On Mon, Aug 14, 2023 at 1:02 PM Jann Horn <jannh@xxxxxxxxxx> wrote:
>
> On Mon, Aug 14, 2023 at 9:15 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, 14 Aug 2023 16:54:01 +0200 Jann Horn <jannh@xxxxxxxxxx> wrote:
> >
> > > > @@ -403,6 +403,8 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
> > > >
> > > > vma_iter_store(&vmi, vma);
> > > >
> > > > + vma_start_write(vma);
> > > > +
> > > > if (vma->vm_file) {
> > > > mapping = vma->vm_file->f_mapping;
> > > > i_mmap_lock_write(mapping);
> > >
> > > The "vma_start_write()" has to be ordered before the
> > > "vma_iter_store(&vmi, vma)".
> >
> > Thanks. This?
> >
> >
> > --- a/mm/mmap.c~mm-always-lock-new-vma-before-inserting-into-vma-tree-fix
> > +++ a/mm/mmap.c
> > @@ -401,10 +401,10 @@ static int vma_link(struct mm_struct *mm
> > if (vma_iter_prealloc(&vmi, vma))
> > return -ENOMEM;
> >
> > - vma_iter_store(&vmi, vma);
> > -
> > vma_start_write(vma);
> >
> > + vma_iter_store(&vmi, vma);
> > +
> > if (vma->vm_file) {
> > mapping = vma->vm_file->f_mapping;
> > i_mmap_lock_write(mapping);
>
> Yes, thanks, that looks good.
Ack. Thanks!
