selinux: print sum of chain lengths^2 for hash tables

Print the sum of chain lengths squared as a metric for hash tables to
provide more insights, similar to avtabs.

While on it add a comma in the avtab message to improve readability of
the output.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index 86d98a8e291b4c5ad33e4336db18047700739ce7..955cfe4956067e37a5c3ebbbbe5e45deb92e8fcd 100644 (file)
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -349,7 +349,7 @@ void avtab_hash_eval(struct avtab *h, const char *tag)
        }
 
        pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, "
-              "longest chain length %d sum of chain length^2 %llu\n",
+              "longest chain length %d, sum of chain length^2 %llu\n",
               tag, h->nel, slots_used, h->nslot, max_chain_len,
               chain2_len_sum);
 }

diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
index ac5cdddfbf783a659fbefb8b39fa2fff2cf679d8..c05d8346a94a8bf726a079c383d30d66c38054ca 100644 (file)
--- a/security/selinux/ss/hashtab.c
+++ b/security/selinux/ss/hashtab.c
@@ -107,10 +107,12 @@ int hashtab_map(struct hashtab *h,
 void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
 {
        u32 i, chain_len, slots_used, max_chain_len;
+       u64 chain2_len_sum;
        struct hashtab_node *cur;
 
        slots_used = 0;
        max_chain_len = 0;
+       chain2_len_sum = 0;
        for (i = 0; i < h->size; i++) {
                cur = h->htable[i];
                if (cur) {
@@ -123,11 +125,14 @@ void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
 
                        if (chain_len > max_chain_len)
                                max_chain_len = chain_len;
+
+                       chain2_len_sum += (u64)chain_len * chain_len;
                }
        }
 
        info->slots_used = slots_used;
        info->max_chain_len = max_chain_len;
+       info->chain2_len_sum = chain2_len_sum;
 }
 #endif /* CONFIG_SECURITY_SELINUX_DEBUG */
 

diff --git a/security/selinux/ss/hashtab.h b/security/selinux/ss/hashtab.h
index f9713b56d3d034330e63980aba0421b64d9789f6..09b0a37449376e5d039fe46fa650617e77bfa673 100644 (file)
--- a/security/selinux/ss/hashtab.h
+++ b/security/selinux/ss/hashtab.h
@@ -38,6 +38,7 @@ struct hashtab {
 struct hashtab_info {
        u32 slots_used;
        u32 max_chain_len;
+       u64 chain2_len_sum;
 };
 
 /*

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 2d528f699a2297ed798a0d1c1a3d29a5e1cf524c..d420c6c12f5457ec28af725e7df6d0dd6e1be7a3 100644 (file)
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -684,9 +684,9 @@ static void hash_eval(struct hashtab *h, const char *hash_name)
        struct hashtab_info info;
 
        hashtab_stat(h, &info);
-       pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, longest chain length %d\n",
+       pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, longest chain length %d, sum of chain length^2 %llu\n",
                 hash_name, h->nel, info.slots_used, h->size,
-                info.max_chain_len);
+                info.max_chain_len, info.chain2_len_sum);
 }
 
 static void symtab_hash_eval(struct symtab *s)