From: Kaike Wan kaike.wan@intel.com
commit ca9033ba69c7e3477f207df69867b2ea969197c8 upstream.
In the iowait structure, two iowait_work entries were included to queue a given object: one for normal IB operations, and the other for TID RDMA operations. For non-TID RDMA operations, the iowait_work structure for TID RDMA is initialized to contain a NULL function (not used). When the QP is reset, the function iowait_cancel_work will be called to cancel any pending work. The problem is that this function will call cancel_work_sync() for both iowait_work entries, even though the one for TID RDMA is not used at all. Eventually, the call cascades to __flush_work(), wherein a WARN_ON will be triggered due to the fact that work->func is NULL.
The WARN_ON was introduced in commit 4d43d395fed1 ("workqueue: Try to catch flush_work() without INIT_WORK().")
This patch fixes the issue by making sure that a work function is present for TID RDMA before calling cancel_work_sync in iowait_cancel_work.
Fixes: 4d43d395fed1 ("workqueue: Try to catch flush_work() without INIT_WORK().") Fixes: 5da0fc9dbf89 ("IB/hfi1: Prepare resource waits for dual leg") Link: https://lore.kernel.org/r/20191219211941.58387.39883.stgit@awfm-01.aw.intel.... Reviewed-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Kaike Wan kaike.wan@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/hfi1/iowait.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/hw/hfi1/iowait.c +++ b/drivers/infiniband/hw/hfi1/iowait.c @@ -81,7 +81,9 @@ void iowait_init(struct iowait *wait, u3 void iowait_cancel_work(struct iowait *w) { cancel_work_sync(&iowait_get_ib_work(w)->iowork); - cancel_work_sync(&iowait_get_tid_work(w)->iowork); + /* Make sure that the iowork for TID RDMA is used */ + if (iowait_get_tid_work(w)->iowork.func) + cancel_work_sync(&iowait_get_tid_work(w)->iowork); }
/**