| Message ID | 20170407075723.9669-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
From: Colin King <colin.king@canonical.com> Date: Fri, 7 Apr 2017 08:57:23 +0100 > From: Colin Ian King <colin.king@canonical.com> > > There is a path where ibmr is null and ret has not been initialized > and hence a pr_warn message is printing an uninitialized value in > ret. Fix this by initializing ret to zero. > > Detected by CoverityScan, CID#1357946 ("Uninitialized scalar variable") > > Signed-off-by: Colin Ian King <colin.king@canonical.com> These are exactly the kinds of CoverityScan fixes I really do not want to see. Initializing ret to zero is not going to fix the problem. This function gets error pointers back from the functions that are used to obtain the ibmr pointer. Therefore if there is a problem ibmr won't be NULL, it will be an error pointer. Therefore, the real problem is that the code isn't checking if ibmr encodes error value. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Setting it to zero doesn't seem like the right thing, it should be an
error code. Oh, heh... Smatch parses this one correctly. "ret" is
always initialized but the code is probably buggy in a different way:
net/rds/ib_rdma.c
539 void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
540 struct rds_sock *rs, u32 *key_ret)
541 {
542 struct rds_ib_device *rds_ibdev;
543 struct rds_ib_mr *ibmr = NULL;
544 struct rds_ib_connection *ic = rs->rs_conn->c_transport_data;
545 int ret;
546
547 rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
548 if (!rds_ibdev) {
549 ret = -ENODEV;
550 goto out;
551 }
552
553 if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) {
554 ret = -ENODEV;
555 goto out;
556 }
557
558 if (rds_ibdev->use_fastreg)
559 ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
560 else
561 ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret);
562 if (ibmr)
^^^^
This condition is always true because those functions return ERR_PTRs
not NULLs.
563 rds_ibdev = NULL;
564
565 out:
566 if (!ibmr)
^^^^^
This condition implies that "ret" is set to an error code.
567 pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
568
569 if (rds_ibdev)
570 rds_ib_dev_put(rds_ibdev);
571
572 return ibmr;
573 }
regards,
dan carpenter
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On 4/7/2017 7:24 AM, Dan Carpenter wrote: > Setting it to zero doesn't seem like the right thing, it should be an > error code. Oh, heh... Smatch parses this one correctly. "ret" is > always initialized but the code is probably buggy in a different way: > [...] > 561 ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret); > 562 if (ibmr) > ^^^^ > This condition is always true because those functions return ERR_PTRs > not NULLs. > Thanks Dan. I will fix that up. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c index 977f69886c00..4fd637491dd5 100644 --- a/net/rds/ib_rdma.c +++ b/net/rds/ib_rdma.c @@ -542,7 +542,7 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, struct rds_ib_device *rds_ibdev; struct rds_ib_mr *ibmr = NULL; struct rds_ib_connection *ic = rs->rs_conn->c_transport_data; - int ret; + int ret = 0; rds_ibdev = rds_ib_get_device(rs->rs_bound_addr); if (!rds_ibdev) {