1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Author: Aleksa Sarai <cyphar@cyphar.com>
4 * Copyright (C) 2018-2019 SUSE LLC.
17 bool needs_openat2(const struct open_how *how)
19 return how->resolve != 0;
22 int raw_openat2(int dfd, const char *path, void *how, size_t size)
24 int ret = syscall(__NR_openat2, dfd, path, how, size);
25 return ret >= 0 ? ret : -errno;
28 int sys_openat2(int dfd, const char *path, struct open_how *how)
30 return raw_openat2(dfd, path, how, sizeof(*how));
33 int sys_openat(int dfd, const char *path, struct open_how *how)
35 int ret = openat(dfd, path, how->flags, how->mode);
36 return ret >= 0 ? ret : -errno;
39 int sys_renameat2(int olddirfd, const char *oldpath,
40 int newdirfd, const char *newpath, unsigned int flags)
42 int ret = syscall(__NR_renameat2, olddirfd, oldpath,
43 newdirfd, newpath, flags);
44 return ret >= 0 ? ret : -errno;
47 int touchat(int dfd, const char *path)
49 int fd = openat(dfd, path, O_CREAT, 0700);
55 char *fdreadlink(int fd)
59 E_asprintf(&tmp, "/proc/self/fd/%d", fd);
61 target = malloc(PATH_MAX);
63 ksft_exit_fail_msg("fdreadlink: malloc failed\n");
64 memset(target, 0, PATH_MAX);
66 E_readlink(tmp, target, PATH_MAX);
71 bool fdequal(int fd, int dfd, const char *path)
73 char *fdpath, *dfdpath, *other;
76 fdpath = fdreadlink(fd);
77 dfdpath = fdreadlink(dfd);
80 E_asprintf(&other, "%s", dfdpath);
81 else if (*path == '/')
82 E_asprintf(&other, "%s", path);
84 E_asprintf(&other, "%s/%s", dfdpath, path);
86 cmp = !strcmp(fdpath, other);
94 bool openat2_supported = false;
96 void __attribute__((constructor)) init(void)
98 struct open_how how = {};
101 BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0);
103 /* Check openat2(2) support. */
104 fd = sys_openat2(AT_FDCWD, ".", &how);
105 openat2_supported = (fd >= 0);