zstd_v03.c in extzstd-0.3.1

- old
+ new

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
  * 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).
@@ -9,11 +9,11 @@
  */
 
 
 #include <stddef.h>    /* size_t, ptrdiff_t */
 #include "zstd_v03.h"
-#include "error_private.h"
+#include "../common/error_private.h"
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
@@ -189,11 +189,11 @@
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 
-#endif // MEM_FORCE_MEMORY_ACCESS
+#endif /* MEM_FORCE_MEMORY_ACCESS */
 
 
 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
 {
     if (MEM_isLittleEndian())
@@ -217,10 +217,15 @@
         p[0] = (BYTE)val;
         p[1] = (BYTE)(val>>8);
     }
 }
 
+MEM_STATIC U32 MEM_readLE24(const void* memPtr)
+{
+    return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
+}
+
 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read32(memPtr);
     else
@@ -349,11 +354,11 @@
 #   if defined(_MSC_VER)   /* Visual */
     unsigned long r=0;
     _BitScanReverse ( &r, val );
     return (unsigned) r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
-    return 31 - __builtin_clz (val);
+    return __builtin_clz (val) ^ 31;
 #   else   /* Software version */
     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
     U32 v = val;
     unsigned r;
     v |= v >> 1;
@@ -2470,11 +2475,13 @@
 }
 
 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
-    memcpy(dst, src, srcSize);
+    if (srcSize > 0) {
+        memcpy(dst, src, srcSize);
+    }
     return srcSize;
 }
 
 
 /** ZSTD_decompressLiterals
@@ -2523,10 +2530,11 @@
     case IS_RAW:
         {
             const size_t litSize = (MEM_readLE32(istart) & 0xFFFFFF) >> 2;   /* no buffer issue : srcSize >= MIN_CBLOCK_SIZE */
             if (litSize > srcSize-11)   /* risk of reading too far with wildcopy */
             {
+                if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
                 if (litSize > srcSize-3) return ERROR(corruption_detected);
                 memcpy(dctx->litBuffer, istart, litSize);
                 dctx->litPtr = dctx->litBuffer;
                 dctx->litSize = litSize;
                 memset(dctx->litBuffer + dctx->litSize, 0, 8);
@@ -2682,15 +2690,15 @@
     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
     prevOffset = litLength ? seq->offset : seqState->prevOffset;
     seqState->prevOffset = seq->offset;
     if (litLength == MaxLL)
     {
-        U32 add = *dumps++;
+        const U32 add = dumps<de ? *dumps++ : 0;
         if (add < 255) litLength += add;
-        else
+        else if (dumps + 3 <= de)
         {
-            litLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
+            litLength = MEM_readLE24(dumps);
             dumps += 3;
         }
         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
     }
 
@@ -2712,15 +2720,15 @@
 
     /* MatchLength */
     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
     if (matchLength == MaxML)
     {
-        U32 add = *dumps++;
+        const U32 add = dumps<de ? *dumps++ : 0;
         if (add < 255) matchLength += add;
-        else
+        else if (dumps + 3 <= de)
         {
-            matchLength = MEM_readLE32(dumps) & 0xFFFFFF;  /* no pb : dumps is always followed by seq tables > 1 byte */
+            matchLength = MEM_readLE24(dumps);
             dumps += 3;
         }
         if (dumps >= de) dumps = de-1;   /* late correction, to avoid read overflow (data is now corrupted anyway) */
     }
     matchLength += MINMATCH;
@@ -2862,11 +2870,13 @@
         /* last literal segment */
         {
             size_t lastLLSize = litEnd - litPtr;
             if (litPtr > litEnd) return ERROR(corruption_detected);
             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
-            if (op != litPtr) memmove(op, litPtr, lastLLSize);
-            op += lastLLSize;
+            if (lastLLSize > 0) {
+                if (op != litPtr) memmove(op, litPtr, lastLLSize);
+                op += lastLLSize;
+            }
         }
     }
 
     return op-ostart;
 }