root/tools/testing/selftests/filesystems/anon_inode_test.c
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#define __SANE_USERSPACE_TYPES__

#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>

#include "kselftest_harness.h"
#include "wrappers.h"

TEST(anon_inode_no_chown)
{
        int fd_context;

        fd_context = sys_fsopen("tmpfs", 0);
        ASSERT_GE(fd_context, 0);

        ASSERT_LT(fchown(fd_context, 1234, 5678), 0);
        ASSERT_EQ(errno, EOPNOTSUPP);

        EXPECT_EQ(close(fd_context), 0);
}

TEST(anon_inode_no_chmod)
{
        int fd_context;

        fd_context = sys_fsopen("tmpfs", 0);
        ASSERT_GE(fd_context, 0);

        ASSERT_LT(fchmod(fd_context, 0777), 0);
        ASSERT_EQ(errno, EOPNOTSUPP);

        EXPECT_EQ(close(fd_context), 0);
}

TEST(anon_inode_no_exec)
{
        int fd_context;

        fd_context = sys_fsopen("tmpfs", 0);
        ASSERT_GE(fd_context, 0);

        char *const empty_argv[] = {NULL};
        char *const empty_envp[] = {NULL};

        ASSERT_LT(execveat(fd_context, "", empty_argv, empty_envp, AT_EMPTY_PATH), 0);
        ASSERT_EQ(errno, EACCES);

        EXPECT_EQ(close(fd_context), 0);
}

TEST(anon_inode_no_open)
{
        int fd_context;

        fd_context = sys_fsopen("tmpfs", 0);
        ASSERT_GE(fd_context, 0);

        ASSERT_GE(dup2(fd_context, 500), 0);
        ASSERT_EQ(close(fd_context), 0);
        fd_context = 500;

        ASSERT_LT(open("/proc/self/fd/500", 0), 0);
        ASSERT_EQ(errno, ENXIO);

        EXPECT_EQ(close(fd_context), 0);
}

TEST_HARNESS_MAIN