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-rw-r--r--security/selinux/ss/sidtab.c39
-rw-r--r--security/selinux/ss/sidtab.h2
2 files changed, 39 insertions, 2 deletions
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index e817989764cd..5840a35155fc 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -147,6 +147,17 @@ out:
return rc;
}
+static void sidtab_update_cache(struct sidtab *s, struct sidtab_node *n, int loc)
+{
+ BUG_ON(loc >= SIDTAB_CACHE_LEN);
+
+ while (loc > 0) {
+ s->cache[loc] = s->cache[loc - 1];
+ loc--;
+ }
+ s->cache[0] = n;
+}
+
static inline u32 sidtab_search_context(struct sidtab *s,
struct context *context)
{
@@ -156,14 +167,33 @@ static inline u32 sidtab_search_context(struct sidtab *s,
for (i = 0; i < SIDTAB_SIZE; i++) {
cur = s->htable[i];
while (cur) {
- if (context_cmp(&cur->context, context))
+ if (context_cmp(&cur->context, context)) {
+ sidtab_update_cache(s, cur, SIDTAB_CACHE_LEN - 1);
return cur->sid;
+ }
cur = cur->next;
}
}
return 0;
}
+static inline u32 sidtab_search_cache(struct sidtab *s, struct context *context)
+{
+ int i;
+ struct sidtab_node *node;
+
+ for (i = 0; i < SIDTAB_CACHE_LEN; i++) {
+ node = s->cache[i];
+ if (unlikely(!node))
+ return 0;
+ if (context_cmp(&node->context, context)) {
+ sidtab_update_cache(s, node, i);
+ return node->sid;
+ }
+ }
+ return 0;
+}
+
int sidtab_context_to_sid(struct sidtab *s,
struct context *context,
u32 *out_sid)
@@ -174,7 +204,9 @@ int sidtab_context_to_sid(struct sidtab *s,
*out_sid = SECSID_NULL;
- sid = sidtab_search_context(s, context);
+ sid = sidtab_search_cache(s, context);
+ if (!sid)
+ sid = sidtab_search_context(s, context);
if (!sid) {
spin_lock_irqsave(&s->lock, flags);
/* Rescan now that we hold the lock. */
@@ -259,12 +291,15 @@ void sidtab_destroy(struct sidtab *s)
void sidtab_set(struct sidtab *dst, struct sidtab *src)
{
unsigned long flags;
+ int i;
spin_lock_irqsave(&src->lock, flags);
dst->htable = src->htable;
dst->nel = src->nel;
dst->next_sid = src->next_sid;
dst->shutdown = 0;
+ for (i = 0; i < SIDTAB_CACHE_LEN; i++)
+ dst->cache[i] = NULL;
spin_unlock_irqrestore(&src->lock, flags);
}
diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h
index 64ea5b1cdea4..84dc154d9389 100644
--- a/security/selinux/ss/sidtab.h
+++ b/security/selinux/ss/sidtab.h
@@ -26,6 +26,8 @@ struct sidtab {
unsigned int nel; /* number of elements */
unsigned int next_sid; /* next SID to allocate */
unsigned char shutdown;
+#define SIDTAB_CACHE_LEN 3
+ struct sidtab_node *cache[SIDTAB_CACHE_LEN];
spinlock_t lock;
};

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