From 9420bce8a491e21821c4b372f837bf4bd47e5870 Mon Sep 17 00:00:00 2001 From: Yonatan Komornik <11005061+yoniko@users.noreply.github.com> Date: Mon, 13 Mar 2023 13:20:49 -0700 Subject: [PATCH] Add init once memory (#3528) (#3529) - Adds memory type that is guaranteed to have been initialized at least once in the workspace's lifetime. - Changes tag space in row hash to be based on init once memory. --- lib/common/compiler.h | 4 + lib/compress/zstd_compress.c | 92 +++++++++--------- lib/compress/zstd_cwksp.h | 181 +++++++++++++++++++++++------------ lib/compress/zstd_opt.c | 2 + 4 files changed, 174 insertions(+), 105 deletions(-) diff --git a/lib/common/compiler.h b/lib/common/compiler.h index d4f2f285d79..73f8d01998b 100644 --- a/lib/common/compiler.h +++ b/lib/common/compiler.h @@ -311,6 +311,10 @@ void __msan_poison(const volatile void *a, size_t size); /* Returns the offset of the first (at least partially) poisoned byte in the memory range, or -1 if the whole range is good. */ intptr_t __msan_test_shadow(const volatile void *x, size_t size); + +/* Print shadow and origin for the memory range to stderr in a human-readable + format. */ +void __msan_print_shadow(const volatile void *x, size_t size); #endif #if ZSTD_ADDRESS_SANITIZER && !defined(ZSTD_ASAN_DONT_POISON_WORKSPACE) diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c index 15a7a666db4..49aa385466d 100644 --- a/lib/compress/zstd_compress.c +++ b/lib/compress/zstd_compress.c @@ -1955,6 +1955,17 @@ ZSTD_reset_matchState(ZSTD_matchState_t* ms, ZSTD_cwksp_clean_tables(ws); } + if (ZSTD_rowMatchFinderUsed(cParams->strategy, useRowMatchFinder)) { + /* Row match finder needs an additional table of hashes ("tags") */ + size_t const tagTableSize = hSize; + ms->tagTable = (BYTE*) ZSTD_cwksp_reserve_aligned_init_once(ws, tagTableSize); + { /* Switch to 32-entry rows if searchLog is 5 (or more) */ + U32 const rowLog = BOUNDED(4, cParams->searchLog, 6); + assert(cParams->hashLog >= rowLog); + ms->rowHashLog = cParams->hashLog - rowLog; + } + } + /* opt parser space */ if ((forWho == ZSTD_resetTarget_CCtx) && (cParams->strategy >= ZSTD_btopt)) { DEBUGLOG(4, "reserving optimal parser space"); @@ -1966,19 +1977,6 @@ ZSTD_reset_matchState(ZSTD_matchState_t* ms, ms->opt.priceTable = (ZSTD_optimal_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t)); } - if (ZSTD_rowMatchFinderUsed(cParams->strategy, useRowMatchFinder)) { - { /* Row match finder needs an additional table of hashes ("tags") */ - size_t const tagTableSize = hSize; - ms->tagTable = (BYTE*)ZSTD_cwksp_reserve_aligned(ws, tagTableSize); - if (ms->tagTable) ZSTD_memset(ms->tagTable, 0, tagTableSize); - } - { /* Switch to 32-entry rows if searchLog is 5 (or more) */ - U32 const rowLog = BOUNDED(4, cParams->searchLog, 6); - assert(cParams->hashLog >= rowLog); - ms->rowHashLog = cParams->hashLog - rowLog; - } - } - ms->cParams = *cParams; RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation, @@ -2125,13 +2123,46 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc, ZSTD_reset_compressedBlockState(zc->blockState.prevCBlock); + FORWARD_IF_ERROR(ZSTD_reset_matchState( + &zc->blockState.matchState, + ws, + ¶ms->cParams, + params->useRowMatchFinder, + crp, + needsIndexReset, + ZSTD_resetTarget_CCtx), ""); + + zc->seqStore.sequencesStart = (seqDef*)ZSTD_cwksp_reserve_aligned(ws, maxNbSeq * sizeof(seqDef)); + + /* ldm hash table */ + if (params->ldmParams.enableLdm == ZSTD_ps_enable) { + /* TODO: avoid memset? */ + size_t const ldmHSize = ((size_t)1) << params->ldmParams.hashLog; + zc->ldmState.hashTable = (ldmEntry_t*)ZSTD_cwksp_reserve_aligned(ws, ldmHSize * sizeof(ldmEntry_t)); + ZSTD_memset(zc->ldmState.hashTable, 0, ldmHSize * sizeof(ldmEntry_t)); + zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq)); + zc->maxNbLdmSequences = maxNbLdmSeq; + + ZSTD_window_init(&zc->ldmState.window); + zc->ldmState.loadedDictEnd = 0; + } + + /* reserve space for block-level external sequences */ + if (params->useSequenceProducer) { + size_t const maxNbExternalSeq = ZSTD_sequenceBound(blockSize); + zc->externalMatchCtx.seqBufferCapacity = maxNbExternalSeq; + zc->externalMatchCtx.seqBuffer = + (ZSTD_Sequence*)ZSTD_cwksp_reserve_aligned(ws, maxNbExternalSeq * sizeof(ZSTD_Sequence)); + } + + /* buffers */ + /* ZSTD_wildcopy() is used to copy into the literals buffer, * so we have to oversize the buffer by WILDCOPY_OVERLENGTH bytes. */ zc->seqStore.litStart = ZSTD_cwksp_reserve_buffer(ws, blockSize + WILDCOPY_OVERLENGTH); zc->seqStore.maxNbLit = blockSize; - /* buffers */ zc->bufferedPolicy = zbuff; zc->inBuffSize = buffInSize; zc->inBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffInSize); @@ -2154,40 +2185,9 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc, zc->seqStore.llCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE)); zc->seqStore.mlCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE)); zc->seqStore.ofCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE)); - zc->seqStore.sequencesStart = (seqDef*)ZSTD_cwksp_reserve_aligned(ws, maxNbSeq * sizeof(seqDef)); - - FORWARD_IF_ERROR(ZSTD_reset_matchState( - &zc->blockState.matchState, - ws, - ¶ms->cParams, - params->useRowMatchFinder, - crp, - needsIndexReset, - ZSTD_resetTarget_CCtx), ""); - - /* ldm hash table */ - if (params->ldmParams.enableLdm == ZSTD_ps_enable) { - /* TODO: avoid memset? */ - size_t const ldmHSize = ((size_t)1) << params->ldmParams.hashLog; - zc->ldmState.hashTable = (ldmEntry_t*)ZSTD_cwksp_reserve_aligned(ws, ldmHSize * sizeof(ldmEntry_t)); - ZSTD_memset(zc->ldmState.hashTable, 0, ldmHSize * sizeof(ldmEntry_t)); - zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq)); - zc->maxNbLdmSequences = maxNbLdmSeq; - - ZSTD_window_init(&zc->ldmState.window); - zc->ldmState.loadedDictEnd = 0; - } - - /* reserve space for block-level external sequences */ - if (params->useSequenceProducer) { - size_t const maxNbExternalSeq = ZSTD_sequenceBound(blockSize); - zc->externalMatchCtx.seqBufferCapacity = maxNbExternalSeq; - zc->externalMatchCtx.seqBuffer = - (ZSTD_Sequence*)ZSTD_cwksp_reserve_aligned(ws, maxNbExternalSeq * sizeof(ZSTD_Sequence)); - } DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws)); - assert(ZSTD_cwksp_estimated_space_within_bounds(ws, neededSpace, resizeWorkspace)); + assert(ZSTD_cwksp_estimated_space_within_bounds(ws, neededSpace)); zc->initialized = 1; diff --git a/lib/compress/zstd_cwksp.h b/lib/compress/zstd_cwksp.h index 9113cdbd4fb..cc7fb1c715c 100644 --- a/lib/compress/zstd_cwksp.h +++ b/lib/compress/zstd_cwksp.h @@ -16,6 +16,7 @@ ***************************************/ #include "../common/allocations.h" /* ZSTD_customMalloc, ZSTD_customFree */ #include "../common/zstd_internal.h" +#include "../common/portability_macros.h" #if defined (__cplusplus) extern "C" { @@ -45,8 +46,9 @@ extern "C" { ***************************************/ typedef enum { ZSTD_cwksp_alloc_objects, - ZSTD_cwksp_alloc_buffers, - ZSTD_cwksp_alloc_aligned + ZSTD_cwksp_alloc_aligned_init_once, + ZSTD_cwksp_alloc_aligned, + ZSTD_cwksp_alloc_buffers } ZSTD_cwksp_alloc_phase_e; /** @@ -99,8 +101,8 @@ typedef enum { * * Workspace Layout: * - * [ ... workspace ... ] - * [objects][tables ... ->] free space [<- ... aligned][<- ... buffers] + * [ ... workspace ... ] + * [objects][tables ->] free space [<- buffers][<- aligned][<- init once] * * The various objects that live in the workspace are divided into the * following categories, and are allocated separately: @@ -124,9 +126,18 @@ typedef enum { * uint32_t arrays, all of whose values are between 0 and (nextSrc - base). * Their sizes depend on the cparams. These tables are 64-byte aligned. * - * - Aligned: these buffers are used for various purposes that require 4 byte - * alignment, but don't require any initialization before they're used. These - * buffers are each aligned to 64 bytes. + * - Init once: these buffers require to be initialized at least once before + * use. They should be used when we want to skip memory initialization + * while not triggering memory checkers (like Valgrind) when reading from + * from this memory without writing to it first. + * These buffers should be used carefully as they might contain data + * from previous compressions. + * Buffers are aligned to 64 bytes. + * + * - Aligned: these buffers don't require any initialization before they're + * used. The user of the buffer should make sure they write into a buffer + * location before reading from it. + * Buffers are aligned to 64 bytes. * * - Buffers: these buffers are used for various purposes that don't require * any alignment or initialization before they're used. This means they can @@ -138,8 +149,9 @@ typedef enum { * correctly packed into the workspace buffer. That order is: * * 1. Objects - * 2. Buffers - * 3. Aligned/Tables + * 2. Init once / Tables + * 3. Aligned / Tables + * 4. Buffers / Tables * * Attempts to reserve objects of different types out of order will fail. */ @@ -151,6 +163,7 @@ typedef struct { void* tableEnd; void* tableValidEnd; void* allocStart; + void* initOnceStart; BYTE allocFailed; int workspaceOversizedDuration; @@ -163,6 +176,7 @@ typedef struct { ***************************************/ MEM_STATIC size_t ZSTD_cwksp_available_space(ZSTD_cwksp* ws); +MEM_STATIC void* ZSTD_cwksp_initialAllocStart(ZSTD_cwksp* ws); MEM_STATIC void ZSTD_cwksp_assert_internal_consistency(ZSTD_cwksp* ws) { (void)ws; @@ -172,6 +186,20 @@ MEM_STATIC void ZSTD_cwksp_assert_internal_consistency(ZSTD_cwksp* ws) { assert(ws->tableEnd <= ws->allocStart); assert(ws->tableValidEnd <= ws->allocStart); assert(ws->allocStart <= ws->workspaceEnd); + assert(ws->initOnceStart <= ZSTD_cwksp_initialAllocStart(ws)); + assert(ws->workspace <= ws->initOnceStart); +#if ZSTD_MEMORY_SANITIZER + { + intptr_t const offset = __msan_test_shadow(ws->initOnceStart, + (U8*)ZSTD_cwksp_initialAllocStart(ws) - (U8*)ws->initOnceStart); +#if defined(ZSTD_MSAN_PRINT) + if(offset!=-1) { + __msan_print_shadow((U8*)ws->initOnceStart + offset - 8, 32); + } +#endif + assert(offset==-1); + }; +#endif } /** @@ -218,14 +246,10 @@ MEM_STATIC size_t ZSTD_cwksp_aligned_alloc_size(size_t size) { * for internal purposes (currently only alignment). */ MEM_STATIC size_t ZSTD_cwksp_slack_space_required(void) { - /* For alignment, the wksp will always allocate an additional n_1=[1, 64] bytes - * to align the beginning of tables section, as well as another n_2=[0, 63] bytes - * to align the beginning of the aligned section. - * - * n_1 + n_2 == 64 bytes if the cwksp is freshly allocated, due to tables and - * aligneds being sized in multiples of 64 bytes. + /* For alignment, the wksp will always allocate an additional 2*ZSTD_CWKSP_ALIGNMENT_BYTES + * bytes to align the beginning of tables section and end of buffers; */ - size_t const slackSpace = ZSTD_CWKSP_ALIGNMENT_BYTES; + size_t const slackSpace = ZSTD_CWKSP_ALIGNMENT_BYTES * 2; return slackSpace; } @@ -238,10 +262,18 @@ MEM_STATIC size_t ZSTD_cwksp_bytes_to_align_ptr(void* ptr, const size_t alignByt size_t const alignBytesMask = alignBytes - 1; size_t const bytes = (alignBytes - ((size_t)ptr & (alignBytesMask))) & alignBytesMask; assert((alignBytes & alignBytesMask) == 0); - assert(bytes != ZSTD_CWKSP_ALIGNMENT_BYTES); + assert(bytes < alignBytes); return bytes; } +/** + * Returns the initial value for allocStart which is used to determine the position from + * which we can allocate from the end of the workspace. + */ +MEM_STATIC void* ZSTD_cwksp_initialAllocStart(ZSTD_cwksp* ws) { + return (void*)((size_t)ws->workspaceEnd & ~(ZSTD_CWKSP_ALIGNMENT_BYTES-1)); +} + /** * Internal function. Do not use directly. * Reserves the given number of bytes within the aligned/buffer segment of the wksp, @@ -282,27 +314,16 @@ ZSTD_cwksp_internal_advance_phase(ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase { assert(phase >= ws->phase); if (phase > ws->phase) { - /* Going from allocating objects to allocating buffers */ - if (ws->phase < ZSTD_cwksp_alloc_buffers && - phase >= ZSTD_cwksp_alloc_buffers) { + /* Going from allocating objects to allocating initOnce / tables */ + if (ws->phase < ZSTD_cwksp_alloc_aligned_init_once && + phase >= ZSTD_cwksp_alloc_aligned_init_once) { ws->tableValidEnd = ws->objectEnd; - } + ws->initOnceStart = ZSTD_cwksp_initialAllocStart(ws); - /* Going from allocating buffers to allocating aligneds/tables */ - if (ws->phase < ZSTD_cwksp_alloc_aligned && - phase >= ZSTD_cwksp_alloc_aligned) { - { /* Align the start of the "aligned" to 64 bytes. Use [1, 64] bytes. */ - size_t const bytesToAlign = - ZSTD_CWKSP_ALIGNMENT_BYTES - ZSTD_cwksp_bytes_to_align_ptr(ws->allocStart, ZSTD_CWKSP_ALIGNMENT_BYTES); - DEBUGLOG(5, "reserving aligned alignment addtl space: %zu", bytesToAlign); - ZSTD_STATIC_ASSERT((ZSTD_CWKSP_ALIGNMENT_BYTES & (ZSTD_CWKSP_ALIGNMENT_BYTES - 1)) == 0); /* power of 2 */ - RETURN_ERROR_IF(!ZSTD_cwksp_reserve_internal_buffer_space(ws, bytesToAlign), - memory_allocation, "aligned phase - alignment initial allocation failed!"); - } { /* Align the start of the tables to 64 bytes. Use [0, 63] bytes */ - void* const alloc = ws->objectEnd; + void *const alloc = ws->objectEnd; size_t const bytesToAlign = ZSTD_cwksp_bytes_to_align_ptr(alloc, ZSTD_CWKSP_ALIGNMENT_BYTES); - void* const objectEnd = (BYTE*)alloc + bytesToAlign; + void *const objectEnd = (BYTE *) alloc + bytesToAlign; DEBUGLOG(5, "reserving table alignment addtl space: %zu", bytesToAlign); RETURN_ERROR_IF(objectEnd > ws->workspaceEnd, memory_allocation, "table phase - alignment initial allocation failed!"); @@ -310,7 +331,9 @@ ZSTD_cwksp_internal_advance_phase(ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase ws->tableEnd = objectEnd; /* table area starts being empty */ if (ws->tableValidEnd < ws->tableEnd) { ws->tableValidEnd = ws->tableEnd; - } } } + } + } + } ws->phase = phase; ZSTD_cwksp_assert_internal_consistency(ws); } @@ -322,7 +345,7 @@ ZSTD_cwksp_internal_advance_phase(ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase */ MEM_STATIC int ZSTD_cwksp_owns_buffer(const ZSTD_cwksp* ws, const void* ptr) { - return (ptr != NULL) && (ws->workspace <= ptr) && (ptr <= ws->workspaceEnd); + return (ptr != NULL) && (ws->workspace <= ptr) && (ptr < ws->workspaceEnd); } /** @@ -367,6 +390,36 @@ MEM_STATIC BYTE* ZSTD_cwksp_reserve_buffer(ZSTD_cwksp* ws, size_t bytes) return (BYTE*)ZSTD_cwksp_reserve_internal(ws, bytes, ZSTD_cwksp_alloc_buffers); } +/** + * Reserves and returns memory sized on and aligned on ZSTD_CWKSP_ALIGNMENT_BYTES (64 bytes). + * This memory has been initialized at least once in the past. + * This doesn't mean it has been initialized this time, and it might contain data from previous + * operations. + * The main usage is for algorithms that might need read access into uninitialized memory. + * The algorithm must maintain safety under these conditions and must make sure it doesn't + * leak any of the past data (directly or in side channels). + */ +MEM_STATIC void* ZSTD_cwksp_reserve_aligned_init_once(ZSTD_cwksp* ws, size_t bytes) +{ + size_t const alignedBytes = ZSTD_cwksp_align(bytes, ZSTD_CWKSP_ALIGNMENT_BYTES); + void* ptr = ZSTD_cwksp_reserve_internal(ws, alignedBytes, ZSTD_cwksp_alloc_aligned_init_once); + assert(((size_t)ptr & (ZSTD_CWKSP_ALIGNMENT_BYTES-1))== 0); + if(ptr && ptr < ws->initOnceStart) { + /* We assume the memory following the current allocation is either: + * 1. Not usable as initOnce memory (end of workspace) + * 2. Another initOnce buffer that has been allocated before (and so was previously memset) + * 3. An ASAN redzone, in which case we don't want to write on it + * For these reasons it should be fine to not explicitly zero every byte up to ws->initOnceStart. + * Note that we assume here that MSAN and ASAN cannot run in the same time. */ + ZSTD_memset(ptr, 0, MIN((size_t)((U8*)ws->initOnceStart - (U8*)ptr), alignedBytes)); + ws->initOnceStart = ptr; + } +#if ZSTD_MEMORY_SANITIZER + assert(__msan_test_shadow(ptr, bytes) == -1); +#endif + return ptr; +} + /** * Reserves and returns memory sized on and aligned on ZSTD_CWKSP_ALIGNMENT_BYTES (64 bytes). */ @@ -385,13 +438,17 @@ MEM_STATIC void* ZSTD_cwksp_reserve_aligned(ZSTD_cwksp* ws, size_t bytes) */ MEM_STATIC void* ZSTD_cwksp_reserve_table(ZSTD_cwksp* ws, size_t bytes) { - const ZSTD_cwksp_alloc_phase_e phase = ZSTD_cwksp_alloc_aligned; + const ZSTD_cwksp_alloc_phase_e phase = ZSTD_cwksp_alloc_aligned_init_once; void* alloc; void* end; void* top; - if (ZSTD_isError(ZSTD_cwksp_internal_advance_phase(ws, phase))) { - return NULL; + /* We can only start allocating tables after we are done reserving space for objects at the + * start of the workspace */ + if(ws->phase < phase) { + if (ZSTD_isError(ZSTD_cwksp_internal_advance_phase(ws, phase))) { + return NULL; + } } alloc = ws->tableEnd; end = (BYTE *)alloc + bytes; @@ -470,11 +527,19 @@ MEM_STATIC void ZSTD_cwksp_mark_tables_dirty(ZSTD_cwksp* ws) #if ZSTD_MEMORY_SANITIZER && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE) /* To validate that the table re-use logic is sound, and that we don't * access table space that we haven't cleaned, we re-"poison" the table - * space every time we mark it dirty. */ + * space every time we mark it dirty. + * Since tableValidEnd space and initOnce space may overlap we don't poison + * the initOnce portion as it break its promise. This means that this poisoning + * check isn't always applied fully. */ { size_t size = (BYTE*)ws->tableValidEnd - (BYTE*)ws->objectEnd; assert(__msan_test_shadow(ws->objectEnd, size) == -1); - __msan_poison(ws->objectEnd, size); + if((BYTE*)ws->tableValidEnd < (BYTE*)ws->initOnceStart) { + __msan_poison(ws->objectEnd, size); + } else { + assert(ws->initOnceStart >= ws->objectEnd); + __msan_poison(ws->objectEnd, (BYTE*)ws->initOnceStart - (BYTE*)ws->objectEnd); + } } #endif @@ -539,11 +604,14 @@ MEM_STATIC void ZSTD_cwksp_clear(ZSTD_cwksp* ws) { #if ZSTD_MEMORY_SANITIZER && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE) /* To validate that the context re-use logic is sound, and that we don't * access stuff that this compression hasn't initialized, we re-"poison" - * the workspace (or at least the non-static, non-table parts of it) - * every time we start a new compression. */ + * the workspace except for the areas in which we expect memory re-use + * without initialization (objects, valid tables area and init once + * memory). */ { - size_t size = (BYTE*)ws->workspaceEnd - (BYTE*)ws->tableValidEnd; - __msan_poison(ws->tableValidEnd, size); + if((BYTE*)ws->tableValidEnd < (BYTE*)ws->initOnceStart) { + size_t size = (BYTE*)ws->initOnceStart - (BYTE*)ws->tableValidEnd; + __msan_poison(ws->tableValidEnd, size); + } } #endif @@ -559,10 +627,10 @@ MEM_STATIC void ZSTD_cwksp_clear(ZSTD_cwksp* ws) { #endif ws->tableEnd = ws->objectEnd; - ws->allocStart = ws->workspaceEnd; + ws->allocStart = ZSTD_cwksp_initialAllocStart(ws); ws->allocFailed = 0; - if (ws->phase > ZSTD_cwksp_alloc_buffers) { - ws->phase = ZSTD_cwksp_alloc_buffers; + if (ws->phase > ZSTD_cwksp_alloc_aligned_init_once) { + ws->phase = ZSTD_cwksp_alloc_aligned_init_once; } ZSTD_cwksp_assert_internal_consistency(ws); } @@ -579,6 +647,7 @@ MEM_STATIC void ZSTD_cwksp_init(ZSTD_cwksp* ws, void* start, size_t size, ZSTD_c ws->workspaceEnd = (BYTE*)start + size; ws->objectEnd = ws->workspace; ws->tableValidEnd = ws->objectEnd; + ws->initOnceStart = ZSTD_cwksp_initialAllocStart(ws); ws->phase = ZSTD_cwksp_alloc_objects; ws->isStatic = isStatic; ZSTD_cwksp_clear(ws); @@ -631,17 +700,11 @@ MEM_STATIC int ZSTD_cwksp_reserve_failed(const ZSTD_cwksp* ws) { * Returns if the estimated space needed for a wksp is within an acceptable limit of the * actual amount of space used. */ -MEM_STATIC int ZSTD_cwksp_estimated_space_within_bounds(const ZSTD_cwksp* const ws, - size_t const estimatedSpace, int resizedWorkspace) { - if (resizedWorkspace) { - /* Resized/newly allocated wksp should have exact bounds */ - return ZSTD_cwksp_used(ws) == estimatedSpace; - } else { - /* Due to alignment, when reusing a workspace, we can actually consume 63 fewer or more bytes - * than estimatedSpace. See the comments in zstd_cwksp.h for details. - */ - return (ZSTD_cwksp_used(ws) >= estimatedSpace - 63) && (ZSTD_cwksp_used(ws) <= estimatedSpace + 63); - } +MEM_STATIC int ZSTD_cwksp_estimated_space_within_bounds(const ZSTD_cwksp *const ws, size_t const estimatedSpace) { + /* We have an alignment space between objects and tables between tables and buffers, so we can have up to twice + * the alignment bytes difference between estimation and actual usage */ + return (estimatedSpace - ZSTD_cwksp_slack_space_required()) <= ZSTD_cwksp_used(ws) && + ZSTD_cwksp_used(ws) <= estimatedSpace; } diff --git a/lib/compress/zstd_opt.c b/lib/compress/zstd_opt.c index fdd7f9d8b5a..f02a760946e 100644 --- a/lib/compress/zstd_opt.c +++ b/lib/compress/zstd_opt.c @@ -1086,6 +1086,8 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, ZSTD_optimal_t lastSequence; ZSTD_optLdm_t optLdm; + ZSTD_memset(&lastSequence, 0, sizeof(ZSTD_optimal_t)); + optLdm.seqStore = ms->ldmSeqStore ? *ms->ldmSeqStore : kNullRawSeqStore; optLdm.endPosInBlock = optLdm.startPosInBlock = optLdm.offset = 0; ZSTD_opt_getNextMatchAndUpdateSeqStore(&optLdm, (U32)(ip-istart), (U32)(iend-ip));