Wasm: Test for reaching stack overflow

ethcore/wasm/Cargo.toml

@@ -12,4 +12,4 @@ libc = "0.2"
 pwasm-utils = "0.2.2"
 vm = { path = "../vm" }
 ethcore-logger = { path = "../../logger" }
-wasmi = "0.2.1"
+wasmi = "0.3.0"

ethcore/wasm/src/tests.rs

@@ -86,7 +86,7 @@ fn empty() {
 		test_finalize(interpreter.exec(params, &mut ext)).unwrap()
 	};
 
-	assert_eq!(gas_left, U256::from(98462));
+	assert_eq!(gas_left, U256::from(96_926));
 }
 
 // This test checks if the contract deserializes payload header properly.
@@ -138,7 +138,7 @@ fn logger() {
 		U256::from(1_000_000_000),
 		"Logger sets 0x04 key to the trasferred value"
 	);
-	assert_eq!(gas_left, U256::from(17_578));
+	assert_eq!(gas_left, U256::from(16_181));
 }
 
 // This test checks if the contract can allocate memory and pass pointer to the result stream properly.
@@ -173,7 +173,7 @@ fn identity() {
 		sender,
 		"Idenity test contract does not return the sender passed"
 	);
-	assert_eq!(gas_left, U256::from(98_408));
+	assert_eq!(gas_left, U256::from(96_883));
 }
 
 // Dispersion test sends byte array and expect the contract to 'disperse' the original elements with
@@ -207,7 +207,7 @@ fn dispersion() {
 		result,
 		vec![0u8, 0, 125, 11, 197, 7, 255, 8, 19, 0]
 	);
-	assert_eq!(gas_left, U256::from(94_013));
+	assert_eq!(gas_left, U256::from(92_371));
 }
 
 #[test]
@@ -235,7 +235,7 @@ fn suicide_not() {
 		result,
 		vec![0u8]
 	);
-	assert_eq!(gas_left, U256::from(94_984));
+	assert_eq!(gas_left, U256::from(93_378));
 }
 
 #[test]
@@ -267,7 +267,7 @@ fn suicide() {
 	};
 
 	assert!(ext.suicides.contains(&refund));
-	assert_eq!(gas_left, U256::from(94_925));
+	assert_eq!(gas_left, U256::from(93_348));
 }
 
 #[test]
@@ -297,15 +297,15 @@ fn create() {
 	assert!(ext.calls.contains(
 		&FakeCall {
 			call_type: FakeCallType::Create,
-			gas: U256::from(60_914),
+			gas: U256::from(59_269),
 			sender_address: None,
 			receive_address: None,
 			value: Some(1_000_000_000.into()),
 			data: vec![0u8, 2, 4, 8, 16, 32, 64, 128],
 			code_address: None,
 		}
 	));
-	assert_eq!(gas_left, U256::from(60_900));
+	assert_eq!(gas_left, U256::from(59_212));
 }
 
 #[test]
@@ -349,7 +349,7 @@ fn call_msg() {
 		}
 	));
 
-	assert_eq!(gas_left, U256::from(93_511));
+	assert_eq!(gas_left, U256::from(91_672));
 }
 
 #[test]
@@ -394,7 +394,7 @@ fn call_code() {
 	// siphash result
 	let res = LittleEndian::read_u32(&result[..]);
 	assert_eq!(res, 4198595614);
-	assert_eq!(gas_left, U256::from(92_381));
+	assert_eq!(gas_left, U256::from(90_038));
 }
 
 #[test]
@@ -442,7 +442,7 @@ fn call_static() {
 	let res = LittleEndian::read_u32(&result[..]);
 	assert_eq!(res, 317632590);
 
-	assert_eq!(gas_left, U256::from(92_381));
+	assert_eq!(gas_left, U256::from(90_043));
 }
 
 // Realloc test
@@ -465,7 +465,7 @@ fn realloc() {
 		}
 	};
 	assert_eq!(result, vec![0u8; 2]);
-	assert_eq!(gas_left, U256::from(94_372));
+	assert_eq!(gas_left, U256::from(92_842));
 }
 
 #[test]
@@ -486,8 +486,8 @@ fn alloc() {
 				GasLeft::NeedsReturn { gas_left: gas, data: result, apply_state: _apply } => (gas, result.to_vec()),
 		}
 	};
-	assert_eq!(result, vec![5u8; 1024*450]);
-	assert_eq!(gas_left, U256::from(6_506_844));
+	assert_eq!(result, vec![5u8; 1024*400]);
+	assert_eq!(gas_left, U256::from(6_893_883));
 }
 
 // Tests that contract's ability to read from a storage
@@ -515,7 +515,7 @@ fn storage_read() {
 	};
 
 	assert_eq!(Address::from(&result[12..32]), address);
-	assert_eq!(gas_left, U256::from(98_298));
+	assert_eq!(gas_left, U256::from(96_833));
 }
 
 // Tests keccak calculation
@@ -541,7 +541,7 @@ fn keccak() {
 	};
 
 	assert_eq!(H256::from_slice(&result), H256::from("68371d7e884c168ae2022c82bd837d51837718a7f7dfb7aa3f753074a35e1d87"));
-	assert_eq!(gas_left, U256::from(84_240));
+	assert_eq!(gas_left, U256::from(84_134));
 }
 
 // math_* tests check the ability of wasm contract to perform big integer operations
@@ -570,7 +570,7 @@ fn math_add() {
 		U256::from_dec_str("1888888888888888888888888888887").unwrap(),
 		(&result[..]).into()
 	);
-	assert_eq!(gas_left, U256::from(93_814));
+	assert_eq!(gas_left, U256::from(92_086));
 }
 
 // multiplication
@@ -592,7 +592,7 @@ fn math_mul() {
 		U256::from_dec_str("888888888888888888888888888887111111111111111111111111111112").unwrap(),
 		(&result[..]).into()
 	);
-	assert_eq!(gas_left, U256::from(93_300));
+	assert_eq!(gas_left, U256::from(91_414));
 }
 
 // subtraction
@@ -614,7 +614,7 @@ fn math_sub() {
 		U256::from_dec_str("111111111111111111111111111111").unwrap(),
 		(&result[..]).into()
 	);
-	assert_eq!(gas_left, U256::from(93_826));
+	assert_eq!(gas_left, U256::from(92_086));
 }
 
 // subtraction with overflow
@@ -656,7 +656,7 @@ fn math_div() {
 		U256::from_dec_str("1125000").unwrap(),
 		(&result[..]).into()
 	);
-	assert_eq!(gas_left, U256::from(90_603));
+	assert_eq!(gas_left, U256::from(87_376));
 }
 
 #[test]
@@ -684,7 +684,7 @@ fn storage_metering() {
 	};
 
 	// 0 -> not 0
-	assert_eq!(gas_left, U256::from(74_338));
+	assert_eq!(gas_left, U256::from(72_399));
 
 	// #2
 
@@ -703,7 +703,7 @@ fn storage_metering() {
 	};
 
 	// not 0 -> not 0
-	assert_eq!(gas_left, U256::from(89_338));
+	assert_eq!(gas_left, U256::from(87_399));
 }
 
 // This test checks the ability of wasm contract to invoke
@@ -791,7 +791,7 @@ fn externs() {
 		"Gas limit requested and returned does not match"
 	);
 
-	assert_eq!(gas_left, U256::from(92_110));
+	assert_eq!(gas_left, U256::from(90_435));
 }
 
 #[test]
@@ -817,7 +817,7 @@ fn embedded_keccak() {
 	};
 
 	assert_eq!(H256::from_slice(&result), H256::from("68371d7e884c168ae2022c82bd837d51837718a7f7dfb7aa3f753074a35e1d87"));
-	assert_eq!(gas_left, U256::from(84_240));
+	assert_eq!(gas_left, U256::from(84_134));
 }
 
 /// This test checks the correctness of log extern
@@ -852,5 +852,45 @@ fn events() {
 	assert_eq!(&log_entry.data, b"gnihtemos");
 
 	assert_eq!(&result, b"gnihtemos");
-	assert_eq!(gas_left, U256::from(81_292));
+	assert_eq!(gas_left, U256::from(81_351));
+}
+
+#[test]
+fn recursive() {
+	::ethcore_logger::init_log();
+	let code = load_sample!("recursive.wasm");
+
+	let mut params = ActionParams::default();
+	params.gas = U256::from(100_000_000);
+	params.code = Some(Arc::new(code));
+	params.data = Some({
+		// `recursive` expects only one 32-bit word in LE that
+		// represents an iteration count.
+		//
+		// We pick a relative big number to definitely hit stack overflow.
+		use byteorder::WriteBytesExt;
+		let mut data = vec![];
+		data.write_u32::<LittleEndian>(100000).unwrap();
+		data
+	});
+
+	let mut ext = FakeExt::new().with_wasm();
+
+	let mut interpreter = wasm_interpreter();
+	let result = interpreter.exec(params, &mut ext);
+
+	// We expect that stack overflow will occur and it should be generated by
+	// deterministic stack metering. Exceeding deterministic stack height limit
+	// always ends with a trap generated by `unreachable` instruction.
+	match result {
+		Err(trap) => {
+			let err_description = trap.to_string();
+			assert!(
+				err_description.contains("Unreachable"),
+				"err_description: {} should contain 'Unreachable'",
+				err_description
+			);
+		},
+		_ => panic!("this test should trap"),
+	}
 }