Fix generic non-virtual method call in Ready-to-Run images

Issue #5201 revealed a bug in the Ready-to-Run implementation.
This bug can cause the runtime to dispatch a method call to the
wrong target when all the following conditions are met:
* A shared generic method in a Ready-to-Run module calls a method
  in a shared generic class.
* The target is a non-virtual instance method, but is called through
  callvirt instruction (as C# compiler normally does).
* The target is in a different module.
* The target method is defined in a base class, while the actual
  object instance is of a derived class.

This commit fixes this bug by changing a virtual call to a regular
call when the target is non-virtual.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/vm/genericdict.cpp b/src/vm/genericdict.cpp
index 87eef8749c..04e2550e1e 100644
--- a/src/vm/genericdict.cpp
+++ b/src/vm/genericdict.cpp
@@ -880,6 +880,14 @@ Dictionary::PopulateEntry(
                 result = (CORINFO_GENERIC_HANDLE)pMethod->GetMultiCallableAddrOfCode();
             }
             else
+            if (kind == DispatchStubAddrSlot)
+            {
+                _ASSERTE((methodFlags & ENCODE_METHOD_SIG_SlotInsteadOfToken) == 0);
+                PCODE *ppCode = (PCODE*)(void*)pMethod->GetLoaderAllocator()->GetHighFrequencyHeap()->AllocMem(S_SIZE_T(sizeof(PCODE)));
+                *ppCode = pMethod->GetMultiCallableAddrOfCode();
+                result = (CORINFO_GENERIC_HANDLE)ppCode;
+            }
+            else
             {
                 _ASSERTE(kind == MethodDescSlot);
                 result = (CORINFO_GENERIC_HANDLE)pMethod;