check cp->killed before returning to user from a timer interrupt

15ce79de · kolya · 00ce31c0 · 15ce79de
--- a/trap.c
+++ b/trap.c
@@ -91,4 +91,8 @@ trap(struct trapframe *tf)
  // If interrupts were on while locks held, would need to check nlock.
  if(cp && cp->state == RUNNING && tf->trapno == IRQ_OFFSET+IRQ_TIMER)
    yield();
+
+  // Check if the process has been killed since we yielded
+  if(cp && cp->killed && (tf->cs&3) == DPL_USER)
+    exit();
 }