pps: add ioctl_compat function to correct ioctl definitions

ioctl definitions use the pointer size of the architecture which is fine when userspace and kernel are the same bitsize. This patchset workarounds an issue with mixed bitsize kernel + userspace by rewriting the cmd to the kernelspace architecture pointer size. Acked-by: Rodolfo Giometti <[email protected]> Signed-off-by: Matt Ranostay <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
josf · Mar 17, 2017 · 2ac6665 · 2ac6665
1 parent 48a5e6b
commit 2ac6665
Showing 1 changed file with 13 additions and 0 deletions.
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
@@ -242,6 +242,18 @@ static long pps_cdev_ioctl(struct file *file,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+static long pps_cdev_compat_ioctl(struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
+
+	return pps_cdev_ioctl(file, cmd, arg);
+}
+#else
+#define pps_cdev_compat_ioctl	NULL
+#endif
+
 static int pps_cdev_open(struct inode *inode, struct file *file)
 {
 	struct pps_device *pps = container_of(inode->i_cdev,
@@ -268,6 +280,7 @@ static const struct file_operations pps_cdev_fops = {
 	.llseek		= no_llseek,
 	.poll		= pps_cdev_poll,
 	.fasync		= pps_cdev_fasync,
+	.compat_ioctl	= pps_cdev_compat_ioctl,
 	.unlocked_ioctl	= pps_cdev_ioctl,
 	.open		= pps_cdev_open,
 	.release	= pps_cdev_release,