diff --git a/interpreter/llvm/src/lib/ExecutionEngine/SectionMemoryManager.cpp b/interpreter/llvm/src/lib/ExecutionEngine/SectionMemoryManager.cpp
index 1ad5f1740115b..08b54827e33db 100644
--- a/interpreter/llvm/src/lib/ExecutionEngine/SectionMemoryManager.cpp
+++ b/interpreter/llvm/src/lib/ExecutionEngine/SectionMemoryManager.cpp
@@ -83,6 +83,8 @@ uint8_t *SectionMemoryManager::allocateSection(MemoryGroup &MemGroup,
   //
   // FIXME: Initialize the Near member for each memory group to avoid
   // interleaving.
+  // Note: this would not be sufficient as the Near member is just a hint
+  // to mmap.
   std::error_code ec;
   sys::MemoryBlock MB = sys::Memory::allocateMappedMemory(RequiredSize,
                                                           &MemGroup.Near,
@@ -94,6 +96,35 @@ uint8_t *SectionMemoryManager::allocateSection(MemoryGroup &MemGroup,
     return nullptr;
   }
 
+  // To be sure that there is no interleaving, enforce the monotonic decrease
+  // of the memory adddress.  This is required by libgcc's _Unwind_Find_FDE
+  // which does a linear search (of the top level dwarf objects) and note in the code
+  // "Note that pc_begin is sorted descending, and we expect objects to be
+  // non-overlapping. "
+  if (MemGroup.Near.base() && (size_t)MB.base() > (size_t)MemGroup.Near.base()) {
+    SmallVector<sys::MemoryBlock, 16> MemToDelete;
+    while ((size_t)MB.base() > (size_t)MemGroup.Near.base()) {
+      // Hold on to the memory until we get an acceptable one
+      // just so that we are not given it back.
+      MemToDelete.push_back(MB);
+      MB = sys::Memory::allocateMappedMemory(RequiredSize,
+                                             &MemGroup.Near,
+                                             sys::Memory::MF_READ |
+                                               sys::Memory::MF_WRITE,
+                                             ec);
+      if (ec) {
+        for (sys::MemoryBlock &Block : MemToDelete) {
+          sys::Memory::releaseMappedMemory(Block);
+        }
+        // FIXME: Add error propagation to the interface.
+        return nullptr;
+      }
+    }
+    for (sys::MemoryBlock &Block : MemToDelete) {
+      sys::Memory::releaseMappedMemory(Block);
+    }
+  }
+
   // Save this address as the basis for our next request
   MemGroup.Near = MB;