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fix locking issue
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@cheat-engine
cheat-engine committed Nov 19, 2020
1 parent 23eb690 commit fb424b2
Showing 1 changed file with 42 additions and 38 deletions.
80 changes: 42 additions & 38 deletions DBKKernel/debugger.c
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Original file line number Diff line number Diff line change
Expand Up @@ -236,10 +236,15 @@ void debugger_shutdown(void)
}

void debugger_growstack()
//only call when the critical section has been obtained
//called in passive mode
{
if (Stacks)
{
KIRQL oldIRQL=KeRaiseIrqlToDpcLevel();

csEnter(&StacksCS);
enableInterrupts(); //csEnter disables it, but we need it

int newStackCount = StackCount * 2;
int i;
PSavedStack *newStacks;
Expand All @@ -258,14 +263,18 @@ void debugger_growstack()
else
{
ExFreePool(newStacks);
csLeave(&StacksCS);
return;
}
}


ExFreePool(Stacks);
Stacks = newStacks;
}

csLeave(&StacksCS);

}
}

Expand Down Expand Up @@ -1242,13 +1251,13 @@ int interrupt1_handler(UINT_PTR *stackpointer, UINT_PTR *currentdebugregs)
{
//DbgPrint("DebuggerState.isDebugging\n");
//check if this should break
if (CurrentProcessID==(HANDLE)(UINT_PTR)DebuggerState.debuggedProcessID)
{
if (CurrentProcessID == (HANDLE)(UINT_PTR)DebuggerState.debuggedProcessID)
{
UINT_PTR originaldebugregs[6];
UINT64 oldDR7=getDR7();
UINT64 oldDR7 = getDR7();


if ((((PEFLAGS)&stackpointer[si_eflags])->IF==0) || (KeGetCurrentIrql() != PASSIVE_LEVEL))
if ((((PEFLAGS)&stackpointer[si_eflags])->IF == 0) || (KeGetCurrentIrql() != PASSIVE_LEVEL))
{
//There's no way to display the state to the usermode part of CE
//DbgPrint("int1 at unstoppable location");
Expand All @@ -1259,34 +1268,34 @@ int interrupt1_handler(UINT_PTR *stackpointer, UINT_PTR *currentdebugregs)
}
else
{
// DbgPrint("Stepping until valid\n");
// DbgPrint("Stepping until valid\n");
((PEFLAGS)&stackpointer[si_eflags])->TF = 1; //keep going until a valid state
DebuggerState.isSteppingTillClear = TRUE; //Just in case a taskswitch happens right after enabling passive level with interrupts
}

((PEFLAGS)&stackpointer[si_eflags])->RF=1;
((PEFLAGS)&stackpointer[si_eflags])->RF = 1;
debugger_dr6_setValue(0xffff0ff0);
return 1;
}

DebuggerState.isSteppingTillClear = FALSE;



//DbgPrint("CurrentProcessID==(HANDLE)(UINT_PTR)DebuggerState.debuggedProcessID\n");

if (DebuggerState.globalDebug)
{
originaldebugregs[0]=DebuggerState.FakedDebugRegisterState[cpunr()].DR0;
originaldebugregs[1]=DebuggerState.FakedDebugRegisterState[cpunr()].DR1;
originaldebugregs[2]=DebuggerState.FakedDebugRegisterState[cpunr()].DR2;
originaldebugregs[3]=DebuggerState.FakedDebugRegisterState[cpunr()].DR3;
originaldebugregs[4]=DebuggerState.FakedDebugRegisterState[cpunr()].DR6;
originaldebugregs[5]=DebuggerState.FakedDebugRegisterState[cpunr()].DR7;
originaldebugregs[0] = DebuggerState.FakedDebugRegisterState[cpunr()].DR0;
originaldebugregs[1] = DebuggerState.FakedDebugRegisterState[cpunr()].DR1;
originaldebugregs[2] = DebuggerState.FakedDebugRegisterState[cpunr()].DR2;
originaldebugregs[3] = DebuggerState.FakedDebugRegisterState[cpunr()].DR3;
originaldebugregs[4] = DebuggerState.FakedDebugRegisterState[cpunr()].DR6;
originaldebugregs[5] = DebuggerState.FakedDebugRegisterState[cpunr()].DR7;
}

//DbgPrint("BP in target process\n");

//no extra checks if it's caused by the debugger or not. That is now done in the usermode part
//if (*(PEFLAGS)(&stackpointer[si_eflags]).IF)
/*
Expand All @@ -1302,16 +1311,16 @@ int interrupt1_handler(UINT_PTR *stackpointer, UINT_PTR *currentdebugregs)

//set the real debug registers to what it is according to the guest (so taskswitches take over these values) .... shouldn't be needed as global debug is on which fakes that read...



if (DebuggerState.globalDebug)
{
//enable the GD flag for taskswitches that will occur as soon as interrupts are enabled
//this also means: DO NOT EDIT THE DEBUG REGISTERS IN GLOBAL DEBUG MODE at this point. Only in the epilogue

if (!DebuggerState.stoppingTheDebugger) //This is set when the driver is unloading. So do NOT set it back then
debugger_dr7_setGD(DebuggerState.globalDebug);
}
debugger_dr7_setGD(DebuggerState.globalDebug);
}
else
{
//unset ALL debug registers before enabling taskswitching. Just re-enable it when back when interrupts are disabled again
Expand All @@ -1332,57 +1341,52 @@ int interrupt1_handler(UINT_PTR *stackpointer, UINT_PTR *currentdebugregs)
//todo: breaks 32-bit
int i;
BOOL NeedsToGrowStackList = FALSE;
UINT_PTR *newStackPointer = NULL;
PSavedStack SelectedStackEntry = NULL;

csEnter(&StacksCS);
for (i = 0; i < StackCount; i++)
{
if (Stacks[i]->inuse == FALSE)
{
Stacks[i]->inuse = TRUE;
newStackPointer = (UINT_PTR *)Stacks[i]->stacksnapshot;

RtlCopyMemory(newStackPointer, stackpointer, 600 * 8);
SelectedStackEntry = Stacks[i];
SelectedStackEntry->inuse = TRUE;
RtlCopyMemory(SelectedStackEntry->stacksnapshot, stackpointer, 600 * 8);

if (i > StackCount / 2)
NeedsToGrowStackList = TRUE;

break;
}
}
csLeave(&StacksCS);

enableInterrupts();

//grow stack if needed

if (NeedsToGrowStackList)
debugger_growstack();

csLeave(&StacksCS);


{
int rs=1;
int RestoreStack = newStackPointer != NULL;


//DbgPrint("calling breakpointHandler_kernel\n");

if (newStackPointer == NULL) //fuck
newStackPointer = stackpointer;
if (SelectedStackEntry == NULL) //fuck
rs = breakpointHandler_kernel(stackpointer, currentdebugregs, LBR_Stack, causedbyDBVM);
else
rs = breakpointHandler_kernel(SelectedStackEntry->stacksnapshot, currentdebugregs, LBR_Stack, causedbyDBVM);


rs = breakpointHandler_kernel(newStackPointer, currentdebugregs, LBR_Stack, causedbyDBVM);

//DbgPrint("After handler\n");

if (RestoreStack) //restore the stack
if (SelectedStackEntry) //restore the stack
{
RtlCopyMemory(stackpointer, newStackPointer, 600 * 8);

csEnter(&StacksCS);
Stacks[i]->inuse = FALSE;
csLeave(&StacksCS);
RtlCopyMemory(stackpointer, SelectedStackEntry->stacksnapshot, 600 * 8);
SelectedStackEntry->inuse = FALSE;
}



//DbgPrint("rs=%d\n",rs);

Expand Down

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