diff options
| author | Tejun Heo <tj@kernel.org> | 2012-12-21 17:57:10 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-02-09 11:34:19 -0800 |
| commit | 23663c873154f01220ef679558e1ca110c4c4ca4 (patch) | |
| tree | 5d142c7485c667e4ff7553267f38893a65b482ef | |
| parent | ad72b3bea744b4db01c89af0f86f3e8920d354df (diff) | |
| download | linux-23663c873154f01220ef679558e1ca110c4c4ca4.tar.bz2 | |
wimax/i2400m: fix i2400m->wake_tx_skb handling
i2400m_net_wake_tx() sets ->wake_tx_skb with the given skb if
->wake_tx_ws is not pending; however, i2400m_wake_tx_work() could have
just started execution and haven't fetched -><wake_tx_skb yet. The
previous packet will be leaked.
Update ->wake_tx_skb handling.
* i2400m_net_wake_tx() now tests whether the previous ->wake_tx_skb
has been consumed by ->wake_tx_ws instead of testing work_pending().
* i2400m_net_wake_stop() is simplified similarly. It always puts
->wake_tx_skb if non-NULL.
* Spurious ->wake_tx_skb dereference outside critical section dropped
from i2400m_wake_tx_work().
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: linux-wimax@intel.com
Cc: wimax@linuxwimax.org
| -rw-r--r-- | drivers/net/wimax/i2400m/netdev.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/net/wimax/i2400m/netdev.c b/drivers/net/wimax/i2400m/netdev.c index 1d76ae855f07..530581ca0191 100644 --- a/drivers/net/wimax/i2400m/netdev.c +++ b/drivers/net/wimax/i2400m/netdev.c @@ -156,7 +156,7 @@ void i2400m_wake_tx_work(struct work_struct *ws) struct i2400m *i2400m = container_of(ws, struct i2400m, wake_tx_ws); struct net_device *net_dev = i2400m->wimax_dev.net_dev; struct device *dev = i2400m_dev(i2400m); - struct sk_buff *skb = i2400m->wake_tx_skb; + struct sk_buff *skb; unsigned long flags; spin_lock_irqsave(&i2400m->tx_lock, flags); @@ -236,23 +236,26 @@ void i2400m_tx_prep_header(struct sk_buff *skb) void i2400m_net_wake_stop(struct i2400m *i2400m) { struct device *dev = i2400m_dev(i2400m); + struct sk_buff *wake_tx_skb; + unsigned long flags; d_fnstart(3, dev, "(i2400m %p)\n", i2400m); - /* See i2400m_hard_start_xmit(), references are taken there - * and here we release them if the work was still - * pending. Note we can't differentiate work not pending vs - * never scheduled, so the NULL check does that. */ - if (cancel_work_sync(&i2400m->wake_tx_ws) == 0 - && i2400m->wake_tx_skb != NULL) { - unsigned long flags; - struct sk_buff *wake_tx_skb; - spin_lock_irqsave(&i2400m->tx_lock, flags); - wake_tx_skb = i2400m->wake_tx_skb; /* compat help */ - i2400m->wake_tx_skb = NULL; /* compat help */ - spin_unlock_irqrestore(&i2400m->tx_lock, flags); + /* + * See i2400m_hard_start_xmit(), references are taken there and + * here we release them if the packet was still pending. + */ + cancel_work_sync(&i2400m->wake_tx_ws); + + spin_lock_irqsave(&i2400m->tx_lock, flags); + wake_tx_skb = i2400m->wake_tx_skb; + i2400m->wake_tx_skb = NULL; + spin_unlock_irqrestore(&i2400m->tx_lock, flags); + + if (wake_tx_skb) { i2400m_put(i2400m); kfree_skb(wake_tx_skb); } + d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); } @@ -288,7 +291,7 @@ int i2400m_net_wake_tx(struct i2400m *i2400m, struct net_device *net_dev, * and if pending, release those resources. */ result = 0; spin_lock_irqsave(&i2400m->tx_lock, flags); - if (!work_pending(&i2400m->wake_tx_ws)) { + if (!i2400m->wake_tx_skb) { netif_stop_queue(net_dev); i2400m_get(i2400m); i2400m->wake_tx_skb = skb_get(skb); /* transfer ref count */ |