XVM CE: Sufficient charged gas check before XVM execution. (#1073)

* Sufficient charged gas check before XVM execution. * Charge actual weight limit instead of 32KB placeholder.
AstarNetwork · Oct 31, 2023 · 95e5d9f · 95e5d9f
1 parent 0589b5f
commit 95e5d9f
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Showing 3 changed files with 25 additions and 6 deletions.
diff --git a/chain-extensions/types/xvm/src/lib.rs b/chain-extensions/types/xvm/src/lib.rs
@@ -48,6 +48,7 @@ impl From<FailureReason> for XvmExecutionResult {
             FailureReason::Error(FailureError::SameVmCallDenied) => 129,
             FailureReason::Error(FailureError::ReentranceDenied) => 130,
             FailureReason::Error(FailureError::VmError(_)) => 131,
+            FailureReason::Error(FailureError::OutOfGas) => 132,
         };
         Self::Err(error_code)
     }

diff --git a/chain-extensions/xvm/src/lib.rs b/chain-extensions/xvm/src/lib.rs
@@ -23,7 +23,7 @@ use alloc::format;
 
 use astar_primitives::{
     evm::UnifiedAddressMapper,
-    xvm::{Context, VmId, XvmCall},
+    xvm::{CallFailure, Context, FailureError, VmId, XvmCall},
 };
 use frame_support::{dispatch::Encode, weights::Weight};
 use frame_system::RawOrigin;
@@ -78,10 +78,7 @@ where
             XvmFuncId::Call => {
                 // We need to immediately charge for the worst case scenario. Gas equals Weight in pallet-contracts context.
                 let weight_limit = env.ext().gas_meter().gas_left();
-                // TODO: track proof size in align fees ticket
-                // We don't track used proof size, so we can't refund after.
-                // So we will charge a 32KB dummy value as a temporary replacement.
-                let charged_weight = env.charge_weight(weight_limit.set_proof_size(32 * 1024))?;
+                let charged_weight = env.charge_weight(weight_limit)?;
 
                 let XvmCallArgs {
                     vm_id,
@@ -103,9 +100,16 @@ where
                         <T as pallet_unified_accounts::Config>::WeightInfo::to_h160(),
                     );
 
+                    if actual_weight.any_gt(weight_limit) {
+                        return out_of_gas_err(actual_weight);
+                    }
+
                     if UA::to_h160(&source).is_none() {
                         let weight_of_claim = <T as pallet_unified_accounts::Config>::WeightInfo::claim_default_evm_address();
                         actual_weight.saturating_accrue(weight_of_claim);
+                        if actual_weight.any_gt(weight_limit) {
+                            return out_of_gas_err(actual_weight);
+                        }
 
                         let claim_result =
                             pallet_unified_accounts::Pallet::<T>::claim_default_evm_address(
@@ -122,7 +126,8 @@ where
 
                 let xvm_context = Context {
                     source_vm_id: VmId::Wasm,
-                    weight_limit,
+                    // Weight limit left for XVM call.
+                    weight_limit: weight_limit.saturating_sub(actual_weight),
                 };
                 let vm_id = {
                     match TryInto::<VmId>::try_into(vm_id) {
@@ -174,3 +179,14 @@ where
         }
     }
 }
+
+fn out_of_gas_err(actual_weight: Weight) -> Result<RetVal, DispatchError> {
+    Ok(RetVal::Diverging {
+        flags: ReturnFlags::REVERT,
+        data: format!(
+            "{:?}",
+            CallFailure::error(FailureError::OutOfGas, actual_weight)
+        )
+        .into(),
+    })
+}
diff --git a/primitives/src/xvm.rs b/primitives/src/xvm.rs
@@ -131,6 +131,8 @@ pub enum FailureError {
     ReentranceDenied,
     /// The call failed with error on EVM or WASM execution.
     VmError(Vec<u8>),
+    /// Out of gas.
+    OutOfGas,
 }
 
 /// XVM call result.