Windows AArch64: Break out of tracing when no longer making progress

Author: dpaoliello

src/backtrace/dbghelp64.rs

@@ -89,8 +89,9 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
     let mut context = core::mem::zeroed::<MyContext>();
     RtlCaptureContext(&mut context.0);
 
-    // Call `RtlVirtualUnwind` to find the previous stack frame, walking until we hit ip = 0.
-    while context.ip() != 0 {
+    // Call `RtlVirtualUnwind` to find the previous stack frame, walking until we hit ip = 0
+    // or we are no longer making progress.
+    loop {
         // The base address of the module containing the function will be stored here
         // when RtlLookupFunctionEntry returns successfully.
         let mut base = 0;
@@ -114,6 +115,8 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
             break;
         }
 
+        let previous_ip = context.ip();
+        let previous_sp = context.sp();
         let mut handler_data = 0usize;
         let mut establisher_frame = 0;
 
@@ -127,5 +130,9 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
             &mut establisher_frame,
             ptr::null_mut(),
         );
+
+        if context.ip() == 0 || (context.ip() == previous_ip && context.sp() == previous_sp) {
+            break;
+        }
     }
 }