On Thu, Feb 10, 2022 at 3:07 AM Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > > On 2/7/22 23:36, Muchun Song wrote: > > The userfaultfd calls copy_huge_page_from_user() which does not do > > any cache flushing for the target page. Then the target page will > > be mapped to the user space with a different address (user address), > > which might have an alias issue with the kernel address used to copy > > the data from the user to. Fix this issue by flushing dcache in > > copy_huge_page_from_user(). > > Quick question. > > Should this also be done for the non-hugetlb case? Take a look at the > routines __mcopy_atomic() and mcopy_atomic_pte(). Or, is that somehow > handled? Actually, you are right. __mcopy_atomic() and mcopy_atomic_pte() should also be fixed. And shmem_mfill_atomic_pte() also should be fixed. I'll fix those places in the next version. Thanks. > > For this change, > Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Thanks Mike.
