From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Date: Thu, 12 Nov 2020 18:30:23 +0000 Subject: Re: [PATCH] IB/srpt: Fix passing zero to 'PTR_ERR' Message-Id: <20201112183023.GB917484@nvidia.com> List-Id: References: <20201112145443.17832-1-yuehaibing@huawei.com> <20201112172008.GA944848@nvidia.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Bart Van Assche Cc: YueHaibing , dledford@redhat.com, linux-rdma@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org On Thu, Nov 12, 2020 at 10:25:48AM -0800, Bart Van Assche wrote: > On 11/12/20 9:20 AM, Jason Gunthorpe wrote: > > I think it should be like this, Bart? > > > > diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c > > index 6017d525084a0c..80f9673956ced2 100644 > > +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c > > @@ -2311,7 +2311,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, > > mutex_lock(&sport->port_guid_id.mutex); > > list_for_each_entry(stpg, &sport->port_guid_id.tpg_list, entry) { > > - if (!IS_ERR_OR_NULL(ch->sess)) > > + if (ch->sess) > > break; > > ch->sess = target_setup_session(&stpg->tpg, tag_num, > > tag_size, TARGET_PROT_NORMAL, > > @@ -2321,12 +2321,12 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, > > mutex_lock(&sport->port_gid_id.mutex); > > list_for_each_entry(stpg, &sport->port_gid_id.tpg_list, entry) { > > - if (!IS_ERR_OR_NULL(ch->sess)) > > + if (ch->sess) > > break; > > ch->sess = target_setup_session(&stpg->tpg, tag_num, > > tag_size, TARGET_PROT_NORMAL, i_port_id, > > ch, NULL); > > - if (!IS_ERR_OR_NULL(ch->sess)) > > + if (ch->sess) > > break; > > /* Retry without leading "0x" */ > > ch->sess = target_setup_session(&stpg->tpg, tag_num, > > @@ -2335,7 +2335,9 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, > > } > > mutex_unlock(&sport->port_gid_id.mutex); > > - if (IS_ERR_OR_NULL(ch->sess)) { > > + if (!ch->sess) > > + ch->sess = ERR_PTR(-ENOENT); > > + if (IS_ERR(ch->sess)) { > > WARN_ON_ONCE(ch->sess = NULL); > > ret = PTR_ERR(ch->sess); > > ch->sess = NULL; > > > > Hi Jason, > > The ib_srpt driver accepts three different formats for the initiator ACL. Up > to two of the three target_setup_session() calls will fail if the fifth > argument of target_setup_session() does not use the format of the initiator > ID in configfs. If the first or the second target_setup_session() call fails > it is essential that later target_setup_session() calls happen. Hence the > IS_ERR_OR_NULL(ch->sess) checks in the above loops. IS_ERR_OR_NULL is an abomination, it should not be used. I see I didn't quite get it right, but that is still closer to sane, probably target_setup_session() should return NULL not err_ptr Jason