On 2020/4/24 0:07, Alexei Starovoitov wrote:
> On Wed, Apr 22, 2020 at 11:25 PM maowenan <maowenan@xxxxxxxxxx> wrote:
>>
>> On 2020/4/23 13:43, Alexei Starovoitov wrote:
>>> On Wed, Apr 22, 2020 at 8:31 PM Mao Wenan <maowenan@xxxxxxxxxx> wrote:
>>>>
>>>> There is one error printed when use BPF_MAP_TYPE_SOCKMAP to create map:
>>>> libbpf: failed to create map (name: 'sock_map'): Invalid argument(-22)
>>>>
>>>> This is because CONFIG_BPF_STREAM_PARSER is not set, and
>>>> bpf_map_types[type] return invalid ops. It is not clear to show the
>>>> cause of config missing with return code -EINVAL, so add pr_warn() and
>>>> change error code to describe the reason.
>>>>
>>>> Signed-off-by: Mao Wenan <maowenan@xxxxxxxxxx>
>>>> ---
>>>> kernel/bpf/syscall.c | 7 ++++---
>>>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
>>>> index d85f37239540..7686778457c7 100644
>>>> --- a/kernel/bpf/syscall.c
>>>> +++ b/kernel/bpf/syscall.c
>>>> @@ -112,9 +112,10 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
>>>> return ERR_PTR(-EINVAL);
>>>> type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
>>>> ops = bpf_map_types[type];
>>>> - if (!ops)
>>>> - return ERR_PTR(-EINVAL);
>>>> -
>>>> + if (!ops) {
>>>> + pr_warn("map type %d not supported or kernel config not opened\n", type);
>>>> + return ERR_PTR(-EOPNOTSUPP);
>>>> + }
>>>
>>> I don't think users will like it when kernel spams dmesg.
>>> If you need this level of verbosity please teach consumer of libbpf to
>>> print them.
>>> It's not a job of libbpf either.
>> thanks for reviw, so is it better to delete redundant pr_warn()?
>
> which one?
I mean pr_warn is no need, this patch just change the return code ERR_PTR(-EOPNOTSUPP);
+ pr_warn("map type %d not supported or kernel config not opened\n", type);
>
> .
>
