diff --git a/include/llvm/Config/config.h.cmake b/include/llvm/Config/config.h.cmake
index b0b81042051..94870834313 100644
--- a/include/llvm/Config/config.h.cmake
+++ b/include/llvm/Config/config.h.cmake
@@ -468,9 +468,6 @@
 /* Define to 1 if the system has the type `u_int64_t'. */
 #cmakedefine HAVE_U_INT64_T ${HAVE_U_INT64_T}
 
-/* Define to 1 if you have the <sanitizer/msan_interface.h> header file. */
-#cmakedefine HAVE_SANITIZER_MSAN_INTERFACE_H ${HAVE_SANITIZER_MSAN_INTERFACE_H}
-
 /* Define to 1 if you have the <valgrind/valgrind.h> header file. */
 #cmakedefine HAVE_VALGRIND_VALGRIND_H ${HAVE_VALGRIND_VALGRIND_H}
 
diff --git a/include/llvm/Config/llvm-config.h.cmake b/include/llvm/Config/llvm-config.h.cmake
index fbc3040dd2e..b2be7b4f072 100644
--- a/include/llvm/Config/llvm-config.h.cmake
+++ b/include/llvm/Config/llvm-config.h.cmake
@@ -124,4 +124,7 @@
 /* Minor version of the LLVM API */
 #cmakedefine LLVM_VERSION_MINOR ${LLVM_VERSION_MINOR}
 
+/* Define to 1 if you have the <sanitizer/msan_interface.h> header file. */
+#cmakedefine LLVM_HAVE_MSAN_ANNOTATIONS ${HAVE_SANITIZER_MSAN_INTERFACE_H}
+
 #endif
diff --git a/include/llvm/Support/Compiler.h b/include/llvm/Support/Compiler.h
index 6ca86bdd502..61c40f4a19a 100644
--- a/include/llvm/Support/Compiler.h
+++ b/include/llvm/Support/Compiler.h
@@ -15,7 +15,7 @@
 #ifndef LLVM_SUPPORT_COMPILER_H
 #define LLVM_SUPPORT_COMPILER_H
 
-#include "llvm/Config/config.h"
+#include "llvm/Config/llvm-config.h"
 
 #ifndef __has_feature
 # define __has_feature(x) 0
@@ -295,12 +295,11 @@
 # define LLVM_FUNCTION_NAME __func__
 #endif
 
-/// \macro LLVM_ENABLE_MSAN_ANNOTATIONS
-/// \brief Are MemorySanitizer annotations available.
-#if defined(HAVE_SANITIZER_MSAN_INTERFACE_H)
+#if defined(LLVM_HAVE_MSAN_ANNOTATIONS)
 # include <sanitizer/msan_interface.h>
 #else
 # define __msan_allocated_memory(p, size)
+# define __msan_unpoison(p, size)
 #endif
 
 /// \macro LLVM_MEMORY_SANITIZER_BUILD
@@ -311,6 +310,14 @@
 # define LLVM_MEMORY_SANITIZER_BUILD 0
 #endif
 
+/// \macro LLVM_ADDRESS_SANITIZER_BUILD
+/// \brief Whether LLVM itself is built with AddressSanitizer instrumentation.
+#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
+# define LLVM_ADDRESS_SANITIZER_BUILD 1
+#else
+# define LLVM_ADDRESS_SANITIZER_BUILD 0
+#endif
+
 /// \macro LLVM_IS_UNALIGNED_ACCESS_FAST
 /// \brief Is unaligned memory access fast on the host machine.
 ///
diff --git a/lib/Support/Allocator.cpp b/lib/Support/Allocator.cpp
index b4fdc1e1bc1..e269cf997a0 100644
--- a/lib/Support/Allocator.cpp
+++ b/lib/Support/Allocator.cpp
@@ -104,8 +104,8 @@ void *BumpPtrAllocator::Allocate(size_t Size, size_t Alignment) {
   if (Ptr + Size <= End) {
     CurPtr = Ptr + Size;
     // Update the allocation point of this memory block in MemorySanitizer.
-    // Without this, MemorySanitizer reports for values originating from it will
-    // point to the allocation point of the entire slab.
+    // Without this, MemorySanitizer messages for values originated from here
+    // will point to the allocation of the entire slab.
     __msan_allocated_memory(Ptr, Size);
     return Ptr;
   }
diff --git a/lib/Support/Unix/Program.inc b/lib/Support/Unix/Program.inc
index c384316e209..117151c91d8 100644
--- a/lib/Support/Unix/Program.inc
+++ b/lib/Support/Unix/Program.inc
@@ -17,6 +17,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/FileSystem.h"
 #include <llvm/Config/config.h>
 #if HAVE_SYS_STAT_H
@@ -164,12 +165,16 @@ static void SetMemoryLimits (unsigned size)
   setrlimit (RLIMIT_RSS, &r);
 #endif
 #ifdef RLIMIT_AS  // e.g. NetBSD doesn't have it.
+  // Don't set virtual memory limit if built with any Sanitizer. They need 80Tb
+  // of virtual memory for shadow memory mapping.
+#if !LLVM_MEMORY_SANITIZER_BUILD && !LLVM_ADDRESS_SANITIZER_BUILD
   // Virtual memory.
   getrlimit (RLIMIT_AS, &r);
   r.rlim_cur = limit;
   setrlimit (RLIMIT_AS, &r);
 #endif
 #endif
+#endif
 }
 
 bool
diff --git a/lib/Target/X86/X86JITInfo.cpp b/lib/Target/X86/X86JITInfo.cpp
index cca391f647a..0a4accee990 100644
--- a/lib/Target/X86/X86JITInfo.cpp
+++ b/lib/Target/X86/X86JITInfo.cpp
@@ -351,6 +351,9 @@ static
 void LLVM_ATTRIBUTE_USED
 X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) {
   intptr_t *RetAddrLoc = &StackPtr[1];
+  // We are reading raw stack data here. Tell MemorySanitizer that it is
+  // sufficiently initialized.
+  __msan_unpoison(RetAddrLoc, sizeof(*RetAddrLoc));
   assert(*RetAddrLoc == RetAddr &&
          "Could not find return address on the stack!");