IB/ipath: Don't corrupt pending mmap list when unmapped objects are freed

Fix the pending mmap code so it doesn't corrupt the list of pending
mmaps and crash the machine when pending mmaps are destroyed without
first being mapped.  Also, remove an unused variable, and use standard
kernel lists instead of our own homebrewed linked list implementation
to keep the pending mmap list.

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 30 insertions, 22 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
index 16db9ac0b402..bfef08ecd342 100644
--- a/drivers/infiniband/hw/ipath/ipath_qp.c
+++ b/drivers/infiniband/hw/ipath/ipath_qp.c
@@ -844,34 +844,36 @@ struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
 	 * See ipath_mmap() for details.
 	 */
 	if (udata && udata->outlen >= sizeof(__u64)) {
-		struct ipath_mmap_info *ip;
-		__u64 offset = (__u64) qp->r_rq.wq;
 		int err;
 
-		err = ib_copy_to_udata(udata, &offset, sizeof(offset));
-		if (err) {
-			ret = ERR_PTR(err);
-			goto bail_rwq;
-		}
+		if (!qp->r_rq.wq) {
+			__u64 offset = 0;
 
-		if (qp->r_rq.wq) {
-			/* Allocate info for ipath_mmap(). */
-			ip = kmalloc(sizeof(*ip), GFP_KERNEL);
-			if (!ip) {
+			err = ib_copy_to_udata(udata, &offset,
+					       sizeof(offset));
+			if (err) {
+				ret = ERR_PTR(err);
+				goto bail_rwq;
+			}
+		} else {
+			u32 s = sizeof(struct ipath_rwq) +
+				qp->r_rq.size * sz;
+
+			qp->ip =
+			    ipath_create_mmap_info(dev, s,
+						   ibpd->uobject->context,
+						   qp->r_rq.wq);
+			if (!qp->ip) {
 				ret = ERR_PTR(-ENOMEM);
 				goto bail_rwq;
 			}
-			qp->ip = ip;
-			ip->context = ibpd->uobject->context;
-			ip->obj = qp->r_rq.wq;
-			kref_init(&ip->ref);
-			ip->mmap_cnt = 0;
-			ip->size = PAGE_ALIGN(sizeof(struct ipath_rwq) +
-					      qp->r_rq.size * sz);
-			spin_lock_irq(&dev->pending_lock);
-			ip->next = dev->pending_mmaps;
-			dev->pending_mmaps = ip;
-			spin_unlock_irq(&dev->pending_lock);
+
+			err = ib_copy_to_udata(udata, &(qp->ip->offset),
+					       sizeof(qp->ip->offset));
+			if (err) {
+				ret = ERR_PTR(err);
+				goto bail_ip;
+			}
 		}
 	}
 
@@ -885,6 +887,12 @@ struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
 	dev->n_qps_allocated++;
 	spin_unlock(&dev->n_qps_lock);
 
+	if (qp->ip) {
+		spin_lock_irq(&dev->pending_lock);
+		list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
+		spin_unlock_irq(&dev->pending_lock);
+	}
+
 	ret = &qp->ibqp;
 	goto bail;