net: remove address space warnings in net/socket.c

Casts __kernel to __user pointer require __force markup, so add it. Also
sock_get/setsockopt() takes @optval and/or @optlen arguments as user pointers
but were taking kernel pointers, use new variables 'uoptval' and/or 'uoptlen'
to fix it. These remove following warnings from sparse:

 net/socket.c:1922:46: warning: cast adds address space to expression (<asn:1>)
 net/socket.c:3061:61: warning: incorrect type in argument 4 (different address spaces)
 net/socket.c:3061:61:    expected char [noderef] <asn:1>*optval
 net/socket.c:3061:61:    got char *optval
 net/socket.c:3061:69: warning: incorrect type in argument 5 (different address spaces)
 net/socket.c:3061:69:    expected int [noderef] <asn:1>*optlen
 net/socket.c:3061:69:    got int *optlen
 net/socket.c:3063:67: warning: incorrect type in argument 4 (different address spaces)
 net/socket.c:3063:67:    expected char [noderef] <asn:1>*optval
 net/socket.c:3063:67:    got char *optval
 net/socket.c:3064:45: warning: incorrect type in argument 5 (different address spaces)
 net/socket.c:3064:45:    expected int [noderef] <asn:1>*optlen
 net/socket.c:3064:45:    got int *optlen
 net/socket.c:3078:61: warning: incorrect type in argument 4 (different address spaces)
 net/socket.c:3078:61:    expected char [noderef] <asn:1>*optval
 net/socket.c:3078:61:    got char *optval
 net/socket.c:3080:67: warning: incorrect type in argument 4 (different address spaces)
 net/socket.c:3080:67:    expected char [noderef] <asn:1>*optval
 net/socket.c:3080:67:    got char *optval

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 6 deletions

diff --git a/net/socket.c b/net/socket.c
index 7848d12f5e4d..717a5f1c8792 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1918,7 +1918,8 @@ SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned, flags)
                  * Afterwards, it will be a kernel pointer. Thus the compiler-assisted
                  * checking falls down on this.
                  */
-                if (copy_from_user(ctl_buf, (void __user *)msg_sys.msg_control,
+                if (copy_from_user(ctl_buf,
+                                   (void __user __force *)msg_sys.msg_control,
                                    ctl_len))
                         goto out_freectl;
                 msg_sys.msg_control = ctl_buf;
@@ -3053,14 +3054,19 @@ int kernel_getsockopt(struct socket *sock, int level, int optname,
                         char *optval, int *optlen)
 {
         mm_segment_t oldfs = get_fs();
+        char __user *uoptval;
+        int __user *uoptlen;
         int err;
 
+        uoptval = (char __user __force *) optval;
+        uoptlen = (int __user __force *) optlen;
+
         set_fs(KERNEL_DS);
         if (level == SOL_SOCKET)
-                err = sock_getsockopt(sock, level, optname, optval, optlen);
+                err = sock_getsockopt(sock, level, optname, uoptval, uoptlen);
         else
-                err = sock->ops->getsockopt(sock, level, optname, optval,
-                                            optlen);
+                err = sock->ops->getsockopt(sock, level, optname, uoptval,
+                                            uoptlen);
         set_fs(oldfs);
         return err;
 }
@@ -3070,13 +3076,16 @@ int kernel_setsockopt(struct socket *sock, int level, int optname,
                         char *optval, unsigned int optlen)
 {
         mm_segment_t oldfs = get_fs();
+        char __user *uoptval;
         int err;
 
+        uoptval = (char __user __force *) optval;
+
         set_fs(KERNEL_DS);
         if (level == SOL_SOCKET)
-                err = sock_setsockopt(sock, level, optname, optval, optlen);
+                err = sock_setsockopt(sock, level, optname, uoptval, optlen);
         else
-                err = sock->ops->setsockopt(sock, level, optname, optval,
+                err = sock->ops->setsockopt(sock, level, optname, uoptval,
                                             optlen);
         set_fs(oldfs);
         return err;