On 26.06.24 00:38, Andrew Morton wrote:
On Wed, 5 Jun 2024 09:30:59 +0800 Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
protection to catch successive writes (mprotect, uffd-wp) -- and
they all
face the same issue regarding R/W access via GUP (FOLL_PIN and
FOLL_GET).
User space better be aware that using read-protection to catch
writes to
a page can miss writes via GUP. Softdirt tracking cannot reliably
catch
modifications via GUP after clearing softdirty and returning to user
space.
But I understand if you want to be careful :) So I might send that patch
out at
some point myself ...
Thank for your detail explanation, let's wait it out.
Did we wait long enough? Should we move ahead with this change
or should we drop it and have another run at it?
The change is fine, we will revisit removing this code (instead of
cleaning it up) separately.
--
Cheers,
David / dhildenb
