There are functions that calls tcg2_agile_log_append() outside
of the TCG protocol invocation (e.g tcg2_measure_pe_image).
These functions must to check that tcg2 protocol is installed.
If not, measurement shall be skipped.
Together with above change, this commit also removes the
unnecessary tcg2_uninit() call in efi_tcg2_register(),
refactors efi_tcg2_register() not to include the process
that is not related to the tcg2 protocol registration.
Signed-off-by: Masahisa Kojima <masahisa.koj...@linaro.org>
---
Changes in v3:
- add static qualifier to is_tcg2_protocol_installed()
- simplify is_tcg2_protocol_installed() return handling
Changes in v2:
- rebased on top of the TF-A eventlog handover support
include/efi_loader.h | 4 ++
lib/efi_loader/efi_setup.c | 3 ++
lib/efi_loader/efi_tcg2.c | 89 +++++++++++++++++++++++++++++++-------
3 files changed, 81 insertions(+), 15 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index d52e399841..fe29c10906 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -525,6 +525,10 @@ efi_status_t efi_disk_register(void);
efi_status_t efi_rng_register(void);
/* Called by efi_init_obj_list() to install EFI_TCG2_PROTOCOL */
efi_status_t efi_tcg2_register(void);
+/* Called by efi_init_obj_list() to do the required setup for the measurement
*/
+efi_status_t efi_tcg2_setup_measurement(void);
+/* Called by efi_init_obj_list() to do initial measurement */
+efi_status_t efi_tcg2_do_initial_measurement(void);
/* measure the pe-coff image, extend PCR and add Event Log */
efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
struct efi_loaded_image_obj *handle,
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index a2338d74af..781d10590d 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -271,6 +271,9 @@ efi_status_t efi_init_obj_list(void)
ret = efi_tcg2_register();
if (ret != EFI_SUCCESS)
goto out;
+
+ efi_tcg2_setup_measurement();
+ efi_tcg2_do_initial_measurement();
}
/* Secure boot */
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index b44eed0ec9..2196af49a6 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -153,6 +153,20 @@ static u16 alg_to_len(u16 hash_alg)
return 0;
}
+/**
+ * is_tcg2_protocol_installed - chech whether tcg2 protocol is installed
+ *
+ * @Return: true if tcg2 protocol is installed, false if not
+ */
+static bool is_tcg2_protocol_installed(void)
+{
+ struct efi_handler *handler;
+ efi_status_t ret;
+
+ ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler);
+ return (ret == EFI_SUCCESS);
+}
+
static u32 tcg_event_final_size(struct tpml_digest_values *digest_list)
{
u32 len;
@@ -962,6 +976,9 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
IMAGE_NT_HEADERS32 *nt;
struct efi_handler *handler;
+ if (!is_tcg2_protocol_installed())
+ return EFI_NOT_READY;
+
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
@@ -2140,6 +2157,9 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(struct
efi_loaded_image_obj *ha
u32 event = 0;
struct smbios_entry *entry;
+ if (!is_tcg2_protocol_installed())
+ return EFI_NOT_READY;
+
if (tcg2_efi_app_invoked)
return EFI_SUCCESS;
@@ -2190,6 +2210,9 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
efi_status_t ret;
struct udevice *dev;
+ if (!is_tcg2_protocol_installed())
+ return EFI_NOT_READY;
+
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
return ret;
@@ -2214,6 +2237,11 @@ efi_tcg2_notify_exit_boot_services(struct efi_event
*event, void *context)
EFI_ENTRY("%p, %p", event, context);
+ if (!is_tcg2_protocol_installed()) {
+ ret = EFI_NOT_READY;
+ goto out;
+ }
+
event_log.ebs_called = true;
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
@@ -2244,6 +2272,9 @@ efi_status_t
efi_tcg2_notify_exit_boot_services_failed(void)
struct udevice *dev;
efi_status_t ret;
+ if (!is_tcg2_protocol_installed())
+ return EFI_NOT_READY;
+
ret = platform_get_tpm2_device(&dev);
if (ret != EFI_SUCCESS)
goto out;
@@ -2313,6 +2344,45 @@ error:
return ret;
}
+/**
+ * efi_tcg2_setup_measurement() - setup for the measurement
+ *
+ * Return: status code
+ */
+efi_status_t efi_tcg2_setup_measurement(void)
+{
+ efi_status_t ret;
+ struct efi_event *event;
+
+ ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
+ efi_tcg2_notify_exit_boot_services, NULL,
+ NULL, &event);
+
+ return ret;
+}
+
+/**
+ * efi_tcg2_do_initial_measurement() - do initial measurement
+ *
+ * Return: status code
+ */
+efi_status_t efi_tcg2_do_initial_measurement(void)
+{
+ efi_status_t ret;
+ struct udevice *dev;
+
+ ret = platform_get_tpm2_device(&dev);
+ if (ret != EFI_SUCCESS)
+ goto out;
+
+ ret = tcg2_measure_secure_boot_variable(dev);
+ if (ret != EFI_SUCCESS)
+ goto out;
+
+out:
+ return ret;
+}
+
/**
* efi_tcg2_register() - register EFI_TCG2_PROTOCOL
*
@@ -2324,7 +2394,6 @@ efi_status_t efi_tcg2_register(void)
{
efi_status_t ret = EFI_SUCCESS;
struct udevice *dev;
- struct efi_event *event;
u32 err;
ret = platform_get_tpm2_device(&dev);
@@ -2344,6 +2413,10 @@ efi_status_t efi_tcg2_register(void)
if (ret != EFI_SUCCESS)
goto fail;
+ /*
+ * efi_add_protocol() is called at last on purpose.
+ * tcg2_uninit() does not uninstall the tcg2 protocol, but it is
intended.
+ */
ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
(void *)&efi_tcg2_protocol);
if (ret != EFI_SUCCESS) {
@@ -2351,20 +2424,6 @@ efi_status_t efi_tcg2_register(void)
goto fail;
}
- ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
- efi_tcg2_notify_exit_boot_services, NULL,
- NULL, &event);
- if (ret != EFI_SUCCESS) {
- tcg2_uninit();
- goto fail;
- }
-
- ret = tcg2_measure_secure_boot_variable(dev);
- if (ret != EFI_SUCCESS) {
- tcg2_uninit();
- goto fail;
- }
-
return ret;
fail:
--
2.17.1
