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

[Athira Rajeev]

> On 7 Jan 2025, at 2:45 AM, Namhyung Kim <namhyung at kernel.org> wrote:
> 
> Hello,
> 
> On Mon, Dec 23, 2024 at 07:26:55PM +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
>> 
>> Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
> 
> Thanks for the fix, the change itself looks good but I think we need the
> same for setup_output_field() and select_key() as well.
> 
> Thanks,
> Namhyung

Hi Namhyung

Thanks for reviewing and pointing out setup_output_field() and select_key()
I will send a V2 with handling return code for these two functions as well

Thanks
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 	(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