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| author | Yann Collet <Cyan4973@users.noreply.github.com> | 2018-09-11 10:01:23 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-09-11 10:01:23 -0700 |
| commit | 82a693c1365ca30a99c620c3f157847bef65d46f (patch) | |
| tree | 2e4f1bb6f3f3ec035365e441079e37aed43e153d | |
| parent | f9725fdc46cc96c49d3cf3905a3b084b27151f33 (diff) | |
| parent | 6d32240b2e9cb921f9b34b790d787d0ee1ea51cb (diff) | |
| download | lz4-82a693c1365ca30a99c620c3f157847bef65d46f.tar.gz | |
Merge pull request #571 from lz4/mflimit
clarify constant MFLIMIT
| -rw-r--r-- | lib/lz4.c | 9 |
1 files changed, 5 insertions, 4 deletions
@@ -297,8 +297,9 @@ void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd) #define MINMATCH 4 #define WILDCOPYLENGTH 8 -#define LASTLITERALS 5 -#define MFLIMIT (WILDCOPYLENGTH+MINMATCH) +#define LASTLITERALS 5 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ +#define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ +#define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */ static const int LZ4_minLength = (MFLIMIT+1); #define KB *(1 <<10) @@ -1588,7 +1589,7 @@ _copy_match: /* partialDecoding : may not respect endBlock parsing restrictions */ assert(op<=oend); - if (partialDecoding && (cpy > oend-12)) { + 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; @@ -1616,7 +1617,7 @@ _copy_match: } op += 8; - if (unlikely(cpy > oend-12)) { + if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1); if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals (uncompressed) */ if (op < oCopyLimit) { |