[tpmdd-devel,2/2] TPM2.0:Adds securityfs support for TPM2.0 eventlog

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 9136762..3f4b8bc 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 tpm2_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 5a2f043..57b2201 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -283,20 +283,9 @@  static int tpm1_chip_register(struct tpm_chip *chip)
 
 	tpm_sysfs_add_device(chip);
 
-	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
-
 	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->bios_dir);
-}
-
 static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
 {
 	struct attribute **i;
@@ -358,11 +347,14 @@  int tpm_chip_register(struct tpm_chip *chip)
 	if (rc)
 		return rc;
 
+	chip->bios_dir = tpm_bios_log_setup(chip);
+
 	tpm_add_ppi(chip);
 
 	rc = tpm_add_char_device(chip);
 	if (rc) {
-		tpm1_chip_unregister(chip);
+		if (chip->bios_dir)
+			tpm_bios_log_teardown(chip);
 		return rc;
 	}
 
@@ -398,7 +390,9 @@  void tpm_chip_unregister(struct tpm_chip *chip)
 
 	tpm_del_legacy_sysfs(chip);
 
-	tpm1_chip_unregister(chip);
+	if (chip->bios_dir)
+		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..0b1a871a
--- /dev/null
+++ b/drivers/char/tpm/tpm2.h
@@ -0,0 +1,75 @@ 
+#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
+
+extern const struct seq_operations tpm2_binary_b_measurments_seqops;
+
+/* 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;
+
+#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/tpm2_of.c b/drivers/char/tpm/tpm2_of.c
new file mode 100644
index 0000000..b6403b9
--- /dev/null
+++ b/drivers/char/tpm/tpm2_of.c
@@ -0,0 +1,77 @@ 
+/*
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Authors:
+ *      Nayna Jain <nayna@linux.vnet.ibm.com>
+ *
+ * Defined read_log for PowerPC to identify event log location
+ * using device tree entries.
+ *
+ * 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/slab.h>
+#include <linux/of.h>
+
+#include "tpm.h"
+#include "tpm_eventlog.h"
+
+int read_log(struct tpm_bios_log *log)
+{
+	struct device_node *np;
+	u32 logSize;
+	const u32 *sizep;
+	const u64 *basep;
+
+	if (log->bios_event_log != NULL) {
+		pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
+		return -EFAULT;
+	}
+
+	np = of_find_node_by_name(NULL, "tpm");
+	if (!np) {
+		pr_err("%s: ERROR - tpm entry not supported\n", __func__);
+		return -ENODEV;
+	}
+
+	sizep = of_get_property(np, "linux,sml-size", NULL);
+	if (sizep == NULL) {
+		pr_err("%s: ERROR - sml-get-allocated-size not found\n",
+				__func__);
+		goto cleanup_eio;
+	}
+	logSize = be32_to_cpup(sizep);
+
+	if (logSize == 0) {
+		pr_err("%s: ERROR - event log area empty\n", __func__);
+		goto cleanup_eio;
+	}
+
+	basep = of_get_property(np, "linux,sml-base", NULL);
+	if (basep == NULL) {
+		pr_err("%s: ERROR - sml-handover not found\n", __func__);
+		goto cleanup_eio;
+	}
+
+	log->bios_event_log = kmalloc(logSize, GFP_KERNEL);
+	if (!log->bios_event_log) {
+		pr_err("%s: ERROR - Not enough memory for firmware measurements\n",
+				__func__);
+		of_node_put(np);
+		return -ENOMEM;
+	}
+
+	log->bios_event_log_end = log->bios_event_log + logSize;
+
+	memcpy(log->bios_event_log, __va(be64_to_cpup(basep)), logSize);
+
+	of_node_put(np);
+	return 0;
+
+cleanup_eio:
+	of_node_put(np);
+	return -EIO;
+}
diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
index 37efac3..d4e884b 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -79,15 +79,15 @@  enum tcpa_pc_event_ids {
 int read_log(struct tpm_bios_log *log);
 
 #if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
-	defined(CONFIG_ACPI)
-extern struct dentry **tpm_bios_log_setup(const char *);
-extern void tpm_bios_log_teardown(struct dentry **);
+	defined(CONFIG_ACPI) || defined(CONFIG_PPC64)
+extern struct dentry **tpm_bios_log_setup(struct tpm_chip *chip);
+extern void tpm_bios_log_teardown(struct tpm_chip *chip);
 #else
-static inline struct dentry **tpm_bios_log_setup(const char *name)
+static inline struct dentry **tpm_bios_log_setup(struct tpm_chip *chip)
 {
 	return NULL;
 }
-static inline void tpm_bios_log_teardown(struct dentry **dir)
+static inline void tpm_bios_log_teardown(struct tpm_chip *chip)
 {
 }
 #endif
diff --git a/drivers/char/tpm/tpm_eventlog_init.c b/drivers/char/tpm/tpm_eventlog_init.c
index 8153509..504aa9b 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"
 
 
@@ -89,6 +90,7 @@  static int tpm_binary_bios_measurements_open(struct inode *inode,
 {
 	int err;
 	struct tpm_bios_log *log;
+	struct tpm_chip *chip;
 	struct seq_file *seq;
 
 	log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
@@ -99,8 +101,14 @@  static int tpm_binary_bios_measurements_open(struct inode *inode,
 	if (err)
 		goto out_free;
 
+	chip = tpm_chip_find_get(TPM_ANY_NUM);
+
 	/* now register seq file */
-	err = seq_open(file, &tpm_binary_b_measurments_seqops);
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		err = seq_open(file, &tpm2_binary_b_measurments_seqops);
+	else
+		err = seq_open(file, &tpm_binary_b_measurments_seqops);
+
 	if (!err) {
 		seq = file->private_data;
 		seq->private = log;
@@ -109,6 +117,7 @@  static int tpm_binary_bios_measurements_open(struct inode *inode,
 	}
 
 out:
+	tpm_put_ops(chip);
 	return err;
 out_free:
 	kfree(log->bios_event_log);
@@ -132,9 +141,23 @@  static int is_bad(void *p)
 	return 0;
 }
 
-struct dentry **tpm_bios_log_setup(const char *name)
+struct dentry **tpm_bios_log_setup(struct tpm_chip *chip)
 {
+	int num_files = 0;
 	struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
+	const char *name = dev_name(&chip->dev);
+
+	/*
+	 * 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;
+	ret = kmalloc_array(num_files, sizeof(struct dentry *), GFP_KERNEL);
+	if (!ret)
+		goto out;
 
 	tpm_dir = securityfs_create_dir(name, NULL);
 	if (is_bad(tpm_dir))
@@ -147,25 +170,22 @@  struct dentry **tpm_bios_log_setup(const char *name)
 	if (is_bad(bin_file))
 		goto out_tpm;
 
-	ascii_file =
-	    securityfs_create_file("ascii_bios_measurements",
-				   S_IRUSR | S_IRGRP, tpm_dir, NULL,
-				   &tpm_ascii_bios_measurements_ops);
-	if (is_bad(ascii_file))
-		goto out_bin;
 
-	ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
-	if (!ret)
-		goto out_ascii;
+	ret[num_files-1] = tpm_dir;
+	ret[num_files-2] = bin_file;
+	if (num_files == 3) {
+		ascii_file =
+			securityfs_create_file("ascii_bios_measurements",
+					S_IRUSR | S_IRGRP, tpm_dir, NULL,
+					&tpm_ascii_bios_measurements_ops);
+		if (is_bad(ascii_file))
+			goto out_bin;
 
-	ret[0] = ascii_file;
-	ret[1] = bin_file;
-	ret[2] = tpm_dir;
+		ret[num_files - 3] = ascii_file;
+	}
 
 	return ret;
 
-out_ascii:
-	securityfs_remove(ascii_file);
 out_bin:
 	securityfs_remove(bin_file);
 out_tpm:
@@ -174,10 +194,23 @@  out:
 	return NULL;
 }
 
-void tpm_bios_log_teardown(struct dentry **lst)
+void tpm_bios_log_teardown(struct tpm_chip *chip)
 {
-	int i;
+	int i, n_entries;
+	struct dentry **lst;
+
+	lst = chip->bios_dir;
+
+	/*
+	 * NOTE: For same reason as in tpm_bios_log_setup()
+	 * number of entries for TPM2.0 are only 2 i.e. tpm0 dir
+	 * and binary_bios_measurements file. and for TPM1.2, there
+	 * are three i.e. tpm0 dir, binary_bios_measurements and
+	 * ascii_bios_measurements.
+	 */
+
+	n_entries = (chip->flags & TPM_CHIP_FLAG_TPM2) ? 2 : 3;
 
-	for (i = 0; i < 3; i++)
+	for (i = 0; i < n_entries; i++)
 		securityfs_remove(lst[i]);
 }