Re: [PATCH v2 3/5] Linux: Remove DL_FIND_ARG_COMPONENTS

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 03/02/2022 08:08, Florian Weimer via Libc-alpha wrote:
> The generic definition is always used since the Native Client
> port has been removed.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/unix/sysv/linux/dl-sysdep.c | 25 ++++++++++---------------
>  1 file changed, 10 insertions(+), 15 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
> index 72aa109f2f..a13e0ea7ad 100644
> --- a/sysdeps/unix/sysv/linux/dl-sysdep.c
> +++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
> @@ -59,19 +59,6 @@ void *__libc_stack_end attribute_relro = NULL;
>  rtld_hidden_data_def(__libc_stack_end)
>  void *_dl_random attribute_relro = NULL;
>  
> -#ifndef DL_FIND_ARG_COMPONENTS
> -# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp)	\
> -  do {									      \
> -    void **_tmp;							      \
> -    (argc) = *(long int *) cookie;					      \
> -    (argv) = (char **) ((long int *) cookie + 1);			      \
> -    (envp) = (argv) + (argc) + 1;					      \
> -    for (_tmp = (void **) (envp); *_tmp; ++_tmp)			      \
> -      continue;								      \
> -    (auxp) = (void *) ++_tmp;						      \
> -  } while (0)
> -#endif
> -
>  #ifndef DL_STACK_END
>  # define DL_STACK_END(cookie) ((void *) (cookie))
>  #endif
> @@ -90,8 +77,16 @@ _dl_sysdep_start (void **start_argptr,
>  #endif
>  
>    __libc_stack_end = DL_STACK_END (start_argptr);
> -  DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ,
> -			  GLRO(dl_auxv));
> +  _dl_argc = (intptr_t) *start_argptr;
> +  _dl_argv = (char **) (start_argptr + 1); /* Necessary aliasing violation.  */
> +  _environ = _dl_argv + _dl_argc + 1;
> +  for (char **tmp = _environ + 1; ; ++tmp)
> +    if (*tmp == NULL)
> +      {
> +	/* Another necessary aliasing violation.  */
> +	GLRO(dl_auxv) = (ElfW(auxv_t) *) (tmp + 1);
> +	break;
> +      }
>  
>    user_entry = (ElfW(Addr)) ENTRY_POINT;
>    GLRO(dl_platform) = NULL; /* Default to nothing known about the platform.  */