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xen/gntdev: Do not use mm notifiers with autotranslating guests

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Commit d3eeb1d77c ("xen/gntdev: use mmu_interval_notifier_insert")
missed a test for use_ptemod when calling mmu_interval_read_begin(). Fix
that.

Fixes: d3eeb1d77c ("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>
This commit is contained in:
Boris Ostrovsky 2020-01-28 10:31:26 -05:00
parent eda4eabf86
commit 9293724192
1 changed files with 12 additions and 12 deletions
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24
drivers/xen/gntdev.c
View file

@ -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,