From: Lukasz Majewski <lukma@denx.de>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>,
Alistair Francis <alistair23@gmail.com>,
Joseph Myers <joseph@codesourcery.com>,
Florian Weimer <fweimer@redhat.com>,
GNU C Library <libc-alpha@sourceware.org>,
Palmer Dabbelt <palmerdabbelt@google.com>,
Zong Li <zongbox@gmail.com>,
Alistair Francis <alistair.francis@wdc.com>,
Adhemerval Zanella <adhemerval.zanella@linaro.org>,
"Maciej W. Rozycki" <macro@wdc.com>,
arcml <linux-snps-arc@lists.infradead.org>,
debian-arm@lists.debian.org, Helmut Grohne <helmutg@debian.org>,
Viresh Kumar <vireshk@kernel.org>
Subject: Re: switching ARC to 64-bit time_t (Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64)
Date: Thu, 20 Feb 2020 16:42:45 +0100 [thread overview]
Message-ID: <20200220164245.035e09b1@jawa> (raw)
In-Reply-To: <CAK8P3a2qLZBAuP-YT2=KZoP+V23TAKvw5W1_2t7rEr2RobLsWw@mail.gmail.com>
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Hi Arnd,
> On Thu, Feb 20, 2020 at 2:15 PM Lukasz Majewski <lukma@denx.de> wrote:
> > > On Thu, Feb 20, 2020 at 10:37 AM Lukasz Majewski <lukma@denx.de>
> > > wrote:
> > > > > On Thu, Feb 20, 2020 at 12:11 AM Lukasz Majewski
> > > > > <lukma@denx.de> Are there any glibc issues that prevent it
> > > > > from working correctly,
> > > >
> > > > I think that the glibc wrappers for most important syscalls are
> > > > now converted.
> > > >
> > > > What is missing:
> > > >
> > > > - NTPL (threads)
> > > > - stat
> > >
> > > Do you mean that code using these will fail to work correctly with
> > > -D_TIME_BITS=64 at the moment, or that the interfaces are there
> > > but they are not y2038 safe?
> >
> > For ARM32 (branch [2]):
> >
> > - Without -D_TIME_BITS=64 defined during compilation (as we do have
> > now) the glibc is fully functional, but when you set date after
> > 03:14:08 UTC on 19.01.2038 you will see the date reset (to 1901)
> > in the user space programs (after calling e.g. 'date').
>
> I'd actually consider intentionally breaking this for a Debian
> bootstrap, at least initially, so that any application that
> accidentally gets built without -D_TIME_BITS=64 runs into a build or
> link failure.
I do see two approaches here:
1. In glibc:
When -D_TIME_BITS=64 is set - redirections are enabled for syscall
wrappers; for example __clock_settime64 is used instead of
__clock_settime (e.g. sysdeps/unix/sysv/linux/clock_settime).
The latter is guarded by #ifdef __TIMESIZE != 64 so we could change
mechanically that __clock_settime returns -1 and sets errno to -ENOTSUPP
2. In kernel - return -ENOTSUPP when clock_settime syscall instead of
clock_settime64 is invoked.
>
> > - With -D_TIME_BITS=64 set during compilation - and using branch
> > [2] - syscalls listed in [1] will provide correct date after Y2038
> > 32 bit overflow. Other (i.e. not converted ones) will use overflow
> > date (1901 year). The glibc will also be fully functional up till
> > Y2038 overflow.
>
> Ok.
>
> > > > - In-glibc test coverage when -D_TIME_BITS=64 is used. I do have
> > > > some basic tests [4], but this may be not enough.
> > >
> > > This is probably something where debian-rebootstrap could help,
> > > as building and testing more user space packages will excercise
> > > additional code paths in glibc as well.
> >
> > Yes this _could_ help. Do you have any tutorial/howto similar to one
> > from [4]?
>
> Not sure, maybe Helmut has some references.
>
> > > There is also some work
> > > in Linaro to ensure that LTP tests the low-level syscall
> > > interfaces in both the time32 and time64 variants.
> >
> > Interesting. Is this work now publicly available?
>
> I think this is currently in the planning stage, but once patches
> are available, they would be posted to the ltp mailing list. Viresh
> should have more details on this.
>
> Arnd
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
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next prev parent reply other threads:[~2020-02-20 15:42 UTC|newest]
Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-12 10:33 [RFC v6 00/23] RISC-V glibc port for the 32-bit Alistair Francis
2020-01-12 10:33 ` [RFC v6 01/23] math/gen-libm-test.py: Convert to Python 3 Alistair Francis
2020-01-12 14:46 ` Joseph Myers
2020-01-14 6:53 ` Alistair Francis
2020-01-12 10:33 ` [RFC v6 02/23] tst-clone3: Use __NR_futex_time64 if we don't have __NR_futex Alistair Francis
2020-01-12 10:33 ` [RFC v6 03/23] time: Add a timeval with a long tv_sec and tv_usec Alistair Francis
2020-01-12 14:48 ` Joseph Myers
2020-01-14 7:18 ` Alistair Francis
2020-01-14 11:27 ` Lukasz Majewski
2020-01-14 10:16 ` Lukasz Majewski
2020-01-15 5:15 ` Alistair Francis
2020-01-15 8:01 ` Arnd Bergmann
2020-01-15 8:48 ` Lukasz Majewski
2020-01-12 10:33 ` [RFC v6 04/23] linux: Use 32-bit time_t for itimerval Alistair Francis
2020-01-14 10:58 ` Lukasz Majewski
2020-01-15 23:39 ` Alistair Francis
2020-01-16 1:21 ` Joseph Myers
2020-01-16 1:33 ` Alistair Francis
2020-01-16 13:34 ` Lukasz Majewski
2020-01-17 6:39 ` Alistair Francis
2020-01-17 11:14 ` Lukasz Majewski
2020-01-17 12:03 ` Alistair Francis
2020-01-17 12:19 ` Lukasz Majewski
2020-01-17 14:14 ` Joseph Myers
2020-01-16 16:19 ` Joseph Myers
2020-01-17 6:40 ` Alistair Francis
2020-01-12 10:33 ` [RFC v6 05/23] linux: Use 32-bit time_t for rusage Alistair Francis
2020-01-14 11:58 ` Lukasz Majewski
2020-01-15 23:42 ` Alistair Francis
2020-01-12 10:33 ` [RFC v6 06/23] sysdeps: Use long types with 64-bit time_t on 32-bit archs Alistair Francis
2020-01-12 21:41 ` Arnd Bergmann
2020-01-16 7:30 ` Alistair Francis
2020-01-16 7:41 ` Alistair Francis
2020-01-16 8:36 ` Arnd Bergmann
2020-01-16 22:16 ` Alistair Francis
2020-01-16 22:41 ` Joseph Myers
2020-01-12 10:33 ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Alistair Francis
2020-01-14 12:07 ` Lukasz Majewski
2020-01-15 5:09 ` Alistair Francis
2020-02-12 0:14 ` Vineet Gupta
2020-02-12 0:14 ` Alistair Francis
2020-02-12 1:30 ` Joseph Myers
2020-02-14 22:39 ` Alistair Francis
2020-02-18 23:05 ` switching ARC to 64-bit time_t (Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64) Vineet Gupta
2020-02-18 23:13 ` Joseph Myers
2020-02-19 23:09 ` Lukasz Majewski
2020-02-19 23:11 ` Lukasz Majewski
2020-02-20 8:31 ` Arnd Bergmann
2020-02-20 9:37 ` Lukasz Majewski
2020-02-20 12:37 ` Arnd Bergmann
2020-02-20 13:14 ` Lukasz Majewski
2020-02-20 14:44 ` Arnd Bergmann
2020-02-20 15:42 ` Lukasz Majewski [this message]
2020-02-20 16:08 ` Arnd Bergmann
2020-02-20 16:31 ` Lukasz Majewski
2020-02-24 2:48 ` Viresh Kumar
2020-02-21 19:56 ` Alistair Francis
2020-02-22 8:42 ` Arnd Bergmann
2020-02-24 9:00 ` Lukasz Majewski
2020-02-24 9:46 ` Andreas Schwab
2020-02-24 10:14 ` Lukasz Majewski
2020-02-24 10:23 ` Andreas Schwab
2020-02-24 10:36 ` Lukasz Majewski
2020-02-24 10:42 ` Andreas Schwab
2020-02-24 11:13 ` Lukasz Majewski
2020-02-24 12:41 ` Lukasz Majewski
2020-02-25 0:03 ` Joseph Myers
2020-02-25 11:39 ` Lukasz Majewski
2020-02-25 14:36 ` Joseph Myers
2020-02-26 13:18 ` Lukasz Majewski
2020-02-26 14:48 ` Joseph Myers
2020-02-26 16:28 ` Lukasz Majewski
2020-02-25 9:03 ` Arnd Bergmann
2020-02-20 16:27 ` Helmut Grohne
2020-03-26 0:25 ` ARC rebootstrap prereq (was Re: switching ARC to 64-bit time_t ) Vineet Gupta via Libc-alpha
2020-03-26 5:54 ` Helmut Grohne
2020-03-26 11:51 ` Alexey Brodkin via Libc-alpha
2020-03-26 12:24 ` Helmut Grohne
2020-03-26 12:53 ` Alexey Brodkin via Libc-alpha
2020-03-26 14:28 ` Helmut Grohne
2020-03-26 19:04 ` Lennart Sorensen via Libc-alpha
2020-08-26 14:39 ` Vineet Gupta via Libc-alpha
2020-08-26 15:43 ` Helmut Grohne
2020-08-26 21:16 ` Aurelien Jarno
2021-02-24 20:17 ` Vineet Gupta via Libc-alpha
2021-02-26 9:47 ` Helmut Grohne
2021-02-26 15:58 ` Vineet Gupta via Libc-alpha
2021-08-21 17:36 ` Aurelien Jarno
2020-02-12 1:42 ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Vineet Gupta
2020-02-12 12:58 ` Arnd Bergmann
2020-02-19 0:56 ` Vineet Gupta
2020-02-19 1:03 ` Alistair Francis
2020-02-19 1:31 ` Vineet Gupta
2020-02-19 8:30 ` Andreas Schwab
2020-02-19 18:42 ` Vineet Gupta
2020-02-19 23:18 ` Lukasz Majewski
2020-02-20 0:26 ` Vineet Gupta
2020-02-20 0:46 ` Joseph Myers
2020-02-20 8:24 ` Arnd Bergmann
2020-02-20 10:28 ` Lukasz Majewski
2020-02-20 14:14 ` Joseph Myers
2020-01-12 10:33 ` [RFC v6 08/23] RISC-V: Define __NR_* as __NR_*_time64/64 for 32-bit Alistair Francis
2020-01-13 13:39 ` Arnd Bergmann
2020-01-14 7:14 ` Alistair Francis
2020-01-14 12:47 ` Arnd Bergmann
2020-01-15 7:03 ` Alistair Francis
2020-01-25 20:33 ` Khem Raj
2020-01-27 8:39 ` Arnd Bergmann
2020-01-27 10:02 ` Florian Weimer
2020-01-27 13:11 ` Arnd Bergmann
2020-01-27 13:17 ` Florian Weimer
2020-01-27 14:08 ` Arnd Bergmann
2020-01-12 10:33 ` [RFC v6 09/23] RISC-V: Add support for 32-bit vDSO calls Alistair Francis
2020-01-13 13:33 ` Arnd Bergmann
2020-01-14 7:23 ` Alistair Francis
2020-01-12 10:33 ` [RFC v6 10/23] RISC-V: Add socket-constants.h for RV32 Alistair Francis
2020-01-12 10:34 ` [RFC v6 11/23] RISC-V: Support dynamic loader for the 32-bit Alistair Francis
2020-01-12 10:34 ` [RFC v6 12/23] RISC-V: Add path of library directories " Alistair Francis
2020-01-12 10:34 ` [RFC v6 13/23] RISC-V: Add arch-syscall.h for RV32 Alistair Francis
2020-01-12 10:34 ` [RFC v6 14/23] RISC-V: The ABI implementation for the 32-bit Alistair Francis
2020-01-12 10:34 ` [RFC v6 15/23] RISC-V: Hard float support for 32-bit Alistair Francis
2020-01-12 10:34 ` [RFC v6 16/23] RISC-V: Add ABI lists Alistair Francis
2020-01-12 10:34 ` [RFC v6 17/23] RISC-V: Add the RV32 libm-test-ulps Alistair Francis
2020-01-12 10:34 ` [RFC v6 18/23] RISC-V: Fix llrint and llround missing exceptions on RV32 Alistair Francis
2020-01-12 10:34 ` [RFC v6 19/23] RISC-V: Build Infastructure for 32-bit Alistair Francis
2020-01-12 10:34 ` [RFC v6 20/23] riscv32: Specify the arch_minimum_kernel as 5.4 Alistair Francis
2020-01-12 10:56 ` Andreas Schwab
2020-01-14 7:25 ` Alistair Francis
2020-01-14 9:03 ` Andreas Schwab
2020-01-12 10:34 ` [RFC v6 21/23] RISC-V: Add rv32 path to RTLDLIST in ldd Alistair Francis
2020-01-12 10:34 ` [RFC v6 22/23] Documentation for the RISC-V 32-bit port Alistair Francis
2020-01-12 10:34 ` [RFC v6 23/23] Add RISC-V 32-bit target to build-many-glibcs.py Alistair Francis
2020-01-12 14:44 ` [RFC v6 00/23] RISC-V glibc port for the 32-bit Joseph Myers
2020-01-14 7:30 ` Alistair Francis
2020-01-14 22:08 ` Joseph Myers
2020-01-15 4:30 ` Alistair Francis
2020-01-15 21:50 ` Joseph Myers
2020-01-15 23:50 ` Alistair Francis
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