1/*
 2 * uncompress.c
 3 *
 4 * (C) Copyright 1999 Linus Torvalds
 5 *
 6 * cramfs interfaces to the uncompression library. There's really just
 7 * three entrypoints:
 8 *
 9 *  - cramfs_uncompress_init() - called to initialize the thing.
10 *  - cramfs_uncompress_exit() - tell me when you're done
11 *  - cramfs_uncompress_block() - uncompress a block.
12 *
13 * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
14 * only have one stream, and we'll initialize it only once even if it
15 * then is used by multiple filesystems.
16 */
17
 
 
18#include <linux/kernel.h>
19#include <linux/errno.h>
20#include <linux/vmalloc.h>
21#include <linux/zlib.h>
22#include <linux/cramfs_fs.h>
23
24static z_stream stream;
25static int initialized;
26
27/* Returns length of decompressed data. */
28int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
29{
30	int err;
31
32	stream.next_in = src;
33	stream.avail_in = srclen;
34
35	stream.next_out = dst;
36	stream.avail_out = dstlen;
37
38	err = zlib_inflateReset(&stream);
39	if (err != Z_OK) {
40		printk("zlib_inflateReset error %d\n", err);
41		zlib_inflateEnd(&stream);
42		zlib_inflateInit(&stream);
43	}
44
45	err = zlib_inflate(&stream, Z_FINISH);
46	if (err != Z_STREAM_END)
47		goto err;
48	return stream.total_out;
49
50err:
51	printk("Error %d while decompressing!\n", err);
52	printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
53	return -EIO;
54}
55
56int cramfs_uncompress_init(void)
57{
58	if (!initialized++) {
59		stream.workspace = vmalloc(zlib_inflate_workspacesize());
60		if ( !stream.workspace ) {
61			initialized = 0;
62			return -ENOMEM;
63		}
64		stream.next_in = NULL;
65		stream.avail_in = 0;
66		zlib_inflateInit(&stream);
67	}
68	return 0;
69}
70
71void cramfs_uncompress_exit(void)
72{
73	if (!--initialized) {
74		zlib_inflateEnd(&stream);
75		vfree(stream.workspace);
76	}
77}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * uncompress.c
 4 *
 5 * (C) Copyright 1999 Linus Torvalds
 6 *
 7 * cramfs interfaces to the uncompression library. There's really just
 8 * three entrypoints:
 9 *
10 *  - cramfs_uncompress_init() - called to initialize the thing.
11 *  - cramfs_uncompress_exit() - tell me when you're done
12 *  - cramfs_uncompress_block() - uncompress a block.
13 *
14 * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
15 * only have one stream, and we'll initialize it only once even if it
16 * then is used by multiple filesystems.
17 */
18
19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/vmalloc.h>
24#include <linux/zlib.h>
25#include "internal.h"
26
27static z_stream stream;
28static int initialized;
29
30/* Returns length of decompressed data. */
31int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
32{
33	int err;
34
35	stream.next_in = src;
36	stream.avail_in = srclen;
37
38	stream.next_out = dst;
39	stream.avail_out = dstlen;
40
41	err = zlib_inflateReset(&stream);
42	if (err != Z_OK) {
43		pr_err("zlib_inflateReset error %d\n", err);
44		zlib_inflateEnd(&stream);
45		zlib_inflateInit(&stream);
46	}
47
48	err = zlib_inflate(&stream, Z_FINISH);
49	if (err != Z_STREAM_END)
50		goto err;
51	return stream.total_out;
52
53err:
54	pr_err("Error %d while decompressing!\n", err);
55	pr_err("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
56	return -EIO;
57}
58
59int cramfs_uncompress_init(void)
60{
61	if (!initialized++) {
62		stream.workspace = vmalloc(zlib_inflate_workspacesize());
63		if (!stream.workspace) {
64			initialized = 0;
65			return -ENOMEM;
66		}
67		stream.next_in = NULL;
68		stream.avail_in = 0;
69		zlib_inflateInit(&stream);
70	}
71	return 0;
72}
73
74void cramfs_uncompress_exit(void)
75{
76	if (!--initialized) {
77		zlib_inflateEnd(&stream);
78		vfree(stream.workspace);
79	}
80}