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SubjectRe: [PATCH 2/2] ftpm: firmware TPM running in TEE
On Tue, Apr 02, 2019 at 03:33:16PM -0400, Sasha Levin wrote:

> +/*
> + * Undo what has been done in ftpm_tee_probe
> + */
> +static void ftpm_tee_deinit(struct ftpm_tee_private *pvt_data)
> +{
> + /* Release the chip */
> + if (pvt_data->state & STATE_REGISTERED_FLAG)
> + tpm_chip_unregister(pvt_data->chip);
> +
> + if (pvt_data->ctx != NULL) {
> +
> + /* Free the shared memory pool */
> + if (pvt_data->state & STATE_TEE_SHMALLOC_FLAG)
> + tee_shm_free(pvt_data->shm);
> +
> + /* close the existing session with fTPM TA*/
> + if (pvt_data->state & STATE_TEE_OPENED_FLAG)
> + tee_client_close_session(pvt_data->ctx,
> + pvt_data->session);
> +
> + /* close the context with TEE driver */
> + tee_client_close_context(pvt_data->ctx);
> + }

all these flags are ugly, just use a normal goto unwind during probe
please


> +
> + /* memory allocated with devm_kzalloc() is freed automatically */
> +}
> +
> +/*
> + * ftpm_tee_probe initialize the fTPM
> + * @param: pdev, the platform_device description.
> + * @return: 0 in case of success.
> + * or a negative value describing the error.
> + */
> +static int ftpm_tee_probe(struct platform_device *pdev)
> +{
> + int rc;
> + struct tpm_chip *chip;
> + struct device *dev = &pdev->dev;
> + struct ftpm_tee_private *pvt_data = NULL;
> + struct tee_ioctl_open_session_arg sess_arg;
> +
> + dev_dbg(dev, "%s++\n", __func__);

Please don't push tracing like this to the upstream kernel, we have
ftrace and what not to do this generally :(

> + pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private),
> + GFP_KERNEL);
> + if (!pvt_data)
> + return -ENOMEM;
> +
> + dev_set_drvdata(dev, pvt_data);
> +
> + /* Open context with TEE driver */
> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL,
> + NULL);
> + if (IS_ERR(pvt_data->ctx)) {
> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__);
> + return -EPROBE_DEFER;
> + }
> +
> + /* Open a session with fTPM TA*/
> + memset(&sess_arg, 0, sizeof(sess_arg));
> + memcpy(sess_arg.uuid, ftpm_ta_uuid.b, TEE_IOCTL_UUID_LEN);
> + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> + sess_arg.num_params = 0;
> +
> + rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL);
> + if ((rc < 0) || (sess_arg.ret != 0)) {
> + dev_err(dev, "%s:tee_client_open_session failed, err=%x\n",
> + __func__, sess_arg.ret);
> + rc = -EINVAL;
> + goto out;
> + }
> + pvt_data->session = sess_arg.session;
> + pvt_data->state |= STATE_TEE_OPENED_FLAG;
> +
> + /* Allocate dynamic shared memory with fTPM TA */
> + pvt_data->shm = tee_shm_alloc(pvt_data->ctx,
> + (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE),
> + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
> + if (IS_ERR(pvt_data->shm)) {
> + dev_err(dev, "%s:tee_shm_alloc failed\n", __func__);
> + rc = -ENOMEM;
> + goto out;
> + }
> + pvt_data->state |= STATE_TEE_SHMALLOC_FLAG;
> +
> + /* Allocate new struct tpm_chip instance */
> + chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops);

Why not tpmm_chip_alloc ? Using devm in other places

Doesn't this leak memory? I don't see a put_device cleanup for chip_alloc?

> + if (IS_ERR(chip)) {
> + dev_err(dev, "%s:tpm_chip_alloc failed\n", __func__);
> + rc = PTR_ERR(chip);
> + goto out;
> + }
> +
> + pvt_data->chip = chip;
> + pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
> +
> + /* Create a character device for the fTPM */
> + rc = tpm_chip_register(pvt_data->chip);

It is a bad idea to do things after tpm_chip_register, it should be
the last thing done during probe except for error cleanup via a goto
unwind.

Jason

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