1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd |
4 | * |
5 | * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> |
6 | */ |
7 | |
8 | #ifdef STATIC |
9 | #define PREBOOT |
10 | #include "lz4/lz4_decompress.c" |
11 | #else |
12 | #include <linux/decompress/unlz4.h> |
13 | #endif |
14 | #include <linux/types.h> |
15 | #include <linux/lz4.h> |
16 | #include <linux/decompress/mm.h> |
17 | #include <linux/compiler.h> |
18 | |
19 | #include <asm/unaligned.h> |
20 | |
21 | /* |
22 | * Note: Uncompressed chunk size is used in the compressor side |
23 | * (userspace side for compression). |
24 | * It is hardcoded because there is not proper way to extract it |
25 | * from the binary stream which is generated by the preliminary |
26 | * version of LZ4 tool so far. |
27 | */ |
28 | #define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20) |
29 | #define ARCHIVE_MAGICNUMBER 0x184C2102 |
30 | |
31 | STATIC inline int INIT unlz4(u8 *input, long in_len, |
32 | long (*fill)(void *, unsigned long), |
33 | long (*flush)(void *, unsigned long), |
34 | u8 *output, long *posp, |
35 | void (*error) (char *x)) |
36 | { |
37 | int ret = -1; |
38 | size_t chunksize = 0; |
39 | size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE; |
40 | u8 *inp; |
41 | u8 *inp_start; |
42 | u8 *outp; |
43 | long size = in_len; |
44 | #ifdef PREBOOT |
45 | size_t out_len = get_unaligned_le32(input + in_len); |
46 | #endif |
47 | size_t dest_len; |
48 | |
49 | |
50 | if (output) { |
51 | outp = output; |
52 | } else if (!flush) { |
53 | error("NULL output pointer and no flush function provided" ); |
54 | goto exit_0; |
55 | } else { |
56 | outp = large_malloc(uncomp_chunksize); |
57 | if (!outp) { |
58 | error("Could not allocate output buffer" ); |
59 | goto exit_0; |
60 | } |
61 | } |
62 | |
63 | if (input && fill) { |
64 | error("Both input pointer and fill function provided," ); |
65 | goto exit_1; |
66 | } else if (input) { |
67 | inp = input; |
68 | } else if (!fill) { |
69 | error("NULL input pointer and missing fill function" ); |
70 | goto exit_1; |
71 | } else { |
72 | inp = large_malloc(LZ4_compressBound(uncomp_chunksize)); |
73 | if (!inp) { |
74 | error("Could not allocate input buffer" ); |
75 | goto exit_1; |
76 | } |
77 | } |
78 | inp_start = inp; |
79 | |
80 | if (posp) |
81 | *posp = 0; |
82 | |
83 | if (fill) { |
84 | size = fill(inp, 4); |
85 | if (size < 4) { |
86 | error("data corrupted" ); |
87 | goto exit_2; |
88 | } |
89 | } |
90 | |
91 | chunksize = get_unaligned_le32(p: inp); |
92 | if (chunksize == ARCHIVE_MAGICNUMBER) { |
93 | if (!fill) { |
94 | inp += 4; |
95 | size -= 4; |
96 | } |
97 | } else { |
98 | error("invalid header" ); |
99 | goto exit_2; |
100 | } |
101 | |
102 | if (posp) |
103 | *posp += 4; |
104 | |
105 | for (;;) { |
106 | |
107 | if (fill) { |
108 | size = fill(inp, 4); |
109 | if (size == 0) |
110 | break; |
111 | if (size < 4) { |
112 | error("data corrupted" ); |
113 | goto exit_2; |
114 | } |
115 | } else if (size < 4) { |
116 | /* empty or end-of-file */ |
117 | goto exit_3; |
118 | } |
119 | |
120 | chunksize = get_unaligned_le32(p: 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 | if (!fill && chunksize == 0) { |
132 | /* empty or end-of-file */ |
133 | goto exit_3; |
134 | } |
135 | |
136 | if (posp) |
137 | *posp += 4; |
138 | |
139 | if (!fill) { |
140 | inp += 4; |
141 | size -= 4; |
142 | } else { |
143 | if (chunksize > LZ4_compressBound(isize: uncomp_chunksize)) { |
144 | error("chunk length is longer than allocated" ); |
145 | goto exit_2; |
146 | } |
147 | size = fill(inp, chunksize); |
148 | if (size < chunksize) { |
149 | error("data corrupted" ); |
150 | goto exit_2; |
151 | } |
152 | } |
153 | #ifdef PREBOOT |
154 | if (out_len >= uncomp_chunksize) { |
155 | dest_len = uncomp_chunksize; |
156 | out_len -= dest_len; |
157 | } else |
158 | dest_len = out_len; |
159 | |
160 | ret = LZ4_decompress_fast(inp, outp, dest_len); |
161 | chunksize = ret; |
162 | #else |
163 | dest_len = uncomp_chunksize; |
164 | |
165 | ret = LZ4_decompress_safe(source: inp, dest: outp, compressedSize: chunksize, maxDecompressedSize: dest_len); |
166 | dest_len = ret; |
167 | #endif |
168 | if (ret < 0) { |
169 | error("Decoding failed" ); |
170 | goto exit_2; |
171 | } |
172 | |
173 | ret = -1; |
174 | if (flush && flush(outp, dest_len) != dest_len) |
175 | goto exit_2; |
176 | if (output) |
177 | outp += dest_len; |
178 | if (posp) |
179 | *posp += chunksize; |
180 | |
181 | if (!fill) { |
182 | size -= chunksize; |
183 | |
184 | if (size == 0) |
185 | break; |
186 | else if (size < 0) { |
187 | error("data corrupted" ); |
188 | goto exit_2; |
189 | } |
190 | inp += chunksize; |
191 | } |
192 | } |
193 | |
194 | exit_3: |
195 | ret = 0; |
196 | exit_2: |
197 | if (!input) |
198 | large_free(inp_start); |
199 | exit_1: |
200 | if (!output) |
201 | large_free(outp); |
202 | exit_0: |
203 | return ret; |
204 | } |
205 | |
206 | #ifdef PREBOOT |
207 | STATIC int INIT __decompress(unsigned char *buf, long in_len, |
208 | long (*fill)(void*, unsigned long), |
209 | long (*flush)(void*, unsigned long), |
210 | unsigned char *output, long out_len, |
211 | long *posp, |
212 | void (*error)(char *x) |
213 | ) |
214 | { |
215 | return unlz4(buf, in_len - 4, fill, flush, output, posp, error); |
216 | } |
217 | #endif |
218 | |