diff --git a/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td b/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
index 77820aeea30c..e04649cc8cb7 100644
--- a/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
+++ b/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
@@ -394,6 +394,10 @@ let ParentPackage = Security in {
   def FloatLoopCounter : Checker<"FloatLoopCounter">,
     HelpText<"Warn on using a floating point value as a loop counter (CERT: FLP30-C, FLP30-CPP)">,
     DescFile<"CheckSecuritySyntaxOnly.cpp">;
+
+  def MmapWriteExecChecker : Checker<"MmapWriteExec">,
+    HelpText<"Check if mmap() call is not both writable and executable">,
+    DescFile<"MmapWriteExecChecker.cpp">;
 }
 
 let ParentPackage = SecurityAlpha in {
diff --git a/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt b/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
index 7ab9c6114eae..1137032aacc1 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
+++ b/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
@@ -50,6 +50,7 @@ add_clang_library(clangStaticAnalyzerCheckers
   MallocOverflowSecurityChecker.cpp
   MallocSizeofChecker.cpp
   MisusedMovedObjectChecker.cpp
+  MmapWriteExecChecker.cpp
   MPI-Checker/MPIBugReporter.cpp
   MPI-Checker/MPIChecker.cpp
   MPI-Checker/MPIFunctionClassifier.cpp
diff --git a/clang/lib/StaticAnalyzer/Checkers/MmapWriteExecChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MmapWriteExecChecker.cpp
new file mode 100644
index 000000000000..5dcac2018068
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/MmapWriteExecChecker.cpp
@@ -0,0 +1,75 @@
+// MmapWriteExecChecker.cpp - Check for the prot argument -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This checker tests the 3rd argument of mmap's calls to check if
+// it is writable and executable in the same time. It's somehow
+// an optional checker since for example in JIT libraries it is pretty common.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+
+using namespace clang;
+using namespace ento;
+using llvm::APSInt;
+
+namespace {
+class MmapWriteExecChecker : public Checker<check::PreCall> {
+  CallDescription MmapFn;
+  static int ProtWrite;
+  static int ProtExec;
+  mutable std::unique_ptr<BugType> BT;
+public:
+  MmapWriteExecChecker() : MmapFn("mmap", 6) {}
+  void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
+};
+}
+
+int MmapWriteExecChecker::ProtWrite = 0x02;
+int MmapWriteExecChecker::ProtExec  = 0x04;
+
+void MmapWriteExecChecker::checkPreCall(const CallEvent &Call,
+                                         CheckerContext &C) const {
+  if (Call.isCalled(MmapFn)) {
+    llvm::Triple Triple = C.getASTContext().getTargetInfo().getTriple();
+
+    if (Triple.isOSGlibc())
+      ProtExec = 0x01;
+
+    SVal ProtVal = Call.getArgSVal(2); 
+    Optional<nonloc::ConcreteInt> ProtLoc = ProtVal.getAs<nonloc::ConcreteInt>();
+    int64_t Prot = ProtLoc->getValue().getSExtValue();
+
+    if ((Prot & (ProtWrite | ProtExec)) == (ProtWrite | ProtExec)) {
+      if (!BT)
+        BT.reset(new BugType(this, "W^X check fails, Write Exec prot flags set", "Security"));
+
+      ExplodedNode *N = C.generateNonFatalErrorNode();
+      if (!N)
+        return;
+
+      auto Report = llvm::make_unique<BugReport>(
+          *BT, "Both PROT_WRITE and PROT_EXEC flags had been set. It can "
+               "lead to exploitable memory regions, overwritten with malicious code"
+         , N);
+      Report->addRange(Call.getArgSourceRange(2));
+      C.emitReport(std::move(Report));
+    }
+  }
+}
+
+void ento::registerMmapWriteExecChecker(CheckerManager &mgr) {
+  mgr.registerChecker<MmapWriteExecChecker>();
+}
diff --git a/clang/test/Analysis/mmap-writeexec.c b/clang/test/Analysis/mmap-writeexec.c
new file mode 100644
index 000000000000..071eb2a397ef
--- /dev/null
+++ b/clang/test/Analysis/mmap-writeexec.c
@@ -0,0 +1,27 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=security.MmapWriteExec -verify %s
+
+#define PROT_READ   0x01
+#define PROT_WRITE  0x02
+#define PROT_EXEC   0x04
+#define MAP_PRIVATE 0x0002
+#define MAP_ANON    0x1000
+#define MAP_FIXED   0x0010
+#define NULL        ((void *)0)
+
+typedef __typeof(sizeof(int)) size_t;
+void *mmap(void *, size_t, int, int, int, long);
+
+void f1()
+{
+  void *a = mmap(NULL, 16, PROT_READ | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0); // no-warning
+  void *b = mmap(a, 16, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_ANON, -1, 0); // no-warning
+  void *c = mmap(NULL, 32, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0); // expected-warning{{Both PROT_WRITE and PROT_EXEC flags had been set. It can lead to exploitable memory regions, overwritten with malicious code}}
+}
+
+void f2()
+{
+  void *(*callm)(void *, size_t, int, int, int, long);
+  callm = mmap;
+  int prot = PROT_WRITE | PROT_EXEC;
+  (void)callm(NULL, 1024, prot, MAP_PRIVATE | MAP_ANON, -1, 0); // expected-warning{{Both PROT_WRITE and PROT_EXEC flags had been set. It can lead to exploitable memory regions, overwritten with malicious code}}
+}