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 17:31:32 +0100
Message-ID: <20200220173132.05f2fad5@jawa> (raw)
In-Reply-To: <CAK8P3a2vvuqzLQqrYkyyYBFATDjCpBuR2Zquu-xB2BWmc5GQWA@mail.gmail.com>
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Hi Arnd,
> On Thu, Feb 20, 2020 at 4:42 PM Lukasz Majewski <lukma@denx.de> wrote:
> > > On Thu, Feb 20, 2020 at 2:15 PM Lukasz Majewski <lukma@denx.de>
> > > wrote:
>
> >
> > 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
>
> What I meant is to remove the __clock_settime function from the
> library entirely to cause a link failure. I suppose replacing most
> "__TIMESIZE != 64" with '0' would do that. Ideally I'd just set
I think that replacing "__TIMESIZE != 64" with '0' would be the
simplest option.
> __TIMESIZE to 64, but doing that would make the ABI incompatible
> with mainline glibc.
>
> > 2. In kernel - return -ENOTSUPP when clock_settime syscall instead
> > of clock_settime64 is invoked.
>
> We already have that with CONFIG_COMPAT_32BIT_TIME, but
> at the moment I think that still breaks glibc's usage of __NR_futex,
> and a compile-time error is always better than a runtime error,
> as it's easier to catch them reliably
Ok.
>
> Arnd
Best regards,
Lukasz Majewski
--
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Thread overview: 55+ 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
2020-02-20 16:08 ` Arnd Bergmann
2020-02-20 16:31 ` Lukasz Majewski [this message]
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
2020-02-12 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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