tpm: replace dynamically allocated bios_dir with a static array

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: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 836f056..d0c1872 100644 (file)
--- 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 (file)
--- 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..9c64476 100644 (file)
--- a/drivers/char/tpm/tpm_eventlog.c
+++ b/drivers/char/tpm/tpm_eventlog.c
@@ -359,63 +359,50 @@ static const struct file_operations tpm_bios_measurements_ops = {
        .release = tpm_bios_measurements_release,
 };
 
-static int is_bad(void *p)
+int tpm_bios_log_setup(struct tpm_chip *chip)
 {
-       if (!p)
-               return 1;
-       if (IS_ERR(p) && (PTR_ERR(p) != -ENODEV))
-               return 1;
-       return 0;
-}
-
-struct dentry **tpm_bios_log_setup(const char *name)
-{
-       struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
-
-       tpm_dir = securityfs_create_dir(name, NULL);
-       if (is_bad(tpm_dir))
-               goto out;
-
-       bin_file =
+       const char *name = dev_name(&chip->dev);
+       unsigned int cnt;
+
+       cnt = 0;
+       chip->bios_dir[cnt] = securityfs_create_dir(name, NULL);
+       /* NOTE: securityfs_create_dir can return ENODEV if securityfs is
+        * compiled out. The caller should ignore the ENODEV return code.
+        */
+       if (IS_ERR(chip->bios_dir[cnt]))
+               goto err;
+       cnt++;
+
+       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_ERR(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;
-
-       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;
+       if (IS_ERR(chip->bios_dir[cnt]))
+               goto err;
+       cnt++;
 
-       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 (file)
--- 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