From 1ec779cc29238e6f4d315bff53cd36165819bfd5 Mon Sep 17 00:00:00 2001 From: Vipul Pandya Date: Mon, 7 Jan 2013 13:11:56 +0000 Subject: [PATCH] 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 Signed-off-by: Roland Dreier --- drivers/infiniband/hw/cxgb4/cm.c | 29 ++++++++++++++++------------- drivers/infiniband/hw/cxgb4/iw_cxgb4.h | 1 + 2 files changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index 51ceb61..ab5b4dd 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 0aaaa0e..94a3b3c 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, }; -- 2.7.4