Re: [PATCH v3 07/16] mm/mmap: Extract validate_mm() from vma_complete()

[Suren Baghdasaryan <surenb@google.com>]

On Fri, Jul 5, 2024 at 12:35 PM Lorenzo Stoakes
<lorenzo.stoakes@oracle.com> wrote:
>
> On Thu, Jul 04, 2024 at 02:27:09PM GMT, Liam R. Howlett wrote:
> > vma_complete() will need to be called during an unsafe time to call
> > validate_mm().  Extract the call in all places now so that only one
> > location can be modified in the next change.
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> > ---
> >  mm/mmap.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index 2a1a49f98fa3..8d9be791997a 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -646,7 +646,6 @@ static inline void vma_complete(struct vma_prepare *vp,
> >       }
> >       if (vp->insert && vp->file)
> >               uprobe_mmap(vp->insert);
> > -     validate_mm(mm);
> >  }
> >
> >  /*
> > @@ -734,6 +733,7 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >       vma_iter_store(vmi, vma);
> >
> >       vma_complete(&vp, vmi, vma->vm_mm);
> > +     validate_mm(vma->vm_mm);
> >       return 0;
> >
> >  nomem:
> > @@ -775,6 +775,7 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >       vma_iter_clear(vmi);
> >       vma_set_range(vma, start, end, pgoff);
> >       vma_complete(&vp, vmi, vma->vm_mm);
> > +     validate_mm(vma->vm_mm);
> >       return 0;
> >  }
> >
> > @@ -1103,6 +1104,7 @@ static struct vm_area_struct
> >       }
> >
> >       vma_complete(&vp, vmi, mm);
> > +     validate_mm(mm);
> >       khugepaged_enter_vma(res, vm_flags);
> >       return res;
> >
> > @@ -2481,6 +2483,7 @@ static int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >
> >       /* vma_complete stores the new vma */
> >       vma_complete(&vp, vmi, vma->vm_mm);
> > +     validate_mm(vma->vm_mm);
> >
> >       /* Success. */
> >       if (new_below)
> > @@ -3353,6 +3356,7 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
> >               vma_iter_store(vmi, vma);
> >
> >               vma_complete(&vp, vmi, mm);
> > +             validate_mm(mm);
> >               khugepaged_enter_vma(vma, flags);
> >               goto out;
> >       }
> > --
> > 2.43.0
> >
> >
>
> LGTM
>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Reviewed-by: Suren Baghdasaryan <surenb@google.com>