| From c85a2283bac21ca5f0fd005721ab055468ae3d23 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 28 Feb 2022 17:53:30 +0100 |
| Subject: IB/rdmavt: add lock to call to rvt_error_qp to prevent a race |
| condition |
| |
| From: Niels Dossche <dossche.niels@gmail.com> |
| |
| [ Upstream commit 4d809f69695d4e7d1378b3a072fa9aef23123018 ] |
| |
| The documentation of the function rvt_error_qp says both r_lock and s_lock |
| need to be held when calling that function. It also asserts using lockdep |
| that both of those locks are held. However, the commit I referenced in |
| Fixes accidentally makes the call to rvt_error_qp in rvt_ruc_loopback no |
| longer covered by r_lock. This results in the lockdep assertion failing |
| and also possibly in a race condition. |
| |
| Fixes: d757c60eca9b ("IB/rdmavt: Fix concurrency panics in QP post_send and modify to error") |
| Link: https://lore.kernel.org/r/20220228165330.41546-1-dossche.niels@gmail.com |
| Signed-off-by: Niels Dossche <dossche.niels@gmail.com> |
| Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> |
| Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/infiniband/sw/rdmavt/qp.c | 6 +++++- |
| 1 file changed, 5 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c |
| index ae50b56e8913..8ef112f883a7 100644 |
| --- a/drivers/infiniband/sw/rdmavt/qp.c |
| +++ b/drivers/infiniband/sw/rdmavt/qp.c |
| @@ -3190,7 +3190,11 @@ void rvt_ruc_loopback(struct rvt_qp *sqp) |
| spin_lock_irqsave(&sqp->s_lock, flags); |
| rvt_send_complete(sqp, wqe, send_status); |
| if (sqp->ibqp.qp_type == IB_QPT_RC) { |
| - int lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR); |
| + int lastwqe; |
| + |
| + spin_lock(&sqp->r_lock); |
| + lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR); |
| + spin_unlock(&sqp->r_lock); |
| |
| sqp->s_flags &= ~RVT_S_BUSY; |
| spin_unlock_irqrestore(&sqp->s_lock, flags); |
| -- |
| 2.35.1 |
| |