LibWasm: Remove some unnecessary memory checks

Also make `store_to_memory` take a `MemoryArgument` so that we no longer
have to make "synthetic instructions" in some scenarios.
This commit is contained in:
Diego Frias 2024-07-18 13:29:17 -07:00 committed by Ali Mohammad Pur
parent 56ae6b3968
commit ea67bc989f
Notes: sideshowbarker 2024-07-19 15:29:29 +09:00
2 changed files with 23 additions and 74 deletions

View file

@ -92,20 +92,10 @@ void BytecodeInterpreter::load_and_push(Configuration& configuration, Instructio
auto& arg = instruction.arguments().get<Instruction::MemoryArgument>();
auto& address = configuration.frame().module().memories()[arg.memory_index.value()];
auto memory = configuration.store().get(address);
if (!memory) {
m_trap = Trap { "Nonexistent memory" };
return;
}
auto& entry = configuration.stack().peek();
auto base = entry.get<Value>().to<i32>();
if (!base.has_value()) {
m_trap = Trap { "Memory access out of bounds" };
return;
}
u64 instance_address = static_cast<u64>(bit_cast<u32>(base.value())) + arg.offset;
Checked addition { instance_address };
addition += sizeof(ReadType);
if (addition.has_overflow() || addition.value() > memory->size()) {
auto base = *entry.get<Value>().to<i32>();
u64 instance_address = static_cast<u64>(bit_cast<u32>(base)) + arg.offset;
if (instance_address + sizeof(ReadType) > memory->size()) {
m_trap = Trap { "Memory access out of bounds" };
dbgln("LibWasm: Memory access out of bounds (expected {} to be less than or equal to {})", instance_address + sizeof(ReadType), memory->size());
return;
@ -127,20 +117,10 @@ void BytecodeInterpreter::load_and_push_mxn(Configuration& configuration, Instru
auto& arg = instruction.arguments().get<Instruction::MemoryArgument>();
auto& address = configuration.frame().module().memories()[arg.memory_index.value()];
auto memory = configuration.store().get(address);
if (!memory) {
m_trap = Trap { "Nonexistent memory" };
return;
}
auto& entry = configuration.stack().peek();
auto base = entry.get<Value>().to<i32>();
if (!base.has_value()) {
m_trap = Trap { "Memory access out of bounds" };
return;
}
u64 instance_address = static_cast<u64>(bit_cast<u32>(base.value())) + arg.offset;
Checked addition { instance_address };
addition += M * N / 8;
if (addition.has_overflow() || addition.value() > memory->size()) {
auto base = *entry.get<Value>().to<i32>();
u64 instance_address = static_cast<u64>(bit_cast<u32>(base)) + arg.offset;
if (instance_address + M * N / 8 > memory->size()) {
m_trap = Trap { "Memory access out of bounds" };
dbgln("LibWasm: Memory access out of bounds (expected {} to be less than or equal to {})", instance_address + M * N / 8, memory->size());
return;
@ -168,9 +148,7 @@ void BytecodeInterpreter::load_and_push_lane_n(Configuration& configuration, Ins
auto vector = *configuration.stack().pop().get<Value>().to<u128>();
auto base = *configuration.stack().pop().get<Value>().to<u32>();
u64 instance_address = static_cast<u64>(bit_cast<u32>(base)) + memarg_and_lane.memory.offset;
Checked addition { instance_address };
addition += N / 8;
if (addition.has_overflow() || addition.value() > memory->size()) {
if (instance_address + N / 8 > memory->size()) {
m_trap = Trap { "Memory access out of bounds" };
return;
}
@ -188,9 +166,7 @@ void BytecodeInterpreter::load_and_push_zero_n(Configuration& configuration, Ins
auto memory = configuration.store().get(address);
auto base = *configuration.stack().pop().get<Value>().to<u32>();
u64 instance_address = static_cast<u64>(bit_cast<u32>(base)) + memarg_and_lane.offset;
Checked addition { instance_address };
addition += N / 8;
if (addition.has_overflow() || addition.value() > memory->size()) {
if (instance_address + N / 8 > memory->size()) {
m_trap = Trap { "Memory access out of bounds" };
return;
}
@ -206,20 +182,10 @@ void BytecodeInterpreter::load_and_push_m_splat(Configuration& configuration, In
auto& arg = instruction.arguments().get<Instruction::MemoryArgument>();
auto& address = configuration.frame().module().memories()[arg.memory_index.value()];
auto memory = configuration.store().get(address);
if (!memory) {
m_trap = Trap { "Nonexistent memory" };
return;
}
auto& entry = configuration.stack().peek();
auto base = entry.get<Value>().to<i32>();
if (!base.has_value()) {
m_trap = Trap { "Memory access out of bounds" };
return;
}
u64 instance_address = static_cast<u64>(bit_cast<u32>(base.value())) + arg.offset;
Checked addition { instance_address };
addition += M / 8;
if (addition.has_overflow() || addition.value() > memory->size()) {
auto base = *entry.get<Value>().to<i32>();
u64 instance_address = static_cast<u64>(bit_cast<u32>(base)) + arg.offset;
if (instance_address + M / 8 > memory->size()) {
m_trap = Trap { "Memory access out of bounds" };
dbgln("LibWasm: Memory access out of bounds (expected {} to be less than or equal to {})", instance_address + M / 8, memory->size());
return;
@ -416,12 +382,13 @@ struct ConvertToRaw<double> {
template<typename PopT, typename StoreT>
void BytecodeInterpreter::pop_and_store(Configuration& configuration, Instruction const& instruction)
{
auto& memarg = instruction.arguments().get<Instruction::MemoryArgument>();
auto entry = configuration.stack().pop();
auto value = ConvertToRaw<StoreT> {}(*entry.get<Value>().to<PopT>());
dbgln_if(WASM_TRACE_DEBUG, "stack({}) -> temporary({}b)", value, sizeof(StoreT));
auto base_entry = configuration.stack().pop();
auto base = base_entry.get<Value>().to<i32>();
store_to_memory(configuration, instruction, { &value, sizeof(StoreT) }, *base);
store_to_memory(configuration, memarg, { &value, sizeof(StoreT) }, *base);
}
template<size_t N>
@ -431,16 +398,11 @@ void BytecodeInterpreter::pop_and_store_lane_n(Configuration& configuration, Ins
auto vector = *configuration.stack().pop().get<Value>().to<u128>();
auto src = bit_cast<u8*>(&vector) + memarg_and_lane.lane * N / 8;
auto base = *configuration.stack().pop().get<Value>().to<u32>();
Instruction synthetic_store_instruction {
Instructions::i32_store8,
memarg_and_lane.memory,
};
store_to_memory(configuration, synthetic_store_instruction, { src, N / 8 }, base);
store_to_memory(configuration, memarg_and_lane.memory, { src, N / 8 }, base);
}
void BytecodeInterpreter::store_to_memory(Configuration& configuration, Instruction const& instruction, ReadonlyBytes data, u32 base)
void BytecodeInterpreter::store_to_memory(Configuration& configuration, Instruction::MemoryArgument const& arg, ReadonlyBytes data, u32 base)
{
auto& arg = instruction.arguments().get<Instruction::MemoryArgument>();
auto& address = configuration.frame().module().memories()[arg.memory_index.value()];
auto memory = configuration.store().get(address);
u64 instance_address = static_cast<u64>(base) + arg.offset;
@ -784,14 +746,9 @@ void BytecodeInterpreter::interpret(Configuration& configuration, InstructionPoi
if (count == 0)
return;
Instruction synthetic_store_instruction {
Instructions::i32_store8,
Instruction::MemoryArgument { 0, 0 }
};
for (u32 i = 0; i < count; ++i)
store_to_memory(configuration, Instruction::MemoryArgument { 0, 0 }, { &value, sizeof(value) }, destination_offset + i);
for (u32 i = 0; i < count; ++i) {
store_to_memory(configuration, synthetic_store_instruction, { &value, sizeof(value) }, destination_offset + i);
}
return;
}
// https://webassembly.github.io/spec/core/bikeshed/#exec-memory-copy
@ -816,20 +773,16 @@ void BytecodeInterpreter::interpret(Configuration& configuration, InstructionPoi
if (count == 0)
return;
Instruction synthetic_store_instruction {
Instructions::i32_store8,
Instruction::MemoryArgument { 0, 0, args.dst_index }
};
Instruction::MemoryArgument memarg { 0, 0, args.dst_index };
if (destination_offset <= source_offset) {
for (auto i = 0; i < count; ++i) {
auto value = source_instance->data()[source_offset + i];
store_to_memory(configuration, synthetic_store_instruction, { &value, sizeof(value) }, destination_offset + i);
store_to_memory(configuration, memarg, { &value, sizeof(value) }, destination_offset + i);
}
} else {
for (auto i = count - 1; i >= 0; --i) {
auto value = source_instance->data()[source_offset + i];
store_to_memory(configuration, synthetic_store_instruction, { &value, sizeof(value) }, destination_offset + i);
store_to_memory(configuration, memarg, { &value, sizeof(value) }, destination_offset + i);
}
}
@ -856,14 +809,10 @@ void BytecodeInterpreter::interpret(Configuration& configuration, InstructionPoi
if (count == 0)
return;
Instruction synthetic_store_instruction {
Instructions::i32_store8,
Instruction::MemoryArgument { 0, 0, args.memory_index }
};
Instruction::MemoryArgument memarg { 0, 0, args.memory_index };
for (size_t i = 0; i < (size_t)count; ++i) {
auto value = data.data()[source_offset + i];
store_to_memory(configuration, synthetic_store_instruction, { &value, sizeof(value) }, destination_offset + i);
store_to_memory(configuration, memarg, { &value, sizeof(value) }, destination_offset + i);
}
return;
}

View file

@ -68,7 +68,7 @@ protected:
Optional<VectorType> pop_vector(Configuration&);
template<typename M, template<typename> typename SetSign, typename VectorType = Native128ByteVectorOf<M, SetSign>>
Optional<VectorType> peek_vector(Configuration&);
void store_to_memory(Configuration&, Instruction const&, ReadonlyBytes data, u32 base);
void store_to_memory(Configuration&, Instruction::MemoryArgument const&, ReadonlyBytes data, u32 base);
void call_address(Configuration&, FunctionAddress);
template<typename PopTypeLHS, typename PushType, typename Operator, typename PopTypeRHS = PopTypeLHS, typename... Args>