From 73c0df18e22297f61342a0ee65bc565cabe96a86 Mon Sep 17 00:00:00 2001
From: mohanson <mohanson@outlook.com>
Date: Fri, 17 May 2024 13:49:14 +0800
Subject: [PATCH] Set an executable page at the top of the stack

---
 Cargo.toml              |  1 +
 src/machine/mod.rs      | 10 ++++++++++
 tests/test_asm.rs       |  1 +
 tests/test_dy_memory.rs |  1 +
 tests/test_resume.rs    |  1 +
 tests/test_resume2.rs   |  1 +
 6 files changed, 15 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index f1eea408..6046d70d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,6 +21,7 @@ enable-chaos-mode-by-default = ["ckb-vm-definitions/enable-chaos-mode-by-default
 # Disable slow tests to run miri on CI
 miri-ci = []
 pprof = []
+heap-stack-overlap-detect = []
 
 [dependencies]
 byteorder = "1"
diff --git a/src/machine/mod.rs b/src/machine/mod.rs
index be231177..5bf3e459 100644
--- a/src/machine/mod.rs
+++ b/src/machine/mod.rs
@@ -175,6 +175,16 @@ pub trait SupportMachine: CoreMachine {
         stack_start: u64,
         stack_size: u64,
     ) -> Result<u64, Error> {
+        #[cfg(feature = "heap-stack-overlap-detect")]
+        {
+            use super::memory::FLAG_EXECUTABLE;
+            use super::RISCV_PAGESIZE;
+            // When the heap or stack attempts to write data to this area,
+            // ckb-vm will return an error due to wxorx rules.
+            self.memory_mut()
+                .set_flag(stack_start / RISCV_PAGESIZE as u64, FLAG_EXECUTABLE)?;
+        }
+
         // When we re-ordered the sections of a program, writing data in high memory
         // will cause unnecessary changes. At the same time, for ckb, argc is always 0
         // and the memory is initialized to 0, so memory writing can be safely skipped.
diff --git a/tests/test_asm.rs b/tests/test_asm.rs
index 1fe93313..2ca5a28e 100644
--- a/tests/test_asm.rs
+++ b/tests/test_asm.rs
@@ -266,6 +266,7 @@ pub fn test_asm_wxorx_crash_64() {
     );
 }
 
+#[cfg(not(feature = "heap-stack-overlap-detect"))]
 #[test]
 pub fn test_asm_alloc_many() {
     let buffer = fs::read("tests/programs/alloc_many").unwrap().into();
diff --git a/tests/test_dy_memory.rs b/tests/test_dy_memory.rs
index d5b8c6d4..49372528 100644
--- a/tests/test_dy_memory.rs
+++ b/tests/test_dy_memory.rs
@@ -42,6 +42,7 @@ fn run_memory_suc(memory_size: usize, bin_path: String, bin_name: String) {
     }
 }
 
+#[cfg(not(feature = "heap-stack-overlap-detect"))]
 #[test]
 fn test_dy_memory() {
     run_memory_suc(
diff --git a/tests/test_resume.rs b/tests/test_resume.rs
index f0200195..6efc2fde 100644
--- a/tests/test_resume.rs
+++ b/tests/test_resume.rs
@@ -1,4 +1,5 @@
 #![cfg(has_asm)]
+#![cfg(not(feature = "heap-stack-overlap-detect"))]
 pub mod machine_build;
 use bytes::Bytes;
 use ckb_vm::cost_model::constant_cycles;
diff --git a/tests/test_resume2.rs b/tests/test_resume2.rs
index d3360f2f..3ded6bda 100644
--- a/tests/test_resume2.rs
+++ b/tests/test_resume2.rs
@@ -1,4 +1,5 @@
 #![cfg(has_asm)]
+#![cfg(not(feature = "heap-stack-overlap-detect"))]
 pub mod machine_build;
 use bytes::Bytes;
 use ckb_vm::cost_model::constant_cycles;