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Data opcodes zero padding #741

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Merged
gumb0 merged 1 commit into from
Dec 5, 2023
Merged

Data opcodes zero padding #741

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38 changes: 23 additions & 15 deletions lib/evmone/instructions.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -959,16 +959,23 @@ inline Result mcopy(StackTop stack, int64_t gas_left, ExecutionState& state) noe
return {EVMC_SUCCESS, gas_left};
}

inline Result dataload(StackTop stack, int64_t gas_left, ExecutionState& state) noexcept
inline void dataload(StackTop stack, ExecutionState& state) noexcept
{
auto& index = stack.top();

if (state.data.size() < 32 || (state.data.size() - 32) < index)
return {EVMC_INVALID_MEMORY_ACCESS, gas_left}; // TODO: Introduce EVMC_INVALID_DATA_ACCESS
if (state.data.size() < index)
index = 0;
else
{
const auto begin = static_cast<size_t>(index);
const auto end = std::min(begin + 32, state.data.size());

const auto begin = static_cast<size_t>(index);
index = intx::be::unsafe::load<uint256>(&state.data[begin]);
return {EVMC_SUCCESS, gas_left};
uint8_t data[32] = {};
for (size_t i = 0; i < (end - begin); ++i)
data[i] = state.data[begin + i];

index = intx::be::unsafe::load<uint256>(data);
}
}

inline void datasize(StackTop stack, ExecutionState& state) noexcept
Expand All @@ -993,20 +1000,21 @@ inline Result datacopy(StackTop stack, int64_t gas_left, ExecutionState& state)
if (!check_memory(gas_left, state.memory, mem_index, size))
return {EVMC_OUT_OF_GAS, gas_left};

const auto dst = static_cast<size_t>(mem_index);
// TODO why?
const auto src =
state.data.size() < data_index ? state.data.size() : static_cast<size_t>(data_index);
const auto s = static_cast<size_t>(size);

if (state.data.size() < s || state.data.size() - s < data_index)
return {EVMC_INVALID_MEMORY_ACCESS, gas_left}; // TODO: Introduce EVMC_INVALID_DATA_ACCESS
const auto copy_size = std::min(s, state.data.size() - src);

if (const auto cost = copy_cost(s); (gas_left -= cost) < 0)
return {EVMC_OUT_OF_GAS, gas_left};

if (s > 0)
{
const auto src = static_cast<size_t>(data_index);
const auto dst = static_cast<size_t>(mem_index);
std::memcpy(&state.memory[dst], &state.data[src], s);
}
if (copy_size > 0)
std::memcpy(&state.memory[dst], &state.data[src], copy_size);

if (s - copy_size > 0)
std::memset(&state.memory[dst + copy_size], 0, s - copy_size);

return {EVMC_SUCCESS, gas_left};
}
Expand Down
20 changes: 15 additions & 5 deletions test/unittests/evm_eof_test.cpp
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Expand Up @@ -182,15 +182,21 @@ TEST_P(evm, eof1_dataload)

// DATALOAD(33) - truncated word
execute(code, "0000000000000000000000000000000000000000000000000000000000000021"_hex);
EXPECT_STATUS(EVMC_INVALID_MEMORY_ACCESS);
EXPECT_STATUS(EVMC_SUCCESS);
EXPECT_EQ(bytes_view(result.output_data, result.output_size),
"aaaaaaaaaaaaaabbbbbbbbbbbbbbbbccccccccccccccccdddddddddddddddd00"_hex);

// DATALOAD(64) - out of data bounds
execute(code, "0000000000000000000000000000000000000000000000000000000000000040"_hex);
EXPECT_STATUS(EVMC_INVALID_MEMORY_ACCESS);
EXPECT_STATUS(EVMC_SUCCESS);
EXPECT_EQ(bytes_view(result.output_data, result.output_size),
"0000000000000000000000000000000000000000000000000000000000000000"_hex);

// DATALOAD(u256_max) - out of data bounds
execute(code, "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"_hex);
EXPECT_STATUS(EVMC_INVALID_MEMORY_ACCESS);
EXPECT_STATUS(EVMC_SUCCESS);
EXPECT_EQ(bytes_view(result.output_data, result.output_size),
"0000000000000000000000000000000000000000000000000000000000000000"_hex);
}

TEST_P(evm, eof1_dataloadn)
Expand Down Expand Up @@ -319,11 +325,15 @@ TEST_P(evm, eof1_datacopy)

code = eof1_bytecode(bytecode(8) + 63 + 0 + OP_DATACOPY + ret(0, 32), 3, data);
execute(code);
EXPECT_STATUS(EVMC_INVALID_MEMORY_ACCESS);
EXPECT_STATUS(EVMC_SUCCESS);
EXPECT_EQ(bytes_view(result.output_data, result.output_size),
"dd00000000000000000000000000000000000000000000000000000000000000"_hex);

code = eof1_bytecode(bytecode(0) + 65 + 0 + OP_DATACOPY + ret(0, 32), 3, data);
execute(code);
EXPECT_STATUS(EVMC_INVALID_MEMORY_ACCESS);
EXPECT_STATUS(EVMC_SUCCESS);
EXPECT_EQ(bytes_view(result.output_data, result.output_size),
"0000000000000000000000000000000000000000000000000000000000000000"_hex);
}

TEST_P(evm, datacopy_memory_cost)
Expand Down