On Wed, Jun 20, 2018 at 12:19:43PM -0400, Stefan Berger wrote:
> Introduce a kref for the tpm_chip that we initialize when the tpm_chip has
> been allocated and release before the tpm_chip is to be freed.
>
> Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
> drivers/char/tpm/tpm-chip.c | 24 +++++++++++++++++++-----
> drivers/char/tpm/tpm.h | 1 +
> 2 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 0a62c19937b6..a933676194a4 100644
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -119,8 +119,24 @@ struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip)
> return res;
> }
>
> +static void tpm_chip_free(struct kref *kref)
> +{
> + struct tpm_chip *chip = container_of(kref, struct tpm_chip, kref);
> +
> + kfree(chip->log.bios_event_log);
> + kfree(chip->work_space.context_buf);
> + kfree(chip->work_space.session_buf);
> + kfree(chip);
> +}
> +
> +static void tpm_chip_put(struct tpm_chip *chip)
> +{
> + if (chip)
> + kref_put(&chip->kref, tpm_chip_free);
> +}
> +
> /**
> - * tpm_dev_release() - free chip memory and the device number
> + * tpm_dev_release() - free the device number and release reference to chip
> * @dev: the character device for the TPM chip
> *
> * This is used as the release function for the character device.
> @@ -133,10 +149,7 @@ static void tpm_dev_release(struct device *dev)
> idr_remove(&dev_nums_idr, chip->dev_num);
> mutex_unlock(&idr_lock);
>
> - kfree(chip->log.bios_event_log);
> - kfree(chip->work_space.context_buf);
> - kfree(chip->work_space.session_buf);
> - kfree(chip);
> + tpm_chip_put(chip);
> }
> static void tpm_devs_release(struct device *dev)
> @@ -195,6 +208,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
>
> mutex_init(&chip->tpm_mutex);
> init_rwsem(&chip->ops_sem);
> + kref_init(&chip->kref);
>
> chip->ops = ops;
>
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 7f2d0f489e9c..098d7dcc04a4 100644
> +++ b/drivers/char/tpm/tpm.h
> @@ -211,6 +211,7 @@ struct tpm_chip {
> struct cdev cdev;
> struct cdev cdevs;
>
> + struct kref kref;
NAK, there is already a kref in struct device, that one must be used.
Jason
