Re: [PATCH v3 0/4] Bring back vmlinux.h generation

Jiri Olsa
2023-06-10T22:14:37Z

On Thu, Jun 08, 2023 at 09:32:36PM -0700, Ian Rogers wrote:
> Commit 760ebc45746b ("perf lock contention: Add empty 'struct rq' to
> satisfy libbpf 'runqueue' type verification") inadvertently created a
> declaration of 'struct rq' that conflicted with a generated
> vmlinux.h's:
>
> ```
> util/bpf_skel/lock_contention.bpf.c:419:8: error: redefinition of 'rq'
> struct rq {};
> ^
> /tmp/perf/util/bpf_skel/.tmp/../vmlinux.h:45630:8: note: previous definition is here
> struct rq {
> ^
> 1 error generated.
> ```
>
> Fix the issue by moving the declaration to vmlinux.h. So this can't
> happen again, bring back build support for generating vmlinux.h then
> add build tests.
>
> v3. Address Namhyung's comments on filtering ELF files with readelf.

Acked-by: Jiri Olsa <jolsa@kernel.org>

jirka

> v2. Rebase on perf-tools-next. Add Andrii's acked-by. Add patch to
> filter out kernels that lack a .BTF section and cause the build to
> break.
>
> Ian Rogers (4):
> perf build: Add ability to build with a generated vmlinux.h
> perf bpf: Move the declaration of struct rq
> perf test: Add build tests for BUILD_BPF_SKEL
> perf build: Filter out BTF sources without a .BTF section
>
> tools/perf/Makefile.config | 4 ++
> tools/perf/Makefile.perf | 39 ++++++++++++++++++-
> tools/perf/tests/make | 4 ++
> tools/perf/util/bpf_skel/.gitignore | 1 +
> .../perf/util/bpf_skel/lock_contention.bpf.c | 2 -
> .../util/bpf_skel/{ => vmlinux}/vmlinux.h | 10 +++++
> 6 files changed, 57 insertions(+), 3 deletions(-)
> rename tools/perf/util/bpf_skel/{ => vmlinux}/vmlinux.h (90%)
>
> --
> 2.41.0.162.gfafddb0af9-goog
>