nfc: nci: constify several pointers to u8, sk_buff and other structs

Several functions receive pointers to u8, sk_buff or other structs but
do not modify the contents so make them const.  This allows doing the
same for local variables and in total makes the code a little bit safer.

This makes const also data passed as "unsigned long opt" argument to
nci_request() function.  Usual flow for such functions is:
1. Receive "u8 *" and store it (the pointer) in a structure
   allocated on stack (e.g. struct nci_set_config_param),
2. Call nci_request() or __nci_request() passing a callback function an
   the pointer to the structure via an "unsigned long opt",
3. nci_request() calls the callback which dereferences "unsigned long
   opt" in a read-only way.

This converts all above paths to use proper pointer to const data, so
entire flow is safer.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index d6732e5e8958..71a306b29735 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -142,7 +142,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 			     const u8 data_type, const u8 *data,
 			     size_t data_len)
 {
-	struct nci_conn_info    *conn_info;
+	const struct nci_conn_info *conn_info;
 	struct sk_buff *skb;
 	int len, i, r;
 	u8 cb = pipe;
@@ -197,7 +197,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 
 static void nci_hci_send_data_req(struct nci_dev *ndev, unsigned long opt)
 {
-	struct nci_data *data = (struct nci_data *)opt;
+	const struct nci_data *data = (struct nci_data *)opt;
 
 	nci_hci_send_data(ndev, data->pipe, data->cmd,
 			  data->data, data->data_len);
@@ -221,8 +221,8 @@ int nci_hci_send_cmd(struct nci_dev *ndev, u8 gate, u8 cmd,
 		     const u8 *param, size_t param_len,
 		     struct sk_buff **skb)
 {
-	struct nci_hcp_message *message;
-	struct nci_conn_info   *conn_info;
+	const struct nci_hcp_message *message;
+	const struct nci_conn_info *conn_info;
 	struct nci_data data;
 	int r;
 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
@@ -406,7 +406,7 @@ static void nci_hci_msg_rx_work(struct work_struct *work)
 	struct nci_hci_dev *hdev =
 		container_of(work, struct nci_hci_dev, msg_rx_work);
 	struct sk_buff *skb;
-	struct nci_hcp_message *message;
+	const struct nci_hcp_message *message;
 	u8 pipe, type, instruction;
 
 	while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
@@ -498,7 +498,7 @@ void nci_hci_data_received_cb(void *context,
 int nci_hci_open_pipe(struct nci_dev *ndev, u8 pipe)
 {
 	struct nci_data data;
-	struct nci_conn_info    *conn_info;
+	const struct nci_conn_info *conn_info;
 
 	conn_info = ndev->hci_dev->conn_info;
 	if (!conn_info)
@@ -523,7 +523,7 @@ static u8 nci_hci_create_pipe(struct nci_dev *ndev, u8 dest_host,
 	u8 pipe;
 	struct sk_buff *skb;
 	struct nci_hci_create_pipe_params params;
-	struct nci_hci_create_pipe_resp *resp;
+	const struct nci_hci_create_pipe_resp *resp;
 
 	pr_debug("gate=%d\n", dest_gate);
 
@@ -557,8 +557,8 @@ static int nci_hci_delete_pipe(struct nci_dev *ndev, u8 pipe)
 int nci_hci_set_param(struct nci_dev *ndev, u8 gate, u8 idx,
 		      const u8 *param, size_t param_len)
 {
-	struct nci_hcp_message *message;
-	struct nci_conn_info *conn_info;
+	const struct nci_hcp_message *message;
+	const struct nci_conn_info *conn_info;
 	struct nci_data data;
 	int r;
 	u8 *tmp;
@@ -605,8 +605,8 @@ EXPORT_SYMBOL(nci_hci_set_param);
 int nci_hci_get_param(struct nci_dev *ndev, u8 gate, u8 idx,
 		      struct sk_buff **skb)
 {
-	struct nci_hcp_message *message;
-	struct nci_conn_info    *conn_info;
+	const struct nci_hcp_message *message;
+	const struct nci_conn_info *conn_info;
 	struct nci_data data;
 	int r;
 	u8 pipe = ndev->hci_dev->gate2pipe[gate];
@@ -697,7 +697,7 @@ EXPORT_SYMBOL(nci_hci_connect_gate);
 
 static int nci_hci_dev_connect_gates(struct nci_dev *ndev,
 				     u8 gate_count,
-				     struct nci_hci_gate *gates)
+				     const struct nci_hci_gate *gates)
 {
 	int r;