From: Niels Dossche dossche.niels@gmail.com
stable inclusion from stable-v5.10.111 commit 43c2d7890ecabe527448a6c391fb2d9a5e6bbfe0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5GL1Z
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- 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 09f0dbf941c0..d8d52a00a1be 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -3241,7 +3241,11 @@ 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);