Programs were not spawned by SystemProgram (#1533)

* SystemProgram spawns programs

src/bank.rs

@@ -486,13 +486,10 @@ impl Bank {
         account: &Account,
     ) -> Result<()> {
         // Verify the transaction
-        // make sure that program_id is still the same or this was just assigned by the system call contract
-        if !((*pre_program_id == account.program_id)
-            || (SystemProgram::check_id(&tx_program_id)
-                && SystemProgram::check_id(&pre_program_id)))
-        {
-            //TODO, this maybe redundant bpf should be able to guarantee this property
-            // return Err(BankError::ModifiedContractId(instruction_index as u8));
+
+        // Make sure that program_id is still the same or this was just assigned by the system call contract
+        if *pre_program_id != account.program_id && !SystemProgram::check_id(&tx_program_id) {
+            return Err(BankError::ModifiedContractId(instruction_index as u8));
         }
         // For accounts unassigned to the contract, the individual balance of each accounts cannot decrease.
         if *tx_program_id != account.program_id && pre_tokens > account.tokens {

src/native_loader.rs

@@ -65,21 +65,18 @@ pub fn process_transaction(keyed_accounts: &mut [KeyedAccount], tx_data: &[u8])
             }
         };
         trace!("Call native {:?}", name);
-        {
-            // create native program
-            let path = create_path(&name);
-            // TODO linux tls bug can cause crash on dlclose(), workaround by never unloading
-            let library = Library::open(Some(path), libc::RTLD_NODELETE | libc::RTLD_NOW).unwrap();
-            unsafe {
-                let entrypoint: Symbol<Entrypoint> = match library.get(ENTRYPOINT.as_bytes()) {
-                    Ok(s) => s,
-                    Err(e) => {
-                        warn!("{:?}: Unable to find {:?} in program", e, ENTRYPOINT);
-                        return false;
-                    }
-                };
-                return entrypoint(&mut keyed_accounts[1..], tx_data);
-            }
+        let path = create_path(&name);
+        // TODO linux tls bug can cause crash on dlclose(), workaround by never unloading
+        let library = Library::open(Some(path), libc::RTLD_NODELETE | libc::RTLD_NOW).unwrap();
+        unsafe {
+            let entrypoint: Symbol<Entrypoint> = match library.get(ENTRYPOINT.as_bytes()) {
+                Ok(s) => s,
+                Err(e) => {
+                    warn!("{:?}: Unable to find {:?} in program", e, ENTRYPOINT);
+                    return false;
+                }
+            };
+            return entrypoint(&mut keyed_accounts[1..], tx_data);
         }
     } else if let Ok(instruction) = deserialize(tx_data) {
         match instruction {
@@ -96,23 +93,15 @@ pub fn process_transaction(keyed_accounts: &mut [KeyedAccount], tx_data: &[u8])
                 }
                 // native loader takes a name and we assume it all comes in at once
                 keyed_accounts[0].account.userdata = bytes;
-                return true;
             }
 
             LoaderInstruction::Finalize => {
                 keyed_accounts[0].account.executable = true;
-                keyed_accounts[0].account.loader_program_id = id();
-                keyed_accounts[0].account.program_id = *keyed_accounts[0].key;
-                trace!(
-                    "NativeLoader::Finalize prog: {:?} loader {:?}",
-                    keyed_accounts[0].account.program_id,
-                    keyed_accounts[0].account.loader_program_id
-                );
-                return true;
+                trace!("NativeLoader::Finalize prog: {:?}", keyed_accounts[0].key);
             }
         }
     } else {
         warn!("Invalid program transaction: {:?}", tx_data);
     }
-    false
+    true
 }

src/system_program.rs

@@ -9,6 +9,8 @@ use transaction::Transaction;
 #[derive(Debug)]
 pub enum Error {
     InvalidArgument,
+    AssignOfUnownedAccount,
+    AccountNotFinalized,
 }
 impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
@@ -39,6 +41,9 @@ pub enum SystemProgram {
     /// * Transaction::keys[0] - source
     /// * Transaction::keys[1] - destination
     Move { tokens: i64 },
+
+    /// Spawn a new program from an account
+    Spawn,
 }
 
 pub const SYSTEM_PROGRAM_ID: [u8; 32] = [0u8; 32];
@@ -85,7 +90,7 @@ impl SystemProgram {
                 }
                 SystemProgram::Assign { program_id } => {
                     if !Self::check_id(&accounts[0].program_id) {
-                        Err(Error::InvalidArgument)?;
+                        Err(Error::AssignOfUnownedAccount)?;
                     }
                     accounts[0].program_id = program_id;
                 }
@@ -94,6 +99,14 @@ impl SystemProgram {
                     accounts[0].tokens -= tokens;
                     accounts[1].tokens += tokens;
                 }
+                SystemProgram::Spawn => {
+                    if !accounts[0].executable || accounts[0].loader_program_id != Pubkey::default()
+                    {
+                        Err(Error::AccountNotFinalized)?;
+                    }
+                    accounts[0].loader_program_id = accounts[0].program_id;
+                    accounts[0].program_id = tx.account_keys[0];
+                }
             }
             Ok(())
         } else {

src/system_transaction.rs

@@ -36,6 +36,8 @@ pub trait SystemTransaction {
         last_id: Hash,
         fee: i64,
     ) -> Self;
+
+    fn system_spawn(from_keypair: &Keypair, last_id: Hash, fee: i64) -> Self;
 }
 
 impl SystemTransaction for Transaction {
@@ -100,7 +102,7 @@ impl SystemTransaction for Transaction {
             fee,
         )
     }
-
+    /// Create and sign new SystemProgram::Move transaction to many destinations
     fn system_move_many(from: &Keypair, moves: &[(Pubkey, i64)], last_id: Hash, fee: i64) -> Self {
         let instructions: Vec<_> = moves
             .iter()
@@ -124,6 +126,19 @@ impl SystemTransaction for Transaction {
             instructions,
         )
     }
+    /// Create and sign new SystemProgram::Spawn transaction
+    fn system_spawn(from_keypair: &Keypair, last_id: Hash, fee: i64) -> Self {
+        let spawn = SystemProgram::Spawn;
+        let userdata = serialize(&spawn).unwrap();
+        Transaction::new(
+            from_keypair,
+            &[],
+            SystemProgram::id(),
+            userdata,
+            last_id,
+            fee,
+        )
+    }
 }
 
 pub fn test_tx() -> Transaction {