[B.A.T.M.A.N.] Staging: batman-adv for 2.6.37 (2)

[B.A.T.M.A.N.] Staging: batman-adv for 2.6.37 (2)

[Sven Eckelmann]

Hi,

here are some smaller cleanup/bugfix patches for 2.6.37. All patches needed for
that patchset are already part of your staging-next tree.

All patches are cleanup patches and no new feature is added.

thanks,
	Sven

Linus Lüssing (1):
      Staging: batman-adv: Always synchronize rcu's on module shutdown

Marek Lindner (1):
      Staging: batman-adv: removing redundant assignment of skb->dev

Sven Eckelmann (2):
      Staging: batman-adv: Remove currently unused gw_* datastructures
      Staging: batman-adv: Add rcu TODO

Vasiliy Kulikov (1):
      Staging: batman-adv: check kmalloc() return value

 drivers/staging/batman-adv/TODO             |    5 +++++
 drivers/staging/batman-adv/main.c           |    7 ++-----
 drivers/staging/batman-adv/routing.c        |    8 ++++++--
 drivers/staging/batman-adv/soft-interface.c |    5 +----
 drivers/staging/batman-adv/types.h          |    3 ---
 drivers/staging/batman-adv/unicast.c        |    8 ++++++--
 drivers/staging/batman-adv/unicast.h        |    2 +-
 7 files changed, 21 insertions(+), 17 deletions(-)

[B.A.T.M.A.N.] [PATCH 1/5] Staging: batman-adv: Always synchronize rcu's on module shutdown

[Sven Eckelmann]

From: Linus Lüssing <linus.luessing@web.de>

During the module shutdown procedure in batman_exit(), a rcu callback is
being scheduled (batman_exit -> hardif_remove_interfaces ->
hardif_remove_interfae -> call_rcu). However, when the kernel unloads
the module, the rcu callback might not have been executed yet, resulting
in a "unable to handle kernel paging request" in __rcu_process_callback
afterwards, causing the kernel to freeze.

The synchronize_net and synchronize_rcu in mesh_free are currently
called before the call_rcu in hardif_remove_interface and have no real
effect on it.

Therefore, we should always flush all rcu callback functions scheduled
during the shutdown procedure using synchronize_net. The call to
synchronize_rcu can be omitted because synchronize_net already calls it.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 drivers/staging/batman-adv/main.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/batman-adv/main.c b/drivers/staging/batman-adv/main.c
index 498861f..b3e23e1 100644
--- a/drivers/staging/batman-adv/main.c
+++ b/drivers/staging/batman-adv/main.c
@@ -71,6 +71,8 @@ static void __exit batman_exit(void)
 	flush_workqueue(bat_event_workqueue);
 	destroy_workqueue(bat_event_workqueue);
 	bat_event_workqueue = NULL;
+
+	synchronize_net();
 }
 
 int mesh_init(struct net_device *soft_iface)
@@ -132,9 +134,6 @@ void mesh_free(struct net_device *soft_iface)
 	hna_local_free(bat_priv);
 	hna_global_free(bat_priv);
 
-	synchronize_net();
-
-	synchronize_rcu();
 	atomic_set(&bat_priv->mesh_state, MESH_INACTIVE);
 }
 
-- 
1.7.2.3

[B.A.T.M.A.N.] [PATCH 2/5] Staging: batman-adv: Remove currently unused gw_* datastructures

[Sven Eckelmann]

gw_list_lock, gw_list and curr_gw are currently unused members of struct
bat_priv. They will be readded when gateway support is really
implemented.

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 drivers/staging/batman-adv/main.c  |    2 --
 drivers/staging/batman-adv/types.h |    3 ---
 2 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/batman-adv/main.c b/drivers/staging/batman-adv/main.c
index b3e23e1..78ceebf 100644
--- a/drivers/staging/batman-adv/main.c
+++ b/drivers/staging/batman-adv/main.c
@@ -84,13 +84,11 @@ int mesh_init(struct net_device *soft_iface)
 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
 	spin_lock_init(&bat_priv->hna_lhash_lock);
 	spin_lock_init(&bat_priv->hna_ghash_lock);
-	spin_lock_init(&bat_priv->gw_list_lock);
 	spin_lock_init(&bat_priv->vis_hash_lock);
 	spin_lock_init(&bat_priv->vis_list_lock);
 
 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
-	INIT_HLIST_HEAD(&bat_priv->gw_list);
 
 	if (originator_init(bat_priv) < 1)
 		goto err;
diff --git a/drivers/staging/batman-adv/types.h b/drivers/staging/batman-adv/types.h
index e779c4a..9d744d8 100644
--- a/drivers/staging/batman-adv/types.h
+++ b/drivers/staging/batman-adv/types.h
@@ -128,7 +128,6 @@ struct bat_priv {
 	struct dentry *debug_dir;
 	struct hlist_head forw_bat_list;
 	struct hlist_head forw_bcast_list;
-	struct hlist_head gw_list;
 	struct list_head vis_send_list;
 	struct hashtable_t *orig_hash;
 	struct hashtable_t *hna_local_hash;
@@ -139,7 +138,6 @@ struct bat_priv {
 	spinlock_t forw_bcast_list_lock;
 	spinlock_t hna_lhash_lock;
 	spinlock_t hna_ghash_lock;
-	spinlock_t gw_list_lock;
 	spinlock_t vis_hash_lock;
 	spinlock_t vis_list_lock;
 	int16_t num_local_hna;
@@ -147,7 +145,6 @@ struct bat_priv {
 	struct delayed_work hna_work;
 	struct delayed_work orig_work;
 	struct delayed_work vis_work;
-	struct gw_node *curr_gw;
 	struct vis_info *my_vis_info;
 };
 
-- 
1.7.2.3

[B.A.T.M.A.N.] [PATCH 3/5] Staging: batman-adv: Add rcu TODO

[Sven Eckelmann]

Paul E. McKenney informed us that rcu is misused by leaking pointers to
rcu related elements outside read-side protected critical sections.

He also recommended that it should be checked against the rcu checklist.

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 drivers/staging/batman-adv/TODO |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/batman-adv/TODO b/drivers/staging/batman-adv/TODO
index 1457c7f..3af8028 100644
--- a/drivers/staging/batman-adv/TODO
+++ b/drivers/staging/batman-adv/TODO
@@ -1,3 +1,8 @@
+ * Rework usage of RCU
+    - don't leak pointers from rcu out of rcu critical area which may
+      get freed
+    - check were synchronize_rcu must be used
+    - go through Documentation/RCU/checklist.txt
  * Request a new review
  * Process the comments from the review
  * Move into mainline proper
-- 
1.7.2.3

[B.A.T.M.A.N.] [PATCH 4/5] Staging: batman-adv: removing redundant assignment of skb->dev

[Sven Eckelmann]

From: Marek Lindner <lindner_marek@yahoo.de>

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 drivers/staging/batman-adv/soft-interface.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/batman-adv/soft-interface.c b/drivers/staging/batman-adv/soft-interface.c
index 8d14343..3904db9 100644
--- a/drivers/staging/batman-adv/soft-interface.c
+++ b/drivers/staging/batman-adv/soft-interface.c
@@ -201,7 +201,7 @@ void interface_rx(struct net_device *soft_iface,
 	skb_pull_rcsum(skb, hdr_size);
 /*	skb_set_mac_header(skb, -sizeof(struct ethhdr));*/
 
-	skb->dev = soft_iface;
+	/* skb->dev & skb->pkt_type are set here */
 	skb->protocol = eth_type_trans(skb, soft_iface);
 
 	/* should not be neccesary anymore as we use skb_pull_rcsum()
@@ -210,9 +210,6 @@ void interface_rx(struct net_device *soft_iface,
 
 /*	skb->ip_summed = CHECKSUM_UNNECESSARY;*/
 
-	/* TODO: set skb->pkt_type to PACKET_BROADCAST, PACKET_MULTICAST,
-	 * PACKET_OTHERHOST or PACKET_HOST */
-
 	priv->stats.rx_packets++;
 	priv->stats.rx_bytes += skb->len + sizeof(struct ethhdr);
 
-- 
1.7.2.3

[B.A.T.M.A.N.] [PATCH 5/5] Staging: batman-adv: check kmalloc() return value

[Sven Eckelmann]

From: Vasiliy Kulikov <segooon@gmail.com>

kmalloc() may fail, if so drop current packet.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Removed new introduced deadlock]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 drivers/staging/batman-adv/routing.c |    8 ++++++--
 drivers/staging/batman-adv/unicast.c |    8 ++++++--
 drivers/staging/batman-adv/unicast.h |    2 +-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/batman-adv/routing.c b/drivers/staging/batman-adv/routing.c
index e12fd99..2cf8cf9 100644
--- a/drivers/staging/batman-adv/routing.c
+++ b/drivers/staging/batman-adv/routing.c
@@ -1232,8 +1232,12 @@ int recv_ucast_frag_packet(struct sk_buff *skb, struct batman_if *recv_if)
 
 		orig_node->last_frag_packet = jiffies;
 
-		if (list_empty(&orig_node->frag_list))
-			create_frag_buffer(&orig_node->frag_list);
+		if (list_empty(&orig_node->frag_list) &&
+			create_frag_buffer(&orig_node->frag_list)) {
+			spin_unlock_irqrestore(&bat_priv->orig_hash_lock,
+					       flags);
+			return NET_RX_DROP;
+		}
 
 		tmp_frag_entry =
 			search_frag_packet(&orig_node->frag_list,
diff --git a/drivers/staging/batman-adv/unicast.c b/drivers/staging/batman-adv/unicast.c
index f951abc..0dac50d 100644
--- a/drivers/staging/batman-adv/unicast.c
+++ b/drivers/staging/batman-adv/unicast.c
@@ -78,7 +78,7 @@ void create_frag_entry(struct list_head *head, struct sk_buff *skb)
 	return;
 }
 
-void create_frag_buffer(struct list_head *head)
+int create_frag_buffer(struct list_head *head)
 {
 	int i;
 	struct frag_packet_list_entry *tfp;
@@ -86,13 +86,17 @@ void create_frag_buffer(struct list_head *head)
 	for (i = 0; i < FRAG_BUFFER_SIZE; i++) {
 		tfp = kmalloc(sizeof(struct frag_packet_list_entry),
 			GFP_ATOMIC);
+		if (!tfp) {
+			frag_list_free(head);
+			return -ENOMEM;
+		}
 		tfp->skb = NULL;
 		tfp->seqno = 0;
 		INIT_LIST_HEAD(&tfp->list);
 		list_add(&tfp->list, head);
 	}
 
-	return;
+	return 0;
 }
 
 struct frag_packet_list_entry *search_frag_packet(struct list_head *head,
diff --git a/drivers/staging/batman-adv/unicast.h b/drivers/staging/batman-adv/unicast.h
index 1d5cbeb..7973697 100644
--- a/drivers/staging/batman-adv/unicast.h
+++ b/drivers/staging/batman-adv/unicast.h
@@ -30,7 +30,7 @@ struct sk_buff *merge_frag_packet(struct list_head *head,
 	struct sk_buff *skb);
 
 void create_frag_entry(struct list_head *head, struct sk_buff *skb);
-void create_frag_buffer(struct list_head *head);
+int create_frag_buffer(struct list_head *head);
 struct frag_packet_list_entry *search_frag_packet(struct list_head *head,
 	struct unicast_frag_packet *up);
 void frag_list_free(struct list_head *head);
-- 
1.7.2.3