X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Finterrupt.c;h=075962f5081cc09b4295ff87a35b8d9f057148e3;hb=03f3426d4da28916900a7b811e72b862c5411d0d;hp=6d3f6bb2e269a909de1cce3cdc8ea9d14ae888b5;hpb=f415a37905c57f61b444806bf84f5405184452aa;p=pintos-anon

diff --git a/src/threads/interrupt.c b/src/threads/interrupt.c
index 6d3f6bb..075962f 100644
--- a/src/threads/interrupt.c
+++ b/src/threads/interrupt.c
@@ -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;
 }
@@ -118,7 +118,7 @@ intr_init (void)
      See [IA32-v2a] "LIDT" and [IA32-v3a] 5.10 "Interrupt
      Descriptor Table (IDT)". */
   idtr_operand = make_idtr_operand (sizeof idt - 1, idt);
-  asm volatile ("lidt %0" :: "m" (idtr_operand));
+  asm volatile ("lidt %0" : : "m" (idtr_operand));
 
   /* Initialize intr_names. */
   for (i = 0; i < INTR_CNT; i++)
@@ -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)