Re: [PATCH v2 2/4] fs/proc/task_mmu: Implement IOCTL to get and clear soft dirty PTE bit

Muhammad Usama Anjum
2022-08-25T10:49:45Z

On 8/25/22 12:22 PM, Greg KH wrote:
> On Thu, Aug 25, 2022 at 12:09:24PM +0500, Muhammad Usama Anjum wrote:
>> - The flags can be specified in the flags field. Currently only one
>> PAGEMAP_SD_NO_REUSED_REGIONS is supported which can be specified to
>> ignore the VMA dirty flags.
>
> You forgot to check that all other bits in that flag are set to 0
> properly, otherwise you can never add a new bit to the field ever as you
> can't expect userspace got it right and did not accidentaly set it
> already.
>
> There is kernel documentation on how to add a new ioctl, you might want
> to read up on that first before resending this.
Thank you so much for the review. I'll revisit and resend a v3.

>
> thanks,
>
> greg k-h

--
Muhammad Usama Anjum