dm cache: fix NULL pointer when switching from cleaner policy

[firefly-linux-kernel-4.4.55.git] / drivers / uio / uio.c

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index b645c47501b42cc4765073fa6a5d2d2bfaf60396..2d57a00dc17368bafd87246df83ce6da97a68884 100644 (file)
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -630,36 +630,57 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
        return 0;
 }
 
-static const struct vm_operations_struct uio_vm_ops = {
+static const struct vm_operations_struct uio_logical_vm_ops = {
        .open = uio_vma_open,
        .close = uio_vma_close,
        .fault = uio_vma_fault,
 };
 
+static int uio_mmap_logical(struct vm_area_struct *vma)
+{
+       vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+       vma->vm_ops = &uio_logical_vm_ops;
+       uio_vma_open(vma);
+       return 0;
+}
+
+static const struct vm_operations_struct uio_physical_vm_ops = {
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+       .access = generic_access_phys,
+#endif
+};
+
 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_ops = &uio_physical_vm_ops;
        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);
 }
 
-static int uio_mmap_logical(struct vm_area_struct *vma)
-{
-       vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
-       vma->vm_ops = &uio_vm_ops;
-       uio_vma_open(vma);
-       return 0;
-}
-
 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 {
        struct uio_listener *listener = filep->private_data;