Redo locking of ax25_list with spinlocks.

include/net/ax25.h

@@ -3,11 +3,12 @@
  *
  *	Alan Cox (GW4PTS) 	10/11/93
  */
- 
 #ifndef _AX25_H
 #define _AX25_H 
+
 #include <linux/config.h>
 #include <linux/ax25.h>
+#include <linux/spinlock.h>
 
 #define	AX25_T1CLAMPLO  		1
 #define	AX25_T1CLAMPHI 			(30 * HZ)
@@ -197,7 +198,8 @@ typedef struct ax25_cb {
 #define ax25_sk(__sk) ((ax25_cb *)(__sk)->protinfo)
 
 /* af_ax25.c */
-extern ax25_cb *volatile ax25_list;
+extern ax25_cb *ax25_list;
+extern spinlock_t ax25_list_lock;
 extern void ax25_free_cb(ax25_cb *);
 extern void ax25_insert_socket(ax25_cb *);
 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);

net/ax25/af_ax25.c

@@ -134,13 +134,15 @@
 #include <linux/netfilter.h>
 #include <linux/sysctl.h>
 #include <linux/init.h>
+#include <linux/spinlock.h>
 #include <net/tcp.h>
 #include <net/ip.h>
 #include <net/arp.h>
 
 
 
-ax25_cb *volatile ax25_list;
+ax25_cb *ax25_list;
+spinlock_t ax25_list_lock = SPIN_LOCK_UNLOCKED;
 
 static struct proto_ops ax25_proto_ops;
 
@@ -173,25 +175,25 @@ static void ax25_remove_socket(ax25_cb *ax25)
 	ax25_cb *s;
 	unsigned long flags;
 
-	save_flags(flags); cli();
+	spin_lock_irqsave(&ax25_list_lock, flags);
 
 	if ((s = ax25_list) == ax25) {
 		ax25_list = s->next;
-		restore_flags(flags);
+		spin_unlock_irqrestore(&ax25_list_lock, flags);
 		return;
 	}
 
 	while (s != NULL && s->next != NULL) {
 		if (s->next == ax25) {
 			s->next = ax25->next;
-			restore_flags(flags);
+			spin_unlock_irqrestore(&ax25_list_lock, flags);
 			return;
 		}
 
 		s = s->next;
 	}
 
-	restore_flags(flags);
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 }
 
 /*
@@ -199,18 +201,21 @@ static void ax25_remove_socket(ax25_cb *ax25)
  */
 static void ax25_kill_by_device(struct net_device *dev)
 {
+	unsigned long flags;
 	ax25_dev *ax25_dev;
 	ax25_cb *s;
 
 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 		return;
 
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (s = ax25_list; s != NULL; s = s->next) {
 		if (s->ax25_dev == ax25_dev) {
 			s->ax25_dev = NULL;
 			ax25_disconnect(s, ENETUNREACH);
 		}
 	}
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 }
 
 /*
@@ -247,13 +252,10 @@ void ax25_insert_socket(ax25_cb *ax25)
 {
 	unsigned long flags;
 
-	save_flags(flags);
-	cli();
-
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	ax25->next = ax25_list;
 	ax25_list  = ax25;
-
-	restore_flags(flags);
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 }
 
 /*
@@ -265,22 +267,21 @@ struct sock *ax25_find_listener(ax25_address *addr, int digi, struct net_device
 	unsigned long flags;
 	ax25_cb *s;
 
-	save_flags(flags);
-	cli();
-
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (s = ax25_list; s != NULL; s = s->next) {
 		if ((s->iamdigi && !digi) || (!s->iamdigi && digi))
 			continue;
 		if (s->sk != NULL && ax25cmp(&s->source_addr, addr) == 0 && s->sk->type == type && s->sk->state == TCP_LISTEN) {
 			/* If device is null we match any device */
 			if (s->ax25_dev == NULL || s->ax25_dev->dev == dev) {
-				restore_flags(flags);
+				spin_unlock_irqrestore(&ax25_list_lock, flags);
+
 				return s->sk;
 			}
 		}
 	}
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
-	restore_flags(flags);
 	return NULL;
 }
 
@@ -292,17 +293,15 @@ struct sock *ax25_find_socket(ax25_address *my_addr, ax25_address *dest_addr, in
 	ax25_cb *s;
 	unsigned long flags;
 
-	save_flags(flags);
-	cli();
-
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (s = ax25_list; s != NULL; s = s->next) {
 		if (s->sk != NULL && ax25cmp(&s->source_addr, my_addr) == 0 && ax25cmp(&s->dest_addr, dest_addr) == 0 && s->sk->type == type) {
-			restore_flags(flags);
+			spin_unlock_irqrestore(&ax25_list_lock, flags);
+
 			return s->sk;
 		}
 	}
-
-	restore_flags(flags);
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
 	return NULL;
 }
@@ -316,9 +315,7 @@ ax25_cb *ax25_find_cb(ax25_address *src_addr, ax25_address *dest_addr, ax25_digi
 	ax25_cb *s;
 	unsigned long flags;
 
-	save_flags(flags);
-	cli();
-
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (s = ax25_list; s != NULL; s = s->next) {
 		if (s->sk != NULL && s->sk->type != SOCK_SEQPACKET)
 			continue;
@@ -334,12 +331,12 @@ ax25_cb *ax25_find_cb(ax25_address *src_addr, ax25_address *dest_addr, ax25_digi
 				if (s->digipeat != NULL && s->digipeat->ndigi != 0)
 					continue;
 			}
-			restore_flags(flags);
+			spin_unlock_irqrestore(&ax25_list_lock, flags);
+
 			return s;
 		}
 	}
-
-	restore_flags(flags);
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
 	return NULL;
 }
@@ -352,17 +349,14 @@ struct sock *ax25_addr_match(ax25_address *addr)
 	unsigned long flags;
 	ax25_cb *s;
 
-	save_flags(flags);
-	cli();
-
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (s = ax25_list; s != NULL; s = s->next) {
 		if (s->sk != NULL && ax25cmp(&s->source_addr, addr) == 0 && s->sk->type == SOCK_RAW) {
-			restore_flags(flags);
+			spin_unlock_irqrestore(&ax25_list_lock, flags);
 			return s->sk;
 		}
 	}
-
-	restore_flags(flags);
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
 	return NULL;
 }
@@ -1738,13 +1732,14 @@ static int ax25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 
 static int ax25_get_info(char *buffer, char **start, off_t offset, int length)
 {
+	unsigned long flags;
 	ax25_cb *ax25;
 	int k;
 	int len = 0;
 	off_t pos = 0;
 	off_t begin = 0;
 
-	cli();
+	spin_lock_irqsave(&ax25_list_lock, flags);
 
 	/*
 	 * New format:
@@ -1799,7 +1794,7 @@ static int ax25_get_info(char *buffer, char **start, off_t offset, int length)
 			break;
 	}
 
-	sti();
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
 	*start = buffer + (offset - begin);
 	len   -= (offset - begin);

net/ax25/ax25_ds_subr.c

@@ -31,6 +31,7 @@
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/sockios.h>
+#include <linux/spinlock.h>
 #include <linux/net.h>
 #include <net/ax25.h>
 #include <linux/inet.h>
@@ -53,6 +54,7 @@ void ax25_ds_nr_error_recovery(ax25_cb *ax25)
  */
 void ax25_ds_enquiry_response(ax25_cb *ax25)
 {
+	unsigned long flags;
 	ax25_cb *ax25o;
 
 	/* Please note that neither DK4EGs nor DG2FEFs
@@ -93,6 +95,7 @@ void ax25_ds_enquiry_response(ax25_cb *ax25)
 	ax25_start_t3timer(ax25);
 	ax25_ds_set_timer(ax25->ax25_dev);
 
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (ax25o = ax25_list; ax25o != NULL; ax25o = ax25o->next) {
 		if (ax25o == ax25)
 			continue;
@@ -118,6 +121,7 @@ void ax25_ds_enquiry_response(ax25_cb *ax25)
 		if (ax25o->state != AX25_STATE_0)
 			ax25_start_t3timer(ax25o);
 	}
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 }
 
 void ax25_ds_establish_data_link(ax25_cb *ax25)
@@ -170,13 +174,19 @@ static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char p
  */
 static int ax25_check_dama_slave(ax25_dev *ax25_dev)
 {
+	unsigned long flags;
 	ax25_cb *ax25;
+	int res = 0;
 
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (ax25 = ax25_list; ax25 != NULL ; ax25 = ax25->next)
-		if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1)
-			return 1;
+		if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
+			res = 1;
+			break;
+		}
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 
-	return 0;
+	return res;
 }
 
 void ax25_dev_dama_on(ax25_dev *ax25_dev)

net/ax25/ax25_ds_timer.c

@@ -18,6 +18,7 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/socket.h>
+#include <linux/spinlock.h>
 #include <linux/in.h>
 #include <linux/kernel.h>
 #include <linux/jiffies.h>
@@ -79,6 +80,7 @@ void ax25_ds_set_timer(ax25_dev *ax25_dev)
 static void ax25_ds_timeout(unsigned long arg)
 {
 	ax25_dev *ax25_dev = (struct ax25_dev *) arg;
+	unsigned long flags;
 	ax25_cb *ax25;
 	
 	if (ax25_dev == NULL || !ax25_dev->dama.slave)
@@ -89,6 +91,7 @@ static void ax25_ds_timeout(unsigned long arg)
 		return;
 	}
 	
+	spin_lock_irqsave(&ax25_list_lock, flags);
 	for (ax25=ax25_list; ax25 != NULL; ax25 = ax25->next) {
 		if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
 			continue;
@@ -96,6 +99,7 @@ static void ax25_ds_timeout(unsigned long arg)
 		ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 		ax25_disconnect(ax25, ETIMEDOUT);
 	}
+	spin_unlock_irqrestore(&ax25_list_lock, flags);
 	
 	ax25_dev_dama_off(ax25_dev);
 }