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![Sven Schmidt](/assets/img/avatar_default.png)
Remove the functions introduced as wrappers for providing backwards compatibility to the prior LZ4 version. They're not needed anymore since there's no callers left. Link: http://lkml.kernel.org/r/1486321748-19085-6-git-send-email-4sschmid@informatik.uni-hamburg.de Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Rui Salvaterra <rsalvaterra@gmail.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David S. Miller <davem@davemloft.net> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
508 lines
14 KiB
C
508 lines
14 KiB
C
/*
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* LZ4 - Fast LZ compression algorithm
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* Copyright (C) 2011 - 2016, Yann Collet.
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* BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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* You can contact the author at :
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* - LZ4 homepage : http://www.lz4.org
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* - LZ4 source repository : https://github.com/lz4/lz4
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*
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* Changed for kernel usage by:
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* Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
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*/
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/*-************************************
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* Dependencies
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**************************************/
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#include <linux/lz4.h>
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#include "lz4defs.h"
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <asm/unaligned.h>
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/*-*****************************
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* Decompression functions
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*******************************/
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/* LZ4_decompress_generic() :
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* This generic decompression function cover all use cases.
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* It shall be instantiated several times, using different sets of directives
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* Note that it is important this generic function is really inlined,
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* in order to remove useless branches during compilation optimization.
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*/
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static FORCE_INLINE int LZ4_decompress_generic(
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const char * const source,
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char * const dest,
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int inputSize,
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/*
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* If endOnInput == endOnInputSize,
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* this value is the max size of Output Buffer.
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*/
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int outputSize,
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/* endOnOutputSize, endOnInputSize */
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int endOnInput,
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/* full, partial */
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int partialDecoding,
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/* only used if partialDecoding == partial */
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int targetOutputSize,
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/* noDict, withPrefix64k, usingExtDict */
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int dict,
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/* == dest when no prefix */
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const BYTE * const lowPrefix,
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/* only if dict == usingExtDict */
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const BYTE * const dictStart,
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/* note : = 0 if noDict */
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const size_t dictSize
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)
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{
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/* Local Variables */
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const BYTE *ip = (const BYTE *) source;
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const BYTE * const iend = ip + inputSize;
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BYTE *op = (BYTE *) dest;
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BYTE * const oend = op + outputSize;
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BYTE *cpy;
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BYTE *oexit = op + targetOutputSize;
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const BYTE * const lowLimit = lowPrefix - dictSize;
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const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
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const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
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const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
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const int safeDecode = (endOnInput == endOnInputSize);
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const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));
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/* Special cases */
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/* targetOutputSize too high => decode everything */
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if ((partialDecoding) && (oexit > oend - MFLIMIT))
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oexit = oend - MFLIMIT;
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/* Empty output buffer */
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if ((endOnInput) && (unlikely(outputSize == 0)))
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return ((inputSize == 1) && (*ip == 0)) ? 0 : -1;
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if ((!endOnInput) && (unlikely(outputSize == 0)))
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return (*ip == 0 ? 1 : -1);
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/* Main Loop : decode sequences */
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while (1) {
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size_t length;
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const BYTE *match;
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size_t offset;
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/* get literal length */
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unsigned int const token = *ip++;
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length = token>>ML_BITS;
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if (length == RUN_MASK) {
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unsigned int s;
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do {
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s = *ip++;
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length += s;
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} while (likely(endOnInput
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? ip < iend - RUN_MASK
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: 1) & (s == 255));
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if ((safeDecode)
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&& unlikely(
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(size_t)(op + length) < (size_t)(op))) {
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/* overflow detection */
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goto _output_error;
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}
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if ((safeDecode)
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&& unlikely(
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(size_t)(ip + length) < (size_t)(ip))) {
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/* overflow detection */
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goto _output_error;
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}
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}
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/* copy literals */
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cpy = op + length;
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if (((endOnInput) && ((cpy > (partialDecoding ? oexit : oend - MFLIMIT))
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|| (ip + length > iend - (2 + 1 + LASTLITERALS))))
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|| ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
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if (partialDecoding) {
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if (cpy > oend) {
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/*
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* Error :
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* write attempt beyond end of output buffer
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*/
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goto _output_error;
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}
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if ((endOnInput)
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&& (ip + length > iend)) {
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/*
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* Error :
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* read attempt beyond
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* end of input buffer
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*/
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goto _output_error;
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}
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} else {
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if ((!endOnInput)
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&& (cpy != oend)) {
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/*
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* Error :
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* block decoding must
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* stop exactly there
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*/
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goto _output_error;
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}
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if ((endOnInput)
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&& ((ip + length != iend)
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|| (cpy > oend))) {
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/*
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* Error :
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* input must be consumed
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*/
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goto _output_error;
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}
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}
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memcpy(op, ip, length);
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ip += length;
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op += length;
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/* Necessarily EOF, due to parsing restrictions */
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break;
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}
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LZ4_wildCopy(op, ip, cpy);
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ip += length;
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op = cpy;
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/* get offset */
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offset = LZ4_readLE16(ip);
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ip += 2;
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match = op - offset;
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if ((checkOffset) && (unlikely(match < lowLimit))) {
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/* Error : offset outside buffers */
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goto _output_error;
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}
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/* costs ~1%; silence an msan warning when offset == 0 */
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LZ4_write32(op, (U32)offset);
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/* get matchlength */
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length = token & ML_MASK;
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if (length == ML_MASK) {
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unsigned int s;
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do {
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s = *ip++;
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if ((endOnInput) && (ip > iend - LASTLITERALS))
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goto _output_error;
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length += s;
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} while (s == 255);
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if ((safeDecode)
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&& unlikely(
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(size_t)(op + length) < (size_t)op)) {
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/* overflow detection */
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goto _output_error;
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}
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}
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length += MINMATCH;
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/* check external dictionary */
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if ((dict == usingExtDict) && (match < lowPrefix)) {
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if (unlikely(op + length > oend - LASTLITERALS)) {
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/* doesn't respect parsing restriction */
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goto _output_error;
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}
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if (length <= (size_t)(lowPrefix - match)) {
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/*
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* match can be copied as a single segment
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* from external dictionary
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*/
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memmove(op, dictEnd - (lowPrefix - match),
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length);
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op += length;
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} else {
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/*
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* match encompass external
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* dictionary and current block
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*/
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size_t const copySize = (size_t)(lowPrefix - match);
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size_t const restSize = length - copySize;
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memcpy(op, dictEnd - copySize, copySize);
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op += copySize;
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if (restSize > (size_t)(op - lowPrefix)) {
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/* overlap copy */
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BYTE * const endOfMatch = op + restSize;
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const BYTE *copyFrom = lowPrefix;
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while (op < endOfMatch)
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*op++ = *copyFrom++;
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} else {
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memcpy(op, lowPrefix, restSize);
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op += restSize;
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}
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}
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continue;
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}
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/* copy match within block */
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cpy = op + length;
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if (unlikely(offset < 8)) {
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const int dec64 = dec64table[offset];
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op[0] = match[0];
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op[1] = match[1];
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op[2] = match[2];
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op[3] = match[3];
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match += dec32table[offset];
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memcpy(op + 4, match, 4);
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match -= dec64;
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} else {
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LZ4_copy8(op, match);
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match += 8;
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}
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op += 8;
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if (unlikely(cpy > oend - 12)) {
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BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
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if (cpy > oend - LASTLITERALS) {
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/*
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* Error : last LASTLITERALS bytes
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* must be literals (uncompressed)
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*/
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goto _output_error;
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}
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if (op < oCopyLimit) {
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LZ4_wildCopy(op, match, oCopyLimit);
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match += oCopyLimit - op;
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op = oCopyLimit;
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}
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while (op < cpy)
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*op++ = *match++;
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} else {
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LZ4_copy8(op, match);
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if (length > 16)
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LZ4_wildCopy(op + 8, match + 8, cpy);
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}
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op = cpy; /* correction */
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}
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/* end of decoding */
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if (endOnInput) {
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/* Nb of output bytes decoded */
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return (int) (((char *)op) - dest);
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} else {
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/* Nb of input bytes read */
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return (int) (((const char *)ip) - source);
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}
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/* Overflow error detected */
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_output_error:
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return -1;
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}
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int LZ4_decompress_safe(const char *source, char *dest,
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int compressedSize, int maxDecompressedSize)
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{
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return LZ4_decompress_generic(source, dest, compressedSize,
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maxDecompressedSize, endOnInputSize, full, 0,
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noDict, (BYTE *)dest, NULL, 0);
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}
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int LZ4_decompress_safe_partial(const char *source, char *dest,
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int compressedSize, int targetOutputSize, int maxDecompressedSize)
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{
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return LZ4_decompress_generic(source, dest, compressedSize,
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maxDecompressedSize, endOnInputSize, partial,
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targetOutputSize, noDict, (BYTE *)dest, NULL, 0);
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}
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int LZ4_decompress_fast(const char *source, char *dest, int originalSize)
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{
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return LZ4_decompress_generic(source, dest, 0, originalSize,
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endOnOutputSize, full, 0, withPrefix64k,
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(BYTE *)(dest - 64 * KB), NULL, 64 * KB);
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}
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int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode,
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const char *dictionary, int dictSize)
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{
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LZ4_streamDecode_t_internal *lz4sd = (LZ4_streamDecode_t_internal *) LZ4_streamDecode;
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lz4sd->prefixSize = (size_t) dictSize;
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lz4sd->prefixEnd = (const BYTE *) dictionary + dictSize;
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lz4sd->externalDict = NULL;
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lz4sd->extDictSize = 0;
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return 1;
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}
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/*
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* *_continue() :
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* These decoding functions allow decompression of multiple blocks
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* in "streaming" mode.
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* Previously decoded blocks must still be available at the memory
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* position where they were decoded.
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* If it's not possible, save the relevant part of
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* decoded data into a safe buffer,
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* and indicate where it stands using LZ4_setStreamDecode()
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*/
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int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode,
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const char *source, char *dest, int compressedSize, int maxOutputSize)
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{
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LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse;
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int result;
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if (lz4sd->prefixEnd == (BYTE *)dest) {
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result = LZ4_decompress_generic(source, dest,
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compressedSize,
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maxOutputSize,
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endOnInputSize, full, 0,
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usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize,
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lz4sd->externalDict,
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lz4sd->extDictSize);
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if (result <= 0)
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return result;
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lz4sd->prefixSize += result;
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lz4sd->prefixEnd += result;
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} else {
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lz4sd->extDictSize = lz4sd->prefixSize;
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lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
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result = LZ4_decompress_generic(source, dest,
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compressedSize, maxOutputSize,
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endOnInputSize, full, 0,
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usingExtDict, (BYTE *)dest,
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lz4sd->externalDict, lz4sd->extDictSize);
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if (result <= 0)
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return result;
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lz4sd->prefixSize = result;
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lz4sd->prefixEnd = (BYTE *)dest + result;
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}
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return result;
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}
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int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode,
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const char *source, char *dest, int originalSize)
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{
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LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse;
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int result;
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if (lz4sd->prefixEnd == (BYTE *)dest) {
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result = LZ4_decompress_generic(source, dest, 0, originalSize,
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endOnOutputSize, full, 0,
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usingExtDict,
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lz4sd->prefixEnd - lz4sd->prefixSize,
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lz4sd->externalDict, lz4sd->extDictSize);
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if (result <= 0)
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return result;
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lz4sd->prefixSize += originalSize;
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lz4sd->prefixEnd += originalSize;
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} else {
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lz4sd->extDictSize = lz4sd->prefixSize;
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lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
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result = LZ4_decompress_generic(source, dest, 0, originalSize,
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endOnOutputSize, full, 0,
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usingExtDict, (BYTE *)dest,
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lz4sd->externalDict, lz4sd->extDictSize);
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if (result <= 0)
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return result;
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lz4sd->prefixSize = originalSize;
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lz4sd->prefixEnd = (BYTE *)dest + originalSize;
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}
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return result;
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}
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/*
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* Advanced decoding functions :
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* *_usingDict() :
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* These decoding functions work the same as "_continue" ones,
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* the dictionary must be explicitly provided within parameters
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*/
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static FORCE_INLINE int LZ4_decompress_usingDict_generic(const char *source,
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char *dest, int compressedSize, int maxOutputSize, int safe,
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const char *dictStart, int dictSize)
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{
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if (dictSize == 0)
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return LZ4_decompress_generic(source, dest,
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compressedSize, maxOutputSize, safe, full, 0,
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noDict, (BYTE *)dest, NULL, 0);
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if (dictStart + dictSize == dest) {
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if (dictSize >= (int)(64 * KB - 1))
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return LZ4_decompress_generic(source, dest,
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compressedSize, maxOutputSize, safe, full, 0,
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withPrefix64k, (BYTE *)dest - 64 * KB, NULL, 0);
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return LZ4_decompress_generic(source, dest, compressedSize,
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maxOutputSize, safe, full, 0, noDict,
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(BYTE *)dest - dictSize, NULL, 0);
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}
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return LZ4_decompress_generic(source, dest, compressedSize,
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maxOutputSize, safe, full, 0, usingExtDict,
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(BYTE *)dest, (const BYTE *)dictStart, dictSize);
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}
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int LZ4_decompress_safe_usingDict(const char *source, char *dest,
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int compressedSize, int maxOutputSize,
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const char *dictStart, int dictSize)
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{
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return LZ4_decompress_usingDict_generic(source, dest,
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compressedSize, maxOutputSize, 1, dictStart, dictSize);
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}
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int LZ4_decompress_fast_usingDict(const char *source, char *dest,
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int originalSize, const char *dictStart, int dictSize)
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{
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return LZ4_decompress_usingDict_generic(source, dest, 0,
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originalSize, 0, dictStart, dictSize);
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}
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#ifndef STATIC
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EXPORT_SYMBOL(LZ4_decompress_safe);
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EXPORT_SYMBOL(LZ4_decompress_safe_partial);
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EXPORT_SYMBOL(LZ4_decompress_fast);
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EXPORT_SYMBOL(LZ4_setStreamDecode);
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EXPORT_SYMBOL(LZ4_decompress_safe_continue);
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EXPORT_SYMBOL(LZ4_decompress_fast_continue);
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EXPORT_SYMBOL(LZ4_decompress_safe_usingDict);
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EXPORT_SYMBOL(LZ4_decompress_fast_usingDict);
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_DESCRIPTION("LZ4 decompressor");
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#endif
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