From 9293724192a73f49c722e9685d45649c6df67dfe Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Tue, 28 Jan 2020 10:31:26 -0500 Subject: [PATCH] xen/gntdev: Do not use mm notifiers with autotranslating guests MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Tested-by: Ilpo Järvinen Signed-off-by: Boris Ostrovsky Reviewed-by: Jason Gunthorpe Acked-by: Juergen Gross --- drivers/xen/gntdev.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 4fc83e3f..0258415 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1006,19 +1006,19 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) } 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, -- 2.7.4