[LTP] [PATCH v1] Add epoll_wait05 test

[Richard Palethorpe]

Hello,

Andrea Cervesato via ltp <ltp@lists.linux.it> writes:

> This test verifies that epoll receives EPOLLHUP/EPOLLRDHUP event
> when we hang a reading half-socket we are polling on.
>
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  .../kernel/syscalls/epoll_wait/.gitignore     |  1 +
>  .../kernel/syscalls/epoll_wait/epoll_wait05.c | 74 +++++++++++++++++++
>  2 files changed, 75 insertions(+)
>  create mode 100644 testcases/kernel/syscalls/epoll_wait/epoll_wait05.c
>
> diff --git a/testcases/kernel/syscalls/epoll_wait/.gitignore b/testcases/kernel/syscalls/epoll_wait/.gitignore
> index 222955dd2..ab5a9c010 100644
> --- a/testcases/kernel/syscalls/epoll_wait/.gitignore
> +++ b/testcases/kernel/syscalls/epoll_wait/.gitignore
> @@ -2,3 +2,4 @@ epoll_wait01
>  epoll_wait02
>  epoll_wait03
>  epoll_wait04
> +epoll_wait05
> diff --git a/testcases/kernel/syscalls/epoll_wait/epoll_wait05.c b/testcases/kernel/syscalls/epoll_wait/epoll_wait05.c
> new file mode 100644
> index 000000000..7909a6586
> --- /dev/null
> +++ b/testcases/kernel/syscalls/epoll_wait/epoll_wait05.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Verify that epoll receives EPOLLHUP/EPOLLRDHUP event when we hang a reading
> + * half-socket we are polling on.
> + */
> +
> +#include <poll.h>
> +#include <sys/epoll.h>
> +#include "tst_test.h"
> +
> +static int sockfd;
> +static int epfd;
> +
> +static void cleanup(void)
> +{
> +	if (epfd > 0)
> +		SAFE_CLOSE(epfd);
> +
> +	if (sockfd > 0)
> +		SAFE_CLOSE(sockfd);
> +}
> +
> +static void run(void)
> +{
> +	int res;
> +	struct epoll_event evt_req;
> +	struct epoll_event evt_rec;
> +
> +	sockfd = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
> +
> +	epfd = epoll_create1(0);

I added safe epoll functions in an unmerged patch-set; see:
https://patchwork.ozlabs.org/project/ltp/patch/20220927161408.23743-2-rpalethorpe@suse.com/

I will merge that so you can use it here.

> +	if (epfd == -1)
> +		tst_brk(TBROK | TERRNO, "fail to create epoll instance");
> +
> +	tst_res(TINFO, "Polling on socket");
> +
> +	evt_req.events = EPOLLRDHUP;
> +	res = epoll_ctl(epfd, EPOLL_CTL_ADD, sockfd, &evt_req);
> +	if (res == -1)
> +		tst_brk(TBROK | TERRNO, "epoll_ctl failure");
> +
> +	tst_res(TINFO, "Hang reading half-socket");
> +	shutdown(sockfd, SHUT_RD);

We should check the return value. It will help with debugging if the
test fails.

> +
> +	res = epoll_wait(epfd, &evt_rec, 1, 2000);
> +	if (res <= 0) {
> +		tst_res(TFAIL | TERRNO, "epoll_wait() returned %i", res);
> +		return;
> +	}
> +
> +	if (evt_rec.events & EPOLLHUP)
> +		tst_res(TPASS, "Received EPOLLHUP");
> +	else
> +		tst_res(TFAIL, "EPOLLHUP has not been received");
> +
> +	if (evt_rec.events & EPOLLRDHUP)
> +		tst_res(TPASS, "Received EPOLLRDHUP");
> +	else
> +		tst_res(TFAIL, "EPOLLRDHUP has not been received");
> +
> +	SAFE_CLOSE(epfd);
> +}
> +
> +static struct tst_test test = {
> +	.cleanup = cleanup,
> +	.test_all = run,
> +	.forks_child = 1,
> +};
> -- 
> 2.35.3


-- 
Thank you,
Richard.