Re: [PATCH bpf-next v13 03/14] bpf, net: introduce bpf_struct_ops_desc.

[Martin KaFai Lau <martin.lau@xxxxxxxxx>]

On 12/8/23 4:26 PM, thinker.li@xxxxxxxxx wrote:
> diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c
> index 2748f9d77b18..bd753dbccaf6 100644
> --- a/net/bpf/bpf_dummy_struct_ops.c
> +++ b/net/bpf/bpf_dummy_struct_ops.c
> @@ -17,6 +17,8 @@ struct bpf_dummy_ops_test_args {
>   	struct bpf_dummy_ops_state state;
>   };
>   
> +static struct btf *bpf_dummy_ops_btf;
> +
>   static struct bpf_dummy_ops_test_args *
>   dummy_ops_init_args(const union bpf_attr *kattr, unsigned int nr)
>   {
> @@ -85,9 +87,13 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
>   	void *image = NULL;
>   	unsigned int op_idx;
>   	int prog_ret;
> +	u32 type_id;

	s32 type_id;

>   	int err;
>   
> -	if (prog->aux->attach_btf_id != st_ops->type_id)
> +	type_id = btf_find_by_name_kind(bpf_dummy_ops_btf,
> +					bpf_bpf_dummy_ops.name,
> +					BTF_KIND_STRUCT);

	if (type_id < 0)
		return -EINVAL;

> +	if (prog->aux->attach_btf_id != type_id)
>   		return -EOPNOTSUPP;
>   
>   	func_proto = prog->aux->attach_func_proto;
> @@ -142,6 +148,7 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
>   
>   static int bpf_dummy_init(struct btf *btf)
>   {
> +	bpf_dummy_ops_btf = btf;
>   	return 0;
>   }
>   
> diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
> index c7bbd8f3c708..5bb56c9ad4e5 100644
> --- a/net/ipv4/bpf_tcp_ca.c
> +++ b/net/ipv4/bpf_tcp_ca.c
> @@ -20,6 +20,7 @@ static u32 unsupported_ops[] = {
>   
>   static const struct btf_type *tcp_sock_type;
>   static u32 tcp_sock_id, sock_id;
> +static const struct btf_type *tcp_congestion_ops_type;
>   
>   static int bpf_tcp_ca_init(struct btf *btf)
>   {
> @@ -36,6 +37,11 @@ static int bpf_tcp_ca_init(struct btf *btf)
>   	tcp_sock_id = type_id;
>   	tcp_sock_type = btf_type_by_id(btf, tcp_sock_id);
>   
> +	type_id = btf_find_by_name_kind(btf, "tcp_congestion_ops", BTF_KIND_STRUCT);
> +	if (type_id < 0)
> +		return -EINVAL;
> +	tcp_congestion_ops_type = btf_type_by_id(btf, type_id);
> +
>   	return 0;
>   }
>   
> @@ -149,7 +155,7 @@ static u32 prog_ops_moff(const struct bpf_prog *prog)
>   	u32 midx;
>   
>   	midx = prog->expected_attach_type;
> -	t = bpf_tcp_congestion_ops.type;
> +	t = tcp_congestion_ops_type;
>   	m = &btf_type_member(t)[midx];
>   
>   	return __btf_member_bit_offset(t, m) / 8;