Re: [RFC PATCH v1] power: don't manage floating point regs when no FPU

[Christophe Leroy]

Le 11/08/2020 à 14:07, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
> >   10 files changed, 44 insertions(+), 1 deletion(-)
>
> In general this looks fine.
>
> It's a bit #ifdef heavy. Maybe some of those can be cleaned up a bit
> with some wrapper inlines?

Looking at it once more, looks like more or less the same level of 
#ifdefs as things like CONFIG_ALTIVEC for instance. I can't really see 
much opportunities to clean it up.

> > diff --git a/arch/powerpc/kernel/ptrace/ptrace-novsx.c b/arch/powerpc/kernel/ptrace/ptrace-novsx.c
> > index b2dc4e92d11a..8f87a11f3f8c 100644
> > --- a/arch/powerpc/kernel/ptrace/ptrace-novsx.c
> > +++ b/arch/powerpc/kernel/ptrace/ptrace-novsx.c
> > @@ -28,6 +29,9 @@ int fpr_get(struct task_struct *target, const struct user_regset *regset,
> >   
> >   	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> >   				   &target->thread.fp_state, 0, -1);
> > +#else
> > +	return 0;
> > +#endif
>
> Should we return -ENODEV/EIO here? Wonder if another arch can give us a clue.

Looks like we have to do another way  ... another #ifdef ... in the 
definition of native_regsets[] in ptrace-view.c . And then we should be 
able to not build ptrace-novsx.c at all. Will try that.

Christophe