On Mon, May 30, 2022 at 07:03:31PM +0200, Heiko Carstens wrote:
> On Mon, May 30, 2022 at 12:00:52PM -0400, Peter Xu wrote:
> > On Mon, May 30, 2022 at 11:52:54AM -0400, Peter Xu wrote:
> > > On Mon, May 30, 2022 at 11:35:10AM +0200, Christian Borntraeger wrote:
> > > > > diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
> > > > > index 4608cc962ecf..e1d40ca341b7 100644
> > > > > --- a/arch/s390/mm/fault.c
> > > > > +++ b/arch/s390/mm/fault.c
> > > > > @@ -436,12 +436,11 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
> > > > > /* The fault is fully completed (including releasing mmap lock) */
> > > > > if (fault & VM_FAULT_COMPLETED) {
> > > > > - /*
> > > > > - * Gmap will need the mmap lock again, so retake it. TODO:
> > > > > - * only conditionally take the lock when CONFIG_PGSTE set.
> > > > > - */
> > > > > - mmap_read_lock(mm);
> > > > > - goto out_gmap;
> > > > > + if (gmap) {
> > > > > + mmap_read_lock(mm);
> > > > > + goto out_gmap;
> > > > > + }
> fault = 0; <----
> > > > > + goto out;
> >
> > Hmm, right after I replied I found "goto out" could be problematic, since
> > all s390 callers of do_exception() will assume it an error condition (side
> > note: "goto out_gmap" contains one step to clear "fault" to 0). I'll
> > replace this with "return 0" instead if it looks good to both of you.
> >
> > I'll wait for a confirmation before reposting. Thanks,
>
> Right, that was stupid. Thanks for double checking!
>
> However could you please add "fault = 0" just in front of the goto out
> like above? I'd like to avoid having returns and gotos mixed.
Sure thing.
--
Peter Xu
