Re: [PATCH] perf stat: Fix error check for bpf_program__attach

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, May 27, 2021 at 03:00:52PM -0700, Namhyung Kim escreveu:
> It seems the bpf_program__attach() returns a negative error code
> instead of a NULL pointer in case of error.

Thanks, applied.

- Arnaldo

 
> Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
> Cc: Song Liu <songliubraving@fb.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/bpf_counter.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
> index ddb52f748c8e..974f10e356f0 100644
> --- a/tools/perf/util/bpf_counter.c
> +++ b/tools/perf/util/bpf_counter.c
> @@ -451,10 +451,10 @@ static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
>  		goto out;
>  	}
>  
> -	err = -1;
>  	link = bpf_program__attach(skel->progs.on_switch);
> -	if (!link) {
> +	if (IS_ERR(link)) {
>  		pr_err("Failed to attach leader program\n");
> +		err = PTR_ERR(link);
>  		goto out;
>  	}
>  
> -- 
> 2.32.0.rc0.204.g9fa02ecfa5-goog
> 

-- 

- Arnaldo