HID: bpf: Fix Rapoo M50 Plus Silent side buttons

The Rapoo M50 Plus Silent mouse has 2 side buttons in addition to the left, right and middles buttons. However, its original HID descriptor has a Usage Maximum of 3, preventing the side buttons to work.

This HID-BPF driver changes that usage to 5.

Link: libinput/libinput#1015 (closed)

---

@jussi.lahtinen here is the fix for your mouse. Following the tutorial: https://libevdev.pages.freedesktop.org/udev-hid-bpf/getting-started.html

You should be able to install the HID-BPF program for your device executing these commands:

$ git clone --branch rapoo-m50 https://gitlab.freedesktop.org/JoseExposito/udev-hid-bpf.git
$ cd udev-hid-bpf
$ meson setup builddir
$ meson compile -C builddir
$ meson install -C builddir

Disconnect and connect your mouse and the side buttons should work.

I couldn't test it properly because the program refuses to load:

$ ninja -C builddir && \
   sudo ./builddir/udev-hid-bpf --verbose add --replace \
   /sys/bus/hid/devices/0003:24AE:2015.* - \
   $(pwd)/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o
ninja: Entering directory `builddir'
ninja: no work to do.
[sudo] password for jexposit: 
DEBUG - loading BPF object at "/home/jexposit/Devel/udev-hid-bpf/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o"
DEBUG - libbpf: elf: skipping unrecognized data section(7) .hid_bpf_config
DEBUG - Using HID_BPF_STRUCT_OPS
WARN - libbpf: struct_ops init_kern: struct bpf_struct_ops_hid_bpf_ops is not found in kernel BTF
WARN - libbpf: failed to load object '/home/jexposit/Devel/udev-hid-bpf/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o'
WARN - Failed to load "/home/jexposit/Devel/udev-hid-bpf/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o": No such file or directory (os error 2)

$ ls /home/jexposit/Devel/udev-hid-bpf/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o
/home/jexposit/Devel/udev-hid-bpf/builddir/src/bpf/10-Rapoo__M50-Plus-Silent.bpf.o

Maybe @bentiss knows why I'm getting a no such file or directory error when the file is present?

mentioned in issue libinput/libinput#1015 (closed)

WARN - libbpf: struct_ops init_kern: struct bpf_struct_ops_hid_bpf_ops is not found in kernel BTF

If you are running on a kernel not supporting struct_ops (only on unreleased kernel, so 99% of the time) you need to manually load the 09-Rapoo__M50-Plus-Silent.bpf.o file. Once installed, you don't notice the difference, but for manual loading, you need to rely on that different file

added 1 commit

• fa5a3c0d - HID: bpf: Fix Rapoo M50 Plus Silent side buttons

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The compilation fails with libbpf: failed to find BTF info for global/extern symbol 'memcmp'

$ clang --version
Ubuntu clang version 14.0.0-1ubuntu1.1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

Maybe this is issue only with Huion files, but I'm not familiar with meson... how I make it ignore this? Or any suggestions to fix the issue?

Maybe this is issue only with Huion files, but I'm not familiar with meson... how I make it ignore this? Or any suggestions to fix the issue?

This looks like a not recent enough LLVM version.

The simplest is to download the artifacts of the last job of the last pipeline (currently https://gitlab.freedesktop.org/JoseExposito/udev-hid-bpf/-/jobs/60965628/artifacts/file/udev-hid-bpf_1.0.1-20240515-63-gfa5a3c0.tar.xz) -> download the artifacts, extract them and then run ./bin/udev-hid-bpf --version. If you don't get any error, you can run the install.sh script, then unplug replug the mouse.

If you get some issues with libc not recent enough, you could comment out all the problematic files in src/bpf/testing/meson.build, src/bpf/stable/meson.build, and src/bpf/userhacks/meson.build because you don't really need them, all you need is the bpf object @jexposit made for you. And if you can not even compile it, you can still take the one from the archive I mentioned above, it should work fine on your kernel.

OK, I tried to change to clang version 15.0.7 (that was newest in the repo), but it didn't help. So I disabled the offending targets and now things go much further... Now compiling stops with these:

../src/bpf/hid_bpf_helpers.h:167:15: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘#pragma’
  167 | } _device_ids SEC(".hid_bpf_config")
      |               ^~~

Still clang version issue? Looks kinda it, when it cannot understand the syntax. I guess the dependency should be at least for clang version 16.

However, I'm happy to tell that using the binaries you wrote and compiled for me work perfectly! Thank you very much for both of you!

lgtm with two minor nitpicks

approved this merge request

mentioned in merge request !119 (merged)

added 1 commit

• 716cd111 - HID: bpf: Fix Rapoo M50 Plus Silent side buttons

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added 10 commits

• 716cd111...a32ec802 - 9 commits from branch libevdev:main
• e9bad3c3 - HID: bpf: Fix Rapoo M50 Plus Silent side buttons

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resolved all threads

enabled an automatic merge when the pipeline for e9bad3c3 succeeds

merged

mentioned in commit bentiss/udev-hid-bpf@90f4bba6

mentioned in commit bentiss/hid@cee9faff