Linux: Fix fcntl, ioctl, prctl redirects for _TIME_BITS=64 (bug 28182)

  __REDIRECT and __THROW are not compatible with C++ due to the ordering of the
__asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
instead.

Fixes commit 8a40aff86ba5f64a3a84883e539cb67b ("io: Add time64 alias
for fcntl"), commit 82c395d91ea4f69120d453aeec398e30 ("misc: Add
time64 alias for ioctl"), commit b39ffab860cd743a82c91946619f1b8158
("Linux: Add time64 alias for prctl").

Tested on i686-linux-gnu and x86_64-linux-gnu.  Built with
build-many-glibcs.py.

---
 io/fcntl.h                          | 8 ++++----
 misc/sys/ioctl.h                    | 4 ++--
 sysdeps/unix/sysv/linux/sys/prctl.h | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)
  

On Aug 04 2021, Florian Weimer via Libc-alpha wrote:

> __REDIRECT and __THROW are not compatible with C++ due to the ordering of the
> __asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
> instead.

There should be a test so that this won't happen again.

Andreas.
  

On Wed, Aug 4, 2021, at 7:19 AM, Andreas Schwab wrote:
> On Aug 04 2021, Florian Weimer via Libc-alpha wrote:
> 
> > __REDIRECT and __THROW are not compatible with C++ due to the ordering of the
> > __asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
> > instead.
> 
> There should be a test so that this won't happen again.

scripts/check-installed-headers.sh already verifies that installed headers are compilable as C++. It doesn’t test -D_TIME_BITS=64 currently though.

zw
  

On 8/4/21 5:36 AM, Florian Weimer via Libc-alpha wrote:
> __REDIRECT and __THROW are not compatible with C++ due to the ordering of the
> __asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
> instead.
> 
> Fixes commit 8a40aff86ba5f64a3a84883e539cb67b ("io: Add time64 alias
> for fcntl"), commit 82c395d91ea4f69120d453aeec398e30 ("misc: Add
> time64 alias for ioctl"), commit b39ffab860cd743a82c91946619f1b8158
> ("Linux: Add time64 alias for prctl").
> 
> Tested on i686-linux-gnu and x86_64-linux-gnu.  Built with
> build-many-glibcs.py.

LGTM. Please backport this to release/2.34/master. I commented down-thread
regarding Andreas' requirement for a test case.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
 
> ---
>  io/fcntl.h                          | 8 ++++----
>  misc/sys/ioctl.h                    | 4 ++--
>  sysdeps/unix/sysv/linux/sys/prctl.h | 2 +-
>  3 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/io/fcntl.h b/io/fcntl.h
> index 8917a73b42..1c96f98f4d 100644
> --- a/io/fcntl.h
> +++ b/io/fcntl.h
> @@ -187,10 +187,10 @@ extern int fcntl64 (int __fd, int __cmd, ...);
>  # endif
>  #else /* __USE_TIME_BITS64 */
>  # ifdef __REDIRECT
> -extern int __REDIRECT (fcntl, (int __fd, int __request, ...),
> -		       __fcntl_time64)  __THROW;
> -extern int __REDIRECT (fcntl64, (int __fd, int __request, ...),
> -		       __fcntl_time64)  __THROW;
> +extern int __REDIRECT_NTH (fcntl, (int __fd, int __request, ...),
> +			   __fcntl_time64);
> +extern int __REDIRECT_NTH (fcntl64, (int __fd, int __request, ...),
> +			   __fcntl_time64);

OK.

>  # else
>  extern int __fcntl_time64 (int __fd, int __request, ...) __THROW;
>  #  define fcntl64 __fcntl_time64
> diff --git a/misc/sys/ioctl.h b/misc/sys/ioctl.h
> index 6884d9925f..9945c1e918 100644
> --- a/misc/sys/ioctl.h
> +++ b/misc/sys/ioctl.h
> @@ -42,8 +42,8 @@ __BEGIN_DECLS
>  extern int ioctl (int __fd, unsigned long int __request, ...) __THROW;
>  #else
>  # ifdef __REDIRECT
> -extern int __REDIRECT (ioctl, (int __fd, unsigned long int __request, ...),
> -		       __ioctl_time64) __THROW;
> +extern int __REDIRECT_NTH (ioctl, (int __fd, unsigned long int __request, ...),
> +			   __ioctl_time64);

OK.

>  # else
>  extern int __ioctl_time64 (int __fd, unsigned long int __request, ...) __THROW;
>  #  define ioctl __ioctl_time64
> diff --git a/sysdeps/unix/sysv/linux/sys/prctl.h b/sysdeps/unix/sysv/linux/sys/prctl.h
> index db88938b3a..f0e0d2f27f 100644
> --- a/sysdeps/unix/sysv/linux/sys/prctl.h
> +++ b/sysdeps/unix/sysv/linux/sys/prctl.h
> @@ -42,7 +42,7 @@ __BEGIN_DECLS
>  extern int prctl (int __option, ...) __THROW;
>  #else
>  # ifdef __REDIRECT
> -extern int __REDIRECT (prctl, (int __option, ...), __prctl_time64) __THROW;
> +extern int __REDIRECT_NTH (prctl, (int __option, ...), __prctl_time64);

OK.

>  # else
>  extern int __prctl_time64 (int __option,d ...) __THROW;
>  #  define ioctl __prctl_time64
>
  

On 8/4/21 7:19 AM, Andreas Schwab wrote:
> On Aug 04 2021, Florian Weimer via Libc-alpha wrote:
> 
>> __REDIRECT and __THROW are not compatible with C++ due to the ordering of the
>> __asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
>> instead.
> 
> There should be a test so that this won't happen again.

While I agree with this sentiment, as 2.34 RM I would like to see these fixes
go into master and release/2.34/master immediately in order to correct any
downstream distro issues that relate to these headers.

I spoke with Florian off-line about this, and we both would like to see a
broader set of changes that do more verification for the installed headers.
So I think we will do this for glibc 2.35 as a broader set of changes.

Does that work for you?
  

On Aug 05 2021, Carlos O'Donell wrote:

> Does that work for you?

Sure.

Andreas.