From 9c631a01c13fa6e765d8c401c0a1f21eee351d1c Mon Sep 17 00:00:00 2001
From: Michael Vines <mvines@gmail.com>
Date: Tue, 2 Jun 2020 17:34:12 -0700
Subject: [PATCH] Enable rolling upgrade of system_instruction_processor

---
 runtime/src/bank.rs                           | 12 ++++-
 runtime/src/builtin_programs.rs               | 52 ++++++++++++++++---
 .../legacy_system_instruction_processor0.rs   |  2 +-
 3 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index d88ff05af9..9657ad5d0a 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -10,7 +10,7 @@ use crate::{
     accounts_db::{ErrorCounters, SnapshotStorages},
     accounts_index::Ancestors,
     blockhash_queue::BlockhashQueue,
-    builtin_programs::get_builtin_programs,
+    builtin_programs::{get_builtin_programs, get_epoch_activated_builtin_programs},
     epoch_stakes::{EpochStakes, NodeVoteAccounts},
     message_processor::MessageProcessor,
     nonce_utils,
@@ -457,6 +457,14 @@ impl Bank {
             {
                 entered_epoch_callback(&mut new)
             }
+
+            if let Some(builtin_programs) =
+                get_epoch_activated_builtin_programs(new.operating_mode(), new.epoch)
+            {
+                for program in builtin_programs.iter() {
+                    new.add_builtin_program(&program.name, program.id, program.process_instruction);
+                }
+            }
         }
 
         new.update_epoch_stakes(leader_schedule_epoch);
@@ -2049,7 +2057,7 @@ impl Bank {
     }
 
     pub fn finish_init(&mut self) {
-        let builtin_programs = get_builtin_programs();
+        let builtin_programs = get_builtin_programs(self.operating_mode(), self.epoch);
         for program in builtin_programs.iter() {
             self.add_builtin_program(&program.name, program.id, program.process_instruction);
         }
diff --git a/runtime/src/builtin_programs.rs b/runtime/src/builtin_programs.rs
index 5fd7396dc5..7c6671bcde 100644
--- a/runtime/src/builtin_programs.rs
+++ b/runtime/src/builtin_programs.rs
@@ -1,5 +1,8 @@
-use crate::system_instruction_processor;
-use solana_sdk::{entrypoint_native::ProcessInstruction, pubkey::Pubkey, system_program};
+use crate::{legacy_system_instruction_processor0, system_instruction_processor};
+use solana_sdk::{
+    clock::Epoch, entrypoint_native::ProcessInstruction, genesis_config::OperatingMode,
+    pubkey::Pubkey, system_program,
+};
 
 pub struct BuiltinProgram {
     pub name: String,
@@ -16,13 +19,30 @@ impl BuiltinProgram {
     }
 }
 
-pub fn get_builtin_programs() -> Vec<BuiltinProgram> {
+fn new_system_program_activation_epoch(operating_mode: OperatingMode) -> Epoch {
+    match operating_mode {
+        OperatingMode::Development => 0,
+        OperatingMode::Preview => std::u64::MAX / 2,
+        OperatingMode::Stable => std::u64::MAX / 2,
+    }
+}
+
+/// All builtin programs that should be active at the given (operating_mode, epoch)
+pub fn get_builtin_programs(operating_mode: OperatingMode, epoch: Epoch) -> Vec<BuiltinProgram> {
     vec![
-        BuiltinProgram::new(
-            "system_program",
-            system_program::id(),
-            system_instruction_processor::process_instruction,
-        ),
+        if epoch < new_system_program_activation_epoch(operating_mode) {
+            BuiltinProgram::new(
+                "system_program",
+                system_program::id(),
+                legacy_system_instruction_processor0::process_instruction,
+            )
+        } else {
+            BuiltinProgram::new(
+                "system_program",
+                system_program::id(),
+                system_instruction_processor::process_instruction,
+            )
+        },
         BuiltinProgram::new(
             "config_program",
             solana_config_program::id(),
@@ -40,3 +60,19 @@ pub fn get_builtin_programs() -> Vec<BuiltinProgram> {
         ),
     ]
 }
+
+/// Builtin programs that activate at the given (operating_mode, epoch)
+pub fn get_epoch_activated_builtin_programs(
+    operating_mode: OperatingMode,
+    epoch: Epoch,
+) -> Option<Vec<BuiltinProgram>> {
+    if epoch == new_system_program_activation_epoch(operating_mode) {
+        Some(vec![BuiltinProgram::new(
+            "system_program",
+            system_program::id(),
+            system_instruction_processor::process_instruction,
+        )])
+    } else {
+        None
+    }
+}
diff --git a/runtime/src/legacy_system_instruction_processor0.rs b/runtime/src/legacy_system_instruction_processor0.rs
index 1043b34167..dc3693a354 100644
--- a/runtime/src/legacy_system_instruction_processor0.rs
+++ b/runtime/src/legacy_system_instruction_processor0.rs
@@ -2,7 +2,7 @@ use log::*;
 use solana_sdk::{
     account::{get_signers, Account, KeyedAccount},
     instruction::InstructionError,
-    nonce::{Account as NonceAccount},
+    nonce::Account as NonceAccount,
     program_utils::{limited_deserialize, next_keyed_account},
     pubkey::Pubkey,
     system_instruction::{SystemError, SystemInstruction, MAX_PERMITTED_DATA_LENGTH},