[tip:perf/core] perf config: Handle the error when config set is NULL at collect_config()

[tip-bot for Taeung Song]

Commit-ID:  7db91f251056f90fec4121f028680ab3153a0f3c
Gitweb:     http://git.kernel.org/tip/7db91f251056f90fec4121f028680ab3153a0f3c
Author:     Taeung Song <treeze.taeung@xxxxxxxxx>
AuthorDate: Mon, 6 Jun 2016 19:52:54 +0900
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 6 Jun 2016 17:43:19 -0300

perf config: Handle the error when config set is NULL at collect_config()

collect_config() collect all config key-value pairs from config files
and put each config info in config set.  But if config set (i.e. 'set'
variable at collect_config()) is NULL, this is wrong so handle it.

Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1465210380-26749-4-git-send-email-treeze.taeung@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/config.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index b500737..c73f1c4 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -607,8 +607,12 @@ static int collect_config(const char *var, const char *value,
 	struct perf_config_section *section = NULL;
 	struct perf_config_item *item = NULL;
 	struct perf_config_set *set = perf_config_set;
-	struct list_head *sections = &set->sections;
+	struct list_head *sections;
 
+	if (set == NULL)
+		return -1;
+
+	sections = &set->sections;
 	key = ptr = strdup(var);
 	if (!key) {
 		pr_debug("%s: strdup failed\n", __func__);