Interrupt signal propagation

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## **[Unreleased]**
+- [#1496](https://github.com/wasmerio/wasmer/pull/1496) Propagate interrupt signal(SIGINT) to previous signal handler
 
 ## 0.17.1 - 2020-06-24
 

lib/runtime-core/src/fault.rs

@@ -265,6 +265,23 @@ pub fn allocate_and_run<R, F: FnOnce() -> R>(size: usize, f: F) -> R {
     }
 }
 
+unsafe fn call_signal_handler(
+    sig: Signal,
+    siginfo: *mut siginfo_t,
+    ucontext: *mut c_void,
+    sig_action: &SigAction,
+) {
+    match sig_action.handler() {
+        SigHandler::SigDfl => {
+            sigaction(sig, sig_action).unwrap();
+            return;
+        }
+        SigHandler::SigIgn => return,
+        SigHandler::Handler(handler) => handler(sig as _),
+        SigHandler::SigAction(handler) => handler(sig as _, siginfo as _, ucontext),
+    }
+}
+
 extern "C" fn signal_trap_handler(
     signum: ::nix::libc::c_int,
     siginfo: *mut siginfo_t,
@@ -439,17 +456,33 @@ extern "C" fn signal_trap_handler(
     }
 }
 
+static mut SIGINT_SYS_HANDLER: Option<SigAction> = None;
+
 extern "C" fn sigint_handler(
     _signum: ::nix::libc::c_int,
     _siginfo: *mut siginfo_t,
     _ucontext: *mut c_void,
 ) {
-    if INTERRUPT_SIGNAL_DELIVERED.swap(true, Ordering::SeqCst) {
-        eprintln!("Got another SIGINT before trap is triggered on WebAssembly side, aborting");
-        process::abort();
-    }
     unsafe {
-        set_wasm_interrupt();
+        match SIGINT_SYS_HANDLER {
+            Some(prev_handler) => {
+                if !INTERRUPT_SIGNAL_DELIVERED.swap(true, Ordering::SeqCst) {
+                    set_wasm_interrupt();
+                }
+
+                call_signal_handler(SIGINT, _siginfo, _ucontext, &prev_handler);
+            }
+            None => {
+                if !INTERRUPT_SIGNAL_DELIVERED.swap(true, Ordering::SeqCst) {
+                    eprintln!(
+                        "Got another SIGINT before trap is triggered on WebAssembly side, aborting"
+                    );
+                    process::abort();
+                }
+
+                set_wasm_interrupt();
+            }
+        }
     }
 }
 
@@ -479,7 +512,7 @@ unsafe fn install_sighandler() {
         SaFlags::SA_ONSTACK,
         SigSet::empty(),
     );
-    sigaction(SIGINT, &sa_interrupt).unwrap();
+    SIGINT_SYS_HANDLER = Some(sigaction(SIGINT, &sa_interrupt).unwrap());
 }
 
 #[derive(Debug, Clone)]