static void handle_rpc_func_cmd_shm_alloc()

in optee/smc_abi.c [624:718]

• 77 lines of code
• 13 McCabe index (conditional complexity)

static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
					  struct optee_msg_arg *arg,
					  struct optee_call_ctx *call_ctx)
{
	phys_addr_t pa;
	struct tee_shm *shm;
	size_t sz;
	size_t n;

	arg->ret_origin = TEEC_ORIGIN_COMMS;

	if (!arg->num_params ||
	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
		return;
	}

	for (n = 1; n < arg->num_params; n++) {
		if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
			return;
		}
	}

	sz = arg->params[0].u.value.b;
	switch (arg->params[0].u.value.a) {
	case OPTEE_RPC_SHM_TYPE_APPL:
		shm = optee_rpc_cmd_alloc_suppl(ctx, sz);
		break;
	case OPTEE_RPC_SHM_TYPE_KERNEL:
		shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED | TEE_SHM_PRIV);
		break;
	default:
		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
		return;
	}

	if (IS_ERR(shm)) {
		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
		return;
	}

	if (tee_shm_get_pa(shm, 0, &pa)) {
		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
		goto bad;
	}

	sz = tee_shm_get_size(shm);

	if (tee_shm_is_registered(shm)) {
		struct page **pages;
		u64 *pages_list;
		size_t page_num;

		pages = tee_shm_get_pages(shm, &page_num);
		if (!pages || !page_num) {
			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
			goto bad;
		}

		pages_list = optee_allocate_pages_list(page_num);
		if (!pages_list) {
			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
			goto bad;
		}

		call_ctx->pages_list = pages_list;
		call_ctx->num_entries = page_num;

		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
				      OPTEE_MSG_ATTR_NONCONTIG;
		/*
		 * In the least bits of u.tmem.buf_ptr we store buffer offset
		 * from 4k page, as described in OP-TEE ABI.
		 */
		arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
			(tee_shm_get_page_offset(shm) &
			 (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
		arg->params[0].u.tmem.size = tee_shm_get_size(shm);
		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;

		optee_fill_pages_list(pages_list, pages, page_num,
				      tee_shm_get_page_offset(shm));
	} else {
		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
		arg->params[0].u.tmem.buf_ptr = pa;
		arg->params[0].u.tmem.size = sz;
		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
	}

	arg->ret = TEEC_SUCCESS;
	return;
bad:
	tee_shm_free(shm);
}