Prevent crashes during exit due to deregistering frames on exit (v2)

lib/compiler/src/engine/artifact.rs

@@ -1,9 +1,13 @@
 //! Define `Artifact`, based on `ArtifactBuild`
 //! to allow compiling and instantiating to be done as separate steps.
 
-use std::sync::{
-    Arc,
-    atomic::{AtomicUsize, Ordering::SeqCst},
+use std::{
+    sync::{
+        Arc,
+        atomic::{AtomicUsize, Ordering::SeqCst},
+    },
+    thread::sleep,
+    time::Duration,
 };
 
 #[cfg(feature = "compiler")]
@@ -128,6 +132,7 @@ impl Artifact {
         tunables: &dyn Tunables,
         hash_algorithm: Option<HashAlgorithm>,
     ) -> Result<Self, CompileError> {
+        let data = Box::leak(Box::from(data));
         let mut inner_engine = engine.inner_mut();
         let environ = ModuleEnvironment::new();
         let translation = environ.translate(data).map_err(CompileError::Wasm)?;
@@ -1298,3 +1303,9 @@ impl Artifact {
         }
     }
 }
+
+impl Drop for Artifact {
+    fn drop(&mut self) {
+        eprintln!("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Dropping Artifact");
+    }
+}

lib/compiler/src/engine/unwind/systemv.rs

@@ -3,7 +3,11 @@
 
 //! Module for System V ABI unwind registry.
 
-use core::sync::atomic::{AtomicUsize, Ordering::Relaxed};
+use core::sync::atomic::{
+    AtomicBool, AtomicUsize,
+    Ordering::{self, Relaxed},
+};
+use std::sync::Once;
 
 use crate::types::unwind::CompiledFunctionUnwindInfoReference;
 
@@ -14,7 +18,6 @@ pub struct UnwindRegistry {
     #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
     compact_unwind_mgr: compact_unwind::CompactUnwindManager,
 }
-
 unsafe extern "C" {
     // libunwind import
     fn __register_frame(fde: *const u8);
@@ -145,6 +148,12 @@ impl UnwindRegistry {
 
     #[allow(clippy::cast_ptr_alignment)]
     unsafe fn register_frames(&mut self, eh_frame: &[u8]) {
+        // Register atexit handler that will tell us if exit has been called.
+        static INIT: Once = Once::new();
+        INIT.call_once(|| unsafe {
+            libc::atexit(atexit_handler);
+        });
+
         #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
         {
             // Special call for macOS on aarch64 to register the `.eh_frame` section.
@@ -243,8 +252,15 @@ impl UnwindRegistry {
     }
 }
 
+static EXIT_CALLED: AtomicBool = AtomicBool::new(false);
+
+extern "C" fn atexit_handler() {
+    EXIT_CALLED.store(true, Ordering::SeqCst);
+}
+
 impl Drop for UnwindRegistry {
     fn drop(&mut self) {
+        eprintln!("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Dropping UnwindRegistry");
         if self.published {
             unsafe {
                 // libgcc stores the frame entries as a linked list in decreasing sort order
@@ -264,6 +280,12 @@ impl Drop for UnwindRegistry {
 
                     #[cfg(not(all(target_os = "macos", target_arch = "aarch64")))]
                     {
+                        // We don't want to deregister frames in UnwindRegistry::Drop as that could be called during
+                        // program shutdown and can collide with release_registered_frames and lead to
+                        // crashes.
+                        if EXIT_CALLED.load(Ordering::SeqCst) {
+                            return;
+                        }
                         __deregister_frame(*registration as *const _);
                     }
                 }