From 45673e784b795611f72986d4a587058b78664fa2 Mon Sep 17 00:00:00 2001
From: smtmfft <smtm@taiko.xzy>
Date: Mon, 10 Oct 2022 09:34:44 +0000
Subject: [PATCH] use last_callee_id as src_id of copy table

Signed-off-by: smtmfft <smtm@taiko.xzy>
---
 bus-mapping/src/evm/opcodes/return.rs         |  2 +-
 bus-mapping/src/evm/opcodes/returndatacopy.rs | 13 ++++++--
 .../evm_circuit/execution/returndatacopy.rs   | 33 +++++++++++++++++--
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/bus-mapping/src/evm/opcodes/return.rs b/bus-mapping/src/evm/opcodes/return.rs
index dff801b6cbf..4062ed53936 100644
--- a/bus-mapping/src/evm/opcodes/return.rs
+++ b/bus-mapping/src/evm/opcodes/return.rs
@@ -55,7 +55,7 @@ impl Opcode for Return {
 
             state.call_context_write(
                 &mut exec_step,
-                state.call()?.call_id,
+                state.caller()?.call_id,
                 CallContextField::LastCalleeId,
                 state.call()?.call_id.into(),
             );
diff --git a/bus-mapping/src/evm/opcodes/returndatacopy.rs b/bus-mapping/src/evm/opcodes/returndatacopy.rs
index 5ce4824671b..2a7429525d4 100644
--- a/bus-mapping/src/evm/opcodes/returndatacopy.rs
+++ b/bus-mapping/src/evm/opcodes/returndatacopy.rs
@@ -34,6 +34,7 @@ impl Opcode for Returndatacopy {
         let call_id = state.call()?.call_id;
         let call_ctx = state.call_ctx()?;
         let return_data = call_ctx.return_data.clone();
+        let last_callee_id = state.call()?.last_callee_id;
         let last_callee_return_data_offset = state.call()?.last_callee_return_data_offset;
         let last_callee_return_data_length = state.call()?.last_callee_return_data_length;
         assert_eq!(
@@ -44,6 +45,7 @@ impl Opcode for Returndatacopy {
 
         // read last callee info
         for (field, value) in [
+            (CallContextField::LastCalleeId, last_callee_id.into()),
             (
                 CallContextField::LastCalleeReturnDataOffset,
                 last_callee_return_data_offset.into(),
@@ -165,15 +167,20 @@ fn gen_copy_event(
         state.call()?.is_root,
     )?;
 
-    let (src_type, src_id) = (CopyDataType::Memory, state.call()?.call_id);
+    let (src_type, dst_type, src_id, dst_id) = (
+        CopyDataType::Memory,
+        CopyDataType::Memory,
+        state.call()?.last_callee_id,
+        state.call()?.call_id,
+    );
 
     Ok(CopyEvent {
         src_type,
         src_id: NumberOrHash::Number(src_id),
         src_addr,
         src_addr_end,
-        dst_type: CopyDataType::Memory,
-        dst_id: NumberOrHash::Number(src_id),
+        dst_type,
+        dst_id: NumberOrHash::Number(dst_id),
         dst_addr: dst_memory_offset,
         log_id: None,
         length,
diff --git a/zkevm-circuits/src/evm_circuit/execution/returndatacopy.rs b/zkevm-circuits/src/evm_circuit/execution/returndatacopy.rs
index 0fe4ff0e04f..2ef71c78edc 100644
--- a/zkevm-circuits/src/evm_circuit/execution/returndatacopy.rs
+++ b/zkevm-circuits/src/evm_circuit/execution/returndatacopy.rs
@@ -27,6 +27,8 @@ use halo2_proofs::{circuit::Value, plonk::Error};
 #[derive(Clone, Debug)]
 pub(crate) struct ReturnDataCopyGadget<F> {
     same_context: SameContextGadget<F>,
+    /// Holds the last_called_id for copy table.
+    last_callee_id: Cell<F>,
     /// Holds the memory address for return data from where we read.
     return_data_offset: Cell<F>,
     /// Holds the size of the return data.
@@ -68,8 +70,15 @@ impl<F: Field> ExecutionGadget<F> for ReturnDataCopyGadget<F> {
         cb.stack_pop(size.expr());
 
         // 2. Add lookup constraint in the call context for the returndatacopy field.
+        let last_callee_id = cb.query_cell();
         let return_data_offset = cb.query_cell();
         let return_data_size = cb.query_cell();
+        cb.call_context_lookup(
+            false.expr(),
+            None,
+            CallContextFieldTag::LastCalleeId,
+            last_callee_id.expr(),
+        );
         cb.call_context_lookup(
             false.expr(),
             None,
@@ -112,7 +121,7 @@ impl<F: Field> ExecutionGadget<F> for ReturnDataCopyGadget<F> {
         let copy_rwc_inc = cb.query_cell();
         cb.condition(dst_memory_addr.has_length(), |cb| {
             cb.copy_table_lookup(
-                cb.curr.state.call_id.expr(),
+                last_callee_id.expr(),
                 CopyDataType::Memory.expr(),
                 cb.curr.state.call_id.expr(),
                 CopyDataType::Memory.expr(),
@@ -147,6 +156,7 @@ impl<F: Field> ExecutionGadget<F> for ReturnDataCopyGadget<F> {
 
         Self {
             same_context,
+            last_callee_id,
             return_data_offset,
             return_data_size,
             dst_memory_addr,
@@ -182,8 +192,25 @@ impl<F: Field> ExecutionGadget<F> for ReturnDataCopyGadget<F> {
             ),
         )?;
 
-        let [return_data_offset, return_data_size] =
-            [3, 4].map(|i| block.rws[step.rw_indices[i as usize]].call_context_value());
+        let [last_callee_id, return_data_offset, return_data_size] = [
+            (3, CallContextFieldTag::LastCalleeId),
+            (4, CallContextFieldTag::LastCalleeReturnDataOffset),
+            (5, CallContextFieldTag::LastCalleeReturnDataLength),
+        ]
+        .map(|(i, tag)| {
+            let rw = block.rws[step.rw_indices[i as usize]];
+            assert_eq!(rw.field_tag(), Some(tag as u64));
+            rw.call_context_value()
+        });
+        self.last_callee_id.assign(
+            region,
+            offset,
+            Value::known(
+                last_callee_id
+                    .to_scalar()
+                    .expect("unexpected U256 -> Scalar conversion failure"),
+            ),
+        )?;
         self.return_data_offset.assign(
             region,
             offset,