From d3884fe8336be793e3b3ad5813f5e6c436d78d60 Mon Sep 17 00:00:00 2001 From: Lans Zhang Date: Fri, 30 Sep 2016 10:46:31 +0800 Subject: shim: trigger to record further logs to tcg 2.0 final event log area According to TCG EFI Protocol Specification for TPM 2.0 family, all events generated after the invocation of EFI_TCG2_GET_EVENT_LOG shall be stored in an instance of an EFI_CONFIGURATION_TABLE aka EFI TCG 2.0 final events table. Hence, it is necessary to trigger the internal switch through calling get_event_log() in order to allow to retrieve the logs from OS runtime. Signed-off-by: Lans Zhang --- tpm.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'tpm.c') diff --git a/tpm.c b/tpm.c index 71bcf9b9..0305b401 100644 --- a/tpm.c +++ b/tpm.c @@ -61,6 +61,21 @@ static BOOLEAN tpm2_present(efi_tpm2_protocol_t *tpm) return FALSE; } +/* + * According to TCG EFI Protocol Specification for TPM 2.0 family, + * all events generated after the invocation of EFI_TCG2_GET_EVENT_LOG + * shall be stored in an instance of an EFI_CONFIGURATION_TABLE aka + * EFI TCG 2.0 final events table. Hence, it is necessary to trigger the + * internal switch through calling get_event_log() in order to allow + * to retrieve the logs from OS runtime. + */ +static EFI_STATUS trigger_tcg2_final_events_table(efi_tpm2_protocol_t *tpm2) +{ + return uefi_call_wrapper(tpm2->get_event_log, 5, tpm2, + EFI_TCG2_EVENT_LOG_FORMAT_TCG_2, NULL, + NULL, NULL); +} + EFI_STATUS tpm_log_event(EFI_PHYSICAL_ADDRESS buf, UINTN size, UINT8 pcr, const CHAR8 *description) { @@ -76,6 +91,12 @@ EFI_STATUS tpm_log_event(EFI_PHYSICAL_ADDRESS buf, UINTN size, UINT8 pcr, if (!tpm2_present(tpm2)) return EFI_SUCCESS; + status = trigger_tcg2_final_events_table(tpm2); + if (EFI_ERROR(status)) { + perror(L"Unable to trigger tcg2 final events table\n"); + return status; + } + event = AllocatePool(sizeof(*event) + strlen(description) + 1); if (!event) { perror(L"Unable to allocate event structure\n"); -- cgit v1.2.3