[PATCH] tools/perf: Fix return code for lock_contention_prepare

[Athira Rajeev]

> On 23 Dec 2024, at 7:26 PM, Athira Rajeev <atrajeev at linux.vnet.ibm.com> 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
> 
> Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>

Hi,

Looking for review comments on this

Athira

> ---
> tools/perf/builtin-lock.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> index 208c482daa56..2226c7dd4ae6 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;
> }
> -- 
> 2.43.5
>