Commit 9f34c566 authored by Michal Koutný's avatar Michal Koutný Committed by Tejun Heo
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selftests: cgroup: Add basic tests for pids controller 



This commit adds (and wires in) new test program for checking basic pids
controller functionality -- restricting tasks in a cgroup and correct
event counting.

Signed-off-by: default avatarMichal Koutný <mkoutny@suse.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 70559685

tools/testing/selftests/cgroup/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -7,5 +7,6 @@ test_hugetlb_memcg 
test_kill

test_kmem

test_memcontrol

test_pids

test_zswap

wait_inotify

tools/testing/selftests/cgroup/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ TEST_GEN_PROGS += test_hugetlb_memcg 
TEST_GEN_PROGS += test_kill

TEST_GEN_PROGS += test_kmem

TEST_GEN_PROGS += test_memcontrol

TEST_GEN_PROGS += test_pids

TEST_GEN_PROGS += test_zswap



LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h
@@ -29,4 +30,5 @@ $(OUTPUT)/test_hugetlb_memcg: cgroup_util.c 
$(OUTPUT)/test_kill: cgroup_util.c

$(OUTPUT)/test_kmem: cgroup_util.c

$(OUTPUT)/test_memcontrol: cgroup_util.c

$(OUTPUT)/test_pids: cgroup_util.c

$(OUTPUT)/test_zswap: cgroup_util.c

tools/testing/selftests/cgroup/test_pids.c

0 → 100644
+178 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE



#include <errno.h>

#include <linux/limits.h>

#include <signal.h>

#include <string.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <unistd.h>



#include "../kselftest.h"

#include "cgroup_util.h"



static int run_success(const char *cgroup, void *arg)

{

	return 0;

}



static int run_pause(const char *cgroup, void *arg)

{

	return pause();

}



/*

 * This test checks that pids.max prevents forking new children above the

 * specified limit in the cgroup.

 */

static int test_pids_max(const char *root)

{

	int ret = KSFT_FAIL;

	char *cg_pids;

	int pid;



	cg_pids = cg_name(root, "pids_test");

	if (!cg_pids)

		goto cleanup;



	if (cg_create(cg_pids))

		goto cleanup;



	if (cg_read_strcmp(cg_pids, "pids.max", "max\n"))

		goto cleanup;



	if (cg_write(cg_pids, "pids.max", "2"))

		goto cleanup;



	if (cg_enter_current(cg_pids))

		goto cleanup;



	pid = cg_run_nowait(cg_pids, run_pause, NULL);

	if (pid < 0)

		goto cleanup;



	if (cg_run_nowait(cg_pids, run_success, NULL) != -1 || errno != EAGAIN)

		goto cleanup;



	if (kill(pid, SIGINT))

		goto cleanup;



	ret = KSFT_PASS;



cleanup:

	cg_enter_current(root);

	cg_destroy(cg_pids);

	free(cg_pids);



	return ret;

}



/*

 * This test checks that pids.events are counted in cgroup associated with pids.max

 */

static int test_pids_events(const char *root)

{

	int ret = KSFT_FAIL;

	char *cg_parent = NULL, *cg_child = NULL;

	int pid;



	cg_parent = cg_name(root, "pids_parent");

	cg_child = cg_name(cg_parent, "pids_child");

	if (!cg_parent || !cg_child)

		goto cleanup;



	if (cg_create(cg_parent))

		goto cleanup;

	if (cg_write(cg_parent, "cgroup.subtree_control", "+pids"))

		goto cleanup;

	if (cg_create(cg_child))

		goto cleanup;



	if (cg_write(cg_parent, "pids.max", "2"))

		goto cleanup;



	if (cg_read_strcmp(cg_child, "pids.max", "max\n"))

		goto cleanup;



	if (cg_enter_current(cg_child))

		goto cleanup;



	pid = cg_run_nowait(cg_child, run_pause, NULL);

	if (pid < 0)

		goto cleanup;



	if (cg_run_nowait(cg_child, run_success, NULL) != -1 || errno != EAGAIN)

		goto cleanup;



	if (kill(pid, SIGINT))

		goto cleanup;



	if (cg_read_key_long(cg_child, "pids.events", "max ") != 0)

		goto cleanup;

	if (cg_read_key_long(cg_parent, "pids.events", "max ") != 1)

		goto cleanup;





	ret = KSFT_PASS;



cleanup:

	cg_enter_current(root);

	if (cg_child)

		cg_destroy(cg_child);

	if (cg_parent)

		cg_destroy(cg_parent);

	free(cg_child);

	free(cg_parent);



	return ret;

}







#define T(x) { x, #x }

struct pids_test {

	int (*fn)(const char *root);

	const char *name;

} tests[] = {

	T(test_pids_max),

	T(test_pids_events),

};

#undef T



int main(int argc, char **argv)

{

	char root[PATH_MAX];



	ksft_print_header();

	ksft_set_plan(ARRAY_SIZE(tests));

	if (cg_find_unified_root(root, sizeof(root), NULL))

		ksft_exit_skip("cgroup v2 isn't mounted\n");



	/*

	 * Check that pids controller is available:

	 * pids is listed in cgroup.controllers

	 */

	if (cg_read_strstr(root, "cgroup.controllers", "pids"))

		ksft_exit_skip("pids controller isn't available\n");



	if (cg_read_strstr(root, "cgroup.subtree_control", "pids"))

		if (cg_write(root, "cgroup.subtree_control", "+pids"))

			ksft_exit_skip("Failed to set pids controller\n");



	for (int i = 0; i < ARRAY_SIZE(tests); i++) {

		switch (tests[i].fn(root)) {

		case KSFT_PASS:

			ksft_test_result_pass("%s\n", tests[i].name);

			break;

		case KSFT_SKIP:

			ksft_test_result_skip("%s\n", tests[i].name);

			break;

		default:

			ksft_test_result_fail("%s\n", tests[i].name);

			break;

		}

	}



	ksft_finished();

}