Subject: Re: [PATCH] perf stat: Fix NULL vs IS_ERR() checking in check_per_pkg
To:     Miaoqian Lin <linmq006@gmail.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        James Clark <james.clark@arm.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Song Liu <songliubraving@fb.com>,
        Jin Yao <yao.jin@linux.intel.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20211212042325.9751-1-linmq006@gmail.com>
From:   German Gomez <german.gomez@arm.com>
Message-ID: <864ad02d-6afe-791c-f742-56582b633482@arm.com>
Date:   Sun, 12 Dec 2021 14:55:21 +0000
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Hi Miaoqian,

On 12/12/2021 04:23, Miaoqian Lin wrote:
> The hashmap__new() function does not return NULL on errors. It returns
> ERR_PTR(-ENOMEM). Using IS_ERR() to check the return value
> to fix this.
>
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  tools/perf/util/stat.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index 09ea334586f2..a77052680087 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -311,8 +311,8 @@ static int check_per_pkg(struct evsel *counter,
>  
>  	if (!mask) {
>  		mask = hashmap__new(pkg_id_hash, pkg_id_equal, NULL);
> -		if (!mask)
> -			return -ENOMEM;
> +		if (IS_ERR(mask))
> +			return PTR_ERR(mask);

I see that callers to "ids__new" are also missing these checks. Did you
consider patching those also?

Thanks,
German

>  
>  		counter->per_pkg_mask = mask;
>  	}