/* ** binding-base.h ** ** This file is part of mkxp. ** ** Copyright (C) 2013 - 2021 Amaryllis Kulla ** ** mkxp is free software: you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation, either version 2 of the License, or ** (at your option) any later version. ** ** mkxp is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with mkxp. If not, see . */ #ifndef MKXPZ_SANDBOX_BINDING_BASE_H #define MKXPZ_SANDBOX_BINDING_BASE_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include "types.h" // LLVM uses a stack alignment of 16 on WebAssembly targets #define WASMSTACKALIGN 16 // Rounds a number up to the nearest multiple of the WebAssembly stack alignment #define CEIL_WASMSTACKALIGN(x) (((wasm_size_t)(x) + (wasm_size_t)(WASMSTACKALIGN - 1)) & ~(wasm_size_t)(WASMSTACKALIGN - 1)) namespace mkxp_sandbox { template struct decl_slots {}; template struct get_num_slots; template <> struct get_num_slots> { static constexpr wasm_size_t value = 0; }; template struct get_num_slots> { static constexpr wasm_size_t value = 1 + get_num_slots>::value; }; // typename concat_slots, decl_slots>::type -> decl_slots template struct concat_slots; template struct concat_slots, struct decl_slots> { using type = decl_slots; }; // typename get_last_slot>::type -> xn template struct get_last_slot; template struct get_last_slot> { using type = Tail; }; template struct get_last_slot> { using type = typename get_last_slot>::type; }; // typename pop_last_slot>::type -> decl_slots template struct pop_last_slot; template struct pop_last_slot> { using type = decl_slots<>; }; template struct pop_last_slot> { using type = typename concat_slots, typename pop_last_slot>::type>::type; }; // `slot_type::type` is the type of the `i`th slot. // For example: // typedef decl_slots slots; // slot_type<0, slots>::type var0; // this variable should be of type `uint64_t` // slot_type<1, slots>::type var1; // this variable should be of type `uint32_t` // slot_type<2, slots>::type var2; // this variable should be of type `uint16_t` // slot_type<3, slots>::type var3; // this variable should be of type `uint8_t` template struct slot_type; template struct slot_type<0, struct decl_slots> { static_assert(std::is_integral::value || std::is_floating_point::value, "slots must have numeric types"); typedef Head type; }; template struct slot_type> : slot_type> {}; // `slots_size::value` is the total number of bytes required to store all the slots, including padding bytes between the slots but not including padding bytes after the last slot. // For example: // typedef decl_slots slots; // constexpr wasm_size_t size = slots_size::value; // should be 15 template struct slots_size; template <> struct slots_size> { static constexpr wasm_size_t value = 0; }; template struct slots_size> { static_assert(std::is_integral>::type>::value || std::is_floating_point>::type>::value, "slots must have numeric types"); private: static constexpr wasm_size_t last_size = sizeof(typename get_last_slot>::type); static constexpr wasm_size_t rest_size = slots_size>::type>::value; static constexpr wasm_size_t rest_size_aligned_to_last_size = (rest_size - 1 + last_size) / last_size * last_size; public: static constexpr wasm_size_t value = rest_size_aligned_to_last_size + last_size; }; template struct slot_offset_nothrow; template struct slot_offset_nothrow> { static constexpr wasm_size_t value = 0; }; template struct slot_offset_nothrow> { static constexpr wasm_size_t value = get_num_slots>::value <= Index ? slots_size>::value : slot_offset_nothrow>::type>::value; }; // `slot_offset::value` is the byte offset of the `i`th slot. // For example: // typedef decl_slots slots; // constexpr wasm_size_t slot0_offset = slot_offset<0, slots>::value; // should be 0 // constexpr wasm_size_t slot1_offset = slot_offset<1, slots>::value; // should be 8 // constexpr wasm_size_t slot2_offset = slot_offset<2, slots>::value; // should be 12 // constexpr wasm_size_t slot3_offset = slot_offset<3, slots>::value; // should be 14 template struct slot_offset; template struct slot_offset> { static_assert(Index < get_num_slots>::value, "index out of range"); static constexpr wasm_size_t value = slot_offset_nothrow>::value; }; // If the type `T::slots` exists, // then `declared_slots_size::value` is equal to `slots_size::value` (i.e. the total size of the slots used by `T`). // Otherwise, it's equal to 0. template struct declared_slots_size; template using slots_declaration = typename T::slots; template struct declared_slots_size>::type> { static constexpr wasm_size_t value = slots_size::value; }; template struct declared_slots_size>::type> { static constexpr wasm_size_t value = 0; }; struct binding_base { private: typedef std::tuple key_t; struct stack_frame { void *coroutine; void (*destructor)(void *coroutine); wasm_ptr_t stack_ptr; stack_frame(void *coroutine, void (*destructor)(void *coroutine), wasm_ptr_t stack_ptr); stack_frame(const struct stack_frame &frame) = delete; stack_frame(struct stack_frame &&frame) noexcept; struct stack_frame &operator=(const struct stack_frame &frame) = delete; struct stack_frame &operator=(struct stack_frame &&frame) noexcept; ~stack_frame(); }; struct fiber { key_t key; std::vector stack; size_t stack_index; }; std::shared_ptr _instance; std::unordered_map> fibers; wasm_ptr_t next_func_ptr; wasm_ptr_t stack_ptr; public: binding_base(std::shared_ptr m); ~binding_base(); struct w2c_ruby &instance() const noexcept; wasm_ptr_t sandbox_malloc(wasm_size_t); void sandbox_free(wasm_ptr_t ptr); wasm_ptr_t rtypeddata_data(VALUE obj) const noexcept; void rtypeddata_dmark(wasm_ptr_t data, wasm_ptr_t ptr); void rtypeddata_dfree(wasm_ptr_t data, wasm_ptr_t ptr); wasm_size_t rtypeddata_dsize(wasm_ptr_t data, wasm_ptr_t ptr); void rtypeddata_dcompact(wasm_ptr_t data, wasm_ptr_t ptr); // Gets a pointer to the given address in sandbox memory. void *ptr(wasm_ptr_t address) const noexcept { #ifdef MKXPZ_BIG_ENDIAN return instance().w2c_memory.data + instance().w2c_memory.size - address; #else return instance().w2c_memory.data + address; #endif // MKXPZ_BIG_ENDIAN } // Gets a reference to the value stored at a given address in sandbox memory. template T &ref(wasm_ptr_t address) const noexcept { // TODO: require T to be numeric #ifdef MKXPZ_BIG_ENDIAN return *(T *)(ptr(address) - sizeof(T)); #else return *(T *)ptr(address); #endif // MKXPZ_BIG_ENDIAN } // Gets a reference to the value stored at the given index in the array at a given address in sandbox memory. template T &ref(wasm_ptr_t array_address, wasm_size_t array_index) const noexcept { return ref(array_address + array_index * sizeof(T)); } // Gets a string stored at a given address in sandbox memory. // The returned string doesn't need to be freed but only lives until the next call to this function, // so you need to store the returned string in a buffer somewhere if you need to get more than one. const char *str(wasm_ptr_t address) { #ifdef MKXPZ_BIG_ENDIAN static std::string buf; buf.clear(); const char *s = (const char *)ptr(address); const char *t = s; wasm_size_t n = -1; while (*--s) { ++n; } buf.reserve(n); while (*--t) { buf.push_back(*t); } return buf.c_str(); #else return (const char *)ptr(address); #endif // MKXPZ_BIG_ENDIAN } template struct stack_frame_guard { static_assert(std::is_base_of::value, "`T` must be a subclass of `boost::asio::coroutine`"); friend struct binding_base; private: T *coroutine; struct binding_base *bind; struct fiber *fiber; static void coroutine_destructor(void *coroutine) { ((T *)coroutine)->~T(); } static struct fiber &init_fiber(struct binding_base &bind) { key_t key = { bind.ref(bind.instance().w2c_mkxp_sandbox_fiber_entry_point), bind.ref(bind.instance().w2c_mkxp_sandbox_fiber_arg0), bind.ref(bind.instance().w2c_mkxp_sandbox_fiber_arg1), }; if (bind.fibers.count(key) == 0) { bind.fibers[key] = (struct fiber){.key = key}; } return bind.fibers[key]; } template static typename boost::enable_if, U *>::type construct_frame(struct binding_base &bind) { return new U(bind); } template static typename boost::disable_if, U *>::type construct_frame(struct binding_base &bind) { return new U; } stack_frame_guard(struct binding_base &b) : bind(&b), fiber(&init_fiber(b)) { uint32_t state = w2c_ruby_asyncify_get_state(&b.instance()); if (fiber->stack_index > fiber->stack.size()) { std::abort(); } // If Asyncify is rewinding, restore the stack frame from before Asyncify started unwinding if (state == 2) { if (fiber->stack_index == fiber->stack.size()) { std::abort(); } struct stack_frame &frame = fiber->stack[fiber->stack_index++]; b.stack_ptr = frame.stack_ptr; coroutine = (T *)frame.coroutine; return; } // Otherwise, create a new stack frame assert(state == 0); while (fiber->stack.size() > fiber->stack_index) { bind->stack_ptr = fiber->stack.back().stack_ptr; fiber->stack.pop_back(); } ++fiber->stack_index; b.stack_ptr = w2c_ruby_rb_wasm_get_stack_pointer(&b.instance()) #ifdef MKXPZ_BIG_ENDIAN + #else - #endif // MKXPZ_BIG_ENDIAN CEIL_WASMSTACKALIGN(declared_slots_size::value); assert(b.stack_ptr % sizeof(VALUE) == 0); assert(b.stack_ptr % WASMSTACKALIGN == 0); if (declared_slots_size::value != 0) { w2c_ruby_rb_wasm_set_stack_pointer(&b.instance(), b.stack_ptr); } coroutine = construct_frame(b); fiber->stack.emplace_back( coroutine, coroutine_destructor, b.stack_ptr ); } public: stack_frame_guard(const stack_frame_guard &frame) = delete; stack_frame_guard(stack_frame_guard &&frame) noexcept : coroutine(std::exchange(frame.coroutine, nullptr)), bind(std::exchange(frame.bind, nullptr)), fiber(std::exchange(frame.fiber, nullptr)) {} struct stack_frame_guard &operator=(const stack_frame_guard &frame) = delete; struct stack_frame_guard &operator=(stack_frame_guard &&frame) noexcept { coroutine = std::exchange(frame.coroutine, nullptr); bind = std::exchange(frame.bind, nullptr); fiber = std::exchange(frame.fiber, nullptr); return *this; } ~stack_frame_guard() { if (fiber == nullptr) { return; } assert(fiber->stack_index > 0); assert(fiber->stack_index - 1 < fiber->stack.size()); if (get()->is_complete()) { while (fiber->stack.size() > fiber->stack_index) { bind->stack_ptr = fiber->stack.back().stack_ptr; fiber->stack.pop_back(); } assert(fiber->stack.size() == fiber->stack_index); w2c_ruby_rb_wasm_set_stack_pointer( &bind->instance(), fiber->stack.back().stack_ptr #ifdef MKXPZ_BIG_ENDIAN - #else + #endif // MKXPZ_BIG_ENDIAN CEIL_WASMSTACKALIGN(declared_slots_size::value) ); bind->stack_ptr = fiber->stack.back().stack_ptr; fiber->stack.pop_back(); } if (--fiber->stack_index > 0) { bind->stack_ptr = fiber->stack[fiber->stack_index - 1].stack_ptr; } if (fiber->stack.empty()) { bind->fibers.erase(fiber->key); } } inline T *get() const noexcept { return coroutine; } inline T &operator()() const noexcept { return *get(); } }; template struct stack_frame_guard bind() { return *this; } wasm_ptr_t stack_pointer() const noexcept { return stack_ptr; } }; } #endif // MKXPZ_SANDBOX_BINDING_BASE