hc
2023-12-06 08f87f769b595151be1afeff53e144f543faa614
kernel/drivers/firmware/efi/libstub/tpm.c
....@@ -1,3 +1,4 @@
1
+// SPDX-License-Identifier: GPL-2.0
12 /*
23 * TPM handling.
34 *
....@@ -5,9 +6,6 @@
56 * Copyright (C) 2017 Google, Inc.
67 * Matthew Garrett <mjg59@google.com>
78 * Thiebaud Weksteen <tweek@google.com>
8
- *
9
- * This file is part of the Linux kernel, and is made available under the
10
- * terms of the GNU General Public License version 2.
119 */
1210 #include <linux/efi.h>
1311 #include <linux/tpm_eventlog.h>
....@@ -22,23 +20,13 @@
2220 #define MEMORY_ONLY_RESET_CONTROL_GUID \
2321 EFI_GUID(0xe20939be, 0x32d4, 0x41be, 0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29)
2422
25
-#define get_efi_var(name, vendor, ...) \
26
- efi_call_runtime(get_variable, \
27
- (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
28
- __VA_ARGS__)
29
-
30
-#define set_efi_var(name, vendor, ...) \
31
- efi_call_runtime(set_variable, \
32
- (efi_char16_t *)(name), (efi_guid_t *)(vendor), \
33
- __VA_ARGS__)
34
-
3523 /*
3624 * Enable reboot attack mitigation. This requests that the firmware clear the
3725 * RAM on next reboot before proceeding with boot, ensuring that any secrets
3826 * are cleared. If userland has ensured that all secrets have been removed
3927 * from RAM before reboot it can simply reset this variable.
4028 */
41
-void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg)
29
+void efi_enable_reset_attack_mitigation(void)
4230 {
4331 u8 val = 1;
4432 efi_guid_t var_guid = MEMORY_ONLY_RESET_CONTROL_GUID;
....@@ -59,31 +47,39 @@
5947
6048 #endif
6149
62
-static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg)
50
+void efi_retrieve_tpm2_eventlog(void)
6351 {
6452 efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID;
6553 efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID;
6654 efi_status_t status;
6755 efi_physical_addr_t log_location = 0, log_last_entry = 0;
6856 struct linux_efi_tpm_eventlog *log_tbl = NULL;
57
+ struct efi_tcg2_final_events_table *final_events_table = NULL;
6958 unsigned long first_entry_addr, last_entry_addr;
7059 size_t log_size, last_entry_size;
7160 efi_bool_t truncated;
72
- void *tcg2_protocol = NULL;
61
+ int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
62
+ efi_tcg2_protocol_t *tcg2_protocol = NULL;
63
+ int final_events_size = 0;
7364
74
- status = efi_call_early(locate_protocol, &tcg2_guid, NULL,
75
- &tcg2_protocol);
65
+ status = efi_bs_call(locate_protocol, &tcg2_guid, NULL,
66
+ (void **)&tcg2_protocol);
7667 if (status != EFI_SUCCESS)
7768 return;
7869
79
- status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol,
80
- EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2,
70
+ status = efi_call_proto(tcg2_protocol, get_event_log, version,
8171 &log_location, &log_last_entry, &truncated);
82
- if (status != EFI_SUCCESS)
83
- return;
8472
85
- if (!log_location)
86
- return;
73
+ if (status != EFI_SUCCESS || !log_location) {
74
+ version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
75
+ status = efi_call_proto(tcg2_protocol, get_event_log, version,
76
+ &log_location, &log_last_entry,
77
+ &truncated);
78
+ if (status != EFI_SUCCESS || !log_location)
79
+ return;
80
+
81
+ }
82
+
8783 first_entry_addr = (unsigned long) log_location;
8884
8985 /*
....@@ -98,39 +94,74 @@
9894 * We need to calculate its size to deduce the full size of
9995 * the logs.
10096 */
101
- last_entry_size = sizeof(struct tcpa_event) +
102
- ((struct tcpa_event *) last_entry_addr)->event_size;
97
+ if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
98
+ /*
99
+ * The TCG2 log format has variable length entries,
100
+ * and the information to decode the hash algorithms
101
+ * back into a size is contained in the first entry -
102
+ * pass a pointer to the final entry (to calculate its
103
+ * size) and the first entry (so we know how long each
104
+ * digest is)
105
+ */
106
+ last_entry_size =
107
+ __calc_tpm2_event_size((void *)last_entry_addr,
108
+ (void *)(long)log_location,
109
+ false);
110
+ } else {
111
+ last_entry_size = sizeof(struct tcpa_event) +
112
+ ((struct tcpa_event *) last_entry_addr)->event_size;
113
+ }
103114 log_size = log_last_entry - log_location + last_entry_size;
104115 }
105116
106117 /* Allocate space for the logs and copy them. */
107
- status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
108
- sizeof(*log_tbl) + log_size,
109
- (void **) &log_tbl);
118
+ status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
119
+ sizeof(*log_tbl) + log_size, (void **)&log_tbl);
110120
111121 if (status != EFI_SUCCESS) {
112
- efi_printk(sys_table_arg,
113
- "Unable to allocate memory for event log\n");
122
+ efi_err("Unable to allocate memory for event log\n");
114123 return;
124
+ }
125
+
126
+ /*
127
+ * Figure out whether any events have already been logged to the
128
+ * final events structure, and if so how much space they take up
129
+ */
130
+ if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2)
131
+ final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID);
132
+ if (final_events_table && final_events_table->nr_events) {
133
+ struct tcg_pcr_event2_head *header;
134
+ int offset;
135
+ void *data;
136
+ int event_size;
137
+ int i = final_events_table->nr_events;
138
+
139
+ data = (void *)final_events_table;
140
+ offset = sizeof(final_events_table->version) +
141
+ sizeof(final_events_table->nr_events);
142
+
143
+ while (i > 0) {
144
+ header = data + offset + final_events_size;
145
+ event_size = __calc_tpm2_event_size(header,
146
+ (void *)(long)log_location,
147
+ false);
148
+ final_events_size += event_size;
149
+ i--;
150
+ }
115151 }
116152
117153 memset(log_tbl, 0, sizeof(*log_tbl) + log_size);
118154 log_tbl->size = log_size;
119
- log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
155
+ log_tbl->final_events_preboot_size = final_events_size;
156
+ log_tbl->version = version;
120157 memcpy(log_tbl->log, (void *) first_entry_addr, log_size);
121158
122
- status = efi_call_early(install_configuration_table,
123
- &linux_eventlog_guid, log_tbl);
159
+ status = efi_bs_call(install_configuration_table,
160
+ &linux_eventlog_guid, log_tbl);
124161 if (status != EFI_SUCCESS)
125162 goto err_free;
126163 return;
127164
128165 err_free:
129
- efi_call_early(free_pool, log_tbl);
130
-}
131
-
132
-void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg)
133
-{
134
- /* Only try to retrieve the logs in 1.2 format. */
135
- efi_retrieve_tpm2_eventlog_1_2(sys_table_arg);
166
+ efi_bs_call(free_pool, log_tbl);
136167 }