Hello Steve Wise,
The patch 056f9c7f39bf: "iw_cxgb4: dump detailed driver-specific QP
information" from May 3, 2018, leads to the following static checker
warning:
drivers/infiniband/hw/cxgb4/restrack.c:228 fill_res_qp_entry()
error: uninitialized symbol 'first_sq_idx'.
drivers/infiniband/hw/cxgb4/restrack.c
170 static int fill_res_qp_entry(struct sk_buff *msg,
171 struct rdma_restrack_entry *res)
172 {
173 struct ib_qp *ibqp = container_of(res, struct ib_qp, res);
174 struct t4_swsqe *fsp = NULL, *lsp = NULL;
175 struct t4_swrqe *frp = NULL, *lrp = NULL;
176 struct c4iw_qp *qhp = to_c4iw_qp(ibqp);
177 struct t4_swsqe first_sqe, last_sqe;
178 struct t4_swrqe first_rqe, last_rqe;
179 u16 first_sq_idx, last_sq_idx;
^^^^^^^^^^^^
180 u16 first_rq_idx, last_rq_idx;
181 struct nlattr *table_attr;
182 struct t4_wq wq;
183
184 /* User qp state is not available, so don't dump user qps */
185 if (qhp->ucontext)
186 return 0;
187
188 table_attr = nla_nest_start(msg, RDMA_NLDEV_ATTR_DRIVER);
189 if (!table_attr)
190 goto err;
191
192 /* Get a consistent snapshot */
193 spin_lock_irq(&qhp->lock);
194 wq = qhp->wq;
195
196 /* If there are any pending sqes, copy the first and last */
197 if (wq.sq.cidx != wq.sq.pidx) {
198 first_sq_idx = wq.sq.cidx;
^^^^^^^^^^^^^^^^^^^^^^^^^
Only initialized here.
199 first_sqe = qhp->wq.sq.sw_sq[first_sq_idx];
200 fsp = &first_sqe;
201 last_sq_idx = wq.sq.pidx;
202 if (last_sq_idx-- == 0)
203 last_sq_idx = wq.sq.size - 1;
204 if (last_sq_idx != first_sq_idx) {
205 last_sqe = qhp->wq.sq.sw_sq[last_sq_idx];
206 lsp = &last_sqe;
207 }
208 }
209
210 /* If there are any pending rqes, copy the first and last */
211 if (wq.rq.cidx != wq.rq.pidx) {
212 first_rq_idx = wq.rq.cidx;
213 first_rqe = qhp->wq.rq.sw_rq[first_rq_idx];
214 frp = &first_rqe;
215 last_rq_idx = wq.rq.pidx;
216 if (last_rq_idx-- == 0)
217 last_rq_idx = wq.rq.size - 1;
218 if (last_rq_idx != first_rq_idx) {
219 last_rqe = qhp->wq.rq.sw_rq[last_rq_idx];
220 lrp = &last_rqe;
221 }
222 }
223 spin_unlock_irq(&qhp->lock);
224
225 if (fill_sq(msg, &wq))
226 goto err_cancel_table;
227
228 if (fill_swsqes(msg, &wq.sq, first_sq_idx, fsp, last_sq_idx, lsp))
^^^^^^^^^^^^
On the one hand, it's not a bug to pass uninitialized data when "fsb" is
NULL...
229 goto err_cancel_table;
230
231 if (fill_rq(msg, &wq))
232 goto err_cancel_table;
233
234 if (fill_swrqes(msg, &wq.rq, first_rq_idx, frp, last_rq_idx, lrp))
235 goto err_cancel_table;
236
237 nla_nest_end(msg, table_attr);
238 return 0;
239
240 err_cancel_table:
241 nla_nest_cancel(msg, table_attr);
242 err:
243 return -EMSGSIZE;
244 }
See also:
drivers/infiniband/hw/cxgb4/restrack.c:228 fill_res_qp_entry() error: uninitialized symbol 'last_sq_idx'.
drivers/infiniband/hw/cxgb4/restrack.c:234 fill_res_qp_entry() error: uninitialized symbol 'first_rq_idx'.
drivers/infiniband/hw/cxgb4/restrack.c:234 fill_res_qp_entry() error: uninitialized symbol 'last_rq_idx'.
regards,
dan carpenter
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