diff options
Diffstat (limited to 'lib/efi_loader/efi_variable_tee.c')
| -rw-r--r-- | lib/efi_loader/efi_variable_tee.c | 82 |
1 files changed, 47 insertions, 35 deletions
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c index 37fa5fef1d..be6f3dfad4 100644 --- a/lib/efi_loader/efi_variable_tee.c +++ b/lib/efi_loader/efi_variable_tee.c @@ -15,6 +15,8 @@ #include <malloc.h> #include <mm_communication.h> +#define OPTEE_PAGE_SIZE BIT(12) +extern struct efi_var_file __efi_runtime_data *efi_var_buf; static efi_uintn_t max_buffer_size; /* comm + var + func + data */ static efi_uintn_t max_payload_size; /* func + data */ @@ -237,8 +239,32 @@ efi_status_t EFIAPI get_max_payload(efi_uintn_t *size) if (ret != EFI_SUCCESS) goto out; + /* Make sure the buffer is big enough for storing variables */ + if (var_payload->size < MM_VARIABLE_ACCESS_HEADER_SIZE + 0x20) { + ret = EFI_DEVICE_ERROR; + goto out; + } *size = var_payload->size; - + /* + * Although the max payload is configurable on StMM, we only share a + * single page from OP-TEE for the non-secure buffer used to communicate + * with StMM. Since OP-TEE will reject to map anything bigger than that, + * make sure we are in bounds. + */ + if (*size > OPTEE_PAGE_SIZE) + *size = OPTEE_PAGE_SIZE - MM_COMMUNICATE_HEADER_SIZE - + MM_VARIABLE_COMMUNICATE_SIZE; + /* + * There seems to be a bug in EDK2 miscalculating the boundaries and + * size checks, so deduct 2 more bytes to fulfill this requirement. Fix + * it up here to ensure backwards compatibility with older versions + * (cf. StandaloneMmPkg/Drivers/StandaloneMmCpu/AArch64/EventHandle.c. + * sizeof (EFI_MM_COMMUNICATE_HEADER) instead the size minus the + * flexible array member). + * + * size is guaranteed to be > 2 due to checks on the beginning. + */ + *size -= 2; out: free(comm_buf); return ret; @@ -593,39 +619,6 @@ out: } /** - * efi_get_variable_runtime() - runtime implementation of GetVariable() - * - * @variable_name: name of the variable - * @guid: vendor GUID - * @attributes: attributes of the variable - * @data_size: size of the buffer to which the variable value is copied - * @data: buffer to which the variable value is copied - * Return: status code - */ -static efi_status_t __efi_runtime EFIAPI -efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid, - u32 *attributes, efi_uintn_t *data_size, void *data) -{ - return EFI_UNSUPPORTED; -} - -/** - * efi_get_next_variable_name_runtime() - runtime implementation of - * GetNextVariable() - * - * @variable_name_size: size of variable_name buffer in byte - * @variable_name: name of uefi variable's name in u16 - * @guid: vendor's guid - * Return: status code - */ -static efi_status_t __efi_runtime EFIAPI -efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size, - u16 *variable_name, efi_guid_t *guid) -{ - return EFI_UNSUPPORTED; -} - -/** * efi_query_variable_info() - get information about EFI variables * * This function implements the QueryVariableInfo() runtime service. @@ -674,8 +667,10 @@ efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid, */ void efi_variables_boot_exit_notify(void) { - u8 *comm_buf; efi_status_t ret; + u8 *comm_buf; + loff_t len; + struct efi_var_file *var_buf; comm_buf = setup_mm_hdr(NULL, 0, SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret); @@ -688,6 +683,18 @@ void efi_variables_boot_exit_notify(void) log_err("Unable to notify StMM for ExitBootServices\n"); free(comm_buf); + /* + * Populate the list for runtime variables. + * asking EFI_VARIABLE_RUNTIME_ACCESS is redundant, since + * efi_var_mem_notify_exit_boot_services will clean those, but that's fine + */ + ret = efi_var_collect(&var_buf, &len, EFI_VARIABLE_RUNTIME_ACCESS); + if (ret != EFI_SUCCESS) + log_err("Can't populate EFI variables. No runtime variables will be available\n"); + else + memcpy(efi_var_buf, var_buf, len); + free(var_buf); + /* Update runtime service table */ efi_runtime_services.query_variable_info = efi_query_variable_info_runtime; @@ -707,6 +714,11 @@ efi_status_t efi_init_variables(void) { efi_status_t ret; + /* Create a cached copy of the variables that will be enabled on ExitBootServices() */ + ret = efi_var_mem_init(); + if (ret != EFI_SUCCESS) + return ret; + ret = get_max_payload(&max_payload_size); if (ret != EFI_SUCCESS) return ret; |