This patch added support for hashmap, percpu hashmap,
lru hashmap and percpu lru hashmap.
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
include/linux/bpf.h | 4 +++
kernel/bpf/hashtab.c | 65 +++++++++++++++++++++++++++++++++++++++++++
kernel/bpf/verifier.c | 27 ++++++++++++++++++
3 files changed, 96 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 791266314b24..a69324026d19 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1397,6 +1397,10 @@ void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
struct bpf_link_info *info);
+int map_set_for_each_callback_args(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee);
+
int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index d63912e73ad9..330d721dd2af 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1869,6 +1869,63 @@ static const struct bpf_iter_seq_info iter_seq_info = {
.seq_priv_size = sizeof(struct bpf_iter_seq_hash_map_info),
};
+static int bpf_for_each_hash_elem(struct bpf_map *map, void *callback_fn,
+ void *callback_ctx, u64 flags)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct hlist_nulls_head *head;
+ struct hlist_nulls_node *n;
+ struct htab_elem *elem;
+ u32 roundup_key_size;
+ int i, num_elems = 0;
+ void __percpu *pptr;
+ struct bucket *b;
+ void *key, *val;
+ bool is_percpu;
+ u64 ret = 0;
+
+ if (flags != 0)
+ return -EINVAL;
+
+ is_percpu = htab_is_percpu(htab);
+
+ roundup_key_size = round_up(map->key_size, 8);
+ /* disable migration so percpu value prepared here will be the
+ * same as the one seen by the bpf program with bpf_map_lookup_elem().
+ */
+ if (is_percpu)
+ migrate_disable();
+ for (i = 0; i < htab->n_buckets; i++) {
+ b = &htab->buckets[i];
+ rcu_read_lock();
+ head = &b->head;
+ hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
+ key = elem->key;
+ if (is_percpu) {
+ /* current cpu value for percpu map */
+ pptr = htab_elem_get_ptr(elem, map->key_size);
+ val = this_cpu_ptr(pptr);
+ } else {
+ val = elem->key + roundup_key_size;
+ }
+ num_elems++;
+ ret = BPF_CAST_CALL(callback_fn)((u64)(long)map,
+ (u64)(long)key, (u64)(long)val,
+ (u64)(long)callback_ctx, 0);
+ /* return value: 0 - continue, 1 - stop and return */
+ if (ret) {
+ rcu_read_unlock();
+ goto out;
+ }
+ }
+ rcu_read_unlock();
+ }
+out:
+ if (is_percpu)
+ migrate_enable();
+ return num_elems;
+}
+
static int htab_map_btf_id;
const struct bpf_map_ops htab_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
@@ -1881,6 +1938,8 @@ const struct bpf_map_ops htab_map_ops = {
.map_delete_elem = htab_map_delete_elem,
.map_gen_lookup = htab_map_gen_lookup,
.map_seq_show_elem = htab_map_seq_show_elem,
+ .map_set_for_each_callback_args = map_set_for_each_callback_args,
+ .map_for_each_callback = bpf_for_each_hash_elem,
BATCH_OPS(htab),
.map_btf_name = "bpf_htab",
.map_btf_id = &htab_map_btf_id,
@@ -1900,6 +1959,8 @@ const struct bpf_map_ops htab_lru_map_ops = {
.map_delete_elem = htab_lru_map_delete_elem,
.map_gen_lookup = htab_lru_map_gen_lookup,
.map_seq_show_elem = htab_map_seq_show_elem,
+ .map_set_for_each_callback_args = map_set_for_each_callback_args,
+ .map_for_each_callback = bpf_for_each_hash_elem,
BATCH_OPS(htab_lru),
.map_btf_name = "bpf_htab",
.map_btf_id = &htab_lru_map_btf_id,
@@ -2019,6 +2080,8 @@ const struct bpf_map_ops htab_percpu_map_ops = {
.map_update_elem = htab_percpu_map_update_elem,
.map_delete_elem = htab_map_delete_elem,
.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+ .map_set_for_each_callback_args = map_set_for_each_callback_args,
+ .map_for_each_callback = bpf_for_each_hash_elem,
BATCH_OPS(htab_percpu),
.map_btf_name = "bpf_htab",
.map_btf_id = &htab_percpu_map_btf_id,
@@ -2036,6 +2099,8 @@ const struct bpf_map_ops htab_lru_percpu_map_ops = {
.map_update_elem = htab_lru_percpu_map_update_elem,
.map_delete_elem = htab_lru_map_delete_elem,
.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+ .map_set_for_each_callback_args = map_set_for_each_callback_args,
+ .map_for_each_callback = bpf_for_each_hash_elem,
BATCH_OPS(htab_lru_percpu),
.map_btf_name = "bpf_htab",
.map_btf_id = &htab_lru_percpu_map_btf_id,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 53afe9461b03..9fe90ce52a65 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5403,6 +5403,33 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return 0;
}
+int map_set_for_each_callback_args(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee)
+{
+ /* bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn,
+ * void *callback_ctx, u64 flags);
+ * callback_fn(struct bpf_map *map, void *key, void *value,
+ * void *callback_ctx);
+ */
+ callee->regs[BPF_REG_1] = caller->regs[BPF_REG_1];
+
+ callee->regs[BPF_REG_2].type = PTR_TO_MAP_KEY;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_2]);
+ callee->regs[BPF_REG_2].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ callee->regs[BPF_REG_3].type = PTR_TO_MAP_VALUE;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_3]);
+ callee->regs[BPF_REG_3].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ /* pointer to stack or null */
+ callee->regs[BPF_REG_4] = caller->regs[BPF_REG_3];
+
+ /* unused */
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
+ return 0;
+}
+
static int set_callee_state(struct bpf_verifier_env *env,
struct bpf_func_state *caller,
struct bpf_func_state *callee, int insn_idx)
--
2.24.1
