[PATCH linux dev-4.10 v3 19/31] drivers: fsi: occ: Return ENODEV if client is NULL

[Eddie James]

From: "Edward A. James" <eajames at us.ibm.com>

Safeguard the in-kernel api functions.

Signed-off-by: Edward A. James <eajames at us.ibm.com>
---
 drivers/fsi/occ.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/fsi/occ.c b/drivers/fsi/occ.c
index 55f293d..a551349 100644
--- a/drivers/fsi/occ.c
+++ b/drivers/fsi/occ.c
@@ -654,18 +654,27 @@ struct occ_client *occ_drv_open(struct device *dev, unsigned long flags)
 
 int occ_drv_read(struct occ_client *client, char *buf, size_t len)
 {
+	if (!client)
+		return -ENODEV;
+
 	return occ_read_common(client, NULL, buf, len);
 }
 EXPORT_SYMBOL_GPL(occ_drv_read);
 
 int occ_drv_write(struct occ_client *client, const char *buf, size_t len)
 {
+	if (!client)
+		return -ENODEV;
+
 	return occ_write_common(client, NULL, buf, len);
 }
 EXPORT_SYMBOL_GPL(occ_drv_write);
 
 void occ_drv_release(struct occ_client *client)
 {
+	if (!client)
+		return;
+
 	occ_release_common(client);
 }
 EXPORT_SYMBOL_GPL(occ_drv_release);
-- 
1.8.3.1