Revert "Support fixed address mmap without replacement"

This reverts commit 0f68ff5c92924deb9401ce66458e67f250ccde74.

diff --git a/Zend/zend_alloc.c b/Zend/zend_alloc.c
index 8eec54c6f703fcb37328462e91f669328c10b3a8..11691d837759d2d1b0812431047951606b8a5cf1 100644 (file)
--- a/Zend/zend_alloc.c
+++ b/Zend/zend_alloc.c
@@ -423,13 +423,8 @@ static void *zend_mm_mmap_fixed(void *addr, size_t size)
 #ifdef _WIN32
        return VirtualAlloc(addr, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
 #else
-       int flags = MAP_PRIVATE | MAP_ANON;
-#ifdef MAP_FIXED_NOREPLACE
-       flags |= MAP_FIXED_NOREPLACE;
-#elif defined MAP_EXCL
-       flags |= MAP_FIXED | MAP_EXCL;
-#endif
-       void *ptr = mmap(addr, size, PROT_READ | PROT_WRITE, flags /*| MAP_POPULATE | MAP_HUGETLB*/, -1, 0);
+       /* MAP_FIXED leads to discarding of the old mapping, so it can't be used. */
+       void *ptr = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON /*| MAP_POPULATE | MAP_HUGETLB*/, -1, 0);
 
        if (ptr == MAP_FAILED) {
 #if ZEND_MM_ERROR