On Wed, Jun 28, 2023 at 09:22:24AM -0700, Suren Baghdasaryan wrote: > Ack. I was not sure if the ctx->mm would always be the same as vmf->mm. Feel free to look at the entrance of handle_userfault(), where there's: struct vm_area_struct *vma = vmf->vma; struct mm_struct *mm = vma->vm_mm; struct userfaultfd_ctx *ctx; ... ctx = vma->vm_userfaultfd_ctx.ctx; ... BUG_ON(ctx->mm != mm); ... So I think we should be safe. Thanks, -- Peter Xu