[PATCH] mmu_notifiers: Notify on pte permission upgrades

[Qi Zheng]

On 2023/5/22 15:45, Alistair Popple wrote:
> 
> Qi Zheng <qi.zheng at linux.dev> 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