Re: [PATCH RFC bpf-next v2 01/18] bpf: Register rhash map

Emil Tsalapatis
2026-04-14T17:50:37Z

On Mon Apr 13, 2026 at 4:10 AM EDT, Mykyta Yatsenko wrote:
> On 4/10/26 11:31 PM, Emil Tsalapatis wrote:
>> On Wed Apr 8, 2026 at 11:10 AM EDT, Mykyta Yatsenko wrote:
>>> From: Mykyta Yatsenko <yatsenko@meta.com>
>>>
>>> Add resizable hash map into enums where it is needed.
>>>
>>
>> These changes in isolation are difficult to reason about,
>> can we roll this into subsequent patches? Right now this
>> adds a the BPF_MAP_TYPE_RHASH without there being a way
>> to create one.
>>
>
> Thanks for taking a look, makes sense, I can squash it into the latter
> commits.
>

For the squashed commit:

Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>

>>> Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
>>> ---
>>> include/uapi/linux/bpf.h | 1 +
>>> kernel/bpf/map_iter.c | 3 ++-
>>> kernel/bpf/syscall.c | 3 +++
>>> kernel/bpf/verifier.c | 1 +
>>> tools/include/uapi/linux/bpf.h | 1 +
>>> 5 files changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>>> index 552bc5d9afbd..822582c04f22 100644
>>> --- a/include/uapi/linux/bpf.h
>>> +++ b/include/uapi/linux/bpf.h
>>> @@ -1046,6 +1046,7 @@ enum bpf_map_type {
>>> BPF_MAP_TYPE_CGRP_STORAGE,
>>> BPF_MAP_TYPE_ARENA,
>>> BPF_MAP_TYPE_INSN_ARRAY,
>>> + BPF_MAP_TYPE_RHASH,
>>> __MAX_BPF_MAP_TYPE
>>> };
>>>
>>> diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
>>> index 261a03ea73d3..4a2aafbe28b4 100644
>>> --- a/kernel/bpf/map_iter.c
>>> +++ b/kernel/bpf/map_iter.c
>>> @@ -119,7 +119,8 @@ static int bpf_iter_attach_map(struct bpf_prog *prog,
>>> is_percpu = true;
>>> else if (map->map_type != BPF_MAP_TYPE_HASH &&
>>> map->map_type != BPF_MAP_TYPE_LRU_HASH &&
>>> - map->map_type != BPF_MAP_TYPE_ARRAY)
>>> + map->map_type != BPF_MAP_TYPE_ARRAY &&
>>> + map->map_type != BPF_MAP_TYPE_RHASH)
>>> goto put_map;
>>>
>>> key_acc_size = prog->aux->max_rdonly_access;
>>> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
>>> index 51ade3cde8bb..0a5ec417638d 100644
>>> --- a/kernel/bpf/syscall.c
>>> +++ b/kernel/bpf/syscall.c
>>> @@ -1287,6 +1287,7 @@ static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
>>> case BPF_SPIN_LOCK:
>>> case BPF_RES_SPIN_LOCK:
>>> if (map->map_type != BPF_MAP_TYPE_HASH &&
>>> + map->map_type != BPF_MAP_TYPE_RHASH &&
>>> map->map_type != BPF_MAP_TYPE_ARRAY &&
>>> map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
>>> map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
>>> @@ -1464,6 +1465,7 @@ static int map_create(union bpf_attr *attr, bpfptr_t uattr)
>>> case BPF_MAP_TYPE_CGROUP_ARRAY:
>>> case BPF_MAP_TYPE_ARRAY_OF_MAPS:
>>> case BPF_MAP_TYPE_HASH:
>>> + case BPF_MAP_TYPE_RHASH:
>>> case BPF_MAP_TYPE_PERCPU_HASH:
>>> case BPF_MAP_TYPE_HASH_OF_MAPS:
>>> case BPF_MAP_TYPE_RINGBUF:
>>> @@ -2199,6 +2201,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
>>> map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
>>> map->map_type == BPF_MAP_TYPE_LRU_HASH ||
>>> map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
>>> + map->map_type == BPF_MAP_TYPE_RHASH ||
>>> map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
>>> if (!bpf_map_is_offloaded(map)) {
>>> bpf_disable_instrumentation();
>>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
>>> index 8c1cf2eb6cbb..53523ab953c2 100644
>>> --- a/kernel/bpf/verifier.c
>>> +++ b/kernel/bpf/verifier.c
>>> @@ -21816,6 +21816,7 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
>>> if (prog->sleepable)
>>> switch (map->map_type) {
>>> case BPF_MAP_TYPE_HASH:
>>> + case BPF_MAP_TYPE_RHASH:
>>> case BPF_MAP_TYPE_LRU_HASH:
>>> case BPF_MAP_TYPE_ARRAY:
>>> case BPF_MAP_TYPE_PERCPU_HASH:
>>> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
>>> index 677be9a47347..9d7df174770a 100644
>>> --- a/tools/include/uapi/linux/bpf.h
>>> +++ b/tools/include/uapi/linux/bpf.h
>>> @@ -1046,6 +1046,7 @@ enum bpf_map_type {
>>> BPF_MAP_TYPE_CGRP_STORAGE,
>>> BPF_MAP_TYPE_ARENA,
>>> BPF_MAP_TYPE_INSN_ARRAY,
>>> + BPF_MAP_TYPE_RHASH,
>>> __MAX_BPF_MAP_TYPE
>>> };
>>>
>>