From: Daniel Borkmann <daniel@iogearbox•net>
To: Sargun Dhillon <sargun@sargun•me>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail•com>,
netdev <netdev@vger•kernel.org>,
tj@kernel•org
Subject: Re: [PATCH net-next v4 2/3] bpf: Add bpf_current_task_under_cgroup helper
Date: Fri, 12 Aug 2016 09:40:39 +0200 [thread overview]
Message-ID: <57AD7D77.4090205@iogearbox.net> (raw)
In-Reply-To: <20160812072247.GB31242@ircssh.c.rugged-nimbus-611.internal>
On 08/12/2016 09:22 AM, Sargun Dhillon wrote:
> On Fri, Aug 12, 2016 at 09:16:07AM +0200, Daniel Borkmann wrote:
>> On 08/12/2016 06:50 AM, Sargun Dhillon wrote:
>>> I realize that in_cgroup is more consistent, but under_cgroup makes
>>> far more sense to me. I think it's more intuitive.
>>>
>>> On Thu, Aug 11, 2016 at 9:48 PM, Alexei Starovoitov
>>> <alexei.starovoitov@gmail•com> wrote:
>>>> On Thu, Aug 11, 2016 at 08:14:56PM -0700, Sargun Dhillon wrote:
>>>>> This adds a bpf helper that's similar to the skb_in_cgroup helper to check
>>>>> whether the probe is currently executing in the context of a specific
>>>>> subset of the cgroupsv2 hierarchy. It does this based on membership test
>>>>> for a cgroup arraymap. It is invalid to call this in an interrupt, and
>>>>> it'll return an error. The helper is primarily to be used in debugging
>>>>> activities for containers, where you may have multiple programs running in
>>>>> a given top-level "container".
>>>>>
>>>>> Signed-off-by: Sargun Dhillon <sargun@sargun•me>
>>>>> Cc: Alexei Starovoitov <ast@kernel•org>
>>>>> Cc: Daniel Borkmann <daniel@iogearbox•net>
>>>>> Cc: Tejun Heo <tj@kernel•org>
>>>>> ---
>>>>> + /**
>>>>> + * bpf_current_task_under_cgroup(map, index) - Check cgroup2 membership of current task
>>>>> + * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
>>>>> + * @index: index of the cgroup in the bpf_map
>>>>> + * Return:
>>>>> + * == 0 current failed the cgroup2 descendant test
>>>>> + * == 1 current succeeded the cgroup2 descendant test
>>>>> + * < 0 error
>>>>> + */
>>>>> + BPF_FUNC_current_task_under_cgroup,
>>>> ..
>>>>> case BPF_MAP_TYPE_CGROUP_ARRAY:
>>>>> - if (func_id != BPF_FUNC_skb_in_cgroup)
>>>>> + if (func_id != BPF_FUNC_skb_in_cgroup &&
>>>>> + func_id != BPF_FUNC_current_task_under_cgroup)
>>>>> goto error;
>>>> ...
>>>>> + case BPF_FUNC_current_task_under_cgroup:
>>>>> case BPF_FUNC_skb_in_cgroup:
>>>>
>>>> Tejun,
>>>> do you feel strongly about 'under' ?
>>>> It just looks inconsistent vs existing skb_in_cgroup...
>>>> "in cgroup" - 4k google hits
>>>> "under cgroup" - 2k google hits
>>
>> Alternative could be that we take "BPF_FUNC_current_in_cgroup" as a
>> helper enum to keep consistency with what we have wrt skb helper, but
>> for the cgroup header have the suggested task_under_cgroup_hierarchy()
>> name.
>
> I actually wish we could rename skb_in_cgroup to skb_under_cgroup. If we ever
> introduced a check for absolute membership versus ancestral membership, what
> would we call that?
That option is, by the way, still on the table for -net tree, since 4.8 is not
released yet, so it could still be renamed into BPF_FUNC_skb_under_cgroup.
Then you could make this one here for -net-next as "BPF_FUNC_current_under_cgroup".
Tejun, Alexei?
next prev parent reply other threads:[~2016-08-12 8:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-12 3:14 [PATCH net-next v4 2/3] bpf: Add bpf_current_task_under_cgroup helper Sargun Dhillon
2016-08-12 4:48 ` Alexei Starovoitov
2016-08-12 4:50 ` Sargun Dhillon
2016-08-12 7:16 ` Daniel Borkmann
2016-08-12 7:22 ` Sargun Dhillon
2016-08-12 7:40 ` Daniel Borkmann [this message]
2016-08-12 13:29 ` Tejun Heo
2016-08-12 15:21 ` Alexei Starovoitov
2016-08-12 15:28 ` Tejun Heo
2016-08-12 13:21 ` Tejun Heo
2016-08-12 13:23 ` Tejun Heo
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