// 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();
}