[PATCH 1/2] pvcalls: check return value from copy_from/to_iter

[PATCH 1/2] pvcalls: check return value from copy_from/to_iter

[Stefano Stabellini]

Check the return value of copy_from_iter in __write_ring and
copy_to_iter in __read_ring. Update "len" accordingly.

In the cases where we issue two consecutive copy_from_iter, or two
consecutive copy_to_iter, first check return, then goto out if it is not
what we expect.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 drivers/xen/pvcalls-front.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 8e7426083..f2dcac88 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -456,18 +456,21 @@ static int __write_ring(struct pvcalls_data_intf *intf,
 	masked_cons = pvcalls_mask(cons, array_size);
 
 	if (masked_prod < masked_cons) {
-		copy_from_iter(data->out + masked_prod, len, msg_iter);
+		len = copy_from_iter(data->out + masked_prod, len, msg_iter);
 	} else {
 		if (len > array_size - masked_prod) {
-			copy_from_iter(data->out + masked_prod,
+			int ret = copy_from_iter(data->out + masked_prod,
 				       array_size - masked_prod, msg_iter);
-			copy_from_iter(data->out,
-				       len - (array_size - masked_prod),
-				       msg_iter);
+			if (ret != array_size - masked_prod) {
+				len = ret;
+				goto out;
+			}
+			len = ret + copy_from_iter(data->out, len - ret, msg_iter);
 		} else {
-			copy_from_iter(data->out + masked_prod, len, msg_iter);
+			len = copy_from_iter(data->out + masked_prod, len, msg_iter);
 		}
 	}
+out:
 	/* write to ring before updating pointer */
 	virt_wmb();
 	intf->out_prod += len;
@@ -557,18 +560,21 @@ static int __read_ring(struct pvcalls_data_intf *intf,
 		len = size;
 
 	if (masked_prod > masked_cons) {
-		copy_to_iter(data->in + masked_cons, len, msg_iter);
+		len = copy_to_iter(data->in + masked_cons, len, msg_iter);
 	} else {
 		if (len > (array_size - masked_cons)) {
-			copy_to_iter(data->in + masked_cons,
+			int ret = copy_to_iter(data->in + masked_cons,
 				     array_size - masked_cons, msg_iter);
-			copy_to_iter(data->in,
-				     len - (array_size - masked_cons),
-				     msg_iter);
+			if (ret != array_size - masked_cons) {
+				len = ret;
+				goto out;
+			}
+			len = ret + copy_to_iter(data->in, len - ret, msg_iter);
 		} else {
-			copy_to_iter(data->in + masked_cons, len, msg_iter);
+			len = copy_to_iter(data->in + masked_cons, len, msg_iter);
 		}
 	}
+out:
 	/* read data from the ring before increasing the index */
 	virt_mb();
 	if (!(flags & MSG_PEEK))
-- 
1.9.1

[PATCH 2/2] pvcalls: fix casts to avoid warnings on 32 bit

[Stefano Stabellini]

Cast the map pointers to uintptr_t instead of uint64_t everywhere when
setting the socket ids.

In pvcalls_front_event_handler, first cast the poll id to uintptr_t,
then to struct sock_mapping * to avoid warnings. We know that the poll
id is fine because it is was set by the frontend initially in the poll
request.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 drivers/xen/pvcalls-front.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index f2dcac88..0c1ec68 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -157,7 +157,7 @@ static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id)
 
 		req_id = rsp->req_id;
 		if (rsp->cmd == PVCALLS_POLL) {
-			struct sock_mapping *map = (struct sock_mapping *)
+			struct sock_mapping *map = (struct sock_mapping *)(uintptr_t)
 						   rsp->u.poll.id;
 
 			clear_bit(PVCALLS_FLAG_POLL_INFLIGHT,
@@ -280,7 +280,7 @@ int pvcalls_front_socket(struct socket *sock)
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_SOCKET;
-	req->u.socket.id = (uint64_t) map;
+	req->u.socket.id = (uintptr_t) map;
 	req->u.socket.domain = AF_INET;
 	req->u.socket.type = SOCK_STREAM;
 	req->u.socket.protocol = IPPROTO_IP;
@@ -402,7 +402,7 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_CONNECT;
-	req->u.connect.id = (uint64_t)map;
+	req->u.connect.id = (uintptr_t)map;
 	req->u.connect.len = addr_len;
 	req->u.connect.flags = flags;
 	req->u.connect.ref = map->active.ref;
@@ -663,7 +663,7 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 	req->req_id = req_id;
 	map->sock = sock;
 	req->cmd = PVCALLS_BIND;
-	req->u.bind.id = (uint64_t)map;
+	req->u.bind.id = (uintptr_t)map;
 	memcpy(req->u.bind.addr, addr, sizeof(*addr));
 	req->u.bind.len = addr_len;
 
@@ -725,7 +725,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_LISTEN;
-	req->u.listen.id = (uint64_t) map;
+	req->u.listen.id = (uintptr_t) map;
 	req->u.listen.backlog = backlog;
 
 	bedata->ring.req_prod_pvt++;
@@ -829,9 +829,9 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_ACCEPT;
-	req->u.accept.id = (uint64_t) map;
+	req->u.accept.id = (uintptr_t) map;
 	req->u.accept.ref = map2->active.ref;
-	req->u.accept.id_new = (uint64_t) map2;
+	req->u.accept.id_new = (uintptr_t) map2;
 	req->u.accept.evtchn = evtchn;
 	map->passive.accept_map = map2;
 
@@ -925,7 +925,7 @@ static unsigned int pvcalls_front_poll_passive(struct file *file,
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_POLL;
-	req->u.poll.id = (uint64_t) map;
+	req->u.poll.id = (uintptr_t) map;
 
 	bedata->ring.req_prod_pvt++;
 	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
@@ -1023,7 +1023,7 @@ int pvcalls_front_release(struct socket *sock)
 	req = RING_GET_REQUEST(&bedata->ring, req_id);
 	req->req_id = req_id;
 	req->cmd = PVCALLS_RELEASE;
-	req->u.release.id = (uint64_t)map;
+	req->u.release.id = (uintptr_t)map;
 
 	bedata->ring.req_prod_pvt++;
 	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
-- 
1.9.1