Re: [PATCH bpf-next 5/6] bpf: support epoll from bpf struct_ops links.

[Kui-Feng Lee <sinquersw@gmail.com>]

On 5/1/24 10:03, Andrii Nakryiko wrote:
> On Mon, Apr 29, 2024 at 2:36 PM Kui-Feng Lee <thinker.li@gmail.com> wrote:
>>
>> Add epoll support to bpf struct_ops links to trigger EPOLLHUP event upon
>> detachment.
>>
>> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
>> ---
>>   include/linux/bpf.h         |  2 ++
>>   kernel/bpf/bpf_struct_ops.c | 14 ++++++++++++++
>>   kernel/bpf/syscall.c        | 15 +++++++++++++++
>>   3 files changed, 31 insertions(+)
>>
>> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
>> index eeeed4b1bd32..a4550b927352 100644
>> --- a/include/linux/bpf.h
>> +++ b/include/linux/bpf.h
>> @@ -1574,6 +1574,7 @@ struct bpf_link {
>>          const struct bpf_link_ops *ops;
>>          struct bpf_prog *prog;
>>          struct work_struct work;
>> +       wait_queue_head_t wait_hup;
> 
> let's keep it struct_ops-specific, there is no need to pay for this
> for all existing BPF link types. We can always generalize later, if
> necessary.
> 
sure!

> pw-bot: cr
> 
> 
>>   };
>>
>>   struct bpf_link_ops {
>> @@ -1587,6 +1588,7 @@ struct bpf_link_ops {
>>                                struct bpf_link_info *info);
>>          int (*update_map)(struct bpf_link *link, struct bpf_map *new_map,
>>                            struct bpf_map *old_map);
>> +       __poll_t (*poll)(struct file *file, struct poll_table_struct *pts);
>>   };
>>
>>   struct bpf_tramp_link {
> 
> [...]