xen/gntdev.c: convert to use vm_map_pages()

Convert to use vm_map_pages() to map range of kernel memory to user vma.

map->count is passed to vm_map_pages() and internal API verify map->count
against count ( count = vma_pages(vma)) for page array boundary overrun
condition.

Link: http://lkml.kernel.org/r/88e56e82d2db98705c2d842e9c9806c00b366d67.1552921225.git.jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Heiko Stuebner <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Kyungmin Park <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oleksandr Andrushchenko <[email protected]>
Cc: Pawel Osciak <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Robin Murphy <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sandy Huang <[email protected]>
Cc: Stefan Richter <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 559d4b7f807d5270bc4fa3cfdd328175051802a8..469dfbd6cf90fb623af99c790be967e7127851eb 100644 (file)
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -1084,7 +1084,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
        int index = vma->vm_pgoff;
        int count = vma_pages(vma);
        struct gntdev_grant_map *map;
-       int i, err = -EINVAL;
+       int err = -EINVAL;
 
        if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
                return -EINVAL;
@@ -1145,12 +1145,9 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
                goto out_put_map;
 
        if (!use_ptemod) {
-               for (i = 0; i < count; i++) {
-                       err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
-                               map->pages[i]);
-                       if (err)
-                               goto out_put_map;
-               }
+               err = vm_map_pages(vma, map->pages, map->count);
+               if (err)
+                       goto out_put_map;
        } else {
 #ifdef CONFIG_X86
                /*