Re: [PATCH v3 2/4] x86-64/cet: Move dl-cet.[ch] to x86_64 directories

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

On 09/01/24 17:23, H.J. Lu wrote:
> Since CET is only enabled for x86-64, move dl-cet.[ch] to x86_64
> directories.

LGTM, thanks.

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

> ---
>  sysdeps/unix/sysv/linux/x86/dl-cet.h    | 63 -------------------------
>  sysdeps/unix/sysv/linux/x86_64/dl-cet.h | 47 +++++++++++++++++-
>  sysdeps/{x86 => x86_64}/dl-cet.c        |  2 +-
>  3 files changed, 47 insertions(+), 65 deletions(-)
>  delete mode 100644 sysdeps/unix/sysv/linux/x86/dl-cet.h
>  rename sysdeps/{x86 => x86_64}/dl-cet.c (99%)
> 
> diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h
> deleted file mode 100644
> index c10773ab0e..0000000000
> --- a/sysdeps/unix/sysv/linux/x86/dl-cet.h
> +++ /dev/null
> @@ -1,63 +0,0 @@
> -/* Linux/x86 CET initializers function.
> -   Copyright (C) 2018-2024 Free Software Foundation, Inc.
> -
> -   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/>.  */
> -
> -#include <sys/prctl.h>
> -#include <asm/prctl.h>
> -
> -static __always_inline int
> -dl_cet_disable_cet (unsigned int cet_feature)
> -{
> -  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
> -    return -1;
> -  long long int kernel_feature = ARCH_SHSTK_SHSTK;
> -  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_DISABLE,
> -				      kernel_feature);
> -}
> -
> -static __always_inline int
> -dl_cet_lock_cet (unsigned int cet_feature)
> -{
> -  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
> -    return -1;
> -  /* Lock all SHSTK features.  */
> -  long long int kernel_feature = -1;
> -  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK,
> -				      kernel_feature);
> -}
> -
> -static __always_inline unsigned int
> -dl_cet_get_cet_status (void)
> -{
> -  unsigned long long kernel_feature;
> -  unsigned int status = 0;
> -  if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS,
> -			     &kernel_feature) == 0)
> -    {
> -      if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0)
> -	status = GNU_PROPERTY_X86_FEATURE_1_SHSTK;
> -    }
> -  return status;
> -}
> -
> -/* Enable shadow stack with a macro to avoid shadow stack underflow.  */
> -#define ENABLE_X86_CET(cet_feature)				\
> -  if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK))		\
> -    {								\
> -      long long int kernel_feature = ARCH_SHSTK_SHSTK;		\
> -      INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE,	\
> -			     kernel_feature);			\
> -    }
> diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
> index c89dd6bd42..94e9b9aa86 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
> +++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
> @@ -15,8 +15,53 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> +#include <sys/prctl.h>
> +#include <asm/prctl.h>
>  #include <cpu-features-offsets.h>
> -#include_next <dl-cet.h>
> +
> +static __always_inline int
> +dl_cet_disable_cet (unsigned int cet_feature)
> +{
> +  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
> +    return -1;
> +  long long int kernel_feature = ARCH_SHSTK_SHSTK;
> +  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_DISABLE,
> +				      kernel_feature);
> +}
> +
> +static __always_inline int
> +dl_cet_lock_cet (unsigned int cet_feature)
> +{
> +  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
> +    return -1;
> +  /* Lock all SHSTK features.  */
> +  long long int kernel_feature = -1;
> +  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK,
> +				      kernel_feature);
> +}
> +
> +static __always_inline unsigned int
> +dl_cet_get_cet_status (void)
> +{
> +  unsigned long long kernel_feature;
> +  unsigned int status = 0;
> +  if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS,
> +			     &kernel_feature) == 0)
> +    {
> +      if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0)
> +	status = GNU_PROPERTY_X86_FEATURE_1_SHSTK;
> +    }
> +  return status;
> +}
> +
> +/* Enable shadow stack with a macro to avoid shadow stack underflow.  */
> +#define ENABLE_X86_CET(cet_feature)				\
> +  if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK))		\
> +    {								\
> +      long long int kernel_feature = ARCH_SHSTK_SHSTK;		\
> +      INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE,	\
> +			     kernel_feature);			\
> +    }
>  
>  #define X86_STRINGIFY_1(x)	#x
>  #define X86_STRINGIFY(x)	X86_STRINGIFY_1 (x)
> diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86_64/dl-cet.c
> similarity index 99%
> rename from sysdeps/x86/dl-cet.c
> rename to sysdeps/x86_64/dl-cet.c
> index d1d42ab002..1297c09f84 100644
> --- a/sysdeps/x86/dl-cet.c
> +++ b/sysdeps/x86_64/dl-cet.c
> @@ -1,4 +1,4 @@
> -/* x86 CET initializers function.
> +/* x86-64 CET initializers function.
>     Copyright (C) 2018-2024 Free Software Foundation, Inc.
>  
>     The GNU C Library is free software; you can redistribute it and/or