diff options
Diffstat (limited to 'security/selinux/ss/hashtab.c')
-rw-r--r-- | security/selinux/ss/hashtab.c | 63 |
1 files changed, 31 insertions, 32 deletions
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c index ebfdaa31ee32..5ee868116d70 100644 --- a/security/selinux/ss/hashtab.c +++ b/security/selinux/ss/hashtab.c @@ -12,31 +12,38 @@ static struct kmem_cache *hashtab_node_cachep; -struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key), - int (*keycmp)(struct hashtab *h, const void *key1, const void *key2), - u32 size) +/* + * Here we simply round the number of elements up to the nearest power of two. + * I tried also other options like rouding down or rounding to the closest + * power of two (up or down based on which is closer), but I was unable to + * find any significant difference in lookup/insert performance that would + * justify switching to a different (less intuitive) formula. It could be that + * a different formula is actually more optimal, but any future changes here + * should be supported with performance/memory usage data. + * + * The total memory used by the htable arrays (only) with Fedora policy loaded + * is approximately 163 KB at the time of writing. + */ +static u32 hashtab_compute_size(u32 nel) { - struct hashtab *p; - u32 i; - - p = kzalloc(sizeof(*p), GFP_KERNEL); - if (!p) - return p; - - p->size = size; - p->nel = 0; - p->hash_value = hash_value; - p->keycmp = keycmp; - p->htable = kmalloc_array(size, sizeof(*p->htable), GFP_KERNEL); - if (!p->htable) { - kfree(p); - return NULL; - } + return nel == 0 ? 0 : roundup_pow_of_two(nel); +} - for (i = 0; i < size; i++) - p->htable[i] = NULL; +int hashtab_init(struct hashtab *h, + u32 (*hash_value)(struct hashtab *h, const void *key), + int (*keycmp)(struct hashtab *h, const void *key1, + const void *key2), + u32 nel_hint) +{ + h->size = hashtab_compute_size(nel_hint); + h->nel = 0; + h->hash_value = hash_value; + h->keycmp = keycmp; + if (!h->size) + return 0; - return p; + h->htable = kcalloc(h->size, sizeof(*h->htable), GFP_KERNEL); + return h->htable ? 0 : -ENOMEM; } int hashtab_insert(struct hashtab *h, void *key, void *datum) @@ -46,7 +53,7 @@ int hashtab_insert(struct hashtab *h, void *key, void *datum) cond_resched(); - if (!h || h->nel == HASHTAB_MAX_NODES) + if (!h->size || h->nel == HASHTAB_MAX_NODES) return -EINVAL; hvalue = h->hash_value(h, key); @@ -82,7 +89,7 @@ void *hashtab_search(struct hashtab *h, const void *key) u32 hvalue; struct hashtab_node *cur; - if (!h) + if (!h->size) return NULL; hvalue = h->hash_value(h, key); @@ -101,9 +108,6 @@ void hashtab_destroy(struct hashtab *h) u32 i; struct hashtab_node *cur, *temp; - if (!h) - return; - for (i = 0; i < h->size; i++) { cur = h->htable[i]; while (cur) { @@ -116,8 +120,6 @@ void hashtab_destroy(struct hashtab *h) kfree(h->htable); h->htable = NULL; - - kfree(h); } int hashtab_map(struct hashtab *h, @@ -128,9 +130,6 @@ int hashtab_map(struct hashtab *h, int ret; struct hashtab_node *cur; - if (!h) - return 0; - for (i = 0; i < h->size; i++) { cur = h->htable[i]; while (cur) { |