for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
void *entry;
- struct page *page;
entry = xa_load(&dmirror->pt, pfn);
- page = xa_untag_pointer(entry);
if (xa_pointer_tag(entry) == DPT_XA_TAG_ATOMIC)
return -EPERM;
}
mmap_read_lock(mm);
for (addr = start; addr < end; addr = next) {
- unsigned long mapped;
+ unsigned long mapped = 0;
int i;
if (end < addr + (ARRAY_SIZE(pages) << PAGE_SHIFT))
next = addr + (ARRAY_SIZE(pages) << PAGE_SHIFT);
ret = make_device_exclusive_range(mm, addr, next, pages, NULL);
- mapped = dmirror_atomic_map(addr, next, pages, dmirror);
+ /*
+ * Do dmirror_atomic_map() iff all pages are marked for
+ * exclusive access to avoid accessing uninitialized
+ * fields of pages.
+ */
+ if (ret == (next - addr) >> PAGE_SHIFT)
+ mapped = dmirror_atomic_map(addr, next, pages, dmirror);
for (i = 0; i < ret; i++) {
if (pages[i]) {
unlock_page(pages[i]);
return 0;
}
+static int dmirror_fops_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ unsigned long addr;
+
+ for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) {
+ struct page *page;
+ int ret;
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page)
+ return -ENOMEM;
+
+ ret = vm_insert_page(vma, addr, page);
+ if (ret) {
+ __free_page(page);
+ return ret;
+ }
+ put_page(page);
+ }
+
+ return 0;
+}
+
static const struct file_operations dmirror_fops = {
.open = dmirror_fops_open,
.release = dmirror_fops_release,
+ .mmap = dmirror_fops_mmap,
.unlocked_ioctl = dmirror_fops_unlocked_ioctl,
.llseek = default_llseek,
.owner = THIS_MODULE,