[PATCH 04/63] perf stat: Avoid segfaults caused by negated options

[Arnaldo Carvalho de Melo]

From: Michael Petlan <mpetlan@xxxxxxxxxx>

Some 'perf stat' options do not make sense to be negated (event,
cgroup), some do not have negated path implemented (metrics). Due to
that, it is better to disable the "no-" prefix for them, since
otherwise, the later opt-parsing segfaults.

Before:

  $ perf stat --no-metrics -- ls
  Segmentation fault (core dumped)

After:

  $ perf stat --no-metrics -- ls
   Error: option `no-metrics' isn't available
   Usage: perf stat [<options>] [<command>]

Signed-off-by: Michael Petlan <mpetlan@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
LPU-Reference: 1485912065.62416880.1544457604340.JavaMail.zimbra@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/builtin-stat.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a635abfa77b6..1410d66192f7 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -709,7 +709,7 @@ static int parse_metric_groups(const struct option *opt,
 	return metricgroup__parse_groups(opt, str, &stat_config.metric_events);
 }
 
-static const struct option stat_options[] = {
+static struct option stat_options[] = {
 	OPT_BOOLEAN('T', "transaction", &transaction_run,
 		    "hardware transaction statistics"),
 	OPT_CALLBACK('e', "event", &evsel_list, "event",
@@ -1599,6 +1599,12 @@ int cmd_stat(int argc, const char **argv)
 		return -ENOMEM;
 
 	parse_events__shrink_config_terms();
+
+	/* String-parsing callback-based options would segfault when negated */
+	set_option_flag(stat_options, 'e', "event", PARSE_OPT_NONEG);
+	set_option_flag(stat_options, 'M', "metrics", PARSE_OPT_NONEG);
+	set_option_flag(stat_options, 'G', "cgroup", PARSE_OPT_NONEG);
+
 	argc = parse_options_subcommand(argc, argv, stat_options, stat_subcommands,
 					(const char **) stat_usage,
 					PARSE_OPT_STOP_AT_NON_OPTION);
-- 
2.19.2