From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 348 invoked from network); 27 Dec 2020 18:55:44 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 27 Dec 2020 18:55:44 -0000 Received: (qmail 11366 invoked by uid 550); 27 Dec 2020 18:55:42 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 3767 invoked from network); 27 Dec 2020 18:39:18 -0000 Date: Sun, 27 Dec 2020 18:39:03 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail; t=1609094346; bh=yBemZjig1R76KnEqRisFk+4RIxtGQOmQLSvjGgGQoNY=; h=Date:To:From:Cc:Reply-To:Subject:From; b=OqQIT5hknST2Mm6H06SfaQGZieEVr9fgL77JpeGEhs4Ox1u6TrEaNsNLZF74jiqiA Dufqad323tqCOhgtm5ptHeWE94H5Tftf+LxAFaQBayFW6WcbeuRU5ZqsVZ1djZ3LSx N/EbxBwrOZGzN8jkpHLD9Y3KpPrs/vVcW42QW5SK1THFnBTELLxL6X6pcpf935C2mg Q+aKGer0TpvTo/auWilTdyxT3B5sYuW3rGZajYYTtQMMtzl0IpTiqje6RP/eeb85L/ V4Gqm8/5nh7xXatxnU+EFCDiHiTv9l6snqE7rHnetRhhoqVPXUN3PGHkIC1zw3XcxJ KgFTDdF3LFiHg== To: Rich Felker , musl@lists.openwall.com From: Alexander Lobakin Cc: Alexander Lobakin Message-ID: <20201227183842.22030-1-alobakin@pm.me> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: [musl] [PATCH 00/18] time64: always prefer time64 syscalls Since Linux 4.18, there's an option CONFIG_COMPAT_32BIT_TIME that allows to ultimately test libc and userland programs if they are using the latest available syscall variants, time64 variants in particular. With this option turned off, old time32 syscalls don't get compiled at all. The same applies to some deprecated syscalls such as nanosleep. Unfortunately, on 32-bit systems Musl fails on this hardly with at least non-working sleeps, signal and sockets. That's because Musl currently uses time64 variants only as "fallbacks" when some of the arguments exceeds 32-bit width. Moreover, Musl currently prefers deprecated adjtimex over clock_adjtime, ipc over semtimedop, nanosleep over clock_nanosleep etc. As for me, libc should always use the latest available syscalls, especially when it comes to y2038, and get back to fallbacks only in case of -ENOSYS (on older systems). Newer systems might just don't get deprecated stuff compiled in, as it is with mentioned Kconfig option. BTW, code size savings from excluding deprecated syscalls are quite nice (bloat-o-meter): add/remove: 0/39 grow/shrink: 8/4 up/down: 3464/-10480 (-7016) Function old new delta sys_timerfd_settime 180 1604 +1424 sys_rt_sigtimedwait 236 884 +648 sys_timerfd_gettime 116 724 +608 sys_pselect6 128 356 +228 sys_timer_settime 256 472 +216 sys_timer_gettime 116 268 +152 sys_sched_rr_get_interval 108 260 +152 do_nanosleep.constprop 424 460 +36 sys_futimesat_time32 8 - -8 sys_clock_adjtime32 8 - -8 sys_adjtimex_time32 8 - -8 sys_utimes_time32 16 - -16 nanosleep_copyout 104 76 -28 poll_select_finish 600 564 -36 sock_gettstamp 524 480 -44 ksys_ipc 828 784 -44 sys_time32 80 - -80 put_old_itimerspec32 80 - -80 sys_sched_rr_get_interval_time32 108 - -108 sys_timerfd_gettime32 116 - -116 sys_timer_gettime32 116 - -116 __put_old_timespec32 124 - -124 sys_pselect6_time32 128 - -128 __do_sys_adjtimex_time32 144 - -144 sys_stime32 164 - -164 sys_timerfd_settime32 180 - -180 compat_ksys_semtimedop 188 - -188 sys_utime32 196 - -196 get_old_itimerspec32 204 - -204 sys_utimensat_time32 216 - -216 sys_clock_gettime32 224 - -224 sys_clock_getres_time32 232 - -232 sys_rt_sigtimedwait_time32 236 - -236 sys_clock_settime32 236 - -236 sys_ppoll_time32 244 - -244 do_timer_gettime 252 - -252 sys_timer_settime32 256 - -256 sys_recvmmsg_time32 256 - -256 sched_rr_get_interval 256 - -256 __do_sys_clock_adjtime32 260 - -260 sys_nanosleep_time32 276 - -276 do_compat_futimesat 300 - -300 put_old_timex32 316 - -316 do_pselect 316 - -316 do_timer_settime.part 320 - -320 sys_clock_nanosleep_time32 340 - -340 sys_futex_time32 480 - -480 get_old_timex32 480 - -480 do_sigtimedwait 696 - -696 do_timerfd_gettime 708 - -708 do_timerfd_settime 1560 - -1560 Total: Before=3D4538992, After=3D4531976, chg -0.15% This set ensures that all 18 syscalls are being run as follows: 1. time64 variant. 2. -ENOSYS? time32 variant. 3. -ENOSYS again? Any old stuff (adjtimex, ipc, nanosleep). With this set, all syscalls and userspace programs work as expected with CONFIG_COMPAT_32BIT_TIME turned off, just by using time64 variants. Tested on MIPS32R2 (OABI), Linux 5.11-rc1 (pre) + Musl latest git snapshot. Alexander Lobakin (18): clock_gettime: prefer time64 variant if available clock_settime: prefer time64 variant if available clock_adjtime: try adjtimex at last clock_getres: use time64 variant by default clock_nanosleep: prefer time64 variant if available timer_gettime: prefer time64 variant if available timer_settime: prefer time64 variant if available timerfd_gettime: prefer time64 variant if available timerfd_settime: prefer time64 variant if available utimensat: prefer time64 variant if available pselect, select: prefer time64 variant of pselect6 if available poll, ppoll: prefer time64 variant of ppoll if available mq_timedsend: prefer time64 variant if available mq_timedreceive: prefer time64 variant if available semtimedop: prefer time64 variant of semtimedop if available [rt_]sigtimedwait: prefer time64 variant if available futex: prefer time64 variant if available sched_rr_get_interval: use time64 variant if available src/internal/pthread_impl.h | 22 +++++++++++++++++---- src/ipc/semtimedop.c | 20 +++++++++---------- src/linux/clock_adjtime.c | 12 ++++++----- src/linux/ppoll.c | 8 +++----- src/linux/timerfd.c | 11 +++-------- src/mq/mq_timedreceive.c | 6 ++---- src/mq/mq_timedsend.c | 6 ++---- src/sched/sched_rr_get_interval.c | 21 ++++++++++---------- src/select/poll.c | 23 +++++++++++++++++----- src/select/pselect.c | 6 ++---- src/select/select.c | 22 +++++++++++---------- src/signal/sigtimedwait.c | 6 ++---- src/stat/utimensat.c | 6 ++---- src/thread/__timedwait.c | 6 ++---- src/thread/__wait.c | 4 ++-- src/thread/pthread_barrier_wait.c | 6 +++--- src/thread/pthread_cond_timedwait.c | 10 +++++----- src/thread/pthread_mutex_timedlock.c | 8 +++----- src/thread/pthread_mutex_trylock.c | 2 +- src/thread/pthread_mutex_unlock.c | 2 +- src/thread/pthread_mutexattr_setprotocol.c | 2 +- src/time/clock_getres.c | 21 ++++++++++---------- src/time/clock_gettime.c | 4 +--- src/time/clock_nanosleep.c | 22 +++++++++++---------- src/time/clock_settime.c | 6 ++---- src/time/timer_gettime.c | 4 +--- src/time/timer_settime.c | 7 ++----- 27 files changed, 137 insertions(+), 136 deletions(-) --=20 2.29.2