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baseline: Do not check for out-of-buffer push load
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This cannot overflow code buffer because code ends with valid STOP
instruction.
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@chfast
chfast committed Jun 4, 2021
1 parent 5d7cade commit 6538e6a
Showing 1 changed file with 34 additions and 39 deletions.
73 changes: 34 additions & 39 deletions lib/evmone/baseline.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -58,14 +58,10 @@ const uint8_t* op_jump(
}

template <size_t Len>
inline const uint8_t* load_push(
ExecutionState& state, const uint8_t* code, const uint8_t* code_end) noexcept
inline const uint8_t* load_push(ExecutionState& state, const uint8_t* code) noexcept
{
// TODO: Also last full push can be ignored.
if (code + Len > code_end) // Trimmed push data can be ignored.
return code_end;

uint8_t buffer[Len];
// This valid because code is padded with garbage to satisfy push data read pass the code end.
std::memcpy(buffer, code, Len);
state.stack.push(intx::be::load<intx::uint256>(buffer));
return code + Len;
Expand Down Expand Up @@ -122,7 +118,6 @@ evmc_result execute(const VM& vm, ExecutionState& state, const CodeAnalysis& ana
const auto instruction_metrics = evmc_get_instruction_metrics_table(state.rev);

const auto* const code = state.code.data();
const auto* const code_end = code + state.code.size();
auto pc = code;
while (true) // Guaranteed to terminate because padded code ends with STOP.
{
Expand Down Expand Up @@ -448,100 +443,100 @@ evmc_result execute(const VM& vm, ExecutionState& state, const CodeAnalysis& ana
break;

case OP_PUSH1:
pc = load_push<1>(state, pc + 1, code_end);
pc = load_push<1>(state, pc + 1);
continue;
case OP_PUSH2:
pc = load_push<2>(state, pc + 1, code_end);
pc = load_push<2>(state, pc + 1);
continue;
case OP_PUSH3:
pc = load_push<3>(state, pc + 1, code_end);
pc = load_push<3>(state, pc + 1);
continue;
case OP_PUSH4:
pc = load_push<4>(state, pc + 1, code_end);
pc = load_push<4>(state, pc + 1);
continue;
case OP_PUSH5:
pc = load_push<5>(state, pc + 1, code_end);
pc = load_push<5>(state, pc + 1);
continue;
case OP_PUSH6:
pc = load_push<6>(state, pc + 1, code_end);
pc = load_push<6>(state, pc + 1);
continue;
case OP_PUSH7:
pc = load_push<7>(state, pc + 1, code_end);
pc = load_push<7>(state, pc + 1);
continue;
case OP_PUSH8:
pc = load_push<8>(state, pc + 1, code_end);
pc = load_push<8>(state, pc + 1);
continue;
case OP_PUSH9:
pc = load_push<9>(state, pc + 1, code_end);
pc = load_push<9>(state, pc + 1);
continue;
case OP_PUSH10:
pc = load_push<10>(state, pc + 1, code_end);
pc = load_push<10>(state, pc + 1);
continue;
case OP_PUSH11:
pc = load_push<11>(state, pc + 1, code_end);
pc = load_push<11>(state, pc + 1);
continue;
case OP_PUSH12:
pc = load_push<12>(state, pc + 1, code_end);
pc = load_push<12>(state, pc + 1);
continue;
case OP_PUSH13:
pc = load_push<13>(state, pc + 1, code_end);
pc = load_push<13>(state, pc + 1);
continue;
case OP_PUSH14:
pc = load_push<14>(state, pc + 1, code_end);
pc = load_push<14>(state, pc + 1);
continue;
case OP_PUSH15:
pc = load_push<15>(state, pc + 1, code_end);
pc = load_push<15>(state, pc + 1);
continue;
case OP_PUSH16:
pc = load_push<16>(state, pc + 1, code_end);
pc = load_push<16>(state, pc + 1);
continue;
case OP_PUSH17:
pc = load_push<17>(state, pc + 1, code_end);
pc = load_push<17>(state, pc + 1);
continue;
case OP_PUSH18:
pc = load_push<18>(state, pc + 1, code_end);
pc = load_push<18>(state, pc + 1);
continue;
case OP_PUSH19:
pc = load_push<19>(state, pc + 1, code_end);
pc = load_push<19>(state, pc + 1);
continue;
case OP_PUSH20:
pc = load_push<20>(state, pc + 1, code_end);
pc = load_push<20>(state, pc + 1);
continue;
case OP_PUSH21:
pc = load_push<21>(state, pc + 1, code_end);
pc = load_push<21>(state, pc + 1);
continue;
case OP_PUSH22:
pc = load_push<22>(state, pc + 1, code_end);
pc = load_push<22>(state, pc + 1);
continue;
case OP_PUSH23:
pc = load_push<23>(state, pc + 1, code_end);
pc = load_push<23>(state, pc + 1);
continue;
case OP_PUSH24:
pc = load_push<24>(state, pc + 1, code_end);
pc = load_push<24>(state, pc + 1);
continue;
case OP_PUSH25:
pc = load_push<25>(state, pc + 1, code_end);
pc = load_push<25>(state, pc + 1);
continue;
case OP_PUSH26:
pc = load_push<26>(state, pc + 1, code_end);
pc = load_push<26>(state, pc + 1);
continue;
case OP_PUSH27:
pc = load_push<27>(state, pc + 1, code_end);
pc = load_push<27>(state, pc + 1);
continue;
case OP_PUSH28:
pc = load_push<28>(state, pc + 1, code_end);
pc = load_push<28>(state, pc + 1);
continue;
case OP_PUSH29:
pc = load_push<29>(state, pc + 1, code_end);
pc = load_push<29>(state, pc + 1);
continue;
case OP_PUSH30:
pc = load_push<30>(state, pc + 1, code_end);
pc = load_push<30>(state, pc + 1);
continue;
case OP_PUSH31:
pc = load_push<31>(state, pc + 1, code_end);
pc = load_push<31>(state, pc + 1);
continue;
case OP_PUSH32:
pc = load_push<32>(state, pc + 1, code_end);
pc = load_push<32>(state, pc + 1);
continue;

case OP_DUP1:
Expand Down

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