206 lines
7.1 KiB
C
206 lines
7.1 KiB
C
/* futex helper functions for glibc-internal use.
|
|
Copyright (C) 2020-2022 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 /* Ununsed. */,
|
|
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_time_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_time_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 ();
|
|
}
|
|
}
|