selinux: convert range transition list to a hashtab

Per https://bugzilla.redhat.com/show_bug.cgi?id=548145
there are sufficient range transition rules in modern (Fedora) policy to
make mls_compute_sid a significant factor on the shmem file setup path
due to the length of the range_tr list.  Replace the simple range_tr
list with a hashtab inside the security server to help mitigate this
problem.

Signed-off-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index cdcc5700946f..193736b64de8 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -113,8 +113,6 @@ struct range_trans {
         u32 source_type;
         u32 target_type;
         u32 target_class;
-        struct mls_range target_range;
-        struct range_trans *next;
 };
 
 /* Boolean data type */
@@ -240,8 +238,8 @@ struct policydb {
            fixed labeling behavior. */
         struct genfs *genfs;
 
-        /* range transitions */
-        struct range_trans *range_tr;
+        /* range transitions table (range_trans_key -> mls_range) */
+        struct hashtab *range_tr;
 
         /* type -> attribute reverse mapping */
         struct ebitmap *type_attr_map;