[LTP] [PATCH 2/2] syscalls/pidfd_open04: Add new test with PIDFD_NONBLOCK flag

[Cyril Hrubis]

Hi!
> diff --git a/testcases/kernel/syscalls/pidfd_open/pidfd_open04.c b/testcases/kernel/syscalls/pidfd_open/pidfd_open04.c
> new file mode 100644
> index 000000000..436351f23
> --- /dev/null
> +++ b/testcases/kernel/syscalls/pidfd_open/pidfd_open04.c
> @@ -0,0 +1,78 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
> + * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Verify that the PIDFD_NONBLOCK flag works with pidfd_open() and
> + * that waitid() with a non-blocking pidfd returns EAGAIN.
> + */
> +
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <sys/wait.h>
> +#include "tst_test.h"
> +#include "lapi/pidfd_open.h"
> +
> +#ifndef PIDFD_NONBLOCK
> +#define PIDFD_NONBLOCK O_NONBLOCK
> +#endif
> +
> +#ifndef P_PIDFD
> +#define P_PIDFD  3
> +#endif
> +
> +static void run(void)
> +{
> +	int flag, pid, pidfd;
> +	siginfo_t info;
> +
> +	pid = SAFE_FORK();
> +	if (!pid)
> +		pause();
> +
> +	TST_EXP_PID_SILENT(pidfd_open(pid, PIDFD_NONBLOCK),
> +				"pidfd_open(%d,  PIDFD_NONBLOCK)", pid);

Here as well FD_SILENT();

> +	pidfd = TST_RET;
> +	flag = fcntl(pidfd, F_GETFL);
> +	if (flag == -1)
> +		tst_brk(TFAIL | TERRNO, "fcntl(F_GETFL) failed");
> +
> +	if (!(flag & O_NONBLOCK))
> +		tst_brk(TFAIL, "pidfd_open(%d, O_NONBLOCK) didn't set O_NONBLOCK flag", pid);
> +
> +	tst_res(TPASS, "pidfd_open(%d, O_NONBLOCK) sets O_NONBLOCK flag", pid);
> +
> +	TST_EXP_FAIL(waitid(P_PIDFD, pidfd, &info, WEXITED), EAGAIN,
> +			"waitid(P_PIDFD,...,WEXITED)");
> +
> +	SAFE_KILL(pid, SIGTERM);
> +	SAFE_WAIT(NULL);
> +	SAFE_CLOSE(pidfd);

I guess that we can also test that the waitid() succeds now, right?

> +}
> +
> +static void setup(void)
> +{
> +	pidfd_open_supported();
> +
> +	TEST(pidfd_open(getpid(), PIDFD_NONBLOCK));
> +	if (TST_RET == -1) {
> +		if (TST_ERR == EINVAL) {
> +			tst_brk(TCONF, "PIDFD_NONBLOCK was supported since linux 5.10");
> +			return;
> +		}
> +		tst_brk(TFAIL | TTERRNO,
> +			"pidfd_open(getpid(),PIDFD_NONBLOCK) failed unexpectedly");
> +	}
> +}
> +
> +static struct tst_test test = {
> +	.needs_root = 1,
> +	.forks_child = 1,
> +	.setup = setup,
> +	.test_all = run,
> +};

-- 
Cyril Hrubis
chrubis@suse.cz