hi,
> On Wed, Feb 22, 2023 at 5:29 AM Xiaoguang Wang
> <xiaoguang.wang@xxxxxxxxxxxxxxxxx> wrote:
>> Currenly only one bpf_ublk_queue_sqe() ebpf is added, ublksrv target
>> can use this helper to write ebpf prog to support ublk kernel & usersapce
>> zero copy, please see ublksrv test codes for more info.
>>
>>
>> +const struct bpf_func_proto ublk_bpf_queue_sqe_proto = {
>> + .func = bpf_ublk_queue_sqe,
>> + .gpl_only = false,
>> + .ret_type = RET_INTEGER,
>> + .arg1_type = ARG_ANYTHING,
>> + .arg2_type = ARG_ANYTHING,
>> + .arg3_type = ARG_ANYTHING,
>> + .arg4_type = ARG_ANYTHING,
>> +};
> You know that the above is unsafe, right?
Yes, I know it's not safe, will improve it in next version.
>
>> +
>> static const struct bpf_func_proto *
>> ublk_bpf_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>> {
>> - return bpf_base_func_proto(func_id);
>> + switch (func_id) {
>> + case BPF_FUNC_ublk_queue_sqe:
>> + return &ublk_bpf_queue_sqe_proto;
>> + default:
>> + return bpf_base_func_proto(func_id);
>> + }
>> }
>>
>> static bool ublk_bpf_is_valid_access(int off, int size,
>> @@ -200,6 +252,23 @@ static bool ublk_bpf_is_valid_access(int off, int size,
>> const struct bpf_prog *prog,
>> struct bpf_insn_access_aux *info)
>> {
>> + if (off < 0 || off >= sizeof(struct ublk_bpf_ctx))
>> + return false;
>> + if (off % size != 0)
>> + return false;
>> +
>> + switch (off) {
>> + case offsetof(struct ublk_bpf_ctx, q_id):
>> + return size == sizeof_field(struct ublk_bpf_ctx, q_id);
>> + case offsetof(struct ublk_bpf_ctx, tag):
>> + return size == sizeof_field(struct ublk_bpf_ctx, tag);
>> + case offsetof(struct ublk_bpf_ctx, op):
>> + return size == sizeof_field(struct ublk_bpf_ctx, op);
>> + case offsetof(struct ublk_bpf_ctx, nr_sectors):
>> + return size == sizeof_field(struct ublk_bpf_ctx, nr_sectors);
>> + case offsetof(struct ublk_bpf_ctx, start_sector):
>> + return size == sizeof_field(struct ublk_bpf_ctx, start_sector);
>> + }
>> return false;
> We don't introduce stable 'ctx' anymore.
> Please see how hid-bpf is doing things.
ok, will learn it, thanks.
Regards,
Xiaoguang Wang
