From 34f0a2ca46bda37c49caf0a4e2feb25e1ce9ad4f Mon Sep 17 00:00:00 2001 From: George Marques Date: Tue, 7 Feb 2023 17:09:40 -0300 Subject: GDScript: Add limit to call depth The hard limit is set at 2048 depth which seems sensible between legitimate recursive calls while still avoiding a crash because of a stack overflow in most of the cases. Note that it is still possible to reach the stack limit and get an overflow before reaching a call depth. This is intended as a half-way measure to stop crashing in most cases, since there's no reliable nor portable way to check the amount of stack memory left. --- modules/gdscript/gdscript.cpp | 2 +- modules/gdscript/gdscript_function.h | 2 ++ modules/gdscript/gdscript_vm.cpp | 32 ++++++++++++++++++++++++++++++++ 3 files changed, 35 insertions(+), 1 deletion(-) (limited to 'modules/gdscript') diff --git a/modules/gdscript/gdscript.cpp b/modules/gdscript/gdscript.cpp index a876229276..4a3bddb747 100644 --- a/modules/gdscript/gdscript.cpp +++ b/modules/gdscript/gdscript.cpp @@ -2563,7 +2563,7 @@ GDScriptLanguage::GDScriptLanguage() { script_frame_time = 0; _debug_call_stack_pos = 0; - int dmcs = GLOBAL_DEF(PropertyInfo(Variant::INT, "debug/settings/gdscript/max_call_stack", PROPERTY_HINT_RANGE, "1024,4096,1,or_greater"), 1024); + int dmcs = GLOBAL_DEF(PropertyInfo(Variant::INT, "debug/settings/gdscript/max_call_stack", PROPERTY_HINT_RANGE, "512," + itos(GDScriptFunction::MAX_CALL_DEPTH - 1) + ",1"), 1024); if (EngineDebugger::is_active()) { //debugging enabled! diff --git a/modules/gdscript/gdscript_function.h b/modules/gdscript/gdscript_function.h index f45c1f9577..2624fb8dd9 100644 --- a/modules/gdscript/gdscript_function.h +++ b/modules/gdscript/gdscript_function.h @@ -544,6 +544,8 @@ private: #endif public: + static constexpr int MAX_CALL_DEPTH = 2048; // Limit to try to avoid crash because of a stack overflow. + struct CallState { GDScript *script = nullptr; GDScriptInstance *instance = nullptr; diff --git a/modules/gdscript/gdscript_vm.cpp b/modules/gdscript/gdscript_vm.cpp index b99f5d2685..26eee142f2 100644 --- a/modules/gdscript/gdscript_vm.cpp +++ b/modules/gdscript/gdscript_vm.cpp @@ -456,6 +456,33 @@ Variant GDScriptFunction::call(GDScriptInstance *p_instance, const Variant **p_a r_err.error = Callable::CallError::CALL_OK; + static thread_local int call_depth = 0; + if (unlikely(++call_depth > MAX_CALL_DEPTH)) { + call_depth--; +#ifdef DEBUG_ENABLED + String err_file; + if (p_instance && ObjectDB::get_instance(p_instance->owner_id) != nullptr && p_instance->script->is_valid() && !p_instance->script->path.is_empty()) { + err_file = p_instance->script->path; + } else if (_script) { + err_file = _script->path; + } + if (err_file.is_empty()) { + err_file = ""; + } + String err_func = name; + if (p_instance && ObjectDB::get_instance(p_instance->owner_id) != nullptr && p_instance->script->is_valid() && !p_instance->script->name.is_empty()) { + err_func = p_instance->script->name + "." + err_func; + } + int err_line = _initial_line; + const char *err_text = "Stack overflow. Check for infinite recursion in your script."; + if (!GDScriptLanguage::get_singleton()->debug_break(err_text, false)) { + // Debugger break did not happen. + _err_print_error(err_func.utf8().get_data(), err_file.utf8().get_data(), err_line, err_text, false, ERR_HANDLER_SCRIPT); + } +#endif + return _get_default_variant_for_data_type(return_type); + } + Variant retvalue; Variant *stack = nullptr; Variant **instruction_args = nullptr; @@ -490,10 +517,12 @@ Variant GDScriptFunction::call(GDScriptInstance *p_instance, const Variant **p_a r_err.error = Callable::CallError::CALL_ERROR_TOO_MANY_ARGUMENTS; r_err.argument = _argument_count; + call_depth--; return _get_default_variant_for_data_type(return_type); } else if (p_argcount < _argument_count - _default_arg_count) { r_err.error = Callable::CallError::CALL_ERROR_TOO_FEW_ARGUMENTS; r_err.argument = _argument_count - _default_arg_count; + call_depth--; return _get_default_variant_for_data_type(return_type); } else { defarg = _argument_count - p_argcount; @@ -521,6 +550,7 @@ Variant GDScriptFunction::call(GDScriptInstance *p_instance, const Variant **p_a r_err.error = Callable::CallError::CALL_ERROR_INVALID_ARGUMENT; r_err.argument = i; r_err.expected = argument_types[i].builtin_type; + call_depth--; return _get_default_variant_for_data_type(return_type); } if (argument_types[i].kind == GDScriptDataType::BUILTIN) { @@ -3570,5 +3600,7 @@ Variant GDScriptFunction::call(GDScriptInstance *p_instance, const Variant **p_a stack[i].~Variant(); } + call_depth--; + return retvalue; } -- cgit v1.2.3