string: factorize skip_spaces and export it to be generally available

[safe/jmp/linux-2.6] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 02c09f3..d9c77b2 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1198,8 +1198,20 @@ munmap_back:
                        goto free_vma;
        }
 
-       if (vma_wants_writenotify(vma))
+       if (vma_wants_writenotify(vma)) {
+               pgprot_t pprot = vma->vm_page_prot;
+
+               /* Can vma->vm_page_prot have changed??
+                *
+                * Answer: Yes, drivers may have changed it in their
+                *         f_op->mmap method.
+                *
+                * Ensures that vmas marked as uncached stay that way.
+                */
                vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
+               if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot)))
+                       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+       }
 
        vma_link(mm, vma, prev, rb_link, rb_parent);
        file = vma->vm_file;