Merge branch 'msg_control-split'

Kevin Brodsky says:

====================
net: Finish up ->msg_control{,_user} split

Commit 1f466e1f15cf ("net: cleanly handle kernel vs user buffers for
->msg_control") introduced the msg_control_user and
msg_control_is_user fields in struct msghdr, to ensure that user
pointers are represented as such. It also took care of converting most
users of struct msghdr::msg_control where user pointers are involved. It
did however miss a number of cases, and some code using msg_control
inappropriately has also appeared in the meantime.

This series is attempting to complete the split, by eliminating the
remaining cases where msg_control is used when in fact a user
pointer is stored in the union (patch 1).

It also addresses a couple of issues with msg_control_is_user: one where
it is not updated as it should (patch 2), and one where it is not
initialised (patch 3).

v1..v2:
* Split out the msg_control_is_user fixes into separate patches.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/core/scm.c b/net/core/scm.c
index acb7d776fa6e..3cd7dd377e53 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -250,7 +250,10 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
 	}
 
 	cmlen = min(CMSG_SPACE(len), msg->msg_controllen);
-	msg->msg_control += cmlen;
+	if (msg->msg_control_is_user)
+		msg->msg_control_user += cmlen;
+	else
+		msg->msg_control += cmlen;
 	msg->msg_controllen -= cmlen;
 	return 0;
 
@@ -299,7 +302,7 @@ static int scm_max_fds(struct msghdr *msg)
 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 {
 	struct cmsghdr __user *cm =
-		(__force struct cmsghdr __user *)msg->msg_control;
+		(__force struct cmsghdr __user *)msg->msg_control_user;
 	unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
 	int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count);
 	int __user *cmsg_data = CMSG_USER_DATA(cm);
@@ -332,7 +335,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 			cmlen = CMSG_SPACE(i * sizeof(int));
 			if (msg->msg_controllen < cmlen)
 				cmlen = msg->msg_controllen;
-			msg->msg_control += cmlen;
+			msg->msg_control_user += cmlen;
 			msg->msg_controllen -= cmlen;
 		}
 	}