[PATCH] mm: mremap correct rmap accounting

[linux.git] / mm / madvise.c

diff --git a/mm/madvise.c b/mm/madvise.c
index ae0ae3ea299a7a83b72939236ef4931eb5ac16d0..4e196155a0c3635801bd0f8dcff0b18ce1bbcf37 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -22,16 +22,23 @@ static long madvise_behavior(struct vm_area_struct * vma,
        struct mm_struct * mm = vma->vm_mm;
        int error = 0;
        pgoff_t pgoff;
-       int new_flags = vma->vm_flags & ~VM_READHINTMASK;
+       int new_flags = vma->vm_flags;
 
        switch (behavior) {
+       case MADV_NORMAL:
+               new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ;
+               break;
        case MADV_SEQUENTIAL:
-               new_flags |= VM_SEQ_READ;
+               new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ;
                break;
        case MADV_RANDOM:
-               new_flags |= VM_RAND_READ;
+               new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ;
                break;
-       default:
+       case MADV_DONTFORK:
+               new_flags |= VM_DONTCOPY;
+               break;
+       case MADV_DOFORK:
+               new_flags &= ~VM_DONTCOPY;
                break;
        }
 
@@ -161,6 +168,9 @@ static long madvise_remove(struct vm_area_struct *vma,
                        return -EINVAL;
        }
 
+       if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
+               return -EACCES;
+
        mapping = vma->vm_file->f_mapping;
 
        offset = (loff_t)(start - vma->vm_start)
@@ -177,6 +187,12 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
        long error;
 
        switch (behavior) {
+       case MADV_DOFORK:
+               if (vma->vm_flags & VM_IO) {
+                       error = -EINVAL;
+                       break;
+               }
+       case MADV_DONTFORK:
        case MADV_NORMAL:
        case MADV_SEQUENTIAL:
        case MADV_RANDOM: