Safe zero copy implementation with no change to existing byte layout

programs/marginfi/src/instructions/marginfi_group/handle_bankruptcy.rs

@@ -67,7 +67,7 @@ pub fn lending_pool_handle_bankruptcy<'info>(
         .lending_account
         .balances
         .iter_mut()
-        .find(|balance| balance.active && balance.bank_pk == bank_loader.key());
+        .find(|balance| balance.is_active() && balance.bank_pk == bank_loader.key());
 
     check!(
         lending_account_balance.is_some(),

programs/marginfi/src/state/marginfi_account.rs

@@ -15,6 +15,7 @@ use crate::{
 };
 use anchor_lang::prelude::*;
 use anchor_spl::token_interface::Mint;
+use bytemuck::{Pod, Zeroable};
 use fixed::types::I80F48;
 use std::{
     cmp::{max, min},
@@ -25,7 +26,7 @@ use type_layout::TypeLayout;
 
 assert_struct_size!(MarginfiAccount, 2304);
 assert_struct_align!(MarginfiAccount, 8);
-#[account(zero_copy(unsafe))]
+#[account(zero_copy)]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
@@ -42,7 +43,8 @@ pub struct MarginfiAccount {
     /// - DISABLED_FLAG = 1 << 0 = 1 - This flag indicates that the account is disabled,
     /// and no further actions can be taken on it.
     pub account_flags: u64, // 8
-    pub _padding: [u64; 63],             // 504
+    pub _padding0: [u64; 32],            // 504
+    pub _padding1: [u64; 31],
 }
 
 pub const DISABLED_FLAG: u64 = 1 << 0;
@@ -61,7 +63,7 @@ impl MarginfiAccount {
         self.lending_account
             .balances
             .iter()
-            .filter(|b| b.active)
+            .filter(|b| b.is_active())
             .count()
             * 2 // TODO: Make account count oracle setup specific
     }
@@ -169,7 +171,7 @@ impl<'info> BankAccountWithPriceFeed<'_, 'info> {
         let active_balances = lending_account
             .balances
             .iter()
-            .filter(|balance| balance.active)
+            .filter(|balance| balance.is_active())
             .collect::<Vec<_>>();
 
         debug!("Expecting {} remaining accounts", active_balances.len() * 2);
@@ -709,20 +711,20 @@ const MAX_LENDING_ACCOUNT_BALANCES: usize = 16;
 
 assert_struct_size!(LendingAccount, 1728);
 assert_struct_align!(LendingAccount, 8);
-#[zero_copy(unsafe)]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
     derive(Debug, PartialEq, Eq, TypeLayout)
 )]
+#[derive(AnchorDeserialize, AnchorSerialize, Copy, Clone, Zeroable, Pod)]
 pub struct LendingAccount {
     pub balances: [Balance; MAX_LENDING_ACCOUNT_BALANCES], // 104 * 16 = 1664
     pub _padding: [u64; 8],                                // 8 * 8 = 64
 }
 
 impl LendingAccount {
     pub fn get_first_empty_balance(&self) -> Option<usize> {
-        self.balances.iter().position(|b| !b.active)
+        self.balances.iter().position(|b| !b.is_active())
     }
 }
 
@@ -731,24 +733,24 @@ impl LendingAccount {
     pub fn get_balance(&self, bank_pk: &Pubkey) -> Option<&Balance> {
         self.balances
             .iter()
-            .find(|balance| balance.active && balance.bank_pk.eq(bank_pk))
+            .find(|balance| balance.is_active() && balance.bank_pk.eq(bank_pk))
     }
 
     pub fn get_active_balances_iter(&self) -> impl Iterator<Item = &Balance> {
-        self.balances.iter().filter(|b| b.active)
+        self.balances.iter().filter(|b| b.is_active())
     }
 }
 
 assert_struct_size!(Balance, 104);
 assert_struct_align!(Balance, 8);
-#[zero_copy(unsafe)]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
     derive(Debug, PartialEq, Eq, TypeLayout)
 )]
+#[derive(AnchorDeserialize, AnchorSerialize, Copy, Clone, Zeroable, Pod)]
 pub struct Balance {
-    pub active: bool,
+    pub active: u8,
     pub bank_pk: Pubkey,
     pub _pad0: [u8; 7],
     pub asset_shares: WrappedI80F48,
@@ -759,6 +761,14 @@ pub struct Balance {
 }
 
 impl Balance {
+    pub fn is_active(&self) -> bool {
+        self.active != 0
+    }
+
+    pub fn set_active(&mut self, value: bool) {
+        self.active = value as u8;
+    }
+
     /// Check whether a balance is empty while accounting for any rounding errors
     /// that might have occured during depositing/withdrawing.
     #[inline]
@@ -820,7 +830,7 @@ impl Balance {
 
     pub fn empty_deactivated() -> Self {
         Balance {
-            active: false,
+            active: 0,
             bank_pk: Pubkey::default(),
             _pad0: [0; 7],
             asset_shares: WrappedI80F48::from(I80F48::ZERO),
@@ -847,7 +857,7 @@ impl<'a> BankAccountWrapper<'a> {
         let balance = lending_account
             .balances
             .iter_mut()
-            .find(|balance| balance.active && balance.bank_pk.eq(bank_pk))
+            .find(|balance| balance.is_active() && balance.bank_pk.eq(bank_pk))
             .ok_or_else(|| error!(MarginfiError::BankAccountNotFound))?;
 
         Ok(Self { balance, bank })
@@ -863,7 +873,7 @@ impl<'a> BankAccountWrapper<'a> {
         let balance_index = lending_account
             .balances
             .iter()
-            .position(|balance| balance.active && balance.bank_pk.eq(bank_pk));
+            .position(|balance| balance.is_active() && balance.bank_pk.eq(bank_pk));
 
         match balance_index {
             Some(balance_index) => {
@@ -880,7 +890,7 @@ impl<'a> BankAccountWrapper<'a> {
                     .ok_or_else(|| error!(MarginfiError::LendingAccountBalanceSlotsFull))?;
 
                 lending_account.balances[empty_index] = Balance {
-                    active: true,
+                    active: 1,
                     bank_pk: *bank_pk,
                     _pad0: [0; 7],
                     asset_shares: I80F48::ZERO.into(),
@@ -1410,7 +1420,7 @@ mod test {
             authority: authority.into(),
             lending_account: LendingAccount {
                 balances: [Balance {
-                    active: true,
+                    active: 1,
                     bank_pk: bank_pk.into(),
                     _pad0: [0; 7],
                     asset_shares: WrappedI80F48::default(),
@@ -1422,7 +1432,8 @@ mod test {
                 _padding: [0; 8],
             },
             account_flags: TRANSFER_AUTHORITY_ALLOWED_FLAG,
-            _padding: [0; 63],
+            _padding0: [0; 32],
+            _padding1: [0; 31],
         };
 
         assert!(acc.get_flag(TRANSFER_AUTHORITY_ALLOWED_FLAG));

programs/marginfi/src/state/marginfi_group.rs

@@ -23,6 +23,7 @@ use crate::{
 use anchor_lang::prelude::borsh;
 use anchor_lang::prelude::*;
 use anchor_spl::token_interface::*;
+use bytemuck::{Pod, Zeroable};
 use fixed::types::I80F48;
 use pyth_sdk_solana::{state::SolanaPriceAccount, PriceFeed};
 use pyth_solana_receiver_sdk::price_update::FeedId;
@@ -129,13 +130,12 @@ impl From<InterestRateConfig> for InterestRateConfigCompact {
     }
 }
 
-#[zero_copy]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
     derive(PartialEq, Eq, TypeLayout)
 )]
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Copy, Clone, AnchorSerialize, AnchorDeserialize, Zeroable, Pod)]
 pub struct InterestRateConfig {
     // Curve Params
     pub optimal_utilization_rate: WrappedI80F48,
@@ -282,7 +282,7 @@ pub struct InterestRateConfigOpt {
 
 assert_struct_size!(Bank, 1856);
 assert_struct_align!(Bank, 8);
-#[account(zero_copy(unsafe))]
+#[account(zero_copy)]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
@@ -921,12 +921,14 @@ fn calc_interest_payment_for_period(apr: I80F48, time_delta: u64, value: I80F48)
 
 #[repr(u8)]
 #[cfg_attr(any(feature = "test", feature = "client"), derive(PartialEq, Eq))]
-#[derive(Copy, Clone, Debug, AnchorSerialize, AnchorDeserialize)]
+#[derive(Debug, Clone, Copy, AnchorDeserialize, AnchorSerialize)]
 pub enum BankOperationalState {
-    Paused,
-    Operational,
-    ReduceOnly,
+    Paused = 0,
+    Operational = 1,
+    ReduceOnly = 2,
 }
+unsafe impl Zeroable for BankOperationalState {}
+unsafe impl Pod for BankOperationalState {}
 
 #[cfg(feature = "client")]
 impl Display for BankOperationalState {
@@ -942,15 +944,17 @@ impl Display for BankOperationalState {
 #[repr(u8)]
 #[derive(Copy, Clone, Debug, AnchorSerialize, AnchorDeserialize, PartialEq, Eq)]
 pub enum RiskTier {
-    Collateral,
+    Collateral = 0,
     /// ## Isolated Risk
     /// Assets in this trance can be borrowed only in isolation.
     /// They can't be borrowed together with other assets.
     ///
     /// For example, if users has USDC, and wants to borrow XYZ which is isolated,
     /// they can't borrow XYZ together with SOL, only XYZ alone.
-    Isolated,
+    Isolated = 1,
 }
+unsafe impl Zeroable for RiskTier {}
+unsafe impl Pod for RiskTier {}
 
 #[repr(C)]
 #[cfg_attr(
@@ -1019,7 +1023,8 @@ impl From<BankConfigCompact> for BankConfig {
             _pad1: [0; 7],
             total_asset_value_init_limit: config.total_asset_value_init_limit,
             oracle_max_age: config.oracle_max_age,
-            _padding: [0; 38],
+            _padding0: [0; 6],
+            _padding1: [0; 32],
         }
     }
 }
@@ -1047,13 +1052,12 @@ impl From<BankConfig> for BankConfigCompact {
 
 assert_struct_size!(BankConfig, 544);
 assert_struct_align!(BankConfig, 8);
-#[zero_copy(unsafe)]
 #[repr(C)]
 #[cfg_attr(
     any(feature = "test", feature = "client"),
     derive(PartialEq, Eq, TypeLayout)
 )]
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy, AnchorDeserialize, AnchorSerialize, Zeroable, Pod)]
 /// TODO: Convert weights to (u64, u64) to avoid precision loss (maybe?)
 pub struct BankConfig {
     pub asset_weight_init: WrappedI80F48,
@@ -1092,7 +1096,8 @@ pub struct BankConfig {
     /// Time window in seconds for the oracle price feed to be considered live.
     pub oracle_max_age: u16,
 
-    pub _padding: [u8; 38],
+    pub _padding0: [u8; 6],
+    pub _padding1: [u8; 32],
 }
 
 impl Default for BankConfig {
@@ -1113,7 +1118,8 @@ impl Default for BankConfig {
             _pad1: [0; 7],
             total_asset_value_init_limit: TOTAL_ASSET_VALUE_INIT_LIMIT_INACTIVE,
             oracle_max_age: 0,
-            _padding: [0; 38],
+            _padding0: [0; 6],
+            _padding1: [0; 32],
         }
     }
 }

programs/marginfi/src/state/price.rs

@@ -1,6 +1,7 @@
 use std::{cell::Ref, cmp::min};
 
 use anchor_lang::prelude::*;
+use bytemuck::{Pod, Zeroable};
 use enum_dispatch::enum_dispatch;
 use fixed::types::I80F48;
 use pyth_sdk_solana::{state::SolanaPriceAccount, Price, PriceFeed};
@@ -30,12 +31,14 @@ use pyth_solana_receiver_sdk::PYTH_PUSH_ORACLE_ID;
 #[cfg_attr(any(feature = "test", feature = "client"), derive(PartialEq, Eq))]
 #[derive(Copy, Clone, Debug, AnchorSerialize, AnchorDeserialize)]
 pub enum OracleSetup {
-    None,
-    PythLegacy,
-    SwitchboardV2,
-    PythPushOracle,
-    SwitchboardPull,
+    None = 0,
+    PythLegacy = 1,
+    SwitchboardV2 = 2,
+    PythPushOracle = 3,
+    SwitchboardPull = 4,
 }
+unsafe impl Zeroable for OracleSetup {}
+unsafe impl Pod for OracleSetup {}
 
 #[derive(Copy, Clone, Debug)]
 pub enum PriceBias {

programs/marginfi/tests/misc/regression.rs

@@ -42,10 +42,11 @@ async fn account_field_values_reg() -> anyhow::Result<()> {
         pubkey!("Dq7wypbedtaqQK9QqEFvfrxc4ppfRGXCeTVd7ee7n2jw")
     );
     assert_eq!(account.account_flags, 0);
-    assert_eq!(account._padding, [0; 63]);
+    assert_eq!(account._padding0, [0; 32]);
+    assert_eq!(account._padding1, [0; 31]);
 
     let balance_1 = account.lending_account.balances[0];
-    assert!(balance_1.active);
+    assert!(balance_1.is_active());
     assert_eq!(
         balance_1.bank_pk,
         pubkey!("2s37akK2eyBbp8DZgCm7RtsaEz8eJP3Nxd4urLHQv7yB")
@@ -70,7 +71,7 @@ async fn account_field_values_reg() -> anyhow::Result<()> {
     assert_eq!(balance_1._padding, [0; 1]);
 
     let balance_2 = account.lending_account.balances[1];
-    assert!(balance_2.active);
+    assert!(balance_2.is_active());
     assert_eq!(
         balance_2.bank_pk,
         pubkey!("CCKtUs6Cgwo4aaQUmBPmyoApH2gUDErxNZCAntD6LYGh")
@@ -117,10 +118,11 @@ async fn account_field_values_reg() -> anyhow::Result<()> {
         pubkey!("3T1kGHp7CrdeW9Qj1t8NMc2Ks233RyvzVhoaUPWoBEFK")
     );
     assert_eq!(account.account_flags, 0);
-    assert_eq!(account._padding, [0; 63]);
+    assert_eq!(account._padding0, [0; 32]);
+    assert_eq!(account._padding1, [0; 31]);
 
     let balance_1 = account.lending_account.balances[0];
-    assert!(balance_1.active);
+    assert!(balance_1.is_active());
     assert_eq!(
         balance_1.bank_pk,
         pubkey!("6hS9i46WyTq1KXcoa2Chas2Txh9TJAVr6n1t3tnrE23K")
@@ -145,7 +147,7 @@ async fn account_field_values_reg() -> anyhow::Result<()> {
     assert_eq!(balance_1._padding, [0; 1]);
 
     let balance_2 = account.lending_account.balances[1];
-    assert!(!balance_2.active);
+    assert!(!balance_2.is_active());
     assert_eq!(
         balance_2.bank_pk,
         pubkey!("11111111111111111111111111111111")
@@ -192,10 +194,11 @@ async fn account_field_values_reg() -> anyhow::Result<()> {
         pubkey!("7hmfVTuXc7HeX3YQjpiCXGVQuTeXonzjp795jorZukVR")
     );
     assert_eq!(account.account_flags, 0);
-    assert_eq!(account._padding, [0; 63]);
+    assert_eq!(account._padding0, [0; 32]);
+    assert_eq!(account._padding1, [0; 31]);
 
     let balance_1 = account.lending_account.balances[0];
-    assert!(!balance_1.active);
+    assert!(!balance_1.is_active());
     assert_eq!(
         balance_1.bank_pk,
         pubkey!("11111111111111111111111111111111")
@@ -638,7 +641,8 @@ async fn bank_field_values_reg() -> anyhow::Result<()> {
     assert_eq!(bank.config._pad1, [0; 7]);
     assert_eq!(bank.config.total_asset_value_init_limit, 0);
     assert_eq!(bank.config.oracle_max_age, 300);
-    assert_eq!(bank.config._padding, [0; 38]);
+    assert_eq!(bank.config._padding0, [0; 6]);
+    assert_eq!(bank.config._padding1, [0; 32]);
 
     assert_eq!(bank.flags, 2);
 

programs/marginfi/tests/user_actions/create_account.rs

@@ -51,7 +51,7 @@ async fn marginfi_account_create_success() -> anyhow::Result<()> {
         .lending_account
         .balances
         .iter()
-        .all(|bank| !bank.active));
+        .all(|bank| !bank.is_active()));
 
     Ok(())
 }