small fixes and add locks

1 files changed, 6 insertions, 11 deletions

diff --git a/kernel/vm/shadow.c b/kernel/vm/shadow.c
index 4166597..e0a8674 100644
--- a/kernel/vm/shadow.c
+++ b/kernel/vm/shadow.c
@@ -128,10 +128,10 @@ void shadow_collapse(mobj_t *o)
 
     dbg(DBG_PRINT, "shadow_collapse: refcount bottom: %d\n", so->bottom_mobj->mo_refcount);
 
-    while (shadowed->mo_type == MOBJ_SHADOW)
+    while (shadowed && shadowed->mo_type == MOBJ_SHADOW)
     {
-        mobj_shadow_t *so_shadowed = MOBJ_TO_SO(shadowed);
-        mobj_t *shadowed_shadowed = so_shadowed->shadowed;
+        // mobj_shadow_t *so_shadowed = MOBJ_TO_SO(shadowed);
+        mobj_t *shadowed_shadowed = MOBJ_TO_SO(shadowed)->shadowed;
 
         // if the refcount is not 1, then we can't collapse
         if (shadowed_shadowed->mo_refcount != 1)
@@ -157,19 +157,14 @@ void shadow_collapse(mobj_t *o)
                 pframe_release(&pf_shadow);
             }
         }
-        mobj_unlock(shadowed_shadowed);
-
-        if (shadowed_shadowed->mo_type != MOBJ_SHADOW)
-        {
-            // put the shadowed object
-            mobj_put(&shadowed);
-            break;
-        }
 
         // get the pointer to the shadowed object
         mobj_shadow_t *so_shadowed_shadowed = MOBJ_TO_SO(shadowed_shadowed);
         so->shadowed = shadowed_shadowed;
+
+        mobj_lock(so->shadowed);
         mobj_ref(so->shadowed);
+        mobj_unlock(so->shadowed);
 
         // put the shadowed object
         mobj_put(&shadowed);