Correct implementation of memcmp

substrate/Cargo.lock

@@ -498,11 +498,6 @@ dependencies = [
  "libc 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "memcmp"
-version = "0.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "memorydb"
 version = "0.1.1"
@@ -731,7 +726,7 @@ dependencies = [
  "assert_matches 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "memcmp 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "native-runtime 0.1.0",
  "parity-wasm 0.15.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "polkadot-primitives 0.1.0",
@@ -1339,7 +1334,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum libc 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "5ba3df4dcb460b9dfbd070d41c94c19209620c191b0340b929ce748a2bcd42d2"
 "checksum log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "880f77541efa6e5cc74e76910c9884d9859683118839d6a1dc3b11e63512565b"
 "checksum memchr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "148fab2e51b4f1cfc66da2a7c32981d1d3c083a803978268bb11fe4b86925e7a"
-"checksum memcmp 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "9a1b44fee357b6a05a9e22554ded6c1bbe57844b58190295257ac0ad4c5944e1"
 "checksum memorydb 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "013b7e4c5e10c764936ebc6bd3662d8e3c92292d267bf6a42ef3f5cad9c793ee"
 "checksum mime 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e2e00e17be181010a91dbfefb01660b17311059dc8c7f48b9017677721e732bd"
 "checksum mio 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)" = "0e8411968194c7b139e9105bc4ae7db0bae232af087147e72f0616ebf5fdb9cb"

substrate/executor/Cargo.toml

@@ -15,7 +15,7 @@ byteorder = "1.1"
 rustc-hex = "1.0.0"
 native-runtime = { path = "../native-runtime", version = "0.1" }
 runtime-std = { path = "../native-runtime/std", version = "0.1" }
-memcmp = { version = "0.0.6" }
+libc = { version = "0.2.33" }
 
 [dev-dependencies]
 assert_matches = "1.1"

substrate/executor/src/error.rs

@@ -59,5 +59,11 @@ error_chain! {
 			description("runtime failure"),
 			display("Runtime error"),
 		}
+
+		/// Runtime failed.
+		InvalidMemoryReference {
+			description("invalid memory reference"),
+			display("Invalid memory reference"),
+		}
 	}
 }

substrate/executor/src/lib.rs

@@ -36,7 +36,7 @@ extern crate byteorder;
 extern crate rustc_hex;
 extern crate native_runtime;
 extern crate runtime_std;
-extern crate memcmp;
+extern crate libc;
 
 #[macro_use]
 extern crate error_chain;

substrate/executor/src/wasm_executor.rs

@@ -16,10 +16,11 @@
 
 //! Rust implementation of Polkadot contracts.
 
+use libc::{memcmp, c_void};
 use std::sync::Arc;
 use std::collections::HashMap;
 use parity_wasm::{deserialize_buffer, ModuleInstanceInterface, ProgramInstance};
-use parity_wasm::interpreter::{ItemIndex};
+use parity_wasm::interpreter::{ItemIndex, DummyUserError};
 use parity_wasm::RuntimeValue::{I32, I64};
 use primitives::contract::CallData;
 use state_machine::{Externalities, CodeExecutor};
@@ -96,10 +97,13 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	ext_memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 => {
 		if let (Ok(sl1), Ok(sl2))
 			= (this.memory.get(s1, n as usize), this.memory.get(s2, n as usize)) {
-			use memcmp::Memcmp;
-			(&sl1).memcmp(&sl2) as i32
+			unsafe {
+				memcmp(sl1.as_ptr() as *const u8 as *const c_void,
+					sl2.as_ptr() as *const u8 as *const c_void,
+					n as usize) as i32
+			}	
 		} else {
-			0
+			return Err(DummyUserError.into());
 		}
 	},
 	ext_memcpy(dest: *mut u8, src: *const u8, count: usize) -> *mut u8 => {

substrate/wasm-runtime/pwasm-libc/src/lib.rs

@@ -22,7 +22,7 @@ pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut
 	ext_memcpy(dest, src, n)
 }
 
-/// memcpy extern
+/// memcmp extern
 #[no_mangle]
 pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
 	ext_memcmp(s1, s2, n)