diff --git a/llvm/include/llvm/ExecutionEngine/Orc/MemoryMapper.h b/llvm/include/llvm/ExecutionEngine/Orc/MemoryMapper.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/ExecutionEngine/Orc/MemoryMapper.h
@@ -0,0 +1,80 @@
+//===- MemoryMapper.h - Cross-process memory mapper -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// TODO
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_MEMORYMAPPER_H
+#define LLVM_EXECUTIONENGINE_ORC_MEMORYMAPPER_H
+
+#include "llvm/ExecutionEngine/Orc/Core.h"
+#include "llvm/Support/Error.h"
+
+namespace llvm {
+namespace orc {
+
+class MemoryMapper {
+public:
+  struct Mapping {
+    ExecutorAddr RemoteAddr;
+    void *LocalAddr;
+    size_t Size;
+  };
+
+  using ReserveResult = Expected<Mapping>;
+  using OnReservedFunction = unique_function<void(ReserveResult)>;
+  virtual void reserve(size_t NumBytes, OnReservedFunction OnReserved) = 0;
+  virtual ReserveResult reserve(size_t NumBytes);
+
+  using OnFinalizedFunction = unique_function<void(Error)>;
+  virtual void finalize(Mapping &M,
+                        tpctypes::SharedMemoryFinalizeRequest &Actions,
+                        OnFinalizedFunction OnReserved) = 0;
+  virtual Error finalize(Mapping &M,
+                         tpctypes::SharedMemoryFinalizeRequest &Actions);
+
+  using OnDeallocatedFunction = unique_function<void(Error)>;
+  virtual Error release(std::vector<Mapping> &Allocs,
+                        OnDeallocatedFunction OnDeallocation) = 0;
+  virtual Error release(std::vector<Mapping> &Allocs);
+
+  virtual ~MemoryMapper();
+};
+
+class SharedMemoryMapper final : public MemoryMapper {
+public:
+  struct SymbolAddrs {
+    ExecutorAddr Manager;
+    ExecutorAddr Reserve;
+    ExecutorAddr Finalize;
+    ExecutorAddr Deallocate;
+  };
+
+  SharedMemoryMapper(ExecutorProcessControl &EPC, SymbolAddrs SAs)
+      : EPC(EPC), SAs(SAs) {}
+
+  void reserve(size_t NumBytes, OnReservedFunction OnReserved) override;
+
+  void finalize(Mapping &M, tpctypes::SharedMemoryFinalizeRequest &Actions,
+                OnFinalizedFunction OnReserved) override;
+
+  Error release(std::vector<Mapping> &Mappings,
+                OnDeallocatedFunction OnDeallocated) override;
+
+  ~SharedMemoryMapper() override;
+
+private:
+  ExecutorProcessControl &EPC;
+  SymbolAddrs SAs;
+};
+
+} // namespace orc
+} // end namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_ORC_MEMORYMAPPER_H
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h b/llvm/include/llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h
@@ -31,6 +31,11 @@
 extern const char *SimpleExecutorMemoryManagerFinalizeWrapperName;
 extern const char *SimpleExecutorMemoryManagerDeallocateWrapperName;
 
+extern const char *ExecutorSharedMemoryManagerInstanceName;
+extern const char *ExecutorSharedMemoryManagerReserveWrapperName;
+extern const char *ExecutorSharedMemoryManagerFinalizeWrapperName;
+extern const char *ExecutorSharedMemoryManagerReleaseWrapperName;
+
 extern const char *MemoryWriteUInt8sWrapperName;
 extern const char *MemoryWriteUInt16sWrapperName;
 extern const char *MemoryWriteUInt32sWrapperName;
@@ -58,6 +63,14 @@
 using SPSSimpleExecutorMemoryManagerDeallocateSignature = shared::SPSError(
     shared::SPSExecutorAddr, shared::SPSSequence<shared::SPSExecutorAddr>);
 
+using SPSExecutorSharedMemoryManagerReserveSignature = shared::SPSExpected<
+    shared::SPSTuple<shared::SPSExecutorAddr, shared::SPSString>>(
+    shared::SPSExecutorAddr, uint64_t);
+using SPSExecutorSharedMemoryManagerFinalizeSignature = shared::SPSError(
+    shared::SPSExecutorAddr, shared::SPSSharedMemoryFinalizeRequest);
+using SPSExecutorSharedMemoryManagerDeallocateSignature = shared::SPSError(
+    shared::SPSExecutorAddr, shared::SPSSequence<shared::SPSExecutorAddr>);
+
 using SPSRunAsMainSignature = int64_t(shared::SPSExecutorAddr,
                                       shared::SPSSequence<shared::SPSString>);
 
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h b/llvm/include/llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h
@@ -82,6 +82,17 @@
   shared::AllocActions Actions;
 };
 
+struct SharedMemorySegFinalizeRequest {
+  WireProtectionFlags Prot;
+  ExecutorAddr Addr;
+  uint64_t Size;
+};
+
+struct SharedMemoryFinalizeRequest {
+  std::vector<SharedMemorySegFinalizeRequest> Segments;
+  shared::AllocActions Actions;
+};
+
 template <typename T> struct UIntWrite {
   UIntWrite() = default;
   UIntWrite(ExecutorAddr Addr, T Value) : Addr(Addr), Value(Value) {}
@@ -131,6 +142,13 @@
 using SPSFinalizeRequest = SPSTuple<SPSSequence<SPSSegFinalizeRequest>,
                                     SPSSequence<SPSAllocActionCallPair>>;
 
+using SPSSharedMemorySegFinalizeRequest =
+    SPSTuple<SPSMemoryProtectionFlags, SPSExecutorAddr, uint64_t>;
+
+using SPSSharedMemoryFinalizeRequest =
+    SPSTuple<SPSSequence<SPSSharedMemorySegFinalizeRequest>,
+             SPSSequence<SPSAllocActionCallPair>>;
+
 template <typename T>
 using SPSMemoryAccessUIntWrite = SPSTuple<SPSExecutorAddr, T>;
 
@@ -204,6 +222,49 @@
   }
 };
 
+template <>
+class SPSSerializationTraits<SPSSharedMemorySegFinalizeRequest,
+                             tpctypes::SharedMemorySegFinalizeRequest> {
+  using SFRAL = SPSSharedMemorySegFinalizeRequest::AsArgList;
+
+public:
+  static size_t size(const tpctypes::SharedMemorySegFinalizeRequest &SFR) {
+    return SFRAL::size(SFR.Prot, SFR.Addr, SFR.Size);
+  }
+
+  static bool serialize(SPSOutputBuffer &OB,
+                        const tpctypes::SharedMemorySegFinalizeRequest &SFR) {
+
+    return SFRAL::serialize(OB, SFR.Prot, SFR.Addr, SFR.Size);
+  }
+
+  static bool deserialize(SPSInputBuffer &IB,
+                          tpctypes::SharedMemorySegFinalizeRequest &SFR) {
+    return SFRAL::deserialize(IB, SFR.Prot, SFR.Addr, SFR.Size);
+  }
+};
+
+template <>
+class SPSSerializationTraits<SPSSharedMemoryFinalizeRequest,
+                             tpctypes::SharedMemoryFinalizeRequest> {
+  using FRAL = SPSSharedMemoryFinalizeRequest::AsArgList;
+
+public:
+  static size_t size(const tpctypes::SharedMemoryFinalizeRequest &FR) {
+    return FRAL::size(FR.Segments, FR.Actions);
+  }
+
+  static bool serialize(SPSOutputBuffer &OB,
+                        const tpctypes::SharedMemoryFinalizeRequest &FR) {
+    return FRAL::serialize(OB, FR.Segments, FR.Actions);
+  }
+
+  static bool deserialize(SPSInputBuffer &IB,
+                          tpctypes::SharedMemoryFinalizeRequest &FR) {
+    return FRAL::deserialize(IB, FR.Segments, FR.Actions);
+  }
+};
+
 template <typename T>
 class SPSSerializationTraits<SPSMemoryAccessUIntWrite<T>,
                              tpctypes::UIntWrite<T>> {
@@ -244,7 +305,6 @@
   }
 };
 
-
 } // end namespace shared
 } // end namespace orc
 } // end namespace llvm
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h b/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h
@@ -0,0 +1,67 @@
+//===---------------- ExecutorSharedMemoryManager.h -------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// TODO
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_EXECUTORSHAREDMEMORYMANAGER_H
+#define LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_EXECUTORSHAREDMEMORYMANAGER_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h"
+#include "llvm/ExecutionEngine/Orc/TargetProcess/ExecutorBootstrapService.h"
+#include "llvm/Support/Error.h"
+
+#include <atomic>
+#include <mutex>
+
+namespace llvm {
+namespace orc {
+namespace rt_bootstrap {
+
+class ExecutorSharedMemoryManager : public ExecutorBootstrapService {
+public:
+  virtual ~ExecutorSharedMemoryManager();
+
+  Expected<std::pair<ExecutorAddr, std::string>> reserve(uint64_t Size);
+  Error finalize(tpctypes::SharedMemoryFinalizeRequest &FR);
+  Error release(const std::vector<ExecutorAddr> &Bases);
+
+  Error shutdown() override;
+  void addBootstrapSymbols(StringMap<ExecutorAddr> &M) override;
+
+private:
+  struct Allocation {
+    size_t Size = 0;
+    std::vector<shared::WrapperFunctionCall> DeallocationActions;
+  };
+
+  using AllocationsMap = DenseMap<void *, Allocation>;
+
+  Error releaseImpl(void *Base, Allocation &A);
+
+  static llvm::orc::shared::CWrapperFunctionResult
+  reserveWrapper(const char *ArgData, size_t ArgSize);
+
+  static llvm::orc::shared::CWrapperFunctionResult
+  finalizeWrapper(const char *ArgData, size_t ArgSize);
+
+  static llvm::orc::shared::CWrapperFunctionResult
+  deallocateWrapper(const char *ArgData, size_t ArgSize);
+
+  std::atomic<int> SharedMemoryCount{0};
+  std::mutex M;
+  AllocationsMap Allocations;
+};
+
+} // end namespace rt_bootstrap
+} // end namespace orc
+} // end namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_EXECUTORSHAREDMEMORYMANAGER_H
diff --git a/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt b/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
--- a/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
+++ b/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
@@ -23,6 +23,7 @@
   LookupAndRecordAddrs.cpp
   LLJIT.cpp
   MachOPlatform.cpp
+  MemoryMapper.cpp
   ELFNixPlatform.cpp
   Mangling.cpp
   ObjectLinkingLayer.cpp
diff --git a/llvm/lib/ExecutionEngine/Orc/MemoryMapper.cpp b/llvm/lib/ExecutionEngine/Orc/MemoryMapper.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/MemoryMapper.cpp
@@ -0,0 +1,147 @@
+//===- MemoryMapper.cpp - Cross-process memory mapper ------------*- C++ -*-==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// TODO
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/MemoryMapper.h"
+#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
+
+#include <string>
+
+#ifdef LLVM_ON_UNIX
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#endif
+
+namespace llvm {
+namespace orc {
+
+MemoryMapper::ReserveResult MemoryMapper::reserve(size_t NumBytes) {
+  std::promise<ReserveResult> P;
+  auto F = P.get_future();
+  reserve(NumBytes,
+          [&](MemoryMapper::ReserveResult R) { P.set_value(std::move(R)); });
+  return F.get();
+}
+
+Error MemoryMapper::finalize(MemoryMapper::Mapping &M,
+                             tpctypes::SharedMemoryFinalizeRequest &Actions) {
+  std::promise<Error> P;
+  auto F = P.get_future();
+  finalize(M, Actions, [&](Error R) { P.set_value(std::move(R)); });
+  return F.get();
+}
+
+Error MemoryMapper::release(std::vector<MemoryMapper::Mapping> &Allocs) {
+  std::promise<Error> P;
+  auto F = P.get_future();
+  Error ErrLocal = release(Allocs, [&](Error R) { P.set_value(std::move(R)); });
+  return joinErrors(std::move(ErrLocal), F.get());
+}
+
+MemoryMapper::~MemoryMapper() {}
+
+void SharedMemoryMapper::reserve(size_t Size, OnReservedFunction OnReserved) {
+  EPC.callSPSWrapperAsync<rt::SPSExecutorSharedMemoryManagerReserveSignature>(
+      SAs.Reserve,
+      [Size, OnReserved = std::move(OnReserved)](
+          Error SerializationErr,
+          Expected<std::pair<ExecutorAddr, std::string>> Result) mutable {
+        if (SerializationErr) {
+          cantFail(Result.takeError());
+          return OnReserved(std::move(SerializationErr));
+        }
+        if (!Result)
+          return OnReserved(Result.takeError());
+
+        ExecutorAddr RemoteAddr;
+        std::string SharedMemoryName;
+        std::tie(RemoteAddr, SharedMemoryName) = std::move(*Result);
+
+#ifdef LLVM_ON_UNIX
+        int SharedMemoryFile = shm_open(SharedMemoryName.c_str(), O_RDWR, 0700);
+        if (SharedMemoryFile < 0) {
+          return OnReserved(errorCodeToError(
+              std::error_code(errno, std::generic_category())));
+        }
+
+        // this prevents other programs from accessing it by name
+        shm_unlink(SharedMemoryName.c_str());
+
+        void *LocalAddr = mmap(nullptr, Size, PROT_READ | PROT_WRITE,
+                               MAP_SHARED, SharedMemoryFile, 0);
+        if (LocalAddr == MAP_FAILED) {
+          return OnReserved(errorCodeToError(
+              std::error_code(errno, std::generic_category())));
+        }
+        close(SharedMemoryFile);
+#endif
+        OnReserved(Mapping{RemoteAddr, LocalAddr, Size});
+      },
+      SAs.Manager, Size);
+}
+
+void SharedMemoryMapper::finalize(Mapping &M,
+                                  tpctypes::SharedMemoryFinalizeRequest &FR,
+                                  OnFinalizedFunction OnFinalize) {
+  EPC.callSPSWrapperAsync<rt::SPSExecutorSharedMemoryManagerFinalizeSignature>(
+      SAs.Finalize,
+      [OnFinalize = std::move(OnFinalize)](Error SerializationErr,
+                                           Error FinalizeErr) mutable {
+        if (SerializationErr) {
+          cantFail(std::move(FinalizeErr));
+          OnFinalize(std::move(SerializationErr));
+        } else if (FinalizeErr)
+          OnFinalize(std::move(FinalizeErr));
+        else
+          OnFinalize(Error::success());
+      },
+      SAs.Manager, std::move(FR));
+}
+
+Error SharedMemoryMapper::release(std::vector<Mapping> &Mappings,
+                                  OnDeallocatedFunction OnDeallocated) {
+  std::vector<ExecutorAddr> Bases(Mappings.size());
+  std::transform(Mappings.begin(), Mappings.end(), Bases.begin(),
+                 [](Mapping M) { return M.RemoteAddr; });
+
+  EPC.callSPSWrapperAsync<
+      rt::SPSExecutorSharedMemoryManagerDeallocateSignature>(
+      SAs.Deallocate,
+      [OnDeallocated = std::move(OnDeallocated)](Error SerErr,
+                                                 Error DeallocErr) mutable {
+        if (SerErr) {
+          cantFail(std::move(DeallocErr));
+          OnDeallocated(std::move(SerErr));
+        } else
+          OnDeallocated(std::move(DeallocErr));
+      },
+      SAs.Manager, Bases);
+
+  Error Err = Error::success();
+
+  for (auto M : Mappings) {
+#ifdef LLVM_ON_UNIX
+    if (munmap(M.LocalAddr, M.Size) != 0) {
+      Err = joinErrors(std::move(Err), errorCodeToError(std::error_code(
+                                           errno, std::generic_category())));
+    }
+#endif
+  }
+
+  return Err;
+}
+
+SharedMemoryMapper::~SharedMemoryMapper() {}
+
+} // namespace orc
+
+} // namespace llvm
diff --git a/llvm/lib/ExecutionEngine/Orc/Shared/OrcRTBridge.cpp b/llvm/lib/ExecutionEngine/Orc/Shared/OrcRTBridge.cpp
--- a/llvm/lib/ExecutionEngine/Orc/Shared/OrcRTBridge.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Shared/OrcRTBridge.cpp
@@ -26,6 +26,14 @@
     "__llvm_orc_SimpleExecutorMemoryManager_finalize_wrapper";
 const char *SimpleExecutorMemoryManagerDeallocateWrapperName =
     "__llvm_orc_SimpleExecutorMemoryManager_deallocate_wrapper";
+const char *ExecutorSharedMemoryManagerInstanceName =
+    "__llvm_orc_ExecutorSharedMemoryManager_Instance";
+const char *ExecutorSharedMemoryManagerReserveWrapperName =
+    "__llvm_orc_ExecutorSharedMemoryManager_reserve_wrapper";
+const char *ExecutorSharedMemoryManagerFinalizeWrapperName =
+    "__llvm_orc_ExecutorSharedMemoryManager_finalize_wrapper";
+const char *ExecutorSharedMemoryManagerReleaseWrapperName =
+    "__llvm_orc_ExecutorSharedMemoryManager_release_wrapper";
 const char *MemoryWriteUInt8sWrapperName =
     "__llvm_orc_bootstrap_mem_write_uint8s_wrapper";
 const char *MemoryWriteUInt16sWrapperName =
diff --git a/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt b/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
--- a/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
+++ b/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_llvm_component_library(LLVMOrcTargetProcess
+  ExecutorSharedMemoryManager.cpp
   JITLoaderGDB.cpp
   OrcRTBootstrap.cpp
   RegisterEHFrames.cpp
diff --git a/llvm/lib/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.cpp b/llvm/lib/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.cpp
@@ -0,0 +1,297 @@
+//===- ExecutorShardMemoryManagare.cpp - Executor-side shared memory mgmt -===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h"
+
+#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/Process.h"
+
+#include <sstream>
+
+#ifdef LLVM_ON_UNIX
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#endif
+
+namespace llvm {
+namespace orc {
+namespace rt_bootstrap {
+
+ExecutorSharedMemoryManager::~ExecutorSharedMemoryManager() {
+  assert(Allocations.empty() && "shutdown not called?");
+}
+
+Expected<std::pair<ExecutorAddr, std::string>>
+ExecutorSharedMemoryManager::reserve(uint64_t Size) {
+#ifdef LLVM_ON_UNIX
+  std::string SharedMemoryName;
+  {
+    std::stringstream SharedMemoryNameStream;
+    SharedMemoryNameStream << "/jitlink_" << sys::Process::getProcessId() << '_'
+                           << (++SharedMemoryCount);
+    SharedMemoryName = SharedMemoryNameStream.str();
+  }
+
+  int SharedMemoryFile =
+      shm_open(SharedMemoryName.c_str(), O_RDWR | O_CREAT | O_EXCL, 0700);
+  if (SharedMemoryFile < 0) {
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+  }
+
+  // by default size is 0
+  if (ftruncate(SharedMemoryFile, Size) < 0) {
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+  }
+
+  void *Addr = mmap(nullptr, Size, PROT_NONE, MAP_SHARED, SharedMemoryFile, 0);
+  if (Addr == MAP_FAILED) {
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+  }
+
+  close(SharedMemoryFile);
+
+  {
+    std::lock_guard<std::mutex> Lock(M);
+    assert(!Allocations.count(Addr) && "Duplicate allocation addr");
+    Allocations[Addr].Size = Size;
+  }
+
+  return std::make_pair(ExecutorAddr::fromPtr(Addr),
+                        std::move(SharedMemoryName));
+#endif
+}
+
+Error ExecutorSharedMemoryManager::finalize(
+    tpctypes::SharedMemoryFinalizeRequest &FR) {
+  ExecutorAddr Base(~0ULL);
+  std::vector<shared::WrapperFunctionCall> DeallocationActions;
+  size_t SuccessfulFinalizationActions = 0;
+
+  if (FR.Segments.empty()) {
+    if (FR.Actions.empty())
+      return Error::success();
+    return make_error<StringError>(
+        "Finalization actions attached to empty finalization request",
+        inconvertibleErrorCode());
+  }
+
+  for (auto &Seg : FR.Segments)
+    Base = std::min(Base, Seg.Addr);
+
+  for (auto &ActPair : FR.Actions)
+    if (ActPair.Dealloc)
+      DeallocationActions.push_back(ActPair.Dealloc);
+
+  // Get the Allocation for this finalization.
+  size_t AllocSize = 0;
+  {
+    std::lock_guard<std::mutex> Lock(M);
+    auto I = Allocations.find(Base.toPtr<void *>());
+    if (I == Allocations.end())
+      return make_error<StringError>(
+          formatv("Attempt to finalize unrecognized allocation {0:x}",
+                  Base.getValue()),
+          inconvertibleErrorCode());
+    AllocSize = I->second.Size;
+    I->second.DeallocationActions = std::move(DeallocationActions);
+  }
+  ExecutorAddr AllocEnd = Base + ExecutorAddrDiff(AllocSize);
+
+  // Bail-out function: this will run deallocation actions corresponding to any
+  // completed finalization actions, then deallocate memory.
+  auto BailOut = [&](Error Err) {
+    std::pair<void *, Allocation> AllocToDestroy;
+
+    // Get allocation to destory.
+    {
+      std::lock_guard<std::mutex> Lock(M);
+      auto I = Allocations.find(Base.toPtr<void *>());
+
+      // Check for missing allocation (effective a double free).
+      if (I == Allocations.end())
+        return joinErrors(
+            std::move(Err),
+            make_error<StringError>(
+                formatv("No allocation entry found for {0:x}", Base.getValue()),
+                inconvertibleErrorCode()));
+      AllocToDestroy = std::move(*I);
+      Allocations.erase(I);
+    }
+
+    // Run deallocation actions for all completed finalization actions.
+    while (SuccessfulFinalizationActions)
+      Err =
+          joinErrors(std::move(Err), FR.Actions[--SuccessfulFinalizationActions]
+                                         .Dealloc.runWithSPSRetErrorMerged());
+
+    // Deallocate memory.
+    // TODO
+    sys::MemoryBlock MB(AllocToDestroy.first, AllocToDestroy.second.Size);
+    if (auto EC = sys::Memory::releaseMappedMemory(MB))
+      Err = joinErrors(std::move(Err), errorCodeToError(EC));
+
+    return Err;
+  };
+
+  // Copy content and apply permissions.
+  for (auto &Seg : FR.Segments) {
+
+    ExecutorAddr SegEnd = Seg.Addr + ExecutorAddrDiff(Seg.Size);
+    if (LLVM_UNLIKELY(Seg.Addr < Base || SegEnd > AllocEnd))
+      return BailOut(make_error<StringError>(
+          formatv("Segment {0:x} -- {1:x} crosses boundary of "
+                  "allocation {2:x} -- {3:x}",
+                  Seg.Addr.getValue(), SegEnd.getValue(), Base.getValue(),
+                  AllocEnd.getValue()),
+          inconvertibleErrorCode()));
+
+    char *Mem = Seg.Addr.toPtr<char *>();
+    assert(Seg.Size <= std::numeric_limits<size_t>::max());
+
+#ifdef LLVM_ON_UNIX
+
+    int MmapProt = 0;
+    if (Seg.Prot & tpctypes::WPF_Read)
+      MmapProt |= PROT_READ;
+    if (Seg.Prot & tpctypes::WPF_Write)
+      MmapProt |= PROT_WRITE;
+    if (Seg.Prot & tpctypes::WPF_Exec)
+      MmapProt |= PROT_EXEC;
+    mprotect(Mem, Seg.Size, MmapProt);
+
+    if (Seg.Prot & tpctypes::WPF_Exec)
+      sys::Memory::InvalidateInstructionCache(Mem, Seg.Size);
+  }
+#endif
+
+  // Run finalization actions.
+  for (auto &ActPair : FR.Actions) {
+    if (auto Err = ActPair.Finalize.runWithSPSRetErrorMerged())
+      return BailOut(std::move(Err));
+    ++SuccessfulFinalizationActions;
+  }
+
+  return Error::success();
+}
+
+Error ExecutorSharedMemoryManager::release(
+    const std::vector<ExecutorAddr> &Bases) {
+  std::vector<std::pair<void *, Allocation>> AllocPairs;
+  AllocPairs.reserve(Bases.size());
+
+  // Get allocation to destory.
+  Error Err = Error::success();
+  {
+    std::lock_guard<std::mutex> Lock(M);
+    for (auto &Base : Bases) {
+      auto I = Allocations.find(Base.toPtr<void *>());
+
+      // Check for missing allocation (effective a double free).
+      if (I != Allocations.end()) {
+        AllocPairs.push_back(std::move(*I));
+        Allocations.erase(I);
+      } else
+        Err = joinErrors(
+            std::move(Err),
+            make_error<StringError>(
+                formatv("No allocation entry found for {0:x}", Base.getValue()),
+                inconvertibleErrorCode()));
+    }
+  }
+
+  while (!AllocPairs.empty()) {
+    auto &P = AllocPairs.back();
+    Err = joinErrors(std::move(Err), releaseImpl(P.first, P.second));
+    AllocPairs.pop_back();
+  }
+
+  return Err;
+}
+
+Error ExecutorSharedMemoryManager::shutdown() {
+
+  AllocationsMap AM;
+  {
+    std::lock_guard<std::mutex> Lock(M);
+    AM = std::move(Allocations);
+  }
+
+  Error Err = Error::success();
+  for (auto &KV : AM)
+    Err = joinErrors(std::move(Err), releaseImpl(KV.first, KV.second));
+  return Err;
+}
+
+void ExecutorSharedMemoryManager::addBootstrapSymbols(
+    StringMap<ExecutorAddr> &M) {
+  M[rt::ExecutorSharedMemoryManagerInstanceName] = ExecutorAddr::fromPtr(this);
+  M[rt::ExecutorSharedMemoryManagerReserveWrapperName] =
+      ExecutorAddr::fromPtr(&reserveWrapper);
+  M[rt::ExecutorSharedMemoryManagerFinalizeWrapperName] =
+      ExecutorAddr::fromPtr(&finalizeWrapper);
+  M[rt::ExecutorSharedMemoryManagerReleaseWrapperName] =
+      ExecutorAddr::fromPtr(&deallocateWrapper);
+}
+
+Error ExecutorSharedMemoryManager::releaseImpl(void *Base, Allocation &A) {
+  Error Err = Error::success();
+
+  while (!A.DeallocationActions.empty()) {
+    Err = joinErrors(std::move(Err),
+                     A.DeallocationActions.back().runWithSPSRetErrorMerged());
+    A.DeallocationActions.pop_back();
+  }
+
+#ifdef LLVM_ON_UNIX
+  if (munmap(Base, A.Size) != 0)
+    Err = joinErrors(std::move(Err), errorCodeToError(std::error_code(
+                                         errno, std::generic_category())));
+#endif
+
+  return Err;
+}
+
+llvm::orc::shared::CWrapperFunctionResult
+ExecutorSharedMemoryManager::reserveWrapper(const char *ArgData,
+                                            size_t ArgSize) {
+  return shared::WrapperFunction<
+             rt::SPSExecutorSharedMemoryManagerReserveSignature>::
+      handle(ArgData, ArgSize,
+             shared::makeMethodWrapperHandler(
+                 &ExecutorSharedMemoryManager::reserve))
+          .release();
+}
+
+llvm::orc::shared::CWrapperFunctionResult
+ExecutorSharedMemoryManager::finalizeWrapper(const char *ArgData,
+                                             size_t ArgSize) {
+  return shared::WrapperFunction<
+             rt::SPSExecutorSharedMemoryManagerFinalizeSignature>::
+      handle(ArgData, ArgSize,
+             shared::makeMethodWrapperHandler(
+                 &ExecutorSharedMemoryManager::finalize))
+          .release();
+}
+
+llvm::orc::shared::CWrapperFunctionResult
+ExecutorSharedMemoryManager::deallocateWrapper(const char *ArgData,
+                                               size_t ArgSize) {
+  return shared::WrapperFunction<
+             rt::SPSExecutorSharedMemoryManagerDeallocateSignature>::
+      handle(ArgData, ArgSize,
+             shared::makeMethodWrapperHandler(
+                 &ExecutorSharedMemoryManager::release))
+          .release();
+}
+
+} // namespace rt_bootstrap
+} // end namespace orc
+} // end namespace llvm
diff --git a/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt b/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
--- a/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
+++ b/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
@@ -18,12 +18,14 @@
   CoreAPIsTest.cpp
   ExecutorAddressTest.cpp
   ExecutionSessionWrapperFunctionCallsTest.cpp
+  ExecutorSharedMemoryManagerTest.cpp
   EPCGenericJITLinkMemoryManagerTest.cpp
   EPCGenericMemoryAccessTest.cpp
   IndirectionUtilsTest.cpp
   JITTargetMachineBuilderTest.cpp
   LazyCallThroughAndReexportsTest.cpp
   LookupAndRecordAddrsTest.cpp
+  SharedMemoryMapperTest.cpp
   ObjectLinkingLayerTest.cpp
   OrcCAPITest.cpp
   OrcTestCommon.cpp
diff --git a/llvm/unittests/ExecutionEngine/Orc/ExecutorSharedMemoryManagerTest.cpp b/llvm/unittests/ExecutionEngine/Orc/ExecutorSharedMemoryManagerTest.cpp
new file mode 100755
--- /dev/null
+++ b/llvm/unittests/ExecutionEngine/Orc/ExecutorSharedMemoryManagerTest.cpp
@@ -0,0 +1,104 @@
+//===---------------- ExecutorSharedMemoryManagerTest.cpp -----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+
+#include <cstring>
+#include <limits>
+#include <vector>
+
+#ifdef LLVM_ON_UNIX
+#include <fcntl.h>
+#include <sys/mman.h>
+#endif
+
+using namespace llvm;
+using namespace llvm::orc;
+using namespace llvm::orc::shared;
+using namespace llvm::orc::rt_bootstrap;
+
+namespace {
+
+#ifdef LLVM_ON_UNIX
+orc::shared::CWrapperFunctionResult incrementWrapper(const char *ArgData,
+                                                     size_t ArgSize) {
+  return WrapperFunction<SPSError(SPSExecutorAddr)>::handle(
+             ArgData, ArgSize,
+             [](ExecutorAddr A) -> Error {
+               *A.toPtr<int *>() += 1;
+               return Error::success();
+             })
+      .release();
+}
+
+TEST(ExecutorSharedMemoryManagerTest, AllocFinalizeFree) {
+  ExecutorSharedMemoryManager MemMgr;
+
+  constexpr unsigned AllocSize = 16384;
+
+  auto Mem = MemMgr.reserve(AllocSize);
+  EXPECT_THAT_ERROR(Mem.takeError(), Succeeded());
+
+  ExecutorAddr ExecAddr;
+  std::string Name;
+  std::tie(ExecAddr, Name) = *Mem;
+
+  int File = shm_open(Name.c_str(), O_RDWR, 0700);
+  EXPECT_GT(File, 0);
+
+  void *WorkingAddr =
+      mmap(nullptr, AllocSize, PROT_READ | PROT_WRITE, MAP_SHARED, File, 0);
+  EXPECT_NE(WorkingAddr, MAP_FAILED);
+
+  shm_unlink(Name.c_str());
+
+  std::string HW = "Hello, world!";
+
+  std::strcpy((char *)WorkingAddr, HW.c_str());
+
+  int FinalizeCounter = 0;
+  int DeallocateCounter = 0;
+
+  tpctypes::SharedMemoryFinalizeRequest FR;
+  FR.Segments.push_back(tpctypes::SharedMemorySegFinalizeRequest{
+      tpctypes::WPF_Read | tpctypes::WPF_Write,
+      ExecAddr,
+      AllocSize,
+  });
+  FR.Actions.push_back(
+      {/* Finalize: */
+       cantFail(WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
+           ExecutorAddr::fromPtr(incrementWrapper),
+           ExecutorAddr::fromPtr(&FinalizeCounter))),
+       /*  Deallocate: */
+       cantFail(WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
+           ExecutorAddr::fromPtr(incrementWrapper),
+           ExecutorAddr::fromPtr(&DeallocateCounter)))});
+
+  EXPECT_EQ(FinalizeCounter, 0);
+  EXPECT_EQ(DeallocateCounter, 0);
+
+  auto FinalizeErr = MemMgr.finalize(FR);
+  EXPECT_THAT_ERROR(std::move(FinalizeErr), Succeeded());
+
+  EXPECT_EQ(FinalizeCounter, 1);
+  EXPECT_EQ(DeallocateCounter, 0);
+
+  EXPECT_EQ(HW, std::string(ExecAddr.toPtr<const char *>()));
+
+  auto DeallocateErr = MemMgr.release({ExecAddr});
+  EXPECT_THAT_ERROR(std::move(DeallocateErr), Succeeded());
+
+  EXPECT_EQ(FinalizeCounter, 1);
+  EXPECT_EQ(DeallocateCounter, 1);
+}
+#endif
+
+} // namespace
diff --git a/llvm/unittests/ExecutionEngine/Orc/SharedMemoryMapperTest.cpp b/llvm/unittests/ExecutionEngine/Orc/SharedMemoryMapperTest.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/unittests/ExecutionEngine/Orc/SharedMemoryMapperTest.cpp
@@ -0,0 +1,79 @@
+//===- SharedMemoryMapperTest.cpp -- Tests for SharedMemoryMapper ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "OrcTestCommon.h"
+
+#include "llvm/ExecutionEngine/Orc/MemoryMapper.h"
+#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
+#include "llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryManager.h"
+#include "llvm/Testing/Support/Error.h"
+
+using namespace llvm;
+using namespace llvm::orc;
+using namespace llvm::orc::shared;
+using namespace llvm::orc::rt_bootstrap;
+
+TEST(SharedMemoryMapperTest, MemReserveFinalizeDealloc) {
+  auto SelfEPC = cantFail(SelfExecutorProcessControl::Create());
+
+  ExecutorSharedMemoryManager MemMgr;
+
+  SharedMemoryMapper::SymbolAddrs SAs;
+  {
+    StringMap<ExecutorAddr> Map;
+    MemMgr.addBootstrapSymbols(Map);
+    SAs.Manager = Map[rt::ExecutorSharedMemoryManagerInstanceName];
+    SAs.Reserve = Map[rt::ExecutorSharedMemoryManagerReserveWrapperName];
+    SAs.Finalize = Map[rt::ExecutorSharedMemoryManagerFinalizeWrapperName];
+    SAs.Deallocate = Map[rt::ExecutorSharedMemoryManagerReleaseWrapperName];
+  }
+
+  // barrier
+  std::promise<void> RP;
+  auto RF = RP.get_future();
+
+  {
+    size_t ReqSize = 4096 * 4;
+    auto Mapper = std::make_unique<SharedMemoryMapper>(*SelfEPC, SAs);
+    Mapper->reserve(ReqSize, [Mapper = std::move(Mapper), RP = std::move(RP),
+                              ReqSize](
+                                 Expected<MemoryMapper::Mapping> M) mutable {
+      EXPECT_THAT_ERROR(M.takeError(), Succeeded());
+      EXPECT_GE(M->Size, ReqSize);
+
+      tpctypes::SharedMemoryFinalizeRequest FR;
+      FR.Segments.push_back(tpctypes::SharedMemorySegFinalizeRequest{
+          tpctypes::WPF_Read | tpctypes::WPF_Write,
+          M->RemoteAddr,
+          ReqSize,
+      });
+
+      Mapper->finalize(*M, FR,
+                       [Mapper = std::move(Mapper), RP = std::move(RP),
+                        M = std::move(*M)](Error Err) mutable {
+                         EXPECT_THAT_ERROR(std::move(Err), Succeeded());
+
+                         std::vector<MemoryMapper::Mapping> Blocks = {M};
+                         auto Res = Mapper->release(
+                             Blocks, [RP = std::move(RP)](Error Err) mutable {
+                               EXPECT_THAT_ERROR(std::move(Err), Succeeded());
+                               RP.set_value();
+                             });
+
+                         // Unmapping from controller process succeeded
+                         EXPECT_THAT_ERROR(std::move(Res), Succeeded());
+                       });
+    });
+  }
+
+  RF.wait();
+
+  EXPECT_THAT_ERROR(MemMgr.shutdown(), Succeeded());
+
+  cantFail(SelfEPC->disconnect());
+}