IB/core: Check for global flag when using ah_attr

Read/write grh fields of the ah_attr only if the
ah_flags field has the IB_AH_GRH bit enabled

Reviewed-by: Ira Weiny <[e-mail]>
Reviewed-by: Don Hiatt <[e-mail]>
Reviewed-by: Sean Hefty <[e-mail]>
Signed-off-by: Dasaratharaman Chandramouli <[e-mail]>
Signed-off-by: Doug Ledford <[e-mail]>

drivers/infiniband/core/uverbs_cmd.c

···
 	resp.alt_port_num           = attr->alt_port_num;
 	resp.alt_timeout            = attr->alt_timeout;
 
-	memcpy(resp.dest.dgid, attr->ah_attr.grh.dgid.raw, 16);
-	resp.dest.flow_label        = attr->ah_attr.grh.flow_label;
-	resp.dest.sgid_index        = attr->ah_attr.grh.sgid_index;
-	resp.dest.hop_limit         = attr->ah_attr.grh.hop_limit;
-	resp.dest.traffic_class     = attr->ah_attr.grh.traffic_class;
 	resp.dest.dlid              = attr->ah_attr.dlid;
 	resp.dest.sl                = attr->ah_attr.sl;
 	resp.dest.src_path_bits     = attr->ah_attr.src_path_bits;
 	resp.dest.static_rate       = attr->ah_attr.static_rate;
 	resp.dest.is_global         = !!(attr->ah_attr.ah_flags & IB_AH_GRH);
+	if (resp.dest.is_global) {
+		memcpy(resp.dest.dgid, attr->ah_attr.grh.dgid.raw, 16);
+		resp.dest.flow_label        = attr->ah_attr.grh.flow_label;
+		resp.dest.sgid_index        = attr->ah_attr.grh.sgid_index;
+		resp.dest.hop_limit         = attr->ah_attr.grh.hop_limit;
+		resp.dest.traffic_class     = attr->ah_attr.grh.traffic_class;
+	}
 	resp.dest.port_num          = attr->ah_attr.port_num;
 
-	memcpy(resp.alt_dest.dgid, attr->alt_ah_attr.grh.dgid.raw, 16);
-	resp.alt_dest.flow_label    = attr->alt_ah_attr.grh.flow_label;
-	resp.alt_dest.sgid_index    = attr->alt_ah_attr.grh.sgid_index;
-	resp.alt_dest.hop_limit     = attr->alt_ah_attr.grh.hop_limit;
-	resp.alt_dest.traffic_class = attr->alt_ah_attr.grh.traffic_class;
 	resp.alt_dest.dlid          = attr->alt_ah_attr.dlid;
 	resp.alt_dest.sl            = attr->alt_ah_attr.sl;
 	resp.alt_dest.src_path_bits = attr->alt_ah_attr.src_path_bits;
 	resp.alt_dest.static_rate   = attr->alt_ah_attr.static_rate;
 	resp.alt_dest.is_global     = !!(attr->alt_ah_attr.ah_flags & IB_AH_GRH);
+	if (resp.alt_dest.is_global) {
+		memcpy(resp.alt_dest.dgid, attr->alt_ah_attr.grh.dgid.raw, 16);
+		resp.alt_dest.flow_label    = attr->alt_ah_attr.grh.flow_label;
+		resp.alt_dest.sgid_index    = attr->alt_ah_attr.grh.sgid_index;
+		resp.alt_dest.hop_limit     = attr->alt_ah_attr.grh.hop_limit;
+		resp.alt_dest.traffic_class =
+				attr->alt_ah_attr.grh.traffic_class;
+	}
 	resp.alt_dest.port_num      = attr->alt_ah_attr.port_num;
 
 	resp.max_send_wr            = init_attr->cap.max_send_wr;
···
 	attr->alt_timeout	  = cmd->base.alt_timeout;
 	attr->rate_limit	  = cmd->rate_limit;
 
-	memcpy(attr->ah_attr.grh.dgid.raw, cmd->base.dest.dgid, 16);
-	attr->ah_attr.grh.flow_label	= cmd->base.dest.flow_label;
-	attr->ah_attr.grh.sgid_index	= cmd->base.dest.sgid_index;
-	attr->ah_attr.grh.hop_limit	= cmd->base.dest.hop_limit;
-	attr->ah_attr.grh.traffic_class	= cmd->base.dest.traffic_class;
+	if (cmd->base.dest.is_global) {
+		memcpy(attr->ah_attr.grh.dgid.raw, cmd->base.dest.dgid, 16);
+		attr->ah_attr.grh.flow_label	= cmd->base.dest.flow_label;
+		attr->ah_attr.grh.sgid_index	= cmd->base.dest.sgid_index;
+		attr->ah_attr.grh.hop_limit	= cmd->base.dest.hop_limit;
+		attr->ah_attr.grh.traffic_class	= cmd->base.dest.traffic_class;
+		attr->ah_attr.ah_flags		= IB_AH_GRH;
+	} else {
+		attr->ah_attr.ah_flags = 0;
+	}
 	attr->ah_attr.dlid		= cmd->base.dest.dlid;
 	attr->ah_attr.sl		= cmd->base.dest.sl;
 	attr->ah_attr.src_path_bits	= cmd->base.dest.src_path_bits;
 	attr->ah_attr.static_rate	= cmd->base.dest.static_rate;
-	attr->ah_attr.ah_flags		= cmd->base.dest.is_global ?
-					  IB_AH_GRH : 0;
 	attr->ah_attr.port_num		= cmd->base.dest.port_num;
 
-	memcpy(attr->alt_ah_attr.grh.dgid.raw, cmd->base.alt_dest.dgid, 16);
-	attr->alt_ah_attr.grh.flow_label    = cmd->base.alt_dest.flow_label;
-	attr->alt_ah_attr.grh.sgid_index    = cmd->base.alt_dest.sgid_index;
-	attr->alt_ah_attr.grh.hop_limit     = cmd->base.alt_dest.hop_limit;
-	attr->alt_ah_attr.grh.traffic_class = cmd->base.alt_dest.traffic_class;
+	if (cmd->base.alt_dest.is_global) {
+		memcpy(attr->alt_ah_attr.grh.dgid.raw,
+		       cmd->base.alt_dest.dgid, 16);
+		attr->alt_ah_attr.grh.flow_label =
+				cmd->base.alt_dest.flow_label;
+		attr->alt_ah_attr.grh.sgid_index =
+				cmd->base.alt_dest.sgid_index;
+		attr->alt_ah_attr.grh.hop_limit =
+				cmd->base.alt_dest.hop_limit;
+		attr->alt_ah_attr.grh.traffic_class =
+				cmd->base.alt_dest.traffic_class;
+		attr->alt_ah_attr.ah_flags = IB_AH_GRH;
+	} else {
+		attr->alt_ah_attr.ah_flags = 0;
+	}
 	attr->alt_ah_attr.dlid		    = cmd->base.alt_dest.dlid;
 	attr->alt_ah_attr.sl		    = cmd->base.alt_dest.sl;
 	attr->alt_ah_attr.src_path_bits	    = cmd->base.alt_dest.src_path_bits;
 	attr->alt_ah_attr.static_rate	    = cmd->base.alt_dest.static_rate;
-	attr->alt_ah_attr.ah_flags	    = cmd->base.alt_dest.is_global ?
-					      IB_AH_GRH : 0;
 	attr->alt_ah_attr.port_num	    = cmd->base.alt_dest.port_num;
 
 	if (qp->real_qp == qp) {
···
 	attr.sl 	       = cmd.attr.sl;
 	attr.src_path_bits     = cmd.attr.src_path_bits;
 	attr.static_rate       = cmd.attr.static_rate;
-	attr.ah_flags          = cmd.attr.is_global ? IB_AH_GRH : 0;
 	attr.port_num 	       = cmd.attr.port_num;
-	attr.grh.flow_label    = cmd.attr.grh.flow_label;
-	attr.grh.sgid_index    = cmd.attr.grh.sgid_index;
-	attr.grh.hop_limit     = cmd.attr.grh.hop_limit;
-	attr.grh.traffic_class = cmd.attr.grh.traffic_class;
 	memset(&attr.dmac, 0, sizeof(attr.dmac));
-	memcpy(attr.grh.dgid.raw, cmd.attr.grh.dgid, 16);
+	if (cmd.attr.is_global) {
+		attr.ah_flags          = IB_AH_GRH;
+		attr.grh.flow_label    = cmd.attr.grh.flow_label;
+		attr.grh.sgid_index    = cmd.attr.grh.sgid_index;
+		attr.grh.hop_limit     = cmd.attr.grh.hop_limit;
+		attr.grh.traffic_class = cmd.attr.grh.traffic_class;
+		memcpy(attr.grh.dgid.raw, cmd.attr.grh.dgid, 16);
+	} else {
+		attr.ah_flags = 0;
+	}
 
 	ah = pd->device->create_ah(pd, &attr, &udata);
 

drivers/infiniband/core/uverbs_marshall.c

···
 void ib_copy_ah_attr_to_user(struct ib_uverbs_ah_attr *dst,
 			     struct ib_ah_attr *src)
 {
-	memcpy(dst->grh.dgid, src->grh.dgid.raw, sizeof(src->grh.dgid));
-	dst->grh.flow_label        = src->grh.flow_label;
-	dst->grh.sgid_index        = src->grh.sgid_index;
-	dst->grh.hop_limit         = src->grh.hop_limit;
-	dst->grh.traffic_class     = src->grh.traffic_class;
 	memset(&dst->grh.reserved, 0, sizeof(dst->grh.reserved));
 	dst->dlid 	    	   = src->dlid;
 	dst->sl   	    	   = src->sl;
 	dst->src_path_bits 	   = src->src_path_bits;
 	dst->static_rate   	   = src->static_rate;
 	dst->is_global             = src->ah_flags & IB_AH_GRH ? 1 : 0;
+	if (dst->is_global) {
+		memcpy(dst->grh.dgid, src->grh.dgid.raw, sizeof(src->grh.dgid));
+		dst->grh.flow_label        = src->grh.flow_label;
+		dst->grh.sgid_index        = src->grh.sgid_index;
+		dst->grh.hop_limit         = src->grh.hop_limit;
+		dst->grh.traffic_class     = src->grh.traffic_class;
+	}
 	dst->port_num 	    	   = src->port_num;
 	dst->reserved 		   = 0;
 }