Commit 4de211f1 authored by Jarek Poplawski's avatar Jarek Poplawski Committed by David S. Miller
Browse files

[AX25] ax25_route: make ax25_route_lock BH safe 



> =================================
> [ INFO: inconsistent lock state ]
> 2.6.24-dg8ngn-p02 #1
> ---------------------------------
> inconsistent {softirq-on-W} -> {in-softirq-R} usage.
> linuxnet/3046 [HC0[0]:SC1[2]:HE1:SE0] takes:
>  (ax25_route_lock){--.+}, at: [<f8a0cfb7>] ax25_get_route+0x18/0xb7 [ax25]
> {softirq-on-W} state was registered at:
...

This lockdep report shows that ax25_route_lock is taken for reading in
softirq context, and for writing in process context with BHs enabled.
So, to make this safe, all write_locks in ax25_route.c are changed to
_bh versions.

Reported-by: default avatarJann Traschewski <jann@gmx.de&gt;,>
Signed-off-by: default avatarJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1105b5d1

net/ax25/ax25_route.c

+14 −14
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ void ax25_rt_device_down(struct net_device *dev) 
{

	ax25_route *s, *t, *ax25_rt;



	write_lock(&ax25_route_lock);

	write_lock_bh(&ax25_route_lock);

	ax25_rt = ax25_route_list;

	while (ax25_rt != NULL) {

		s       = ax25_rt;
@@ -68,7 +68,7 @@ void ax25_rt_device_down(struct net_device *dev) 
			}

		}

	}

	write_unlock(&ax25_route_lock);

	write_unlock_bh(&ax25_route_lock);

}



static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
@@ -82,7 +82,7 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
	if (route->digi_count > AX25_MAX_DIGIS)

		return -EINVAL;



	write_lock(&ax25_route_lock);

	write_lock_bh(&ax25_route_lock);



	ax25_rt = ax25_route_list;

	while (ax25_rt != NULL) {
@@ -92,7 +92,7 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
			ax25_rt->digipeat = NULL;

			if (route->digi_count != 0) {

				if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {

					write_unlock(&ax25_route_lock);

					write_unlock_bh(&ax25_route_lock);

					return -ENOMEM;

				}

				ax25_rt->digipeat->lastrepeat = -1;
@@ -102,14 +102,14 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
					ax25_rt->digipeat->calls[i]    = route->digi_addr[i];

				}

			}

			write_unlock(&ax25_route_lock);

			write_unlock_bh(&ax25_route_lock);

			return 0;

		}

		ax25_rt = ax25_rt->next;

	}



	if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {

		write_unlock(&ax25_route_lock);

		write_unlock_bh(&ax25_route_lock);

		return -ENOMEM;

	}
@@ -120,7 +120,7 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
	ax25_rt->ip_mode      = ' ';

	if (route->digi_count != 0) {

		if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {

			write_unlock(&ax25_route_lock);

			write_unlock_bh(&ax25_route_lock);

			kfree(ax25_rt);

			return -ENOMEM;

		}
@@ -133,7 +133,7 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
	}

	ax25_rt->next   = ax25_route_list;

	ax25_route_list = ax25_rt;

	write_unlock(&ax25_route_lock);

	write_unlock_bh(&ax25_route_lock);



	return 0;

}
@@ -152,7 +152,7 @@ static int ax25_rt_del(struct ax25_routes_struct *route) 
	if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)

		return -EINVAL;



	write_lock(&ax25_route_lock);

	write_lock_bh(&ax25_route_lock);



	ax25_rt = ax25_route_list;

	while (ax25_rt != NULL) {
@@ -174,7 +174,7 @@ static int ax25_rt_del(struct ax25_routes_struct *route) 
			}

		}

	}

	write_unlock(&ax25_route_lock);

	write_unlock_bh(&ax25_route_lock);



	return 0;

}
@@ -188,7 +188,7 @@ static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 
	if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)

		return -EINVAL;



	write_lock(&ax25_route_lock);

	write_lock_bh(&ax25_route_lock);



	ax25_rt = ax25_route_list;

	while (ax25_rt != NULL) {
@@ -216,7 +216,7 @@ static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 
	}



out:

	write_unlock(&ax25_route_lock);

	write_unlock_bh(&ax25_route_lock);

	return err;

}
@@ -492,7 +492,7 @@ void __exit ax25_rt_free(void) 
{

	ax25_route *s, *ax25_rt = ax25_route_list;



	write_lock(&ax25_route_lock);

	write_lock_bh(&ax25_route_lock);

	while (ax25_rt != NULL) {

		s       = ax25_rt;

		ax25_rt = ax25_rt->next;
@@ -500,5 +500,5 @@ void __exit ax25_rt_free(void) 
		kfree(s->digipeat);

		kfree(s);

	}

	write_unlock(&ax25_route_lock);

	write_unlock_bh(&ax25_route_lock);

}

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