tmp_suning_uos_patched/drivers/infiniband
Jason Gunthorpe aa116b810a RDMA/mlx5: Order num_pending_prefetch properly with synchronize_srcu
During destroy setting live = 0 and then synchronize_srcu() prevents
num_pending_prefetch from incrementing, and also, ensures that all work
holding that count is queued on the WQ. Testing before causes races of the
form:

    CPU0                                         CPU1
  dereg_mr()
                                          mlx5_ib_advise_mr_prefetch()
            				   srcu_read_lock()
                                            num_pending_prefetch_inc()
					      if (!live)
   live = 0
   atomic_read() == 0
     // skip flush_workqueue()
                                              atomic_inc()
 					      queue_work();
            				   srcu_read_unlock()
   WARN_ON(atomic_read())  // Fails

Swap the order so that the synchronize_srcu() prevents this.

Fixes: a6bc3875f1 ("IB/mlx5: Protect against prefetch of invalid MR")
Link: https://lore.kernel.org/r/20191001153821.23621-5-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-04 15:54:22 -03:00
..
core RDMA/odp: Lift umem_mutex out of ib_umem_odp_unmap_dma_pages() 2019-10-04 15:54:21 -03:00
hw RDMA/mlx5: Order num_pending_prefetch properly with synchronize_srcu 2019-10-04 15:54:22 -03:00
sw RDMA/siw: Fix serialization issue in write_space() 2019-10-01 10:55:27 -03:00
ulp RDMA subsystem updates for 5.4 2019-09-21 10:26:24 -07:00
Kconfig RDMA/odp: Use the common interval tree library instead of generic 2019-08-21 13:34:09 -03:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00