linux: Only use 64-bit syscall if required for mq_timedreceive

For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one.  The 64-bit usage should
be rare since the timeout is a relative one.

Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
This commit is contained in:
Adhemerval Zanella 2021-06-15 23:05:21 -03:00
parent 2c0982eb93
commit e9e912d334
4 changed files with 88 additions and 20 deletions

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@ -68,7 +68,8 @@ tests := tst-shm tst-timer tst-timer2 \
tst-mqueue5 tst-mqueue6 tst-mqueue7 tst-mqueue8 tst-mqueue9 \ tst-mqueue5 tst-mqueue6 tst-mqueue7 tst-mqueue8 tst-mqueue9 \
tst-timer3 tst-timer4 tst-timer5 \ tst-timer3 tst-timer4 tst-timer5 \
tst-cpuclock2 tst-cputimer1 tst-cputimer2 tst-cputimer3 \ tst-cpuclock2 tst-cputimer1 tst-cputimer2 tst-cputimer3 \
tst-shm-cancel tst-shm-cancel \
tst-mqueue10
tests-internal := tst-timer-sigmask tests-internal := tst-timer-sigmask
tests-time64 := \ tests-time64 := \
@ -78,6 +79,7 @@ tests-time64 := \
tst-mqueue2-time64 \ tst-mqueue2-time64 \
tst-mqueue4-time64 \ tst-mqueue4-time64 \
tst-mqueue8-time64 \ tst-mqueue8-time64 \
tst-mqueue10-time64 \
tst-timer4-time64 tst-timer4-time64
extra-libs := librt extra-libs := librt

1
rt/tst-mqueue10-time64.c Normal file
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@ -0,0 +1 @@
#include "tst-mqueue10.c"

62
rt/tst-mqueue10.c Normal file
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@ -0,0 +1,62 @@
/* Check for large timeout with mq_timedsend and mq_timedreceive.
Copyright (C) 2021 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 <intprops.h>
#include <mqueue.h>
#include <stdio.h>
#include <support/check.h>
#include <support/support.h>
#include <support/temp_file.h>
#include <unistd.h>
static char name[sizeof "/tst-mqueue2-" + INT_BUFSIZE_BOUND (pid_t)];
static void
do_cleanup (void)
{
mq_unlink (name);
}
#define CLEANUP_HANDLER do_cleanup
static int
do_test (void)
{
snprintf (name, sizeof (name), "/tst-mqueue2-%u", getpid ());
char msg[8] = { 0x55 };
struct mq_attr attr = { .mq_maxmsg = 1, .mq_msgsize = sizeof (msg) };
mqd_t q = mq_open (name, O_CREAT | O_EXCL | O_RDWR, 0600, &attr);
TEST_VERIFY_EXIT (q != (mqd_t) -1);
struct timespec ts = { TYPE_MAXIMUM (time_t), 0 };
{
timer_t timer = support_create_timer (0, 100000000, false, NULL);
TEST_COMPARE (mq_timedreceive (q, msg, sizeof (msg), NULL, &ts), -1);
TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
support_delete_timer (timer);
}
mq_unlink (name);
return 0;
}
#include <support/test-driver.c>

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@ -29,30 +29,33 @@ __mq_timedreceive_time64 (mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len,
#ifndef __NR_mq_timedreceive_time64 #ifndef __NR_mq_timedreceive_time64
# define __NR_mq_timedreceive_time64 __NR_mq_timedreceive # define __NR_mq_timedreceive_time64 __NR_mq_timedreceive
#endif #endif
int ret = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
msg_prio, abs_timeout);
#ifndef __ASSUME_TIME64_SYSCALLS #ifdef __ASSUME_TIME64_SYSCALLS
if (ret == 0 || errno != ENOSYS) return SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
return ret; msg_prio, abs_timeout);
#else
struct timespec ts32; bool need_time64 = abs_timeout != NULL
if (abs_timeout != NULL) && !in_time_t_range (abs_timeout->tv_sec);
if (need_time64)
{ {
if (! in_time_t_range (abs_timeout->tv_sec)) int r = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len,
{ msg_prio, abs_timeout);
__set_errno (EOVERFLOW); if (r == 0 || errno != ENOSYS)
return -1; return r;
} __set_errno (EOVERFLOW);
return -1;
ts32 = valid_timespec64_to_timespec (*abs_timeout);
} }
ret = SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio, struct timespec ts32, *pts32 = NULL;
abs_timeout != NULL ? &ts32 : NULL); if (abs_timeout != NULL)
#endif {
ts32 = valid_timespec64_to_timespec (*abs_timeout);
pts32 = &ts32;
}
return ret; return SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio,
pts32);
#endif
} }
#if __TIMESIZE != 64 #if __TIMESIZE != 64