Correctly initialize the esp0 pointer in the TSS for the initial

[pintos-anon] / src / userprog / tss.c

diff --git a/src/userprog/tss.c b/src/userprog/tss.c
index f103823bb869d765b9fb5e28e1a5bd4d8090f29f..569e8d183336657aa82e04f882cd9ebd80c65b0d 100644 (file)
--- a/src/userprog/tss.c
+++ b/src/userprog/tss.c
@@ -82,9 +82,9 @@ tss_init (void)
      few fields of it are ever referenced, and those are the only
      ones we initialize. */
   tss = palloc_get_page (PAL_ASSERT | PAL_ZERO);
-  tss->esp0 = ptov(0x20000);
   tss->ss0 = SEL_KDSEG;
   tss->bitmap = 0xdfff;
+  tss_update ();
 }
 
 /* Returns the kernel TSS. */
@@ -95,10 +95,11 @@ tss_get (void)
   return tss;
 }
 
-/* Sets the ring 0 stack pointer in the TSS to ESP0. */
+/* Sets the ring 0 stack pointer in the TSS to point to the end
+   of the thread stack. */
 void
-tss_set_esp0 (uint8_t *esp0) 
+tss_update (void) 
 {
   ASSERT (tss != NULL);
-  tss->esp0 = esp0;
+  tss->esp0 = (uint8_t *) thread_current () + PGSIZE;
 }