port: AIX compatibility, by @likema
port: HP-UX compatibility, by @likema
doc: Improved specification accuracy, by @elasota
+bug: Fix and deprecate ZSTD_generateSequences (#3981)
v1.5.5 (Apr 2023)
fix: fix rare corruption bug affecting the high compression mode, reported by @danlark1 (#3517, @terrelln)
return ZSTDbss_compress;
}
-static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
+static size_t ZSTD_copyBlockSequences(SeqCollector* seqCollector, const seqStore_t* seqStore, const U32 prevRepcodes[ZSTD_REP_NUM])
{
- const seqStore_t* seqStore = ZSTD_getSeqStore(zc);
- const seqDef* seqStoreSeqs = seqStore->sequencesStart;
- size_t seqStoreSeqSize = seqStore->sequences - seqStoreSeqs;
- size_t seqStoreLiteralsSize = (size_t)(seqStore->lit - seqStore->litStart);
- size_t literalsRead = 0;
- size_t lastLLSize;
+ const seqDef* inSeqs = seqStore->sequencesStart;
+ const size_t nbInSequences = seqStore->sequences - inSeqs;
+ const size_t nbInLiterals = (size_t)(seqStore->lit - seqStore->litStart);
- ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex];
+ ZSTD_Sequence* outSeqs = seqCollector->seqIndex == 0 ? seqCollector->seqStart : seqCollector->seqStart + seqCollector->seqIndex;
+ const size_t nbOutSequences = nbInSequences + 1;
+ size_t nbOutLiterals = 0;
+ repcodes_t repcodes;
size_t i;
- repcodes_t updatedRepcodes;
- assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences);
- /* Ensure we have enough space for last literals "sequence" */
- assert(zc->seqCollector.maxSequences >= seqStoreSeqSize + 1);
- ZSTD_memcpy(updatedRepcodes.rep, zc->blockState.prevCBlock->rep, sizeof(repcodes_t));
- for (i = 0; i < seqStoreSeqSize; ++i) {
- U32 rawOffset = seqStoreSeqs[i].offBase - ZSTD_REP_NUM;
- outSeqs[i].litLength = seqStoreSeqs[i].litLength;
- outSeqs[i].matchLength = seqStoreSeqs[i].mlBase + MINMATCH;
+ /* Bounds check that we have enough space for every input sequence
+ * and the block delimiter
+ */
+ assert(seqCollector->seqIndex <= seqCollector->maxSequences);
+ RETURN_ERROR_IF(
+ nbOutSequences > (size_t)(seqCollector->maxSequences - seqCollector->seqIndex),
+ dstSize_tooSmall,
+ "Not enough space to copy sequences");
+
+ ZSTD_memcpy(&repcodes, prevRepcodes, sizeof(repcodes));
+ for (i = 0; i < nbInSequences; ++i) {
+ U32 rawOffset;
+ outSeqs[i].litLength = inSeqs[i].litLength;
+ outSeqs[i].matchLength = inSeqs[i].mlBase + MINMATCH;
outSeqs[i].rep = 0;
+ /* Handle the possible single length >= 64K
+ * There can only be one because we add MINMATCH to every match length,
+ * and blocks are at most 128K.
+ */
if (i == seqStore->longLengthPos) {
if (seqStore->longLengthType == ZSTD_llt_literalLength) {
outSeqs[i].litLength += 0x10000;
}
}
- if (seqStoreSeqs[i].offBase <= ZSTD_REP_NUM) {
- /* Derive the correct offset corresponding to a repcode */
- outSeqs[i].rep = seqStoreSeqs[i].offBase;
+ /* Determine the raw offset given the offBase, which may be a repcode. */
+ if (OFFBASE_IS_REPCODE(inSeqs[i].offBase)) {
+ const U32 repcode = OFFBASE_TO_REPCODE(inSeqs[i].offBase);
+ assert(repcode > 0);
+ outSeqs[i].rep = repcode;
if (outSeqs[i].litLength != 0) {
- rawOffset = updatedRepcodes.rep[outSeqs[i].rep - 1];
+ rawOffset = repcodes.rep[repcode - 1];
} else {
- if (outSeqs[i].rep == 3) {
- rawOffset = updatedRepcodes.rep[0] - 1;
+ if (repcode == 3) {
+ assert(repcodes.rep[0] > 1);
+ rawOffset = repcodes.rep[0] - 1;
} else {
- rawOffset = updatedRepcodes.rep[outSeqs[i].rep];
+ rawOffset = repcodes.rep[repcode];
}
}
+ } else {
+ rawOffset = OFFBASE_TO_OFFSET(inSeqs[i].offBase);
}
outSeqs[i].offset = rawOffset;
- /* seqStoreSeqs[i].offset == offCode+1, and ZSTD_updateRep() expects offCode
- so we provide seqStoreSeqs[i].offset - 1 */
- ZSTD_updateRep(updatedRepcodes.rep,
- seqStoreSeqs[i].offBase,
- seqStoreSeqs[i].litLength == 0);
- literalsRead += outSeqs[i].litLength;
+
+ /* Update repcode history for the sequence */
+ ZSTD_updateRep(repcodes.rep,
+ inSeqs[i].offBase,
+ inSeqs[i].litLength == 0);
+
+ nbOutLiterals += outSeqs[i].litLength;
}
/* Insert last literals (if any exist) in the block as a sequence with ml == off == 0.
* If there are no last literals, then we'll emit (of: 0, ml: 0, ll: 0), which is a marker
* for the block boundary, according to the API.
*/
- assert(seqStoreLiteralsSize >= literalsRead);
- lastLLSize = seqStoreLiteralsSize - literalsRead;
- outSeqs[i].litLength = (U32)lastLLSize;
- outSeqs[i].matchLength = outSeqs[i].offset = outSeqs[i].rep = 0;
- seqStoreSeqSize++;
- zc->seqCollector.seqIndex += seqStoreSeqSize;
+ assert(nbInLiterals >= nbOutLiterals);
+ {
+ const size_t lastLLSize = nbInLiterals - nbOutLiterals;
+ outSeqs[nbInSequences].litLength = (U32)lastLLSize;
+ outSeqs[nbInSequences].matchLength = 0;
+ outSeqs[nbInSequences].offset = 0;
+ assert(nbOutSequences == nbInSequences + 1);
+ }
+ seqCollector->seqIndex += nbOutSequences;
+ assert(seqCollector->seqIndex <= seqCollector->maxSequences);
+
+ return 0;
}
size_t ZSTD_sequenceBound(size_t srcSize) {
- return (srcSize / ZSTD_MINMATCH_MIN) + 1;
+ const size_t maxNbSeq = (srcSize / ZSTD_MINMATCH_MIN) + 1;
+ const size_t maxNbDelims = (srcSize / ZSTD_BLOCKSIZE_MAX_MIN) + 1;
+ return maxNbSeq + maxNbDelims;
}
size_t ZSTD_generateSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
const size_t dstCapacity = ZSTD_compressBound(srcSize);
void* dst = ZSTD_customMalloc(dstCapacity, ZSTD_defaultCMem);
SeqCollector seqCollector;
+ {
+ int targetCBlockSize;
+ FORWARD_IF_ERROR(ZSTD_CCtx_getParameter(zc, ZSTD_c_targetCBlockSize, &targetCBlockSize), "");
+ RETURN_ERROR_IF(targetCBlockSize != 0, parameter_unsupported, "targetCBlockSize != 0");
+ }
+ {
+ int nbWorkers;
+ FORWARD_IF_ERROR(ZSTD_CCtx_getParameter(zc, ZSTD_c_nbWorkers, &nbWorkers), "");
+ RETURN_ERROR_IF(nbWorkers != 0, parameter_unsupported, "nbWorkers != 0");
+ }
RETURN_ERROR_IF(dst == NULL, memory_allocation, "NULL pointer!");
seqCollector.maxSequences = outSeqsSize;
zc->seqCollector = seqCollector;
- ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
- ZSTD_customFree(dst, ZSTD_defaultCMem);
+ {
+ const size_t ret = ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
+ ZSTD_customFree(dst, ZSTD_defaultCMem);
+ FORWARD_IF_ERROR(ret, "ZSTD_compress2 failed");
+ }
+ assert(zc->seqCollector.seqIndex <= ZSTD_sequenceBound(srcSize));
return zc->seqCollector.seqIndex;
}
cSeqsSize = 1;
}
+ /* Sequence collection not supported when block splitting */
if (zc->seqCollector.collectSequences) {
- ZSTD_copyBlockSequences(zc);
+ FORWARD_IF_ERROR(ZSTD_copyBlockSequences(&zc->seqCollector, seqStore, dRepOriginal.rep), "copyBlockSequences failed");
ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
return 0;
}
if (bss == ZSTDbss_noCompress) {
if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
+ RETURN_ERROR_IF(zc->seqCollector.collectSequences, sequenceProducer_failed, "Uncompressible block");
cSize = ZSTD_noCompressBlock(dst, dstCapacity, src, srcSize, lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
DEBUGLOG(4, "ZSTD_compressBlock_splitBlock: Nocompress block");
{ const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
- if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
+ if (bss == ZSTDbss_noCompress) {
+ RETURN_ERROR_IF(zc->seqCollector.collectSequences, sequenceProducer_failed, "Uncompressible block");
+ cSize = 0;
+ goto out;
+ }
}
if (zc->seqCollector.collectSequences) {
- ZSTD_copyBlockSequences(zc);
+ FORWARD_IF_ERROR(ZSTD_copyBlockSequences(&zc->seqCollector, ZSTD_getSeqStore(zc), zc->blockState.prevCBlock->rep), "copyBlockSequences failed");
ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
return 0;
}
static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned maxNbBuffers, ZSTD_customMem cMem)
{
- ZSTDMT_bufferPool* const bufPool =
+ ZSTDMT_bufferPool* const bufPool =
(ZSTDMT_bufferPool*)ZSTD_customCalloc(sizeof(ZSTDMT_bufferPool), cMem);
if (bufPool==NULL) return NULL;
if (ZSTD_pthread_mutex_init(&bufPool->poolMutex, NULL)) {
static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(int nbWorkers,
ZSTD_customMem cMem)
{
- ZSTDMT_CCtxPool* const cctxPool =
+ ZSTDMT_CCtxPool* const cctxPool =
(ZSTDMT_CCtxPool*) ZSTD_customCalloc(sizeof(ZSTDMT_CCtxPool), cMem);
assert(nbWorkers > 0);
if (!cctxPool) return NULL;
ZSTDLIB_STATIC_API size_t ZSTD_sequenceBound(size_t srcSize);
/*! ZSTD_generateSequences() :
+ * WARNING: This function is meant for debugging and informational purposes ONLY!
+ * Its implementation is flawed, and it will be deleted in a future version.
+ * It is not guaranteed to succeed, as there are several cases where it will give
+ * up and fail. You should NOT use this function in production code.
+ *
+ * This function is deprecated, and will be removed in a future version.
+ *
* Generate sequences using ZSTD_compress2(), given a source buffer.
*
+ * @param zc The compression context to be used for ZSTD_compress2(). Set any
+ * compression parameters you need on this context.
+ * @param outSeqs The output sequences buffer of size @p outSeqsSize
+ * @param outSeqsSize The size of the output sequences buffer.
+ * ZSTD_sequenceBound(srcSize) is an upper bound on the number
+ * of sequences that can be generated.
+ * @param src The source buffer to generate sequences from of size @p srcSize.
+ * @param srcSize The size of the source buffer.
+ *
* Each block will end with a dummy sequence
* with offset == 0, matchLength == 0, and litLength == length of last literals.
* litLength may be == 0, and if so, then the sequence of (of: 0 ml: 0 ll: 0)
* simply acts as a block delimiter.
*
- * @zc can be used to insert custom compression params.
- * This function invokes ZSTD_compress2().
- *
- * The output of this function can be fed into ZSTD_compressSequences() with CCtx
- * setting of ZSTD_c_blockDelimiters as ZSTD_sf_explicitBlockDelimiters
- * @return : number of sequences generated
+ * @returns The number of sequences generated, necessarily less than
+ * ZSTD_sequenceBound(srcSize), or an error code that can be checked
+ * with ZSTD_isError().
*/
-
+ZSTD_DEPRECATED("For debugging only, will be replaced by ZSTD_extractSequences()")
ZSTDLIB_STATIC_API size_t
-ZSTD_generateSequences( ZSTD_CCtx* zc,
- ZSTD_Sequence* outSeqs, size_t outSeqsSize,
- const void* src, size_t srcSize);
+ZSTD_generateSequences(ZSTD_CCtx* zc,
+ ZSTD_Sequence* outSeqs, size_t outSeqsSize,
+ const void* src, size_t srcSize);
/*! ZSTD_mergeBlockDelimiters() :
* Given an array of ZSTD_Sequence, remove all sequences that represent block delimiters/last literals
seekable_roundtrip \
huf_round_trip \
huf_decompress \
- decompress_cross_format
+ decompress_cross_format \
+ generate_sequences
all: libregression.a $(FUZZ_TARGETS)
huf_decompress: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_huf_decompress.o
$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_huf_decompress.o $(LIB_FUZZING_ENGINE) -o $@
-
+
decompress_cross_format: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_decompress_cross_format.o
$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_decompress_cross_format.o $(LIB_FUZZING_ENGINE) -o $@
+generate_sequences: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_generate_sequences.o
+ $(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_generate_sequences.o $(LIB_FUZZING_ENGINE) -o $@
+
libregression.a: $(FUZZ_HEADERS) $(PRGDIR)/util.h $(PRGDIR)/util.c d_fuzz_regression_driver.o
$(AR) $(FUZZ_ARFLAGS) $@ d_fuzz_regression_driver.o
'huf_round_trip': TargetInfo(InputType.RAW_DATA),
'huf_decompress': TargetInfo(InputType.RAW_DATA),
'decompress_cross_format': TargetInfo(InputType.RAW_DATA),
+ 'generate_sequences': TargetInfo(InputType.RAW_DATA),
}
TARGETS = list(TARGET_INFO.keys())
ALL_TARGETS = TARGETS + ['all']
--- /dev/null
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "fuzz_data_producer.h"
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+
+/**
+ * This fuzz target ensures that ZSTD_generateSequences() does not crash and
+ * if it succeeds that ZSTD_compressSequences() round trips.
+ */
+
+static void testRoundTrip(ZSTD_CCtx* cctx, ZSTD_Sequence const* seqs, size_t nbSeqs, const void* src, size_t srcSize) {
+ /* Compress the sequences with block delimiters */
+ const size_t compressBound = ZSTD_compressBound(srcSize);
+ void* dst = FUZZ_malloc(compressBound);
+ FUZZ_ASSERT(dst);
+
+ size_t compressedSize = ZSTD_compressSequences(cctx, dst, compressBound, seqs, nbSeqs, src, srcSize);
+ FUZZ_ZASSERT(compressedSize);
+
+ void* decompressed = FUZZ_malloc(srcSize);
+ FUZZ_ASSERT(srcSize == 0 || decompressed);
+ size_t decompressedSize = ZSTD_decompress(decompressed, srcSize, dst, compressedSize);
+ FUZZ_ZASSERT(decompressedSize);
+ FUZZ_ASSERT(decompressedSize == srcSize);
+ if (srcSize != 0) {
+ FUZZ_ASSERT(!memcmp(src, decompressed, srcSize));
+ }
+
+ free(decompressed);
+ free(dst);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+
+ FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
+ size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+ ZSTD_CCtx* cctx = ZSTD_createCCtx();
+ FUZZ_ASSERT(cctx);
+
+ const size_t seqsCapacity = FUZZ_dataProducer_uint32Range(producer, 0, 2 * ZSTD_sequenceBound(size));
+ ZSTD_Sequence* seqs = (ZSTD_Sequence*)FUZZ_malloc(sizeof(ZSTD_Sequence) * seqsCapacity);
+ FUZZ_ASSERT(seqsCapacity == 0 || seqs);
+
+ FUZZ_setRandomParameters(cctx, size, producer);
+ FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 0));
+ FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 0));
+
+ const size_t nbSeqs = ZSTD_generateSequences(cctx, seqs, seqsCapacity, data, size);
+ if (ZSTD_isError(nbSeqs)) {
+ /* Allowed to error if the destination is too small */
+ if (ZSTD_getErrorCode(nbSeqs) == ZSTD_error_dstSize_tooSmall) {
+ FUZZ_ASSERT(seqsCapacity < ZSTD_sequenceBound(size));
+ }
+ } else {
+ /* Ensure we round trip with and without block delimiters*/
+
+ FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_explicitBlockDelimiters));
+ testRoundTrip(cctx, seqs, nbSeqs, data, size);
+
+ const size_t nbMergedSeqs = ZSTD_mergeBlockDelimiters(seqs, nbSeqs);
+ FUZZ_ASSERT(nbMergedSeqs <= nbSeqs);
+ FUZZ_ZASSERT(ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only));
+ FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters));
+ testRoundTrip(cctx, seqs, nbMergedSeqs, data, size);
+ }
+
+ free(seqs);
+ ZSTD_freeCCtx(cctx);
+ FUZZ_dataProducer_free(producer);
+ return 0;
+}
}
DISPLAYLEVEL(3, "OK \n");
+ DISPLAYLEVEL(3, "test%3i : ZSTD_generateSequences too small output buffer : ", testNb++);
+ {
+ const size_t seqsCapacity = 10;
+ const size_t srcSize = 150 KB;
+ const BYTE* src = (BYTE*)CNBuffer;
+
+ ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+ ZSTD_Sequence* const seqs = (ZSTD_Sequence*)malloc(seqsCapacity * sizeof(ZSTD_Sequence));
+
+ if (seqs == NULL) goto _output_error;
+ if (cctx == NULL) goto _output_error;
+ /* Populate src with random data */
+ RDG_genBuffer(CNBuffer, srcSize, compressibility, 0.5, seed);
+
+ /* Test with block delimiters roundtrip */
+ {
+ size_t const seqsSize = ZSTD_generateSequences(cctx, seqs, seqsCapacity, src, srcSize);
+ if (!ZSTD_isError(seqsSize)) goto _output_error;
+ }
+
+ ZSTD_freeCCtx(cctx);
+ free(seqs);
+ }
+ DISPLAYLEVEL(3, "OK \n");
+
DISPLAYLEVEL(3, "test%3i : ZSTD_getSequences followed by ZSTD_compressSequences : ", testNb++);
{
const size_t srcSize = 500 KB;