On 10/02, Andrii Nakryiko wrote: > > On Wed, Oct 2, 2024 at 12:25 AM Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > > > > > + vm_file = READ_ONCE(vma->vm_file); > > > + if (!vm_file) > > > + return NULL; > > > + > > > + offset = (loff_t)(vma->vm_pgoff << PAGE_SHIFT) + (bp_vaddr - vma->vm_start); > > > > LGTM. But perhaps vma->vm_pgoff and vma->vm_start need READ_ONCE() as well, > > if nothing else to shut up KCSAN if this code races with, say, __split_vma() ? > > We keep going back and forth between reading directly, using > READ_ONCE(), and annotating with data_race(). I don't think it matters > in terms of correctness or performance, so I'm happy to add whatever > incantations that will make everyone satisfied. Let's see what others > think, and I'll incorporate that into the next revision. OK, agreed... And I guess I was wrong anyway, READ_ONCE() alone won't shutup KCSAN in this case. Oleg.
