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 <[email protected]>
Signed-off-by: Nayna Jain <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
  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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