mdadm: add map_num_s()

map_num() returns NULL if key is not defined. This patch adds
alternative, non NULL version for cases where NULL is not expected.

There are many printf() calls where map_num() is called on variable
without NULL verification. It works, even if NULL is passed because
gcc is able to ignore NULL argument quietly but the behavior is
undefined. For safety reasons such usages will use map_num_s() now.
It is a potential point of regression.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/mdadm.h b/mdadm.h
index cd72e711..09915a00 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -770,7 +770,7 @@ extern int restore_stripes(int *dest, unsigned long long *offsets,
 #endif
 
 #define SYSLOG_FACILITY LOG_DAEMON
-
+extern char *map_num_s(mapping_t *map, int num);
 extern char *map_num(mapping_t *map, int num);
 extern int map_name(mapping_t *map, char *name);
 extern mapping_t r0layout[], r5layout[], r6layout[],