From 4b91fa68c0533450d0f402958fd8e8969f3ab8ff Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Sun, 29 Aug 2004 06:54:14 +0000
Subject: [PATCH] Fix wild bit in interrupt gate addresses.  Make some things
 static.

---
 src/threads/interrupt.c | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/src/threads/interrupt.c b/src/threads/interrupt.c
index 9058775..0d7b119 100644
--- a/src/threads/interrupt.c
+++ b/src/threads/interrupt.c
@@ -102,8 +102,8 @@ static const char *intr_names[INTR_CNT];
 
 void intr_handler (struct intr_frame *args);
 
-bool intr_in_progress;
-bool yield_on_return;
+static bool intr_in_progress;
+static bool yield_on_return;
 
 const char *
 intr_name (int vec) 
@@ -159,25 +159,29 @@ intr_handler_func intr_panic NO_RETURN;
 intr_handler_func intr_kill NO_RETURN;
 
 static uint64_t
-make_intr_gate (void (*target) (void),
-                int dpl)
+make_gate (void (*target) (void), int dpl, enum seg_type type)
 {
   uint32_t offset = (uint32_t) target;
   uint32_t e0 = ((offset & 0xffff)            /* Offset 15:0. */
                  | (SEL_KCSEG << 16));        /* Target code segment. */
   uint32_t e1 = ((offset & 0xffff0000)        /* Offset 31:16. */
                  | (1 << 15)                  /* Present. */
-                 | (dpl << 13)                /* Descriptor privilege. */
+                 | ((uint32_t) dpl << 13)     /* Descriptor privilege. */
                  | (SYS_SYSTEM << 12)         /* System. */
-                 | (TYPE_INT_32 << 8));       /* 32-bit interrupt gate. */
+                 | ((uint32_t) type << 8));   /* Gate type. */
   return e0 | ((uint64_t) e1 << 32);
 }
 
 static uint64_t
-make_trap_gate (void (*target) (void),
-                int dpl)
+make_intr_gate (void (*target) (void), int dpl)
 {
-  return make_intr_gate (target, dpl) | (1 << 8);
+  return make_gate (target, dpl, TYPE_INT_32);
+}
+
+static uint64_t
+make_trap_gate (void (*target) (void), int dpl)
+{
+  return make_gate (target, dpl, TYPE_TRAP_32);
 }
 
 /* We don't support nested interrupts generated by external
@@ -276,13 +280,14 @@ intr_kill (struct intr_frame *f)
               thread_current (), f->vec_no, intr_name (f->vec_no));
       thread_exit (); 
 
-    default:
-      panic ("Interrupt %#04x (%s) in unknown segment %04x",
-             f->vec_no, intr_name (f->vec_no), f->cs);
-
     case SEL_KCSEG:
-      printk ("intr_kill -> panic %d\n", f->vec_no);
+      printk ("Kernel bug - unexpected interrupt in kernel context\n");
       intr_panic (f);
+
+    default:
+      printk ("Interrupt %#04x (%s) in unknown segment %04x\n",
+             f->vec_no, intr_name (f->vec_no), f->cs);
+      thread_exit ();
     }
 }
 
-- 
2.30.2