Re: [PATCH] aarch64: Add memory clobber to pkey_write

On 26/08/26 09:41, Yury Khrustalev wrote:
> Add memory clobber for writing to the POR_EL0 register since a change
> to this register affects subsequent memory accesses.
> 
> ---
> Passes regression on aarch64. OK for trunk?
> OK to backport to 2.44, 2.43, 2.42, 2.41?
> 
> Base commit: 9c86ea03aa

Should we open a bug report for this (and does it change the code
generation for current wrappers)?

Reviewed-by: Adhemerval Zanella  <[email protected]>

> 
> ---
>  sysdeps/unix/sysv/linux/aarch64/arch-pkey.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/aarch64/arch-pkey.h b/sysdeps/unix/sysv/linux/aarch64/arch-pkey.h
> index 7276aa0b77..662ff73df3 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/arch-pkey.h
> +++ b/sysdeps/unix/sysv/linux/aarch64/arch-pkey.h
> @@ -47,7 +47,7 @@ pkey_read (void)
>  static __always_inline void
>  pkey_write (unsigned long value)
>  {
> -  __asm__ volatile ("msr s3_3_c10_c2_4, %0; isb" : : "r" (value));
> +  __asm__ volatile ("msr s3_3_c10_c2_4, %0; isb" : : "r" (value) : "memory");
>  }
>  
>  #endif /* _ARCH_PKEY_H */