9p: Fix sparse error

Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

net/9p/protocol.c

@@ -468,7 +468,8 @@ p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 		case 'E':{
 				 int32_t cnt = va_arg(ap, int32_t);
 				 const char *k = va_arg(ap, const void *);
-				 const char *u = va_arg(ap, const void *);
+				 const char __user *u = va_arg(ap,
+							const void __user *);
 				 errcode = p9pdu_writef(pdu, proto_version, "d",
 						 cnt);
 				 if (!errcode && pdu_write_urw(pdu, k, u, cnt))

net/9p/trans_common.c

@@ -66,7 +66,7 @@ p9_payload_gup(struct p9_req_t *req, size_t *pdata_off, int *pdata_len,
 	uint32_t pdata_mapped_pages;
 	struct trans_rpage_info  *rpinfo;
 
-	*pdata_off = (size_t)req->tc->pubuf & (PAGE_SIZE-1);
+	*pdata_off = (__force size_t)req->tc->pubuf & (PAGE_SIZE-1);
 
 	if (*pdata_off)
 		first_page_bytes = min(((size_t)PAGE_SIZE - *pdata_off),

net/9p/trans_virtio.c

@@ -326,8 +326,11 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 			outp = pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
 					pdata_off, rpinfo->rp_data, pdata_len);
 		} else {
-			char *pbuf = req->tc->pubuf ? req->tc->pubuf :
-								req->tc->pkbuf;
+			char *pbuf;
+			if (req->tc->pubuf)
+				pbuf = (__force char *) req->tc->pubuf;
+			else
+				pbuf = req->tc->pkbuf;
 			outp = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, pbuf,
 					req->tc->pbuf_size);
 		}
@@ -352,8 +355,12 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 			in = pack_sg_list_p(chan->sg, out+inp, VIRTQUEUE_NUM,
 					pdata_off, rpinfo->rp_data, pdata_len);
 		} else {
-			char *pbuf = req->tc->pubuf ? req->tc->pubuf :
-								req->tc->pkbuf;
+			char *pbuf;
+			if (req->tc->pubuf)
+				pbuf = (__force char *) req->tc->pubuf;
+			else
+				pbuf = req->tc->pkbuf;
+
 			in = pack_sg_list(chan->sg, out+inp, VIRTQUEUE_NUM,
 					pbuf, req->tc->pbuf_size);
 		}