efi/tpm: Differentiate missing and invalid final event log table.

Missing TPM final event log table is not a firmware bug.

Clearly if providing event log in the old format makes the final event
log invalid it should not be provided at least in that case.

Fixes: b4f1874c6216 ("tpm: check event log version before reading final events")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index c1955d3..8f66567 100644 (file)
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -62,9 +62,11 @@ int __init efi_tpm_eventlog_init(void)
        tbl_size = sizeof(*log_tbl) + log_tbl->size;
        memblock_reserve(efi.tpm_log, tbl_size);
 
-       if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR ||
-           log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
-               pr_warn(FW_BUG "TPM Final Events table missing or invalid\n");
+       if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) {
+               pr_info("TPM Final Events table not present\n");
+               goto out;
+       } else if (log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
+               pr_warn(FW_BUG "TPM Final Events table invalid\n");
                goto out;
        }