Restore ability for programs to upgrade themselves (solana-labs#20265)

* Make helper associated fn

* Add feature definition

* Add handling to preserve program-id write lock when upgradeable loader is present; restore bpf upgrade-self test

* Use single feature

programs/bpf/tests/programs.rs

@@ -1867,7 +1867,7 @@ fn test_program_bpf_upgrade_and_invoke_in_same_tx() {
         "solana_bpf_rust_panic",
     );
 
-    // Attempt to invoke, then upgrade the program in same tx
+    // Invoke, then upgrade the program, and then invoke again in same tx
     let message = Message::new(
         &[
             invoke_instruction.clone(),
@@ -1886,12 +1886,10 @@ fn test_program_bpf_upgrade_and_invoke_in_same_tx() {
         message.clone(),
         bank.last_blockhash(),
     );
-    // program_id is automatically demoted to readonly, preventing the upgrade, which requires
-    // writeability
     let (result, _) = process_transaction_and_record_inner(&bank, tx);
     assert_eq!(
         result.unwrap_err(),
-        TransactionError::InstructionError(1, InstructionError::InvalidArgument)
+        TransactionError::InstructionError(2, InstructionError::ProgramFailedToComplete)
     );
 }
 
@@ -2187,6 +2185,96 @@ fn test_program_bpf_upgrade_via_cpi() {
     assert_ne!(programdata, original_programdata);
 }
 
+#[cfg(feature = "bpf_rust")]
+#[test]
+fn test_program_bpf_upgrade_self_via_cpi() {
+    solana_logger::setup();
+
+    let GenesisConfigInfo {
+        genesis_config,
+        mint_keypair,
+        ..
+    } = create_genesis_config(50);
+    let mut bank = Bank::new_for_tests(&genesis_config);
+    let (name, id, entrypoint) = solana_bpf_loader_program!();
+    bank.add_builtin(&name, id, entrypoint);
+    let (name, id, entrypoint) = solana_bpf_loader_upgradeable_program!();
+    bank.add_builtin(&name, id, entrypoint);
+    let bank = Arc::new(bank);
+    let bank_client = BankClient::new_shared(&bank);
+    let noop_program_id = load_bpf_program(
+        &bank_client,
+        &bpf_loader::id(),
+        &mint_keypair,
+        "solana_bpf_rust_noop",
+    );
+
+    // Deploy upgradeable program
+    let buffer_keypair = Keypair::new();
+    let program_keypair = Keypair::new();
+    let program_id = program_keypair.pubkey();
+    let authority_keypair = Keypair::new();
+    load_upgradeable_bpf_program(
+        &bank_client,
+        &mint_keypair,
+        &buffer_keypair,
+        &program_keypair,
+        &authority_keypair,
+        "solana_bpf_rust_invoke_and_return",
+    );
+
+    let mut invoke_instruction = Instruction::new_with_bytes(
+        program_id,
+        &[0],
+        vec![
+            AccountMeta::new_readonly(noop_program_id, false),
+            AccountMeta::new_readonly(noop_program_id, false),
+            AccountMeta::new_readonly(clock::id(), false),
+        ],
+    );
+
+    // Call the upgraded program
+    invoke_instruction.data[0] += 1;
+    let result =
+        bank_client.send_and_confirm_instruction(&mint_keypair, invoke_instruction.clone());
+    assert!(result.is_ok());
+
+    // Prepare for upgrade
+    let buffer_keypair = Keypair::new();
+    load_upgradeable_buffer(
+        &bank_client,
+        &mint_keypair,
+        &buffer_keypair,
+        &authority_keypair,
+        "solana_bpf_rust_panic",
+    );
+
+    // Invoke, then upgrade the program, and then invoke again in same tx
+    let message = Message::new(
+        &[
+            invoke_instruction.clone(),
+            bpf_loader_upgradeable::upgrade(
+                &program_id,
+                &buffer_keypair.pubkey(),
+                &authority_keypair.pubkey(),
+                &mint_keypair.pubkey(),
+            ),
+            invoke_instruction,
+        ],
+        Some(&mint_keypair.pubkey()),
+    );
+    let tx = Transaction::new(
+        &[&mint_keypair, &authority_keypair],
+        message.clone(),
+        bank.last_blockhash(),
+    );
+    let (result, _) = process_transaction_and_record_inner(&bank, tx);
+    assert_eq!(
+        result.unwrap_err(),
+        TransactionError::InstructionError(2, InstructionError::ProgramFailedToComplete)
+    );
+}
+
 #[cfg(feature = "bpf_rust")]
 #[test]
 fn test_program_bpf_set_upgrade_authority_via_cpi() {

runtime/src/accounts.rs

@@ -241,7 +241,6 @@ impl Accounts {
             let rent_for_sysvars = feature_set.is_active(&feature_set::rent_for_sysvars::id());
             let demote_program_write_locks =
                 feature_set.is_active(&feature_set::demote_program_write_locks::id());
-            let is_upgradeable_loader_present = is_upgradeable_loader_present(message);
 
             for (i, key) in message.account_keys_iter().enumerate() {
                 let account = if !message.is_non_loader_key(i) {
@@ -280,7 +279,7 @@ impl Accounts {
                         if bpf_loader_upgradeable::check_id(account.owner()) {
                             if demote_program_write_locks
                                 && message.is_writable(i, demote_program_write_locks)
-                                && !is_upgradeable_loader_present
+                                && !message.is_upgradeable_loader_present()
                             {
                                 error_counters.invalid_writable_account += 1;
                                 return Err(TransactionError::InvalidWritableAccount);
@@ -1133,12 +1132,6 @@ pub fn prepare_if_nonce_account(
     false
 }
 
-fn is_upgradeable_loader_present(message: &SanitizedMessage) -> bool {
-    message
-        .account_keys_iter()
-        .any(|&key| key == bpf_loader_upgradeable::id())
-}
-
 pub fn create_test_accounts(
     accounts: &Accounts,
     pubkeys: &mut Vec<Pubkey>,

sdk/program/src/message/legacy.rs

@@ -354,6 +354,9 @@ impl Message {
     }
 
     pub fn is_writable(&self, i: usize, demote_program_write_locks: bool) -> bool {
+        let demote_program_id = demote_program_write_locks
+            && self.is_key_called_as_program(i)
+            && !self.is_upgradeable_loader_present();
         (i < (self.header.num_required_signatures - self.header.num_readonly_signed_accounts)
             as usize
             || (i >= self.header.num_required_signatures as usize
@@ -363,7 +366,7 @@ impl Message {
                 let key = self.account_keys[i];
                 sysvar::is_sysvar_id(&key) || BUILTIN_PROGRAMS_KEYS.contains(&key)
             }
-            && !(demote_program_write_locks && self.is_key_called_as_program(i))
+            && !demote_program_id
     }
 
     pub fn is_signer(&self, i: usize) -> bool {
@@ -503,6 +506,13 @@ impl Message {
         }
         false
     }
+
+    /// Returns true if any account is the bpf upgradeable loader
+    pub fn is_upgradeable_loader_present(&self) -> bool {
+        self.account_keys
+            .iter()
+            .any(|&key| key == bpf_loader_upgradeable::id())
+    }
 }
 
 #[cfg(test)]

sdk/program/src/message/mapped.rs

@@ -1,5 +1,6 @@
 use {
     crate::{
+        bpf_loader_upgradeable,
         message::{legacy::BUILTIN_PROGRAMS_KEYS, v0},
         pubkey::Pubkey,
         sysvar,
@@ -99,8 +100,12 @@ impl MappedMessage {
     pub fn is_writable(&self, key_index: usize, demote_program_write_locks: bool) -> bool {
         if self.is_writable_index(key_index) {
             if let Some(key) = self.get_account_key(key_index) {
-                return !(sysvar::is_sysvar_id(key) || BUILTIN_PROGRAMS_KEYS.contains(key)
-                    || (demote_program_write_locks && self.is_key_called_as_program(key_index)));
+                let demote_program_id = demote_program_write_locks
+                    && self.is_key_called_as_program(key_index)
+                    && !self.is_upgradeable_loader_present();
+                return !(sysvar::is_sysvar_id(key)
+                    || BUILTIN_PROGRAMS_KEYS.contains(key)
+                    || demote_program_id);
             }
         }
         false
@@ -116,6 +121,12 @@ impl MappedMessage {
             false
         }
     }
+
+    /// Returns true if any account is the bpf upgradeable loader
+    pub fn is_upgradeable_loader_present(&self) -> bool {
+        self.account_keys_iter()
+            .any(|&key| key == bpf_loader_upgradeable::id())
+    }
 }
 
 #[cfg(test)]

sdk/program/src/message/sanitized.rs

@@ -308,6 +308,14 @@ impl SanitizedMessage {
                 .saturating_add(num_secp256k1_signatures),
         )
     }
+
+    /// Inspect all message keys for the bpf upgradeable loader
+    pub fn is_upgradeable_loader_present(&self) -> bool {
+        match self {
+            Self::Legacy(message) => message.is_upgradeable_loader_present(),
+            Self::V0(message) => message.is_upgradeable_loader_present(),
+        }
+    }
 }
 
 #[cfg(test)]

sdk/src/feature_set.rs

@@ -264,7 +264,7 @@ lazy_static! {
         (instructions_sysvar_owned_by_sysvar::id(), "fix owner for instructions sysvar"),
         (close_upgradeable_program_accounts::id(), "enable closing upgradeable program accounts"),
         (stake_program_advance_activating_credits_observed::id(), "Enable advancing credits observed for activation epoch #19309"),
-        (demote_program_write_locks::id(), "demote program write locks to readonly #19593"),
+        (demote_program_write_locks::id(), "demote program write locks to readonly, except when upgradeable loader present #19593 #20265"),
         (ed25519_program_enabled::id(), "enable builtin ed25519 signature verify program"),
         (allow_native_ids::id(), "allow native program ids in program derived addresses"),
         (check_seed_length::id(), "Check program address seed lengths"),