Re: [PATCH v6 07/19] arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat)

[Yury Norov <ynorov@caviumnetworks.com>]

On Thu, Dec 03, 2015 at 12:13:03PM +0000, Catalin Marinas wrote:
> On Wed, Nov 18, 2015 at 12:16:47AM +0300, Yury Norov wrote:
> > diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
> > index 7fbed69..9700e5e 100644
> > --- a/arch/arm64/include/asm/compat.h
> > +++ b/arch/arm64/include/asm/compat.h
> > @@ -299,19 +299,44 @@ struct compat_shmid64_ds {
> >  	compat_ulong_t __unused5;
> >  };
> >  
> > -static inline int is_compat_task(void)
> > +#ifdef CONFIG_AARCH32_EL0
> > +
> > +static inline int is_a32_compat_task(void)
> >  {
> >  	return test_thread_flag(TIF_32BIT);
> >  }
> >  
> > -static inline int is_compat_thread(struct thread_info *thread)
> > +static inline int is_a32_compat_thread(struct thread_info *thread)
> >  {
> >  	return test_ti_thread_flag(thread, TIF_32BIT);
> >  }
> >  
> > +#else
> > +
> > +static inline int is_a32_compat_task(void)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline int is_a32_compat_thread(struct thread_info *thread)
> > +{
> > +	return 0;
> > +}
> > +#endif
> > +
> > +static inline int is_compat_task(void)
> > +{
> > +	return is_a32_compat_task();
> > +}
> > +
> >  #else /* !CONFIG_COMPAT */
> >  
> > -static inline int is_compat_thread(struct thread_info *thread)
> > +static inline int is_a32_compat_thread(struct thread_info *thread)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline int is_a32_compat_task(void)
> >  {
> >  	return 0;
> >  }
> 
> My main worry with this patch is a potential #include mess. I can see
> that you already had to include asm/compat.h explicitly in
> hw_breakpoint.c even though linux/compat.h was already included. In
> subsequent files (asm/elf.h, asm/memory.h) you check is_compat_task()
> without explicitly including asm/compat.h and hope that it won't break.
> 
> A solution would be to add these functions in a separate header file
> that gets included where needed (also by asm/compat.h).

Thank you for pointing that. I don't see big advantage in moving that
to new file, only if you insist. What about just fixing that mess?