Index: llvm/include/llvm/BinaryFormat/ELF.h
===================================================================
--- llvm/include/llvm/BinaryFormat/ELF.h
+++ llvm/include/llvm/BinaryFormat/ELF.h
@@ -1419,6 +1419,7 @@
 // LLVM-specific notes.
 enum {
   NT_LLVM_HWASAN_GLOBALS = 3,
+  NT_LLVM_WATERMARK = 4,
 };
 
 // GNU note types
Index: llvm/test/tools/llvm-readobj/note-llvm.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-readobj/note-llvm.test
@@ -0,0 +1,74 @@
+## Test tools are able to dump the LLVM Watermark note section. Also test the
+## output when the type field is incorrect.
+
+# RUN: yaml2obj -docnum=1 %s > %t1.o
+# RUN: llvm-readobj --notes %t1.o | FileCheck %s --check-prefix=LLVM
+# RUN: llvm-readelf --notes %t1.o | FileCheck %s --check-prefix=GNU
+
+# LLVM:      Notes [
+# LLVM-NEXT:   NoteSection {
+# LLVM-NEXT:     Offset: 0x40
+# LLVM-NEXT:     Size: 0x20
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: LLVM
+# LLVM-NEXT:       Data size: 0xC
+# LLVM-NEXT:       Type: NT_LLVM_WATERMARK (Loadable sections watermark)
+# LLVM-NEXT:       Version: 01000000
+# LLVM-NEXT:       Watermark: 45e69f81a671eaac
+# LLVM-NEXT:     }
+# LLVM-NEXT:   }
+# LLVM-NEXT: ]
+
+# GNU:      Displaying notes found at file offset 0x00000040 with length 0x00000020:
+# GNU-NEXT: Owner                Data size    Description
+# GNU-NEXT: LLVM                 0x0000000c       NT_LLVM_WATERMARK (Loadable sections watermark)
+# GNU-NEXT:    LLVM Watermark: 45e69f81a671eaac Version: 0x01000000
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name:         .note.llvm.watermark
+    Type:         SHT_NOTE
+    AddressAlign: 0x0000000000000004
+    Size:         32
+    Flags:        [ SHF_ALLOC ]
+    Content:      050000000c000000040000004c4c564d000000000100000045e69f81a671eaac
+
+
+# RUN: yaml2obj -docnum=2 %s > %t2.o
+# RUN: llvm-readobj --notes %t2.o | FileCheck %s --check-prefix=LLVM_UNKNOWNTYPE
+# RUN: llvm-readelf --notes %t2.o | FileCheck %s --check-prefix=GNU_UNKNOWNTYPE
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name:         .note.llvm.watermark
+    Type:         SHT_NOTE
+    AddressAlign: 0x0000000000000004
+    Size:         32
+    Flags:        [ SHF_ALLOC ]
+    Content: 050000000c000000ff0000004c4c564d000000000100000045e69f81a671eaac
+
+# LLVM_UNKNOWNTYPE:      Notes [
+# LLVM_UNKNOWNTYPE-NEXT:  NoteSection {
+# LLVM_UNKNOWNTYPE-NEXT:    Offset: 0x40
+# LLVM_UNKNOWNTYPE-NEXT:    Size: 0x20
+# LLVM_UNKNOWNTYPE-NEXT:    Note {
+# LLVM_UNKNOWNTYPE-NEXT:      Owner: LLVM
+# LLVM_UNKNOWNTYPE-NEXT:      Data size: 0xC
+# LLVM_UNKNOWNTYPE-NEXT:      Type: Unknown note type (0x000000ff)
+# LLVM_UNKNOWNTYPE-NEXT:     }
+# LLVM_UNKNOWNTYPE-NEXT:   }
+# LLVM_UNKNOWNTYPE-NEXT: ]
+
+# GNU_UNKNOWNTYPE:      Displaying notes found at file offset 0x00000040 with length 0x00000020:
+# GNU_UNKNOWNTYPE-NEXT: Owner                Data size        Description
+# GNU_UNKNOWNTYPE-NEXT: LLVM                 0x0000000c       Unknown note type (0x000000ff)
Index: llvm/tools/llvm-readobj/ELFDumper.cpp
===================================================================
--- llvm/tools/llvm-readobj/ELFDumper.cpp
+++ llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -4236,6 +4236,16 @@
   return OS.str();
 }
 
+static std::string getLLVMNoteTypeName(const uint32_t NT) {
+  if (NT == NT_LLVM_WATERMARK)
+    return std::string("NT_LLVM_WATERMARK (Loadable sections watermark)");
+
+  std::string string;
+  raw_string_ostream OS(string);
+  OS << format("Unknown note type (0x%08x)", NT);
+  return OS.str();
+}
+
 static std::string getFreeBSDNoteTypeName(const uint32_t NT) {
   static const struct {
     uint32_t ID;
@@ -4571,6 +4581,39 @@
   }
 }
 
+template <typename ELFT>
+static void printLLVMWatermarkLLVMStyle(uint32_t NoteType,
+                                        ArrayRef<uint8_t> Desc,
+                                        ScopedPrinter &W) {
+  if (NoteType != NT_LLVM_WATERMARK)
+    return;
+
+  const size_t HashSize = 8;
+  const size_t VersionSize = 4;
+  auto Version =
+      StringRef(reinterpret_cast<const char *>(Desc.data()), VersionSize);
+  auto Hash = StringRef(
+      reinterpret_cast<const char *>(Desc.data() + VersionSize), HashSize);
+  W.printString("Version", toHex(Version, true));
+  W.printString("Watermark", toHex(Hash, true));
+}
+
+template <typename ELFT>
+static void printLLVMWatermark(raw_ostream &OS, uint32_t NoteType,
+                               ArrayRef<uint8_t> Desc) {
+
+  if (NoteType != NT_LLVM_WATERMARK)
+    return;
+
+  const size_t HashSize = 8;
+  const size_t VersionSize = 4;
+  auto Hash = StringRef(
+      reinterpret_cast<const char *>(Desc.data() + VersionSize), HashSize);
+  auto Version= StringRef(reinterpret_cast<const char *>(Desc.data()), VersionSize);
+  OS << "    LLVM Watermark: " << toHex(Hash, true)
+     << "    Version: 0x" << toHex(Version);
+}
+
 struct CoreFileMapping {
   uint64_t Start, End, Offset;
   StringRef Filename;
@@ -4668,6 +4711,8 @@
       OS << getAMDNoteTypeName(Type) << '\n';
     } else if (Name == "AMDGPU") {
       OS << getAMDGPUNoteTypeName(Type) << '\n';
+    } else if (Name == "LLVM") {
+      OS << getLLVMNoteTypeName(Type) << '\n';
     } else {
       StringRef NoteType = Obj->getHeader()->e_type == ELF::ET_CORE
                                ? getCoreNoteTypeName(Type)
@@ -4701,6 +4746,8 @@
         else
           reportWarning(Note.takeError(), this->FileName);
       }
+    } else if (Name == "LLVM") {
+      printLLVMWatermark<ELFT>(OS, Type, Descriptor);
     } else if (!Descriptor.empty()) {
       OS << "   description data:";
       for (uint8_t B : Descriptor)
@@ -5563,7 +5610,8 @@
   this->dumper()->printSymbolsHelper(true);
 }
 
-template <class ELFT> void LLVMStyle<ELFT>::printDynamic(const ELFFile<ELFT> *Obj) {
+template <class ELFT>
+void LLVMStyle<ELFT>::printDynamic(const ELFFile<ELFT> *Obj) {
   Elf_Dyn_Range Table = this->dumper()->dynamic_table();
   if (Table.empty())
     return;
@@ -5941,6 +5989,8 @@
       W.printString("Type", getAMDNoteTypeName(Type));
     } else if (Name == "AMDGPU") {
       W.printString("Type", getAMDGPUNoteTypeName(Type));
+    } else if (Name == "LLVM") {
+      W.printString("Type", getLLVMNoteTypeName(Type));
     } else {
       StringRef NoteType = Obj->getHeader()->e_type == ELF::ET_CORE
                                ? getCoreNoteTypeName(Type)
@@ -5975,6 +6025,8 @@
         else
           reportWarning(Note.takeError(), this->FileName);
       }
+    } else if (Name == "LLVM") {
+      printLLVMWatermarkLLVMStyle<ELFT>(Type, Descriptor, W);
     } else if (!Descriptor.empty()) {
       W.printBinaryBlock("Description data", Descriptor);
     }
@@ -6019,7 +6071,7 @@
 
     ArrayRef<uint8_t> Contents =
         unwrapOrError(this->FileName, Obj->getSectionContents(&Shdr));
-    for (const uint8_t *P = Contents.begin(), *E = Contents.end(); P < E; ) {
+    for (const uint8_t *P = Contents.begin(), *E = Contents.end(); P < E;) {
       StringRef Key = StringRef(reinterpret_cast<const char *>(P));
       StringRef Value =
           StringRef(reinterpret_cast<const char *>(P) + Key.size() + 1);