llvm-project/lldb/source/Plugins/Process/Windows/Live/DebuggerThread.cpp

550 lines
20 KiB
C++

//===-- DebuggerThread.DebuggerThread --------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "DebuggerThread.h"
#include "ExceptionRecord.h"
#include "IDebugDelegate.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Host/Predicate.h"
#include "lldb/Host/ThisThread.h"
#include "lldb/Host/ThreadLauncher.h"
#include "lldb/Host/windows/HostProcessWindows.h"
#include "lldb/Host/windows/HostThreadWindows.h"
#include "lldb/Host/windows/ProcessLauncherWindows.h"
#include "lldb/Target/ProcessLaunchInfo.h"
#include "lldb/Target/Process.h"
#include "Plugins/Process/Windows/Common/ProcessWindowsLog.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/raw_ostream.h"
using namespace lldb;
using namespace lldb_private;
namespace
{
struct DebugLaunchContext
{
DebugLaunchContext(DebuggerThread *thread, const ProcessLaunchInfo &launch_info)
: m_thread(thread)
, m_launch_info(launch_info)
{
}
DebuggerThread *m_thread;
ProcessLaunchInfo m_launch_info;
};
struct DebugAttachContext
{
DebugAttachContext(DebuggerThread *thread, lldb::pid_t pid, const ProcessAttachInfo &attach_info)
: m_thread(thread)
, m_pid(pid)
, m_attach_info(attach_info)
{
}
DebuggerThread *m_thread;
lldb::pid_t m_pid;
ProcessAttachInfo m_attach_info;
};
}
DebuggerThread::DebuggerThread(DebugDelegateSP debug_delegate)
: m_debug_delegate(debug_delegate)
, m_image_file(nullptr)
, m_debugging_ended_event(nullptr)
, m_is_shutting_down(false)
, m_pid_to_detach(0)
, m_detached(false)
{
m_debugging_ended_event = ::CreateEvent(nullptr, TRUE, FALSE, nullptr);
}
DebuggerThread::~DebuggerThread()
{
::CloseHandle(m_debugging_ended_event);
}
Error
DebuggerThread::DebugLaunch(const ProcessLaunchInfo &launch_info)
{
WINLOG_IFALL(WINDOWS_LOG_PROCESS,
"DebuggerThread::DebugLaunch launching '%s'", launch_info.GetExecutableFile().GetPath().c_str());
Error error;
DebugLaunchContext *context = new DebugLaunchContext(this, launch_info);
HostThread slave_thread(ThreadLauncher::LaunchThread("lldb.plugin.process-windows.slave[?]",
DebuggerThreadLaunchRoutine, context, &error));
if (!error.Success())
{
WINERR_IFALL(WINDOWS_LOG_PROCESS,
"DebugLaunch couldn't launch debugger thread. %s", error.AsCString());
}
return error;
}
Error
DebuggerThread::DebugAttach(lldb::pid_t pid, const ProcessAttachInfo &attach_info)
{
WINLOG_IFALL(WINDOWS_LOG_PROCESS, "DebuggerThread::DebugAttach attaching to '%u'", (DWORD)pid);
Error error;
DebugAttachContext *context = new DebugAttachContext(this, pid, attach_info);
HostThread slave_thread(ThreadLauncher::LaunchThread("lldb.plugin.process-windows.slave[?]",
DebuggerThreadAttachRoutine, context, &error));
if (!error.Success())
{
WINERR_IFALL(WINDOWS_LOG_PROCESS, "DebugAttach couldn't attach to process '%u'. %s", (DWORD)pid,
error.AsCString());
}
return error;
}
lldb::thread_result_t
DebuggerThread::DebuggerThreadLaunchRoutine(void *data)
{
DebugLaunchContext *context = static_cast<DebugLaunchContext *>(data);
lldb::thread_result_t result = context->m_thread->DebuggerThreadLaunchRoutine(context->m_launch_info);
delete context;
return result;
}
lldb::thread_result_t
DebuggerThread::DebuggerThreadAttachRoutine(void *data)
{
DebugAttachContext *context = static_cast<DebugAttachContext *>(data);
lldb::thread_result_t result =
context->m_thread->DebuggerThreadAttachRoutine(context->m_pid, context->m_attach_info);
delete context;
return result;
}
lldb::thread_result_t
DebuggerThread::DebuggerThreadLaunchRoutine(const ProcessLaunchInfo &launch_info)
{
// Grab a shared_ptr reference to this so that we know it won't get deleted until after the
// thread routine has exited.
std::shared_ptr<DebuggerThread> this_ref(shared_from_this());
WINLOG_IFALL(WINDOWS_LOG_PROCESS, "DebuggerThread preparing to launch '%s' on background thread.",
launch_info.GetExecutableFile().GetPath().c_str());
Error error;
ProcessLauncherWindows launcher;
HostProcess process(launcher.LaunchProcess(launch_info, error));
// If we couldn't create the process, notify waiters immediately. Otherwise enter the debug
// loop and wait until we get the create process debug notification. Note that if the process
// was created successfully, we can throw away the process handle we got from CreateProcess
// because Windows will give us another (potentially more useful?) handle when it sends us the
// CREATE_PROCESS_DEBUG_EVENT.
if (error.Success())
DebugLoop();
else
m_debug_delegate->OnDebuggerError(error, 0);
return 0;
}
lldb::thread_result_t
DebuggerThread::DebuggerThreadAttachRoutine(lldb::pid_t pid, const ProcessAttachInfo &attach_info)
{
// Grab a shared_ptr reference to this so that we know it won't get deleted until after the
// thread routine has exited.
std::shared_ptr<DebuggerThread> this_ref(shared_from_this());
WINLOG_IFALL(WINDOWS_LOG_PROCESS, "DebuggerThread preparing to attach to process '%u' on background thread.",
(DWORD)pid);
if (!DebugActiveProcess((DWORD)pid))
{
Error error(::GetLastError(), eErrorTypeWin32);
m_debug_delegate->OnDebuggerError(error, 0);
return 0;
}
// The attach was successful, enter the debug loop. From here on out, this is no different than
// a create process operation, so all the same comments in DebugLaunch should apply from this
// point out.
DebugLoop();
return 0;
}
Error
DebuggerThread::StopDebugging(bool terminate)
{
Error error;
lldb::pid_t pid = m_process.GetProcessId();
WINLOG_IFALL(WINDOWS_LOG_PROCESS,
"StopDebugging('%s') called (inferior=%I64u).",
(terminate ? "true" : "false"), pid);
// Set m_is_shutting_down to true if it was false. Return if it was already true.
bool expected = false;
if (!m_is_shutting_down.compare_exchange_strong(expected, true))
return error;
// Make a copy of the process, since the termination sequence will reset
// DebuggerThread's internal copy and it needs to remain open for the Wait operation.
HostProcess process_copy = m_process;
lldb::process_t handle = m_process.GetNativeProcess().GetSystemHandle();
if (terminate)
{
// Initiate the termination before continuing the exception, so that the next debug
// event we get is the exit process event, and not some other event.
BOOL terminate_suceeded = TerminateProcess(handle, 0);
WINLOG_IFALL(WINDOWS_LOG_PROCESS,
"StopDebugging called TerminateProcess(0x%p, 0) (inferior=%I64u), success='%s'",
handle, pid, (terminate_suceeded ? "true" : "false"));
}
// If we're stuck waiting for an exception to continue (e.g. the user is at a breakpoint
// messing around in the debugger), continue it now. But only AFTER calling TerminateProcess
// to make sure that the very next call to WaitForDebugEvent is an exit process event.
if (m_active_exception.get())
{
WINLOG_IFANY(WINDOWS_LOG_PROCESS|WINDOWS_LOG_EXCEPTION,
"StopDebugging masking active exception");
ContinueAsyncException(ExceptionResult::MaskException);
}
if (!terminate)
{
// Indicate that we want to detach.
m_pid_to_detach = GetProcess().GetProcessId();
// Force a fresh break so that the detach can happen from the debugger thread.
if (!::DebugBreakProcess(GetProcess().GetNativeProcess().GetSystemHandle()))
{
error.SetError(::GetLastError(), eErrorTypeWin32);
}
}
WINLOG_IFALL(WINDOWS_LOG_PROCESS, "StopDebugging waiting for detach from process %u to complete.", pid);
DWORD wait_result = WaitForSingleObject(m_debugging_ended_event, 5000);
if (wait_result != WAIT_OBJECT_0)
{
error.SetError(GetLastError(), eErrorTypeWin32);
WINERR_IFALL(WINDOWS_LOG_PROCESS, "StopDebugging WaitForSingleObject(0x%p, 5000) returned %u",
m_debugging_ended_event, wait_result);
}
else
{
WINLOG_IFALL(WINDOWS_LOG_PROCESS, "StopDebugging detach from process %u completed successfully.", pid);
}
if (!error.Success())
{
WINERR_IFALL(WINDOWS_LOG_PROCESS,
"StopDebugging encountered an error while trying to stop process %u. %s",
pid, error.AsCString());
}
return error;
}
void
DebuggerThread::ContinueAsyncException(ExceptionResult result)
{
if (!m_active_exception.get())
return;
WINLOG_IFANY(WINDOWS_LOG_PROCESS|WINDOWS_LOG_EXCEPTION,
"ContinueAsyncException called for inferior process %I64u, broadcasting.",
m_process.GetProcessId());
m_active_exception.reset();
m_exception_pred.SetValue(result, eBroadcastAlways);
}
void
DebuggerThread::FreeProcessHandles()
{
m_process = HostProcess();
m_main_thread = HostThread();
if (m_image_file)
{
::CloseHandle(m_image_file);
m_image_file = nullptr;
}
}
void
DebuggerThread::DebugLoop()
{
DEBUG_EVENT dbe = {0};
bool should_debug = true;
WINLOG_IFALL(WINDOWS_LOG_EVENT, "Entering WaitForDebugEvent loop");
while (should_debug)
{
WINLOGD_IFALL(WINDOWS_LOG_EVENT, "Calling WaitForDebugEvent");
BOOL wait_result = WaitForDebugEvent(&dbe, INFINITE);
if (wait_result)
{
DWORD continue_status = DBG_CONTINUE;
switch (dbe.dwDebugEventCode)
{
case EXCEPTION_DEBUG_EVENT:
{
ExceptionResult status = HandleExceptionEvent(dbe.u.Exception, dbe.dwThreadId);
if (status == ExceptionResult::MaskException)
continue_status = DBG_CONTINUE;
else if (status == ExceptionResult::SendToApplication)
continue_status = DBG_EXCEPTION_NOT_HANDLED;
break;
}
case CREATE_THREAD_DEBUG_EVENT:
continue_status = HandleCreateThreadEvent(dbe.u.CreateThread, dbe.dwThreadId);
break;
case CREATE_PROCESS_DEBUG_EVENT:
continue_status = HandleCreateProcessEvent(dbe.u.CreateProcessInfo, dbe.dwThreadId);
break;
case EXIT_THREAD_DEBUG_EVENT:
continue_status = HandleExitThreadEvent(dbe.u.ExitThread, dbe.dwThreadId);
break;
case EXIT_PROCESS_DEBUG_EVENT:
continue_status = HandleExitProcessEvent(dbe.u.ExitProcess, dbe.dwThreadId);
should_debug = false;
break;
case LOAD_DLL_DEBUG_EVENT:
continue_status = HandleLoadDllEvent(dbe.u.LoadDll, dbe.dwThreadId);
break;
case UNLOAD_DLL_DEBUG_EVENT:
continue_status = HandleUnloadDllEvent(dbe.u.UnloadDll, dbe.dwThreadId);
break;
case OUTPUT_DEBUG_STRING_EVENT:
continue_status = HandleODSEvent(dbe.u.DebugString, dbe.dwThreadId);
break;
case RIP_EVENT:
continue_status = HandleRipEvent(dbe.u.RipInfo, dbe.dwThreadId);
if (dbe.u.RipInfo.dwType == SLE_ERROR)
should_debug = false;
break;
}
WINLOGD_IFALL(WINDOWS_LOG_EVENT, "DebugLoop calling ContinueDebugEvent(%u, %u, %u) on thread %u.",
dbe.dwProcessId, dbe.dwThreadId, continue_status, ::GetCurrentThreadId());
::ContinueDebugEvent(dbe.dwProcessId, dbe.dwThreadId, continue_status);
if (m_detached)
{
should_debug = false;
}
}
else
{
WINERR_IFALL(WINDOWS_LOG_EVENT,
"DebugLoop returned FALSE from WaitForDebugEvent. Error = %u",
::GetCurrentThreadId(), ::GetLastError());
should_debug = false;
}
}
FreeProcessHandles();
WINLOG_IFALL(WINDOWS_LOG_EVENT, "WaitForDebugEvent loop completed, exiting.");
SetEvent(m_debugging_ended_event);
}
ExceptionResult
DebuggerThread::HandleExceptionEvent(const EXCEPTION_DEBUG_INFO &info, DWORD thread_id)
{
if (m_is_shutting_down)
{
// A breakpoint that occurs while `m_pid_to_detach` is non-zero is a magic exception that
// we use simply to wake up the DebuggerThread so that we can close out the debug loop.
if (m_pid_to_detach != 0 && info.ExceptionRecord.ExceptionCode == EXCEPTION_BREAKPOINT)
{
WINLOG_IFANY(WINDOWS_LOG_EVENT | WINDOWS_LOG_EXCEPTION | WINDOWS_LOG_PROCESS,
"Breakpoint exception is cue to detach from process 0x%x",
m_pid_to_detach);
::DebugActiveProcessStop(m_pid_to_detach);
m_detached = true;
}
// Don't perform any blocking operations while we're shutting down. That will
// cause TerminateProcess -> WaitForSingleObject to time out.
return ExceptionResult::SendToApplication;
}
bool first_chance = (info.dwFirstChance != 0);
m_active_exception.reset(new ExceptionRecord(info.ExceptionRecord, thread_id));
WINLOG_IFANY(WINDOWS_LOG_EVENT | WINDOWS_LOG_EXCEPTION,
"HandleExceptionEvent encountered %s chance exception 0x%x on thread 0x%x",
first_chance ? "first" : "second", info.ExceptionRecord.ExceptionCode, thread_id);
ExceptionResult result = m_debug_delegate->OnDebugException(first_chance,
*m_active_exception);
m_exception_pred.SetValue(result, eBroadcastNever);
WINLOG_IFANY(WINDOWS_LOG_EVENT|WINDOWS_LOG_EXCEPTION,
"DebuggerThread::HandleExceptionEvent waiting for ExceptionPred != BreakInDebugger");
m_exception_pred.WaitForValueNotEqualTo(ExceptionResult::BreakInDebugger, result);
WINLOG_IFANY(WINDOWS_LOG_EVENT|WINDOWS_LOG_EXCEPTION,
"DebuggerThread::HandleExceptionEvent got ExceptionPred = %u",
m_exception_pred.GetValue());
return result;
}
DWORD
DebuggerThread::HandleCreateThreadEvent(const CREATE_THREAD_DEBUG_INFO &info, DWORD thread_id)
{
WINLOG_IFANY(WINDOWS_LOG_EVENT|WINDOWS_LOG_THREAD,
"HandleCreateThreadEvent Thread 0x%x spawned in process %I64u",
thread_id, m_process.GetProcessId());
HostThread thread(info.hThread);
thread.GetNativeThread().SetOwnsHandle(false);
m_debug_delegate->OnCreateThread(thread);
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleCreateProcessEvent(const CREATE_PROCESS_DEBUG_INFO &info, DWORD thread_id)
{
uint32_t process_id = ::GetProcessId(info.hProcess);
WINLOG_IFANY(WINDOWS_LOG_EVENT | WINDOWS_LOG_PROCESS, "HandleCreateProcessEvent process %u spawned", process_id);
std::string thread_name;
llvm::raw_string_ostream name_stream(thread_name);
name_stream << "lldb.plugin.process-windows.slave[" << process_id << "]";
name_stream.flush();
ThisThread::SetName(thread_name.c_str());
// info.hProcess and info.hThread are closed automatically by Windows when
// EXIT_PROCESS_DEBUG_EVENT is received.
m_process = HostProcess(info.hProcess);
((HostProcessWindows &)m_process.GetNativeProcess()).SetOwnsHandle(false);
m_main_thread = HostThread(info.hThread);
m_main_thread.GetNativeThread().SetOwnsHandle(false);
m_image_file = info.hFile;
lldb::addr_t load_addr = reinterpret_cast<lldb::addr_t>(info.lpBaseOfImage);
m_debug_delegate->OnDebuggerConnected(load_addr);
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleExitThreadEvent(const EXIT_THREAD_DEBUG_INFO &info, DWORD thread_id)
{
WINLOG_IFANY(WINDOWS_LOG_EVENT|WINDOWS_LOG_THREAD,
"HandleExitThreadEvent Thread %u exited with code %u in process %I64u",
thread_id, info.dwExitCode, m_process.GetProcessId());
m_debug_delegate->OnExitThread(thread_id, info.dwExitCode);
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleExitProcessEvent(const EXIT_PROCESS_DEBUG_INFO &info, DWORD thread_id)
{
WINLOG_IFANY(WINDOWS_LOG_EVENT|WINDOWS_LOG_THREAD,
"HandleExitProcessEvent process %I64u exited with code %u",
m_process.GetProcessId(), info.dwExitCode);
m_debug_delegate->OnExitProcess(info.dwExitCode);
FreeProcessHandles();
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleLoadDllEvent(const LOAD_DLL_DEBUG_INFO &info, DWORD thread_id)
{
if (info.hFile == nullptr)
{
// Not sure what this is, so just ignore it.
WINWARN_IFALL(WINDOWS_LOG_EVENT, "Inferior %I64u - HandleLoadDllEvent has a NULL file handle, returning...",
m_process.GetProcessId());
return DBG_CONTINUE;
}
std::vector<wchar_t> buffer(1);
DWORD required_size = GetFinalPathNameByHandleW(info.hFile, &buffer[0], 0, VOLUME_NAME_DOS);
if (required_size > 0)
{
buffer.resize(required_size + 1);
required_size = GetFinalPathNameByHandleW(info.hFile, &buffer[0], required_size, VOLUME_NAME_DOS);
std::string path_str_utf8;
llvm::convertWideToUTF8(buffer.data(), path_str_utf8);
llvm::StringRef path_str = path_str_utf8;
const char *path = path_str.data();
if (path_str.startswith("\\\\?\\"))
path += 4;
FileSpec file_spec(path, false);
ModuleSpec module_spec(file_spec);
lldb::addr_t load_addr = reinterpret_cast<lldb::addr_t>(info.lpBaseOfDll);
WINLOG_IFALL(WINDOWS_LOG_EVENT, "Inferior %I64u - HandleLoadDllEvent DLL '%s' loaded at address 0x%p...",
m_process.GetProcessId(), path, info.lpBaseOfDll);
m_debug_delegate->OnLoadDll(module_spec, load_addr);
}
else
{
WINERR_IFALL(WINDOWS_LOG_EVENT,
"Inferior %I64u - HandleLoadDllEvent Error %u occurred calling GetFinalPathNameByHandle",
m_process.GetProcessId(), ::GetLastError());
}
// Windows does not automatically close info.hFile, so we need to do it.
::CloseHandle(info.hFile);
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleUnloadDllEvent(const UNLOAD_DLL_DEBUG_INFO &info, DWORD thread_id)
{
WINLOG_IFALL(WINDOWS_LOG_EVENT,
"HandleUnloadDllEvent process %I64u unloading DLL at addr 0x%p.",
m_process.GetProcessId(), info.lpBaseOfDll);
m_debug_delegate->OnUnloadDll(reinterpret_cast<lldb::addr_t>(info.lpBaseOfDll));
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleODSEvent(const OUTPUT_DEBUG_STRING_INFO &info, DWORD thread_id)
{
return DBG_CONTINUE;
}
DWORD
DebuggerThread::HandleRipEvent(const RIP_INFO &info, DWORD thread_id)
{
WINERR_IFALL(WINDOWS_LOG_EVENT,
"HandleRipEvent encountered error %u (type=%u) in process %I64u thread %u",
info.dwError, info.dwType, m_process.GetProcessId(), thread_id);
Error error(info.dwError, eErrorTypeWin32);
m_debug_delegate->OnDebuggerError(error, info.dwType);
return DBG_CONTINUE;
}