exit() seems to work, but needs more testing.

- Added cleaner allocation of shm addresses by moving the allocation to do_mmap().
- Added deletion routine for all objects: shadow, vm_file of type vfs_file, shm_file, etc.
  - Need to make sure objects get deleted properly after exit().
- Currently we allow a single, unique virtual address for each shm segment.

tasks/mm0/include/shm.h

@@ -41,9 +41,10 @@ struct shm_descriptor {
 #define SHM_SHMMAX			10
 
 /* Initialises shared memory bookkeeping structures */
-void shm_init();
+int shm_pool_init();
 
 void *shmat_shmget_internal(struct tcb *task, key_t key, void *shmaddr);
 struct vm_file *shm_new(key_t key, unsigned long npages);
+void *shm_new_address(int npages);
 
 #endif /* __SHM_H__ */

tasks/mm0/include/utcb.h

@@ -3,9 +3,9 @@
 
 #include <l4lib/types.h>
 #include <task.h>
-void *utcb_vaddr_new(void);
 int utcb_pool_init(void);
-int utcb_vaddr_del(void *utcb_addr);
+void *utcb_new_address(void);
+int utcb_delete_address(void *utcb_addr);
 
 
 /* IPC to send utcb address information to tasks */

tasks/mm0/include/vm_area.h

@@ -143,6 +143,7 @@ struct vm_file {
 	unsigned long length;
 	unsigned int type;
 	struct vm_object vm_obj;
+	void (*destroy_priv_data)(struct vm_file *f);
 	void *priv_data;	/* Device pagers use to access device info */
 };