On Wed, Jul 04, 2018 at 12:41:53PM +0200, Walter Harms wrote: > > Am 04.07.2018 11:32, schrieb Dan Carpenter: > > "nents" is an unsigned int, so if ib_map_mr_sg() returns a negative > > error code then it's type promoted to a high unsigned int which is > > treated as success. > > > > Fixes: a060b5629ab0 ("IB/core: generic RDMA READ/WRITE API") > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > > > diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c > > index c8963e91f92a..3ee0adfb45e9 100644 > > --- a/drivers/infiniband/core/rw.c > > +++ b/drivers/infiniband/core/rw.c > > @@ -87,7 +87,7 @@ static int rdma_rw_init_one_mr(struct ib_qp *qp, u8 > > port_num, > > } > > > > ret = ib_map_mr_sg(reg->mr, sg, nents, &offset, PAGE_SIZE); > > - if (ret < nents) { > > + if (ret < 0 || ret < nents) { > > ib_mr_pool_put(qp, &qp->rdma_mrs, reg->mr); > > return -EINVAL; > > } > > I do not understand the error here. > > ib_map_mr_sg() obviously knows about nents and returns an invalid value ? > Or is that a special case here ? > ib_map_mr_sg() can return -ENOMEM, -EINVAL, other error codes or a positive number <= to nents. If it returns -ENOMEM then that's type promoted to a high positive value (more than nents for sure) and treated as success. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html