Minor fixes to returndata and create (#1043)

* Fix returndata

* Add AccountCreated event

* returndatacopy_afterFailing_create.json passes

* Fix

evm/src/cpu/kernel/aggregator.rs

@@ -145,6 +145,7 @@ pub(crate) fn combined_kernel() -> Kernel {
         include_str!("asm/journal/storage_loaded.asm"),
         include_str!("asm/journal/code_change.asm"),
         include_str!("asm/journal/refund.asm"),
+        include_str!("asm/journal/account_created.asm"),
         include_str!("asm/journal/revert.asm"),
         include_str!("asm/transactions/common_decoding.asm"),
         include_str!("asm/transactions/router.asm"),

evm/src/cpu/kernel/asm/core/call.asm

@@ -230,6 +230,8 @@ call_insufficient_balance:
     %stack (new_ctx, kexit_info, callgas, address, value, args_offset, args_size, ret_offset, ret_size) ->
         (callgas, kexit_info, 0)
     %shl_const(192) SWAP1 SUB
+    // stack: kexit_info', 0
+    %mstore_context_metadata(@CTX_METADATA_RETURNDATA_SIZE, 0)
     EXIT_KERNEL
 
 // Set @CTX_METADATA_STATIC to 1. Note that there is no corresponding set_static_false routine

evm/src/cpu/kernel/asm/core/create.asm

@@ -70,11 +70,15 @@ global create_common:
     // stack: address, value, code_offset, code_len, kexit_info
     DUP1 %insert_accessed_addresses_no_return
 
+    // TODO: Check call stack depth.
+    // TODO: Check balance of caller first.
     // Increment the sender's nonce.
     %address
     %increment_nonce
     // stack: address, value, code_offset, code_len, kexit_info
 
+    %checkpoint
+
     // Deduct value from the caller.
     DUP2
     %address
@@ -133,13 +137,15 @@ run_constructor:
     // (Old context) stack: new_ctx, address, kexit_info
 
 after_constructor:
+    // stack: success, leftover_gas, new_ctx, address, kexit_info
+    DUP1 ISZERO %jumpi(after_constructor_failed)
+    %pop_checkpoint
+
     // stack: success, leftover_gas, new_ctx, address, kexit_info
     SWAP2
     // stack: new_ctx, leftover_gas, success, address, kexit_info
     POP
 
-
-    // TODO: Skip blocks below if success is false.
     // EIP-3541: Reject new contract code starting with the 0xEF byte
     PUSH 0 %mload_current(@SEGMENT_RETURNDATA) %eq_const(0xEF) %jumpi(fault_exception)
 
@@ -168,6 +174,7 @@ after_constructor:
     // Set the return data size to 0.
     %mstore_context_metadata(@CTX_METADATA_RETURNDATA_SIZE, 0)
 
+after_constructor_contd:
     // stack: leftover_gas, success, address, kexit_info
     %shl_const(192)
     // stack: leftover_gas << 192, success, address, kexit_info
@@ -181,6 +188,11 @@ after_constructor:
     // stack: kexit_info, address_if_success
     EXIT_KERNEL
 
+after_constructor_failed:
+    %revert_checkpoint
+    %stack (success, leftover_gas, new_ctx, address, kexit_info) -> (leftover_gas, success, address, kexit_info)
+    %jump(after_constructor_contd)
+
 %macro set_codehash
     %stack (addr, codehash) -> (addr, codehash, %%after)
     %jump(set_codehash)

evm/src/cpu/kernel/asm/core/create_contract_account.asm

@@ -3,6 +3,7 @@
 // Post stack: status
 %macro create_contract_account
     // stack: value, address
+    DUP2 %journal_add_account_created
     DUP2 %insert_touched_addresses
     DUP2 %mpt_read_state_trie
     // stack: existing_account_ptr, value, address

evm/src/cpu/kernel/asm/core/terminate.asm

@@ -139,7 +139,7 @@ global sys_revert:
 sys_revert_finish:
     %leftover_gas
     // stack: leftover_gas
-    // TODO: Revert state changes.
+    %revert_checkpoint
     PUSH 0 // success
     %jump(terminate_common)
 

evm/src/cpu/kernel/asm/journal/account_created.asm

@@ -0,0 +1,13 @@
+// struct AccountCreated { address }
+
+%macro journal_add_account_created
+    %journal_add_1(@JOURNAL_ENTRY_ACCOUNT_CREATED)
+%endmacro
+
+global revert_account_created:
+    // stack: entry_type, ptr, retdest
+    POP
+    %journal_load_1
+    // stack: address, retdest
+    %delete_account
+    JUMP

evm/src/cpu/kernel/asm/journal/revert.asm

@@ -15,6 +15,7 @@
     DUP1 %eq_const(@JOURNAL_ENTRY_STORAGE_LOADED)    %jumpi(revert_storage_loaded)
     DUP1 %eq_const(@JOURNAL_ENTRY_CODE_CHANGE)       %jumpi(revert_code_change)
     DUP1 %eq_const(@JOURNAL_ENTRY_REFUND)            %jumpi(revert_refund)
+    DUP1 %eq_const(@JOURNAL_ENTRY_ACCOUNT_CREATED)   %jumpi(revert_account_created)
     PANIC // This should never happen.
 %%after:
     // stack: journal_size-1

evm/src/cpu/kernel/asm/memory/syscalls.asm

@@ -126,7 +126,7 @@ sys_calldataload_after_mload_packing:
     PUSH @GAS_VERYLOW
     DUP5
     // stack: size, Gverylow, kexit_info, dest_offset, offset, size
-    ISZERO %jumpi(%%wcopy_empty)
+    ISZERO %jumpi(wcopy_empty)
     // stack: Gverylow, kexit_info, dest_offset, offset, size
     DUP5 %num_bytes_to_num_words %mul_const(@GAS_COPY) ADD %charge_gas
 
@@ -140,31 +140,31 @@ sys_calldataload_after_mload_packing:
     // stack: total_size, kexit_info, dest_offset, offset, size
     DUP4
     // stack: offset, total_size, kexit_info, dest_offset, offset, size
-    GT %jumpi(%%wcopy_large_offset)
+    GT %jumpi(wcopy_large_offset)
 
     GET_CONTEXT
     %stack (context, kexit_info, dest_offset, offset, size) ->
-        (context, @SEGMENT_MAIN_MEMORY, dest_offset, context, $segment, offset, size, %%after, kexit_info)
+        (context, @SEGMENT_MAIN_MEMORY, dest_offset, context, $segment, offset, size, wcopy_after, kexit_info)
     %jump(memcpy)
+%endmacro
 
-%%after:
-    // stack: kexit_info
-    EXIT_KERNEL
-
-%%wcopy_empty:
+wcopy_empty:
     // stack: Gverylow, kexit_info, dest_offset, offset, size
     %charge_gas
     %stack (kexit_info, dest_offset, offset, size) -> (kexit_info)
     EXIT_KERNEL
 
-%%wcopy_large_offset:
+wcopy_large_offset:
     // offset is larger than the size of the {CALLDATA,CODE,RETURNDATA}. So we just have to write zeros.
     // stack: kexit_info, dest_offset, offset, size
     GET_CONTEXT
     %stack (context, kexit_info, dest_offset, offset, size) ->
-        (context, @SEGMENT_MAIN_MEMORY, dest_offset, 0, size, %%after, kexit_info)
+        (context, @SEGMENT_MAIN_MEMORY, dest_offset, 0, size, wcopy_after, kexit_info)
     %jump(memset)
-%endmacro
+
+wcopy_after:
+    // stack: kexit_info
+    EXIT_KERNEL
 
 global sys_calldatacopy:
     %wcopy(@SEGMENT_CALLDATA, @CTX_METADATA_CALLDATA_SIZE)
@@ -172,5 +172,32 @@ global sys_calldatacopy:
 global sys_codecopy:
     %wcopy(@SEGMENT_CODE, @CTX_METADATA_CODE_SIZE)
 
+// Same as %wcopy but with overflow checks.
 global sys_returndatacopy:
-    %wcopy(@SEGMENT_RETURNDATA, @CTX_METADATA_RETURNDATA_SIZE)
+    // stack: kexit_info, dest_offset, offset, size
+    PUSH @GAS_VERYLOW
+    DUP5
+    // stack: size, Gverylow, kexit_info, dest_offset, offset, size
+    ISZERO %jumpi(wcopy_empty)
+    // stack: Gverylow, kexit_info, dest_offset, offset, size
+    DUP5 %num_bytes_to_num_words %mul_const(@GAS_COPY) ADD %charge_gas
+
+    %stack (kexit_info, dest_offset, offset, size) -> (dest_offset, size, kexit_info, dest_offset, offset, size)
+    %add_or_fault
+    // stack: expanded_num_bytes, kexit_info, dest_offset, offset, size, kexit_info
+    DUP1 %ensure_reasonable_offset
+    %update_mem_bytes
+    // stack: kexit_info, dest_offset, offset, size, kexit_info
+    DUP4 DUP4 %add_or_fault // Overflow check
+    %mload_context_metadata(@CTX_METADATA_RETURNDATA_SIZE) LT %jumpi(fault_exception) // Data len check
+
+    %mload_context_metadata(@CTX_METADATA_RETURNDATA_SIZE)
+    // stack: total_size, kexit_info, dest_offset, offset, size
+    DUP4
+    // stack: offset, total_size, kexit_info, dest_offset, offset, size
+    GT %jumpi(wcopy_large_offset)
+
+    GET_CONTEXT
+    %stack (context, kexit_info, dest_offset, offset, size) ->
+        (context, @SEGMENT_MAIN_MEMORY, dest_offset, context, @SEGMENT_RETURNDATA, offset, size, wcopy_after, kexit_info)
+    %jump(memcpy)

evm/src/cpu/kernel/constants/journal_entry.rs

@@ -10,10 +10,11 @@ pub(crate) enum JournalEntry {
     StorageLoaded = 6,
     CodeChange = 7,
     Refund = 8,
+    AccountCreated = 9,
 }
 
 impl JournalEntry {
-    pub(crate) const COUNT: usize = 9;
+    pub(crate) const COUNT: usize = 10;
 
     pub(crate) fn all() -> [Self; Self::COUNT] {
         [
@@ -26,6 +27,7 @@ impl JournalEntry {
             Self::StorageLoaded,
             Self::CodeChange,
             Self::Refund,
+            Self::AccountCreated,
         ]
     }
 
@@ -41,6 +43,7 @@ impl JournalEntry {
             Self::StorageLoaded => "JOURNAL_ENTRY_STORAGE_LOADED",
             Self::CodeChange => "JOURNAL_ENTRY_CODE_CHANGE",
             Self::Refund => "JOURNAL_ENTRY_REFUND",
+            Self::AccountCreated => "JOURNAL_ENTRY_ACCOUNT_CREATED",
         }
     }
 }