diff options
| author | Jack Morgenstein <jackm@mellanox.co.il> | 2006-08-03 10:56:42 -0700 |
|---|---|---|
| committer | Roland Dreier <rolandd@cisco.com> | 2006-08-03 10:56:42 -0700 |
| commit | fd60ae404f104f12369e654af9cf03b1f1047661 (patch) | |
| tree | 81fcc683f41936597e62cdba254b89ab569e5526 | |
| parent | 8ddc7c5326064434048ec1ecfe57659e08345cc1 (diff) | |
IB/uverbs: Avoid a crash on device hot remove
Wait until all users have closed their device context before allowing
device unregistration to complete. This prevents a crash caused by
referring to stale data structures.
A better solution would be to have a way to revoke contexts rather
than waiting for userspace to close the context, but that's a much
bigger change that will have to wait. For now let's at least avoid
the crash.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
| -rw-r--r-- | drivers/infiniband/core/uverbs.h | 2 | ||||
| -rw-r--r-- | drivers/infiniband/core/uverbs_main.c | 8 |
2 files changed, 9 insertions, 1 deletions
diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index bb9bee56a82..102a59c033f 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -42,6 +42,7 @@ #include <linux/kref.h> #include <linux/idr.h> #include <linux/mutex.h> +#include <linux/completion.h> #include <rdma/ib_verbs.h> #include <rdma/ib_user_verbs.h> @@ -69,6 +70,7 @@ struct ib_uverbs_device { struct kref ref; + struct completion comp; int devnum; struct cdev *dev; struct class_device *class_dev; diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index e725cccc7cd..4e16314e8e6 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -122,7 +122,7 @@ static void ib_uverbs_release_dev(struct kref *ref) struct ib_uverbs_device *dev = container_of(ref, struct ib_uverbs_device, ref); - kfree(dev); + complete(&dev->comp); } void ib_uverbs_release_ucq(struct ib_uverbs_file *file, @@ -740,6 +740,7 @@ static void ib_uverbs_add_one(struct ib_device *device) return; kref_init(&uverbs_dev->ref); + init_completion(&uverbs_dev->comp); spin_lock(&map_lock); uverbs_dev->devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES); @@ -793,6 +794,8 @@ err_cdev: err: kref_put(&uverbs_dev->ref, ib_uverbs_release_dev); + wait_for_completion(&uverbs_dev->comp); + kfree(uverbs_dev); return; } @@ -812,7 +815,10 @@ static void ib_uverbs_remove_one(struct ib_device *device) spin_unlock(&map_lock); clear_bit(uverbs_dev->devnum, dev_map); + kref_put(&uverbs_dev->ref, ib_uverbs_release_dev); + wait_for_completion(&uverbs_dev->comp); + kfree(uverbs_dev); } static int uverbs_event_get_sb(struct file_system_type *fs_type, int flags, |