Re: [PATCH v8 4/5] perf config: Use zfree() instead of free() at perf_config_set__delete()

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Taeung Song <treeze.taeung@gmail.com>
Cc: linux-kernel@vger.kernel.org, Jiri Olsa <jolsa@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Wang Nan <wangnan0@huawei.com>, Jiri Olsa <jolsa@redhat.com>
Subject: Re: [PATCH v8 4/5] perf config: Use zfree() instead of free() at perf_config_set__delete()
Date: Thu, 9 Jun 2016 10:37:38 -0300	[thread overview]
Message-ID: <20160609133738.GK11589@kernel.org> (raw)
In-Reply-To: <1465389413-8936-5-git-send-email-treeze.taeung@gmail.com>

Em Wed, Jun 08, 2016 at 09:36:52PM +0900, Taeung Song escreveu:
> perf_config_set__delete() delete allocated the config set
> but the global variable 'config_set' is used all around.

> So purge and zfree by an address of the global variable
> , i.e. 'struct perf_config_set **' type
> instead of using local variable 'set' of which type
> is 'struct perf_config_set *'.

> -void perf_config_set__delete(struct perf_config_set *set)
> +void perf_config_set__delete(struct perf_config_set **set)
>  {
> -	if (set == NULL)
> +	if (*set == NULL)
>  		return;
>  
> -	perf_config_set__purge(set);
> -	free(set);
> +	perf_config_set__purge(*set);
> +	zfree(set);
>  }

Nope, don't change conventions like taht, a delete method should not
receive a pointer to the pointer to be deleted, no odd cases, please.

If you really think this is interesting, please introduce zdelete(),
i.e.:

void perf_config_set__zdelete(struct perf_config_set **set)
{
	if (!set)
		return;

	perf_config_set__delete(*set);
	*set = NULL;
}

- Arnaldo