[PATCH v1 1/1] selftests: mm: uufd-unit-tests: remove a format warning in printf

[Mirsad Todorovac]

GCC 11.3.0 issued warnings about macros and types of arguments [edited]:

gcc -Wall -I ../tools/testing/selftests/../../.. \
	-I ../tools/testing/selftests/../../../tools/include/uapi \
	-isystem ../usr/include -no-pie uffd-unit-tests.c vm_util.c \
	uffd-common.c -lrt -lpthread -o \
	../tools/testing/selftests/mm/uffd-unit-tests
uffd-unit-tests.c: In function ‘main’:
uffd-unit-tests.c:1198:41: warning: format not a string literal and no \
	format arguments [-Wformat-security]
 1198 |                         uffd_test_start(test_name);
      |                                         ^~~~~~~~~
uffd-unit-tests.c:100:24: note: in definition of macro ‘uffd_test_start’
  100 |                 printf(__VA_ARGS__);            \
      |                        ^~~~~~~~~~~
uffd-unit-tests.c:1205:33: warning: format not a string literal and no \
	format arguments [-Wformat-security]
 1205 |                                 uffd_test_skip(errmsg);
      |                                 ^~~~~~~~~~~~~~

The macros are defined as:

 #define  uffd_test_start(...)  do {             \
                printf("Testing ");             \
                printf(__VA_ARGS__);            \
                printf("... ");                 \
                fflush(stdout);                 \
        } while (0)

 #define  uffd_test_skip(...)  do {              \
                printf("skipped [reason: ");    \
                printf(__VA_ARGS__);            \
                printf("]\n");                  \
                ksft_inc_xskip_cnt();           \
        } while (0)

Minor workaround, adding "%s" first argument to macro expansion calls seems
to be the easiest way to eliminate the warnings.

Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Fixes: 43759d44dc34 ("selftests/mm: add uffdio register ioctls test")
Fixes: 16a45b57cbf2 ("selftests/mm: add framework for uffd-unit-test")
Signed-off-by: Mirsad Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
---
 tools/testing/selftests/mm/uffd-unit-tests.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index 269c86768a02..d356dd271c84 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -1195,14 +1195,14 @@ int main(int argc, char *argv[])
 			snprintf(test_name, sizeof(test_name),
 				 "%s on %s", test->name, mem_type->name);
 
-			uffd_test_start(test_name);
+			uffd_test_start("%s", test_name);
 			if (!uffd_feature_supported(test)) {
 				uffd_test_skip("feature missing");
 				continue;
 			}
 			if (uffd_setup_environment(&args, test, mem_type,
 						   &errmsg)) {
-				uffd_test_skip(errmsg);
+				uffd_test_skip("%s", errmsg);
 				continue;
 			}
 			test->uffd_fn(&args);
-- 
2.34.1