[Devel] [PATCH vz10 08/15] selftests/memfd: fix -Wmaybe-uninitialized warning in memfd_test

[Konstantin Khorenko]

  memfd_test.c: In function 'mfd_fail_grow_write.part.0':
  memfd_test.c:685:13: warning: '<unknown>' may be used uninitialized [-Wmaybe-uninitialized]
    685 |         l = pwrite(fd, buf, mfd_def_size * 8, 0);
        |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

pwrite() is declared with attribute 'access (read_only, 2, 3)', so GCC
knows it reads from the buffer. malloc() returns uninitialized memory,
hence the warning. Use calloc() to zero-initialize the buffer. The
actual contents don't matter here since the test verifies that pwrite()
fails on a sealed memfd.

https://virtuozzo.atlassian.net/browse/VSTOR-127529
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>

Feature: fix selftests
Made-with: Cursor
---
 tools/testing/selftests/memfd/memfd_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 95af2d78fd31..a6fb7128a5ac 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -676,7 +676,7 @@ static void mfd_fail_grow_write(int fd)
 	if (hugetlbfs_test)
 		return;
 
-	buf = malloc(mfd_def_size * 8);
+	buf = calloc(1, mfd_def_size * 8);
 	if (!buf) {
 		printf("malloc(%zu) failed: %m\n", mfd_def_size * 8);
 		abort();
-- 
2.47.1