lssubsys: Fix strncpy() truncation warning

Fix the following strncpy() string truncation warning:

In function ‘strncpy’,
    inlined from ‘print_all_controllers_in_hierarchy’ at lssubsys.c:127:4,
    inlined from ‘cgroup_list_all_controllers’ at lssubsys.c:223:9,
    inlined from ‘main’ at lssubsys.c:291:8:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: warning: ‘__builtin_strncpy’ output may be truncated copying 4095 bytes from a string of length 4095 [-Wstringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>

diff --git a/src/tools/lssubsys.c b/src/tools/lssubsys.c
index e77859b40e331c45f1c8f6b13352aa52eacf1253..a6713b8bf0669f0c662893a9d1d8730697def99c 100644 (file)
--- a/src/tools/lssubsys.c
+++ b/src/tools/lssubsys.c
@@ -125,6 +125,8 @@ static int print_all_controllers_in_hierarchy(const char *tname,
                        /* the first controller in the hierarchy */
                        memset(cont_name, 0, FILENAME_MAX);
                        strncpy(cont_name, info.name, FILENAME_MAX-1);
+                       cont_name[sizeof(cont_name) - 1] = '\0';
+
                        memset(cont_names, 0, FILENAME_MAX);
                        strncpy(cont_names, info.name, FILENAME_MAX-1);
                        first = 0;