From: Leon Romanovsky <leon@kernel.org>
To: Doug Ledford <dledford@redhat.com>, Jason Gunthorpe <jgg@nvidia.com>
Cc: Leon Romanovsky <leonro@mellanox.com>, linux-rdma@vger.kernel.org
Subject: [PATCH rdma-next 01/14] RDMA/ucma: Fix refcount 0 incr in ucma_get_ctx()
Date: Tue, 18 Aug 2020 15:05:13 +0300 [thread overview]
Message-ID: <20200818120526.702120-2-leon@kernel.org> (raw)
In-Reply-To: <20200818120526.702120-1-leon@kernel.org>
From: Jason Gunthorpe <jgg@nvidia.com>
Both ucma_destroy_id() and ucma_close_id() (triggered from an event via a
wq) can drive the refcount to zero. ucma_get_ctx() was wrongly assuming
that the refcount can only go to zero from ucma_destroy_id() which also
removes it from the xarray.
Use refcount_inc_not_zero() instead.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
drivers/infiniband/core/ucma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index d03dacaef788..625168563443 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -153,8 +153,8 @@ static struct ucma_context *ucma_get_ctx(struct ucma_file *file, int id)
if (!IS_ERR(ctx)) {
if (ctx->closing)
ctx = ERR_PTR(-EIO);
- else
- refcount_inc(&ctx->ref);
+ else if (!refcount_inc_not_zero(&ctx->ref))
+ ctx = ERR_PTR(-ENXIO);
}
xa_unlock(&ctx_table);
return ctx;
--
2.26.2
next prev parent reply other threads:[~2020-08-18 12:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-18 12:05 [PATCH rdma-next 00/14] Cleanup locking and events in ucma Leon Romanovsky
2020-08-18 12:05 ` Leon Romanovsky [this message]
2020-08-18 12:05 ` [PATCH rdma-next 02/14] RDMA/ucma: Remove unnecessary locking of file->ctx_list in close Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 03/14] RDMA/ucma: Consolidate the two destroy flows Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 04/14] RDMA/ucma: Fix error cases around ucma_alloc_ctx() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 05/14] RDMA/ucma: Remove mc_list and rely on xarray Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 06/14] RDMA/cma: Add missing locking to rdma_accept() Leon Romanovsky
2021-02-09 14:46 ` Chuck Lever
2021-02-09 15:40 ` Jason Gunthorpe
2020-08-18 12:05 ` [PATCH rdma-next 07/14] RDMA/ucma: Do not use file->mut to lock destroying Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 08/14] RDMA/ucma: Fix the locking of ctx->file Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 09/14] RDMA/ucma: Fix locking for ctx->events_reported Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 10/14] RDMA/ucma: Add missing locking around rdma_leave_multicast() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 11/14] RDMA/ucma: Change backlog into an atomic Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 12/14] RDMA/ucma: Narrow file->mut in ucma_event_handler() Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 13/14] RDMA/ucma: Rework how new connections are passed through event delivery Leon Romanovsky
2020-08-18 12:05 ` [PATCH rdma-next 14/14] RDMA/ucma: Remove closing and the close_wq Leon Romanovsky
2020-08-27 11:39 ` [PATCH rdma-next 00/14] Cleanup locking and events in ucma Jason Gunthorpe
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