[PATCH 20/23] userfaultfd: UFFDIO_COPY|UFFDIO_ZEROPAGE uAPI

From: Andrea Arcangeli
Date: Thu May 14 2015 - 13:39:50 EST


This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.

Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
include/uapi/linux/userfaultfd.h | 42 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 8e42bc3..c8a543f 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -21,7 +21,9 @@
(__u64)1 << _UFFDIO_UNREGISTER | \
(__u64)1 << _UFFDIO_API)
#define UFFD_API_RANGE_IOCTLS \
- ((__u64)1 << _UFFDIO_WAKE)
+ ((__u64)1 << _UFFDIO_WAKE | \
+ (__u64)1 << _UFFDIO_COPY | \
+ (__u64)1 << _UFFDIO_ZEROPAGE)

/*
* Valid ioctl command number range with this API is from 0x00 to
@@ -34,6 +36,8 @@
#define _UFFDIO_REGISTER (0x00)
#define _UFFDIO_UNREGISTER (0x01)
#define _UFFDIO_WAKE (0x02)
+#define _UFFDIO_COPY (0x03)
+#define _UFFDIO_ZEROPAGE (0x04)
#define _UFFDIO_API (0x3F)

/* userfaultfd ioctl ids */
@@ -46,6 +50,10 @@
struct uffdio_range)
#define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \
struct uffdio_range)
+#define UFFDIO_COPY _IOWR(UFFDIO, _UFFDIO_COPY, \
+ struct uffdio_copy)
+#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
+ struct uffdio_zeropage)

/* read() structure */
struct uffd_msg {
@@ -118,4 +126,36 @@ struct uffdio_register {
__u64 ioctls;
};

+struct uffdio_copy {
+ __u64 dst;
+ __u64 src;
+ __u64 len;
+ /*
+ * There will be a wrprotection flag later that allows to map
+ * pages wrprotected on the fly. And such a flag will be
+ * available if the wrprotection ioctl are implemented for the
+ * range according to the uffdio_register.ioctls.
+ */
+#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
+ __u64 mode;
+
+ /*
+ * "copy" is written by the ioctl and must be at the end: the
+ * copy_from_user will not read the last 8 bytes.
+ */
+ __s64 copy;
+};
+
+struct uffdio_zeropage {
+ struct uffdio_range range;
+#define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0)
+ __u64 mode;
+
+ /*
+ * "zeropage" is written by the ioctl and must be at the end:
+ * the copy_from_user will not read the last 8 bytes.
+ */
+ __s64 zeropage;
+};
+
#endif /* _LINUX_USERFAULTFD_H */
--
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