1/* Check if path supports 64-bit time interfaces.
2 Copyright (C) 2021-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <fcntl.h>
20#include <unistd.h>
21#include <support/check.h>
22#include <support/support.h>
23#include <sys/stat.h>
24#ifdef __linux__
25#include <sysdep.h>
26#endif
27
28#ifdef __linux__
29static int
30utimesat_call (const char *path, const struct __timespec64 tsp[2])
31{
32# ifndef __NR_utimensat_time64
33# define __NR_utimensat_time64 __NR_utimensat
34# endif
35 return syscall (__NR_utimensat_time64, AT_FDCWD, path, &tsp[0], 0);
36}
37#endif
38
39bool
40support_path_support_time64_value (const char *path, int64_t at, int64_t mt)
41{
42#ifdef __linux__
43 /* Obtain the original timestamps to restore at the end. */
44 struct statx ostx;
45 TEST_VERIFY_EXIT (statx (AT_FDCWD, path, 0, STATX_BASIC_STATS, &ostx) == 0);
46
47 const struct __timespec64 tsp[] = { { at, 0 }, { mt, 0 } };
48
49 /* Return is kernel does not support __NR_utimensat_time64. */
50 if (utimesat_call (path, tsp) == -1)
51 return false;
52
53 /* Verify if the last access and last modification time match the ones
54 obtained with statx. */
55 struct statx stx;
56 TEST_VERIFY_EXIT (statx (AT_FDCWD, path, 0, STATX_BASIC_STATS, &stx) == 0);
57
58 bool support = stx.stx_atime.tv_sec == tsp[0].tv_sec
59 && stx.stx_mtime.tv_sec == tsp[1].tv_sec;
60
61 /* Reset to original timestamps. */
62 const struct __timespec64 otsp[] =
63 {
64 { ostx.stx_atime.tv_sec, ostx.stx_atime.tv_nsec },
65 { ostx.stx_mtime.tv_sec, ostx.stx_mtime.tv_nsec },
66 };
67 TEST_VERIFY_EXIT (utimesat_call (path, otsp) == 0);
68
69 return support;
70#else
71 return true;
72#endif
73}
74

source code of glibc/support/support_path_support_time64.c