Index: include/clang/Basic/Sanitizers.def
===================================================================
--- include/clang/Basic/Sanitizers.def
+++ include/clang/Basic/Sanitizers.def
@@ -135,6 +135,9 @@
 SANITIZER_GROUP("efficiency-all", Efficiency,
                 EfficiencyCacheFrag | EfficiencyWorkingSet)
 
+// Scudo hardened allocator
+SANITIZER("scudo", Scudo)
+
 // Magic group, containing all sanitizers. For example, "-fno-sanitize=all"
 // can be used to disable all the sanitizers.
 SANITIZER_GROUP("all", All, ~0ULL)
Index: include/clang/Driver/SanitizerArgs.h
===================================================================
--- include/clang/Driver/SanitizerArgs.h
+++ include/clang/Driver/SanitizerArgs.h
@@ -71,6 +71,7 @@
   bool needsEsanRt() const {
     return Sanitizers.hasOneOf(SanitizerKind::Efficiency);
   }
+  bool needsScudoRt() const { return Sanitizers.has(SanitizerKind::Scudo); }
 
   bool requiresPIE() const;
   bool needsUnwindTables() const;
Index: lib/Driver/SanitizerArgs.cpp
===================================================================
--- lib/Driver/SanitizerArgs.cpp
+++ lib/Driver/SanitizerArgs.cpp
@@ -30,7 +30,7 @@
   NeedsUbsanCxxRt = Vptr | CFI,
   NotAllowedWithTrap = Vptr,
   NotAllowedWithMinimalRuntime = Vptr,
-  RequiresPIE = DataFlow,
+  RequiresPIE = DataFlow | Scudo,
   NeedsUnwindTables = Address | Thread | Memory | DataFlow,
   SupportsCoverage = Address | KernelAddress | Memory | Leak | Undefined |
                      Integer | Nullability | DataFlow | Fuzzer | FuzzerNoLink,
@@ -173,7 +173,7 @@
 bool SanitizerArgs::needsUbsanRt() const {
   // All of these include ubsan.
   if (needsAsanRt() || needsMsanRt() || needsTsanRt() || needsDfsanRt() ||
-      needsLsanRt() || needsCfiDiagRt())
+      needsLsanRt() || needsCfiDiagRt() || needsScudoRt())
     return false;
 
   return (Sanitizers.Mask & NeedsUbsanRt & ~TrapSanitizers.Mask) ||
@@ -370,17 +370,14 @@
 
   // Warn about incompatible groups of sanitizers.
   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
-      std::make_pair(Address, Thread), std::make_pair(Address, Memory),
-      std::make_pair(Thread, Memory), std::make_pair(Leak, Thread),
-      std::make_pair(Leak, Memory), std::make_pair(KernelAddress, Address),
-      std::make_pair(KernelAddress, Leak),
-      std::make_pair(KernelAddress, Thread),
-      std::make_pair(KernelAddress, Memory),
-      std::make_pair(Efficiency, Address),
-      std::make_pair(Efficiency, Leak),
-      std::make_pair(Efficiency, Thread),
-      std::make_pair(Efficiency, Memory),
-      std::make_pair(Efficiency, KernelAddress)};
+      std::make_pair(Address, Thread | Memory),
+      std::make_pair(Thread, Memory),
+      std::make_pair(Leak, Thread | Memory),
+      std::make_pair(KernelAddress, Address| Leak | Thread | Memory),
+      std::make_pair(Efficiency, Address | Leak | Thread | Memory |
+                                 KernelAddress),
+      std::make_pair(Scudo, Address | Leak | Thread | Memory | KernelAddress |
+                            Efficiency) };
   for (auto G : IncompatibleGroups) {
     SanitizerMask Group = G.first;
     if (Kinds & Group) {
Index: lib/Driver/ToolChains/CommonArgs.cpp
===================================================================
--- lib/Driver/ToolChains/CommonArgs.cpp
+++ lib/Driver/ToolChains/CommonArgs.cpp
@@ -566,7 +566,6 @@
       if (!Args.hasArg(options::OPT_shared) && !TC.getTriple().isAndroid())
         HelperStaticRuntimes.push_back("asan-preinit");
     }
-
     if (SanArgs.needsUbsanRt()) {
       if (SanArgs.requiresMinimalRuntime()) {
         SharedRuntimes.push_back("ubsan_minimal");
@@ -574,6 +573,8 @@
         SharedRuntimes.push_back("ubsan_standalone");
       }
     }
+    if (SanArgs.needsScudoRt())
+      SharedRuntimes.push_back("scudo");
   }
 
   // The stats_client library is also statically linked into DSOs.
@@ -630,6 +631,11 @@
   }
   if (SanArgs.needsEsanRt())
     StaticRuntimes.push_back("esan");
+  if (SanArgs.needsScudoRt()) {
+    StaticRuntimes.push_back("scudo");
+    if (SanArgs.linkCXXRuntimes())
+      StaticRuntimes.push_back("scudo_cxx");
+  }
 }
 
 // Should be called before we add system libraries (C++ ABI, libstdc++/libc++,
Index: lib/Driver/ToolChains/Linux.cpp
===================================================================
--- lib/Driver/ToolChains/Linux.cpp
+++ lib/Driver/ToolChains/Linux.cpp
@@ -845,9 +845,10 @@
     Res |= SanitizerKind::Memory;
   if (IsX86_64 || IsMIPS64)
     Res |= SanitizerKind::Efficiency;
-  if (IsX86 || IsX86_64) {
+  if (IsX86 || IsX86_64)
     Res |= SanitizerKind::Function;
-  }
+  if (IsX86_64 || IsMIPS64 || IsAArch64 || IsX86 || IsArmArch)
+    Res |= SanitizerKind::Scudo;
   return Res;
 }
 
Index: lib/Lex/PPMacroExpansion.cpp
===================================================================
--- lib/Lex/PPMacroExpansion.cpp
+++ lib/Lex/PPMacroExpansion.cpp
@@ -1138,6 +1138,7 @@
       .Case("dataflow_sanitizer", LangOpts.Sanitize.has(SanitizerKind::DataFlow))
       .Case("efficiency_sanitizer",
             LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency))
+      .Case("scudo", LangOpts.Sanitize.hasOneOf(SanitizerKind::Scudo))
       // Objective-C features
       .Case("objc_arr", LangOpts.ObjCAutoRefCount) // FIXME: REMOVE?
       .Case("objc_arc", LangOpts.ObjCAutoRefCount)
Index: test/Driver/fsanitize.c
===================================================================
--- test/Driver/fsanitize.c
+++ test/Driver/fsanitize.c
@@ -600,3 +600,29 @@
 // CHECK-CFI-NOICALL-MINIMAL: "-fsanitize=cfi-derived-cast,cfi-unrelated-cast,cfi-nvcall,cfi-vcall"
 // CHECK-CFI-NOICALL-MINIMAL: "-fsanitize-trap=cfi-derived-cast,cfi-unrelated-cast,cfi-nvcall,cfi-vcall"
 // CHECK-CFI-NOICALL-MINIMAL: "-fsanitize-minimal-runtime"
+
+// RUN: %clang -target aarch64-linux-gnu -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO
+// RUN: %clang -target arm-linux-androideabi -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO
+// RUN: %clang -target i386-linux-gnu -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO
+// CHECK-SCUDO: "-fsanitize=scudo"
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-PIE
+// RUN: %clang -target arm-linux-androideabi -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-PIE
+// CHECK-SCUDO-PIE: "-mrelocation-model" "pic" "-pic-level" "2" "-pic-is-pie"
+// CHECK-SCUDO-PIE: "-pie"
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,undefined %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-UBSAN
+// CHECK-SCUDO-UBSAN: "-fsanitize={{.*}}scudo"
+
+// RUN: %clang -target powerpc-unknown-linux -fsanitize=scudo %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-SCUDO
+// CHECK-NO-SCUDO: unsupported option
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,address  %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-ASAN
+// CHECK-SCUDO-ASAN: error: invalid argument '-fsanitize=scudo' not allowed with '-fsanitize=address'
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,leak  %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-LSAN
+// CHECK-SCUDO-LSAN: error: invalid argument '-fsanitize=scudo' not allowed with '-fsanitize=leak'
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,memory  %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-MSAN
+// CHECK-SCUDO-MSAN: error: invalid argument '-fsanitize=scudo' not allowed with '-fsanitize=memory'
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=scudo,thread  %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SCUDO-TSAN
+// CHECK-SCUDO-TSAN: error: invalid argument '-fsanitize=scudo' not allowed with '-fsanitize=thread'
Index: test/Driver/sanitizer-ld.c
===================================================================
--- test/Driver/sanitizer-ld.c
+++ test/Driver/sanitizer-ld.c
@@ -644,3 +644,53 @@
 //
 // CHECK-ESAN-LINUX: "{{(.*[^-.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
 // CHECK-ESAN-LINUX: libclang_rt.esan-x86_64.a
+
+// RUN: %clang -fsanitize=scudo %s -### -o %t.o 2>&1 \
+// RUN:     -target i386-unknown-linux -fuse-ld=ld \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-SCUDO-LINUX %s
+// CHECK-SCUDO-LINUX: "{{.*}}ld{{(.exe)?}}"
+// CHECK-SCUDO-LINUX: "-pie"
+// CHECK-SCUDO-LINUX: "-whole-archive" "{{.*}}libclang_rt.scudo-i386.a" "-no-whole-archive"
+// CHECK-SCUDO-LINUX-NOT: "-lstdc++"
+// CHECK-SCUDO-LINUX: "-lpthread"
+// CHECK-SCUDO-LINUX: "-ldl"
+
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.so -shared 2>&1 \
+// RUN:     -target i386-unknown-linux -fuse-ld=ld -fsanitize=scudo -shared-libsan \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-SCUDO-SHARED-LINUX %s
+//
+// CHECK-SCUDO-SHARED-LINUX: "{{(.*[^-.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "-lc"
+// CHECK-SCUDO-SHARED-LINUX-NOT: libclang_rt.scudo-i386.a"
+// CHECK-SCUDO-SHARED-LINUX: libclang_rt.scudo-i386.so"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "-lpthread"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "-lrt"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "-ldl"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "-export-dynamic"
+// CHECK-SCUDO-SHARED-LINUX-NOT: "--dynamic-list"
+
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     -target arm-linux-androideabi -fuse-ld=ld -fsanitize=scudo \
+// RUN:     --sysroot=%S/Inputs/basic_android_tree/sysroot \
+// RUN:   | FileCheck --check-prefix=CHECK-SCUDO-ANDROID %s
+//
+// CHECK-SCUDO-ANDROID: "{{(.*[^.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
+// CHECK-SCUDO-ANDROID-NOT: "-lc"
+// CHECK-SCUDO-ANDROID: "-pie"
+// CHECK-SCUDO-ANDROID-NOT: "-lpthread"
+// CHECK-SCUDO-ANDROID: libclang_rt.scudo-arm-android.so"
+// CHECK-SCUDO-ANDROID-NOT: "-lpthread"
+
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     -target arm-linux-androideabi -fuse-ld=ld -fsanitize=scudo \
+// RUN:     --sysroot=%S/Inputs/basic_android_tree/sysroot \
+// RUN:     -static-libsan \
+// RUN:   | FileCheck --check-prefix=CHECK-SCUDO-ANDROID-STATIC %s
+// CHECK-SCUDO-ANDROID-STATIC: "{{(.*[^.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
+// CHECK-SCUDO-ANDROID-STATIC: "-pie"
+// CHECK-SCUDO-ANDROID-STATIC: "-whole-archive" "{{.*}}libclang_rt.scudo-arm-android.a" "-no-whole-archive"
+// CHECK-SCUDO-ANDROID-STATIC-NOT: "-lstdc++"
+// CHECK-SCUDO-ANDROID-STATIC: "-lpthread"