Messages in this thread | | | Date | Tue, 15 Mar 2022 19:04:19 +0200 | Subject | Re: [PATCH bpf-next v2 00/28] Introduce eBPF support for HID devices | From | Tero Kristo <> |
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Hi Benjamin,
On 04/03/2022 19:28, Benjamin Tissoires wrote: > Hi, > > This is a followup of my v1 at [0]. > > The short summary of the previous cover letter and discussions is that > HID could benefit from BPF for the following use cases: > > - simple fixup of report descriptor: > benefits are faster development time and testing, with the produced > bpf program being shipped in the kernel directly (the shipping part > is *not* addressed here). > > - Universal Stylus Interface: > allows a user-space program to define its own kernel interface > > - Surface Dial: > somehow similar to the previous one except that userspace can decide > to change the shape of the exported device > > - firewall: > still partly missing there, there is not yet interception of hidraw > calls, but it's coming in a followup series, I promise > > - tracing: > well, tracing. > > > I tried to address as many comments as I could and here is the short log > of changes: > > v2: > === > > - split the series by subsystem (bpf, HID, libbpf, selftests and > samples) > > - Added an extra patch at the beginning to not require CAP_NET_ADMIN for > BPF_PROG_TYPE_LIRC_MODE2 (please shout if this is wrong) > > - made the bpf context attached to HID program of dynamic size: > * the first 1 kB will be able to be addressed directly > * the rest can be retrieved through bpf_hid_{set|get}_data > (note that I am definitivey not happy with that API, because there > is part of it in bits and other in bytes. ouch) > > - added an extra patch to prevent non GPL HID bpf programs to be loaded > of type BPF_PROG_TYPE_HID > * same here, not really happy but I don't know where to put that check > in verifier.c > > - added a new flag BPF_F_INSERT_HEAD for BPF_LINK_CREATE syscall when in > used with HID program types. > * this flag is used for tracing, to be able to load a program before > any others that might already have been inserted and that might > change the data stream. > > Cheers, > Benjamin
I posted a couple of comments to the series, but other than that for the whole series you can use:
Reviewed-by: Tero Kristo <tero.kristo@linux.intel.com>
Tested-by: Tero Kristo <tero.kristo@linux.intel.com>
I did test this with my USI-BPF program + userspace code, they work with few minor updates compared to previous version.
-Tero
> > > > [0] https://lore.kernel.org/linux-input/20220224110828.2168231-1-benjamin.tissoires@redhat.com/T/#t > > > Benjamin Tissoires (28): > bpf: add new is_sys_admin_prog_type() helper > bpf: introduce hid program type > HID: hook up with bpf > libbpf: add HID program type and API > selftests/bpf: add tests for the HID-bpf initial implementation > samples/bpf: add new hid_mouse example > bpf/hid: add a new attach type to change the report descriptor > HID: allow to change the report descriptor from an eBPF program > libbpf: add new attach type BPF_HID_RDESC_FIXUP > selftests/bpf: add report descriptor fixup tests > samples/bpf: add a report descriptor fixup > bpf/hid: add hid_{get|set}_data helpers > HID: bpf: implement hid_bpf_get|set_data > selftests/bpf: add tests for hid_{get|set}_data helpers > bpf/hid: add new BPF type to trigger commands from userspace > libbpf: add new attach type BPF_HID_USER_EVENT > selftests/bpf: add test for user call of HID bpf programs > selftests/bpf: hid: rely on uhid event to know if a test device is > ready > bpf/hid: add bpf_hid_raw_request helper function > HID: add implementation of bpf_hid_raw_request > selftests/bpf: add tests for bpf_hid_hw_request > bpf/verifier: prevent non GPL programs to be loaded against HID > HID: bpf: compute only the required buffer size for the device > HID: bpf: only call hid_bpf_raw_event() if a ctx is available > bpf/hid: Add a flag to add the program at the beginning of the list > libbpf: add handling for BPF_F_INSERT_HEAD in HID programs > selftests/bpf: Add a test for BPF_F_INSERT_HEAD > samples/bpf: fix bpf_program__attach_hid() api change > > drivers/hid/Makefile | 1 + > drivers/hid/hid-bpf.c | 361 +++++++++ > drivers/hid/hid-core.c | 34 +- > include/linux/bpf-hid.h | 129 +++ > include/linux/bpf_types.h | 4 + > include/linux/hid.h | 25 + > include/uapi/linux/bpf.h | 59 ++ > include/uapi/linux/bpf_hid.h | 50 ++ > kernel/bpf/Makefile | 3 + > kernel/bpf/hid.c | 652 +++++++++++++++ > kernel/bpf/syscall.c | 26 +- > kernel/bpf/verifier.c | 7 + > samples/bpf/.gitignore | 1 + > samples/bpf/Makefile | 4 + > samples/bpf/hid_mouse_kern.c | 91 +++ > samples/bpf/hid_mouse_user.c | 129 +++ > tools/include/uapi/linux/bpf.h | 59 ++ > tools/lib/bpf/libbpf.c | 22 +- > tools/lib/bpf/libbpf.h | 2 + > tools/lib/bpf/libbpf.map | 1 + > tools/testing/selftests/bpf/prog_tests/hid.c | 788 +++++++++++++++++++ > tools/testing/selftests/bpf/progs/hid.c | 216 +++++ > 22 files changed, 2649 insertions(+), 15 deletions(-) > create mode 100644 drivers/hid/hid-bpf.c > create mode 100644 include/linux/bpf-hid.h > create mode 100644 include/uapi/linux/bpf_hid.h > create mode 100644 kernel/bpf/hid.c > create mode 100644 samples/bpf/hid_mouse_kern.c > create mode 100644 samples/bpf/hid_mouse_user.c > create mode 100644 tools/testing/selftests/bpf/prog_tests/hid.c > create mode 100644 tools/testing/selftests/bpf/progs/hid.c >
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