diff --git a/ntoskrnl/cache/section/newmm.h b/ntoskrnl/cache/section/newmm.h
index d5f9998993..e567d7121e 100644
--- a/ntoskrnl/cache/section/newmm.h
+++ b/ntoskrnl/cache/section/newmm.h
@@ -21,7 +21,7 @@
 
 #define MM_SEGMENT_FINALIZE (0x40000000)
 
-#define RMAP_SEGMENT_MASK ~((ULONG_PTR)0xff)
+#define RMAP_SEGMENT_MASK ~((ULONG_PTR)0x7ff)
 #define RMAP_IS_SEGMENT(x) (((ULONG_PTR)(x) & RMAP_SEGMENT_MASK) == RMAP_SEGMENT_MASK)
 
 #define MIN(x,y) (((x)<(y))?(x):(y))
diff --git a/ntoskrnl/cache/section/sptab.c b/ntoskrnl/cache/section/sptab.c
index 454fb25af4..82791eec69 100644
--- a/ntoskrnl/cache/section/sptab.c
+++ b/ntoskrnl/cache/section/sptab.c
@@ -360,6 +360,11 @@ MmSetSectionAssociation(PFN_NUMBER Page,
     ASSERT(PageTable);
 
     ActualOffset = (ULONG)(Offset->QuadPart - PageTable->FileOffset.QuadPart);
+    if (((ActualOffset >> PAGE_SHIFT) & ~0xff) != 0)
+    {
+        DPRINT1("MmSetSectionAssociation with large offset 0x%lx for Page 0x%lx\n",
+                ActualOffset, Page);
+    }
     MmInsertRmap(Page,
                  (PEPROCESS)PageTable,
                  (PVOID)(RMAP_SEGMENT_MASK | (ActualOffset >> PAGE_SHIFT)));
diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index d5094e0915..a079afef53 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -237,7 +237,7 @@ typedef struct _MM_RMAP_ENTRY
    PEPROCESS Process;
    PVOID Address;
 #if DBG
-   PVOID Caller;
+   PVOID Backtrace[5];
 #endif
 }
 MM_RMAP_ENTRY, *PMM_RMAP_ENTRY;
diff --git a/ntoskrnl/mm/rmap.c b/ntoskrnl/mm/rmap.c
index 0064ba27da..b46a96b2ca 100644
--- a/ntoskrnl/mm/rmap.c
+++ b/ntoskrnl/mm/rmap.c
@@ -281,11 +281,10 @@ MmInsertRmap(PFN_NUMBER Page, PEPROCESS Process,
     new_entry->Address = Address;
     new_entry->Process = (PEPROCESS)Process;
 #if DBG
-#ifdef __GNUC__
-    new_entry->Caller = __builtin_return_address(0);
-#else
-    new_entry->Caller = _ReturnAddress();
-#endif
+    RtlCaptureStackBackTrace(1,
+                             RTL_NUMBER_OF(new_entry->Backtrace),
+                             new_entry->Backtrace,
+                             NULL);
 #endif
 
     if (
@@ -306,15 +305,27 @@ MmInsertRmap(PFN_NUMBER Page, PEPROCESS Process,
 #if DBG
     while (current_entry)
     {
-        if (current_entry->Address == new_entry->Address && current_entry->Process == new_entry->Process)
+        ASSERT(new_entry->Address == Address);
+        if (current_entry->Process == new_entry->Process)
         {
-            DbgPrint("MmInsertRmap tries to add a second rmap entry for address %p\n    current caller ",
-                     current_entry->Address);
-            DbgPrint("%p", new_entry->Caller);
-            DbgPrint("\n    previous caller ");
-            DbgPrint("%p", current_entry->Caller);
-            DbgPrint("\n");
-            KeBugCheck(MEMORY_MANAGEMENT);
+            if (RMAP_IS_SEGMENT(current_entry->Address) && RMAP_IS_SEGMENT(new_entry->Address) &&
+                ((ULONG_PTR)current_entry->Address & 0xff) == ((ULONG_PTR)new_entry->Address & 0xff))
+            {
+                DPRINT1("Segment RMAPs with same lower byte. %p vs %p\n",
+                        current_entry->Address,
+                        new_entry->Address);
+            }
+            if (current_entry->Address == new_entry->Address)
+            {
+                DbgPrint("MmInsertRmap tries to add a second rmap entry for address %p",
+                         current_entry->Address);
+                DbgPrint("\n    current caller ");
+                DbgPrint("%p %p %p %p %p", new_entry->Backtrace[0], new_entry->Backtrace[1], new_entry->Backtrace[2], new_entry->Backtrace[3], new_entry->Backtrace[4]);
+                DbgPrint("\n    previous caller ");
+                DbgPrint("%p %p %p %p %p", current_entry->Backtrace[0], current_entry->Backtrace[1], current_entry->Backtrace[2], current_entry->Backtrace[3], current_entry->Backtrace[4]);
+                DbgPrint("\n");
+                KeBugCheck(MEMORY_MANAGEMENT);
+            }
         }
         current_entry = current_entry->Next;
     }