From: Stella Lau <laus@fb.com>
Date: Thu, 27 Jul 2017 22:37:37 +0000 (-0700)
Subject: Add checks in initialization code
X-Git-Tag: v1.3.1^2~12^2~7^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=627621839cf39310793fc5c2358985929497d42b;p=thirdparty%2Fzstd.git

Add checks in initialization code
---

diff --git a/contrib/long_distance_matching/ldm.c b/contrib/long_distance_matching/ldm.c
index ff9d94d07..c2cdb21ed 100644
--- a/contrib/long_distance_matching/ldm.c
+++ b/contrib/long_distance_matching/ldm.c
@@ -111,13 +111,25 @@ struct LDM_hashTable {
 /**
  * Create a hash table that can contain size elements.
  * The number of buckets is determined by size >> HASH_BUCKET_SIZE_LOG.
+ *
+ * Returns NULL if table creation failed.
  */
 static LDM_hashTable *HASH_createTable(U32 size) {
   LDM_hashTable *table = malloc(sizeof(LDM_hashTable));
+  if (!table) return NULL;
+
   table->numBuckets = size >> HASH_BUCKET_SIZE_LOG;
   table->numEntries = size;
   table->entries = calloc(size, sizeof(LDM_hashEntry));
   table->bucketOffsets = calloc(size >> HASH_BUCKET_SIZE_LOG, sizeof(BYTE));
+
+  if (!table->entries || !table->bucketOffsets) {
+    free(table->bucketOffsets);
+    free(table->entries);
+    free(table);
+    return NULL;
+  }
+
   return table;
 }
 
@@ -566,9 +578,9 @@ static void LDM_putHashOfCurrentPosition(LDM_CCtx *cctx) {
   putHashOfCurrentPositionFromHash(cctx, hash);
 }
 
-void LDM_initializeCCtx(LDM_CCtx *cctx,
-                        const void *src, size_t srcSize,
-                        void *dst, size_t maxDstSize) {
+size_t LDM_initializeCCtx(LDM_CCtx *cctx,
+                          const void *src, size_t srcSize,
+                          void *dst, size_t maxDstSize) {
   cctx->isize = srcSize;
   cctx->maxOSize = maxDstSize;
 
@@ -590,16 +602,20 @@ void LDM_initializeCCtx(LDM_CCtx *cctx,
 #else
   cctx->hashTable = HASH_createTable(LDM_HASHTABLESIZE_U32);
 #endif
+
+  if (!cctx->hashTable) return 1;
+
   cctx->stats.minOffset = UINT_MAX;
   cctx->stats.windowSizeLog = LDM_WINDOW_SIZE_LOG;
   cctx->stats.hashTableSizeLog = LDM_MEMORY_USAGE;
 
-
   cctx->lastPosHashed = NULL;
 
   cctx->step = 1;   // Fixed to be 1 for now. Changing may break things.
   cctx->nextIp = cctx->ip + cctx->step;
   cctx->nextPosHashed = 0;
+
+  return 0;
 }
 
 void LDM_destroyCCtx(LDM_CCtx *cctx) {
@@ -726,7 +742,10 @@ size_t LDM_compress(const void *src, size_t srcSize,
   U64 forwardMatchLength = 0;
   U64 backwardsMatchLength = 0;
 
-  LDM_initializeCCtx(&cctx, src, srcSize, dst, maxDstSize);
+  if (LDM_initializeCCtx(&cctx, src, srcSize, dst, maxDstSize)) {
+    // Initialization failed.
+    return 0;
+  }
 
 #ifdef OUTPUT_CONFIGURATION
   LDM_outputConfiguration();
@@ -744,8 +763,8 @@ size_t LDM_compress(const void *src, size_t srcSize,
    * is less than the minimum match length), then stop searching for matches
    * and encode the final literals.
    */
-  while (LDM_findBestMatch(&cctx, &match, &forwardMatchLength,
-         &backwardsMatchLength) == 0) {
+  while (!LDM_findBestMatch(&cctx, &match, &forwardMatchLength,
+                           &backwardsMatchLength)) {
 
 #ifdef COMPUTE_STATS
     cctx.stats.numMatches++;
diff --git a/contrib/long_distance_matching/ldm.h b/contrib/long_distance_matching/ldm.h
index 456ec5aa4..4adadbd0a 100644
--- a/contrib/long_distance_matching/ldm.h
+++ b/contrib/long_distance_matching/ldm.h
@@ -82,6 +82,7 @@ typedef struct LDM_DCtx LDM_DCtx;
 
 /**
  *  Compresses src into dst.
+ *  Returns the compressed size if successful, 0 otherwise.
  *
  *  NB: This currently ignores maxDstSize and assumes enough space is available.
  *
@@ -113,10 +114,12 @@ size_t LDM_compress(const void *src, size_t srcSize,
  * Initialize the compression context.
  *
  * Allocates memory for the hash table.
+ *
+ * Returns 0 if successful, 1 otherwise.
  */
-void LDM_initializeCCtx(LDM_CCtx *cctx,
-                        const void *src, size_t srcSize,
-                        void *dst, size_t maxDstSize);
+size_t LDM_initializeCCtx(LDM_CCtx *cctx,
+                          const void *src, size_t srcSize,
+                          void *dst, size_t maxDstSize);
 
 /**
  * Frees up memory allocated in LDM_initializeCCtx().
diff --git a/contrib/long_distance_matching/ldm_common.c b/contrib/long_distance_matching/ldm_common.c
index 26b716a1b..8b34f8ad4 100644
--- a/contrib/long_distance_matching/ldm_common.c
+++ b/contrib/long_distance_matching/ldm_common.c
@@ -2,19 +2,29 @@
 
 #include "ldm.h"
 
+/**
+ * This function reads the header at the beginning of src and writes
+ * the compressed and decompressed size to compressedSize and
+ * decompressedSize.
+ *
+ * The header consists of 16 bytes: 8 bytes each in little-endian format
+ * of the compressed size and the decompressed size.
+ */
 void LDM_readHeader(const void *src, U64 *compressedSize,
                     U64 *decompressedSize) {
   const BYTE *ip = (const BYTE *)src;
   *compressedSize = MEM_readLE64(ip);
-  ip += sizeof(U64);
-  *decompressedSize = MEM_readLE64(ip);
-  // ip += sizeof(U64);
+  *decompressedSize = MEM_readLE64(ip + 8);
 }
 
+/**
+ * Writes the 16-byte header (8-bytes each of the compressedSize and
+ * decompressedSize in little-endian format) to memPtr.
+ */
 void LDM_writeHeader(void *memPtr, U64 compressedSize,
                      U64 decompressedSize) {
-  MEM_write64(memPtr, compressedSize);
-  MEM_write64((BYTE *)memPtr + 8, decompressedSize);
+  MEM_writeLE64(memPtr, compressedSize);
+  MEM_writeLE64((BYTE *)memPtr + 8, decompressedSize);
 }
 
 struct LDM_DCtx {
diff --git a/contrib/long_distance_matching/main.c b/contrib/long_distance_matching/main.c
index d55e01d32..72af54049 100644
--- a/contrib/long_distance_matching/main.c
+++ b/contrib/long_distance_matching/main.c
@@ -12,7 +12,7 @@
 #include "ldm.h"
 #include "zstd.h"
 
-// #define DECOMPRESS_AND_VERIFY
+#define DECOMPRESS_AND_VERIFY
 
 /* Compress file given by fname and output to oname.
  * Returns 0 if successful, error code otherwise.
@@ -186,9 +186,18 @@ static int compare(FILE *fp0, FILE *fp1) {
 }
 
 /* Verify the input file is the same as the decompressed file. */
-static void verify(const char *inpFilename, const char *decFilename) {
-  FILE *inpFp = fopen(inpFilename, "rb");
-  FILE *decFp = fopen(decFilename, "rb");
+static int verify(const char *inpFilename, const char *decFilename) {
+  FILE *inpFp, *decFp;
+
+  if ((inpFp = fopen(inpFilename, "rb")) == NULL) {
+    perror("Could not open input file\n");
+    return 1;
+  }
+
+  if ((decFp = fopen(decFilename, "rb")) == NULL) {
+    perror("Could not open decompressed file\n");
+    return 1;
+  }
 
   printf("verify : %s <-> %s\n", inpFilename, decFilename);
   {
@@ -202,6 +211,7 @@ static void verify(const char *inpFilename, const char *decFilename) {
 
 	fclose(decFp);
 	fclose(inpFp);
+  return 0;
 }
 #endif