Merge git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb

[pandora-kernel.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index d14b251..2302d22 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1151,7 +1151,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         * be processed until returning to user space.
                         */
                        if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE)))
-                               return -ENOMEM;
+                               return i ? i : -ENOMEM;
 
                        if (write)
                                foll_flags |= FOLL_WRITE;
@@ -1697,8 +1697,19 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
        struct page *dirty_page = NULL;
 
        old_page = vm_normal_page(vma, address, orig_pte);
-       if (!old_page)
+       if (!old_page) {
+               /*
+                * VM_MIXEDMAP !pfn_valid() case
+                *
+                * We should not cow pages in a shared writeable mapping.
+                * Just mark the pages writable as we can't do any dirty
+                * accounting on raw pfn maps.
+                */
+               if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+                                    (VM_WRITE|VM_SHARED))
+                       goto reuse;
                goto gotten;
+       }
 
        /*
         * Take out anonymous pages first, anonymous shared vmas are
@@ -1751,6 +1762,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
        }
 
        if (reuse) {
+reuse:
                flush_cache_page(vma, address, pte_pfn(orig_pte));
                entry = pte_mkyoung(orig_pte);
                entry = maybe_mkwrite(pte_mkdirty(entry), vma);