Make sure that userspace does not retrieve stale asynchronous or

completion events after destroying a CQ, QP or SRQ.  We do this by
sweeping the event lists before returning from a destroy calls, and
then return the number of events already reported before the destroy
call.  This allows userspace wait until it has processed all events
for an object returned from the kernel before it frees its context for
the object.

The ABI of the destroy CQ, destroy QP and destroy SRQ commands has to
change to return the event count, so bump the ABI version from 1 to 2.
The userspace libibverbs library has already been updated to handle
both the old and new ABI versions.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 112 insertions, 43 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index ebccf9f38af9..e91ebde46481 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -590,7 +590,7 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
 	struct ib_uverbs_create_cq      cmd;
 	struct ib_uverbs_create_cq_resp resp;
 	struct ib_udata                 udata;
-	struct ib_uobject              *uobj;
+	struct ib_ucq_object           *uobj;
 	struct ib_cq                   *cq;
 	int                             ret;
 
@@ -611,8 +611,12 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
 	if (!uobj)
 		return -ENOMEM;
 
-	uobj->user_handle = cmd.user_handle;
-	uobj->context     = file->ucontext;
+	uobj->uobject.user_handle   = cmd.user_handle;
+	uobj->uobject.context       = file->ucontext;
+	uobj->comp_events_reported  = 0;
+	uobj->async_events_reported = 0;
+	INIT_LIST_HEAD(&uobj->comp_list);
+	INIT_LIST_HEAD(&uobj->async_list);
 
 	cq = file->device->ib_dev->create_cq(file->device->ib_dev, cmd.cqe,
 					     file->ucontext, &udata);
@@ -622,7 +626,7 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
 	}
 
 	cq->device        = file->device->ib_dev;
-	cq->uobject       = uobj;
+	cq->uobject       = &uobj->uobject;
 	cq->comp_handler  = ib_uverbs_comp_handler;
 	cq->event_handler = ib_uverbs_cq_event_handler;
 	cq->cq_context    = file;
@@ -635,7 +639,7 @@ retry:
 	}
 
 	down(&ib_uverbs_idr_mutex);
-	ret = idr_get_new(&ib_uverbs_cq_idr, cq, &uobj->id);
+	ret = idr_get_new(&ib_uverbs_cq_idr, cq, &uobj->uobject.id);
 	up(&ib_uverbs_idr_mutex);
 
 	if (ret == -EAGAIN)
@@ -644,11 +648,11 @@ retry:
 		goto err_cq;
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_add_tail(&uobj->list, &file->ucontext->cq_list);
+	list_add_tail(&uobj->uobject.list, &file->ucontext->cq_list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 	memset(&resp, 0, sizeof resp);
-	resp.cq_handle = uobj->id;
+	resp.cq_handle = uobj->uobject.id;
 	resp.cqe       = cq->cqe;
 
 	if (copy_to_user((void __user *) (unsigned long) cmd.response,
@@ -661,11 +665,11 @@ retry:
 
 err_list:
  	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 	down(&ib_uverbs_idr_mutex);
-	idr_remove(&ib_uverbs_cq_idr, uobj->id);
+	idr_remove(&ib_uverbs_cq_idr, uobj->uobject.id);
 	up(&ib_uverbs_idr_mutex);
 
 err_cq:
@@ -680,21 +684,27 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
 			     const char __user *buf, int in_len,
 			     int out_len)
 {
-	struct ib_uverbs_destroy_cq cmd;
-	struct ib_cq               *cq;
-	struct ib_uobject          *uobj;
-	int                         ret = -EINVAL;
+	struct ib_uverbs_destroy_cq      cmd;
+	struct ib_uverbs_destroy_cq_resp resp;
+	struct ib_cq               	*cq;
+	struct ib_ucq_object        	*uobj;
+	struct ib_uverbs_event		*evt, *tmp;
+	u64				 user_handle;
+	int                        	 ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
 		return -EFAULT;
 
+	memset(&resp, 0, sizeof resp);
+
 	down(&ib_uverbs_idr_mutex);
 
 	cq = idr_find(&ib_uverbs_cq_idr, cmd.cq_handle);
 	if (!cq || cq->uobject->context != file->ucontext)
 		goto out;
 
-	uobj = cq->uobject;
+	user_handle = cq->uobject->user_handle;
+	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
 
 	ret = ib_destroy_cq(cq);
 	if (ret)
@@ -703,11 +713,32 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
 	idr_remove(&ib_uverbs_cq_idr, cmd.cq_handle);
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
+	spin_lock_irq(&file->comp_file[0].lock);
+	list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
+		list_del(&evt->list);
+		kfree(evt);
+	}
+	spin_unlock_irq(&file->comp_file[0].lock);
+
+	spin_lock_irq(&file->async_file.lock);
+	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
+		list_del(&evt->list);
+		kfree(evt);
+	}
+	spin_unlock_irq(&file->async_file.lock);
+
+	resp.comp_events_reported  = uobj->comp_events_reported;
+	resp.async_events_reported = uobj->async_events_reported;
+
 	kfree(uobj);
 
+	if (copy_to_user((void __user *) (unsigned long) cmd.response,
+			 &resp, sizeof resp))
+		ret = -EFAULT;
+
 out:
 	up(&ib_uverbs_idr_mutex);
 
@@ -721,7 +752,7 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file,
 	struct ib_uverbs_create_qp      cmd;
 	struct ib_uverbs_create_qp_resp resp;
 	struct ib_udata                 udata;
-	struct ib_uobject              *uobj;
+	struct ib_uevent_object        *uobj;
 	struct ib_pd                   *pd;
 	struct ib_cq                   *scq, *rcq;
 	struct ib_srq                  *srq;
@@ -772,8 +803,10 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file,
 	attr.cap.max_recv_sge    = cmd.max_recv_sge;
 	attr.cap.max_inline_data = cmd.max_inline_data;
 
-	uobj->user_handle = cmd.user_handle;
-	uobj->context     = file->ucontext;
+	uobj->uobject.user_handle = cmd.user_handle;
+	uobj->uobject.context     = file->ucontext;
+	uobj->events_reported     = 0;
+	INIT_LIST_HEAD(&uobj->event_list);
 
 	qp = pd->device->create_qp(pd, &attr, &udata);
 	if (IS_ERR(qp)) {
@@ -786,7 +819,7 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file,
 	qp->send_cq    	  = attr.send_cq;
 	qp->recv_cq    	  = attr.recv_cq;
 	qp->srq	       	  = attr.srq;
-	qp->uobject       = uobj;
+	qp->uobject       = &uobj->uobject;
 	qp->event_handler = attr.event_handler;
 	qp->qp_context    = attr.qp_context;
 	qp->qp_type	  = attr.qp_type;
@@ -805,17 +838,17 @@ retry:
 		goto err_destroy;
 	}
 
-	ret = idr_get_new(&ib_uverbs_qp_idr, qp, &uobj->id);
+	ret = idr_get_new(&ib_uverbs_qp_idr, qp, &uobj->uobject.id);
 
 	if (ret == -EAGAIN)
 		goto retry;
 	if (ret)
 		goto err_destroy;
 
-	resp.qp_handle = uobj->id;
+	resp.qp_handle = uobj->uobject.id;
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_add_tail(&uobj->list, &file->ucontext->qp_list);
+	list_add_tail(&uobj->uobject.list, &file->ucontext->qp_list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 	if (copy_to_user((void __user *) (unsigned long) cmd.response,
@@ -830,7 +863,7 @@ retry:
 
 err_list:
 	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 err_destroy:
@@ -930,21 +963,25 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
 			     const char __user *buf, int in_len,
 			     int out_len)
 {
-	struct ib_uverbs_destroy_qp cmd;
-	struct ib_qp               *qp;
-	struct ib_uobject          *uobj;
-	int                         ret = -EINVAL;
+	struct ib_uverbs_destroy_qp      cmd;
+	struct ib_uverbs_destroy_qp_resp resp;
+	struct ib_qp               	*qp;
+	struct ib_uevent_object        	*uobj;
+	struct ib_uverbs_event		*evt, *tmp;
+	int                        	 ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
 		return -EFAULT;
 
+	memset(&resp, 0, sizeof resp);
+
 	down(&ib_uverbs_idr_mutex);
 
 	qp = idr_find(&ib_uverbs_qp_idr, cmd.qp_handle);
 	if (!qp || qp->uobject->context != file->ucontext)
 		goto out;
 
-	uobj = qp->uobject;
+	uobj = container_of(qp->uobject, struct ib_uevent_object, uobject);
 
 	ret = ib_destroy_qp(qp);
 	if (ret)
@@ -953,11 +990,24 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
 	idr_remove(&ib_uverbs_qp_idr, cmd.qp_handle);
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
+	spin_lock_irq(&file->async_file.lock);
+	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
+		list_del(&evt->list);
+		kfree(evt);
+	}
+	spin_unlock_irq(&file->async_file.lock);
+
+	resp.events_reported = uobj->events_reported;
+
 	kfree(uobj);
 
+	if (copy_to_user((void __user *) (unsigned long) cmd.response,
+			 &resp, sizeof resp))
+		ret = -EFAULT;
+
 out:
 	up(&ib_uverbs_idr_mutex);
 
@@ -1015,7 +1065,7 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file,
 	struct ib_uverbs_create_srq      cmd;
 	struct ib_uverbs_create_srq_resp resp;
 	struct ib_udata                  udata;
-	struct ib_uobject               *uobj;
+	struct ib_uevent_object         *uobj;
 	struct ib_pd                    *pd;
 	struct ib_srq                   *srq;
 	struct ib_srq_init_attr          attr;
@@ -1050,8 +1100,10 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file,
 	attr.attr.max_sge   = cmd.max_sge;
 	attr.attr.srq_limit = cmd.srq_limit;
 
-	uobj->user_handle = cmd.user_handle;
-	uobj->context     = file->ucontext;
+	uobj->uobject.user_handle = cmd.user_handle;
+	uobj->uobject.context     = file->ucontext;
+	uobj->events_reported     = 0;
+	INIT_LIST_HEAD(&uobj->event_list);
 
 	srq = pd->device->create_srq(pd, &attr, &udata);
 	if (IS_ERR(srq)) {
@@ -1061,7 +1113,7 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file,
 
 	srq->device    	   = pd->device;
 	srq->pd        	   = pd;
-	srq->uobject       = uobj;
+	srq->uobject       = &uobj->uobject;
 	srq->event_handler = attr.event_handler;
 	srq->srq_context   = attr.srq_context;
 	atomic_inc(&pd->usecnt);
@@ -1075,17 +1127,17 @@ retry:
 		goto err_destroy;
 	}
 
-	ret = idr_get_new(&ib_uverbs_srq_idr, srq, &uobj->id);
+	ret = idr_get_new(&ib_uverbs_srq_idr, srq, &uobj->uobject.id);
 
 	if (ret == -EAGAIN)
 		goto retry;
 	if (ret)
 		goto err_destroy;
 
-	resp.srq_handle = uobj->id;
+	resp.srq_handle = uobj->uobject.id;
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_add_tail(&uobj->list, &file->ucontext->srq_list);
+	list_add_tail(&uobj->uobject.list, &file->ucontext->srq_list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 	if (copy_to_user((void __user *) (unsigned long) cmd.response,
@@ -1100,7 +1152,7 @@ retry:
 
 err_list:
 	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
 err_destroy:
@@ -1149,21 +1201,25 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
 			      const char __user *buf, int in_len,
 			      int out_len)
 {
-	struct ib_uverbs_destroy_srq cmd;
-	struct ib_srq               *srq;
-	struct ib_uobject           *uobj;
-	int                          ret = -EINVAL;
+	struct ib_uverbs_destroy_srq      cmd;
+	struct ib_uverbs_destroy_srq_resp resp;
+	struct ib_srq               	 *srq;
+	struct ib_uevent_object        	 *uobj;
+	struct ib_uverbs_event		 *evt, *tmp;
+	int                         	  ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
 		return -EFAULT;
 
 	down(&ib_uverbs_idr_mutex);
 
+	memset(&resp, 0, sizeof resp);
+
 	srq = idr_find(&ib_uverbs_srq_idr, cmd.srq_handle);
 	if (!srq || srq->uobject->context != file->ucontext)
 		goto out;
 
-	uobj = srq->uobject;
+	uobj = container_of(srq->uobject, struct ib_uevent_object, uobject);
 
 	ret = ib_destroy_srq(srq);
 	if (ret)
@@ -1172,11 +1228,24 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
 	idr_remove(&ib_uverbs_srq_idr, cmd.srq_handle);
 
 	spin_lock_irq(&file->ucontext->lock);
-	list_del(&uobj->list);
+	list_del(&uobj->uobject.list);
 	spin_unlock_irq(&file->ucontext->lock);
 
+	spin_lock_irq(&file->async_file.lock);
+	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
+		list_del(&evt->list);
+		kfree(evt);
+	}
+	spin_unlock_irq(&file->async_file.lock);
+
+	resp.events_reported = uobj->events_reported;
+
 	kfree(uobj);
 
+	if (copy_to_user((void __user *) (unsigned long) cmd.response,
+			 &resp, sizeof resp))
+		ret = -EFAULT;
+
 out:
 	up(&ib_uverbs_idr_mutex);