Changeset 6a10709 in rtems

Timestamp:

03/31/99 22:33:14 (25 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, 5, master

Children:

f470989

Parents:

5c95996

Message:

Patch from Chris Johns <ccj@…>:

joel@… wrote:

Chris,

sp09 fails on the rtems_port_delete(0) call. This is supposed to give an
invalid id error. I can't find any changes other than the unlimited
objects patch which would have tripped this so would appreciate it if you
could look into it. I suspect that this is a side-effect of the unlimited
objects patch.

It is me.

Basically, there are 0 ports configured in sp09. The test ends up
dereferecing NULL in local_table[0] and comes up with a non-NULL invalid
pointer.

The issue is not actually allocating a local_table for an object type
which has a maximum value of 0. I cannot remember the exact workings of
the id values and the local_table. I might have changed the nature from
the pre-unlimited change. As you know the id's are an interesting game
where performance is most important.

I know the problem could be solved by adding a check for index == 0. But
I hate to slow this path down. I think you may have changed the way the
object information structure gets initialized.

---

This change lets the unlimited and sp09 tests run on the posix Linux
BSP. A static local variable `null_local_table' has been added. This
variable is always set to NULL. The `local_table' element of the
information structure is set to point to this variable earily in the
initialisation. If the object type has more than 0 elements the
`local_table' element is updated. All object types which have 0 elements
reference `null_local_table'. This change fixes the problem sp09 found
yet does not add any extra processing to the critical
`_Objects_Get_local_object' function.

---

Files:

• c/src/exec/score/src/object.c (modified) (5 diffs)
• cpukit/score/src/object.c (modified) (5 diffs)

c/src/exec/score/src/object.c

@@ -96 +96 @@
 
   minimum_index = _Objects_Get_index( information->minimum_id );
-  index_base = minimum_index;
-  block = 0;
-  
-  if (information->maximum < minimum_index)
+  index_base    = minimum_index;
+  block         = 0;
+  
+  if ( information->maximum < minimum_index )
     block_count = 0;
   else {
@@ -440 +440 @@
 )
 {
+  static Objects_Control *null_local_table = NULL;
+  
   unsigned32       minimum_index;
   unsigned32       index;
@@ -472 +474 @@
 
   information->auto_extend = (maximum & OBJECTS_UNLIMITED_OBJECTS) ? TRUE : FALSE;
-  maximum &= ~OBJECTS_UNLIMITED_OBJECTS;
+  maximum                 &= ~OBJECTS_UNLIMITED_OBJECTS;
   
   /*
@@ -479 +481 @@
 
   information->allocation_size = maximum;
+
+  /*
+   *  Provide a null local table entry for the case of any empty table.
+   */
+
+  information->local_table = &null_local_table;
 
   /*
@@ -496 +504 @@
   name_length = maximum_name_length;
 
-  if (name_length & (OBJECTS_NAME_ALIGNMENT-1))
+  if ( name_length & (OBJECTS_NAME_ALIGNMENT-1) )
     name_length = (name_length + OBJECTS_NAME_ALIGNMENT) & 
                   ~(OBJECTS_NAME_ALIGNMENT-1);

cpukit/score/src/object.c

@@ -96 +96 @@
 
   minimum_index = _Objects_Get_index( information->minimum_id );
-  index_base = minimum_index;
-  block = 0;
-  
-  if (information->maximum < minimum_index)
+  index_base    = minimum_index;
+  block         = 0;
+  
+  if ( information->maximum < minimum_index )
     block_count = 0;
   else {
@@ -440 +440 @@
 )
 {
+  static Objects_Control *null_local_table = NULL;
+  
   unsigned32       minimum_index;
   unsigned32       index;
@@ -472 +474 @@
 
   information->auto_extend = (maximum & OBJECTS_UNLIMITED_OBJECTS) ? TRUE : FALSE;
-  maximum &= ~OBJECTS_UNLIMITED_OBJECTS;
+  maximum                 &= ~OBJECTS_UNLIMITED_OBJECTS;
   
   /*
@@ -479 +481 @@
 
   information->allocation_size = maximum;
+
+  /*
+   *  Provide a null local table entry for the case of any empty table.
+   */
+
+  information->local_table = &null_local_table;
 
   /*
@@ -496 +504 @@
   name_length = maximum_name_length;
 
-  if (name_length & (OBJECTS_NAME_ALIGNMENT-1))
+  if ( name_length & (OBJECTS_NAME_ALIGNMENT-1) )
     name_length = (name_length + OBJECTS_NAME_ALIGNMENT) & 
                   ~(OBJECTS_NAME_ALIGNMENT-1);