Re: [PATCH 1/3] elf: Add hook for checking HWCAP bits after auxiliary vector parsing

[Stefan Liebler <stli@linux.ibm.com>]

On 06/05/2021 14:30, Florian Weimer via Libc-alpha wrote:
> ---
>  elf/dl-sysdep.c                  |  3 +++
>  sysdeps/generic/dl-hwcap-check.h | 28 ++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
>  create mode 100644 sysdeps/generic/dl-hwcap-check.h
> 
> diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
> index bd5066fe3b..d47bef1340 100644
> --- a/elf/dl-sysdep.c
> +++ b/elf/dl-sysdep.c
> @@ -46,6 +46,7 @@
> 
>  #include <dl-tunables.h>
>  #include <dl-auxv.h>
> +#include <dl-hwcap-check.h>
> 
>  extern char **_environ attribute_hidden;
>  extern char _end[] attribute_hidden;
> @@ -190,6 +191,8 @@ _dl_sysdep_start (void **start_argptr,
>        DL_PLATFORM_AUXV
>        }
> 
> +  dl_hwcap_check ();
> +
OK.
(GLRO(dl_hwcap) is setup with content of AT_HWCAP in the loop above)
>  #ifndef HAVE_AUX_SECURE
>    if (seen != -1)
>      {
> diff --git a/sysdeps/generic/dl-hwcap-check.h b/sysdeps/generic/dl-hwcap-check.h
> new file mode 100644
> index 0000000000..8db7a86256
> --- /dev/null
> +++ b/sysdeps/generic/dl-hwcap-check.h
> @@ -0,0 +1,28 @@
> +/* Check for hardware capabilities after HWCAP parsing.  Generic version.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _DL_HWCAP_CHECK_H
> +#define _DL_HWCAP_CHECK_H
> +
> +static inline void
> +dl_hwcap_check (void)
> +{
> +  /* The generic implementation does not perform any checks.  */
> +}
> +
> +#endif /* _DL_HWCAP_CHECK_H */
> 
OK

Reviewed-by: Stefan Liebler <stli@linux.ibm.com>