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Improve logging of GC ref map mismatches #80219

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Merged
merged 4 commits into from
Jan 6, 2023
Merged

Improve logging of GC ref map mismatches #80219

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fff5df3
Improve logging of GC ref map mismatches
trylek Jan 4, 2023
e7f54a4
Use printf instead of wprintf per JanV's PR feedback
trylek Jan 5, 2023
25e78a0
Optimize the GC ref map validation loop per JanV's PR feedback
trylek Jan 5, 2023
33f0e8a
Add missing break statement per JanV's PR feedback
trylek Jan 5, 2023
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119 changes: 102 additions & 17 deletions src/coreclr/vm/frames.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1372,6 +1372,17 @@ UINT TransitionFrame::CbStackPopUsingGCRefMap(PTR_BYTE pGCRefMap)
}
#endif

static UINT OffsetFromGCRefMapPos(int pos)
{
#ifdef TARGET_X86
return (pos < NUM_ARGUMENT_REGISTERS) ?
(TransitionBlock::GetOffsetOfArgumentRegisters() + ARGUMENTREGISTERS_SIZE - (pos + 1) * sizeof(TADDR)) :
(TransitionBlock::GetOffsetOfArgs() + (pos - NUM_ARGUMENT_REGISTERS) * sizeof(TADDR));
#else
return TransitionBlock::GetOffsetOfFirstGCRefMapSlot() + pos * sizeof(TADDR);
#endif
}

void TransitionFrame::PromoteCallerStackUsingGCRefMap(promote_func* fn, ScanContext* sc, PTR_BYTE pGCRefMap)
{
WRAPPER_NO_CONTRACT;
Expand All @@ -1389,16 +1400,7 @@ void TransitionFrame::PromoteCallerStackUsingGCRefMap(promote_func* fn, ScanCont
{
int pos = decoder.CurrentPos();
int token = decoder.ReadToken();

int ofs;

#ifdef TARGET_X86
ofs = (pos < NUM_ARGUMENT_REGISTERS) ?
(TransitionBlock::GetOffsetOfArgumentRegisters() + ARGUMENTREGISTERS_SIZE - (pos + 1) * sizeof(TADDR)) :
(TransitionBlock::GetOffsetOfArgs() + (pos - NUM_ARGUMENT_REGISTERS) * sizeof(TADDR));
#else
ofs = TransitionBlock::GetOffsetOfFirstGCRefMapSlot() + pos * sizeof(TADDR);
#endif
int ofs = OffsetFromGCRefMapPos(pos);

PTR_TADDR ppObj = dac_cast<PTR_TADDR>(pTransitionBlock + ofs);

Expand Down Expand Up @@ -2060,6 +2062,76 @@ void FakeGcScanRoots(MetaSig& msig, ArgIterator& argit, MethodDesc * pMD, BYTE *
}
}

#ifdef _DEBUG
static void DumpGCRefMap(const char *name, BYTE *address)
{
GCRefMapDecoder decoder(address);

printf("%s GC ref map: ", name);
#if TARGET_X86
uint32_t stackPop = decoder.ReadStackPop();
printf("POP(0x%x)", stackPop);
#endif

int previousToken = GCREFMAP_SKIP;
while (!decoder.AtEnd())
{
int pos = decoder.CurrentPos();
int token = decoder.ReadToken();
if (token != previousToken)
{
if (previousToken != GCREFMAP_SKIP)
{
printf(") ");
}
switch (token)
{
case GCREFMAP_SKIP:
break;

case GCREFMAP_REF:
printf("R(");
break;

case GCREFMAP_INTERIOR:
printf("I(");
break;

case GCREFMAP_METHOD_PARAM:
printf("M(");
break;

case GCREFMAP_TYPE_PARAM:
printf("T(");
break;

case GCREFMAP_VASIG_COOKIE:
printf("V(");
break;

default:
// Not implemented
_ASSERTE(false);
}
}
else if (token != GCREFMAP_SKIP)
{
printf(" ");
}
if (token != GCREFMAP_SKIP)
{
printf("%02x", OffsetFromGCRefMapPos(pos));
}
previousToken = token;
}
if (previousToken != GCREFMAP_SKIP)
{
printf(")");
}
printf("\n");
}
#endif

bool CheckGCRefMapEqual(PTR_BYTE pGCRefMap, MethodDesc* pMD, bool isDispatchCell)
{
#ifdef _DEBUG
Expand All @@ -2074,16 +2146,29 @@ bool CheckGCRefMapEqual(PTR_BYTE pGCRefMap, MethodDesc* pMD, bool isDispatchCell
GCRefMapDecoder decoderNew((BYTE *)pBlob);
GCRefMapDecoder decoderExisting(pGCRefMap);

bool invalidGCRefMap = false;

#ifdef TARGET_X86
_ASSERTE(decoderNew.ReadStackPop() == decoderExisting.ReadStackPop());
if (decoderNew.ReadStackPop() != decoderExisting.ReadStackPop())
{
invalidGCRefMap = true;
}
#endif

_ASSERTE(decoderNew.AtEnd() == decoderExisting.AtEnd());
while (!decoderNew.AtEnd())
while (!invalidGCRefMap && !(decoderNew.AtEnd() && decoderExisting.AtEnd()))
{
if (decoderNew.AtEnd() != decoderExisting.AtEnd() ||
decoderNew.CurrentPos() != decoderExisting.CurrentPos() ||
decoderNew.ReadToken() != decoderExisting.ReadToken())
{
invalidGCRefMap = true;
}
}
if (invalidGCRefMap)
{
_ASSERTE(decoderNew.CurrentPos() == decoderExisting.CurrentPos());
_ASSERTE(decoderNew.ReadToken() == decoderExisting.ReadToken());
_ASSERTE(decoderNew.AtEnd() == decoderExisting.AtEnd());
printf("GC ref map mismatch detected for method: %s::%s\n", pMD->GetMethodTable()->GetDebugClassName(), pMD->GetName());
DumpGCRefMap(" Runtime", (BYTE *)pBlob);
DumpGCRefMap("Crossgen2", pGCRefMap);
_ASSERTE(false);
}
#endif
return true;
Expand Down