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Diffstat (limited to 'drivers/uio/uio.c')
-rw-r--r--drivers/uio/uio.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index e941367dd28f..e3804d3a1cbc 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -669,16 +669,30 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
{
struct uio_device *idev = vma->vm_private_data;
int mi = uio_find_mem_index(vma);
+ struct uio_mem *mem;
if (mi < 0)
return -EINVAL;
+ mem = idev->info->mem + mi;
+
+ if (vma->vm_end - vma->vm_start > mem->size)
+ return -EINVAL;
vma->vm_flags |= VM_IO | VM_RESERVED;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ /*
+ * We cannot use the vm_iomap_memory() helper here,
+ * because vma->vm_pgoff is the map index we looked
+ * up above in uio_find_mem_index(), rather than an
+ * actual page offset into the mmap.
+ *
+ * So we just do the physical mmap without a page
+ * offset.
+ */
return remap_pfn_range(vma,
vma->vm_start,
- idev->info->mem[mi].addr >> PAGE_SHIFT,
+ mem->addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}