shared/efi-loader: fix compilation with !ENABLE_EFI, improve messages

When compiled without ENABLE_EFI, efi_stub_measured() was not defined, so
compilation would fail. But it's not enough to add a stub that returns
-EOPNOTSUPP. We call this function in various places and usually print the error
at warning or error level, so we'd print a confusing message. We also can't add
a stub that always returns 0, because then we'd print a message like "Kernel
stub did not measure", which would be confusing too. Adding special handling for
-EOPNOTSUPP in every caller is also unattractive. So instead efi_stub_measured()
is reworked to log the warning or error internally, and such logging is removed
from the callers, and a stub is added that logs a custom message.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/boot/pcrphase.c b/src/boot/pcrphase.c
index 003e0b8ad8..2add7f1f89 100644
--- a/src/boot/pcrphase.c
+++ b/src/boot/pcrphase.c
@@ -334,9 +334,9 @@ static int run(int argc, char *argv[]) {
         length = strlen(word);
 
         /* Skip logic if sd-stub is not used, after all PCR 11 might have a very different purpose then. */
-        r = efi_stub_measured();
+        r = efi_stub_measured(LOG_ERR);
         if (r < 0)
-                return log_error_errno(r, "Failed to detect if we are running on a kernel image with TPM measurement enabled: %m");
+                return r;
         if (r == 0) {
                 log_info("Kernel stub did not measure kernel image into PCR %u, skipping userspace measurement, too.", TPM_PCR_INDEX_KERNEL_IMAGE);
                 return EXIT_SUCCESS;