From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
This implements the uABI of UFFDIO_REMAP.
Notably one mode bitflag is also forwarded (and in turn known) by the
lowlevel remap_pages method.
Acked-by: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
include/uapi/linux/userfaultfd.h | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 48f1a7c..a0d6106 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -34,7 +34,8 @@
#define UFFD_API_RANGE_IOCTLS \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
- (__u64)1 << _UFFDIO_ZEROPAGE)
+ (__u64)1 << _UFFDIO_ZEROPAGE | \
+ (__u64)1 << _UFFDIO_REMAP)
#define UFFD_API_RANGE_IOCTLS_BASIC \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY)
@@ -52,6 +53,7 @@
#define _UFFDIO_WAKE (0x02)
#define _UFFDIO_COPY (0x03)
#define _UFFDIO_ZEROPAGE (0x04)
+#define _UFFDIO_REMAP (0x05)
#define _UFFDIO_API (0x3F)
/* userfaultfd ioctl ids */
@@ -68,6 +70,8 @@
struct uffdio_copy)
#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
struct uffdio_zeropage)
+#define UFFDIO_REMAP _IOWR(UFFDIO, _UFFDIO_REMAP, \
+ struct uffdio_remap)
/* read() structure */
struct uffd_msg {
@@ -231,4 +235,23 @@ struct uffdio_zeropage {
__s64 zeropage;
};
+struct uffdio_remap {
+ __u64 dst;
+ __u64 src;
+ __u64 len;
+ /*
+ * Especially if used to atomically remove memory from the
+ * address space the wake on the dst range is not needed.
+ */
+#define UFFDIO_REMAP_MODE_DONTWAKE ((__u64)1<<0)
+#define UFFDIO_REMAP_MODE_ALLOW_SRC_HOLES ((__u64)1<<1)
+ __u64 mode;
+
+ /*
+ * "remap" is written by the ioctl and must be at the end: the
+ * copy_from_user will not read the last 8 bytes.
+ */
+ __s64 remap;
+};
+
#endif /* _LINUX_USERFAULTFD_H */
--
1.8.3.1
