Add preliminary bits for Plugins/Process/NetBSD

[krytarowski]

Summary

It's still not functional (there are bugs), but it has all or mostly all
of the code needed for amd64.

This code is based on FreeBSD with removed unsupported features, missing
in the current version of NetBSD.

It will be easier to keep development it in sync with HEAD and should be
usable for other teams to take it into account in further changes.

[krytarowski]

Addressed few nits pointed out by @joerg

[clayborg]

If you want remote debugging, you should actually implement the lldb-server code and not do a native Process plug-in. What linux and macosx do is even when debugging locally we run through lldb-server (a GDB remote protocol server). This way when you need to remotely debug, it doesn't change anything. I would highly suggest that we go this route. Todd Fiala can help guide you with this. Does remote debugging interest you?

[emaste]

In D20274#431058, @clayborg wrote:

What linux and macosx do is even when debugging locally we run through lldb-server (a GDB remote protocol server).

And this is the way we plan to go on FreeBSD as well and will drop the in-process debugging support when that's ready.

[krytarowski]

Does remote debugging interest you?

Yes.

However, on the other hand it's low priority for me right now. I will rebase to FreeBSD once I will get improved system support in ptrace(2) and functional process/core instrumentation.

[krytarowski]

It no longer builds due to mutex refactoring. Remove as it will need to be redone for remote debugging.

source/Plugins/Process/CMakeLists.txt

 if (CMAKE_SYSTEM_NAME MATCHES "Linux")
   add_subdirectory(Linux)
   add_subdirectory(POSIX)
 elseif (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
   add_subdirectory(FreeBSD)
   add_subdirectory(POSIX)
 elseif (CMAKE_SYSTEM_NAME MATCHES "NetBSD")
+  add_subdirectory(NetBSD)
   add_subdirectory(POSIX)
 elseif (CMAKE_SYSTEM_NAME MATCHES "Windows")
   add_subdirectory(Windows/Live)
   add_subdirectory(Windows/MiniDump)
   add_subdirectory(Windows/Common)
 elseif (CMAKE_SYSTEM_NAME MATCHES "Darwin")
   add_subdirectory(MacOSX-Kernel)
 endif()
 add_subdirectory(gdb-remote)
 add_subdirectory(Utility)
 add_subdirectory(mach-core)
 add_subdirectory(elf-core)

source/Plugins/Process/NetBSD/CMakeLists.txt

+include_directories(.)
+include_directories(../POSIX)
+include_directories(../Utility)
+
+add_lldb_library(lldbPluginProcessNetBSD
+  ProcessNetBSD.cpp
+  NetBSDThread.cpp
+  ProcessMonitor.cpp
+
+  POSIXStopInfo.cpp
+  RegisterContextPOSIXProcessMonitor_x86.cpp
+  )

source/Plugins/Process/NetBSD/NetBSDThread.h

+//===-- NetBSDThread.h -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_NetBSDThread_H_
+#define liblldb_NetBSDThread_H_
+
+// C++ Includes
+#include <memory>
+#include <string>
+
+// Other libraries and framework includes
+#include "lldb/Target/Thread.h"
+#include "RegisterContextPOSIX.h"
+
+class ProcessMessage;
+class ProcessMonitor;
+class POSIXBreakpointProtocol;
+
+//------------------------------------------------------------------------------
+// @class NetBSDThread
+// @brief Abstraction of a NetBSD thread.
+class NetBSDThread
+    : public lldb_private::Thread
+{
+public:
+
+    //------------------------------------------------------------------
+    // Constructors and destructors
+    //------------------------------------------------------------------
+    NetBSDThread(lldb_private::Process &process, lldb::tid_t tid);
+
+    virtual ~NetBSDThread();
+
+    // POSIXThread
+    void
+    RefreshStateAfterStop() override;
+
+    // This notifies the thread when a private stop occurs.
+    void
+    DidStop () override;
+
+    const char *
+    GetInfo() override;
+
+    void
+    SetName (const char *name) override;
+
+    const char *
+    GetName () override;
+
+    lldb::RegisterContextSP
+    GetRegisterContext() override;
+
+    lldb::RegisterContextSP
+    CreateRegisterContextForFrame (lldb_private::StackFrame *frame) override;
+
+    lldb::addr_t
+    GetThreadPointer () override;
+
+    //--------------------------------------------------------------------------
+    // These functions provide a mapping from the register offset
+    // back to the register index or name for use in debugging or log
+    // output.
+
+    unsigned
+    GetRegisterIndexFromOffset(unsigned offset);
+
+    const char *
+    GetRegisterName(unsigned reg);
+
+    const char *
+    GetRegisterNameFromOffset(unsigned offset);
+
+    //--------------------------------------------------------------------------
+    // These methods form a specialized interface to POSIX threads.
+    //
+    bool Resume();
+
+    void Notify(const ProcessMessage &message);
+
+    //--------------------------------------------------------------------------
+    // These methods provide an interface to watchpoints
+    //
+    bool EnableHardwareWatchpoint(lldb_private::Watchpoint *wp);
+
+    bool DisableHardwareWatchpoint(lldb_private::Watchpoint *wp);
+
+    uint32_t NumSupportedHardwareWatchpoints();
+
+    uint32_t FindVacantWatchpointIndex();
+
+protected:
+    POSIXBreakpointProtocol *
+    GetPOSIXBreakpointProtocol ()
+    {
+        if (!m_reg_context_sp)
+            m_reg_context_sp = GetRegisterContext();
+        return m_posix_thread;
+    }
+
+    std::unique_ptr<lldb_private::StackFrame> m_frame_ap;
+
+    lldb::BreakpointSiteSP m_breakpoint;
+
+    bool m_thread_name_valid;
+    std::string m_thread_name;
+    POSIXBreakpointProtocol *m_posix_thread;
+
+    ProcessMonitor &
+    GetMonitor();
+
+    bool
+    CalculateStopInfo() override;
+
+    void BreakNotify(const ProcessMessage &message);
+    void WatchNotify(const ProcessMessage &message);
+    virtual void TraceNotify(const ProcessMessage &message);
+    void LimboNotify(const ProcessMessage &message);
+    void SignalNotify(const ProcessMessage &message);
+    void SignalDeliveredNotify(const ProcessMessage &message);
+    void CrashNotify(const ProcessMessage &message);
+    void ExitNotify(const ProcessMessage &message);
+    void ExecNotify(const ProcessMessage &message);
+
+    lldb_private::Unwind *
+    GetUnwinder() override;
+
+    //--------------------------------------------------------------------------
+    // NetBSDThread internal API.
+
+    // POSIXThread override
+    virtual void
+    WillResume(lldb::StateType resume_state) override;
+};
+
+#endif // #ifndef liblldb_NetBSDThread_H_

source/Plugins/Process/NetBSD/NetBSDThread.cpp

+//===-- NetBSDThread.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// C Includes
+#include <errno.h>
+
+// C++ Includes
+// Other libraries and framework includes
+#include "lldb/Core/State.h"
+#include "lldb/Target/UnixSignals.h"
+
+// Project includes
+#include "lldb/Breakpoint/Watchpoint.h"
+#include "lldb/Breakpoint/BreakpointLocation.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Core/State.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Host/HostNativeThread.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/StopInfo.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/ThreadSpec.h"
+#include "llvm/ADT/SmallString.h"
+#include "POSIXStopInfo.h"
+#include "NetBSDThread.h"
+#include "ProcessNetBSD.h"
+#include "ProcessPOSIXLog.h"
+#include "ProcessMonitor.h"
+#include "RegisterContextPOSIXProcessMonitor_x86.h"
+#include "Plugins/Process/Utility/RegisterContextNetBSD_x86_64.h"
+#include "Plugins/Process/Utility/UnwindLLDB.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+NetBSDThread::NetBSDThread(Process &process, lldb::tid_t tid)
+    : Thread(process, tid),
+      m_frame_ap (),
+      m_breakpoint (),
+      m_thread_name_valid (false),
+      m_thread_name (),
+      m_posix_thread(NULL)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
+        log->Printf ("NetBSDThread::%s (tid = %" PRIi64 ")", __FUNCTION__, tid);
+
+    // Set the current watchpoints for this thread.
+    Target &target = GetProcess()->GetTarget();
+    const WatchpointList &wp_list = target.GetWatchpointList();
+    size_t wp_size = wp_list.GetSize();
+
+    for (uint32_t wp_idx = 0; wp_idx < wp_size; wp_idx++)
+    {
+        lldb::WatchpointSP wp = wp_list.GetByIndex(wp_idx);
+        if (wp.get() && wp->IsEnabled())
+        {
+            // This watchpoint as been enabled; obviously this "new" thread
+            // has been created since that watchpoint was enabled.  Since
+            // the POSIXBreakpointProtocol has yet to be initialized, its
+            // m_watchpoints_initialized member will be FALSE.  Attempting to
+            // read the debug status register to determine if a watchpoint
+            // has been hit would result in the zeroing of that register.
+            // Since the active debug registers would have been cloned when
+            // this thread was created, simply force the m_watchpoints_initized
+            // member to TRUE and avoid resetting dr6 and dr7.
+            GetPOSIXBreakpointProtocol()->ForceWatchpointsInitialized();
+        }
+    }
+}
+
+NetBSDThread::~NetBSDThread()
+{
+    DestroyThread();
+}
+
+ProcessMonitor &
+NetBSDThread::GetMonitor()
+{
+    ProcessSP base = GetProcess();
+    ProcessNetBSD &process = static_cast<ProcessNetBSD&>(*base);
+    return process.GetMonitor();
+}
+
+void
+NetBSDThread::RefreshStateAfterStop()
+{
+    // Invalidate all registers in our register context. We don't set "force" to
+    // true because the stop reply packet might have had some register values
+    // that were expedited and these will already be copied into the register
+    // context by the time this function gets called. The KDPRegisterContext
+    // class has been made smart enough to detect when it needs to invalidate
+    // which registers are valid by putting hooks in the register read and
+    // register supply functions where they check the process stop ID and do
+    // the right thing.
+    //if (StateIsStoppedState(GetState())
+    {
+        const bool force = false;
+        GetRegisterContext()->InvalidateIfNeeded (force);
+    }
+}
+
+const char *
+NetBSDThread::GetInfo()
+{
+    return NULL;
+}
+
+void
+NetBSDThread::SetName (const char *name)
+{
+    m_thread_name_valid = (name && name[0]);
+    if (m_thread_name_valid)
+        m_thread_name.assign (name);
+    else
+        m_thread_name.clear();
+}
+
+const char *
+NetBSDThread::GetName ()
+{
+    if (!m_thread_name_valid)
+    {
+        llvm::SmallString<32> thread_name;
+        HostNativeThread::GetName(::pthread_self(), thread_name);
+        m_thread_name = thread_name.c_str();
+        m_thread_name_valid = true;
+    }
+
+    if (m_thread_name.empty())
+        return NULL;
+    return m_thread_name.c_str();
+}
+
+lldb::RegisterContextSP
+NetBSDThread::GetRegisterContext()
+{
+    if (!m_reg_context_sp)
+    {
+        m_posix_thread = NULL;
+
+        RegisterInfoInterface *reg_interface = NULL;
+        const ArchSpec &target_arch = GetProcess()->GetTarget().GetArchitecture();
+
+        assert(target_arch.GetTriple().getOS() == llvm::Triple::NetBSD);
+        switch (target_arch.GetMachine())
+        {
+            case llvm::Triple::x86_64:
+                reg_interface = new RegisterContextNetBSD_x86_64(target_arch);
+                break;
+            default:
+                llvm_unreachable("CPU not supported");
+        }
+
+        switch (target_arch.GetMachine())
+        {
+            case llvm::Triple::x86_64:
+                {
+                    RegisterContextPOSIXProcessMonitor_x86_64 *reg_ctx = new RegisterContextPOSIXProcessMonitor_x86_64(*this, 0, reg_interface);
+                    m_posix_thread = reg_ctx;
+                    m_reg_context_sp.reset(reg_ctx);
+                    break;
+                }
+            default:
+                break;
+        }
+    }
+    return m_reg_context_sp;
+}
+
+lldb::RegisterContextSP
+NetBSDThread::CreateRegisterContextForFrame(lldb_private::StackFrame *frame)
+{
+    lldb::RegisterContextSP reg_ctx_sp;
+    uint32_t concrete_frame_idx = 0;
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
+        log->Printf ("NetBSDThread::%s ()", __FUNCTION__);
+
+    if (frame)
+        concrete_frame_idx = frame->GetConcreteFrameIndex();
+
+    if (concrete_frame_idx == 0)
+        reg_ctx_sp = GetRegisterContext();
+    else
+    {
+        assert(GetUnwinder());
+        reg_ctx_sp = GetUnwinder()->CreateRegisterContextForFrame(frame);
+    }
+
+    return reg_ctx_sp;
+}
+
+lldb::addr_t
+NetBSDThread::GetThreadPointer ()
+{
+    ProcessMonitor &monitor = GetMonitor();
+    addr_t addr;
+    if (monitor.ReadThreadPointer (GetID(), addr))
+        return addr;
+    else
+        return LLDB_INVALID_ADDRESS;
+}
+
+bool
+NetBSDThread::CalculateStopInfo()
+{
+    SetStopInfo (m_stop_info_sp);
+    return true;
+}
+
+Unwind *
+NetBSDThread::GetUnwinder()
+{
+    if (m_unwinder_ap.get() == NULL)
+        m_unwinder_ap.reset(new UnwindLLDB(*this));
+
+    return m_unwinder_ap.get();
+}
+
+void
+NetBSDThread::DidStop()
+{
+    // Don't set the thread state to stopped unless we really stopped.
+}
+
+void
+NetBSDThread::WillResume(lldb::StateType resume_state)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log)
+        log->Printf("tid %lu resume_state = %s", GetID(),
+                    lldb_private::StateAsCString(resume_state));
+    ProcessSP process_sp(GetProcess());
+    ProcessNetBSD *process = static_cast<ProcessNetBSD *>(process_sp.get());
+    int signo = GetResumeSignal();
+    bool signo_valid = process->GetUnixSignals()->SignalIsValid(signo);
+
+    switch (resume_state)
+    {
+    case eStateSuspended:
+    case eStateStopped:
+        process->m_suspend_tids.push_back(GetID());
+        break;
+    case eStateRunning:
+        process->m_run_tids.push_back(GetID());
+        if (signo_valid)
+            process->m_resume_signo = signo;
+        break;
+    case eStateStepping:
+        process->m_step_tids.push_back(GetID());
+        if (signo_valid)
+            process->m_resume_signo = signo;
+        break;
+    default:
+        break;
+    }
+}
+
+bool
+NetBSDThread::Resume()
+{
+    lldb::StateType resume_state = GetResumeState();
+    ProcessMonitor &monitor = GetMonitor();
+    bool status;
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log)
+        log->Printf ("NetBSDThread::%s (), resume_state = %s", __FUNCTION__,
+                         StateAsCString(resume_state));
+
+    switch (resume_state)
+    {
+    default:
+        assert(false && "Unexpected state for resume!");
+        status = false;
+        break;
+
+    case lldb::eStateRunning:
+        SetState(resume_state);
+        status = monitor.Resume(GetID(), GetResumeSignal());
+        break;
+
+    case lldb::eStateStepping:
+        SetState(resume_state);
+        status = monitor.SingleStep(GetID(), GetResumeSignal());
+        break;
+    case lldb::eStateStopped:
+    case lldb::eStateSuspended:
+        status = true;
+        break;
+    }
+
+    return status;
+}
+
+void
+NetBSDThread::Notify(const ProcessMessage &message)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log)
+        log->Printf ("NetBSDThread::%s () message kind = '%s' for tid %" PRIu64,
+                     __FUNCTION__, message.PrintKind(), GetID());
+
+    switch (message.GetKind())
+    {
+    default:
+        assert(false && "Unexpected message kind!");
+        break;
+
+    case ProcessMessage::eExitMessage:
+        // Nothing to be done.
+        break;
+
+    case ProcessMessage::eLimboMessage:
+        LimboNotify(message);
+        break;
+
+    case ProcessMessage::eSignalMessage:
+        SignalNotify(message);
+        break;
+
+    case ProcessMessage::eSignalDeliveredMessage:
+        SignalDeliveredNotify(message);
+        break;
+
+    case ProcessMessage::eTraceMessage:
+        TraceNotify(message);
+        break;
+
+    case ProcessMessage::eBreakpointMessage:
+        BreakNotify(message);
+        break;
+
+    case ProcessMessage::eWatchpointMessage:
+        WatchNotify(message);
+        break;
+
+    case ProcessMessage::eCrashMessage:
+        CrashNotify(message);
+        break;
+
+    case ProcessMessage::eExecMessage:
+        ExecNotify(message);
+        break;
+    }
+}
+
+bool
+NetBSDThread::EnableHardwareWatchpoint(Watchpoint *wp)
+{
+    bool wp_set = false;
+    if (wp)
+    {
+        addr_t wp_addr = wp->GetLoadAddress();
+        size_t wp_size = wp->GetByteSize();
+        bool wp_read = wp->WatchpointRead();
+        bool wp_write = wp->WatchpointWrite();
+        uint32_t wp_hw_index = wp->GetHardwareIndex();
+        POSIXBreakpointProtocol* reg_ctx = GetPOSIXBreakpointProtocol();
+        if (reg_ctx)
+            wp_set = reg_ctx->SetHardwareWatchpointWithIndex(wp_addr, wp_size,
+                                                             wp_read, wp_write,
+                                                             wp_hw_index);
+    }
+    return wp_set;
+}
+
+bool
+NetBSDThread::DisableHardwareWatchpoint(Watchpoint *wp)
+{
+    bool result = false;
+    if (wp)
+    {
+        lldb::RegisterContextSP reg_ctx_sp = GetRegisterContext();
+        if (reg_ctx_sp.get())
+            result = reg_ctx_sp->ClearHardwareWatchpoint(wp->GetHardwareIndex());
+    }
+    return result;
+}
+
+uint32_t
+NetBSDThread::NumSupportedHardwareWatchpoints()
+{
+    lldb::RegisterContextSP reg_ctx_sp = GetRegisterContext();
+    if (reg_ctx_sp.get())
+        return reg_ctx_sp->NumSupportedHardwareWatchpoints();
+    return 0;
+}
+
+uint32_t
+NetBSDThread::FindVacantWatchpointIndex()
+{
+    uint32_t hw_index = LLDB_INVALID_INDEX32;
+    uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
+    uint32_t wp_idx;
+    POSIXBreakpointProtocol* reg_ctx = GetPOSIXBreakpointProtocol();
+    if (reg_ctx)
+    {
+        for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
+        {
+            if (reg_ctx->IsWatchpointVacant(wp_idx))
+            {
+                hw_index = wp_idx;
+                break;
+            }
+        }
+    }
+    return hw_index;
+}
+
+void
+NetBSDThread::BreakNotify(const ProcessMessage &message)
+{
+    bool status;
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+
+    assert(GetRegisterContext());
+    status = GetPOSIXBreakpointProtocol()->UpdateAfterBreakpoint();
+    assert(status && "Breakpoint update failed!");
+
+    // With our register state restored, resolve the breakpoint object
+    // corresponding to our current PC.
+    assert(GetRegisterContext());
+    lldb::addr_t pc = GetRegisterContext()->GetPC();
+    if (log)
+        log->Printf ("NetBSDThread::%s () PC=0x%8.8" PRIx64, __FUNCTION__, pc);
+    lldb::BreakpointSiteSP bp_site(GetProcess()->GetBreakpointSiteList().FindByAddress(pc));
+
+    // If the breakpoint is for this thread, then we'll report the hit, but if it is for another thread,
+    // we create a stop reason with should_stop=false.  If there is no breakpoint location, then report
+    // an invalid stop reason. We don't need to worry about stepping over the breakpoint here, that will
+    // be taken care of when the thread resumes and notices that there's a breakpoint under the pc.
+    if (bp_site)
+    {
+        lldb::break_id_t bp_id = bp_site->GetID();
+        // If we have an operating system plug-in, we might have set a thread specific breakpoint using the
+        // operating system thread ID, so we can't make any assumptions about the thread ID so we must always
+        // report the breakpoint regardless of the thread.
+        if (bp_site->ValidForThisThread(this) || GetProcess()->GetOperatingSystem () != NULL)
+            SetStopInfo (StopInfo::CreateStopReasonWithBreakpointSiteID(*this, bp_id));
+        else
+        {
+            const bool should_stop = false;
+            SetStopInfo (StopInfo::CreateStopReasonWithBreakpointSiteID(*this, bp_id, should_stop));
+        }
+    }
+    else
+        SetStopInfo(StopInfoSP());
+}
+
+void
+NetBSDThread::WatchNotify(const ProcessMessage &message)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+
+    lldb::addr_t halt_addr = message.GetHWAddress();
+    if (log)
+        log->Printf ("NetBSDThread::%s () Hardware Watchpoint Address = 0x%8.8"
+                     PRIx64, __FUNCTION__, halt_addr);
+
+    POSIXBreakpointProtocol* reg_ctx = GetPOSIXBreakpointProtocol();
+    if (reg_ctx)
+    {
+        uint32_t num_hw_wps = reg_ctx->NumSupportedHardwareWatchpoints();
+        uint32_t wp_idx;
+        for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
+        {
+            if (reg_ctx->IsWatchpointHit(wp_idx))
+            {
+                // Clear the watchpoint hit here
+                reg_ctx->ClearWatchpointHits();
+                break;
+            }
+        }
+
+        if (wp_idx == num_hw_wps)
+            return;
+
+        Target &target = GetProcess()->GetTarget();
+        lldb::addr_t wp_monitor_addr = reg_ctx->GetWatchpointAddress(wp_idx);
+        const WatchpointList &wp_list = target.GetWatchpointList();
+        lldb::WatchpointSP wp_sp = wp_list.FindByAddress(wp_monitor_addr);
+
+        assert(wp_sp.get() && "No watchpoint found");
+        SetStopInfo (StopInfo::CreateStopReasonWithWatchpointID(*this,
+                                                                wp_sp->GetID()));
+    }
+}
+
+void
+NetBSDThread::TraceNotify(const ProcessMessage &message)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+
+    // Try to resolve the breakpoint object corresponding to the current PC.
+    assert(GetRegisterContext());
+    lldb::addr_t pc = GetRegisterContext()->GetPC();
+    if (log)
+        log->Printf ("NetBSDThread::%s () PC=0x%8.8" PRIx64, __FUNCTION__, pc);
+    lldb::BreakpointSiteSP bp_site(GetProcess()->GetBreakpointSiteList().FindByAddress(pc));
+
+    // If the current pc is a breakpoint site then set the StopInfo to Breakpoint.
+    // Otherwise, set the StopInfo to Watchpoint or Trace.
+    // If we have an operating system plug-in, we might have set a thread specific breakpoint using the
+    // operating system thread ID, so we can't make any assumptions about the thread ID so we must always
+    // report the breakpoint regardless of the thread.
+    if (bp_site && (bp_site->ValidForThisThread(this) || GetProcess()->GetOperatingSystem () != NULL))
+        SetStopInfo(StopInfo::CreateStopReasonWithBreakpointSiteID(*this, bp_site->GetID()));
+    else
+    {
+        POSIXBreakpointProtocol* reg_ctx = GetPOSIXBreakpointProtocol();
+        if (reg_ctx)
+        {
+            uint32_t num_hw_wps = reg_ctx->NumSupportedHardwareWatchpoints();
+            uint32_t wp_idx;
+            for (wp_idx = 0; wp_idx < num_hw_wps; wp_idx++)
+            {
+                if (reg_ctx->IsWatchpointHit(wp_idx))
+                {
+                    WatchNotify(message);
+                    return;
+                }
+            }
+        }
+        SetStopInfo (StopInfo::CreateStopReasonToTrace(*this));
+    }
+}
+
+void
+NetBSDThread::LimboNotify(const ProcessMessage &message)
+{
+    SetStopInfo (lldb::StopInfoSP(new POSIXLimboStopInfo(*this)));
+}
+
+void
+NetBSDThread::SignalNotify(const ProcessMessage &message)
+{
+    int signo = message.GetSignal();
+    SetStopInfo (StopInfo::CreateStopReasonWithSignal(*this, signo));
+}
+
+void
+NetBSDThread::SignalDeliveredNotify(const ProcessMessage &message)
+{
+    int signo = message.GetSignal();
+    SetStopInfo (StopInfo::CreateStopReasonWithSignal(*this, signo));
+}
+
+void
+NetBSDThread::CrashNotify(const ProcessMessage &message)
+{
+    // FIXME: Update stop reason as per bugzilla 14598
+    int signo = message.GetSignal();
+
+    assert(message.GetKind() == ProcessMessage::eCrashMessage);
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
+    if (log)
+        log->Printf ("NetBSDThread::%s () signo = %i, reason = '%s'",
+                     __FUNCTION__, signo, message.PrintCrashReason());
+
+    SetStopInfo (lldb::StopInfoSP(new POSIXCrashStopInfo(*this, signo,
+                                                         message.GetCrashReason(),
+                                                         message.GetFaultAddress())));
+}
+
+unsigned
+NetBSDThread::GetRegisterIndexFromOffset(unsigned offset)
+{
+    unsigned reg = LLDB_INVALID_REGNUM;
+    ArchSpec arch = HostInfo::GetArchitecture();
+
+    switch (arch.GetMachine())
+    {
+    default:
+        llvm_unreachable("CPU type not supported!");
+        break;
+
+    case llvm::Triple::x86_64:
+        {
+            POSIXBreakpointProtocol* reg_ctx = GetPOSIXBreakpointProtocol();
+            reg = reg_ctx->GetRegisterIndexFromOffset(offset);
+        }
+        break;
+    }
+    return reg;
+}
+
+void
+NetBSDThread::ExecNotify(const ProcessMessage &message)
+{
+    SetStopInfo (StopInfo::CreateStopReasonWithExec(*this));
+}
+
+const char *
+NetBSDThread::GetRegisterName(unsigned reg)
+{
+    const char * name = nullptr;
+    ArchSpec arch = HostInfo::GetArchitecture();
+
+    switch (arch.GetMachine())
+    {
+    default:
+        assert(false && "CPU type not supported!");
+        break;
+
+    case llvm::Triple::x86_64:
+        name = GetRegisterContext()->GetRegisterName(reg);
+        break;
+    }
+    return name;
+}
+
+const char *
+NetBSDThread::GetRegisterNameFromOffset(unsigned offset)
+{
+    return GetRegisterName(GetRegisterIndexFromOffset(offset));
+}

source/Plugins/Process/NetBSD/POSIXStopInfo.h

+//===-- POSIXStopInfo.h -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_POSIXStopInfo_H_
+#define liblldb_POSIXStopInfo_H_
+
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
+#include "lldb/Target/StopInfo.h"
+
+#include "CrashReason.h"
+#include "NetBSDThread.h"
+
+#include <string>
+
+//===----------------------------------------------------------------------===//
+/// @class POSIXStopInfo
+/// @brief Simple base class for all POSIX-specific StopInfo objects.
+///
+class POSIXStopInfo
+    : public lldb_private::StopInfo
+{
+public:
+    POSIXStopInfo(lldb_private::Thread &thread, uint32_t status)
+        : StopInfo(thread, status)
+        { }
+};
+
+//===----------------------------------------------------------------------===//
+/// @class POSIXLimboStopInfo
+/// @brief Represents the stop state of a process ready to exit.
+///
+class POSIXLimboStopInfo
+    : public POSIXStopInfo
+{
+public:
+    POSIXLimboStopInfo(NetBSDThread &thread)
+        : POSIXStopInfo(thread, 0)
+        { }
+
+    ~POSIXLimboStopInfo();
+
+    lldb::StopReason
+    GetStopReason() const;
+
+    const char *
+    GetDescription();
+
+    bool
+    ShouldStop(lldb_private::Event *event_ptr);
+
+    bool
+    ShouldNotify(lldb_private::Event *event_ptr);
+};
+
+
+//===----------------------------------------------------------------------===//
+/// @class POSIXCrashStopInfo
+/// @brief Represents the stop state of process that is ready to crash.
+///
+class POSIXCrashStopInfo
+    : public POSIXStopInfo
+{
+public:
+    POSIXCrashStopInfo(NetBSDThread &thread, uint32_t status,
+                       CrashReason reason,
+                       lldb::addr_t fault_addr);
+    ~POSIXCrashStopInfo();
+
+    lldb::StopReason
+    GetStopReason() const;
+};
+
+//===----------------------------------------------------------------------===//
+/// @class POSIXNewThreadStopInfo
+/// @brief Represents the stop state of process when a new thread is spawned.
+///
+
+class POSIXNewThreadStopInfo
+    : public POSIXStopInfo
+{
+public:
+    POSIXNewThreadStopInfo (NetBSDThread &thread)
+        : POSIXStopInfo (thread, 0)
+        { }
+
+    ~POSIXNewThreadStopInfo();
+
+    lldb::StopReason
+    GetStopReason() const;
+
+    const char *
+    GetDescription();
+
+    bool
+    ShouldStop(lldb_private::Event *event_ptr);
+
+    bool
+    ShouldNotify(lldb_private::Event *event_ptr);
+};
+
+#endif

source/Plugins/Process/NetBSD/POSIXStopInfo.cpp

+//===-- POSIXStopInfo.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "POSIXStopInfo.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+
+//===----------------------------------------------------------------------===//
+// POSIXLimboStopInfo
+
+POSIXLimboStopInfo::~POSIXLimboStopInfo() { }
+
+lldb::StopReason
+POSIXLimboStopInfo::GetStopReason() const
+{
+    return lldb::eStopReasonThreadExiting;
+}
+
+const char *
+POSIXLimboStopInfo::GetDescription()
+{
+    return "thread exiting";
+}
+
+bool
+POSIXLimboStopInfo::ShouldStop(Event *event_ptr)
+{
+    return false;
+}
+
+bool
+POSIXLimboStopInfo::ShouldNotify(Event *event_ptr)
+{
+    return false;
+}
+
+//===----------------------------------------------------------------------===//
+// POSIXCrashStopInfo
+
+POSIXCrashStopInfo::POSIXCrashStopInfo(NetBSDThread &thread,
+                                       uint32_t status,
+                                       CrashReason reason,
+                                       lldb::addr_t fault_addr)
+    : POSIXStopInfo(thread, status)
+{
+    m_description = ::GetCrashReasonString(reason, fault_addr);
+}
+
+POSIXCrashStopInfo::~POSIXCrashStopInfo() { }
+
+lldb::StopReason
+POSIXCrashStopInfo::GetStopReason() const
+{
+    return lldb::eStopReasonException;
+}
+
+//===----------------------------------------------------------------------===//
+// POSIXNewThreadStopInfo
+
+POSIXNewThreadStopInfo::~POSIXNewThreadStopInfo() { }
+
+lldb::StopReason
+POSIXNewThreadStopInfo::GetStopReason() const
+{
+    return lldb::eStopReasonNone;
+}
+
+const char *
+POSIXNewThreadStopInfo::GetDescription()
+{
+    return "thread spawned";
+}
+
+bool
+POSIXNewThreadStopInfo::ShouldStop(Event *event_ptr)
+{
+    return false;
+}
+
+bool
+POSIXNewThreadStopInfo::ShouldNotify(Event *event_ptr)
+{
+    return false;
+}

source/Plugins/Process/NetBSD/ProcessMonitor.h

+//===-- ProcessMonitor.h -------------------------------------- -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_ProcessMonitor_H_
+#define liblldb_ProcessMonitor_H_
+
+// C Includes
+#include <semaphore.h>
+#include <signal.h>
+
+// C++ Includes
+// Other libraries and framework includes
+#include "lldb/lldb-types.h"
+#include "lldb/Host/FileSpec.h"
+#include "lldb/Host/HostThread.h"
+#include "lldb/Host/Mutex.h"
+
+namespace lldb_private
+{
+class Error;
+class Module;
+class Scalar;
+} // End lldb_private namespace.
+
+class ProcessNetBSD;
+class Operation;
+
+/// @class ProcessMonitor
+/// @brief Manages communication with the inferior (debugee) process.
+///
+/// Upon construction, this class prepares and launches an inferior process for
+/// debugging.
+///
+/// Changes in the inferior process state are propagated to the associated
+/// ProcessNetBSD instance by calling ProcessNetBSD::SendMessage with the
+/// appropriate ProcessMessage events.
+///
+/// A purposely minimal set of operations are provided to interrogate and change
+/// the inferior process state.
+class ProcessMonitor
+{
+public:
+
+    /// Launches an inferior process ready for debugging.  Forms the
+    /// implementation of Process::DoLaunch.
+    ProcessMonitor(ProcessNetBSD *process,
+                   lldb_private::Module *module,
+                   char const *argv[],
+                   char const *envp[],
+                   const lldb_private::FileSpec &stdin_file_spec,
+                   const lldb_private::FileSpec &stdout_file_spec,
+                   const lldb_private::FileSpec &stderr_file_spec,
+                   const lldb_private::FileSpec &working_dir,
+                   const lldb_private::ProcessLaunchInfo &launch_info,
+                   lldb_private::Error &error);
+
+    ProcessMonitor(ProcessNetBSD *process,
+                   lldb::pid_t pid,
+                   lldb_private::Error &error);
+
+    ~ProcessMonitor();
+
+    /// Provides the process number of debugee.
+    lldb::pid_t
+    GetPID() const { return m_pid; }
+
+    /// Returns the process associated with this ProcessMonitor.
+    ProcessNetBSD &
+    GetProcess() { return *m_process; }
+
+    /// Returns a file descriptor to the controlling terminal of the inferior
+    /// process.
+    ///
+    /// Reads from this file descriptor yield both the standard output and
+    /// standard error of this debugee.  Even if stderr and stdout were
+    /// redirected on launch it may still happen that data is available on this
+    /// descriptor (if the inferior process opens /dev/tty, for example). This descriptor is
+    /// closed after a call to StopMonitor().
+    ///
+    /// If this monitor was attached to an existing process this method returns
+    /// -1.
+    int
+    GetTerminalFD() const { return m_terminal_fd; }
+
+    /// Reads @p size bytes from address @vm_adder in the inferior process
+    /// address space.
+    ///
+    /// This method is provided to implement Process::DoReadMemory.
+    size_t
+    ReadMemory(lldb::addr_t vm_addr, void *buf, size_t size,
+               lldb_private::Error &error);
+
+    /// Writes @p size bytes from address @p vm_adder in the inferior process
+    /// address space.
+    ///
+    /// This method is provided to implement Process::DoWriteMemory.
+    size_t
+    WriteMemory(lldb::addr_t vm_addr, const void *buf, size_t size,
+                lldb_private::Error &error);
+
+    /// Reads the contents from the register identified by the given (architecture
+    /// dependent) offset.
+    ///
+    /// This method is provided for use by RegisterContextNetBSD derivatives.
+    bool
+    ReadRegisterValue(lldb::tid_t tid, unsigned offset, const char *reg_name,
+                      unsigned size, lldb_private::RegisterValue &value);
+
+    /// Writes the given value to the register identified by the given
+    /// (architecture dependent) offset.
+    ///
+    /// This method is provided for use by RegisterContextNetBSD derivatives.
+    bool
+    WriteRegisterValue(lldb::tid_t tid, unsigned offset, const char *reg_name,
+                       const lldb_private::RegisterValue &value);
+
+    /// Reads all general purpose registers into the specified buffer.
+    bool
+    ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size);
+
+    /// Reads all floating point registers into the specified buffer.
+    bool
+    ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size);
+
+    /// Reads the specified register set into the specified buffer.
+    ///
+    /// This method is provided for use by RegisterContextNetBSD derivatives.
+    bool
+    ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset);
+
+    /// Writes all general purpose registers into the specified buffer.
+    bool
+    WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size);
+
+    /// Writes all floating point registers into the specified buffer.
+    bool
+    WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size);
+
+    /// Writes the specified register set into the specified buffer.
+    ///
+    /// This method is provided for use by RegisterContextNetBSD derivatives.
+    bool
+    WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset);
+
+    /// Reads the value of the thread-specific pointer for a given thread ID.
+    bool
+    ReadThreadPointer(lldb::tid_t tid, lldb::addr_t &value);
+
+    /// Returns current thread IDs in process
+    size_t
+    GetCurrentThreadIDs(std::vector<lldb::tid_t> &thread_ids);
+
+    /// Writes a ptrace_lwpinfo structure corresponding to the given thread ID
+    /// to the memory region pointed to by @p lwpinfo.
+    bool
+    GetLwpInfo(lldb::tid_t tid, void *lwpinfo, int &error_no);
+
+    /// Suspends or unsuspends a thread prior to process resume or step.
+    bool
+    ThreadSuspend(lldb::tid_t tid, bool suspend);
+
+    /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
+    /// corresponding to the given thread IDto the memory pointed to by @p
+    /// message.
+    bool
+    GetEventMessage(lldb::tid_t tid, unsigned long *message);
+
+    /// Resumes the process.  If @p signo is anything but
+    /// LLDB_INVALID_SIGNAL_NUMBER, deliver that signal to the process.
+    bool
+    Resume(lldb::tid_t unused, uint32_t signo);
+
+    /// Single steps the process.  If @p signo is anything but
+    /// LLDB_INVALID_SIGNAL_NUMBER, deliver that signal to the process.
+    bool
+    SingleStep(lldb::tid_t unused, uint32_t signo);
+
+    /// Terminate the traced process.
+    bool
+    Kill();
+
+    lldb_private::Error
+    Detach(lldb::tid_t tid);
+
+    void
+    StopMonitor();
+
+    // Waits for the initial stop message from a new thread.
+    bool
+    WaitForInitialTIDStop(lldb::tid_t tid);
+
+private:
+    ProcessNetBSD *m_process;
+
+    lldb_private::HostThread m_operation_thread;
+    lldb_private::HostThread m_monitor_thread;
+    lldb::pid_t m_pid;
+
+    int m_terminal_fd;
+
+    // current operation which must be executed on the privileged thread
+    Operation *m_operation;
+    lldb_private::Mutex m_operation_mutex;
+
+    // semaphores notified when Operation is ready to be processed and when
+    // the operation is complete.
+    sem_t m_operation_pending;
+    sem_t m_operation_done;
+
+    struct OperationArgs
+    {
+        OperationArgs(ProcessMonitor *monitor);
+
+        ~OperationArgs();
+
+        ProcessMonitor *m_monitor;      // The monitor performing the attach.
+        sem_t m_semaphore;              // Posted to once operation complete.
+        lldb_private::Error m_error;    // Set if process operation failed.
+    };
+
+    /// @class LauchArgs
+    ///
+    /// @brief Simple structure to pass data to the thread responsible for
+    /// launching a child process.
+    struct LaunchArgs : OperationArgs
+    {
+        LaunchArgs(ProcessMonitor *monitor,
+                   lldb_private::Module *module,
+                   char const **argv,
+                   char const **envp,
+                   const lldb_private::FileSpec &stdin_file_spec,
+                   const lldb_private::FileSpec &stdout_file_spec,
+                   const lldb_private::FileSpec &stderr_file_spec,
+                   const lldb_private::FileSpec &working_dir);
+
+        ~LaunchArgs();
+
+        lldb_private::Module *m_module;                  // The executable image to launch.
+        char const **m_argv;                             // Process arguments.
+        char const **m_envp;                             // Process environment.
+        const lldb_private::FileSpec m_stdin_file_spec;  // Redirect stdin or empty.
+        const lldb_private::FileSpec m_stdout_file_spec; // Redirect stdout or empty.
+        const lldb_private::FileSpec m_stderr_file_spec; // Redirect stderr or empty.
+        const lldb_private::FileSpec m_working_dir;      // Working directory or empty.
+    };
+
+    void
+    StartLaunchOpThread(LaunchArgs *args, lldb_private::Error &error);
+
+    static void *
+    LaunchOpThread(void *arg);
+
+    static bool
+    Launch(LaunchArgs *args);
+
+    struct AttachArgs : OperationArgs
+    {
+        AttachArgs(ProcessMonitor *monitor,
+                   lldb::pid_t pid);
+
+        ~AttachArgs();
+
+        lldb::pid_t m_pid;              // pid of the process to be attached.
+    };
+
+    void
+    StartAttachOpThread(AttachArgs *args, lldb_private::Error &error);
+
+    static void *
+    AttachOpThread(void *args);
+
+    static void
+    Attach(AttachArgs *args);
+
+    static void
+    ServeOperation(OperationArgs *args);
+
+    static bool
+    DupDescriptor(const lldb_private::FileSpec &file_spec, int fd, int flags);
+
+    static bool
+    MonitorCallback(ProcessMonitor *monitor, lldb::pid_t pid, bool exited, int signal, int status);
+
+    void
+    DoOperation(Operation *op);
+
+    /// Stops the child monitor thread.
+    void
+    StopMonitoringChildProcess();
+
+    /// Stops the operation thread used to attach/launch a process.
+    void
+    StopOpThread();
+};
+
+#endif // #ifndef liblldb_ProcessMonitor_H_

source/Plugins/Process/NetBSD/ProcessMonitor.cpp

+//===-- ProcessMonitor.cpp ------------------------------------ -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// C Includes
+#include <errno.h>
+#include <poll.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/ptrace.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+// C++ Includes
+// Other libraries and framework includes
+#include "lldb/Core/Error.h"
+#include "lldb/Core/RegisterValue.h"
+#include "lldb/Core/Scalar.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Host/ThreadLauncher.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/UnixSignals.h"
+#include "lldb/Utility/PseudoTerminal.h"
+
+#include "Plugins/Process/POSIX/CrashReason.h"
+#include "NetBSDThread.h"
+#include "ProcessNetBSD.h"
+#include "ProcessPOSIXLog.h"
+#include "ProcessMonitor.h"
+
+extern "C" {
+      extern char ** environ;
+ }
+
+using namespace lldb;
+using namespace lldb_private;
+
+// We disable the tracing of ptrace calls for integration builds to
+// avoid the additional indirection and checks.
+#ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
+// Wrapper for ptrace to catch errors and log calls.
+
+const char *
+Get_PT_IO_OP(int op)
+{
+    switch (op) {
+        case PIOD_READ_D:  return "READ_D";
+        case PIOD_WRITE_D: return "WRITE_D";
+        case PIOD_READ_I:  return "READ_I";
+        case PIOD_WRITE_I: return "WRITE_I";
+        default:           return "Unknown op";
+    }
+}
+
+// Wrapper for ptrace to catch errors and log calls.
+// Note that ptrace sets errno on error because -1 is reserved as a valid result.
+extern long
+PtraceWrapper(int req, lldb::pid_t pid, void *addr, int data,
+              const char* reqName, const char* file, int line)
+{
+    long int result;
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
+
+    if (log) {
+        log->Printf("ptrace(%s, %" PRIu64 ", %p, %x) called from file %s line %d",
+                    reqName, pid, addr, data, file, line);
+        if (req == PT_IO) {
+            struct ptrace_io_desc *pi = (struct ptrace_io_desc *) addr;
+
+            log->Printf("PT_IO: op=%s offs=%zx size=%zu",
+                     Get_PT_IO_OP(pi->piod_op), (size_t)pi->piod_offs, pi->piod_len);
+        }
+    }
+
+    //PtraceDisplayBytes(req, data);
+
+    errno = 0;
+    result = ptrace(req, pid, (caddr_t) addr, data);
+
+    //PtraceDisplayBytes(req, data);
+
+    if (log && errno != 0)
+    {
+        const char* str;
+        switch (errno)
+        {
+        case ESRCH:  str = "ESRCH"; break;
+        case EINVAL: str = "EINVAL"; break;
+        case EBUSY:  str = "EBUSY"; break;
+        case EPERM:  str = "EPERM"; break;
+        default:     str = "<unknown>";
+        }
+        log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
+    }
+
+    if (log) {
+#ifdef __amd64__
+        if (req == PT_GETREGS) {
+            struct reg *r = (struct reg *) addr;
+
+            log->Printf("PT_GETREGS: rip=0x%lx rsp=0x%lx rbp=0x%lx rax=0x%lx",
+                        r->regs[_REG_RIP], r->regs[_REG_RSP], r->regs[_REG_RBP], r->regs[_REG_RAX]);
+        }
+#endif
+    }
+
+    return result;
+}
+
+// Wrapper for ptrace when logging is not required.
+// Sets errno to 0 prior to calling ptrace.
+extern long
+PtraceWrapper(int req, lldb::pid_t pid, void *addr, int data)
+{
+    long result = 0;
+    errno = 0;
+    result = ptrace(req, pid, (caddr_t)addr, data);
+    return result;
+}
+
+#define PTRACE(req, pid, addr, data) \
+    PtraceWrapper((req), (pid), (addr), (data), #req, __FILE__, __LINE__)
+#else
+    PtraceWrapper((req), (pid), (addr), (data))
+#endif
+
+//------------------------------------------------------------------------------
+// Static implementations of ProcessMonitor::ReadMemory and
+// ProcessMonitor::WriteMemory.  This enables mutual recursion between these
+// functions without needed to go thru the thread funnel.
+
+static size_t
+DoReadMemory(lldb::pid_t pid, lldb::addr_t vm_addr, void *buf, size_t size,
+             Error &error)
+{
+    struct ptrace_io_desc pi_desc;
+
+    pi_desc.piod_op = PIOD_READ_D;
+    pi_desc.piod_offs = (void *)vm_addr;
+    pi_desc.piod_addr = buf;
+    pi_desc.piod_len = size;
+
+    if (PTRACE(PT_IO, pid, (caddr_t)&pi_desc, 0) < 0)
+        error.SetErrorToErrno();
+    return pi_desc.piod_len;
+}
+
+static size_t
+DoWriteMemory(lldb::pid_t pid, lldb::addr_t vm_addr, const void *buf,
+              size_t size, Error &error)
+{
+    struct ptrace_io_desc pi_desc;
+
+    pi_desc.piod_op = PIOD_WRITE_D;
+    pi_desc.piod_offs = (void *)vm_addr;
+    pi_desc.piod_addr = (void *)buf;
+    pi_desc.piod_len = size;
+
+    if (PTRACE(PT_IO, pid, (caddr_t)&pi_desc, 0) < 0)
+        error.SetErrorToErrno();
+    return pi_desc.piod_len;
+}
+
+// Simple helper function to ensure flags are enabled on the given file
+// descriptor.
+static bool
+EnsureFDFlags(int fd, int flags, Error &error)
+{
+    int status;
+
+    if ((status = fcntl(fd, F_GETFL)) == -1)
+    {
+        error.SetErrorToErrno();
+        return false;
+    }
+
+    if (fcntl(fd, F_SETFL, status | flags) == -1)
+    {
+        error.SetErrorToErrno();
+        return false;
+    }
+
+    return true;
+}
+
+//------------------------------------------------------------------------------
+/// @class Operation
+/// @brief Represents a ProcessMonitor operation.
+///
+/// Not implemented
+class Operation
+{
+public:
+    virtual ~Operation() {}
+    virtual void Execute(ProcessMonitor *monitor) = 0;
+};
+
+//------------------------------------------------------------------------------
+/// @class ReadOperation
+/// @brief Implements ProcessMonitor::ReadMemory.
+class ReadOperation : public Operation
+{
+public:
+    ReadOperation(lldb::addr_t addr, void *buff, size_t size,
+                  Error &error, size_t &result)
+        : m_addr(addr), m_buff(buff), m_size(size),
+          m_error(error), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::addr_t m_addr;
+    void *m_buff;
+    size_t m_size;
+    Error &m_error;
+    size_t &m_result;
+};
+
+void
+ReadOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+
+    m_result = DoReadMemory(pid, m_addr, m_buff, m_size, m_error);
+}
+
+//------------------------------------------------------------------------------
+/// @class WriteOperation
+/// @brief Implements ProcessMonitor::WriteMemory.
+class WriteOperation : public Operation
+{
+public:
+    WriteOperation(lldb::addr_t addr, const void *buff, size_t size,
+                   Error &error, size_t &result)
+        : m_addr(addr), m_buff(buff), m_size(size),
+          m_error(error), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::addr_t m_addr;
+    const void *m_buff;
+    size_t m_size;
+    Error &m_error;
+    size_t &m_result;
+};
+
+void
+WriteOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+
+    m_result = DoWriteMemory(pid, m_addr, m_buff, m_size, m_error);
+}
+
+//------------------------------------------------------------------------------
+/// @class ReadRegOperation
+/// @brief Implements ProcessMonitor::ReadRegisterValue.
+class ReadRegOperation : public Operation
+{
+public:
+    ReadRegOperation(lldb::tid_t tid, unsigned offset, unsigned size,
+                     RegisterValue &value, bool &result)
+        : m_tid(tid), m_offset(offset), m_size(size),
+          m_value(value), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    unsigned m_offset;
+    unsigned m_size;
+    RegisterValue &m_value;
+    bool &m_result;
+};
+
+void
+ReadRegOperation::Execute(ProcessMonitor *monitor)
+{
+    struct reg regs;
+    int rc;
+
+    if ((rc = PTRACE(PT_GETREGS, m_tid, (caddr_t)&regs, 0)) < 0) {
+        m_result = false;
+    } else {
+        // 'struct reg' contains only 32- or 64-bit register values.  Punt on
+        // others.  Also, not all entries may be uintptr_t sized, such as 32-bit
+        // processes on powerpc64 (probably the same for i386 on amd64)
+        if (m_size == sizeof(uint32_t))
+            m_value = *(uint32_t *)(((caddr_t)&regs) + m_offset);
+        else if (m_size == sizeof(uint64_t))
+            m_value = *(uint64_t *)(((caddr_t)&regs) + m_offset);
+        else
+            memcpy((void *)&m_value, (((caddr_t)&regs) + m_offset), m_size);
+        m_result = true;
+    }
+}
+
+//------------------------------------------------------------------------------
+/// @class WriteRegOperation
+/// @brief Implements ProcessMonitor::WriteRegisterValue.
+class WriteRegOperation : public Operation
+{
+public:
+    WriteRegOperation(lldb::tid_t tid, unsigned offset,
+                      const RegisterValue &value, bool &result)
+        : m_tid(tid), m_offset(offset),
+          m_value(value), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    unsigned m_offset;
+    const RegisterValue &m_value;
+    bool &m_result;
+};
+
+void
+WriteRegOperation::Execute(ProcessMonitor *monitor)
+{
+    struct reg regs;
+
+    if (PTRACE(PT_GETREGS, m_tid, (caddr_t)&regs, 0) < 0) {
+        m_result = false;
+        return;
+    }
+    *(uintptr_t *)(((caddr_t)&regs) + m_offset) = (uintptr_t)m_value.GetAsUInt64();
+    if (PTRACE(PT_SETREGS, m_tid, (caddr_t)&regs, 0) < 0)
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class ReadGPROperation
+/// @brief Implements ProcessMonitor::ReadGPR.
+class ReadGPROperation : public Operation
+{
+public:
+    ReadGPROperation(lldb::tid_t tid, void *buf, bool &result)
+        : m_tid(tid), m_buf(buf), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    void *m_buf;
+    bool &m_result;
+};
+
+void
+ReadGPROperation::Execute(ProcessMonitor *monitor)
+{
+    int rc;
+
+    errno = 0;
+    rc = PTRACE(PT_GETREGS, m_tid, (caddr_t)m_buf, 0);
+    if (errno != 0)
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class ReadFPROperation
+/// @brief Implements ProcessMonitor::ReadFPR.
+class ReadFPROperation : public Operation
+{
+public:
+    ReadFPROperation(lldb::tid_t tid, void *buf, bool &result)
+        : m_tid(tid), m_buf(buf), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    void *m_buf;
+    bool &m_result;
+};
+
+void
+ReadFPROperation::Execute(ProcessMonitor *monitor)
+{
+    if (PTRACE(PT_GETFPREGS, m_tid, (caddr_t)m_buf, 0) < 0)
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class WriteGPROperation
+/// @brief Implements ProcessMonitor::WriteGPR.
+class WriteGPROperation : public Operation
+{
+public:
+    WriteGPROperation(lldb::tid_t tid, void *buf, bool &result)
+        : m_tid(tid), m_buf(buf), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    void *m_buf;
+    bool &m_result;
+};
+
+void
+WriteGPROperation::Execute(ProcessMonitor *monitor)
+{
+    if (PTRACE(PT_SETREGS, m_tid, (caddr_t)m_buf, 0) < 0)
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class WriteFPROperation
+/// @brief Implements ProcessMonitor::WriteFPR.
+class WriteFPROperation : public Operation
+{
+public:
+    WriteFPROperation(lldb::tid_t tid, void *buf, bool &result)
+        : m_tid(tid), m_buf(buf), m_result(result)
+        { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    void *m_buf;
+    bool &m_result;
+};
+
+void
+WriteFPROperation::Execute(ProcessMonitor *monitor)
+{
+    if (PTRACE(PT_SETFPREGS, m_tid, (caddr_t)m_buf, 0) < 0)
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class ResumeOperation
+/// @brief Implements ProcessMonitor::Resume.
+class ResumeOperation : public Operation
+{
+public:
+    ResumeOperation(uint32_t signo, bool &result) :
+        m_signo(signo), m_result(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    uint32_t m_signo;
+    bool &m_result;
+};
+
+void
+ResumeOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+    int data = 0;
+
+    if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
+        data = m_signo;
+
+    if (PTRACE(PT_CONTINUE, pid, (caddr_t)1, data))
+    {
+        Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
+
+        if (log)
+            log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", pid, strerror(errno));
+        m_result = false;
+    }
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class SingleStepOperation
+/// @brief Implements ProcessMonitor::SingleStep.
+class SingleStepOperation : public Operation
+{
+public:
+    SingleStepOperation(uint32_t signo, bool &result)
+        : m_signo(signo), m_result(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    uint32_t m_signo;
+    bool &m_result;
+};
+
+void
+SingleStepOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+    int data = 0;
+
+    if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
+        data = m_signo;
+
+    if (PTRACE(PT_STEP, pid, NULL, data))
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class LwpInfoOperation
+/// @brief Implements ProcessMonitor::GetLwpInfo.
+class LwpInfoOperation : public Operation
+{
+public:
+    LwpInfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
+        : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    void *m_info;
+    bool &m_result;
+    int &m_err;
+};
+
+void
+LwpInfoOperation::Execute(ProcessMonitor *monitor)
+{
+    struct ptrace_lwpinfo plwp;
+
+    if (PTRACE(PT_LWPINFO, m_tid, (caddr_t)&plwp, sizeof(plwp))) {
+        m_result = false;
+        m_err = errno;
+    } else {
+        memcpy(m_info, &plwp, sizeof(plwp));
+        m_result = true;
+    }
+}
+
+//------------------------------------------------------------------------------
+/// @class ThreadSuspendOperation
+/// @brief Implements ProcessMonitor::ThreadSuspend.
+class ThreadSuspendOperation : public Operation
+{
+public:
+    ThreadSuspendOperation(lldb::tid_t tid, bool suspend, bool &result)
+        : m_tid(tid), m_suspend(suspend), m_result(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    bool m_suspend;
+    bool &m_result;
+} ;
+
+//------------------------------------------------------------------------------
+/// @class EventMessageOperation
+/// @brief Implements ProcessMonitor::GetEventMessage.
+class EventMessageOperation : public Operation
+{
+public:
+    EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
+        : m_tid(tid), m_message(message), m_result(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    lldb::tid_t m_tid;
+    unsigned long *m_message;
+    bool &m_result;
+};
+
+void
+EventMessageOperation::Execute(ProcessMonitor *monitor)
+{
+    struct ptrace_lwpinfo plwp;
+
+    if (PTRACE(PT_LWPINFO, m_tid, (caddr_t)&plwp, sizeof(plwp)))
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class KillOperation
+/// @brief Implements ProcessMonitor::Kill.
+class KillOperation : public Operation
+{
+public:
+    KillOperation(bool &result) : m_result(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    bool &m_result;
+};
+
+void
+KillOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+
+    if (PTRACE(PT_KILL, pid, NULL, 0))
+        m_result = false;
+    else
+        m_result = true;
+}
+
+//------------------------------------------------------------------------------
+/// @class DetachOperation
+/// @brief Implements ProcessMonitor::Detach.
+class DetachOperation : public Operation
+{
+public:
+    DetachOperation(Error &result) : m_error(result) { }
+
+    void Execute(ProcessMonitor *monitor);
+
+private:
+    Error &m_error;
+};
+
+void
+DetachOperation::Execute(ProcessMonitor *monitor)
+{
+    lldb::pid_t pid = monitor->GetPID();
+
+    if (PTRACE(PT_DETACH, pid, NULL, 0) < 0)
+        m_error.SetErrorToErrno();
+
+}
+
+ProcessMonitor::OperationArgs::OperationArgs(ProcessMonitor *monitor)
+    : m_monitor(monitor)
+{
+    sem_init(&m_semaphore, 0, 0);
+}
+
+ProcessMonitor::OperationArgs::~OperationArgs()
+{
+    sem_destroy(&m_semaphore);
+}
+
+ProcessMonitor::LaunchArgs::LaunchArgs(ProcessMonitor *monitor,
+                                       lldb_private::Module *module,
+                                       char const **argv,
+                                       char const **envp,
+                                       const FileSpec &stdin_file_spec,
+                                       const FileSpec &stdout_file_spec,
+                                       const FileSpec &stderr_file_spec,
+                                       const FileSpec &working_dir)
+    : OperationArgs(monitor),
+      m_module(module),
+      m_argv(argv),
+      m_envp(envp),
+      m_stdin_file_spec(stdin_file_spec),
+      m_stdout_file_spec(stdout_file_spec),
+      m_stderr_file_spec(stderr_file_spec),
+      m_working_dir(working_dir) { }
+
+ProcessMonitor::LaunchArgs::~LaunchArgs()
+{ }
+
+ProcessMonitor::AttachArgs::AttachArgs(ProcessMonitor *monitor,
+                                       lldb::pid_t pid)
+    : OperationArgs(monitor), m_pid(pid) { }
+
+ProcessMonitor::AttachArgs::~AttachArgs()
+{ }
+
+//------------------------------------------------------------------------------
+/// The basic design of the ProcessMonitor is built around two threads.
+///
+/// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
+/// for changes in the debugee state.  When a change is detected a
+/// ProcessMessage is sent to the associated ProcessNetBSD instance.  This thread
+/// "drives" state changes in the debugger.
+///
+/// The second thread (@see OperationThread) is responsible for two things 1)
+/// launching or attaching to the inferior process, and then 2) servicing
+/// operations such as register reads/writes, stepping, etc.  See the comments
+/// on the Operation class for more info as to why this is needed.
+ProcessMonitor::ProcessMonitor(ProcessNetBSD *process,
+                               Module *module,
+                               const char *argv[],
+                               const char *envp[],
+                               const FileSpec &stdin_file_spec,
+                               const FileSpec &stdout_file_spec,
+                               const FileSpec &stderr_file_spec,
+                               const FileSpec &working_dir,
+                               const lldb_private::ProcessLaunchInfo & /* launch_info */,
+                               lldb_private::Error &error)
+    : m_process(static_cast<ProcessNetBSD *>(process)),
+      m_pid(LLDB_INVALID_PROCESS_ID),
+      m_terminal_fd(-1),
+      m_operation(0)
+{
+    using namespace std::placeholders;
+
+    std::unique_ptr<LaunchArgs> args(new LaunchArgs(this, module, argv, envp,
+                                                    stdin_file_spec,
+                                                    stdout_file_spec,
+                                                    stderr_file_spec,
+                                                    working_dir));
+
+
+    sem_init(&m_operation_pending, 0, 0);
+    sem_init(&m_operation_done, 0, 0);
+
+    StartLaunchOpThread(args.get(), error);
+    if (!error.Success())
+        return;
+
+WAIT_AGAIN:
+    // Wait for the operation thread to initialize.
+    if (sem_wait(&args->m_semaphore))
+    {
+        if (errno == EINTR)
+            goto WAIT_AGAIN;
+        else
+        {
+            error.SetErrorToErrno();
+            return;
+        }
+    }
+
+    // Check that the launch was a success.
+    if (!args->m_error.Success())
+    {
+        StopOpThread();
+        error = args->m_error;
+        return;
+    }
+
+    // Finally, start monitoring the child process for change in state.
+    m_monitor_thread = Host::StartMonitoringChildProcess(
+        std::bind(&ProcessMonitor::MonitorCallback, this, _1, _2, _3, _4), GetPID(), true);
+    if (!m_monitor_thread.IsJoinable())
+    {
+        error.SetErrorToGenericError();
+        error.SetErrorString("Process launch failed.");
+        return;
+    }
+}
+
+ProcessMonitor::ProcessMonitor(ProcessNetBSD *process,
+                               lldb::pid_t pid,
+                               lldb_private::Error &error)
+    : m_process(static_cast<ProcessNetBSD *>(process)),
+      m_pid(pid),
+      m_terminal_fd(-1),
+      m_operation(0)
+{
+    using namespace std::placeholders;
+
+    sem_init(&m_operation_pending, 0, 0);
+    sem_init(&m_operation_done, 0, 0);
+
+
+    std::unique_ptr<AttachArgs> args(new AttachArgs(this, pid));
+
+    StartAttachOpThread(args.get(), error);
+    if (!error.Success())
+        return;
+
+WAIT_AGAIN:
+    // Wait for the operation thread to initialize.
+    if (sem_wait(&args->m_semaphore))
+    {
+        if (errno == EINTR)
+            goto WAIT_AGAIN;
+        else
+        {
+            error.SetErrorToErrno();
+            return;
+        }
+    }
+
+    // Check that the attach was a success.
+    if (!args->m_error.Success())
+    {
+        StopOpThread();
+        error = args->m_error;
+        return;
+    }
+
+    // Finally, start monitoring the child process for change in state.
+    m_monitor_thread = Host::StartMonitoringChildProcess(
+        std::bind(&ProcessMonitor::MonitorCallback, this, _1, _2, _3, _4), GetPID(), true);
+    if (!m_monitor_thread.IsJoinable())
+    {
+        error.SetErrorToGenericError();
+        error.SetErrorString("Process attach failed.");
+        return;
+    }
+}
+
+ProcessMonitor::~ProcessMonitor()
+{
+    StopMonitor();
+}
+
+//------------------------------------------------------------------------------
+// Thread setup and tear down.
+void
+ProcessMonitor::StartLaunchOpThread(LaunchArgs *args, Error &error)
+{
+    static const char *g_thread_name = "lldb.process.netbsd.operation";
+
+    if (m_operation_thread.IsJoinable())
+        return;
+
+    m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args, &error);
+}
+
+void *
+ProcessMonitor::LaunchOpThread(void *arg)
+{
+    LaunchArgs *args = static_cast<LaunchArgs*>(arg);
+
+    if (!Launch(args)) {
+        sem_post(&args->m_semaphore);
+        return NULL;
+    }
+
+    ServeOperation(args);
+    return NULL;
+}
+
+bool
+ProcessMonitor::Launch(LaunchArgs *args)
+{
+    ProcessMonitor *monitor = args->m_monitor;
+    ProcessNetBSD &process = monitor->GetProcess();
+    const char **argv = args->m_argv;
+    const char **envp = args->m_envp;
+    const FileSpec &stdin_file_spec = args->m_stdin_file_spec;
+    const FileSpec &stdout_file_spec = args->m_stdout_file_spec;
+    const FileSpec &stderr_file_spec = args->m_stderr_file_spec;
+    const FileSpec &working_dir = args->m_working_dir;
+
+    lldb_utility::PseudoTerminal terminal;
+    const size_t err_len = 1024;
+    char err_str[err_len];
+    ::pid_t pid;
+
+    // Propagate the environment if one is not supplied.
+    if (envp == NULL || envp[0] == NULL)
+        envp = const_cast<const char **>(environ);
+
+    if ((pid = terminal.Fork(err_str, err_len)) == -1)
+    {
+        args->m_error.SetErrorToGenericError();
+        args->m_error.SetErrorString("Process fork failed.");
+        goto FINISH;
+    }
+
+    // Recognized child exit status codes.
+    enum {
+        ePtraceFailed = 1,
+        eDupStdinFailed,
+        eDupStdoutFailed,
+        eDupStderrFailed,
+        eChdirFailed,
+        eExecFailed,
+        eSetGidFailed
+    };
+
+    // Child process.
+    if (pid == 0)
+    {
+        // Trace this process.
+        if (PTRACE(PT_TRACE_ME, 0, NULL, 0) < 0)
+            exit(ePtraceFailed);
+
+        // terminal has already dupped the tty descriptors to stdin/out/err.
+        // This closes original fd from which they were copied (and avoids
+        // leaking descriptors to the debugged process.
+        terminal.CloseSlaveFileDescriptor();
+
+        // Do not inherit setgid powers.
+        if (setgid(getgid()) != 0)
+            exit(eSetGidFailed);
+
+        // Let us have our own process group.
+        setpgid(0, 0);
+
+        // Dup file descriptors if needed.
+        //
+        // FIXME: If two or more of the paths are the same we needlessly open
+        // the same file multiple times.
+        if (stdin_file_spec)
+            if (!DupDescriptor(stdin_file_spec, STDIN_FILENO, O_RDONLY))
+                exit(eDupStdinFailed);
+
+        if (stdout_file_spec)
+            if (!DupDescriptor(stdout_file_spec, STDOUT_FILENO, O_WRONLY | O_CREAT))
+                exit(eDupStdoutFailed);
+
+        if (stderr_file_spec)
+            if (!DupDescriptor(stderr_file_spec, STDERR_FILENO, O_WRONLY | O_CREAT))
+                exit(eDupStderrFailed);
+
+        // Change working directory
+        if (working_dir && 0 != ::chdir(working_dir.GetCString()))
+            exit(eChdirFailed);
+
+        // Execute.  We should never return.
+        execve(argv[0],
+               const_cast<char *const *>(argv),
+               const_cast<char *const *>(envp));
+        exit(eExecFailed);
+    }
+
+    // Wait for the child process to to trap on its call to execve.
+    ::pid_t wpid;
+    int status;
+    if ((wpid = waitpid(pid, &status, 0)) < 0)
+    {
+        args->m_error.SetErrorToErrno();
+        goto FINISH;
+    }
+    else if (WIFEXITED(status))
+    {
+        // open, dup or execve likely failed for some reason.
+        args->m_error.SetErrorToGenericError();
+        switch (WEXITSTATUS(status))
+        {
+            case ePtraceFailed:
+                args->m_error.SetErrorString("Child ptrace failed.");
+                break;
+            case eDupStdinFailed:
+                args->m_error.SetErrorString("Child open stdin failed.");
+                break;
+            case eDupStdoutFailed:
+                args->m_error.SetErrorString("Child open stdout failed.");
+                break;
+            case eDupStderrFailed:
+                args->m_error.SetErrorString("Child open stderr failed.");
+                break;
+            case eChdirFailed:
+                args->m_error.SetErrorString("Child failed to set working directory.");
+                break;
+            case eExecFailed:
+                args->m_error.SetErrorString("Child exec failed.");
+                break;
+            case eSetGidFailed:
+                args->m_error.SetErrorString("Child setgid failed.");
+                break;
+            default:
+                args->m_error.SetErrorString("Child returned unknown exit status.");
+                break;
+        }
+        goto FINISH;
+    }
+    assert(WIFSTOPPED(status) && wpid == (::pid_t)pid &&
+           "Could not sync with inferior process.");
+
+#ifdef notyet
+    // Have the child raise an event on exit.  This is used to keep the child in
+    // limbo until it is destroyed.
+    if (PTRACE(PTRACE_SETOPTIONS, pid, NULL, PTRACE_O_TRACEEXIT) < 0)
+    {
+        args->m_error.SetErrorToErrno();
+        goto FINISH;
+    }
+#endif
+    // Release the master terminal descriptor and pass it off to the
+    // ProcessMonitor instance.  Similarly stash the inferior pid.
+    monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
+    monitor->m_pid = pid;
+
+    // Set the terminal fd to be in non blocking mode (it simplifies the
+    // implementation of ProcessNetBSD::GetSTDOUT to have a non-blocking
+    // descriptor to read from).
+    if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
+        goto FINISH;
+
+    process.SendMessage(ProcessMessage::Attach(pid));
+
+FINISH:
+    return args->m_error.Success();
+}
+
+void
+ProcessMonitor::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
+{
+    static const char *g_thread_name = "lldb.process.netbsd.operation";
+
+    if (m_operation_thread.IsJoinable())
+        return;
+
+    m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args, &error);
+}
+
+void *
+ProcessMonitor::AttachOpThread(void *arg)
+{
+    AttachArgs *args = static_cast<AttachArgs*>(arg);
+
+    Attach(args);
+
+    ServeOperation(args);
+    return NULL;
+}
+
+void
+ProcessMonitor::Attach(AttachArgs *args)
+{
+    lldb::pid_t pid = args->m_pid;
+
+    ProcessMonitor *monitor = args->m_monitor;
+    ProcessNetBSD &process = monitor->GetProcess();
+
+    if (pid <= 1)
+    {
+        args->m_error.SetErrorToGenericError();
+        args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
+        return;
+    }
+
+    // Attach to the requested process.
+    if (PTRACE(PT_ATTACH, pid, NULL, 0) < 0)
+    {
+        args->m_error.SetErrorToErrno();
+        return;
+    }
+
+    int status;
+    if ((status = waitpid(pid, NULL, 0)) < 0)
+    {
+        args->m_error.SetErrorToErrno();
+        return;
+    }
+
+    process.SendMessage(ProcessMessage::Attach(pid));
+}
+
+bool
+ProcessMonitor::MonitorCallback(ProcessMonitor *monitor, lldb::pid_t pid, bool exited, int signal, int status)
+{
+    ProcessMessage message;
+
+    ProcessNetBSD *process = monitor->m_process;
+    assert(process);
+    bool stop_monitoring;
+    struct ptrace_lwpinfo plwp;
+    int ptrace_err;
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
+
+    if (exited)
+    {
+        if (log)
+            log->Printf ("ProcessMonitor::%s() got exit signal, tid = %"  PRIu64, __FUNCTION__, pid);
+        message = ProcessMessage::Exit(pid, status);
+        process->SendMessage(message);
+        return pid == process->GetID();
+    }
+
+    if (!monitor->GetLwpInfo(pid, &plwp, ptrace_err))
+    {
+        stop_monitoring = true; // pid is gone.  Bail.
+    }
+
+    return stop_monitoring;
+}
+
+void
+ProcessMonitor::ServeOperation(OperationArgs *args)
+{
+    ProcessMonitor *monitor = args->m_monitor;
+
+    // We are finised with the arguments and are ready to go.  Sync with the
+    // parent thread and start serving operations on the inferior.
+    sem_post(&args->m_semaphore);
+
+    for (;;)
+    {
+        // wait for next pending operation
+        sem_wait(&monitor->m_operation_pending);
+
+        monitor->m_operation->Execute(monitor);
+
+        // notify calling thread that operation is complete
+        sem_post(&monitor->m_operation_done);
+    }
+}
+
+void
+ProcessMonitor::DoOperation(Operation *op)
+{
+    Mutex::Locker lock(m_operation_mutex);
+
+    m_operation = op;
+
+    // notify operation thread that an operation is ready to be processed
+    sem_post(&m_operation_pending);
+
+    // wait for operation to complete
+    sem_wait(&m_operation_done);
+}
+
+size_t
+ProcessMonitor::ReadMemory(lldb::addr_t vm_addr, void *buf, size_t size,
+                           Error &error)
+{
+    size_t result;
+    ReadOperation op(vm_addr, buf, size, error, result);
+    DoOperation(&op);
+    return result;
+}
+
+size_t
+ProcessMonitor::WriteMemory(lldb::addr_t vm_addr, const void *buf, size_t size,
+                            lldb_private::Error &error)
+{
+    size_t result;
+    WriteOperation op(vm_addr, buf, size, error, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::ReadRegisterValue(lldb::tid_t tid, unsigned offset, const char* reg_name,
+                                  unsigned size, RegisterValue &value)
+{
+    bool result;
+    ReadRegOperation op(tid, offset, size, value, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
+                                   const char* reg_name, const RegisterValue &value)
+{
+    bool result;
+    WriteRegOperation op(tid, offset, value, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
+{
+    bool result;
+    ReadGPROperation op(tid, buf, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
+{
+    bool result;
+    ReadFPROperation op(tid, buf, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
+{
+    return false;
+}
+
+bool
+ProcessMonitor::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
+{
+    bool result;
+    WriteGPROperation op(tid, buf, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
+{
+    bool result;
+    WriteFPROperation op(tid, buf, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
+{
+    return false;
+}
+
+bool
+ProcessMonitor::ReadThreadPointer(lldb::tid_t tid, lldb::addr_t &value)
+{
+    return false;
+}
+
+bool
+ProcessMonitor::SingleStep(lldb::tid_t unused, uint32_t signo)
+{
+    bool result;
+    SingleStepOperation op(signo, result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::Kill()
+{
+    bool result;
+    KillOperation op(result);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::GetLwpInfo(lldb::tid_t tid, void *lwpinfo, int &ptrace_err)
+{
+    bool result;
+    LwpInfoOperation op(tid, lwpinfo, result, ptrace_err);
+    DoOperation(&op);
+    return result;
+}
+
+bool
+ProcessMonitor::GetEventMessage(lldb::tid_t tid, unsigned long *message)
+{
+    bool result;
+    EventMessageOperation op(tid, message, result);
+    DoOperation(&op);
+    return result;
+}
+
+lldb_private::Error
+ProcessMonitor::Detach(lldb::tid_t tid)
+{
+    lldb_private::Error error;
+    if (tid != LLDB_INVALID_THREAD_ID)
+    {
+        DetachOperation op(error);
+        DoOperation(&op);
+    }
+    return error;
+}
+
+bool
+ProcessMonitor::DupDescriptor(const FileSpec &file_spec, int fd, int flags)
+{
+    int target_fd = open(file_spec.GetCString(), flags, 0666);
+
+    if (target_fd == -1)
+        return false;
+
+    if (dup2(target_fd, fd) == -1)
+        return false;
+
+    return (close(target_fd) == -1) ? false : true;
+}
+
+void
+ProcessMonitor::StopMonitoringChildProcess()
+{
+    if (m_monitor_thread.IsJoinable())
+    {
+        m_monitor_thread.Cancel();
+        m_monitor_thread.Join(nullptr);
+        m_monitor_thread.Reset();
+    }
+}
+
+void
+ProcessMonitor::StopMonitor()
+{
+    StopMonitoringChildProcess();
+    StopOpThread();
+    sem_destroy(&m_operation_pending);
+    sem_destroy(&m_operation_done);
+    if (m_terminal_fd >= 0) {
+        close(m_terminal_fd);
+        m_terminal_fd = -1;
+    }
+}
+
+// FIXME: On Linux, when a new thread is created, we receive to notifications,
+// (1) a SIGTRAP|PTRACE_EVENT_CLONE from the main process thread with the
+// child thread id as additional information, and (2) a SIGSTOP|SI_USER from
+// the new child thread indicating that it has is stopped because we attached.
+// We have no guarantee of the order in which these arrive, but we need both
+// before we are ready to proceed.  We currently keep a list of threads which
+// have sent the initial SIGSTOP|SI_USER event.  Then when we receive the
+// SIGTRAP|PTRACE_EVENT_CLONE notification, if the initial stop has not occurred
+// we call ProcessMonitor::WaitForInitialTIDStop() to wait for it.
+//
+// Right now, the above logic is in ProcessPOSIX, so we need a definition of
+// this function in the NetBSD ProcessMonitor implementation even if it isn't
+// logically needed.
+//
+// We really should figure out what actually happens on NetBSD and move the
+// Linux-specific logic out of ProcessPOSIX as needed.
+
+bool
+ProcessMonitor::WaitForInitialTIDStop(lldb::tid_t tid)
+{
+    return true;
+}
+
+void
+ProcessMonitor::StopOpThread()
+{
+    if (!m_operation_thread.IsJoinable())
+        return;
+
+    m_operation_thread.Cancel();
+    m_operation_thread.Join(nullptr);
+    m_operation_thread.Reset();
+}

source/Plugins/Process/NetBSD/ProcessNetBSD.h

+//===-- ProcessNetBSD.h ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_ProcessNetBSD_H_
+#define liblldb_ProcessNetBSD_H_
+
+// C Includes
+
+// C++ Includes
+#include <set>
+#include <queue>
+
+// Other libraries and framework includes
+#include "lldb/Target/Process.h"
+#include "lldb/Target/ThreadList.h"
+#include "ProcessMessage.h"
+#include "ProcessNetBSD.h"
+
+class ProcessMonitor;
+class NetBSDThread;
+
+class ProcessNetBSD :
+    public lldb_private::Process
+{
+
+public:
+    //------------------------------------------------------------------
+    // Static functions.
+    //------------------------------------------------------------------
+    static lldb::ProcessSP
+    CreateInstance(lldb::TargetSP target_sp,
+                   lldb::ListenerSP listener_sp,
+                   const lldb_private::FileSpec *crash_file_path);
+
+    static void
+    Initialize();
+
+    static void
+    Terminate();
+
+    static lldb_private::ConstString
+    GetPluginNameStatic();
+
+    static const char *
+    GetPluginDescriptionStatic();
+
+    //------------------------------------------------------------------
+    // Constructors and destructors
+    //------------------------------------------------------------------
+    ProcessNetBSD(lldb::TargetSP target_sp,
+                   lldb::ListenerSP listener_sp,
+                   lldb::UnixSignalsSP &unix_signals_sp);
+
+    ~ProcessNetBSD();
+
+    virtual lldb_private::Error
+    WillResume() override;
+
+    //------------------------------------------------------------------
+    // PluginInterface protocol
+    //------------------------------------------------------------------
+    virtual lldb_private::ConstString
+    GetPluginName() override;
+
+    virtual uint32_t
+    GetPluginVersion() override;
+
+public:
+    //------------------------------------------------------------------
+    // Process protocol.
+    //------------------------------------------------------------------
+    void
+    Finalize() override;
+
+    bool
+    CanDebug(lldb::TargetSP target_sp, bool plugin_specified_by_name) override;
+
+    lldb_private::Error
+    WillLaunch(lldb_private::Module *module) override;
+
+    lldb_private::Error
+    DoAttachToProcessWithID (lldb::pid_t pid, const lldb_private::ProcessAttachInfo &attach_info) override;
+
+    lldb_private::Error
+    DoLaunch (lldb_private::Module *exe_module,
+              lldb_private::ProcessLaunchInfo &launch_info) override;
+
+    void
+    DidLaunch() override;
+
+    lldb_private::Error
+    DoResume() override;
+
+    lldb_private::Error
+    DoHalt(bool &caused_stop) override;
+
+    lldb_private::Error
+    DoDetach(bool keep_stopped) override;
+
+    lldb_private::Error
+    DoSignal(int signal) override;
+
+    lldb_private::Error
+    DoDestroy() override;
+
+    void
+    DoDidExec() override;
+
+    void
+    RefreshStateAfterStop() override;
+
+    bool
+    IsAlive() override;
+
+    size_t
+    DoReadMemory(lldb::addr_t vm_addr,
+                 void *buf,
+                 size_t size,
+                 lldb_private::Error &error) override;
+
+    size_t
+    DoWriteMemory(lldb::addr_t vm_addr, const void *buf, size_t size,
+                  lldb_private::Error &error) override;
+
+    lldb::addr_t
+    DoAllocateMemory(size_t size, uint32_t permissions,
+                     lldb_private::Error &error) override;
+
+    lldb_private::Error
+    DoDeallocateMemory(lldb::addr_t ptr) override;
+
+    virtual size_t
+    GetSoftwareBreakpointTrapOpcode(lldb_private::BreakpointSite* bp_site);
+
+    lldb_private::Error
+    EnableBreakpointSite(lldb_private::BreakpointSite *bp_site) override;
+
+    lldb_private::Error
+    DisableBreakpointSite(lldb_private::BreakpointSite *bp_site) override;
+
+    lldb_private::Error
+    EnableWatchpoint(lldb_private::Watchpoint *wp, bool notify = true) override;
+
+    lldb_private::Error
+    DisableWatchpoint(lldb_private::Watchpoint *wp, bool notify = true) override;
+
+    lldb_private::Error
+    GetWatchpointSupportInfo(uint32_t &num) override;
+
+    lldb_private::Error
+    GetWatchpointSupportInfo(uint32_t &num, bool &after) override;
+
+    virtual uint32_t
+    UpdateThreadListIfNeeded();
+
+    bool
+    UpdateThreadList(lldb_private::ThreadList &old_thread_list,
+                     lldb_private::ThreadList &new_thread_list) override;
+
+    virtual lldb::ByteOrder
+    GetByteOrder() const;
+
+    lldb::addr_t
+    GetImageInfoAddress() override;
+
+    size_t
+    PutSTDIN(const char *buf, size_t len, lldb_private::Error &error) override;
+
+    const lldb::DataBufferSP
+    GetAuxvData () override;
+
+    //--------------------------------------------------------------------------
+    // ProcessNetBSD internal API.
+
+    /// Registers the given message with this process.
+    virtual void
+    SendMessage(const ProcessMessage &message);
+
+    ProcessMonitor &
+    GetMonitor() { assert(m_monitor); return *m_monitor; }
+
+    lldb_private::FileSpec
+    GetFileSpec(const lldb_private::FileAction *file_action,
+                const lldb_private::FileSpec &default_file_spec,
+                const lldb_private::FileSpec &dbg_pts_file_spec);
+
+    /// Adds the thread to the list of threads for which we have received the initial stopping signal.
+    /// The \p stop_tid parameter indicates the thread which the stop happened for.
+    bool
+    AddThreadForInitialStopIfNeeded(lldb::tid_t stop_tid);
+
+    bool
+    WaitingForInitialStop(lldb::tid_t stop_tid);
+
+    virtual NetBSDThread *
+    CreateNewNetBSDThread(lldb_private::Process &process, lldb::tid_t tid);
+
+protected:
+    /// Target byte order.
+    lldb::ByteOrder m_byte_order;
+
+    /// Process monitor;
+    ProcessMonitor *m_monitor;
+
+    /// The module we are executing.
+    lldb_private::Module *m_module;
+
+    /// Message queue notifying this instance of inferior process state changes.
+    lldb_private::Mutex m_message_mutex;
+    std::queue<ProcessMessage> m_message_queue;
+
+    /// Drive any exit events to completion.
+    bool m_exit_now;
+
+    /// Returns true if the process has exited.
+    bool HasExited();
+
+    /// Returns true if the process is stopped.
+    bool IsStopped();
+
+    /// Returns true if at least one running is currently running
+    bool IsAThreadRunning();
+
+    typedef std::map<lldb::addr_t, lldb::addr_t> MMapMap;
+    MMapMap m_addr_to_mmap_size;
+
+    typedef std::set<lldb::tid_t> ThreadStopSet;
+    /// Every thread begins with a stop signal. This keeps track
+    /// of the threads for which we have received the stop signal.
+    ThreadStopSet m_seen_initial_stop;
+
+    friend class NetBSDThread;
+
+    typedef std::vector<lldb::tid_t> tid_collection;
+    tid_collection m_suspend_tids;
+    tid_collection m_run_tids;
+    tid_collection m_step_tids;
+
+    int m_resume_signo;
+
+};
+
+#endif  // liblldb_ProcessNetBSD_H_

source/Plugins/Process/NetBSD/ProcessNetBSD.cpp

+//===-- ProcessNetBSD.cpp ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// C Includes
+#include <errno.h>
+
+// C++ Includes
+#include <mutex>
+
+// Other libraries and framework includes
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/State.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Target/DynamicLoader.h"
+#include "lldb/Target/Target.h"
+
+#include "ProcessNetBSD.h"
+#include "ProcessPOSIXLog.h"
+#include "Plugins/Process/Utility/InferiorCallPOSIX.h"
+#include "Plugins/Process/Utility/NetBSDSignals.h"
+#include "ProcessMonitor.h"
+#include "NetBSDThread.h"
+
+// Other libraries and framework includes
+#include "lldb/Breakpoint/BreakpointLocation.h"
+#include "lldb/Breakpoint/Watchpoint.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleSpec.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/State.h"
+#include "lldb/Host/FileSpec.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Target/DynamicLoader.h"
+#include "lldb/Target/Platform.h"
+#include "lldb/Target/Target.h"
+
+#include "lldb/Host/posix/Fcntl.h"
+
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace
+{
+    UnixSignalsSP&
+    GetNetBSDSignals ()
+    {
+        static UnixSignalsSP s_netbsd_signals_sp (new NetBSDSignals ());
+        return s_netbsd_signals_sp;
+    }
+}
+
+//------------------------------------------------------------------------------
+// Static functions.
+
+lldb::ProcessSP
+ProcessNetBSD::CreateInstance(lldb::TargetSP target_sp,
+                               lldb::ListenerSP listener_sp,
+                               const FileSpec *crash_file_path)
+{
+    lldb::ProcessSP process_sp;
+    if (crash_file_path == NULL)
+        process_sp.reset(new ProcessNetBSD (target_sp, listener_sp, GetNetBSDSignals()));
+    return process_sp;
+}
+
+void
+ProcessNetBSD::Initialize()
+{
+    static std::once_flag g_once_flag;
+
+    std::call_once(g_once_flag, []() {
+        PluginManager::RegisterPlugin(GetPluginNameStatic(),
+                                      GetPluginDescriptionStatic(),
+                                      CreateInstance);
+        ProcessPOSIXLog::Initialize(GetPluginNameStatic());
+    });
+}
+
+lldb_private::ConstString
+ProcessNetBSD::GetPluginNameStatic()
+{
+    static ConstString g_name("netbsd");
+    return g_name;
+}
+
+const char *
+ProcessNetBSD::GetPluginDescriptionStatic()
+{
+    return "Process plugin for NetBSD";
+}
+
+//------------------------------------------------------------------------------
+// ProcessInterface protocol.
+
+lldb_private::ConstString
+ProcessNetBSD::GetPluginName()
+{
+    return GetPluginNameStatic();
+}
+
+uint32_t
+ProcessNetBSD::GetPluginVersion()
+{
+    return 1;
+}
+
+void
+ProcessNetBSD::Terminate()
+{
+}
+
+Error
+ProcessNetBSD::DoDetach(bool keep_stopped)
+{
+    Error error;
+    if (keep_stopped)
+    {
+        error.SetErrorString("Detaching with keep_stopped true is not currently supported on NetBSD.");
+        return error;
+    }
+
+    error = m_monitor->Detach(GetID());
+
+    if (error.Success())
+        SetPrivateState(eStateDetached);
+
+    return error;
+}
+
+bool
+ProcessNetBSD::UpdateThreadList(ThreadList &old_thread_list, ThreadList &new_thread_list)
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
+    if (log)
+        log->Printf("ProcessNetBSD::%s (pid = %" PRIu64 ")", __FUNCTION__, GetID());
+
+    std::vector<lldb::pid_t> tds;
+    if (!GetMonitor().GetCurrentThreadIDs(tds))
+    {
+        return false;
+    }
+
+    ThreadList old_thread_list_copy(old_thread_list);
+    for (size_t i = 0; i < tds.size(); ++i)
+    {
+        tid_t tid = tds[i];
+        ThreadSP thread_sp (old_thread_list_copy.RemoveThreadByID(tid, false));
+        if (!thread_sp)
+        {
+            thread_sp.reset(new NetBSDThread(*this, tid));
+            if (log)
+                log->Printf("ProcessNetBSD::%s new tid = %" PRIu64, __FUNCTION__, tid);
+        }
+        else
+        {
+            if (log)
+                log->Printf("ProcessNetBSD::%s existing tid = %" PRIu64, __FUNCTION__, tid);
+        }
+        new_thread_list.AddThread(thread_sp);
+    }
+    for (size_t i = 0; i < old_thread_list_copy.GetSize(false); ++i)
+    {
+        ThreadSP old_thread_sp(old_thread_list_copy.GetThreadAtIndex(i, false));
+        if (old_thread_sp)
+        {
+            if (log)
+                log->Printf("ProcessNetBSD::%s remove tid", __FUNCTION__);
+        }
+    }
+
+    return true;
+}
+
+Error
+ProcessNetBSD::WillResume()
+{
+    m_resume_signo = 0;
+    m_suspend_tids.clear();
+    m_run_tids.clear();
+    m_step_tids.clear();
+    return Process::WillResume();
+}
+
+void
+ProcessNetBSD::SendMessage(const ProcessMessage &message)
+{
+    Mutex::Locker lock(m_message_mutex);
+
+    switch (message.GetKind())
+    {
+    case ProcessMessage::eInvalidMessage:
+        return;
+
+    case ProcessMessage::eAttachMessage:
+        SetPrivateState(eStateStopped);
+        return;
+
+    case ProcessMessage::eLimboMessage:
+    case ProcessMessage::eExitMessage:
+        SetExitStatus(message.GetExitStatus(), NULL);
+        break;
+
+    case ProcessMessage::eSignalMessage:
+    case ProcessMessage::eSignalDeliveredMessage:
+    case ProcessMessage::eBreakpointMessage:
+    case ProcessMessage::eTraceMessage:
+    case ProcessMessage::eWatchpointMessage:
+    case ProcessMessage::eCrashMessage:
+        SetPrivateState(eStateStopped);
+        break;
+
+    case ProcessMessage::eNewThreadMessage:
+        llvm_unreachable("eNewThreadMessage unexpected on NetBSD");
+        break;
+
+    case ProcessMessage::eExecMessage:
+        SetPrivateState(eStateStopped);
+        break;
+    }
+
+    m_message_queue.push(message);
+}
+
+//------------------------------------------------------------------------------
+// Constructors and destructors.
+
+ProcessNetBSD::ProcessNetBSD(lldb::TargetSP target_sp, lldb::ListenerSP listener_sp, UnixSignalsSP &unix_signals_sp)
+    : Process(target_sp, listener_sp, unix_signals_sp),
+      m_byte_order(endian::InlHostByteOrder()),
+      m_monitor(NULL),
+      m_module(NULL),
+      m_message_mutex (Mutex::eMutexTypeRecursive),
+      m_exit_now(false),
+      m_seen_initial_stop(),
+      m_resume_signo(0)
+{
+    // FIXME: Putting this code in the ctor and saving the byte order in a
+    // member variable is a hack to avoid const qual issues in GetByteOrder.
+    lldb::ModuleSP module = GetTarget().GetExecutableModule();
+    if (module && module->GetObjectFile())
+        m_byte_order = module->GetObjectFile()->GetByteOrder();
+}
+
+ProcessNetBSD::~ProcessNetBSD()
+{
+    delete m_monitor;
+}
+
+//------------------------------------------------------------------------------
+// Process protocol.
+void
+ProcessNetBSD::Finalize()
+{
+  Process::Finalize();
+
+  if (m_monitor)
+    m_monitor->StopMonitor();
+}
+
+bool
+ProcessNetBSD::CanDebug(lldb::TargetSP target_sp, bool plugin_specified_by_name)
+{
+    // For now we are just making sure the file exists for a given module
+    ModuleSP exe_module_sp(target_sp->GetExecutableModule());
+    if (exe_module_sp.get())
+        return exe_module_sp->GetFileSpec().Exists();
+    // If there is no executable module, we return true since we might be preparing to attach.
+    return true;
+}
+
+Error
+ProcessNetBSD::DoAttachToProcessWithID (lldb::pid_t pid,  const ProcessAttachInfo &attach_info)
+{
+    Error error;
+    assert(m_monitor == NULL);
+
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
+    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
+        log->Printf ("ProcessNetBSD::%s(pid = %" PRIi64 ")", __FUNCTION__, GetID());
+
+    m_monitor = new ProcessMonitor(this, pid, error);
+
+    if (!error.Success())
+        return error;
+
+    PlatformSP platform_sp (GetTarget().GetPlatform ());
+    assert (platform_sp.get());
+    if (!platform_sp)
+        return error;  // FIXME: Detatch?
+
+    // Find out what we can about this process
+    ProcessInstanceInfo process_info;
+    platform_sp->GetProcessInfo (pid, process_info);
+
+    // Resolve the executable module
+    ModuleSP exe_module_sp;
+    FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
+    ModuleSpec exe_module_spec(process_info.GetExecutableFile(), GetTarget().GetArchitecture());
+    error = platform_sp->ResolveExecutable(exe_module_spec,
+                                           exe_module_sp,
+                                           executable_search_paths.GetSize() ? &executable_search_paths : NULL);
+    if (!error.Success())
+        return error;
+
+    // Fix the target architecture if necessary
+    const ArchSpec &module_arch = exe_module_sp->GetArchitecture();
+    if (module_arch.IsValid() && !GetTarget().GetArchitecture().IsExactMatch(module_arch))
+        GetTarget().SetArchitecture(module_arch);
+
+    // Initialize the target module list
+    GetTarget().SetExecutableModule (exe_module_sp, true);
+
+    SetSTDIOFileDescriptor(m_monitor->GetTerminalFD());
+
+    SetID(pid);
+
+    return error;
+}
+
+Error
+ProcessNetBSD::WillLaunch(Module* module)
+{
+    Error error;
+    return error;
+}
+
+FileSpec
+ProcessNetBSD::GetFileSpec(const lldb_private::FileAction *file_action,
+                          const FileSpec &default_file_spec,
+                          const FileSpec &dbg_pts_file_spec)
+{
+    FileSpec file_spec{};
+
+    if (file_action && file_action->GetAction() == FileAction::eFileActionOpen)
+    {
+        file_spec = file_action->GetFileSpec();
+        // By default the stdio paths passed in will be pseudo-terminal
+        // (/dev/pts). If so, convert to using a different default path
+        // instead to redirect I/O to the debugger console. This should
+        // also handle user overrides to /dev/null or a different file.
+        if (!file_spec || file_spec == dbg_pts_file_spec)
+            file_spec = default_file_spec;
+    }
+    return file_spec;
+}
+
+Error
+ProcessNetBSD::DoLaunch (Module *module,
+                        ProcessLaunchInfo &launch_info)
+{
+    Error error;
+    assert(m_monitor == NULL);
+
+    FileSpec working_dir = launch_info.GetWorkingDirectory();
+    if (working_dir &&
+            (!working_dir.ResolvePath() ||
+             working_dir.GetFileType() != FileSpec::eFileTypeDirectory))
+    {
+        error.SetErrorStringWithFormat("No such file or directory: %s",
+                working_dir.GetCString());
+        return error;
+    }
+
+    SetPrivateState(eStateLaunching);
+
+    const lldb_private::FileAction *file_action;
+
+    // Default of empty will mean to use existing open file descriptors
+    FileSpec stdin_file_spec{};
+    FileSpec stdout_file_spec{};
+    FileSpec stderr_file_spec{};
+
+    const FileSpec dbg_pts_file_spec{launch_info.GetPTY().GetSlaveName(NULL,0), false};
+
+    file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
+    stdin_file_spec = GetFileSpec(file_action, stdin_file_spec, dbg_pts_file_spec);
+
+    file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
+    stdout_file_spec = GetFileSpec(file_action, stdout_file_spec, dbg_pts_file_spec);
+
+    file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
+    stderr_file_spec = GetFileSpec(file_action, stderr_file_spec, dbg_pts_file_spec);
+
+    m_monitor = new ProcessMonitor(this,
+                                   module,
+                                   launch_info.GetArguments().GetConstArgumentVector(),
+                                   launch_info.GetEnvironmentEntries().GetConstArgumentVector(),
+                                   stdin_file_spec,
+                                   stdout_file_spec,
+                                   stderr_file_spec,
+                                   working_dir,
+                                   launch_info,
+                                   error);
+
+    m_module = module;
+
+    if (!error.Success())
+        return error;
+
+    int terminal = m_monitor->GetTerminalFD();
+    if (terminal >= 0) {
+        // The reader thread will close the file descriptor when done, so we pass it a copy.
+        int stdio = fcntl(terminal, F_DUPFD_CLOEXEC, 0);
+        if (stdio == -1) {
+            error.SetErrorToErrno();
+            return error;
+        }
+        SetSTDIOFileDescriptor(stdio);
+    }
+
+    SetID(m_monitor->GetPID());
+    return error;
+}
+
+void
+ProcessNetBSD::DidLaunch()
+{
+}
+
+addr_t
+ProcessNetBSD::GetImageInfoAddress()
+{
+    Target *target = &GetTarget();
+    ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
+    Address addr = obj_file->GetImageInfoAddress(target);
+
+    if (addr.IsValid())
+        return addr.GetLoadAddress(target);
+    return LLDB_INVALID_ADDRESS;
+}
+
+Error
+ProcessNetBSD::DoHalt(bool &caused_stop)
+{
+    Error error;
+
+    if (IsStopped())
+    {
+        caused_stop = false;
+    }
+    else if (kill(GetID(), SIGSTOP))
+    {
+        caused_stop = false;
+        error.SetErrorToErrno();
+    }
+    else
+    {
+        caused_stop = true;
+    }
+    return error;
+}
+
+Error
+ProcessNetBSD::DoSignal(int signal)
+{
+    Error error;
+
+    if (kill(GetID(), signal))
+        error.SetErrorToErrno();
+
+    return error;
+}
+
+Error
+ProcessNetBSD::DoDestroy()
+{
+    Error error;
+
+    if (!HasExited())
+    {
+        assert(m_monitor);
+        m_exit_now = true;
+        if (GetID() == LLDB_INVALID_PROCESS_ID)
+        {
+            error.SetErrorString("invalid process id");
+            return error;
+        }
+        if (!m_monitor->Kill())
+        {
+            error.SetErrorToErrno();
+            return error;
+        }
+
+        SetPrivateState(eStateExited);
+    }
+
+    return error;
+}
+
+void
+ProcessNetBSD::DoDidExec()
+{
+    Target *target = &GetTarget();
+    if (target)
+    {
+        PlatformSP platform_sp (target->GetPlatform());
+        assert (platform_sp.get());
+        if (platform_sp)
+        {
+            ProcessInstanceInfo process_info;
+            platform_sp->GetProcessInfo(GetID(), process_info);
+            ModuleSP exe_module_sp;
+            ModuleSpec exe_module_spec(process_info.GetExecutableFile(), target->GetArchitecture());
+            FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
+            Error error = platform_sp->ResolveExecutable(exe_module_spec,
+                                                         exe_module_sp,
+                                                         executable_search_paths.GetSize() ? &executable_search_paths : NULL);
+            if (!error.Success())
+                return;
+            target->SetExecutableModule(exe_module_sp, true);
+        }
+    }
+}
+
+bool
+ProcessNetBSD::AddThreadForInitialStopIfNeeded(lldb::tid_t stop_tid)
+{
+    bool added_to_set = false;
+    ThreadStopSet::iterator it = m_seen_initial_stop.find(stop_tid);
+    if (it == m_seen_initial_stop.end())
+    {
+        m_seen_initial_stop.insert(stop_tid);
+        added_to_set = true;
+    }
+    return added_to_set;
+}
+
+bool
+ProcessNetBSD::WaitingForInitialStop(lldb::tid_t stop_tid)
+{
+    return (m_seen_initial_stop.find(stop_tid) == m_seen_initial_stop.end());
+}
+
+NetBSDThread *
+ProcessNetBSD::CreateNewNetBSDThread(lldb_private::Process &process, lldb::tid_t tid)
+{
+    return new NetBSDThread(process, tid);
+}
+
+void
+ProcessNetBSD::RefreshStateAfterStop()
+{
+    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
+    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
+        log->Printf ("ProcessNetBSD::%s(), message_queue size = %d", __FUNCTION__, (int)m_message_queue.size());
+
+    Mutex::Locker lock(m_message_mutex);
+
+    // This method used to only handle one message.  Changing it to loop allows
+    // it to handle the case where we hit a breakpoint while handling a different
+    // breakpoint.
+    while (!m_message_queue.empty())
+    {
+        ProcessMessage &message = m_message_queue.front();
+
+        // Resolve the thread this message corresponds to and pass it along.
+        lldb::tid_t tid = message.GetTID();
+        if (log)
+            log->Printf ("ProcessNetBSD::%s(), message_queue size = %d, pid = %" PRIi64, __FUNCTION__, (int)m_message_queue.size(), tid);
+
+        m_thread_list.RefreshStateAfterStop();
+
+        NetBSDThread *thread = static_cast<NetBSDThread*>(
+            GetThreadList().FindThreadByID(tid, false).get());
+        if (thread)
+            thread->Notify(message);
+
+        if (message.GetKind() == ProcessMessage::eExitMessage)
+        {
+            // FIXME: We should tell the user about this, but the limbo message is probably better for that.
+            if (log)
+                log->Printf ("ProcessNetBSD::%s() removing thread, tid = %" PRIi64, __FUNCTION__, tid);
+
+            Mutex::Locker lock(m_thread_list.GetMutex());
+
+            ThreadSP thread_sp = m_thread_list.RemoveThreadByID(tid, false);
+            thread_sp.reset();
+            m_seen_initial_stop.erase(tid);
+        }
+
+        m_message_queue.pop();
+    }
+}
+
+bool
+ProcessNetBSD::IsAlive()
+{
+    StateType state = GetPrivateState();
+    return state != eStateDetached
+        && state != eStateExited
+        && state != eStateInvalid
+        && state != eStateUnloaded;
+}
+
+size_t
+ProcessNetBSD::DoReadMemory(addr_t vm_addr,
+                           void *buf, size_t size, Error &error)
+{
+    assert(m_monitor);
+    return m_monitor->ReadMemory(vm_addr, buf, size, error);
+}
+
+size_t
+ProcessNetBSD::DoWriteMemory(addr_t vm_addr, const void *buf, size_t size,
+                            Error &error)
+{
+    assert(m_monitor);
+    return m_monitor->WriteMemory(vm_addr, buf, size, error);
+}
+
+addr_t
+ProcessNetBSD::DoAllocateMemory(size_t size, uint32_t permissions,
+                               Error &error)
+{
+    addr_t allocated_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;
+
+    if (InferiorCallMmap(this, allocated_addr, 0, size, prot,
+                         eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
+        m_addr_to_mmap_size[allocated_addr] = size;
+        error.Clear();
+    } else {
+        allocated_addr = LLDB_INVALID_ADDRESS;
+        error.SetErrorStringWithFormat("unable to allocate %zu bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
+    }
+
+    return allocated_addr;
+}
+
+Error
+ProcessNetBSD::DoDeallocateMemory(lldb::addr_t addr)
+{
+    Error error;
+    MMapMap::iterator pos = m_addr_to_mmap_size.find(addr);
+    if (pos != m_addr_to_mmap_size.end() &&
+        InferiorCallMunmap(this, addr, pos->second))
+        m_addr_to_mmap_size.erase (pos);
+    else
+        error.SetErrorStringWithFormat("unable to deallocate memory at 0x%" PRIx64, addr);
+
+    return error;
+}
+
+size_t
+ProcessNetBSD::GetSoftwareBreakpointTrapOpcode(BreakpointSite* bp_site)
+{
+    static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xD4 };
+    static const uint8_t g_i386_opcode[] = { 0xCC };
+
+    ArchSpec arch = GetTarget().GetArchitecture();
+    const uint8_t *opcode = NULL;
+    size_t opcode_size = 0;
+
+    switch (arch.GetMachine())
+    {
+    default:
+        assert(false && "CPU type not supported!");
+        break;
+
+    case llvm::Triple::x86_64:
+        opcode = g_i386_opcode;
+        opcode_size = sizeof(g_i386_opcode);
+        break;
+    }
+
+    bp_site->SetTrapOpcode(opcode, opcode_size);
+    return opcode_size;
+}
+
+Error
+ProcessNetBSD::EnableBreakpointSite(BreakpointSite *bp_site)
+{
+    return EnableSoftwareBreakpoint(bp_site);
+}
+
+Error
+ProcessNetBSD::DisableBreakpointSite(BreakpointSite *bp_site)
+{
+    return DisableSoftwareBreakpoint(bp_site);
+}
+
+Error
+ProcessNetBSD::EnableWatchpoint(Watchpoint *wp, bool notify)
+{
+    Error error;
+    if (wp)
+    {
+        user_id_t watchID = wp->GetID();
+        addr_t addr = wp->GetLoadAddress();
+        Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_WATCHPOINTS));
+        if (log)
+            log->Printf ("ProcessNetBSD::EnableWatchpoint(watchID = %" PRIu64 ")",
+                         watchID);
+        if (wp->IsEnabled())
+        {
+            if (log)
+                log->Printf("ProcessNetBSD::EnableWatchpoint(watchID = %" PRIu64
+                            ") addr = 0x%8.8" PRIx64 ": watchpoint already enabled.",
+                            watchID, (uint64_t)addr);
+            return error;
+        }
+
+        // Try to find a vacant watchpoint slot in the inferiors' main thread
+        uint32_t wp_hw_index = LLDB_INVALID_INDEX32;
+        Mutex::Locker lock(m_thread_list.GetMutex());
+        NetBSDThread *thread = static_cast<NetBSDThread*>(
+                               m_thread_list.GetThreadAtIndex(0, false).get());
+
+        if (thread)
+            wp_hw_index = thread->FindVacantWatchpointIndex();
+
+        if (wp_hw_index == LLDB_INVALID_INDEX32)
+        {
+            error.SetErrorString("Setting hardware watchpoint failed.");
+        }
+        else
+        {
+            wp->SetHardwareIndex(wp_hw_index);
+            bool wp_enabled = true;
+            uint32_t thread_count = m_thread_list.GetSize(false);
+            for (uint32_t i = 0; i < thread_count; ++i)
+            {
+                thread = static_cast<NetBSDThread*>(
+                         m_thread_list.GetThreadAtIndex(i, false).get());
+                if (thread)
+                    wp_enabled &= thread->EnableHardwareWatchpoint(wp);
+                else
+                    wp_enabled = false;
+            }
+            if (wp_enabled)
+            {
+                wp->SetEnabled(true, notify);
+                return error;
+            }
+            else
+            {
+                // Watchpoint enabling failed on at least one
+                // of the threads so roll back all of them
+                DisableWatchpoint(wp, false);
+                error.SetErrorString("Setting hardware watchpoint failed");
+            }
+        }
+    }
+    else
+        error.SetErrorString("Watchpoint argument was NULL.");
+    return error;
+}
+
+Error
+ProcessNetBSD::DisableWatchpoint(Watchpoint *wp, bool notify)
+{
+    Error error;
+    if (wp)
+    {
+        user_id_t watchID = wp->GetID();
+        addr_t addr = wp->GetLoadAddress();
+        Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_WATCHPOINTS));
+        if (log)
+            log->Printf("ProcessNetBSD::DisableWatchpoint(watchID = %" PRIu64 ")",
+                        watchID);
+        if (!wp->IsEnabled())
+        {
+            if (log)
+                log->Printf("ProcessNetBSD::DisableWatchpoint(watchID = %" PRIu64
+                            ") addr = 0x%8.8" PRIx64 ": watchpoint already disabled.",
+                            watchID, (uint64_t)addr);
+            // This is needed (for now) to keep watchpoints disabled correctly
+            wp->SetEnabled(false, notify);
+            return error;
+        }
+
+        if (wp->IsHardware())
+        {
+            bool wp_disabled = true;
+            Mutex::Locker lock(m_thread_list.GetMutex());
+            uint32_t thread_count = m_thread_list.GetSize(false);
+            for (uint32_t i = 0; i < thread_count; ++i)
+            {
+                NetBSDThread *thread = static_cast<NetBSDThread*>(
+                                      m_thread_list.GetThreadAtIndex(i, false).get());
+                if (thread)
+                    wp_disabled &= thread->DisableHardwareWatchpoint(wp);
+                else
+                    wp_disabled = false;
+            }
+            if (wp_disabled)
+            {
+                wp->SetHardwareIndex(LLDB_INVALID_INDEX32);
+                wp->SetEnabled(false, notify);
+                return error;
+            }
+            else
+                error.SetErrorString("Disabling hardware watchpoint failed");
+        }
+    }
+    else
+        error.SetErrorString("Watchpoint argument was NULL.");
+    return error;
+}
+
+Error
+ProcessNetBSD::GetWatchpointSupportInfo(uint32_t &num)
+{
+    Error error;
+    Mutex::Locker lock(m_thread_list.GetMutex());
+    NetBSDThread *thread = static_cast<NetBSDThread*>(
+                          m_thread_list.GetThreadAtIndex(0, false).get());
+    if (thread)
+        num = thread->NumSupportedHardwareWatchpoints();
+    else
+        error.SetErrorString("Process does not exist.");
+    return error;
+}
+
+Error
+ProcessNetBSD::GetWatchpointSupportInfo(uint32_t &num, bool &after)
+{
+    Error error = GetWatchpointSupportInfo(num);
+    // Watchpoints trigger and halt the inferior after
+    // the corresponding instruction has been executed.
+    after = true;
+    return error;
+}
+
+uint32_t
+ProcessNetBSD::UpdateThreadListIfNeeded()
+{
+    Mutex::Locker lock(m_thread_list.GetMutex());
+    // Do not allow recursive updates.
+    return m_thread_list.GetSize(false);
+}
+
+ByteOrder
+ProcessNetBSD::GetByteOrder() const
+{
+    // FIXME: We should be able to extract this value directly.  See comment in
+    // ProcessNetBSD().
+    return m_byte_order;
+}
+
+size_t
+ProcessNetBSD::PutSTDIN(const char *buf, size_t len, Error &error)
+{
+    ssize_t status;
+    if ((status = write(m_monitor->GetTerminalFD(), buf, len)) < 0)
+    {
+        error.SetErrorToErrno();
+        return 0;
+    }
+    return status;
+}
+
+//------------------------------------------------------------------------------
+// Utility functions.
+
+bool
+ProcessNetBSD::HasExited()
+{
+    switch (GetPrivateState())
+    {
+    default:
+        break;
+
+    case eStateDetached:
+    case eStateExited:
+        return true;
+    }
+
+    return false;
+}
+
+bool
+ProcessNetBSD::IsStopped()
+{
+    switch (GetPrivateState())
+    {
+    default:
+        break;
+
+    case eStateStopped:
+    case eStateCrashed:
+    case eStateSuspended:
+        return true;
+    }
+
+    return false;
+}
+
+bool
+ProcessNetBSD::IsAThreadRunning()
+{
+    bool is_running = false;
+    Mutex::Locker lock(m_thread_list.GetMutex());
+    uint32_t thread_count = m_thread_list.GetSize(false);
+    for (uint32_t i = 0; i < thread_count; ++i)
+    {
+        NetBSDThread *thread = static_cast<NetBSDThread*>(
+            m_thread_list.GetThreadAtIndex(i, false).get());
+        StateType thread_state = thread->GetState();
+        if (thread_state == eStateRunning || thread_state == eStateStepping)
+        {
+            is_running = true;
+            break;
+        }
+    }
+    return is_running;
+}
+
+const DataBufferSP
+ProcessNetBSD::GetAuxvData ()
+{
+    // If we're the local platform, we can ask the host for auxv data.
+    PlatformSP platform_sp = GetTarget().GetPlatform ();
+    if (platform_sp && platform_sp->IsHost ())
+        return lldb_private::Host::GetAuxvData(this);
+
+    // Somewhat unexpected - the process is not running locally or we don't have a platform.
+    assert (false && "no platform or not the host - how did we get here with ProcessNetBSD?");
+    return DataBufferSP ();
+}

source/Plugins/Process/NetBSD/RegisterContextPOSIX.h

+//===-- RegisterContextPOSIX.h --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_RegisterContextPOSIX_H_
+#define liblldb_RegisterContextPOSIX_H_
+
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+#include "lldb/Core/ArchSpec.h"
+#include "lldb/Target/RegisterContext.h"
+#include "RegisterInfoInterface.h"
+
+//------------------------------------------------------------------------------
+/// @class POSIXBreakpointProtocol
+///
+/// @brief Extends RegisterClass with a few virtual operations useful on POSIX.
+class POSIXBreakpointProtocol
+{
+public:
+    POSIXBreakpointProtocol()
+        { m_watchpoints_initialized = false; }
+    virtual ~POSIXBreakpointProtocol() {}
+
+    /// Updates the register state of the associated thread after hitting a
+    /// breakpoint (if that make sense for the architecture).  Default
+    /// implementation simply returns true for architectures which do not
+    /// require any update.
+    ///
+    /// @return
+    ///    True if the operation succeeded and false otherwise.
+    virtual bool UpdateAfterBreakpoint() = 0;
+
+    /// Determines the index in lldb's register file given a kernel byte offset.
+    virtual unsigned
+    GetRegisterIndexFromOffset(unsigned offset) = 0;
+
+    // Checks to see if a watchpoint specified by hw_index caused the inferior
+    // to stop.
+    virtual bool
+    IsWatchpointHit (uint32_t hw_index) = 0;
+
+    // Resets any watchpoints that have been hit.
+    virtual bool
+    ClearWatchpointHits () = 0;
+
+    // Returns the watchpoint address associated with a watchpoint hardware
+    // index.
+    virtual lldb::addr_t
+    GetWatchpointAddress (uint32_t hw_index) = 0;
+
+    virtual bool
+    IsWatchpointVacant (uint32_t hw_index) = 0;
+
+    virtual bool
+    SetHardwareWatchpointWithIndex (lldb::addr_t addr, size_t size,
+                                    bool read, bool write,
+                                    uint32_t hw_index) = 0;
+
+    // From lldb_private::RegisterContext
+    virtual uint32_t
+    NumSupportedHardwareWatchpoints () = 0;
+
+    // Force m_watchpoints_initialized to TRUE
+    void
+    ForceWatchpointsInitialized () {m_watchpoints_initialized = true;}
+
+protected:
+    bool m_watchpoints_initialized;
+};
+
+#endif // #ifndef liblldb_RegisterContextPOSIX_H_
+

source/Plugins/Process/NetBSD/RegisterContextPOSIXProcessMonitor_x86.h

+//===-- RegisterContextPOSIXProcessMonitor_x86.h ----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_RegisterContextPOSIXProcessMonitor_x86_H_
+#define liblldb_RegisterContextPOSIXProcessMonitor_x86_H_
+
+#include "RegisterContextPOSIX.h"
+#include "Plugins/Process/Utility/RegisterContextPOSIX_x86.h"
+
+class RegisterContextPOSIXProcessMonitor_x86_64:
+    public RegisterContextPOSIX_x86,
+    public POSIXBreakpointProtocol
+{
+public:
+    RegisterContextPOSIXProcessMonitor_x86_64(lldb_private::Thread &thread,
+                                              uint32_t concrete_frame_idx,
+                                              lldb_private::RegisterInfoInterface *register_info);
+
+protected:
+    bool
+    ReadGPR();
+
+    bool
+    ReadFPR();
+
+    bool
+    WriteGPR();
+
+    bool
+    WriteFPR();
+
+    // lldb_private::RegisterContext
+    bool
+    ReadRegister(const unsigned reg, lldb_private::RegisterValue &value);
+
+    bool
+    WriteRegister(const unsigned reg, const lldb_private::RegisterValue &value);
+
+    bool
+    ReadRegister(const lldb_private::RegisterInfo *reg_info, lldb_private::RegisterValue &value);
+
+    bool
+    WriteRegister(const lldb_private::RegisterInfo *reg_info, const lldb_private::RegisterValue &value);
+
+    bool
+    ReadAllRegisterValues(lldb::DataBufferSP &data_sp);
+
+    bool
+    WriteAllRegisterValues(const lldb::DataBufferSP &data_sp);
+
+    uint32_t
+    SetHardwareWatchpoint(lldb::addr_t addr, size_t size, bool read, bool write);
+
+    bool
+    ClearHardwareWatchpoint(uint32_t hw_index);
+
+    bool
+    HardwareSingleStep(bool enable);
+
+    // POSIXBreakpointProtocol
+    bool
+    UpdateAfterBreakpoint();
+
+    unsigned
+    GetRegisterIndexFromOffset(unsigned offset);
+
+    bool
+    IsWatchpointHit(uint32_t hw_index);
+
+    bool
+    ClearWatchpointHits();
+
+    lldb::addr_t
+    GetWatchpointAddress(uint32_t hw_index);
+
+    bool
+    IsWatchpointVacant(uint32_t hw_index);
+
+    bool
+    SetHardwareWatchpointWithIndex(lldb::addr_t addr, size_t size, bool read, bool write, uint32_t hw_index);
+
+    uint32_t
+    NumSupportedHardwareWatchpoints();
+
+private:
+    ProcessMonitor &
+    GetMonitor();
+    uint32_t m_fctrl_offset_in_userarea;  // Offset of 'fctrl' in 'UserArea' Structure
+};
+
+#endif

source/Plugins/Process/NetBSD/RegisterContextPOSIXProcessMonitor_x86.cpp

+//===-- RegisterContextPOSIXProcessMonitor_x86.h ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+
+#include "lldb/Core/DataBufferHeap.h"
+#include "lldb/Core/RegisterValue.h"
+#include "lldb/Target/Thread.h"
+
+#include "Plugins/Process/NetBSD/ProcessNetBSD.h"
+#include "RegisterContextPOSIXProcessMonitor_x86.h"
+#include "Plugins/Process/NetBSD/ProcessMonitor.h"
+
+using namespace lldb_private;
+using namespace lldb;
+
+// Support ptrace extensions even when compiled without required kernel support
+#ifndef NT_X86_XSTATE
+  #define NT_X86_XSTATE 0x202
+#endif
+
+#define REG_CONTEXT_SIZE (GetGPRSize() + sizeof(FPR))
+
+static uint32_t
+size_and_rw_bits(size_t size, bool read, bool write)
+{
+    uint32_t rw;
+
+    if (read)
+        rw = 0x3; // READ or READ/WRITE
+    else if (write)
+        rw = 0x1; // WRITE
+    else
+        assert(0 && "read and write cannot both be false");
+
+    switch (size)
+    {
+    case 1:
+        return rw;
+    case 2:
+        return (0x1 << 2) | rw;
+    case 4:
+        return (0x3 << 2) | rw;
+    case 8:
+        return (0x2 << 2) | rw;
+    default:
+        assert(0 && "invalid size, must be one of 1, 2, 4, or 8");
+        return 0; // Unreachable. Just to silence compiler.
+    }
+}
+
+RegisterContextPOSIXProcessMonitor_x86_64::RegisterContextPOSIXProcessMonitor_x86_64(Thread &thread,
+                                                                                     uint32_t concrete_frame_idx,
+                                                                                     lldb_private::RegisterInfoInterface *register_info)
+    : RegisterContextPOSIX_x86(thread, concrete_frame_idx, register_info)
+{
+    // Store byte offset of fctrl (i.e. first register of FPR) wrt 'UserArea'
+    const RegisterInfo *reg_info_fctrl = GetRegisterInfoByName("fctrl");
+    m_fctrl_offset_in_userarea = reg_info_fctrl->byte_offset;
+}
+
+ProcessMonitor &
+RegisterContextPOSIXProcessMonitor_x86_64::GetMonitor()
+{
+    ProcessSP base = CalculateProcess();
+    ProcessNetBSD *process = static_cast<ProcessNetBSD*>(base.get());
+    return process->GetMonitor();
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ReadGPR()
+{
+     ProcessMonitor &monitor = GetMonitor();
+     return monitor.ReadGPR(m_thread.GetID(), &m_gpr_x86_64, GetGPRSize());
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ReadFPR()
+{
+    ProcessMonitor &monitor = GetMonitor();
+    if (GetFPRType() == eFXSAVE)
+        return monitor.ReadFPR(m_thread.GetID(), &m_fpr.xstate.fxsave, sizeof(m_fpr.xstate.fxsave));
+
+    if (GetFPRType() == eXSAVE)
+        return monitor.ReadRegisterSet(m_thread.GetID(), &m_iovec, sizeof(m_fpr.xstate.xsave), NT_X86_XSTATE);
+    return false;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::WriteGPR()
+{
+    ProcessMonitor &monitor = GetMonitor();
+    return monitor.WriteGPR(m_thread.GetID(), &m_gpr_x86_64, GetGPRSize());
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::WriteFPR()
+{
+    ProcessMonitor &monitor = GetMonitor();
+    if (GetFPRType() == eFXSAVE)
+        return monitor.WriteFPR(m_thread.GetID(), &m_fpr.xstate.fxsave, sizeof(m_fpr.xstate.fxsave));
+
+    if (GetFPRType() == eXSAVE)
+        return monitor.WriteRegisterSet(m_thread.GetID(), &m_iovec, sizeof(m_fpr.xstate.xsave), NT_X86_XSTATE);
+    return false;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ReadRegister(const unsigned reg,
+                                                        RegisterValue &value)
+{
+    ProcessMonitor &monitor = GetMonitor();
+
+    return monitor.ReadRegisterValue(m_thread.GetID(),
+                                     GetRegisterOffset(reg),
+                                     GetRegisterName(reg),
+                                     GetRegisterSize(reg),
+                                     value);
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::WriteRegister(const unsigned reg,
+                                                         const RegisterValue &value)
+{
+    unsigned reg_to_write = reg;
+    RegisterValue value_to_write = value;
+
+    // Check if this is a subregister of a full register.
+    const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg);
+    if (reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM))
+    {
+        RegisterValue full_value;
+        uint32_t full_reg = reg_info->invalidate_regs[0];
+        const RegisterInfo *full_reg_info = GetRegisterInfoAtIndex(full_reg);
+
+        // Read the full register.
+        if (ReadRegister(full_reg_info, full_value))
+        {
+            Error error;
+            ByteOrder byte_order = GetByteOrder();
+            uint8_t dst[RegisterValue::kMaxRegisterByteSize];
+
+            // Get the bytes for the full register.
+            const uint32_t dest_size = full_value.GetAsMemoryData (full_reg_info,
+                                                                   dst,
+                                                                   sizeof(dst),
+                                                                   byte_order,
+                                                                   error);
+            if (error.Success() && dest_size)
+            {
+                uint8_t src[RegisterValue::kMaxRegisterByteSize];
+
+                // Get the bytes for the source data.
+                const uint32_t src_size = value.GetAsMemoryData (reg_info, src, sizeof(src), byte_order, error);
+                if (error.Success() && src_size && (src_size < dest_size))
+                {
+                    // Copy the src bytes to the destination.
+                    memcpy (dst + (reg_info->byte_offset & 0x1), src, src_size);
+                    // Set this full register as the value to write.
+                    value_to_write.SetBytes(dst, full_value.GetByteSize(), byte_order);
+                    value_to_write.SetType(full_reg_info);
+                    reg_to_write = full_reg;
+                }
+            }
+        }
+    }
+
+    ProcessMonitor &monitor = GetMonitor();
+
+    return monitor.WriteRegisterValue(m_thread.GetID(),
+                                      GetRegisterOffset(reg_to_write),
+                                      GetRegisterName(reg_to_write),
+                                      value_to_write);
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ReadRegister(const RegisterInfo *reg_info, RegisterValue &value)
+{
+    if (!reg_info)
+        return false;
+
+    const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
+
+    if (IsFPR(reg, GetFPRType()))
+    {
+        if (!ReadFPR())
+            return false;
+    }
+    else
+    {
+        uint32_t full_reg = reg;
+        bool is_subreg = reg_info->invalidate_regs && (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM);
+
+        if (is_subreg)
+        {
+            // Read the full aligned 64-bit register.
+            full_reg = reg_info->invalidate_regs[0];
+        }
+
+        bool success = ReadRegister(full_reg, value);
+
+        if (success)
+        {
+            // If our read was not aligned (for ah,bh,ch,dh), shift our returned value one byte to the right.
+            if (is_subreg && (reg_info->byte_offset & 0x1))
+                value.SetUInt64(value.GetAsUInt64() >> 8);
+
+            // If our return byte size was greater than the return value reg size, then
+            // use the type specified by reg_info rather than the uint64_t default
+            if (value.GetByteSize() > reg_info->byte_size)
+                value.SetType(reg_info);
+        }
+        return success;
+    }
+
+    if (reg_info->encoding == eEncodingVector)
+    {
+        ByteOrder byte_order = GetByteOrder();
+
+        if (byte_order != ByteOrder::eByteOrderInvalid)
+        {
+            if (reg >= m_reg_info.first_st && reg <= m_reg_info.last_st)
+               value.SetBytes(m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_st].bytes, reg_info->byte_size, byte_order);
+            if (reg >= m_reg_info.first_mm && reg <= m_reg_info.last_mm)
+               value.SetBytes(m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_mm].bytes, reg_info->byte_size, byte_order);
+            if (reg >= m_reg_info.first_xmm && reg <= m_reg_info.last_xmm)
+                value.SetBytes(m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_xmm].bytes, reg_info->byte_size, byte_order);
+            if (reg >= m_reg_info.first_ymm && reg <= m_reg_info.last_ymm)
+            {
+                // Concatenate ymm using the register halves in xmm.bytes and ymmh.bytes
+                if (GetFPRType() == eXSAVE && CopyXSTATEtoYMM(reg, byte_order))
+                    value.SetBytes(m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes, reg_info->byte_size, byte_order);
+                else
+                    return false;
+            }
+            return value.GetType() == RegisterValue::eTypeBytes;
+        }
+        return false;
+    }
+
+    // Get pointer to m_fpr.xstate.fxsave variable and set the data from it.
+    // Byte offsets of all registers are calculated wrt 'UserArea' structure.
+    // However, ReadFPR() reads fpu registers {using ptrace(PT_GETFPREGS,..)}
+    // and stores them in 'm_fpr' (of type FPR structure). To extract values of fpu
+    // registers, m_fpr should be read at byte offsets calculated wrt to FPR structure.
+
+    // Since, FPR structure is also one of the member of UserArea structure.
+    // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
+    assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
+    uint8_t *src = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
+    switch (reg_info->byte_size)
+    {
+        case 1:
+            value.SetUInt8(*(uint8_t *)src);
+            return true;
+        case 2:
+            value.SetUInt16(*(uint16_t *)src);
+            return true;
+        case 4:
+            value.SetUInt32(*(uint32_t *)src);
+            return true;
+        case 8:
+            value.SetUInt64(*(uint64_t *)src);
+            return true;
+        default:
+            assert(false && "Unhandled data size.");
+            return false;
+    }
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::WriteRegister(const RegisterInfo *reg_info, const RegisterValue &value)
+{
+    const uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
+
+    if (IsGPR(reg))
+        return WriteRegister(reg, value);
+
+    if (IsFPR(reg, GetFPRType()))
+    {
+        if (reg_info->encoding == eEncodingVector)
+        {
+            if (reg >= m_reg_info.first_st && reg <= m_reg_info.last_st)
+               ::memcpy (m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_st].bytes, value.GetBytes(), value.GetByteSize());
+
+            if (reg >= m_reg_info.first_mm && reg <= m_reg_info.last_mm)
+               ::memcpy (m_fpr.xstate.fxsave.stmm[reg - m_reg_info.first_mm].bytes, value.GetBytes(), value.GetByteSize());
+
+            if (reg >= m_reg_info.first_xmm && reg <= m_reg_info.last_xmm)
+               ::memcpy (m_fpr.xstate.fxsave.xmm[reg - m_reg_info.first_xmm].bytes, value.GetBytes(), value.GetByteSize());
+
+            if (reg >= m_reg_info.first_ymm && reg <= m_reg_info.last_ymm)
+            {
+               if (GetFPRType() != eXSAVE)
+                   return false; // the target processor does not support AVX
+
+               // Store ymm register content, and split into the register halves in xmm.bytes and ymmh.bytes
+               ::memcpy (m_ymm_set.ymm[reg - m_reg_info.first_ymm].bytes, value.GetBytes(), value.GetByteSize());
+               if (false == CopyYMMtoXSTATE(reg, GetByteOrder()))
+                   return false;
+            }
+        }
+        else
+        {
+            // Get pointer to m_fpr.xstate.fxsave variable and set the data to it.
+            // Byte offsets of all registers are calculated wrt 'UserArea' structure.
+            // However, WriteFPR() takes m_fpr (of type FPR structure) and writes only fpu
+            // registers using ptrace(PT_SETFPREGS,..) API. Hence fpu registers should
+            // be written in m_fpr at byte offsets calculated wrt FPR structure.
+
+            // Since, FPR structure is also one of the member of UserArea structure.
+            // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
+            assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
+            uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
+            switch (reg_info->byte_size)
+            {
+                case 1:
+                    *(uint8_t *)dst = value.GetAsUInt8();
+                    break;
+                case 2:
+                    *(uint16_t *)dst = value.GetAsUInt16();
+                    break;
+                case 4:
+                    *(uint32_t *)dst = value.GetAsUInt32();
+                    break;
+                case 8:
+                    *(uint64_t *)dst = value.GetAsUInt64();
+                    break;
+                default:
+                    assert(false && "Unhandled data size.");
+                    return false;
+            }
+        }
+
+        if (WriteFPR())
+        {
+            if (IsAVX(reg))
+                return CopyYMMtoXSTATE(reg, GetByteOrder());
+            return true;
+        }
+    }
+    return false;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ReadAllRegisterValues(DataBufferSP &data_sp)
+{
+    bool success = false;
+    data_sp.reset (new DataBufferHeap (REG_CONTEXT_SIZE, 0));
+    if (data_sp && ReadGPR () && ReadFPR ())
+    {
+        uint8_t *dst = data_sp->GetBytes();
+        success = dst != 0;
+
+        if (success)
+        {
+          ::memcpy (dst, &m_gpr_x86_64, GetGPRSize());
+          dst += GetGPRSize();
+          if (GetFPRType() == eFXSAVE)
+              ::memcpy (dst, &m_fpr.xstate.fxsave, sizeof(m_fpr.xstate.fxsave));
+        }
+
+        if (GetFPRType() == eXSAVE)
+        {
+            ByteOrder byte_order = GetByteOrder();
+
+            // Assemble the YMM register content from the register halves.
+            for (uint32_t reg  = m_reg_info.first_ymm; success && reg <= m_reg_info.last_ymm; ++reg)
+                success = CopyXSTATEtoYMM(reg, byte_order);
+
+            if (success)
+            {
+                // Copy the extended register state including the assembled ymm registers.
+                ::memcpy (dst, &m_fpr, sizeof(m_fpr));
+            }
+        }
+    }
+    return success;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::WriteAllRegisterValues(const DataBufferSP &data_sp)
+{
+    bool success = false;
+    if (data_sp && data_sp->GetByteSize() == REG_CONTEXT_SIZE)
+    {
+        uint8_t *src = data_sp->GetBytes();
+        if (src)
+        {
+            ::memcpy (&m_gpr_x86_64, src, GetGPRSize());
+
+            if (WriteGPR())
+            {
+                src += GetGPRSize();
+                if (GetFPRType() == eFXSAVE)
+                    ::memcpy (&m_fpr.xstate.fxsave, src, sizeof(m_fpr.xstate.fxsave));
+                if (GetFPRType() == eXSAVE)
+                    ::memcpy (&m_fpr.xstate.xsave, src, sizeof(m_fpr.xstate.xsave));
+
+                success = WriteFPR();
+                if (success)
+                {
+                    if (GetFPRType() == eXSAVE)
+                    {
+                        ByteOrder byte_order = GetByteOrder();
+
+                        // Parse the YMM register content from the register halves.
+                        for (uint32_t reg = m_reg_info.first_ymm; success && reg <= m_reg_info.last_ymm; ++reg)
+                            success = CopyYMMtoXSTATE(reg, byte_order);
+                    }
+                }
+            }
+        }
+    }
+    return success;
+}
+
+uint32_t
+RegisterContextPOSIXProcessMonitor_x86_64::SetHardwareWatchpoint(addr_t addr, size_t size,
+                                              bool read, bool write)
+{
+    const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
+    uint32_t hw_index;
+
+    for (hw_index = 0; hw_index < num_hw_watchpoints; ++hw_index)
+    {
+        if (IsWatchpointVacant(hw_index))
+            return SetHardwareWatchpointWithIndex(addr, size,
+                                                  read, write,
+                                                  hw_index);
+    }
+
+    return LLDB_INVALID_INDEX32;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ClearHardwareWatchpoint(uint32_t hw_index)
+{
+    if (hw_index < NumSupportedHardwareWatchpoints())
+    {
+        RegisterValue current_dr7_bits;
+
+        if (ReadRegister(m_reg_info.first_dr + 7, current_dr7_bits))
+        {
+            uint64_t new_dr7_bits = current_dr7_bits.GetAsUInt64() & ~(3 << (2*hw_index));
+
+            if (WriteRegister(m_reg_info.first_dr + 7, RegisterValue(new_dr7_bits)))
+                return true;
+        }
+    }
+
+    return false;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::HardwareSingleStep(bool enable)
+{
+    enum { TRACE_BIT = 0x100 };
+    uint64_t rflags;
+
+    if ((rflags = ReadRegisterAsUnsigned(m_reg_info.gpr_flags, -1UL)) == -1UL)
+        return false;
+
+    if (enable)
+    {
+        if (rflags & TRACE_BIT)
+            return true;
+
+        rflags |= TRACE_BIT;
+    }
+    else
+    {
+        if (!(rflags & TRACE_BIT))
+            return false;
+
+        rflags &= ~TRACE_BIT;
+    }
+
+    return WriteRegisterFromUnsigned(m_reg_info.gpr_flags, rflags);
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::UpdateAfterBreakpoint()
+{
+    // PC points one byte past the int3 responsible for the breakpoint.
+    lldb::addr_t pc;
+
+    if ((pc = GetPC()) == LLDB_INVALID_ADDRESS)
+        return false;
+
+    SetPC(pc - 1);
+    return true;
+}
+
+unsigned
+RegisterContextPOSIXProcessMonitor_x86_64::GetRegisterIndexFromOffset(unsigned offset)
+{
+    unsigned reg;
+    for (reg = 0; reg < m_reg_info.num_registers; reg++)
+    {
+        if (GetRegisterInfo()[reg].byte_offset == offset)
+            break;
+    }
+    assert(reg < m_reg_info.num_registers && "Invalid register offset.");
+    return reg;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::IsWatchpointHit(uint32_t hw_index)
+{
+    bool is_hit = false;
+
+    if (m_watchpoints_initialized == false)
+    {
+        // Reset the debug status and debug control registers
+        RegisterValue zero_bits = RegisterValue(uint64_t(0));
+        if (!WriteRegister(m_reg_info.first_dr + 6, zero_bits) || !WriteRegister(m_reg_info.first_dr + 7, zero_bits))
+            assert(false && "Could not initialize watchpoint registers");
+        m_watchpoints_initialized = true;
+    }
+
+    if (hw_index < NumSupportedHardwareWatchpoints())
+    {
+        RegisterValue value;
+
+        if (ReadRegister(m_reg_info.first_dr + 6, value))
+        {
+            uint64_t val = value.GetAsUInt64();
+            is_hit = val & (1 << hw_index);
+        }
+    }
+
+    return is_hit;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::ClearWatchpointHits()
+{
+    return WriteRegister(m_reg_info.first_dr + 6, RegisterValue((uint64_t)0));
+}
+
+addr_t
+RegisterContextPOSIXProcessMonitor_x86_64::GetWatchpointAddress(uint32_t hw_index)
+{
+    addr_t wp_monitor_addr = LLDB_INVALID_ADDRESS;
+
+    if (hw_index < NumSupportedHardwareWatchpoints())
+    {
+        if (!IsWatchpointVacant(hw_index))
+        {
+            RegisterValue value;
+
+            if (ReadRegister(m_reg_info.first_dr + hw_index, value))
+                wp_monitor_addr = value.GetAsUInt64();
+        }
+    }
+
+    return wp_monitor_addr;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::IsWatchpointVacant(uint32_t hw_index)
+{
+    bool is_vacant = false;
+    RegisterValue value;
+
+    assert(hw_index < NumSupportedHardwareWatchpoints());
+
+    if (m_watchpoints_initialized == false)
+    {
+        // Reset the debug status and debug control registers
+        RegisterValue zero_bits = RegisterValue(uint64_t(0));
+        if (!WriteRegister(m_reg_info.first_dr + 6, zero_bits) || !WriteRegister(m_reg_info.first_dr + 7, zero_bits))
+            assert(false && "Could not initialize watchpoint registers");
+        m_watchpoints_initialized = true;
+    }
+
+    if (ReadRegister(m_reg_info.first_dr + 7, value))
+    {
+        uint64_t val = value.GetAsUInt64();
+        is_vacant = (val & (3 << 2*hw_index)) == 0;
+    }
+
+    return is_vacant;
+}
+
+bool
+RegisterContextPOSIXProcessMonitor_x86_64::SetHardwareWatchpointWithIndex(addr_t addr, size_t size,
+                                                       bool read, bool write,
+                                                       uint32_t hw_index)
+{
+    const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
+
+    if (num_hw_watchpoints == 0 || hw_index >= num_hw_watchpoints)
+        return false;
+
+    if (!(size == 1 || size == 2 || size == 4 || size == 8))
+        return false;
+
+    if (read == false && write == false)
+        return false;
+
+    if (!IsWatchpointVacant(hw_index))
+        return false;
+
+    return false;
+}
+
+uint32_t
+RegisterContextPOSIXProcessMonitor_x86_64::NumSupportedHardwareWatchpoints()
+{
+    // Available debug address registers: NONE
+    return 0;
+}