IB/usnic: Handle 0 counts in resource allocation

Signed-off-by: Dave Goodell <dgoodell@cisco.com>
Reviewed-by: Reese Faucette <rfaucett@cisco.com>
Reviewed-by: Xuyang Wang <xuywang@cisco.com>
Signed-off-by: Nelson Escobar <neescoba@cisco.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/usnic/usnic_vnic.c

@@ -237,7 +237,7 @@ usnic_vnic_get_resources(struct usnic_vnic *vnic, enum usnic_vnic_res_type type,
 	struct usnic_vnic_res *res;
 	int i;
 
-	if (usnic_vnic_res_free_cnt(vnic, type) < cnt || cnt < 1 || !owner)
+	if (usnic_vnic_res_free_cnt(vnic, type) < cnt || cnt < 0 || !owner)
 		return ERR_PTR(-EINVAL);
 
 	ret = kzalloc(sizeof(*ret), GFP_ATOMIC);
@@ -247,7 +247,8 @@ usnic_vnic_get_resources(struct usnic_vnic *vnic, enum usnic_vnic_res_type type,
 		return ERR_PTR(-ENOMEM);
 	}
 
-	ret->res = kzalloc(sizeof(*(ret->res))*cnt, GFP_ATOMIC);
+	if (cnt > 0) {
+		ret->res = kcalloc(cnt, sizeof(*(ret->res)), GFP_ATOMIC);
 		if (!ret->res) {
 			usnic_err("Failed to allocate resources for %s. Out of memory\n",
 					usnic_vnic_pci_name(vnic));
@@ -267,6 +268,7 @@ usnic_vnic_get_resources(struct usnic_vnic *vnic, enum usnic_vnic_res_type type,
 		}
 
 		spin_unlock(&vnic->res_lock);
+	}
 	ret->type = type;
 	ret->vnic = vnic;
 	WARN_ON(ret->cnt != cnt);
@@ -281,6 +283,7 @@ void usnic_vnic_put_resources(struct usnic_vnic_res_chunk *chunk)
 	int i;
 	struct usnic_vnic *vnic = chunk->vnic;
 
+	if (chunk->cnt > 0) {
 		spin_lock(&vnic->res_lock);
 		while ((i = --chunk->cnt) >= 0) {
 			res = chunk->res[i];
@@ -289,6 +292,7 @@ void usnic_vnic_put_resources(struct usnic_vnic_res_chunk *chunk)
 			vnic->chunks[res->type].free_cnt++;
 		}
 		spin_unlock(&vnic->res_lock);
+	}
 
 	kfree(chunk->res);
 	kfree(chunk);