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>

diff --git a/net/socket.c b/net/socket.c
index 7848d12..717a5f1 100644 (file)
--- 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;