Re: [PATCH 1/2] powerpc: drop dependency on <asm/machdep.h> in archrandom.h

From: Yury Norov
Date: Tue Jul 26 2022 - 11:19:28 EST


On Tue, Jul 26, 2022 at 04:57:38PM +1000, Michael Ellerman wrote:
> Yury Norov <yury.norov@xxxxxxxxx> writes:
> > On Mon, Jul 25, 2022 at 09:28:12AM +0200, Andy Shevchenko wrote:
> >> On Sun, Jul 24, 2022 at 12:19 AM Yury Norov <yury.norov@xxxxxxxxx> wrote:
> >> >
> >> > archrandom.h includes <asm/machdep.h> to refer ppc_md. This causes
> >> > circular header dependency, if generic nodemask.h includes random.h:
> >> >
> >> > In file included from include/linux/cred.h:16,
> >> > from include/linux/seq_file.h:13,
> >> > from arch/powerpc/include/asm/machdep.h:6,
> >> > from arch/powerpc/include/asm/archrandom.h:5,
> >> > from include/linux/random.h:109,
> >> > from include/linux/nodemask.h:97,
> >> > from include/linux/list_lru.h:12,
> >> > from include/linux/fs.h:13,
> >> > from include/linux/compat.h:17,
> >> > from arch/powerpc/kernel/asm-offsets.c:12:
> >> > include/linux/sched.h:1203:9: error: unknown type name 'nodemask_t'
> >> > 1203 | nodemask_t mems_allowed;
> >> > | ^~~~~~~~~~
> >> >
> >> > Fix it by removing <asm/machdep.h> dependency from archrandom.h
> >>
> >> ...
> >>
> >> > EXPORT_SYMBOL_GPL(pm_power_off);
> >>
> >> ^^^ (Note this and read below)
> >>
> >> ...
> >>
> >> > +EXPORT_SYMBOL(arch_get_random_seed_long);
> >>
> >> It can't be like this. Brief browsing of the callees shows that.
> >
> > Is my understanding correct that you're suggesting to make it GPL?
> >
> > ppc_md is exported with EXPORT_SYMBOL(), and the function is in header,
> > so it's available for non-GPL code now. I don't want to change it.
>
> That's true, your change maintains the status quo.
>
> But I think we actually don't need it exported to modules, I think it's
> a private detail of the RNG <-> architecture interface, not something
> that modules should be calling.
>
> So I think it's OK to drop the EXPORT_SYMBOL, either in this patch or a
> subsequent one if you don't want to rebase.

OK, changed.