Re: [PATCH v4 3/4] xen/arm: switch ARM to use generic implementation of bug.h

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Thu, 2023-03-02 at 10:55 +0100, Jan Beulich wrote:
> On 02.03.2023 10:20, Oleksii Kurochko wrote:
> > The following changes were made:
> > * make GENERIC_BUG_FRAME mandatory for ARM
> > * As do_bug_frame() returns -EINVAL in case something goes wrong
> >   otherwise id of bug frame. Thereby 'if' cases where
> > do_bug_frame() was
> >   updated to check if the returned value is less than 0
> > * Switch ARM's implementation of bug.h macros to generic one
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> > ---
> > Changes in V4:
> >  * Switch ARM implementation to generic one
> >  * Remove BUG_FN_REG from arm{16,32}/bug.h as it isn't needed after
> > switch to generic implementation
> 
> In which case why ...
> 
> > --- a/xen/common/bug.c
> > +++ b/xen/common/bug.c
> > @@ -46,11 +46,7 @@ int do_bug_frame(struct cpu_user_regs *regs,
> > unsigned long pc)
> >  
> >      if ( id == BUGFRAME_run_fn )
> >      {
> > -#ifdef BUG_FN_REG
> > -        void (*fn)(const struct cpu_user_regs *) = (void *)regs-
> > >BUG_FN_REG;
> > -#else
> >          void (*fn)(const struct cpu_user_regs *) = bug_ptr(bug);
> > -#endif
> >  
> >          fn(regs);
> 
> ... is what is being removed here again introduced in the first place
> (in an earlier patch)?
Missed that.

I looked again at the current patch and realized that ARM-specific
do_bug_frame() has been removed only in the current patch.

So you are right, there is no any sense to introduce these lines in
first patch of the patch series.
> 
> Jan

~ Oleksii