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 */ 27static u32 global_sid; 28static DEFINE_SPINLOCK(sid_lock); 29 30 31/** 32 * aa_alloc_sid - allocate a new sid for a profile 33 */ 34u32 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 */ 48void aa_free_sid(u32 sid) 49{ 50 ; /* NOP ATM */ 51} 52