1/* clock_gettime -- Get current time from a POSIX clockid_t. Linux version.
2 Copyright (C) 2003-2021 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 <sysdep.h>
20#include <kernel-features.h>
21#include <errno.h>
22#include <time.h>
23#include "kernel-posix-cpu-timers.h"
24#include <sysdep-vdso.h>
25#include <shlib-compat.h>
26
27/* Get current value of CLOCK and store it in TP. */
28int
29__clock_gettime64 (clockid_t clock_id, struct __timespec64 *tp)
30{
31 int r;
32
33#ifndef __NR_clock_gettime64
34# define __NR_clock_gettime64 __NR_clock_gettime
35#endif
36
37#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
38 int (*vdso_time64) (clockid_t clock_id, struct __timespec64 *tp)
39 = GLRO(dl_vdso_clock_gettime64);
40 if (vdso_time64 != NULL)
41 {
42 r = INTERNAL_VSYSCALL_CALL (vdso_time64, 2, clock_id, tp);
43 if (r == 0)
44 return 0;
45 return INLINE_SYSCALL_ERROR_RETURN_VALUE (-r);
46 }
47#endif
48
49#ifdef HAVE_CLOCK_GETTIME_VSYSCALL
50 int (*vdso_time) (clockid_t clock_id, struct timespec *tp)
51 = GLRO(dl_vdso_clock_gettime);
52 if (vdso_time != NULL)
53 {
54 struct timespec tp32;
55 r = INTERNAL_VSYSCALL_CALL (vdso_time, 2, clock_id, &tp32);
56 if (r == 0 && tp32.tv_sec > 0)
57 {
58 *tp = valid_timespec_to_timespec64 (tp32);
59 return 0;
60 }
61 else if (r != 0)
62 return INLINE_SYSCALL_ERROR_RETURN_VALUE (-r);
63
64 /* Fallback to syscall if the 32-bit time_t vDSO returns overflows. */
65 }
66#endif
67
68 r = INTERNAL_SYSCALL_CALL (clock_gettime64, clock_id, tp);
69 if (r == 0)
70 return 0;
71 if (r != -ENOSYS)
72 return INLINE_SYSCALL_ERROR_RETURN_VALUE (-r);
73
74#ifndef __ASSUME_TIME64_SYSCALLS
75 /* Fallback code that uses 32-bit support. */
76 struct timespec tp32;
77 r = INTERNAL_SYSCALL_CALL (clock_gettime, clock_id, &tp32);
78 if (r == 0)
79 {
80 *tp = valid_timespec_to_timespec64 (tp32);
81 return 0;
82 }
83#endif
84
85 return INLINE_SYSCALL_ERROR_RETURN_VALUE (-r);
86}
87
88#if __TIMESIZE != 64
89libc_hidden_def (__clock_gettime64)
90
91int
92__clock_gettime (clockid_t clock_id, struct timespec *tp)
93{
94 int ret;
95 struct __timespec64 tp64;
96
97 ret = __clock_gettime64 (clock_id, &tp64);
98
99 if (ret == 0)
100 {
101 if (! in_time_t_range (tp64.tv_sec))
102 {
103 __set_errno (EOVERFLOW);
104 return -1;
105 }
106
107 *tp = valid_timespec64_to_timespec (tp64);
108 }
109
110 return ret;
111}
112#endif
113libc_hidden_def (__clock_gettime)
114
115versioned_symbol (libc, __clock_gettime, clock_gettime, GLIBC_2_17);
116/* clock_gettime moved to libc in version 2.17;
117 old binaries may expect the symbol version it had in librt. */
118#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
119strong_alias (__clock_gettime, __clock_gettime_2);
120compat_symbol (libc, __clock_gettime_2, clock_gettime, GLIBC_2_2);
121#endif
122