kni: fix ioctl signature

[ upstream commit f1b2991 ]

Fix kni's ioctl signature to correctly match the kernel's
structs. This shaves off the (void*) casts and uses struct file*
instead of struct inode*. With the correct signature, control flow
integrity checkers are no longer confused at this point.

Signed-off-by: Markus Theil <markus.theil@secunet.com>
Tested-by: Michael Pfeiffer <michael.pfeiffer@tu-ilmenau.de>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>

kernel/linux/kni/kni_misc.c

@@ -485,10 +485,10 @@ kni_ioctl_release(struct net *net, uint32_t ioctl_num,
 	return ret;
 }
 
-static int
-kni_ioctl(struct inode *inode, uint32_t ioctl_num, unsigned long ioctl_param)
+static long
+kni_ioctl(struct file *file, unsigned int ioctl_num, unsigned long ioctl_param)
 {
-	int ret = -EINVAL;
+	long ret = -EINVAL;
 	struct net *net = current->nsproxy->net_ns;
 
 	pr_debug("IOCTL num=0x%0x param=0x%0lx\n", ioctl_num, ioctl_param);
@@ -514,8 +514,8 @@ kni_ioctl(struct inode *inode, uint32_t ioctl_num, unsigned long ioctl_param)
 	return ret;
 }
 
-static int
-kni_compat_ioctl(struct inode *inode, uint32_t ioctl_num,
+static long
+kni_compat_ioctl(struct file *file, unsigned int ioctl_num,
 		unsigned long ioctl_param)
 {
 	/* 32 bits app on 64 bits OS to be supported later */
@@ -528,8 +528,8 @@ static const struct file_operations kni_fops = {
 	.owner = THIS_MODULE,
 	.open = kni_open,
 	.release = kni_release,
-	.unlocked_ioctl = (void *)kni_ioctl,
-	.compat_ioctl = (void *)kni_compat_ioctl,
+	.unlocked_ioctl = kni_ioctl,
+	.compat_ioctl = kni_compat_ioctl,
 };
 
 static struct miscdevice kni_misc = {