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tpm: have event log use the tpm_chip

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Move the backing memory for the event log into tpm_chip and push
the tpm_chip into read_log. This optimizes read_log processing by
only doing it once and prepares things for the next patches in the
series which require the tpm_chip to locate the event log via
ACPI and OF handles instead of searching.

This is straightfoward except for the issue of passing a kref through
i_private with securityfs. Since securityfs_remove does not have any
removal fencing like sysfs we use the inode lock to safely get a
kref on the tpm_chip.

Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
This commit is contained in:
Nayna Jain 2016-11-14 05:00:52 -05:00 committed by Jarkko Sakkinen
parent 7518a21a9d
commit 748935eeb7
6 changed files with 83 additions and 36 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
drivers/char/tpm/tpm-chip.c
View file

@ -127,6 +127,7 @@ static void tpm_dev_release(struct device *dev)
idr_remove(&dev_nums_idr, chip->dev_num);
mutex_unlock(&idr_lock);
kfree(chip->log.bios_event_log);
kfree(chip);
}
@ -345,7 +346,7 @@ int tpm_chip_register(struct tpm_chip *chip)
tpm_sysfs_add_device(chip);
rc = tpm_bios_log_setup(chip);
if (rc)
if (rc == -ENODEV)
return rc;
tpm_add_ppi(chip);

11
drivers/char/tpm/tpm.h
View file

@ -35,6 +35,8 @@
#include <linux/cdev.h>
#include <linux/highmem.h>
#include "tpm_eventlog.h"
enum tpm_const {
TPM_MINOR = 224, /* officially assigned */
TPM_BUFSIZE = 4096,
@ -146,6 +148,11 @@ enum tpm_chip_flags {
TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4),
};
struct tpm_chip_seqops {
struct tpm_chip *chip;
const struct seq_operations *seqops;
};
struct tpm_chip {
struct device dev;
struct cdev cdev;
@ -157,6 +164,10 @@ struct tpm_chip {
struct rw_semaphore ops_sem;
const struct tpm_class_ops *ops;
struct tpm_bios_log log;
struct tpm_chip_seqops bin_log_seqops;
struct tpm_chip_seqops ascii_log_seqops;
unsigned int flags;
int dev_num; /* /dev/tpm# */

15
drivers/char/tpm/tpm_acpi.c
View file

@ -9,7 +9,7 @@
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Access to the eventlog extended by the TCG BIOS of PC platform
* Access to the event log extended by the TCG BIOS of PC platform
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@ -45,13 +45,15 @@ struct acpi_tcpa {
};
/* read binary bios log */
int read_log(struct tpm_bios_log *log)
int read_log(struct tpm_chip *chip)
{
struct acpi_tcpa *buff;
acpi_status status;
void __iomem *virt;
u64 len, start;
struct tpm_bios_log *log;
log = &chip->log;
if (log->bios_event_log != NULL) {
printk(KERN_ERR
"%s: ERROR - Eventlog already initialized\n",
@ -97,13 +99,18 @@ int read_log(struct tpm_bios_log *log)
virt = acpi_os_map_iomem(start, len);
if (!virt) {
kfree(log->bios_event_log);
printk("%s: ERROR - Unable to map memory\n", __func__);
return -EIO;
goto err;
}
memcpy_fromio(log->bios_event_log, virt, len);
acpi_os_unmap_iomem(virt, len);
return 0;
err:
kfree(log->bios_event_log);
log->bios_event_log = NULL;
return -EIO;
}

84
drivers/char/tpm/tpm_eventlog.c
View file

@ -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;
struct tpm_chip_seqops *chip_seqops;
const struct seq_operations *seqops;
struct tpm_chip *chip;
log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
if (!log)
return -ENOMEM;
if ((err = read_log(log)))
goto out_free;
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]);
}
}

2
drivers/char/tpm/tpm_eventlog.h
View file

@ -73,7 +73,7 @@ enum tcpa_pc_event_ids {
HOST_TABLE_OF_DEVICES,
};
int read_log(struct tpm_bios_log *log);
int read_log(struct tpm_chip *chip);
#if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
defined(CONFIG_ACPI)

4
drivers/char/tpm/tpm_of.c
View file

@ -20,12 +20,14 @@
#include "tpm.h"
#include "tpm_eventlog.h"
int read_log(struct tpm_bios_log *log)
int read_log(struct tpm_chip *chip)
{
struct device_node *np;
const u32 *sizep;
const u64 *basep;
struct tpm_bios_log *log;
log = &chip->log;
if (log->bios_event_log != NULL) {
pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
return -EFAULT;