On 4/5/23 8:05 AM, Aditi Ghag wrote:
Looks quite promising for the sock_destroy use case, and also as a generic filtering mechanism, but I'm not aware of other use cases. I haven't had a chance to apply this patch locally, but I'm planning to do it soon. Thanks!
Please don't top post.
Other use case is to allow different sets of kfuncs to struct_ops programs from
David: https://lore.kernel.org/bpf/Y9KLHZ1TNXVHdVKm@maniforge/
From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
This set (https://lore.kernel.org/bpf/https://lore.kernel.org/bpf/500d452b-f9d5-d01f-d365-2949c4fd37ab@xxxxxxxxx/)
needs to limit bpf_sock_destroy kfunc to BPF_TRACE_ITER.
In the earlier reply, I thought of adding a BTF_KFUNC_HOOK_TRACING_ITER.
Instead of adding BTF_KFUNC_HOOK_TRACING_ITER, I quickly hacked something
that added a callback filter to 'struct btf_kfunc_id_set'. The filter has
access to the prog such that it can filter by other properties of a prog.
The prog->expected_attached_type is used in the tracing_iter_filter().
It is mostly compiler tested only, so it is still very rough but should
be good enough to show the idea.
would like to hear how others think. It is pretty much the only
piece left for the above mentioned set.
