From e9e912d3349d8caf3c40bc09370509724c72ac2f Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 15 Jun 2021 23:05:21 -0300 Subject: [PATCH] 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 --- rt/Makefile | 4 +- rt/tst-mqueue10-time64.c | 1 + rt/tst-mqueue10.c | 62 +++++++++++++++++++++++ sysdeps/unix/sysv/linux/mq_timedreceive.c | 41 ++++++++------- 4 files changed, 88 insertions(+), 20 deletions(-) create mode 100644 rt/tst-mqueue10-time64.c create mode 100644 rt/tst-mqueue10.c diff --git a/rt/Makefile b/rt/Makefile index 329db09c32..6c7728a318 100644 --- a/rt/Makefile +++ b/rt/Makefile @@ -68,7 +68,8 @@ tests := tst-shm tst-timer tst-timer2 \ tst-mqueue5 tst-mqueue6 tst-mqueue7 tst-mqueue8 tst-mqueue9 \ tst-timer3 tst-timer4 tst-timer5 \ tst-cpuclock2 tst-cputimer1 tst-cputimer2 tst-cputimer3 \ - tst-shm-cancel + tst-shm-cancel \ + tst-mqueue10 tests-internal := tst-timer-sigmask tests-time64 := \ @@ -78,6 +79,7 @@ tests-time64 := \ tst-mqueue2-time64 \ tst-mqueue4-time64 \ tst-mqueue8-time64 \ + tst-mqueue10-time64 \ tst-timer4-time64 extra-libs := librt diff --git a/rt/tst-mqueue10-time64.c b/rt/tst-mqueue10-time64.c new file mode 100644 index 0000000000..2c8a4ae372 --- /dev/null +++ b/rt/tst-mqueue10-time64.c @@ -0,0 +1 @@ +#include "tst-mqueue10.c" diff --git a/rt/tst-mqueue10.c b/rt/tst-mqueue10.c new file mode 100644 index 0000000000..7fb53a1cae --- /dev/null +++ b/rt/tst-mqueue10.c @@ -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 + . */ + +#include +#include +#include +#include +#include +#include +#include +#include + +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 diff --git a/sysdeps/unix/sysv/linux/mq_timedreceive.c b/sysdeps/unix/sysv/linux/mq_timedreceive.c index eb948ccc18..1a7b7a9c11 100644 --- a/sysdeps/unix/sysv/linux/mq_timedreceive.c +++ b/sysdeps/unix/sysv/linux/mq_timedreceive.c @@ -29,30 +29,33 @@ __mq_timedreceive_time64 (mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len, #ifndef __NR_mq_timedreceive_time64 # define __NR_mq_timedreceive_time64 __NR_mq_timedreceive #endif - int ret = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len, - msg_prio, abs_timeout); -#ifndef __ASSUME_TIME64_SYSCALLS - if (ret == 0 || errno != ENOSYS) - return ret; - - struct timespec ts32; - if (abs_timeout != NULL) +#ifdef __ASSUME_TIME64_SYSCALLS + return SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len, + msg_prio, abs_timeout); +#else + bool need_time64 = abs_timeout != NULL + && !in_time_t_range (abs_timeout->tv_sec); + if (need_time64) { - if (! in_time_t_range (abs_timeout->tv_sec)) - { - __set_errno (EOVERFLOW); - return -1; - } - - ts32 = valid_timespec64_to_timespec (*abs_timeout); + int r = SYSCALL_CANCEL (mq_timedreceive_time64, mqdes, msg_ptr, msg_len, + msg_prio, abs_timeout); + if (r == 0 || errno != ENOSYS) + return r; + __set_errno (EOVERFLOW); + return -1; } - ret = SYSCALL_CANCEL (mq_timedreceive, mqdes, msg_ptr, msg_len, msg_prio, - abs_timeout != NULL ? &ts32 : NULL); -#endif + struct timespec ts32, *pts32 = NULL; + if (abs_timeout != NULL) + { + 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