Add memory clobbers to several asm statements,

[pintos-anon] / src / threads / interrupt.c

diff --git a/src/threads/interrupt.c b/src/threads/interrupt.c
index 29aea870ba547e4e67a5534c36c2f498e82c03e6..3e37213876768fcded5b4ad671636671231e3ea4 100644 (file)
--- a/src/threads/interrupt.c
+++ b/src/threads/interrupt.c
@@ -6,8 +6,8 @@
 #include "threads/flags.h"
 #include "threads/intr-stubs.h"
 #include "threads/io.h"
-#include "threads/mmu.h"
 #include "threads/thread.h"
+#include "threads/vaddr.h"
 #include "devices/timer.h"
 
 /* Number of x86 interrupts. */
@@ -95,7 +95,7 @@ intr_disable (void)
   /* Disable interrupts by clearing the interrupt flag.
      See [IA32-v2b] "CLI" and [IA32-v3a] 5.8.1 "Masking Maskable
      Hardware Interrupts". */
-  asm volatile ("cli");
+  asm volatile ("cli" : : : "memory");
 
   return old_level;
 }
@@ -355,16 +355,23 @@ intr_handler (struct intr_frame *frame)
       yield_on_return = false;
     }
 
-  /* Invoke the interrupt's handler.
-     If there is no handler, invoke the unexpected interrupt
-     handler. */
+  /* Invoke the interrupt's handler. */
   handler = intr_handlers[frame->vec_no];
-  if (handler == NULL)
+  if (handler != NULL)
+    handler (frame);
+  else if (frame->vec_no == 0x27 || frame->vec_no == 0x2f)
     {
+      /* There is no handler, but this interrupt can trigger
+         spuriously due to a hardware fault or hardware race
+         condition.  Ignore it. */
+    }
+  else 
+    {
+      /* No handler and not spurious.  Invoke the unexpected
+         interrupt handler. */
       intr_dump_frame (frame);
-      PANIC ("Unexpected interrupt");
+      PANIC ("Unexpected interrupt"); 
     }
-  handler (frame);
 
   /* Complete the processing of an external interrupt. */
   if (external)