From: Lukasz Majewski <lukma@denx.de> To: Arnd Bergmann <arnd@arndb.de> Cc: Florian Weimer <fweimer@redhat.com>, Helmut Grohne <helmutg@debian.org>, GNU C Library <libc-alpha@sourceware.org>, Viresh Kumar <vireshk@kernel.org>, Vineet Gupta <Vineet.Gupta1@synopsys.com>, Palmer Dabbelt <palmerdabbelt@google.com>, Zong Li <zongbox@gmail.com>, debian-arm@lists.debian.org, Alistair Francis <alistair.francis@wdc.com>, Adhemerval Zanella <adhemerval.zanella@linaro.org>, "Maciej W. Rozycki" <macro@wdc.com>, Alistair Francis <alistair23@gmail.com>, arcml <linux-snps-arc@lists.infradead.org>, Joseph Myers <joseph@codesourcery.com> 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 Message-ID: <20200220164245.035e09b1@jawa> (raw) In-Reply-To: <CAK8P3a2qLZBAuP-YT2=KZoP+V23TAKvw5W1_2t7rEr2RobLsWw@mail.gmail.com> [-- Attachment #1.1: Type: text/plain, Size: 3254 bytes --] 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 HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de [-- Attachment #1.2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 170 bytes --] _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
next prev parent reply index Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <cover.1578824547.git.alistair.francis@wdc.com> [not found] ` <4e95f95966d8d7c6a8339160dc62d81c1f6a1bfb.1578824547.git.alistair.francis@wdc.com> 2020-02-12 0:14 ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 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 2020-03-26 5:54 ` Helmut Grohne 2020-03-26 11:51 ` Alexey Brodkin 2020-03-26 12:24 ` Helmut Grohne 2020-03-26 12:53 ` Alexey Brodkin 2020-03-26 14:28 ` Helmut Grohne 2020-03-26 19:04 ` Lennart Sorensen 2020-08-26 14:39 ` Vineet Gupta 2020-08-26 15:43 ` Helmut Grohne 2020-08-26 21:16 ` Aurelien Jarno 2021-02-24 20:17 ` Vineet Gupta 2021-02-26 9:47 ` Helmut Grohne 2021-02-26 15:58 ` Vineet Gupta 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
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