[lldb-server][linux] Add ability to allocate memory

[labath]

Summary

This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:

• finding an executable page of memory
• writing the syscall opcode to it
• setting up registers according to the os syscall convention
• single stepping over the syscall

The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.

Depends on D89121.

[labath]

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1350

How much of this would be useful for BSDs? Should some of this be pushed to the base classes?

[DavidSpickett]

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1400

Is it possible that the page we find is executable but not writeable and is this part intended to handle that?
(maybe this is a silly question, the code had to be written into that page in the first place I guess)

1404

Could you add a comment here explaining this? Like "either we single step just syscall, or continue then hit a trap instruction after the syscall"
(if I have that right)

The description for PTRACE_SINGLESTEP confused me a bit with "next entry to":

Restart the stopped tracee as for PTRACE_CONT, but arrange for
the tracee to be stopped at the next entry to or exit from a
system call, or after execution of a single instruction,
respectively.

But I assume what happens here is you step "syscall" and then the whole mmap call happens, then you come back. Instead of getting kept before the mmap actually happens.

1419

What does this calculation do/mean? (0x1000 is 4k which is a page size maybe?)

1421

For these ifs, are you putting {} because the return is split over two lines? I think it would compile without but is this one of the exceptions to the coding standard? (if clang-format isn't doing this for you that is)

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp

1249

What's the source for these numbers?

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp

2346

(assuming this packet type is supported by GDB already) Does it also use hex for the size field? I ask because I came across some file loading packets that were hex for lldb, int for gdb.

Obviously we don't have a hard requirement to match but if we're adding something new might as well.

2366

Is no permissions here a valid packet? (as long as mmap doesn't mind I guess it is)

lldb/test/API/lang/c/stepping/TestStepAndBreakpoints.py

23

This test now passes *because* we have the ability to allocate memory, correct? (I thought it was a stray change at first)

[DavidSpickett]

lldb/test/API/lang/c/stepping/TestStepAndBreakpoints.py

23

Actually shouldn't this be an expected failure on non x86 linux?

[jankratochvil]

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1354

Finding arbitrary address would not be safe if LLDB supports non-stop mode if implemented. It also makes the address a bit non-deterministic. IIRC GDB is using executable's e_entry (="_start" if it exists). But I do not have any strong reason for that.

1444

Some sanity check 'permissions' does not have set a bit which NativeProcessLinux::AllocateMemory does not understand?

[labath]

address review comments

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1354

Lldb also uses the program entry point for the "call mmap(...)" approach of allocating memory. That is a pretty good choice when one needs to find a line of code that will not be executed during normal program operation (not stop or otherwise). However:

• here we don't need that requirement (for all-stop mode, anyway), as we're not calling any function (even mmap can execute a fair amount of code). We're just executing a single instruction.
• technically, there's nothing preventing the application from unmapping the entry point address, or reusing it for something else. If I wanted a foolproof solution, I'd still need to implement a fallback algorithm (as well as the code to search for the entry point, as we right now don't have anything that lldb-server could use).

Given that, it seems better to just go for the more complete solution straight away. It's true that this makes the address harder to predict (I'm trying not to use the word nondeterministic, because that's not really it), but such is life. And coming up with a non-stop-compatible solution for this is so complicated that I'd leave this for some other time (worst case: we disable this feature, or force a temporary stop of all threads).

1400

Ptrace bypasses normal write-protection checks (~all code is not writable these days, and we wouldn't be able to set breakpoints otherwise), so checking for writable addresses would not be useful.

1404

Yes, that's exactly what happens. Ptrace can't step "into" the kernel. The reason that description is confusing is because it a description of both PTRACE_SINGLESTEP *and* PTRACE_SYSCALL, with the latter stopping before the syscall.

I've considered using a sequence of two PTRACE_SYSCALLs to avoid the trap instruction requirement, but it wasn't clear to me that this would help in any way (and it would make the code longer).

1419

This is the linux syscall convention for returning errors. The fact that it matches the page size is probably not accidental, though it was not strictly necessary.

I've added a short comment to elaborate.

1421

clang-format never adds new tokens -- it just reformats existing ones.

Regarding the coding standard, this is in a fairly grey area. I could invoke the "braces should be used when a single-statement body is complex enough that it becomes difficult to see where the block containing the following statement began" rule and say this statement is "complex enough" (I think it was even more complex when I've first written it). I'm sure some people wouldn't consider it complex, but I think it's better to err on the side of adding more braces (I generally add braces for all multi-line statements).

1444

A new permission flag seems fairly unlikely, but sure, why not..

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp

1249

There are plenty of ways to find this -- internet is full of linux system call tables. I just preprocessed a file referencing SYS_MMAP/MUNMAP constants. :P

I also added a note about the file they can be found in (/usr/include/asm/unistd.h)

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp

2346

This isn't adding a completely new packet (you'll notice the patch does not include any clientside changes). This packet is already supported by debugserver, and I believe it is an lldb addition -- I did not come across anything like it in the gdb docs.

However, I would be interested to hear about the protocol mismatches you've found.

2366

Yeah, you can do that in theory -- permissions can be later changed with mprotect(2). Lldb does not make any use of that though.

lldb/test/API/lang/c/stepping/TestStepAndBreakpoints.py

23

This is a funny one. The reason this test fails is because of the stop-id check on line 148 (IIRC). Without this feature lldb will allocate memory by finding and calling the mmap libc function. This seems to mess up the "expression stop id" counter. So it's a real bug, but not one that is likely to cause problems for most people.

However, you're right that this "bug" is not "fixed" only on x86.

[jankratochvil]

In file included from /home/jkratoch/redhat/llvm-monorepo/lldb/source/Host/common/NativeProcessProtocol.cpp:9:
/home/jkratoch/redhat/llvm-monorepo/lldb/include/lldb/Host/common/NativeProcessProtocol.h:20:10: fatal error: 'lldb/Utility/UnimplementedError.h' file not found
#include "lldb/Utility/UnimplementedError.h"

[labath]

In D89124#2325008, @jankratochvil wrote:

In file included from /home/jkratoch/redhat/llvm-monorepo/lldb/source/Host/common/NativeProcessProtocol.cpp:9:
/home/jkratoch/redhat/llvm-monorepo/lldb/include/lldb/Host/common/NativeProcessProtocol.h:20:10: fatal error: 'lldb/Utility/UnimplementedError.h' file not found
#include "lldb/Utility/UnimplementedError.h"

That's because you need the dependant revision D89121 (which is now merged).

[jankratochvil]

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1362

There does not need to exist a thread with TID equal to the process PID. That TID could already exit while other TIDs of that PID may be still running.
https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=432b4d03ad0f23970315e9f9dec080ab4a9ab94b
simplified and deGPLed as: https://people.redhat.com/jkratoch/leader-exit2.C
Just currently LLDB server cannot attach to such TID as:

lldb-server g --attach >TID< :1234
ptrace(PTRACE_ATTACH, >PID<) = -1 EPERM (Operation not permitted)
write(2, "error: failed to attach to pid >TID<: Operation not permitted\n", 64) = 64

But if this bug was fixed then I think this statement could SEGV (unless LLDB will have some internal zombie TID==PID).

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp

1237

static const ... (4x)

[labath]

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

1362

Thanks for catching that. I had a vague feeling that it might be possible for the process to outlive its main thread, but I didn't know how. I've changed this to GetCurrentThread which should be always present.

[labath]

• GetCurrentThread
• const

[stella.stamenova]

It looks like this changed caused a failure on the windows bot and your follow up change to fix the test left it still broken. Can you have a look?

[labath]

It looks like the windows lldb-server implementation does not support all permission combinations (ConvertLldbToWinApiProtect in ProcessDebugger.cpp). I've xfailed the test for now -- I'll try to add the missing bits tomorrow.

I've also messed up the decorators on one of the tests.

a1ab2b77 should get that green again, I hope.

lldb/include/lldb/Host/common/NativeProcessProtocol.h

 #include "NativeBreakpointList.h"
 #include "NativeThreadProtocol.h"
 #include "NativeWatchpointList.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/MainLoop.h"
 #include "lldb/Utility/ArchSpec.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/TraceOptions.h"
+#include "lldb/Utility/UnimplementedError.h"
 #include "lldb/lldb-private-forward.h"
 #include "lldb/lldb-types.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <mutex>
public:
   ///     Returns a StringRef backed up by the \p buffer passed in.
   llvm::Expected<llvm::StringRef>
   ReadCStringFromMemory(lldb::addr_t addr, char *buffer, size_t max_size,
                         size_t &total_bytes_read);
 
   virtual Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
                              size_t &bytes_written) = 0;
 
-  virtual Status AllocateMemory(size_t size, uint32_t permissions,
-                                lldb::addr_t &addr) = 0;
+  virtual llvm::Expected<lldb::addr_t> AllocateMemory(size_t size,
+                                                      uint32_t permissions) {
+    return llvm::make_error<UnimplementedError>();
+  }
 
-  virtual Status DeallocateMemory(lldb::addr_t addr) = 0;
+  virtual llvm::Error DeallocateMemory(lldb::addr_t addr) {
+    return llvm::make_error<UnimplementedError>();
+  }
 
   virtual lldb::addr_t GetSharedLibraryInfoAddress() = 0;
 
   virtual llvm::Expected<std::vector<SVR4LibraryInfo>>
   GetLoadedSVR4Libraries() {
     return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                    "Not implemented");
   }

lldb/source/Plugins/Process/FreeBSDRemote/NativeProcessFreeBSD.h

Status GetMemoryRegionInfo(lldb::addr_t load_addr,
                              MemoryRegionInfo &range_info) override;
 
   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
                     size_t &bytes_read) override;
 
   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
                      size_t &bytes_written) override;
 
-  Status AllocateMemory(size_t size, uint32_t permissions,
-                        lldb::addr_t &addr) override;
-
-  Status DeallocateMemory(lldb::addr_t addr) override;
-
   lldb::addr_t GetSharedLibraryInfoAddress() override;
 
   size_t UpdateThreads() override;
 
   const ArchSpec &GetArchitecture() const override { return m_arch; }
 
   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
                        bool hardware) override;

lldb/source/Plugins/Process/FreeBSDRemote/NativeProcessFreeBSD.cpp

Status NativeProcessFreeBSD::PopulateMemoryRegionCache() {
   LLDB_LOG(log, "read {0} memory region entries from process {1}",
            m_mem_region_cache.size(), GetID());
   // We support memory retrieval, remember that.
   m_supports_mem_region = LazyBool::eLazyBoolYes;
 
   return Status();
 }
 
-Status NativeProcessFreeBSD::AllocateMemory(size_t size, uint32_t permissions,
-                                            lldb::addr_t &addr) {
-  return Status("Unimplemented");
-}
-
-Status NativeProcessFreeBSD::DeallocateMemory(lldb::addr_t addr) {
-  return Status("Unimplemented");
-}
-
 lldb::addr_t NativeProcessFreeBSD::GetSharedLibraryInfoAddress() {
   // punt on this for now
   return LLDB_INVALID_ADDRESS;
 }
 
 size_t NativeProcessFreeBSD::UpdateThreads() { return m_threads.size(); }
 
 Status NativeProcessFreeBSD::SetBreakpoint(lldb::addr_t addr, uint32_t size,

lldb/source/Plugins/Process/Linux/NativeProcessLinux.h

 //===-- NativeProcessLinux.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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef liblldb_NativeProcessLinux_H_
 #define liblldb_NativeProcessLinux_H_
 
 #include <csignal>
 #include <unordered_set>
 
 #include "lldb/Host/Debug.h"
 #include "lldb/Host/HostThread.h"
 #include "lldb/Host/linux/Support.h"
 #include "lldb/Target/MemoryRegionInfo.h"
 #include "lldb/Utility/ArchSpec.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/lldb-types.h"
 
 #include "NativeThreadLinux.h"
Status GetMemoryRegionInfo(lldb::addr_t load_addr,
                              MemoryRegionInfo &range_info) override;
 
   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
                     size_t &bytes_read) override;
 
   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
                      size_t &bytes_written) override;
 
-  Status AllocateMemory(size_t size, uint32_t permissions,
-                        lldb::addr_t &addr) override;
+  llvm::Expected<lldb::addr_t> AllocateMemory(size_t size,
+                                              uint32_t permissions) override;
 
-  Status DeallocateMemory(lldb::addr_t addr) override;
+  llvm::Error DeallocateMemory(lldb::addr_t addr) override;
 
   size_t UpdateThreads() override;
 
   const ArchSpec &GetArchitecture() const override { return m_arch; }
 
   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
                        bool hardware) override;
 
static Status PtraceWrapper(int req, lldb::pid_t pid, void *addr = nullptr,
                               long *result = nullptr);
 
   bool SupportHardwareSingleStepping() const;
 
 protected:
   llvm::Expected<llvm::ArrayRef<uint8_t>>
   GetSoftwareBreakpointTrapOpcode(size_t size_hint) override;
 
+  llvm::Expected<uint64_t> Syscall(llvm::ArrayRef<uint64_t> args);
+
 private:
   MainLoop::SignalHandleUP m_sigchld_handle;
   ArchSpec m_arch;
 
   LazyBool m_supports_mem_region = eLazyBoolCalculate;
   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
 
   lldb::tid_t m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
 
   // List of thread ids stepping with a breakpoint with the address of
   // the relevan breakpoint
   std::map<lldb::tid_t, lldb::addr_t> m_threads_stepping_with_breakpoint;
 
+  /// Inferior memory (allocated by us) and its size.
+  llvm::DenseMap<lldb::addr_t, lldb::addr_t> m_allocated_memory;
+
   // Private Instance Methods
   NativeProcessLinux(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
                      const ArchSpec &arch, MainLoop &mainloop,
                      llvm::ArrayRef<::pid_t> tids);
 
   // Returns a list of process threads that we have attached to.
   static llvm::Expected<std::vector<::pid_t>> Attach(::pid_t pid);
 

lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp

 #include <unistd.h>
 
 #include <fstream>
 #include <mutex>
 #include <sstream>
 #include <string>
 #include <unordered_map>
 
+#include "NativeThreadLinux.h"
+#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
+#include "Plugins/Process/Utility/LinuxProcMaps.h"
+#include "Procfs.h"
 #include "lldb/Core/EmulateInstruction.h"
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostProcess.h"
 #include "lldb/Host/ProcessLaunchInfo.h"
 #include "lldb/Host/PseudoTerminal.h"
 #include "lldb/Host/ThreadLauncher.h"
 #include "lldb/Host/common/NativeRegisterContext.h"
 #include "lldb/Host/linux/Ptrace.h"
 #include "lldb/Host/linux/Uio.h"
 #include "lldb/Host/posix/ProcessLauncherPosixFork.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/RegisterValue.h"
 #include "lldb/Utility/State.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/StringExtractor.h"
+#include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/Errno.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Threading.h"
 
-#include "NativeThreadLinux.h"
-#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
-#include "Plugins/Process/Utility/LinuxProcMaps.h"
-#include "Procfs.h"
-
 #include <linux/unistd.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/user.h>
 #include <sys/wait.h>
 
 // Support hardware breakpoints in case it has not been defined

 void NativeProcessLinux::DoStopIDBumped(uint32_t newBumpId) {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
   LLDB_LOG(log, "newBumpId={0}", newBumpId);
   LLDB_LOG(log, "clearing {0} entries from memory region cache",
            m_mem_region_cache.size());
   m_mem_region_cache.clear();
 }
 
-Status NativeProcessLinux::AllocateMemory(size_t size, uint32_t permissions,
-                                          lldb::addr_t &addr) {
-// FIXME implementing this requires the equivalent of
-// InferiorCallPOSIX::InferiorCallMmap, which depends on functional ThreadPlans
-// working with Native*Protocol.
-#if 1
-  return Status("not implemented yet");
-#else
-  addr = LLDB_INVALID_ADDRESS;
-
-  unsigned prot = 0;
-  if (permissions & lldb::ePermissionsReadable)
-    prot |= eMmapProtRead;
-  if (permissions & lldb::ePermissionsWritable)
-    prot |= eMmapProtWrite;
-  if (permissions & lldb::ePermissionsExecutable)
-    prot |= eMmapProtExec;
-
-  // TODO implement this directly in NativeProcessLinux
-  // (and lift to NativeProcessPOSIX if/when that class is refactored out).
-  if (InferiorCallMmap(this, addr, 0, size, prot,
-                       eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
-    m_addr_to_mmap_size[addr] = size;
-    return Status();
-  } else {
-    addr = LLDB_INVALID_ADDRESS;
-    return Status("unable to allocate %" PRIu64
-                  " bytes of memory with permissions %s",
-                  size, GetPermissionsAsCString(permissions));
+llvm::Expected<uint64_t>
+NativeProcessLinux::Syscall(llvm::ArrayRef<uint64_t> args) {
+  PopulateMemoryRegionCache();
+  auto region_it = llvm::find_if(m_mem_region_cache, [](const auto &pair) {
+    return pair.first.GetExecutable() == MemoryRegionInfo::eYes;
+  });
+  if (region_it == m_mem_region_cache.end())
+    return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                   "No executable memory region found!");
+
+  addr_t exe_addr = region_it->first.GetRange().GetRangeBase();
+
+  NativeThreadLinux &thread = *GetThreadByID(GetID());
+  assert(thread.GetState() == eStateStopped);
+  NativeRegisterContextLinux &reg_ctx = thread.GetRegisterContext();
+
+  NativeRegisterContextLinux::SyscallData syscall_data =
+      *reg_ctx.GetSyscallData();
+
+  DataBufferSP registers_sp;
+  if (llvm::Error Err = reg_ctx.ReadAllRegisterValues(registers_sp).ToError())
+    return std::move(Err);
+  auto restore_regs = llvm::make_scope_exit(
+      [&] { reg_ctx.WriteAllRegisterValues(registers_sp); });
+
+  llvm::SmallVector<uint8_t, 8> memory(syscall_data.Insn.size());
+  size_t bytes_read;
+  if (llvm::Error Err =
+          ReadMemory(exe_addr, memory.data(), memory.size(), bytes_read)
+              .ToError()) {
+    return std::move(Err);
+  }
+
+  auto restore_mem = llvm::make_scope_exit(
+      [&] { WriteMemory(exe_addr, memory.data(), memory.size(), bytes_read); });
+
+  if (llvm::Error Err = reg_ctx.SetPC(exe_addr).ToError())
+    return std::move(Err);
+
+  for (const auto &zip : llvm::zip_first(args, syscall_data.Args)) {
+    if (llvm::Error Err =
+            reg_ctx
+                .WriteRegisterFromUnsigned(std::get<1>(zip), std::get<0>(zip))
+                .ToError()) {
+      return std::move(Err);
+    }
+  }
+  if (llvm::Error Err = WriteMemory(exe_addr, syscall_data.Insn.data(),
+                                    syscall_data.Insn.size(), bytes_read)
+                            .ToError())
+    return std::move(Err);
+
+  m_mem_region_cache.clear();
+
+  int req = SupportHardwareSingleStepping() ? PTRACE_SINGLESTEP : PTRACE_CONT;
+  if (llvm::Error Err =
+          PtraceWrapper(req, thread.GetID(), nullptr, nullptr).ToError())
+    return std::move(Err);
+
+  int status;
+  ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, thread.GetID(),
+                                                 &status, __WALL);
+  if (wait_pid == -1) {
+    return llvm::errorCodeToError(
+        std::error_code(errno, std::generic_category()));
   }
-#endif
+  assert((unsigned)wait_pid == thread.GetID());
+
+  uint64_t result = reg_ctx.ReadRegisterAsUnsigned(syscall_data.Result, -ESRCH);
+  uint64_t errno_threshold =
+      (uint64_t(-1) >> (64 - 8 * m_arch.GetAddressByteSize())) - 0x1000;
+  if (result > errno_threshold) {
+    return llvm::errorCodeToError(
+        std::error_code(-result & 0xfff, std::generic_category()));
   }
 
-Status NativeProcessLinux::DeallocateMemory(lldb::addr_t addr) {
-  // FIXME see comments in AllocateMemory - required lower-level
-  // bits not in place yet (ThreadPlans)
-  return Status("not implemented");
+  return result;
+}
+
+llvm::Expected<addr_t>
+NativeProcessLinux::AllocateMemory(size_t size, uint32_t permissions) {
+
+  llvm::Optional<NativeRegisterContextLinux::MmapData> mmap_data =
+      GetThreadByID(GetID())->GetRegisterContext().GetMmapData();
+  if (!mmap_data)
+    return llvm::make_error<UnimplementedError>();
+
+  unsigned prot = PROT_NONE;
+  if (permissions & ePermissionsReadable)
+    prot |= PROT_READ;
+  if (permissions & ePermissionsWritable)
+    prot |= PROT_WRITE;
+  if (permissions & ePermissionsExecutable)
+    prot |= PROT_EXEC;
+
+  llvm::Expected<uint64_t> Result =
+      Syscall({mmap_data->SysMmap, 0, size, prot, MAP_ANONYMOUS | MAP_PRIVATE,
+               uint64_t(-1), 0});
+  if (Result)
+    m_allocated_memory.try_emplace(*Result, size);
+  return Result;
+}
+
+llvm::Error NativeProcessLinux::DeallocateMemory(lldb::addr_t addr) {
+  llvm::Optional<NativeRegisterContextLinux::MmapData> mmap_data =
+      GetThreadByID(GetID())->GetRegisterContext().GetMmapData();
+  if (!mmap_data)
+    return llvm::make_error<UnimplementedError>();
+
+  auto it = m_allocated_memory.find(addr);
+  if (it == m_allocated_memory.end())
+    return llvm::createStringError(llvm::errc::invalid_argument,
+                                   "Memory not allocated by the debugger.");
+
+  llvm::Expected<uint64_t> Result =
+      Syscall({mmap_data->SysMunmap, addr, it->second});
+  if (!Result)
+    return Result.takeError();
+
+  m_allocated_memory.erase(it);
+  return llvm::Error::success();
 }
 
 size_t NativeProcessLinux::UpdateThreads() {
   // The NativeProcessLinux monitoring threads are always up to date with
   // respect to thread state and they keep the thread list populated properly.
   // All this method needs to do is return the thread count.
   return m_threads.size();
 }

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h

 //===-- NativeRegisterContextLinux.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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef lldb_NativeRegisterContextLinux_h
 #define lldb_NativeRegisterContextLinux_h
 
 #include "Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h"
 #include "lldb/Host/common/NativeThreadProtocol.h"
 
 namespace lldb_private {
 namespace process_linux {
 
 class NativeRegisterContextLinux : public NativeRegisterContextRegisterInfo {
 public:
   NativeRegisterContextLinux(NativeThreadProtocol &native_thread,
                              RegisterInfoInterface *reg_info_interface_p);
 
   // This function is implemented in the NativeRegisterContextLinux_* subclasses
   // to create a new instance of the host specific NativeRegisterContextLinux.
   // The implementations can't collide as only one NativeRegisterContextLinux_*
   // variant should be compiled into the final executable.
   static std::unique_ptr<NativeRegisterContextLinux>
   CreateHostNativeRegisterContextLinux(const ArchSpec &target_arch,
                                        NativeThreadProtocol &native_thread);
 
   // Invalidates cached values in register context data structures
   virtual void InvalidateAllRegisters(){}
 
+  struct SyscallData {
+    /// The syscall instruction. If the architecture uses software
+    /// single-stepping, the instruction should also be followed by a trap to
+    /// ensure the process is stopped after the syscall.
+    llvm::ArrayRef<uint8_t> Insn;
+
+    /// Registers used for syscall arguments. The first register is used to
+    /// store the syscall number.
+    llvm::ArrayRef<uint32_t> Args;
+
+    uint32_t Result; ///< Register containing the syscall result.
+  };
+  /// Return architecture-specific data needed to make inferior syscalls, if
+  /// they are supported.
+  virtual llvm::Optional<SyscallData> GetSyscallData() { return llvm::None; }
+
+  struct MmapData {
+    unsigned SysMmap;   ///< mmap syscall number.
+    unsigned SysMunmap; ///< munmap syscall number
+  };
+  /// Return the architecture-specific data needed to make mmap syscalls, if
+  /// they are supported.
+  virtual llvm::Optional<MmapData> GetMmapData() { return llvm::None; }
+
 protected:
   lldb::ByteOrder GetByteOrder() const;
 
   virtual Status ReadRegisterRaw(uint32_t reg_index, RegisterValue &reg_value);
 
   virtual Status WriteRegisterRaw(uint32_t reg_index,
                                   const RegisterValue &reg_value);
 

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h

 //===-- NativeRegisterContextLinux_x86_64.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
 //
 //===----------------------------------------------------------------------===//
 
 #if defined(__i386__) || defined(__x86_64__)
 
 #ifndef lldb_NativeRegisterContextLinux_x86_64_h
 #define lldb_NativeRegisterContextLinux_x86_64_h
 
 #include "Plugins/Process/Linux/NativeRegisterContextLinux.h"
 #include "Plugins/Process/Utility/RegisterContext_x86.h"
 #include "Plugins/Process/Utility/lldb-x86-register-enums.h"
 #include <sys/uio.h>
 
 namespace lldb_private {
 namespace process_linux {
 
 class NativeProcessLinux;
public:
 
   uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
                                  uint32_t watch_flags) override;
 
   lldb::addr_t GetWatchpointAddress(uint32_t wp_index) override;
 
   uint32_t NumSupportedHardwareWatchpoints() override;
 
+  llvm::Optional<SyscallData> GetSyscallData() override;
+
+  llvm::Optional<MmapData> GetMmapData() override;
+
 protected:
   void *GetGPRBuffer() override { return &m_gpr_x86_64; }
 
   void *GetFPRBuffer() override;
 
   size_t GetFPRSize() override;
 
   Status ReadFPR() override;

lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp

 
 uint32_t
 NativeRegisterContextLinux_x86_64::GetPtraceOffset(uint32_t reg_index) {
   // If register is MPX, remove extra factor from gdb offset
   return GetRegisterInfoAtIndex(reg_index)->byte_offset -
          (IsMPX(reg_index) ? 128 : 0);
 }
 
+llvm::Optional<NativeRegisterContextLinux::SyscallData>
+NativeRegisterContextLinux_x86_64::GetSyscallData() {
+  switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
+  case llvm::Triple::x86: {
+    static uint8_t Int80[] = {0xcd, 0x80};
+    static uint32_t Args[] = {lldb_eax_i386, lldb_ebx_i386, lldb_ecx_i386,
+                              lldb_edx_i386, lldb_esi_i386, lldb_edi_i386,
+                              lldb_ebp_i386};
+    return SyscallData{Int80, Args, lldb_eax_i386};
+  }
+  case llvm::Triple::x86_64: {
+    static uint8_t Syscall[] = {0x0f, 0x05};
+    static uint32_t Args[] = {lldb_rax_x86_64, lldb_rdi_x86_64, lldb_rsi_x86_64,
+                              lldb_rdx_x86_64, lldb_r10_x86_64, lldb_r8_x86_64,
+                              lldb_r9_x86_64};
+    return SyscallData{Syscall, Args, lldb_rax_x86_64};
+  }
+  default:
+    llvm_unreachable("Unhandled architecture!");
+  }
+}
+
+llvm::Optional<NativeRegisterContextLinux::MmapData>
+NativeRegisterContextLinux_x86_64::GetMmapData() {
+  switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
+  case llvm::Triple::x86:
+    return MmapData{192, 91};
+  case llvm::Triple::x86_64:
+    return MmapData{9, 11};
+  default:
+    llvm_unreachable("Unhandled architecture!");
+  }
+}
+
 #endif // defined(__i386__) || defined(__x86_64__)

lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h

Status GetMemoryRegionInfo(lldb::addr_t load_addr,
                              MemoryRegionInfo &range_info) override;
 
   Status ReadMemory(lldb::addr_t addr, void *buf, size_t size,
                     size_t &bytes_read) override;
 
   Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
                      size_t &bytes_written) override;
 
-  Status AllocateMemory(size_t size, uint32_t permissions,
-                        lldb::addr_t &addr) override;
-
-  Status DeallocateMemory(lldb::addr_t addr) override;
-
   lldb::addr_t GetSharedLibraryInfoAddress() override;
 
   size_t UpdateThreads() override;
 
   const ArchSpec &GetArchitecture() const override { return m_arch; }
 
   Status SetBreakpoint(lldb::addr_t addr, uint32_t size,
                        bool hardware) override;

lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp

Status NativeProcessNetBSD::PopulateMemoryRegionCache() {
   }
   LLDB_LOG(log, "read {0} memory region entries from process {1}",
            m_mem_region_cache.size(), GetID());
   // We support memory retrieval, remember that.
   m_supports_mem_region = LazyBool::eLazyBoolYes;
   return Status();
 }
 
-Status NativeProcessNetBSD::AllocateMemory(size_t size, uint32_t permissions,
-                                           lldb::addr_t &addr) {
-  return Status("Unimplemented");
-}
-
-Status NativeProcessNetBSD::DeallocateMemory(lldb::addr_t addr) {
-  return Status("Unimplemented");
-}
-
 lldb::addr_t NativeProcessNetBSD::GetSharedLibraryInfoAddress() {
   // punt on this for now
   return LLDB_INVALID_ADDRESS;
 }
 
 size_t NativeProcessNetBSD::UpdateThreads() { return m_threads.size(); }
 
 Status NativeProcessNetBSD::SetBreakpoint(lldb::addr_t addr, uint32_t size,

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h

 //===-- GDBRemoteCommunicationServerLLGS.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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H
 #define LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H
 
 #include <mutex>
 #include <unordered_map>
 
 #include "lldb/Core/Communication.h"
 #include "lldb/Host/MainLoop.h"
 #include "lldb/Host/common/NativeProcessProtocol.h"
 #include "lldb/lldb-private-forward.h"
 
 #include "GDBRemoteCommunicationServerCommon.h"
 
 class StringExtractorGDBRemote;
 
protected:
   PacketResult Handle_I(StringExtractorGDBRemote &packet);
 
   PacketResult Handle_interrupt(StringExtractorGDBRemote &packet);
 
   // Handles $m and $x packets.
   PacketResult Handle_memory_read(StringExtractorGDBRemote &packet);
 
   PacketResult Handle_M(StringExtractorGDBRemote &packet);
+  PacketResult Handle__M(StringExtractorGDBRemote &packet);
+  PacketResult Handle__m(StringExtractorGDBRemote &packet);
 
   PacketResult
   Handle_qMemoryRegionInfoSupported(StringExtractorGDBRemote &packet);
 
   PacketResult Handle_qMemoryRegionInfo(StringExtractorGDBRemote &packet);
 
   PacketResult Handle_Z(StringExtractorGDBRemote &packet);
 

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp

 //===-- GDBRemoteCommunicationServerLLGS.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 <errno.h>
 
 #include "lldb/Host/Config.h"
 
 
 #include <chrono>
 #include <cstring>
 #include <thread>
 
 #include "GDBRemoteCommunicationServerLLGS.h"
 #include "lldb/Host/ConnectionFileDescriptor.h"
void GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers() {
   RegisterMemberFunctionHandler(
       StringExtractorGDBRemote::eServerPacketType_interrupt,
       &GDBRemoteCommunicationServerLLGS::Handle_interrupt);
   RegisterMemberFunctionHandler(
       StringExtractorGDBRemote::eServerPacketType_m,
       &GDBRemoteCommunicationServerLLGS::Handle_memory_read);
   RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_M,
                                 &GDBRemoteCommunicationServerLLGS::Handle_M);
+  RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType__M,
+                                &GDBRemoteCommunicationServerLLGS::Handle__M);
+  RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType__m,
+                                &GDBRemoteCommunicationServerLLGS::Handle__m);
   RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_p,
                                 &GDBRemoteCommunicationServerLLGS::Handle_p);
   RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_P,
                                 &GDBRemoteCommunicationServerLLGS::Handle_P);
   RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qC,
                                 &GDBRemoteCommunicationServerLLGS::Handle_qC);
   RegisterMemberFunctionHandler(
       StringExtractorGDBRemote::eServerPacketType_qfThreadInfo,
else {
     for (size_t i = 0; i < bytes_read; ++i)
       response.PutHex8(buf[i]);
   }
 
   return SendPacketNoLock(response.GetString());
 }
 
 GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServerLLGS::Handle__M(StringExtractorGDBRemote &packet) {
+  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
+
+  if (!m_debugged_process_up ||
+      (m_debugged_process_up->GetID() == LLDB_INVALID_PROCESS_ID)) {
+    LLDB_LOGF(
+        log,
+        "GDBRemoteCommunicationServerLLGS::%s failed, no process available",
+        __FUNCTION__);
+    return SendErrorResponse(0x15);
+  }
+
+  // Parse out the memory address.
+  packet.SetFilePos(strlen("_M"));
+  if (packet.GetBytesLeft() < 1)
+    return SendIllFormedResponse(packet, "Too short _M packet");
+
+  const lldb::addr_t size = packet.GetHexMaxU64(false, LLDB_INVALID_ADDRESS);
+  if (size == LLDB_INVALID_ADDRESS)
+    return SendIllFormedResponse(packet, "Address not valid");
+  if (packet.GetChar() != ',')
+    return SendIllFormedResponse(packet, "Bad packet");
+  Permissions perms = {};
+  while (packet.GetBytesLeft() > 0) {
+    switch (packet.GetChar()) {
+    case 'r':
+      perms |= ePermissionsReadable;
+      break;
+    case 'w':
+      perms |= ePermissionsWritable;
+      break;
+    case 'x':
+      perms |= ePermissionsExecutable;
+      break;
+    default:
+      return SendIllFormedResponse(packet, "Bad permissions");
+    }
+  }
+
+  llvm::Expected<addr_t> addr =
+      m_debugged_process_up->AllocateMemory(size, perms);
+  if (!addr)
+    return SendErrorResponse(addr.takeError());
+
+  StreamGDBRemote response;
+  response.PutHex64(*addr);
+  return SendPacketNoLock(response.GetString());
+}
+
+GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServerLLGS::Handle__m(StringExtractorGDBRemote &packet) {
+  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
+
+  if (!m_debugged_process_up ||
+      (m_debugged_process_up->GetID() == LLDB_INVALID_PROCESS_ID)) {
+    LLDB_LOGF(
+        log,
+        "GDBRemoteCommunicationServerLLGS::%s failed, no process available",
+        __FUNCTION__);
+    return SendErrorResponse(0x15);
+  }
+
+  // Parse out the memory address.
+  packet.SetFilePos(strlen("_m"));
+  if (packet.GetBytesLeft() < 1)
+    return SendIllFormedResponse(packet, "Too short m packet");
+
+  const lldb::addr_t addr = packet.GetHexMaxU64(false, LLDB_INVALID_ADDRESS);
+  if (addr == LLDB_INVALID_ADDRESS)
+    return SendIllFormedResponse(packet, "Address not valid");
+
+  if (llvm::Error Err = m_debugged_process_up->DeallocateMemory(addr))
+    return SendErrorResponse(std::move(Err));
+
+  return SendOKResponse();
+}
+
+GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerLLGS::Handle_M(StringExtractorGDBRemote &packet) {
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
 
   if (!m_debugged_process_up ||
       (m_debugged_process_up->GetID() == LLDB_INVALID_PROCESS_ID)) {
     LLDB_LOGF(
         log,
         "GDBRemoteCommunicationServerLLGS::%s failed, no process available",

lldb/test/API/lang/c/stepping/TestStepAndBreakpoints.py

class TestCStepping(TestBase):
     def setUp(self):
         # Call super's setUp().
         TestBase.setUp(self)
         # Find the line numbers that we will step to in main:
         self.main_source = "main.c"
 
     @add_test_categories(['pyapi', 'basic_process'])
     @expectedFailureAll(oslist=['freebsd'], bugnumber='llvm.org/pr17932')
-    @expectedFailureAll(oslist=["linux"], bugnumber="llvm.org/pr14437")
     @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24777")
     @expectedFailureNetBSD
     def test_and_python_api(self):
         """Test stepping over vrs. hitting breakpoints & subsequent stepping in various forms."""
         self.build()
         exe = self.getBuildArtifact("a.out")
 
         target = self.dbg.CreateTarget(exe)

lldb/test/API/tools/lldb-server/memory-allocation/Makefile

+C_SOURCES := main.c
+
+include Makefile.rules

lldb/test/API/tools/lldb-server/memory-allocation/TestGdbRemoteMemoryAllocation.py

+
+import gdbremote_testcase
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+supported_linux_archs = ["x86_64", "i386"]
+supported_oses = ["linux"]
+
+class TestGdbRemoteMemoryAllocation(gdbremote_testcase.GdbRemoteTestCaseBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    def allocate(self, size, permissions):
+        self.test_sequence.add_log_lines(["read packet: $_M{:x},{}#00".format(size, permissions),
+                                          {"direction": "send",
+                                           "regex":
+                                           r"^\$([0-9a-f]+)#[0-9a-fA-F]{2}$",
+                                           "capture": {
+                                               1: "addr"}},
+                                          ],
+                                         True)
+        context = self.expect_gdbremote_sequence()
+        self.assertIsNotNone(context)
+
+        addr = int(context.get("addr"), 16)
+        self.test_sequence.add_log_lines(["read packet: $qMemoryRegionInfo:{:x}#00".format(addr),
+                                          {"direction": "send",
+                                           "regex":
+                                           r"^\$start:([0-9a-fA-F]+);size:([0-9a-fA-F]+);permissions:([rwx]*);.*#[0-9a-fA-F]{2}$",
+                                           "capture": {
+                                               1: "addr",
+                                               2: "size",
+                                               3: "permissions"}},
+                                           "read packet: $_m{:x}#00".format(addr),
+                                           "send packet: $OK#00",
+                                          ],
+                                         True)
+        context = self.expect_gdbremote_sequence()
+        self.assertIsNotNone(context)
+
+        self.assertEqual(addr, int(context.get("addr"), 16))
+        self.assertLessEqual(size, int(context.get("size"), 16))
+        self.assertEqual(permissions, context.get("permissions"))
+
+    @skipIf(oslist=no_match(supported_oses))
+    @skipIf(oslist=["linux"], archs=no_match(supported_linux_archs))
+    @llgs_test
+    def test_supported(self):
+        """Make sure (de)allocation works on platforms where it's supposed to
+        work"""
+        self.init_llgs_test()
+        self.build()
+        self.set_inferior_startup_launch()
+        procs = self.prep_debug_monitor_and_inferior()
+
+        self.allocate(0x1000, "r")
+        self.allocate(0x2000, "rw")
+        self.allocate(0x100, "rx")
+        self.allocate(0x1100, "rwx")
+
+    @skipIf(oslist=["linux"], archs=supported_linux_archs)
+    @llgs_test
+    def test_unsupported(self):
+        """Make sure we get an "unsupported" error on platforms where the
+        feature is not implemented."""
+
+        self.init_llgs_test()
+        self.build()
+        self.set_inferior_startup_launch()
+        procs = self.prep_debug_monitor_and_inferior()
+
+        self.test_sequence.add_log_lines(["read packet: $_M1000,rw#00",
+                                           "send packet: $#00",
+                                          ],
+                                         True)
+        self.expect_gdbremote_sequence()
+
+    @llgs_test
+    def test_bad_packet(self):
+        """Make sure we get a proper error for malformed packets."""
+
+        self.init_llgs_test()
+        self.build()
+        self.set_inferior_startup_launch()
+        procs = self.prep_debug_monitor_and_inferior()
+
+        def e():
+            return {"direction": "send",
+                    "regex":
+                    r"^\$E([0-9a-fA-F]+){2}#[0-9a-fA-F]{2}$"}
+
+        self.test_sequence.add_log_lines([
+            "read packet: $_M#00", e(),
+            "read packet: $_M1x#00", e(),
+            "read packet: $_M1:#00", e(),
+            "read packet: $_M1,q#00", e(),
+            "read packet: $_m#00", e(),
+            ], True)
+        self.expect_gdbremote_sequence()

lldb/test/API/tools/lldb-server/memory-allocation/main.c

+int main() { return 0; }

lldb/test/Shell/Expr/nodefaultlib.cpp

+// Test that we're able to evaluate expressions in inferiors without the
+// standard library (and mmap-like functions in particular).
+
+// RUN: %build %s --nodefaultlib -o %t
+// RUN: %lldb %t -o "b main" -o run -o "p call_me(5, 6)" -o exit \
+// RUN:   | FileCheck %s
+
+// CHECK: (int) $0 = 30
+
+int call_me(int x, long y) { return x * y; }
+
+int main() { return call_me(4, 5); }

lldb/unittests/TestingSupport/Host/NativeProcessTestUtils.h

 //===-- NativeProcessTestUtils.cpp ------------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLDB_UNITTESTS_TESTINGSUPPORT_HOST_NATIVEPROCESSTESTUTILS_H
 #define LLDB_UNITTESTS_TESTINGSUPPORT_HOST_NATIVEPROCESSTESTUTILS_H
 
 #include "lldb/Host/common/NativeProcessProtocol.h"
 #include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock.h"
 
 using namespace lldb_private;
 using namespace lldb;
 using namespace testing;
 
 namespace lldb_private {
MockProcess(NativeProcessProtocol::NativeDelegate &Delegate,
               const ArchSpec &Arch, lldb::pid_t Pid = 1)
       : T(Pid, -1, Delegate), Arch(Arch) {}
 
   MOCK_METHOD1(Resume, Status(const ResumeActionList &ResumeActions));
   MOCK_METHOD0(Halt, Status());
   MOCK_METHOD0(Detach, Status());
   MOCK_METHOD1(Signal, Status(int Signo));
   MOCK_METHOD0(Kill, Status());
-  MOCK_METHOD3(AllocateMemory,
-               Status(size_t Size, uint32_t Permissions, addr_t &Addr));
-  MOCK_METHOD1(DeallocateMemory, Status(addr_t Addr));
   MOCK_METHOD0(GetSharedLibraryInfoAddress, addr_t());
   MOCK_METHOD0(UpdateThreads, size_t());
   MOCK_CONST_METHOD0(GetAuxvData,
                      llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>());
   MOCK_METHOD2(GetLoadedModuleFileSpec,
                Status(const char *ModulePath, FileSpec &Spec));
   MOCK_METHOD2(GetFileLoadAddress,
                Status(const llvm::StringRef &FileName, addr_t &Addr));
public:
   }
 
 private:
   std::vector<uint8_t> Data;
   addr_t m_start_addr;
 };
 } // namespace lldb_private
 
-#endif
+#endif