Index: llvm/include/llvm/BinaryFormat/ELF.h
===================================================================
--- llvm/include/llvm/BinaryFormat/ELF.h
+++ llvm/include/llvm/BinaryFormat/ELF.h
@@ -1308,6 +1308,13 @@
 enum {
   GNU_PROPERTY_STACK_SIZE = 1,
   GNU_PROPERTY_NO_COPY_ON_PROTECTED = 2,
+  GNU_PROPERTY_X86_FEATURE_1_AND = 0xc0000002
+};
+
+// CET properties
+enum {
+  GNU_PROPERTY_X86_FEATURE_1_IBT = 1 << 0,
+  GNU_PROPERTY_X86_FEATURE_1_SHSTK = 1 << 1
 };
 
 // AMDGPU specific notes.
Index: llvm/lib/Target/X86/X86AsmPrinter.cpp
===================================================================
--- llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -19,6 +19,7 @@
 #include "X86InstrInfo.h"
 #include "X86MachineFunctionInfo.h"
 #include "llvm/BinaryFormat/COFF.h"
+#include "llvm/BinaryFormat/ELF.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
@@ -539,6 +540,45 @@
 void X86AsmPrinter::EmitStartOfAsmFile(Module &M) {
   const Triple &TT = TM.getTargetTriple();
 
+  if (TT.isOSBinFormatELF()) {
+    // Assemble feature flags that may require creation of a note section.
+    char FeatureFlagsAnd = 0;
+    if (M.getModuleFlag("cf-protection-branch"))
+      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_IBT;
+    if (M.getModuleFlag("cf-protection-return"))
+      FeatureFlagsAnd |= ELF::GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+
+    if (FeatureFlagsAnd) {
+      // Emit a .note.gnu.property section with the flags.
+      MCSection *Cur = OutStreamer->getCurrentSectionOnly();
+      MCSection *Nt = (MCSection *)MMI->getContext().getELFSection(
+          ".note.gnu.property", ELF::SHT_NOTE, ELF::SHF_ALLOC);
+      int WordSize = TT.isArch64Bit() ? 8 : 4;
+      assert((TT.isArch32Bit() || WordSize == 8) &&
+             "CFProtection used on invalid architecture");
+      OutStreamer->SwitchSection(Nt);
+
+      // Emitting note header.
+      EmitAlignment(WordSize == 4 ? 2 : 3);
+      OutStreamer->EmitIntValue(4, 4 /*size*/); // data size for "GNU\0"
+      OutStreamer->EmitIntValue(8 + WordSize, 4 /*size*/); // Elf_Prop size
+      OutStreamer->EmitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4 /*size*/);
+      OutStreamer->EmitIntValue('G', 1 /*size*/); // note name "GNU"
+      OutStreamer->EmitIntValue('N', 1 /*size*/);
+      OutStreamer->EmitIntValue('U', 1 /*size*/);
+      OutStreamer->EmitIntValue(0, 1 /*size*/);
+
+      // Emitting an Elf_Prop for the CET properties.
+      OutStreamer->EmitIntValue(ELF::GNU_PROPERTY_X86_FEATURE_1_AND, 4);
+      OutStreamer->EmitIntValue(WordSize, 4);               // data size
+      OutStreamer->EmitIntValue(FeatureFlagsAnd, WordSize); // data
+      EmitAlignment(WordSize == 4 ? 2 : 3);                 // padding
+
+      OutStreamer->endSection(Nt);
+      OutStreamer->SwitchSection(Cur);
+    }
+  }
+
   if (TT.isOSBinFormatMachO())
     OutStreamer->SwitchSection(getObjFileLowering().getTextSection());
 
Index: llvm/test/CodeGen/X86/note-cet-property.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/X86/note-cet-property.ll
@@ -0,0 +1,22 @@
+; RUN: llc -mtriple x86_64-pc-linux < %s | FileCheck %s
+
+; This test checks that the compiler emits a .note.gnu.property section for
+; modules with "cf-protection" module flags.
+
+; CHECK:      .section        .note.gnu.property,"a",@note
+; CHECK-NEXT: .p2align 3
+; CHECK-NEXT: .long   4
+; CHECK-NEXT: .long   16
+; CHECK-NEXT: .long   5
+; CHECK-NEXT: .byte   71
+; CHECK-NEXT: .byte   78
+; CHECK-NEXT: .byte   85
+; CHECK-NEXT: .byte   0
+; CHECK-NEXT: .long   3221225474
+; CHECK-NEXT: .long   8
+; CHECK-NEXT: .quad   2
+; CHECK-NEXT: .p2align 3
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 4, !"cf-protection-return", i32 1}