* [B.A.T.M.A.N.] [RFC] batman-adv: Set special lockdep classes to avoid lockdep warning
@ 2012-08-19 7:29 Sven Eckelmann
2012-08-19 7:57 ` Simon Wunderlich
2012-08-19 23:22 ` [B.A.T.M.A.N.] [PATCH] " Sven Eckelmann
0 siblings, 2 replies; 6+ messages in thread
From: Sven Eckelmann @ 2012-08-19 7:29 UTC (permalink / raw)
To: b.a.t.m.a.n
[text will be added after I am awake... maybe]
[Should be fix the problem found in bug 162... formerly known as 161. code
stolen from macvlan... this is just a reimplementation of a solution proposed
by Simon Wunderlich]
Reported-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
soft-interface.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/soft-interface.c b/soft-interface.c
index 1aee7db..588c6f6 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -344,7 +344,36 @@ out:
return;
}
+/*
+ * batman-adv network devices have devices nesting below it and are a special
+ * "super class" of normal network devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key batadv_netdev_xmit_lock_key;
+static struct lock_class_key batadv_netdev_addr_lock_key;
+
+static void batadv_set_lockdep_class_one(struct net_device *dev,
+ struct netdev_queue *txq,
+ void *_unused)
+{
+ lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
+}
+
+static void batadv_set_lockdep_class(struct net_device *dev)
+{
+ lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
+ netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
+}
+
+static int batadv_softif_init(struct net_device *dev)
+{
+ batadv_set_lockdep_class(dev);
+
+ return 0;
+}
+
static const struct net_device_ops batadv_netdev_ops = {
+ .ndo_init = batadv_softif_init,
.ndo_open = batadv_interface_open,
.ndo_stop = batadv_interface_release,
.ndo_get_stats = batadv_interface_stats,
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [B.A.T.M.A.N.] [RFC] batman-adv: Set special lockdep classes to avoid lockdep warning
2012-08-19 7:29 [B.A.T.M.A.N.] [RFC] batman-adv: Set special lockdep classes to avoid lockdep warning Sven Eckelmann
@ 2012-08-19 7:57 ` Simon Wunderlich
2012-08-19 23:22 ` [B.A.T.M.A.N.] [PATCH] " Sven Eckelmann
1 sibling, 0 replies; 6+ messages in thread
From: Simon Wunderlich @ 2012-08-19 7:57 UTC (permalink / raw)
To: The list for a Better Approach To Mobile Ad-hoc Networking
[-- Attachment #1: Type: text/plain, Size: 2117 bytes --]
Hey Sven,
it works in my QEMU machines (and I could reproduce the bug report from 162).
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
(provided you add some sane commit message. ;] )
Cheers,
Simon
On Sun, Aug 19, 2012 at 09:29:53AM +0200, Sven Eckelmann wrote:
> [text will be added after I am awake... maybe]
>
> [Should be fix the problem found in bug 162... formerly known as 161. code
> stolen from macvlan... this is just a reimplementation of a solution proposed
> by Simon Wunderlich]
>
> Reported-by: Linus Lüssing <linus.luessing@web.de>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> soft-interface.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/soft-interface.c b/soft-interface.c
> index 1aee7db..588c6f6 100644
> --- a/soft-interface.c
> +++ b/soft-interface.c
> @@ -344,7 +344,36 @@ out:
> return;
> }
>
> +/*
> + * batman-adv network devices have devices nesting below it and are a special
> + * "super class" of normal network devices; split their locks off into a
> + * separate class since they always nest.
> + */
> +static struct lock_class_key batadv_netdev_xmit_lock_key;
> +static struct lock_class_key batadv_netdev_addr_lock_key;
> +
> +static void batadv_set_lockdep_class_one(struct net_device *dev,
> + struct netdev_queue *txq,
> + void *_unused)
> +{
> + lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
> +}
> +
> +static void batadv_set_lockdep_class(struct net_device *dev)
> +{
> + lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
> + netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
> +}
> +
> +static int batadv_softif_init(struct net_device *dev)
> +{
> + batadv_set_lockdep_class(dev);
> +
> + return 0;
> +}
> +
> static const struct net_device_ops batadv_netdev_ops = {
> + .ndo_init = batadv_softif_init,
> .ndo_open = batadv_interface_open,
> .ndo_stop = batadv_interface_release,
> .ndo_get_stats = batadv_interface_stats,
> --
> 1.7.10.4
>
>
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^ permalink raw reply [flat|nested] 6+ messages in thread
* [B.A.T.M.A.N.] [PATCH] batman-adv: Set special lockdep classes to avoid lockdep warning
2012-08-19 7:29 [B.A.T.M.A.N.] [RFC] batman-adv: Set special lockdep classes to avoid lockdep warning Sven Eckelmann
2012-08-19 7:57 ` Simon Wunderlich
@ 2012-08-19 23:22 ` Sven Eckelmann
2012-08-20 7:00 ` Sven Eckelmann
2012-08-20 7:03 ` [B.A.T.M.A.N.] [PATCHv2] " Sven Eckelmann
1 sibling, 2 replies; 6+ messages in thread
From: Sven Eckelmann @ 2012-08-19 23:22 UTC (permalink / raw)
To: b.a.t.m.a.n
Transmissions over batman-adv devices always start another nested transmission
over devices attached to the batman-adv interface. These devices usually use
the ethernet lockdep class for the tx_queue lock which is also set by default
for all batman-adv devices. Lockdep will detect a nested locking attempt of two
locks with the same class and warn about a possible deadlock.
This is the default and expected behavior and should not alarm the locking
correctness prove mechanism. Therefore, the locks for all netdevice specific
lock get a special batman-adv lock class to avoid a false positive for each
transmission.
Reported-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
soft-interface.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/soft-interface.c b/soft-interface.c
index 1aee7db..513d50a 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -354,6 +354,27 @@ static const struct net_device_ops batadv_netdev_ops = {
.ndo_validate_addr = eth_validate_addr
};
+/*
+ * batman-adv network devices have devices nesting below it and are a special
+ * "super class" of normal network devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key batadv_netdev_xmit_lock_key;
+static struct lock_class_key batadv_netdev_addr_lock_key;
+
+static void batadv_set_lockdep_class_one(struct net_device *dev,
+ struct netdev_queue *txq,
+ void *_unused)
+{
+ lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
+}
+
+static void batadv_set_lockdep_class(struct net_device *dev)
+{
+ lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
+ netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
+}
+
static void batadv_interface_setup(struct net_device *dev)
{
struct batadv_priv *priv = netdev_priv(dev);
@@ -363,6 +384,7 @@ static void batadv_interface_setup(struct net_device *dev)
dev->netdev_ops = &batadv_netdev_ops;
dev->destructor = free_netdev;
dev->tx_queue_len = 0;
+ batadv_set_lockdep_class(dev);
/* can't call min_mtu, because the needed variables
* have not been initialized yet
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCH] batman-adv: Set special lockdep classes to avoid lockdep warning
2012-08-19 23:22 ` [B.A.T.M.A.N.] [PATCH] " Sven Eckelmann
@ 2012-08-20 7:00 ` Sven Eckelmann
2012-08-20 7:03 ` [B.A.T.M.A.N.] [PATCHv2] " Sven Eckelmann
1 sibling, 0 replies; 6+ messages in thread
From: Sven Eckelmann @ 2012-08-20 7:00 UTC (permalink / raw)
To: b.a.t.m.a.n
[-- Attachment #1: Type: text/plain, Size: 199 bytes --]
On Monday 20 August 2012 01:22:39 Sven Eckelmann wrote:
> lock get a special batman-adv lock class to avoid a false positive for each
The first "lock" should have been "queues"
Kind regards,
Sven
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^ permalink raw reply [flat|nested] 6+ messages in thread
* [B.A.T.M.A.N.] [PATCHv2] batman-adv: Set special lockdep classes to avoid lockdep warning
2012-08-19 23:22 ` [B.A.T.M.A.N.] [PATCH] " Sven Eckelmann
2012-08-20 7:00 ` Sven Eckelmann
@ 2012-08-20 7:03 ` Sven Eckelmann
2012-08-24 21:42 ` Marek Lindner
1 sibling, 1 reply; 6+ messages in thread
From: Sven Eckelmann @ 2012-08-20 7:03 UTC (permalink / raw)
To: b.a.t.m.a.n
Transmissions over batman-adv devices always start another nested transmission
over devices attached to the batman-adv interface. These devices usually use
the ethernet lockdep class for the tx_queue lock which is also set by default
for all batman-adv devices. Lockdep will detect a nested locking attempt of two
locks with the same class and warn about a possible deadlock.
This is the default and expected behavior and should not alarm the locking
correctness prove mechanism. Therefore, the locks for all netdevice specific tx
queues get a special batman-adv lock class to avoid a false positive for each
transmission.
Reported-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
* fixed comment style
* fixed commit message
soft-interface.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/soft-interface.c b/soft-interface.c
index 1aee7db..909ab54 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -354,6 +354,26 @@ static const struct net_device_ops batadv_netdev_ops = {
.ndo_validate_addr = eth_validate_addr
};
+/* batman-adv network devices have devices nesting below it and are a special
+ * "super class" of normal network devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key batadv_netdev_xmit_lock_key;
+static struct lock_class_key batadv_netdev_addr_lock_key;
+
+static void batadv_set_lockdep_class_one(struct net_device *dev,
+ struct netdev_queue *txq,
+ void *_unused)
+{
+ lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
+}
+
+static void batadv_set_lockdep_class(struct net_device *dev)
+{
+ lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
+ netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
+}
+
static void batadv_interface_setup(struct net_device *dev)
{
struct batadv_priv *priv = netdev_priv(dev);
@@ -363,6 +383,7 @@ static void batadv_interface_setup(struct net_device *dev)
dev->netdev_ops = &batadv_netdev_ops;
dev->destructor = free_netdev;
dev->tx_queue_len = 0;
+ batadv_set_lockdep_class(dev);
/* can't call min_mtu, because the needed variables
* have not been initialized yet
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCHv2] batman-adv: Set special lockdep classes to avoid lockdep warning
2012-08-20 7:03 ` [B.A.T.M.A.N.] [PATCHv2] " Sven Eckelmann
@ 2012-08-24 21:42 ` Marek Lindner
0 siblings, 0 replies; 6+ messages in thread
From: Marek Lindner @ 2012-08-24 21:42 UTC (permalink / raw)
To: b.a.t.m.a.n
On Monday, August 20, 2012 09:03:59 Sven Eckelmann wrote:
> Transmissions over batman-adv devices always start another nested
> transmission over devices attached to the batman-adv interface. These
> devices usually use the ethernet lockdep class for the tx_queue lock which
> is also set by default for all batman-adv devices. Lockdep will detect a
> nested locking attempt of two locks with the same class and warn about a
> possible deadlock.
>
> This is the default and expected behavior and should not alarm the locking
> correctness prove mechanism. Therefore, the locks for all netdevice
> specific tx queues get a special batman-adv lock class to avoid a false
> positive for each transmission.
>
> Reported-by: Linus Lüssing <linus.luessing@web.de>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> * fixed comment style
> * fixed commit message
>
> soft-interface.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
Applied in revision e27bb6f.
Thanks,
Marek
^ permalink raw reply [flat|nested] 6+ messages in thread
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2012-08-19 7:29 [B.A.T.M.A.N.] [RFC] batman-adv: Set special lockdep classes to avoid lockdep warning Sven Eckelmann
2012-08-19 7:57 ` Simon Wunderlich
2012-08-19 23:22 ` [B.A.T.M.A.N.] [PATCH] " Sven Eckelmann
2012-08-20 7:00 ` Sven Eckelmann
2012-08-20 7:03 ` [B.A.T.M.A.N.] [PATCHv2] " Sven Eckelmann
2012-08-24 21:42 ` Marek Lindner
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