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, 26 insertions, 29 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_srq.c b/drivers/infiniband/hw/ipath/ipath_srq.c
index 94033503400c..03acae66ba81 100644
--- a/drivers/infiniband/hw/ipath/ipath_srq.c
+++ b/drivers/infiniband/hw/ipath/ipath_srq.c
@@ -139,33 +139,24 @@ struct ib_srq *ipath_create_srq(struct ib_pd *ibpd,
 	 * See ipath_mmap() for details.
 	 */
 	if (udata && udata->outlen >= sizeof(__u64)) {
-		struct ipath_mmap_info *ip;
-		__u64 offset = (__u64) srq->rq.wq;
 		int err;
+		u32 s = sizeof(struct ipath_rwq) + srq->rq.size * sz;
 
-		err = ib_copy_to_udata(udata, &offset, sizeof(offset));
-		if (err) {
-			ret = ERR_PTR(err);
+		srq->ip =
+		    ipath_create_mmap_info(dev, s,
+					   ibpd->uobject->context,
+					   srq->rq.wq);
+		if (!srq->ip) {
+			ret = ERR_PTR(-ENOMEM);
 			goto bail_wq;
 		}
 
-		/* Allocate info for ipath_mmap(). */
-		ip = kmalloc(sizeof(*ip), GFP_KERNEL);
-		if (!ip) {
-			ret = ERR_PTR(-ENOMEM);
-			goto bail_wq;
+		err = ib_copy_to_udata(udata, &srq->ip->offset,
+				       sizeof(srq->ip->offset));
+		if (err) {
+			ret = ERR_PTR(err);
+			goto bail_ip;
 		}
-		srq->ip = ip;
-		ip->context = ibpd->uobject->context;
-		ip->obj = srq->rq.wq;
-		kref_init(&ip->ref);
-		ip->mmap_cnt = 0;
-		ip->size = PAGE_ALIGN(sizeof(struct ipath_rwq) +
-				      srq->rq.size * sz);
-		spin_lock_irq(&dev->pending_lock);
-		ip->next = dev->pending_mmaps;
-		dev->pending_mmaps = ip;
-		spin_unlock_irq(&dev->pending_lock);
 	} else
 		srq->ip = NULL;
 
@@ -181,21 +172,27 @@ struct ib_srq *ipath_create_srq(struct ib_pd *ibpd,
 	if (dev->n_srqs_allocated == ib_ipath_max_srqs) {
 		spin_unlock(&dev->n_srqs_lock);
 		ret = ERR_PTR(-ENOMEM);
-		goto bail_wq;
+		goto bail_ip;
 	}
 
  	dev->n_srqs_allocated++;
 	spin_unlock(&dev->n_srqs_lock);
 
+	if (srq->ip) {
+		spin_lock_irq(&dev->pending_lock);
+		list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
+		spin_unlock_irq(&dev->pending_lock);
+	}
+
 	ret = &srq->ibsrq;
 	goto done;
 
+bail_ip:
+	kfree(srq->ip);
 bail_wq:
 	vfree(srq->rq.wq);
-
 bail_srq:
 	kfree(srq);
-
 done:
 	return ret;
 }
@@ -312,13 +309,13 @@ int ipath_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 		if (srq->ip) {
 			struct ipath_mmap_info *ip = srq->ip;
 			struct ipath_ibdev *dev = to_idev(srq->ibsrq.device);
+			u32 s = sizeof(struct ipath_rwq) + size * sz;
 
-			ip->obj = wq;
-			ip->size = PAGE_ALIGN(sizeof(struct ipath_rwq) +
-					      size * sz);
+			ipath_update_mmap_info(dev, ip, s, wq);
 			spin_lock_irq(&dev->pending_lock);
-			ip->next = dev->pending_mmaps;
-			dev->pending_mmaps = ip;
+			if (list_empty(&ip->pending_mmaps))
+				list_add(&ip->pending_mmaps,
+					 &dev->pending_mmaps);
 			spin_unlock_irq(&dev->pending_lock);
 		}
 	} else if (attr_mask & IB_SRQ_LIMIT) {