[LTP] [PATCH v2] clone3: Add clone3's clone_args cgroup

[Cyril Hrubis]

Hi!
> --- /dev/null
> +++ b/testcases/kernel/syscalls/clone3/clone303.c
> @@ -0,0 +1,98 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2023 SUSE LLC <wegao@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * This test case check clone3 CLONE_INTO_CGROUP flag
> + *
> + */
> +
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/wait.h>
> +
> +#include "tst_test.h"
> +#include "lapi/sched.h"
> +#include "lapi/pidfd.h"
> +
> +#define BUF_LEN 20
> +#define CLONE_INTO_CGROUP 0x200000000ULL

This should be added as a fallback definition into lapi/sched.h

> +static struct tst_cg_group *cg_child_test_simple;
> +static struct clone_args *args;
> +
> +static pid_t clone_into_cgroup(int cgroup_fd)
> +{
> +	pid_t pid;
> +
> +	args->flags = CLONE_INTO_CGROUP;
> +	args->exit_signal = SIGCHLD;
> +	args->cgroup = cgroup_fd;
> +
> +	pid = clone3(args, sizeof(*args));
> +
> +	if (pid < 0)
> +		tst_res(TFAIL | TTERRNO, "clone3() failed !");
> +
> +	return pid;
> +}
> +
> +static void run(void)
> +{
> +	char path[100];
> +	int fd;
> +	pid_t pid;
> +
> +	cg_child_test_simple = tst_cg_group_mk(tst_cg, "cg_test_simple");
> +	sprintf(path, "/sys/fs/cgroup/ltp/%s/%s", tst_cg_group_name(tst_cg), tst_cg_group_name(cg_child_test_simple));

There is no guarantee that the cgroup is mounted in this hardcoded path
and that the top level directory for LTP tests is called ltp.

Moreover we already do have a file descriptor pointing to the directory
for cgroup v2 opened in the cgroup library. All we need is a function in
the library that would find the take the tst_cg_group and find the right
cgroup_dir in the dirs[] array.

> +	tst_res(TINFO, "cgroup path is %s", path);
> +	fd = SAFE_OPEN(path, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW | O_PATH);
> +
> +	pid = clone_into_cgroup(fd);
> +
> +	if (!pid) {
> +		TST_CHECKPOINT_WAIT(0);

Just add reutrn; here and drop the else below.

> +	} else {
> +
> +		char buf[BUF_LEN];
> +
> +		SAFE_CG_READ(cg_child_test_simple, "cgroup.procs", buf, BUF_LEN);
                                                                          ^
									  sizeof(buf);
> +
> +		int x = atoi(buf);
> +
> +		if (x == pid)
> +			tst_res(TPASS, "clone3 case pass!");
> +		else
> +			tst_brk(TFAIL | TTERRNO, "clone3() failed !");
> +
> +		TST_CHECKPOINT_WAKE(0);
> +
> +		SAFE_WAITPID(pid, NULL, 0);
> +
> +		cg_child_test_simple = tst_cg_group_rm(cg_child_test_simple);
> +	}
> +}
> +
> +static void setup(void)
> +{
> +	clone3_supported_by_kernel();
> +}
> +
> +static struct tst_test test = {
> +	.test_all = run,
> +	.setup = setup,
> +	.forks_child = 1,
> +	.max_runtime = 20,
> +	.needs_cgroup_ctrls = (const char *const []){ "memory", NULL },
> +	.needs_cgroup_ver = TST_CG_V2,
> +	.needs_checkpoints = 1,
> +	.min_kver = "5.7",
> +	.bufs = (struct tst_buffers []) {
> +		{&args, .size = sizeof(*args)},
> +		{},
> +	}
> +};
> -- 
> 2.35.3
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz