Re: [PATCH v6 3/9] tpm: replace dynamically allocated bios_dir with a static array

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Mon, Nov 14, 2016 at 05:00:50AM -0500, Nayna Jain wrote:
> This commit is based on a commit by Nayna Jain. Replaced dynamically
> allocated bios_dir with a static array as the size is always constant.
> 
> Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

This commit remains unreviewed and tested. I'm in the author role here
so I cannot help with this. If that does not happen soon I cannot put
this into the pull request.

/Jarkko


> ---
>  drivers/char/tpm/tpm-chip.c     |  9 ++++---
>  drivers/char/tpm/tpm.h          |  3 ++-
>  drivers/char/tpm/tpm_eventlog.c | 59 ++++++++++++++++++-----------------------
>  drivers/char/tpm/tpm_eventlog.h | 10 +++----
>  4 files changed, 38 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 836f056..d0c1872 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -278,14 +278,16 @@ static void tpm_del_char_device(struct tpm_chip *chip)
>  
>  static int tpm1_chip_register(struct tpm_chip *chip)
>  {
> +	int rc;
> +
>  	if (chip->flags & TPM_CHIP_FLAG_TPM2)
>  		return 0;
>  
>  	tpm_sysfs_add_device(chip);
>  
> -	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
> +	rc = tpm_bios_log_setup(chip);
>  
> -	return 0;
> +	return rc;
>  }
>  
>  static void tpm1_chip_unregister(struct tpm_chip *chip)
> @@ -293,8 +295,7 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
>  	if (chip->flags & TPM_CHIP_FLAG_TPM2)
>  		return;
>  
> -	if (chip->bios_dir)
> -		tpm_bios_log_teardown(chip->bios_dir);
> +	tpm_bios_log_teardown(chip);
>  }
>  
>  static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index f9401ca..9d69580 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -40,6 +40,7 @@ enum tpm_const {
>  	TPM_BUFSIZE = 4096,
>  	TPM_NUM_DEVICES = 65536,
>  	TPM_RETRY = 50,		/* 5 seconds */
> +	TPM_NUM_EVENT_LOG_FILES = 3,
>  };
>  
>  enum tpm_timeout {
> @@ -171,7 +172,7 @@ struct tpm_chip {
>  	unsigned long duration[3]; /* jiffies */
>  	bool duration_adjusted;
>  
> -	struct dentry **bios_dir;
> +	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
>  
>  	const struct attribute_group *groups[3];
>  	unsigned int groups_cnt;
> diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
> index 9467e31..62e9da6 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm_eventlog.c
> @@ -368,54 +368,47 @@ static int is_bad(void *p)
>  	return 0;
>  }
>  
> -struct dentry **tpm_bios_log_setup(const char *name)
> +int tpm_bios_log_setup(struct tpm_chip *chip)
>  {
> -	struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
> +	const char *name = dev_name(&chip->dev);
> +	unsigned int cnt;
>  
> -	tpm_dir = securityfs_create_dir(name, NULL);
> -	if (is_bad(tpm_dir))
> -		goto out;
> +	cnt = 0;
> +	chip->bios_dir[cnt] = securityfs_create_dir(name, NULL);
> +	if (is_bad(chip->bios_dir[cnt]))
> +		goto err;
> +	cnt++;
>  
> -	bin_file =
> +	chip->bios_dir[cnt] =
>  	    securityfs_create_file("binary_bios_measurements",
> -				   0440, tpm_dir,
> +				   0440, chip->bios_dir[0],
>  				   (void *)&tpm_binary_b_measurements_seqops,
>  				   &tpm_bios_measurements_ops);
> -	if (is_bad(bin_file))
> -		goto out_tpm;
> +	if (is_bad(chip->bios_dir[cnt]))
> +		goto err;
> +	cnt++;
>  
> -	ascii_file =
> +	chip->bios_dir[cnt] =
>  	    securityfs_create_file("ascii_bios_measurements",
> -				   0440, tpm_dir,
> +				   0440, chip->bios_dir[0],
>  				   (void *)&tpm_ascii_b_measurements_seqops,
>  				   &tpm_bios_measurements_ops);
> -	if (is_bad(ascii_file))
> -		goto out_bin;
> +	if (is_bad(chip->bios_dir[cnt]))
> +		goto err;
> +	cnt++;
>  
> -	ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
> -	if (!ret)
> -		goto out_ascii;
> -
> -	ret[0] = ascii_file;
> -	ret[1] = bin_file;
> -	ret[2] = tpm_dir;
> -
> -	return ret;
> +	return 0;
>  
> -out_ascii:
> -	securityfs_remove(ascii_file);
> -out_bin:
> -	securityfs_remove(bin_file);
> -out_tpm:
> -	securityfs_remove(tpm_dir);
> -out:
> -	return NULL;
> +err:
> +	chip->bios_dir[cnt] = NULL;
> +	tpm_bios_log_teardown(chip);
> +	return -EIO;
>  }
>  
> -void tpm_bios_log_teardown(struct dentry **lst)
> +void tpm_bios_log_teardown(struct tpm_chip *chip)
>  {
>  	int i;
>  
> -	for (i = 0; i < 3; i++)
> -		securityfs_remove(lst[i]);
> +	for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--)
> +		securityfs_remove(chip->bios_dir[i]);
>  }
> diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
> index 8de62b0..fd3357e 100644
> --- a/drivers/char/tpm/tpm_eventlog.h
> +++ b/drivers/char/tpm/tpm_eventlog.h
> @@ -77,14 +77,14 @@ int read_log(struct tpm_bios_log *log);
>  
>  #if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
>  	defined(CONFIG_ACPI)
> -extern struct dentry **tpm_bios_log_setup(const char *);
> -extern void tpm_bios_log_teardown(struct dentry **);
> +extern int tpm_bios_log_setup(struct tpm_chip *chip);
> +extern void tpm_bios_log_teardown(struct tpm_chip *chip);
>  #else
> -static inline struct dentry **tpm_bios_log_setup(const char *name)
> +static inline int tpm_bios_log_setup(struct tpm_chip *chip)
>  {
> -	return NULL;
> +	return 0;
>  }
> -static inline void tpm_bios_log_teardown(struct dentry **dir)
> +static inline void tpm_bios_log_teardown(struct tpm_chip *chip)
>  {
>  }
>  #endif
> -- 
> 2.5.0
>