diff options
Diffstat (limited to 'drivers/char/tpm/tpm_eventlog.c')
| -rw-r--r-- | drivers/char/tpm/tpm_eventlog.c | 86 |
1 files changed, 56 insertions, 30 deletions
diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c index 0afb0f4e81f0..2c4bc99729e5 100644 --- a/drivers/char/tpm/tpm_eventlog.c +++ b/drivers/char/tpm/tpm_eventlog.c @@ -11,7 +11,7 @@ * * Maintained by: <tpmdd-devel@lists.sourceforge.net> * - * Access to the eventlog created by a system's firmware / BIOS + * Access to the event log created by a system's firmware / BIOS * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -73,7 +73,8 @@ static const char* tcpa_pc_event_id_strings[] = { static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos) { loff_t i; - struct tpm_bios_log *log = m->private; + struct tpm_chip *chip = m->private; + struct tpm_bios_log *log = &chip->log; void *addr = log->bios_event_log; void *limit = log->bios_event_log_end; struct tcpa_event *event; @@ -120,7 +121,8 @@ static void *tpm_bios_measurements_next(struct seq_file *m, void *v, loff_t *pos) { struct tcpa_event *event = v; - struct tpm_bios_log *log = m->private; + struct tpm_chip *chip = m->private; + struct tpm_bios_log *log = &chip->log; void *limit = log->bios_event_log_end; u32 converted_event_size; u32 converted_event_type; @@ -261,13 +263,10 @@ static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v) static int tpm_bios_measurements_release(struct inode *inode, struct file *file) { - struct seq_file *seq = file->private_data; - struct tpm_bios_log *log = seq->private; + struct seq_file *seq = (struct seq_file *)file->private_data; + struct tpm_chip *chip = (struct tpm_chip *)seq->private; - if (log) { - kfree(log->bios_event_log); - kfree(log); - } + put_device(&chip->dev); return seq_release(inode, file); } @@ -323,33 +322,30 @@ static int tpm_bios_measurements_open(struct inode *inode, struct file *file) { int err; - struct tpm_bios_log *log; struct seq_file *seq; - const struct seq_operations *seqops = - (const struct seq_operations *)inode->i_private; - - log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL); - if (!log) - return -ENOMEM; - - if ((err = read_log(log))) - goto out_free; + struct tpm_chip_seqops *chip_seqops; + const struct seq_operations *seqops; + struct tpm_chip *chip; + + inode_lock(inode); + if (!inode->i_private) { + inode_unlock(inode); + return -ENODEV; + } + chip_seqops = (struct tpm_chip_seqops *)inode->i_private; + seqops = chip_seqops->seqops; + chip = chip_seqops->chip; + get_device(&chip->dev); + inode_unlock(inode); /* now register seq file */ err = seq_open(file, seqops); if (!err) { seq = file->private_data; - seq->private = log; - } else { - goto out_free; + seq->private = chip; } -out: return err; -out_free: - kfree(log->bios_event_log); - kfree(log); - goto out; } static const struct file_operations tpm_bios_measurements_ops = { @@ -363,10 +359,22 @@ int tpm_bios_log_setup(struct tpm_chip *chip) { const char *name = dev_name(&chip->dev); unsigned int cnt; + int rc = 0; if (chip->flags & TPM_CHIP_FLAG_TPM2) return 0; + rc = read_log(chip); + /* + * read_log failure means event log is not supported except for ENOMEM. + */ + if (rc < 0) { + if (rc == -ENOMEM) + return -ENODEV; + else + return rc; + } + cnt = 0; chip->bios_dir[cnt] = securityfs_create_dir(name, NULL); /* NOTE: securityfs_create_dir can return ENODEV if securityfs is @@ -376,19 +384,25 @@ int tpm_bios_log_setup(struct tpm_chip *chip) goto err; cnt++; + chip->bin_log_seqops.chip = chip; + chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops; + chip->bios_dir[cnt] = securityfs_create_file("binary_bios_measurements", 0440, chip->bios_dir[0], - (void *)&tpm_binary_b_measurements_seqops, + (void *)&chip->bin_log_seqops, &tpm_bios_measurements_ops); if (IS_ERR(chip->bios_dir[cnt])) goto err; cnt++; + chip->ascii_log_seqops.chip = chip; + chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops; + chip->bios_dir[cnt] = securityfs_create_file("ascii_bios_measurements", 0440, chip->bios_dir[0], - (void *)&tpm_ascii_b_measurements_seqops, + (void *)&chip->ascii_log_seqops, &tpm_bios_measurements_ops); if (IS_ERR(chip->bios_dir[cnt])) goto err; @@ -405,7 +419,19 @@ err: void tpm_bios_log_teardown(struct tpm_chip *chip) { int i; + struct inode *inode; - for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--) + /* securityfs_remove currently doesn't take care of handling sync + * between removal and opening of pseudo files. To handle this, a + * workaround is added by making i_private = NULL here during removal + * and to check it during open(), both within inode_lock()/unlock(). + * This design ensures that open() either safely gets kref or fails. + */ + for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--) { + inode = d_inode(chip->bios_dir[i]); + inode_lock(inode); + inode->i_private = NULL; + inode_unlock(inode); securityfs_remove(chip->bios_dir[i]); + } } |