Re: Ask for help about bpf map

["luwei (O)" <luwei32@huawei.com>]

I have updated the iproute2 according this page: 
https://github.com/cilium/cilium/issues/7446

Now I use this version of iproute2: https://github.com/shemminger/iproute2

The version of iproute2 is 5.11, and the kernel version is 5.13(the 
latest version).


在 2021/7/14 1:07 AM, Toke Høiland-Jørgensen 写道:
> Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:
>
>> On Mon, Jul 12, 2021 at 11:35 PM luwei (O) <luwei32@huawei.com> wrote:
>>> Hi, List:
>>>
>>>         I am a beginner about bpf and working on XDP now. I meet a
>>> problem and feel difficult to figure it out.
>>>
>>>         In my following codes, I use two ways to define my_map: in SEC
>>> maps and SEC .maps respectively. When I load the xdp_kern.o file,
>>>
>>> It has different results. The way I load is: ip link set dev ens3 xdp
>>> obj xdp1_kern.o sec xdp1.
>>>
>>>         when I define my_map using SEC maps, it loads successfully but
>>> fails to load using SEC .maps, it reports:
>>>
>>> "
>>>
>>> [12] TYPEDEF __u32 type_id=13
>>> [13] INT unsigned int size=4 bits_offset=0 nr_bits=32 encoding=(none)
>>> [14] FUNC_PROTO (anon) return=2 args=(10 ctx)
>>> [15] FUNC xdp_prog1 type_id=14
>>> [16] INT char size=1 bits_offset=0 nr_bits=8 encoding=SIGNED
>>> [17] ARRAY (anon) type_id=16 index_type_id=4 nr_elems=4
>>> [18] VAR _license type_id=17 linkage=1
>>> [19] DATASEC .maps size=0 vlen=1 size == 0
>>>
>>>
>>> Prog section 'xdp1' rejected: Permission denied (13)!
>>>    - Type:         6
>>>    - Instructions: 9 (0 over limit)
>>>    - License:      GPL
>>>
>>> Verifier analysis:
>>>
>>> 0: (b7) r1 = 0
>>> 1: (63) *(u32 *)(r10 -4) = r1
>>> last_idx 1 first_idx 0
>>> regs=2 stack=0 before 0: (b7) r1 = 0
>>> 2: (bf) r2 = r10
>>> 3: (07) r2 += -4
>>> 4: (18) r1 = 0x0
>> this shouldn't be 0x0.
>>
>> I suspect you have an old iproute2 which doesn't yet use libbpf to
>> load BPF programs, so .maps definition is not yet supported. cc'ing
>> netdev@vger, David and Toke
> That would be my guess as well; what's the output of 'ip -V'?
>
> -Toke
>
> .

-- 
Best Regards,
Lu Wei