[ATM]: Cleanup pppoatm_ioctl_hook.

net/atm/common.c

@@ -129,8 +129,19 @@ EXPORT_SYMBOL(atm_clip_ops_set);
 #endif
 
 #if defined(CONFIG_PPPOATM) || defined(CONFIG_PPPOATM_MODULE)
-int (*pppoatm_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
-EXPORT_SYMBOL(pppoatm_ioctl_hook);
+static DECLARE_MUTEX(pppoatm_ioctl_mutex);
+
+static int (*pppoatm_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
+
+void pppoatm_ioctl_set(int (*hook)(struct atm_vcc *, unsigned int, unsigned long))
+{
+	down(&pppoatm_ioctl_mutex);
+	pppoatm_ioctl_hook = hook;
+	up(&pppoatm_ioctl_mutex);
+}
+#ifdef CONFIG_PPPOATM_MODULE
+EXPORT_SYMBOL(pppoatm_ioctl_set);
+#endif
 #endif
 
 #if defined(CONFIG_ATM_BR2684) || defined(CONFIG_ATM_BR2684_MODULE)
@@ -859,12 +870,14 @@ int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 		default:
 			break;
 	}
+	error = -ENOIOCTLCMD;
 #if defined(CONFIG_PPPOATM) || defined(CONFIG_PPPOATM_MODULE)
-	if (pppoatm_ioctl_hook) {
+	down(&pppoatm_ioctl_mutex);
+	if (pppoatm_ioctl_hook)
 		error = pppoatm_ioctl_hook(vcc, cmd, arg);
+	up(&pppoatm_ioctl_mutex);
 	if (error != -ENOIOCTLCMD)
 		goto done;
-	}
 #endif
 #if defined(CONFIG_ATM_BR2684) || defined(CONFIG_ATM_BR2684_MODULE)
 	if (br2684_ioctl_hook) {

net/atm/common.h

@@ -26,6 +26,8 @@ int vcc_getsockopt(struct socket *sock, int level, int optname, char *optval,
 
 void atm_shutdown_dev(struct atm_dev *dev);
 
+void pppoatm_ioctl_set(int (*hook)(struct atm_vcc *, unsigned int, unsigned long));
+
 int atmpvc_init(void);
 void atmpvc_exit(void);
 int atmsvc_init(void);

net/atm/pppoatm.c

@@ -44,6 +44,8 @@
 #include <linux/ppp_channel.h>
 #include <linux/atmppp.h>
 
+#include "common.h"
+
 #if 0
 #define DPRINTK(format, args...) \
 	printk(KERN_DEBUG "pppoatm: " format, ##args)
@@ -344,17 +346,15 @@ static int pppoatm_ioctl(struct atm_vcc *atmvcc, unsigned int cmd,
 /* the following avoids some spurious warnings from the compiler */
 #define UNUSED __attribute__((unused))
 
-extern int (*pppoatm_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
-
 static int __init UNUSED pppoatm_init(void)
 {
-	pppoatm_ioctl_hook = pppoatm_ioctl;
+	pppoatm_ioctl_set(pppoatm_ioctl);
 	return 0;
 }
 
 static void __exit UNUSED pppoatm_exit(void)
 {
-	pppoatm_ioctl_hook = NULL;
+	pppoatm_ioctl_set(NULL);
 }
 
 module_init(pppoatm_init);