bool
ThreadHandler::_DoStepOver(CpuState* cpuState)
{
TRACE_CONTROL("ThreadHandler::_DoStepOver()\n");
// The basic strategy is to single-step out of the statement like for
// "step into", only we have to avoid stepping into subroutines. Hence we
// check whether the current instruction is a subroutine call. If not, we
// just single-step, otherwise we set a breakpoint after the instruction.
InstructionInfo info;
if (fDebuggerInterface->GetArchitecture()->GetInstructionInfo(
cpuState->InstructionPointer(), info, cpuState) != B_OK) {
TRACE_CONTROL(" failed to get instruction info\n");
return false;
}
if (info.Type() != INSTRUCTION_TYPE_SUBROUTINE_CALL) {
_SingleStepThread(cpuState->InstructionPointer());
TRACE_CONTROL(" not a subroutine call\n");
return true;
}
TRACE_CONTROL(" subroutine call -- installing breakpoint at address "
"%#" B_PRIx64 "\n", info.Address() + info.Size());
if (_InstallTemporaryBreakpoint(info.Address() + info.Size()) != B_OK)
return false;
fSteppedOverFunctionAddress = info.TargetAddress();
_RunThread(cpuState->InstructionPointer());
return true;
}
bool
ThreadHandler::_HandleBreakpointHitStep(CpuState* cpuState)
{
// in any case uninstall the temporary breakpoint
_UninstallTemporaryBreakpoint();
switch (fStepMode) {
case STEP_OVER:
{
StackTrace* stackTrace = fThread->GetStackTrace();
BReference<StackTrace> stackTraceReference(stackTrace);
if (stackTrace == NULL && cpuState != NULL) {
if (fDebuggerInterface->GetArchitecture()->CreateStackTrace(
fThread->GetTeam(), this, cpuState, stackTrace, NULL,
1, false, false) == B_OK) {
stackTraceReference.SetTo(stackTrace, true);
}
}
if (stackTrace != NULL) {
StackFrame* frame = stackTrace->FrameAt(0);
// If we're not in the same frame we started in,
// keep executing.
if (frame != NULL && fPreviousFrameAddress
!= frame->FrameAddress()) {
status_t error = _InstallTemporaryBreakpoint(
cpuState->InstructionPointer());
if (error != B_OK)
_StepFallback();
else
_RunThread(cpuState->InstructionPointer());
return true;
}
}
if (fPreviousFrameAddress != 0 && fSteppedOverFunctionAddress
!= cpuState->InstructionPointer()) {
TRACE_CONTROL("STEP_OVER: called function address %#" B_PRIx64
", previous frame address: %#" B_PRIx64 ", frame address: %#"
B_PRIx64 ", adding return info\n", fSteppedOverFunctionAddress,
fPreviousFrameAddress, stackTrace->FrameAt(0)->FrameAddress());
ReturnValueInfo* returnInfo = new(std::nothrow) ReturnValueInfo(
fSteppedOverFunctionAddress, cpuState);
if (returnInfo == NULL)
return false;
BReference<ReturnValueInfo> returnInfoReference(returnInfo, true);
if (fThread->AddReturnValueInfo(returnInfo) != B_OK)
return false;
returnInfoReference.Detach();
fSteppedOverFunctionAddress = 0;
}
// If we're still in the statement, we continue single-stepping,
// otherwise we're done.
if (fStepStatement->ContainsAddress(
cpuState->InstructionPointer())) {
if (!_DoStepOver(cpuState))
_StepFallback();
return true;
}
fPreviousFrameAddress = 0;
return false;
}
case STEP_INTO:
// Should never happen -- we don't set a breakpoint in this case.
return false;
case STEP_OUT:
{
// That's the return address, so we're done in theory,
// unless we're a recursive function. Check if we've actually
// exited the previous stack frame or not
if (!_HasExitedFrame(cpuState->StackFramePointer())) {
status_t error = _InstallTemporaryBreakpoint(
cpuState->InstructionPointer());
if (error != B_OK)
_StepFallback();
else
_RunThread(cpuState->InstructionPointer());
return true;
}
if (fPreviousFrameAddress == 0)
return false;
TRACE_CONTROL("ThreadHandler::_HandleBreakpointHitStep() - "
"frame pointer 0x%#" B_PRIx64 ", previous: 0x%#" B_PRIx64
" - step out adding return value\n", cpuState
->StackFramePointer(), fPreviousFrameAddress);
ReturnValueInfo* info = new(std::nothrow) ReturnValueInfo(
fPreviousInstructionPointer, cpuState);
if (info == NULL)
return false;
BReference<ReturnValueInfo> infoReference(info, true);
if (fThread->AddReturnValueInfo(info) != B_OK)
return false;
infoReference.Detach();
fPreviousFrameAddress = 0;
}
default:
return false;
}
}
void
ThreadHandler::HandleThreadAction(uint32 action, target_addr_t address)
{
AutoLocker<Team> locker(fThread->GetTeam());
if (fThread->State() == THREAD_STATE_UNKNOWN)
return;
// When stop is requested, thread must be running, otherwise stopped.
if (action == MSG_THREAD_STOP
? fThread->State() != THREAD_STATE_RUNNING
: fThread->State() != THREAD_STATE_STOPPED) {
return;
}
// When stepping we need a stack trace. Save it before unsetting the state.
CpuState* cpuState = fThread->GetCpuState();
StackTrace* stackTrace = fThread->GetStackTrace();
BReference<CpuState> cpuStateReference(cpuState);
BReference<StackTrace> stackTraceReference(stackTrace);
if (action == MSG_THREAD_SET_ADDRESS) {
_HandleSetAddress(cpuState, address);
return;
}
// When continuing the thread update thread state before actually issuing
// the command, since we need to unlock.
if (action != MSG_THREAD_STOP) {
_SetThreadState(THREAD_STATE_RUNNING, NULL, THREAD_STOPPED_UNKNOWN,
BString());
}
locker.Unlock();
switch (action) {
case MSG_THREAD_RUN:
fStepMode = address != 0 ? STEP_UNTIL : STEP_NONE;
if (address != 0)
_InstallTemporaryBreakpoint(address);
_RunThread(0);
return;
case MSG_THREAD_STOP:
fStepMode = STEP_NONE;
if (fDebuggerInterface->StopThread(ThreadID()) == B_OK)
fThread->SetStopRequestPending();
return;
case MSG_THREAD_STEP_OVER:
case MSG_THREAD_STEP_INTO:
case MSG_THREAD_STEP_OUT:
break;
}
TRACE_CONTROL("ThreadHandler::HandleThreadAction(MSG_THREAD_STEP_*)\n");
// We want to step. We need a stack trace for that purpose. If we don't
// have one yet, get it. Start with the CPU state.
if (stackTrace == NULL && cpuState == NULL) {
if (fDebuggerInterface->GetCpuState(fThread->ID(), cpuState) == B_OK)
cpuStateReference.SetTo(cpuState, true);
}
if (stackTrace == NULL && cpuState != NULL) {
if (fDebuggerInterface->GetArchitecture()->CreateStackTrace(
fThread->GetTeam(), this, cpuState, stackTrace, NULL, 1,
false, false) == B_OK) {
stackTraceReference.SetTo(stackTrace, true);
}
}
if (stackTrace == NULL || stackTrace->CountFrames() == 0) {
_StepFallback();
return;
}
StackFrame* frame = stackTrace->FrameAt(0);
TRACE_CONTROL(" ip: %#" B_PRIx64 "\n", frame->InstructionPointer());
target_addr_t frameIP = frame->GetCpuState()->InstructionPointer();
// When the thread is in a syscall, do the same for all step kinds: Stop it
// when it returns by means of a breakpoint.
if (frame->Type() == STACK_FRAME_TYPE_SYSCALL) {
// set a breakpoint at the CPU state's instruction pointer (points to
// the return address, unlike the stack frame's instruction pointer)
// TODO: This is doesn't work correctly anymore. When stepping over a "syscall"
// instruction the thread is stopped twice. The after the first step the PC is
// incorrectly shown at the "syscall" instruction. Then we step again and are
// stopped at the temporary breakpoint after the "syscall" instruction. There
// are two problems. The first one is that we don't (cannot?) discriminate
// between the thread being in a syscall (like in a blocking syscall) and the
// thread having been stopped (or singled-stepped) at the end of the syscall.
// The second issue is that the temporary breakpoint is probably not necessary
// anymore, since single-stepping over "syscall" instructions should just work
// as expected.
status_t error = _InstallTemporaryBreakpoint(frameIP);
if (error != B_OK) {
_StepFallback();
return;
}
fStepMode = STEP_OUT;
_RunThread(frameIP);
return;
}
// For "step out" just set a temporary breakpoint on the return address.
if (action == MSG_THREAD_STEP_OUT) {
status_t error = _InstallTemporaryBreakpoint(frame->ReturnAddress());
if (error != B_OK) {
_StepFallback();
return;
}
fPreviousInstructionPointer = frameIP;
fPreviousFrameAddress = frame->FrameAddress();
fStepMode = STEP_OUT;
_RunThread(frameIP);
return;
}
// For "step in" and "step over" we also need the source code statement at
// the current instruction pointer.
fStepStatement = _GetStatementAtInstructionPointer(frame);
if (fStepStatement == NULL) {
_StepFallback();
return;
}
TRACE_CONTROL(" statement: %#" B_PRIx64 " - %#" B_PRIx64 "\n",
fStepStatement->CoveringAddressRange().Start(),
fStepStatement->CoveringAddressRange().End());
if (action == MSG_THREAD_STEP_INTO) {
// step into
fStepMode = STEP_INTO;
_SingleStepThread(frameIP);
} else {
fPreviousFrameAddress = frame->FrameAddress();
// step over
fStepMode = STEP_OVER;
if (!_DoStepOver(frame->GetCpuState()))
_StepFallback();
}
}
bool
ThreadHandler::_HandleBreakpointHitStep(CpuState* cpuState)
{
// in any case uninstall the temporary breakpoint
_UninstallTemporaryBreakpoint();
switch (fStepMode) {
case STEP_OVER:
{
StackTrace* stackTrace = fThread->GetStackTrace();
BReference<StackTrace> stackTraceReference(stackTrace);
if (stackTrace == NULL && cpuState != NULL) {
if (fDebuggerInterface->GetArchitecture()->CreateStackTrace(
fThread->GetTeam(), this, cpuState, stackTrace, 0, 1,
false, false) == B_OK) {
stackTraceReference.SetTo(stackTrace, true);
}
}
if (stackTrace != NULL) {
StackFrame* frame = stackTrace->FrameAt(0);
// If we're not in the same frame we started in,
// keep executing.
if (frame != NULL && fPreviousFrameAddress
!= frame->FrameAddress()) {
status_t error = _InstallTemporaryBreakpoint(
cpuState->InstructionPointer());
if (error != B_OK)
_StepFallback();
else
_RunThread(cpuState->InstructionPointer());
return true;
}
}
// If we're still in the statement, we continue single-stepping,
// otherwise we're done.
if (fStepStatement->ContainsAddress(
cpuState->InstructionPointer())) {
if (!_DoStepOver(cpuState))
_StepFallback();
return true;
}
fPreviousFrameAddress = 0;
return false;
}
case STEP_INTO:
// Should never happen -- we don't set a breakpoint in this case.
return false;
case STEP_OUT:
{
// That's the return address, so we're done in theory,
// unless we're a recursive function. Check if we've actually
// exited the previous stack frame or not.
fThread->SetExecutedSubroutine(cpuState->InstructionPointer());
target_addr_t framePointer = cpuState->StackFramePointer();
bool hasExitedFrame = fDebuggerInterface->GetArchitecture()
->StackGrowthDirection() == STACK_GROWTH_DIRECTION_POSITIVE
? framePointer < fPreviousFrameAddress
: framePointer > fPreviousFrameAddress;
if (!hasExitedFrame) {
status_t error = _InstallTemporaryBreakpoint(
cpuState->InstructionPointer());
if (error != B_OK)
_StepFallback();
else
_RunThread(cpuState->InstructionPointer());
return true;
}
fPreviousFrameAddress = 0;
}
default:
return false;
}
}
void
ThreadHandler::HandleThreadAction(uint32 action)
{
AutoLocker<Team> locker(fThread->GetTeam());
if (fThread->State() == THREAD_STATE_UNKNOWN)
return;
// When stop is requested, thread must be running, otherwise stopped.
if (action == MSG_THREAD_STOP
? fThread->State() != THREAD_STATE_RUNNING
: fThread->State() != THREAD_STATE_STOPPED) {
return;
}
// When stepping we need a stack trace. Save it before unsetting the state.
CpuState* cpuState = fThread->GetCpuState();
StackTrace* stackTrace = fThread->GetStackTrace();
Reference<CpuState> cpuStateReference(cpuState);
Reference<StackTrace> stackTraceReference(stackTrace);
// When continuing the thread update thread state before actually issuing
// the command, since we need to unlock.
if (action != MSG_THREAD_STOP) {
_SetThreadState(THREAD_STATE_RUNNING, NULL, THREAD_STOPPED_UNKNOWN,
BString());
}
locker.Unlock();
switch (action) {
case MSG_THREAD_RUN:
fStepMode = STEP_NONE;
_RunThread(0);
return;
case MSG_THREAD_STOP:
fStepMode = STEP_NONE;
fDebuggerInterface->StopThread(ThreadID());
return;
case MSG_THREAD_STEP_OVER:
case MSG_THREAD_STEP_INTO:
case MSG_THREAD_STEP_OUT:
break;
}
TRACE_CONTROL("ThreadHandler::HandleThreadAction(MSG_THREAD_STEP_*)\n");
// We want to step. We need a stack trace for that purpose. If we don't
// have one yet, get it. Start with the CPU state.
if (stackTrace == NULL && cpuState == NULL) {
if (fDebuggerInterface->GetCpuState(fThread->ID(), cpuState) == B_OK)
cpuStateReference.SetTo(cpuState, true);
}
if (stackTrace == NULL && cpuState != NULL) {
if (fDebuggerInterface->GetArchitecture()->CreateStackTrace(
fThread->GetTeam(), this, cpuState, stackTrace) == B_OK) {
stackTraceReference.SetTo(stackTrace, true);
}
}
if (stackTrace == NULL || stackTrace->CountFrames() == 0) {
_StepFallback();
return;
}
StackFrame* frame = stackTrace->FrameAt(0);
TRACE_CONTROL(" ip: %#llx\n", frame->InstructionPointer());
// When the thread is in a syscall, do the same for all step kinds: Stop it
// when it return by means of a breakpoint.
if (frame->Type() == STACK_FRAME_TYPE_SYSCALL) {
// set a breakpoint at the CPU state's instruction pointer (points to
// the return address, unlike the stack frame's instruction pointer)
status_t error = _InstallTemporaryBreakpoint(
frame->GetCpuState()->InstructionPointer());
if (error != B_OK) {
_StepFallback();
return;
}
fStepMode = STEP_OUT;
_RunThread(frame->GetCpuState()->InstructionPointer());
return;
}
// For "step out" just set a temporary breakpoint on the return address.
if (action == MSG_THREAD_STEP_OUT) {
// TODO: That's OK in principle, but needs additional work with recursive
// functions. We need to store some information that allows us to determine
// whether we've actually stepped out of the current frame when we have hit
// the breakpoint.
status_t error = _InstallTemporaryBreakpoint(frame->ReturnAddress());
if (error != B_OK) {
_StepFallback();
return;
}
fStepMode = STEP_OUT;
_RunThread(frame->GetCpuState()->InstructionPointer());
return;
}
// For "step in" and "step over" we also need the source code statement at
// the current instruction pointer.
fStepStatement = _GetStatementAtInstructionPointer(frame);
if (fStepStatement == NULL) {
_StepFallback();
return;
}
TRACE_CONTROL(" statement: %#llx - %#llx\n",
fStepStatement->CoveringAddressRange().Start(),
fStepStatement->CoveringAddressRange().End());
if (action == MSG_THREAD_STEP_INTO) {
// step into
fStepMode = STEP_INTO;
_SingleStepThread(frame->GetCpuState()->InstructionPointer());
} else {
// step over
fStepMode = STEP_OVER;
if (!_DoStepOver(frame->GetCpuState()))
_StepFallback();
}
}
void CImageManager::_BeginPrefetch () {
_RunThread(THREAD_PREFETCH);
}
void CImageManager::_BeginLoad () {
_RunThread(THREAD_LOAD);
}
