[CRIU] [PATCH 1/2] Update criu/include/linux/userfaultfd.h

[Mike Rapoport]

Use latest version from usefaultfd tree [1]. Judging by comments about the
last re-spin of userfaultfd updates, the API will go in "as is", so we can
pretty much rely on the current API definitions for proper detection of
supported userfaultfd features.

[1] https://git.kernel.org/cgit/linux/kernel/git/andrea/aa.git/

Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
---
 criu/include/linux/userfaultfd.h | 53 ++++++++++++++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 10 deletions(-)

diff --git a/criu/include/linux/userfaultfd.h b/criu/include/linux/userfaultfd.h
index 9057d7a..a9c3389 100644
--- a/criu/include/linux/userfaultfd.h
+++ b/criu/include/linux/userfaultfd.h
@@ -11,13 +11,17 @@
 
 #include <linux/types.h>
 
-#define UFFD_API ((__u64)0xAA)
 /*
- * After implementing the respective features it will become:
- * #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
- *			      UFFD_FEATURE_EVENT_FORK)
+ * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and
+ * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR.  In
+ * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ
+ * means the userland is reading).
  */
-#define UFFD_API_FEATURES (0)
+#define UFFD_API ((__u64)0xAA)
+#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
+			   UFFD_FEATURE_EVENT_FORK |	    \
+			   UFFD_FEATURE_EVENT_REMAP |	    \
+			   UFFD_FEATURE_EVENT_MADVDONTNEED)
 #define UFFD_API_IOCTLS				\
 	((__u64)1 << _UFFDIO_REGISTER |		\
 	 (__u64)1 << _UFFDIO_UNREGISTER |	\
@@ -25,7 +29,11 @@
 #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)
+#define UFFD_API_RANGE_IOCTLS_BASIC		\
+	((__u64)1 << _UFFDIO_WAKE |		\
+	 (__u64)1 << _UFFDIO_COPY)
 
 /*
  * Valid ioctl command number range with this API is from 0x00 to
@@ -40,6 +48,7 @@
 #define _UFFDIO_WAKE			(0x02)
 #define _UFFDIO_COPY			(0x03)
 #define _UFFDIO_ZEROPAGE		(0x04)
+#define _UFFDIO_WRITEPROTECT		(0x05)
 #define _UFFDIO_API			(0x3F)
 
 /* userfaultfd ioctl ids */
@@ -56,6 +65,8 @@
 				      struct uffdio_copy)
 #define UFFDIO_ZEROPAGE		_IOWR(UFFDIO, _UFFDIO_ZEROPAGE,	\
 				      struct uffdio_zeropage)
+#define UFFDIO_WRITEPROTECT	_IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
+				      struct uffdio_writeprotect)
 
 /* read() structure */
 struct uffd_msg {
@@ -72,6 +83,21 @@ struct uffd_msg {
 		} pagefault;
 
 		struct {
+			__u32	ufd;
+		} fork;
+
+		struct {
+			__u64	from;
+			__u64	to;
+			__u64	len;
+		} remap;
+
+		struct {
+			__u64	start;
+			__u64	end;
+		} madv_dn;
+
+		struct {
 			/* unused reserved fields */
 			__u64	reserved1;
 			__u64	reserved2;
@@ -84,9 +110,9 @@ struct uffd_msg {
  * Start at 0x12 and not at 0 to be more strict against bugs.
  */
 #define UFFD_EVENT_PAGEFAULT	0x12
-#if 0 /* not available yet */
 #define UFFD_EVENT_FORK		0x13
-#endif
+#define UFFD_EVENT_REMAP	0x14
+#define UFFD_EVENT_MADVDONTNEED	0x15
 
 /* flags for UFFD_EVENT_PAGEFAULT */
 #define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */
@@ -105,10 +131,10 @@ 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)
 #define UFFD_FEATURE_EVENT_FORK			(1<<1)
-#endif
+#define UFFD_FEATURE_EVENT_REMAP		(1<<2)
+#define UFFD_FEATURE_EVENT_MADVDONTNEED		(1<<3)
 	__u64 features;
 
 	__u64 ioctls;
@@ -164,4 +190,11 @@ struct uffdio_zeropage {
 	__s64 zeropage;
 };
 
+struct uffdio_writeprotect {
+	struct uffdio_range range;
+	/* !WP means undo writeprotect. DONTWAKE is valid only with !WP */
+#define UFFDIO_WRITEPROTECT_MODE_WP		((__u64)1<<0)
+#define UFFDIO_WRITEPROTECT_MODE_DONTWAKE	((__u64)1<<1)
+	__u64 mode;
+};
 #endif /* _LINUX_USERFAULTFD_H */
-- 
1.9.1