[bug report] PCI: endpoint: Remove "core_init_notifier" flag

From: Dan Carpenter <dan.carpenter@linaro.org>
To: manivannan.sadhasivam@linaro.org
Cc: linux-pci@vger.kernel.org
Subject: [bug report] PCI: endpoint: Remove "core_init_notifier" flag
Date: Wed, 17 Apr 2024 15:47:48 +0300	[thread overview]
Message-ID: <024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain> (raw)

Hello Manivannan Sadhasivam,

Commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
flag") from Mar 27, 2024 (linux-next), leads to the following Smatch
static checker warning:

	drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init()
	error: we previously assumed 'epc_features' could be null (see line 747)

drivers/pci/endpoint/functions/pci-epf-test.c
    734 static int pci_epf_test_core_init(struct pci_epf *epf)
    735 {
    736         struct pci_epf_test *epf_test = epf_get_drvdata(epf);
    737         struct pci_epf_header *header = epf->header;
    738         const struct pci_epc_features *epc_features;
    739         struct pci_epc *epc = epf->epc;
    740         struct device *dev = &epf->dev;
    741         bool linkup_notifier = false;
    742         bool msix_capable = false;
    743         bool msi_capable = true;
    744         int ret;
    745 
    746         epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
    747         if (epc_features) {
                    ^^^^^^^^^^^^
epc_features can be NULL

    748                 msix_capable = epc_features->msix_capable;
    749                 msi_capable = epc_features->msi_capable;
    750         }
    751 
    752         if (epf->vfunc_no <= 1) {
    753                 ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no, header);
    754                 if (ret) {
    755                         dev_err(dev, "Configuration header write failed\n");
    756                         return ret;
    757                 }
    758         }
    759 
    760         ret = pci_epf_test_set_bar(epf);
    761         if (ret)
    762                 return ret;
    763 
    764         if (msi_capable) {
    765                 ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
    766                                       epf->msi_interrupts);
    767                 if (ret) {
    768                         dev_err(dev, "MSI configuration failed\n");
    769                         return ret;
    770                 }
    771         }
    772 
    773         if (msix_capable) {
    774                 ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no,
    775                                        epf->msix_interrupts,
    776                                        epf_test->test_reg_bar,
    777                                        epf_test->msix_table_offset);
    778                 if (ret) {
    779                         dev_err(dev, "MSI-X configuration failed\n");
    780                         return ret;
    781                 }
    782         }
    783 
--> 784         linkup_notifier = epc_features->linkup_notifier;
                                  ^^^^^^^^^^^^^^
Unchecked dereference.

    785         if (!linkup_notifier)
    786                 queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);
    787 
    788         return 0;
    789 }

regards,
dan carpenter