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Make bpgoto and NOP breakpoint MT-safe #63

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Make bpgoto and NOP breakpoint MT-safe #63

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36 changes: 27 additions & 9 deletions GleeBug/Debugger.Loop.Exception.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -51,15 +51,6 @@ namespace GleeBug
//set back the instruction pointer
Registers(mThread->hThread, CONTEXT_CONTROL).Gip = info.address;

//restore the original breakpoint byte and do an internal step
mProcess->MemWriteUnsafe(info.address, info.internal.software.oldbytes, info.internal.software.size);
mThread->StepInternal(std::bind([this, info]()
{
//only restore the bytes if the breakpoint still exists
if(mProcess->breakpoints.find({ BreakpointType::Software, info.address }) != mProcess->breakpoints.end())
mProcess->MemWriteUnsafe(info.address, info.internal.software.newbytes, info.internal.software.size);
}));

//call the generic callback
cbBreakpoint(info);

Expand All @@ -71,6 +62,33 @@ namespace GleeBug
//delete the breakpoint if it is singleshoot
if(info.singleshoot)
mProcess->DeleteGenericBreakpoint(info);
else
{
auto Gip = Registers(mThread->hThread, CONTEXT_CONTROL).Gip.Get();
//Only restore the breakpoint if we need to resume from there. (make "bpgoto" MT-safe)
if(Gip >= info.address && Gip < info.address + info.internal.software.size)
{
//Deal with the NOP instruction (90 / 66 90). It doesn't need to be restored. (make the NOP breakpoint MT-safe)
if(((info.internal.software.oldbytes[0] == 0x90 && info.internal.software.size == 1) ||
(info.internal.software.oldbytes[0] == 0x66 && info.internal.software.oldbytes[1] == 0x90 && info.internal.software.size == 2)) &&
//We cannot use such shortcut if we need to produce a single step debug event this time.
!(mThread->isInternalStepping || mThread->isSingleStepping)) {
//Increment the instruction pointer without executing the original breakpoint instruction
Registers(mThread->hThread, CONTEXT_CONTROL).Gip = info.address + info.internal.software.size;
}
else
{
//restore the original breakpoint byte and do an internal step
mProcess->MemWriteUnsafe(info.address, info.internal.software.oldbytes, info.internal.software.size);
mThread->StepInternal(std::bind([this, info]()
{
//only restore the bytes if the breakpoint still exists
if(mProcess->breakpoints.find({ BreakpointType::Software, info.address }) != mProcess->breakpoints.end())
mProcess->MemWriteUnsafe(info.address, info.internal.software.newbytes, info.internal.software.size);
}));
}
}
}
}

void Debugger::exceptionSingleStep(const EXCEPTION_RECORD & exceptionRecord, const bool firstChance)
Expand Down