-----Original Message-----
From: David Ahern <dsahern@xxxxxxxxx>
Sent: Wednesday, September 23, 2020 7:19 PM
To: Maciej Żenczykowski <maze@xxxxxxxxxx>; Pujari, Bimmy <bimmy.pujari@xxxxxxxxx>
Cc: bpf <bpf@xxxxxxxxxxxxxxx>; Linux NetDev <netdev@xxxxxxxxxxxxxxx>; mchehab@xxxxxxxxxx; Alexei Starovoitov <ast@xxxxxxxxxx>; Daniel Borkmann <daniel@xxxxxxxxxxxxx>; Martin Lau <kafai@xxxxxx>; Nikravesh, Ashkan <ashkan.nikravesh@xxxxxxxxx>
Subject: Re: [PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns
On 9/23/20 7:19 PM, Maciej Żenczykowski wrote:
>> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index
>> 5cc7425ee476..776ff58f969d 100644
>> --- a/kernel/bpf/helpers.c
>> +++ b/kernel/bpf/helpers.c
>> @@ -155,6 +155,17 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
>> .ret_type = RET_INTEGER,
>> };
>>
>> +BPF_CALL_0(bpf_ktime_get_real_ns)
>> +{
>> + /* NMI safe access to clock realtime */
>> + return ktime_get_real_fast_ns(); }
>> +
>> +const struct bpf_func_proto bpf_ktime_get_real_ns_proto = {
>> + .func = bpf_ktime_get_real_ns,
>> + .gpl_only = true,
>
> imho should be false, this is normally accessible to userspace code
> via syscall, no reason why it should be gpl only for bpf
>
agreed, no reason for the bpf hook to be gpl_only.
Glad to see the v2 of this patch; I wondered what happened to this helper.
BP: Thanks Maciej & Ahern for taking time to look at it. I will update the changes suggested shortly.
