Re: [PATCH v8 2/4] userfaultfd: split mwriteprotect_range()

[Muhammad Usama Anjum]

On 1/27/23 10:05 PM, Peter Xu wrote:
> On Tue, Jan 24, 2023 at 01:43:21PM +0500, Muhammad Usama Anjum wrote:
>> Split mwriteprotect_range() to create a unlocked version. This
>> will be used in the next patch to write protect a memory area.
>> Add a helper function, wp_range_async() as well.
>>
>> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
> 
> IIUC this patch is not needed.  You have a stable vma, so I think you can
> directly use uffd_wp_range(), while most of the mwriteprotect_range() is
> not needed.
> 
> There's one trivial detail of ignoring userfaultfd_ctx->mmap_changing when
> it's set to true, but I don't think it applies here either because it was
> used to resolve a problem in uffd non-cooperative mode on the predictable
> behavior of events, here I don't think it matters a lot either.
> 
Thanks, I'll drop this patch and do direct wiring to uffd_wp_range().

-- 
BR,
Muhammad Usama Anjum