Now it's safe to enable write protection in userfaultfd API
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
---
include/uapi/linux/userfaultfd.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 8898bd7..12c7a36 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -17,7 +17,7 @@
* #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
* UFFD_FEATURE_EVENT_FORK)
*/
-#define UFFD_API_FEATURES (0)
+#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP)
#define UFFD_API_IOCTLS \
((__u64)1 << _UFFDIO_REGISTER | \
(__u64)1 << _UFFDIO_UNREGISTER | \
@@ -25,7 +25,8 @@
#define UFFD_API_RANGE_IOCTLS \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
- (__u64)1 << _UFFDIO_ZEROPAGE)
+ (__u64)1 << _UFFDIO_ZEROPAGE | \
+ (__u64)1 << _UFFDIO_WRITEPROTECT)
/*
* Valid ioctl command number range with this API is from 0x00 to
@@ -108,8 +109,8 @@ struct uffdio_api {
* are to be considered implicitly always enabled in all kernels as
* long as the uffdio_api.api requested matches UFFD_API.
*/
-#if 0 /* not available yet */
#define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0)
+#if 0 /* not available yet */
#define UFFD_FEATURE_EVENT_FORK (1<<1)
#endif
__u64 features;
--
2.4.6
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