Change DATALOADN immediate argument to mean offset in bytes

Author: gumb0

lib/evmone/eof.cpp

@@ -225,7 +225,7 @@ EOFValidationError validate_instructions(
         else if (op == OP_DATALOADN)
         {
             const auto index = read_uint16_be(&code[i + 1]);
-            if (index >= header.data_size / 32)
+            if (header.data_size < 32 || index > header.data_size - 32)
                 return EOFValidationError::invalid_dataloadn_index;
             i += 2;
         }

lib/evmone/instructions.hpp

@@ -946,8 +946,7 @@ inline code_iterator dataloadn(StackTop stack, ExecutionState& state, code_itera
 {
     const auto index = read_uint16_be(&pos[1]);
 
-    const auto begin = static_cast<size_t>(index * 32);
-    stack.push(intx::be::unsafe::load<uint256>(&state.data[begin]));
+    stack.push(intx::be::unsafe::load<uint256>(&state.data[index]));
     return pos + 3;
 }
 

test/unittests/eof_validation_test.cpp

@@ -1256,7 +1256,12 @@ TEST(eof_validation, dataloadn)
         EOFValidationError::success);
 
     // DATALOADN{1}
-    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030040 00 00000001 b900015000"
+    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030021 00 00000001 b900015000"
+                           "000000000000000011111111111111112222222222222222333333333333333344"),
+        EOFValidationError::success);
+
+    // DATALOADN{32}
+    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030040 00 00000001 b900205000"
                            "0000000000000000111111111111111122222222222222223333333333333333"
                            "0000000000000000111111111111111122222222222222223333333333333333"),
         EOFValidationError::success);
@@ -1266,7 +1271,12 @@ TEST(eof_validation, dataloadn)
         EOFValidationError::invalid_dataloadn_index);
 
     // DATALOADN{1} - out of data section bounds
-    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030020 00 00000001 b900015000"
+    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030001 00 00000001 b900015000"
+                           "00"),
+        EOFValidationError::invalid_dataloadn_index);
+
+    // DATALOADN{32} - out of data section bounds
+    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 030020 00 00000001 b900205000"
                            "0000000000000000111111111111111122222222222222223333333333333333"),
         EOFValidationError::invalid_dataloadn_index);
 
@@ -1275,9 +1285,8 @@ TEST(eof_validation, dataloadn)
                            "0000000000000000111111111111111122222222222222223333333333333333"),
         EOFValidationError::invalid_dataloadn_index);
 
-    // DATALOADN{2} - truncated word
-    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 03005f 00 00000001 b900025000"
-                           "0000000000000000111111111111111122222222222222223333333333333333"
+    // DATALOADN{32} - truncated word
+    EXPECT_EQ(validate_eof("EF0001 010004 0200010005 03003F 00 00000001 b900205000"
                            "0000000000000000111111111111111122222222222222223333333333333333"
                            "00000000000000001111111111111111222222222222222233333333333333"),
         EOFValidationError::invalid_dataloadn_index);

test/unittests/evm_eof_test.cpp

@@ -215,6 +215,13 @@ TEST_P(evm, eof1_dataloadn)
     code = eof1_bytecode(bytecode(OP_DATALOADN) + "0001" + ret_top(), 2, data);
     execute(code);
     EXPECT_STATUS(EVMC_SUCCESS);
+    EXPECT_EQ(bytes_view(result.output_data, result.output_size),
+        "00000000000000111111111111111122222222222222223333333333333333aa"_hex);
+
+    // DATALOADN{32}
+    code = eof1_bytecode(bytecode(OP_DATALOADN) + "0020" + ret_top(), 2, data);
+    execute(code);
+    EXPECT_STATUS(EVMC_SUCCESS);
     EXPECT_EQ(bytes_view(result.output_data, result.output_size),
         "aaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbccccccccccccccccdddddddddddddddd"_hex);
 }