Re: [PATCH v5 09/22] powerpc/syscall: Make interrupt.c buildable on PPC32

[Christophe Leroy]

Le 09/02/2021 à 02:27, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
> > To allow building interrupt.c on PPC32, ifdef out specific PPC64
> > code or use helpers which are available on both PP32 and PPC64
> >
> > Modify Makefile to always build interrupt.o
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > ---
> > v5:
> > - Also for interrupt exit preparation
> > - Opted out kuap related code, ppc32 keeps it in ASM for the time being
> > ---
> >   arch/powerpc/kernel/Makefile    |  4 ++--
> >   arch/powerpc/kernel/interrupt.c | 31 ++++++++++++++++++++++++-------
> >   2 files changed, 26 insertions(+), 9 deletions(-)

> > diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> > index d6be4f9a67e5..2dac4d2bb1cf 100644
> > --- a/arch/powerpc/kernel/interrupt.c
> > +++ b/arch/powerpc/kernel/interrupt.c
> > @@ -39,7 +39,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
> >   		BUG_ON(!(regs->msr & MSR_RI));
> >   	BUG_ON(!(regs->msr & MSR_PR));
> >   	BUG_ON(!FULL_REGS(regs));
> > -	BUG_ON(regs->softe != IRQS_ENABLED);
> > +	BUG_ON(arch_irq_disabled_regs(regs));
> >   
> >   #ifdef CONFIG_PPC_PKEY
> >   	if (mmu_has_feature(MMU_FTR_PKEY)) {
> > @@ -65,7 +65,9 @@ notrace long system_call_exception(long r3, long r4, long r5,
> >   			isync();
> >   	} else
> >   #endif
> > +#ifdef CONFIG_PPC64
> >   		kuap_check_amr();
> > +#endif
>
> Wouldn't mind trying to get rid of these ifdefs at some point, but
> there's some kuap / keys changes going on recently so I'm happy enough
> to let this settle then look at whether we can refactor.

I have a follow up series that implements interrupts entries/exits in C and that removes all kuap 
assembly, I will likely release it as RFC later today.

> >   
> >   	account_cpu_user_entry();
> >   
> > @@ -318,7 +323,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
> >   	return ret;
> >   }
> >   
> > -#ifdef CONFIG_PPC_BOOK3S /* BOOK3E not yet using this */
> > +#ifndef CONFIG_PPC_BOOK3E_64 /* BOOK3E not yet using this */
> >   notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
> >   {
> >   #ifdef CONFIG_PPC_BOOK3E
>
> Why are you building this for 32? I don't mind if it's just to keep
> things similar and make it build for now, but you're not using it yet,
> right?

The series using that will follow, I thought it would be worth doing this at once.

>   
> Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>