373
374 if (strcmp(collected, "TRAILER!!!") == 0) {
375 free_hash();
376 return 0;
377 }
378 clean_path(path: collected, fmode: mode);
379 if (S_ISREG(mode)) {
380 int ml = maybe_link();
381 if (ml >= 0) {
382 int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
383 if (ml != 1)
384 openflags |= O_TRUNC;
385 wfile = filp_open(collected, openflags, mode);
386 if (IS_ERR(ptr: wfile))
387 return 0;
388 wfile_pos = 0;
389 io_csum = 0;
390
391 vfs_fchown(file: wfile, user: uid, group: gid);
392 vfs_fchmod(file: wfile, mode);
393 if (body_len)
394 vfs_truncate(&wfile->f_path, body_len);
395 state = CopyFile;
396 }
397 } else if (S_ISDIR(mode)) {
398 init_mkdir(pathname: collected, mode);
399 init_chown(filename: collected, user: uid, group: gid, flags: 0);
400 init_chmod(filename: collected, mode);
401 dir_add(name: collected, nlen: name_len, mtime);
402 } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
403 S_ISFIFO(mode) || S_ISSOCK(mode)) {
404 if (maybe_link() == 0) {
405 init_mknod(filename: collected, mode, dev: rdev);
406 init_chown(filename: collected, user: uid, group: gid, flags: 0);
407 init_chmod(filename: collected, mode);
408 do_utime(filename: collected, mtime);
409 }
410 }
411 return 0;
412}
413
414static int __init do_copy(void)
415{
416 if (byte_count >= body_len) {
417 if (xwrite(file: wfile, p: victim, count: body_len, pos: &wfile_pos) != body_len)
418 error(x: "write error");
419
420 do_utime_path(path: &wfile->f_path, mtime);
421 fput(wfile);
422 if (csum_present && io_csum != hdr_csum)
423 error(x: "bad data checksum");
424 eat(n: body_len);
425 state = SkipIt;
426 return 0;
427 } else {
428 if (xwrite(file: wfile, p: victim, count: byte_count, pos: &wfile_pos) != byte_count)
429 error(x: "write error");
430 body_len -= byte_count;
431 eat(n: byte_count);
432 return 1;
433 }
434}
435
436static int __init do_symlink(void)
437{
438 if (collected[name_len - 1] != '\0') {
439 pr_err("initramfs symlink without nulterm: %.*s\n",
440 (int)name_len, collected);
441 error(x: "malformed archive");
442 return 1;
443 }
444 collected[N_ALIGN(name_len) + body_len] = '\0';
445 clean_path(path: collected, fmode: 0);
446 init_symlink(oldname: collected + N_ALIGN(name_len), newname: collected);
447 init_chown(filename: collected, user: uid, group: gid, AT_SYMLINK_NOFOLLOW);
448 do_utime(filename: collected, mtime);
449 state = SkipIt;
450 next_state = Reset;
451 return 0;
452}
453
454static __initdata int (*actions[])(void) = {
455 [Start] = do_start,
456 [Collect] = do_collect,
457 [GotHeader] = do_header,
458 [SkipIt] = do_skip,
459 [GotName] = do_name,
460 [CopyFile] = do_copy,
461 [GotSymlink] = do_symlink,
462 [Reset] = do_reset,
463};
464
465static long __init write_buffer(char *buf, unsigned long len)
466{
467 byte_count = len;
468 victim = buf;
469
470 while (!actions[state]())
471 ;
472 return len - byte_count;
473}
474
475static long __init flush_buffer(void *bufv, unsigned long len)
476{
477 char *buf = bufv;
478 long written;
479 long origLen = len;
480 if (message)
481 return -1;
482 while ((written = write_buffer(buf, len)) < len && !message) {
483 char c = buf[written];
484 if (c == '0') {
485 buf += written;
486 len -= written;
487 state = Start;
488 } else if (c == 0) {
489 buf += written;
490 len -= written;
491 state = Reset;
492 } else
493 error(x: "junk within compressed archive");
494 }
495 return origLen;
496}
497
498static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
499
500#include <linux/decompress/generic.h>
501
502/**
503 * unpack_to_rootfs - decompress and extract an initramfs archive
504 * @buf: input initramfs archive to extract
505 * @len: length of initramfs data to process
506 *
507 * Returns: NULL for success or an error message string
508 *
509 * This symbol shouldn't be used externally. It's available for unit tests.
510 */
511char * __init unpack_to_rootfs(char *buf, unsigned long len)
512{
513 long written;
514 decompress_fn decompress;
515 const char *compress_name;
516 struct {
517 char header[CPIO_HDRLEN];
518 char symlink[PATH_MAX + N_ALIGN(PATH_MAX) + 1];
519 char name[N_ALIGN(PATH_MAX)];
520 } *bufs = kmalloc(sizeof(*bufs), GFP_KERNEL);
521
522 if (!bufs)
523 panic_show_mem("can't allocate buffers");
524
525 header_buf = bufs->header;
526 symlink_buf = bufs->symlink;
527 name_buf = bufs->name;
528
529 state = Start;
530 this_header = 0;
531 message = NULL;
532 while (!message && len) {
533 loff_t saved_offset = this_header;
534 if (*buf == '0' && !(this_header & 3)) {
535 state = Start;
536 written = write_buffer(buf, len);
537 buf += written;
538 len -= written;
539 continue;
540 }
541 if (!*buf) {
542 buf++;
543 len--;
544 this_header++;
545 continue;
546 }
547 this_header = 0;
548 decompress = decompress_method(inbuf: buf, len, name: &compress_name);
549 pr_debug("Detected %s compressed data\n", compress_name);
550 if (decompress) {
551 int res = decompress(buf, len, NULL, flush_buffer, NULL,
552 &my_inptr, error);
553 if (res)
554 error(x: "decompressor failed");
555 } else if (compress_name) {
556 pr_err("compression method %s not configured\n",
557 compress_name);
558 error(x: "decompressor failed");
559 } else
560 error(x: "invalid magic at start of compressed archive");
561 if (state != Reset)
562 error(x: "junk at the end of compressed archive");
563 this_header = saved_offset + my_inptr;
564 buf += my_inptr;
565 len -= my_inptr;
566 }
567 dir_utime();
568 /* free any hardlink state collected without optional TRAILER!!! */
569 free_hash();
570 kfree(objp: bufs);
571 return message;
572}
573
574static int __initdata do_retain_initrd;
575
576static int __init retain_initrd_param(char *str)
577{
578 if (*str)
579 return 0;
580 do_retain_initrd = 1;
581 return 1;
582}
583__setup("retain_initrd", retain_initrd_param);
584
585#ifdef CONFIG_ARCH_HAS_KEEPINITRD
586static int __init keepinitrd_setup(char *__unused)
587{
588 do_retain_initrd = 1;
589 return 1;
590}
591__setup("keepinitrd", keepinitrd_setup);
592#endif
593
594static bool __initdata initramfs_async = true;
595static int __init initramfs_async_setup(char *str)
596{
597 return kstrtobool(s: str, res: &initramfs_async) == 0;
598}
599__setup("initramfs_async=", initramfs_async_setup);
600
601extern char __initramfs_start[];
602extern unsigned long __initramfs_size;
603#include <linux/initrd.h>
604#include <linux/kexec.h>
605
606static BIN_ATTR(initrd, 0440, sysfs_bin_attr_simple_read, NULL, 0);
607
608void __init reserve_initrd_mem(void)
609{
610 phys_addr_t start;
611 unsigned long size;
612
613 /* Ignore the virtul address computed during device tree parsing */
614 initrd_start = initrd_end = 0;
615
616 if (!phys_initrd_size)
617 return;
618 /*
619 * Round the memory region to page boundaries as per free_initrd_mem()
620 * This allows us to detect whether the pages overlapping the initrd
621 * are in use, but more importantly, reserves the entire set of pages
622 * as we don't want these pages allocated for other purposes.
623 */
624 start = round_down(phys_initrd_start, PAGE_SIZE);
625 size = phys_initrd_size + (phys_initrd_start - start);
626 size = round_up(size, PAGE_SIZE);
627
628 if (!memblock_is_region_memory(base: start, size)) {
629 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
630 (u64)start, size);
631 goto disable;
632 }
633
634 if (memblock_is_region_reserved(base: start, size)) {
635 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
636 (u64)start, size);
637 goto disable;
638 }
639
640 memblock_reserve(base: start, size);
641 /* Now convert initrd to virtual addresses */
642 initrd_start = (unsigned long)__va(phys_initrd_start);
643 initrd_end = initrd_start + phys_initrd_size;
644 initrd_below_start_ok = 1;
645
646 return;
647disable:
648 pr_cont(" - disabling initrd\n");
649 initrd_start = 0;
650 initrd_end = 0;
651}
652
653void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
654{
655#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
656 unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
657 unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
658
659 memblock_free((void *)aligned_start, aligned_end - aligned_start);
660#endif
661
662 free_reserved_area(start: (void *)start, end: (void *)end, POISON_FREE_INITMEM,
663 s: "initrd");
664}
665
666#ifdef CONFIG_CRASH_RESERVE
667static bool __init kexec_free_initrd(void)
668{
669 unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
670 unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
671
672 /*
673 * If the initrd region is overlapped with crashkernel reserved region,
674 * free only memory that is not part of crashkernel region.
675 */
676 if (initrd_start >= crashk_end || initrd_end <= crashk_start)
677 return false;
678
679 /*
680 * Initialize initrd memory region since the kexec boot does not do.
681 */
682 memset(s: (void *)initrd_start, c: 0, n: initrd_end - initrd_start);
683 if (initrd_start < crashk_start)
684 free_initrd_mem(start: initrd_start, end: crashk_start);
685 if (initrd_end > crashk_end)
686 free_initrd_mem(start: crashk_end, end: initrd_end);
687 return true;
688}
689#else
690static inline bool kexec_free_initrd(void)
691{
692 return false;
693}
694#endif /* CONFIG_KEXEC_CORE */
695
696#ifdef CONFIG_BLK_DEV_RAM
697static void __init populate_initrd_image(char *err)
698{
699 ssize_t written;
700 struct file *file;
701 loff_t pos = 0;
702
703 printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
704 err);
705 file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
706 if (IS_ERR(file))
707 return;
708
709 written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
710 &pos);
711 if (written != initrd_end - initrd_start)
712 pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
713 written, initrd_end - initrd_start);
714 fput(file);
715}
716#endif /* CONFIG_BLK_DEV_RAM */
717
718static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
719{
720 /* Load the built in initramfs */
721 char *err = unpack_to_rootfs(buf: __initramfs_start, len: __initramfs_size);
722 if (err)
723 panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
724
725 if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
726 goto done;
727
728 if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
729 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
730 else
731 printk(KERN_INFO "Unpacking initramfs...\n");
732
733 err = unpack_to_rootfs(buf: (char *)initrd_start, len: initrd_end - initrd_start);
734 if (err) {
735#ifdef CONFIG_BLK_DEV_RAM
736 populate_initrd_image(err);
737#else
738 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
739#endif
740 }
741
742done:
743 security_initramfs_populated();
744
745 /*
746 * If the initrd region is overlapped with crashkernel reserved region,
747 * free only memory that is not part of crashkernel region.
748 */
749 if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
750 free_initrd_mem(start: initrd_start, end: initrd_end);
751 } else if (do_retain_initrd && initrd_start) {
752 bin_attr_initrd.size = initrd_end - initrd_start;
753 bin_attr_initrd.private = (void *)initrd_start;
754 if (sysfs_create_bin_file(kobj: firmware_kobj, attr: &bin_attr_initrd))
755 pr_err("Failed to create initrd sysfs file");
756 }
757 initrd_start = 0;
758 initrd_end = 0;
759
760 init_flush_fput();
761}
762
763static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
764static async_cookie_t initramfs_cookie;
765
766void wait_for_initramfs(void)
767{
768 if (!initramfs_cookie) {
769 /*
770 * Something before rootfs_initcall wants to access
771 * the filesystem/initramfs. Probably a bug. Make a
772 * note, avoid deadlocking the machine, and let the
773 * caller's access fail as it used to.
774 */
775 pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
776 return;
777 }
778 async_synchronize_cookie_domain(cookie: initramfs_cookie + 1, domain: &initramfs_domain);
779}
780EXPORT_SYMBOL_GPL(wait_for_initramfs);
781
782static int __init populate_rootfs(void)
783{
784 initramfs_cookie = async_schedule_domain(func: do_populate_rootfs, NULL,
785 domain: &initramfs_domain);
786 usermodehelper_enable();
787 if (!initramfs_async)
788 wait_for_initramfs();
789 return 0;
790}
791rootfs_initcall(populate_rootfs);
792