Re: [PATCH] struct thread_struct, asm-i386/processor.h: wrong datatype?

[Ingo Molnar <mingo@elte.hu>]

* Herbert Rosmanith <kernel@wildsau.enemy.org> wrote:

> 
> or better: 
> 
> > -       unsigned long   fs;
> > -       unsigned long   gs;
> > +       unsigned short  fs;
> > +       unsigned short  gs;
> >  /* Hardware debugging registers */
> >         unsigned long   debugreg[8];  /* %%db0-7 debug registers */
> >  /* fault info */
> 
> + unsigned short fs, __fsh; 
> + unsigned short gs, __gsh; 
> 
> which is also done this way the structure above, the TSS. I don't know 
> why it's done this way, but I guess it's probably better pad with 16 
> bits to avoid potential problems with 32bit movl which might overwrite 
> portions of the next field.

no. 'struct thread_struct' is the 'soft' thread-state structure. We 
store data in the most convenient (and best performing) format - word 
size in this case. The 'hard' data structure is 'struct tss_struct' - 
where we of course define things in the way the CPU expects it.

	Ingo