[PATCH V2 3/3] drivers/char/tpm: Add securityfs support for event log

Ashley Lai
2012-08-09T23:11:36Z

This patch retrieves the event log data from the device tree
during file open. The event log data will then displayed through
securityfs.

Signed-off-by: Ashley Lai <adlai@us.ibm.com>
---
drivers/char/tpm/Makefile | 8 ++++-
drivers/char/tpm/tpm.h | 12 ------
drivers/char/tpm/tpm_eventlog.c | 7 ++++
drivers/char/tpm/tpm_eventlog.h | 14 +++++++
drivers/char/tpm/tpm_noeventlog.c | 21 +++++++++++
drivers/char/tpm/tpm_of.c | 68 +++++++++++++++++++++++++++++++++++++
6 files changed, 117 insertions(+), 13 deletions(-)
create mode 100644 drivers/char/tpm/tpm_noeventlog.c
create mode 100644 drivers/char/tpm/tpm_of.c

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 547509d..b53da57 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -2,9 +2,15 @@
# Makefile for the kernel tpm device drivers.
#
obj-$(CONFIG_TCG_TPM) += tpm.o
+obj-$(CONFIG_TCG_TPM) += tpm_bios.o
ifdef CONFIG_ACPI
- obj-$(CONFIG_TCG_TPM) += tpm_bios.o
tpm_bios-objs += tpm_eventlog.o tpm_acpi.o
+else
+ifdef CONFIG_TCG_IBMVTPM
+ tpm_bios-objs += tpm_eventlog.o tpm_of.o
+else
+ tpm_bios-objs += tpm_eventlog.o tpm_noeventlog.o
+endif
endif
obj-$(CONFIG_TCG_TIS) += tpm_tis.o
obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index aece857..08f6a07 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -304,15 +304,3 @@ extern int tpm_pm_suspend(struct device *, pm_message_t);
extern int tpm_pm_resume(struct device *);
extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
wait_queue_head_t *);
-#ifdef CONFIG_ACPI
-extern struct dentry ** tpm_bios_log_setup(char *);
-extern void tpm_bios_log_teardown(struct dentry **);
-#else
-static inline struct dentry ** tpm_bios_log_setup(char *name)
-{
- return NULL;
-}
-static inline void tpm_bios_log_teardown(struct dentry **dir)
-{
-}
-#endif
diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
index 84ddc55..814b202 100644
--- a/drivers/char/tpm/tpm_eventlog.c
+++ b/drivers/char/tpm/tpm_eventlog.c
@@ -24,6 +24,7 @@
#include <linux/security.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/of.h>

#include "tpm.h"
#include "tpm_eventlog.h"
@@ -369,6 +370,9 @@ struct dentry **tpm_bios_log_setup(char *name)
{
struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;

+ if (TPM_NO_EVENT_LOG)
+ return NULL;
+
tpm_dir = securityfs_create_dir(name, NULL);
if (is_bad(tpm_dir))
goto out;
@@ -412,6 +416,9 @@ void tpm_bios_log_teardown(struct dentry **lst)
{
int i;

+ if (TPM_NO_EVENT_LOG)
+ return;
+
for (i = 0; i < 3; i++)
securityfs_remove(lst[i]);
}
diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
index 8e23ccd..21ac6af 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -68,4 +68,18 @@ enum tcpa_pc_event_ids {
};

int read_log(struct tpm_bios_log *log);
+
+extern struct dentry **tpm_bios_log_setup(char *);
+extern void tpm_bios_log_teardown(struct dentry **);
+
+#ifdef CONFIG_PPC64
+#define TPM_NO_EVENT_LOG !of_find_node_by_name(NULL, "ibm,vtpm")
+#else
+#ifdef CONFIG_ACPI
+#define TPM_NO_EVENT_LOG 0
+#else
+#define TPM_NO_EVENT_LOG 1
+#endif
+#endif
+
#endif
diff --git a/drivers/char/tpm/tpm_noeventlog.c b/drivers/char/tpm/tpm_noeventlog.c
new file mode 100644
index 0000000..f30a2bf
--- /dev/null
+++ b/drivers/char/tpm/tpm_noeventlog.c
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <adlai@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * 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 "tpm_eventlog.h"
+
+int read_log(struct tpm_bios_log *log)
+{
+ return -EINVAL;
+}
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
new file mode 100644
index 0000000..6d44adb
--- /dev/null
+++ b/drivers/char/tpm/tpm_of.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <adlai@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Read the event log created by the firmware on PPC64
+ *
+ * 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;
+ const u32 *sizep;
+ const __be64 *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, "ibm,vtpm");
+ if (!np) {
+ pr_err("%s: ERROR - IBMVTPM not supported\n", __func__);
+ return -ENODEV;
+ }
+
+ sizep = of_get_property(np, "linux,sml-size", NULL);
+ if (sizep == NULL) {
+ pr_err("%s: ERROR - SML size not found\n", __func__);
+ return -EIO;
+ }
+ if (*sizep == 0) {
+ pr_err("%s: ERROR - event log area empty\n", __func__);
+ return -EIO;
+ }
+
+ basep = of_get_property(np, "linux,sml-base", NULL);
+ if (basep == NULL) {
+ pr_err(KERN_ERR "%s: ERROR - SML not found\n", __func__);
+ return -EIO;
+ }
+
+ log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
+ if (!log->bios_event_log) {
+ pr_err("%s: ERROR - Not enough memory for BIOS measurements\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ log->bios_event_log_end = log->bios_event_log + *sizep;
+
+ memcpy(log->bios_event_log, __va(be64_to_cpup(basep)), *sizep);
+
+ return 0;
+}
--
1.7.1