From: Yishai Hadas <yishaih@mellanox.com>
To: linux-rdma@vger.kernel.org, jgg@mellanox.com, dledford@redhat.com
Cc: yishaih@mellanox.com, maorg@mellanox.com, michaelgur@mellanox.com
Subject: [PATCH rdma-next 11/14] RDMA/core: Fix locking in ib_uverbs_event_read
Date: Wed, 8 Jan 2020 19:22:03 +0200 [thread overview]
Message-ID: <1578504126-9400-12-git-send-email-yishaih@mellanox.com> (raw)
In-Reply-To: <1578504126-9400-1-git-send-email-yishaih@mellanox.com>
From: Jason Gunthorpe <jgg@mellanox.com>
This should not be using ib_dev to test for disassociation, during
disassociation is_closed is set under lock and the waitq is triggered.
Instead check is_closed and be sure to re-obtain the lock to test the
value after the wait_event returns.
Fixes: 036b10635739 ("IB/uverbs: Enable device removal when there are active user space applications")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
drivers/infiniband/core/uverbs_main.c | 32 ++++++++++++++------------------
1 file changed, 14 insertions(+), 18 deletions(-)
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 85dbd81..97770e7 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -215,7 +215,6 @@ void ib_uverbs_release_file(struct kref *ref)
}
static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
- struct ib_uverbs_file *uverbs_file,
struct file *filp, char __user *buf,
size_t count, loff_t *pos,
size_t eventsz)
@@ -233,19 +232,16 @@ static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
if (wait_event_interruptible(ev_queue->poll_wait,
(!list_empty(&ev_queue->event_list) ||
- /* The barriers built into wait_event_interruptible()
- * and wake_up() guarentee this will see the null set
- * without using RCU
- */
- !uverbs_file->device->ib_dev)))
+ ev_queue->is_closed)))
return -ERESTARTSYS;
+ spin_lock_irq(&ev_queue->lock);
+
/* If device was disassociated and no event exists set an error */
- if (list_empty(&ev_queue->event_list) &&
- !uverbs_file->device->ib_dev)
+ if (list_empty(&ev_queue->event_list) && ev_queue->is_closed) {
+ spin_unlock_irq(&ev_queue->lock);
return -EIO;
-
- spin_lock_irq(&ev_queue->lock);
+ }
}
event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
@@ -280,8 +276,7 @@ static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
{
struct ib_uverbs_async_event_file *file = filp->private_data;
- return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
- buf, count, pos,
+ return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos,
sizeof(struct ib_uverbs_async_event_desc));
}
@@ -291,9 +286,8 @@ static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
struct ib_uverbs_completion_event_file *comp_ev_file =
filp->private_data;
- return ib_uverbs_event_read(&comp_ev_file->ev_queue,
- comp_ev_file->uobj.ufile, filp,
- buf, count, pos,
+ return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count,
+ pos,
sizeof(struct ib_uverbs_comp_event_desc));
}
@@ -316,7 +310,9 @@ static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
static __poll_t ib_uverbs_async_event_poll(struct file *filp,
struct poll_table_struct *wait)
{
- return ib_uverbs_event_poll(filp->private_data, filp, wait);
+ struct ib_uverbs_async_event_file *file = filp->private_data;
+
+ return ib_uverbs_event_poll(&file->ev_queue, filp, wait);
}
static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
@@ -330,9 +326,9 @@ static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
{
- struct ib_uverbs_event_queue *ev_queue = filp->private_data;
+ struct ib_uverbs_async_event_file *file = filp->private_data;
- return fasync_helper(fd, filp, on, &ev_queue->async_queue);
+ return fasync_helper(fd, filp, on, &file->ev_queue.async_queue);
}
static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
--
1.8.3.1
next prev parent reply other threads:[~2020-01-08 17:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-08 17:21 [PATCH rdma-next 00/14] Refactoring FD usage Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 01/14] RDMA/mlx5: Use RCU and direct refcounts to keep memory alive Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 02/14] RDMA/core: Simplify destruction of FD uobjects Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 03/14] RDMA/mlx5: Simplify devx async commands Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 04/14] RDMA/core: Do not allow alloc_commit to fail Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 05/14] RDMA/core: Make ib_ucq_object use ib_uevent_object Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 06/14] RDMA/core: Do not erase the type of ib_cq.uobject Yishai Hadas
2020-01-08 17:21 ` [PATCH rdma-next 07/14] RDMA/core: Do not erase the type of ib_qp.uobject Yishai Hadas
2020-01-08 17:22 ` [PATCH rdma-next 08/14] RDMA/core: Do not erase the type of ib_srq.uobject Yishai Hadas
2020-01-08 17:22 ` [PATCH rdma-next 09/14] RDMA/core: Do not erase the type of ib_wq.uobject Yishai Hadas
2020-01-08 17:22 ` [PATCH rdma-next 10/14] RDMA/core: Simplify type usage for ib_uverbs_async_handler() Yishai Hadas
2020-01-08 17:22 ` Yishai Hadas [this message]
2020-01-10 14:54 ` [PATCH rdma-next 11/14] RDMA/core: Fix locking in ib_uverbs_event_read Jason Gunthorpe
2020-01-08 17:22 ` [PATCH rdma-next 12/14] RDMA/core: Remove the ufile arg from rdma_alloc_begin_uobject Yishai Hadas
2020-01-08 17:22 ` [PATCH rdma-next 13/14] RDMA/core: Make ib_uverbs_async_event_file into a uobject Yishai Hadas
2020-01-08 17:22 ` [PATCH rdma-next 14/14] RDMA/core: Use READ_ONCE for ib_ufile.async_file Yishai Hadas
2020-01-13 20:37 ` [PATCH rdma-next 00/14] Refactoring FD usage Jason Gunthorpe
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