glibc/sysdeps/unix/sysv/linux/mq_timedreceive.c
Lukasz Majewski 0b65a8fbaf y2038: linux: Provide __mq_timedreceive_time64 implementation
This patch provides new __mq_timedreceive_time64 explicit 64 bit function for
receiving messages with absolute timeout.
Moreover, a 32 bit version - __mq_timedreceive has been refactored to
internally use __mq_timedreceive_time64.

The __mq_timedreceive is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64 from struct timespec.

The new mq_timedsend_time64 syscall available from Linux 5.1+ has been used,
when applicable.

As this wrapper function is also used internally in the glibc, to e.g. provide
mq_receive implementation, an explicit check for abs_timeout being NULL has been
added due to conversions between struct timespec and struct __timespec64.
Before this change the Linux kernel handled this NULL pointer.

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

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

Linux kernel, headers and minimal kernel version for glibc build test matrix:
- Linux v5.1 (with mq_timedreceive_time64) and glibc built with v5.1 as
  minimal kernel version (--enable-kernel="5.1.0")
  The __ASSUME_TIME64_SYSCALLS flag defined.

- Linux v5.1 and default minimal kernel version
  The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
  mq_timedreceive_time64 syscall.

- Linux v4.19 (no mq_timedreceive_time64 support) with default minimal kernel
  version for contemporary glibc (3.2.0)
  This kernel doesn't support mq_timedreceive_time64 syscall, so the fallback to
  mq_timedreceive is tested.

Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-04-06 23:05:11 +02:00

78 lines
2.7 KiB
C

/* Receive a message from a message queue with a timeout. Linux version.
Copyright (C) 2017-2020 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 <mqueue.h>
#include <sysdep-cancel.h>
/* Receive the oldest from highest priority messages in message queue
MQDES, stop waiting if ABS_TIMEOUT expires. */
ssize_t
__mq_timedreceive_time64 (mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len,
unsigned int *__restrict msg_prio,
const struct __timespec64 *__restrict abs_timeout)
{
#ifdef __ASSUME_TIME64_SYSCALLS
# ifndef __NR_mq_timedreceive_time64
# define __NR_mq_timedreceive_time64 __NR_mq_timedreceive
# endif
return SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
msg_prio, abs_timeout);
#else
int ret = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
msg_prio, abs_timeout);
if (ret == 0 || errno != ENOSYS)
return ret;
struct timespec ts32;
if (abs_timeout != NULL)
{
if (! in_time_t_range (abs_timeout->tv_sec))
{
__set_errno (EOVERFLOW);
return -1;
}
ts32 = valid_timespec64_to_timespec (*abs_timeout);
}
return SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio,
abs_timeout != NULL ? &ts32 : NULL);
#endif
}
#if __TIMESIZE != 64
librt_hidden_def (__mq_timedreceive_time64)
ssize_t
__mq_timedreceive (mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len,
unsigned int *__restrict msg_prio,
const struct timespec *__restrict abs_timeout)
{
struct __timespec64 ts64;
if (abs_timeout != NULL)
ts64 = valid_timespec_to_timespec64 (*abs_timeout);
return __mq_timedreceive_time64 (mqdes, msg_ptr, msg_len, msg_prio,
abs_timeout != NULL ? &ts64 : NULL);
}
#endif
hidden_def (__mq_timedreceive)
weak_alias (__mq_timedreceive, mq_timedreceive)
hidden_weak (mq_timedreceive)