[PATCH v7 0/2] securityfs support for TPM 2.0 firmware event log

[PATCH v7 0/2] securityfs support for TPM 2.0 firmware event log

[Nayna Jain]

The TPM device driver defines ascii and binary methods for
displaying the TPM 1.2 event log via securityfs files, which are
needed for validating a TPM quote. The device driver for TPM 2.0
does not have similar support for displaying the TPM 2.0
event log. This patch set adds the support for displaying
TPM 2.0 event log in binary format.

The parsing mechanism to display the TPM 2.0 event log in binary
format is implemented as defined in the TPM 2.0 TCG specification[1].
If the firmware event log support exists and is successfully read,
the securityfs file is created to provide the event log in binary
format for both the OF device tree and ACPI.

   - Patch 1 adds the device tree bindings support for Physical TPM.
   - Patch 2 adds the support for creating securityfs files and for
     displaying the TPM 2.0 crypto agile event log in binary format.

[1] TCG EFI Protocol Specification, Family "2.0" - Section 5 "Event
Log Structure"

Changelog History

v7:
- Rebased to the Jarkko's latest master branch (b2505f6 tpm/vtpm:
  fix kdoc warnings)
- Included Jarkko's feedbacks on version v6.
- Cleaned up #defines in tpm2_eventlog.c
  - renamed HASH_COUNT to TPM2_ACTIVE_PCR_BANKS
  - deleted MAX_DIGEST_SIZE, used SHA384_DIGEST_SIZE directly from 
  <crypto/hash_info.h>
  - deleted MAX_TPM_LOG_MSG. Redefined event[MAX_TPM_LOG_MSG]
  as event[0].

v6:

- Rebased to the Jarkko's latest master branch (e717b5c:tpm: vtpm_proxy: 
  conditionally call tpm_chip_unregister)
- Retained securityfs setup functions in tpm_eventlog.c
- Renamed tpm_eventlog.c to tpm1_eventlog.c
- Fixed tpm_read_log_of() for NULL check and memcpy function.

v5:

- Upstreamed cleanup and fixes as different patchset
- Rebased to the Jarkko's latest master branch (e5be084 tpm: vtpm_proxy:
  Do not access host's event log)
- Patch "tpm: enhance read_log_of() to support Physical TPM event log
  - New Patch.
- Patch "tpm: add securityfs support for TPM 2.0 firmware event log"
  - Moved the changes in read_log_of() to a different patch
  - TPM 2.0 event log data types are declared in tpm_eventlog.h, tpm2.h
  is removed.
  - Included other feedbacks also from Jarkko on aligment and extra
    line

v4:

- Includes feedbacks from Jarkko and Jason.
- Patch "tpm: define a generic open() method for ascii & bios
measurements".
  - Fix indentation issue.
- Patch "tpm: replace the dynamically allocated bios_dir as
  struct dentry array".
  - Continue to use bios_dir_count variable to use is_bad() checks and
    to maintain correct order for securityfs_remove() during teardown.
  - Reset chip->bios_dir_count in teardown() function.
- Patch "tpm: validate the eventlog access before tpm_bios_log_setup".
  - Retain TPM2 check which was removed in previous patch.
  - Add tpm_bios_log_setup failure handling.
  - Remove use of private data from v3 version of patch. Add a
  new member to struct tpm_chip to achieve the same purpose.
- Patch "tpm: redefine the read_log method to check for ACPI/OF 
properties sequentially".
  - Move replacement of CONFIG_TCG_IBMVTPM with CONFIG_OF to this
    patch from patch 3.
  - Replace -1 error code with -ENODEV.
- Patch "tpm: replace the of_find_node_by_name() with dev of_node
property".
  - Uses chip->dev.parent->of_node.
  - Created separate patch for cleanup of pr_err messages.
- Patch "tpm: remove printk error messages".
  - New Patch.
- Patch "tpm: add the securityfs file support for TPM 2.0 eventlog".
  - Parses event digests using event alg_id rather than event log header
    alg_id.
  - Uses of_property_match_string to differentiate tpm/vtpm compatible

v3:

- Includes the review feedbacks as suggested by Jason.
- Split of patches into one patch per idea.
- Generic open() method for ascii/bios measurements.
- Replacement of of **bios_dir with *bios_dir[3].
- Verifying readlog() is successful before creating securityfs entries.
- Generic readlog() to check for ACPI/OF in sequence.
- read_log_of() method now uses of_node propertry rather than
calling find_device_by_name.
- read_log differentiates vtpm/tpm using its compatible property.
- Cleans pr_err with dev_dbg.
- Commit msgs subject line prefixed with tpm.

v2:

- Fixes issues as given in feedback by Jason.
- Adds documentation for device tree.

Nayna Jain (2):
  tpm: enhance read_log_of() to support Physical TPM event log
  tpm: add securityfs support for TPM 2.0 firmware event log

 drivers/char/tpm/Makefile                          |   2 +-
 .../char/tpm/{tpm_eventlog.c => tpm1_eventlog.c}   |  35 ++--
 drivers/char/tpm/tpm2_eventlog.c                   | 203 +++++++++++++++++++++
 drivers/char/tpm/tpm_eventlog.h                    |  70 +++++++
 drivers/char/tpm/tpm_of.c                          |  27 ++-
 5 files changed, 318 insertions(+), 19 deletions(-)
 rename drivers/char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} (95%)
 create mode 100644 drivers/char/tpm/tpm2_eventlog.c

-- 
2.5.0

[PATCH v7 1/2] tpm: enhance read_log_of() to support Physical TPM event log

[Nayna Jain]

Physical TPMs use Open Firmware Device Tree bindings that are similar
to the IBM Power virtual TPM to support event log. However, these
properties store the values in different endianness for Physical
and Virtual TPM.

This patch fixes the endianness issue by doing appropriate conversion
based on Physical or Virtual TPM.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm_of.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 7dee42d7..de57d4a 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -27,6 +27,8 @@ int tpm_read_log_of(struct tpm_chip *chip)
 	const u32 *sizep;
 	const u64 *basep;
 	struct tpm_bios_log *log;
+	u32 size;
+	u64 base;
 
 	log = &chip->log;
 	if (chip->dev.parent && chip->dev.parent->of_node)
@@ -41,18 +43,35 @@ int tpm_read_log_of(struct tpm_chip *chip)
 	if (sizep == NULL || basep == NULL)
 		return -EIO;
 
-	if (*sizep == 0) {
+	/*
+	 * For both vtpm/tpm, firmware has log addr and log size in big
+	 * endian format. But in case of vtpm, there is a method called
+	 * sml-handover which is run during kernel init even before
+	 * device tree is setup. This sml-handover function takes care
+	 * of endianness and writes to sml-base and sml-size in little
+	 * endian format. For this reason, vtpm doesn't need conversion
+	 * but physical tpm needs the conversion.
+	 */
+	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
+		size = be32_to_cpup(sizep);
+		base = be64_to_cpup(basep);
+	} else {
+		size = *sizep;
+		base = *basep;
+	}
+
+	if (size == 0) {
 		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
 		return -EIO;
 	}
 
-	log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
+	log->bios_event_log = kmalloc(size, GFP_KERNEL);
 	if (!log->bios_event_log)
 		return -ENOMEM;
 
-	log->bios_event_log_end = log->bios_event_log + *sizep;
+	log->bios_event_log_end = log->bios_event_log + size;
 
-	memcpy(log->bios_event_log, __va(*basep), *sizep);
+	memcpy(log->bios_event_log, __va(base), size);
 
 	return 0;
 }
-- 
2.5.0

[PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Nayna Jain]

Unlike the device driver support for TPM 1.2, the TPM 2.0 does
not support the securityfs pseudo files for displaying the
firmware event log.

This patch enables support for providing the TPM 2.0 event log in
binary form. TPM 2.0 event log supports a crypto agile format that
records multiple digests, which is different from TPM 1.2. This
patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
event log parser which understand the TPM 2.0 crypto agile format.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
---
 drivers/char/tpm/Makefile                          |   2 +-
 .../char/tpm/{tpm_eventlog.c => tpm1_eventlog.c}   |  35 ++--
 drivers/char/tpm/tpm2_eventlog.c                   | 203 +++++++++++++++++++++
 drivers/char/tpm/tpm_eventlog.h                    |  70 +++++++
 4 files changed, 295 insertions(+), 15 deletions(-)
 rename drivers/char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} (95%)
 create mode 100644 drivers/char/tpm/tpm2_eventlog.c

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index a05b1eb..3d386a8 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -3,7 +3,7 @@
 #
 obj-$(CONFIG_TCG_TPM) += tpm.o
 tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
-		tpm_eventlog.o
+		tpm1_eventlog.o tpm2_eventlog.o
 tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
 tpm-$(CONFIG_OF) += tpm_of.o
 obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm1_eventlog.c
similarity index 95%
rename from drivers/char/tpm/tpm_eventlog.c
rename to drivers/char/tpm/tpm1_eventlog.c
index 11bb113..9a8605e 100644
--- a/drivers/char/tpm/tpm_eventlog.c
+++ b/drivers/char/tpm/tpm1_eventlog.c
@@ -390,9 +390,6 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
 	unsigned int cnt;
 	int rc = 0;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2)
-		return 0;
-
 	rc = tpm_read_log(chip);
 	if (rc)
 		return rc;
@@ -407,7 +404,13 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
 	cnt++;
 
 	chip->bin_log_seqops.chip = chip;
-	chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops;
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		chip->bin_log_seqops.seqops =
+			&tpm2_binary_b_measurements_seqops;
+	else
+		chip->bin_log_seqops.seqops =
+			&tpm_binary_b_measurements_seqops;
+
 
 	chip->bios_dir[cnt] =
 	    securityfs_create_file("binary_bios_measurements",
@@ -418,17 +421,21 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
 		goto err;
 	cnt++;
 
-	chip->ascii_log_seqops.chip = chip;
-	chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops;
+	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
 
-	chip->bios_dir[cnt] =
-	    securityfs_create_file("ascii_bios_measurements",
-				   0440, chip->bios_dir[0],
-				   (void *)&chip->ascii_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 *)&chip->ascii_log_seqops,
+					       &tpm_bios_measurements_ops);
+		if (IS_ERR(chip->bios_dir[cnt]))
+			goto err;
+		cnt++;
+	}
 
 	return 0;
 
diff --git a/drivers/char/tpm/tpm2_eventlog.c b/drivers/char/tpm/tpm2_eventlog.c
new file mode 100644
index 0000000..63690d3
--- /dev/null
+++ b/drivers/char/tpm/tpm2_eventlog.c
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Authors:
+ *      Nayna Jain <nayna@linux.vnet.ibm.com>
+ *
+ * Access to TPM 2.0 event log as written by Firmware.
+ * It assumes that writer of event log has followed TCG Specification
+ * for Family "2.0" and written the event 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 "tpm_eventlog.h"
+
+static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
+		struct tcg_pcr_event *event_header)
+{
+	struct tcg_efi_specid_event *efispecid;
+	struct tcg_event_field *event_field;
+	void *marker;
+	void *marker_start;
+	int i;
+	int j;
+	u16 halg;
+	u32 halg_size;
+	size_t size;
+
+	/*
+	 * TPM 2.0 supports extend to multiple PCR Banks. This implies
+	 * event log also has multiple digest values, one for each PCR Bank.
+	 * This is called Crypto Agile Log Entry Format.
+	 * Below code implements the procedure defined in TCG EFI Protocol
+	 * Specification Family "2.0" to parse the event log in Crypto Agile
+	 * Log Entry Format.
+	 */
+
+	marker = event;
+	marker_start = marker;
+	marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
+		+ sizeof(event->digests.count);
+
+	efispecid = (struct tcg_efi_specid_event *) event_header->event;
+
+	for (i = 0; (i < event->digests.count) && (i < TPM2_ACTIVE_PCR_BANKS);
+	     i++) {
+		halg_size = sizeof(event->digests.digests[i].alg_id);
+		memcpy(&halg, marker, halg_size);
+		marker = marker + halg_size;
+		for (j = 0; (j < efispecid->num_algs); j++) {
+			if (halg == efispecid->digest_sizes[j].alg_id) {
+				marker = marker +
+					efispecid->digest_sizes[j].digest_size;
+				break;
+			}
+		}
+	}
+
+	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_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 tcg_pcr_event *event_header;
+	struct tcg_pcr_event2 *event;
+	int i;
+	size_t size;
+
+	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;
+	}
+
+	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_chip *chip = m->private;
+	struct tpm_bios_log *log = &chip->log;
+	void *limit = log->bios_event_log_end;
+	void *marker;
+	size_t event_size;
+
+	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_chip *chip = m->private;
+	struct tpm_bios_log *log = &chip->log;
+	struct tcg_pcr_event *event_header = log->bios_event_log;
+	struct tcg_pcr_event2 *event = v;
+	void *temp_ptr;
+	size_t size;
+
+	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_measurements_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 1660d74..6886a11 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -2,9 +2,12 @@
 #ifndef __TPM_EVENTLOG_H__
 #define __TPM_EVENTLOG_H__
 
+#include <crypto/hash_info.h>
+
 #define TCG_EVENT_NAME_LEN_MAX	255
 #define MAX_TEXT_EVENT		1000	/* Max event string length */
 #define ACPI_TCPA_SIG		"TCPA"	/* 0x41504354 /'TCPA' */
+#define TPM2_ACTIVE_PCR_BANKS	3
 
 #ifdef CONFIG_PPC64
 #define do_endian_conversion(x) be32_to_cpu(x)
@@ -73,6 +76,73 @@ enum tcpa_pc_event_ids {
 	HOST_TABLE_OF_DEVICES,
 };
 
+/*
+ * All the structures related to TPM 2.0 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 TPM 2.0 are defined in document
+ * Trusted Platform Module Library Part 2: Structures, Family "2.0".
+ */
+
+/* TPM 2.0 Event log header algorithm spec. */
+struct tcg_efi_specid_event_algs {
+	u16 alg_id;
+	u16 digest_size;
+} __packed;
+
+/* TPM 2.0 Event log header data. */
+struct tcg_efi_specid_event {
+	u8 signature[16];
+	u32 platform_class;
+	u8 spec_version_minor;
+	u8 spec_version_major;
+	u8 spec_errata;
+	u8 uintnsize;
+	u32 num_algs;
+	struct tcg_efi_specid_event_algs digest_sizes[TPM2_ACTIVE_PCR_BANKS];
+	u8 vendor_info_size;
+	u8 vendor_info[0];
+} __packed;
+
+/* TPM 2.0 Event Log Header. */
+struct tcg_pcr_event {
+	u32 pcr_idx;
+	u32 event_type;
+	u8 digest[20];
+	u32 event_size;
+	u8 event[0];
+} __packed;
+
+/* TPM 2.0 Crypto agile algorithm and respective digest. */
+struct tpmt_ha {
+	u16 alg_id;
+	u8 digest[SHA384_DIGEST_SIZE];
+} __packed;
+
+/* TPM 2.0 Crypto agile digests list. */
+struct tpml_digest_values {
+	u32 count;
+	struct tpmt_ha digests[TPM2_ACTIVE_PCR_BANKS];
+} __packed;
+
+/* TPM 2.0 Event field structure. */
+struct tcg_event_field {
+	u32 event_size;
+	u8 event[0];
+} __packed;
+
+/* TPM 2.0 Crypto agile log entry format. */
+struct tcg_pcr_event2 {
+	u32 pcr_idx;
+	u32 event_type;
+	struct tpml_digest_values digests;
+	struct tcg_event_field event;
+} __packed;
+
+extern const struct seq_operations tpm2_binary_b_measurements_seqops;
+
 #if defined(CONFIG_ACPI)
 int tpm_read_log_acpi(struct tpm_chip *chip);
 #else
-- 
2.5.0

Re: [PATCH v7 1/2] tpm: enhance read_log_of() to support Physical TPM event log

[Jarkko Sakkinen]

On Sun, Dec 11, 2016 at 12:35:32AM -0500, Nayna Jain wrote:
> Physical TPMs use Open Firmware Device Tree bindings that are similar
> to the IBM Power virtual TPM to support event log. However, these
> properties store the values in different endianness for Physical
> and Virtual TPM.
> 
> This patch fixes the endianness issue by doing appropriate conversion
> based on Physical or Virtual TPM.

Will other device tree using firmwares than OF use the same bindings?

> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> ---
>  drivers/char/tpm/tpm_of.c | 27 +++++++++++++++++++++++----
>  1 file changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
> index 7dee42d7..de57d4a 100644
> --- a/drivers/char/tpm/tpm_of.c
> +++ b/drivers/char/tpm/tpm_of.c
> @@ -27,6 +27,8 @@ int tpm_read_log_of(struct tpm_chip *chip)
>  	const u32 *sizep;
>  	const u64 *basep;
>  	struct tpm_bios_log *log;
> +	u32 size;
> +	u64 base;
>  
>  	log = &chip->log;
>  	if (chip->dev.parent && chip->dev.parent->of_node)
> @@ -41,18 +43,35 @@ int tpm_read_log_of(struct tpm_chip *chip)
>  	if (sizep == NULL || basep == NULL)
>  		return -EIO;
>  
> -	if (*sizep == 0) {
> +	/*
> +	 * For both vtpm/tpm, firmware has log addr and log size in big
> +	 * endian format. But in case of vtpm, there is a method called
> +	 * sml-handover which is run during kernel init even before
> +	 * device tree is setup. This sml-handover function takes care
> +	 * of endianness and writes to sml-base and sml-size in little
> +	 * endian format. For this reason, vtpm doesn't need conversion
> +	 * but physical tpm needs the conversion.
> +	 */
> +	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
> +		size = be32_to_cpup(sizep);
> +		base = be64_to_cpup(basep);
> +	} else {
> +		size = *sizep;
> +		base = *basep;
> +	}
> +
> +	if (size == 0) {
>  		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
>  		return -EIO;
>  	}
>  
> -	log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
> +	log->bios_event_log = kmalloc(size, GFP_KERNEL);
>  	if (!log->bios_event_log)
>  		return -ENOMEM;
>  
> -	log->bios_event_log_end = log->bios_event_log + *sizep;
> +	log->bios_event_log_end = log->bios_event_log + size;
>  
> -	memcpy(log->bios_event_log, __va(*basep), *sizep);
> +	memcpy(log->bios_event_log, __va(base), size);
>  
>  	return 0;
>  }
> -- 
> 2.5.0
> 

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

/Jarkko

Re: [PATCH v7 1/2] tpm: enhance read_log_of() to support Physical TPM event log

[Nayna]

On 12/12/2016 08:10 PM, Jarkko Sakkinen wrote:
> On Sun, Dec 11, 2016 at 12:35:32AM -0500, Nayna Jain wrote:
>> Physical TPMs use Open Firmware Device Tree bindings that are similar
>> to the IBM Power virtual TPM to support event log. However, these
>> properties store the values in different endianness for Physical
>> and Virtual TPM.
>>
>> This patch fixes the endianness issue by doing appropriate conversion
>> based on Physical or Virtual TPM.
>
> Will other device tree using firmwares than OF use the same bindings?

Yes, that is what expected that all other device tree using firmware 
will also use same bindings.

Thanks & Regards,
     - Nayna

>
>> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
>> ---
>>   drivers/char/tpm/tpm_of.c | 27 +++++++++++++++++++++++----
>>   1 file changed, 23 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
>> index 7dee42d7..de57d4a 100644
>> --- a/drivers/char/tpm/tpm_of.c
>> +++ b/drivers/char/tpm/tpm_of.c
>> @@ -27,6 +27,8 @@ int tpm_read_log_of(struct tpm_chip *chip)
>>   	const u32 *sizep;
>>   	const u64 *basep;
>>   	struct tpm_bios_log *log;
>> +	u32 size;
>> +	u64 base;
>>
>>   	log = &chip->log;
>>   	if (chip->dev.parent && chip->dev.parent->of_node)
>> @@ -41,18 +43,35 @@ int tpm_read_log_of(struct tpm_chip *chip)
>>   	if (sizep == NULL || basep == NULL)
>>   		return -EIO;
>>
>> -	if (*sizep == 0) {
>> +	/*
>> +	 * For both vtpm/tpm, firmware has log addr and log size in big
>> +	 * endian format. But in case of vtpm, there is a method called
>> +	 * sml-handover which is run during kernel init even before
>> +	 * device tree is setup. This sml-handover function takes care
>> +	 * of endianness and writes to sml-base and sml-size in little
>> +	 * endian format. For this reason, vtpm doesn't need conversion
>> +	 * but physical tpm needs the conversion.
>> +	 */
>> +	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
>> +		size = be32_to_cpup(sizep);
>> +		base = be64_to_cpup(basep);
>> +	} else {
>> +		size = *sizep;
>> +		base = *basep;
>> +	}
>> +
>> +	if (size == 0) {
>>   		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
>>   		return -EIO;
>>   	}
>>
>> -	log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
>> +	log->bios_event_log = kmalloc(size, GFP_KERNEL);
>>   	if (!log->bios_event_log)
>>   		return -ENOMEM;
>>
>> -	log->bios_event_log_end = log->bios_event_log + *sizep;
>> +	log->bios_event_log_end = log->bios_event_log + size;
>>
>> -	memcpy(log->bios_event_log, __va(*basep), *sizep);
>> +	memcpy(log->bios_event_log, __va(base), size);
>>
>>   	return 0;
>>   }
>> --
>> 2.5.0
>>
>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>
> /Jarkko
>

Re: [PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Jarkko Sakkinen]

On Sun, Dec 11, 2016 at 12:35:33AM -0500, Nayna Jain wrote:
> Unlike the device driver support for TPM 1.2, the TPM 2.0 does
> not support the securityfs pseudo files for displaying the
> firmware event log.
> 
> This patch enables support for providing the TPM 2.0 event log in
> binary form. TPM 2.0 event log supports a crypto agile format that
> records multiple digests, which is different from TPM 1.2. This
> patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
> event log parser which understand the TPM 2.0 crypto agile format.
> 
> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>

There is something fundamentally wrong in this commit.

You must not allow this feature unless CONFIG_OF is set. It is the only
interface where the supply path of the event log is well defined on
platforms that include a TPM 2.0 chip.

There's buch casts in the form '(char *) foo'. They should be
'(char *)foo'.

> ---
>  drivers/char/tpm/Makefile                          |   2 +-
>  .../char/tpm/{tpm_eventlog.c => tpm1_eventlog.c}   |  35 ++--
>  drivers/char/tpm/tpm2_eventlog.c                   | 203 +++++++++++++++++++++
>  drivers/char/tpm/tpm_eventlog.h                    |  70 +++++++
>  4 files changed, 295 insertions(+), 15 deletions(-)
>  rename drivers/char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} (95%)
>  create mode 100644 drivers/char/tpm/tpm2_eventlog.c
> 
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index a05b1eb..3d386a8 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -3,7 +3,7 @@
>  #
>  obj-$(CONFIG_TCG_TPM) += tpm.o
>  tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
> -		tpm_eventlog.o
> +		tpm1_eventlog.o tpm2_eventlog.o
>  tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
>  tpm-$(CONFIG_OF) += tpm_of.o
>  obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
> diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm1_eventlog.c
> similarity index 95%
> rename from drivers/char/tpm/tpm_eventlog.c
> rename to drivers/char/tpm/tpm1_eventlog.c
> index 11bb113..9a8605e 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm1_eventlog.c
> @@ -390,9 +390,6 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>  	unsigned int cnt;
>  	int rc = 0;
>  
> -	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> -		return 0;
> -
>  	rc = tpm_read_log(chip);
>  	if (rc)
>  		return rc;
> @@ -407,7 +404,13 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>  	cnt++;
>  
>  	chip->bin_log_seqops.chip = chip;
> -	chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops;
> +	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> +		chip->bin_log_seqops.seqops =
> +			&tpm2_binary_b_measurements_seqops;
> +	else
> +		chip->bin_log_seqops.seqops =
> +			&tpm_binary_b_measurements_seqops;
> +
>  
>  	chip->bios_dir[cnt] =
>  	    securityfs_create_file("binary_bios_measurements",
> @@ -418,17 +421,21 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>  		goto err;
>  	cnt++;
>  
> -	chip->ascii_log_seqops.chip = chip;
> -	chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops;
> +	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
>  
> -	chip->bios_dir[cnt] =
> -	    securityfs_create_file("ascii_bios_measurements",
> -				   0440, chip->bios_dir[0],
> -				   (void *)&chip->ascii_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 *)&chip->ascii_log_seqops,
> +					       &tpm_bios_measurements_ops);
> +		if (IS_ERR(chip->bios_dir[cnt]))
> +			goto err;
> +		cnt++;
> +	}
>  
>  	return 0;
>  
> diff --git a/drivers/char/tpm/tpm2_eventlog.c b/drivers/char/tpm/tpm2_eventlog.c
> new file mode 100644
> index 0000000..63690d3
> --- /dev/null
> +++ b/drivers/char/tpm/tpm2_eventlog.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright (C) 2016 IBM Corporation
> + *
> + * Authors:
> + *      Nayna Jain <nayna@linux.vnet.ibm.com>
> + *
> + * Access to TPM 2.0 event log as written by Firmware.
> + * It assumes that writer of event log has followed TCG Specification
> + * for Family "2.0" and written the event 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 "tpm_eventlog.h"
> +
> +static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
> +		struct tcg_pcr_event *event_header)

Bad alignment.

> +{
> +	struct tcg_efi_specid_event *efispecid;
> +	struct tcg_event_field *event_field;
> +	void *marker;
> +	void *marker_start;
> +	int i;
> +	int j;
> +	u16 halg;
> +	u32 halg_size;
> +	size_t size;
> +
> +	/*
> +	 * TPM 2.0 supports extend to multiple PCR Banks. This implies
> +	 * event log also has multiple digest values, one for each PCR Bank.
> +	 * This is called Crypto Agile Log Entry Format.
> +	 * Below code implements the procedure defined in TCG EFI Protocol
> +	 * Specification Family "2.0" to parse the event log in Crypto Agile
> +	 * Log Entry Format.
> +	 */

Please, document the function and remove this inline comment.

> +
> +	marker = event;
> +	marker_start = marker;
> +	marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
> +		+ sizeof(event->digests.count);
> +
> +	efispecid = (struct tcg_efi_specid_event *) event_header->event;
> +
> +	for (i = 0; (i < event->digests.count) && (i < TPM2_ACTIVE_PCR_BANKS);
> +	     i++) {
> +		halg_size = sizeof(event->digests.digests[i].alg_id);
> +		memcpy(&halg, marker, halg_size);
> +		marker = marker + halg_size;
> +		for (j = 0; (j < efispecid->num_algs); j++) {
> +			if (halg == efispecid->digest_sizes[j].alg_id) {
> +				marker = marker +
> +					efispecid->digest_sizes[j].digest_size;
> +				break;
> +			}
> +		}
> +	}
> +
> +	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_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 tcg_pcr_event *event_header;
> +	struct tcg_pcr_event2 *event;
> +	int i;
> +	size_t size;
> +
> +	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;
> +	}
> +
> +	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_chip *chip = m->private;
> +	struct tpm_bios_log *log = &chip->log;
> +	void *limit = log->bios_event_log_end;
> +	void *marker;
> +	size_t event_size;
> +
> +	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;

Bad alignment. Please, check the whole commit and if there is more of
these..

> +		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_chip *chip = m->private;
> +	struct tpm_bios_log *log = &chip->log;
> +	struct tcg_pcr_event *event_header = log->bios_event_log;
> +	struct tcg_pcr_event2 *event = v;
> +	void *temp_ptr;
> +	size_t size;
> +
> +	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_measurements_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 1660d74..6886a11 100644
> --- a/drivers/char/tpm/tpm_eventlog.h
> +++ b/drivers/char/tpm/tpm_eventlog.h
> @@ -2,9 +2,12 @@
>  #ifndef __TPM_EVENTLOG_H__
>  #define __TPM_EVENTLOG_H__
>  
> +#include <crypto/hash_info.h>
> +
>  #define TCG_EVENT_NAME_LEN_MAX	255
>  #define MAX_TEXT_EVENT		1000	/* Max event string length */
>  #define ACPI_TCPA_SIG		"TCPA"	/* 0x41504354 /'TCPA' */
> +#define TPM2_ACTIVE_PCR_BANKS	3
>  
>  #ifdef CONFIG_PPC64
>  #define do_endian_conversion(x) be32_to_cpu(x)
> @@ -73,6 +76,73 @@ enum tcpa_pc_event_ids {
>  	HOST_TABLE_OF_DEVICES,
>  };
>  
> +/*
> + * All the structures related to TPM 2.0 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 TPM 2.0 are defined in document
> + * Trusted Platform Module Library Part 2: Structures, Family "2.0".
> + */
> +
> +/* TPM 2.0 Event log header algorithm spec. */
> +struct tcg_efi_specid_event_algs {
> +	u16 alg_id;
> +	u16 digest_size;
> +} __packed;
> +
> +/* TPM 2.0 Event log header data. */
> +struct tcg_efi_specid_event {
> +	u8 signature[16];
> +	u32 platform_class;
> +	u8 spec_version_minor;
> +	u8 spec_version_major;
> +	u8 spec_errata;
> +	u8 uintnsize;
> +	u32 num_algs;
> +	struct tcg_efi_specid_event_algs digest_sizes[TPM2_ACTIVE_PCR_BANKS];
> +	u8 vendor_info_size;
> +	u8 vendor_info[0];
> +} __packed;
> +
> +/* TPM 2.0 Event Log Header. */
> +struct tcg_pcr_event {
> +	u32 pcr_idx;
> +	u32 event_type;
> +	u8 digest[20];
> +	u32 event_size;
> +	u8 event[0];
> +} __packed;
> +
> +/* TPM 2.0 Crypto agile algorithm and respective digest. */
> +struct tpmt_ha {
> +	u16 alg_id;
> +	u8 digest[SHA384_DIGEST_SIZE];
> +} __packed;
> +
> +/* TPM 2.0 Crypto agile digests list. */
> +struct tpml_digest_values {
> +	u32 count;
> +	struct tpmt_ha digests[TPM2_ACTIVE_PCR_BANKS];
> +} __packed;
> +
> +/* TPM 2.0 Event field structure. */
> +struct tcg_event_field {
> +	u32 event_size;
> +	u8 event[0];
> +} __packed;
> +
> +/* TPM 2.0 Crypto agile log entry format. */

These one line comments are next to useless. Please remove them.

> +struct tcg_pcr_event2 {
> +	u32 pcr_idx;
> +	u32 event_type;
> +	struct tpml_digest_values digests;
> +	struct tcg_event_field event;
> +} __packed;
> +
> +extern const struct seq_operations tpm2_binary_b_measurements_seqops;
> +
>  #if defined(CONFIG_ACPI)
>  int tpm_read_log_acpi(struct tpm_chip *chip);
>  #else
> -- 
> 2.5.0
> 

/Jarkko

Re: [PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Nayna]

On 01/03/2017 03:42 AM, Jarkko Sakkinen wrote:
> On Sun, Dec 11, 2016 at 12:35:33AM -0500, Nayna Jain wrote:
>> Unlike the device driver support for TPM 1.2, the TPM 2.0 does
>> not support the securityfs pseudo files for displaying the
>> firmware event log.
>>
>> This patch enables support for providing the TPM 2.0 event log in
>> binary form. TPM 2.0 event log supports a crypto agile format that
>> records multiple digests, which is different from TPM 1.2. This
>> patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
>> event log parser which understand the TPM 2.0 crypto agile format.
>>
>> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
>
> There is something fundamentally wrong in this commit.
>
> You must not allow this feature unless CONFIG_OF is set. It is the only
> interface where the supply path of the event log is well defined on
> platforms that include a TPM 2.0 chip.

As per current implementation, if ACPI with TPM 2.0 doesn't support 
event log, tpm_read_log_acpi() is expected to return rc and 
tpm_bios_log_setup will not create securityfs. This is inline with our 
design for TPM 1.2 event log.

>
> There's buch casts in the form '(char *) foo'. They should be
> '(char *)foo'.

Will fix these and other comments.

Thanks & Regards,
     - Nayna

>
>> ---
>>   drivers/char/tpm/Makefile                          |   2 +-
>>   .../char/tpm/{tpm_eventlog.c => tpm1_eventlog.c}   |  35 ++--
>>   drivers/char/tpm/tpm2_eventlog.c                   | 203 +++++++++++++++++++++
>>   drivers/char/tpm/tpm_eventlog.h                    |  70 +++++++
>>   4 files changed, 295 insertions(+), 15 deletions(-)
>>   rename drivers/char/tpm/{tpm_eventlog.c => tpm1_eventlog.c} (95%)
>>   create mode 100644 drivers/char/tpm/tpm2_eventlog.c
>>
>> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
>> index a05b1eb..3d386a8 100644
>> --- a/drivers/char/tpm/Makefile
>> +++ b/drivers/char/tpm/Makefile
>> @@ -3,7 +3,7 @@
>>   #
>>   obj-$(CONFIG_TCG_TPM) += tpm.o
>>   tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \
>> -		tpm_eventlog.o
>> +		tpm1_eventlog.o tpm2_eventlog.o
>>   tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o
>>   tpm-$(CONFIG_OF) += tpm_of.o
>>   obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
>> diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm1_eventlog.c
>> similarity index 95%
>> rename from drivers/char/tpm/tpm_eventlog.c
>> rename to drivers/char/tpm/tpm1_eventlog.c
>> index 11bb113..9a8605e 100644
>> --- a/drivers/char/tpm/tpm_eventlog.c
>> +++ b/drivers/char/tpm/tpm1_eventlog.c
>> @@ -390,9 +390,6 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>>   	unsigned int cnt;
>>   	int rc = 0;
>>
>> -	if (chip->flags & TPM_CHIP_FLAG_TPM2)
>> -		return 0;
>> -
>>   	rc = tpm_read_log(chip);
>>   	if (rc)
>>   		return rc;
>> @@ -407,7 +404,13 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>>   	cnt++;
>>
>>   	chip->bin_log_seqops.chip = chip;
>> -	chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops;
>> +	if (chip->flags & TPM_CHIP_FLAG_TPM2)
>> +		chip->bin_log_seqops.seqops =
>> +			&tpm2_binary_b_measurements_seqops;
>> +	else
>> +		chip->bin_log_seqops.seqops =
>> +			&tpm_binary_b_measurements_seqops;
>> +
>>
>>   	chip->bios_dir[cnt] =
>>   	    securityfs_create_file("binary_bios_measurements",
>> @@ -418,17 +421,21 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
>>   		goto err;
>>   	cnt++;
>>
>> -	chip->ascii_log_seqops.chip = chip;
>> -	chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops;
>> +	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
>>
>> -	chip->bios_dir[cnt] =
>> -	    securityfs_create_file("ascii_bios_measurements",
>> -				   0440, chip->bios_dir[0],
>> -				   (void *)&chip->ascii_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 *)&chip->ascii_log_seqops,
>> +					       &tpm_bios_measurements_ops);
>> +		if (IS_ERR(chip->bios_dir[cnt]))
>> +			goto err;
>> +		cnt++;
>> +	}
>>
>>   	return 0;
>>
>> diff --git a/drivers/char/tpm/tpm2_eventlog.c b/drivers/char/tpm/tpm2_eventlog.c
>> new file mode 100644
>> index 0000000..63690d3
>> --- /dev/null
>> +++ b/drivers/char/tpm/tpm2_eventlog.c
>> @@ -0,0 +1,203 @@
>> +/*
>> + * Copyright (C) 2016 IBM Corporation
>> + *
>> + * Authors:
>> + *      Nayna Jain <nayna@linux.vnet.ibm.com>
>> + *
>> + * Access to TPM 2.0 event log as written by Firmware.
>> + * It assumes that writer of event log has followed TCG Specification
>> + * for Family "2.0" and written the event 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 "tpm_eventlog.h"
>> +
>> +static int calc_tpm2_event_size(struct tcg_pcr_event2 *event,
>> +		struct tcg_pcr_event *event_header)
>
> Bad alignment.
>
>> +{
>> +	struct tcg_efi_specid_event *efispecid;
>> +	struct tcg_event_field *event_field;
>> +	void *marker;
>> +	void *marker_start;
>> +	int i;
>> +	int j;
>> +	u16 halg;
>> +	u32 halg_size;
>> +	size_t size;
>> +
>> +	/*
>> +	 * TPM 2.0 supports extend to multiple PCR Banks. This implies
>> +	 * event log also has multiple digest values, one for each PCR Bank.
>> +	 * This is called Crypto Agile Log Entry Format.
>> +	 * Below code implements the procedure defined in TCG EFI Protocol
>> +	 * Specification Family "2.0" to parse the event log in Crypto Agile
>> +	 * Log Entry Format.
>> +	 */
>
> Please, document the function and remove this inline comment.
>
>> +
>> +	marker = event;
>> +	marker_start = marker;
>> +	marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
>> +		+ sizeof(event->digests.count);
>> +
>> +	efispecid = (struct tcg_efi_specid_event *) event_header->event;
>> +
>> +	for (i = 0; (i < event->digests.count) && (i < TPM2_ACTIVE_PCR_BANKS);
>> +	     i++) {
>> +		halg_size = sizeof(event->digests.digests[i].alg_id);
>> +		memcpy(&halg, marker, halg_size);
>> +		marker = marker + halg_size;
>> +		for (j = 0; (j < efispecid->num_algs); j++) {
>> +			if (halg == efispecid->digest_sizes[j].alg_id) {
>> +				marker = marker +
>> +					efispecid->digest_sizes[j].digest_size;
>> +				break;
>> +			}
>> +		}
>> +	}
>> +
>> +	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_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 tcg_pcr_event *event_header;
>> +	struct tcg_pcr_event2 *event;
>> +	int i;
>> +	size_t size;
>> +
>> +	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;
>> +	}
>> +
>> +	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_chip *chip = m->private;
>> +	struct tpm_bios_log *log = &chip->log;
>> +	void *limit = log->bios_event_log_end;
>> +	void *marker;
>> +	size_t event_size;
>> +
>> +	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;
>
> Bad alignment. Please, check the whole commit and if there is more of
> these..
>
>> +		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_chip *chip = m->private;
>> +	struct tpm_bios_log *log = &chip->log;
>> +	struct tcg_pcr_event *event_header = log->bios_event_log;
>> +	struct tcg_pcr_event2 *event = v;
>> +	void *temp_ptr;
>> +	size_t size;
>> +
>> +	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_measurements_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 1660d74..6886a11 100644
>> --- a/drivers/char/tpm/tpm_eventlog.h
>> +++ b/drivers/char/tpm/tpm_eventlog.h
>> @@ -2,9 +2,12 @@
>>   #ifndef __TPM_EVENTLOG_H__
>>   #define __TPM_EVENTLOG_H__
>>
>> +#include <crypto/hash_info.h>
>> +
>>   #define TCG_EVENT_NAME_LEN_MAX	255
>>   #define MAX_TEXT_EVENT		1000	/* Max event string length */
>>   #define ACPI_TCPA_SIG		"TCPA"	/* 0x41504354 /'TCPA' */
>> +#define TPM2_ACTIVE_PCR_BANKS	3
>>
>>   #ifdef CONFIG_PPC64
>>   #define do_endian_conversion(x) be32_to_cpu(x)
>> @@ -73,6 +76,73 @@ enum tcpa_pc_event_ids {
>>   	HOST_TABLE_OF_DEVICES,
>>   };
>>
>> +/*
>> + * All the structures related to TPM 2.0 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 TPM 2.0 are defined in document
>> + * Trusted Platform Module Library Part 2: Structures, Family "2.0".
>> + */
>> +
>> +/* TPM 2.0 Event log header algorithm spec. */
>> +struct tcg_efi_specid_event_algs {
>> +	u16 alg_id;
>> +	u16 digest_size;
>> +} __packed;
>> +
>> +/* TPM 2.0 Event log header data. */
>> +struct tcg_efi_specid_event {
>> +	u8 signature[16];
>> +	u32 platform_class;
>> +	u8 spec_version_minor;
>> +	u8 spec_version_major;
>> +	u8 spec_errata;
>> +	u8 uintnsize;
>> +	u32 num_algs;
>> +	struct tcg_efi_specid_event_algs digest_sizes[TPM2_ACTIVE_PCR_BANKS];
>> +	u8 vendor_info_size;
>> +	u8 vendor_info[0];
>> +} __packed;
>> +
>> +/* TPM 2.0 Event Log Header. */
>> +struct tcg_pcr_event {
>> +	u32 pcr_idx;
>> +	u32 event_type;
>> +	u8 digest[20];
>> +	u32 event_size;
>> +	u8 event[0];
>> +} __packed;
>> +
>> +/* TPM 2.0 Crypto agile algorithm and respective digest. */
>> +struct tpmt_ha {
>> +	u16 alg_id;
>> +	u8 digest[SHA384_DIGEST_SIZE];
>> +} __packed;
>> +
>> +/* TPM 2.0 Crypto agile digests list. */
>> +struct tpml_digest_values {
>> +	u32 count;
>> +	struct tpmt_ha digests[TPM2_ACTIVE_PCR_BANKS];
>> +} __packed;
>> +
>> +/* TPM 2.0 Event field structure. */
>> +struct tcg_event_field {
>> +	u32 event_size;
>> +	u8 event[0];
>> +} __packed;
>> +
>> +/* TPM 2.0 Crypto agile log entry format. */
>
> These one line comments are next to useless. Please remove them.
>
>> +struct tcg_pcr_event2 {
>> +	u32 pcr_idx;
>> +	u32 event_type;
>> +	struct tpml_digest_values digests;
>> +	struct tcg_event_field event;
>> +} __packed;
>> +
>> +extern const struct seq_operations tpm2_binary_b_measurements_seqops;
>> +
>>   #if defined(CONFIG_ACPI)
>>   int tpm_read_log_acpi(struct tpm_chip *chip);
>>   #else
>> --
>> 2.5.0
>>
>
> /Jarkko
>

Re: [PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Jarkko Sakkinen]

On Tue, Jan 03, 2017 at 01:09:18PM +0530, Nayna wrote:
> 
> 
> On 01/03/2017 03:42 AM, Jarkko Sakkinen wrote:
> > On Sun, Dec 11, 2016 at 12:35:33AM -0500, Nayna Jain wrote:
> > > Unlike the device driver support for TPM 1.2, the TPM 2.0 does
> > > not support the securityfs pseudo files for displaying the
> > > firmware event log.
> > > 
> > > This patch enables support for providing the TPM 2.0 event log in
> > > binary form. TPM 2.0 event log supports a crypto agile format that
> > > records multiple digests, which is different from TPM 1.2. This
> > > patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
> > > event log parser which understand the TPM 2.0 crypto agile format.
> > > 
> > > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> > 
> > There is something fundamentally wrong in this commit.
> > 
> > You must not allow this feature unless CONFIG_OF is set. It is the only
> > interface where the supply path of the event log is well defined on
> > platforms that include a TPM 2.0 chip.
> 
> As per current implementation, if ACPI with TPM 2.0 doesn't support event
> log, tpm_read_log_acpi() is expected to return rc and tpm_bios_log_setup
> will not create securityfs. This is inline with our design for TPM 1.2 event
> log.

At minimum you must have a check for TPM_CHIP_FLAG_TPM2 in the beginning
of tpm_read_log_acpi. It is wrong to even try to open TCPA in this case.

/Jarkko

Re: [PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Nayna]

On 01/03/2017 07:03 PM, Jarkko Sakkinen wrote:
> On Tue, Jan 03, 2017 at 01:09:18PM +0530, Nayna wrote:
>>
>>
>> On 01/03/2017 03:42 AM, Jarkko Sakkinen wrote:
>>> On Sun, Dec 11, 2016 at 12:35:33AM -0500, Nayna Jain wrote:
>>>> Unlike the device driver support for TPM 1.2, the TPM 2.0 does
>>>> not support the securityfs pseudo files for displaying the
>>>> firmware event log.
>>>>
>>>> This patch enables support for providing the TPM 2.0 event log in
>>>> binary form. TPM 2.0 event log supports a crypto agile format that
>>>> records multiple digests, which is different from TPM 1.2. This
>>>> patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
>>>> event log parser which understand the TPM 2.0 crypto agile format.
>>>>
>>>> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
>>>
>>> There is something fundamentally wrong in this commit.
>>>
>>> You must not allow this feature unless CONFIG_OF is set. It is the only
>>> interface where the supply path of the event log is well defined on
>>> platforms that include a TPM 2.0 chip.
>>
>> As per current implementation, if ACPI with TPM 2.0 doesn't support event
>> log, tpm_read_log_acpi() is expected to return rc and tpm_bios_log_setup
>> will not create securityfs. This is inline with our design for TPM 1.2 event
>> log.
>
> At minimum you must have a check for TPM_CHIP_FLAG_TPM2 in the beginning
> of tpm_read_log_acpi. It is wrong to even try to open TCPA in this case.

Sure, will add this check and return -ENODEV if check passes.

Thanks & Regards,
     - Nayna

>
> /Jarkko
>

Re: [PATCH v7 2/2] tpm: add securityfs support for TPM 2.0 firmware event log

[Jarkko Sakkinen]

On Wed, Jan 04, 2017 at 02:08:06PM +0530, Nayna wrote:
> 
> 
> On 01/03/2017 07:03 PM, Jarkko Sakkinen wrote:
> > On Tue, Jan 03, 2017 at 01:09:18PM +0530, Nayna wrote:
> > > 
> > > 
> > > On 01/03/2017 03:42 AM, Jarkko Sakkinen wrote:
> > > > On Sun, Dec 11, 2016 at 12:35:33AM -0500, Nayna Jain wrote:
> > > > > Unlike the device driver support for TPM 1.2, the TPM 2.0 does
> > > > > not support the securityfs pseudo files for displaying the
> > > > > firmware event log.
> > > > > 
> > > > > This patch enables support for providing the TPM 2.0 event log in
> > > > > binary form. TPM 2.0 event log supports a crypto agile format that
> > > > > records multiple digests, which is different from TPM 1.2. This
> > > > > patch enables the tpm_bios_log_setup for TPM 2.0  and adds the
> > > > > event log parser which understand the TPM 2.0 crypto agile format.
> > > > > 
> > > > > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> > > > 
> > > > There is something fundamentally wrong in this commit.
> > > > 
> > > > You must not allow this feature unless CONFIG_OF is set. It is the only
> > > > interface where the supply path of the event log is well defined on
> > > > platforms that include a TPM 2.0 chip.
> > > 
> > > As per current implementation, if ACPI with TPM 2.0 doesn't support event
> > > log, tpm_read_log_acpi() is expected to return rc and tpm_bios_log_setup
> > > will not create securityfs. This is inline with our design for TPM 1.2 event
> > > log.
> > 
> > At minimum you must have a check for TPM_CHIP_FLAG_TPM2 in the beginning
> > of tpm_read_log_acpi. It is wrong to even try to open TCPA in this case.
> 
> Sure, will add this check and return -ENODEV if check passes.

Yeah, this is acceptable for me.

> Thanks & Regards,
>     - Nayna

/Jarkko