diff mbox

[tpmdd-devel,v2,3/3] TPM2.0:Adds securityfs support for TPM2.0 eventlog

Message ID 1470771295-15680-4-git-send-email-nayna@linux.vnet.ibm.com
State New
Headers show

Commit Message

Nayna Aug. 9, 2016, 7:34 p.m. UTC
Adds securityfs support for TPM2.0.
This patch currently supports only binary_bios_measurements.

Changelog v2:
        * Single tpm_of.c for reading both tpm and vtpm device tree values.
        * Some of the issues are fixed in Patch 1 itself.
        * Comments in tpm2.h give reference to the standard from where structs
	are taken.
	* Now, tpm_of.c has same code applied for both tpm and vtpm, so I think
	that now it is needed to have generic types rather than endian specific type.

There are few preexisting issues as being mentioned in feedback and are not 
addressed in this patch. Reason being, I don't have much expertise of ACPI side as of now, 
and these changes will affect acpi,tpm,vtpm, all paths, so I would like to go slow
and fix them as different patch later after better understanding.
Hope this sounds ok to have them as different patch.

Issues which are not addressed are as below:
        * tpm_eventlog.h still has #ifdef defined, for tpm_bios_log_setup()
        * tpm_bios_log_setup is still being called in tpm-chip register function.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/Makefile            |   8 +-
 drivers/char/tpm/tpm-chip.c          |  20 +---
 drivers/char/tpm/tpm2.h              |  85 +++++++++++++
 drivers/char/tpm/tpm2_eventlog.c     | 224 +++++++++++++++++++++++++++++++++++
 drivers/char/tpm/tpm_eventlog.h      |   2 +-
 drivers/char/tpm/tpm_eventlog_init.c |  43 +++++--
 drivers/char/tpm/tpm_of.c            |  17 ++-
 7 files changed, 366 insertions(+), 33 deletions(-)
 create mode 100644 drivers/char/tpm/tpm2.h
 create mode 100644 drivers/char/tpm/tpm2_eventlog.c

Comments

Jason Gunthorpe Aug. 9, 2016, 10:19 p.m. UTC | #1
On Tue, Aug 09, 2016 at 03:34:55PM -0400, Nayna Jain wrote:
> Adds securityfs support for TPM2.0.
> This patch currently supports only binary_bios_measurements.
> 
> Changelog v2:
>         * Single tpm_of.c for reading both tpm and vtpm device tree values.
>         * Some of the issues are fixed in Patch 1 itself.
>         * Comments in tpm2.h give reference to the standard from where structs
> 	are taken.
> 	* Now, tpm_of.c has same code applied for both tpm and vtpm, so I think
> 	that now it is needed to have generic types rather than endian specific type.
> 
> There are few preexisting issues as being mentioned in feedback and are not 
> addressed in this patch. Reason being, I don't have much expertise of ACPI side as of now, 
> and these changes will affect acpi,tpm,vtpm, all paths, so I would like to go slow
> and fix them as different patch later after better understanding.
> Hope this sounds ok to have them as different patch.

Yes, but do the patches first please, this stuff is obviously broken,
do not make the mess larger.

You are the only person ever to come up who can test the _of side of
this, so the rest of us have the opposite problem to you.

If you have doubts about the acpi stuff then ask.

> +	/*
> +	 * NOTE: Currently, support is added only for binary_bios_measurements
> +	 * for TPM2.0. And so it is required to check that if device is TPM2,
> +	 * only 2 entries are allocated i.e. tpm0 dir and
> +	 * binary_bios_measurements file.
> +	 */
> +
> +	num_files = chip->flags & TPM_CHIP_FLAG_TPM2 ? 2 : 3;

?? just ++ as you go like sysfs does

>  	const u32 *sizep;
>  	const u64 *basep;
> +	u32 log_size;
>  
>  	if (log->bios_event_log != NULL) {
>  		pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
> @@ -52,6 +53,11 @@ int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
>  		goto cleanup_eio;
>  	}
>  
> +	if (!strncmp(np->name, "tpm", 3))
> +		log_size = be32_to_cpup(sizep);
> +	else
> +		log_size = *sizep;

?? That deserves a comment, one of your systems has swapped
endianness?? 'np->name' is not an appropriate way to detect
that. compatible string would be better, or something else..

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Jarkko Sakkinen Aug. 10, 2016, 11:25 a.m. UTC | #2
On Tue, Aug 09, 2016 at 03:34:55PM -0400, Nayna Jain wrote:
> Adds securityfs support for TPM2.0.
> This patch currently supports only binary_bios_measurements.
> 
> Changelog v2:
>         * Single tpm_of.c for reading both tpm and vtpm device tree values.
>         * Some of the issues are fixed in Patch 1 itself.
>         * Comments in tpm2.h give reference to the standard from where structs
> 	are taken.
> 	* Now, tpm_of.c has same code applied for both tpm and vtpm, so I think
> 	that now it is needed to have generic types rather than endian specific type.
> 
> There are few preexisting issues as being mentioned in feedback and are not 
> addressed in this patch. Reason being, I don't have much expertise of ACPI side as of now, 
> and these changes will affect acpi,tpm,vtpm, all paths, so I would like to go slow
> and fix them as different patch later after better understanding.
> Hope this sounds ok to have them as different patch.
> 
> Issues which are not addressed are as below:
>         * tpm_eventlog.h still has #ifdef defined, for tpm_bios_log_setup()
>         * tpm_bios_log_setup is still being called in tpm-chip register function.

I do not understand your changelog entries. Please provide a nice one or
most two paragraph english language description and keep breakdowns and
changelogs in the cover letter.

Commit message does not equal to a discussion forum and I do not have
any idea what feedback you are talking about...

Not reviewing this further. This is just terrible.

/Jarkko

> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> ---
>  drivers/char/tpm/Makefile            |   8 +-
>  drivers/char/tpm/tpm-chip.c          |  20 +---
>  drivers/char/tpm/tpm2.h              |  85 +++++++++++++
>  drivers/char/tpm/tpm2_eventlog.c     | 224 +++++++++++++++++++++++++++++++++++
>  drivers/char/tpm/tpm_eventlog.h      |   2 +-
>  drivers/char/tpm/tpm_eventlog_init.c |  43 +++++--
>  drivers/char/tpm/tpm_of.c            |  17 ++-
>  7 files changed, 366 insertions(+), 33 deletions(-)
>  create mode 100644 drivers/char/tpm/tpm2.h
>  create mode 100644 drivers/char/tpm/tpm2_eventlog.c
> 
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index 9136762..509ace2 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -6,10 +6,14 @@ tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o
>  tpm-$(CONFIG_ACPI) += tpm_ppi.o
>  
>  ifdef CONFIG_ACPI
> -	tpm-y += tpm_eventlog_init.o tpm_eventlog.o tpm_acpi.o
> +	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_acpi.o
>  else
>  ifdef CONFIG_TCG_IBMVTPM
> -	tpm-y += tpm_eventlog_init.o tpm_eventlog.o tpm_of.o
> +	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_of.o
> +else
> +ifdef CONFIG_PPC64
> +	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_of.o
> +endif
>  endif
>  endif
>  obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 7f6cdab..3f1c489 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -285,20 +285,9 @@ static int tpm1_chip_register(struct tpm_chip *chip)
>  
>  	tpm_sysfs_add_device(chip);
>  
> -	tpm_bios_log_setup(chip);
> -
>  	return 0;
>  }
>  
> -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);
> -}
> -
>  static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
>  {
>  	struct attribute **i;
> @@ -372,10 +361,8 @@ int tpm_chip_register(struct tpm_chip *chip)
>  	tpm_add_ppi(chip);
>  
>  	rc = tpm_add_char_device(chip);
> -	if (rc) {
> -		tpm1_chip_unregister(chip);
> +	if (rc)
>  		return rc;
> -	}
>  
>  	chip->flags |= TPM_CHIP_FLAG_REGISTERED;
>  
> @@ -385,6 +372,8 @@ int tpm_chip_register(struct tpm_chip *chip)
>  		return rc;
>  	}
>  
> +	tpm_bios_log_setup(chip);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(tpm_chip_register);
> @@ -409,7 +398,8 @@ void tpm_chip_unregister(struct tpm_chip *chip)
>  
>  	tpm_del_legacy_sysfs(chip);
>  
> -	tpm1_chip_unregister(chip);
> +	tpm_bios_log_teardown(chip);
> +
>  	tpm_del_char_device(chip);
>  }
>  EXPORT_SYMBOL_GPL(tpm_chip_unregister);
> diff --git a/drivers/char/tpm/tpm2.h b/drivers/char/tpm/tpm2.h
> new file mode 100644
> index 0000000..38a8073
> --- /dev/null
> +++ b/drivers/char/tpm/tpm2.h
> @@ -0,0 +1,85 @@
> +#ifndef __TPM2_H__
> +#define __TPM2_H__
> +
> +#define TPM_ALG_SHA1_DIGEST_SIZE	20
> +#define TPM_ALG_SHA256_DIGEST_SIZE	32
> +#define TPM_ALG_SHA384_DIGEST_SIZE	48
> +
> +#define HASH_COUNT	3
> +#define MAX_TPM_LOG_MSG	128
> +
> +/**
> + * All the structures related to Event Log are taken from TCG EFI Protocol
> + * Specification, Family "2.0". Document is available on link
> + * http://www.trustedcomputinggroup.org/tcg-efi-protocol-specification/
> + * Information is also available on TCG PC Client Platform Firmware Profile
> + * Specification, Family "2.0"
> + * Detailed digest structures for TPM2.0 are defined in document
> + * Trusted Platform Module Library Part 2: Structures, Family "2.0".
> + */
> +
> +/* Event log header algorithm spec. */
> +struct tcg_efispecideventalgorithmsize {
> +	u16	algorithm_id;
> +	u16	digest_size;
> +} __packed;
> +
> +/* Event log header data. */
> +struct tcg_efispecideventstruct {
> +	u8					signature[16];
> +	u32					platform_class;
> +	u8					spec_version_minor;
> +	u8					spec_version_major;
> +	u8					spec_errata;
> +	u8					uintnsize;
> +	u32					num_algs;
> +	struct tcg_efispecideventalgorithmsize	digest_sizes[HASH_COUNT];
> +	u8					vendor_info_size;
> +	u8					vendor_info[0];
> +} __packed;
> +
> +/* Header entry for eventlog. */
> +struct tcg_pcr_event {
> +	u32	pcr_index;
> +	u32	event_type;
> +	u8	digest[20];
> +	u32	event_size;
> +	u8	event[MAX_TPM_LOG_MSG];
> +} __packed;
> +
> +/* Digest union for crypto agility. */
> +union tpmu_ha {
> +	u8	 sha1[TPM_ALG_SHA1_DIGEST_SIZE];
> +	u8	 sha256[TPM_ALG_SHA256_DIGEST_SIZE];
> +	u8	 sha384[TPM_ALG_SHA384_DIGEST_SIZE];
> +} __packed;
> +
> +/* Crypto Agile algorithm and respective digest. */
> +struct tpmt_ha {
> +	u16		algorithm_id;
> +	union tpmu_ha	digest;
> +} __packed;
> +
> +/* Crypto agile digests list. */
> +struct tpml_digest_values {
> +	u32		count;
> +	struct tpmt_ha	digests[HASH_COUNT];
> +} __packed;
> +
> +/* Event field structure. */
> +struct tcg_event_field {
> +	u32	event_size;
> +	u8      event[MAX_TPM_LOG_MSG];
> +} __packed;
> +
> +/* Crypto agile log entry format for TPM 2.0. */
> +struct tcg_pcr_event2 {
> +	u32				pcr_index;
> +	u32				event_type;
> +	struct tpml_digest_values	digests;
> +	struct tcg_event_field		event;
> +} __packed;
> +
> +extern const struct seq_operations tpm2_binary_b_measurments_seqops;
> +
> +#endif
> diff --git a/drivers/char/tpm/tpm2_eventlog.c b/drivers/char/tpm/tpm2_eventlog.c
> new file mode 100644
> index 0000000..f1e8c4a
> --- /dev/null
> +++ b/drivers/char/tpm/tpm2_eventlog.c
> @@ -0,0 +1,224 @@
> +/*
> + * Copyright (C) 2016 IBM Corporation
> + *
> + * Authors:
> + *      Nayna Jain <nayna@linux.vnet.ibm.com>
> +
> + * Access to TPM2.0 event log as written by Firmware.
> + * It assumes that writer of event log has followed TCG Spec 2.0
> + * has written the event struct data in little endian. With that,
> + * it doesn't need any endian conversion for structure content.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/seq_file.h>
> +#include <linux/fs.h>
> +#include <linux/security.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +
> +#include "tpm.h"
> +#include "tpm2.h"
> +#include "tpm_eventlog.h"
> +
> +
> +static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
> +		struct tcg_pcr_event *event_header)
> +{
> +	struct tcg_efispecideventstruct *efispecid;
> +	struct tcg_event_field *event_field;
> +	void *marker, *marker_start;
> +	int j;
> +	size_t size = 0;
> +
> +	/*
> +	 * NOTE: TPM2.0 allows support for extend to multiple PCR Banks.
> +	 * This implies that eventlog also has multiple digest values
> +	 * one for each PCR Bank. This is called Crypto Agile Log Entry
> +	 * Format. Current support implementation is for SHA1 and SHA256.
> +	 * Number of digest values are identified by parsing first
> +	 * structure stored in event log also called event header.
> +	 * Further, the eventlog is written in packed form so to calculate
> +	 * offset it is important to know the type of algorithm used.
> +	 * Eg. 1:
> +	 * digest_values.count = 1;
> +	 * digest_values.digest[0].algorithm_id = sha1;
> +	 * digest_values.digest[0].digest.sha1 = {20 bytes raw data};
> +	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 20
> +	 *
> +	 * Eg. 2:
> +	 * digest_values.count = 1;
> +	 * digest_values.digest[0].algorithm_id = sha256;
> +	 * digest_values.digest[0].digest.sha1 = {32 bytes raw data};
> +	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 32
> +
> +	 * Eg. 3:
> +	 * digest_values.count = 2;
> +	 * digest_values.digest[0].algorithm_id = sha1;
> +	 * digest_values.digest[0].digest.sha1 = {20 bytes raw data};
> +	 * digest_values.digest[1].algorithm_id = sha256;
> +	 * digest_values.digest[1].digest.sha256 = {32 bytes raw data};
> +	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 20
> +	 *			+ sizeof(algorithm_id) + 32;
> +	 *
> +	 * So, it implies that offset of event_size can vary based on digest
> +	 * values as defined by vendor. And so we have to calculate the
> +	 * offset by parsing through number and type of digests being used.
> +	 * And this is the purpose of using *marker to traverse the structure
> +	 * and calculate the offset of event_size. This function uses *marker
> +	 * to parse and calculate the dynamic size of the whole event structure.
> +	 */
> +
> +	marker = event;
> +	marker_start = marker;
> +	marker = marker + sizeof(event->pcr_index) + sizeof(event->event_type)
> +		+ sizeof(event->digests.count);
> +
> +	efispecid = (struct tcg_efispecideventstruct *) event_header->event;
> +
> +	for (j = 0; (j < efispecid->num_algs) && (j < HASH_COUNT); j++) {
> +		marker = marker
> +			+ sizeof(efispecid->digest_sizes[j].algorithm_id);
> +		marker = marker + efispecid->digest_sizes[j].digest_size;
> +	}
> +
> +	event_field = (struct tcg_event_field *) marker;
> +	marker = marker + sizeof(event_field->event_size)
> +		+ event_field->event_size;
> +	size = marker - marker_start;
> +
> +	if ((event->event_type == 0) && (event_field->event_size == 0))
> +		return 0;
> +
> +	return size;
> +}
> +
> +static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
> +{
> +	struct tpm_bios_log *log = m->private;
> +	void *addr = log->bios_event_log;
> +	void *limit = log->bios_event_log_end;
> +	struct tcg_pcr_event *event_header;
> +	struct tcg_pcr_event2 *event;
> +	int i;
> +	size_t size = 0;
> +
> +	event_header = addr;
> +
> +	size = sizeof(struct tcg_pcr_event) - sizeof(event_header->event)
> +		+ event_header->event_size;
> +
> +
> +	if (*pos == 0) {
> +		if (addr + size < limit) {
> +			if ((event_header->event_type == 0) &&
> +					(event_header->event_size == 0))
> +				return NULL;
> +			return SEQ_START_TOKEN;
> +		}
> +	}
> +
> +	if (*pos > 0) {
> +		addr += size;
> +		event = addr;
> +		size = calc_tpm2_event_size(event, event_header);
> +		if ((addr + size >=  limit) || (size == 0))
> +			return NULL;
> +	}
> +
> +	/* read over *pos measurements */
> +	for (i = 0; i < (*pos - 1); i++) {
> +		event = addr;
> +		size = calc_tpm2_event_size(event, event_header);
> +
> +		if ((addr + size >= limit) || (size == 0))
> +			return NULL;
> +		addr += size;
> +	}
> +
> +	return addr;
> +}
> +
> +static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
> +		loff_t *pos)
> +{
> +	struct tcg_pcr_event *event_header;
> +	struct tcg_pcr_event2 *event;
> +	struct tpm_bios_log *log = m->private;
> +	void *limit = log->bios_event_log_end;
> +	void *marker;
> +	size_t event_size = 0;
> +
> +	event_header = log->bios_event_log;
> +
> +	if (v == SEQ_START_TOKEN) {
> +		event_size = sizeof(struct tcg_pcr_event)
> +			- sizeof(event_header->event)
> +			+ event_header->event_size;
> +		marker = event_header;
> +	} else {
> +		event = v;
> +		event_size = calc_tpm2_event_size(event, event_header);
> +		if (event_size == 0)
> +			return NULL;
> +		marker =  event;
> +	}
> +
> +	marker = marker + event_size;
> +	if (marker >= limit)
> +		return NULL;
> +	v = marker;
> +	event = v;
> +
> +	event_size = calc_tpm2_event_size(event, event_header);
> +	if (((v + event_size) >= limit) || (event_size == 0))
> +		return NULL;
> +
> +	(*pos)++;
> +	return v;
> +}
> +
> +static void tpm2_bios_measurements_stop(struct seq_file *m, void *v)
> +{
> +}
> +
> +static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
> +{
> +	struct tpm_bios_log *log = m->private;
> +	struct tcg_pcr_event *event_header = log->bios_event_log;
> +	struct tcg_pcr_event2 *event = v;
> +	void *temp_ptr;
> +	size_t size = 0;
> +
> +	if (v == SEQ_START_TOKEN) {
> +
> +		size = sizeof(struct tcg_pcr_event)
> +			- sizeof(event_header->event)
> +			+ event_header->event_size;
> +
> +		temp_ptr = event_header;
> +
> +		if (size > 0)
> +			seq_write(m, temp_ptr, size);
> +	} else {
> +
> +		size = calc_tpm2_event_size(event, event_header);
> +
> +		temp_ptr = event;
> +		if (size > 0)
> +			seq_write(m, temp_ptr, size);
> +	}
> +
> +	return 0;
> +}
> +
> +const struct seq_operations tpm2_binary_b_measurments_seqops = {
> +	.start = tpm2_bios_measurements_start,
> +	.next = tpm2_bios_measurements_next,
> +	.stop = tpm2_bios_measurements_stop,
> +	.show = tpm2_binary_bios_measurements_show,
> +};
> diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
> index b888c77..3297fda 100644
> --- a/drivers/char/tpm/tpm_eventlog.h
> +++ b/drivers/char/tpm/tpm_eventlog.h
> @@ -78,7 +78,7 @@ enum tcpa_pc_event_ids {
>  int read_log(struct tpm_bios_log *log, struct tpm_chip *chip);
>  
>  #if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
> -	defined(CONFIG_ACPI)
> +	defined(CONFIG_ACPI) || defined(CONFIG_PPC64)
>  extern void tpm_bios_log_setup(struct tpm_chip *chip);
>  extern void tpm_bios_log_teardown(struct tpm_chip *chip);
>  #else
> diff --git a/drivers/char/tpm/tpm_eventlog_init.c b/drivers/char/tpm/tpm_eventlog_init.c
> index dd5dbc4..a3fb5bc 100644
> --- a/drivers/char/tpm/tpm_eventlog_init.c
> +++ b/drivers/char/tpm/tpm_eventlog_init.c
> @@ -28,6 +28,7 @@
>  #include <linux/slab.h>
>  
>  #include "tpm.h"
> +#include "tpm2.h"
>  #include "tpm_eventlog.h"
>  
>  
> @@ -103,36 +104,54 @@ void tpm_bios_log_setup(struct tpm_chip *chip)
>  {
>  	struct dentry *tpm_dir, *bin_file, *ascii_file;
>  	const char *name = dev_name(&chip->dev);
> +	void *seq_ops;
> +	int num_files = 0;
>  	int i;
>  
>  	for (i = 0; i < 3; i++)
>  		chip->bios_dir[i] = NULL;
>  
> +	/*
> +	 * NOTE: Currently, support is added only for binary_bios_measurements
> +	 * for TPM2.0. And so it is required to check that if device is TPM2,
> +	 * only 2 entries are allocated i.e. tpm0 dir and
> +	 * binary_bios_measurements file.
> +	 */
> +
> +	num_files = chip->flags & TPM_CHIP_FLAG_TPM2 ? 2 : 3;
> +
>  	tpm_dir = securityfs_create_dir(name, NULL);
>  	if (is_bad(tpm_dir))
>  		goto out;
>  
>  	tpm_dir->d_inode->i_private = chip;
>  
> +	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> +		seq_ops = (void *)&tpm2_binary_b_measurments_seqops;
> +	else
> +		seq_ops = (void *)&tpm_binary_b_measurments_seqops;
> +
>  	bin_file =
>  	    securityfs_create_file("binary_bios_measurements",
>  				   S_IRUSR | S_IRGRP, tpm_dir,
> -				   (void *)&tpm_binary_b_measurments_seqops,
> +				   seq_ops,
>  				   &tpm_bios_measurements_ops);
>  	if (is_bad(bin_file))
>  		goto out_tpm;
>  
> -	ascii_file =
> -	    securityfs_create_file("ascii_bios_measurements",
> -				   S_IRUSR | S_IRGRP, tpm_dir,
> -				   (void *)&tpm_ascii_b_measurments_seqops,
> -				   &tpm_bios_measurements_ops);
> -	if (is_bad(ascii_file))
> -		goto out_bin;
> -
> -	chip->bios_dir[0] = ascii_file;
> -	chip->bios_dir[1] = bin_file;
> -	chip->bios_dir[2] = tpm_dir;
> +	chip->bios_dir[num_files-1] = tpm_dir;
> +	chip->bios_dir[num_files-2] = bin_file;
> +
> +	if (num_files == 3) {
> +		ascii_file =
> +			securityfs_create_file("ascii_bios_measurements",
> +					S_IRUSR | S_IRGRP, tpm_dir,
> +					(void *)&tpm_ascii_b_measurments_seqops,
> +					&tpm_bios_measurements_ops);
> +		if (is_bad(ascii_file))
> +			goto out_bin;
> +		chip->bios_dir[num_files-3] = ascii_file;
> +	}
>  
>  	return;
>  
> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
> index 30a9905..d3c72ce 100644
> --- a/drivers/char/tpm/tpm_of.c
> +++ b/drivers/char/tpm/tpm_of.c
> @@ -26,6 +26,7 @@ int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
>  	struct device_node *np;
>  	const u32 *sizep;
>  	const u64 *basep;
> +	u32 log_size;
>  
>  	if (log->bios_event_log != NULL) {
>  		pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
> @@ -52,6 +53,11 @@ int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
>  		goto cleanup_eio;
>  	}
>  
> +	if (!strncmp(np->name, "tpm", 3))
> +		log_size = be32_to_cpup(sizep);
> +	else
> +		log_size = *sizep;
> +
>  	basep = of_get_property(np, "linux,sml-base", NULL);
>  	if (basep == NULL) {
>  		dev_dbg(&chip->dev, "%s: ERROR - SML not found\n",
> @@ -59,15 +65,20 @@ int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
>  		goto cleanup_eio;
>  	}
>  
> -	log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
> +	log->bios_event_log = kmalloc(log_size, GFP_KERNEL);
>  	if (!log->bios_event_log) {
>  		of_node_put(np);
>  		return -ENOMEM;
>  	}
>  
> -	log->bios_event_log_end = log->bios_event_log + *sizep;
> +	log->bios_event_log_end = log->bios_event_log + log_size;
> +
> +	if (!strncmp(np->name, "tpm", 3))
> +		memcpy(log->bios_event_log, __va(be64_to_cpup(basep)),
> +		log_size);
> +	else
> +		memcpy(log->bios_event_log, __va(*basep), log_size);
>  
> -	memcpy(log->bios_event_log, __va(*basep), *sizep);
>  	of_node_put(np);
>  
>  	return 0;
> -- 
> 2.5.0
> 
> 
> ------------------------------------------------------------------------------
> What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
> patterns at an interface-level. Reveals which users, apps, and protocols are 
> consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
> J-Flow, sFlow and other flows. Make informed decisions using capacity 
> planning reports. http://sdm.link/zohodev2dev
> _______________________________________________
> tpmdd-devel mailing list
> tpmdd-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are 
consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
J-Flow, sFlow and other flows. Make informed decisions using capacity 
planning reports. http://sdm.link/zohodev2dev
Jarkko Sakkinen Aug. 10, 2016, 11:26 a.m. UTC | #3
On Wed, Aug 10, 2016 at 02:25:30PM +0300, Jarkko Sakkinen wrote:
> On Tue, Aug 09, 2016 at 03:34:55PM -0400, Nayna Jain wrote:
> > Adds securityfs support for TPM2.0.
> > This patch currently supports only binary_bios_measurements.
> > 
> > Changelog v2:
> >         * Single tpm_of.c for reading both tpm and vtpm device tree values.
> >         * Some of the issues are fixed in Patch 1 itself.
> >         * Comments in tpm2.h give reference to the standard from where structs
> > 	are taken.
> > 	* Now, tpm_of.c has same code applied for both tpm and vtpm, so I think
> > 	that now it is needed to have generic types rather than endian specific type.
> > 
> > There are few preexisting issues as being mentioned in feedback and are not 
> > addressed in this patch. Reason being, I don't have much expertise of ACPI side as of now, 
> > and these changes will affect acpi,tpm,vtpm, all paths, so I would like to go slow
> > and fix them as different patch later after better understanding.
> > Hope this sounds ok to have them as different patch.
> > 
> > Issues which are not addressed are as below:
> >         * tpm_eventlog.h still has #ifdef defined, for tpm_bios_log_setup()
> >         * tpm_bios_log_setup is still being called in tpm-chip register function.
> 
> I do not understand your changelog entries. Please provide a nice one or
> most two paragraph english language description and keep breakdowns and
> changelogs in the cover letter.
> 
> Commit message does not equal to a discussion forum and I do not have
> any idea what feedback you are talking about...
> 
> Not reviewing this further. This is just terrible.

Whoops, my email client did tricks for me. Please ignore the two other
responses from me.

/Jarkko

------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are 
consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
J-Flow, sFlow and other flows. Make informed decisions using capacity 
planning reports. http://sdm.link/zohodev2dev
diff mbox

Patch

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 9136762..509ace2 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -6,10 +6,14 @@  tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o
 tpm-$(CONFIG_ACPI) += tpm_ppi.o
 
 ifdef CONFIG_ACPI
-	tpm-y += tpm_eventlog_init.o tpm_eventlog.o tpm_acpi.o
+	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_acpi.o
 else
 ifdef CONFIG_TCG_IBMVTPM
-	tpm-y += tpm_eventlog_init.o tpm_eventlog.o tpm_of.o
+	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_of.o
+else
+ifdef CONFIG_PPC64
+	tpm-y += tpm_eventlog_init.o tpm2_eventlog.o tpm_eventlog.o tpm_of.o
+endif
 endif
 endif
 obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 7f6cdab..3f1c489 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -285,20 +285,9 @@  static int tpm1_chip_register(struct tpm_chip *chip)
 
 	tpm_sysfs_add_device(chip);
 
-	tpm_bios_log_setup(chip);
-
 	return 0;
 }
 
-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);
-}
-
 static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
 {
 	struct attribute **i;
@@ -372,10 +361,8 @@  int tpm_chip_register(struct tpm_chip *chip)
 	tpm_add_ppi(chip);
 
 	rc = tpm_add_char_device(chip);
-	if (rc) {
-		tpm1_chip_unregister(chip);
+	if (rc)
 		return rc;
-	}
 
 	chip->flags |= TPM_CHIP_FLAG_REGISTERED;
 
@@ -385,6 +372,8 @@  int tpm_chip_register(struct tpm_chip *chip)
 		return rc;
 	}
 
+	tpm_bios_log_setup(chip);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_chip_register);
@@ -409,7 +398,8 @@  void tpm_chip_unregister(struct tpm_chip *chip)
 
 	tpm_del_legacy_sysfs(chip);
 
-	tpm1_chip_unregister(chip);
+	tpm_bios_log_teardown(chip);
+
 	tpm_del_char_device(chip);
 }
 EXPORT_SYMBOL_GPL(tpm_chip_unregister);
diff --git a/drivers/char/tpm/tpm2.h b/drivers/char/tpm/tpm2.h
new file mode 100644
index 0000000..38a8073
--- /dev/null
+++ b/drivers/char/tpm/tpm2.h
@@ -0,0 +1,85 @@ 
+#ifndef __TPM2_H__
+#define __TPM2_H__
+
+#define TPM_ALG_SHA1_DIGEST_SIZE	20
+#define TPM_ALG_SHA256_DIGEST_SIZE	32
+#define TPM_ALG_SHA384_DIGEST_SIZE	48
+
+#define HASH_COUNT	3
+#define MAX_TPM_LOG_MSG	128
+
+/**
+ * All the structures related to Event Log are taken from TCG EFI Protocol
+ * Specification, Family "2.0". Document is available on link
+ * http://www.trustedcomputinggroup.org/tcg-efi-protocol-specification/
+ * Information is also available on TCG PC Client Platform Firmware Profile
+ * Specification, Family "2.0"
+ * Detailed digest structures for TPM2.0 are defined in document
+ * Trusted Platform Module Library Part 2: Structures, Family "2.0".
+ */
+
+/* Event log header algorithm spec. */
+struct tcg_efispecideventalgorithmsize {
+	u16	algorithm_id;
+	u16	digest_size;
+} __packed;
+
+/* Event log header data. */
+struct tcg_efispecideventstruct {
+	u8					signature[16];
+	u32					platform_class;
+	u8					spec_version_minor;
+	u8					spec_version_major;
+	u8					spec_errata;
+	u8					uintnsize;
+	u32					num_algs;
+	struct tcg_efispecideventalgorithmsize	digest_sizes[HASH_COUNT];
+	u8					vendor_info_size;
+	u8					vendor_info[0];
+} __packed;
+
+/* Header entry for eventlog. */
+struct tcg_pcr_event {
+	u32	pcr_index;
+	u32	event_type;
+	u8	digest[20];
+	u32	event_size;
+	u8	event[MAX_TPM_LOG_MSG];
+} __packed;
+
+/* Digest union for crypto agility. */
+union tpmu_ha {
+	u8	 sha1[TPM_ALG_SHA1_DIGEST_SIZE];
+	u8	 sha256[TPM_ALG_SHA256_DIGEST_SIZE];
+	u8	 sha384[TPM_ALG_SHA384_DIGEST_SIZE];
+} __packed;
+
+/* Crypto Agile algorithm and respective digest. */
+struct tpmt_ha {
+	u16		algorithm_id;
+	union tpmu_ha	digest;
+} __packed;
+
+/* Crypto agile digests list. */
+struct tpml_digest_values {
+	u32		count;
+	struct tpmt_ha	digests[HASH_COUNT];
+} __packed;
+
+/* Event field structure. */
+struct tcg_event_field {
+	u32	event_size;
+	u8      event[MAX_TPM_LOG_MSG];
+} __packed;
+
+/* Crypto agile log entry format for TPM 2.0. */
+struct tcg_pcr_event2 {
+	u32				pcr_index;
+	u32				event_type;
+	struct tpml_digest_values	digests;
+	struct tcg_event_field		event;
+} __packed;
+
+extern const struct seq_operations tpm2_binary_b_measurments_seqops;
+
+#endif
diff --git a/drivers/char/tpm/tpm2_eventlog.c b/drivers/char/tpm/tpm2_eventlog.c
new file mode 100644
index 0000000..f1e8c4a
--- /dev/null
+++ b/drivers/char/tpm/tpm2_eventlog.c
@@ -0,0 +1,224 @@ 
+/*
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Authors:
+ *      Nayna Jain <nayna@linux.vnet.ibm.com>
+
+ * Access to TPM2.0 event log as written by Firmware.
+ * It assumes that writer of event log has followed TCG Spec 2.0
+ * has written the event struct data in little endian. With that,
+ * it doesn't need any endian conversion for structure content.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "tpm.h"
+#include "tpm2.h"
+#include "tpm_eventlog.h"
+
+
+static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
+		struct tcg_pcr_event *event_header)
+{
+	struct tcg_efispecideventstruct *efispecid;
+	struct tcg_event_field *event_field;
+	void *marker, *marker_start;
+	int j;
+	size_t size = 0;
+
+	/*
+	 * NOTE: TPM2.0 allows support for extend to multiple PCR Banks.
+	 * This implies that eventlog also has multiple digest values
+	 * one for each PCR Bank. This is called Crypto Agile Log Entry
+	 * Format. Current support implementation is for SHA1 and SHA256.
+	 * Number of digest values are identified by parsing first
+	 * structure stored in event log also called event header.
+	 * Further, the eventlog is written in packed form so to calculate
+	 * offset it is important to know the type of algorithm used.
+	 * Eg. 1:
+	 * digest_values.count = 1;
+	 * digest_values.digest[0].algorithm_id = sha1;
+	 * digest_values.digest[0].digest.sha1 = {20 bytes raw data};
+	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 20
+	 *
+	 * Eg. 2:
+	 * digest_values.count = 1;
+	 * digest_values.digest[0].algorithm_id = sha256;
+	 * digest_values.digest[0].digest.sha1 = {32 bytes raw data};
+	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 32
+
+	 * Eg. 3:
+	 * digest_values.count = 2;
+	 * digest_values.digest[0].algorithm_id = sha1;
+	 * digest_values.digest[0].digest.sha1 = {20 bytes raw data};
+	 * digest_values.digest[1].algorithm_id = sha256;
+	 * digest_values.digest[1].digest.sha256 = {32 bytes raw data};
+	 * Offset of eventsize is sizeof(count) + sizeof(algorithm_id) + 20
+	 *			+ sizeof(algorithm_id) + 32;
+	 *
+	 * So, it implies that offset of event_size can vary based on digest
+	 * values as defined by vendor. And so we have to calculate the
+	 * offset by parsing through number and type of digests being used.
+	 * And this is the purpose of using *marker to traverse the structure
+	 * and calculate the offset of event_size. This function uses *marker
+	 * to parse and calculate the dynamic size of the whole event structure.
+	 */
+
+	marker = event;
+	marker_start = marker;
+	marker = marker + sizeof(event->pcr_index) + sizeof(event->event_type)
+		+ sizeof(event->digests.count);
+
+	efispecid = (struct tcg_efispecideventstruct *) event_header->event;
+
+	for (j = 0; (j < efispecid->num_algs) && (j < HASH_COUNT); j++) {
+		marker = marker
+			+ sizeof(efispecid->digest_sizes[j].algorithm_id);
+		marker = marker + efispecid->digest_sizes[j].digest_size;
+	}
+
+	event_field = (struct tcg_event_field *) marker;
+	marker = marker + sizeof(event_field->event_size)
+		+ event_field->event_size;
+	size = marker - marker_start;
+
+	if ((event->event_type == 0) && (event_field->event_size == 0))
+		return 0;
+
+	return size;
+}
+
+static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
+{
+	struct tpm_bios_log *log = m->private;
+	void *addr = log->bios_event_log;
+	void *limit = log->bios_event_log_end;
+	struct tcg_pcr_event *event_header;
+	struct tcg_pcr_event2 *event;
+	int i;
+	size_t size = 0;
+
+	event_header = addr;
+
+	size = sizeof(struct tcg_pcr_event) - sizeof(event_header->event)
+		+ event_header->event_size;
+
+
+	if (*pos == 0) {
+		if (addr + size < limit) {
+			if ((event_header->event_type == 0) &&
+					(event_header->event_size == 0))
+				return NULL;
+			return SEQ_START_TOKEN;
+		}
+	}
+
+	if (*pos > 0) {
+		addr += size;
+		event = addr;
+		size = calc_tpm2_event_size(event, event_header);
+		if ((addr + size >=  limit) || (size == 0))
+			return NULL;
+	}
+
+	/* read over *pos measurements */
+	for (i = 0; i < (*pos - 1); i++) {
+		event = addr;
+		size = calc_tpm2_event_size(event, event_header);
+
+		if ((addr + size >= limit) || (size == 0))
+			return NULL;
+		addr += size;
+	}
+
+	return addr;
+}
+
+static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
+		loff_t *pos)
+{
+	struct tcg_pcr_event *event_header;
+	struct tcg_pcr_event2 *event;
+	struct tpm_bios_log *log = m->private;
+	void *limit = log->bios_event_log_end;
+	void *marker;
+	size_t event_size = 0;
+
+	event_header = log->bios_event_log;
+
+	if (v == SEQ_START_TOKEN) {
+		event_size = sizeof(struct tcg_pcr_event)
+			- sizeof(event_header->event)
+			+ event_header->event_size;
+		marker = event_header;
+	} else {
+		event = v;
+		event_size = calc_tpm2_event_size(event, event_header);
+		if (event_size == 0)
+			return NULL;
+		marker =  event;
+	}
+
+	marker = marker + event_size;
+	if (marker >= limit)
+		return NULL;
+	v = marker;
+	event = v;
+
+	event_size = calc_tpm2_event_size(event, event_header);
+	if (((v + event_size) >= limit) || (event_size == 0))
+		return NULL;
+
+	(*pos)++;
+	return v;
+}
+
+static void tpm2_bios_measurements_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
+{
+	struct tpm_bios_log *log = m->private;
+	struct tcg_pcr_event *event_header = log->bios_event_log;
+	struct tcg_pcr_event2 *event = v;
+	void *temp_ptr;
+	size_t size = 0;
+
+	if (v == SEQ_START_TOKEN) {
+
+		size = sizeof(struct tcg_pcr_event)
+			- sizeof(event_header->event)
+			+ event_header->event_size;
+
+		temp_ptr = event_header;
+
+		if (size > 0)
+			seq_write(m, temp_ptr, size);
+	} else {
+
+		size = calc_tpm2_event_size(event, event_header);
+
+		temp_ptr = event;
+		if (size > 0)
+			seq_write(m, temp_ptr, size);
+	}
+
+	return 0;
+}
+
+const struct seq_operations tpm2_binary_b_measurments_seqops = {
+	.start = tpm2_bios_measurements_start,
+	.next = tpm2_bios_measurements_next,
+	.stop = tpm2_bios_measurements_stop,
+	.show = tpm2_binary_bios_measurements_show,
+};
diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
index b888c77..3297fda 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -78,7 +78,7 @@  enum tcpa_pc_event_ids {
 int read_log(struct tpm_bios_log *log, struct tpm_chip *chip);
 
 #if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
-	defined(CONFIG_ACPI)
+	defined(CONFIG_ACPI) || defined(CONFIG_PPC64)
 extern void tpm_bios_log_setup(struct tpm_chip *chip);
 extern void tpm_bios_log_teardown(struct tpm_chip *chip);
 #else
diff --git a/drivers/char/tpm/tpm_eventlog_init.c b/drivers/char/tpm/tpm_eventlog_init.c
index dd5dbc4..a3fb5bc 100644
--- a/drivers/char/tpm/tpm_eventlog_init.c
+++ b/drivers/char/tpm/tpm_eventlog_init.c
@@ -28,6 +28,7 @@ 
 #include <linux/slab.h>
 
 #include "tpm.h"
+#include "tpm2.h"
 #include "tpm_eventlog.h"
 
 
@@ -103,36 +104,54 @@  void tpm_bios_log_setup(struct tpm_chip *chip)
 {
 	struct dentry *tpm_dir, *bin_file, *ascii_file;
 	const char *name = dev_name(&chip->dev);
+	void *seq_ops;
+	int num_files = 0;
 	int i;
 
 	for (i = 0; i < 3; i++)
 		chip->bios_dir[i] = NULL;
 
+	/*
+	 * NOTE: Currently, support is added only for binary_bios_measurements
+	 * for TPM2.0. And so it is required to check that if device is TPM2,
+	 * only 2 entries are allocated i.e. tpm0 dir and
+	 * binary_bios_measurements file.
+	 */
+
+	num_files = chip->flags & TPM_CHIP_FLAG_TPM2 ? 2 : 3;
+
 	tpm_dir = securityfs_create_dir(name, NULL);
 	if (is_bad(tpm_dir))
 		goto out;
 
 	tpm_dir->d_inode->i_private = chip;
 
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		seq_ops = (void *)&tpm2_binary_b_measurments_seqops;
+	else
+		seq_ops = (void *)&tpm_binary_b_measurments_seqops;
+
 	bin_file =
 	    securityfs_create_file("binary_bios_measurements",
 				   S_IRUSR | S_IRGRP, tpm_dir,
-				   (void *)&tpm_binary_b_measurments_seqops,
+				   seq_ops,
 				   &tpm_bios_measurements_ops);
 	if (is_bad(bin_file))
 		goto out_tpm;
 
-	ascii_file =
-	    securityfs_create_file("ascii_bios_measurements",
-				   S_IRUSR | S_IRGRP, tpm_dir,
-				   (void *)&tpm_ascii_b_measurments_seqops,
-				   &tpm_bios_measurements_ops);
-	if (is_bad(ascii_file))
-		goto out_bin;
-
-	chip->bios_dir[0] = ascii_file;
-	chip->bios_dir[1] = bin_file;
-	chip->bios_dir[2] = tpm_dir;
+	chip->bios_dir[num_files-1] = tpm_dir;
+	chip->bios_dir[num_files-2] = bin_file;
+
+	if (num_files == 3) {
+		ascii_file =
+			securityfs_create_file("ascii_bios_measurements",
+					S_IRUSR | S_IRGRP, tpm_dir,
+					(void *)&tpm_ascii_b_measurments_seqops,
+					&tpm_bios_measurements_ops);
+		if (is_bad(ascii_file))
+			goto out_bin;
+		chip->bios_dir[num_files-3] = ascii_file;
+	}
 
 	return;
 
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 30a9905..d3c72ce 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -26,6 +26,7 @@  int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
 	struct device_node *np;
 	const u32 *sizep;
 	const u64 *basep;
+	u32 log_size;
 
 	if (log->bios_event_log != NULL) {
 		pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
@@ -52,6 +53,11 @@  int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
 		goto cleanup_eio;
 	}
 
+	if (!strncmp(np->name, "tpm", 3))
+		log_size = be32_to_cpup(sizep);
+	else
+		log_size = *sizep;
+
 	basep = of_get_property(np, "linux,sml-base", NULL);
 	if (basep == NULL) {
 		dev_dbg(&chip->dev, "%s: ERROR - SML not found\n",
@@ -59,15 +65,20 @@  int read_log(struct tpm_bios_log *log, struct tpm_chip *chip)
 		goto cleanup_eio;
 	}
 
-	log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
+	log->bios_event_log = kmalloc(log_size, GFP_KERNEL);
 	if (!log->bios_event_log) {
 		of_node_put(np);
 		return -ENOMEM;
 	}
 
-	log->bios_event_log_end = log->bios_event_log + *sizep;
+	log->bios_event_log_end = log->bios_event_log + log_size;
+
+	if (!strncmp(np->name, "tpm", 3))
+		memcpy(log->bios_event_log, __va(be64_to_cpup(basep)),
+		log_size);
+	else
+		memcpy(log->bios_event_log, __va(*basep), log_size);
 
-	memcpy(log->bios_event_log, __va(*basep), *sizep);
 	of_node_put(np);
 
 	return 0;