From: Joseph Myers <joseph@codesourcery.com>
To: Lukasz Majewski <lukma@denx.de>
Cc: Stepan Golosunov <stepan@golosunov.pp.ru>,
<libc-alpha@sourceware.org>, Arnd Bergmann <arnd@arndb.de>,
Paul Eggert <eggert@cs.ucla.edu>
Subject: Re: [PATCH v5] y2038: Introduce __ASSUME_TIME64_SYSCALLS define
Date: Tue, 28 May 2019 19:53:17 +0000 [thread overview]
Message-ID: <alpine.DEB.2.21.1905281947410.27415@digraph.polyomino.org.uk> (raw)
In-Reply-To: <20190526143944.7a11d0d6@jawa>
[-- Attachment #1: Type: text/plain, Size: 2098 bytes --]
On Sun, 26 May 2019, Lukasz Majewski wrote:
> Shall the __ASSUME_TIME64_SYSCALLS be defined as:
> (@ sysdeps/unix/sysv/linux/kernel-features.h):
>
> #if __WORDSIZE == 32
> # if __LINUX_KERNEL_VERSION >= 0x050100
> # define __ASSUME_TIME64_SYSCALLS 1
> # endif
> #endif
>
> And also for __TIMESIZE==64
> (@ include/time.h)
>
> #if __TIMESIZE==64
> # define __ASSUME_TIME64_SYSCALLS 1
> #endif
__ASSUME_* should *only* be defined in kernel-features.h. A definition in
include/* would be incorrect.
It's not clear to me that __TIMESIZE == 64 would be the right condition
(in kernel-features.h) for defining __ASSUME_TIME64_SYSCALLS independent
of kernel version, because it would get wrong the case of 32-bit
architectures with old kernel support and glibc support added in future
with 64-bit time only (if we decide that any such future glibc port should
use only 64-bit time in userspace, but without also requiring a new kernel
for such a port). Rather, __WORDSIZE == 64 (with a special case for x32)
is, as previously discussed, closer to what we want (which is that the
"long" in the syscall ABI is 64-bit, which corresponds to __WORDSIZE and
the userspace "long" in all cases except for x32).
> Then the code would be (it is easier for me to understand the
> execution paths when providing the pseudo code):
>
> __clock_settime64(....)
> {
> ...
>
> #ifdef __ASSUME_TIME64_SYSCALLS
> # ifndef __NR_clock_settime64
> # define __NR_clock_settime64 __NR_clock_settime [1]
> # endif
> INLINE_SYSCALL_CALL (clock_settime64, …) [2]
> #else [3]
> int ret = INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp);
> if (ret == 0 || errno != ENOSYS)
> return ret;
This part of the code inside the #else needs to be conditional, as well,
on "#ifdef __NR_clock_settime64". (Unless we require very new kernel
headers to build glibc. But we obviously can't right now - there's no
existing kernel release whose headers both include these syscalls and are
suitable for testing glibc, because of the fds_bits namespace issue.)
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2019-05-28 19:53 UTC|newest]
Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-14 22:08 [PATCH 0/6] y2038: Linux: Provide __clock_* functions supporting 64 bit time Lukasz Majewski
2019-04-14 22:08 ` [PATCH 1/6] y2038: Introduce internal for glibc struct __timespec64 Lukasz Majewski
2019-04-14 22:08 ` [PATCH 2/6] y2038: Provide conversion helpers for " Lukasz Majewski
2019-04-14 22:08 ` [PATCH 3/6] y2038: linux: Provide __clock_settime64 implementation Lukasz Majewski
2019-04-17 22:08 ` Joseph Myers
2019-04-18 6:46 ` Lukasz Majewski
2019-04-20 0:20 ` Stepan Golosunov
2019-04-20 11:21 ` Lukasz Majewski
2019-04-22 9:07 ` Stepan Golosunov
2019-04-22 21:45 ` Arnd Bergmann
2019-04-23 15:45 ` Lukasz Majewski
2019-04-14 22:08 ` [PATCH 4/6] y2038: linux: Provide __clock_getres64 implementation Lukasz Majewski
2019-04-14 22:08 ` [PATCH 5/6] y2038: linux: Provide __clock_gettime64 implementation Lukasz Majewski
2019-04-14 22:08 ` [PATCH 6/6] y2038: linux: Provide __clock_nanosleep64 implementation Lukasz Majewski
2019-04-17 22:11 ` Joseph Myers
2019-04-18 5:54 ` Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 0/7] y2038: Linux: Provide __clock_* functions supporting 64 bit time Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 1/7] y2038: Introduce internal for glibc struct __timespec64 Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 2/7] y2038: Introduce __ASSUME_64BIT_TIME define Lukasz Majewski
2019-04-29 21:50 ` Joseph Myers
2019-04-30 9:05 ` Lukasz Majewski
2019-04-30 21:47 ` Stepan Golosunov
2019-05-02 8:51 ` Lukasz Majewski
2019-05-02 11:54 ` Stepan Golosunov
2019-05-02 13:55 ` Lukasz Majewski
2019-05-06 13:38 ` Lukasz Majewski
2019-05-06 14:26 ` Lukasz Majewski
2019-05-06 19:36 ` Stepan Golosunov
2019-05-06 21:14 ` Lukasz Majewski
2019-05-07 20:03 ` Stepan Golosunov
2019-05-07 20:44 ` Joseph Myers
2019-05-08 7:51 ` Lukasz Majewski
2019-05-08 19:48 ` Stepan Golosunov
2019-05-09 16:12 ` Joseph Myers
2019-05-16 4:00 ` Arnd Bergmann
2019-05-16 19:54 ` Stepan Golosunov
2019-05-16 19:59 ` Joseph Myers
2019-05-17 7:23 ` Florian Weimer
2019-05-17 8:34 ` Arnd Bergmann
2019-05-07 15:43 ` Joseph Myers
2019-05-02 15:04 ` Joseph Myers
2019-05-05 14:10 ` Stepan Golosunov
2019-05-05 20:46 ` Lukasz Majewski
2019-05-06 14:56 ` Lukasz Majewski
2019-05-07 15:35 ` Joseph Myers
2019-05-08 10:18 ` Lukasz Majewski
2019-05-09 15:46 ` Joseph Myers
2019-05-15 15:39 ` Lukasz Majewski
2019-05-16 3:57 ` Arnd Bergmann
2019-05-16 6:58 ` Lukasz Majewski
2019-05-31 11:37 ` Stepan Golosunov
2019-06-05 16:35 ` Lukasz Majewski
2019-06-06 6:50 ` Stepan Golosunov
2019-04-29 10:46 ` [PATCH v2 3/7] y2038: Provide conversion helpers for struct __timespec64 Lukasz Majewski
2019-05-02 11:56 ` Stepan Golosunov
2019-05-02 14:17 ` Lukasz Majewski
2019-05-02 15:59 ` Joseph Myers
2019-05-02 16:19 ` Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 4/7] y2038: linux: Provide __clock_settime64 implementation Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 5/7] y2038: linux: Provide __clock_getres64 implementation Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 6/7] y2038: linux: Provide __clock_gettime64 implementation Lukasz Majewski
2019-04-29 10:46 ` [PATCH v2 7/7] y2038: linux: Provide __clock_nanosleep64 implementation Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 0/5] y2038: Linux: Provide __clock_settime function supporting 64 bit time Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 1/5] y2038: Introduce __ASSUME_TIME64_SYSCALLS define Lukasz Majewski
2019-05-07 16:04 ` Joseph Myers
2019-05-07 13:18 ` [PATCH v3 2/5] y2038: Introduce internal for glibc struct __timespec64 Lukasz Majewski
2019-05-07 13:30 ` Andreas Schwab
2019-05-07 14:07 ` Lukasz Majewski
2019-05-07 14:13 ` Andreas Schwab
2019-05-08 8:32 ` Lukasz Majewski
2019-05-08 8:38 ` Andreas Schwab
2019-05-08 9:10 ` Lukasz Majewski
2019-05-08 9:12 ` Andreas Schwab
2019-05-08 9:37 ` Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 3/5] y2038: Provide conversion helpers for " Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 4/5] y2038: linux: Provide __clock_settime64 implementation Lukasz Majewski
2019-05-07 16:40 ` Joseph Myers
2019-05-07 13:18 ` [PATCH v3 5/5] y2038: Support for Y2038 safe time on 32 bit systems Lukasz Majewski
2019-05-07 16:37 ` Joseph Myers
2019-05-08 10:27 ` Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 0/5] y2038: Linux: Provide __clock_settime function supporting 64 bit time Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 1/5] y2038: Introduce __ASSUME_TIME64_SYSCALLS define Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 2/5] y2038: Introduce internal for glibc struct __timespec64 Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 3/5] y2038: Provide conversion helpers for " Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 4/5] y2038: linux: Provide __clock_settime64 implementation Lukasz Majewski
2019-05-07 13:18 ` [PATCH v3 5/5] y2038: Support for Y2038 safe time on 32 bit systems Lukasz Majewski
2019-05-07 13:34 ` Andreas Schwab
2019-05-08 15:56 ` [PATCH] y2038: Introduce __ASSUME_TIME64_SYSCALLS define Lukasz Majewski
2019-05-09 15:58 ` Joseph Myers
2019-05-09 16:18 ` Stepan Golosunov
2019-05-15 14:27 ` [PATCH v5] " Lukasz Majewski
2019-05-21 15:15 ` Lukasz Majewski
2019-05-23 7:34 ` Stepan Golosunov
2019-05-23 9:35 ` Lukasz Majewski
2019-05-25 16:19 ` Lukasz Majewski
2019-05-25 19:45 ` Stepan Golosunov
2019-05-26 12:39 ` Lukasz Majewski
2019-05-28 16:00 ` Lukasz Majewski
2019-05-28 19:53 ` Joseph Myers [this message]
2019-05-28 22:46 ` Lukasz Majewski
2019-05-28 22:50 ` Joseph Myers
2019-05-28 19:47 ` Joseph Myers
2019-05-28 22:09 ` Lukasz Majewski
2019-05-28 22:43 ` Joseph Myers
2019-05-23 21:17 ` Joseph Myers
2019-05-20 10:27 ` [PATCH v4 0/3] y2038: Linux: Provide __clock_settime64 function supporting 64 bit time Lukasz Majewski
2019-05-20 10:27 ` [PATCH v4 1/3] y2038: Introduce internal for glibc struct __timespec64 Lukasz Majewski
2019-05-20 10:27 ` [PATCH v4 2/3] y2038: Provide conversion helpers for " Lukasz Majewski
2019-05-20 10:27 ` [PATCH v4 3/3] y2038: linux: Provide __clock_settime64 implementation Lukasz Majewski
2019-05-23 7:08 ` Stepan Golosunov
2019-05-23 9:28 ` Lukasz Majewski
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