selinux: reduce the number of calls to synchronize_net() when flushing caches

When flushing the AVC, such as during a policy load, the various
network caches are also flushed, with each making a call to
synchronize_net() which has shown to be expensive in some cases.
This patch consolidates the network cache flushes into a single AVC
callback which only calls synchronize_net() once for each AVC cache
flush.

Reported-by: Jaejyn Shin <flagon22bass@gmail.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

1 files changed, 1 insertions, 14 deletions

diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c
index 03a72c32afd7..ddf315260839 100644
--- a/security/selinux/netnode.c
+++ b/security/selinux/netnode.c
@@ -283,7 +283,7 @@ int sel_netnode_sid(void *addr, u16 family, u32 *sid)
  * Remove all entries from the network address table.
  *
  */
-static void sel_netnode_flush(void)
+void sel_netnode_flush(void)
 {
         unsigned int idx;
         struct sel_netnode *node, *node_tmp;
@@ -300,15 +300,6 @@ static void sel_netnode_flush(void)
         spin_unlock_bh(&sel_netnode_lock);
 }
 
-static int sel_netnode_avc_callback(u32 event)
-{
-        if (event == AVC_CALLBACK_RESET) {
-                sel_netnode_flush();
-                synchronize_net();
-        }
-        return 0;
-}
-
 static __init int sel_netnode_init(void)
 {
         int iter;
@@ -322,10 +313,6 @@ static __init int sel_netnode_init(void)
                 sel_netnode_hash[iter].size = 0;
         }
 
-        ret = avc_add_callback(sel_netnode_avc_callback, AVC_CALLBACK_RESET);
-        if (ret != 0)
-                panic("avc_add_callback() failed, error %d\n", ret);
-
         return ret;
 }