Commit 14e23bd6 authored by Jason Gunthorpe's avatar Jason Gunthorpe

RDMA/core: Fix locking in ib_uverbs_event_read

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: 036b1063 ("IB/uverbs: Enable device removal when there are active user space applications")
Link: https://lore.kernel.org/r/1578504126-9400-12-git-send-email-yishaih@mellanox.comSigned-off-by: default avatarYishai Hadas <yishaih@mellanox.com>
Reviewed-by: default avatarHåkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 74f75cda
......@@ -220,7 +220,6 @@ 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)
......@@ -238,19 +237,16 @@ 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);
......@@ -285,8 +281,7 @@ 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));
}
......@@ -296,9 +291,8 @@ 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));
}
......@@ -321,7 +315,9 @@ 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,
......@@ -335,9 +331,9 @@ 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)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment