From: Konstantin Khorenko Date: Sun, 24 May 2026 19:35:56 +0000 (+0300) Subject: selftests/memfd: fix -Wmaybe-uninitialized warning in memfd_test X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=528db7d37e08dc7eae70d046cda5a2ee30208448;p=thirdparty%2Flinux.git selftests/memfd: fix -Wmaybe-uninitialized warning in memfd_test Patch series "selftests/memfd: fix compilation warnings". This patchset fixes warnings about unused but initialized variables, and unused dummy buffer passed to pwrite() syscall in the tests. This patch (of 2): memfd_test.c: In function 'mfd_fail_grow_write.part.0': memfd_test.c:685:13: warning: '' 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. Link: https://lore.kernel.org/20260524193732.48853-1-eva.kurchatova@virtuozzo.com Link: https://lore.kernel.org/20260524193732.48853-2-eva.kurchatova@virtuozzo.com Signed-off-by: Konstantin Khorenko Signed-off-by: Eva Kurchatova Cc: Aristeu Rozanski Cc: Shuah Khan Signed-off-by: Andrew Morton --- diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c index 2ca07ea7202a5..cdab3a8376244 100644 --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -688,9 +688,9 @@ static void mfd_assert_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); + printf("calloc(1, %zu) failed: %m\n", mfd_def_size * 8); abort(); }