hardif_list_lock is unneccessary because we already ensure that no
multiple admin operations can take place through rtnl_lock.
hardif_list_lock only adds additional overhead and complexity.
Critical functions now check whether they are called with rtnl_lock
using ASSERT_RTNL.
It indirectly fixes the problem that orig_hash_del_if() expects that
only one interface is deleted from hardif_list at a time, but
hardif_remove_interfaces() removes all at once and then calls
orig_hash_del_if().
Reported-by: Linus Lüssing <linus.luess...@web.de>
Signed-off-by: Sven Eckelmann <s...@narfation.org>
---
net/batman-adv/bat_sysfs.c | 2 ++
net/batman-adv/hard-interface.c | 30 +++++++-----------------------
net/batman-adv/main.c | 3 +++
net/batman-adv/soft-interface.c | 2 +-
4 files changed, 13 insertions(+), 24 deletions(-)
diff --git a/net/batman-adv/bat_sysfs.c b/net/batman-adv/bat_sysfs.c
index e449bf6..85ba20d 100644
--- a/net/batman-adv/bat_sysfs.c
+++ b/net/batman-adv/bat_sysfs.c
@@ -502,7 +502,9 @@ static ssize_t store_mesh_iface(struct kobject *kobj,
struct attribute *attr,
rtnl_unlock();
}
+ rtnl_lock();
ret = hardif_enable_interface(hard_iface, buff);
+ rtnl_unlock();
out:
hardif_free_ref(hard_iface);
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 3e888f1..7e2f772 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -31,9 +31,6 @@
#include <linux/if_arp.h>
-/* protect update critical side of hardif_list - but not the content */
-static DEFINE_SPINLOCK(hardif_list_lock);
-
static int batman_skb_recv(struct sk_buff *skb,
struct net_device *dev,
@@ -136,7 +133,7 @@ static void primary_if_select(struct bat_priv *bat_priv,
struct hard_iface *curr_hard_iface;
struct batman_packet *batman_packet;
- spin_lock_bh(&hardif_list_lock);
+ ASSERT_RTNL();
if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
new_hard_iface = NULL;
@@ -148,7 +145,7 @@ static void primary_if_select(struct bat_priv *bat_priv,
hardif_free_ref(curr_hard_iface);
if (!new_hard_iface)
- goto out;
+ return;
batman_packet = (struct batman_packet *)(new_hard_iface->packet_buff);
batman_packet->flags = PRIMARIES_FIRST_HOP;
@@ -161,9 +158,6 @@ static void primary_if_select(struct bat_priv *bat_priv,
* our new primary interface
*/
atomic_set(&bat_priv->hna_local_changed, 1);
-
-out:
- spin_unlock_bh(&hardif_list_lock);
}
static bool hardif_is_iface_up(struct hard_iface *hard_iface)
@@ -456,6 +450,8 @@ static struct hard_iface *hardif_add_interface(struct
net_device *net_dev)
struct hard_iface *hard_iface;
int ret;
+ ASSERT_RTNL();
+
ret = is_valid_iface(net_dev);
if (ret != 1)
goto out;
@@ -482,10 +478,7 @@ static struct hard_iface *hardif_add_interface(struct
net_device *net_dev)
atomic_set(&hard_iface->refcount, 2);
check_known_mac_addr(hard_iface->net_dev);
-
- spin_lock(&hardif_list_lock);
list_add_tail_rcu(&hard_iface->list, &hardif_list);
- spin_unlock(&hardif_list_lock);
return hard_iface;
@@ -499,6 +492,8 @@ out:
static void hardif_remove_interface(struct hard_iface *hard_iface)
{
+ ASSERT_RTNL();
+
/* first deactivate interface */
if (hard_iface->if_status != IF_NOT_IN_USE)
hardif_disable_interface(hard_iface);
@@ -514,20 +509,11 @@ static void hardif_remove_interface(struct hard_iface
*hard_iface)
void hardif_remove_interfaces(void)
{
struct hard_iface *hard_iface, *hard_iface_tmp;
- struct list_head if_queue;
- INIT_LIST_HEAD(&if_queue);
-
- spin_lock(&hardif_list_lock);
+ rtnl_lock();
list_for_each_entry_safe(hard_iface, hard_iface_tmp,
&hardif_list, list) {
list_del_rcu(&hard_iface->list);
- list_add_tail(&hard_iface->list, &if_queue);
- }
- spin_unlock(&hardif_list_lock);
-
- rtnl_lock();
- list_for_each_entry_safe(hard_iface, hard_iface_tmp, &if_queue, list) {
hardif_remove_interface(hard_iface);
}
rtnl_unlock();
@@ -556,9 +542,7 @@ static int hard_if_event(struct notifier_block *this,
hardif_deactivate_interface(hard_iface);
break;
case NETDEV_UNREGISTER:
- spin_lock(&hardif_list_lock);
list_del_rcu(&hard_iface->list);
- spin_unlock(&hardif_list_lock);
hardif_remove_interface(hard_iface);
break;
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 705e8be..7edf8d7 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -33,6 +33,9 @@
#include "vis.h"
#include "hash.h"
+
+/* List manipulations on hardif_list have to be rtnl_lock()'ed,
+ * list traversals just rcu-locked */
struct list_head hardif_list;
unsigned char broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 8cb13a0..9301e21 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -819,7 +819,7 @@ struct net_device *softif_create(char *name)
goto out;
}
- ret = register_netdev(soft_iface);
+ ret = register_netdevice(soft_iface);
if (ret < 0) {
pr_err("Unable to register the batman interface '%s': %i\n",
name, ret);
--
1.7.5.1
