AuroraMiddleware/lz4
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fixed lz4hc assert error

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when src ptr is in very low memory area (< 64K),
the virtual reference to data in dictionary
might end up in a very high memory address.

Since it's not a "real" memory address,
just a virtual one, to calculate distance,
it doesn't matter : only distance matters.

The assert was to restrictive.
Fixed.
This commit is contained in:
Yann Collet 2019-12-03 14:49:22 -08:00
parent 0f6cbd996f
commit d755f87f9f
2 changed files with 11 additions and 11 deletions
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16
lib/lz4.c
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@ -225,15 +225,15 @@ static const int LZ4_minLength = (MFLIMIT+1);
#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
# include <stdio.h>
static int g_debuglog_enable = 1;
# define DEBUGLOG(l, ...) { \
if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
fprintf(stderr, __FILE__ ": "); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, " \n"); \
} }
static int g_debuglog_enable = 1;
# define DEBUGLOG(l, ...) { \
if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
fprintf(stderr, __FILE__ ": "); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, " \n"); \
} }
#else
# define DEBUGLOG(l, ...) {} /* disabled */
# define DEBUGLOG(l, ...) {} /* disabled */
#endif

6
lib/lz4hc.c
View File

@ -389,8 +389,8 @@ LZ4HC_InsertAndGetWiderMatch (
if (lookBackLength==0) { /* no back possible */
size_t const maxML = MIN(currentSegmentLength, srcPatternLength);
if ((size_t)longest < maxML) {
assert(base + matchIndex < ip);
if (ip - (base+matchIndex) > LZ4_DISTANCE_MAX) break;
assert(base + matchIndex != ip);
if ((size_t)(ip - base) - matchIndex > LZ4_DISTANCE_MAX) break;
assert(maxML < 2 GB);
longest = (int)maxML;
*matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */
@ -1028,7 +1028,7 @@ int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr,
const char* dictionary, int dictSize)
{
LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
DEBUGLOG(4, "LZ4_loadDictHC(%p, %p, %d)", LZ4_streamHCPtr, dictionary, dictSize);
DEBUGLOG(4, "LZ4_loadDictHC(ctx:%p, dict:%p, dictSize:%d)", LZ4_streamHCPtr, dictionary, dictSize);
assert(LZ4_streamHCPtr != NULL);
if (dictSize > 64 KB) {
dictionary += (size_t)dictSize - 64 KB;