selinux: clean up avc node cache when disabling selinux

Added a call to free the avc_node_cache when inside selinux_disable because
it should not waste resources allocated during avc_init if SELinux is disabled
and the cache will never be used.

Signed-off-by: Thomas Liu <tliu@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 7823e84..236aaa2 100644 (file)
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -970,3 +970,9 @@ u32 avc_policy_seqno(void)
 {
        return avc_cache.latest_notif;
 }
 {
        return avc_cache.latest_notif;
 }

+
+void avc_disable(void)
+{
+       if (avc_node_cachep)
+               kmem_cache_destroy(avc_node_cachep);
+}

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e3b4f30..2081055 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5683,6 +5683,9 @@ int selinux_disable(void)
        selinux_disabled = 1;
        selinux_enabled = 0;
 
        selinux_disabled = 1;
        selinux_enabled = 0;
 

+       /* Try to destroy the avc node cache */
+       avc_disable();
+

        /* Reset security_ops to the secondary module, dummy or capability. */
        security_ops = secondary_ops;
 
        /* Reset security_ops to the secondary module, dummy or capability. */
        security_ops = secondary_ops;
 

diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index 46a940d..ae4c3a0 100644 (file)
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -131,6 +131,9 @@ int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
 int avc_get_hash_stats(char *page);
 extern unsigned int avc_cache_threshold;
 
 int avc_get_hash_stats(char *page);
 extern unsigned int avc_cache_threshold;
 

+/* Attempt to free avc node cache */
+void avc_disable(void);
+

 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
 #endif
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
 #endif