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SubjectRe: [PATCH RESEND 2/3] tpm: replace dynamically allocated bios_dir with a static array
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On 10/02/2016 12:55 AM, Jarkko Sakkinen 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>
> ---
> drivers/char/tpm/tpm-chip.c | 9 +++---
> drivers/char/tpm/tpm.h | 3 +-
> drivers/char/tpm/tpm_eventlog.c | 62 +++++++++++++++++++----------------------
> drivers/char/tpm/tpm_eventlog.h | 10 +++----
> 4 files changed, 41 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index e595013..a56b609 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 4d183c9..4c118a4 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 75e6644..f5e1d06 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm_eventlog.c
> @@ -368,54 +368,50 @@ 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",
> - S_IRUSR | S_IRGRP, tpm_dir,
> + S_IRUSR | S_IRGRP, chip->bios_dir[0],
> (void *)&tpm_binary_b_measurments_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",
> - S_IRUSR | S_IRGRP, tpm_dir,
> + S_IRUSR | S_IRGRP, chip->bios_dir[0],
> (void *)&tpm_ascii_b_measurments_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;

The updated patch looks fine.
Just, I am not sure if NULL assignment is needed.

> + 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--) {
> + if (chip->bios_dir[i])

Probably, this check is not required because securityfs_remove() takes
care of checking both NULL and err dentry.

Thanks & Regards,
- Nayna

> + 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
>

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