Subject: Re: [PATCH 1/2] powerpc: Remove Mac-on-Linux hooks

From: Ben Hutchings <[email-masked]>
Date: Fri, 2 Dec 2016 05:05:42 +0000

On Fri, Dec 02, 2016 at 02:56:47PM +1100, Michael Ellerman wrote:
> Ben Hutchings <[email-masked]> writes:
> 
> > [ Unknown signature status ]
> > The symbols exported for use by MOL aren't getting CRCs and I was
> > about to fix that.  But MOL is dead upstream, and the latest work on
> > it was to make it use KVM instead of its own kernel module.  So remove
> > them instead.
> 
> Sounds good to me.
> 
> > diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
> > index 9d963547d243..87998430cd9b 100644
> > --- a/arch/powerpc/kernel/head_32.S
> > +++ b/arch/powerpc/kernel/head_32.S
> > @@ -735,11 +735,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
> >  	EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
> >  	EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
> >  	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
> > -	EXCEPTION(0x2f00, MOLTrampoline, unknown_exception, EXC_XFER_EE_LITE)
> > -
> > -	.globl mol_trampoline
> > -	.set mol_trampoline, i0x2f00
> > -	EXPORT_SYMBOL(mol_trampoline)
> > +	EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_EE)
> >  
> >  	. = 0x3000
> >  
> > @@ -1289,7 +1285,6 @@ intercept_table:
> >  	.long 0, 0, 0, 0, 0, 0, 0, 0
> >  	.long 0, 0, 0, 0, 0, 0, 0, 0
> >  	.long 0, 0, 0, 0, 0, 0, 0, 0
> > -EXPORT_SYMBOL(intercept_table)
> 
> I don't see intercept_table used anywhere, so I think we can just remove
> it entirely?

That's strange, so it's actually constant data.

And... I've managed to confuse myself about which symbols are for
MOL.  This one was actually used by rtlinux, which AFAICS is also
long dead.
 
> > diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
> > index 09cc50c8dace..cddf14f60bf3 100644
> > --- a/arch/powerpc/mm/hash_low_32.S
> > +++ b/arch/powerpc/mm/hash_low_32.S
> > @@ -34,7 +34,6 @@
> >  	.globl mmu_hash_lock
> >  mmu_hash_lock:
> >  	.space	4
> > -EXPORT_SYMBOL(mmu_hash_lock)
> >  #endif /* CONFIG_SMP */
> 
> And now mmu_hash_lock is only used in this file, so doesn't need to be
> global anymore.

Right.

Ben.

> I can fix both of those up here, will just wait a bit to see if anyone
> else has comments.
> 
> cheers

-- 
Ben Hutchings
It's easier to fight for one's principles than to live up to them.