Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Author: Aleksa Sarai <cyphar@cyphar.com>
 * Copyright (C) 2018-2019 SUSE LLC.
 */
 
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <string.h>
#include <syscall.h>
#include <limits.h>
 
#include "helpers.h"
 
bool needs_openat2(const struct open_how *how)
{
<------>return how->resolve != 0;
}
 
int raw_openat2(int dfd, const char *path, void *how, size_t size)
{
<------>int ret = syscall(__NR_openat2, dfd, path, how, size);
<------>return ret >= 0 ? ret : -errno;
}
 
int sys_openat2(int dfd, const char *path, struct open_how *how)
{
<------>return raw_openat2(dfd, path, how, sizeof(*how));
}
 
int sys_openat(int dfd, const char *path, struct open_how *how)
{
<------>int ret = openat(dfd, path, how->flags, how->mode);
<------>return ret >= 0 ? ret : -errno;
}
 
int sys_renameat2(int olddirfd, const char *oldpath,
<------><------>  int newdirfd, const char *newpath, unsigned int flags)
{
<------>int ret = syscall(__NR_renameat2, olddirfd, oldpath,
<------><------><------><------><------>  newdirfd, newpath, flags);
<------>return ret >= 0 ? ret : -errno;
}
 
int touchat(int dfd, const char *path)
{
<------>int fd = openat(dfd, path, O_CREAT, 0700);
<------>if (fd >= 0)
<------><------>close(fd);
<------>return fd;
}
 
char *fdreadlink(int fd)
{
<------>char *target, *tmp;
 
<------>E_asprintf(&tmp, "/proc/self/fd/%d", fd);
 
<------>target = malloc(PATH_MAX);
<------>if (!target)
<------><------>ksft_exit_fail_msg("fdreadlink: malloc failed\n");
<------>memset(target, 0, PATH_MAX);
 
<------>E_readlink(tmp, target, PATH_MAX);
<------>free(tmp);
<------>return target;
}
 
bool fdequal(int fd, int dfd, const char *path)
{
<------>char *fdpath, *dfdpath, *other;
<------>bool cmp;
 
<------>fdpath = fdreadlink(fd);
<------>dfdpath = fdreadlink(dfd);
 
<------>if (!path)
<------><------>E_asprintf(&other, "%s", dfdpath);
<------>else if (*path == '/')
<------><------>E_asprintf(&other, "%s", path);
<------>else
<------><------>E_asprintf(&other, "%s/%s", dfdpath, path);
 
<------>cmp = !strcmp(fdpath, other);
 
<------>free(fdpath);
<------>free(dfdpath);
<------>free(other);
<------>return cmp;
}
 
bool openat2_supported = false;
 
void __attribute__((constructor)) init(void)
{
<------>struct open_how how = {};
<------>int fd;
 
<------>BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0);
 
<------>/* Check openat2(2) support. */
<------>fd = sys_openat2(AT_FDCWD, ".", &how);
<------>openat2_supported = (fd >= 0);
 
<------>if (fd >= 0)
<------><------>close(fd);
}