testcases/kernel/syscalls/setpriority/setpriority01.c

/*
 * Copyright (c) International Business Machines  Corp., 2001
 *  03/2001 Written by Wayne Boyer
 *  11/2016 Modified by Guangwen Feng <fenggw-fnst@cn.fujitsu.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Verify that setpriority(2) succeeds set the scheduling priority of
 * the current process, process group or user.
 */

#define _GNU_SOURCE
#include <errno.h>
#include <pwd.h>
#include <stdlib.h>
#include <sys/resource.h>

#include "tst_test.h"

static const char *username = "ltp_setpriority01";
static int pid, uid, user_added;

static struct tcase {
	int which;
	int *who;
} tcases[] = {
	{PRIO_PROCESS, &pid},
	{PRIO_PGRP, &pid},
	{PRIO_USER, &uid}
};

static const char *str_which(int which)
{
	switch (which) {
	case PRIO_PROCESS:
		return "PRIO_PROCESS";
	case PRIO_PGRP:
		return "PRIO_PGRP";
	case PRIO_USER:
		return "PRIO_USER";
	default:
		return "???";
	}
}

static void setpriority_test(struct tcase *tc)
{
	int new_prio, cur_prio;
	int failflag = 0;

	for (new_prio = -20; new_prio < 20; new_prio++) {
		TEST(setpriority(tc->which, *tc->who, new_prio));

		if (TEST_RETURN != 0) {
			tst_res(TFAIL | TTERRNO,
				"setpriority(%d, %d, %d) failed",
				tc->which, *tc->who, new_prio);
			failflag = 1;
			continue;
		}

		cur_prio = SAFE_GETPRIORITY(tc->which, *tc->who);

		if (cur_prio != new_prio) {
			tst_res(TFAIL, "current priority(%d) and "
				"new priority(%d) do not match",
				cur_prio, new_prio);
			failflag = 1;
		}
	}

	if (!failflag) {
		tst_res(TPASS, "setpriority(%s(%d), %d, -20..19) succeeded",
			str_which(tc->which), tc->which, *tc->who);
	}
}

static void verify_setpriority(unsigned int n)
{
	struct tcase *tc = &tcases[n];

	pid = SAFE_FORK();
	if (pid == 0) {
		SAFE_SETUID(uid);
		SAFE_SETPGID(0, 0);

		TST_CHECKPOINT_WAKE_AND_WAIT(0);

		exit(0);
	}

	TST_CHECKPOINT_WAIT(0);

	setpriority_test(tc);

	TST_CHECKPOINT_WAKE(0);

	tst_reap_children();
}

static void setup(void)
{
	const char *const cmd_useradd[] = {"useradd", username, NULL};
	struct passwd *ltpuser;

	if (eaccess("/etc/passwd", W_OK))
		tst_brk(TCONF, "/etc/passwd is not accessible");

	tst_run_cmd(cmd_useradd, NULL, NULL, 0);
	user_added = 1;

	ltpuser = SAFE_GETPWNAM(username);
	uid = ltpuser->pw_uid;
}

static void cleanup(void)
{
	if (!user_added)
		return;

	const char *const cmd_userdel[] = {"userdel", "-r", username, NULL};

	if (tst_run_cmd(cmd_userdel, NULL, NULL, 1))
		tst_res(TWARN | TERRNO, "'userdel -r %s' failed", username);
}

static struct tst_test test = {
	.tcnt = ARRAY_SIZE(tcases),
	.needs_root = 1,
	.forks_child = 1,
	.needs_checkpoints = 1,
	.setup = setup,
	.cleanup = cleanup,
	.test = verify_setpriority,
};