release/src-rt-6.x.4708/linux/linux-2.6.36/security/apparmor/sid.c

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains AppArmor security identifier (sid) manipulation fns
   5  *
   6  * Copyright 2009-2010 Canonical Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation, version 2 of the
  11  * License.
  12  *
  13  *
  14  * AppArmor allocates a unique sid for every profile loaded.  If a profile
  15  * is replaced it receives the sid of the profile it is replacing.
  16  *
  17  * The sid value of 0 is invalid.
  18  */
  19
  20 #include <linux/spinlock.h>
  21 #include <linux/errno.h>
  22 #include <linux/err.h>
  23
  24 #include "include/sid.h"
  25
  26 /* global counter from which sids are allocated */
  27 static u32 global_sid;
  28 static DEFINE_SPINLOCK(sid_lock);
  29
  30
  31 /**
  32  * aa_alloc_sid - allocate a new sid for a profile
  33  */
  34 u32 aa_alloc_sid(void)
  35 {
  36         u32 sid;
  37
  38         spin_lock(&sid_lock);
  39         sid = (++global_sid);
  40         spin_unlock(&sid_lock);
  41         return sid;
  42 }
  43
  44 /**
  45  * aa_free_sid - free a sid
  46  * @sid: sid to free
  47  */
  48 void aa_free_sid(u32 sid)
  49 {
  50         ;                       /* NOP ATM */
  51 }