selftests/pidfd: check PIDFD_THREAD survives open_by_handle_at()

Verify that a thread pidfd reopened via open_by_handle_at() still
reports PIDFD_THREAD in F_GETFL.

Signed-off-by: Li Chen <me@linux.beauty>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260716052726.1032092-1-me@linux.beauty
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

diff --git a/tools/testing/selftests/pidfd/pidfd_file_handle_test.c b/tools/testing/selftests/pidfd/pidfd_file_handle_test.c
index 68918734dcf3247a516d55e7da2000d73cb8224e..1e03ae9575fe6672cb7dfb4eb72a82623e75515c 100644 (file)
--- a/tools/testing/selftests/pidfd/pidfd_file_handle_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_file_handle_test.c
@@ -373,6 +373,7 @@ TEST_F(file_handle, open_by_handle_at_valid_flags)
                                  O_CLOEXEC |
                                  O_EXCL);
        ASSERT_GE(pidfd, 0);
+       ASSERT_NE(fcntl(pidfd, F_GETFL) & PIDFD_THREAD, 0);
 
        ASSERT_EQ(fstat(pidfd, &st2), 0);
        ASSERT_TRUE(st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);