Re: [PATCH 2/2] Y2038: make __tz_convert compatible with 64-bit-time

[Joseph Myers <joseph at codesourcery dot com>]

On Wed, 13 Jun 2018, Albert ARIBAUD (3ADEV) wrote:

> diff --git a/time/Versions b/time/Versions
> index fd838181e4..8b83f5b041 100644
> --- a/time/Versions
> +++ b/time/Versions
> @@ -65,4 +65,9 @@ libc {
>    GLIBC_2.16 {
>      timespec_get;
>    }
> +  GLIBC_2.28 {
> +    __ctime64; __ctime64_r;
> +    __gmtime64; __gmtime64_r;
> +    __localtime64; __localtime64_r;
> +  }

I suggest not adding any such public ABI exports until everything 
necessary to support _TIME_BITS=64 is in glibc.  (If a function is needed 
from another glibc shared library, a GLIBC_PRIVATE export may be added.)

> +  if (t == NULL)
> +    {
> +      __set_errno (EINVAL);
> +      return NULL;
> +    }

Such explicit NULL checks, for functions where NULL is not a valid input, 
are contrary to glibc standards; you should just dereference the input 
unconditionally.

https://sourceware.org/glibc/wiki/Style_and_Conventions#Error_Handling

-- 
Joseph S. Myers
joseph@codesourcery.com