From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/drivers/firmware/efi/libstub/tpm.c | 113 ++++++++++++++++++++++++++++++++++++--------------------
1 files changed, 72 insertions(+), 41 deletions(-)
diff --git a/kernel/drivers/firmware/efi/libstub/tpm.c b/kernel/drivers/firmware/efi/libstub/tpm.c
index a90b0b8..7acbac1 100644
--- a/kernel/drivers/firmware/efi/libstub/tpm.c
+++ b/kernel/drivers/firmware/efi/libstub/tpm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* TPM handling.
*
@@ -5,9 +6,6 @@
* Copyright (C) 2017 Google, Inc.
* Matthew Garrett <mjg59@google.com>
* Thiebaud Weksteen <tweek@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>
@@ -22,23 +20,13 @@
#define MEMORY_ONLY_RESET_CONTROL_GUID \
EFI_GUID(0xe20939be, 0x32d4, 0x41be, 0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29)
-#define get_efi_var(name, vendor, ...) \
- efi_call_runtime(get_variable, \
- (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
- __VA_ARGS__)
-
-#define set_efi_var(name, vendor, ...) \
- efi_call_runtime(set_variable, \
- (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
- __VA_ARGS__)
-
/*
* Enable reboot attack mitigation. This requests that the firmware clear the
* RAM on next reboot before proceeding with boot, ensuring that any secrets
* are cleared. If userland has ensured that all secrets have been removed
* from RAM before reboot it can simply reset this variable.
*/
-void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg)
+void efi_enable_reset_attack_mitigation(void)
{
u8 val = 1;
efi_guid_t var_guid = MEMORY_ONLY_RESET_CONTROL_GUID;
@@ -59,31 +47,39 @@
#endif
-static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg)
+void efi_retrieve_tpm2_eventlog(void)
{
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 = 0, log_last_entry = 0;
struct linux_efi_tpm_eventlog *log_tbl = NULL;
+ struct efi_tcg2_final_events_table *final_events_table = NULL;
unsigned long first_entry_addr, last_entry_addr;
size_t log_size, last_entry_size;
efi_bool_t truncated;
- void *tcg2_protocol = NULL;
+ int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
+ efi_tcg2_protocol_t *tcg2_protocol = NULL;
+ int final_events_size = 0;
- status = efi_call_early(locate_protocol, &tcg2_guid, NULL,
- &tcg2_protocol);
+ status = efi_bs_call(locate_protocol, &tcg2_guid, NULL,
+ (void **)&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,
+ status = efi_call_proto(tcg2_protocol, get_event_log, version,
&log_location, &log_last_entry, &truncated);
- if (status != EFI_SUCCESS)
- return;
- if (!log_location)
- return;
+ if (status != EFI_SUCCESS || !log_location) {
+ version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+ status = efi_call_proto(tcg2_protocol, get_event_log, version,
+ &log_location, &log_last_entry,
+ &truncated);
+ if (status != EFI_SUCCESS || !log_location)
+ return;
+
+ }
+
first_entry_addr = (unsigned long) log_location;
/*
@@ -98,39 +94,74 @@
* 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;
+ if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
+ /*
+ * The TCG2 log format has variable length entries,
+ * and the information to decode the hash algorithms
+ * back into a size is contained in the first entry -
+ * pass a pointer to the final entry (to calculate its
+ * size) and the first entry (so we know how long each
+ * digest is)
+ */
+ last_entry_size =
+ __calc_tpm2_event_size((void *)last_entry_addr,
+ (void *)(long)log_location,
+ false);
+ } else {
+ 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);
+ status = efi_bs_call(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");
+ efi_err("Unable to allocate memory for event log\n");
return;
+ }
+
+ /*
+ * Figure out whether any events have already been logged to the
+ * final events structure, and if so how much space they take up
+ */
+ if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2)
+ final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID);
+ if (final_events_table && final_events_table->nr_events) {
+ struct tcg_pcr_event2_head *header;
+ int offset;
+ void *data;
+ int event_size;
+ int i = final_events_table->nr_events;
+
+ data = (void *)final_events_table;
+ offset = sizeof(final_events_table->version) +
+ sizeof(final_events_table->nr_events);
+
+ while (i > 0) {
+ header = data + offset + final_events_size;
+ event_size = __calc_tpm2_event_size(header,
+ (void *)(long)log_location,
+ false);
+ final_events_size += event_size;
+ i--;
+ }
}
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;
+ log_tbl->final_events_preboot_size = final_events_size;
+ log_tbl->version = version;
memcpy(log_tbl->log, (void *) first_entry_addr, log_size);
- status = efi_call_early(install_configuration_table,
- &linux_eventlog_guid, log_tbl);
+ status = efi_bs_call(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);
+ efi_bs_call(free_pool, log_tbl);
}
--
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