[v3] Bring back vmlinux.h generation

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

Posted by Ian Rogers 2 years, 8 months ago

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.
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

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

Posted by Jiri Olsa 2 years, 8 months ago

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
>

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

Posted by Namhyung Kim 2 years, 8 months ago

Hi Ian,

On Thu, Jun 8, 2023 at 9:32 PM Ian Rogers <irogers@google.com> 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.
> 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

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


>
>  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
>