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dotnet · Sep 20, 2024 · e91f3f9 · e91f3f9
1 parent b810c3c
commit e91f3f9
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/src/coreclr/vm/i386/asmconstants.h b/src/coreclr/vm/i386/asmconstants.h
@@ -223,6 +223,9 @@ ASMCONSTANTS_C_ASSERT(CLRToCOMCallInfo__m_pRetThunk == offsetof(CLRToCOMCallInfo
 #define COMMETHOD_PREPAD_ASM  8
 ASMCONSTANTS_C_ASSERT(COMMETHOD_PREPAD_ASM == COMMETHOD_PREPAD)
 
+#define OFFSETOF__UnmanagedToManagedFrame__m_pvDatum 8
+ASMCONSTANTS_C_ASSERT(OFFSETOF__UnmanagedToManagedFrame__m_pvDatum == offsetof(UnmanagedToManagedFrame, m_pvDatum))
+
 #endif // FEATURE_COMINTEROP
 
 #define ASM__VTABLE_SLOTS_PER_CHUNK 8

diff --git a/src/coreclr/vm/i386/asmhelpers.asm b/src/coreclr/vm/i386/asmhelpers.asm
@@ -1242,6 +1242,8 @@ _GenericComCallStub@0 proc public
     ; Pop ComCallMethodDesc* pushed by prestub
     pop         eax
 
+    ; Create UnmanagedToManagedFrame on stack
+
     ; push ebp-frame
     push        ebp
     mov         ebp,esp
@@ -1251,15 +1253,15 @@ _GenericComCallStub@0 proc public
     push        esi
     push        edi
 
-    push        eax         ; datum
-    sub         esp, 3*4    ; next, vtable, gscookie
+    push        eax         ; UnmanagedToManagedFrame::m_pvDatum = ComCallMethodDesc*
+    sub         esp, (SIZEOF_GSCookie + OFFSETOF__UnmanagedToManagedFrame__m_pvDatum)
 
     lea         eax, [esp+4]
 
     push        eax
     call        _COMToCLRWorker@4
 
-    add         esp, 3*4
+    add         esp, (SIZEOF_GSCookie + OFFSETOF__UnmanagedToManagedFrame__m_pvDatum)
 
     ; pop the MethodDesc*
     pop         ecx