Hello Azhar Shaikh,
This is a semi-automatic email about new static checker warnings.
The patch b3e958ce4c58: "tpm: Keep CLKRUN enabled throughout the
duration of transmit_cmd()" from Dec 22, 2017, leads to the following
Smatch complaint:
drivers/char/tpm/tpm_tis_core.c:1004 tpm_tis_core_init()
warn: variable dereferenced before check 'chip->ops' (see line 902)
drivers/char/tpm/tpm_tis_core.c
901
902 if (chip->ops->clk_enable != NULL)
^^^^^^^^^^^
The patch adds a new unchecked dereference.
903 chip->ops->clk_enable(chip, true);
904
905 if (wait_startup(chip, 0) != 0) {
906 rc = -ENODEV;
907 goto out_err;
908 }
909
910 /* Take control of the TPM's interrupt hardware and shut it off */
911 rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
912 if (rc < 0)
913 goto out_err;
914
915 intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
916 TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
917 intmask &= ~TPM_GLOBAL_INT_ENABLE;
918 tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
919
920 rc = tpm2_probe(chip);
921 if (rc)
922 goto out_err;
923
924 rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
925 if (rc < 0)
926 goto out_err;
927
928 priv->manufacturer_id = vendor;
929
930 rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
931 if (rc < 0)
932 goto out_err;
933
934 dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
935 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
936 vendor >> 16, rid);
937
938 probe = probe_itpm(chip);
939 if (probe < 0) {
940 rc = -ENODEV;
941 goto out_err;
942 }
943
944 /* Figure out the capabilities */
945 rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
946 if (rc < 0)
947 goto out_err;
948
949 dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
950 intfcaps);
951 if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
952 dev_dbg(dev, "\tBurst Count Static\n");
953 if (intfcaps & TPM_INTF_CMD_READY_INT)
954 dev_dbg(dev, "\tCommand Ready Int Support\n");
955 if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
956 dev_dbg(dev, "\tInterrupt Edge Falling\n");
957 if (intfcaps & TPM_INTF_INT_EDGE_RISING)
958 dev_dbg(dev, "\tInterrupt Edge Rising\n");
959 if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
960 dev_dbg(dev, "\tInterrupt Level Low\n");
961 if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
962 dev_dbg(dev, "\tInterrupt Level High\n");
963 if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
964 dev_dbg(dev, "\tLocality Change Int Support\n");
965 if (intfcaps & TPM_INTF_STS_VALID_INT)
966 dev_dbg(dev, "\tSts Valid Int Support\n");
967 if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
968 dev_dbg(dev, "\tData Avail Int Support\n");
969
970 /* INTERRUPT Setup */
971 init_waitqueue_head(&priv->read_queue);
972 init_waitqueue_head(&priv->int_queue);
973 if (irq != -1) {
974 /* Before doing irq testing issue a command to the TPM in polling mode
975 * to make sure it works. May as well use that command to set the
976 * proper timeouts for the driver.
977 */
978 if (tpm_get_timeouts(chip)) {
979 dev_err(dev, "Could not get TPM timeouts and durations\n");
980 rc = -ENODEV;
981 goto out_err;
982 }
983
984 if (irq) {
985 tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
986 irq);
987 if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
988 dev_err(&chip->dev, FW_BUG
989 "TPM interrupt not working, polling instead\n");
990 } else {
991 tpm_tis_probe_irq(chip, intmask);
992 }
993 }
994
995 rc = tpm_chip_register(chip);
996 if (rc)
997 goto out_err;
998
999 if (chip->ops->clk_enable != NULL)
1000 chip->ops->clk_enable(chip, false);
1001
1002 return 0;
1003 out_err:
1004 if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
^^^^^^^^^
And a new check. Presumably the check can be removed.
1005 chip->ops->clk_enable(chip, false);
1006
regards,
dan carpenter
