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()?
>
> .
>
