Re: [PATCH 09/20] perf report: free generated help strings for sort option

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

Em Thu, Jul 15, 2021 at 06:07:14PM +0200, Riccardo Mancini escreveu:
> ASan reports the memory leak of the strings allocated by sort_help when
> running perf report.
> 
> This patch changes the returned pointer to char* (instead of const char*),
> saves it in a temporary variable, and finally deallocates it at function
> exit.

Fixes: 702fb9b415e7c99b ("perf report: Show all sort keys in help output")

Thanks, applied.

- Arnaldo

 
> Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
> ---
>  tools/perf/builtin-report.c | 33 ++++++++++++++++++++++-----------
>  tools/perf/util/sort.c      |  2 +-
>  tools/perf/util/sort.h      |  2 +-
>  3 files changed, 24 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index 6386af6a2612367c..dc0364f671b97d26 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -1175,6 +1175,8 @@ int cmd_report(int argc, const char **argv)
>  		.annotation_opts	 = annotation__default_options,
>  		.skip_empty		 = true,
>  	};
> +	char *sort_order_help = sort_help("sort by key(s):");
> +	char *field_order_help = sort_help("output field(s): overhead period sample ");
>  	const struct option options[] = {
>  	OPT_STRING('i', "input", &input_name, "file",
>  		    "input file name"),
> @@ -1209,9 +1211,9 @@ int cmd_report(int argc, const char **argv)
>  	OPT_BOOLEAN(0, "header-only", &report.header_only,
>  		    "Show only data header."),
>  	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
> -		   sort_help("sort by key(s):")),
> +		   sort_order_help),
>  	OPT_STRING('F', "fields", &field_order, "key[,keys...]",
> -		   sort_help("output field(s): overhead period sample ")),
> +		   field_order_help),
>  	OPT_BOOLEAN(0, "show-cpu-utilization", &symbol_conf.show_cpu_utilization,
>  		    "Show sample percentage for different cpu modes"),
>  	OPT_BOOLEAN_FLAG(0, "showcpuutilization", &symbol_conf.show_cpu_utilization,
> @@ -1344,11 +1346,11 @@ int cmd_report(int argc, const char **argv)
>  	char sort_tmp[128];
>  
>  	if (ret < 0)
> -		return ret;
> +		goto exit;
>  
>  	ret = perf_config(report__config, &report);
>  	if (ret)
> -		return ret;
> +		goto exit;
>  
>  	argc = parse_options(argc, argv, options, report_usage, 0);
>  	if (argc) {
> @@ -1362,8 +1364,10 @@ int cmd_report(int argc, const char **argv)
>  		report.symbol_filter_str = argv[0];
>  	}
>  
> -	if (annotate_check_args(&report.annotation_opts) < 0)
> -		return -EINVAL;
> +	if (annotate_check_args(&report.annotation_opts) < 0) {
> +		ret = -EINVAL;
> +		goto exit;
> +	}
>  
>  	if (report.mmaps_mode)
>  		report.tasks_mode = true;
> @@ -1377,12 +1381,14 @@ int cmd_report(int argc, const char **argv)
>  	if (symbol_conf.vmlinux_name &&
>  	    access(symbol_conf.vmlinux_name, R_OK)) {
>  		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
> -		return -EINVAL;
> +		ret = -EINVAL;
> +		goto exit;
>  	}
>  	if (symbol_conf.kallsyms_name &&
>  	    access(symbol_conf.kallsyms_name, R_OK)) {
>  		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
> -		return -EINVAL;
> +		ret = -EINVAL;
> +		goto exit;
>  	}
>  
>  	if (report.inverted_callchain)
> @@ -1406,12 +1412,14 @@ int cmd_report(int argc, const char **argv)
>  
>  repeat:
>  	session = perf_session__new(&data, false, &report.tool);
> -	if (IS_ERR(session))
> -		return PTR_ERR(session);
> +	if (IS_ERR(session)) {
> +		ret = PTR_ERR(session);
> +		goto exit;
> +	}
>  
>  	ret = evswitch__init(&report.evswitch, session->evlist, stderr);
>  	if (ret)
> -		return ret;
> +		goto exit;
>  
>  	if (zstd_init(&(session->zstd_data), 0) < 0)
>  		pr_warning("Decompression initialization failed. Reported data may be incomplete.\n");
> @@ -1646,5 +1654,8 @@ int cmd_report(int argc, const char **argv)
>  
>  	zstd_fini(&(session->zstd_data));
>  	perf_session__delete(session);
> +exit:
> +	free(sort_order_help);
> +	free(field_order_help);
>  	return ret;
>  }
> diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
> index 88ce47f2547e3558..568a88c001c6cb5a 100644
> --- a/tools/perf/util/sort.c
> +++ b/tools/perf/util/sort.c
> @@ -3370,7 +3370,7 @@ static void add_hpp_sort_string(struct strbuf *sb, struct hpp_dimension *s, int
>  		add_key(sb, s[i].name, llen);
>  }
>  
> -const char *sort_help(const char *prefix)
> +char *sort_help(const char *prefix)
>  {
>  	struct strbuf sb;
>  	char *s;
> diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
> index 87a092645aa72e41..b67c469aba79587f 100644
> --- a/tools/perf/util/sort.h
> +++ b/tools/perf/util/sort.h
> @@ -302,7 +302,7 @@ void reset_output_field(void);
>  void sort__setup_elide(FILE *fp);
>  void perf_hpp__set_elide(int idx, bool elide);
>  
> -const char *sort_help(const char *prefix);
> +char *sort_help(const char *prefix);
>  
>  int report_parse_ignore_callees_opt(const struct option *opt, const char *arg, int unset);
>  
> -- 
> 2.31.1
> 

-- 

- Arnaldo