tpm: Don't duplicate events from the final event log in the TCG2 log

[linux-2.6-block.git] / drivers / firmware / efi / libstub / tpm.c

diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
index 6b3b507a54eb08641c822ebb7226d0ef527b816a..eb9af83e4d5914d83decda4c5503dec6eaab0daa 100644 (file)
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -64,11 +64,13 @@ void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg)
        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;
        unsigned long first_entry_addr, last_entry_addr;
        size_t log_size, last_entry_size;
        efi_bool_t truncated;
        int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
        void *tcg2_protocol = NULL;
+       int final_events_size = 0;
 
        status = efi_call_early(locate_protocol, &tcg2_guid, NULL,
                                &tcg2_protocol);
@@ -134,8 +136,36 @@ void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg)
                return;
        }
 
+       /*
+        * Figure out whether any events have already been logged to the
+        * final events structure, and if so how much space they take up
+        */
+       final_events_table = get_efi_config_table(sys_table_arg,
+                                               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->final_events_preboot_size = final_events_size;
        log_tbl->version = version;
        memcpy(log_tbl->log, (void *) first_entry_addr, log_size);