selinux: avoid unnecessary avc cache stat hit count

There is no point in counting hits - we can calculate it from the number
of lookups and misses.

This makes the avc statistics a bit smaller, and makes the code
generation better too.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 11 insertions, 9 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 5971e30e8239..3d2715fd35ea 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -343,11 +343,10 @@ static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass)
         node = avc_search_node(ssid, tsid, tclass);
 
         if (node)
-                avc_cache_stats_incr(hits);
-        else
-                avc_cache_stats_incr(misses);
+                return node;
 
-        return node;
+        avc_cache_stats_incr(misses);
+        return NULL;
 }
 
 static int avc_latest_notif_update(int seqno, int is_insert)
@@ -765,7 +764,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
         rcu_read_lock();
 
         node = avc_lookup(ssid, tsid, tclass);
-        if (!node) {
+        if (unlikely(!node)) {
                 rcu_read_unlock();
 
                 if (in_avd)
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index e77b2ac2908b..47fda963495d 100644
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -41,7 +41,6 @@ struct sk_buff;
  */
 struct avc_cache_stats {
         unsigned int lookups;
-        unsigned int hits;
         unsigned int misses;
         unsigned int allocations;
         unsigned int reclaims;
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index ea39cb742ae5..c0e1a0f52462 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1380,10 +1380,14 @@ static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
         if (v == SEQ_START_TOKEN)
                 seq_printf(seq, "lookups hits misses allocations reclaims "
                            "frees\n");
-        else
-                seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
-                           st->hits, st->misses, st->allocations,
+        else {
+                unsigned int lookups = st->lookups;
+                unsigned int misses = st->misses;
+                unsigned int hits = lookups - misses;
+                seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
+                           hits, misses, st->allocations,
                            st->reclaims, st->frees);
+        }
         return 0;
 }