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29e9874a048f47e2d46c40253036c8d2de921548
glibc/sysdeps/nptl/futex-internal.c
Lukasz Majewski 29e9874a04 y2038: nptl: Convert pthread_mutex_{clock|timed}lock to support 64 bit 
The pthread_mutex_clocklock and pthread_mutex_timedlock have been converted
to support 64 bit time.

This change uses:
- New __futex_clocklock_wait64 (instead of lll_timedwait)

from ./sysdeps/nptl/futex-helpers.c and

- New __futex_clocklock64 function (instead of lll_clocklock)
- New futex_lock_pi64

defined in sysdeps/nptl/futex-internal.h

The pthread_mutex_{clock|timed}lock only accepts absolute time.
Moreover, there is no need to check for NULL passed as *abstime pointer to the
syscalls as those calls have exported symbols marked with __nonull attribute
for abstime.

Some architectures - namely x86, powerpc and s390 - do support lock elision.
For those - adjustments have been made in arch specific elision-*.c files
to use __futex_clocklock64 instead of lll_clocklock.
The __lll_lock_elision (aliased to __lll_clocklock_elision in e.g.
sysdeps/unix/sysv/linux/s390/elision-timed.c) just uses, in this patch
provided, __futex_clocklock64.

For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_mutex_{clock|timed}lock will provide support for 64
bit time

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-15 09:35:43 +02:00

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/* futex helper functions for glibc-internal use.
Copyright (C) 2020 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_cancelable32 (unsigned int* futex_word,
unsigned int expected, clockid_t clockid,
const struct __timespec64* abstime,
int private)
{
struct timespec ts32, *pts32 = NULL;
if (abstime != NULL)
{
if (! in_time_t_range (abstime->tv_sec))
return -EOVERFLOW;
ts32 = valid_timespec64_to_timespec (*abstime);
pts32 = &ts32;
}
unsigned int clockbit = (clockid == CLOCK_REALTIME)
? FUTEX_CLOCK_REALTIME : 0;
int op = __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private);
return INTERNAL_SYSCALL_CANCEL (futex, futex_word, op, expected,
pts32, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
}
static int
__futex_abstimed_wait32 (unsigned int* futex_word,
unsigned int expected, clockid_t clockid,
const struct __timespec64* abstime,
int private)
{
struct timespec ts32;
if (abstime != NULL && ! in_time_t_range (abstime->tv_sec))
return -EOVERFLOW;
unsigned int clockbit = (clockid == CLOCK_REALTIME) ?
FUTEX_CLOCK_REALTIME : 0;
int op = __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private);
if (abstime != NULL)
ts32 = valid_timespec64_to_timespec (*abstime);
return INTERNAL_SYSCALL_CALL (futex, futex_word, op, expected,
abstime != NULL ? &ts32 : NULL,
NULL /* Unused. */, FUTEX_BITSET_MATCH_ANY);
}
#endif
int
__futex_abstimed_wait_cancelable64 (unsigned int* futex_word,
unsigned int expected, clockid_t clockid,
const struct __timespec64* abstime,
int private)
{
unsigned int clockbit;
int err;
/* 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);
err = INTERNAL_SYSCALL_CANCEL (futex_time64, futex_word, op, expected,
abstime, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
#ifndef __ASSUME_TIME64_SYSCALLS
if (err == -ENOSYS)
err = __futex_abstimed_wait_cancelable32 (futex_word, expected,
clockid, abstime, private);
#endif
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
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 -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. 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)
{
unsigned int clockbit;
int err;
/* 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);
err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op, expected,
abstime, NULL /* Unused. */,
FUTEX_BITSET_MATCH_ANY);
#ifndef __ASSUME_TIME64_SYSCALLS
if (err == -ENOSYS)
err = __futex_abstimed_wait32 (futex_word, expected,
clockid, abstime, private);
#endif
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment, unsupported
clockid or due to the timeout not being
normalized. 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_clocklock_wait64 (int *futex, int val, clockid_t clockid,
const struct __timespec64 *abstime, int private)
{
struct __timespec64 ts, *tsp = NULL;
if (abstime != NULL)
{
/* Reject invalid timeouts. */
if (! valid_nanoseconds (abstime->tv_nsec))
return EINVAL;
/* Get the current time. This can only fail if clockid is not valid. */
if (__glibc_unlikely (__clock_gettime64 (clockid, &ts) != 0))
return EINVAL;
/* Compute relative timeout. */
ts.tv_sec = abstime->tv_sec - ts.tv_sec;
ts.tv_nsec = abstime->tv_nsec - ts.tv_nsec;
if (ts.tv_nsec < 0)
{
ts.tv_nsec += 1000000000;
--ts.tv_sec;
}
if (ts.tv_sec < 0)
return ETIMEDOUT;
tsp = &ts;
}
int err = INTERNAL_SYSCALL_CALL (futex_time64, futex,
__lll_private_flag (FUTEX_WAIT, private),
val, tsp);
#ifndef __ASSUME_TIME64_SYSCALLS
if (err == -ENOSYS)
{
if (tsp != NULL && ! in_time_t_range (tsp->tv_sec))
return EOVERFLOW;
struct timespec ts32;
if (tsp != NULL)
ts32 = valid_timespec64_to_timespec (*tsp);
err = INTERNAL_SYSCALL_CALL (futex, futex,
__lll_private_flag (FUTEX_WAIT, private),
val, tsp != NULL ? &ts32 : NULL);
}
#endif
return -err;
}
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