diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst index 456e15097d87..8ae8f49801cb 100644 --- a/Documentation/hid/hid-bpf.rst +++ b/Documentation/hid/hid-bpf.rst @@ -129,6 +129,23 @@ When a BPF program needs to emit input events, it needs to talk with the HID protocol, and rely on the HID kernel processing to translate the HID data into input events. +In-tree HID-BPF programs and ``udev-hid-bpf`` +============================================= + +Official device fixes are shipped in the kernel tree as source in the +``drivers/hid/bpf/progs`` directory. This allows to add selftests to them in +``tools/testing/selftests/hid``. + +However, the compilation of these objects is not part of a regular kernel compilation +given that they need an external tool to be loaded. This tool is currently +`udev-hid-bpf `_. + +For convenience, that external repository duplicates the files from here in +``drivers/hid/bpf/progs`` into its own ``src/bpf/stable`` directory. This allows +distributions to not have to pull the entire kernel source tree to ship and package +those HID-BPF fixes. ``udev-hid-bpf`` also has capabilities of handling multiple +objects files depending on the kernel the user is running. + Available types of programs ===========================