Re: [hurd,commited] hurd: Add THREAD_GET/SETMEM/_NC

[Andreas Schwab]

On Feb 15 2020, Samuel Thibault wrote:

> diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
> index c0341ce2c9..7ec8c81a76 100644
> --- a/sysdeps/mach/hurd/i386/tls.h
> +++ b/sysdeps/mach/hurd/i386/tls.h
> @@ -163,6 +163,114 @@ out:
>             : "i" (offsetof (tcbhead_t, tcb)));                             \
>       __tcb;})
>  
> +/* Read member of the thread descriptor directly.  */
> +# define THREAD_GETMEM(descr, member) \
> +  ({ __typeof (descr->member) __value;                                       
>       \
> +     if (sizeof (__value) == 1)                                              
>       \
> +       asm volatile ("movb %%gs:%P2,%b0"                                   \
> +                  : "=q" (__value)                                         \
> +                  : "0" (0), "i" (offsetof (tcbhead_t, member)));          \
> +     else if (sizeof (__value) == 4)                                       \
> +       asm volatile ("movl %%gs:%P1,%0"                                      
>       \
> +                  : "=r" (__value)                                         \
> +                  : "i" (offsetof (tcbhead_t, member)));                   \
> +     else                                                                  \
> +       {                                                                   \
> +      if (sizeof (__value) != 8)                                           \
> +        /* There should not be any value with a size other than 1,         \
> +           4 or 8.  */                                                     \
> +        abort ();                                                          \

_Static_assert?

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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