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authorVipul Pandya <vipul@chelsio.com>2013-01-07 13:11:56 +0000
committerRoland Dreier <roland@purestorage.com>2013-02-14 15:51:57 -0800
commit1ec779cc29238e6f4d315bff53cd36165819bfd5 (patch)
treeee580b96f17f19ae0f1badc761cc5ef5ee2347d6 /drivers/infiniband
parente8e5b9278ba0502ada73b8b94b8498cc19def743 (diff)
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RDMA/cxgb4: Fix endpoint timeout race condition
The endpoint timeout logic had a race that could cause an endpoint object to be freed while it was still on the timedout list. This can happen if the timer is stopped after it had fired, but before the timedout thread processed the endpoint timeout. Signed-off-by: Vipul Pandya <vipul@chelsio.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/hw/cxgb4/cm.c29
-rw-r--r--drivers/infiniband/hw/cxgb4/iw_cxgb4.h1
2 files changed, 17 insertions, 13 deletions
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 51ceb618beb..ab5b4dd39de 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -159,10 +159,12 @@ static void start_ep_timer(struct c4iw_ep *ep)
{
PDBG("%s ep %p\n", __func__, ep);
if (timer_pending(&ep->timer)) {
- PDBG("%s stopped / restarted timer ep %p\n", __func__, ep);
- del_timer_sync(&ep->timer);
- } else
- c4iw_get_ep(&ep->com);
+ pr_err("%s timer already started! ep %p\n",
+ __func__, ep);
+ return;
+ }
+ clear_bit(TIMEOUT, &ep->com.flags);
+ c4iw_get_ep(&ep->com);
ep->timer.expires = jiffies + ep_timeout_secs * HZ;
ep->timer.data = (unsigned long)ep;
ep->timer.function = ep_timeout;
@@ -171,14 +173,10 @@ static void start_ep_timer(struct c4iw_ep *ep)
static void stop_ep_timer(struct c4iw_ep *ep)
{
- PDBG("%s ep %p\n", __func__, ep);
- if (!timer_pending(&ep->timer)) {
- WARN(1, "%s timer stopped when its not running! "
- "ep %p state %u\n", __func__, ep, ep->com.state);
- return;
- }
+ PDBG("%s ep %p stopping\n", __func__, ep);
del_timer_sync(&ep->timer);
- c4iw_put_ep(&ep->com);
+ if (!test_and_set_bit(TIMEOUT, &ep->com.flags))
+ c4iw_put_ep(&ep->com);
}
static int c4iw_l2t_send(struct c4iw_rdev *rdev, struct sk_buff *skb,
@@ -3191,11 +3189,16 @@ static DECLARE_WORK(skb_work, process_work);
static void ep_timeout(unsigned long arg)
{
struct c4iw_ep *ep = (struct c4iw_ep *)arg;
+ int kickit = 0;
spin_lock(&timeout_lock);
- list_add_tail(&ep->entry, &timeout_list);
+ if (!test_and_set_bit(TIMEOUT, &ep->com.flags)) {
+ list_add_tail(&ep->entry, &timeout_list);
+ kickit = 1;
+ }
spin_unlock(&timeout_lock);
- queue_work(workq, &skb_work);
+ if (kickit)
+ queue_work(workq, &skb_work);
}
/*
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 0aaaa0e81f2..94a3b3c47a8 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -716,6 +716,7 @@ enum c4iw_ep_flags {
ABORT_REQ_IN_PROGRESS = 1,
RELEASE_RESOURCES = 2,
CLOSE_SENT = 3,
+ TIMEOUT = 4,
QP_REFERENCED = 5,
};