Hello Horatiu Vultur,
This is a semi-automatic email about new static checker warnings.
The patch 7c588c3e96e9: "net: ocelot: Extend MRP" from Mar 16, 2021,
leads to the following Smatch complaint:
drivers/net/ethernet/mscc/ocelot_mrp.c:180 ocelot_mrp_del()
error: we previously assumed 'ocelot_port' could be null (see line 173)
drivers/net/ethernet/mscc/ocelot_mrp.c
153 int ocelot_mrp_del(struct ocelot *ocelot, int port,
154 const struct switchdev_obj_mrp *mrp)
155 {
156 struct ocelot_port *ocelot_port = ocelot->ports[port];
157 int i;
158
159 if (!ocelot_port)
160 return -EOPNOTSUPP;
161
162 if (ocelot_port->mrp_ring_id != mrp->ring_id)
163 return 0;
164
165 ocelot_mrp_del_vcap(ocelot, port);
166 ocelot_mrp_del_vcap(ocelot, port + ocelot->num_phys_ports);
167
168 ocelot_port->mrp_ring_id = 0;
169
170 for (i = 0; i < ocelot->num_phys_ports; ++i) {
This loop tries to verify that all the ports have ring_id == 0 otherwise
we return. It's slightly confusing why this matters.
171 ocelot_port = ocelot->ports[i];
172
173 if (!ocelot_port)
^^^^^^^^^^^
Assume the last element of the array is NULL
174 continue;
175
176 if (ocelot_port->mrp_ring_id != 0)
177 goto out;
This would be more clear if instead of a "goto out;" it just did a
direct "return 0;"
178 }
179
180 ocelot_mrp_del_mac(ocelot, ocelot_port);
We delete the last mac address of all the ring_ids are zero but if the
last port is zero it will crash.
181 out:
182 return 0;
regards,
dan carpenter
