Index: compiler-rt/lib/scudo/standalone/mem_map_base.h
===================================================================
--- compiler-rt/lib/scudo/standalone/mem_map_base.h
+++ compiler-rt/lib/scudo/standalone/mem_map_base.h
@@ -25,6 +25,7 @@
   // only a suggestion to the system.
   bool map(uptr Addr, uptr Size, const char *Name, uptr Flags = 0) {
     DCHECK(!isAllocated());
+    DCHECK_EQ(Flags & ~AllowedMapFlags, 0);
     return invokeImpl(&Derived::mapImpl, Addr, Size, Name, Flags);
   }
 
@@ -42,6 +43,7 @@
   bool remap(uptr Addr, uptr Size, const char *Name, uptr Flags = 0) {
     DCHECK(isAllocated());
     DCHECK((Addr >= getBase()) && (Addr + Size <= getBase() + getCapacity()));
+    DCHECK_EQ(Flags & ~AllowedMapFlags, 0);
     return invokeImpl(&Derived::remapImpl, Addr, Size, Name, Flags);
   }
 
@@ -50,6 +52,7 @@
   void setMemoryPermission(uptr Addr, uptr Size, uptr Flags) {
     DCHECK(isAllocated());
     DCHECK((Addr >= getBase()) && (Addr + Size <= getBase() + getCapacity()));
+    DCHECK_EQ(Flags & ~MAP_NOACCESS, 0);
     return static_cast<Derived *>(this)->setMemoryPermissionImpl(Addr, Size,
                                                                  Flags);
   }
@@ -80,6 +83,11 @@
   R invokeImpl(R (Derived::*MemFn)(Args...), Args... args) {
     return (static_cast<Derived *>(this)->*MemFn)(args...);
   }
+
+private:
+  static const uptr AllowedMapFlags = MAP_ALLOWNOMEM | MAP_NOACCESS |
+                                      MAP_MEMTAG | MAP_PRECOMMIT |
+                                      MAP_RESIZABLE;
 };
 
 // `ReservedMemory` is a special memory handle which can be viewed as a page
@@ -96,6 +104,7 @@
   // Reserve a chunk of memory at a suggested address.
   bool create(uptr Addr, uptr Size, const char *Name, uptr Flags = 0) {
     DCHECK(!isCreated());
+    DCHECK_EQ(Flags & ~MAP_ALLOWNOMEM, 0);
     return invokeImpl(&Derived::createImpl, Addr, Size, Name, Flags);
   }