kernel: avoid signed overflow UB on MSVC

3 files changed, 25 insertions, 1 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 58ff5f2f3..61ab68864 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -91,6 +91,7 @@ add_library(common STATIC
     multi_level_page_table.h
     nvidia_flags.cpp
     nvidia_flags.h
+    overflow.h
     page_table.cpp
     page_table.h
     param_package.cpp
diff --git a/src/common/overflow.h b/src/common/overflow.h
new file mode 100644
index 000000000..44d8e7e73
--- /dev/null
+++ b/src/common/overflow.h
@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <type_traits>
+#include "bit_cast.h"
+
+namespace Common {
+
+template <typename T>
+    requires(std::is_integral_v<T> && std::is_signed_v<T>)
+inline T WrappingAdd(T lhs, T rhs) {
+    using U = std::make_unsigned_t<T>;
+
+    U lhs_u = BitCast<U>(lhs);
+    U rhs_u = BitCast<U>(rhs);
+
+    return BitCast<T>(lhs_u + rhs_u);
+}
+
+} // namespace Common
diff --git a/src/core/hle/kernel/k_resource_limit.cpp b/src/core/hle/kernel/k_resource_limit.cpp
index b9d22b414..626517619 100644
--- a/src/core/hle/kernel/k_resource_limit.cpp
+++ b/src/core/hle/kernel/k_resource_limit.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "common/assert.h"
+#include "common/overflow.h"
 #include "core/core.h"
 #include "core/core_timing.h"
 #include "core/hle/kernel/k_resource_limit.h"
@@ -104,7 +105,7 @@ bool KResourceLimit::Reserve(LimitableResource which, s64 value, s64 timeout) {
         ASSERT(current_hints[index] <= current_values[index]);
 
         // If we would overflow, don't allow to succeed.
-        if (current_values[index] + value <= current_values[index]) {
+        if (Common::WrappingAdd(current_values[index], value) <= current_values[index]) {
             break;
         }