dmnt: cheats: Silence memory errors

src/core/memory/cheat_engine.cpp

@@ -47,12 +47,23 @@ StandardVmCallbacks::StandardVmCallbacks(System& system_, const CheatProcessMeta
 
 StandardVmCallbacks::~StandardVmCallbacks() = default;
 
-void StandardVmCallbacks::MemoryRead(VAddr address, void* data, u64 size) {
-    system.ApplicationMemory().ReadBlock(SanitizeAddress(address), data, size);
+void StandardVmCallbacks::MemoryReadUnsafe(VAddr address, void* data, u64 size) {
+    // Return zero on invalid address
+    if (!IsAddressInRange(address) || !system.ApplicationMemory().IsValidVirtualAddress(address)) {
+        std::memset(data, 0, size);
+        return;
+    }
+
+    system.ApplicationMemory().ReadBlock(address, data, size);
 }
 
-void StandardVmCallbacks::MemoryWrite(VAddr address, const void* data, u64 size) {
-    system.ApplicationMemory().WriteBlock(SanitizeAddress(address), data, size);
+void StandardVmCallbacks::MemoryWriteUnsafe(VAddr address, const void* data, u64 size) {
+    // Skip invalid memory write address
+    if (!IsAddressInRange(address) || !system.ApplicationMemory().IsValidVirtualAddress(address)) {
+        return;
+    }
+
+    system.ApplicationMemory().WriteBlock(address, data, size);
 }
 
 u64 StandardVmCallbacks::HidKeysDown() {
@@ -82,7 +93,7 @@ void StandardVmCallbacks::CommandLog(std::string_view data) {
               data.back() == '\n' ? data.substr(0, data.size() - 1) : data);
 }
 
-VAddr StandardVmCallbacks::SanitizeAddress(VAddr in) const {
+bool StandardVmCallbacks::IsAddressInRange(VAddr in) const {
     if ((in < metadata.main_nso_extents.base ||
          in >= metadata.main_nso_extents.base + metadata.main_nso_extents.size) &&
         (in < metadata.heap_extents.base ||
@@ -97,10 +108,10 @@ VAddr StandardVmCallbacks::SanitizeAddress(VAddr in) const {
                   "the cheat may be incorrect. However, this may be normal early in execution if "
                   "the game has not properly set up yet.",
                   in);
-        return 0; ///< Invalid addresses will hard crash
+        return false; ///< Invalid addresses will hard crash
     }
 
-    return in;
+    return true;
 }
 
 CheatParser::~CheatParser() = default;

src/core/memory/cheat_engine.h

@@ -27,14 +27,14 @@ public:
     StandardVmCallbacks(System& system_, const CheatProcessMetadata& metadata_);
     ~StandardVmCallbacks() override;
 
-    void MemoryRead(VAddr address, void* data, u64 size) override;
-    void MemoryWrite(VAddr address, const void* data, u64 size) override;
+    void MemoryReadUnsafe(VAddr address, void* data, u64 size) override;
+    void MemoryWriteUnsafe(VAddr address, const void* data, u64 size) override;
     u64 HidKeysDown() override;
     void DebugLog(u8 id, u64 value) override;
     void CommandLog(std::string_view data) override;
 
 private:
-    VAddr SanitizeAddress(VAddr address) const;
+    bool IsAddressInRange(VAddr address) const;
 
     const CheatProcessMetadata& metadata;
     Core::System& system;

src/core/memory/dmnt_cheat_vm.cpp

@@ -773,7 +773,7 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
             case 2:
             case 4:
             case 8:
-                callbacks->MemoryWrite(dst_address, &dst_value, store_static->bit_width);
+                callbacks->MemoryWriteUnsafe(dst_address, &dst_value, store_static->bit_width);
                 break;
             }
         } else if (auto begin_cond = std::get_if<BeginConditionalOpcode>(&cur_opcode.opcode)) {
@@ -786,7 +786,7 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
             case 2:
             case 4:
             case 8:
-                callbacks->MemoryRead(src_address, &src_value, begin_cond->bit_width);
+                callbacks->MemoryReadUnsafe(src_address, &src_value, begin_cond->bit_width);
                 break;
             }
             // Check against condition.
@@ -857,8 +857,8 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
             case 2:
             case 4:
             case 8:
-                callbacks->MemoryRead(src_address, &registers[ldr_memory->reg_index],
-                                      ldr_memory->bit_width);
+                callbacks->MemoryReadUnsafe(src_address, &registers[ldr_memory->reg_index],
+                                            ldr_memory->bit_width);
                 break;
             }
         } else if (auto str_static = std::get_if<StoreStaticToAddressOpcode>(&cur_opcode.opcode)) {
@@ -874,7 +874,7 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
             case 2:
             case 4:
             case 8:
-                callbacks->MemoryWrite(dst_address, &dst_value, str_static->bit_width);
+                callbacks->MemoryWriteUnsafe(dst_address, &dst_value, str_static->bit_width);
                 break;
             }
             // Increment register if relevant.
@@ -1032,7 +1032,7 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
             case 2:
             case 4:
             case 8:
-                callbacks->MemoryWrite(dst_address, &dst_value, str_register->bit_width);
+                callbacks->MemoryWriteUnsafe(dst_address, &dst_value, str_register->bit_width);
                 break;
             }
 
@@ -1111,7 +1111,8 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
                 case 2:
                 case 4:
                 case 8:
-                    callbacks->MemoryRead(cond_address, &cond_value, begin_reg_cond->bit_width);
+                    callbacks->MemoryReadUnsafe(cond_address, &cond_value,
+                                                begin_reg_cond->bit_width);
                     break;
                 }
             }
@@ -1253,7 +1254,7 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
                 case 2:
                 case 4:
                 case 8:
-                    callbacks->MemoryRead(val_address, &log_value, debug_log->bit_width);
+                    callbacks->MemoryReadUnsafe(val_address, &log_value, debug_log->bit_width);
                     break;
                 }
             }

src/core/memory/dmnt_cheat_vm.h

@@ -266,8 +266,8 @@ public:
     public:
         virtual ~Callbacks();
 
-        virtual void MemoryRead(VAddr address, void* data, u64 size) = 0;
-        virtual void MemoryWrite(VAddr address, const void* data, u64 size) = 0;
+        virtual void MemoryReadUnsafe(VAddr address, void* data, u64 size) = 0;
+        virtual void MemoryWriteUnsafe(VAddr address, const void* data, u64 size) = 0;
 
         virtual u64 HidKeysDown() = 0;