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Prevent HashTable compaction below HT_MIN_SIZE (this may lead to hash collisions).

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This commit is contained in:
Dmitry Stogov 2015-09-02 13:03:31 +03:00
parent 9c35f87e9a
commit a2f8a7675b
2 changed files with 18 additions and 14 deletions
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16
ext/opcache/zend_persist.c
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@ -94,13 +94,15 @@ static void zend_hash_persist(HashTable *ht, zend_persist_func_t pPersistElement
/* compact table */
void *old_data = HT_GET_DATA_ADDR(ht);
Bucket *old_buckets = ht->arData;
int32_t hash_size = -(int32_t)ht->nTableMask;
int32_t hash_size;
if (ht->nNumUsed <= HT_MIN_SIZE) {
hash_size = HT_MIN_SIZE;
} else {
hash_size = -(int32_t)ht->nTableMask;
while (hash_size >> 1 > ht->nNumUsed) {
hash_size >>= 1;
}
if (hash_size < -HT_MIN_MASK) {
hash_size = -HT_MIN_MASK;
}
ht->nTableMask = -hash_size;
ZEND_ASSERT(((zend_uintptr_t)ZCG(mem) & 0x7) == 0); /* should be 8 byte aligned */
@ -174,13 +176,15 @@ static void zend_hash_persist_immutable(HashTable *ht)
/* compact table */
void *old_data = HT_GET_DATA_ADDR(ht);
Bucket *old_buckets = ht->arData;
int32_t hash_size = -(int32_t)ht->nTableMask;
int32_t hash_size;
if (ht->nNumUsed <= HT_MIN_SIZE) {
hash_size = HT_MIN_SIZE;
} else {
hash_size = -(int32_t)ht->nTableMask;
while (hash_size >> 1 > ht->nNumUsed) {
hash_size >>= 1;
}
if (hash_size < -HT_MIN_MASK) {
hash_size = -HT_MIN_MASK;
}
ht->nTableMask = -hash_size;
ZEND_ASSERT(((zend_uintptr_t)ZCG(mem) & 0x7) == 0); /* should be 8 byte aligned */

4
ext/opcache/zend_persist_calc.c
View file

@ -65,8 +65,8 @@ static void zend_hash_persist_calc(HashTable *ht, void (*pPersistElement)(zval *
while (hash_size >> 1 > ht->nNumUsed) {
hash_size >>= 1;
}
if (hash_size < -HT_MIN_MASK) {
hash_size = -HT_MIN_MASK;
if (hash_size < HT_MIN_SIZE) {
hash_size = HT_MIN_SIZE;
}
ADD_SIZE(hash_size * sizeof(uint32_t) + ht->nNumUsed * sizeof(Bucket));
} else {