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Diffstat (limited to 'kernel/bpf/hashtab.c')
-rw-r--r--kernel/bpf/hashtab.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 04b8eda94e7d..03cc59ee9c95 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -15,6 +15,7 @@
#include <linux/jhash.h>
#include <linux/filter.h>
#include <linux/rculist_nulls.h>
+#include <linux/random.h>
#include <uapi/linux/btf.h>
#include "percpu_freelist.h"
#include "bpf_lru_list.h"
@@ -41,6 +42,7 @@ struct bpf_htab {
atomic_t count; /* number of elements in this hashtable */
u32 n_buckets; /* number of hash buckets */
u32 elem_size; /* size of each element in bytes */
+ u32 hashrnd;
};
/* each htab element is struct htab_elem + key + value */
@@ -371,6 +373,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
if (!htab->buckets)
goto free_htab;
+ htab->hashrnd = get_random_int();
for (i = 0; i < htab->n_buckets; i++) {
INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
raw_spin_lock_init(&htab->buckets[i].lock);
@@ -402,9 +405,9 @@ free_htab:
return ERR_PTR(err);
}
-static inline u32 htab_map_hash(const void *key, u32 key_len)
+static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd)
{
- return jhash(key, key_len, 0);
+ return jhash(key, key_len, hashrnd);
}
static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
@@ -470,7 +473,7 @@ static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
head = select_bucket(htab, hash);
@@ -597,7 +600,7 @@ static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
if (!key)
goto find_first_elem;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
head = select_bucket(htab, hash);
@@ -824,7 +827,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;
@@ -880,7 +883,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;
@@ -945,7 +948,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;
@@ -998,7 +1001,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;
@@ -1071,7 +1074,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;
@@ -1103,7 +1106,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
key_size = map->key_size;
- hash = htab_map_hash(key, key_size);
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
b = __select_bucket(htab, hash);
head = &b->head;