On 08/15/2018 08:49 PM, Yang Shi wrote:
+ start_vma = munmap_lookup_vma(mm, start, end);You sure it's ok to redo this in case of goto regular path? The
+ if (!start_vma)
+ goto out;
+ if (IS_ERR(start_vma)) {
+ ret = PTR_ERR(start_vma);
+ goto out;
+ }
+
+ prev = start_vma->vm_prev;
+
+ if (unlikely(uf)) {
+ ret = userfaultfd_unmap_prep(start_vma, start, end, uf);
+ if (ret)
+ goto out;
+ }
+
preparations have some side-effects... I would rather move this after
the regular path check?