From c9029a200df89f5598c5f8e77963b6f901e264fe Mon Sep 17 00:00:00 2001
From: Jan Vorlicek <janvorli@microsoft.com>
Date: Mon, 14 Jul 2025 22:05:04 +0200
Subject: [PATCH 1/2] Fix ExecutionManager::GetCodeMethodDesc for interpreter

The ExecutionManager::GetCodeMethodDesc expects that the address
passed to it is an address of actual JIT/AOT or interpreter generated
code. However, it is sometimes passed an address of the interpreter
precode, e.g. in the case when called by the
MethodTable::GetMethodDescForSlotAddress. The VTable slots need to point
to the interpreter stub so that these methods can be called by virtual
calls from native code.

This change adds a check for the interpreter precode to the
ExecutionManager::GetCodeMethodDesc and extracts the MethodDesc from the
interpreter data in case it is passed the precode address.
---
 src/coreclr/vm/codeman.cpp | 13 ++++++++++++-
 src/coreclr/vm/precode.cpp | 13 ++++++++++++-
 src/coreclr/vm/precode.h   | 15 +++++++++++++++
 3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/vm/codeman.cpp b/src/coreclr/vm/codeman.cpp
index cdb8a2ddbef47f..03e14e90796e80 100644
--- a/src/coreclr/vm/codeman.cpp
+++ b/src/coreclr/vm/codeman.cpp
@@ -5088,6 +5088,17 @@ MethodDesc * ExecutionManager::GetCodeMethodDesc(PCODE currentPC)
     }
     CONTRACTL_END
 
+#ifdef FEATURE_INTERPRETER
+    // For interpreted methods, the currentPC can point to the InterpreterPrecode. So we need to get the MethodDesc from it,
+    // the EECodeInfo works only for the actual IR bytecode.
+    PTR_Precode pPrecode = Precode::GetPrecodeFromEntryPoint(currentPC);
+    if (pPrecode != NULL && pPrecode->GetType() == InterpreterPrecode::Type)
+    {
+        // If we are in an interpreter precode, we get the MethodDesc from the precode
+        return pPrecode->GetMethodDesc();
+    }
+#endif // FEATURE_INTERPRETER
+
     EECodeInfo codeInfo(currentPC);
     if (!codeInfo.IsValid())
         return NULL;
@@ -6396,7 +6407,7 @@ size_t ReadyToRunJitManager::WalkILOffsets(
     BoundsType boundsType,
     void* pContext,
     size_t (* pfnWalkILOffsets)(ICorDebugInfo::OffsetMapping *pOffsetMapping, void *pContext))
-{   
+{
     CONTRACTL {
         THROWS;       // on OOM.
         GC_NOTRIGGER; // getting vars shouldn't trigger
diff --git a/src/coreclr/vm/precode.cpp b/src/coreclr/vm/precode.cpp
index bafa39a9a9104a..12de5e49105349 100644
--- a/src/coreclr/vm/precode.cpp
+++ b/src/coreclr/vm/precode.cpp
@@ -10,6 +10,7 @@
 
 #include "common.h"
 #include "dllimportcallback.h"
+#include "../interpreter/interpretershared.h"
 
 #ifdef FEATURE_PERFMAP
 #include "perfmap.h"
@@ -158,7 +159,7 @@ MethodDesc* Precode::GetMethodDesc(BOOL fSpeculative /*= FALSE*/)
         break;
 #ifdef FEATURE_INTERPRETER
     case PRECODE_INTERPRETER:
-        return NULL;
+        pMD = AsInterpreterPrecode()->GetMethodDesc();
         break;
 #endif // FEATURE_INTERPRETER
 
@@ -180,6 +181,16 @@ MethodDesc* Precode::GetMethodDesc(BOOL fSpeculative /*= FALSE*/)
     return (PTR_MethodDesc)pMD;
 }
 
+#ifdef FEATURE_INTERPRETER
+TADDR InterpreterPrecode::GetMethodDesc()
+{
+    LIMITED_METHOD_DAC_CONTRACT;
+
+    InterpByteCodeStart* pInterpreterCode = dac_cast<PTR_InterpByteCodeStart>(GetData()->ByteCodeAddr);
+    return (TADDR)pInterpreterCode->Method->methodHnd;
+}
+#endif // FEATURE_INTERPRETER
+
 BOOL Precode::IsPointingToPrestub(PCODE target)
 {
     CONTRACTL
diff --git a/src/coreclr/vm/precode.h b/src/coreclr/vm/precode.h
index 6a5abf0e099de6..8e96b3064c4ecc 100644
--- a/src/coreclr/vm/precode.h
+++ b/src/coreclr/vm/precode.h
@@ -335,7 +335,12 @@ struct InterpreterPrecode
         LIMITED_METHOD_CONTRACT;
         return (InterpreterPrecode*)PCODEToPINSTR(entryPoint);
     }
+
+    TADDR GetMethodDesc();
 };
+
+typedef DPTR(InterpreterPrecode) PTR_InterpreterPrecode;
+
 #endif // FEATURE_INTERPRETER
 
 #ifdef HAS_FIXUP_PRECODE
@@ -593,6 +598,16 @@ class Precode {
     }
 #endif // HAS_THISPTR_RETBUF_PRECODE
 
+#ifdef FEATURE_INTERPRETER
+    InterpreterPrecode* AsInterpreterPrecode()
+    {
+        LIMITED_METHOD_CONTRACT;
+        SUPPORTS_DAC;
+
+        return dac_cast<PTR_InterpreterPrecode>(this);
+    }
+#endif // FEATURE_INTERPRETER
+
     TADDR GetStart()
     {
         SUPPORTS_DAC;

From 54168216ed1dc3df3e16e15868dda8ad65e92893 Mon Sep 17 00:00:00 2001
From: Jan Vorlicek <janvorli@microsoft.com>
Date: Tue, 15 Jul 2025 00:00:32 +0200
Subject: [PATCH 2/2] Revert changes in codeman.cpp

---
 src/coreclr/vm/codeman.cpp | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/src/coreclr/vm/codeman.cpp b/src/coreclr/vm/codeman.cpp
index 03e14e90796e80..cdb8a2ddbef47f 100644
--- a/src/coreclr/vm/codeman.cpp
+++ b/src/coreclr/vm/codeman.cpp
@@ -5088,17 +5088,6 @@ MethodDesc * ExecutionManager::GetCodeMethodDesc(PCODE currentPC)
     }
     CONTRACTL_END
 
-#ifdef FEATURE_INTERPRETER
-    // For interpreted methods, the currentPC can point to the InterpreterPrecode. So we need to get the MethodDesc from it,
-    // the EECodeInfo works only for the actual IR bytecode.
-    PTR_Precode pPrecode = Precode::GetPrecodeFromEntryPoint(currentPC);
-    if (pPrecode != NULL && pPrecode->GetType() == InterpreterPrecode::Type)
-    {
-        // If we are in an interpreter precode, we get the MethodDesc from the precode
-        return pPrecode->GetMethodDesc();
-    }
-#endif // FEATURE_INTERPRETER
-
     EECodeInfo codeInfo(currentPC);
     if (!codeInfo.IsValid())
         return NULL;
@@ -6407,7 +6396,7 @@ size_t ReadyToRunJitManager::WalkILOffsets(
     BoundsType boundsType,
     void* pContext,
     size_t (* pfnWalkILOffsets)(ICorDebugInfo::OffsetMapping *pOffsetMapping, void *pContext))
-{
+{   
     CONTRACTL {
         THROWS;       // on OOM.
         GC_NOTRIGGER; // getting vars shouldn't trigger