Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

[Puneet Kumar Yatnal (QUIC)]

[-- Attachment #1: Type: text/plain, Size: 2194 bytes --]

All

if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

From pthread.h
extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")

From gthread_posix.h:
static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));


__gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.

normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.

From: pthread_cond_wait.c

#if __TIMESIZE == 64
strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
#else
strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
libc_hidden_def (__pthread_cond_timedwait64)

int
___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
                            const struct timespec *abstime)
{
  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);

  return __pthread_cond_timedwait64 (cond, mutex, &ts64);
}
#endif /* __TIMESIZE == 64 */
versioned_symbol (libc, ___pthread_cond_timedwait,
                  pthread_cond_timedwait, GLIBC_2_3_2);
libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
#ifndef SHARED
strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
#endif

if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34

Regards
Puneet

RE: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Puneet Kumar Yatnal (QUIC)]

[-- Attachment #1: Type: text/plain, Size: 2392 bytes --]


++
From: Puneet Kumar Yatnal (QUIC)
Sent: Monday, April 17, 2023 9:26 AM
To: gcc-help@gcc.gnu.org
Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

All

if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

From pthread.h
extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")

From gthread_posix.h:
static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));


__gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.

normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.

From: pthread_cond_wait.c

#if __TIMESIZE == 64
strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
#else
strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
libc_hidden_def (__pthread_cond_timedwait64)

int
___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
                            const struct timespec *abstime)
{
  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);

  return __pthread_cond_timedwait64 (cond, mutex, &ts64);
}
#endif /* __TIMESIZE == 64 */
versioned_symbol (libc, ___pthread_cond_timedwait,
                  pthread_cond_timedwait, GLIBC_2_3_2);
libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
#ifndef SHARED
strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
#endif

if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34

Regards
Puneet

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Andrew Pinski]

On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via
Gcc-bugs <gcc-bugs@gcc.gnu.org> wrote:
>
>
> ++
> From: Puneet Kumar Yatnal (QUIC)
> Sent: Monday, April 17, 2023 9:26 AM
> To: gcc-help@gcc.gnu.org
> Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

First gcc-bugs@ is not the right place to report a bug report as
gcc-bugs is mainly for automated emails from bugzilla. Please use
bugzilla first.

>
> All
>
> if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

Note libstdc++ does ABI changes too which is NOT part of that ABI design.
This is where the symbol
__gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So
any changes you might do to fix __gthrw_pthread_cond_timedwait is not
really going to work without wider ABI fixes to libstdc++.
I don't know any one who is making those changes/fixes. So you should
file an bug requesting it. And maybe even have a design document ready
for it. There are many/some classes which have timespec inside them
and not just the mutex related ones.

Thanks,
Andrew

>
> From pthread.h
> extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")
>
> From gthread_posix.h:
> static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));
>
>
> __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.
>
> normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.
>
> From: pthread_cond_wait.c
>
> #if __TIMESIZE == 64
> strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
> #else
> strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
> libc_hidden_def (__pthread_cond_timedwait64)
>
> int
> ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
>                             const struct timespec *abstime)
> {
>   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
>
>   return __pthread_cond_timedwait64 (cond, mutex, &ts64);
> }
> #endif /* __TIMESIZE == 64 */
> versioned_symbol (libc, ___pthread_cond_timedwait,
>                   pthread_cond_timedwait, GLIBC_2_3_2);
> libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #ifndef SHARED
> strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #endif
>
> if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34
>
> Regards
> Puneet
>

RE: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Puneet Kumar Yatnal]

Hi @Andrew Pinski

>Note libstdc++ does ABI changes too which is NOT part of that ABI design.
>This is where the symbol
>__gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So any changes you might do to fix __gthrw_pthread_cond_timedwait is not really going to work >without wider ABI fixes to libstdc++.
>I don't know any one who is making those changes/fixes. So you should file an bug requesting it. And maybe even have a design document ready for it. There are many/some >classes which have timespec inside them and not just the mutex related ones.

Are you saying the fix need to add in libstdc++ abi changes? If yes could you please tell how to request that? What is file which has all libstdc++  abi changes?
I don’t have design document of any such, this need to be fixed as its bug identified in 32 bit system which uses 64  timer values.

Regards
Puneet

-----Original Message-----
From: Andrew Pinski <pinskia@gmail.com> 
Sent: Monday, April 17, 2023 11:24 AM
To: Puneet Kumar Yatnal (QUIC) <quic_puneety@quicinc.com>
Cc: gcc-help@gcc.gnu.org; gcc-bugs@gcc.gnu.org
Subject: Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via Gcc-bugs <gcc-bugs@gcc.gnu.org> wrote:
>
>
> ++
> From: Puneet Kumar Yatnal (QUIC)
> Sent: Monday, April 17, 2023 9:26 AM
> To: gcc-help@gcc.gnu.org
> Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has 
> impact on time values

First gcc-bugs@ is not the right place to report a bug report as gcc-bugs is mainly for automated emails from bugzilla. Please use bugzilla first.

>
> All
>
> if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

Note libstdc++ does ABI changes too which is NOT part of that ABI design.
This is where the symbol
__gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So any changes you might do to fix __gthrw_pthread_cond_timedwait is not really going to work without wider ABI fixes to libstdc++.
I don't know any one who is making those changes/fixes. So you should file an bug requesting it. And maybe even have a design document ready for it. There are many/some classes which have timespec inside them and not just the mutex related ones.

Thanks,
Andrew

>
> From pthread.h
> extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, 
> pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict 
> __abstime) __asm__ ("" "__pthread_cond_timedwait64")
>
> From gthread_posix.h:
> static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait 
> __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ 
> (pthread_cond_timedwait)));
>
>
> __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.
>
> normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.
>
> From: pthread_cond_wait.c
>
> #if __TIMESIZE == 64
> strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait) 
> #else strong_alias (___pthread_cond_timedwait64, 
> __pthread_cond_timedwait64) libc_hidden_def 
> (__pthread_cond_timedwait64)
>
> int
> ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
>                             const struct timespec *abstime) {
>   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
>
>   return __pthread_cond_timedwait64 (cond, mutex, &ts64); } #endif /* 
> __TIMESIZE == 64 */ versioned_symbol (libc, ___pthread_cond_timedwait,
>                   pthread_cond_timedwait, GLIBC_2_3_2); 
> libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait) 
> #ifndef SHARED strong_alias (___pthread_cond_timedwait, 
> __pthread_cond_timedwait) #endif
>
> if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34
>
> Regards
> Puneet
>

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Jonathan Wakely]

[-- Attachment #1: Type: text/plain, Size: 3738 bytes --]

On Mon, 17 Apr 2023, 07:54 Andrew Pinski via Gcc-help, <gcc-help@gcc.gnu.org>
wrote:

> On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via
> Gcc-bugs <gcc-bugs@gcc.gnu.org> wrote:
> >
> >
> > ++
> > From: Puneet Kumar Yatnal (QUIC)
> > Sent: Monday, April 17, 2023 9:26 AM
> > To: gcc-help@gcc.gnu.org
> > Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has
> impact on time values
>
> First gcc-bugs@ is not the right place to report a bug report as
> gcc-bugs is mainly for automated emails from bugzilla. Please use
> bugzilla first.
>
> >
> > All
> >
> > if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign
> for Y2038 fix(where all timer related variable moved to 64 bit instead of
> 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling
> different function in pthrea_cond_wait.c of glibc(due to weakref of symbol
> pthread_cond_timedwait())  which impacting the time value.
>
> Note libstdc++ does ABI changes too which is NOT part of that ABI design.
> This is where the symbol
> __gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So
> any changes you might do to fix __gthrw_pthread_cond_timedwait is not
> really going to work without wider ABI fixes to libstdc++.
> I don't know any one who is making those changes/fixes. So you should
> file an bug requesting it. And maybe even have a design document ready
> for it. There are many/some classes which have timespec inside them


I don't think that's true. We don't use timespec members, they're just
local variables, and very occasionally function parameters.



and not just the mutex related ones.
>
> Thanks,
> Andrew
>
> >
> > From pthread.h
> > extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond,
> pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict
> __abstime) __asm__ ("" "__pthread_cond_timedwait64")
> >
> > From gthread_posix.h:
> > static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait
> __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__
> (pthread_cond_timedwait)));
> >
> >
> > __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait
>  invoking in glibc instead of   __pthread_cond_timedwait64 which is
> impacting time value as __pthread_cond_timedwait is converting value from
> 32 bit to 64 bit.
> >
> > normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64
> properly and its working fine.
> >
> > From: pthread_cond_wait.c
> >
> > #if __TIMESIZE == 64
> > strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
> > #else
> > strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
> > libc_hidden_def (__pthread_cond_timedwait64)
> >
> > int
> > ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
> >                             const struct timespec *abstime)
> > {
> >   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
> >
> >   return __pthread_cond_timedwait64 (cond, mutex, &ts64);
> > }
> > #endif /* __TIMESIZE == 64 */
> > versioned_symbol (libc, ___pthread_cond_timedwait,
> >                   pthread_cond_timedwait, GLIBC_2_3_2);
> > libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
> > #ifndef SHARED
> > strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
> > #endif
> >
> > if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is
> resolved but that is not correct way as it disable weakref for all symbol,
> please let me know what is correct way to fix this, this i observed with
>  gcc-9.3.0 gcc and glibc 2.34
> >
> > Regards
> > Puneet
> >
>

RE: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Puneet Kumar Yatnal (QUIC)]

[-- Attachment #1: Type: text/plain, Size: 4315 bytes --]

Here issue is weakref symbol in gcc not using the __asm_ function pointed by pthread.h instead its calling directly ___pthread_cond_timedwait which is exposed by version_symbol in pthread_cond_wait.c of glibc


From: Jonathan Wakely <jwakely.gcc@gmail.com>
Sent: Monday, April 17, 2023 12:53 PM
To: Andrew Pinski <pinskia@gmail.com>
Cc: Puneet Kumar Yatnal (QUIC) <quic_puneety@quicinc.com>; gcc-help <gcc-help@gcc.gnu.org>; gcc-bugs@gcc.gnu.org
Subject: Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values


WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Mon, 17 Apr 2023, 07:54 Andrew Pinski via Gcc-help, <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>> wrote:
On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via
Gcc-bugs <gcc-bugs@gcc.gnu.org<mailto:gcc-bugs@gcc.gnu.org>> wrote:
>
>
> ++
> From: Puneet Kumar Yatnal (QUIC)
> Sent: Monday, April 17, 2023 9:26 AM
> To: gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>
> Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

First gcc-bugs@ is not the right place to report a bug report as
gcc-bugs is mainly for automated emails from bugzilla. Please use
bugzilla first.

>
> All
>
> if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

Note libstdc++ does ABI changes too which is NOT part of that ABI design.
This is where the symbol
__gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So
any changes you might do to fix __gthrw_pthread_cond_timedwait is not
really going to work without wider ABI fixes to libstdc++.
I don't know any one who is making those changes/fixes. So you should
file an bug requesting it. And maybe even have a design document ready
for it. There are many/some classes which have timespec inside them

I don't think that's true. We don't use timespec members, they're just local variables, and very occasionally function parameters.



and not just the mutex related ones.

Thanks,
Andrew

>
> From pthread.h
> extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")
>
> From gthread_posix.h:
> static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));
>
>
> __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.
>
> normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.
>
> From: pthread_cond_wait.c
>
> #if __TIMESIZE == 64
> strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
> #else
> strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
> libc_hidden_def (__pthread_cond_timedwait64)
>
> int
> ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
>                             const struct timespec *abstime)
> {
>   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
>
>   return __pthread_cond_timedwait64 (cond, mutex, &ts64);
> }
> #endif /* __TIMESIZE == 64 */
> versioned_symbol (libc, ___pthread_cond_timedwait,
>                   pthread_cond_timedwait, GLIBC_2_3_2);
> libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #ifndef SHARED
> strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #endif
>
> if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34
>
> Regards
> Puneet
>

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Jonathan Wakely]

[-- Attachment #1: Type: text/plain, Size: 4739 bytes --]

On Mon, 17 Apr 2023, 09:27 Puneet Kumar Yatnal (QUIC), <
quic_puneety@quicinc.com> wrote:

> Here issue is weakref symbol in gcc not using the __asm_ function pointed
> by pthread.h instead its calling directly ___pthread_cond_timedwait which
> is exposed by version_symbol in pthread_cond_wait.c of glibc
>

Yes, I understand that.

Like Andrew said, please file it in bugzilla. Somebody will create your
account later today.




>
> *From:* Jonathan Wakely <jwakely.gcc@gmail.com>
> *Sent:* Monday, April 17, 2023 12:53 PM
> *To:* Andrew Pinski <pinskia@gmail.com>
> *Cc:* Puneet Kumar Yatnal (QUIC) <quic_puneety@quicinc.com>; gcc-help <
> gcc-help@gcc.gnu.org>; gcc-bugs@gcc.gnu.org
> *Subject:* Re: Y2038: GCC gthr-posix.h weakref symbol invoking function
> has impact on time values
>
>
>
> *WARNING:* This email originated from outside of Qualcomm. Please be wary
> of any links or attachments, and do not enable macros.
>
>
>
> On Mon, 17 Apr 2023, 07:54 Andrew Pinski via Gcc-help, <
> gcc-help@gcc.gnu.org> wrote:
>
> On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via
> Gcc-bugs <gcc-bugs@gcc.gnu.org> wrote:
> >
> >
> > ++
> > From: Puneet Kumar Yatnal (QUIC)
> > Sent: Monday, April 17, 2023 9:26 AM
> > To: gcc-help@gcc.gnu.org
> > Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has
> impact on time values
>
> First gcc-bugs@ is not the right place to report a bug report as
> gcc-bugs is mainly for automated emails from bugzilla. Please use
> bugzilla first.
>
> >
> > All
> >
> > if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign
> for Y2038 fix(where all timer related variable moved to 64 bit instead of
> 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling
> different function in pthrea_cond_wait.c of glibc(due to weakref of symbol
> pthread_cond_timedwait())  which impacting the time value.
>
> Note libstdc++ does ABI changes too which is NOT part of that ABI design.
> This is where the symbol
> __gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So
> any changes you might do to fix __gthrw_pthread_cond_timedwait is not
> really going to work without wider ABI fixes to libstdc++.
> I don't know any one who is making those changes/fixes. So you should
> file an bug requesting it. And maybe even have a design document ready
> for it. There are many/some classes which have timespec inside them
>
>
>
> I don't think that's true. We don't use timespec members, they're just
> local variables, and very occasionally function parameters.
>
>
>
>
>
>
>
> and not just the mutex related ones.
>
> Thanks,
> Andrew
>
> >
> > From pthread.h
> > extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond,
> pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict
> __abstime) __asm__ ("" "__pthread_cond_timedwait64")
> >
> > From gthread_posix.h:
> > static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait
> __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__
> (pthread_cond_timedwait)));
> >
> >
> > __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait
>  invoking in glibc instead of   __pthread_cond_timedwait64 which is
> impacting time value as __pthread_cond_timedwait is converting value from
> 32 bit to 64 bit.
> >
> > normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64
> properly and its working fine.
> >
> > From: pthread_cond_wait.c
> >
> > #if __TIMESIZE == 64
> > strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
> > #else
> > strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
> > libc_hidden_def (__pthread_cond_timedwait64)
> >
> > int
> > ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
> >                             const struct timespec *abstime)
> > {
> >   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
> >
> >   return __pthread_cond_timedwait64 (cond, mutex, &ts64);
> > }
> > #endif /* __TIMESIZE == 64 */
> > versioned_symbol (libc, ___pthread_cond_timedwait,
> >                   pthread_cond_timedwait, GLIBC_2_3_2);
> > libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
> > #ifndef SHARED
> > strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
> > #endif
> >
> > if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is
> resolved but that is not correct way as it disable weakref for all symbol,
> please let me know what is correct way to fix this, this i observed with
>  gcc-9.3.0 gcc and glibc 2.34
> >
> > Regards
> > Puneet
> >
>
>

RE: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Puneet Kumar Yatnal (QUIC)]

[-- Attachment #1: Type: text/plain, Size: 5145 bytes --]

What is next step here? How do I post this in Bugzilla and get support.

Regards
Puneet

From: Jonathan Wakely <jwakely.gcc@gmail.com>
Sent: Monday, April 17, 2023 1:06 PM
To: Puneet Kumar Yatnal (QUIC) <quic_puneety@quicinc.com>
Cc: Andrew Pinski <pinskia@gmail.com>; gcc-help <gcc-help@gcc.gnu.org>; gcc-bugs@gcc.gnu.org
Subject: Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values


On Mon, 17 Apr 2023, 09:27 Puneet Kumar Yatnal (QUIC), <quic_puneety@quicinc.com<mailto:quic_puneety@quicinc.com>> wrote:
Here issue is weakref symbol in gcc not using the __asm_ function pointed by pthread.h instead its calling directly ___pthread_cond_timedwait which is exposed by version_symbol in pthread_cond_wait.c of glibc

Yes, I understand that.

Like Andrew said, please file it in bugzilla. Somebody will create your account later today.




From: Jonathan Wakely <jwakely.gcc@gmail.com<mailto:jwakely.gcc@gmail.com>>
Sent: Monday, April 17, 2023 12:53 PM
To: Andrew Pinski <pinskia@gmail.com<mailto:pinskia@gmail.com>>
Cc: Puneet Kumar Yatnal (QUIC) <quic_puneety@quicinc.com<mailto:quic_puneety@quicinc.com>>; gcc-help <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>>; gcc-bugs@gcc.gnu.org<mailto:gcc-bugs@gcc.gnu.org>
Subject: Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values


WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

On Mon, 17 Apr 2023, 07:54 Andrew Pinski via Gcc-help, <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>> wrote:
On Sun, Apr 16, 2023 at 10:41 PM Puneet Kumar Yatnal (QUIC) via
Gcc-bugs <gcc-bugs@gcc.gnu.org<mailto:gcc-bugs@gcc.gnu.org>> wrote:
>
>
> ++
> From: Puneet Kumar Yatnal (QUIC)
> Sent: Monday, April 17, 2023 9:26 AM
> To: gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>
> Subject: Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

First gcc-bugs@ is not the right place to report a bug report as
gcc-bugs is mainly for automated emails from bugzilla. Please use
bugzilla first.

>
> All
>
> if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

Note libstdc++ does ABI changes too which is NOT part of that ABI design.
This is where the symbol
__gthread_cond_timedwait/__gthrw_pthread_cond_timedwait are used. So
any changes you might do to fix __gthrw_pthread_cond_timedwait is not
really going to work without wider ABI fixes to libstdc++.
I don't know any one who is making those changes/fixes. So you should
file an bug requesting it. And maybe even have a design document ready
for it. There are many/some classes which have timespec inside them

I don't think that's true. We don't use timespec members, they're just local variables, and very occasionally function parameters.



and not just the mutex related ones.

Thanks,
Andrew

>
> From pthread.h
> extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")
>
> From gthread_posix.h:
> static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));
>
>
> __gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.
>
> normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.
>
> From: pthread_cond_wait.c
>
> #if __TIMESIZE == 64
> strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
> #else
> strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
> libc_hidden_def (__pthread_cond_timedwait64)
>
> int
> ___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
>                             const struct timespec *abstime)
> {
>   struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);
>
>   return __pthread_cond_timedwait64 (cond, mutex, &ts64);
> }
> #endif /* __TIMESIZE == 64 */
> versioned_symbol (libc, ___pthread_cond_timedwait,
>                   pthread_cond_timedwait, GLIBC_2_3_2);
> libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #ifndef SHARED
> strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
> #endif
>
> if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34
>
> Regards
> Puneet
>

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Florian Weimer]

* Puneet Kumar Yatnal via Gcc-bugs:

> What is next step here? How do I post this in Bugzilla and get
> support.

This issue has already been fixed with this commit:

commit 80fe172ba9820199c2bbce5d0611ffca27823049
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Nov 9 23:45:36 2021 +0000

    libstdc++: Disable gthreads weak symbols for glibc 2.34 [PR103133]
    
    Since Glibc 2.34 all pthreads symbols are defined directly in libc not
    libpthread, and since Glibc 2.32 we have used __libc_single_threaded to
    avoid unnecessary locking in single-threaded programs. This means there
    is no reason to avoid linking to libpthread now, and so no reason to use
    weak symbols defined in gthr-posix.h for all the pthread_xxx functions.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/100748
            PR libstdc++/103133
            * config/os/gnu-linux/os_defines.h (_GLIBCXX_GTHREAD_USE_WEAK):
            Define for glibc 2.34 and later.

It's been backported to GCC 10, but not GCC 9.  Backporting to 9
requires some messaging to get into 9 which lacks commit
b11cbbbb74b0e357652a1f1f0d93 ("libstdc++: Avoid calling undefined
__gthread_self weak symbol [PR 95989]").

Thanks,
Florian

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Jonathan Wakely]

On Fri, 5 May 2023 at 12:13, Florian Weimer <fweimer@redhat.com> wrote:
>
> * Puneet Kumar Yatnal via Gcc-bugs:
>
> > What is next step here? How do I post this in Bugzilla and get
> > support.
>
> This issue has already been fixed with this commit:
>
> commit 80fe172ba9820199c2bbce5d0611ffca27823049
> Author: Jonathan Wakely <jwakely@redhat.com>
> Date:   Tue Nov 9 23:45:36 2021 +0000
>
>     libstdc++: Disable gthreads weak symbols for glibc 2.34 [PR103133]

Indeed, as pointed out in bugzilla after the discussion moved there:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109540

>
>     Since Glibc 2.34 all pthreads symbols are defined directly in libc not
>     libpthread, and since Glibc 2.32 we have used __libc_single_threaded to
>     avoid unnecessary locking in single-threaded programs. This means there
>     is no reason to avoid linking to libpthread now, and so no reason to use
>     weak symbols defined in gthr-posix.h for all the pthread_xxx functions.
>
>     libstdc++-v3/ChangeLog:
>
>             PR libstdc++/100748
>             PR libstdc++/103133
>             * config/os/gnu-linux/os_defines.h (_GLIBCXX_GTHREAD_USE_WEAK):
>             Define for glibc 2.34 and later.
>
> It's been backported to GCC 10, but not GCC 9.  Backporting to 9
> requires some messaging to get into 9 which lacks commit
> b11cbbbb74b0e357652a1f1f0d93 ("libstdc++: Avoid calling undefined
> __gthread_self weak symbol [PR 95989]").
>
> Thanks,
> Florian
>

Re: Y2038: GCC gthr-posix.h weakref symbol invoking function has impact on time values

[Jakub Jelinek]

On Fri, May 05, 2023 at 01:13:50PM +0200, Florian Weimer via Gcc-bugs wrote:
> * Puneet Kumar Yatnal via Gcc-bugs:
> 
> > What is next step here? How do I post this in Bugzilla and get
> > support.
> 
> This issue has already been fixed with this commit:
> 
> commit 80fe172ba9820199c2bbce5d0611ffca27823049
> Author: Jonathan Wakely <jwakely@redhat.com>
> Date:   Tue Nov 9 23:45:36 2021 +0000
> 
>     libstdc++: Disable gthreads weak symbols for glibc 2.34 [PR103133]
>     
>     Since Glibc 2.34 all pthreads symbols are defined directly in libc not
>     libpthread, and since Glibc 2.32 we have used __libc_single_threaded to
>     avoid unnecessary locking in single-threaded programs. This means there
>     is no reason to avoid linking to libpthread now, and so no reason to use
>     weak symbols defined in gthr-posix.h for all the pthread_xxx functions.
>     
>     libstdc++-v3/ChangeLog:
>     
>             PR libstdc++/100748
>             PR libstdc++/103133
>             * config/os/gnu-linux/os_defines.h (_GLIBCXX_GTHREAD_USE_WEAK):
>             Define for glibc 2.34 and later.
> 
> It's been backported to GCC 10, but not GCC 9.  Backporting to 9
> requires some messaging to get into 9 which lacks commit
> b11cbbbb74b0e357652a1f1f0d93 ("libstdc++: Avoid calling undefined
> __gthread_self weak symbol [PR 95989]").

GCC 9 is not supported anymore, so backporting anything to it (at least
upstream) is not possible.

	Jakub

Y2038: GCC gthr-posix.h wekref symbol invoking function has impact on time values

[Puneet Kumar Yatnal]

[-- Attachment #1: Type: text/plain, Size: 2194 bytes --]

All

if we fallowed https://sourceware.org/glibc/wiki/Y2038ProofnessDesign for Y2038 fix(where all timer related variable moved to 64 bit instead of 32 bit ), pthread_cond_timedwait function from gthr_posix.h is calling different function in pthrea_cond_wait.c of glibc(due to weakref of symbol pthread_cond_timedwait())  which impacting the time value.

From pthread.h
extern int pthread_cond_timedwait (pthread_cond_t *__restrict __cond, pthread_mutex_t *__restrict __mutex, const struct timespec *__restrict __abstime) __asm__ ("" "__pthread_cond_timedwait64")

From gthread_posix.h:
static __typeof(pthread_cond_timedwait) __gthrw_pthread_cond_timedwait __attribute__ ((__weakref__("pthread_cond_timedwait"), __copy__ (pthread_cond_timedwait)));


__gthrw_(pthread_cond_timedwait) --> ___pthread_cond_timedwait   invoking in glibc instead of   __pthread_cond_timedwait64 which is impacting time value as __pthread_cond_timedwait is converting value from 32 bit to 64 bit.

normal pthread_cond_timedwait is invoking __pthread_cond_timedwait64 properly and its working fine.

From: pthread_cond_wait.c

#if __TIMESIZE == 64
strong_alias (___pthread_cond_timedwait64, ___pthread_cond_timedwait)
#else
strong_alias (___pthread_cond_timedwait64, __pthread_cond_timedwait64)
libc_hidden_def (__pthread_cond_timedwait64)

int
___pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
                            const struct timespec *abstime)
{
  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*abstime);

  return __pthread_cond_timedwait64 (cond, mutex, &ts64);
}
#endif /* __TIMESIZE == 64 */
versioned_symbol (libc, ___pthread_cond_timedwait,
                  pthread_cond_timedwait, GLIBC_2_3_2);
libc_hidden_ver (___pthread_cond_timedwait, __pthread_cond_timedwait)
#ifndef SHARED
strong_alias (___pthread_cond_timedwait, __pthread_cond_timedwait)
#endif

if add  #defing GTHREAD_USE_WEAK 0  in libgcc/gthr-posix.h issue is resolved but that is not correct way as it disable weakref for all symbol, please let me know what is correct way to fix this, this i observed with   gcc-9.3.0 gcc and glibc 2.34

Regards
Puneet