Addressing leftover comments from #21531 (#21782)

* Addressing leftover comments from #21531

* Add feature flag

* Feature gate new vote instruction

* add clock & slot hashes sysvar to test

programs/vote/src/vote_instruction.rs

@@ -161,18 +161,14 @@ pub enum VoteInstruction {
     ///
     /// # Account references
     ///   0. `[Write]` Vote account to vote with
-    ///   1. `[]` Slot hashes sysvar
+    ///   1. `[SIGNER]` Vote authority
-    ///   2. `[]` Clock sysvar
-    ///   3. `[SIGNER]` Vote authority
     UpdateVoteState(VoteStateUpdate),
 
     /// Update the onchain vote state for the signer along with a switching proof.
     ///
     /// # Account references
     ///   0. `[Write]` Vote account to vote with
-    ///   1. `[]` Slot hashes sysvar
+    ///   1. `[SIGNER]` Vote authority
-    ///   2. `[]` Clock sysvar
-    ///   3. `[SIGNER]` Vote authority
     UpdateVoteStateSwitch(VoteStateUpdate, Hash),
 }
 
@@ -338,8 +334,6 @@ pub fn update_vote_state(
 ) -> Instruction {
     let account_metas = vec![
         AccountMeta::new(*vote_pubkey, false),
-        AccountMeta::new_readonly(sysvar::slot_hashes::id(), false),
-        AccountMeta::new_readonly(sysvar::clock::id(), false),
         AccountMeta::new_readonly(*authorized_voter_pubkey, true),
     ];
 
@@ -358,8 +352,6 @@ pub fn update_vote_state_switch(
 ) -> Instruction {
     let account_metas = vec![
         AccountMeta::new(*vote_pubkey, false),
-        AccountMeta::new_readonly(sysvar::slot_hashes::id(), false),
-        AccountMeta::new_readonly(sysvar::clock::id(), false),
         AccountMeta::new_readonly(*authorized_voter_pubkey, true),
     ];
 
@@ -465,20 +457,23 @@ pub fn process_instruction(
         }
         VoteInstruction::UpdateVoteState(vote_state_update)
         | VoteInstruction::UpdateVoteStateSwitch(vote_state_update, _) => {
-            inc_new_counter_info!("vote-state-native", 1);
+            if invoke_context
-            vote_state::process_vote_state_update(
+                .feature_set
-                me,
+                .is_active(&feature_set::allow_votes_to_directly_update_vote_state::id())
-                &from_keyed_account::<SlotHashes>(keyed_account_at_index(
+            {
-                    keyed_accounts,
+                inc_new_counter_info!("vote-state-native", 1);
-                    first_instruction_account + 1,
+                let slot_hashes: SlotHashes =
-                )?)?,
+                    invoke_context.get_sysvar(&sysvar::slot_hashes::id())?;
-                &from_keyed_account::<Clock>(keyed_account_at_index(
+                vote_state::process_vote_state_update(
-                    keyed_accounts,
+                    me,
-                    first_instruction_account + 2,
+                    slot_hashes.slot_hashes(),
-                )?)?,
+                    &invoke_context.get_sysvar(&sysvar::clock::id())?,
-                &vote_state_update,
+                    vote_state_update,
-                &signers,
+                    &signers,
-            )
+                )
+            } else {
+                Err(InstructionError::InvalidInstructionData)
+            }
         }
         VoteInstruction::Withdraw(lamports) => {
             let to = keyed_account_at_index(keyed_accounts, first_instruction_account + 1)?;
@@ -585,12 +580,19 @@ mod tests {
 
         let rent = Rent::default();
         let rent_sysvar = (sysvar::rent::id(), bincode::serialize(&rent).unwrap());
+        let clock = Clock::default();
+        let clock_sysvar = (sysvar::clock::id(), bincode::serialize(&clock).unwrap());
+        let slot_hashes = SlotHashes::default();
+        let slot_hashes_sysvar = (
+            sysvar::slot_hashes::id(),
+            bincode::serialize(&slot_hashes).unwrap(),
+        );
         solana_program_runtime::invoke_context::mock_process_instruction_with_sysvars(
             &id(),
             Vec::new(),
             &instruction.data,
             &keyed_accounts,
-            &[rent_sysvar],
+            &[rent_sysvar, clock_sysvar, slot_hashes_sysvar],
             super::process_instruction,
         )
     }

programs/vote/src/vote_state/mod.rs

@@ -38,7 +38,7 @@ pub const INITIAL_LOCKOUT: usize = 2;
 // Maximum number of credits history to keep around
 pub const MAX_EPOCH_CREDITS_HISTORY: usize = 64;
 
-// Offset of VoteState::pri : Clone + Debug {or_voters, for determining initialization status without deserialization
+// Offset of VoteState::prior_voters, for determining initialization status without deserialization
 const DEFAULT_PRIOR_VOTERS_OFFSET: usize = 82;
 
 // VoteTransactionClone hack is done so that we can derive clone on the tower that uses the
@@ -1156,14 +1156,14 @@ pub fn process_vote_state_update<S: std::hash::BuildHasher>(
     vote_account: &KeyedAccount,
     slot_hashes: &[SlotHash],
     clock: &Clock,
-    vote_state_update: &VoteStateUpdate,
+    vote_state_update: VoteStateUpdate,
     signers: &HashSet<Pubkey, S>,
 ) -> Result<(), InstructionError> {
     let mut vote_state = verify_and_get_vote_state(vote_account, clock, signers)?;
 
-    vote_state.check_slots_are_valid(vote_state_update, slot_hashes)?;
+    vote_state.check_slots_are_valid(&vote_state_update, slot_hashes)?;
     vote_state.process_new_vote_state(
-        vote_state_update.lockouts.clone(),
+        vote_state_update.lockouts,
         vote_state_update.root,
         vote_state_update.timestamp,
         clock.epoch,

sdk/src/feature_set.rs

@@ -275,6 +275,10 @@ pub mod evict_invalid_stakes_cache_entries {
     solana_sdk::declare_id!("EMX9Q7TVFAmQ9V1CggAkhMzhXSg8ECp7fHrWQX2G1chf");
 }
 
+pub mod allow_votes_to_directly_update_vote_state {
+    solana_sdk::declare_id!("Ff8b1fBeB86q8cjq47ZhsQLgv5EkHu3G1C99zjUfAzrq");
+}
+
 lazy_static! {
     /// Map of feature identifiers to user-visible description
     pub static ref FEATURE_NAMES: HashMap<Pubkey, &'static str> = [
@@ -338,6 +342,7 @@ lazy_static! {
         (fixed_memcpy_nonoverlapping_check::id(), "use correct check for nonoverlapping regions in memcpy syscall"),
         (reject_non_rent_exempt_vote_withdraws::id(), "fail vote withdraw instructions which leave the account non-rent-exempt"),
         (evict_invalid_stakes_cache_entries::id(), "evict invalid stakes cache entries on epoch boundaries"),
+        (allow_votes_to_directly_update_vote_state::id(), "enable direct vote state update"),
         /*************** ADD NEW FEATURES HERE ***************/
     ]
     .iter()