Re: [tpmdd-devel] [PATCH v7 06/10] tpm: fix: move sysfs attributes to the correct place.

[Stefan Berger]

On 11/11/2014 08:45 AM, Jarkko Sakkinen wrote:
> The sysfs attributes of the TPM device were created to the platform
> device directory that owns the character device instead of placing
> them correctly to the directory of the character device,
>
> They were also created in a racy way so that character device might
> become visible before sysfs attributes become available.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
>   drivers/char/tpm/tpm-chip.c  | 15 ++++++---------
>   drivers/char/tpm/tpm-dev.c   |  2 --
>   drivers/char/tpm/tpm-sysfs.c | 23 +----------------------
>   drivers/char/tpm/tpm.h       |  4 +---
>   4 files changed, 8 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index df40eee..5d268ac 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -29,6 +29,8 @@
>   #include "tpm.h"
>   #include "tpm_eventlog.h"
>
> +ATTRIBUTE_GROUPS(tpm_dev);
> +
>   static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
>   static LIST_HEAD(tpm_chip_list);
>   static DEFINE_SPINLOCK(driver_lock);
> @@ -136,6 +138,8 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
>   	else
>   		chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
>
> +	chip->dev.groups = tpm_dev_groups;
> +
>   	dev_set_name(&chip->dev, chip->devname);
>
>   	device_initialize(&chip->dev);
> @@ -209,13 +213,9 @@ int tpm_chip_register(struct tpm_chip *chip)
>   	if (rc)
>   		return rc;
>
> -	rc = tpm_sysfs_add_device(chip);
> -	if (rc)
> -		goto del_misc;
> -
>   	rc = tpm_add_ppi(chip);
>   	if (rc)
> -		goto del_sysfs;
> +		goto out_err;
>
>   	chip->bios_dir = tpm_bios_log_setup(chip->devname);
>
> @@ -225,9 +225,7 @@ int tpm_chip_register(struct tpm_chip *chip)
>   	spin_unlock(&driver_lock);
>
>   	return 0;
> -del_sysfs:
> -	tpm_sysfs_del_device(chip);
> -del_misc:
> +out_err:
>   	tpm_dev_del_device(chip);
>   	return rc;
>   }
> @@ -250,7 +248,6 @@ void tpm_chip_unregister(struct tpm_chip *chip)
>   	spin_unlock(&driver_lock);
>   	synchronize_rcu();
>
> -	tpm_sysfs_del_device(chip);
>   	tpm_remove_ppi(chip);
>
>   	if (chip->bios_dir)
> diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
> index de0337e..f3f073f 100644
> --- a/drivers/char/tpm/tpm-dev.c
> +++ b/drivers/char/tpm/tpm-dev.c
> @@ -179,5 +179,3 @@ const struct file_operations tpm_fops = {
>   	.write = tpm_write,
>   	.release = tpm_release,
>   };
> -
> -

Unnecessary changes.
> diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> index ee66fd4..9f5b85a 100644
> --- a/drivers/char/tpm/tpm-sysfs.c
> +++ b/drivers/char/tpm/tpm-sysfs.c
> @@ -263,7 +263,7 @@ static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
>   }
>   static DEVICE_ATTR_RO(timeouts);
>
> -static struct attribute *tpm_dev_attrs[] = {
> +struct attribute *tpm_dev_attrs[] = {
>   	&dev_attr_pubek.attr,
>   	&dev_attr_pcrs.attr,
>   	&dev_attr_enabled.attr,
> @@ -276,24 +276,3 @@ static struct attribute *tpm_dev_attrs[] = {
>   	&dev_attr_timeouts.attr,
>   	NULL,
>   };
> -
> -static const struct attribute_group tpm_dev_group = {
> -	.attrs = tpm_dev_attrs,
> -};
> -
> -int tpm_sysfs_add_device(struct tpm_chip *chip)
> -{
> -	int err;
> -	err = sysfs_create_group(&chip->pdev->kobj,
> -				 &tpm_dev_group);
> -
> -	if (err)
> -		dev_err(chip->pdev,
> -			"failed to create sysfs attributes, %d\n", err);
> -	return err;
> -}
> -
> -void tpm_sysfs_del_device(struct tpm_chip *chip)
> -{
> -	sysfs_remove_group(&chip->pdev->kobj, &tpm_dev_group);
> -}
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 83103e0..9d062e6 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -325,6 +325,7 @@ struct tpm_cmd_t {
>   extern struct class *tpm_class;
>   extern dev_t tpm_devt;
>   extern const struct file_operations tpm_fops;
> +extern struct attribute *tpm_dev_attrs[];
>
>   ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);
>   ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
> @@ -346,9 +347,6 @@ extern struct tpm_chip *tpmm_chip_alloc(struct device *dev,
>   extern int tpm_chip_register(struct tpm_chip *chip);
>   extern void tpm_chip_unregister(struct tpm_chip *chip);
>
> -int tpm_sysfs_add_device(struct tpm_chip *chip);
> -void tpm_sysfs_del_device(struct tpm_chip *chip);
> -
>   int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
>
>   #ifdef CONFIG_ACPI

Other than those stray line deletions, it looks good to me.

   Stefan

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