On Fri, Jan 10, 2025 at 03:07:30PM +0530, Athira Rajeev wrote:
> perf lock contention returns zero exit value even if the lock contention
> BPF setup failed.
>
> # ./perf lock con -b true
> libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was
> CONFIG_DEBUG_INFO_BTF enabled?
> libbpf: failed to find '.BTF' ELF section in
> /lib/modules/6.13.0-rc3+/build/vmlinux
> libbpf: failed to find valid kernel BTF
> libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was
> CONFIG_DEBUG_INFO_BTF enabled?
> libbpf: failed to find '.BTF' ELF section in
> /lib/modules/6.13.0-rc3+/build/vmlinux
> libbpf: failed to find valid kernel BTF
> libbpf: Error loading vmlinux BTF: -ESRCH
> libbpf: failed to load object 'lock_contention_bpf'
> libbpf: failed to load BPF skeleton 'lock_contention_bpf': -ESRCH
> Failed to load lock-contention BPF skeleton
> lock contention BPF setup failed
> # echo $?
> 0
>
> Fix this by saving the return code for lock_contention_prepare
> so that command exits with proper return code. Similarly set the
> return code properly for two other functions in builtin-lock, namely
> setup_output_field() and select_key().
>
> Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com>
Reviewed-by: Namhyung Kim <namhy...@kernel.org>
Thanks,
Namhyung
> ---
> Changelog:
> v1 -> v2
> Fixed return code in functions: setup_output_field()
> and select_key() as pointed out by Namhyung.
>
> tools/perf/builtin-lock.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> index 208c482daa56..94a2bc15a2fa 100644
> --- a/tools/perf/builtin-lock.c
> +++ b/tools/perf/builtin-lock.c
> @@ -2049,7 +2049,8 @@ static int __cmd_contention(int argc, const char **argv)
> goto out_delete;
> }
>
> - if (lock_contention_prepare(&con) < 0) {
> + err = lock_contention_prepare(&con);
> + if (err < 0) {
> pr_err("lock contention BPF setup failed\n");
> goto out_delete;
> }
> @@ -2070,10 +2071,14 @@ static int __cmd_contention(int argc, const char
> **argv)
> }
> }
>
> - if (setup_output_field(true, output_fields))
> + err = setup_output_field(true, output_fields);
> + if (err) {
> + pr_err("Failed to setup output field\n");
> goto out_delete;
> + }
>
> - if (select_key(true))
> + err = select_key(true);
> + if (err)
> goto out_delete;
>
> if (symbol_conf.field_sep) {
> --
> 2.43.5
>
