Runtime: Core BPF Migration: Struct for loading and checking builtin …

…program accounts (#331)

* runtime: core_bpf_migration: add builtin config

* runtime: core_bpf_migration: add builtin config tests

* some renaming feedback

runtime/src/bank/builtins/core_bpf_migration/error.rs

@@ -0,0 +1,18 @@
+use {solana_sdk::pubkey::Pubkey, thiserror::Error};
+
+/// Errors returned by a Core BPF migration.
+#[derive(Debug, Error, PartialEq)]
+pub enum CoreBpfMigrationError {
+    /// Account not found
+    #[error("Account not found: {0:?}")]
+    AccountNotFound(Pubkey),
+    /// Account exists
+    #[error("Account exists: {0:?}")]
+    AccountExists(Pubkey),
+    /// Incorrect account owner
+    #[error("Incorrect account owner for {0:?}")]
+    IncorrectOwner(Pubkey),
+    /// Program has a data account
+    #[error("Data account exists for program {0:?}")]
+    ProgramHasDataAccount(Pubkey),
+}

runtime/src/bank/builtins/core_bpf_migration/mod.rs

@@ -0,0 +1,8 @@
+#![allow(dead_code)] // Removed in later commit
+pub(crate) mod error;
+mod target_builtin;
+
+pub(crate) enum CoreBpfMigrationTargetType {
+    Builtin,
+    Stateless,
+}

runtime/src/bank/builtins/core_bpf_migration/target_builtin.rs

@@ -0,0 +1,251 @@
+use {
+    super::{error::CoreBpfMigrationError, CoreBpfMigrationTargetType},
+    crate::bank::Bank,
+    solana_sdk::{
+        account::{AccountSharedData, ReadableAccount},
+        bpf_loader_upgradeable::get_program_data_address,
+        native_loader::ID as NATIVE_LOADER_ID,
+        pubkey::Pubkey,
+    },
+};
+
+/// Used to validate a built-in program's account before migrating to Core BPF.
+#[derive(Debug)]
+pub(crate) struct TargetProgramBuiltin {
+    pub program_address: Pubkey,
+    pub program_account: AccountSharedData,
+    pub program_data_address: Pubkey,
+    pub total_data_size: usize,
+}
+
+impl TargetProgramBuiltin {
+    /// Create a new migration configuration for a built-in program.
+    pub(crate) fn new_checked(
+        bank: &Bank,
+        program_address: &Pubkey,
+        migration_target: &CoreBpfMigrationTargetType,
+    ) -> Result<Self, CoreBpfMigrationError> {
+        let program_account = match migration_target {
+            CoreBpfMigrationTargetType::Builtin => {
+                // The program account should exist.
+                let program_account = bank
+                    .get_account_with_fixed_root(program_address)
+                    .ok_or(CoreBpfMigrationError::AccountNotFound(*program_address))?;
+
+                // The program account should be owned by the native loader.
+                if program_account.owner() != &NATIVE_LOADER_ID {
+                    return Err(CoreBpfMigrationError::IncorrectOwner(*program_address));
+                }
+
+                program_account
+            }
+            CoreBpfMigrationTargetType::Stateless => {
+                // The program account should _not_ exist.
+                if bank.get_account_with_fixed_root(program_address).is_some() {
+                    return Err(CoreBpfMigrationError::AccountExists(*program_address));
+                }
+
+                AccountSharedData::default()
+            }
+        };
+
+        let program_data_address = get_program_data_address(program_address);
+
+        // The program data account should not exist.
+        if bank
+            .get_account_with_fixed_root(&program_data_address)
+            .is_some()
+        {
+            return Err(CoreBpfMigrationError::ProgramHasDataAccount(
+                *program_address,
+            ));
+        }
+
+        // The total data size is the size of the program account's data.
+        let total_data_size = program_account.data().len();
+
+        Ok(Self {
+            program_address: *program_address,
+            program_account,
+            program_data_address,
+            total_data_size,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use {
+        super::*,
+        crate::bank::{tests::create_simple_test_bank, ApplyFeatureActivationsCaller},
+        solana_sdk::{
+            account::Account,
+            bpf_loader_upgradeable::{UpgradeableLoaderState, ID as BPF_LOADER_UPGRADEABLE_ID},
+            feature, feature_set,
+        },
+        test_case::test_case,
+    };
+
+    fn store_account<T: serde::Serialize>(
+        bank: &Bank,
+        address: &Pubkey,
+        data: &T,
+        executable: bool,
+        owner: &Pubkey,
+    ) {
+        let data = bincode::serialize(data).unwrap();
+        let data_len = data.len();
+        let lamports = bank.get_minimum_balance_for_rent_exemption(data_len);
+        let account = AccountSharedData::from(Account {
+            data,
+            executable,
+            lamports,
+            owner: *owner,
+            ..Account::default()
+        });
+        bank.store_account_and_update_capitalization(address, &account);
+    }
+
+    #[test_case(solana_sdk::address_lookup_table::program::id(), None)]
+    #[test_case(solana_sdk::bpf_loader::id(), None)]
+    #[test_case(solana_sdk::bpf_loader_deprecated::id(), None)]
+    #[test_case(solana_sdk::bpf_loader_upgradeable::id(), None)]
+    #[test_case(solana_sdk::compute_budget::id(), None)]
+    #[test_case(solana_config_program::id(), None)]
+    #[test_case(solana_stake_program::id(), None)]
+    #[test_case(solana_system_program::id(), None)]
+    #[test_case(solana_vote_program::id(), None)]
+    #[test_case(
+        solana_sdk::loader_v4::id(),
+        Some(feature_set::enable_program_runtime_v2_and_loader_v4::id())
+    )]
+    #[test_case(
+        solana_zk_token_sdk::zk_token_proof_program::id(),
+        Some(feature_set::zk_token_sdk_enabled::id())
+    )]
+    fn test_target_program_builtin(program_address: Pubkey, activation_feature: Option<Pubkey>) {
+        let migration_target = CoreBpfMigrationTargetType::Builtin;
+        let mut bank = create_simple_test_bank(0);
+
+        if let Some(feature_id) = activation_feature {
+            // Activate the feature to enable the built-in program
+            bank.store_account(
+                &feature_id,
+                &feature::create_account(
+                    &feature::Feature { activated_at: None },
+                    bank.get_minimum_balance_for_rent_exemption(feature::Feature::size_of()),
+                ),
+            );
+            bank.apply_feature_activations(ApplyFeatureActivationsCaller::NewFromParent, false);
+        }
+
+        let program_account = bank.get_account_with_fixed_root(&program_address).unwrap();
+        let program_data_address = get_program_data_address(&program_address);
+
+        // Success
+        let builtin_config =
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target).unwrap();
+        assert_eq!(builtin_config.program_address, program_address);
+        assert_eq!(builtin_config.program_account, program_account);
+        assert_eq!(builtin_config.program_data_address, program_data_address);
+        assert_eq!(builtin_config.total_data_size, program_account.data().len());
+
+        // Fail if the program account is not owned by the native loader
+        store_account(
+            &bank,
+            &program_address,
+            &String::from("some built-in program"),
+            true,
+            &Pubkey::new_unique(), // Not the native loader
+        );
+        assert_eq!(
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target)
+                .unwrap_err(),
+            CoreBpfMigrationError::IncorrectOwner(program_address)
+        );
+
+        // Fail if the program data account exists
+        store_account(
+            &bank,
+            &program_address,
+            &program_account.data(),
+            program_account.executable(),
+            program_account.owner(),
+        );
+        store_account(
+            &bank,
+            &program_data_address,
+            &UpgradeableLoaderState::ProgramData {
+                slot: 0,
+                upgrade_authority_address: Some(Pubkey::new_unique()),
+            },
+            false,
+            &BPF_LOADER_UPGRADEABLE_ID,
+        );
+        assert_eq!(
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target)
+                .unwrap_err(),
+            CoreBpfMigrationError::ProgramHasDataAccount(program_address)
+        );
+
+        // Fail if the program account does not exist
+        bank.store_account_and_update_capitalization(
+            &program_address,
+            &AccountSharedData::default(),
+        );
+        assert_eq!(
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target)
+                .unwrap_err(),
+            CoreBpfMigrationError::AccountNotFound(program_address)
+        );
+    }
+
+    #[test_case(solana_sdk::feature::id())]
+    #[test_case(solana_sdk::native_loader::id())]
+    fn test_target_program_stateless_builtin(program_address: Pubkey) {
+        let migration_target = CoreBpfMigrationTargetType::Stateless;
+        let bank = create_simple_test_bank(0);
+
+        let program_account = AccountSharedData::default();
+        let program_data_address = get_program_data_address(&program_address);
+
+        // Success
+        let builtin_config =
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target).unwrap();
+        assert_eq!(builtin_config.program_address, program_address);
+        assert_eq!(builtin_config.program_account, program_account);
+        assert_eq!(builtin_config.program_data_address, program_data_address);
+        assert_eq!(builtin_config.total_data_size, program_account.data().len());
+
+        // Fail if the program data account exists
+        store_account(
+            &bank,
+            &program_data_address,
+            &UpgradeableLoaderState::ProgramData {
+                slot: 0,
+                upgrade_authority_address: Some(Pubkey::new_unique()),
+            },
+            false,
+            &BPF_LOADER_UPGRADEABLE_ID,
+        );
+        assert_eq!(
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target)
+                .unwrap_err(),
+            CoreBpfMigrationError::ProgramHasDataAccount(program_address)
+        );
+
+        // Fail if the program account exists
+        store_account(
+            &bank,
+            &program_address,
+            &String::from("some built-in program"),
+            true,
+            &NATIVE_LOADER_ID,
+        );
+        assert_eq!(
+            TargetProgramBuiltin::new_checked(&bank, &program_address, &migration_target)
+                .unwrap_err(),
+            CoreBpfMigrationError::AccountExists(program_address)
+        );
+    }
+}

runtime/src/bank/builtins/mod.rs

@@ -1,3 +1,4 @@
+pub(crate) mod core_bpf_migration;
 pub mod prototypes;
 
 pub use prototypes::{BuiltinPrototype, StatelessBuiltinPrototype};