With TPM 2.0 specification, the event logs may only be accessible by
calling an EFI Boot Service. Modify the EFI stub to copy the log area to
a new Linux-specific EFI configuration table so it remains accessible
once booted.
When calling this service, it is possible to specify the expected format
of the logs: TPM 1.2 (SHA1) or TPM 2.0 ("Crypto Agile"). For now, only the
first format is retrieved.
Signed-off-by: Thiebaud Weksteen <tw...@google.com>
---
arch/x86/boot/compressed/eboot.c | 1 +
drivers/firmware/efi/Makefile | 2 +-
drivers/firmware/efi/efi.c | 4 ++
drivers/firmware/efi/libstub/Makefile | 3 +-
drivers/firmware/efi/libstub/tpm.c | 81 +++++++++++++++++++++++++++++++++++
drivers/firmware/efi/tpm.c | 40 +++++++++++++++++
include/linux/efi.h | 46 ++++++++++++++++++++
7 files changed, 174 insertions(+), 3 deletions(-)
create mode 100644 drivers/firmware/efi/tpm.c
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index a1686f3dc295..ef6abe8b3788 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -999,6 +999,7 @@ struct boot_params *efi_main(struct efi_config *c,
/* Ask the firmware to clear memory on unclean shutdown */
efi_enable_reset_attack_mitigation(sys_table);
+ efi_retrieve_tpm2_eventlog(sys_table);
setup_graphics(boot_params);
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 0329d319d89a..2f074b5cde87 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -10,7 +10,7 @@
KASAN_SANITIZE_runtime-wrappers.o := n
obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
-obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o
+obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o tpm.o
obj-$(CONFIG_EFI) += capsule.o memmap.o
obj-$(CONFIG_EFI_VARS) += efivars.o
obj-$(CONFIG_EFI_ESRT) += esrt.o
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index f97f272e16ee..0308acfaaf76 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -52,6 +52,7 @@ struct efi __read_mostly efi = {
.properties_table = EFI_INVALID_TABLE_ADDR,
.mem_attr_table = EFI_INVALID_TABLE_ADDR,
.rng_seed = EFI_INVALID_TABLE_ADDR,
+ .tpm_log = EFI_INVALID_TABLE_ADDR
};
EXPORT_SYMBOL(efi);
@@ -444,6 +445,7 @@ static __initdata efi_config_table_type_t common_tables[] =
{
{EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
+ {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
{NULL_GUID, NULL, NULL},
};
@@ -532,6 +534,8 @@ int __init efi_config_parse_tables(void *config_tables, int
count, int sz,
if (efi_enabled(EFI_MEMMAP))
efi_memattr_init();
+ efi_tpm_eventlog_init();
+
/* Parse the EFI Properties table if it exists */
if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
efi_properties_table_t *tbl;
diff --git a/drivers/firmware/efi/libstub/Makefile
b/drivers/firmware/efi/libstub/Makefile
index dedf9bde44db..2abe6d22dc5f 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -29,8 +29,7 @@ OBJECT_FILES_NON_STANDARD := y
# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
KCOV_INSTRUMENT := n
-lib-y := efi-stub-helper.o gop.o secureboot.o
-lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o
+lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o
# include the stub's generic dependencies from lib/ when building for ARM/arm64
arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
diff --git a/drivers/firmware/efi/libstub/tpm.c
b/drivers/firmware/efi/libstub/tpm.c
index 6224cdbc9669..da661bf8cb96 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -4,15 +4,18 @@
* Copyright (C) 2016 CoreOS, Inc
* Copyright (C) 2017 Google, Inc.
* Matthew Garrett <mj...@google.com>
+ * Thiebaud Weksteen <tw...@google.com>
*
* This file is part of the Linux kernel, and is made available under the
* terms of the GNU General Public License version 2.
*/
#include <linux/efi.h>
+#include <linux/tpm_eventlog.h>
#include <asm/efi.h>
#include "efistub.h"
+#ifdef CONFIG_RESET_ATTACK_MITIGATION
static const efi_char16_t efi_MemoryOverWriteRequest_name[] = {
'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't',
'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o',
@@ -56,3 +59,81 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t
*sys_table_arg)
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS, sizeof(val), &val);
}
+
+#endif
+
+void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg)
+{
+ efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID;
+ efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID;
+ efi_status_t status;
+ efi_physical_addr_t log_location, log_last_entry;
+ struct linux_efi_tpm_eventlog *log_tbl;
+ unsigned long first_entry_addr, last_entry_addr;
+ size_t log_size, last_entry_size;
+ efi_bool_t truncated;
+ void *tcg2_protocol;
+
+ status = efi_call_early(locate_protocol, &tcg2_guid, NULL,
+ &tcg2_protocol);
+ if (status != EFI_SUCCESS)
+ return;
+
+ status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol,
+ EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2,
+ &log_location, &log_last_entry, &truncated);
+ if (status != EFI_SUCCESS)
+ return;
+
+ if (!log_location)
+ return;
+ first_entry_addr = (unsigned long) log_location;
+
+ /*
+ * We populate the EFI table even if the logs are empty.
+ */
+ if (!log_last_entry) {
+ log_size = 0;
+ } else {
+ last_entry_addr = (unsigned long) log_last_entry;
+ /*
+ * get_event_log only returns the address of the last entry.
+ * We need to calculate its size to deduce the full size of
+ * the logs.
+ */
+ last_entry_size = sizeof(struct tcpa_event) +
+ ((struct tcpa_event *) last_entry_addr)->event_size;
+ log_size = log_last_entry - log_location + last_entry_size;
+ }
+
+ /* Allocate space for the logs and copy them. */
+ status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+ sizeof(*log_tbl) + log_size,
+ (void **) &log_tbl);
+
+ if (status != EFI_SUCCESS) {
+ efi_printk(sys_table_arg,
+ "Unable to allocate memory for event log\n");
+ return;
+ }
+
+ memset(log_tbl, 0, sizeof(*log_tbl) + log_size);
+ log_tbl->size = log_size;
+ log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+ memcpy(log_tbl->log, (void *) first_entry_addr, log_size);
+
+ status = efi_call_early(install_configuration_table,
+ &linux_eventlog_guid, log_tbl);
+ if (status != EFI_SUCCESS)
+ goto err_free;
+ return;
+
+err_free:
+ efi_call_early(free_pool, log_tbl);
+}
+
+void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg)
+{
+ /* Only try to retrieve the logs in 1.2 format. */
+ efi_retrieve_tpm2_eventlog_1_2(sys_table_arg);
+}
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
new file mode 100644
index 000000000000..0cbeb3d46b18
--- /dev/null
+++ b/drivers/firmware/efi/tpm.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2017 Google, Inc.
+ * Thiebaud Weksteen <tw...@google.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+
+#include <asm/early_ioremap.h>
+
+/*
+ * Reserve the memory associated with the TPM Event Log configuration table.
+ */
+int __init efi_tpm_eventlog_init(void)
+{
+ struct linux_efi_tpm_eventlog *log_tbl;
+ unsigned int tbl_size;
+
+ if (efi.tpm_log == EFI_INVALID_TABLE_ADDR)
+ return 0;
+
+ log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl));
+ if (!log_tbl) {
+ pr_err("Failed to map TPM Event Log table @ 0x%lx\n",
+ efi.tpm_log);
+ efi.tpm_log = EFI_INVALID_TABLE_ADDR;
+ return -ENOMEM;
+ }
+
+ tbl_size = sizeof(*log_tbl) + log_tbl->size;
+ memblock_reserve(efi.tpm_log, tbl_size);
+ early_memunmap(log_tbl, sizeof(*log_tbl));
+ return 0;
+}
+
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 8dc3d94a3e3c..c5805eb601b1 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -472,6 +472,39 @@ typedef struct {
u64 get_all;
} apple_properties_protocol_64_t;
+typedef struct {
+ u32 get_capability;
+ u32 get_event_log;
+ u32 hash_log_extend_event;
+ u32 submit_command;
+ u32 get_active_pcr_banks;
+ u32 set_active_pcr_banks;
+ u32 get_result_of_set_active_pcr_banks;
+} efi_tcg2_protocol_32_t;
+
+typedef struct {
+ u64 get_capability;
+ u64 get_event_log;
+ u64 hash_log_extend_event;
+ u64 submit_command;
+ u64 get_active_pcr_banks;
+ u64 set_active_pcr_banks;
+ u64 get_result_of_set_active_pcr_banks;
+} efi_tcg2_protocol_64_t;
+
+typedef u32 efi_tcg2_event_log_format;
+
+typedef struct {
+ void *get_capability;
+ efi_status_t (*get_event_log)(efi_handle_t, efi_tcg2_event_log_format,
+ efi_physical_addr_t *, efi_physical_addr_t *, efi_bool_t *);
+ void *hash_log_extend_event;
+ void *submit_command;
+ void *get_active_pcr_banks;
+ void *set_active_pcr_banks;
+ void *get_result_of_set_active_pcr_banks;
+} efi_tcg2_protocol_t;
+
/*
* Types and defines for EFI ResetSystem
*/
@@ -622,6 +655,7 @@ void efi_native_runtime_setup(void);
#define EFI_MEMORY_ATTRIBUTES_TABLE_GUID EFI_GUID(0xdcfa911d, 0x26eb,
0x469f, 0xa2, 0x20, 0x38, 0xb7, 0xdc, 0x46, 0x12, 0x20)
#define EFI_CONSOLE_OUT_DEVICE_GUID EFI_GUID(0xd3b36f2c, 0xd551,
0x11d4, 0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
#define APPLE_PROPERTIES_PROTOCOL_GUID EFI_GUID(0x91bd12fe, 0xf6c3,
0x44fb, 0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0)
+#define EFI_TCG2_PROTOCOL_GUID EFI_GUID(0x607f766c, 0x7455,
0x42be, 0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
#define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a,
0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f)
#define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046,
0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
@@ -634,6 +668,7 @@ void efi_native_runtime_setup(void);
#define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc,
0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95)
#define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c,
0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f)
#define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb,
0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b)
+#define LINUX_EFI_TPM_EVENT_LOG_GUID EFI_GUID(0xb7799cb0, 0xeca2,
0x4943, 0x96, 0x67, 0x1f, 0xae, 0x07, 0xb7, 0x47, 0xfa)
typedef struct {
efi_guid_t guid;
@@ -908,6 +943,7 @@ extern struct efi {
unsigned long properties_table; /* properties table */
unsigned long mem_attr_table; /* memory attributes table */
unsigned long rng_seed; /* UEFI firmware random seed */
+ unsigned long tpm_log; /* TPM2 Event Log table */
efi_get_time_t *get_time;
efi_set_time_t *set_time;
efi_get_wakeup_time_t *get_wakeup_time;
@@ -1504,6 +1540,8 @@ static inline void
efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) { }
#endif
+void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table);
+
/*
* Arch code can implement the following three template macros, avoiding
* reptition for the void/non-void return cases of {__,}efi_call_virt():
@@ -1571,4 +1609,12 @@ struct linux_efi_random_seed {
u8 bits[];
};
+struct linux_efi_tpm_eventlog {
+ u32 size;
+ u8 version;
+ u8 log[];
+};
+
+extern int efi_tpm_eventlog_init(void);
+
#endif /* _LINUX_EFI_H */
--
2.14.1.821.g8fa685d3b7-goog
------------------------------------------------------------------------------
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