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Commit 0519c520 authored by Michael J. Ruhl's avatar Michael J. Ruhl Committed by Doug Ledford
Browse files

IB/hfi1: Race hazard avoidance in user SDMA driver 



Set the errcode before the state and add the smb_wmb() to avoid a
potential race condition with the user.

Reviewed-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarMichael Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent ec8a1423

drivers/infiniband/hw/hfi1/user_sdma.c

+2 −1
Original line number Diff line number Diff line
@@ -1615,9 +1615,10 @@ static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq, 
{

	hfi1_cdbg(SDMA, "[%u:%u:%u:%u] Setting completion status %u %d",

		  pq->dd->unit, pq->ctxt, pq->subctxt, idx, state, ret);

	cq->comps[idx].status = state;

	if (state == ERROR)

		cq->comps[idx].errcode = -ret;

	smp_wmb(); /* make sure errcode is visible first */

	cq->comps[idx].status = state;

	trace_hfi1_sdma_user_completion(pq->dd, pq->ctxt, pq->subctxt,

					idx, state, ret);

}