boot: unify code that measures image options/kernel command line

src/boot/efi/boot.c

@@ -2349,11 +2349,7 @@ static EFI_STATUS image_start(
 
 #if ENABLE_TPM
                 /* Try to log any options to the TPM, especially to catch manually edited options */
-                err = tpm_log_event(TPM_PCR_INDEX_KERNEL_PARAMETERS,
-                                    (EFI_PHYSICAL_ADDRESS) (UINTN) loaded_image->LoadOptions,
-                                    loaded_image->LoadOptionsSize, loaded_image->LoadOptions);
-                if (EFI_ERROR(err))
-                        log_error_stall(L"Unable to add image options measurement: %r", err);
+                (VOID) tpm_log_load_options(options);
 #endif
         }
 

src/boot/efi/measure.c

@@ -162,4 +162,18 @@ EFI_STATUS tpm_log_event(UINT32 pcrindex, const EFI_PHYSICAL_ADDRESS buffer, UIN
         return EFI_SUCCESS;
 }
 
+EFI_STATUS tpm_log_load_options(const CHAR16 *load_options) {
+        EFI_STATUS err;
+
+        /* Measures a load options string into the TPM2, i.e. the kernel command line */
+
+        err = tpm_log_event(TPM_PCR_INDEX_KERNEL_PARAMETERS,
+                            (EFI_PHYSICAL_ADDRESS) (UINTN) load_options,
+                            StrSize(load_options), load_options);
+        if (EFI_ERROR(err))
+                return log_error_status_stall(err, L"Unable to add load options (i.e. kernel command) line measurement: %r", err);
+
+        return EFI_SUCCESS;
+}
+
 #endif

src/boot/efi/measure.h

@@ -4,3 +4,5 @@
 #include <efi.h>
 
 EFI_STATUS tpm_log_event(UINT32 pcrindex, const EFI_PHYSICAL_ADDRESS buffer, UINTN buffer_size, const CHAR16 *description);
+
+EFI_STATUS tpm_log_load_options(const CHAR16 *cmdline);

src/boot/efi/stub.c

@@ -147,12 +147,11 @@ EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
                 cmdline = line;
 
 #if ENABLE_TPM
-                /* Try to log any options to the TPM, especially manually edited options */
-                err = tpm_log_event(TPM_PCR_INDEX_KERNEL_PARAMETERS,
-                                    (EFI_PHYSICAL_ADDRESS) (UINTN) loaded_image->LoadOptions,
-                                    loaded_image->LoadOptionsSize, loaded_image->LoadOptions);
-                if (EFI_ERROR(err))
-                        log_error_stall(L"Unable to add image options measurement: %r", err);
+                /* Let's measure the passed kernel command line into the TPM. Note that this possibly
+                 * duplicates what we already did in the boot menu, if that was already used. However, since
+                 * we want the boot menu to support an EFI binary, and want to this stub to be usable from
+                 * any boot menu, let's measure things anyway. */
+                (VOID) tpm_log_load_options(loaded_image->LoadOptions);
 #endif
         }