// SPDX-License-Identifier: GPL-2.0+ /* * EFI variable service via OP-TEE * * Copyright (C) 2019 Linaro Ltd. * Copyright (C) 2019 Linaro Ltd. */ #include #include #include #include #include #include #include #include #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 */ struct mm_connection { struct udevice *tee; u32 session; }; /** * get_connection() - Retrieve OP-TEE session for a specific UUID. * * @conn: session buffer to fill * Return: status code */ static int get_connection(struct mm_connection *conn) { static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID; struct udevice *tee = NULL; struct tee_open_session_arg arg; int rc = -ENODEV; tee = tee_find_device(tee, NULL, NULL, NULL); if (!tee) goto out; memset(&arg, 0, sizeof(arg)); tee_optee_ta_uuid_to_octets(arg.uuid, &uuid); rc = tee_open_session(tee, &arg, 0, NULL); if (rc) goto out; /* Check the internal OP-TEE result */ if (arg.ret != TEE_SUCCESS) { rc = -EIO; goto out; } conn->tee = tee; conn->session = arg.session; return 0; out: return rc; } /** * optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE * * @comm_buf: locally allocted communcation buffer * @dsize: buffer size * Return: status code */ static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize) { ulong buf_size; efi_status_t ret; struct efi_mm_communicate_header *mm_hdr; struct mm_connection conn = { NULL, 0 }; struct tee_invoke_arg arg; struct tee_param param[2]; struct tee_shm *shm = NULL; int rc; if (!comm_buf) return EFI_INVALID_PARAMETER; mm_hdr = (struct efi_mm_communicate_header *)comm_buf; buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t); if (dsize != buf_size) return EFI_INVALID_PARAMETER; rc = get_connection(&conn); if (rc) { log_err("Unable to open OP-TEE session (err=%d)\n", rc); return EFI_UNSUPPORTED; } if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) { log_err("Unable to register shared memory\n"); tee_close_session(conn.tee, conn.session); return EFI_UNSUPPORTED; } memset(&arg, 0, sizeof(arg)); arg.func = PTA_STMM_CMDID_COMMUNICATE; arg.session = conn.session; memset(param, 0, sizeof(param)); param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT; param[0].u.memref.size = buf_size; param[0].u.memref.shm = shm; param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT; rc = tee_invoke_func(conn.tee, &arg, 2, param); tee_shm_free(shm); tee_close_session(conn.tee, conn.session); if (rc || arg.ret != TEE_SUCCESS) return EFI_DEVICE_ERROR; switch (param[1].u.value.a) { case ARM_SVC_SPM_RET_SUCCESS: ret = EFI_SUCCESS; break; case ARM_SVC_SPM_RET_INVALID_PARAMS: ret = EFI_INVALID_PARAMETER; break; case ARM_SVC_SPM_RET_DENIED: ret = EFI_ACCESS_DENIED; break; case ARM_SVC_SPM_RET_NO_MEMORY: ret = EFI_OUT_OF_RESOURCES; break; default: ret = EFI_ACCESS_DENIED; } return ret; } /** * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send * it to OP-TEE * * @comm_buf: locally allocted communcation buffer * @dsize: buffer size * Return: status code */ static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize) { efi_status_t ret; struct efi_mm_communicate_header *mm_hdr; struct smm_variable_communicate_header *var_hdr; dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE; mm_hdr = (struct efi_mm_communicate_header *)comm_buf; var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; ret = optee_mm_communicate(comm_buf, dsize); if (ret != EFI_SUCCESS) { log_err("%s failed!\n", __func__); return ret; } return var_hdr->ret_status; } /** * setup_mm_hdr() - Allocate a buffer for StandAloneMM and initialize the * header data. * * @dptr: pointer address of the corresponding StandAloneMM * function * @payload_size: buffer size * @func: standAloneMM function number * @ret: EFI return code * Return: buffer or NULL */ static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size, efi_uintn_t func, efi_status_t *ret) { const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID; struct efi_mm_communicate_header *mm_hdr; struct smm_variable_communicate_header *var_hdr; u8 *comm_buf; /* In the init function we initialize max_buffer_size with * get_max_payload(). So skip the test if max_buffer_size is initialized * StandAloneMM will perform similar checks and drop the buffer if it's * too long */ if (max_buffer_size && max_buffer_size < (MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE + payload_size)) { *ret = EFI_INVALID_PARAMETER; return NULL; } comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE + payload_size); if (!comm_buf) { *ret = EFI_OUT_OF_RESOURCES; return NULL; } mm_hdr = (struct efi_mm_communicate_header *)comm_buf; guidcpy(&mm_hdr->header_guid, &mm_var_guid); mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size; var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; var_hdr->function = func; if (dptr) *dptr = var_hdr->data; *ret = EFI_SUCCESS; return comm_buf; } /** * get_max_payload() - Get variable payload size from StandAloneMM. * * @size: size of the variable in storage * Return: status code */ efi_status_t EFIAPI get_max_payload(efi_uintn_t *size) { struct smm_variable_payload_size *var_payload = NULL; efi_uintn_t payload_size; u8 *comm_buf = NULL; efi_status_t ret; if (!size) { ret = EFI_INVALID_PARAMETER; goto out; } payload_size = sizeof(*var_payload); comm_buf = setup_mm_hdr((void **)&var_payload, payload_size, SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret); if (!comm_buf) goto out; ret = mm_communicate(comm_buf, payload_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; } /* * StMM can store internal attributes and properties for variables, i.e enabling * R/O variables */ static efi_status_t set_property_int(u16 *variable_name, efi_uintn_t name_size, const efi_guid_t *vendor, struct var_check_property *var_property) { struct smm_variable_var_check_property *smm_property; efi_uintn_t payload_size; u8 *comm_buf = NULL; efi_status_t ret; payload_size = sizeof(*smm_property) + name_size; if (payload_size > max_payload_size) { ret = EFI_INVALID_PARAMETER; goto out; } comm_buf = setup_mm_hdr((void **)&smm_property, payload_size, SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET, &ret); if (!comm_buf) goto out; guidcpy(&smm_property->guid, vendor); smm_property->name_size = name_size; memcpy(&smm_property->property, var_property, sizeof(smm_property->property)); memcpy(smm_property->name, variable_name, name_size); ret = mm_communicate(comm_buf, payload_size); out: free(comm_buf); return ret; } static efi_status_t get_property_int(u16 *variable_name, efi_uintn_t name_size, const efi_guid_t *vendor, struct var_check_property *var_property) { struct smm_variable_var_check_property *smm_property; efi_uintn_t payload_size; u8 *comm_buf = NULL; efi_status_t ret; memset(var_property, 0, sizeof(*var_property)); payload_size = sizeof(*smm_property) + name_size; if (payload_size > max_payload_size) { ret = EFI_INVALID_PARAMETER; goto out; } comm_buf = setup_mm_hdr((void **)&smm_property, payload_size, SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET, &ret); if (!comm_buf) goto out; guidcpy(&smm_property->guid, vendor); smm_property->name_size = name_size; memcpy(smm_property->name, variable_name, name_size); ret = mm_communicate(comm_buf, payload_size); /* * Currently only R/O property is supported in StMM. * Variables that are not set to R/O will not set the property in StMM * and the call will return EFI_NOT_FOUND. We are setting the * properties to 0x0 so checking against that is enough for the * EFI_NOT_FOUND case. */ if (ret == EFI_NOT_FOUND) ret = EFI_SUCCESS; if (ret != EFI_SUCCESS) goto out; memcpy(var_property, &smm_property->property, sizeof(*var_property)); out: free(comm_buf); return ret; } efi_status_t efi_get_variable_int(u16 *variable_name, const efi_guid_t *vendor, u32 *attributes, efi_uintn_t *data_size, void *data, u64 *timep) { struct var_check_property var_property; struct smm_variable_access *var_acc; efi_uintn_t payload_size; efi_uintn_t name_size; efi_uintn_t tmp_dsize; u8 *comm_buf = NULL; efi_status_t ret; if (!variable_name || !vendor || !data_size) { ret = EFI_INVALID_PARAMETER; goto out; } /* Check payload size */ name_size = u16_strsize(variable_name); if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) { ret = EFI_INVALID_PARAMETER; goto out; } /* Trim output buffer size */ tmp_dsize = *data_size; if (name_size + tmp_dsize > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) { tmp_dsize = max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE - name_size; } /* Get communication buffer and initialize header */ payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize; comm_buf = setup_mm_hdr((void **)&var_acc, payload_size, SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret); if (!comm_buf) goto out; /* Fill in contents */ guidcpy(&var_acc->guid, vendor); var_acc->data_size = tmp_dsize; var_acc->name_size = name_size; var_acc->attr = attributes ? *attributes : 0; memcpy(var_acc->name, variable_name, name_size); /* Communicate */ ret = mm_communicate(comm_buf, payload_size); if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) { /* Update with reported data size for trimmed case */ *data_size = var_acc->data_size; } if (ret != EFI_SUCCESS) goto out; ret = get_property_int(variable_name, name_size, vendor, &var_property); if (ret != EFI_SUCCESS) goto out; if (attributes) { *attributes = var_acc->attr; if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) *attributes |= EFI_VARIABLE_READ_ONLY; } if (data) memcpy(data, (u8 *)var_acc->name + var_acc->name_size, var_acc->data_size); else ret = EFI_INVALID_PARAMETER; out: free(comm_buf); return ret; } efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size, u16 *variable_name, efi_guid_t *guid) { struct smm_variable_getnext *var_getnext; efi_uintn_t payload_size; efi_uintn_t out_name_size; efi_uintn_t in_name_size; u8 *comm_buf = NULL; efi_status_t ret; if (!variable_name_size || !variable_name || !guid) { ret = EFI_INVALID_PARAMETER; goto out; } out_name_size = *variable_name_size; in_name_size = u16_strsize(variable_name); if (out_name_size < in_name_size) { ret = EFI_INVALID_PARAMETER; goto out; } if (in_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) { ret = EFI_INVALID_PARAMETER; goto out; } /* Trim output buffer size */ if (out_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) out_name_size = max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE; payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size; comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size, SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME, &ret); if (!comm_buf) goto out; /* Fill in contents */ guidcpy(&var_getnext->guid, guid); var_getnext->name_size = out_name_size; memcpy(var_getnext->name, variable_name, in_name_size); memset((u8 *)var_getnext->name + in_name_size, 0x0, out_name_size - in_name_size); /* Communicate */ ret = mm_communicate(comm_buf, payload_size); if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) { /* Update with reported data size for trimmed case */ *variable_name_size = var_getnext->name_size; } if (ret != EFI_SUCCESS) goto out; guidcpy(guid, &var_getnext->guid); memcpy(variable_name, var_getnext->name, var_getnext->name_size); out: free(comm_buf); return ret; } efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor, u32 attributes, efi_uintn_t data_size, const void *data, bool ro_check) { efi_status_t ret, alt_ret = EFI_SUCCESS; struct var_check_property var_property; struct smm_variable_access *var_acc; efi_uintn_t payload_size; efi_uintn_t name_size; u8 *comm_buf = NULL; bool ro; if (!variable_name || variable_name[0] == 0 || !vendor) { ret = EFI_INVALID_PARAMETER; goto out; } if (data_size > 0 && !data) { ret = EFI_INVALID_PARAMETER; goto out; } /* Check payload size */ name_size = u16_strsize(variable_name); payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size; if (payload_size > max_payload_size) { ret = EFI_INVALID_PARAMETER; goto out; } /* * Allocate the buffer early, before switching to RW (if needed) * so we won't need to account for any failures in reading/setting * the properties, if the allocation fails */ comm_buf = setup_mm_hdr((void **)&var_acc, payload_size, SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret); if (!comm_buf) goto out; ro = !!(attributes & EFI_VARIABLE_READ_ONLY); attributes &= EFI_VARIABLE_MASK; /* * The API has the ability to override RO flags. If no RO check was * requested switch the variable to RW for the duration of this call */ ret = get_property_int(variable_name, name_size, vendor, &var_property); if (ret != EFI_SUCCESS) goto out; if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) { /* Bypass r/o check */ if (!ro_check) { var_property.property &= ~VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY; ret = set_property_int(variable_name, name_size, vendor, &var_property); if (ret != EFI_SUCCESS) goto out; } else { ret = EFI_WRITE_PROTECTED; goto out; } } /* Fill in contents */ guidcpy(&var_acc->guid, vendor); var_acc->data_size = data_size; var_acc->name_size = name_size; var_acc->attr = attributes; memcpy(var_acc->name, variable_name, name_size); memcpy((u8 *)var_acc->name + name_size, data, data_size); /* Communicate */ ret = mm_communicate(comm_buf, payload_size); if (ret != EFI_SUCCESS) alt_ret = ret; if (ro && !(var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)) { var_property.revision = VAR_CHECK_VARIABLE_PROPERTY_REVISION; var_property.property |= VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY; var_property.attributes = attributes; var_property.minsize = 1; var_property.maxsize = var_acc->data_size; ret = set_property_int(variable_name, name_size, vendor, &var_property); } if (alt_ret != EFI_SUCCESS) goto out; if (!u16_strcmp(variable_name, L"PK")) alt_ret = efi_init_secure_state(); out: free(comm_buf); return alt_ret == EFI_SUCCESS ? ret : alt_ret; } efi_status_t efi_query_variable_info_int(u32 attributes, u64 *max_variable_storage_size, u64 *remain_variable_storage_size, u64 *max_variable_size) { struct smm_variable_query_info *mm_query_info; efi_uintn_t payload_size; efi_status_t ret; u8 *comm_buf; payload_size = sizeof(*mm_query_info); comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size, SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO, &ret); if (!comm_buf) goto out; mm_query_info->attr = attributes; ret = mm_communicate(comm_buf, payload_size); if (ret != EFI_SUCCESS) goto out; *max_variable_storage_size = mm_query_info->max_variable_storage; *remain_variable_storage_size = mm_query_info->remaining_variable_storage; *max_variable_size = mm_query_info->max_variable_size; out: free(comm_buf); return ret; } /** * efi_query_variable_info() - get information about EFI variables * * This function implements the QueryVariableInfo() runtime service. * * See the Unified Extensible Firmware Interface (UEFI) specification for * details. * * @attributes: bitmask to select variables to be * queried * @maximum_variable_storage_size: maximum size of storage area for the * selected variable types * @remaining_variable_storage_size: remaining size of storage are for the * selected variable types * @maximum_variable_size: maximum size of a variable of the * selected type * Return: status code */ efi_status_t EFIAPI __efi_runtime efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size, u64 *remain_variable_storage_size, u64 *max_variable_size) { return EFI_UNSUPPORTED; } /** * efi_set_variable_runtime() - runtime implementation of SetVariable() * * @variable_name: name of the variable * @guid: vendor GUID * @attributes: attributes of the variable * @data_size: size of the buffer with the variable value * @data: buffer with the variable value * Return: status code */ static efi_status_t __efi_runtime EFIAPI efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid, u32 attributes, efi_uintn_t data_size, const void *data) { return EFI_UNSUPPORTED; } /** * efi_variables_boot_exit_notify() - notify ExitBootServices() is called */ void efi_variables_boot_exit_notify(void) { 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); if (comm_buf) ret = mm_communicate(comm_buf, 0); else ret = EFI_NOT_FOUND; if (ret != EFI_SUCCESS) 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 efi_var_buf_update(var_buf); free(var_buf); /* Update runtime service table */ efi_runtime_services.query_variable_info = efi_query_variable_info_runtime; efi_runtime_services.get_variable = efi_get_variable_runtime; efi_runtime_services.get_next_variable_name = efi_get_next_variable_name_runtime; efi_runtime_services.set_variable = efi_set_variable_runtime; efi_update_table_header_crc32(&efi_runtime_services.hdr); } /** * efi_init_variables() - initialize variable services * * Return: status code */ 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; max_buffer_size = MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE + max_payload_size; ret = efi_init_secure_state(); if (ret != EFI_SUCCESS) return ret; return EFI_SUCCESS; }