Re: [PATCH] mmu_notifiers: Notify on pte permission upgrades

[Qi Zheng]

On 2023/5/22 15:45, Alistair Popple wrote:
> Qi Zheng <qi.zheng@xxxxxxxxx> writes:
>
> > Hi Alistair,
> >
> > On 2023/5/22 14:37, Alistair Popple wrote:
>
> [...]
>
> > > +	if (changed) {
> > > +		struct mmu_notifier_range range;
> > > +
> > > +		mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_UPGRADE,
> > > +					0, vmf->vma, vmf->vma->vm_mm,
> > > +					vmf->address & PAGE_MASK,
> > > +					(vmf->address & PAGE_MASK) + PAGE_SIZE);
> > > +		mmu_notifier_invalidate_range_start(&range);
> > > +		mmu_notifier_invalidate_range_end(&range);
> > > +	}
> >
> > There are four similar patterns, can we introduce a helper function to
> > deduplicate them?
>
> For sure. How about something like this?
>
> void mmu_notifier_range_start_end(enum mmu_notifier_event event,
>                                    struct vm_area_struct *vma,
>                                    struct mm_struct *mm,
>                                    unsigned long start,
>                                    unsigned long end)

LGTM. :)

> As an aside I didn't just use mmu_notifier_invalidate_range() as that
> doesn't allow an event type to be set for interval notifiers which may
> want to filter this.
>
> > > +
> > >    	return 0;
> > >    }
> > >    

--
Thanks,
Qi