* [PATCH] y2038: linux: Provide __time64 implementation
@ 2020-10-15 12:34 Lukasz Majewski
2020-10-15 13:03 ` Adhemerval Zanella via Libc-alpha
0 siblings, 1 reply; 3+ messages in thread
From: Lukasz Majewski @ 2020-10-15 12:34 UTC (permalink / raw)
To: Joseph Myers, Paul Eggert, Adhemerval Zanella
Cc: Florian Weimer, GNU C Library, Andreas Schwab, Stepan Golosunov,
Alistair Francis
In the glibc the time function can use vDSO (on power and x86 the
USE_IFUNC_TIME is defined), time syscall or 'default' time() from
./time/time.c (as a fallback).
In this patch the last function (time) has been refactored and moved
to ./sysdeps/unix/sysv/linux/time.c to be Linux specific.
The new __time64 explicit 64 bit function for providing 64 bit value of
seconds after epoch (by internally calling __clock_gettime64) has been
introduced.
Moreover, a 32 bit version - __time has been refactored to internally
use __time64.
The __time is now supposed to be used on systems still supporting 32 bit
time (__TIMESIZE != 64) - hence the necessary check for time_t potential
overflow.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test proper usage of both __time64 and __time.
---
include/time.h | 7 ++++++
sysdeps/unix/sysv/linux/time.c | 39 +++++++++++++++++++++++++++++++++-
2 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/include/time.h b/include/time.h
index edf6cdf829..caf2af5e74 100644
--- a/include/time.h
+++ b/include/time.h
@@ -317,6 +317,13 @@ extern int __timespec_get64 (struct __timespec64 *ts, int base);
libc_hidden_proto (__timespec_get64)
#endif
+#if __TIMESIZE == 64
+# define __time64 __time
+#else
+extern __time64_t __time64 (__time64_t *timer);
+libc_hidden_proto (__time64)
+#endif
+
/* Use in the clock_* functions. Size of the field representing the
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time.c
index 9d8e573c0a..1a9a7c0413 100644
--- a/sysdeps/unix/sysv/linux/time.c
+++ b/sysdeps/unix/sysv/linux/time.c
@@ -47,5 +47,42 @@ time (time_t *t)
}
# endif /* !SHARED */
#else /* USE_IFUNC_TIME */
-# include <time/time.c>
+/* Conversion of time function to support 64 bit time on archs
+ with __WORDSIZE == 32 and __TIMESIZE == 32/64 */
+# include <time.h>
+# include <time-clockid.h>
+# include <errno.h>
+/* Return the time now, and store it in *TIMER if not NULL. */
+
+__time64_t
+__time64 (__time64_t *timer)
+{
+ struct __timespec64 ts;
+ __clock_gettime64 (TIME_CLOCK_GETTIME_CLOCKID, &ts);
+
+ if (timer)
+ *timer = ts.tv_sec;
+ return ts.tv_sec;
+}
+
+# if __TIMESIZE != 64
+libc_hidden_def (__time64)
+
+time_t
+__time (time_t *timer)
+{
+ __time64_t t = __time64 (NULL);
+
+ if (! in_time_t_range (t))
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+
+ if (timer)
+ *timer = t;
+ return t;
+}
+# endif
+weak_alias (__time, time)
#endif
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] y2038: linux: Provide __time64 implementation
2020-10-15 12:34 [PATCH] y2038: linux: Provide __time64 implementation Lukasz Majewski
@ 2020-10-15 13:03 ` Adhemerval Zanella via Libc-alpha
2020-10-16 10:18 ` Lukasz Majewski
0 siblings, 1 reply; 3+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2020-10-15 13:03 UTC (permalink / raw)
To: Lukasz Majewski, Joseph Myers, Paul Eggert
Cc: Florian Weimer, GNU C Library, Andreas Schwab, Stepan Golosunov,
Alistair Francis
On 15/10/2020 09:34, Lukasz Majewski wrote:
> In the glibc the time function can use vDSO (on power and x86 the
> USE_IFUNC_TIME is defined), time syscall or 'default' time() from
> ./time/time.c (as a fallback).
>
> In this patch the last function (time) has been refactored and moved
> to ./sysdeps/unix/sysv/linux/time.c to be Linux specific.
>
> The new __time64 explicit 64 bit function for providing 64 bit value of
> seconds after epoch (by internally calling __clock_gettime64) has been
> introduced.
>
> Moreover, a 32 bit version - __time has been refactored to internally
> use __time64.
>
> The __time is now supposed to be used on systems still supporting 32 bit
> time (__TIMESIZE != 64) - hence the necessary check for time_t potential
> overflow.
>
> Build tests:
> ./src/scripts/build-many-glibcs.py glibcs
>
> Run-time tests:
> - Run specific tests on ARM/x86 32bit systems (qemu):
> https://github.com/lmajewski/meta-y2038 and run tests:
> https://github.com/lmajewski/y2038-tests/commits/master
>
> Above tests were performed with Y2038 redirection applied as well as without
> to test proper usage of both __time64 and __time.
Looks good in general, some comments below.
> ---
> include/time.h | 7 ++++++
> sysdeps/unix/sysv/linux/time.c | 39 +++++++++++++++++++++++++++++++++-
> 2 files changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/include/time.h b/include/time.h
> index edf6cdf829..caf2af5e74 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -317,6 +317,13 @@ extern int __timespec_get64 (struct __timespec64 *ts, int base);
> libc_hidden_proto (__timespec_get64)
> #endif
>
> +#if __TIMESIZE == 64
> +# define __time64 __time
> +#else
> +extern __time64_t __time64 (__time64_t *timer);
> +libc_hidden_proto (__time64)
> +#endif
> +
> /* Use in the clock_* functions. Size of the field representing the
> actual clock ID. */
> #define CLOCK_IDFIELD_SIZE 3
Ok.
> diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time.c
> index 9d8e573c0a..1a9a7c0413 100644
> --- a/sysdeps/unix/sysv/linux/time.c
> +++ b/sysdeps/unix/sysv/linux/time.c
> @@ -47,5 +47,42 @@ time (time_t *t)
> }
> # endif /* !SHARED */
> #else /* USE_IFUNC_TIME */
You need to handle USE_IFUNC_TIME, which is still used for powerpc32 and
i686. I don't think optimizing for vDSO access pay for the complexity in
these cases, so disable it with:
20 #ifdef USE_IFUNC_TIME && __TIMESIZE == 64
21 # include <time.h>
> -# include <time/time.c>
> +/* Conversion of time function to support 64 bit time on archs
> + with __WORDSIZE == 32 and __TIMESIZE == 32/64 */
I think this comment is kinda unnecessary, but if would still want
to add it I would put close to '__time' implementation rather than
the '__time64'.
> +# include <time.h>
> +# include <time-clockid.h>
> +# include <errno.h>
> +/* Return the time now, and store it in *TIMER if not NULL. */
Space after the include.
> +
> +__time64_t
> +__time64 (__time64_t *timer)
> +{
> + struct __timespec64 ts;
> + __clock_gettime64 (TIME_CLOCK_GETTIME_CLOCKID, &ts);
> +
> + if (timer)
No implicit checks, use 'if (timer != NULL)'.
> + *timer = ts.tv_sec;
> + return ts.tv_sec;
> +}
> +
> +# if __TIMESIZE != 64
> +libc_hidden_def (__time64)
Ok.
> +
> +time_t
> +__time (time_t *timer)
> +{
> + __time64_t t = __time64 (NULL);
> +
> + if (! in_time_t_range (t))
> + {
> + __set_errno (EOVERFLOW);
> + return -1;
> + }
> +
> + if (timer)
No implicit checks, use 'if (timer != NULL)'.
> + *timer = t;
> + return t;
> +}
> +# endif
> +weak_alias (__time, time)
> #endif
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] y2038: linux: Provide __time64 implementation
2020-10-15 13:03 ` Adhemerval Zanella via Libc-alpha
@ 2020-10-16 10:18 ` Lukasz Majewski
0 siblings, 0 replies; 3+ messages in thread
From: Lukasz Majewski @ 2020-10-16 10:18 UTC (permalink / raw)
To: Adhemerval Zanella
Cc: Florian Weimer, GNU C Library, Andreas Schwab, Stepan Golosunov,
Alistair Francis, Joseph Myers
[-- Attachment #1: Type: text/plain, Size: 4779 bytes --]
Hi Adhemerval,
> On 15/10/2020 09:34, Lukasz Majewski wrote:
> > In the glibc the time function can use vDSO (on power and x86 the
> > USE_IFUNC_TIME is defined), time syscall or 'default' time() from
> > ./time/time.c (as a fallback).
> >
> > In this patch the last function (time) has been refactored and moved
> > to ./sysdeps/unix/sysv/linux/time.c to be Linux specific.
> >
> > The new __time64 explicit 64 bit function for providing 64 bit
> > value of seconds after epoch (by internally calling
> > __clock_gettime64) has been introduced.
> >
> > Moreover, a 32 bit version - __time has been refactored to
> > internally use __time64.
> >
> > The __time is now supposed to be used on systems still supporting
> > 32 bit time (__TIMESIZE != 64) - hence the necessary check for
> > time_t potential overflow.
> >
> > Build tests:
> > ./src/scripts/build-many-glibcs.py glibcs
> >
> > Run-time tests:
> > - Run specific tests on ARM/x86 32bit systems (qemu):
> > https://github.com/lmajewski/meta-y2038 and run tests:
> > https://github.com/lmajewski/y2038-tests/commits/master
> >
> > Above tests were performed with Y2038 redirection applied as well
> > as without to test proper usage of both __time64 and __time.
>
> Looks good in general, some comments below.
I'm going to send v2 of this patch.
>
> > ---
> > include/time.h | 7 ++++++
> > sysdeps/unix/sysv/linux/time.c | 39
> > +++++++++++++++++++++++++++++++++- 2 files changed, 45
> > insertions(+), 1 deletion(-)
> >
> > diff --git a/include/time.h b/include/time.h
> > index edf6cdf829..caf2af5e74 100644
> > --- a/include/time.h
> > +++ b/include/time.h
> > @@ -317,6 +317,13 @@ extern int __timespec_get64 (struct
> > __timespec64 *ts, int base); libc_hidden_proto (__timespec_get64)
> > #endif
> >
> > +#if __TIMESIZE == 64
> > +# define __time64 __time
> > +#else
> > +extern __time64_t __time64 (__time64_t *timer);
> > +libc_hidden_proto (__time64)
> > +#endif
> > +
> > /* Use in the clock_* functions. Size of the field representing
> > the actual clock ID. */
> > #define CLOCK_IDFIELD_SIZE 3
>
> Ok.
>
> > diff --git a/sysdeps/unix/sysv/linux/time.c
> > b/sysdeps/unix/sysv/linux/time.c index 9d8e573c0a..1a9a7c0413 100644
> > --- a/sysdeps/unix/sysv/linux/time.c
> > +++ b/sysdeps/unix/sysv/linux/time.c
> > @@ -47,5 +47,42 @@ time (time_t *t)
> > }
> > # endif /* !SHARED */
> > #else /* USE_IFUNC_TIME */
>
> You need to handle USE_IFUNC_TIME, which is still used for powerpc32
> and i686. I don't think optimizing for vDSO access pay for the
> complexity in these cases, so disable it with:
>
> 20 #ifdef USE_IFUNC_TIME && __TIMESIZE == 64
> 21 # include <time.h>
>
In the gettimeofday() conversion patch it was enough to use
#ifdef __x86_64__ and #ifdef __powerpc64__ in arch specific time.c so
(SHA1: 7455b700279ec8baccf8dd7b119648f8b3e34eec)
>
> > -# include <time/time.c>
> > +/* Conversion of time function to support 64 bit time on archs
> > + with __WORDSIZE == 32 and __TIMESIZE == 32/64 */
>
> I think this comment is kinda unnecessary, but if would still want
> to add it I would put close to '__time' implementation rather than
> the '__time64'.
Ok. I will remove it.
>
> > +# include <time.h>
> > +# include <time-clockid.h>
> > +# include <errno.h>
> > +/* Return the time now, and store it in *TIMER if not NULL. */
>
> Space after the include.
Those #includes are following the
#else /* USE_IFUNC_TIME */
and the same indentation is used in other places in this file. I've
just followed it.
>
> > +
> > +__time64_t
> > +__time64 (__time64_t *timer)
> > +{
> > + struct __timespec64 ts;
> > + __clock_gettime64 (TIME_CLOCK_GETTIME_CLOCKID, &ts);
> > +
> > + if (timer)
>
> No implicit checks, use 'if (timer != NULL)'.
Ok.
>
> > + *timer = ts.tv_sec;
> > + return ts.tv_sec;
> > +}
> > +
> > +# if __TIMESIZE != 64
> > +libc_hidden_def (__time64)
>
> Ok.
>
> > +
> > +time_t
> > +__time (time_t *timer)
> > +{
> > + __time64_t t = __time64 (NULL);
> > +
> > + if (! in_time_t_range (t))
> > + {
> > + __set_errno (EOVERFLOW);
> > + return -1;
> > + }
> > +
> > + if (timer)
>
> No implicit checks, use 'if (timer != NULL)'.
Ok.
>
> > + *timer = t;
> > + return t;
> > +}
> > +# endif
> > +weak_alias (__time, time)
> > #endif
> >
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 #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-10-16 10:19 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-15 12:34 [PATCH] y2038: linux: Provide __time64 implementation Lukasz Majewski
2020-10-15 13:03 ` Adhemerval Zanella via Libc-alpha
2020-10-16 10:18 ` Lukasz Majewski
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).