[RuntimeAsync] Use truncating sprintf to make resumption stub names (#120698)

* Use truncating sprintf to make resumption stub names

* make sure the resumption stub's name fits instead of truncating.

Author: VSadov

src/coreclr/vm/jitinterface.cpp

@@ -14818,19 +14818,20 @@ CORINFO_METHOD_HANDLE CEEJitInfo::getAsyncResumptionStub()
     }
 #endif // FEATURE_TIERED_COMPILATION
 
-    char name[256];
-    int numWritten = sprintf_s(name, ARRAY_SIZE(name), "IL_STUB_AsyncResume_%s_%s", m_pMethodBeingCompiled->GetName(), optimizationTierName);
-    if (numWritten != -1)
-    {
-        AllocMemTracker amTracker;
-        void* allocedMem = amTracker.Track(m_pMethodBeingCompiled->GetLoaderAllocator()->GetLowFrequencyHeap()->AllocMem(S_SIZE_T(numWritten + 1)));
-        memcpy(allocedMem, name, (size_t)(numWritten + 1));
-        result->AsDynamicMethodDesc()->SetMethodName((LPCUTF8)allocedMem);
-        amTracker.SuppressRelease();
-    }
-
 #ifdef _DEBUG
-    LOG((LF_STUBS, LL_INFO1000, "ASYNC: Resumption stub %s created\n", name));
+    LPCUTF8 methodName = m_pMethodBeingCompiled->GetName();
+    size_t stubNameLen = STRING_LENGTH("IL_STUB_AsyncResume__");
+    stubNameLen += strlen(methodName);
+    stubNameLen += strlen(optimizationTierName);
+    stubNameLen++; // "\n"
+
+    AllocMemTracker amTrackerName;
+    char* allocedMem = (char*)amTrackerName.Track(m_pMethodBeingCompiled->GetLoaderAllocator()->GetLowFrequencyHeap()->AllocMem(S_SIZE_T(stubNameLen)));
+    sprintf_s(allocedMem, stubNameLen, "IL_STUB_AsyncResume_%s_%s", m_pMethodBeingCompiled->GetName(), optimizationTierName);
+    result->AsDynamicMethodDesc()->SetMethodName((LPCUTF8)allocedMem);
+    amTrackerName.SuppressRelease();
+
+    LOG((LF_STUBS, LL_INFO1000, "ASYNC: Resumption stub %s created\n", allocedMem));
     sl.LogILStub(CORJIT_FLAGS());
 #endif