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670 lines
19 KiB
670 lines
19 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* lzx_decompress.c - A decompressor for the LZX compression format, which can |
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* be used in "System Compressed" files. This is based on the code from wimlib. |
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* This code only supports a window size (dictionary size) of 32768 bytes, since |
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* this is the only size used in System Compression. |
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* |
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* Copyright (C) 2015 Eric Biggers |
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*/ |
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|
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#include "decompress_common.h" |
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#include "lib.h" |
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|
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/* Number of literal byte values */ |
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#define LZX_NUM_CHARS 256 |
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|
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/* The smallest and largest allowed match lengths */ |
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#define LZX_MIN_MATCH_LEN 2 |
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#define LZX_MAX_MATCH_LEN 257 |
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|
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/* Number of distinct match lengths that can be represented */ |
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#define LZX_NUM_LENS (LZX_MAX_MATCH_LEN - LZX_MIN_MATCH_LEN + 1) |
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|
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/* Number of match lengths for which no length symbol is required */ |
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#define LZX_NUM_PRIMARY_LENS 7 |
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#define LZX_NUM_LEN_HEADERS (LZX_NUM_PRIMARY_LENS + 1) |
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|
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/* Valid values of the 3-bit block type field */ |
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#define LZX_BLOCKTYPE_VERBATIM 1 |
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#define LZX_BLOCKTYPE_ALIGNED 2 |
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#define LZX_BLOCKTYPE_UNCOMPRESSED 3 |
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|
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/* Number of offset slots for a window size of 32768 */ |
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#define LZX_NUM_OFFSET_SLOTS 30 |
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|
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/* Number of symbols in the main code for a window size of 32768 */ |
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#define LZX_MAINCODE_NUM_SYMBOLS \ |
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(LZX_NUM_CHARS + (LZX_NUM_OFFSET_SLOTS * LZX_NUM_LEN_HEADERS)) |
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|
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/* Number of symbols in the length code */ |
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#define LZX_LENCODE_NUM_SYMBOLS (LZX_NUM_LENS - LZX_NUM_PRIMARY_LENS) |
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|
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/* Number of symbols in the precode */ |
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#define LZX_PRECODE_NUM_SYMBOLS 20 |
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|
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/* Number of bits in which each precode codeword length is represented */ |
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#define LZX_PRECODE_ELEMENT_SIZE 4 |
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|
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/* Number of low-order bits of each match offset that are entropy-encoded in |
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* aligned offset blocks |
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*/ |
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#define LZX_NUM_ALIGNED_OFFSET_BITS 3 |
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|
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/* Number of symbols in the aligned offset code */ |
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#define LZX_ALIGNEDCODE_NUM_SYMBOLS (1 << LZX_NUM_ALIGNED_OFFSET_BITS) |
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|
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/* Mask for the match offset bits that are entropy-encoded in aligned offset |
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* blocks |
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*/ |
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#define LZX_ALIGNED_OFFSET_BITMASK ((1 << LZX_NUM_ALIGNED_OFFSET_BITS) - 1) |
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|
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/* Number of bits in which each aligned offset codeword length is represented */ |
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#define LZX_ALIGNEDCODE_ELEMENT_SIZE 3 |
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|
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/* Maximum lengths (in bits) of the codewords in each Huffman code */ |
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#define LZX_MAX_MAIN_CODEWORD_LEN 16 |
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#define LZX_MAX_LEN_CODEWORD_LEN 16 |
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#define LZX_MAX_PRE_CODEWORD_LEN ((1 << LZX_PRECODE_ELEMENT_SIZE) - 1) |
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#define LZX_MAX_ALIGNED_CODEWORD_LEN ((1 << LZX_ALIGNEDCODE_ELEMENT_SIZE) - 1) |
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|
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/* The default "filesize" value used in pre/post-processing. In the LZX format |
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* used in cabinet files this value must be given to the decompressor, whereas |
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* in the LZX format used in WIM files and system-compressed files this value is |
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* fixed at 12000000. |
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*/ |
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#define LZX_DEFAULT_FILESIZE 12000000 |
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|
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/* Assumed block size when the encoded block size begins with a 0 bit. */ |
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#define LZX_DEFAULT_BLOCK_SIZE 32768 |
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|
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/* Number of offsets in the recent (or "repeat") offsets queue. */ |
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#define LZX_NUM_RECENT_OFFSETS 3 |
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|
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/* These values are chosen for fast decompression. */ |
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#define LZX_MAINCODE_TABLEBITS 11 |
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#define LZX_LENCODE_TABLEBITS 10 |
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#define LZX_PRECODE_TABLEBITS 6 |
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#define LZX_ALIGNEDCODE_TABLEBITS 7 |
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#define LZX_READ_LENS_MAX_OVERRUN 50 |
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|
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/* Mapping: offset slot => first match offset that uses that offset slot. |
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*/ |
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static const u32 lzx_offset_slot_base[LZX_NUM_OFFSET_SLOTS + 1] = { |
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0, 1, 2, 3, 4, /* 0 --- 4 */ |
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6, 8, 12, 16, 24, /* 5 --- 9 */ |
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32, 48, 64, 96, 128, /* 10 --- 14 */ |
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192, 256, 384, 512, 768, /* 15 --- 19 */ |
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1024, 1536, 2048, 3072, 4096, /* 20 --- 24 */ |
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6144, 8192, 12288, 16384, 24576, /* 25 --- 29 */ |
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32768, /* extra */ |
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}; |
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|
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/* Mapping: offset slot => how many extra bits must be read and added to the |
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* corresponding offset slot base to decode the match offset. |
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*/ |
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static const u8 lzx_extra_offset_bits[LZX_NUM_OFFSET_SLOTS] = { |
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0, 0, 0, 0, 1, |
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1, 2, 2, 3, 3, |
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4, 4, 5, 5, 6, |
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6, 7, 7, 8, 8, |
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9, 9, 10, 10, 11, |
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11, 12, 12, 13, 13, |
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}; |
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|
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/* Reusable heap-allocated memory for LZX decompression */ |
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struct lzx_decompressor { |
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|
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/* Huffman decoding tables, and arrays that map symbols to codeword |
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* lengths |
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*/ |
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|
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u16 maincode_decode_table[(1 << LZX_MAINCODE_TABLEBITS) + |
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(LZX_MAINCODE_NUM_SYMBOLS * 2)]; |
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u8 maincode_lens[LZX_MAINCODE_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN]; |
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u16 lencode_decode_table[(1 << LZX_LENCODE_TABLEBITS) + |
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(LZX_LENCODE_NUM_SYMBOLS * 2)]; |
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u8 lencode_lens[LZX_LENCODE_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN]; |
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u16 alignedcode_decode_table[(1 << LZX_ALIGNEDCODE_TABLEBITS) + |
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(LZX_ALIGNEDCODE_NUM_SYMBOLS * 2)]; |
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u8 alignedcode_lens[LZX_ALIGNEDCODE_NUM_SYMBOLS]; |
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u16 precode_decode_table[(1 << LZX_PRECODE_TABLEBITS) + |
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(LZX_PRECODE_NUM_SYMBOLS * 2)]; |
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u8 precode_lens[LZX_PRECODE_NUM_SYMBOLS]; |
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|
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/* Temporary space for make_huffman_decode_table() */ |
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u16 working_space[2 * (1 + LZX_MAX_MAIN_CODEWORD_LEN) + |
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LZX_MAINCODE_NUM_SYMBOLS]; |
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}; |
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static void undo_e8_translation(void *target, s32 input_pos) |
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{ |
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s32 abs_offset, rel_offset; |
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|
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abs_offset = get_unaligned_le32(target); |
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if (abs_offset >= 0) { |
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if (abs_offset < LZX_DEFAULT_FILESIZE) { |
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/* "good translation" */ |
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rel_offset = abs_offset - input_pos; |
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put_unaligned_le32(rel_offset, target); |
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} |
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} else { |
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if (abs_offset >= -input_pos) { |
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/* "compensating translation" */ |
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rel_offset = abs_offset + LZX_DEFAULT_FILESIZE; |
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put_unaligned_le32(rel_offset, target); |
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} |
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} |
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} |
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/* |
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* Undo the 'E8' preprocessing used in LZX. Before compression, the |
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* uncompressed data was preprocessed by changing the targets of suspected x86 |
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* CALL instructions from relative offsets to absolute offsets. After |
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* match/literal decoding, the decompressor must undo the translation. |
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*/ |
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static void lzx_postprocess(u8 *data, u32 size) |
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{ |
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/* |
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* A worthwhile optimization is to push the end-of-buffer check into the |
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* relatively rare E8 case. This is possible if we replace the last six |
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* bytes of data with E8 bytes; then we are guaranteed to hit an E8 byte |
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* before reaching end-of-buffer. In addition, this scheme guarantees |
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* that no translation can begin following an E8 byte in the last 10 |
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* bytes because a 4-byte offset containing E8 as its high byte is a |
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* large negative number that is not valid for translation. That is |
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* exactly what we need. |
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*/ |
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u8 *tail; |
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u8 saved_bytes[6]; |
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u8 *p; |
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if (size <= 10) |
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return; |
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tail = &data[size - 6]; |
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memcpy(saved_bytes, tail, 6); |
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memset(tail, 0xE8, 6); |
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p = data; |
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for (;;) { |
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while (*p != 0xE8) |
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p++; |
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if (p >= tail) |
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break; |
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undo_e8_translation(p + 1, p - data); |
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p += 5; |
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} |
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memcpy(tail, saved_bytes, 6); |
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} |
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/* Read a Huffman-encoded symbol using the precode. */ |
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static forceinline u32 read_presym(const struct lzx_decompressor *d, |
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struct input_bitstream *is) |
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{ |
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return read_huffsym(is, d->precode_decode_table, |
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LZX_PRECODE_TABLEBITS, LZX_MAX_PRE_CODEWORD_LEN); |
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} |
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/* Read a Huffman-encoded symbol using the main code. */ |
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static forceinline u32 read_mainsym(const struct lzx_decompressor *d, |
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struct input_bitstream *is) |
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{ |
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return read_huffsym(is, d->maincode_decode_table, |
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LZX_MAINCODE_TABLEBITS, LZX_MAX_MAIN_CODEWORD_LEN); |
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} |
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|
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/* Read a Huffman-encoded symbol using the length code. */ |
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static forceinline u32 read_lensym(const struct lzx_decompressor *d, |
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struct input_bitstream *is) |
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{ |
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return read_huffsym(is, d->lencode_decode_table, |
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LZX_LENCODE_TABLEBITS, LZX_MAX_LEN_CODEWORD_LEN); |
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} |
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/* Read a Huffman-encoded symbol using the aligned offset code. */ |
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static forceinline u32 read_alignedsym(const struct lzx_decompressor *d, |
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struct input_bitstream *is) |
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{ |
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return read_huffsym(is, d->alignedcode_decode_table, |
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LZX_ALIGNEDCODE_TABLEBITS, |
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LZX_MAX_ALIGNED_CODEWORD_LEN); |
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} |
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|
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/* |
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* Read the precode from the compressed input bitstream, then use it to decode |
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* @num_lens codeword length values. |
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* |
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* @is: The input bitstream. |
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* |
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* @lens: An array that contains the length values from the previous time |
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* the codeword lengths for this Huffman code were read, or all 0's |
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* if this is the first time. This array must have at least |
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* (@num_lens + LZX_READ_LENS_MAX_OVERRUN) entries. |
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* |
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* @num_lens: Number of length values to decode. |
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* |
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* Returns 0 on success, or -1 if the data was invalid. |
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*/ |
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static int lzx_read_codeword_lens(struct lzx_decompressor *d, |
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struct input_bitstream *is, |
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u8 *lens, u32 num_lens) |
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{ |
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u8 *len_ptr = lens; |
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u8 *lens_end = lens + num_lens; |
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int i; |
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|
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/* Read the lengths of the precode codewords. These are given |
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* explicitly. |
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*/ |
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for (i = 0; i < LZX_PRECODE_NUM_SYMBOLS; i++) { |
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d->precode_lens[i] = |
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bitstream_read_bits(is, LZX_PRECODE_ELEMENT_SIZE); |
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} |
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/* Make the decoding table for the precode. */ |
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if (make_huffman_decode_table(d->precode_decode_table, |
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LZX_PRECODE_NUM_SYMBOLS, |
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LZX_PRECODE_TABLEBITS, |
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d->precode_lens, |
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LZX_MAX_PRE_CODEWORD_LEN, |
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d->working_space)) |
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return -1; |
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/* Decode the codeword lengths. */ |
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do { |
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u32 presym; |
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u8 len; |
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/* Read the next precode symbol. */ |
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presym = read_presym(d, is); |
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if (presym < 17) { |
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/* Difference from old length */ |
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len = *len_ptr - presym; |
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if ((s8)len < 0) |
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len += 17; |
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*len_ptr++ = len; |
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} else { |
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/* Special RLE values */ |
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u32 run_len; |
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if (presym == 17) { |
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/* Run of 0's */ |
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run_len = 4 + bitstream_read_bits(is, 4); |
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len = 0; |
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} else if (presym == 18) { |
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/* Longer run of 0's */ |
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run_len = 20 + bitstream_read_bits(is, 5); |
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len = 0; |
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} else { |
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/* Run of identical lengths */ |
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run_len = 4 + bitstream_read_bits(is, 1); |
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presym = read_presym(d, is); |
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if (presym > 17) |
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return -1; |
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len = *len_ptr - presym; |
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if ((s8)len < 0) |
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len += 17; |
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} |
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do { |
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*len_ptr++ = len; |
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} while (--run_len); |
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/* Worst case overrun is when presym == 18, |
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* run_len == 20 + 31, and only 1 length was remaining. |
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* So LZX_READ_LENS_MAX_OVERRUN == 50. |
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* |
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* Overrun while reading the first half of maincode_lens |
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* can corrupt the previous values in the second half. |
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* This doesn't really matter because the resulting |
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* lengths will still be in range, and data that |
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* generates overruns is invalid anyway. |
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*/ |
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} |
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} while (len_ptr < lens_end); |
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|
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return 0; |
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} |
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/* |
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* Read the header of an LZX block and save the block type and (uncompressed) |
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* size in *block_type_ret and *block_size_ret, respectively. |
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* |
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* If the block is compressed, also update the Huffman decode @tables with the |
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* new Huffman codes. If the block is uncompressed, also update the match |
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* offset @queue with the new match offsets. |
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* |
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* Return 0 on success, or -1 if the data was invalid. |
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*/ |
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static int lzx_read_block_header(struct lzx_decompressor *d, |
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struct input_bitstream *is, |
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int *block_type_ret, |
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u32 *block_size_ret, |
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u32 recent_offsets[]) |
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{ |
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int block_type; |
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u32 block_size; |
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int i; |
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bitstream_ensure_bits(is, 4); |
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|
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/* The first three bits tell us what kind of block it is, and should be |
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* one of the LZX_BLOCKTYPE_* values. |
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*/ |
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block_type = bitstream_pop_bits(is, 3); |
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|
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/* Read the block size. */ |
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if (bitstream_pop_bits(is, 1)) { |
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block_size = LZX_DEFAULT_BLOCK_SIZE; |
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} else { |
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block_size = 0; |
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block_size |= bitstream_read_bits(is, 8); |
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block_size <<= 8; |
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block_size |= bitstream_read_bits(is, 8); |
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} |
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switch (block_type) { |
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|
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case LZX_BLOCKTYPE_ALIGNED: |
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|
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/* Read the aligned offset code and prepare its decode table. |
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*/ |
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for (i = 0; i < LZX_ALIGNEDCODE_NUM_SYMBOLS; i++) { |
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d->alignedcode_lens[i] = |
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bitstream_read_bits(is, |
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LZX_ALIGNEDCODE_ELEMENT_SIZE); |
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} |
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if (make_huffman_decode_table(d->alignedcode_decode_table, |
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LZX_ALIGNEDCODE_NUM_SYMBOLS, |
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LZX_ALIGNEDCODE_TABLEBITS, |
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d->alignedcode_lens, |
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LZX_MAX_ALIGNED_CODEWORD_LEN, |
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d->working_space)) |
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return -1; |
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|
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/* Fall though, since the rest of the header for aligned offset |
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* blocks is the same as that for verbatim blocks. |
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*/ |
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fallthrough; |
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|
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case LZX_BLOCKTYPE_VERBATIM: |
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|
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/* Read the main code and prepare its decode table. |
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* |
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* Note that the codeword lengths in the main code are encoded |
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* in two parts: one part for literal symbols, and one part for |
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* match symbols. |
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*/ |
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if (lzx_read_codeword_lens(d, is, d->maincode_lens, |
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LZX_NUM_CHARS)) |
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return -1; |
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|
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if (lzx_read_codeword_lens(d, is, |
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d->maincode_lens + LZX_NUM_CHARS, |
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LZX_MAINCODE_NUM_SYMBOLS - LZX_NUM_CHARS)) |
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return -1; |
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if (make_huffman_decode_table(d->maincode_decode_table, |
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LZX_MAINCODE_NUM_SYMBOLS, |
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LZX_MAINCODE_TABLEBITS, |
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d->maincode_lens, |
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LZX_MAX_MAIN_CODEWORD_LEN, |
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d->working_space)) |
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return -1; |
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|
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/* Read the length code and prepare its decode table. */ |
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if (lzx_read_codeword_lens(d, is, d->lencode_lens, |
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LZX_LENCODE_NUM_SYMBOLS)) |
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return -1; |
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|
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if (make_huffman_decode_table(d->lencode_decode_table, |
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LZX_LENCODE_NUM_SYMBOLS, |
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LZX_LENCODE_TABLEBITS, |
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d->lencode_lens, |
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LZX_MAX_LEN_CODEWORD_LEN, |
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d->working_space)) |
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return -1; |
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|
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break; |
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|
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case LZX_BLOCKTYPE_UNCOMPRESSED: |
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|
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/* Before reading the three recent offsets from the uncompressed |
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* block header, the stream must be aligned on a 16-bit |
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* boundary. But if the stream is *already* aligned, then the |
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* next 16 bits must be discarded. |
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*/ |
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bitstream_ensure_bits(is, 1); |
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bitstream_align(is); |
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|
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recent_offsets[0] = bitstream_read_u32(is); |
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recent_offsets[1] = bitstream_read_u32(is); |
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recent_offsets[2] = bitstream_read_u32(is); |
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|
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/* Offsets of 0 are invalid. */ |
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if (recent_offsets[0] == 0 || recent_offsets[1] == 0 || |
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recent_offsets[2] == 0) |
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return -1; |
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break; |
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|
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default: |
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/* Unrecognized block type. */ |
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return -1; |
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} |
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*block_type_ret = block_type; |
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*block_size_ret = block_size; |
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return 0; |
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} |
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|
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/* Decompress a block of LZX-compressed data. */ |
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static int lzx_decompress_block(const struct lzx_decompressor *d, |
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struct input_bitstream *is, |
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int block_type, u32 block_size, |
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u8 * const out_begin, u8 *out_next, |
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u32 recent_offsets[]) |
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{ |
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u8 * const block_end = out_next + block_size; |
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u32 ones_if_aligned = 0U - (block_type == LZX_BLOCKTYPE_ALIGNED); |
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|
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do { |
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u32 mainsym; |
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u32 match_len; |
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u32 match_offset; |
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u32 offset_slot; |
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u32 num_extra_bits; |
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mainsym = read_mainsym(d, is); |
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if (mainsym < LZX_NUM_CHARS) { |
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/* Literal */ |
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*out_next++ = mainsym; |
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continue; |
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} |
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|
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/* Match */ |
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|
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/* Decode the length header and offset slot. */ |
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mainsym -= LZX_NUM_CHARS; |
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match_len = mainsym % LZX_NUM_LEN_HEADERS; |
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offset_slot = mainsym / LZX_NUM_LEN_HEADERS; |
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|
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/* If needed, read a length symbol to decode the full length. */ |
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if (match_len == LZX_NUM_PRIMARY_LENS) |
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match_len += read_lensym(d, is); |
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match_len += LZX_MIN_MATCH_LEN; |
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|
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if (offset_slot < LZX_NUM_RECENT_OFFSETS) { |
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/* Repeat offset */ |
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|
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/* Note: This isn't a real LRU queue, since using the R2 |
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* offset doesn't bump the R1 offset down to R2. This |
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* quirk allows all 3 recent offsets to be handled by |
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* the same code. (For R0, the swap is a no-op.) |
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*/ |
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match_offset = recent_offsets[offset_slot]; |
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recent_offsets[offset_slot] = recent_offsets[0]; |
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recent_offsets[0] = match_offset; |
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} else { |
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/* Explicit offset */ |
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|
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/* Look up the number of extra bits that need to be read |
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* to decode offsets with this offset slot. |
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*/ |
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num_extra_bits = lzx_extra_offset_bits[offset_slot]; |
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|
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/* Start with the offset slot base value. */ |
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match_offset = lzx_offset_slot_base[offset_slot]; |
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|
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/* In aligned offset blocks, the low-order 3 bits of |
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* each offset are encoded using the aligned offset |
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* code. Otherwise, all the extra bits are literal. |
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*/ |
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|
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if ((num_extra_bits & ones_if_aligned) >= LZX_NUM_ALIGNED_OFFSET_BITS) { |
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match_offset += |
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bitstream_read_bits(is, num_extra_bits - |
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LZX_NUM_ALIGNED_OFFSET_BITS) |
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<< LZX_NUM_ALIGNED_OFFSET_BITS; |
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match_offset += read_alignedsym(d, is); |
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} else { |
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match_offset += bitstream_read_bits(is, num_extra_bits); |
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} |
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|
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/* Adjust the offset. */ |
|
match_offset -= (LZX_NUM_RECENT_OFFSETS - 1); |
|
|
|
/* Update the recent offsets. */ |
|
recent_offsets[2] = recent_offsets[1]; |
|
recent_offsets[1] = recent_offsets[0]; |
|
recent_offsets[0] = match_offset; |
|
} |
|
|
|
/* Validate the match, then copy it to the current position. */ |
|
|
|
if (match_len > (size_t)(block_end - out_next)) |
|
return -1; |
|
|
|
if (match_offset > (size_t)(out_next - out_begin)) |
|
return -1; |
|
|
|
out_next = lz_copy(out_next, match_len, match_offset, |
|
block_end, LZX_MIN_MATCH_LEN); |
|
|
|
} while (out_next != block_end); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* lzx_allocate_decompressor - Allocate an LZX decompressor |
|
* |
|
* Return the pointer to the decompressor on success, or return NULL and set |
|
* errno on failure. |
|
*/ |
|
struct lzx_decompressor *lzx_allocate_decompressor(void) |
|
{ |
|
return kmalloc(sizeof(struct lzx_decompressor), GFP_NOFS); |
|
} |
|
|
|
/* |
|
* lzx_decompress - Decompress a buffer of LZX-compressed data |
|
* |
|
* @decompressor: A decompressor allocated with lzx_allocate_decompressor() |
|
* @compressed_data: The buffer of data to decompress |
|
* @compressed_size: Number of bytes of compressed data |
|
* @uncompressed_data: The buffer in which to store the decompressed data |
|
* @uncompressed_size: The number of bytes the data decompresses into |
|
* |
|
* Return 0 on success, or return -1 and set errno on failure. |
|
*/ |
|
int lzx_decompress(struct lzx_decompressor *decompressor, |
|
const void *compressed_data, size_t compressed_size, |
|
void *uncompressed_data, size_t uncompressed_size) |
|
{ |
|
struct lzx_decompressor *d = decompressor; |
|
u8 * const out_begin = uncompressed_data; |
|
u8 *out_next = out_begin; |
|
u8 * const out_end = out_begin + uncompressed_size; |
|
struct input_bitstream is; |
|
u32 recent_offsets[LZX_NUM_RECENT_OFFSETS] = {1, 1, 1}; |
|
int e8_status = 0; |
|
|
|
init_input_bitstream(&is, compressed_data, compressed_size); |
|
|
|
/* Codeword lengths begin as all 0's for delta encoding purposes. */ |
|
memset(d->maincode_lens, 0, LZX_MAINCODE_NUM_SYMBOLS); |
|
memset(d->lencode_lens, 0, LZX_LENCODE_NUM_SYMBOLS); |
|
|
|
/* Decompress blocks until we have all the uncompressed data. */ |
|
|
|
while (out_next != out_end) { |
|
int block_type; |
|
u32 block_size; |
|
|
|
if (lzx_read_block_header(d, &is, &block_type, &block_size, |
|
recent_offsets)) |
|
goto invalid; |
|
|
|
if (block_size < 1 || block_size > (size_t)(out_end - out_next)) |
|
goto invalid; |
|
|
|
if (block_type != LZX_BLOCKTYPE_UNCOMPRESSED) { |
|
|
|
/* Compressed block */ |
|
|
|
if (lzx_decompress_block(d, |
|
&is, |
|
block_type, |
|
block_size, |
|
out_begin, |
|
out_next, |
|
recent_offsets)) |
|
goto invalid; |
|
|
|
e8_status |= d->maincode_lens[0xe8]; |
|
out_next += block_size; |
|
} else { |
|
/* Uncompressed block */ |
|
|
|
out_next = bitstream_read_bytes(&is, out_next, |
|
block_size); |
|
if (!out_next) |
|
goto invalid; |
|
|
|
if (block_size & 1) |
|
bitstream_read_byte(&is); |
|
|
|
e8_status = 1; |
|
} |
|
} |
|
|
|
/* Postprocess the data unless it cannot possibly contain 0xe8 bytes. */ |
|
if (e8_status) |
|
lzx_postprocess(uncompressed_data, uncompressed_size); |
|
|
|
return 0; |
|
|
|
invalid: |
|
return -1; |
|
} |
|
|
|
/* |
|
* lzx_free_decompressor - Free an LZX decompressor |
|
* |
|
* @decompressor: A decompressor that was allocated with |
|
* lzx_allocate_decompressor(), or NULL. |
|
*/ |
|
void lzx_free_decompressor(struct lzx_decompressor *decompressor) |
|
{ |
|
kfree(decompressor); |
|
}
|
|
|