[PATCH] tpm: add bios measurement log
According to the TCG specifications measurements or hashes of the BIOS code and data are extended into TPM PCRS and a log is kept in an ACPI table of these extensions for later validation if desired. This patch exports the values in the ACPI table through a security-fs seq_file. Signed-off-by: Seiji Munetoh <munetoh@jp.ibm.com> Signed-off-by: Stefan Berger <stefanb@us.ibm.com> Signed-off-by: Reiner Sailer <sailer@us.ibm.com> Signed-off-by: Kylene Hall <kjhall@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Kylene Jo Hall
Linus Torvalds
parent
485a6435ab
commit
55a82ab318
@ -204,11 +204,13 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
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return AE_OK;
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}
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EXPORT_SYMBOL_GPL(acpi_os_map_memory);
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void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
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{
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iounmap(virt);
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}
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EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
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#ifdef ACPI_FUTURE_USAGE
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acpi_status
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@ -2,6 +2,9 @@
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# Makefile for the kernel tpm device drivers.
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#
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obj-$(CONFIG_TCG_TPM) += tpm.o
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ifdef CONFIG_ACPI
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obj-$(CONFIG_TCG_TPM) += tpm_bios.o
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endif
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obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
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obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
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obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
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@ -466,6 +466,7 @@ void tpm_remove_hardware(struct device *dev)
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kfree(chip->vendor->miscdev.name);
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sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
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tpm_bios_log_teardown(chip->bios_dir);
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dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &=
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~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
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@ -593,6 +594,8 @@ dev_num_search_complete:
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sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
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chip->bios_dir = tpm_bios_log_setup(devname);
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return 0;
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}
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EXPORT_SYMBOL_GPL(tpm_register_hardware);
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@ -82,6 +82,8 @@ struct tpm_chip {
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struct tpm_vendor_specific *vendor;
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struct dentry **bios_dir;
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struct list_head list;
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};
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@ -107,3 +109,16 @@ extern ssize_t tpm_read(struct file *, char __user *, size_t, loff_t *);
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extern void tpm_remove_hardware(struct device *);
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extern int tpm_pm_suspend(struct device *, pm_message_t);
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extern int tpm_pm_resume(struct device *);
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#ifdef CONFIG_ACPI
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extern struct dentry ** tpm_bios_log_setup(char *);
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extern void tpm_bios_log_teardown(struct dentry **);
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#else
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static inline struct dentry* tpm_bios_log_setup(char *name)
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{
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return NULL;
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}
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static inline void tpm_bios_log_teardown(struct dentry **dir)
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{
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}
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#endif
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508
drivers/char/tpm/tpm_bios.c
Normal file
508
drivers/char/tpm/tpm_bios.c
Normal file
@ -0,0 +1,508 @@
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/*
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* Copyright (C) 2005 IBM Corporation
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*
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* Authors:
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* Seiji Munetoh <munetoh@jp.ibm.com>
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* Stefan Berger <stefanb@us.ibm.com>
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* Reiner Sailer <sailer@watson.ibm.com>
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* Kylene Hall <kjhall@us.ibm.com>
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*
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* Access to the eventlog extended by the TCG BIOS of PC platform
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/seq_file.h>
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#include <linux/fs.h>
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#include <linux/security.h>
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#include <linux/module.h>
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#include <acpi/acpi.h>
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#include <acpi/actypes.h>
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#include <acpi/actbl.h>
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#include "tpm.h"
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#define TCG_EVENT_NAME_LEN_MAX 255
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#define MAX_TEXT_EVENT 1000 /* Max event string length */
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#define ACPI_TCPA_SIG "TCPA" /* 0x41504354 /'TCPA' */
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struct acpi_tcpa {
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struct acpi_table_header hdr;
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u16 reserved;
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u32 log_max_len __attribute__ ((packed));
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u32 log_start_addr __attribute__ ((packed));
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};
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struct tcpa_event {
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u32 pcr_index;
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u32 event_type;
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u8 pcr_value[20]; /* SHA1 */
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u32 event_size;
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u8 event_data[0];
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};
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enum tcpa_event_types {
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PREBOOT = 0,
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POST_CODE,
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UNUSED,
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NO_ACTION,
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SEPARATOR,
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ACTION,
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EVENT_TAG,
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SCRTM_CONTENTS,
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SCRTM_VERSION,
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CPU_MICROCODE,
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PLATFORM_CONFIG_FLAGS,
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TABLE_OF_DEVICES,
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COMPACT_HASH,
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IPL,
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IPL_PARTITION_DATA,
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NONHOST_CODE,
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NONHOST_CONFIG,
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NONHOST_INFO,
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};
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static const char* tcpa_event_type_strings[] = {
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"PREBOOT",
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"POST CODE",
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"",
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"NO ACTION",
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"SEPARATOR",
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"ACTION",
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"EVENT TAG",
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"S-CRTM Contents",
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"S-CRTM Version",
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"CPU Microcode",
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"Platform Config Flags",
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"Table of Devices",
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"Compact Hash",
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"IPL",
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"IPL Partition Data",
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"Non-Host Code",
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"Non-Host Config",
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"Non-Host Info"
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};
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enum tcpa_pc_event_ids {
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SMBIOS = 1,
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BIS_CERT,
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POST_BIOS_ROM,
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ESCD,
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CMOS,
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NVRAM,
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OPTION_ROM_EXEC,
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OPTION_ROM_CONFIG,
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OPTION_ROM_MICROCODE,
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S_CRTM_VERSION,
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S_CRTM_CONTENTS,
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POST_CONTENTS,
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};
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static const char* tcpa_pc_event_id_strings[] = {
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""
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"SMBIOS",
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"BIS Certificate",
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"POST BIOS ",
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"ESCD ",
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"CMOS",
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"NVRAM",
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"Option ROM",
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"Option ROM config",
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"Option ROM microcode",
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"S-CRTM Version",
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"S-CRTM Contents",
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"S-CRTM POST Contents",
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};
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/* (Binary) bios measurement buffer */
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static void *tcg_eventlog;
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static void *tcg_eventlog_addr_limit; /* MAX */
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/* returns pointer to start of pos. entry of tcg log */
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static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
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{
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loff_t i;
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void *addr = tcg_eventlog;
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struct tcpa_event *event;
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/* read over *pos measurements */
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for (i = 0; i < *pos; i++) {
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event = addr;
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if ((addr + sizeof(struct tcpa_event)) <
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tcg_eventlog_addr_limit) {
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if (event->event_type == 0 && event->event_size == 0)
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return NULL;
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addr +=
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sizeof(struct tcpa_event) + event->event_size;
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}
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}
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/* now check if current entry is valid */
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if ((addr + sizeof(struct tcpa_event)) >= tcg_eventlog_addr_limit)
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return NULL;
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event = addr;
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if ((event->event_type == 0 && event->event_size == 0) ||
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((addr + sizeof(struct tcpa_event) + event->event_size) >=
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tcg_eventlog_addr_limit))
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return NULL;
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return addr;
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}
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static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
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loff_t *pos)
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{
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struct tcpa_event *event = v;
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v += sizeof(struct tcpa_event) + event->event_size;
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/* now check if current entry is valid */
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if ((v + sizeof(struct tcpa_event)) >= tcg_eventlog_addr_limit)
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return NULL;
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event = v;
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if (event->event_type == 0 && event->event_size == 0)
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return NULL;
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if ((event->event_type == 0 && event->event_size == 0) ||
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((v + sizeof(struct tcpa_event) + event->event_size) >=
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tcg_eventlog_addr_limit))
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return NULL;
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(*pos)++;
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return v;
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}
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static void tpm_bios_measurements_stop(struct seq_file *m, void *v)
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{
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}
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static int get_event_name(char *dest, struct tcpa_event *event,
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unsigned char * event_entry)
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{
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const char *name = "";
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char data[40] = "";
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int i, n_len = 0, d_len = 0;
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u32 event_id, event_data_size;
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switch(event->event_type) {
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case PREBOOT:
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case POST_CODE:
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case UNUSED:
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case NO_ACTION:
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case SCRTM_CONTENTS:
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case SCRTM_VERSION:
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case CPU_MICROCODE:
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case PLATFORM_CONFIG_FLAGS:
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case TABLE_OF_DEVICES:
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case COMPACT_HASH:
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case IPL:
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case IPL_PARTITION_DATA:
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case NONHOST_CODE:
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case NONHOST_CONFIG:
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case NONHOST_INFO:
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name = tcpa_event_type_strings[event->event_type];
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n_len = strlen(name);
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break;
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case SEPARATOR:
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case ACTION:
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if (MAX_TEXT_EVENT > event->event_size) {
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name = event_entry;
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n_len = event->event_size;
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}
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break;
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case EVENT_TAG:
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event_id = be32_to_cpu(event_entry);
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event_data_size = be32_to_cpu(&event_entry[4]);
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/* ToDo Row data -> Base64 */
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switch (event_id) {
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case SMBIOS:
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case BIS_CERT:
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case CMOS:
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case NVRAM:
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case OPTION_ROM_EXEC:
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case OPTION_ROM_CONFIG:
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case OPTION_ROM_MICROCODE:
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case S_CRTM_VERSION:
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case S_CRTM_CONTENTS:
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case POST_CONTENTS:
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name = tcpa_pc_event_id_strings[event_id];
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n_len = strlen(name);
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break;
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case POST_BIOS_ROM:
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case ESCD:
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name = tcpa_pc_event_id_strings[event_id];
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n_len = strlen(name);
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for (i = 0; i < 20; i++)
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d_len += sprintf(data, "%02x",
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event_entry[8 + i]);
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break;
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default:
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break;
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}
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default:
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break;
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}
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return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]",
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n_len, name, d_len, data);
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}
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static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
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{
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char *eventname;
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char data[4];
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u32 help;
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int i, len;
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struct tcpa_event *event = (struct tcpa_event *) v;
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unsigned char *event_entry =
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(unsigned char *) (v + sizeof(struct tcpa_event));
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eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
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if (!eventname) {
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printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
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__func__);
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return -ENOMEM;
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}
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/* 1st: PCR used is in little-endian format (4 bytes) */
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help = le32_to_cpu(event->pcr_index);
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memcpy(data, &help, 4);
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for (i = 0; i < 4; i++)
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seq_putc(m, data[i]);
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/* 2nd: SHA1 (20 bytes) */
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for (i = 0; i < 20; i++)
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seq_putc(m, event->pcr_value[i]);
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/* 3rd: event type identifier (4 bytes) */
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help = le32_to_cpu(event->event_type);
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memcpy(data, &help, 4);
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for (i = 0; i < 4; i++)
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seq_putc(m, data[i]);
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len = 0;
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len += get_event_name(eventname, event, event_entry);
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/* 4th: filename <= 255 + \'0' delimiter */
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if (len > TCG_EVENT_NAME_LEN_MAX)
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len = TCG_EVENT_NAME_LEN_MAX;
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for (i = 0; i < len; i++)
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seq_putc(m, eventname[i]);
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/* 5th: delimiter */
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seq_putc(m, '\0');
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return 0;
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}
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static int tpm_bios_measurements_release(struct inode *inode,
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struct file *file)
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{
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if (tcg_eventlog) {
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kfree(tcg_eventlog);
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tcg_eventlog = NULL;
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}
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return seq_release(inode, file);
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}
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static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
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{
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int len = 0;
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int i;
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char *eventname;
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struct tcpa_event *event = v;
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unsigned char *event_entry =
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(unsigned char *) (v + sizeof(struct tcpa_event));
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eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
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if (!eventname) {
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printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
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__func__);
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return -EFAULT;
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}
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seq_printf(m, "%2d ", event->pcr_index);
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/* 2nd: SHA1 */
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for (i = 0; i < 20; i++)
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seq_printf(m, "%02x", event->pcr_value[i]);
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/* 3rd: event type identifier */
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seq_printf(m, " %02x", event->event_type);
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len += get_event_name(eventname, event, event_entry);
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/* 4th: eventname <= max + \'0' delimiter */
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seq_printf(m, " %s\n", eventname);
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return 0;
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}
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static struct seq_operations tpm_ascii_b_measurments_seqops = {
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.start = tpm_bios_measurements_start,
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.next = tpm_bios_measurements_next,
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.stop = tpm_bios_measurements_stop,
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.show = tpm_ascii_bios_measurements_show,
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};
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static struct seq_operations tpm_binary_b_measurments_seqops = {
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.start = tpm_bios_measurements_start,
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.next = tpm_bios_measurements_next,
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.stop = tpm_bios_measurements_stop,
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.show = tpm_binary_bios_measurements_show,
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};
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/* read binary bios log */
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static int read_log(void)
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{
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struct acpi_tcpa *buff;
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acpi_status status;
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void *virt;
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if (tcg_eventlog != NULL) {
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printk(KERN_ERR
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"%s: ERROR - Eventlog already initialized\n",
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__func__);
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return -EFAULT;
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}
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/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
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status = acpi_get_firmware_table(ACPI_TCPA_SIG, 1,
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ACPI_LOGICAL_ADDRESSING,
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(struct acpi_table_header **)
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&buff);
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if (ACPI_FAILURE(status)) {
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printk(KERN_ERR "%s: ERROR - Could not get TCPA table\n",
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__func__);
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return -EIO;
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}
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if (buff->log_max_len == 0) {
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printk(KERN_ERR "%s: ERROR - TCPA log area empty\n",
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__func__);
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return -EIO;
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}
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/* malloc EventLog space */
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tcg_eventlog = kmalloc(buff->log_max_len, GFP_KERNEL);
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if (!tcg_eventlog) {
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printk
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("%s: ERROR - Not enough Memory for BIOS measurements\n",
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__func__);
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return -ENOMEM;
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}
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tcg_eventlog_addr_limit = tcg_eventlog + buff->log_max_len;
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acpi_os_map_memory(buff->log_start_addr, buff->log_max_len, &virt);
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memcpy(tcg_eventlog, virt, buff->log_max_len);
|
||||
|
||||
acpi_os_unmap_memory(virt, buff->log_max_len);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int tpm_ascii_bios_measurements_open(struct inode *inode,
|
||||
struct file *file)
|
||||
{
|
||||
int err;
|
||||
|
||||
if ((err = read_log()))
|
||||
return err;
|
||||
|
||||
/* now register seq file */
|
||||
return seq_open(file, &tpm_ascii_b_measurments_seqops);
|
||||
}
|
||||
|
||||
struct file_operations tpm_ascii_bios_measurements_ops = {
|
||||
.open = tpm_ascii_bios_measurements_open,
|
||||
.read = seq_read,
|
||||
.llseek = seq_lseek,
|
||||
.release = tpm_bios_measurements_release,
|
||||
};
|
||||
|
||||
static int tpm_binary_bios_measurements_open(struct inode *inode,
|
||||
struct file *file)
|
||||
{
|
||||
int err;
|
||||
|
||||
if ((err = read_log()))
|
||||
return err;
|
||||
|
||||
/* now register seq file */
|
||||
return seq_open(file, &tpm_binary_b_measurments_seqops);
|
||||
}
|
||||
|
||||
struct file_operations tpm_binary_bios_measurements_ops = {
|
||||
.open = tpm_binary_bios_measurements_open,
|
||||
.read = seq_read,
|
||||
.llseek = seq_lseek,
|
||||
.release = tpm_bios_measurements_release,
|
||||
};
|
||||
|
||||
struct dentry **tpm_bios_log_setup(char *name)
|
||||
{
|
||||
struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
|
||||
|
||||
tpm_dir = securityfs_create_dir(name, NULL);
|
||||
if (!tpm_dir)
|
||||
goto out;
|
||||
|
||||
bin_file =
|
||||
securityfs_create_file("binary_bios_measurements",
|
||||
S_IRUSR | S_IRGRP, tpm_dir, NULL,
|
||||
&tpm_binary_bios_measurements_ops);
|
||||
if (!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 (!ascii_file)
|
||||
goto out_bin;
|
||||
|
||||
ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
|
||||
if (!ret)
|
||||
goto out_ascii;
|
||||
|
||||
ret[0] = ascii_file;
|
||||
ret[1] = bin_file;
|
||||
ret[2] = tpm_dir;
|
||||
|
||||
return ret;
|
||||
|
||||
out_ascii:
|
||||
securityfs_remove(ascii_file);
|
||||
out_bin:
|
||||
securityfs_remove(bin_file);
|
||||
out_tpm:
|
||||
securityfs_remove(tpm_dir);
|
||||
out:
|
||||
return NULL;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(tpm_bios_log_setup);
|
||||
|
||||
void tpm_bios_log_teardown(struct dentry **lst)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < 3; i++)
|
||||
securityfs_remove(lst[i]);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(tpm_bios_log_teardown);
|
||||
Loading…
Reference in New Issue
Block a user