testcases/kernel/syscalls/access/access03.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 */

/*
 * access(2) test for errno(s) EFAULT as root and nobody respectively.
 */

#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
#include "tst_test.h"

static uid_t uid;

static struct tcase {
	void *addr;
	int mode;
	char *name;
} tcases[] = {
	{(void *)-1, F_OK, "F_OK"},
	{(void *)-1, R_OK, "R_OK"},
	{(void *)-1, W_OK, "W_OK"},
	{(void *)-1, X_OK, "X_OK"},
};

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

	TST_EXP_FAIL(access(tc->addr, tc->mode), EFAULT,
	             "invalid address as root");

	/* test as nobody */
	pid = SAFE_FORK();
	if (pid) {
		SAFE_WAITPID(pid, NULL, 0);
	} else {
		SAFE_SETUID(uid);
		TST_EXP_FAIL(access(tc->addr, tc->mode), EFAULT,
		             "invalid address as nobody");
	}
}

static void setup(void)
{
	struct passwd *pw;

	pw = SAFE_GETPWNAM("nobody");

	uid = pw->pw_uid;
}

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