[PATCH v4 05/17] riscv: Introduce feature variables for holding RISC-V GNU properties

[Deepak Gupta]

Reviewed-by: Deepak Gupta <debug@rivosinc.com>


On Mon, May 25, 2026 at 11:18 PM Jesse Huang <jesse.huang@sifive.com> wrote:
>
> Member l_riscv_feature_1_and is added to struct link_map, which stores
> the feature_1_and property information for each object.
>
> New global _dl_riscv_feature_1 will be used to store what features are
> finally enabled for this process.
> ---
>  sysdeps/riscv/dl-procruntime.c | 60 ++++++++++++++++++++++++++++++++++
>  sysdeps/riscv/link_map.h       | 22 +++++++++++++
>  2 files changed, 82 insertions(+)
>  create mode 100644 sysdeps/riscv/dl-procruntime.c
>  create mode 100644 sysdeps/riscv/link_map.h
>
> diff --git a/sysdeps/riscv/dl-procruntime.c b/sysdeps/riscv/dl-procruntime.c
> new file mode 100644
> index 0000000000..06a582920e
> --- /dev/null
> +++ b/sysdeps/riscv/dl-procruntime.c
> @@ -0,0 +1,60 @@
> +/* Data for processor runtime information.  RISC-V version.
> +   Copyright (C) 2026 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/>.  */
> +
> +/* This information must be kept in sync with the _DL_HWCAP_COUNT,
> +   HWCAP_PLATFORMS_START and HWCAP_PLATFORMS_COUNT definitions in
> +   dl-hwcap.h.
> +
> +   If anything should be added here check whether the size of each string
> +   is still ok with the given array size.
> +
> +   All the #ifdefs in the definitions are quite irritating but
> +   necessary if we want to avoid duplicating the information.  There
> +   are three different modes:
> +
> +   - PROCINFO_DECL is defined.  This means we are only interested in
> +     declarations.
> +
> +   - PROCINFO_DECL is not defined:
> +
> +     + if SHARED is defined the file is included in an array
> +       initializer.  The .element = { ... } syntax is needed.
> +
> +     + if SHARED is not defined a normal array initialization is
> +       needed.
> +  */
> +
> +#ifndef PROCINFO_CLASS
> +# define PROCINFO_CLASS
> +#endif
> +
> +#if !IS_IN (ldconfig)
> +# if !defined PROCINFO_DECL && defined SHARED
> +  ._dl_riscv_feature_1
> +# else
> +PROCINFO_CLASS unsigned int _dl_riscv_feature_1
> +# endif
> +# ifndef PROCINFO_DECL
> += 0
> +# endif
> +# if !defined SHARED || defined PROCINFO_DECL
> +;
> +# else
> +,
> +# endif
> +#endif
> diff --git a/sysdeps/riscv/link_map.h b/sysdeps/riscv/link_map.h
> new file mode 100644
> index 0000000000..4a6428bb24
> --- /dev/null
> +++ b/sysdeps/riscv/link_map.h
> @@ -0,0 +1,22 @@
> +/* Additional fields in struct link_map.  Linux/RISC-V version.
> +   Copyright (C) 2026 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/>.  */
> +
> +/* GNU_PROPERTY_RISCV_FEATURE_1_AND of this object.  */
> +unsigned int l_riscv_feature_1_and;
> +
> +#include <sysdeps/generic/link_map.h>
> --
> 2.43.7
>