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linux-7.2.3/lib/lz4/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ccflags-y += -O3
+
+obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o
+obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o
+obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o

linux-7.2.3/lib/lz4/lz4_compress.c

@@ -0,0 +1,939 @@
+/*
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011 - 2016, Yann Collet.
+ * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+
+/*-************************************
+ *	Dependencies
+ **************************************/
+#include "lz4defs.h"
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/unaligned.h>
+
+static const int LZ4_minLength = (MFLIMIT + 1);
+static const int LZ4_64Klimit = ((64 * KB) + (MFLIMIT - 1));
+
+/*-******************************
+ *	Compression functions
+ ********************************/
+static FORCE_INLINE U32 LZ4_hash4(
+	U32 sequence,
+	tableType_t const tableType)
+{
+	if (tableType == byU16)
+		return ((sequence * 2654435761U)
+			>> ((MINMATCH * 8) - (LZ4_HASHLOG + 1)));
+	else
+		return ((sequence * 2654435761U)
+			>> ((MINMATCH * 8) - LZ4_HASHLOG));
+}
+
+static FORCE_INLINE U32 LZ4_hash5(
+	U64 sequence,
+	tableType_t const tableType)
+{
+	const U32 hashLog = (tableType == byU16)
+		? LZ4_HASHLOG + 1
+		: LZ4_HASHLOG;
+
+#if LZ4_LITTLE_ENDIAN
+	static const U64 prime5bytes = 889523592379ULL;
+
+	return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
+#else
+	static const U64 prime8bytes = 11400714785074694791ULL;
+
+	return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
+#endif
+}
+
+static FORCE_INLINE U32 LZ4_hashPosition(
+	const void *p,
+	tableType_t const tableType)
+{
+#if LZ4_ARCH64
+	if (tableType == byU32)
+		return LZ4_hash5(LZ4_read_ARCH(p), tableType);
+#endif
+
+	return LZ4_hash4(LZ4_read32(p), tableType);
+}
+
+static void LZ4_putPositionOnHash(
+	const BYTE *p,
+	U32 h,
+	void *tableBase,
+	tableType_t const tableType,
+	const BYTE *srcBase)
+{
+	switch (tableType) {
+	case byPtr:
+	{
+		const BYTE **hashTable = (const BYTE **)tableBase;
+
+		hashTable[h] = p;
+		return;
+	}
+	case byU32:
+	{
+		U32 *hashTable = (U32 *) tableBase;
+
+		hashTable[h] = (U32)(p - srcBase);
+		return;
+	}
+	case byU16:
+	{
+		U16 *hashTable = (U16 *) tableBase;
+
+		hashTable[h] = (U16)(p - srcBase);
+		return;
+	}
+	}
+}
+
+static FORCE_INLINE void LZ4_putPosition(
+	const BYTE *p,
+	void *tableBase,
+	tableType_t tableType,
+	const BYTE *srcBase)
+{
+	U32 const h = LZ4_hashPosition(p, tableType);
+
+	LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
+}
+
+static const BYTE *LZ4_getPositionOnHash(
+	U32 h,
+	void *tableBase,
+	tableType_t tableType,
+	const BYTE *srcBase)
+{
+	if (tableType == byPtr) {
+		const BYTE **hashTable = (const BYTE **) tableBase;
+
+		return hashTable[h];
+	}
+
+	if (tableType == byU32) {
+		const U32 * const hashTable = (U32 *) tableBase;
+
+		return hashTable[h] + srcBase;
+	}
+
+	{
+		/* default, to ensure a return */
+		const U16 * const hashTable = (U16 *) tableBase;
+
+		return hashTable[h] + srcBase;
+	}
+}
+
+static FORCE_INLINE const BYTE *LZ4_getPosition(
+	const BYTE *p,
+	void *tableBase,
+	tableType_t tableType,
+	const BYTE *srcBase)
+{
+	U32 const h = LZ4_hashPosition(p, tableType);
+
+	return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
+}
+
+
+/*
+ * LZ4_compress_generic() :
+ * inlined, to ensure branches are decided at compilation time
+ */
+static FORCE_INLINE int LZ4_compress_generic(
+	LZ4_stream_t_internal * const dictPtr,
+	const char * const source,
+	char * const dest,
+	const int inputSize,
+	const int maxOutputSize,
+	const limitedOutput_directive outputLimited,
+	const tableType_t tableType,
+	const dict_directive dict,
+	const dictIssue_directive dictIssue,
+	const U32 acceleration)
+{
+	const BYTE *ip = (const BYTE *) source;
+	const BYTE *base;
+	const BYTE *lowLimit;
+	const BYTE * const lowRefLimit = ip - dictPtr->dictSize;
+	const BYTE * const dictionary = dictPtr->dictionary;
+	const BYTE * const dictEnd = dictionary + dictPtr->dictSize;
+	const size_t dictDelta = dictEnd - (const BYTE *)source;
+	const BYTE *anchor = (const BYTE *) source;
+	const BYTE * const iend = ip + inputSize;
+	const BYTE * const mflimit = iend - MFLIMIT;
+	const BYTE * const matchlimit = iend - LASTLITERALS;
+
+	BYTE *op = (BYTE *) dest;
+	BYTE * const olimit = op + maxOutputSize;
+
+	U32 forwardH;
+	size_t refDelta = 0;
+
+	/* Init conditions */
+	if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) {
+		/* Unsupported inputSize, too large (or negative) */
+		return 0;
+	}
+
+	switch (dict) {
+	case noDict:
+	default:
+		base = (const BYTE *)source;
+		lowLimit = (const BYTE *)source;
+		break;
+	case withPrefix64k:
+		base = (const BYTE *)source - dictPtr->currentOffset;
+		lowLimit = (const BYTE *)source - dictPtr->dictSize;
+		break;
+	case usingExtDict:
+		base = (const BYTE *)source - dictPtr->currentOffset;
+		lowLimit = (const BYTE *)source;
+		break;
+	}
+
+	if ((tableType == byU16)
+		&& (inputSize >= LZ4_64Klimit)) {
+		/* Size too large (not within 64K limit) */
+		return 0;
+	}
+
+	if (inputSize < LZ4_minLength) {
+		/* Input too small, no compression (all literals) */
+		goto _last_literals;
+	}
+
+	/* First Byte */
+	LZ4_putPosition(ip, dictPtr->hashTable, tableType, base);
+	ip++;
+	forwardH = LZ4_hashPosition(ip, tableType);
+
+	/* Main Loop */
+	for ( ; ; ) {
+		const BYTE *match;
+		BYTE *token;
+
+		/* Find a match */
+		{
+			const BYTE *forwardIp = ip;
+			unsigned int step = 1;
+			unsigned int searchMatchNb = acceleration << LZ4_SKIPTRIGGER;
+
+			do {
+				U32 const h = forwardH;
+
+				ip = forwardIp;
+				forwardIp += step;
+				step = (searchMatchNb++ >> LZ4_SKIPTRIGGER);
+
+				if (unlikely(forwardIp > mflimit))
+					goto _last_literals;
+
+				match = LZ4_getPositionOnHash(h,
+					dictPtr->hashTable,
+					tableType, base);
+
+				if (dict == usingExtDict) {
+					if (match < (const BYTE *)source) {
+						refDelta = dictDelta;
+						lowLimit = dictionary;
+					} else {
+						refDelta = 0;
+						lowLimit = (const BYTE *)source;
+				}	 }
+
+				forwardH = LZ4_hashPosition(forwardIp,
+					tableType);
+
+				LZ4_putPositionOnHash(ip, h, dictPtr->hashTable,
+					tableType, base);
+			} while (((dictIssue == dictSmall)
+					? (match < lowRefLimit)
+					: 0)
+				|| ((tableType == byU16)
+					? 0
+					: (match + MAX_DISTANCE < ip))
+				|| (LZ4_read32(match + refDelta)
+					!= LZ4_read32(ip)));
+		}
+
+		/* Catch up */
+		while (((ip > anchor) & (match + refDelta > lowLimit))
+				&& (unlikely(ip[-1] == match[refDelta - 1]))) {
+			ip--;
+			match--;
+		}
+
+		/* Encode Literals */
+		{
+			unsigned const int litLength = (unsigned int)(ip - anchor);
+
+			token = op++;
+
+			if ((outputLimited) &&
+				/* Check output buffer overflow */
+				(unlikely(op + litLength +
+					(2 + 1 + LASTLITERALS) +
+					(litLength / 255) > olimit)))
+				return 0;
+
+			if (litLength >= RUN_MASK) {
+				int len = (int)litLength - RUN_MASK;
+
+				*token = (RUN_MASK << ML_BITS);
+
+				for (; len >= 255; len -= 255)
+					*op++ = 255;
+				*op++ = (BYTE)len;
+			} else
+				*token = (BYTE)(litLength << ML_BITS);
+
+			/* Copy Literals */
+			LZ4_wildCopy(op, anchor, op + litLength);
+			op += litLength;
+		}
+
+_next_match:
+		/* Encode Offset */
+		LZ4_writeLE16(op, (U16)(ip - match));
+		op += 2;
+
+		/* Encode MatchLength */
+		{
+			unsigned int matchCode;
+
+			if ((dict == usingExtDict)
+				&& (lowLimit == dictionary)) {
+				const BYTE *limit;
+
+				match += refDelta;
+				limit = ip + (dictEnd - match);
+
+				if (limit > matchlimit)
+					limit = matchlimit;
+
+				matchCode = LZ4_count(ip + MINMATCH,
+					match + MINMATCH, limit);
+
+				ip += MINMATCH + matchCode;
+
+				if (ip == limit) {
+					unsigned const int more = LZ4_count(ip,
+						(const BYTE *)source,
+						matchlimit);
+
+					matchCode += more;
+					ip += more;
+				}
+			} else {
+				matchCode = LZ4_count(ip + MINMATCH,
+					match + MINMATCH, matchlimit);
+				ip += MINMATCH + matchCode;
+			}
+
+			if (outputLimited &&
+				/* Check output buffer overflow */
+				(unlikely(op +
+					(1 + LASTLITERALS) +
+					(matchCode >> 8) > olimit)))
+				return 0;
+
+			if (matchCode >= ML_MASK) {
+				*token += ML_MASK;
+				matchCode -= ML_MASK;
+				LZ4_write32(op, 0xFFFFFFFF);
+
+				while (matchCode >= 4 * 255) {
+					op += 4;
+					LZ4_write32(op, 0xFFFFFFFF);
+					matchCode -= 4 * 255;
+				}
+
+				op += matchCode / 255;
+				*op++ = (BYTE)(matchCode % 255);
+			} else
+				*token += (BYTE)(matchCode);
+		}
+
+		anchor = ip;
+
+		/* Test end of chunk */
+		if (ip > mflimit)
+			break;
+
+		/* Fill table */
+		LZ4_putPosition(ip - 2, dictPtr->hashTable, tableType, base);
+
+		/* Test next position */
+		match = LZ4_getPosition(ip, dictPtr->hashTable,
+			tableType, base);
+
+		if (dict == usingExtDict) {
+			if (match < (const BYTE *)source) {
+				refDelta = dictDelta;
+				lowLimit = dictionary;
+			} else {
+				refDelta = 0;
+				lowLimit = (const BYTE *)source;
+			}
+		}
+
+		LZ4_putPosition(ip, dictPtr->hashTable, tableType, base);
+
+		if (((dictIssue == dictSmall) ? (match >= lowRefLimit) : 1)
+			&& (match + MAX_DISTANCE >= ip)
+			&& (LZ4_read32(match + refDelta) == LZ4_read32(ip))) {
+			token = op++;
+			*token = 0;
+			goto _next_match;
+		}
+
+		/* Prepare next loop */
+		forwardH = LZ4_hashPosition(++ip, tableType);
+	}
+
+_last_literals:
+	/* Encode Last Literals */
+	{
+		size_t const lastRun = (size_t)(iend - anchor);
+
+		if ((outputLimited) &&
+			/* Check output buffer overflow */
+			((op - (BYTE *)dest) + lastRun + 1 +
+			((lastRun + 255 - RUN_MASK) / 255) > (U32)maxOutputSize))
+			return 0;
+
+		if (lastRun >= RUN_MASK) {
+			size_t accumulator = lastRun - RUN_MASK;
+			*op++ = RUN_MASK << ML_BITS;
+			for (; accumulator >= 255; accumulator -= 255)
+				*op++ = 255;
+			*op++ = (BYTE) accumulator;
+		} else {
+			*op++ = (BYTE)(lastRun << ML_BITS);
+		}
+
+		LZ4_memcpy(op, anchor, lastRun);
+
+		op += lastRun;
+	}
+
+	/* End */
+	return (int) (((char *)op) - dest);
+}
+
+static int LZ4_compress_fast_extState(
+	void *state,
+	const char *source,
+	char *dest,
+	int inputSize,
+	int maxOutputSize,
+	int acceleration)
+{
+	LZ4_stream_t_internal *ctx = &((LZ4_stream_t *)state)->internal_donotuse;
+#if LZ4_ARCH64
+	const tableType_t tableType = byU32;
+#else
+	const tableType_t tableType = byPtr;
+#endif
+
+	LZ4_resetStream((LZ4_stream_t *)state);
+
+	if (acceleration < 1)
+		acceleration = LZ4_ACCELERATION_DEFAULT;
+
+	if (maxOutputSize >= LZ4_COMPRESSBOUND(inputSize)) {
+		if (inputSize < LZ4_64Klimit)
+			return LZ4_compress_generic(ctx, source,
+				dest, inputSize, 0,
+				noLimit, byU16, noDict,
+				noDictIssue, acceleration);
+		else
+			return LZ4_compress_generic(ctx, source,
+				dest, inputSize, 0,
+				noLimit, tableType, noDict,
+				noDictIssue, acceleration);
+	} else {
+		if (inputSize < LZ4_64Klimit)
+			return LZ4_compress_generic(ctx, source,
+				dest, inputSize,
+				maxOutputSize, limitedOutput, byU16, noDict,
+				noDictIssue, acceleration);
+		else
+			return LZ4_compress_generic(ctx, source,
+				dest, inputSize,
+				maxOutputSize, limitedOutput, tableType, noDict,
+				noDictIssue, acceleration);
+	}
+}
+
+int LZ4_compress_fast(const char *source, char *dest, int inputSize,
+	int maxOutputSize, int acceleration, void *wrkmem)
+{
+	return LZ4_compress_fast_extState(wrkmem, source, dest, inputSize,
+		maxOutputSize, acceleration);
+}
+EXPORT_SYMBOL(LZ4_compress_fast);
+
+int LZ4_compress_default(const char *source, char *dest, int inputSize,
+	int maxOutputSize, void *wrkmem)
+{
+	return LZ4_compress_fast(source, dest, inputSize,
+		maxOutputSize, LZ4_ACCELERATION_DEFAULT, wrkmem);
+}
+EXPORT_SYMBOL(LZ4_compress_default);
+
+/*-******************************
+ *	*_destSize() variant
+ ********************************/
+static int LZ4_compress_destSize_generic(
+	LZ4_stream_t_internal * const ctx,
+	const char * const src,
+	char * const dst,
+	int * const srcSizePtr,
+	const int targetDstSize,
+	const tableType_t tableType)
+{
+	const BYTE *ip = (const BYTE *) src;
+	const BYTE *base = (const BYTE *) src;
+	const BYTE *lowLimit = (const BYTE *) src;
+	const BYTE *anchor = ip;
+	const BYTE * const iend = ip + *srcSizePtr;
+	const BYTE * const mflimit = iend - MFLIMIT;
+	const BYTE * const matchlimit = iend - LASTLITERALS;
+
+	BYTE *op = (BYTE *) dst;
+	BYTE * const oend = op + targetDstSize;
+	BYTE * const oMaxLit = op + targetDstSize - 2 /* offset */
+		- 8 /* because 8 + MINMATCH == MFLIMIT */ - 1 /* token */;
+	BYTE * const oMaxMatch = op + targetDstSize
+		- (LASTLITERALS + 1 /* token */);
+	BYTE * const oMaxSeq = oMaxLit - 1 /* token */;
+
+	U32 forwardH;
+
+	/* Init conditions */
+	/* Impossible to store anything */
+	if (targetDstSize < 1)
+		return 0;
+	/* Unsupported input size, too large (or negative) */
+	if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE)
+		return 0;
+	/* Size too large (not within 64K limit) */
+	if ((tableType == byU16) && (*srcSizePtr >= LZ4_64Klimit))
+		return 0;
+	/* Input too small, no compression (all literals) */
+	if (*srcSizePtr < LZ4_minLength)
+		goto _last_literals;
+
+	/* First Byte */
+	*srcSizePtr = 0;
+	LZ4_putPosition(ip, ctx->hashTable, tableType, base);
+	ip++; forwardH = LZ4_hashPosition(ip, tableType);
+
+	/* Main Loop */
+	for ( ; ; ) {
+		const BYTE *match;
+		BYTE *token;
+
+		/* Find a match */
+		{
+			const BYTE *forwardIp = ip;
+			unsigned int step = 1;
+			unsigned int searchMatchNb = 1 << LZ4_SKIPTRIGGER;
+
+			do {
+				U32 h = forwardH;
+
+				ip = forwardIp;
+				forwardIp += step;
+				step = (searchMatchNb++ >> LZ4_SKIPTRIGGER);
+
+				if (unlikely(forwardIp > mflimit))
+					goto _last_literals;
+
+				match = LZ4_getPositionOnHash(h, ctx->hashTable,
+					tableType, base);
+				forwardH = LZ4_hashPosition(forwardIp,
+					tableType);
+				LZ4_putPositionOnHash(ip, h,
+					ctx->hashTable, tableType,
+					base);
+
+			} while (((tableType == byU16)
+				? 0
+				: (match + MAX_DISTANCE < ip))
+				|| (LZ4_read32(match) != LZ4_read32(ip)));
+		}
+
+		/* Catch up */
+		while ((ip > anchor)
+			&& (match > lowLimit)
+			&& (unlikely(ip[-1] == match[-1]))) {
+			ip--;
+			match--;
+		}
+
+		/* Encode Literal length */
+		{
+			unsigned int litLength = (unsigned int)(ip - anchor);
+
+			token = op++;
+			if (op + ((litLength + 240) / 255)
+				+ litLength > oMaxLit) {
+				/* Not enough space for a last match */
+				op--;
+				goto _last_literals;
+			}
+			if (litLength >= RUN_MASK) {
+				unsigned int len = litLength - RUN_MASK;
+				*token = (RUN_MASK<<ML_BITS);
+				for (; len >= 255; len -= 255)
+					*op++ = 255;
+				*op++ = (BYTE)len;
+			} else
+				*token = (BYTE)(litLength << ML_BITS);
+
+			/* Copy Literals */
+			LZ4_wildCopy(op, anchor, op + litLength);
+			op += litLength;
+		}
+
+_next_match:
+		/* Encode Offset */
+		LZ4_writeLE16(op, (U16)(ip - match)); op += 2;
+
+		/* Encode MatchLength */
+		{
+			size_t matchLength = LZ4_count(ip + MINMATCH,
+			match + MINMATCH, matchlimit);
+
+			if (op + ((matchLength + 240)/255) > oMaxMatch) {
+				/* Match description too long : reduce it */
+				matchLength = (15 - 1) + (oMaxMatch - op) * 255;
+			}
+			ip += MINMATCH + matchLength;
+
+			if (matchLength >= ML_MASK) {
+				*token += ML_MASK;
+				matchLength -= ML_MASK;
+				while (matchLength >= 255) {
+					matchLength -= 255;
+					*op++ = 255;
+				}
+				*op++ = (BYTE)matchLength;
+			} else
+				*token += (BYTE)(matchLength);
+		}
+
+		anchor = ip;
+
+		/* Test end of block */
+		if (ip > mflimit)
+			break;
+		if (op > oMaxSeq)
+			break;
+
+		/* Fill table */
+		LZ4_putPosition(ip - 2, ctx->hashTable, tableType, base);
+
+		/* Test next position */
+		match = LZ4_getPosition(ip, ctx->hashTable, tableType, base);
+		LZ4_putPosition(ip, ctx->hashTable, tableType, base);
+
+		if ((match + MAX_DISTANCE >= ip)
+			&& (LZ4_read32(match) == LZ4_read32(ip))) {
+			token = op++; *token = 0;
+			goto _next_match;
+		}
+
+		/* Prepare next loop */
+		forwardH = LZ4_hashPosition(++ip, tableType);
+	}
+
+_last_literals:
+	/* Encode Last Literals */
+	{
+		size_t lastRunSize = (size_t)(iend - anchor);
+
+		if (op + 1 /* token */
+			+ ((lastRunSize + 240) / 255) /* litLength */
+			+ lastRunSize /* literals */ > oend) {
+			/* adapt lastRunSize to fill 'dst' */
+			lastRunSize	= (oend - op) - 1;
+			lastRunSize -= (lastRunSize + 240) / 255;
+		}
+		ip = anchor + lastRunSize;
+
+		if (lastRunSize >= RUN_MASK) {
+			size_t accumulator = lastRunSize - RUN_MASK;
+
+			*op++ = RUN_MASK << ML_BITS;
+			for (; accumulator >= 255; accumulator -= 255)
+				*op++ = 255;
+			*op++ = (BYTE) accumulator;
+		} else {
+			*op++ = (BYTE)(lastRunSize<<ML_BITS);
+		}
+		LZ4_memcpy(op, anchor, lastRunSize);
+		op += lastRunSize;
+	}
+
+	/* End */
+	*srcSizePtr = (int) (((const char *)ip) - src);
+	return (int) (((char *)op) - dst);
+}
+
+static int LZ4_compress_destSize_extState(
+	LZ4_stream_t *state,
+	const char *src,
+	char *dst,
+	int *srcSizePtr,
+	int targetDstSize)
+{
+#if LZ4_ARCH64
+	const tableType_t tableType = byU32;
+#else
+	const tableType_t tableType = byPtr;
+#endif
+
+	LZ4_resetStream(state);
+
+	if (targetDstSize >= LZ4_COMPRESSBOUND(*srcSizePtr)) {
+		/* compression success is guaranteed */
+		return LZ4_compress_fast_extState(
+			state, src, dst, *srcSizePtr,
+			targetDstSize, 1);
+	} else {
+		if (*srcSizePtr < LZ4_64Klimit)
+			return LZ4_compress_destSize_generic(
+				&state->internal_donotuse,
+				src, dst, srcSizePtr,
+				targetDstSize, byU16);
+		else
+			return LZ4_compress_destSize_generic(
+				&state->internal_donotuse,
+				src, dst, srcSizePtr,
+				targetDstSize, tableType);
+	}
+}
+
+
+int LZ4_compress_destSize(
+	const char *src,
+	char *dst,
+	int *srcSizePtr,
+	int targetDstSize,
+	void *wrkmem)
+{
+	return LZ4_compress_destSize_extState(wrkmem, src, dst, srcSizePtr,
+		targetDstSize);
+}
+EXPORT_SYMBOL(LZ4_compress_destSize);
+
+/*-******************************
+ *	Streaming functions
+ ********************************/
+void LZ4_resetStream(LZ4_stream_t *LZ4_stream)
+{
+	memset(LZ4_stream, 0, sizeof(LZ4_stream_t));
+}
+
+int LZ4_loadDict(LZ4_stream_t *LZ4_dict,
+	const char *dictionary, int dictSize)
+{
+	LZ4_stream_t_internal *dict = &LZ4_dict->internal_donotuse;
+	const BYTE *p = (const BYTE *)dictionary;
+	const BYTE * const dictEnd = p + dictSize;
+	const BYTE *base;
+
+	if ((dict->initCheck)
+		|| (dict->currentOffset > 1 * GB)) {
+		/* Uninitialized structure, or reuse overflow */
+		LZ4_resetStream(LZ4_dict);
+	}
+
+	if (dictSize < (int)HASH_UNIT) {
+		dict->dictionary = NULL;
+		dict->dictSize = 0;
+		return 0;
+	}
+
+	if ((dictEnd - p) > 64 * KB)
+		p = dictEnd - 64 * KB;
+	dict->currentOffset += 64 * KB;
+	base = p - dict->currentOffset;
+	dict->dictionary = p;
+	dict->dictSize = (U32)(dictEnd - p);
+	dict->currentOffset += dict->dictSize;
+
+	while (p <= dictEnd - HASH_UNIT) {
+		LZ4_putPosition(p, dict->hashTable, byU32, base);
+		p += 3;
+	}
+
+	return dict->dictSize;
+}
+EXPORT_SYMBOL(LZ4_loadDict);
+
+static void LZ4_renormDictT(LZ4_stream_t_internal *LZ4_dict,
+	const BYTE *src)
+{
+	if ((LZ4_dict->currentOffset > 0x80000000) ||
+		((uptrval)LZ4_dict->currentOffset > (uptrval)src)) {
+		/* address space overflow */
+		/* rescale hash table */
+		U32 const delta = LZ4_dict->currentOffset - 64 * KB;
+		const BYTE *dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
+		int i;
+
+		for (i = 0; i < LZ4_HASH_SIZE_U32; i++) {
+			if (LZ4_dict->hashTable[i] < delta)
+				LZ4_dict->hashTable[i] = 0;
+			else
+				LZ4_dict->hashTable[i] -= delta;
+		}
+		LZ4_dict->currentOffset = 64 * KB;
+		if (LZ4_dict->dictSize > 64 * KB)
+			LZ4_dict->dictSize = 64 * KB;
+		LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
+	}
+}
+
+int LZ4_saveDict(LZ4_stream_t *LZ4_dict, char *safeBuffer, int dictSize)
+{
+	LZ4_stream_t_internal * const dict = &LZ4_dict->internal_donotuse;
+	const BYTE * const previousDictEnd = dict->dictionary + dict->dictSize;
+
+	if ((U32)dictSize > 64 * KB) {
+		/* useless to define a dictionary > 64 * KB */
+		dictSize = 64 * KB;
+	}
+	if ((U32)dictSize > dict->dictSize)
+		dictSize = dict->dictSize;
+
+	memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
+
+	dict->dictionary = (const BYTE *)safeBuffer;
+	dict->dictSize = (U32)dictSize;
+
+	return dictSize;
+}
+EXPORT_SYMBOL(LZ4_saveDict);
+
+int LZ4_compress_fast_continue(LZ4_stream_t *LZ4_stream, const char *source,
+	char *dest, int inputSize, int maxOutputSize, int acceleration)
+{
+	LZ4_stream_t_internal *streamPtr = &LZ4_stream->internal_donotuse;
+	const BYTE * const dictEnd = streamPtr->dictionary
+		+ streamPtr->dictSize;
+
+	const BYTE *smallest = (const BYTE *) source;
+
+	if (streamPtr->initCheck) {
+		/* Uninitialized structure detected */
+		return 0;
+	}
+
+	if ((streamPtr->dictSize > 0) && (smallest > dictEnd))
+		smallest = dictEnd;
+
+	LZ4_renormDictT(streamPtr, smallest);
+
+	if (acceleration < 1)
+		acceleration = LZ4_ACCELERATION_DEFAULT;
+
+	/* Check overlapping input/dictionary space */
+	{
+		const BYTE *sourceEnd = (const BYTE *) source + inputSize;
+
+		if ((sourceEnd > streamPtr->dictionary)
+			&& (sourceEnd < dictEnd)) {
+			streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
+			if (streamPtr->dictSize > 64 * KB)
+				streamPtr->dictSize = 64 * KB;
+			if (streamPtr->dictSize < 4)
+				streamPtr->dictSize = 0;
+			streamPtr->dictionary = dictEnd - streamPtr->dictSize;
+		}
+	}
+
+	/* prefix mode : source data follows dictionary */
+	if (dictEnd == (const BYTE *)source) {
+		int result;
+
+		if ((streamPtr->dictSize < 64 * KB) &&
+			(streamPtr->dictSize < streamPtr->currentOffset)) {
+			result = LZ4_compress_generic(
+				streamPtr, source, dest, inputSize,
+				maxOutputSize, limitedOutput, byU32,
+				withPrefix64k, dictSmall, acceleration);
+		} else {
+			result = LZ4_compress_generic(
+				streamPtr, source, dest, inputSize,
+				maxOutputSize, limitedOutput, byU32,
+				withPrefix64k, noDictIssue, acceleration);
+		}
+		streamPtr->dictSize += (U32)inputSize;
+		streamPtr->currentOffset += (U32)inputSize;
+		return result;
+	}
+
+	/* external dictionary mode */
+	{
+		int result;
+
+		if ((streamPtr->dictSize < 64 * KB) &&
+			(streamPtr->dictSize < streamPtr->currentOffset)) {
+			result = LZ4_compress_generic(
+				streamPtr, source, dest, inputSize,
+				maxOutputSize, limitedOutput, byU32,
+				usingExtDict, dictSmall, acceleration);
+		} else {
+			result = LZ4_compress_generic(
+				streamPtr, source, dest, inputSize,
+				maxOutputSize, limitedOutput, byU32,
+				usingExtDict, noDictIssue, acceleration);
+		}
+		streamPtr->dictionary = (const BYTE *)source;
+		streamPtr->dictSize = (U32)inputSize;
+		streamPtr->currentOffset += (U32)inputSize;
+		return result;
+	}
+}
+EXPORT_SYMBOL(LZ4_compress_fast_continue);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("LZ4 compressor");

linux-7.2.3/lib/lz4/lz4_decompress.c

@@ -0,0 +1,719 @@
+/*
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011 - 2016, Yann Collet.
+ * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+
+/*-************************************
+ *	Dependencies
+ **************************************/
+#include "lz4defs.h"
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/unaligned.h>
+
+/*-*****************************
+ *	Decompression functions
+ *******************************/
+
+#define DEBUGLOG(l, ...) {}	/* disabled */
+
+#ifndef assert
+#define assert(condition) ((void)0)
+#endif
+
+/*
+ * LZ4_decompress_generic() :
+ * This generic decompression function covers all use cases.
+ * It shall be instantiated several times, using different sets of directives.
+ * Note that it is important for performance that this function really get inlined,
+ * in order to remove useless branches during compilation optimization.
+ */
+static FORCE_INLINE int LZ4_decompress_generic(
+	 const char * const src,
+	 char * const dst,
+	 int srcSize,
+		/*
+		 * If endOnInput == endOnInputSize,
+		 * this value is `dstCapacity`
+		 */
+	 int outputSize,
+	 /* endOnOutputSize, endOnInputSize */
+	 endCondition_directive endOnInput,
+	 /* full, partial */
+	 earlyEnd_directive partialDecoding,
+	 /* noDict, withPrefix64k, usingExtDict */
+	 dict_directive dict,
+	 /* always <= dst, == dst when no prefix */
+	 const BYTE * const lowPrefix,
+	 /* only if dict == usingExtDict */
+	 const BYTE * const dictStart,
+	 /* note : = 0 if noDict */
+	 const size_t dictSize
+	 )
+{
+	const BYTE *ip = (const BYTE *) src;
+	const BYTE * const iend = ip + srcSize;
+
+	BYTE *op = (BYTE *) dst;
+	BYTE * const oend = op + outputSize;
+	BYTE *cpy;
+
+	const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
+	static const unsigned int inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
+	static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};
+
+	const int safeDecode = (endOnInput == endOnInputSize);
+	const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));
+
+	/* Set up the "end" pointers for the shortcut. */
+	const BYTE *const shortiend = iend -
+		(endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
+	const BYTE *const shortoend = oend -
+		(endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
+
+	DEBUGLOG(5, "%s (srcSize:%i, dstSize:%i)", __func__,
+		 srcSize, outputSize);
+
+	/* Special cases */
+	assert(lowPrefix <= op);
+	assert(src != NULL);
+
+	/* Empty output buffer */
+	if ((endOnInput) && (unlikely(outputSize == 0)))
+		return ((srcSize == 1) && (*ip == 0)) ? 0 : -1;
+
+	if ((!endOnInput) && (unlikely(outputSize == 0)))
+		return (*ip == 0 ? 1 : -1);
+
+	if ((endOnInput) && unlikely(srcSize == 0))
+		return -1;
+
+	/* Main Loop : decode sequences */
+	while (1) {
+		size_t length;
+		const BYTE *match;
+		size_t offset;
+
+		/* get literal length */
+		unsigned int const token = *ip++;
+		length = token>>ML_BITS;
+
+		/* ip < iend before the increment */
+		assert(!endOnInput || ip <= iend);
+
+		/*
+		 * A two-stage shortcut for the most common case:
+		 * 1) If the literal length is 0..14, and there is enough
+		 * space, enter the shortcut and copy 16 bytes on behalf
+		 * of the literals (in the fast mode, only 8 bytes can be
+		 * safely copied this way).
+		 * 2) Further if the match length is 4..18, copy 18 bytes
+		 * in a similar manner; but we ensure that there's enough
+		 * space in the output for those 18 bytes earlier, upon
+		 * entering the shortcut (in other words, there is a
+		 * combined check for both stages).
+		 *
+		 * The & in the likely() below is intentionally not && so that
+		 * some compilers can produce better parallelized runtime code
+		 */
+		if ((endOnInput ? length != RUN_MASK : length <= 8)
+		   /*
+		    * strictly "less than" on input, to re-enter
+		    * the loop with at least one byte
+		    */
+		   && likely((endOnInput ? ip < shortiend : 1) &
+			     (op <= shortoend))) {
+			/* Copy the literals */
+			LZ4_memcpy(op, ip, endOnInput ? 16 : 8);
+			op += length; ip += length;
+
+			/*
+			 * The second stage:
+			 * prepare for match copying, decode full info.
+			 * If it doesn't work out, the info won't be wasted.
+			 */
+			length = token & ML_MASK; /* match length */
+			offset = LZ4_readLE16(ip);
+			ip += 2;
+			match = op - offset;
+			assert(match <= op); /* check overflow */
+
+			/* Do not deal with overlapping matches. */
+			if ((length != ML_MASK) &&
+			    (offset >= 8) &&
+			    (dict == withPrefix64k || match >= lowPrefix)) {
+				/* Copy the match. */
+				LZ4_memcpy(op + 0, match + 0, 8);
+				LZ4_memcpy(op + 8, match + 8, 8);
+				LZ4_memcpy(op + 16, match + 16, 2);
+				op += length + MINMATCH;
+				/* Both stages worked, load the next token. */
+				continue;
+			}
+
+			/*
+			 * The second stage didn't work out, but the info
+			 * is ready. Propel it right to the point of match
+			 * copying.
+			 */
+			goto _copy_match;
+		}
+
+		/* decode literal length */
+		if (length == RUN_MASK) {
+			unsigned int s;
+
+			if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) {
+				/* overflow detection */
+				goto _output_error;
+			}
+			do {
+				s = *ip++;
+				length += s;
+			} while (likely(endOnInput
+				? ip < iend - RUN_MASK
+				: 1) & (s == 255));
+
+			if ((safeDecode)
+			    && unlikely((uptrval)(op) +
+					length < (uptrval)(op))) {
+				/* overflow detection */
+				goto _output_error;
+			}
+			if ((safeDecode)
+			    && unlikely((uptrval)(ip) +
+					length < (uptrval)(ip))) {
+				/* overflow detection */
+				goto _output_error;
+			}
+		}
+
+		/* copy literals */
+		cpy = op + length;
+		LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
+
+		if (((endOnInput) && ((cpy > oend - MFLIMIT)
+			|| (ip + length > iend - (2 + 1 + LASTLITERALS))))
+			|| ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
+			if (partialDecoding) {
+				if (cpy > oend) {
+					/*
+					 * Partial decoding :
+					 * stop in the middle of literal segment
+					 */
+					cpy = oend;
+					length = oend - op;
+				}
+				if ((endOnInput)
+					&& (ip + length > iend)) {
+					/*
+					 * Error :
+					 * read attempt beyond
+					 * end of input buffer
+					 */
+					goto _output_error;
+				}
+			} else {
+				if ((!endOnInput)
+					&& (cpy != oend)) {
+					/*
+					 * Error :
+					 * block decoding must
+					 * stop exactly there
+					 */
+					goto _output_error;
+				}
+				if ((endOnInput)
+					&& ((ip + length != iend)
+					|| (cpy > oend))) {
+					/*
+					 * Error :
+					 * input must be consumed
+					 */
+					goto _output_error;
+				}
+			}
+
+			/*
+			 * supports overlapping memory regions; only matters
+			 * for in-place decompression scenarios
+			 */
+			LZ4_memmove(op, ip, length);
+			ip += length;
+			op += length;
+
+			/* Necessarily EOF when !partialDecoding.
+			 * When partialDecoding, it is EOF if we've either
+			 * filled the output buffer or
+			 * can't proceed with reading an offset for following match.
+			 */
+			if (!partialDecoding || (cpy == oend) || (ip >= (iend - 2)))
+				break;
+		} else {
+			/* may overwrite up to WILDCOPYLENGTH beyond cpy */
+			LZ4_wildCopy(op, ip, cpy);
+			ip += length;
+			op = cpy;
+		}
+
+		/* get offset */
+		offset = LZ4_readLE16(ip);
+		ip += 2;
+		match = op - offset;
+
+		/* get matchlength */
+		length = token & ML_MASK;
+
+_copy_match:
+		if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) {
+			/* Error : offset outside buffers */
+			goto _output_error;
+		}
+
+		/* costs ~1%; silence an msan warning when offset == 0 */
+		/*
+		 * note : when partialDecoding, there is no guarantee that
+		 * at least 4 bytes remain available in output buffer
+		 */
+		if (!partialDecoding) {
+			assert(oend > op);
+			assert(oend - op >= 4);
+
+			LZ4_write32(op, (U32)offset);
+		}
+
+		if (length == ML_MASK) {
+			unsigned int s;
+
+			do {
+				s = *ip++;
+
+				if ((endOnInput) && (ip > iend - LASTLITERALS))
+					goto _output_error;
+
+				length += s;
+			} while (s == 255);
+
+			if ((safeDecode)
+				&& unlikely(
+					(uptrval)(op) + length < (uptrval)op)) {
+				/* overflow detection */
+				goto _output_error;
+			}
+		}
+
+		length += MINMATCH;
+
+		/* match starting within external dictionary */
+		if ((dict == usingExtDict) && (match < lowPrefix)) {
+			if (unlikely(op + length > oend - LASTLITERALS)) {
+				/* doesn't respect parsing restriction */
+				if (!partialDecoding)
+					goto _output_error;
+				length = min(length, (size_t)(oend - op));
+			}
+
+			if (length <= (size_t)(lowPrefix - match)) {
+				/*
+				 * match fits entirely within external
+				 * dictionary : just copy
+				 */
+				memmove(op, dictEnd - (lowPrefix - match),
+					length);
+				op += length;
+			} else {
+				/*
+				 * match stretches into both external
+				 * dictionary and current block
+				 */
+				size_t const copySize = (size_t)(lowPrefix - match);
+				size_t const restSize = length - copySize;
+
+				LZ4_memcpy(op, dictEnd - copySize, copySize);
+				op += copySize;
+				if (restSize > (size_t)(op - lowPrefix)) {
+					/* overlap copy */
+					BYTE * const endOfMatch = op + restSize;
+					const BYTE *copyFrom = lowPrefix;
+
+					while (op < endOfMatch)
+						*op++ = *copyFrom++;
+				} else {
+					LZ4_memcpy(op, lowPrefix, restSize);
+					op += restSize;
+				}
+			}
+			continue;
+		}
+
+		/* copy match within block */
+		cpy = op + length;
+
+		/*
+		 * partialDecoding :
+		 * may not respect endBlock parsing restrictions
+		 */
+		assert(op <= oend);
+		if (partialDecoding &&
+		    (cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
+			size_t const mlen = min(length, (size_t)(oend - op));
+			const BYTE * const matchEnd = match + mlen;
+			BYTE * const copyEnd = op + mlen;
+
+			if (matchEnd > op) {
+				/* overlap copy */
+				while (op < copyEnd)
+					*op++ = *match++;
+			} else {
+				LZ4_memcpy(op, match, mlen);
+			}
+			op = copyEnd;
+			if (op == oend)
+				break;
+			continue;
+		}
+
+		if (unlikely(offset < 8)) {
+			op[0] = match[0];
+			op[1] = match[1];
+			op[2] = match[2];
+			op[3] = match[3];
+			match += inc32table[offset];
+			LZ4_memcpy(op + 4, match, 4);
+			match -= dec64table[offset];
+		} else {
+			LZ4_copy8(op, match);
+			match += 8;
+		}
+
+		op += 8;
+
+		if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
+			BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
+
+			if (cpy > oend - LASTLITERALS) {
+				/*
+				 * Error : last LASTLITERALS bytes
+				 * must be literals (uncompressed)
+				 */
+				goto _output_error;
+			}
+
+			if (op < oCopyLimit) {
+				LZ4_wildCopy(op, match, oCopyLimit);
+				match += oCopyLimit - op;
+				op = oCopyLimit;
+			}
+			while (op < cpy)
+				*op++ = *match++;
+		} else {
+			LZ4_copy8(op, match);
+			if (length > 16)
+				LZ4_wildCopy(op + 8, match + 8, cpy);
+		}
+		op = cpy; /* wildcopy correction */
+	}
+
+	/* end of decoding */
+	if (endOnInput) {
+		/* Nb of output bytes decoded */
+		return (int) (((char *)op) - dst);
+	} else {
+		/* Nb of input bytes read */
+		return (int) (((const char *)ip) - src);
+	}
+
+	/* Overflow error detected */
+_output_error:
+	return (int) (-(((const char *)ip) - src)) - 1;
+}
+
+int LZ4_decompress_safe(const char *source, char *dest,
+	int compressedSize, int maxDecompressedSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      compressedSize, maxDecompressedSize,
+				      endOnInputSize, decode_full_block,
+				      noDict, (BYTE *)dest, NULL, 0);
+}
+
+int LZ4_decompress_safe_partial(const char *src, char *dst,
+	int compressedSize, int targetOutputSize, int dstCapacity)
+{
+	dstCapacity = min(targetOutputSize, dstCapacity);
+	return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
+				      endOnInputSize, partial_decode,
+				      noDict, (BYTE *)dst, NULL, 0);
+}
+
+int LZ4_decompress_fast(const char *source, char *dest, int originalSize)
+{
+	return LZ4_decompress_generic(source, dest, 0, originalSize,
+				      endOnOutputSize, decode_full_block,
+				      withPrefix64k,
+				      (BYTE *)dest - 64 * KB, NULL, 0);
+}
+
+/* ===== Instantiate a few more decoding cases, used more than once. ===== */
+
+static int LZ4_decompress_safe_withPrefix64k(const char *source, char *dest,
+				      int compressedSize, int maxOutputSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      compressedSize, maxOutputSize,
+				      endOnInputSize, decode_full_block,
+				      withPrefix64k,
+				      (BYTE *)dest - 64 * KB, NULL, 0);
+}
+
+static int LZ4_decompress_safe_withSmallPrefix(const char *source, char *dest,
+					       int compressedSize,
+					       int maxOutputSize,
+					       size_t prefixSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      compressedSize, maxOutputSize,
+				      endOnInputSize, decode_full_block,
+				      noDict,
+				      (BYTE *)dest - prefixSize, NULL, 0);
+}
+
+static int LZ4_decompress_safe_forceExtDict(const char *source, char *dest,
+					    int compressedSize, int maxOutputSize,
+					    const void *dictStart, size_t dictSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      compressedSize, maxOutputSize,
+				      endOnInputSize, decode_full_block,
+				      usingExtDict, (BYTE *)dest,
+				      (const BYTE *)dictStart, dictSize);
+}
+
+static int LZ4_decompress_fast_extDict(const char *source, char *dest,
+				       int originalSize,
+				       const void *dictStart, size_t dictSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      0, originalSize,
+				      endOnOutputSize, decode_full_block,
+				      usingExtDict, (BYTE *)dest,
+				      (const BYTE *)dictStart, dictSize);
+}
+
+/*
+ * The "double dictionary" mode, for use with e.g. ring buffers: the first part
+ * of the dictionary is passed as prefix, and the second via dictStart + dictSize.
+ * These routines are used only once, in LZ4_decompress_*_continue().
+ */
+static FORCE_INLINE
+int LZ4_decompress_safe_doubleDict(const char *source, char *dest,
+				   int compressedSize, int maxOutputSize,
+				   size_t prefixSize,
+				   const void *dictStart, size_t dictSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      compressedSize, maxOutputSize,
+				      endOnInputSize, decode_full_block,
+				      usingExtDict, (BYTE *)dest - prefixSize,
+				      (const BYTE *)dictStart, dictSize);
+}
+
+static FORCE_INLINE
+int LZ4_decompress_fast_doubleDict(const char *source, char *dest,
+				   int originalSize, size_t prefixSize,
+				   const void *dictStart, size_t dictSize)
+{
+	return LZ4_decompress_generic(source, dest,
+				      0, originalSize,
+				      endOnOutputSize, decode_full_block,
+				      usingExtDict, (BYTE *)dest - prefixSize,
+				      (const BYTE *)dictStart, dictSize);
+}
+
+/* ===== streaming decompression functions ===== */
+
+int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode,
+	const char *dictionary, int dictSize)
+{
+	LZ4_streamDecode_t_internal *lz4sd =
+		&LZ4_streamDecode->internal_donotuse;
+
+	lz4sd->prefixSize = (size_t) dictSize;
+	lz4sd->prefixEnd = (const BYTE *) dictionary + dictSize;
+	lz4sd->externalDict = NULL;
+	lz4sd->extDictSize	= 0;
+	return 1;
+}
+
+/*
+ * *_continue() :
+ * These decoding functions allow decompression of multiple blocks
+ * in "streaming" mode.
+ * Previously decoded blocks must still be available at the memory
+ * position where they were decoded.
+ * If it's not possible, save the relevant part of
+ * decoded data into a safe buffer,
+ * and indicate where it stands using LZ4_setStreamDecode()
+ */
+int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode,
+	const char *source, char *dest, int compressedSize, int maxOutputSize)
+{
+	LZ4_streamDecode_t_internal *lz4sd =
+		&LZ4_streamDecode->internal_donotuse;
+	int result;
+
+	if (lz4sd->prefixSize == 0) {
+		/* The first call, no dictionary yet. */
+		assert(lz4sd->extDictSize == 0);
+		result = LZ4_decompress_safe(source, dest,
+			compressedSize, maxOutputSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize = result;
+		lz4sd->prefixEnd = (BYTE *)dest + result;
+	} else if (lz4sd->prefixEnd == (BYTE *)dest) {
+		/* They're rolling the current segment. */
+		if (lz4sd->prefixSize >= 64 * KB - 1)
+			result = LZ4_decompress_safe_withPrefix64k(source, dest,
+				compressedSize, maxOutputSize);
+		else if (lz4sd->extDictSize == 0)
+			result = LZ4_decompress_safe_withSmallPrefix(source,
+				dest, compressedSize, maxOutputSize,
+				lz4sd->prefixSize);
+		else
+			result = LZ4_decompress_safe_doubleDict(source, dest,
+				compressedSize, maxOutputSize,
+				lz4sd->prefixSize,
+				lz4sd->externalDict, lz4sd->extDictSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize += result;
+		lz4sd->prefixEnd  += result;
+	} else {
+		/*
+		 * The buffer wraps around, or they're
+		 * switching to another buffer.
+		 */
+		lz4sd->extDictSize = lz4sd->prefixSize;
+		lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
+		result = LZ4_decompress_safe_forceExtDict(source, dest,
+			compressedSize, maxOutputSize,
+			lz4sd->externalDict, lz4sd->extDictSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize = result;
+		lz4sd->prefixEnd  = (BYTE *)dest + result;
+	}
+
+	return result;
+}
+
+int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode,
+	const char *source, char *dest, int originalSize)
+{
+	LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse;
+	int result;
+
+	if (lz4sd->prefixSize == 0) {
+		assert(lz4sd->extDictSize == 0);
+		result = LZ4_decompress_fast(source, dest, originalSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize = originalSize;
+		lz4sd->prefixEnd = (BYTE *)dest + originalSize;
+	} else if (lz4sd->prefixEnd == (BYTE *)dest) {
+		if (lz4sd->prefixSize >= 64 * KB - 1 ||
+		    lz4sd->extDictSize == 0)
+			result = LZ4_decompress_fast(source, dest,
+						     originalSize);
+		else
+			result = LZ4_decompress_fast_doubleDict(source, dest,
+				originalSize, lz4sd->prefixSize,
+				lz4sd->externalDict, lz4sd->extDictSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize += originalSize;
+		lz4sd->prefixEnd  += originalSize;
+	} else {
+		lz4sd->extDictSize = lz4sd->prefixSize;
+		lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
+		result = LZ4_decompress_fast_extDict(source, dest,
+			originalSize, lz4sd->externalDict, lz4sd->extDictSize);
+		if (result <= 0)
+			return result;
+		lz4sd->prefixSize = originalSize;
+		lz4sd->prefixEnd = (BYTE *)dest + originalSize;
+	}
+	return result;
+}
+
+int LZ4_decompress_safe_usingDict(const char *source, char *dest,
+				  int compressedSize, int maxOutputSize,
+				  const char *dictStart, int dictSize)
+{
+	if (dictSize == 0)
+		return LZ4_decompress_safe(source, dest,
+					   compressedSize, maxOutputSize);
+	if (dictStart+dictSize == dest) {
+		if (dictSize >= 64 * KB - 1)
+			return LZ4_decompress_safe_withPrefix64k(source, dest,
+				compressedSize, maxOutputSize);
+		return LZ4_decompress_safe_withSmallPrefix(source, dest,
+			compressedSize, maxOutputSize, dictSize);
+	}
+	return LZ4_decompress_safe_forceExtDict(source, dest,
+		compressedSize, maxOutputSize, dictStart, dictSize);
+}
+
+int LZ4_decompress_fast_usingDict(const char *source, char *dest,
+				  int originalSize,
+				  const char *dictStart, int dictSize)
+{
+	if (dictSize == 0 || dictStart + dictSize == dest)
+		return LZ4_decompress_fast(source, dest, originalSize);
+
+	return LZ4_decompress_fast_extDict(source, dest, originalSize,
+		dictStart, dictSize);
+}
+
+#ifndef STATIC
+EXPORT_SYMBOL(LZ4_decompress_safe);
+EXPORT_SYMBOL(LZ4_decompress_safe_partial);
+EXPORT_SYMBOL(LZ4_decompress_fast);
+EXPORT_SYMBOL(LZ4_setStreamDecode);
+EXPORT_SYMBOL(LZ4_decompress_safe_continue);
+EXPORT_SYMBOL(LZ4_decompress_fast_continue);
+EXPORT_SYMBOL(LZ4_decompress_safe_usingDict);
+EXPORT_SYMBOL(LZ4_decompress_fast_usingDict);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("LZ4 decompressor");
+#endif

linux-7.2.3/lib/lz4/lz4defs.h

@@ -0,0 +1,247 @@
+#ifndef __LZ4DEFS_H__
+#define __LZ4DEFS_H__
+
+/*
+ * lz4defs.h -- common and architecture specific defines for the kernel usage
+
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011-2016, Yann Collet.
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+
+#include <linux/unaligned.h>
+
+#include <linux/bitops.h>
+#include <linux/string.h>	 /* memset, memcpy */
+#include <linux/lz4.h>
+
+#define FORCE_INLINE __always_inline
+
+/*-************************************
+ *	Basic Types
+ **************************************/
+#include <linux/types.h>
+
+typedef	uint8_t BYTE;
+typedef uint16_t U16;
+typedef uint32_t U32;
+typedef	int32_t S32;
+typedef uint64_t U64;
+typedef uintptr_t uptrval;
+
+/*-************************************
+ *	Architecture specifics
+ **************************************/
+#if defined(CONFIG_64BIT)
+#define LZ4_ARCH64 1
+#else
+#define LZ4_ARCH64 0
+#endif
+
+#if defined(__LITTLE_ENDIAN)
+#define LZ4_LITTLE_ENDIAN 1
+#else
+#define LZ4_LITTLE_ENDIAN 0
+#endif
+
+/*-************************************
+ *	Constants
+ **************************************/
+#define MINMATCH 4
+
+#define WILDCOPYLENGTH 8
+#define LASTLITERALS 5
+#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
+/*
+ * ensure it's possible to write 2 x wildcopyLength
+ * without overflowing output buffer
+ */
+#define MATCH_SAFEGUARD_DISTANCE  ((2 * WILDCOPYLENGTH) - MINMATCH)
+
+/* Increase this value ==> compression run slower on incompressible data */
+#define LZ4_SKIPTRIGGER 6
+
+#define HASH_UNIT sizeof(size_t)
+
+#define KB (1 << 10)
+#define MB (1 << 20)
+#define GB (1U << 30)
+
+#define MAX_DISTANCE LZ4_DISTANCE_MAX
+#define STEPSIZE sizeof(size_t)
+
+#define ML_BITS	4
+#define ML_MASK	((1U << ML_BITS) - 1)
+#define RUN_BITS (8 - ML_BITS)
+#define RUN_MASK ((1U << RUN_BITS) - 1)
+
+/*-************************************
+ *	Reading and writing into memory
+ **************************************/
+static FORCE_INLINE U16 LZ4_read16(const void *ptr)
+{
+	return get_unaligned((const U16 *)ptr);
+}
+
+static FORCE_INLINE U32 LZ4_read32(const void *ptr)
+{
+	return get_unaligned((const U32 *)ptr);
+}
+
+static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
+{
+	return get_unaligned((const size_t *)ptr);
+}
+
+static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
+{
+	put_unaligned(value, (U16 *)memPtr);
+}
+
+static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
+{
+	put_unaligned(value, (U32 *)memPtr);
+}
+
+static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
+{
+	return get_unaligned_le16(memPtr);
+}
+
+static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
+{
+	return put_unaligned_le16(value, memPtr);
+}
+
+/*
+ * LZ4 relies on memcpy with a constant size being inlined. In freestanding
+ * environments, the compiler can't assume the implementation of memcpy() is
+ * standard compliant, so apply its specialized memcpy() inlining logic. When
+ * possible, use __builtin_memcpy() to tell the compiler to analyze memcpy()
+ * as-if it were standard compliant, so it can inline it in freestanding
+ * environments. This is needed when decompressing the Linux Kernel, for example.
+ */
+#define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size)
+#define LZ4_memmove(dst, src, size) __builtin_memmove(dst, src, size)
+
+static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
+{
+#if LZ4_ARCH64
+	U64 a = get_unaligned((const U64 *)src);
+
+	put_unaligned(a, (U64 *)dst);
+#else
+	U32 a = get_unaligned((const U32 *)src);
+	U32 b = get_unaligned((const U32 *)src + 1);
+
+	put_unaligned(a, (U32 *)dst);
+	put_unaligned(b, (U32 *)dst + 1);
+#endif
+}
+
+/*
+ * customized variant of memcpy,
+ * which can overwrite up to 7 bytes beyond dstEnd
+ */
+static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
+	const void *srcPtr, void *dstEnd)
+{
+	BYTE *d = (BYTE *)dstPtr;
+	const BYTE *s = (const BYTE *)srcPtr;
+	BYTE *const e = (BYTE *)dstEnd;
+
+	do {
+		LZ4_copy8(d, s);
+		d += 8;
+		s += 8;
+	} while (d < e);
+}
+
+static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
+{
+#if LZ4_LITTLE_ENDIAN
+	return __ffs(val) >> 3;
+#else
+	return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
+#endif
+}
+
+static FORCE_INLINE unsigned int LZ4_count(
+	const BYTE *pIn,
+	const BYTE *pMatch,
+	const BYTE *pInLimit)
+{
+	const BYTE *const pStart = pIn;
+
+	while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
+		size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
+
+		if (!diff) {
+			pIn += STEPSIZE;
+			pMatch += STEPSIZE;
+			continue;
+		}
+
+		pIn += LZ4_NbCommonBytes(diff);
+
+		return (unsigned int)(pIn - pStart);
+	}
+
+#if LZ4_ARCH64
+	if ((pIn < (pInLimit - 3))
+		&& (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
+		pIn += 4;
+		pMatch += 4;
+	}
+#endif
+
+	if ((pIn < (pInLimit - 1))
+		&& (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
+		pIn += 2;
+		pMatch += 2;
+	}
+
+	if ((pIn < pInLimit) && (*pMatch == *pIn))
+		pIn++;
+
+	return (unsigned int)(pIn - pStart);
+}
+
+typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
+typedef enum { byPtr, byU32, byU16 } tableType_t;
+
+typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
+typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
+
+typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
+typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
+
+#define LZ4_STATIC_ASSERT(c)	BUILD_BUG_ON(!(c))
+
+#endif

linux-7.2.3/lib/lz4/lz4hc_compress.c

@@ -0,0 +1,768 @@
+/*
+ * LZ4 HC - High Compression Mode of LZ4
+ * Copyright (C) 2011-2015, Yann Collet.
+ *
+ * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+
+/*-************************************
+ *	Dependencies
+ **************************************/
+#include "lz4defs.h"
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h> /* memset */
+
+/* *************************************
+ *	Local Constants and types
+ ***************************************/
+
+#define OPTIMAL_ML (int)((ML_MASK - 1) + MINMATCH)
+
+#define HASH_FUNCTION(i)	(((i) * 2654435761U) \
+	>> ((MINMATCH*8) - LZ4HC_HASH_LOG))
+#define DELTANEXTU16(p)	chainTable[(U16)(p)] /* faster */
+
+static U32 LZ4HC_hashPtr(const void *ptr)
+{
+	return HASH_FUNCTION(LZ4_read32(ptr));
+}
+
+/**************************************
+ *	HC Compression
+ **************************************/
+static void LZ4HC_init(LZ4HC_CCtx_internal *hc4, const BYTE *start)
+{
+	memset((void *)hc4->hashTable, 0, sizeof(hc4->hashTable));
+	memset(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
+	hc4->nextToUpdate = 64 * KB;
+	hc4->base = start - 64 * KB;
+	hc4->end = start;
+	hc4->dictBase = start - 64 * KB;
+	hc4->dictLimit = 64 * KB;
+	hc4->lowLimit = 64 * KB;
+}
+
+/* Update chains up to ip (excluded) */
+static FORCE_INLINE void LZ4HC_Insert(LZ4HC_CCtx_internal *hc4,
+	const BYTE *ip)
+{
+	U16 * const chainTable = hc4->chainTable;
+	U32 * const hashTable	= hc4->hashTable;
+	const BYTE * const base = hc4->base;
+	U32 const target = (U32)(ip - base);
+	U32 idx = hc4->nextToUpdate;
+
+	while (idx < target) {
+		U32 const h = LZ4HC_hashPtr(base + idx);
+		size_t delta = idx - hashTable[h];
+
+		if (delta > MAX_DISTANCE)
+			delta = MAX_DISTANCE;
+
+		DELTANEXTU16(idx) = (U16)delta;
+
+		hashTable[h] = idx;
+		idx++;
+	}
+
+	hc4->nextToUpdate = target;
+}
+
+static FORCE_INLINE int LZ4HC_InsertAndFindBestMatch(
+	LZ4HC_CCtx_internal *hc4, /* Index table will be updated */
+	const BYTE *ip,
+	const BYTE * const iLimit,
+	const BYTE **matchpos,
+	const int maxNbAttempts)
+{
+	U16 * const chainTable = hc4->chainTable;
+	U32 * const HashTable = hc4->hashTable;
+	const BYTE * const base = hc4->base;
+	const BYTE * const dictBase = hc4->dictBase;
+	const U32 dictLimit = hc4->dictLimit;
+	const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base))
+		? hc4->lowLimit
+		: (U32)(ip - base) - (64 * KB - 1);
+	U32 matchIndex;
+	int nbAttempts = maxNbAttempts;
+	size_t ml = 0;
+
+	/* HC4 match finder */
+	LZ4HC_Insert(hc4, ip);
+	matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+
+	while ((matchIndex >= lowLimit)
+		&& (nbAttempts)) {
+		nbAttempts--;
+		if (matchIndex >= dictLimit) {
+			const BYTE * const match = base + matchIndex;
+
+			if (*(match + ml) == *(ip + ml)
+				&& (LZ4_read32(match) == LZ4_read32(ip))) {
+				size_t const mlt = LZ4_count(ip + MINMATCH,
+					match + MINMATCH, iLimit) + MINMATCH;
+
+				if (mlt > ml) {
+					ml = mlt;
+					*matchpos = match;
+				}
+			}
+		} else {
+			const BYTE * const match = dictBase + matchIndex;
+
+			if (LZ4_read32(match) == LZ4_read32(ip)) {
+				size_t mlt;
+				const BYTE *vLimit = ip
+					+ (dictLimit - matchIndex);
+
+				if (vLimit > iLimit)
+					vLimit = iLimit;
+				mlt = LZ4_count(ip + MINMATCH,
+					match + MINMATCH, vLimit) + MINMATCH;
+				if ((ip + mlt == vLimit)
+					&& (vLimit < iLimit))
+					mlt += LZ4_count(ip + mlt,
+						base + dictLimit,
+						iLimit);
+				if (mlt > ml) {
+					/* virtual matchpos */
+					ml = mlt;
+					*matchpos = base + matchIndex;
+				}
+			}
+		}
+		matchIndex -= DELTANEXTU16(matchIndex);
+	}
+
+	return (int)ml;
+}
+
+static FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch(
+	LZ4HC_CCtx_internal *hc4,
+	const BYTE * const ip,
+	const BYTE * const iLowLimit,
+	const BYTE * const iHighLimit,
+	int longest,
+	const BYTE **matchpos,
+	const BYTE **startpos,
+	const int maxNbAttempts)
+{
+	U16 * const chainTable = hc4->chainTable;
+	U32 * const HashTable = hc4->hashTable;
+	const BYTE * const base = hc4->base;
+	const U32 dictLimit = hc4->dictLimit;
+	const BYTE * const lowPrefixPtr = base + dictLimit;
+	const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base))
+		? hc4->lowLimit
+		: (U32)(ip - base) - (64 * KB - 1);
+	const BYTE * const dictBase = hc4->dictBase;
+	U32 matchIndex;
+	int nbAttempts = maxNbAttempts;
+	int delta = (int)(ip - iLowLimit);
+
+	/* First Match */
+	LZ4HC_Insert(hc4, ip);
+	matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+
+	while ((matchIndex >= lowLimit)
+		&& (nbAttempts)) {
+		nbAttempts--;
+		if (matchIndex >= dictLimit) {
+			const BYTE *matchPtr = base + matchIndex;
+
+			if (*(iLowLimit + longest)
+				== *(matchPtr - delta + longest)) {
+				if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
+					int mlt = MINMATCH + LZ4_count(
+						ip + MINMATCH,
+						matchPtr + MINMATCH,
+						iHighLimit);
+					int back = 0;
+
+					while ((ip + back > iLowLimit)
+						&& (matchPtr + back > lowPrefixPtr)
+						&& (ip[back - 1] == matchPtr[back - 1]))
+						back--;
+
+					mlt -= back;
+
+					if (mlt > longest) {
+						longest = (int)mlt;
+						*matchpos = matchPtr + back;
+						*startpos = ip + back;
+					}
+				}
+			}
+		} else {
+			const BYTE * const matchPtr = dictBase + matchIndex;
+
+			if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
+				size_t mlt;
+				int back = 0;
+				const BYTE *vLimit = ip + (dictLimit - matchIndex);
+
+				if (vLimit > iHighLimit)
+					vLimit = iHighLimit;
+
+				mlt = LZ4_count(ip + MINMATCH,
+					matchPtr + MINMATCH, vLimit) + MINMATCH;
+
+				if ((ip + mlt == vLimit) && (vLimit < iHighLimit))
+					mlt += LZ4_count(ip + mlt, base + dictLimit,
+						iHighLimit);
+				while ((ip + back > iLowLimit)
+					&& (matchIndex + back > lowLimit)
+					&& (ip[back - 1] == matchPtr[back - 1]))
+					back--;
+
+				mlt -= back;
+
+				if ((int)mlt > longest) {
+					longest = (int)mlt;
+					*matchpos = base + matchIndex + back;
+					*startpos = ip + back;
+				}
+			}
+		}
+
+		matchIndex -= DELTANEXTU16(matchIndex);
+	}
+
+	return longest;
+}
+
+static FORCE_INLINE int LZ4HC_encodeSequence(
+	const BYTE **ip,
+	BYTE **op,
+	const BYTE **anchor,
+	int matchLength,
+	const BYTE * const match,
+	limitedOutput_directive limitedOutputBuffer,
+	BYTE *oend)
+{
+	int length;
+	BYTE *token;
+
+	/* Encode Literal length */
+	length = (int)(*ip - *anchor);
+	token = (*op)++;
+
+	if ((limitedOutputBuffer)
+		&& ((*op + (length>>8)
+			+ length + (2 + 1 + LASTLITERALS)) > oend)) {
+		/* Check output limit */
+		return 1;
+	}
+	if (length >= (int)RUN_MASK) {
+		int len;
+
+		*token = (RUN_MASK<<ML_BITS);
+		len = length - RUN_MASK;
+		for (; len > 254 ; len -= 255)
+			*(*op)++ = 255;
+		*(*op)++ = (BYTE)len;
+	} else
+		*token = (BYTE)(length<<ML_BITS);
+
+	/* Copy Literals */
+	LZ4_wildCopy(*op, *anchor, (*op) + length);
+	*op += length;
+
+	/* Encode Offset */
+	LZ4_writeLE16(*op, (U16)(*ip - match));
+	*op += 2;
+
+	/* Encode MatchLength */
+	length = (int)(matchLength - MINMATCH);
+
+	if ((limitedOutputBuffer)
+		&& (*op + (length>>8)
+			+ (1 + LASTLITERALS) > oend)) {
+		/* Check output limit */
+		return 1;
+	}
+
+	if (length >= (int)ML_MASK) {
+		*token += ML_MASK;
+		length -= ML_MASK;
+
+		for (; length > 509 ; length -= 510) {
+			*(*op)++ = 255;
+			*(*op)++ = 255;
+		}
+
+		if (length > 254) {
+			length -= 255;
+			*(*op)++ = 255;
+		}
+
+		*(*op)++ = (BYTE)length;
+	} else
+		*token += (BYTE)(length);
+
+	/* Prepare next loop */
+	*ip += matchLength;
+	*anchor = *ip;
+
+	return 0;
+}
+
+static int LZ4HC_compress_generic(
+	LZ4HC_CCtx_internal *const ctx,
+	const char * const source,
+	char * const dest,
+	int const inputSize,
+	int const maxOutputSize,
+	int compressionLevel,
+	limitedOutput_directive limit
+	)
+{
+	const BYTE *ip = (const BYTE *) source;
+	const BYTE *anchor = ip;
+	const BYTE * const iend = ip + inputSize;
+	const BYTE * const mflimit = iend - MFLIMIT;
+	const BYTE * const matchlimit = (iend - LASTLITERALS);
+
+	BYTE *op = (BYTE *) dest;
+	BYTE * const oend = op + maxOutputSize;
+
+	unsigned int maxNbAttempts;
+	int ml, ml2, ml3, ml0;
+	const BYTE *ref = NULL;
+	const BYTE *start2 = NULL;
+	const BYTE *ref2 = NULL;
+	const BYTE *start3 = NULL;
+	const BYTE *ref3 = NULL;
+	const BYTE *start0;
+	const BYTE *ref0;
+
+	/* init */
+	if (compressionLevel > LZ4HC_MAX_CLEVEL)
+		compressionLevel = LZ4HC_MAX_CLEVEL;
+	if (compressionLevel < 1)
+		compressionLevel = LZ4HC_DEFAULT_CLEVEL;
+	maxNbAttempts = 1 << (compressionLevel - 1);
+	ctx->end += inputSize;
+
+	ip++;
+
+	/* Main Loop */
+	while (ip < mflimit) {
+		ml = LZ4HC_InsertAndFindBestMatch(ctx, ip,
+			matchlimit, (&ref), maxNbAttempts);
+		if (!ml) {
+			ip++;
+			continue;
+		}
+
+		/* saved, in case we would skip too much */
+		start0 = ip;
+		ref0 = ref;
+		ml0 = ml;
+
+_Search2:
+		if (ip + ml < mflimit)
+			ml2 = LZ4HC_InsertAndGetWiderMatch(ctx,
+				ip + ml - 2, ip + 0,
+				matchlimit, ml, &ref2,
+				&start2, maxNbAttempts);
+		else
+			ml2 = ml;
+
+		if (ml2 == ml) {
+			/* No better match */
+			if (LZ4HC_encodeSequence(&ip, &op,
+				&anchor, ml, ref, limit, oend))
+				return 0;
+			continue;
+		}
+
+		if (start0 < ip) {
+			if (start2 < ip + ml0) {
+				/* empirical */
+				ip = start0;
+				ref = ref0;
+				ml = ml0;
+			}
+		}
+
+		/* Here, start0 == ip */
+		if ((start2 - ip) < 3) {
+			/* First Match too small : removed */
+			ml = ml2;
+			ip = start2;
+			ref = ref2;
+			goto _Search2;
+		}
+
+_Search3:
+		/*
+		* Currently we have :
+		* ml2 > ml1, and
+		* ip1 + 3 <= ip2 (usually < ip1 + ml1)
+		*/
+		if ((start2 - ip) < OPTIMAL_ML) {
+			int correction;
+			int new_ml = ml;
+
+			if (new_ml > OPTIMAL_ML)
+				new_ml = OPTIMAL_ML;
+			if (ip + new_ml > start2 + ml2 - MINMATCH)
+				new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
+
+			correction = new_ml - (int)(start2 - ip);
+
+			if (correction > 0) {
+				start2 += correction;
+				ref2 += correction;
+				ml2 -= correction;
+			}
+		}
+		/*
+		 * Now, we have start2 = ip + new_ml,
+		 * with new_ml = min(ml, OPTIMAL_ML = 18)
+		 */
+
+		if (start2 + ml2 < mflimit)
+			ml3 = LZ4HC_InsertAndGetWiderMatch(ctx,
+				start2 + ml2 - 3, start2,
+				matchlimit, ml2, &ref3, &start3,
+				maxNbAttempts);
+		else
+			ml3 = ml2;
+
+		if (ml3 == ml2) {
+			/* No better match : 2 sequences to encode */
+			/* ip & ref are known; Now for ml */
+			if (start2 < ip + ml)
+				ml = (int)(start2 - ip);
+			/* Now, encode 2 sequences */
+			if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+				ml, ref, limit, oend))
+				return 0;
+			ip = start2;
+			if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+				ml2, ref2, limit, oend))
+				return 0;
+			continue;
+		}
+
+		if (start3 < ip + ml + 3) {
+			/* Not enough space for match 2 : remove it */
+			if (start3 >= (ip + ml)) {
+				/* can write Seq1 immediately
+				 * ==> Seq2 is removed,
+				 * so Seq3 becomes Seq1
+				 */
+				if (start2 < ip + ml) {
+					int correction = (int)(ip + ml - start2);
+
+					start2 += correction;
+					ref2 += correction;
+					ml2 -= correction;
+					if (ml2 < MINMATCH) {
+						start2 = start3;
+						ref2 = ref3;
+						ml2 = ml3;
+					}
+				}
+
+				if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+					ml, ref, limit, oend))
+					return 0;
+				ip = start3;
+				ref = ref3;
+				ml = ml3;
+
+				start0 = start2;
+				ref0 = ref2;
+				ml0 = ml2;
+				goto _Search2;
+			}
+
+			start2 = start3;
+			ref2 = ref3;
+			ml2 = ml3;
+			goto _Search3;
+		}
+
+		/*
+		* OK, now we have 3 ascending matches;
+		* let's write at least the first one
+		* ip & ref are known; Now for ml
+		*/
+		if (start2 < ip + ml) {
+			if ((start2 - ip) < (int)ML_MASK) {
+				int correction;
+
+				if (ml > OPTIMAL_ML)
+					ml = OPTIMAL_ML;
+				if (ip + ml > start2 + ml2 - MINMATCH)
+					ml = (int)(start2 - ip) + ml2 - MINMATCH;
+				correction = ml - (int)(start2 - ip);
+				if (correction > 0) {
+					start2 += correction;
+					ref2 += correction;
+					ml2 -= correction;
+				}
+			} else
+				ml = (int)(start2 - ip);
+		}
+		if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml,
+			ref, limit, oend))
+			return 0;
+
+		ip = start2;
+		ref = ref2;
+		ml = ml2;
+
+		start2 = start3;
+		ref2 = ref3;
+		ml2 = ml3;
+
+		goto _Search3;
+	}
+
+	/* Encode Last Literals */
+	{
+		int lastRun = (int)(iend - anchor);
+
+		if ((limit)
+			&& (((char *)op - dest) + lastRun + 1
+				+ ((lastRun + 255 - RUN_MASK)/255)
+					> (U32)maxOutputSize)) {
+			/* Check output limit */
+			return 0;
+		}
+		if (lastRun >= (int)RUN_MASK) {
+			*op++ = (RUN_MASK<<ML_BITS);
+			lastRun -= RUN_MASK;
+			for (; lastRun > 254 ; lastRun -= 255)
+				*op++ = 255;
+			*op++ = (BYTE) lastRun;
+		} else
+			*op++ = (BYTE)(lastRun<<ML_BITS);
+		LZ4_memcpy(op, anchor, iend - anchor);
+		op += iend - anchor;
+	}
+
+	/* End */
+	return (int) (((char *)op) - dest);
+}
+
+static int LZ4_compress_HC_extStateHC(
+	void *state,
+	const char *src,
+	char *dst,
+	int srcSize,
+	int maxDstSize,
+	int compressionLevel)
+{
+	LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t *)state)->internal_donotuse;
+
+	if (((size_t)(state)&(sizeof(void *) - 1)) != 0) {
+		/* Error : state is not aligned
+		 * for pointers (32 or 64 bits)
+		 */
+		return 0;
+	}
+
+	LZ4HC_init(ctx, (const BYTE *)src);
+
+	if (maxDstSize < LZ4_compressBound(srcSize))
+		return LZ4HC_compress_generic(ctx, src, dst,
+			srcSize, maxDstSize, compressionLevel, limitedOutput);
+	else
+		return LZ4HC_compress_generic(ctx, src, dst,
+			srcSize, maxDstSize, compressionLevel, noLimit);
+}
+
+int LZ4_compress_HC(const char *src, char *dst, int srcSize,
+	int maxDstSize, int compressionLevel, void *wrkmem)
+{
+	return LZ4_compress_HC_extStateHC(wrkmem, src, dst,
+		srcSize, maxDstSize, compressionLevel);
+}
+EXPORT_SYMBOL(LZ4_compress_HC);
+
+/**************************************
+ *	Streaming Functions
+ **************************************/
+void LZ4_resetStreamHC(LZ4_streamHC_t *LZ4_streamHCPtr, int compressionLevel)
+{
+	LZ4_streamHCPtr->internal_donotuse.base = NULL;
+	LZ4_streamHCPtr->internal_donotuse.compressionLevel = (unsigned int)compressionLevel;
+}
+EXPORT_SYMBOL(LZ4_resetStreamHC);
+
+int LZ4_loadDictHC(LZ4_streamHC_t *LZ4_streamHCPtr,
+	const char *dictionary,
+	int dictSize)
+{
+	LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+
+	if (dictSize > 64 * KB) {
+		dictionary += dictSize - 64 * KB;
+		dictSize = 64 * KB;
+	}
+	LZ4HC_init(ctxPtr, (const BYTE *)dictionary);
+	if (dictSize >= 4)
+		LZ4HC_Insert(ctxPtr, (const BYTE *)dictionary + (dictSize - 3));
+	ctxPtr->end = (const BYTE *)dictionary + dictSize;
+	return dictSize;
+}
+EXPORT_SYMBOL(LZ4_loadDictHC);
+
+/* compression */
+
+static void LZ4HC_setExternalDict(
+	LZ4HC_CCtx_internal *ctxPtr,
+	const BYTE *newBlock)
+{
+	if (ctxPtr->end >= ctxPtr->base + 4) {
+		/* Referencing remaining dictionary content */
+		LZ4HC_Insert(ctxPtr, ctxPtr->end - 3);
+	}
+
+	/*
+	 * Only one memory segment for extDict,
+	 * so any previous extDict is lost at this stage
+	 */
+	ctxPtr->lowLimit	= ctxPtr->dictLimit;
+	ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base);
+	ctxPtr->dictBase	= ctxPtr->base;
+	ctxPtr->base = newBlock - ctxPtr->dictLimit;
+	ctxPtr->end	= newBlock;
+	/* match referencing will resume from there */
+	ctxPtr->nextToUpdate = ctxPtr->dictLimit;
+}
+
+static int LZ4_compressHC_continue_generic(
+	LZ4_streamHC_t *LZ4_streamHCPtr,
+	const char *source,
+	char *dest,
+	int inputSize,
+	int maxOutputSize,
+	limitedOutput_directive limit)
+{
+	LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+
+	/* auto - init if forgotten */
+	if (ctxPtr->base == NULL)
+		LZ4HC_init(ctxPtr, (const BYTE *) source);
+
+	/* Check overflow */
+	if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 * GB) {
+		size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base)
+			- ctxPtr->dictLimit;
+		if (dictSize > 64 * KB)
+			dictSize = 64 * KB;
+		LZ4_loadDictHC(LZ4_streamHCPtr,
+			(const char *)(ctxPtr->end) - dictSize, (int)dictSize);
+	}
+
+	/* Check if blocks follow each other */
+	if ((const BYTE *)source != ctxPtr->end)
+		LZ4HC_setExternalDict(ctxPtr, (const BYTE *)source);
+
+	/* Check overlapping input/dictionary space */
+	{
+		const BYTE *sourceEnd = (const BYTE *) source + inputSize;
+		const BYTE * const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
+		const BYTE * const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit;
+
+		if ((sourceEnd > dictBegin)
+			&& ((const BYTE *)source < dictEnd)) {
+			if (sourceEnd > dictEnd)
+				sourceEnd = dictEnd;
+			ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase);
+
+			if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4)
+				ctxPtr->lowLimit = ctxPtr->dictLimit;
+		}
+	}
+
+	return LZ4HC_compress_generic(ctxPtr, source, dest,
+		inputSize, maxOutputSize, ctxPtr->compressionLevel, limit);
+}
+
+int LZ4_compress_HC_continue(
+	LZ4_streamHC_t *LZ4_streamHCPtr,
+	const char *source,
+	char *dest,
+	int inputSize,
+	int maxOutputSize)
+{
+	if (maxOutputSize < LZ4_compressBound(inputSize))
+		return LZ4_compressHC_continue_generic(LZ4_streamHCPtr,
+			source, dest, inputSize, maxOutputSize, limitedOutput);
+	else
+		return LZ4_compressHC_continue_generic(LZ4_streamHCPtr,
+			source, dest, inputSize, maxOutputSize, noLimit);
+}
+EXPORT_SYMBOL(LZ4_compress_HC_continue);
+
+/* dictionary saving */
+
+int LZ4_saveDictHC(
+	LZ4_streamHC_t *LZ4_streamHCPtr,
+	char *safeBuffer,
+	int dictSize)
+{
+	LZ4HC_CCtx_internal *const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
+	int const prefixSize = (int)(streamPtr->end
+		- (streamPtr->base + streamPtr->dictLimit));
+
+	if (dictSize > 64 * KB)
+		dictSize = 64 * KB;
+	if (dictSize < 4)
+		dictSize = 0;
+	if (dictSize > prefixSize)
+		dictSize = prefixSize;
+
+	memmove(safeBuffer, streamPtr->end - dictSize, dictSize);
+
+	{
+		U32 const endIndex = (U32)(streamPtr->end - streamPtr->base);
+
+		streamPtr->end = (const BYTE *)safeBuffer + dictSize;
+		streamPtr->base = streamPtr->end - endIndex;
+		streamPtr->dictLimit = endIndex - dictSize;
+		streamPtr->lowLimit = endIndex - dictSize;
+
+		if (streamPtr->nextToUpdate < streamPtr->dictLimit)
+			streamPtr->nextToUpdate = streamPtr->dictLimit;
+	}
+	return dictSize;
+}
+EXPORT_SYMBOL(LZ4_saveDictHC);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("LZ4 HC compressor");