Index: libcxx/include/atomic
===================================================================
--- libcxx/include/atomic
+++ libcxx/include/atomic
@@ -1685,16 +1685,10 @@
 
 #ifndef _LIBCPP_CXX03_LANG
     __atomic_base(const __atomic_base&) = delete;
-    __atomic_base& operator=(const __atomic_base&) = delete;
-    __atomic_base& operator=(const __atomic_base&) volatile = delete;
 #else
 private:
     _LIBCPP_INLINE_VISIBILITY
     __atomic_base(const __atomic_base&);
-    _LIBCPP_INLINE_VISIBILITY
-    __atomic_base& operator=(const __atomic_base&);
-    _LIBCPP_INLINE_VISIBILITY
-    __atomic_base& operator=(const __atomic_base&) volatile;
 #endif
 };
 
@@ -1804,6 +1798,18 @@
     _LIBCPP_INLINE_VISIBILITY
     _Tp operator=(_Tp __d) _NOEXCEPT
         {__base::store(__d); return __d;}
+
+    // delete explicitly in the most derived class to fix the Bug 41784
+#ifndef _LIBCPP_CXX03_LANG
+    atomic& operator=(const atomic&) = delete;
+    atomic& operator=(const atomic&) volatile = delete;
+#else
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    atomic& operator=(const atomic&);
+    _LIBCPP_INLINE_VISIBILITY
+    atomic& operator=(const atomic&) volatile;
+#endif
 };
 
 // atomic<T*>
@@ -1866,6 +1872,18 @@
     _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
     _LIBCPP_INLINE_VISIBILITY
     _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
+
+    // delete explicitly in the most derived class to fix the Bug 41784
+#ifndef _LIBCPP_CXX03_LANG
+    atomic& operator=(const atomic&) = delete;
+    atomic& operator=(const atomic&) volatile = delete;
+#else
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    atomic& operator=(const atomic&);
+    _LIBCPP_INLINE_VISIBILITY
+    atomic& operator=(const atomic&) volatile;
+#endif
 };
 
 // atomic_is_lock_free
Index: libcxx/test/std/atomics/atomics.types.operations/atomics.types.operations.req/copy.assign.ptr.volatile.fail.cpp
===================================================================
--- /dev/null
+++ libcxx/test/std/atomics/atomics.types.operations/atomics.types.operations.req/copy.assign.ptr.volatile.fail.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <atomic>
+
+// std::atomic
+
+// atomic& operator=( const atomic& ) volatile = delete;
+
+#include <atomic>
+
+int
+main()
+{
+    volatile std::atomic<int*> obj1;
+    std::atomic<int*> obj2;
+    obj1 = obj2; // expected-error {{overload resolution selected deleted operator '='}}
+}
Index: libcxx/test/std/atomics/atomics.types.operations/atomics.types.operations.req/copy.assign.volatile.fail.cpp
===================================================================
--- /dev/null
+++ libcxx/test/std/atomics/atomics.types.operations/atomics.types.operations.req/copy.assign.volatile.fail.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <atomic>
+
+// std::atomic
+
+// atomic& operator=( const atomic& ) volatile = delete;
+
+#include <atomic>
+
+int
+main()
+{
+    volatile std::atomic<int> obj1;
+    std::atomic<int> obj2;
+    obj1 = obj2; // expected-error {{overload resolution selected deleted operator '='}}
+}