Re: [PATCH v2 0/3] selftests/hid: fix building for older kernels

From: Justin Stitt
Date: Tue Oct 03 2023 - 18:35:15 EST


On Mon, Oct 2, 2023 at 7:48 AM Benjamin Tissoires <bentiss@xxxxxxxxxx> wrote:
>
> On Sep 26 2023, Justin Stitt wrote:
> > Hey all,
> >
> > Gentle ping on this patch. Looking to get this patch and [1] slated
> > for 6.7 wherein we can start getting cleaner kselftests builds.
> >
> > I do not think I am able to successfully run the hid/bpf selftests due
> > to my kernel version being too low (and an inability to upgrade it as
> > I'm on a corp rolling release). I'd appreciate some insight on how to
> > get the tests running or if someone could actually build+run the tests
> > with this patch applied.
>
> I wanted to apply this series today, but it failed my own CI now with
> the enums being already defined:
> https://gitlab.freedesktop.org/bentiss/hid/-/jobs/49754306
>
> I'll probably squash the following patch in 1/3, would you mind giving
> it a test?

Works for me with this incantation:
$ make LLVM=1 -j128 ARCH=x86_64 mrproper headers && make LLVM=1 -j128
ARCH=x86_64 -C tools/testing/selftests TARGETS=hid
...
---> BINARY hid_bpf

Although, the tests expectedly fail.

Looks good to me.

>
> ---
> From 37feca6c0e84705ad65e621643206c287b63bb0a Mon Sep 17 00:00:00 2001
> From: Benjamin Tissoires <bentiss@xxxxxxxxxx>
> Date: Mon, 2 Oct 2023 15:37:18 +0200
> Subject: [PATCH] fix selftests/hid: ensure we can compile the tests on kernels
> pre-6.3
>
> Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>
> ---
> .../selftests/hid/progs/hid_bpf_helpers.h | 30 ++++++++++++++++++-
> 1 file changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
> index ab3b18ba48c4..feed5a991e05 100644
> --- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
> +++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
> @@ -5,16 +5,44 @@
> #ifndef __HID_BPF_HELPERS_H
> #define __HID_BPF_HELPERS_H
>
> -/* "undefine" structs in vmlinux.h, because we "override" them below */
> +/* "undefine" structs and enums in vmlinux.h, because we "override" them below */
> #define hid_bpf_ctx hid_bpf_ctx___not_used
> #define hid_report_type hid_report_type___not_used
> #define hid_class_request hid_class_request___not_used
> #define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
> +#define HID_INPUT_REPORT HID_INPUT_REPORT___not_used
> +#define HID_OUTPUT_REPORT HID_OUTPUT_REPORT___not_used
> +#define HID_FEATURE_REPORT HID_FEATURE_REPORT___not_used
> +#define HID_REPORT_TYPES HID_REPORT_TYPES___not_used
> +#define HID_REQ_GET_REPORT HID_REQ_GET_REPORT___not_used
> +#define HID_REQ_GET_IDLE HID_REQ_GET_IDLE___not_used
> +#define HID_REQ_GET_PROTOCOL HID_REQ_GET_PROTOCOL___not_used
> +#define HID_REQ_SET_REPORT HID_REQ_SET_REPORT___not_used
> +#define HID_REQ_SET_IDLE HID_REQ_SET_IDLE___not_used
> +#define HID_REQ_SET_PROTOCOL HID_REQ_SET_PROTOCOL___not_used
> +#define HID_BPF_FLAG_NONE HID_BPF_FLAG_NONE___not_used
> +#define HID_BPF_FLAG_INSERT_HEAD HID_BPF_FLAG_INSERT_HEAD·___not_used
> +#define HID_BPF_FLAG_MAX HID_BPF_FLAG_MAX___not_used
> +
> #include "vmlinux.h"
> +
> #undef hid_bpf_ctx
> #undef hid_report_type
> #undef hid_class_request
> #undef hid_bpf_attach_flags
> +#undef HID_INPUT_REPORT
> +#undef HID_OUTPUT_REPORT
> +#undef HID_FEATURE_REPORT
> +#undef HID_REPORT_TYPES
> +#undef HID_REQ_GET_REPORT
> +#undef HID_REQ_GET_IDLE
> +#undef HID_REQ_GET_PROTOCOL
> +#undef HID_REQ_SET_REPORT
> +#undef HID_REQ_SET_IDLE
> +#undef HID_REQ_SET_PROTOCOL
> +#undef HID_BPF_FLAG_NONE
> +#undef HID_BPF_FLAG_INSERT_HEAD
> +#undef HID_BPF_FLAG_MAX
>
> #include <bpf/bpf_helpers.h>
> #include <bpf/bpf_tracing.h>
> --
> 2.41.0
> ---
>
> Cheers,
> Benjamin
>
> >
> > On Sat, Sep 9, 2023 at 7:22 AM Justin Stitt <justinstitt@xxxxxxxxxx> wrote:
> > >
> > > Hi, I am sending this series on behalf of myself and Benjamin Tissoires. There
> > > existed an initial n=3 patch series which was later expanded to n=4 and
> > > is now back to n=3 with some fixes added in and rebased against
> > > mainline.
> > >
> > > This patch series aims to ensure that the hid/bpf selftests can be built
> > > without errors.
> > >
> > > Here's Benjamin's initial cover letter for context:
> > > | These fixes have been triggered by [0]:
> > > | basically, if you do not recompile the kernel first, and are
> > > | running on an old kernel, vmlinux.h doesn't have the required
> > > | symbols and the compilation fails.
> > > |
> > > | The tests will fail if you run them on that very same machine,
> > > | of course, but the binary should compile.
> > > |
> > > | And while I was sorting out why it was failing, I realized I
> > > | could do a couple of improvements on the Makefile.
> > > |
> > > | [0] https://lore.kernel.org/linux-input/56ba8125-2c6f-a9c9-d498-0ca1c153dcb2@xxxxxxxxxx/T/#t
> > >
> > > Changes from v1 -> v2:
> > > - roll Justin's fix into patch 1/3
> > > - add __attribute__((preserve_access_index)) (thanks Eduard)
> > > - rebased onto mainline (2dde18cd1d8fac735875f2e4987f11817cc0bc2c)
> > > - Link to v1: https://lore.kernel.org/all/20230825-wip-selftests-v1-0-c862769020a8@xxxxxxxxxx/
> > >
> > > Link: https://github.com/ClangBuiltLinux/linux/issues/1698
> > > Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/61
> > > ---
> > > Benjamin Tissoires (3):
> > > selftests/hid: ensure we can compile the tests on kernels pre-6.3
> > > selftests/hid: do not manually call headers_install
> > > selftests/hid: force using our compiled libbpf headers
> > >
> > > tools/testing/selftests/hid/Makefile | 10 ++---
> > > tools/testing/selftests/hid/progs/hid.c | 3 --
> > > .../testing/selftests/hid/progs/hid_bpf_helpers.h | 49 ++++++++++++++++++++++
> > > 3 files changed, 53 insertions(+), 9 deletions(-)
> > > ---
> > > base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c
> > > change-id: 20230908-kselftest-09-08-56d7f4a8d5c4
> > >
> > > Best regards,
> > > --
> > > Justin Stitt <justinstitt@xxxxxxxxxx>
> > >
> >
> > [1]: https://lore.kernel.org/all/20230912-kselftest-param_test-c-v1-1-80a6cffc7374@xxxxxxxxxx/
> >
> > Thanks
> > Justin

Thanks
Justin