Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[platform/kernel/linux-rpi.git] / lib / decompress_unlz4.c
1 /*
2  * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
3  *
4  * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #ifdef STATIC
12 #define PREBOOT
13 #include "lz4/lz4_decompress.c"
14 #else
15 #include <linux/decompress/unlz4.h>
16 #endif
17 #include <linux/types.h>
18 #include <linux/lz4.h>
19 #include <linux/decompress/mm.h>
20 #include <linux/compiler.h>
21
22 #include <asm/unaligned.h>
23
24 /*
25  * Note: Uncompressed chunk size is used in the compressor side
26  * (userspace side for compression).
27  * It is hardcoded because there is not proper way to extract it
28  * from the binary stream which is generated by the preliminary
29  * version of LZ4 tool so far.
30  */
31 #define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
32 #define ARCHIVE_MAGICNUMBER 0x184C2102
33
34 STATIC inline int INIT unlz4(u8 *input, long in_len,
35                                 long (*fill)(void *, unsigned long),
36                                 long (*flush)(void *, unsigned long),
37                                 u8 *output, long *posp,
38                                 void (*error) (char *x))
39 {
40         int ret = -1;
41         size_t chunksize = 0;
42         size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
43         u8 *inp;
44         u8 *inp_start;
45         u8 *outp;
46         long size = in_len;
47 #ifdef PREBOOT
48         size_t out_len = get_unaligned_le32(input + in_len);
49 #endif
50         size_t dest_len;
51
52
53         if (output) {
54                 outp = output;
55         } else if (!flush) {
56                 error("NULL output pointer and no flush function provided");
57                 goto exit_0;
58         } else {
59                 outp = large_malloc(uncomp_chunksize);
60                 if (!outp) {
61                         error("Could not allocate output buffer");
62                         goto exit_0;
63                 }
64         }
65
66         if (input && fill) {
67                 error("Both input pointer and fill function provided,");
68                 goto exit_1;
69         } else if (input) {
70                 inp = input;
71         } else if (!fill) {
72                 error("NULL input pointer and missing fill function");
73                 goto exit_1;
74         } else {
75                 inp = large_malloc(LZ4_compressBound(uncomp_chunksize));
76                 if (!inp) {
77                         error("Could not allocate input buffer");
78                         goto exit_1;
79                 }
80         }
81         inp_start = inp;
82
83         if (posp)
84                 *posp = 0;
85
86         if (fill) {
87                 size = fill(inp, 4);
88                 if (size < 4) {
89                         error("data corrupted");
90                         goto exit_2;
91                 }
92         }
93
94         chunksize = get_unaligned_le32(inp);
95         if (chunksize == ARCHIVE_MAGICNUMBER) {
96                 if (!fill) {
97                         inp += 4;
98                         size -= 4;
99                 }
100         } else {
101                 error("invalid header");
102                 goto exit_2;
103         }
104
105         if (posp)
106                 *posp += 4;
107
108         for (;;) {
109
110                 if (fill) {
111                         size = fill(inp, 4);
112                         if (size == 0)
113                                 break;
114                         if (size < 4) {
115                                 error("data corrupted");
116                                 goto exit_2;
117                         }
118                 }
119
120                 chunksize = get_unaligned_le32(inp);
121                 if (chunksize == ARCHIVE_MAGICNUMBER) {
122                         if (!fill) {
123                                 inp += 4;
124                                 size -= 4;
125                         }
126                         if (posp)
127                                 *posp += 4;
128                         continue;
129                 }
130
131
132                 if (posp)
133                         *posp += 4;
134
135                 if (!fill) {
136                         inp += 4;
137                         size -= 4;
138                 } else {
139                         if (chunksize > LZ4_compressBound(uncomp_chunksize)) {
140                                 error("chunk length is longer than allocated");
141                                 goto exit_2;
142                         }
143                         size = fill(inp, chunksize);
144                         if (size < chunksize) {
145                                 error("data corrupted");
146                                 goto exit_2;
147                         }
148                 }
149 #ifdef PREBOOT
150                 if (out_len >= uncomp_chunksize) {
151                         dest_len = uncomp_chunksize;
152                         out_len -= dest_len;
153                 } else
154                         dest_len = out_len;
155
156                 ret = LZ4_decompress_fast(inp, outp, dest_len);
157                 chunksize = ret;
158 #else
159                 dest_len = uncomp_chunksize;
160
161                 ret = LZ4_decompress_safe(inp, outp, chunksize, dest_len);
162                 dest_len = ret;
163 #endif
164                 if (ret < 0) {
165                         error("Decoding failed");
166                         goto exit_2;
167                 }
168
169                 ret = -1;
170                 if (flush && flush(outp, dest_len) != dest_len)
171                         goto exit_2;
172                 if (output)
173                         outp += dest_len;
174                 if (posp)
175                         *posp += chunksize;
176
177                 if (!fill) {
178                         size -= chunksize;
179
180                         if (size == 0)
181                                 break;
182                         else if (size < 0) {
183                                 error("data corrupted");
184                                 goto exit_2;
185                         }
186                         inp += chunksize;
187                 }
188         }
189
190         ret = 0;
191 exit_2:
192         if (!input)
193                 large_free(inp_start);
194 exit_1:
195         if (!output)
196                 large_free(outp);
197 exit_0:
198         return ret;
199 }
200
201 #ifdef PREBOOT
202 STATIC int INIT __decompress(unsigned char *buf, long in_len,
203                               long (*fill)(void*, unsigned long),
204                               long (*flush)(void*, unsigned long),
205                               unsigned char *output, long out_len,
206                               long *posp,
207                               void (*error)(char *x)
208         )
209 {
210         return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
211 }
212 #endif