[PATCH] vDPA: fix incorrect VDPA_ATTR_MAX value

[kovalev@altlinux.org]

From: Vasiliy Kovalev <kovalev@altlinux.org>

The VDPA_ATTR_MAX value should correspond to the index of the last
available member of the structure, not their total number.

Otherwise, it can lead to interpretation errors in other functions
when the structure (.maxattr = VDPA_ATTR_MAX) member is actually
incremented by one and refers to invalid data.

Fixes: 33b347503f01 ("vdpa: Define vdpa mgmt device, ops and a netlink interface")
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
---
 include/uapi/linux/vdpa.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 43c51698195ceb..ab132a09565232 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -74,7 +74,8 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_BLK_CFG_FLUSH,		/* u8 */
 
 	/* new attributes must be added above here */
-	VDPA_ATTR_MAX,
+	__VDPA_ATTR_MAX,
+	VDPA_ATTR_MAX	= __VDPA_ATTR_MAX - 1,
 };
 
 #endif
-- 
2.33.8