[SPARC]: Fix warning on prom_getproperty in openprom.c

Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/sbus/char/openprom.c b/drivers/sbus/char/openprom.c
index 383a95f34a0d..239e108b8ed1 100644
--- a/drivers/sbus/char/openprom.c
+++ b/drivers/sbus/char/openprom.c
@@ -392,13 +392,16 @@ static int openprom_bsd_ioctl(struct inode * inode, struct file * file,
                         return -ENOMEM;
                 }
 
-                prom_getproperty(op.op_nodeid, str, tmp, len);
-
-                tmp[len] = '\0';
+                cnt = prom_getproperty(op.op_nodeid, str, tmp, len);
+                if (cnt <= 0) {
+                        error = -EINVAL;
+                } else {
+                        tmp[len] = '\0';
 
-                if (__copy_to_user(argp, &op, sizeof(op)) != 0
-                    || copy_to_user(op.op_buf, tmp, len) != 0)
-                        error = -EFAULT;
+                        if (__copy_to_user(argp, &op, sizeof(op)) != 0 ||
+                            copy_to_user(op.op_buf, tmp, len) != 0)
+                                error = -EFAULT;
+                }
 
                 kfree(tmp);
                 kfree(str);