xen/gnttab: leave lazy MMU mode in the case of a m2p override failure

commit 14883a75ec76b44759385fb12629f4a0f1aef4e3 upstream.

Commit f62805f1 introduced a bug where lazy MMU mode isn't exited if a
m2p_add/remove_override call fails.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: Matt Wilson <msw@amazon.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index c4d2298..255e828 100644 (file)
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -921,9 +921,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                ret = m2p_add_override(mfn, pages[i], kmap_ops ?
                                       &kmap_ops[i] : NULL);
                if (ret)
-                       return ret;
+                       goto out;
        }
 
+ out:
        if (lazy)
                arch_leave_lazy_mmu_mode();
 
@@ -954,9 +955,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
                ret = m2p_remove_override(pages[i], kmap_ops ?
                                       &kmap_ops[i] : NULL);
                if (ret)
-                       return ret;
+                       goto out;
        }
 
+ out:
        if (lazy)
                arch_leave_lazy_mmu_mode();