ARM: sunxi_defconfig: enable CONFIG_REGULATOR

[cascardo/linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 93d28c7..7f85520 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -89,6 +89,25 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags)
 }
 EXPORT_SYMBOL(vm_get_page_prot);
 
+static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags)
+{
+       return pgprot_modify(oldprot, vm_get_page_prot(vm_flags));
+}
+
+/* Update vma->vm_page_prot to reflect vma->vm_flags. */
+void vma_set_page_prot(struct vm_area_struct *vma)
+{
+       unsigned long vm_flags = vma->vm_flags;
+
+       vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot, vm_flags);
+       if (vma_wants_writenotify(vma)) {
+               vm_flags &= ~VM_SHARED;
+               vma->vm_page_prot = vm_pgprot_modify(vma->vm_page_prot,
+                                                    vm_flags);
+       }
+}
+
+
 int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS;  /* heuristic overcommit */
 int sysctl_overcommit_ratio __read_mostly = 50;        /* default is 50% */
 unsigned long sysctl_overcommit_kbytes __read_mostly;
@@ -1475,11 +1494,16 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
        if (vma->vm_ops && vma->vm_ops->page_mkwrite)
                return 1;
 
-       /* The open routine did something to the protections already? */
+       /* The open routine did something to the protections that pgprot_modify
+        * won't preserve? */
        if (pgprot_val(vma->vm_page_prot) !=
-           pgprot_val(vm_get_page_prot(vm_flags)))
+           pgprot_val(vm_pgprot_modify(vma->vm_page_prot, vm_flags)))
                return 0;
 
+       /* Do we need to track softdirty? */
+       if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY))
+               return 1;
+
        /* Specialty mapping? */
        if (vm_flags & VM_PFNMAP)
                return 0;
@@ -1615,21 +1639,6 @@ munmap_back:
                        goto free_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);
        /* Once vma denies write, undo our temporary denial count */
        if (file) {
@@ -1663,6 +1672,8 @@ out:
         */
        vma->vm_flags |= VM_SOFTDIRTY;
 
+       vma_set_page_prot(vma);
+
        return addr;
 
 unmap_and_free_vma: