Re: [PATCH bpf-next v5 13/17] HID: bpf: allow to change the report descriptor

Alexei Starovoitov
2022-05-21T02:47:00Z

On Wed, May 18, 2022 at 10:59:20PM +0200, Benjamin Tissoires wrote:
> Add a new tracepoint hid_bpf_rdesc_fixup() so we can trigger a
> report descriptor fixup in the bpf world.
>
> Whenever the program gets attached/detached, the device is reconnected
> meaning that userspace will see it disappearing and reappearing with
> the new report descriptor.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
>
> ---
>
> changes in v5:
> - adapted for new API
>
> not in v4
>
> changes in v3:
> - ensure the ctx.size is properly bounded by allocated size
> - s/link_attached/post_link_attach/
> - removed the switch statement with only one case
>
> changes in v2:
> - split the series by bpf/libbpf/hid/selftests and samples
> ---
> drivers/hid/bpf/entrypoints/entrypoints.bpf.c | 6 +
> .../hid/bpf/entrypoints/entrypoints.lskel.h | 965 +++++++++---------

Probably add the lskel once in the series to avoid the churn.
It's not reviewable anyway.

> drivers/hid/bpf/hid_bpf_dispatch.c | 77 +-
> drivers/hid/bpf/hid_bpf_dispatch.h | 1 +
> drivers/hid/bpf/hid_bpf_jmp_table.c | 8 +

I'll take a close look at dispatch logic next week.