From 4356d0b64b9be53c507f66c572c1e275b4529239 Mon Sep 17 00:00:00 2001 From: Ram Vepa Date: Fri, 27 May 2011 13:41:55 +0000 Subject: [PATCH] IB/qib: Fix potential deadlock with link down interrupt There is a possibility of a deadlock due to the way locks are acquired and released in qib_set_uevent_bits(). The function qib_set_uevent_bits() is called in process context and it uses spin_lock() and spin_unlock(). This same lock is acquired/released in interrupt context which can lead to a deadlock when running on the same cpu. The fix is to replace spin_lock() and spin_unlock() with spin_lock_irqsave() and spin_unlock_irqrestore() respectively in qib_set_uevent_bits(). Signed-off-by: Mike Marciniszyn Signed-off-by: Roland Dreier --- drivers/infiniband/hw/qib/qib_file_ops.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c index a94a46001745..26253039d2c7 100644 --- a/drivers/infiniband/hw/qib/qib_file_ops.c +++ b/drivers/infiniband/hw/qib/qib_file_ops.c @@ -1905,8 +1905,9 @@ int qib_set_uevent_bits(struct qib_pportdata *ppd, const int evtbit) struct qib_ctxtdata *rcd; unsigned ctxt; int ret = 0; + unsigned long flags; - spin_lock(&ppd->dd->uctxt_lock); + spin_lock_irqsave(&ppd->dd->uctxt_lock, flags); for (ctxt = ppd->dd->first_user_ctxt; ctxt < ppd->dd->cfgctxts; ctxt++) { rcd = ppd->dd->rcd[ctxt]; @@ -1925,7 +1926,7 @@ int qib_set_uevent_bits(struct qib_pportdata *ppd, const int evtbit) ret = 1; break; } - spin_unlock(&ppd->dd->uctxt_lock); + spin_unlock_irqrestore(&ppd->dd->uctxt_lock, flags); return ret; } -- 2.39.5