1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* futex helper functions for glibc-internal use.
Copyright (C) 2020-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sysdep.h>
#include <time.h>
#include <futex-internal.h>
#include <kernel-features.h>
#ifndef __ASSUME_TIME64_SYSCALLS
static int
__futex_abstimed_wait_common32 (unsigned int* futex_word,
unsigned int expected, int op,
const struct __timespec64* abstime,
int private, bool cancel)
{
struct timespec ts32, *pts32 = NULL;
if (abstime != NULL)
{
ts32 = valid_timespec64_to_timespec (*abstime);
pts32 = &ts32;
}
if (cancel)
return INTERNAL_SYSCALL_CANCEL (futex, futex_word, op, expected,
pts32, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
else
return INTERNAL_SYSCALL_CALL (futex, futex_word, op, expected,
pts32, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
}
#endif /* ! __ASSUME_TIME64_SYSCALLS */
static int
__futex_abstimed_wait_common64 (unsigned int* futex_word,
unsigned int expected, int op,
const struct __timespec64* abstime,
int private, bool cancel)
{
if (cancel)
return INTERNAL_SYSCALL_CANCEL (futex_time64, futex_word, op, expected,
abstime, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
else
return INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op, expected,
abstime, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
}
static int
__futex_abstimed_wait_common (unsigned int* futex_word,
unsigned int expected, clockid_t clockid,
const struct __timespec64* abstime,
int private, bool cancel)
{
int err;
unsigned int clockbit;
/* Work around the fact that the kernel rejects negative timeout values
despite them being valid. */
if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
return ETIMEDOUT;
if (! lll_futex_supported_clockid (clockid))
return EINVAL;
clockbit = (clockid == CLOCK_REALTIME) ? FUTEX_CLOCK_REALTIME : 0;
int op = __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private);
#ifdef __ASSUME_TIME64_SYSCALLS
err = __futex_abstimed_wait_common64 (futex_word, expected, op, abstime,
private, cancel);
#else
bool need_time64 = abstime != NULL && !in_int32_t_range (abstime->tv_sec);
if (need_time64)
{
err = __futex_abstimed_wait_common64 (futex_word, expected, op, abstime,
private, cancel);
if (err == -ENOSYS)
err = -EOVERFLOW;
}
else
err = __futex_abstimed_wait_common32 (futex_word, expected, op, abstime,
private, cancel);
#endif
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
case -EINVAL:
case -EOVERFLOW: /* Passed absolute timeout uses 64 bit time_t type, but
underlying kernel does not support 64 bit time_t futex
syscalls. */
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
int
__futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected,
clockid_t clockid,
const struct __timespec64* abstime, int private)
{
return __futex_abstimed_wait_common (futex_word, expected, clockid,
abstime, private, false);
}
libc_hidden_def (__futex_abstimed_wait64)
int
__futex_abstimed_wait_cancelable64 (unsigned int* futex_word,
unsigned int expected, clockid_t clockid,
const struct __timespec64* abstime,
int private)
{
return __futex_abstimed_wait_common (futex_word, expected, clockid,
abstime, private, true);
}
libc_hidden_def (__futex_abstimed_wait_cancelable64)
int
__futex_lock_pi64 (int *futex_word, clockid_t clockid,
const struct __timespec64 *abstime, int private)
{
int err;
unsigned int clockbit = clockid == CLOCK_REALTIME
? FUTEX_CLOCK_REALTIME : 0;
int op_pi2 = __lll_private_flag (FUTEX_LOCK_PI2 | clockbit, private);
#if __ASSUME_FUTEX_LOCK_PI2
/* Assume __ASSUME_TIME64_SYSCALLS since FUTEX_LOCK_PI2 was added later. */
err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op_pi2, 0, abstime);
#else
/* FUTEX_LOCK_PI does not support clock selection, so for CLOCK_MONOTONIC
the only option is to use FUTEX_LOCK_PI2. */
int op_pi1 = __lll_private_flag (FUTEX_LOCK_PI, private);
int op_pi = abstime != NULL && clockid != CLOCK_REALTIME ? op_pi2 : op_pi1;
# ifdef __ASSUME_TIME64_SYSCALLS
err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op_pi, 0, abstime);
# else
bool need_time64 = abstime != NULL && !in_int32_t_range (abstime->tv_sec);
if (need_time64)
err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op_pi, 0, abstime);
else
{
struct timespec ts32, *pts32 = NULL;
if (abstime != NULL)
{
ts32 = valid_timespec64_to_timespec (*abstime);
pts32 = &ts32;
}
err = INTERNAL_SYSCALL_CALL (futex, futex_word, op_pi, 0, pts32);
}
# endif /* __ASSUME_TIME64_SYSCALLS */
/* FUTEX_LOCK_PI2 is not available on this kernel. */
if (err == -ENOSYS)
err = -EINVAL;
#endif /* __ASSUME_FUTEX_LOCK_PI2 */
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
case -ESRCH:
case -EDEADLK:
case -EINVAL: /* This indicates either state corruption or that the kernel
found a waiter on futex address which is waiting via
FUTEX_WAIT or FUTEX_WAIT_BITSET. This is reported on
some futex_lock_pi usage (pthread_mutex_timedlock for
instance). */
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
|
