Prevent infinite userspace crash loops.

src/context/context.rs

@@ -203,8 +203,8 @@ pub struct Context {
 pub struct SignalState {
     /// Offset to jump to when a signal is received.
     pub user_handler: NonZeroUsize,
-    /// Offset to jump to when a program fault occurs.
-    pub excp_handler: NonZeroUsize,
+    /// Offset to jump to when a program fault occurs. If None, the context is sigkilled.
+    pub excp_handler: Option<NonZeroUsize>,
 
     /// Signal control pages, shared memory
     pub thread_control: RaiiFrame,

src/context/signal.rs

@@ -48,4 +48,17 @@ pub fn signal_handler() {
     .and_then(|_| ptrace::next_breakpoint().map(|f| f.contains(PTRACE_FLAG_IGNORE)));*/
 }
 pub fn excp_handler(signal: usize) {
+     let Ok(current) = context::current() else {
+         panic!("CPU exception but not inside of context! Trying to switch...");
+     };
+     let mut context = current.write();
+
+     let Some(eh) = context.sig.as_ref().and_then(|s| s.excp_handler) else {
+         context.being_sigkilled = true;
+         context::switch();
+
+         unreachable!();
+     };
+
+     // TODO
 }