source/Plugins/Process/POSIX/ProcessPOSIX.cpp

//===-- ProcessPOSIX.cpp ----------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/lldb-python.h"

// C Includes
#include <errno.h>

// C++ Includes
// Other libraries and framework includes
#include "lldb/Breakpoint/Watchpoint.h"
#include "lldb/Core/Module.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/Target.h"

#include "ProcessPOSIX.h"
#include "ProcessPOSIXLog.h"
#include "Plugins/Process/Utility/InferiorCallPOSIX.h"
#include "ProcessMonitor.h"
#include "POSIXThread.h"

using namespace lldb;
using namespace lldb_private;

//------------------------------------------------------------------------------
// Static functions.
#if 0
Process*
ProcessPOSIX::CreateInstance(Target& target, Listener &listener)
{
    return new ProcessPOSIX(target, listener);
}


void
ProcessPOSIX::Initialize()
{
    static bool g_initialized = false;

    if (!g_initialized)
    {
        g_initialized = true;
        PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                      GetPluginDescriptionStatic(),
                                      CreateInstance);

        Log::Callbacks log_callbacks = {
            ProcessPOSIXLog::DisableLog,
            ProcessPOSIXLog::EnableLog,
            ProcessPOSIXLog::ListLogCategories
        };
        
        Log::RegisterLogChannel (ProcessPOSIX::GetPluginNameStatic(), log_callbacks);
    }
}
#endif

//------------------------------------------------------------------------------
// Constructors and destructors.

ProcessPOSIX::ProcessPOSIX(Target& target, Listener &listener)
    : Process(target, listener),
      m_byte_order(lldb::endian::InlHostByteOrder()),
      m_monitor(NULL),
      m_module(NULL),
      m_in_limbo(false),
      m_exit_now(false)
{
    // 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 != NULL && module->GetObjectFile() != NULL)
		m_byte_order = module->GetObjectFile()->GetByteOrder();
}

ProcessPOSIX::~ProcessPOSIX()
{
    delete m_monitor;
}

//------------------------------------------------------------------------------
// Process protocol.

bool
ProcessPOSIX::CanDebug(Target &target, bool plugin_specified_by_name)
{
    // For now we are just making sure the file exists for a given module
    ModuleSP exe_module_sp(target.GetExecutableModule());
    if (exe_module_sp.get())
        return exe_module_sp->GetFileSpec().Exists();
    return false;
}

Error
ProcessPOSIX::DoAttachToProcessWithID(lldb::pid_t pid)
{
    Error error;
    assert(m_monitor == NULL);

    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("ProcessPOSIX::%s(pid = %" PRIi64 ")", __FUNCTION__, GetID());

    m_monitor = new ProcessMonitor(this, pid, error);

    if (!error.Success())
        return error;

    SetID(pid);
    return error;
}

Error
ProcessPOSIX::DoAttachToProcessWithID (lldb::pid_t pid,  const ProcessAttachInfo &attach_info)
{
    return DoAttachToProcessWithID(pid);
}

Error
ProcessPOSIX::WillLaunch(Module* module)
{
    Error error;
    return error;
}

const char *
ProcessPOSIX::GetFilePath(
    const lldb_private::ProcessLaunchInfo::FileAction *file_action,
    const char *default_path)
{
    const char *pts_name = "/dev/pts/";
    const char *path = NULL;

    if (file_action)
    {
        if (file_action->GetAction () == ProcessLaunchInfo::FileAction::eFileActionOpen)
            path = file_action->GetPath();
            // 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 (::strncmp(path, pts_name, ::strlen(pts_name)) == 0)
                path = default_path;
    }

    return path;
}

Error
ProcessPOSIX::DoLaunch (Module *module,
                       const ProcessLaunchInfo &launch_info)
{
    Error error;
    assert(m_monitor == NULL);

    const char* working_dir = launch_info.GetWorkingDirectory();
    if (working_dir) {
      FileSpec WorkingDir(working_dir, true);
      if (!WorkingDir || WorkingDir.GetFileType() != FileSpec::eFileTypeDirectory)
      {
          error.SetErrorStringWithFormat("No such file or directory: %s", working_dir);
          return error;
      }
    }

    SetPrivateState(eStateLaunching);

    const lldb_private::ProcessLaunchInfo::FileAction *file_action;

    // Default of NULL will mean to use existing open file descriptors
    const char *stdin_path = NULL;
    const char *stdout_path = NULL;
    const char *stderr_path = NULL;

    file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
    stdin_path = GetFilePath(file_action, stdin_path);

    file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
    stdout_path = GetFilePath(file_action, stdout_path);

    file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
    stderr_path = GetFilePath(file_action, stderr_path);

    m_monitor = new ProcessMonitor (this, 
                                    module,
                                    launch_info.GetArguments().GetConstArgumentVector(), 
                                    launch_info.GetEnvironmentEntries().GetConstArgumentVector(),
                                    stdin_path, 
                                    stdout_path, 
                                    stderr_path,
                                    working_dir,
                                    error);

    m_module = module;

    if (!error.Success())
        return error;

    SetSTDIOFileDescriptor(m_monitor->GetTerminalFD());

    SetID(m_monitor->GetPID());
    return error;
}

void
ProcessPOSIX::DidLaunch()
{
}

Error
ProcessPOSIX::DoResume()
{
    StateType state = GetPrivateState();

    assert(state == eStateStopped || state == eStateCrashed);

    // We are about to resume a thread that will cause the process to exit so
    // set our exit status now.  Do not change our state if the inferior
    // crashed.
    if (state == eStateStopped) 
    {
        if (m_in_limbo)
            SetExitStatus(m_exit_status, NULL);
        else
            SetPrivateState(eStateRunning);
    }

    bool did_resume = false;
    uint32_t thread_count = m_thread_list.GetSize(false);
    for (uint32_t i = 0; i < thread_count; ++i)
    {
        POSIXThread *thread = static_cast<POSIXThread*>(
            m_thread_list.GetThreadAtIndex(i, false).get());
        did_resume = thread->Resume() || did_resume;
    }
    assert(did_resume && "Process resume failed!");

    return Error();
}

addr_t
ProcessPOSIX::GetImageInfoAddress()
{
    Target *target = &GetTarget();
    ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
    Address addr = obj_file->GetImageInfoAddress();

    if (addr.IsValid()) 
        return addr.GetLoadAddress(target);
    else
        return LLDB_INVALID_ADDRESS;
}

Error
ProcessPOSIX::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
ProcessPOSIX::DoDetach(bool keep_stopped)
{
    Error error;
    if (keep_stopped)
    {
        // FIXME: If you want to implement keep_stopped on Linux,
        // this would be the place to do it.
        error.SetErrorString("Detaching with keep_stopped true is not currently supported on Linux.");
        return error;
    }

    error = m_monitor->Detach();
    if (error.Success())
        SetPrivateState(eStateDetached);

    return error;
}

Error
ProcessPOSIX::DoSignal(int signal)
{
    Error error;

    if (kill(GetID(), signal))
        error.SetErrorToErrno();

    return error;
}

Error
ProcessPOSIX::DoDestroy()
{
    Error error;

    if (!HasExited())
    {
        // Drive the exit event to completion (do not keep the inferior in
        // limbo).
        m_exit_now = true;

        if ((m_monitor == NULL || kill(m_monitor->GetPID(), SIGKILL)) && error.Success())
        {
            error.SetErrorToErrno();
            return error;
        }

        SetPrivateState(eStateExited);
    }

    return error;
}

void
ProcessPOSIX::SendMessage(const ProcessMessage &message)
{
    Mutex::Locker lock(m_message_mutex);

    switch (message.GetKind())
    {
    case ProcessMessage::eInvalidMessage:
        return;

    case ProcessMessage::eLimboMessage:
        m_in_limbo = true;
        m_exit_status = message.GetExitStatus();
        if (m_exit_now)
        {
            SetPrivateState(eStateExited);
            m_monitor->Detach();
        }
        else
            SetPrivateState(eStateStopped);
        break;

    case ProcessMessage::eExitMessage:
        m_exit_status = message.GetExitStatus();
        SetExitStatus(m_exit_status, NULL);
        break;

    case ProcessMessage::eTraceMessage:
    case ProcessMessage::eBreakpointMessage:
    case ProcessMessage::eWatchpointMessage:
        SetPrivateState(eStateStopped);
        break;

    case ProcessMessage::eSignalMessage:
    case ProcessMessage::eSignalDeliveredMessage:
    {
        lldb::tid_t tid = message.GetTID();
        lldb::tid_t pid = GetID();
        if (tid == pid) {
            SetPrivateState(eStateStopped);
            break;
        } else {
            // FIXME: Ignore any signals generated by children.
            return;
        }
    }

    case ProcessMessage::eCrashMessage:
        // FIXME: Update stop reason as per bugzilla 14598
        SetPrivateState(eStateStopped);
        break;

    case ProcessMessage::eNewThreadMessage:
        SetPrivateState(eStateStopped);
        break;
    }

    m_message_queue.push(message);
}

void
ProcessPOSIX::RefreshStateAfterStop()
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("ProcessPOSIX::%s()", __FUNCTION__);

    Mutex::Locker lock(m_message_mutex);
    if (m_message_queue.empty())
        return;

    ProcessMessage &message = m_message_queue.front();

    // Resolve the thread this message corresponds to and pass it along.
    // FIXME: we're really dealing with the pid here.  This should get
    // fixed when this code is fixed to handle multiple threads.
    lldb::tid_t tid = message.GetTID();
    if (log)
        log->Printf ("ProcessPOSIX::%s() pid = %" PRIi64, __FUNCTION__, tid);
    POSIXThread *thread = static_cast<POSIXThread*>(
        GetThreadList().FindThreadByID(tid, false).get());

    if (message.GetKind() == ProcessMessage::eNewThreadMessage) {
        ThreadSP thread_sp;
        thread_sp.reset(new POSIXThread(*this, message.GetChildTID()));
        m_thread_list.AddThread(thread_sp);
    }

    assert(thread);
    thread->Notify(message);

    m_message_queue.pop();
}

bool
ProcessPOSIX::IsAlive()
{
    StateType state = GetPrivateState();
    return state != eStateDetached
        && state != eStateExited
        && state != eStateInvalid
        && state != eStateUnloaded;
}

size_t
ProcessPOSIX::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
ProcessPOSIX::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
ProcessPOSIX::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
ProcessPOSIX::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;
}

addr_t
ProcessPOSIX::ResolveIndirectFunction(const Address *address, Error &error)
{
    addr_t function_addr = LLDB_INVALID_ADDRESS;
    if (address == NULL) {
        error.SetErrorStringWithFormat("unable to determine direct function call for NULL address");
    } else if (!InferiorCall(this, address, function_addr)) {
        function_addr = LLDB_INVALID_ADDRESS;
        error.SetErrorStringWithFormat("unable to determine direct function call for indirect function %s",
                                       address->CalculateSymbolContextSymbol()->GetName().AsCString());
    }
    return function_addr;
}

size_t
ProcessPOSIX::GetSoftwareBreakpointTrapOpcode(BreakpointSite* bp_site)
{
    static const uint8_t g_i386_opcode[] = { 0xCC };

    ArchSpec arch = GetTarget().GetArchitecture();
    const uint8_t *opcode = NULL;
    size_t opcode_size = 0;

    switch (arch.GetCore())
    {
    default:
        assert(false && "CPU type not supported!");
        break;

    case ArchSpec::eCore_x86_32_i386:
    case ArchSpec::eCore_x86_64_x86_64:
        opcode = g_i386_opcode;
        opcode_size = sizeof(g_i386_opcode);
        break;
    }

    bp_site->SetTrapOpcode(opcode, opcode_size);
    return opcode_size;
}

Error
ProcessPOSIX::EnableBreakpointSite(BreakpointSite *bp_site)
{
    return EnableSoftwareBreakpoint(bp_site);
}

Error
ProcessPOSIX::DisableBreakpointSite(BreakpointSite *bp_site)
{
    return DisableSoftwareBreakpoint(bp_site);
}

Error
ProcessPOSIX::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 ("ProcessPOSIX::EnableWatchpoint(watchID = %" PRIu64 ")",
                         watchID);
        if (wp->IsEnabled())
        {
            if (log)
                log->Printf("ProcessPOSIX::EnableWatchpoint(watchID = %" PRIu64
                            ") addr = 0x%8.8" PRIx64 ": watchpoint already enabled.",
                            watchID, (uint64_t)addr);
            return error;
        }

        bool wp_enabled = true;
        uint32_t thread_count = m_thread_list.GetSize(false);
        for (uint32_t i = 0; i < thread_count; ++i)
        {
            POSIXThread *thread = static_cast<POSIXThread*>(
                                  m_thread_list.GetThreadAtIndex(i, false).get());
            if (thread)
                wp_enabled &= thread->EnableHardwareWatchpoint(wp);
            else
            {
                wp_enabled = false;
                break;
            }
        }
        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
ProcessPOSIX::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("ProcessPOSIX::DisableWatchpoint(watchID = %" PRIu64 ")",
                        watchID);
        if (!wp->IsEnabled())
        {
            if (log)
                log->Printf("ProcessPOSIX::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;
            uint32_t thread_count = m_thread_list.GetSize(false);
            for (uint32_t i = 0; i < thread_count; ++i)
            {
                POSIXThread *thread = static_cast<POSIXThread*>(
                                      m_thread_list.GetThreadAtIndex(i, false).get());
                if (thread)
                    wp_disabled &= thread->DisableHardwareWatchpoint(wp);
                else
                    wp_disabled = false;
            }
            if (wp_disabled)
            {
                wp->SetEnabled(false, notify);
                return error;
            }
            else
                error.SetErrorString("Disabling hardware watchpoint failed");
        }
    }
    else
        error.SetErrorString("Watchpoint argument was NULL.");
    return error;
}

Error
ProcessPOSIX::GetWatchpointSupportInfo(uint32_t &num)
{
    Error error;
    POSIXThread *thread = static_cast<POSIXThread*>(
                          m_thread_list.GetThreadAtIndex(0, false).get());
    if (thread)
        num = thread->NumSupportedHardwareWatchpoints();
    else
        error.SetErrorString("Process does not exist.");
    return error;
}

Error
ProcessPOSIX::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
ProcessPOSIX::UpdateThreadListIfNeeded()
{
    // Do not allow recursive updates.
    return m_thread_list.GetSize(false);
}

bool
ProcessPOSIX::UpdateThreadList(ThreadList &old_thread_list, ThreadList &new_thread_list)
{
    Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_THREAD));
    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("ProcessPOSIX::%s() (pid = %" PRIi64 ")", __FUNCTION__, GetID());

    // Update the process thread list with this new thread.
    // FIXME: We should be using tid, not pid.
    assert(m_monitor);
    ThreadSP thread_sp (old_thread_list.FindThreadByID (GetID(), false));
    if (!thread_sp) {
        thread_sp.reset(new POSIXThread(*this, GetID()));
    }

    if (log && log->GetMask().Test(POSIX_LOG_VERBOSE))
        log->Printf ("ProcessPOSIX::%s() updated pid = %" PRIi64, __FUNCTION__, GetID());
    new_thread_list.AddThread(thread_sp);

    return new_thread_list.GetSize(false) > 0;
}

ByteOrder
ProcessPOSIX::GetByteOrder() const
{
    // FIXME: We should be able to extract this value directly.  See comment in
    // ProcessPOSIX().
    return m_byte_order;
}

size_t
ProcessPOSIX::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;
}

UnixSignals &
ProcessPOSIX::GetUnixSignals()
{
    return m_signals;
}

//------------------------------------------------------------------------------
// Utility functions.

bool
ProcessPOSIX::HasExited()
{
    switch (GetPrivateState())
    {
    default:
        break;

    case eStateDetached:
    case eStateExited:
        return true;
    }

    return false;
}

bool
ProcessPOSIX::IsStopped()
{
    switch (GetPrivateState())
    {
    default:
        break;

    case eStateStopped:
    case eStateCrashed:
    case eStateSuspended:
        return true;
    }

    return false;
}