From: Boris Ostrovsky boris.ostrovsky@oracle.com
commit 9293724192a73f49c722e9685d45649c6df67dfe upstream.
Commit d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert") missed a test for use_ptemod when calling mmu_interval_read_begin(). Fix that.
Fixes: d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert") CC: stable@vger.kernel.org # 5.5 Reported-by: Ilpo Järvinen ilpo.jarvinen@cs.helsinki.fi Tested-by: Ilpo Järvinen ilpo.jarvinen@cs.helsinki.fi Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Reviewed-by: Jason Gunthorpe jgg@mellanox.com Acked-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/xen/gntdev.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
--- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1006,19 +1006,19 @@ static int gntdev_mmap(struct file *flip } mutex_unlock(&priv->lock);
- /* - * gntdev takes the address of the PTE in find_grant_ptes() and passes - * it to the hypervisor in gntdev_map_grant_pages(). The purpose of - * the notifier is to prevent the hypervisor pointer to the PTE from - * going stale. - * - * Since this vma's mappings can't be touched without the mmap_sem, - * and we are holding it now, there is no need for the notifier_range - * locking pattern. - */ - mmu_interval_read_begin(&map->notifier); - if (use_ptemod) { + /* + * gntdev takes the address of the PTE in find_grant_ptes() and + * passes it to the hypervisor in gntdev_map_grant_pages(). The + * purpose of the notifier is to prevent the hypervisor pointer + * to the PTE from going stale. + * + * Since this vma's mappings can't be touched without the + * mmap_sem, and we are holding it now, there is no need for + * the notifier_range locking pattern. + */ + mmu_interval_read_begin(&map->notifier); + map->pages_vm_start = vma->vm_start; err = apply_to_page_range(vma->vm_mm, vma->vm_start, vma->vm_end - vma->vm_start,