Re: [PATCH] s390/mm: Add missing vm_start <= addr check to do_secure_storage_access()

[Heiko Carstens]

On Fri, Jul 24, 2026 at 02:09:32PM +0200, Alexander Gordeev wrote:
> On Fri, Jul 17, 2026 at 03:14:07PM +0200, Heiko Carstens wrote:
> > diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
> > index 028aeb9c48d6..d6c58d78edc5 100644
> > --- a/arch/s390/mm/fault.c
> > +++ b/arch/s390/mm/fault.c
> > @@ -456,10 +456,9 @@ void do_secure_storage_access(struct pt_regs *regs)
> >  		if (faulthandler_disabled())
> >  			return handle_fault_error_nolock(regs, 0);
> >  		mm = current->mm;
> > -		mmap_read_lock(mm);
> > -		vma = find_vma(mm, addr);
> > +		vma = lock_mm_and_find_vma(mm, addr, regs);
> >  		if (!vma)
> > -			return handle_fault_error(regs, SEGV_MAPERR);
> > +			return handle_fault_error_nolock(regs, SEGV_MAPERR);
> >  		folio = folio_walk_start(&fw, vma, addr, 0);
> >  		if (!folio) {
> >  			mmap_read_unlock(mm);
> 
> The Sashiko feedback looks like a false positive to me.
> 
> Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>

This has been integrated into the "[PATCH v4 0/8] s390: Reintroduce
support for DCACHE_WORD_ACCESS" series. First I thought of keeping
things separate, but decided then to address all of Sashiko reports
and make the code look quite similar to do_exception().

So v4 is the only series that matters, everything else can be ignored.

What is still missing is kmemleak handling for which Christian posted
a patch, but that appears to be incomplete. Or least my thinking is
that there will be a subsequent patch.

Christian?