From b82953a78b99c0b7011d1de7b886de982991629e Mon Sep 17 00:00:00 2001
From: Luis Pinto <luis.pinto@consensys.net>
Date: Sat, 30 Nov 2024 22:35:05 +0000
Subject: [PATCH] EIP-7709 Implement gas costs for BLOCKHASH implementation
 with system contract

Signed-off-by: Luis Pinto <luis.pinto@consensys.net>
---
 .../mainnet/MainnetProtocolSpecs.java         |  3 ++-
 .../ethereum/vm/Eip7709BlockHashLookup.java   | 22 +++++++++++++++++++
 ethereum/referencetests/build.gradle          |  2 +-
 .../evm/operation/BlockHashOperation.java     |  9 +++++++-
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java
index 766ae81a7aa..a7d8422fd7b 100644
--- a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java
+++ b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java
@@ -38,6 +38,7 @@
 import org.hyperledger.besu.ethereum.mainnet.ClearEmptyAccountStrategy.NotClearEmptyAccount;
 import org.hyperledger.besu.ethereum.mainnet.ProtocolSpecBuilder.BlockValidatorBuilder;
 import org.hyperledger.besu.ethereum.mainnet.blockhash.CancunBlockHashProcessor;
+import org.hyperledger.besu.ethereum.mainnet.blockhash.Eip7709BlockHashProcessor;
 import org.hyperledger.besu.ethereum.mainnet.blockhash.FrontierBlockHashProcessor;
 import org.hyperledger.besu.ethereum.mainnet.blockhash.PragueBlockHashProcessor;
 import org.hyperledger.besu.ethereum.mainnet.feemarket.BaseFeeMarket;
@@ -991,7 +992,7 @@ static ProtocolSpecBuilder verkleDefinition(
                     CoinbaseFeePriceCalculator.eip1559()))
         .withdrawalsProcessor(new WithdrawalsProcessor(clearEmptyAccountStrategy))
         .executionWitnessValidator(new ExecutionWitnessValidator.AllowedExecutionWitness())
-        .blockHashProcessor(new PragueBlockHashProcessor())
+        .blockHashProcessor(new Eip7709BlockHashProcessor())
         .blockHeaderFunctions(new VerkleDevnetBlockHeaderFunctions())
         .name("Verkle");
   }
diff --git a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/vm/Eip7709BlockHashLookup.java b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/vm/Eip7709BlockHashLookup.java
index 0627a416109..8b939df9cf0 100644
--- a/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/vm/Eip7709BlockHashLookup.java
+++ b/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/vm/Eip7709BlockHashLookup.java
@@ -37,6 +37,7 @@
 public class Eip7709BlockHashLookup implements BlockHashLookup {
   private static final Logger LOG = LoggerFactory.getLogger(Eip7709BlockHashLookup.class);
   private static final long BLOCKHASH_SERVE_WINDOW = 256L;
+  private static final long WARM_STORAGE_READ_COST = 100L;
 
   private final Address contractAddress;
   private final long historyServeWindow;
@@ -81,6 +82,12 @@ public Hash apply(final MessageFrame frame, final Long blockNumber) {
       return ZERO;
     }
 
+    final long cost = cost(frame, blockNumber);
+    if (frame.getRemainingGas() < cost) {
+      return Hash.EMPTY;
+    }
+    frame.decrementRemainingGas(cost);
+
     final Hash cachedHash = hashByNumber.get(blockNumber);
     if (cachedHash != null) {
       return cachedHash;
@@ -105,4 +112,19 @@ public Hash apply(final MessageFrame frame, final Long blockNumber) {
     hashByNumber.put(blockNumber, blockHash);
     return blockHash;
   }
+
+  private long cost(final MessageFrame frame, final long blockNumber) {
+    final UInt256 key = UInt256.valueOf(blockNumber % BLOCKHASH_SERVE_WINDOW);
+    long gas = frame.getAccessWitness().touchAndChargeStorageLoad(contractAddress, key);
+
+    if (gas == 0) {
+      return getWarmStorageReadCost();
+    }
+
+    return gas;
+  }
+
+  protected long getWarmStorageReadCost() {
+    return WARM_STORAGE_READ_COST;
+  }
 }
diff --git a/ethereum/referencetests/build.gradle b/ethereum/referencetests/build.gradle
index a1d3a6ea8e9..e795fa901f9 100644
--- a/ethereum/referencetests/build.gradle
+++ b/ethereum/referencetests/build.gradle
@@ -260,7 +260,7 @@ dependencies {
   }
   verkleRefTestImplemention dependencies.create('ethereum:execution-spec-tests') {
     version {
-      strictly 'verkle@v0.0.8'
+      strictly 'verkle@v0.0.9-alpha-1'
     }
     artifact {
       name = 'fixtures'
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/operation/BlockHashOperation.java b/evm/src/main/java/org/hyperledger/besu/evm/operation/BlockHashOperation.java
index c88dc137093..b1d90e45897 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/operation/BlockHashOperation.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/operation/BlockHashOperation.java
@@ -50,11 +50,18 @@ public OperationResult execute(final MessageFrame frame, final EVM evm) {
       return new OperationResult(cost, null);
     }
 
+    final long remainingGas = frame.getRemainingGas();
     final BlockHashLookup blockHashLookup = frame.getBlockHashLookup();
     final Hash blockHash = blockHashLookup.apply(frame, blockArg.toLong());
+    final long lookupCost = remainingGas - frame.getRemainingGas();
+    if (Hash.EMPTY.equals(blockHash)) {
+      return new OperationResult(lookupCost, ExceptionalHaltReason.INSUFFICIENT_GAS);
+    }
+    // give lookupCost back as it will be taken after
+    frame.incrementRemainingGas(lookupCost);
     frame.pushStackItem(blockHash);
 
-    return new OperationResult(cost, null);
+    return new OperationResult(cost + lookupCost, null);
   }
 
   /**