Emit consume_all_gas in invalid and bounds checks (#433)

Closes #374

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

Author: xermicus

CHANGELOG.md

@@ -15,6 +15,7 @@ Supported `polkadot-sdk` rev: `unstable2507`
 - Instruct the LLVM backend and linker to `--relax` (may lead to smaller contract code size).
 - Standard JSON mode: Don't forward EVM bytecode related output selections to solc.
 - The supported `polkadot-sdk` release is `unstable2507`.
+- The `INVALID` opcode and OOB memory accesses now consume all remaining gas.
 
 ### Fixed:
 - The missing `STOP` instruction at the end of `code` blocks.

crates/integration/codesize.json

@@ -1,10 +1,10 @@
 {
   "Baseline": 911,
-  "Computation": 2293,
-  "DivisionArithmetics": 14353,
-  "ERC20": 16936,
+  "Computation": 2337,
+  "DivisionArithmetics": 14488,
+  "ERC20": 17041,
   "Events": 1672,
   "FibonacciIterative": 1454,
-  "Flipper": 2083,
-  "SHA1": 7727
+  "Flipper": 2106,
+  "SHA1": 7814
 }

crates/integration/src/tests.rs

@@ -669,3 +669,48 @@ fn sbrk_bounds_checks() {
         "not seeing a trap means the contract did not catch the OOB"
     );
 }
+
+#[test]
+fn invalid_opcode_works() {
+    let code = &build_yul(&[(
+        "invalid.yul",
+        r#"object "Test" {
+    code {
+        invalid()
+    }
+    object "Test_deployed" {
+        code {
+            invalid()
+        }
+    }
+}"#,
+    )])
+    .unwrap()["invalid.yul:Test"];
+
+    let results = Specs {
+        actions: vec![
+            Instantiate {
+                origin: TestAddress::Alice,
+                value: 0,
+                gas_limit: Some(GAS_LIMIT),
+                storage_deposit_limit: None,
+                code: Code::Bytes(code.to_vec()),
+                data: Default::default(),
+                salt: OptionalHex::default(),
+            },
+            VerifyCall(VerifyCallExpectation {
+                success: false,
+                ..Default::default()
+            }),
+        ],
+        differential: false,
+        ..Default::default()
+    }
+    .run();
+
+    let CallResult::Instantiate { result, .. } = results.last().unwrap() else {
+        unreachable!()
+    };
+
+    assert_eq!(result.weight_consumed, GAS_LIMIT);
+}

crates/llvm-context/src/polkavm/context/function/runtime/revive.rs

@@ -51,11 +51,11 @@ impl RuntimeFunction for WordToPointer {
         )?;
 
         let block_continue = context.append_basic_block("offset_pointer_ok");
-        let block_trap = context.append_basic_block("offset_pointer_overflow");
-        context.build_conditional_branch(is_overflow, block_trap, block_continue)?;
+        let block_invalid = context.append_basic_block("offset_pointer_overflow");
+        context.build_conditional_branch(is_overflow, block_invalid, block_continue)?;
 
-        context.set_basic_block(block_trap);
-        context.build_call(context.intrinsics().trap, &[], "invalid_trap");
+        context.set_basic_block(block_invalid);
+        context.build_runtime_call(revive_runtime_api::polkavm_imports::INVALID, &[]);
         context.build_unreachable();
 
         context.set_basic_block(block_continue);

crates/llvm-context/src/polkavm/evm/return.rs

@@ -52,12 +52,14 @@ pub fn stop(context: &mut Context) -> anyhow::Result<()> {
 /// Translates the `invalid` instruction.
 /// Burns all gas using an out-of-bounds memory store, causing a panic.
 pub fn invalid(context: &mut Context) -> anyhow::Result<()> {
-    crate::polkavm::evm::memory::store(
-        context,
-        context.word_type().const_all_ones(),
-        context.word_const(0),
-    )?;
-    context.build_call(context.intrinsics().trap, &[], "invalid_trap");
+    let invalid_block = context.append_basic_block("explicit_invalid");
+    context.build_unconditional_branch(invalid_block);
+    context.set_basic_block(invalid_block);
+    context.build_runtime_call(revive_runtime_api::polkavm_imports::INVALID, &[]);
+    context.build_unreachable();
+
+    context.set_basic_block(context.append_basic_block("dead_code"));
+
     Ok(())
 }
 

crates/runtime-api/src/polkavm_imports.c

@@ -69,6 +69,8 @@ POLKAVM_IMPORT(uint64_t, code_size, uint32_t)
 
 POLKAVM_IMPORT(void, code_hash, uint32_t, uint32_t)
 
+POLKAVM_IMPORT(void, consume_all_gas)
+
 POLKAVM_IMPORT(uint32_t, delegate_call, uint64_t, uint64_t, uint64_t, uint32_t, uint64_t, uint64_t)
 
 POLKAVM_IMPORT(void, deposit_event, uint32_t, uint32_t, uint32_t, uint32_t)

crates/runtime-api/src/polkavm_imports.rs

@@ -48,6 +48,8 @@ pub static HASH_KECCAK_256: &str = "hash_keccak_256";
 
 pub static INSTANTIATE: &str = "instantiate";
 
+pub static INVALID: &str = "consume_all_gas";
+
 pub static NOW: &str = "now";
 
 pub static ORIGIN: &str = "origin";
@@ -70,7 +72,7 @@ pub static VALUE_TRANSFERRED: &str = "value_transferred";
 
 /// All imported runtime API symbols.
 /// Useful for configuring common attributes and linkage.
-pub static IMPORTS: [&str; 33] = [
+pub static IMPORTS: [&str; 34] = [
     ADDRESS,
     BALANCE,
     BALANCE_OF,
@@ -94,6 +96,7 @@ pub static IMPORTS: [&str; 33] = [
     GET_STORAGE,
     HASH_KECCAK_256,
     INSTANTIATE,
+    INVALID,
     NOW,
     ORIGIN,
     REF_TIME_LEFT,