Re: [PATCH v4 1/6] perf config: Use new perf_config_set__init() to initialize config set

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

Em Tue, May 31, 2016 at 10:13:43AM +0900, Taeung Song escreveu:
> Instead of perf_config(), This function initialize config set
> collecting all configs from config files (i.e. user config
> ~/.perfconfig and system config $(sysconfdir)/perfconfig).
> 
> If there are the same config variable both user and system
> config file, user config has higher priority than system config.
> 
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
> ---
>  tools/perf/util/config.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
> index dad7d82..5d01899 100644
> --- a/tools/perf/util/config.c
> +++ b/tools/perf/util/config.c
> @@ -645,13 +645,61 @@ out_free:
>  	return -1;
>  }
>  
> +static int perf_config_set__init(struct perf_config_set *set)
> +{
> +	int ret = 0, found = 0;
> +	const char *home = NULL;
> +
> +	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
> +	if (config_exclusive_filename)
> +		return perf_config_from_file(collect_config, config_exclusive_filename, set);
> +	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
> +		ret += perf_config_from_file(collect_config, perf_etc_perfconfig(), set);
> +		found += 1;
> +	}
> +
> +	home = getenv("HOME");
> +	if (perf_config_global() && home) {
> +		char *user_config = strdup(mkpath("%s/.perfconfig", home));
> +		struct stat st;
> +
> +		if (user_config == NULL) {
> +			warning("Not enough memory to process %s/.perfconfig, "
> +				"ignoring it.", home);
> +			goto out;
> +		}
> +
> +		if (stat(user_config, &st) < 0)
> +			goto out_free;
> +
> +		if (st.st_uid && (st.st_uid != geteuid())) {
> +			warning("File %s not owned by current user or root, "
> +				"ignoring it.", user_config);
> +			goto out_free;
> +		}
> +
> +		if (!st.st_size)
> +			goto out_free;
> +
> +		ret += perf_config_from_file(collect_config, user_config, set);
> +		found += 1;
> +out_free:
> +		free(user_config);
> +	}
> +out:
> +	if (found == 0)
> +		return -1;
> +	return ret;
> +}
> +
>  struct perf_config_set *perf_config_set__new(void)
>  {
>  	struct perf_config_set *set = zalloc(sizeof(*set));
>  
>  	if (set) {
>  		INIT_LIST_HEAD(&set->sections);
> -		perf_config(collect_config, set);
> +		if (perf_config_set__init(set) < 0)
> +			return NULL;

So, the usual pattern is: alloc, init, fail? free, return NULL.

I thought you could've been deviating from that pattern and went to look
at perf_config_set__init() to see if that was doing the freeing in case
of failure, which it shouldn't, it isn't, so I guess this is a leak on
failure, no?

- Arnaldo