[RFC PATCH 1/3] powerpc/32: Implement HAVE_CONTEXT_TRACKING_USER support

[Nicholas Piggin]

On Tue Oct 4, 2022 at 9:32 PM AEST, Christophe Leroy wrote:
>
>
> Le 04/10/2022 à 08:33, Nicholas Piggin a écrit :
> > Context tracking involves tracking user, kernel, guest switches. This
> > enables existing context tracking code for interrupt entry on 32-bit.
> > KVM and interrupt exit already has context tracking calls.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> > ---
> >   arch/powerpc/Kconfig                 |  2 +-
> >   arch/powerpc/include/asm/interrupt.h | 21 ++++++---------------
> >   2 files changed, 7 insertions(+), 16 deletions(-)
> > 
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 81c9f895d690..f667279ec74c 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -204,7 +204,7 @@ config PPC
> >   	select HAVE_ARCH_SECCOMP_FILTER
> >   	select HAVE_ARCH_TRACEHOOK
> >   	select HAVE_ASM_MODVERSIONS
> > -	select HAVE_CONTEXT_TRACKING_USER		if PPC64
> > +	select HAVE_CONTEXT_TRACKING_USER
> >   	select HAVE_C_RECORDMCOUNT
> >   	select HAVE_DEBUG_KMEMLEAK
> >   	select HAVE_DEBUG_STACKOVERFLOW
> > diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
> > index 4745bb9998bd..8860a246d51a 100644
> > --- a/arch/powerpc/include/asm/interrupt.h
> > +++ b/arch/powerpc/include/asm/interrupt.h
> > @@ -85,6 +85,8 @@ do {									\
> >   	    (user_mode(regs) || (TRAP(regs) != INTERRUPT_PROGRAM)))	\
> >   		BUG_ON(cond);						\
> >   } while (0)
> > +#else
> > +#define INT_SOFT_MASK_BUG_ON(regs, cond)
>
> Here you can just drop the ifdef CONFIG_PPC64 I guess instead of adding 
> an additional empty macro.

I couldn't because some of the statements use some PPC64-only variables.
It ends up looking a bit better this way.

> >   #endif
> >   
> >   #ifdef CONFIG_PPC_BOOK3S_64
> > @@ -152,19 +154,8 @@ static inline void booke_restore_dbcr0(void)
> >   static inline void interrupt_enter_prepare(struct pt_regs *regs)
> >   {
> >   #ifdef CONFIG_PPC32
> > -	if (!arch_irq_disabled_regs(regs))
> > -		trace_hardirqs_off();
> > -
> > -	if (user_mode(regs))
> > -		kuap_lock();
> > -	else
> > -		kuap_save_and_lock(regs);
> > -
> > -	if (user_mode(regs))
> > -		account_cpu_user_entry();
> > -#endif
> > -
> > -#ifdef CONFIG_PPC64
> > +	bool trace_enable = !arch_irq_disabled_regs(regs);
>
> nit: You could be put this as an #else to the existing #ifdef CONFIG_PPC64

Yep, I was able to clean it up even a bit better actually.

Thanks,
Nick